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https://en.wikipedia.org/wiki/Rhombitrihexagonal%20tiling
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In geometry, the rhombitrihexagonal tiling is a semiregular tiling of the Euclidean plane. There are one triangle, two squares, and one hexagon on each vertex. It has Schläfli symbol of rr{3,6}.
John Conway calls it a rhombihexadeltille. It can be considered a cantellated by Norman Johnson's terminology or an expanded hexagonal tiling by Alicia Boole Stott's operational language.
There are three regular and eight semiregular tilings in the plane.
Uniform colorings
There is only one uniform coloring in a rhombitrihexagonal tiling. (Naming the colors by indices around a vertex (3.4.6.4): 1232.)
With edge-colorings there is a half symmetry form (3*3) orbifold notation. The hexagons can be considered as truncated triangles, t{3} with two types of edges. It has Coxeter diagram , Schläfli symbol s2{3,6}. The bicolored square can be distorted into isosceles trapezoids. In the limit, where the rectangles degenerate into edges, a triangular tiling results, constructed as a snub triangular tiling, .
Examples
Related tilings
There is one related 2-uniform tiling, having hexagons dissected into six triangles. The rhombitrihexagonal tiling is also related to the truncated trihexagonal tiling by replacing some of the hexagons and surrounding squares and triangles with dodecagons:
Circle packing
The rhombitrihexagonal tiling can be used as a circle packing, placing equal diameter circles at the center of every point. Every circle is in contact with four other circles in the packing (kissing number). The translational lattice domain (red rhombus) contains six distinct circles.
Wythoff construction
There are eight uniform tilings that can be based from the regular hexagonal tiling (or the dual triangular tiling).
Drawing the tiles colored as red on the original faces, yellow at the original vertices, and blue along the original edges, there are eight forms, seven topologically distinct. (The truncated triangular tiling is topologically identical to the hexagonal tiling
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https://en.wikipedia.org/wiki/Pertussis%20toxin
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Pertussis toxin (PT) is a protein-based AB5-type exotoxin produced by the bacterium Bordetella pertussis, which causes whooping cough. PT is involved in the colonization of the respiratory tract and the establishment of infection. Research suggests PT may have a therapeutic role in treating a number of common human ailments, including hypertension, viral infection, and autoimmunity.
History
PT clearly plays a central role in the pathogenesis of pertussis although this was discovered only in the early 1980s. The appearance of pertussis is quite recent, compared with other epidemic infectious diseases. The earliest mention of pertussis, or whooping cough, is of an outbreak in Paris in 1414. This was published in Moulton's The Mirror of Health, in 1640. Another epidemic of pertussis took place in Paris in 1578 and was described by a contemporary observer, Guillaume de Baillou. Pertussis was well known throughout Europe by the middle of the 18th century. Jules Bordet and Octave Gengou described in 1900 the finding of a new “ovoid bacillus” in the sputum of a 6-month-old infant with whooping cough. They were also the first to cultivate Bordetella pertussis at the Pasteur Institute in Brussels in 1906.
One difference between the different species of Bordetella is that B. pertussis produces PT and the other species do not. Bordetella parapertussis shows the most similarity to B. pertussis and was therefore used for research determining the role of PT in causing the typical symptoms of whooping cough. Rat studies showed the development of paroxysmal coughing, a characteristic for whooping cough, occurred in rats infected with B. pertussis. Rats infected with B. parapertussis or a PT-deficient mutant of B. pertussis did not show this symptom; neither of these two strains produced PT.
Structure
A large group of bacterial exotoxins are referred to as "A/B toxins", in essence because they are formed from two subunits. The "A" subunit possesses enzyme activity, and is transf
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https://en.wikipedia.org/wiki/Trihexagonal%20tiling
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In geometry, the trihexagonal tiling is one of 11 uniform tilings of the Euclidean plane by regular polygons. It consists of equilateral triangles and regular hexagons, arranged so that each hexagon is surrounded by triangles and vice versa. The name derives from the fact that it combines a regular hexagonal tiling and a regular triangular tiling. Two hexagons and two triangles alternate around each vertex, and its edges form an infinite arrangement of lines. Its dual is the rhombille tiling.
This pattern, and its place in the classification of uniform tilings, was already known to Johannes Kepler in his 1619 book Harmonices Mundi. The pattern has long been used in Japanese basketry, where it is called kagome. The Japanese term for this pattern has been taken up in physics, where it is called a kagome lattice. It occurs also in the crystal structures of certain minerals. Conway calls it a hexadeltille, combining alternate elements from a hexagonal tiling (hextille) and triangular tiling (deltille).
Kagome
Kagome () is a traditional Japanese woven bamboo pattern; its name is composed from the words kago, meaning "basket", and me, meaning "eye(s)", referring to the pattern of holes in a woven basket.
The kagome pattern is common in bamboo weaving in East Asia. In 2022, archaeologists found bamboo weaving remains at the Dongsunba ruins in Chongqing, China, 200 BC. After 2200 years, the kagome pattern is still clear.
It is a woven arrangement of laths composed of interlaced triangles such that each point where two laths cross has four neighboring points, forming the pattern of a trihexagonal tiling. The woven process gives the Kagome a chiral wallpaper group symmetry, p6, (632).
Kagome lattice
The term kagome lattice was coined by Japanese physicist Kôdi Husimi, and first appeared in a 1951 paper by his assistant Ichirō Shōji.
The kagome lattice in this sense consists of the vertices and edges of the trihexagonal tiling.
Despite the name, these crossing points do
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https://en.wikipedia.org/wiki/Majorization
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In mathematics, majorization is a preorder on vectors of real numbers. Let denote the -th largest element of the vector . Given , we say that weakly majorizes (or dominates) from below (or equivalently, we say that is weakly majorized (or dominated) by from below) denoted as if for all . If in addition , we say that majorizes (or dominates) , written as , or equivalently, we say that is majorized (or dominated) by . The order of the entries of the vectors or does not affect the majorization, e.g., the statement is simply equivalent to . As a consequence, majorization is not a partial order, since and do not imply , it only implies that the components of each vector are equal, but not necessarily in the same order.
The majorization partial order on finite dimensional vectors, described here, can be generalized to the Lorenz ordering, a partial order on distribution functions. For example, a wealth distribution is Lorenz-greater than another if its Lorenz curve lies below the other. As such, a Lorenz-greater wealth distribution has a higher Gini coefficient, and has more income disparity. Various other generalizations of majorization are discussed in chapters 14 and 15 of.
The majorization preorder can be naturally extended to density matrices in the context of quantum information. In particular, exactly when (where denotes the state's spectrum).
Examples
(Strong) majorization: . For vectors with components
(Weak) majorization: . For vectors with components:
Geometry of majorization
For we have if and only if is in the convex hull of all vectors obtained by permuting the coordinates of .
Figure 1 displays the convex hull in 2D for the vector . Notice that the center of the convex hull, which is an interval in this case, is the vector . This is the "smallest" vector satisfying for this given vector .
Figure 2 shows the convex hull in 3D. The center of the convex hull, which is a 2D polygon in this case, is the "smallest" vector satisfy
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https://en.wikipedia.org/wiki/Snub%20trihexagonal%20tiling
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In geometry, the snub hexagonal tiling (or snub trihexagonal tiling) is a semiregular tiling of the Euclidean plane. There are four triangles and one hexagon on each vertex. It has Schläfli symbol sr{3,6}. The snub tetrahexagonal tiling is a related hyperbolic tiling with Schläfli symbol sr{4,6}.
Conway calls it a snub hextille, constructed as a snub operation applied to a hexagonal tiling (hextille).
There are three regular and eight semiregular tilings in the plane. This is the only one which does not have a reflection as a symmetry.
There is only one uniform coloring of a snub trihexagonal tiling. (Labeling the colors by numbers, "3.3.3.3.6" gives "11213".)
Circle packing
The snub trihexagonal tiling can be used as a circle packing, placing equal diameter circles at the center of every point. Every circle is in contact with 5 other circles in the packing (kissing number). The lattice domain (red rhombus) repeats 6 distinct circles. The hexagonal gaps can be filled by exactly one circle, leading to the densest packing from the triangular tiling.
Related polyhedra and tilings
Symmetry mutations
This semiregular tiling is a member of a sequence of snubbed polyhedra and tilings with vertex figure (3.3.3.3.n) and Coxeter–Dynkin diagram . These figures and their duals have (n32) rotational symmetry, being in the Euclidean plane for n=6, and hyperbolic plane for any higher n. The series can be considered to begin with n=2, with one set of faces degenerated into digons.
6-fold pentille tiling
In geometry, the 6-fold pentille or floret pentagonal tiling is a dual semiregular tiling of the Euclidean plane. It is one of the 15 known isohedral pentagon tilings. Its six pentagonal tiles radiate out from a central point, like petals on a flower. Each of its pentagonal faces has four 120° and one 60° angle.
It is the dual of the uniform snub trihexagonal tiling, and has rotational symmetries of orders 6-3-2 symmetry.
Variations
The floret pentagonal tiling has ge
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https://en.wikipedia.org/wiki/Elongated%20triangular%20tiling
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In geometry, the elongated triangular tiling is a semiregular tiling of the Euclidean plane. There are three triangles and two squares on each vertex. It is named as a triangular tiling elongated by rows of squares, and given Schläfli symbol {3,6}:e.
Conway calls it a isosnub quadrille.
There are 3 regular and 8 semiregular tilings in the plane. This tiling is similar to the snub square tiling which also has 3 triangles and two squares on a vertex, but in a different order.
Construction
It is also the only convex uniform tiling that can not be created as a Wythoff construction. It can be constructed as alternate layers of apeirogonal prisms and apeirogonal antiprisms.
Uniform colorings
There is one uniform colorings of an elongated triangular tiling. Two 2-uniform colorings have a single vertex figure, 11123, with two colors of squares, but are not 1-uniform, repeated either by reflection or glide reflection, or in general each row of squares can be shifted around independently. The 2-uniform tilings are also called Archimedean colorings. There are infinite variations of these Archimedean colorings by arbitrary shifts in the square row colorings.
Circle packing
The elongated triangular tiling can be used as a circle packing, placing equal diameter circles at the center of every point. Every circle is in contact with 5 other circles in the packing (kissing number).
Related tilings
Sections of stacked triangles and squares can be combined into radial forms. This mixes two vertex configurations, 3.3.3.4.4 and 3.3.4.3.4 on the transitions. Twelve copies are needed to fill the plane with different center arrangements. The duals will mix in cairo pentagonal tiling pentagons.
Symmetry mutations
It is first in a series of symmetry mutations with hyperbolic uniform tilings with 2*n2 orbifold notation symmetry, vertex figure 4.n.4.3.3.3, and Coxeter diagram . Their duals have hexagonal faces in the hyperbolic plane, with face configuration V4.n.4.3.3.3.
There are
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https://en.wikipedia.org/wiki/Fermi%E2%80%93Pasta%E2%80%93Ulam%E2%80%93Tsingou%20problem
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In physics, the Fermi–Pasta–Ulam–Tsingou (FPUT) problem or formerly the Fermi–Pasta–Ulam problem was the apparent paradox in chaos theory that many complicated enough physical systems exhibited almost exactly periodic behavior – called Fermi–Pasta–Ulam–Tsingou recurrence (or Fermi–Pasta–Ulam recurrence) – instead of the expected ergodic behavior. This came as a surprise, as Enrico Fermi, certainly, expected the system to thermalize in a fairly short time. That is, it was expected for all vibrational modes to eventually appear with equal strength, as per the equipartition theorem, or, more generally, the ergodic hypothesis. Yet here was a system that appeared to evade the ergodic hypothesis. Although the recurrence is easily observed, it eventually became apparent that over much, much longer time periods, the system does eventually thermalize. Multiple competing theories have been proposed to explain the behavior of the system, and it remains a topic of active research.
The original intent was to find a physics problem worthy of numerical simulation on the then-new MANIAC computer. Fermi felt that thermalization would pose such a challenge. As such, it represents one of the earliest uses of digital computers in mathematical research; simultaneously, the unexpected results launched the study of nonlinear systems.
The FPUT experiment
In the summer of 1953 Enrico Fermi, John Pasta, Stanislaw Ulam, and Mary Tsingou conducted computer simulations of a vibrating string that included a non-linear term (quadratic in one test, cubic in another, and a piecewise linear approximation to a cubic in a third). They found that the behavior of the system was quite different from what intuition would have led them to expect. Enrico Fermi thought that after many iterations, the system would exhibit thermalization, an ergodic behavior in which the influence of the initial modes of vibration fade and the system becomes more or less random with all modes excited more or less equally.
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https://en.wikipedia.org/wiki/Snub%20square%20tiling
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In geometry, the snub square tiling is a semiregular tiling of the Euclidean plane. There are three triangles and two squares on each vertex. Its Schläfli symbol is s{4,4}.
Conway calls it a snub quadrille, constructed by a snub operation applied to a square tiling (quadrille).
There are 3 regular and 8 semiregular tilings in the plane.
Uniform colorings
There are two distinct uniform colorings of a snub square tiling. (Naming the colors by indices around a vertex (3.3.4.3.4): 11212, 11213.)
Circle packing
The snub square tiling can be used as a circle packing, placing equal diameter circles at the center of every point. Every circle is in contact with 5 other circles in the packing (kissing number).
Wythoff construction
The snub square tiling can be constructed as a snub operation from the square tiling, or as an alternate truncation from the truncated square tiling.
An alternate truncation deletes every other vertex, creating a new triangular faces at the removed vertices, and reduces the original faces to half as many sides. In this case starting with a truncated square tiling with 2 octagons and 1 square per vertex, the octagon faces into squares, and the square faces degenerate into edges and 2 new triangles appear at the truncated vertices around the original square.
If the original tiling is made of regular faces the new triangles will be isosceles. Starting with octagons which alternate long and short edge lengths, derived from a regular dodecagon, will produce a snub tiling with perfect equilateral triangle faces.
Example:
Related tilings
Related k-uniform tilings
This tiling is related to the elongated triangular tiling which also has 3 triangles and two squares on a vertex, but in a different order, 3.3.3.4.4. The two vertex figures can be mixed in many k-uniform tilings.
Related topological series of polyhedra and tiling
The snub square tiling is third in a series of snub polyhedra and tilings with vertex figure 3.3.4.3.n.
The snub squa
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https://en.wikipedia.org/wiki/Ischemic%20cascade
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The ischemic (ischaemic) cascade is a series of biochemical reactions that are initiated in the brain and other aerobic tissues after seconds to minutes of ischemia (inadequate blood supply). This is typically secondary to stroke, injury, or cardiac arrest due to heart attack. Most ischemic neurons that die do so due to the activation of chemicals produced during and after ischemia. The ischemic cascade usually goes on for two to three hours but can last for days, even after normal blood flow returns.
Mechanism
A cascade is a series of events in which one event triggers the next, in a linear fashion. Thus "ischemic cascade" is actually a misnomer, since the events are not always linear: in some cases they are circular, and sometimes one event can cause or be caused by multiple events. In addition, cells receiving different amounts of blood may go through different chemical processes. Despite these facts, the ischemic cascade can be generally characterized as follows:
Lack of oxygen causes the neuron's normal process for making ATP for energy to fail.
The cell switches to anaerobic metabolism, producing lactic acid.
ATP-reliant ion transport pumps fail, causing the cell to become depolarized, allowing ions, including calcium (Ca2+), to flow into the cell.
The ion pumps can no longer transport calcium out of the cell, and intracellular calcium levels get too high.
The presence of calcium triggers the release of the excitatory amino acid neurotransmitter glutamate.
Glutamate stimulates AMPA receptors and Ca2+-permeable NMDA receptors, which open to allow more calcium into cells.
Excess calcium entry overexcites cells and causes the generation of harmful chemicals like free radicals, reactive oxygen species and calcium-dependent enzymes such as calpain, endonucleases, ATPases, and phospholipases in a process called excitotoxicity. Calcium can also cause the release of more glutamate.
As the cell's membrane is broken down by phospholipases, it becomes more per
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https://en.wikipedia.org/wiki/Personal%20equation
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The term personal equation, in 19th- and early 20th-century science, referred to the idea that different observers have different reaction times, which can introduce bias when it comes to measurements and observations.
Astronomy
The term originated in astronomy, when it was discovered that numerous observers making simultaneous observations would record slightly different values (for example, in recording the exact time at which a star crossed the wires of a reticule in a telescope), some of which were of a significant enough difference to afford for problems in larger calculations.
The existence of the effect was first discovered when, in 1796, the Astronomer Royal Neville Maskelyne dismissed his assistant Kinnebrooke because he could not better the error of his observations relative to Maskelyne's own values. The problem was forgotten and only analysed two decades later by Friedrich Wilhelm Bessel at Königsberg Observatory in Prussia. Setting up an experiment to compare the values, Bessel and an assistant measured the times at which several stars crossed the wires of a reticule in different nights. Compared to his assistant, Bessel found himself to be ahead by more than a second.
In response to this realization, astronomers became increasingly suspicious of the results of other astronomers and their own assistants and began systematic programs to attempt to find ways to remove or lessen the effects. These included attempts at the automation of observations (appealing to the presumed objectivity of machines), training observers to try to avoid certain known errors (such as those caused by lack of sleep), developing machines that could allow multiple observers to make observations at the same time, the taking of redundant data and using techniques such as the method of least squares to derive possible values from them, and trying to quantify the biases of individual workers so that they could be subtracted from the data. It became a major topic in experimental p
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https://en.wikipedia.org/wiki/John%20S.%20Rodwell
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John S. Rodwell (1946 – present) is an ecologist who was based at the University of Lancaster, noted for his role in the development of the British National Vegetation Classification and as editor of the five volumes of British Plant Communities.
Education
Rodwell graduated in Botany from the University of Leeds in 1968, then researched limestone vegetation at the University of Southampton under Joyce Lambert for his PhD in Biology, awarded in 1974. He also trained for the priesthood at Ripon College Cuddesdon, University of Oxford, maintaining this vocation as a non-stipendiary priest since 1974 in the Diocese of Blackburn since 1975 and is honorary canon of Blackburn Cathedral.
Career
In the same year, 1975, he became co-ordinator of research leading to the development of the British National Vegetation Classification (NVC). at Lancaster University, becoming editor of the NVC, a task that dominated his working life for more than two decades. All five volumes of British Plant Communities, which describe the NVC, were edited by Rodwell.
He joined the faculty of Lancaster University in 1991, was made Professor of Ecology in 1997 and retired in 2004 but has continued to teach and publish since then. In 2009 he was awarded the Institute of Ecology and Environmental Management medal of honour.
He is a Honorary Member of the International Association for Vegetation Science (2010).
References
1946 births
Living people
English ecologists
British National Vegetation Classification
Alumni of the University of Leeds
Alumni of the University of Southampton
Academics of Lancaster University
20th-century English Anglican priests
21st-century English Anglican priests
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https://en.wikipedia.org/wiki/Intel%20GMA
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The Intel Graphics Media Accelerator (GMA) is a series of integrated graphics processors introduced in 2004 by Intel, replacing the earlier Intel Extreme Graphics series and being succeeded by the Intel HD and Iris Graphics series.
This series targets the market of low-cost graphics solutions. The products in this series are integrated onto the motherboard, have limited graphics processing power, and use the computer's main memory for storage instead of a dedicated video memory. They were commonly found on netbooks, low-priced laptops and desktop computers, as well as business computers which do not need high levels of graphics capability. In early 2007, about 90% of all PC motherboards sold had an integrated GPU.
History
The GMA line of GPUs replaces the earlier Intel Extreme Graphics, and the Intel740 line, the latter of which was a discrete unit in the form of AGP and PCI cards with technology that evolved from companies Real3D and Lockheed Martin. Later, Intel integrated the i740 core into the Intel 810 northbridge.
The original architecture of GMA systems supported only a few functions in hardware, and relied on the host CPU to handle at least some of the graphics pipeline, further decreasing performance. However, with the introduction of Intel's 4th generation of GMA architecture (GMA X3000) in 2006, many of the functions are now built into the hardware, providing an increase in performance. The 4th generation of GMA combines fixed function capabilities with a threaded array of programmable executions units, providing advantages to both graphics and video performance. Many of the advantages of the new GMA architecture come from the ability to flexibly switch as needed between executing graphics-related tasks or video-related tasks. While GMA performance has been widely criticized in the past as being too slow for computer games, sometimes being derogatorily nicknamed Intel 'GMD' (Graphics Media Decelerator) and being essentially referred to as the world's
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https://en.wikipedia.org/wiki/Equipotential
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In mathematics and physics, an equipotential or isopotential refers to a region in space where every point is at the same potential. This usually refers to a scalar potential (in that case it is a level set of the potential), although it can also be applied to vector potentials. An equipotential of a scalar potential function in -dimensional space is typically an ()-dimensional space. The del operator illustrates the relationship between a vector field and its associated scalar potential field. An equipotential region might be referred as being 'of equipotential' or simply be called 'an equipotential'.
An equipotential region of a scalar potential in three-dimensional space is often an equipotential surface (or potential isosurface), but it can also be a three-dimensional mathematical solid in space. The gradient of the scalar potential (and hence also its opposite, as in the case of a vector field with an associated potential field) is everywhere perpendicular to the equipotential surface, and zero inside a three-dimensional equipotential region.
Electrical conductors offer an intuitive example. If a and b are any two points within or at the surface of a given conductor, and given there is no flow of charge being exchanged between the two points, then the potential difference is zero between the two points. Thus, an equipotential would contain both points a and b as they have the same potential. Extending this definition, an isopotential is the locus of all points that are of the same potential.
Gravity is perpendicular to the equipotential surfaces of the gravity potential, and in electrostatics and steady electric currents, the electric field (and hence the current, if any) is perpendicular to the equipotential surfaces of the electric potential (voltage).
In gravity, a hollow sphere has a three-dimensional equipotential region inside, with no gravity from the sphere (see shell theorem). In electrostatics, a conductor is a three-dimensional equipotential reg
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https://en.wikipedia.org/wiki/List%20of%20fossil%20sites
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This list of fossil sites is a worldwide list of localities known well for the presence of fossils. Some entries in this list are notable for a single, unique find, while others are notable for the large number of fossils found there. Many of the entries in this list are considered Lagerstätten (sedimentary deposits that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues). Lagerstätten are indicated by a note () in the noteworthiness column.
Fossils may be found either associated with a geological formation or at a single geographic site. Geological formations consist of rock that was deposited during a specific period of time. They usually extend for large areas, and sometimes there are different important sites in which the same formation is exposed. Such sites may have separate entries if they are considered to be more notable than the formation as a whole. In contrast, extensive formations associated with large areas may be equivalently represented at many locations. Such formations may be listed either without a site, with a site or sites that represent the type locality, or with multiple sites of note. When a type locality is listed as the site for a formation with many good outcrops, the site is flagged with a note (). When a particular site of note is listed for an extensive fossil-bearing formation, but that site is somehow atypical, it is also flagged with a note ().
Many formations are for all practical purposes only studied at a single site, and may not even be named. For example, sites associated with hominin, particularly caves, are frequently not identified with a named geologic formation. Therefore, some sites are listed without an associated formation.
List of sites
Notes
See also
Pleistocene fossils in Michigan
References
Further reading
Sites
Fossil sites
Paleontology lists
Geology-related lists
Lists of places
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https://en.wikipedia.org/wiki/Fiberglass%20molding
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Fiberglass molding is a process in which fiberglass reinforced resin plastics are formed into useful shapes.
The process usually involves first making a mold and then using the mold to make the fiberglass component.
Mold making
The fiberglass mold process begins with an object known as the plug or buck. This is an exact representation of the object to be made. The plug can be made from a variety of materials, usually certain types of foam.
After the plug has been formed, it is sprayed with a mold release agent. The release agent will allow the mold to be separated from the plug once it is finished. The mold release agent is a special wax, and/or PVA (Polyvinyl alcohol). Polyvinyl alcohol, however, is said to have negative effects on the final mold's surface finish.
Once the plug has its release agent applied, gelcoat is applied with a roller, brush or specially-designed spray gun. The gelcoat is pigmented resin, and gives the mold surface a harder, more durable finish.
Once the release agent and gelcoat are applied, layers of fiberglass and resin are laid-up onto the surface. The fiberglass used will typically be identical to that which will be used in the final product.
In the laying-up process, a layer of fiberglass mat is applied, and resin is applied over it. A special roller is then used to remove air bubbles. Air bubbles, if left in the curing resin, would significantly reduce the strength of the finished mold. The fiberglass spray lay-up process is also used to produce molds, and can provide good filling of corners and cavities where a glass mat or weave may prove to be too stiff.
Once the final layers of fiberglass are applied to the mold, the resin is allowed to set up and cure. Wedges are then driven between the plug and the mold in order to separate the two.
Advanced techniques such as resin transfer molding are also used.
Making a component
The component-making process involves building up a component on the fiberglass mold. The mold is a
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https://en.wikipedia.org/wiki/Rhombille%20tiling
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In geometry, the rhombille tiling, also known as tumbling blocks, reversible cubes, or the dice lattice, is a tessellation of identical 60° rhombi on the Euclidean plane. Each rhombus has two 60° and two 120° angles; rhombi with this shape are sometimes also called diamonds. Sets of three rhombi meet at their 120° angles, and sets of six rhombi meet at their 60° angles.
Properties
The rhombille tiling can be seen as a subdivision of a hexagonal tiling with each hexagon divided into three rhombi meeting at the center point of the hexagon. This subdivision represents a regular compound tiling. It can also be seen as a subdivision of four hexagonal tilings with each hexagon divided into 12 rhombi.
The diagonals of each rhomb are in the ratio 1:.
This is the dual tiling of the trihexagonal tiling or kagome lattice. As the dual to a uniform tiling, it is one of eleven possible Laves tilings, and in the face configuration for monohedral tilings it is denoted [3.6.3.6].
It is also one of 56 possible isohedral tilings by quadrilaterals, and one of only eight tilings of the plane in which every edge lies on a line of symmetry of the tiling.
It is possible to embed the rhombille tiling into a subset of a three-dimensional integer lattice, consisting of the points (x,y,z) with |x + y + z| ≤ 1, in such a way that two vertices are adjacent if and only if the corresponding lattice points are at unit distance from each other, and more strongly such that the number of edges in the shortest path between any two vertices of the tiling is the same as the Manhattan distance between the corresponding lattice points. Thus, the rhombille tiling can be viewed as an example of an infinite unit distance graph and partial cube.
Artistic and decorative applications
The rhombille tiling can be interpreted as an isometric projection view of a set of cubes in two different ways, forming a reversible figure related to the Necker Cube. In this context it is known as the "reversible cubes" ill
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https://en.wikipedia.org/wiki/237%20%28number%29
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237 (two hundred [and] thirty-seven) is the natural number following 236 and preceding 238.
237 is a lucky number, and one of the numbers in Aronson's sequence.
The 237th square pyramidal number, 4465475, is also a sum of two smaller square pyramidal numbers. There are only four smaller numbers (55, 70, 147, and 226) with the same property.
References
Integers
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https://en.wikipedia.org/wiki/Posadis
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In computing, Posadis is a GPL-licensed DNS server for Microsoft Windows and Unix that uses a zone file format that is compatible with BIND zone files. Posadis is part of a suite which includes graphical configuration and zone file management programs.
Posadis has IPv6 support.
See also
Comparison of DNS server software
External links
Posadis website
DNS software
Cross-platform free software
Free network-related software
DNS server software for Linux
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https://en.wikipedia.org/wiki/List%20of%20planar%20symmetry%20groups
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This article summarizes the classes of discrete symmetry groups of the Euclidean plane. The symmetry groups are named here by three naming schemes: International notation, orbifold notation, and Coxeter notation.
There are three kinds of symmetry groups of the plane:
2 families of rosette groups – 2D point groups
7 frieze groups – 2D line groups
17 wallpaper groups – 2D space groups.
Rosette groups
There are two families of discrete two-dimensional point groups, and they are specified with parameter n, which is the order of the group of the rotations in the group.
Frieze groups
The 7 frieze groups, the two-dimensional line groups, with a direction of periodicity are given with five notational names. The Schönflies notation is given as infinite limits of 7 dihedral groups. The yellow regions represent the infinite fundamental domain in each.
Wallpaper groups
The 17 wallpaper groups, with finite fundamental domains, are given by International notation, orbifold notation, and Coxeter notation, classified by the 5 Bravais lattices in the plane: square, oblique (parallelogrammatic), hexagonal (equilateral triangular), rectangular (centered rhombic), and rhombic (centered rectangular).
The p1 and p2 groups, with no reflectional symmetry, are repeated in all classes. The related pure reflectional Coxeter group are given with all classes except oblique.
Wallpaper subgroup relationships
See also
List of spherical symmetry groups
Orbifold notation#Hyperbolic plane - Hyperbolic symmetry groups
Notes
References
The Symmetries of Things 2008, John H. Conway, Heidi Burgiel, Chaim Goodman-Strauss, (Orbifold notation for polyhedra, Euclidean and hyperbolic tilings)
On Quaternions and Octonions, 2003, John Horton Conway and Derek A. Smith
Kaleidoscopes: Selected Writings of H. S. M. Coxeter, edited by F. Arthur Sherk, Peter McMullen, Anthony C. Thompson, Asia Ivic Weiss, Wiley-Interscience Publication, 1995,
(Paper 22) H.S.M. Coxeter, Regular and Semi Regular Pol
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https://en.wikipedia.org/wiki/ILIOS
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ILIOS is an acronym of InterLink Internet Operating System. It is an attempt to create a router-only operating system; one specifically oriented towards computer networking purposes, especially routing. It supports IPv4 routing and is a good educational OS, though it is single tasking and does everything via interrupts.
It is released under the BSD License. The author of this research OS is Rink Springer, who is also responsible for porting FreeBSD to the Xbox.
External links
ILIOS - Trac Rink Springer's website
Free software operating systems
Software using the BSD license
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https://en.wikipedia.org/wiki/M32R
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The M32R is a 32-bit RISC instruction set architecture (ISA) developed by Mitsubishi Electric for embedded microprocessors and microcontrollers. The ISA is now owned by Renesas Electronics Corporation, and the company designs and fabricates M32R implementations. M32R processors are used in embedded systems such as Engine Control Units, digital cameras and PDAs. The ISA was supported by Linux and the GNU Compiler Collection but was dropped in Linux kernel version 4.16. GCC removed support for this architecture in the GCC 12.1 release.
References
External links
M32R homepage
Linux/M32R homepage
Interface (CQ Publishing Co.,Ltd.)
Computer-related introductions in 1997
Instruction set architectures
Renesas microcontrollers
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https://en.wikipedia.org/wiki/Wandering%20set
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In dynamical systems and ergodic theory, the concept of a wandering set formalizes a certain idea of movement and mixing. When a dynamical system has a wandering set of non-zero measure, then the system is a dissipative system. This is the opposite of a conservative system, to which the Poincaré recurrence theorem applies. Intuitively, the connection between wandering sets and dissipation is easily understood: if a portion of the phase space "wanders away" during normal time-evolution of the system, and is never visited again, then the system is dissipative. The language of wandering sets can be used to give a precise, mathematical definition to the concept of a dissipative system. The notion of wandering sets in phase space was introduced by Birkhoff in 1927.
Wandering points
A common, discrete-time definition of wandering sets starts with a map of a topological space X. A point is said to be a wandering point if there is a neighbourhood U of x and a positive integer N such that for all , the iterated map is non-intersecting:
A handier definition requires only that the intersection have measure zero. To be precise, the definition requires that X be a measure space, i.e. part of a triple of Borel sets and a measure such that
for all . Similarly, a continuous-time system will have a map defining the time evolution or flow of the system, with the time-evolution operator being a one-parameter continuous abelian group action on X:
In such a case, a wandering point will have a neighbourhood U of x and a time T such that for all times , the time-evolved map is of measure zero:
These simpler definitions may be fully generalized to the group action of a topological group. Let be a measure space, that is, a set with a measure defined on its Borel subsets. Let be a group acting on that set. Given a point , the set
is called the trajectory or orbit of the point x.
An element is called a wandering point if there exists a neighborhood U of x and a neighborh
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https://en.wikipedia.org/wiki/Cocycle
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In mathematics a cocycle is a closed cochain. Cocycles are used in algebraic topology to express obstructions (for example, to integrating a differential equation on a closed manifold). They are likewise used in group cohomology. In autonomous dynamical systems, cocycles are used to describe particular kinds of map, as in the Oseledets theorem.
Definition
Algebraic Topology
Let X be a CW complex and be the singular cochains with coboundary map . Then elements of are cocycles. Elements of are coboundaries. If is a cocycle, then , which means cocycles vanish on boundaries.
See also
Čech cohomology
Cocycle condition
References
Algebraic topology
Cohomology theories
Dynamical systems
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https://en.wikipedia.org/wiki/List%20of%20spherical%20symmetry%20groups
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Finite spherical symmetry groups are also called point groups in three dimensions. There are five fundamental symmetry classes which have triangular fundamental domains: dihedral, cyclic, tetrahedral, octahedral, and icosahedral symmetry.
This article lists the groups by Schoenflies notation, Coxeter notation, orbifold notation, and order. John Conway uses a variation of the Schoenflies notation, based on the groups' quaternion algebraic structure, labeled by one or two upper case letters, and whole number subscripts. The group order is defined as the subscript, unless the order is doubled for symbols with a plus or minus, "±", prefix, which implies a central inversion.
Hermann–Mauguin notation (International notation) is also given. The crystallography groups, 32 in total, are a subset with element orders 2, 3, 4 and 6.
Involutional symmetry
There are four involutional groups: no symmetry (C1), reflection symmetry (Cs), 2-fold rotational symmetry (C2), and central point symmetry (Ci).
Cyclic symmetry
There are four infinite cyclic symmetry families, with n = 2 or higher. (n may be 1 as a special case as no symmetry)
Dihedral symmetry
There are three infinite dihedral symmetry families, with n = 2 or higher (n may be 1 as a special case).
Polyhedral symmetry
There are three types of polyhedral symmetry: tetrahedral symmetry, octahedral symmetry, and icosahedral symmetry, named after the triangle-faced regular polyhedra with these symmetries.
Continuous symmetries
All of the discrete point symmetries are subgroups of certain continuous symmetries. They can be classified as products of orthogonal groups O(n) or special orthogonal groups SO(n). O(1) is a single orthogonal reflection, dihedral symmetry order 2, Dih1. SO(1) is just the identity. Half turns, C2, are needed to complete.
See also
Crystallographic point group
Triangle group
List of planar symmetry groups
Point groups in two dimensions
References
Further reading
Peter R. Cromwell, Polyhedr
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https://en.wikipedia.org/wiki/XLink%20Kai
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XLink Kai is a program developed by Team XLink allowing for online play of video games with support for LAN multiplayer modes. It enables players on the GameCube, Nintendo Switch, PlayStation 2, PlayStation 3, PlayStation 4, PlayStation Portable, PlayStation Vita / PlayStation TV, Xbox, Xbox 360, and Xbox One to play games across the Internet using a network configuration that simulates a local area network (LAN). It notably also allows original Xbox games to be played online again following the Xbox Live shutdown on 21 April 2010 (similar to that of Save Nintendo Wi-Fi for the Wii) and certain GameSpy titles such as Saints Row 2 to be played online after the GameSpy network shutdown on 31 May 2014.
Summary
The purpose of the software is to allow consoles to network with each other over the internet via the consoles' "local network play" capabilities. XLink Kai acts as tunneling software, installed to a compatible Microsoft Windows, macOS, or Linux computer on the same network as the console. Upon the console initiating a game's "network play" feature, the console's requests are routed to the computer. XLink, listening for these requests, allows other consoles to be found over the internet during this search, making it appear to the player's console that these other consoles are simply connected to the local network.
For modified ("modded") Xbox consoles, much of the functionality can be provided directly within the Xbox Media Center (XBMC for Xbox) GUI. The Kai client is still required to be running on a computer on the user's network, but players can control connections directly through the console. It is also possible to run the Kai client on other Linux-based devices, such as Raspberry Pi or NAS devices.
Usage
Users log onto XLink's servers using an XTag username, similar to a "Gamertag" for Xbox Live. XLink has "Arenas" for each compatible System Link game, with more popular games such as Halo 2 and SOCOM II having sub-arenas based on regions within them
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https://en.wikipedia.org/wiki/Internal%20ribosome%20entry%20site
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An internal ribosome entry site, abbreviated IRES, is an RNA element that allows for translation initiation in a cap-independent manner, as part of the greater process of protein synthesis. In eukaryotic translation, initiation typically occurs at the 5' end of mRNA molecules, since 5' cap recognition is required for the assembly of the initiation complex. The location for IRES elements is often in the 5'UTR, but can also occur elsewhere in mRNAs.
History
IRES sequences were first discovered in 1988 in the poliovirus (PV) and encephalomyocarditis virus (EMCV) RNA genomes in the labs of Nahum Sonenberg and Eckard Wimmer, respectively. They are described as distinct regions of RNA molecules that are able to recruit the eukaryotic ribosome to the mRNA. This process is also known as cap-independent translation. It has been shown that IRES elements have a distinct secondary or even tertiary structure, but similar structural features at the levels of either primary or secondary structure that are common to all IRES segments have not been reported to date.
In recent years it has become common for molecular biologists to insert IRES sequences into their vectors to allow for expression of two genes from a single vector—for example, a transgene and a fluorescent reporter molecule. The first gene is initiated at the normal 5' cap, and the second gene is initiated at the IRES.
Location
IRESs are commonly located in the 5'UTR of RNA viruses and allow translation of the RNAs in a cap-independent manner. However, mRNAs of viruses from Dicistroviridae family possess two open reading frames (ORFs), and translation of each is directed by two distinct IRESs. It has also been suggested that some mammalian cellular mRNAs also have IRESs. These cellular IRES elements are thought to be located in eukaryotic mRNAs encoding genes involved in stress survival, and other processes critical to survival. As of September 2009, there are 60 animal and 8 plant viruses reported to contain IRES e
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https://en.wikipedia.org/wiki/Bird%27s-eye%20view
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A bird's-eye view is an elevated view of an object or location from a very steep viewing angle, creating a perspective as if the observer were a bird in flight looking downwards. Bird's-eye views can be an aerial photograph, but also a drawing, and are often used in the making of blueprints, floor plans and maps.
Before crewed flight was common, the term "bird's eye" was used to distinguish views drawn from direct observation at high vantage locations (e.g. a mountain or tower), from those constructed from an imagined bird's perspectives. Bird's eye views as a genre have existed since classical times. They were significantly popular in the mid-to-late 19th century in the United States and Europe as photographic prints.
Terminology
The terms aerial view and aerial viewpoint are also sometimes used synonymous with bird's-eye view. The term aerial view can refer to any view from a great height, even at a wide angle, as for example when looking sideways from an airplane window or from a mountain top. Overhead view is fairly synonymous with bird's-eye view but tends to imply a vantage point of a lesser height than the latter term. For example, in computer and video games, an "overhead view" of a character or situation often places the vantage point only a few feet (a meter or two) above human height. See top-down perspective.
Recent technological and networking developments have made satellite images more accessible. Microsoft Bing Maps offers direct overhead satellite photos of the entire planet but also offers a feature named Bird's eye view in some locations. The Bird's Eye photos are angled at 40 degrees rather than being straight down. Satellite imaging programs and photos have been described as offering a viewer the opportunity to "fly over" and observe the world from this specific angle.
In filmmaking and video production, a bird's-eye shot refers to a shot looking directly down on the subject. The perspective is very foreshortened, making the subject appear
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https://en.wikipedia.org/wiki/Theomatics
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Theomatics is a numerological study of the Hebrew/Aramaic and Greek text of the Christian Bible (see also Biblical numerology), based upon gematria and isopsephia, by which its proponents claim to show the direct intervention of God in the writing of Christian scripture.
Etymology
The term "theomatics" was coined by Del Washburn in 1976 as a combination of "Θεός" ("God") and "mathematics". Washburn wrote three books about theomatics and created a website espousing the hypothesis.
Controversy
An analysis and criticism of theomatics has been published by
Tim Hayes, previously under the pseudonym "A. B. Leever".
A German statistician, Kurt Fettelschoss, published an analysis that claims that "The observed quantity of theomatic hits is significantly not random". A response to the findings was posted by Tim Hayes. A further statistical analysis in defense, of Mr. Hayes response, was provided by Mr. Fettelschoss. [6]
An analysis by Russell Glasser, entitled "Theomatics Debunked", shows the same phenomenon in a secular text.
Washburn's website has a page entitled "Scientific Proof" which discusses and responds to potential arguments against theomatics.
References
Further reading
Theomatics and Other Bible Codes from Ontario Consultants on Religious Tolerance
Bible Code from the Skeptic's Dictionary
Language and mysticism
Bible code
Numerology
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https://en.wikipedia.org/wiki/Lottery%20mathematics
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Lottery mathematics is used to calculate probabilities of winning or losing a lottery game. It is based primarily on combinatorics, particularly the twelvefold way and combinations without replacement.
Choosing 6 from 49
In a typical 6/49 game, each player chooses six distinct numbers from a range of 1-49. If the six numbers on a ticket match the numbers drawn by the lottery, the ticket holder is a jackpot winner—regardless of the order of the numbers. The probability of this happening is 1 in 13,983,816.
The chance of winning can be demonstrated as follows: The first number drawn has a 1 in 49 chance of matching. When the draw comes to the second number, there are now only 48 balls left in the bag, because the balls are drawn without replacement. So there is now a 1 in 48 chance of predicting this number.
Thus for each of the 49 ways of choosing the first number there are 48 different ways of choosing the second. This means that the probability of correctly predicting 2 numbers drawn from 49 in the correct order is calculated as 1 in 49 × 48. On drawing the third number there are only 47 ways of choosing the number; but we could have arrived at this point in any of 49 × 48 ways, so the chances of correctly predicting 3 numbers drawn from 49, again in the correct order, is 1 in 49 × 48 × 47. This continues until the sixth number has been drawn, giving the final calculation, 49 × 48 × 47 × 46 × 45 × 44, which can also be written as or 49 factorial divided by 43 factorial or FACT(49)/FACT(43) or simply PERM(49,6) .
608281864034267560872252163321295376887552831379210240000000000 / 60415263063373835637355132068513997507264512000000000 = 10068347520
This works out to 10,068,347,520, which is much bigger than the ~14 million stated above.
Perm(49,6)=10068347520 and 49 nPr 6 =10068347520.
However, the order of the 6 numbers is not significant for the payout. That is, if a ticket has the numbers 1, 2, 3, 4, 5, and 6, it wins as long as all the numbers 1 through 6
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https://en.wikipedia.org/wiki/Single-minute%20exchange%20of%20die
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Single-minute digit exchange of die (SMED) is one of the many lean production methods for reducing inefficiencies in a manufacturing process. It provides a rapid and efficient way of converting a manufacturing process from running the current product to running the next product. This is key to reducing production lot sizes, and reducing uneven flow (Mura), production loss, and output variability.
The phrase "single minute" does not mean that all changeovers and startups should only take one minute, rather, it should take less than 10 minutes ("single-digit minute"). A closely associated yet more difficult concept is one-touch exchange of die (OTED), which says changeovers can and should take less than 100 seconds. A die is a tool used in manufacturing. However SMED's utility is not limited to manufacturing (see value stream mapping).
History
Frederick Winslow Taylor analyzed non-value-adding parts of setups in his 1911 book, Shop Management (page 171). However, he did not create any method or structured approach around it.
Frank Bunker Gilbreth studied and improved working processes in many different industries, from bricklaying to surgery. As part of his work, he also looked into changeovers. His book Motion Study (also from 1911) described approaches to reduce setup time.
Even Henry Ford's factories were using some setup reduction techniques. In the 1915 publication Ford Methods and Ford Shops, setup reduction approaches were clearly described. However, these approaches never became mainstream. For most parts during the 20th century, the economic order quantity was the gold standard for lot sizing.
The JIT workflow of Toyota had this problem of tools changeover took between two and eight hours, Toyota could neither afford the lost production time nor the enormous lot sizes suggested by the economic order quantity. Lot reduction and set up time reduction had actually been ongoing in TPS since 1945 when Taiichi Ohno became manager of the machine shops in Toyot
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https://en.wikipedia.org/wiki/Interleave%20sequence
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In mathematics, an interleave sequence is obtained by merging two sequences via an in shuffle.
Let be a set, and let and , be two sequences in The interleave sequence is defined to be the sequence . Formally, it is the sequence given by
Properties
The interleave sequence is convergent if and only if the sequences and are convergent and have the same limit.
Consider two real numbers a and b greater than zero and smaller than 1. One can interleave the sequences of digits of a and b, which will determine a third number c, also greater than zero and smaller than 1. In this way one obtains an injection from the square to the interval (0, 1). Different radixes give rise to different injections; the one for the binary numbers is called the Z-order curve or Morton code.
References
Real analysis
Sequences and series
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https://en.wikipedia.org/wiki/Type%20generalization
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Type generalization is a technique commonly used in refactoring. The idea is to draw on the benefits of object-orientation and make more-generalized types, thus enabling more code sharing, leading to better maintainability as there is less code to write. Too-general code can, however, become completely useless, leading to spaghetti code doing effectively nothing.
Type generalization refers to making more general or more abstract some subset of the traits of a specific type. A superclass has wider use than a specific subclass, and so is more 'general'.
An example of generalizing a type would be moving a method from a child to a parent class for common use by all the parent class' children, not just the original child.
Another example, in the Java programming language, would be access to an object via an interface which isn't tied into a specific implementation of that interface.
References
Code refactoring
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https://en.wikipedia.org/wiki/Standard%20algorithms
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In elementary arithmetic, a standard algorithm or method is a specific method of computation which is conventionally taught for solving particular mathematical problems. These methods vary somewhat by nation and time, but generally include exchanging, regrouping, long division, and long multiplication using a standard notation, and standard formulas for average, area, and volume. Similar methods also exist for procedures such as square root and even more sophisticated functions, but have fallen out of the general mathematics curriculum in favor of calculators (or tables and slide rules before them).
The concepts of reform mathematics which the NCTM introduced in 1989 favors an alternative approach. It proposes a deeper understanding of the underlying theory instead of memorization of specific methods will allow students to develop individual methods which solve the same problems. Students' alternative algorithms are often just as correct, efficient, and generalizable as the standard algorithms, and maintain emphasis on the meaning of the quantities involved, especially as relates to place values (something that is usually lost in the memorization of standard algorithms). The development of sophisticated calculators has made manual calculation less important (see the note on square roots, above) and cursory teaching of traditional methods has created failure among many students. Greater achievement among all types of students is among the primary goals of mathematics education put forth by NCTM. Some researchers such as Constance Kamii have suggested that elementary arithmetic, as traditionally taught, is not appropriate in elementary school. Many first editions of textbooks written to the original 1989 standard such as TERC deliberately discouraged teaching of any particular method, instead devoting class and homework time to the solving of nontrivial problems, which stimulate students to develop their own methods of calculation, rooted in number sense and place v
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https://en.wikipedia.org/wiki/Robert%20Aumann
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Robert John Aumann (Hebrew name: , Yisrael Aumann; born June 8, 1930) is an Israeli-American mathematician, and a member of the United States National Academy of Sciences. He is a professor at the Center for the Study of Rationality in the Hebrew University of Jerusalem in Israel. He also holds a visiting position at Stony Brook University, and is one of the founding members of the Stony Brook Center for Game Theory.
Aumann received the Nobel Memorial Prize in Economic Sciences in 2005 for his work on conflict and cooperation through game theory analysis. He shared the prize with Thomas Schelling.
Early years
Aumann was born in Frankfurt am Main, Germany, and fled to the United States with his family in 1938, two weeks before the Kristallnacht pogrom. He attended the Rabbi Jacob Joseph School, a yeshiva high school in New York City.
Academic career
Aumann graduated from the City College of New York in 1950 with a B.Sc. in mathematics. He received his M.Sc. in 1952, and his Ph.D. in Mathematics in 1955, both from the Massachusetts Institute of Technology. His doctoral dissertation, Asphericity of Alternating Linkages, concerned knot theory. His advisor was George Whitehead, Jr.
In 1956 he joined the Mathematics faculty of the Hebrew University of Jerusalem and has been a visiting professor at Stony Brook University since 1989. He has held visiting professorship at the University of California, Berkeley (1971, 1985–1986), Stanford University (1975–1976, 1980–1981), and Universite Catholique de Louvain (1972, 1978, 1984).
Mathematical and scientific contribution
Aumann's greatest contribution was in the realm of repeated games, which are situations in which players encounter the same situation over and over again.
Aumann was the first to define the concept of correlated equilibrium in game theory, which is a type of equilibrium in non-cooperative games that is more flexible than the classical Nash equilibrium. Furthermore, Aumann has introduced the first purely
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https://en.wikipedia.org/wiki/Internet%20transit
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Internet transit is the service of allowing network traffic to cross or "transit" a computer network, usually used to connect a smaller Internet service provider (ISP) to the larger Internet. Technically, it consists of two bundled services:
The advertisement of customer routes to other ISPs, thereby soliciting inbound traffic toward the customer from them
The advertisement of other ISPs' routes (usually but not necessarily in the form of a default route or a full set of routes to all of the destinations on the Internet) to the ISP's customer, thereby soliciting outbound traffic from the customer towards these networks.
In the 1970s and early 1980s-era Internet, the assumption was made that all networks would provide full transit for one another. In the modern private-sector Internet, two forms of interconnect agreements exist between Internet networks: transit, and peering. Transit is distinct from peering, in which only traffic between the two ISPs and their downstream customers is exchanged and neither ISP can see upstream routes over the peering connection. A transit free network uses only peering; a network that uses only unpaid peering and connects to the whole Internet is considered a Tier 1 network. In the 1990s, the network access point concept provided one form of transit.
Pricing for the internet transit varies at different times and geographical locations. The transit service is typically priced per megabit per second per month, and customers are often required to commit to a minimum volume of bandwidth, and usually to a minimum term of service as well, usually using a 95e percentile burstable billing scheme. Some transit agreements provide "service-level agreements" which purport to offer money-back guarantees of performance between the customer's Internet connection and specific points on the Internet, typically major Internet exchange points within a continental geography such as North America. These service level agreements still provide only bes
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https://en.wikipedia.org/wiki/Optimum%20programming
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In the history of computing, optimum programming, or optimum coding is the practice of arranging a computer program's instructions in memory so as to minimize the time the machine spends waiting for instructions. It is of historical interest mainly due to the design of many early digital computers.
Most early computers used some form of serial memory, primarily delay-line memory or magnetic drums. Unlike the random-access memory of modern computers, words in serial memory are made available one at a time; the time required to access a particular word depends on the "distance" between it and the word currently being read. If a given delay line held n words, the average time to read a word would be n/2 word times. Without optimum coding, such a machine would spend most of its time idly waiting for instructions and data.
To circumvent this problem, many machines, particularly Alan Turing's ACE and its descendants, included a field specifying the address of the next instruction to be executed in their instruction format. A programmer employing optimum coding would look up the time needed to perform the current instruction, calculate how far the memory system would move in that time, and then place the next instruction for the program at that location. Thus when the current instruction completed and the computer looked for the next one as specified in the instruction, that memory location would just be arriving and would be able to be read in immediately. For example, if a programmer had just coded an ADD instruction at address 400, and the ADD instruction required 4 word-times to execute, the programmer would set the "next address" field of the instruction to 404, and would place the next instruction there.
In the United States, optimum coding was most commonly employed on the IBM 650 and the Bendix G-15. Both machines had optimizing assemblers (SOAP for the IBM, POGO for Bendix) that could automate this task.
See also
Mel Kaye, who authored one particularly clever
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https://en.wikipedia.org/wiki/Mechannibals
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Mechannibals is a television game show aired on the British television channel BBC Two in 2005. It was made by the independent production company IWC Media. The host was Louise Brady.
The show was sometimes likened to Channel 4's Scrapheap Challenge or the earlier BBC series The Great Egg Race, it centres on taking two families from the same area and setting them a task to create some form of machine. The contestant families were required to create it using only parts found in their home. Machines created include a shed destroyer, a beer chiller and a food cooking and preparing machine. The finished creations were then judged by people who have some knowledge about the subject. The winning family is then given enough money to replace all their used equipment with top-of-the-range alternatives. The other family, however, was left merely with a toolbox.
References
External links
2005 British television series debuts
2005 British television series endings
BBC television game shows
2000s British game shows
Engineering competitions
Engineering education in the United Kingdom
English-language television shows
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https://en.wikipedia.org/wiki/Compressor%20map
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A compressor map is a chart which shows the performance of a turbomachinery compressor. This type of compressor is used in gas turbine engines, for supercharging reciprocating engines and for industrial processes, where it is known as a dynamic compressor. A map is created from compressor rig test results or predicted by a special computer program. Alternatively the map of a similar compressor can be suitably scaled. This article is an overview of compressor maps and their different applications and also has detailed explanations of maps for a fan and intermediate and high-pressure compressors from a three-shaft aero-engine as specific examples.
Compressor maps are an integral part of predicting the performance of gas turbine and turbocharged engines, both at design and off-design conditions. They also serve a critical purpose in selecting the correct compressors for industrial processes.
Fans and turbines also have operating maps, although the latter are significantly different in appearance to that of compressors.
Compressor design
A compressor map shows the operating range of a compressor and how well it works within its operating range. Two fundamental requirements for the gas flowing through a compressor explain why it works best at a design condition and not so well at other conditions, known as off-design. First, the exit area has to be smaller than the inlet area because the compressed gas has a higher density. The exit area is sized to pass the specific volume at the design condition. Second, all the rotor and stator blades in an axial compressor, and impeller inducer and diffuser vanes in a centrifugal compressor, are angled to meet approaching air head-on at the design condition to minimize incidence losses. Incidence losses reduce the efficiency of compression. Satisfactory operation of the compressor relies on controlling the angle at which the gas approaches rotating and stationary blades to within an acceptable range. Deviating from the optimum fir
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https://en.wikipedia.org/wiki/Heath%E2%80%93Jarrow%E2%80%93Morton%20framework
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The Heath–Jarrow–Morton (HJM) framework is a general framework to model the evolution of interest rate curves – instantaneous forward rate curves in particular (as opposed to simple forward rates). When the volatility and drift of the instantaneous forward rate are assumed to be deterministic, this is known as the Gaussian Heath–Jarrow–Morton (HJM) model of forward rates. For direct modeling of simple forward rates the Brace–Gatarek–Musiela model represents an example.
The HJM framework originates from the work of David Heath, Robert A. Jarrow, and Andrew Morton in the late 1980s, especially Bond pricing and the term structure of interest rates: a new methodology (1987) – working paper, Cornell University, and Bond pricing and the term structure of interest rates: a new methodology (1989) – working paper (revised ed.), Cornell University. It has its critics, however, with Paul Wilmott describing it as "...actually just a big rug for [mistakes] to be swept under".
Framework
The key to these techniques is the recognition that the drifts of the no-arbitrage evolution of certain variables can be expressed as functions of their volatilities and the correlations among themselves. In other words, no drift estimation is needed.
Models developed according to the HJM framework are different from the so-called short-rate models in the sense that HJM-type models capture the full dynamics of the entire forward rate curve, while the short-rate models only capture the dynamics of a point on the curve (the short rate).
However, models developed according to the general HJM framework are often non-Markovian and can even have infinite dimensions. A number of researchers have made great contributions to tackle this problem. They show that if the volatility structure of the forward rates satisfy certain conditions, then an HJM model can be expressed entirely by a finite state Markovian system, making it computationally feasible. Examples include a one-factor, two state model (O. Ch
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https://en.wikipedia.org/wiki/Front%20end%20of%20line
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The front-end-of-line (FEOL) is the first portion of IC fabrication where the individual components (transistors, capacitors, resistors, etc.) are patterned in the semiconductor.
FEOL generally covers everything up to (but not including) the deposition of metal interconnect layers.
For the CMOS process, FEOL contains all fabrication steps needed to form isolated CMOS elements:
Selecting the type of wafer to be used; Chemical-mechanical planarization and cleaning of the wafer.
Shallow trench isolation (STI) (or LOCOS in early processes, with feature size > 0.25 μm)
Well formation
Gate module formation
Source and drain module formation
See also
Back end of line
Integrated circuit
References
Further reading
"CMOS: Circuit Design, Layout, and Simulation" Wiley-IEEE, 2010. . pages 177-178 (Chapter 7.2 CMOS Process Integration); pages 180-199 (7.2.1 Frontend-of-the-line integration)
Electronics manufacturing
Semiconductor device fabrication
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https://en.wikipedia.org/wiki/Back%20end%20of%20line
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The back end of line (BEOL) is the second portion of IC fabrication where the individual devices (transistors, capacitors, resistors, etc.) get interconnected with wiring on the wafer, the metalization layer. Common metals are copper and aluminum.
BEOL generally begins when the first layer of metal is deposited on the wafer. BEOL includes contacts, insulating layers (dielectrics), metal levels, and bonding sites for chip-to-package connections.
After the last FEOL step, there is a wafer with isolated transistors (without any wires). In BEOL part of fabrication stage contacts (pads), interconnect wires, vias and dielectric structures are formed. For modern IC process, more than 10 metal layers can be added in the BEOL.
Steps of the BEOL:
Silicidation of source and drain regions and the polysilicon region.
Adding a dielectric (first, lower layer is pre-metal dielectric (PMD) – to isolate metal from silicon and polysilicon), CMP processing it
Make holes in PMD, make a contacts in them.
Add metal layer 1
Add a second dielectric, called the inter-metal dielectric (IMD)
Make vias through dielectric to connect lower metal with higher metal. Vias filled by Metal CVD process.
Repeat steps 4–6 to get all metal layers.
Add final passivation layer to protect the microchip
Before 1998, practically all chips used aluminium for the metal interconnection layers.
The four metals with the highest electrical conductivity are silver with the highest conductivity, then copper, then gold, then aluminium.
After BEOL there is a "back-end process" (also called post-fab), which is done not in the cleanroom, often by a different company.
It includes wafer test, wafer backgrinding, die separation, die tests, IC packaging and final test.
See also
Front end of line
Integrated circuit
Phosphosilicate glass
References
Further reading
Electronics manufacturing
Semiconductor device fabrication
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https://en.wikipedia.org/wiki/Optical%20computing
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Optical computing or photonic computing uses light waves produced by lasers or incoherent sources for data processing, data storage or data communication for computing. For decades, photons have shown promise to enable a higher bandwidth than the electrons used in conventional computers (see optical fibers).
Most research projects focus on replacing current computer components with optical equivalents, resulting in an optical digital computer system processing binary data. This approach appears to offer the best short-term prospects for commercial optical computing, since optical components could be integrated into traditional computers to produce an optical-electronic hybrid. However, optoelectronic devices consume 30% of their energy converting electronic energy into photons and back; this conversion also slows the transmission of messages. All-optical computers eliminate the need for optical-electrical-optical (OEO) conversions, thus reducing electrical power consumption.
Application-specific devices, such as synthetic-aperture radar (SAR) and optical correlators, have been designed to use the principles of optical computing. Correlators can be used, for example, to detect and track objects, and to classify serial time-domain optical data.
Optical components for binary digital computer
The fundamental building block of modern electronic computers is the transistor. To replace electronic components with optical ones, an equivalent optical transistor is required. This is achieved by crystal optics (using materials with a non-linear refractive index). In particular, materials exist where the intensity of incoming light affects the intensity of the light transmitted through the material in a similar manner to the current response of a bipolar transistor. Such an optical transistor can be used to create optical logic gates, which in turn are assembled into the higher level components of the computer's central processing unit (CPU). These will be nonlinear optical c
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https://en.wikipedia.org/wiki/CHMOS
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CHMOS refers to one of a series of Intel CMOS processes developed from their HMOS process. CHMOS stands for "complementary high-performance metal-oxide-silicon. It was first developed in 1981.
CHMOS was used in the Intel 80C51BH, a new version of their standard MCS-51 microcontroller. The chip was also used in later versions of Intel 8086, and the 80C88, which were fully static version of the Intel 8088. The Intel 80386 was made in 1.5 µm CHMOS III, and later in 1.0 µm CHMOS IV.
CHMOS III used 1.5 micron lithography, p-well processing, n-well processing, and two layers of metal.
CHMOS III-E used for the 12.5 MHz Intel 80C186 microprocessor. This technology uses 1 µm process for the EPROM.
CHMOS IV (H stands for High Speed) used 1.0 µm lithography. Many versions of the Intel 80486 were made in 1.0 µm CHMOS IV. Intel uses this technology on these 80C186EB and 80C188EB embedded processors.
CHMOS V used 0.8 µm lithography and 3 metal layers, and was used in later versions of the 80386, 80486, and i860.
See also
Depletion-load NMOS logic#Further development
References
Electronic design
Digital electronics
Integrated circuits
MOSFETs
Intel
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https://en.wikipedia.org/wiki/List%20of%20probability%20distributions
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Many probability distributions that are important in theory or applications have been given specific names.
Discrete distributions
With finite support
The Bernoulli distribution, which takes value 1 with probability p and value 0 with probability q = 1 − p.
The Rademacher distribution, which takes value 1 with probability 1/2 and value −1 with probability 1/2.
The binomial distribution, which describes the number of successes in a series of independent Yes/No experiments all with the same probability of success.
The beta-binomial distribution, which describes the number of successes in a series of independent Yes/No experiments with heterogeneity in the success probability.
The degenerate distribution at x0, where X is certain to take the value x0. This does not look random, but it satisfies the definition of random variable. This is useful because it puts deterministic variables and random variables in the same formalism.
The discrete uniform distribution, where all elements of a finite set are equally likely. This is the theoretical distribution model for a balanced coin, an unbiased die, a casino roulette, or the first card of a well-shuffled deck.
The hypergeometric distribution, which describes the number of successes in the first m of a series of n consecutive Yes/No experiments, if the total number of successes is known. This distribution arises when there is no replacement.
The negative hypergeometric distribution, a distribution which describes the number of attempts needed to get the nth success in a series of Yes/No experiments without replacement.
The Poisson binomial distribution, which describes the number of successes in a series of independent Yes/No experiments with different success probabilities.
Fisher's noncentral hypergeometric distribution
Wallenius' noncentral hypergeometric distribution
Benford's law, which describes the frequency of the first digit of many naturally occurring data.
The ideal and robust soliton distributions.
Zipf's law or
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https://en.wikipedia.org/wiki/Isotropic%20coordinates
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In the theory of Lorentzian manifolds, spherically symmetric spacetimes admit a family of nested round spheres. There are several different types of coordinate chart which are adapted to this family of nested spheres; the best known is the Schwarzschild chart, but the isotropic chart is also often useful.
The defining characteristic of an isotropic chart is that its radial coordinate (which is different from the radial coordinate of a Schwarzschild chart) is defined so that light cones appear round. This means that (except in the trivial case of a locally flat manifold), the angular isotropic coordinates do not faithfully represent distances within the nested spheres, nor does the radial coordinate faithfully represent radial distances. On the other hand, angles in the constant time hyperslices are represented without distortion, hence the name of the chart.
Isotropic charts are most often applied to static spherically symmetric spacetimes in metric theories of gravitation such as general relativity, but they can also be used in modeling a spherically pulsating fluid ball, for example. For isolated spherically symmetric solutions of the Einstein field equation, at large distances, the isotropic and Schwarzschild charts become increasingly similar to the usual polar spherical chart on Minkowski spacetime.
Definition
In an isotropic chart (on a static spherically symmetric spacetime), the metric (aka line element) takes the form
Depending on context, it may be appropriate to regard as undetermined functions of the radial coordinate (for example, in deriving an exact static spherically symmetric solution of the Einstein field equation). Alternatively, we can plug in specific functions (possibly depending on some parameters) to obtain an isotropic coordinate chart on a specific Lorentzian spacetime.
Killing vector fields
The Lie algebra of Killing vector fields of a spherically symmetric static spacetime takes the same form in the isotropic chart as in the Sc
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https://en.wikipedia.org/wiki/Real-Time%20Messaging%20Protocol
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Real-Time Messaging Protocol (RTMP) is a communication protocol for streaming audio, video, and data over the Internet. Originally developed as a proprietary protocol by Macromedia for streaming between Flash Player and the Flash Communication Server, Adobe (which acquired Macromedia) has released an incomplete version of the specification of the protocol for public use.
The RTMP protocol has multiple variations:
RTMP proper, the "plain" protocol which works on top of Transmission Control Protocol (TCP) and uses port number 1935 by default.
RTMPS, which is RTMP over a Transport Layer Security (TLS/SSL) connection.
RTMPE, which is RTMP encrypted using Adobe's own security mechanism. While the details of the implementation are proprietary, the mechanism uses industry standard cryptographic primitives.
RTMPT, which is encapsulated within HTTP requests to traverse firewalls. RTMPT is frequently found utilizing cleartext requests on TCP ports 80 and 443 to bypass most corporate traffic filtering. The encapsulated session may carry plain RTMP, RTMPS, or RTMPE packets within.
RTMFP, which is RTMP over User Datagram Protocol (UDP) instead of TCP, replacing RTMP Chunk Stream. The Secure Real-Time Media Flow Protocol suite has been developed by Adobe Systems and enables end‐users to connect and communicate directly with each other (P2P).
While the primary motivation for RTMP was to be a protocol for playing Flash video, it is also used in some other applications, such as the Adobe LiveCycle Data Services ES.
Basic operation
RTMP is a TCP-based protocol which maintains persistent connections and allows low-latency communication. To deliver streams smoothly and transmit as much information as possible, it splits streams into fragments, and their size is negotiated dynamically between the client and server. Sometimes, it is kept unchanged; the default fragment sizes are 64 bytes for audio data, and 128 bytes for video data and most other data types. Fragments from diffe
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https://en.wikipedia.org/wiki/Glomalin
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Glomalin is a hypothetical glycoprotein produced abundantly on hyphae and spores of arbuscular mycorrhizal (AM) fungi in soil and in roots. Glomalin was proposed in 1996 by Sara F. Wright, a scientist at the USDA Agricultural Research Service, but it was not isolated and described yet. The name comes from Glomerales, an order of fungi. Most AM fungi are of the division Glomeromycota. An elusive substance, it is mostly assumed to have a glue-like effect on soil, but it has not been isolated yet.
Definition and controversy
The specific protein glomalin has not yet been isolated and described. What has been described is an extraction process involving heat and citrate, producing a mixture containing a substance that is reactive to a monoclonal antibody Mab32B11 raised against crushed AM fungi spores. The substance is then provisionally named "glomalin". As many laboratories do not have the equipment to perform an antibody-based isolation (ELISA), a crude mixture called glomalin-related soil proteins (GRSP) is used to refer to the extract portion reactive to the Bradford protein assay. There is significant confusion between the ideal glomalin protein, the antibody-reactive extract portion termed "glomalin", and GRSP.
"Glomalin" was first detected by the Mab32B11 ELISA assay in 1987. According to the scientist that proposed the hypothetical protein, Sarah F. Wright, it eluded extraction until 1996 because "It requires an unusual effort to dislodge glomalin for study: a bath in citrate combined with heating at 250 °F (121 °C) for at least an hour.... No other soil glue found to date required anything as drastic as this." However, using advanced analytical methods in 2010, the citrate-heating extraction procedure for GRSP was proven to co-extract humic substances, so it is still not clear if this "glue effect" comes from glomalin or the other substances that are co-extracted using that method.
Description
Based on her extraction, Wright thinks the "glomalin molecul
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https://en.wikipedia.org/wiki/Russian%20460%20metre%20radio%20mast
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The Russian 460 metres radio masts are among the most secret supertall structures ever built. Three such masts, which were developed by Stako, were erected in mid-1980s near Inta, Dudinka and Taymylyr as masts for the North Siberian Chayka Chain for transmitting navigation signals on 100 kHz with 1200 kW.
All these masts are grounded lattice structures of tubular steel elements with triangular cross section. The side length of the triangle of the mast body is 3.6 metres. Each of these masts is guyed in 6 levels.
These masts were at completion the tallest structures in Asia and are still the second-tallest in Russia.
In 2003 at Moscow Radio Centre 13 a guyed mast for FM-transmission of the same type was built, which is however just 300 metres and not 460 metres tall. It is guyed in 4 levels.
On September 24, 2009, the mast at Taymylyr was demolished by explosives, which was the tallest object ever demolished in this way.
External links
http://ru-abandoned.livejournal.com/713371.html
https://web.archive.org/web/20110816150649/http://www.internavigation.ru/page.phtml?p=95
Towers in Russia
Radio masts and towers
Towers built in the Soviet Union
Radio in the Soviet Union
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https://en.wikipedia.org/wiki/CEBus
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CEBus(r), short for Consumer Electronics Bus, also known as EIA-600, is a set of electrical standards and communication protocols for electronic devices to transmit commands and data. It is suitable for devices in households and offices to use, and might be useful for utility interface and light industrial applications.
History
In 1984, members of the Electronic Industries Alliance (EIA) identified a need for standards that included more capability than the de facto home automation standard X10. X10 provided blind transmission of the commands ON, OFF, DIM, BRIGHT, ALL LIGHTS ON, and ALL UNITS OFF over powerline carrier, and later infrared and short range radio mediums. Over a six-year period, engineers representing international companies met on a regular basis and developed a proposed standard. They called this standard CEBus (pronounced "see bus"). The CEBus standard was released in September 1992.
CEBus is an open architecture set of specification documents which define protocols for products to communicate through power line wire, low voltage twisted pair wire, coaxial cable, infrared, RF, and fiber optics.
The CEBus Standard was developed on the foundation of an IR (infrared) protocol developed by GE (General Electric). This work was transferred to the EIA at the beginning of the EIA's involvement, under the plan that it would be expanded then maintained by the EIA.
Technology
Powerline carrier
The CEBus standard includes such things as spread spectrum modulation on the power line. Spread spectrum involves starting a modulation at one frequency, and altering the frequency during its cycle. The CEBus power line standard begins each burst at 100 kHz, and increases linearly to 400 kHz during a 100 microsecond duration. Both the bursts (referred to as "superior" state) and the absence of burst (referred to as the "inferior" state) create similar digits, so a pause in between is not necessary.
A digit 1 is created by an inferior or superior state that l
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https://en.wikipedia.org/wiki/Parameter%20space
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The parameter space is the space of possible parameter values that define a particular mathematical model, often a subset of finite-dimensional Euclidean space. Often the parameters are inputs of a function, in which case the technical term for the parameter space is domain of a function. The ranges of values of the parameters may form the axes of a plot, and particular outcomes of the model may be plotted against these axes to illustrate how different regions of the parameter space produce different types of behavior in the model.
In statistics, parameter spaces are particularly useful for describing parametric families of probability distributions. They also form the background for parameter estimation. In the case of extremum estimators for parametric models, a certain objective function is maximized or minimized over the parameter space. Theorems of existence and consistency of such estimators require some assumptions about the topology of the parameter space. For instance, compactness of the parameter space, together with continuity of the objective function, suffices for the existence of an extremum estimator.
Examples
A simple model of health deterioration after developing lung cancer could include the two parameters gender and smoker/non-smoker, in which case the parameter space is the following set of four possibilities: .
The logistic map has one parameter, r, which can take any positive value. The parameter space is therefore positive real numbers.
For some values of r, this function ends up cycling round a few values, or fixed on one value. These long-term values can be plotted against r in a bifurcation diagram to show the different behaviours of the function for different values of r.
In a sine wave model the parameters are amplitude A > 0, angular frequency ω > 0, and phase φ ∈ S1. Thus the parameter space is
In complex dynamics, the parameter space is the complex plane C = { z = x + y i : x, y ∈ R }, where i2 = −1.
The famous Mandelbrot
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https://en.wikipedia.org/wiki/Load-link/store-conditional
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In computer science, load-linked/store-conditional (LL/SC), sometimes known as load-reserved/store-conditional (LR/SC), are a pair of instructions used in multithreading to achieve synchronization. Load-link returns the current value of a memory location, while a subsequent store-conditional to the same memory location will store a new value only if no updates have occurred to that location since the load-link. Together, this implements a lock-free, atomic, read-modify-write operation.
"Load-linked" is also known as load-link, load-reserved, and load-locked.
LL/SC was originally proposed by Jensen, Hagensen, and Broughton for the S-1 AAP multiprocessor at Lawrence Livermore National Laboratory.
Comparison of LL/SC and compare-and-swap
If any updates have occurred, the store-conditional is guaranteed to fail, even if the value read by the load-link has since been restored. As such, an LL/SC pair is stronger than a read followed by a compare-and-swap (CAS), which will not detect updates if the old value has been restored (see ABA problem).
Real implementations of LL/SC do not always succeed even if there are no concurrent updates to the memory location in question. Any exceptional events between the two operations, such as a context switch, another load-link, or even (on many platforms) another load or store operation, will cause the store-conditional to spuriously fail. Older implementations will fail if there are any updates broadcast over the memory bus. This is called weak LL/SC by researchers, as it breaks many theoretical LL/SC algorithms. Weakness is relative, and some weak implementations can be used for some algorithms.
LL/SC is more difficult to emulate than CAS. Additionally, stopping running code between paired LL/SC instructions, such as when single-stepping through code, can prevent forward progress, making debugging tricky.
Nevertheless, LL/SC is equivalent to CAS in the sense that either primitive can be implemented in terms of the other, in O(1)
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https://en.wikipedia.org/wiki/FR-V%20%28microprocessor%29
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The Fujitsu FR-V (Fujitsu RISC-VLIW) is one of the very few processors ever able to process both a very long instruction word (VLIW) and vector processor instructions at the same time, increasing throughput with high parallel computing while increasing performance per watt and hardware efficiency. The family was presented in 1999. Its design was influenced by the VPP500/5000 models of the Fujitsu VP/2000 vector processor supercomputer line.
Featuring a 1–8 way very long instruction word (VLIW, Multiple Instruction Multiple Data (MIMD), up to 256 bit) instruction set it additionally uses a 4-way single instruction, multiple data (SIMD) vector processor core. A 32-bit RISC instruction set in the superscalar core is combined with most variants integrating a dual 16-bit media processor also in VLIW and vector architecture. Each processor core is superpipelined as well as 4-unit superscalar.
A typical integrated circuit integrates a system on a chip and further multiplies speed by integrating multiple cores. Due to the very low power requirements it is a solution even for battery-powered applications.
Variants
The family started with the FR-500, includes FR-300, FR-400, FR-450, FR-550 and FR1000 architecture 32-bit processors, can run Linux, RTLinux, VxWorks, eCos, or ITRON and is also supported by the Softune Integrated development environment and the GNU Compiler Collection or GNUPro.
It is often used for image processing or video processing with most variants including a dual 16-bit media-processor.
Technology
The 2005 presented FR1000 uses a core with 8-way 256-bit VLIW (MIMD) filling its superpipeline as well as a 4-unit superscalar architecture (Integer (ALU)-, Floating-point- and two media-processor-units), further increasing its peak performance of each core to up to 28 instructions per clock cycle. Like other VLIW-architectures 1 way is needed to load the next 256-bit instruction: 7-ways usable. Due to the used 4-way single instruction, multiple data (SIMD
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https://en.wikipedia.org/wiki/Super%20Hydlide
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Super Hydlide is an action role-playing game for the Sega Genesis/Mega Drive. It was originally released in 1987 in Japan only under the title for the MSX, MSX2, and PC-8801mkII SR. It's the third game in the Hydlide series. Ports were also released for the X1, Famicom, X68000, and Microsoft Windows. The game was developed by Hydlide series veterans T&E Soft and released worldwide on the Sega Genesis / Mega Drive on October 6, 1989, in Japan, early 1990 in the United States, and 1991 in Europe. This remake evidences substantial graphical upgrades to the original Hydlide 3, though the gameplay remains largely identical. Before its release, it was called Hollo Fighter in some Sega advertising material and was one of the first third party published titles to be released in the U.S, the other being Air Diver.
Story
Many years after the events of Hydlide II, an explosion of flames appeared near The City of the Woods. After that, monsters spread throughout the world. A young man is chosen to find the source of the evil.
Gameplay
The game incorporates a 'good/evil character' morality/alignment system. Like its predecessor Hydlide II: Shine of Darkness (1985), the player has a morality meter that can be aligned with either Justice, Normal, or Evil. The game has both good and evil monsters. Evil monsters attack the player character on sight, while good monsters only attack if the player character attacks them first. Killing any monster, good or evil, results in a reward of experience points, money, and occasionally a piece of equipment. However, if the player kills a good monster, points are lost from a statistic called "MF" (Moral Fiber). If the player's MF stat drops to zero, frequent traps will appear across the world. If the player manages to keep it over 100, rewards appear in the form of random items found around Fairyland. Unlike Hydlide II, the morality meter no longer affects the way in which the townsfolk react to the player.
The game also features an in-game c
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https://en.wikipedia.org/wiki/UDP%20Helper%20Address
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A UDP Helper Address is a special router configuration used to forward broadcast network traffic from a client machine on one subnet to a server in another subnet.
Usage example
The Internet Protocol requires every network interface controller to be assigned at least one unique IP address. Groups of machines with similar addresses are considered to be part of the same logical subnet. One method of assigning IP addresses is DHCP in which addresses typically are issued by a DHCP server running on one or more hosts. If one of these machines is on the same subnet as its clients, the DHCP server can respond to their broadcast DHCP requests and issue an address. But the DHCP servers may be hosted on a different subnet and, by default, most routers do not pass broadcast messages to nodes outside their own subnet.
To resolve this, a UDP helper address is established in the router configuration to forward broadcast network traffic outside the local subnet. If a DHCP client outside the DHCP server's subnet broadcasts an address request, it is the helper that forwards the message to the DHCP server. The server then chooses an address and sends the client a unicast message, using the helper to send the message back to the client's subnet. The address is reserved for a limited time while the DHCP server waits for a response. If the client responds with another broadcast message, the DHCP server distributes the address. Helper addresses also can be used to forward other UDP traffic (for example, BOOTP).
Implementation
Cisco's first implementation of this protocol was introduced in version 10 of their router software. It is implemented through the use of the router configuration commands ip helper-address and ip forward-protocol.
ip helper-address
To enable the forwarding of User Datagram Protocol (UDP) broadcasts, including BOOTP, received on an interface, use the ip helper-address command in interface configuration mode. To disable the forwarding of broadcast packets to
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https://en.wikipedia.org/wiki/Diffusion%20barrier
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A diffusion barrier is a thin layer (usually micrometres thick) of metal usually placed between two other metals. It is done to act as a barrier to protect either one of the metals from corrupting the other.
Adhesion of a plated metal layer to its substrate requires a physical interlocking, inter-diffusion of the deposit or a chemical bonding between plate and substrate in order to work. The role of a diffusion barrier is to prevent or to retard the inter-diffusion of the two superposed metals. Therefore, to be effective, a good diffusion barrier requires inertness with respect to adjacent materials. To obtain good adhesion and a diffusion barrier simultaneously, the bonding between layers needs to come from a chemical reaction of limited range at both boundaries. Materials providing good adhesion are not necessarily good diffusion barriers and vice versa. Consequently, there are cases where two or more separate layers must be used to provide a proper interface between substrates.
Selection
While the choice of diffusion barrier depends on the final function, anticipated operating temperature, and service life, are critical parameters to select diffusion barrier materials. Many thin film metal combinations have been evaluated for their adhesion and diffusion barrier properties.
Aluminum provides good electrical and thermal conductivity, adhesion and reliability because of its oxygen reactivity and the self-passivation properties of its oxide.
Copper also easily reacts with oxygen but its oxides have poor adhesion properties. As for gold its virtue relies in its inertness, and ease of application; its problem is its cost.
Chromium has excellent adhesion to many materials because of its reactivity. Its affinity for oxygen forms a thin stable oxide coat on the outer surface, creating a passivation layer which prevents further oxidation of the chromium, and of the underlying metal (if any), even in corrosive environments. Chromium plating on steel for automotive
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https://en.wikipedia.org/wiki/Automated%20reasoning
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In computer science, in particular in knowledge representation and reasoning and metalogic, the area of automated reasoning is dedicated to understanding different aspects of reasoning. The study of automated reasoning helps produce computer programs that allow computers to reason completely, or nearly completely, automatically. Although automated reasoning is considered a sub-field of artificial intelligence, it also has connections with theoretical computer science and philosophy.
The most developed subareas of automated reasoning are automated theorem proving (and the less automated but more pragmatic subfield of interactive theorem proving) and automated proof checking (viewed as guaranteed correct reasoning under fixed assumptions). Extensive work has also been done in reasoning by analogy using induction and abduction.
Other important topics include reasoning under uncertainty and non-monotonic reasoning. An important part of the uncertainty field is that of argumentation, where further constraints of minimality and consistency are applied on top of the more standard automated deduction. John Pollock's OSCAR system is an example of an automated argumentation system that is more specific than being just an automated theorem prover.
Tools and techniques of automated reasoning include the classical logics and calculi, fuzzy logic, Bayesian inference, reasoning with maximal entropy and many less formal ad hoc techniques.
Early years
The development of formal logic played a big role in the field of automated reasoning, which itself led to the development of artificial intelligence. A formal proof is a proof in which every logical inference has been checked back to the fundamental axioms of mathematics. All the intermediate logical steps are supplied, without exception. No appeal is made to intuition, even if the translation from intuition to logic is routine. Thus, a formal proof is less intuitive and less susceptible to logical errors.
Some consider the Corne
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https://en.wikipedia.org/wiki/Battery%20charger
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A battery charger, recharger, or simply charger, is a device that stores energy in a battery by running an electric current through it. The charging protocol (how much voltage or current for how long, and what to do when charging is complete) depends on the size and type of the battery being charged. Some battery types have high tolerance for overcharging (i.e., continued charging after the battery has been fully charged) and can be recharged by connection to a constant voltage source or a constant current source, depending on battery type. Simple chargers of this type must be manually disconnected at the end of the charge cycle. Other battery types use a timer to cut off when charging should be complete. Other battery types cannot withstand over-charging, becoming damaged (reduced capacity, reduced lifetime), over heating or even exploding. The charger may have temperature or voltage sensing circuits and a microprocessor controller to safely adjust the charging current and voltage, determine the state of charge, and cut off at the end of charge. Chargers may elevate the output voltage proportionally with current to compensate for impedance in the wires.
A trickle charger provides a relatively small amount of current, only enough to counteract self-discharge of a battery that is idle for a long time. Some battery types cannot tolerate trickle charging; attempts to do so may result in damage. Lithium-ion batteries cannot handle indefinite trickle charging. Slow battery chargers may take several hours to complete a charge. High-rate chargers may restore most capacity much faster, but high rate chargers can be more than some battery types can tolerate. Such batteries require active monitoring of the battery to protect it from overcharging. Electric vehicles ideally need high-rate chargers. For public access, installation of such chargers and the distribution support for them is an issue in the proposed adoption of electric cars.
C-rate
Charge and discharge rates a
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https://en.wikipedia.org/wiki/Quadratrix
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In geometry, a quadratrix () is a curve having ordinates which are a measure of the area (or quadrature) of another curve. The two most famous curves of this class are those of Dinostratus and E. W. Tschirnhaus, which are both related to the circle.
Quadratrix of Dinostratus
The quadratrix of Dinostratus (also called the quadratrix of Hippias) was well known to the ancient Greek geometers, and is mentioned by Proclus, who ascribes the invention of the curve to a contemporary of Socrates, probably Hippias of Elis. Dinostratus, a Greek geometer and disciple of Plato, discussed the curve, and showed how it effected a mechanical solution of squaring the circle. Pappus, in his Collections, treats its history, and gives two methods by which it can be generated.
Let a helix be drawn on a right circular cylinder; a screw surface is then obtained by drawing lines from every point of this spiral perpendicular to its axis. The orthogonal projection of a section of this surface by a plane containing one of the perpendiculars and inclined to the axis is the quadratrix.
A right cylinder having for its base an Archimedean spiral is intersected by a right circular cone which has the generating line of the cylinder passing through the initial point of the spiral for its axis. From every point of the curve of intersection, perpendiculars are drawn to the axis. Any plane section of the screw (plectoidal of Pappus) surface so obtained is the quadratrix.
Another construction is as follows. is a quadrant in which the line and the arc are divided into the same number of equal parts. Radii are drawn from the centre of the quadrant to the points of division of the arc, and these radii are intersected by the lines drawn parallel to and through the corresponding points on the radius . The locus of these intersections is the quadratrix.
Letting be the origin of the Cartesian coordinate system, be the point , units from the origin along the -axis, and be the point , units from
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https://en.wikipedia.org/wiki/Active%20record%20pattern
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In software engineering, the active record pattern is an architectural pattern. It is found in software that stores in-memory object data in relational databases. It was named by Martin Fowler in his 2003 book Patterns of Enterprise Application Architecture. The interface of an object conforming to this pattern would include functions such as Insert, Update, and Delete, plus properties that correspond more or less directly to the columns in the underlying database table.
The active record pattern is an approach to accessing data in a database. A database table or view is wrapped into a class. Thus, an object instance is tied to a single row in the table. After creation of an object, a new row is added to the table upon save. Any object loaded gets its information from the database. When an object is updated, the corresponding row in the table is also updated. The wrapper class implements accessor methods or properties for each column in the table or view.
This pattern is commonly used by object persistence tools and in object–relational mapping (ORM). Typically, foreign key relationships will be exposed as an object instance of the appropriate type via a property.
Implementations
Implementations of the concept can be found in various frameworks for many programming environments. For example, if there is a table parts in a database with columns name (string type) and price (number type), and the Active Record pattern is implemented in the class Part, the pseudo-code
will create a new row in the parts table with the given values, and is roughly equivalent to the SQL command
INSERT INTO parts (name, price) VALUES ('Sample part', 123.45);
Conversely, the class can be used to query the database:
This will find a new Part object based on the first matching row from the parts table whose name column has the value "gearbox". The SQL command used might be similar to the following, depending on the SQL implementation details of the database:
SELECT * FROM parts WHERE
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https://en.wikipedia.org/wiki/159%20%28number%29
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159 (one hundred [and] fifty-nine) is a natural number following 158 and preceding 160.
In mathematics
159 is:
the sum of 3 consecutive prime numbers: 47 + 53 + 59.
a Woodall number.
equal to the sum of the squares of the digits of its own square in base 15.
Only 5 numbers (greater than 1) have this property in base 15, none in base 10.
written CLIX in Roman numeral, which spells a proper noun with multiple meanings.
Given 159, the Mertens function returns 0.
In astronomy
159 Aemilia is a large Main belt asteroid
NGC 159 is a galaxy in the constellation of Phoenix
The Saros number of the solar eclipse series which will begin on May 23, 2134 and end June 17, 3378. The duration of Saros series 159 is 1244.0 years, and it will contain 70 solar eclipses
The Saros number of the lunar eclipse series, which will begin on September 9, 2147 and end November 7, 3445. The duration of Saros series 159 is 1298.1 years, and it will contain 73 lunar eclipses
159P/LONEOS is a periodic comet in the Solar System
In geography
The state of Georgia has 159 counties
Sherwood No. 159, Saskatchewan is a rural municipality in Saskatchewan, Canada
In the military
Aero L-159 ALCA (Advanced Light Combat Aircraft) is a Czechoslovakian-built multi-role combat aircraft in service with the Czech Air Force
was a United States Navy during World War II
was a United States Navy during World War II
was a United States Navy during World War II
was a United States Navy concrete barge during World War II
was a United States Navy concrete barge following World War II
was a United States Navy during World War II
was a United States Navy during World War II
In sports
In professional darts, 159 is the lowest score a player can achieve with no available checkout.
In transportation
The Alfa Romeo 159 compact executive car produced from 2005 to 2011
The Ferrari 159 S racecar
The Peugeot Type 159 was produced in 1919
The British Rail Class 159, a member of the Sprinter family)
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https://en.wikipedia.org/wiki/Venix
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Venix is a discontinued version of the Unix operating system for low-end computers, developed by VenturCom, a "company that specialises in the skinniest implementations of Unix".
Overview
A working version of Venix/86 for the IBM PC XT was demoed at COMDEX in May 1983. It was based on Version 7 Unix with some enhancements from BSD (notably vi, more and csh) and custom inter-process communication mechanisms. It was the first licensed UNIX operating system available for the IBM PC and its compatibles, supported read/write access to a separate DOS/FAT-partition and could run in as little as 128 KB (256 KB - 512 KB recommended).
In September 1984, Venix/86 Encore was released; it supported a number of early PC-compatibles, including the AT&T 6300, the Zenith 150, the (first) NCR PC, and the Texas Instruments Professional Computer.
Venix Encore, which then became Venix 2.0, was still based on Version 7 Unix, and ran on the DEC Rainbow 100 (Venix/86R) as well as PCs (Venix/86 and /286). The system contained a number of enhancements, notably tools to access DOS files directly on a DOS/FAT-partition, and an updated ADB debugger. The system came in two flavors: a 2-user version priced at $800, and an 8-user version at $1,000. There were no technical differences between the two.
Confusingly, Venix 2.0 for the DEC PRO-380 microcomputer (Venix/PRO) was based "essentially" on System III. It no longer ran on the PRO-350. This is made clear in the ckermit 4E build instructions, which has a special target for Pro running Venix 1.0, but instructs the user to use the sysiii target for the Pro running Venix 2.0. These same sources also make it clear that Venix had an enhanced TTY interface relative to a pure V7 Unix System.
Venix 2.1 was released for at least the PC. Like the original Venix/86, it included a C compiler, a BASIC interpreter and added a Fortran 77 compiler as an option. An optional driver kit made it possible to develop hardware drivers for the system and generate
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https://en.wikipedia.org/wiki/195%20%28number%29
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195 (one hundred [and] ninety-five) is the natural number following 194 and preceding 196.
In mathematics
195 is:
the sum of eleven consecutive primes: 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37
the smallest number expressed as a sum of distinct squares in 16 different ways
a centered tetrahedral number
in the middle of a prime quadruplet (191, 193, 197, 199).
See also
195 (disambiguation)
References
Integers
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https://en.wikipedia.org/wiki/MAJC
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MAJC (Microprocessor Architecture for Java Computing) was a Sun Microsystems multi-core, multithreaded, very long instruction word (VLIW) microprocessor design from the mid-to-late 1990s. Originally called the UltraJava processor, the MAJC processor was targeted at running Java programs, whose "late compiling" allowed Sun to make several favourable design decisions. The processor was released into two commercial graphical cards from Sun. Lessons learned regarding multi-threads on a multi-core processor provided a basis for later OpenSPARC implementations such as the UltraSPARC T1.
Design elements
Move instruction scheduling to the compiler
Like other VLIW designs, notably Intel's IA-64 (Itanium), MAJC attempted to improve performance by moving several expensive operations out of the processor and into the related compilers. In general, VLIW designs attempt to eliminate the instruction scheduler, which often represents a relatively large amount of the overall processor's transistor budget. With this portion of the CPU removed to software, those transistors can be used for other purposes, often to add additional functional units to process more instructions at once, or to increase the amount of cache memory to reduce the amount of time spent waiting for data to arrive from the much slower main memory. Although MAJC shared these general concepts, it was unlike other VLIW designs, and processors in general, in a number of specific details.
Generalized functional units
Most processors include a number of separate "subprocessors" known as functional units that are tuned to operating on a particular type of data. For instance, a modern CPU typically has two or three functional units dedicated to processing integer data and logic instructions, known as ALUs, while other units handle floating-point numbers, the FPUs, or multimedia data, SIMD. MAJC instead used a single multi-purpose functional unit which could process any sort of data. In theory this approach meant t
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https://en.wikipedia.org/wiki/The%20Geography%20of%20Thought
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The Geography of Thought: How Asians and Westerners Think Differently...and Why is a book by social psychologist Richard Nisbett that was published by Free Press in 2003. By analyzing the differences between Asia and the West, it argues that cultural differences affect people's thought processes more significantly than believed.
Thesis
In the book, Nisbett demonstrates that "people actually think about—and even see—the world differently because of differing ecologies, social structures, philosophies, and educational systems that date back to ancient Greece and China". At its core, the book assumes that human behavior is not “hard-wired” but a function of culture.
The book proposes that the passion for strong ontology and scientific rationality based on forward chaining from axioms is essentially a "Western" phenomenon. Ancient Greece's passion for abstract categories into which the entire world can be taxonomically arranged, he claims, is prototypically Western, as is the notion of causality.
In other words, he claims that the law of the excluded middle is not applied in Chinese thought, and that a different standard applies. This has been described by other thinkers as being hermeneutic reasonableness.
Implications
There are several implications to Nisbett's theory. For instance, in law, Eastern and Western cultures assign different priorities to, and roles of, the law in society. The ratio of lawyers to engineers is forty times higher in the US than in Japan. Moreover, the role of US lawyers is, generally, to handle legal confrontations, and the aim is demands for justice with a clear winner and loser based upon universal principles of justice that apply equally to everyone. In contrast, Eastern lawyers are more often used as intermediaries to reduce hostilities, and reach a compromise; the principles they operate by are more flexible and circumstantial.
Another aspect where there is great divergence between these two systems of thought concerns human rights.
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https://en.wikipedia.org/wiki/Median%20filter
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The median filter is a non-linear digital filtering technique, often used to remove noise from an image or signal. Such noise reduction is a typical pre-processing step to improve the results of later processing (for example, edge detection on an image). Median filtering is very widely used in digital image processing because, under certain conditions, it preserves edges while removing noise (but see the discussion below), also having applications in signal processing.
Algorithm description
The main idea of the median filter is to run through the signal entry by entry, replacing each entry with the median of neighboring entries. The pattern of neighbors is called the "window", which slides, entry by entry, over the entire signal. For one-dimensional signals, the most obvious window is just the first few preceding and following entries, whereas for two-dimensional (or higher-dimensional) data the window must include all entries within a given radius or ellipsoidal region (i.e. the median filter is not a separable filter).
Worked one-dimensional example
To demonstrate, using a window size of three with one entry immediately preceding and following each entry, a median filter will be applied to the following simple one-dimensional signal:
x = (2, 3, 80, 6, 2, 3).
So, the median filtered output signal y will be:
y1 = med(2, 3, 80) = 3, (already 2, 3, and 80 are in the increasing order so no need to arrange them)
y2 = med(3, 80, 6) = med(3, 6, 80) = 6, (3, 80, and 6 are rearranged to find the median)
y3 = med(80, 6, 2) = med(2, 6, 80) = 6,
y4 = med(6, 2, 3) = med(2, 3, 6) = 3,
i.e. y = (3, 6, 6, 3).
Boundary issues
When implementing a median filter, the boundaries of the signal must be handled with special care, as there are not enough entries to fill an entire window. There are several schemes that have different properties that might be preferred in particular circumstances:
When calculating the median of a value near the boundary, missing values are f
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https://en.wikipedia.org/wiki/Intermediate%20film%20system
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The intermediate film system was a television process in which motion picture film was processed almost immediately after it was exposed in a camera, then scanned by a television scanner, and transmitted over the air. This system was used principally in Britain and Germany where television cameras were not sensitive enough to use reflected light, but could transmit a suitable image when a bright light was shone through motion picture film directly into the camera lens. John Logie Baird began developing the process in 1932, borrowing the idea of Georg Oskar Schubert from his licensees in Germany, where it was demonstrated by Fernseh AG in 1932 and used for broadcasting in 1934. The BBC used Baird's version of the process during the first three months of its then-"high-definition" television service from November 1936 through January 1937, and German television used it during broadcasts of the 1936 Summer Olympics. In both cases, intermediate film cameras alternated with newly introduced direct television cameras.
The exposed film, either 35mm or 17.5mm (35mm split in half, to save expense), travelled in a continuous band from the camera, usually atop a remote broadcast vehicle, into a machine that developed and fixed the image. The film was then run through a flying spot scanner (so called because it moved a focused beam of light back and forth across the image), and electronically converted from a negative to a positive image. Depending on the equipment, the time from camera to scanner could be a minute or less. An optical soundtrack was recorded onto the film, between the perforations and the edge of the film, at the same time the image was taken to keep the sound and image in synchronization.
The intermediate film system, with its expensive film usage and relatively immobile cameras, did have the advantage that it left a filmed record of the programme which could be rerun at a different time, with a better image quality than the later kinescope films, which were
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https://en.wikipedia.org/wiki/MacMach
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MacMach is a computer operating system from the early 1990s, developed by Carnegie Mellon University. Architecturally, it consists of Berkeley Software Distribution (BSD) 4.3 code running on the Mach microkernel, with the Apple Macintosh System 7 running experimentally as a Mach task. The entire system runs on Macintoshes based on the Motorola 68000 series (68k) family of microprocessors. Its license requires the user to have an AT&T UNIX license, and includes Apple, Inc.'s restriction against further redistribution.
See also
MkLinux
MachTen
A/UX
NeXTSTEP
References
Berkeley Software Distribution
Mach (kernel)
Microkernel-based operating systems
Microkernels
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https://en.wikipedia.org/wiki/Tetrakis%20square%20tiling
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In geometry, the tetrakis square tiling is a tiling of the Euclidean plane. It is a square tiling with each square divided into four isosceles right triangles from the center point, forming an infinite arrangement of lines. It can also be formed by subdividing each square of a grid into two triangles by a diagonal, with the diagonals alternating in direction, or by overlaying two square grids, one rotated by 45 degrees from the other and scaled by a factor of √2.
Conway, Burgiel, and Goodman-Strauss call it a kisquadrille, represented by a kis operation that adds a center point and triangles to replace the faces of a square tiling (quadrille). It is also called the Union Jack lattice because of the resemblance to the UK flag of the triangles surrounding its degree-8 vertices.
It is labeled V4.8.8 because each isosceles triangle face has two types of vertices: one with 4 triangles, and two with 8 triangles.
As a dual uniform tiling
It is the dual tessellation of the truncated square tiling which has one square and two octagons at each vertex.
Applications
A 5 × 9 portion of the tetrakis square tiling is used to form the board for the Malagasy board game Fanorona. In this game, pieces are placed on the vertices of the tiling, and move along the edges, capturing pieces of the other color until one side has captured all of the other side's pieces. In this game, the degree-4 and degree-8 vertices of the tiling are called respectively weak intersections and strong intersections, a distinction that plays an important role in the strategy of the game. A similar board is also used for the Brazilian game Adugo, and for the game of Hare and Hounds.
The tetrakis square tiling was used for a set of commemorative postage stamps issued by the United States Postal Service in 1997, with an alternating pattern of two different stamps. Compared to the simpler pattern for triangular stamps in which all diagonal perforations are parallel to each other, the tetrakis pattern has the
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https://en.wikipedia.org/wiki/Control%20bus
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In computer architecture,
a control bus is part of the system bus and is used by CPUs for communicating with other devices within the computer. While the address bus carries the information about the device with which the CPU is communicating and the data bus carries the actual data being processed, the control bus carries commands from the CPU and returns status signals from the devices. For example, if the data is being read or written to the device the appropriate line (read or write) will be active (logic one).
Lines
The number and type of lines in a control bus varies but there are basic lines common to all microprocessors, such as:
Read (). A single line that when active (logic zero) indicates the device is being read by the CPU.
Write (). A single line that when active (logic zero) indicates the device is being written by the CPU.
Byte enable (). A group of lines that indicate the size of the data (8, 16, 32, 64 bytes).
The RD and WR signals of the control bus control the reading or writing of RAM, avoiding bus contention on the data bus.
Additional lines are microprocessor-dependent, such as:
Transfer ACK ("acknowledgement"). Delivers information that the data was acknowledged (read) by the device.
Bus request (BR, BREQ, or BRQ). Indicates a device is requesting the use of the (data) bus.
Bus grant (BG or BGRT). Indicates the CPU has granted access to the bus.
Interrupt request (IRQ). A device with lower priority is requesting access to the CPU.
Clock signals. The signal on this line is used to synchronize data between the CPU and a device.
Reset. If this line is active, the CPU will perform a hard reboot.
Systems that have more than one bus master have additional control bus signals that control which bus master drives the address bus, avoiding bus contention on the address bus.
See also
Address bus
Data bus
Bus mastering
References
External links
Definition by Webopedia.
Computer system organization at the University of California, Rivers
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https://en.wikipedia.org/wiki/Plumb%20bob
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A plumb bob, plumb bob level, or plummet, is a weight, usually with a pointed tip on the bottom, suspended from a string and used as a vertical direction as a reference line, or plumb-line. It is a precursor to the spirit level and used to establish a vertical datum. It is typically made of stone, wood, or lead, but can also be made of other metals. If it is used for decoration, it may be made of bone or ivory.
The instrument has been used since at least the time of ancient Egypt to ensure that constructions are "plumb", or vertical. It is also used in surveying, to establish the nadir (opposite of zenith) with respect to gravity of a point in space. It is used with a variety of instruments (including levels, theodolites, and steel tapes) to set the instrument exactly over a fixed survey marker or to transcribe positions onto the ground for placing a marker.
Etymology
The plumb in plumb bob derives from Latin plumbum ('lead'), the material once used for the weighted bob at the end. The adjective plumb developed by extension, as did the noun aplomb, from the notion of "standing upright".
Use
Until the modern age, plumb bobs were used on most tall structures to provide vertical datum lines for the building measurements. A section of the scaffolding would hold a plumb line, which was centered over a datum mark on the floor. As the building proceeded upward, the plumb line would also be taken higher, still centered on the datum. Many cathedral spires, domes and towers still have brass datum marks inlaid into their floors, which signify the center of the structure above.
A plumb bob and line alone can determine only a vertical reference. However, if they are mounted on a suitable scale the instrument may also be used as an inclinometer to measure angles to the vertical.
Ancient Egyptians used a plumb line attached to the top outer part of a tool resembling a letter E; when placed against a wall, the plumb line would indicate a vertical line. An A-frame level wit
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https://en.wikipedia.org/wiki/Wishbone%20%28computer%20bus%29
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The Wishbone Bus is an open source hardware computer bus intended to let the parts of an integrated circuit communicate with each other. The aim is to allow the connection of differing cores to each other inside of a chip. The Wishbone Bus is used by many designs in the OpenCores project.
Wishbone is intended as a "logic bus". It does not specify electrical information or the bus topology. Instead, the specification is written in terms of "signals", clock cycles, and high and low levels.
This ambiguity is intentional. Wishbone is made to let designers combine several designs written in Verilog, VHDL or some other logic-description language for electronic design automation (EDA). Wishbone provides a standard way for designers to combine these hardware logic designs (called "cores").
Wishbone is defined to have 8, 16, 32, and 64-bit buses. All signals are synchronous to a single clock but some slave responses must be generated combinatorially for maximum performance. Wishbone permits addition of a "tag bus" to describe the data. But reset, simple addressed reads and writes, movement of blocks of data, and indivisible bus cycles all work without tags.
Wishbone is open source. To prevent preemption of its technologies by aggressive patenting, the Wishbone specification includes examples of prior art, to prove its concepts are in the public domain.
A device does not conform to the Wishbone specification unless it includes a data sheet that describes what it does, bus width, utilization, etc. Promoting reuse of a design requires the data sheet. Making a design reusable in turn makes it easier to share with others.
The Simple Bus Architecture is a simplified version of the Wishbone specification.
Wishbone topologies
Wishbone adapts well to common topologies such as point-to-point, many-to-many (i.e. the classic bus system), hierarchical, or even switched fabrics such as crossbar switches. In the more exotic topologies, Wishbone requires a bus controller or arbiter,
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https://en.wikipedia.org/wiki/Treadle
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A treadle (from , "to tread") is a mechanism operated with a pedal for converting reciprocating motion into rotating motion. Along with cranks, treadmills, and treadwheels, treadles allow human and animal machine power in the absence of electricity.
Before the widespread availability of electric power, treadles were widely used to power a range of machines. They may still be used as a matter of preference or in environments where electric power is not available.
Operation and uses
A treadle is operated by pressing down on its pedal with one or both feet, causing a rocking motion. This movement can then be stored as rotational motion via a crankshaft driving a flywheel. Alternatively, energy can be stored in a spring as in the pole lathe.
Treadles were once used extensively to power most machines including lathes, rotating or reciprocating saws, spinning wheels, looms, and sewing machines. The last use was popularized by Elias Howe and Isaac Singer in the eponymous Singer sewing machines. Today the use of treadle-powered machines is mostly relegated to hobbyists and historical re-enactors, as well as in areas of the developing world where other forms of power remain unavailable.
See also
Bicycle pedal
Treadle bicycle
Treadle pump
Sewing machine
Mechanical engineering
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https://en.wikipedia.org/wiki/Cadaeic%20Cadenza
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"Cadaeic Cadenza" is a 1996 short story by Mike Keith. It is an example of constrained writing, a story with restrictions on how it can be written. It is also one of the most prodigious examples of piphilology, being written in "pilish". The word "cadaeic" is the alphabetical equivalent of 3.141593, the first six decimal digits of pi when rounded, where each digit is replaced by the Nth letter of the alphabet; a cadenza is a solo passage in music.
In addition to the main restriction, the author attempts to mimic portions, or entire works, of different types and pieces of literature ("The Raven", "Jabberwocky", the lyrics of Yes, "The Love Song of J. Alfred Prufrock", Rubaiyat, Hamlet, and Carl Sandburg's Grass) in story, structure, and rhyme.
The limitations
When the number of letters in each word is written out they form the first 3835 digits of pi.
{|style="border: none; text-align: center;"
|-
|One||/||A||Poem||/||A||Raven||/||Midnights||so||dreary,||tired||and||weary,
|-
|3 ||.||1||4 || ||1||5 || ||9 ||2 ||6 ||5 ||3 ||5
|}
While in this example each word is the same number of letters as the next digit of pi (and ten letters for the digit 0), some sections use words of more than ten letters as a one followed by another digit:
{|style="border: none; text-align: center;"
|-
|And||fear||overcame||my||being||–||the||fear||of||"forevermore".
|-
|3 ||4 ||8 ||2 ||5 || ||3 ||4 ||2 ||11
|}
where 11 represents two consecutive digit "1"s in pi.
Taking "A" as 1, "B" as 2, "C" as 3, etc., the name of the piece itself is based on pi, as "Cadaeic" is the first 7 digits of pi, when rounded to that number of significant digits.
C a d a e i c
3.1 4 1 5 9 3
Near a Raven
The first part of Cadaeic Cadenza is slightly changed from an earlier version, "Near a Raven", which was a retelling of Edgar Allan Poe's "The Raven".
See also
Six nines in pi (handled at the start of chapter 2, "Change")
References
External links
Cadaeic Cadenza
Mne
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https://en.wikipedia.org/wiki/Trusted%20Information%20Systems
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Trusted Information Systems (TIS) was a computer security research and development company during the 1980s and 1990s, performing computer and communications (information) security research for organizations such as NSA, DARPA, ARL, AFRL, SPAWAR, and others.
History
TIS was founded in 1983 by NSA veteran Steve Walker, and at various times employed notable information security experts including David Elliott Bell, Martha Branstad, John Pescatore, Marv Schaefer, Steve Crocker, Marcus Ranum, Wei Xu, John Williams, Steve Lipner and Carl Ellison. TIS was headquartered in Glenwood, Maryland, in a rural location. The company was started in Walker's basement on Shady Lane in Glenwood, MD. As the company grew, rather than move to Baltimore or the Washington D.C. suburbs, a small office building was constructed on land next to Walker's new home on Route 97.
Products
TIS projects included as the following:
Trusted Xenix, the first commercially available B2 operating system;
Trusted Mach, a research project that influenced DTOS and eventually SELinux;
Domain and Type Enforcement (DTE) which likewise influenced SELinux;
FWTK Firewall Toolkit (the first open source firewall software) in 1993;
First whitehouse.gov e-mail server was hosted at TIS headquarters from June 1 of 1993 to January 20 of 1995;
Gauntlet Firewall in 1994, one of the first commercial firewall products, with broad range of Internet Standards, including S/MIME, SNMP, DNS, DNSSEC, and many others. This Firewall became the inception of the third generation firewall;
IP Security (IPSec) product in late 1994, known as the first IPSec VPN commercial product in IT history;
Encryption Recovery technology integrated with IPSEC, ISAKMP, IKE, and RSA.
TIS's operating system work directly affected BSD/OS, which the Gauntlet Firewall and IPSec was based on, as well as Linux, FreeBSD, HP UX, Sun OS, Darwin, and others.
Post company
The company went public in 1996
and soon afterwards attempted to acquire
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https://en.wikipedia.org/wiki/List%20of%20Euclidean%20uniform%20tilings
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This table shows the 11 convex uniform tilings (regular and semiregular) of the Euclidean plane, and their dual tilings.
There are three regular and eight semiregular tilings in the plane. The semiregular tilings form new tilings from their duals, each made from one type of irregular face.
John Conway called these uniform duals Catalan tilings, in parallel to the Catalan solid polyhedra.
Uniform tilings are listed by their vertex configuration, the sequence of faces that exist on each vertex. For example 4.8.8 means one square and two octagons on a vertex.
These 11 uniform tilings have 32 different uniform colorings. A uniform coloring allows identical sided polygons at a vertex to be colored differently, while still maintaining vertex-uniformity and transformational congruence between vertices. (Note: Some of the tiling images shown below are not color-uniform)
In addition to the 11 convex uniform tilings, there are also 14 known nonconvex tilings, using star polygons, and reverse orientation vertex configurations. A further 28 uniform tilings are known using apeirogons. If zigzags are also allowed, there are 23 more known uniform tilings and 10 more known families depending on a parameter: in 8 cases the parameter is continuous, and in the other 2 it is discrete. The set is not known to be complete.
Laves tilings
In the 1987 book, Tilings and Patterns, Branko Grünbaum calls the vertex-uniform tilings Archimedean, in parallel to the Archimedean solids. Their dual tilings are called Laves tilings in honor of crystallographer Fritz Laves. They're also called Shubnikov–Laves tilings after Aleksei Shubnikov. John Conway called the uniform duals Catalan tilings, in parallel to the Catalan solid polyhedra.
The Laves tilings have vertices at the centers of the regular polygons, and edges connecting centers of regular polygons that share an edge. The tiles of the Laves tilings are called planigons. This includes the 3 regular tiles (triangle, square and hexagon) and
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https://en.wikipedia.org/wiki/ZoneAlarm
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ZoneAlarm is an internet security software company that provides consumer antivirus and firewall products. ZoneAlarm was developed by Zone Labs, whose CEOs were Kevin Nickel, Mouad Abid and Shahin and the Company was acquired in March 2004 by Check Point. ZoneAlarm's firewall security products include an inbound intrusion detection system, as well as the ability to control which programs can open outbound connections.
Technical description
In ZoneAlarm, program access is controlled by way of "zones", into which all network connections are divided. The "trusted zone" which generally includes the user's local area network can share resources such as files and printers. The "Internet zone" includes everything without the trusted zone. The user can grant permissions (trusted zone client, trusted zone server, Internet zone client, Internet zone server) to programs before they attempt to access the Internet (e.g. before the first use) or ZoneAlarm will ask the user to grant permissions on the first access attempt.
"True Vector Internet Monitor", also known as "TrueVector Security Engine", is a Windows service that is the core of ZoneAlarm. In the processes list its Image Name is "vsmon.exe". This monitors internet traffic and generates alerts for disallowed access. "Operating System Firewall" (OSFirewall) monitors programs and generates alerts when they perform suspicious behaviors. The OSFirewall is useful in preventing rootkits and other spyware. "SmartDefense Advisor" is the name ZoneAlarm give to a service available in all versions that helps the user with certain types of alert, using a database of trusted program signatures to provide the user with advice on allowing or denying Internet access in response to program requests.
The current free version of Zonealarm has an ad for the paid version that pops up every time you turn on your computer after a short delay.
Awards and certifications
Both the free and Pro editions of ZoneAlarm Firewall were designated as
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https://en.wikipedia.org/wiki/MachTen
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MachTen is a Unix-like operating system from Tenon Intersystems. It is based on 4.4BSD and the Mach kernel, and features the X Window System and GNU programming tools. It runs only as a classic Mac OS application program (in a virtual machine) on Macintosh computers.
MachTen development started in 1989, culminating in the first release in 1991. The Professional MachTen branch, intended for Motorola 68000-based Macintoshes, ended with release 2.3. The Power MachTen branch, which is Power Macintosh compatible, lacks some of the features of Professional MachTen (including true virtual and protected memory models), but takes full advantage of the PowerPC processor and is compatible with Mac OS 9 through its final version, 4.1.4. MachTen is no longer developed, and is functionally superseded by macOS.
See also
A/UX
MacMach
macOS
NeXTSTEP
External links
Floodgap's Power MachTen Hacking Page
Berkeley Software Distribution
Mach (kernel)
Microkernel-based operating systems
Microkernels
Unix emulators
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https://en.wikipedia.org/wiki/Image%20stitching
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Image stitching or photo stitching is the process of combining multiple photographic images with overlapping fields of view to produce a segmented panorama or high-resolution image. Commonly performed through the use of computer software, most approaches to image stitching require nearly exact overlaps between images and identical exposures to produce seamless results, although some stitching algorithms actually benefit from differently exposed images by doing high-dynamic-range imaging in regions of overlap. Some digital cameras can stitch their photos internally.
Applications
Image stitching is widely used in modern applications, such as the following:
Document mosaicing
Image stabilization feature in camcorders that use frame-rate image alignment
High-resolution photomosaics in digital maps and satellite imagery
Medical imaging
Multiple-image super-resolution imaging
Video stitching
Object insertion
Process
The image stitching process can be divided into three main components: image registration, calibration, and blending.
Image stitching algorithms
In order to estimate image alignment, algorithms are needed to determine the appropriate mathematical model relating pixel coordinates in one image to pixel coordinates in another. Algorithms that combine direct pixel-to-pixel comparisons with gradient descent (and other optimization techniques) can be used to estimate these parameters.
Distinctive features can be found in each image and then efficiently matched to rapidly establish correspondences between pairs of images. When multiple images exist in a panorama, techniques have been developed to compute a globally consistent set of alignments and to efficiently discover which images overlap one another.
A final compositing surface onto which to warp or projectively transform and place all of the aligned images is needed, as are algorithms to seamlessly blend the overlapping images, even in the presence of parallax, lens distortion, scene motion, and exposure
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https://en.wikipedia.org/wiki/Interference%20%28communication%29
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In telecommunications, an interference is that which modifies a signal in a disruptive manner, as it travels along a communication channel between its source and receiver. The term is often used to refer to the addition of unwanted signals to a useful signal. Common examples include:
Electromagnetic interference (EMI)
Co-channel interference (CCI), also known as crosstalk
Adjacent-channel interference (ACI)
Intersymbol interference (ISI)
Inter-carrier interference (ICI), caused by doppler shift in OFDM modulation (multitone modulation).
Common-mode interference (CMI)
Conducted interference
Noise is a form of interference but not all interference is noise.
Radio resource management aims at reducing and controlling the co-channel and adjacent-channel interference.
Interference alignment
A solution to interference problems in wireless communication networks is interference alignment, which was crystallized by Syed Ali Jafar at the University of California, Irvine. A specialized application was previously studied by Yitzhak Birk and Tomer Kol for an index coding problem in 1998. For interference management in wireless communication, interference alignment was originally introduced by Mohammad Ali Maddah-Ali, Abolfazl S. Motahari, and Amir Keyvan Khandani, at the University of Waterloo, for communication over wireless X channels. Interference alignment was eventually established as a general principle by Jafar and Viveck R. Cadambe in 2008, when they introduced "a mechanism to align an arbitrarily large number of interferers, leading to the surprising conclusion that wireless networks are not essentially interference limited." This led to the adoption of interference alignment in the design of wireless networks.
Jafar explained:
According to New York University senior researcher Paul Horn:
See also
Distortion
Inter-flow interference
Intra-flow interference
Meaconing
Signal-to-interference ratio (SIR)
Signal-to-noise plus interference (SNIR)
Refere
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https://en.wikipedia.org/wiki/Acoustic%20ecology
|
Acoustic ecology, sometimes called ecoacoustics or soundscape studies, is a discipline studying the relationship, mediated through sound, between human beings and their environment. Acoustic ecology studies started in the late 1960s with R. Murray Schafer a musician, composer and former professor of communication studies at Simon Fraser University (Vancouver, British Columbia, Canada) with the help of his team there as part of the World Soundscape Project. The original WSP team included Barry Truax and Hildegard Westerkamp, Bruce Davies and Peter Huse, among others. The first study produced by the WSP was titled The Vancouver Soundscape. This innovative study raised the interest of researchers and artists worldwide, creating enormous growth in the field of acoustic ecology. In 1993, the members of the by now large and active international acoustic ecology community formed the World Forum for Acoustic Ecology.
The radio art of Schafer and his colleague, has found expression in many different fields.While most have taken some inspiration from Schafer's writings, in recent years there have also been divergences from the initial ideas. The expanded expressions of acoustic ecology are increasing due to the sonic impacts of road and airport construction that affect the soundscapes in and around cities where the human population is more dense. There has also been a broadening of bioacoustics (the use of sound by animals) to consider the subjective and objective responses of animals to human noise, with ocean noise capturing the most attention. Acoustic ecology can also be informative of changes in the climate or other environmental changes since every day we listen to sounds in the world to identify their source such as bird, car, plane, wind, water. But we don't listen those sounds as a network , a mesh of relationships that form an ecology. Acoustic ecology finds expression in many different fields that characterize a soundscape, which are biophony, geophony, and anthro
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https://en.wikipedia.org/wiki/CETAC
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Chalmers Engineering Trainee Appointment Committee (CETAC) is a student group located at Chalmers University of Technology in Gothenburg, Sweden. The sole purpose of the organisation is to bring American companies and Swedish students together. Each summer, CETAC members go to North America to gain practical experience in their particular field of study.
CETAC was founded in 1966 and has since then sent approximately 10-20 students every year to United States and Canada. CETAC is only open for students studying Computer Science & Engineering, Electrical Engineering, Engineering Physics, Engineering Mathematics or Software Engineering.
CETAC helps their members with practical details such as insurances, visas, etc. with the support by the American-Scandinavian Foundation.
Since May 1, 2006, CETAC has an alumni organization called CETAC Alumni
External links
Official webpage of CETAC
Official webpage of CETAC Alumni
American-Scandinavian Foundation
Chalmers University of Technology
Engineering organizations
Student societies in Sweden
Student organizations established in 1966
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https://en.wikipedia.org/wiki/List%20of%20information%20graphics%20software
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This is a list of software to create any kind of information graphics:
either includes the ability to create one or more infographics from a provided data set
either it is provided specifically for information visualization
Vector graphics
Vector graphics software can be used for manual graphing or for editing the output of another program. Please see:
:Category:Vector graphics editors
Comparison of vector graphics editors
A few online editors using vector graphics for specific needs have been created. This kind of creative interfaces work well together with data visualization tools like the ones above.
See also
:Category:Diagramming software
Comparison of numerical-analysis software
List of graphical methods
References
Comparisons of mathematical software
Graphics software
Infographics
Lists of software
Statistics-related lists
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https://en.wikipedia.org/wiki/Equity%20value
|
Equity value is the value of a company available to owners or shareholders. It is the enterprise value plus all cash and cash equivalents, short and long-term investments, and less all short-term debt, long-term debt and minority interests.
Equity value accounts for all the ownership interest in a firm including the value of unexercised stock options and securities convertible to equity.
From a mergers and acquisitions to an academic perspective, equity value differs from market capitalization or market value in that it incorporates all equity interests in a firm whereas market capitalization or market value only reflects those common shares currently outstanding.
Calculating equity value
Equity value can be calculated in two ways, either the intrinsic value method, or the fair market value method. The intrinsic value method is calculated as follows:
Equity Value =
Market capitalization
+ Amount that in-the-money stock options are in the money
+ Value of equity issued from in-the-money convertible securities
- Proceeds from the conversion of convertible securities
The fair market value method is as follows:
Equity Value =
Market capitalization
+ fair value of all stock options (in the money and out of the money), calculated using the Black–Scholes formula or a similar method
+ Value of convertible securities in excess of what the same securities would be valued without the conversion attribute
The fair market value method more accurately captures the value of out of the money securities.
References
Mathematical finance
Fundamental analysis
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https://en.wikipedia.org/wiki/Mechanotransduction
|
In cellular biology, mechanotransduction (mechano + transduction) is any of various mechanisms by which cells convert mechanical stimulus into electrochemical activity. This form of sensory transduction is responsible for a number of senses and physiological processes in the body, including proprioception, touch, balance, and hearing. The basic mechanism of mechanotransduction involves converting mechanical signals into electrical or chemical signals.
In this process, a mechanically gated ion channel makes it possible for sound, pressure, or movement to cause a change in the excitability of specialized sensory cells and sensory neurons. The stimulation of a mechanoreceptor causes mechanically sensitive ion channels to open and produce a transduction current that changes the membrane potential of the cell. Typically the mechanical stimulus gets filtered in the conveying medium before reaching the site of mechanotransduction. Cellular responses to mechanotransduction are variable and give rise to a variety of changes and sensations. Broader issues involved include molecular biomechanics.
Single-molecule biomechanics studies of proteins and DNA, and mechanochemical coupling in molecular motors have demonstrated the critical importance of molecular mechanics as a new frontier in bioengineering and life sciences. Protein domains, connected by intrinsically disordered flexible linker domains, induce long-range allostery via protein domain dynamics.
The resultant dynamic modes cannot be generally predicted from static structures of either the entire protein or individual domains. They can however be inferred by comparing different structures of a protein (as in Database of Molecular Motions). They can also be suggested by sampling in extensive molecular dynamics trajectories and principal component analysis, or they can be directly observed using spectra
measured by neutron spin echo spectroscopy. Current findings indicate that the mechanotransduction channel in hair c
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https://en.wikipedia.org/wiki/Barebone%20computer
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A barebone computer is a partially assembled platform or an unassembled kit of computer parts allowing more customization and lower costs than a retail computer system. They are available for desktop computer, notebook (see barebook) and server purposes, and in nearly any form factor. Manufacturers are also able to produce systems of a specialized or non-standard form factor, since the system is sold as a pre-built unit, with the motherboard and power supply already installed.
Components
Assembling a barebone computer by hand is usually less expensive than buying a pre-configured computer from a retailer, and may save time and labor compared with building a system from scratch. A typical barebone desktop system consists of a CPU, a computer case (or tower), with a pre-fitted motherboard and power supply. If not already provided, the purchaser of such a platform only has to equip it with a RAM, and optionally a hard drive (in some cases, an operating system is/can be installed to a lower-cost flash drive instead). Additional input/output devices may be required depending on their needs. Sometimes, it is necessary to install an operating system if the one built into the motherboard is deemed insufficient (or not present at all). An audio adapter or network adapter may be added but this is less common as recent motherboards often already contain capable solutions.
Peripherals, such as a keyboard, mouse and monitor, almost always must be acquired separately. Barebone systems sometimes include a graphics processor or RAM, but rarely any mass storage media (hard drives), operating system or other software. Sometimes PCs with everything a normal desktop PC has except Microsoft Windows operating systems are sold as a barebone computer, but may include free software such as Linux. Refurbished and used computers may also be repackaged as barebone computers, as many computers returned for refurbishing may have missing, broken, or obsolete parts such as hard drives and peri
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https://en.wikipedia.org/wiki/False%20light
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In US law, false light is a tort concerning privacy that is similar to the tort of defamation. The privacy laws in the United States include a non-public person's right to protection from publicity that creates an untrue or misleading impression about them. That right is balanced against the First Amendment right of free speech.
False light differs from defamation primarily in being intended "to protect the plaintiff's mental or emotional well-being", rather than to protect a plaintiff's reputation as is the case with the tort of defamation and in being about the impression created rather than being about veracity. If a publication of information is false, then a tort of defamation might have occurred. If that communication is not technically false but is still misleading, then a tort of false light might have occurred.
False light privacy claims often arise under the same facts as defamation cases, and therefore not all states recognize false light actions. There is a subtle difference in the way courts view the legal theories—false light cases are about damage to a person's personal feelings or dignity, whereas defamation is about damage to a person's reputation.
The specific elements of the tort of false light vary considerably, even among those jurisdictions which do recognize this tort. Generally, these elements consist of the following:
A publication by the defendant about the plaintiff;
made with actual malice if the plaintiff is a public figure;
which places the plaintiff in a false light;
and that would be highly offensive (i.e., embarrassing to reasonable persons).
Some U.S. state courts have ruled that false light lawsuits brought under their states' laws must be rewritten as defamation lawsuits; these courts generally base their opinion on the premises that a) any publication or statement giving rise to a false-light claim will also give rise to a defamation claim, such that the set of statements creating false light is necessarily, although
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https://en.wikipedia.org/wiki/Netsukuku
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Netsukuku is an experimental peer-to-peer routing system, developed by the FreakNet MediaLab in 2005, created to build up a distributed network, anonymous and censorship-free, fully independent but not necessarily separated from the Internet, without the support of any server, ISP and no central authority.
Netsukuku is designed to handle up to 2128 nodes without any servers or central systems, with minimal CPU and memory resources. This mesh network can be built using existing network infrastructure components such as Wi-Fi.
The project has been in slow development since 2005, never abandoning a beta state. It has also never been tested on large scale.
Operation
As of December 2011, the latest theoretical work on Netsukuku could be found in the author's master thesis Scalable Mesh Networks and the Address Space Balancing problem. The following description takes into account only the basic concepts of the theory.
Netsukuku uses a custom routing protocol called QSPN (Quantum Shortest Path Netsukuku) that strives to be efficient and not taxing on the computational capabilities of each node. The current version of the protocol is QSPNv2. It adopts a hierarchical structure. 256 nodes are grouped inside a gnode (group node), 256 gnodes are grouped in a single ggnode (group of group nodes), 256 ggnodes are grouped in a single gggnode, and so on. This offers a set of advantages main documentation. The protocol relies on the fact that the nodes are not mobile and that the network structure does not change quickly, as several minutes may be required before a change in the network is propagated. However, a node that joins the network is immediately able to communicate using the routes of its neighbors. When a node joins the mesh network, Netsukuku automatically adapts and all other nodes come to know the fastest and most efficient routes to communicate with the newcomer. Each node has no more privileges or restrictions than the other nodes.
The domain name system (DNS)
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https://en.wikipedia.org/wiki/Carbol%20fuchsin
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Carbol fuchsin, carbol-fuchsin, carbolfuchsin, or Castellani's paint (CAS ) is a mixture of phenol and basic fuchsin that is used in bacterial staining procedures. It is commonly used in the staining of mycobacteria because it has an affinity for the mycolic acids found in their cell membranes.
It is a component of Ziehl–Neelsen stain, a differential stain.
Carbol fuchsin is used as the primary stain dye to detect acid-fast bacteria because it is more soluble in the cells' wall lipids than in the acid alcohol. If the bacteria is acid-fast the bacteria will retain the initial red color of the dye because they are able to resist the destaining by acid alcohol (0.4–1% HCl in 70% EtOH). Additionally, it can be used for the staining of bacterial spores.
Carbol-fuchsin is also used as a topical antiseptic and antifungal.
References
Microscopy
Microbiology techniques
Laboratory techniques
Histopathology
Histotechnology
Staining dyes
Staining
Phenols
Antiseptics
Disinfectants
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https://en.wikipedia.org/wiki/Sony%20eVilla
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The Sony eVilla was a discontinued Internet appliance from Sony. After 18 months of development, it was released to the public on June 14, 2001 for $499 USD. With the additional $21.95 USD monthly fee, users could access the Internet, send and receive e-mail, play audio and video, and save files to Sony's Memory Stick.
After less than three months in the market, Sony discontinued the product on September 13, 2001. Customers received full refunds for the product and the monthly subscription fee. Spokesman John Dolak remarked that "[the] product did not meet our expectations, it did not operate as planned."
Sony entered the Internet appliance market as other manufacturers were getting out, canceling their plans, and discontinuing their offerings. By the time the Sony eVilla shipped, only 150,000 internet appliance devices had shipped within the past year. In addition, many customers could not justify the purchase of an inherently limited internet appliance when other manufacturers were offering more capable personal computers for the same price.
Hardware and software
The Sony eVilla was powered by a 266 MHz Geode GX 1 CPU, with 64 MiB DRAM, and 24 MiB flash memory. It weighed 31.5 pounds (14.3 kg) and measured 11.81 × 16.18 × 15.82 inches (30 × 41.1 x 40.2 cm).
There was no hard disk, but the system could read and write to Sony's Memory Stick cards. The included keyboard and mouse were connected by two PS/2 ports, and additional devices could be connected with two USB ports. A 56K V.90 modem was built into the case, which also housed an unused Ethernet port.
The display was a portrait-style 15 inch (38 cm) Sony Trinitron, with 800×1024 pixel resolution.
The system used the BeIA 1.0 operating system from Be Inc., and supported Java applications, Macromedia Flash animations, and some Microsoft Office file formats. Also included was RealNetworks's RealPlayer.
One of the major drawbacks of the eVilla was the inability to save pictures and media from internet site
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https://en.wikipedia.org/wiki/Paltalk
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Paltalk is a proprietary video group chat service that enables users to communicate by video, Internet chat, or voice. It offers chat rooms and the ability for users to create their own public virtual chat room. Paltalk Desktop is available on macOS and Windows, and Paltalk Video Chat App is available for Android and iOS. While basic services are free of charge and basic software is free to download, fee-based memberships and paid upgrades to more capable versions are offered by AVM Software, the creators of Paltalk.
Paltalk had 5.5 million unique users in 2013. An infographic created by the company in 2015 revealed that they had surpassed 100 million users.
Software
Paltalk's main application is "Paltalk Messenger for PCs". They also offered PaltalkExpress, a free web-based Adobe Flash and Java application which could be accessed via an Internet browser. As of December 22, 2016 this program has been discontinued due to its falling support and removal from Google Chrome.
Paltalk has native apps available for Android and iOS which allow users to publish webcam, audio chat, and text chat groups or in private sessions.
Both the mobile and desktop versions of Paltalk allow users to create chat rooms where they can text, voice, and video chat. These chat rooms can host hundreds and in some cases thousands of chatters in one conversion. Paltalk users can also have private video chat sessions with up to 15 other.
Awards and recognition
2007: AlwaysOn 100 top Companies
2007: NET Editor's pick
2005: The Pulver 100
Patent protection
Paltalk filed a series of patent lawsuits against video game developers claiming they were infringing U.S. patents 5,822,523 and 6,226,686 "Server-group messaging system for interactive applications", patents they purchased from the now-defunct company HearMe in 2002. Paltalk first brought a case against Microsoft in 2006, claiming Halo and Xbox Live violated its patent rights, and later settled out of court.
In 2009, Paltalk then mo
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https://en.wikipedia.org/wiki/Horizontal%20scan%20rate
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Horizontal scan rate, or horizontal frequency, usually expressed in kilohertz, is the number of times per second that a raster-scan video system transmits or displays a complete horizontal line, as opposed to vertical scan rate, the number of times per second that an entire screenful of image data is transmitted or displayed.
Cathode ray tubes
Within a cathode-ray tube (CRT), the horizontal scan rate is how many times in a second that the electron beam moves from the left side of the display to the right and back. The number of horizontal lines displayed per second can be roughly derived from this number multiplied by the vertical scan rate.
The horizontal scan frequencies of a CRT include some intervals that occur during the vertical blanking interval, so the horizontal scan rate does not directly correlate to visible display lines unless the quantity of unseen lines are also known.
The horizontal scan rate is one of the primary figures determining the resolution capability of a CRT, since it is determined by how quickly the electromagnetic deflection system can reverse the current flowing in the deflection coil in order to move the electron beam from one side of the display to the other. Reversing the current more quickly requires higher voltages, which require more expensive electrical components.
In analog television systems the horizontal frequency is between 15.625 kHz and 15.750 kHz.
Other technologies
While other display technologies such as liquid-crystal displays do not have the specific electrical characteristics that constrain horizontal scan rates on CRTs, there is still a horizontal scan rate characteristic in the signals that drive these displays.
References
Television technology
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https://en.wikipedia.org/wiki/Languages%20used%20on%20the%20Internet
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Slightly over half of the homepages of the most visited websites on the World Wide Web are in English, with varying amounts of information available in many other languages. Other top languages are Spanish, Russian, Persian, French, German and Japanese.
Of the more than 7,000 existing languages, only a few hundred are recognized as being in use for Web pages on the World Wide Web.
Languages used
There is debate over the most-used languages on the Internet. A 2009 UNESCO report monitoring the languages of websites for 12 years, from 1996 to 2008, found a steady year-on-year decline in the percentage of webpages in English, from 75 percent in 1998 to 45 percent in 2005. The authors found that English remained at 45 percent of content for 2005 to the end of the study but believe this was due to the bias of search engines indexing more English-language content rather than a true stabilization of the percentage of content in English on the World Wide Web.
The number of non-English web pages is rapidly expanding. The use of English online increased by around 281 percent from 2001 to 2011, a lower rate of growth than that of Spanish (743 percent), Chinese (1,277 percent), Russian (1,826 percent) or Arabic (2,501 percent) over the same period.
According to a 2000 study, the international auxiliary language Esperanto ranked 40 out of all languages in search engine queries, also ranking 27 out of all languages that rely on the Latin script.
Usage statistics of content languages for websites
W3Techs estimated percentages of the top 10 million websites on the World Wide Web using various content languages as of 16 October 2023:
All other languages are used in less than 0.1% of websites. Even including all languages, percentages may not sum to 100% because some websites contain multiple content languages.
The figures from the W3Techs study are based on the one million most visited websites (i.e., approximately 0.27 percent of all websites according to December 2011 figur
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https://en.wikipedia.org/wiki/Energy%20%28signal%20processing%29
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In signal processing, the energy of a continuous-time signal x(t) is defined as the area under the squared magnitude of the considered signal i.e., mathematically
Unit of will be (unit of signal)2.
And the energy of a discrete-time signal x(n) is defined mathematically as
Relationship to energy in physics
Energy in this context is not, strictly speaking, the same as the conventional notion of energy in physics and the other sciences. The two concepts are, however, closely related, and it is possible to convert from one to the other:
where Z represents the magnitude, in appropriate units of measure, of the load driven by the signal.
For example, if x(t) represents the potential (in volts) of an electrical signal propagating across a transmission line, then Z would represent the characteristic impedance (in ohms) of the transmission line. The units of measure for the signal energy would appear as volt2·seconds, which is not dimensionally correct for energy in the sense of the physical sciences. After dividing by Z, however, the dimensions of E would become volt2·seconds per ohm,
which is equivalent to joules, the SI unit for energy as defined in the physical sciences.
Spectral energy density
Similarly, the spectral energy density of signal x(t) is
where X(f) is the Fourier transform of x(t).
For example, if x(t) represents the magnitude of the electric field component (in volts per meter) of an optical signal propagating through free space, then the dimensions of X(f) would become volt·seconds per meter and would represent the signal's spectral energy density (in volts2·second2 per meter2) as a function of frequency f (in hertz). Again, these units of measure are not dimensionally correct in the true sense of energy density as defined in physics. Dividing by Zo, the characteristic impedance of free space (in ohms), the dimensions become joule-seconds per meter2 or, equivalently, joules per meter2 per hertz, which is dimensionally correct in SI
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https://en.wikipedia.org/wiki/Internet%20traffic%20engineering
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Internet traffic engineering is defined as that aspect of Internet network engineering dealing with the issue of performance evaluation and performance optimization of operational IP networks. Traffic engineering encompasses the application of technology and scientific principles to the measurement, characterization, modeling, and control of Internet traffic [RFC-2702, AWD2].
Enhancing the performance of an operational network, at both traffic and resource levels, are major objectives of Internet engineering. This is accomplished by addressing traffic performance requirements, while utilizing network economically and reliably. Traffic oriented performance includes packet transfer delay, packet delay variation, packet loss, and throughput.
An important objective of Internet traffic engineering is to facilitate reliable network operations [RFC-2702]. This can be done by providing mechanisms that network integrity and by embracing policies emphasizing survivability. This results in a minimization of the network to service outages arising from errors, faults and failures occurring within the infrastructure.
The Internet exists in order to transfer information from nodes to destination nodes. Accordingly, one of the most crucial functions performed by the Internet is the routing of traffic ingress nodes to egress nodes.
Ultimately, it is the performance of the network as seen by network services that is truly paramount. This crucial function should be considered throughout the development of engineering mechanisms and policies. The characteristics visible to end users are the emergent properties of the network, which are characteristics of the network when viewed as a whole. A goal of the service provider, therefore, is to enhance the properties of the network while taking economic considerations into account.
The importance of the above observation regarding the properties of networks is that special care must be taken when choosing network performance metrics to
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https://en.wikipedia.org/wiki/Miura%20fold
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The is a method of folding a flat surface such as a sheet of paper into a smaller area. The fold is named for its inventor, Japanese astrophysicist Kōryō Miura.
The crease patterns of the Miura fold form a tessellation of the surface by parallelograms. In one direction, the creases lie along straight lines, with each parallelogram forming the mirror reflection of its neighbor across each crease. In the other direction, the creases zigzag, and each parallelogram is the translation of its neighbor across the crease. Each of the zigzag paths of creases consists solely of mountain folds or of valley folds, with mountains alternating with valleys from one zigzag path to the next. Each of the straight paths of creases alternates between mountain and valley folds.
The Miura fold is related to the Kresling fold, the Yoshimura fold and the Hexagonal fold, and can be framed as a generalization of these folds.
The Miura fold is a form of rigid origami, meaning that the fold can be carried out by a continuous motion in which, at each step, each parallelogram is completely flat. This property allows it to be used to fold surfaces made of rigid materials, making it distinct from the Kresling fold and Yoshimura fold which cannot be rigidly folded and require panel deformations to compress to a compact state. For instance, large solar panel arrays for space satellites in the Japanese space program have been Miura folded before launch and then spread out in space. A folded Miura fold can be packed into a compact shape, its thickness reflecting only the thickness of the folded material. Folded material can be unpacked in one motion by pulling on its opposite ends, and likewise folded by pushing the two ends together. In the solar array application, this property reduces the number of motors required to unfold this shape, reducing weight and complexity.
Applications
The 1996 Space Flyer Unit deployed the 2D Array from a Miura folded configuration.
The inflatable membrane stru
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https://en.wikipedia.org/wiki/Model%20category
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In mathematics, particularly in homotopy theory, a model category is a category with distinguished classes of morphisms ('arrows') called 'weak equivalences', 'fibrations' and 'cofibrations' satisfying certain axioms relating them. These abstract from the category of topological spaces or of chain complexes (derived category theory). The concept was introduced by .
In recent decades, the language of model categories has been used in some parts of algebraic K-theory and algebraic geometry, where homotopy-theoretic approaches led to deep results.
Motivation
Model categories can provide a natural setting for homotopy theory: the category of topological spaces is a model category, with the homotopy corresponding to the usual theory. Similarly, objects that are thought of as spaces often admit a model category structure, such as the category of simplicial sets.
Another model category is the category of chain complexes of R-modules for a commutative ring R. Homotopy theory in this context is homological algebra. Homology can then be viewed as a type of homotopy, allowing generalizations of homology to other objects, such as groups and R-algebras, one of the first major applications of the theory. Because of the above example regarding homology, the study of closed model categories is sometimes thought of as homotopical algebra.
Formal definition
The definition given initially by Quillen was that of a closed model category, the assumptions of which seemed strong at the time, motivating others to weaken some of the assumptions to define a model category. In practice the distinction has not proven significant and most recent authors (e.g., Mark Hovey and Philip Hirschhorn) work with closed model categories and simply drop the adjective 'closed'.
The definition has been separated to that of a model structure on a category and then further categorical conditions on that category, the necessity of which may seem unmotivated at first but becomes important later. The follo
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https://en.wikipedia.org/wiki/Crypsis
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In ecology, crypsis is the ability of an animal or a plant to avoid observation or detection by other animals. It may be a predation strategy or an antipredator adaptation. Methods include camouflage, nocturnality, subterranean lifestyle and mimicry. Crypsis can involve visual, olfactory (with pheromones) or auditory concealment. When it is visual, the term cryptic coloration, effectively a synonym for animal camouflage, is sometimes used, but many different methods of camouflage are employed by animals or plants.
Overview
There is a strong evolutionary pressure for animals to blend into their environment or conceal their shape, for prey animals to avoid predators and for predators to be able to avoid detection by prey. Exceptions include large herbivores without natural enemies, brilliantly colored birds that rely on flight to escape predators, and venomous or otherwise powerfully armed animals with warning coloration. Cryptic animals include the tawny frogmouth (feather patterning resembles bark), the tuatara (hides in burrows all day; nocturnal), some jellyfish (transparent), the leafy sea dragon, and the flounder (covers itself in sediment).
Methods
Methods of crypsis include (visual) camouflage, nocturnality, and subterranean lifestyle. Camouflage can be achieved by a wide variety of methods, from disruptive coloration to transparency and some forms of mimicry, even in habitats like the open sea where there is no background.
As a strategy, crypsis is used by predators against prey and by prey against predators.
Crypsis also applies to eggs and pheromone production. Crypsis can in principle involve visual, olfactory, or auditory camouflage.
Visual
Many animals have evolved so that they visually resemble their surroundings by using any of the many methods of natural camouflage that may match the color and texture of the surroundings (cryptic coloration) and/or break up the visual outline of the animal itself (disruptive coloration). Such animals, like the
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https://en.wikipedia.org/wiki/Body%20flex
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Body flex is a lack of rigidity in a motor vehicle's chassis. It is often something to be avoided by car manufacturers as higher levels of body flex is a sign of structural weakness, and means that the vehicle's suspension cannot work as efficiently - the body takes up some of the 'slack', rather than the parts of the car which were specifically designed for this purpose. A chassis that flexes may be prone to fatigue and further "softening" with use will eventually result in failure. Cars of a sporting nature are, therefore, often very 'stiff', while convertibles or cabriolets are not often considered to be good candidates for high-performance sports cars because of their lack of a rigid roof.
Although, for some time, body flex was a result of attempts to keep a car's weight down, makers such as Audi (the A8), and Jaguar (with the 2003 XJ8) have employed the use of aluminium in chassis production to get around this obstacle, ensuring the weight of these cars and their level of body flex can both be kept to a minimum.
Typically, the stiffness of the body is measured in torsion. The body is supported at the spring caps at the rear, and then a torque is applied to the front spring caps via a long beam and a fulcrum. Values achieved range from per degree for pre-War racing cars, up to per degree for some modern production vehicles.
See also
Flexibility (engineering)
References
Automotive engineering
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https://en.wikipedia.org/wiki/Auncel
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The auncel ( or , "little balance") was a balance scale formerly used in England. It consisted of a rod with the fulcrum near one end and a weight that could be moved along the graduated longer arm. The item to be weighed was hung from the end of the shorter arm of the rod. This design made it easier for merchants to falsify the weight than when scales with arms of equal length were used, as a result of which it was banned by Edward III in 1350.
In some British dialects, it is used for the informal weighing of meat by hand instead of by scales.
References
Measuring instruments
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https://en.wikipedia.org/wiki/Windows%20Media%20Center
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Windows Media Center (WMC) is a digital video recorder and media player created by Microsoft. Media Center was first introduced to Windows in 2002 on Windows XP Media Center Edition (MCE). It was included in Home Premium and Ultimate editions of Windows Vista, as well as all editions of Windows 7 except Starter and Home Basic. It was also available on Windows 8 Pro and Windows 8.1 Pro as a paid add-on, before being discontinued in Windows 10, although it can reportedly be unofficially reinstalled using a series of Command Prompt commands.
Media Center can play slideshows, videos and music from local hard drives, optical drives and network locations. Users can stream television programs and films through selected services such as Netflix. Content can be played back on computer monitors or on television sets through the use of devices called Windows Media Center Extenders. It is also possible to watch and pause live TV. Up to six TV tuners on a tuner card are supported simultaneously. Both standard- and high-definition unencrypted video are supported through DVB-T and ATSC standards. It is possible to view encrypted cable television channels by using an internal or external tuner that supported CableCARD.
Shortly after Windows 7's 2009 release, Microsoft disbanded the Media Center development team, thus abandoning any further software developments. Consequently, the Media Center interface remained unchanged for Windows 8 and 8.1 users. In May 2015, Microsoft announced that Windows Media Center would be discontinued on Windows 10, and that it would be removed when upgrading; but stated that those upgrading from a version of Windows that included the Media Center application would receive the paid Windows DVD Player app for free to maintain DVD playback functionality.
Version history
Windows XP Media Center Edition
Windows Media Center, codenamed "Freestyle", was first included with Windows XP Media Center Edition.
Windows Vista
A new version of the WMC was inc
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