1.
Computer
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A computer is a device that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically. The ability of computers to follow a sequence of operations, called a program, such computers are used as control systems for a very wide variety of industrial and consumer devices. The Internet is run on computers and it millions of other computers. Since ancient times, simple manual devices like the abacus aided people in doing calculations, early in the Industrial Revolution, some mechanical devices were built to automate long tedious tasks, such as guiding patterns for looms. More sophisticated electrical machines did specialized analog calculations in the early 20th century, the first digital electronic calculating machines were developed during World War II. The speed, power, and versatility of computers has increased continuously and dramatically since then, conventionally, a modern computer consists of at least one processing element, typically a central processing unit, and some form of memory. The processing element carries out arithmetic and logical operations, and a sequencing, peripheral devices include input devices, output devices, and input/output devices that perform both functions. Peripheral devices allow information to be retrieved from an external source and this usage of the term referred to a person who carried out calculations or computations. The word continued with the same meaning until the middle of the 20th century, from the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations. The Online Etymology Dictionary gives the first attested use of computer in the 1640s, one who calculates, the Online Etymology Dictionary states that the use of the term to mean calculating machine is from 1897. The Online Etymology Dictionary indicates that the use of the term. 1945 under this name, theoretical from 1937, as Turing machine, devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with fingers. The earliest counting device was probably a form of tally stick, later record keeping aids throughout the Fertile Crescent included calculi which represented counts of items, probably livestock or grains, sealed in hollow unbaked clay containers. The use of counting rods is one example, the abacus was initially used for arithmetic tasks. The Roman abacus was developed from used in Babylonia as early as 2400 BC. Since then, many forms of reckoning boards or tables have been invented. In a medieval European counting house, a checkered cloth would be placed on a table, the Antikythera mechanism is believed to be the earliest mechanical analog computer, according to Derek J. de Solla Price. It was designed to calculate astronomical positions and it was discovered in 1901 in the Antikythera wreck off the Greek island of Antikythera, between Kythera and Crete, and has been dated to circa 100 BC
2.
Workstation
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A workstation is a special computer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are connected to a local area network. Workstations offered higher performance than mainstream personal computers, especially with respect to CPU and graphics, memory capacity, and multitasking capability. Typically, the factor is that of a desktop computer, consist of a high resolution display, a keyboard and a mouse at a minimum. Workstations were the first segment of the market to present advanced accessories. The increasing capabilities of mainstream PCs in the late 1990s have blurred the lines somewhat with technical/scientific workstations, perhaps the first computer that might qualify as a workstation was the IBM1620, a small scientific computer designed to be used interactively by a single person sitting at the console. One peculiar feature of the machine was that it lacked any actual arithmetic circuitry, to perform addition, it required a memory-resident table of decimal addition rules. This saved on the cost of logic circuitry, enabling IBM to make it inexpensive, the machine was code-named CADET and rented initially for $1000 a month. In 1965, IBM introduced the IBM1130 scientific computer, which was meant as the successor to the 1620, both of these systems came with the ability to run programs written in Fortran and other languages. Both the 1620 and the 1130 were built into roughly desk-sized cabinets, both were available with add-on disk drives, printers, and both paper-tape and punched-card I/O. A console typewriter for direct interaction was standard on each, early examples of workstations were generally dedicated minicomputers, a system designed to support a number of users would instead be reserved exclusively for one person. A notable example was the PDP-8 from Digital Equipment Corporation, regarded to be the first commercial minicomputer, Lisp Machines were commercialized beginning 1980 by companies like Symbolics, Lisp Machines, Texas Instruments and Xerox. The first computer designed for single-users, with high-resolution graphics facilities was the Xerox Alto developed at Xerox PARC in 1973, other early workstations include the Terak 8510/a, Three Rivers PERQ and the later Xerox Star. Meanwhile, DARPAs VLSI Project created several spinoff graphics products as well, notably the SGI3130 and it was not uncommon to differentiate the target market for the products, with Sun and Apollo considered to be network workstations, while the SGI machines were graphics workstations. As RISC microprocessors became available in the mid-1980s, these were adopted by many workstation vendors, workstations tended to be very expensive, typically several times the cost of a standard PC and sometimes costing as much as a new car. However, minicomputers sometimes cost as much as a house, additionally, workstations, given their more specialized nature, tend to have higher profit margins than commodity-driven PCs. Additionally, the companies that make the products tend to have very good repair/replacement plans, some low-cost workstations are still expensive by PC standards, but offer binary compatibility with higher-end workstations and servers made by the same vendor. This allows software development to take place on low-cost desktop machines, Graphics workstations often shipped with graphics accelerators
3.
Design
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Design is the creation of a plan or convention for the construction of an object, system or measurable human interaction. Design has different connotations in different fields, in some cases, the direct construction of an object is also considered to use design thinking. Designing often necessitates considering the aesthetic, functional, economic, and it may involve considerable research, thought, modeling, interactive adjustment, and re-design. Meanwhile, diverse kinds of objects may be designed, including clothing, graphical user interfaces, skyscrapers, corporate identities, business processes, and even methods or processes of designing. Thus design may be a substantive referring to an abstraction of a created thing or things. It is an act of creativity and innovation, here, a specification can be manifested as either a plan or a finished product, and primitives are the elements from which the design object is composed. With such a broad denotation, there is no language or unifying institution for designers of all disciplines. This allows for many differing philosophies and approaches toward the subject, the person designing is called a designer, which is also a term used for people who work professionally in one of the various design areas usually specifying which area is being dealt with. A designers sequence of activities is called a process while the scientific study of design is called design science. Another definition of design is planning to manufacture an object, system, thus the word design can be used as a noun or a verb. In a broader sense, the design is an applied art, while the definition of design is fairly broad, design has a myriad of specifications that professionals utilize in their fields. Substantial disagreement exists concerning how designers in many fields, whether amateur or professional, alone or in teams, the prevailing view has been called The Rational Model, Technical Problem Solving and The Reason-Centric Perspective. The alternative view has been called Reflection-in-Action, Evolutionary Design, co-evolution, the Rational Model was independently developed by Herbert A. Simon, an American scientist, and Gerhard Pahl and Wolfgang Beitz, two German engineering design theorists. The Rational Model is based on a rationalist philosophy and underlies the waterfall model, systems development life cycle, according to the rationalist philosophy, design is informed by research and knowledge in a predictable and controlled manner. Technical rationality is at the center of the process, each stage has many associated best practices. Unrealistic assumptions – goals are often unknown when a design project begins, the Action-Centric Perspective is a label given to a collection of interrelated concepts, which are antithetical to The Rational Model. Substantial empirical evidence supports the veracity of this perspective in describing the actions of real designers, like the Rational Model, the Action-Centric model sees design as informed by research and knowledge. Designers context-dependent experience and professional judgment take center stage more than technical rationality, at least two views of design activity are consistent with the Action-Centric Perspective
4.
Electronic design automation
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The tools work together in a design flow that chip designers use to design and analyze entire semiconductor chips. Since a modern semiconductor chip can have billions of components, EDA tools are essential for their design and this article describes EDA specifically with respect to integrated circuits. Before EDA, integrated circuits were designed by hand, and manually laid out, some advanced shops used geometric software to generate the tapes for the Gerber photoplotter, but even those copied digital recordings of mechanically drawn components. The process was fundamentally graphic, with the translation from electronics to graphics done manually, the best known company from this era was Calma, whose GDSII format survives. By the mid-1970s, developers started to automate the design along with the drafting, the first placement and routing tools were developed. The proceedings of the Design Automation Conference cover much of this era, the next era began about the time of the publication of Introduction to VLSI Systems by Carver Mead and Lynn Conway in 1980. This ground breaking text advocated chip design with programming languages that compiled to silicon, the immediate result was a considerable increase in the complexity of the chips that could be designed, with improved access to design verification tools that used logic simulation. Often the chips were easier to lay out and more likely to function correctly, the earliest EDA tools were produced academically. One of the most famous was the Berkeley VLSI Tools Tarball, still widely used are the Espresso heuristic logic minimizer and Magic. The basic concept was to use reliable, low-cost, relatively low-technology IC processes, cooperating fabricators either donated the processed wafers, or sold them at cost, seeing the program as helpful to their own long-term growth. 1981 marks the beginning of EDA as an industry, for many years, the larger electronic companies, such as Hewlett Packard, Tektronix, and Intel, had pursued EDA internally. In 1981, managers and developers spun out of companies to concentrate on EDA as a business. Daisy Systems, Mentor Graphics, and Valid Logic Systems were all founded around this time, within a few years there were many companies specializing in EDA, each with a slightly different emphasis. The first trade show for EDA was held at the Design Automation Conference in 1984, in 1981, the U. S. Department of Defense began funding of VHDL as a hardware description language. In 1986, Verilog, another popular high-level design language, was first introduced as a description language by Gateway Design Automation. Simulators quickly followed these introductions, permitting direct simulation of chip designs, in a few more years, back-ends were developed to perform logic synthesis. Current digital flows are extremely modular, the front ends produce standardized design descriptions that compile into invocations of cells, without regard to the cell technology. Cells implement logic or other functions using a particular integrated circuit technology
5.
Mechanical engineering
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Mechanical engineering is the discipline that applies the principles of engineering, physics, and materials science for the design, analysis, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the design, production and it is one of the oldest and broadest of the engineering disciplines. The mechanical engineering field requires an understanding of areas including mechanics, kinematics, thermodynamics, materials science, structural analysis. Mechanical engineering emerged as a field during the Industrial Revolution in Europe in the 18th century, however, Mechanical engineering science emerged in the 19th century as a result of developments in the field of physics. The field has evolved to incorporate advancements in technology, and mechanical engineers today are pursuing developments in such fields as composites, mechatronics. Mechanical engineers may work in the field of biomedical engineering, specifically with biomechanics, transport phenomena, biomechatronics, bionanotechnology. Mechanical engineering finds its application in the archives of various ancient, in ancient Greece, the works of Archimedes deeply influenced mechanics in the Western tradition and Heron of Alexandria created the first steam engine. In China, Zhang Heng improved a water clock and invented a seismometer, during the 7th to 15th century, the era called the Islamic Golden Age, there were remarkable contributions from Muslim inventors in the field of mechanical technology. Al-Jazari, who was one of them, wrote his famous Book of Knowledge of Ingenious Mechanical Devices in 1206 and he is also considered to be the inventor of such mechanical devices which now form the very basic of mechanisms, such as the crankshaft and camshaft. Newton was reluctant to publish his methods and laws for years, gottfried Wilhelm Leibniz is also credited with creating Calculus during the same time frame. On the European continent, Johann von Zimmermann founded the first factory for grinding machines in Chemnitz, education in mechanical engineering has historically been based on a strong foundation in mathematics and science. Degrees in mechanical engineering are offered at universities worldwide. In Spain, Portugal and most of South America, where neither B. Sc. nor B. Tech, programs have been adopted, the formal name for the degree is Mechanical Engineer, and the course work is based on five or six years of training. In Italy the course work is based on five years of education, and training, in Greece, the coursework is based on a five-year curriculum and the requirement of a Diploma Thesis, which upon completion a Diploma is awarded rather than a B. Sc. In Australia, mechanical engineering degrees are awarded as Bachelor of Engineering or similar nomenclature although there are a number of specialisations. The degree takes four years of study to achieve. To ensure quality in engineering degrees, Engineers Australia accredits engineering degrees awarded by Australian universities in accordance with the global Washington Accord, before the degree can be awarded, the student must complete at least 3 months of on the job work experience in an engineering firm. Similar systems are present in South Africa and are overseen by the Engineering Council of South Africa
6.
Technical drawing
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Technical drawing, drafting or drawing, is the act and discipline of composing drawings that visually communicate how something functions or is constructed. Technical drawing is essential for communicating ideas in industry and engineering, to make the drawings easier to understand, people use familiar symbols, perspectives, units of measurement, notation systems, visual styles, and page layout. Together, such conventions constitute a language and help to ensure that the drawing is unambiguous. Many of the symbols and principles of drawing are codified in an international standard called ISO128. The need for communication in the preparation of a functional document distinguishes technical drawing from the expressive drawing of the visual arts. Artistic drawings are subjectively interpreted, their meanings are multiply determined, Technical drawings are understood to have one intended meaning. A drafter, draftsperson, or draughtsman is a person who makes a drawing, a professional drafter who makes technical drawings is sometimes called a drafting technician. Professional drafting is a desirable and necessary function in the design and manufacture of mechanical components. Professional draftspersons bridge the gap between engineers and manufacturers and contribute experience and technical expertise to the design process, the basic drafting procedure is to place a piece of paper on a smooth surface with right-angle corners and straight sides—typically a drawing board. A sliding straightedge known as a T-square is then placed on one of the sides, allowing it to be slid across the side of the table, parallel lines can be drawn simply by moving the T-square and running a pencil or technical pen along the T-squares edge. The T-square is used to other devices such as set squares or triangles. Modern drafting tables come equipped with a machine that is supported on both sides of the table to slide over a large piece of paper. Because it is secured on both sides, lines drawn along the edge are guaranteed to be parallel, in addition, the drafter uses several technical drawing tools to draw curves and circles. Primary among these are the compasses, used for drawing simple arcs and circles, a spline is a rubber coated articulated metal that can be manually bent to most curves. Drafting templates assist the drafter with creating recurring objects in a drawing without having to reproduce the object from scratch every time. Templates are sold commercially by a number of vendors, usually customized to a specific task and this basic drafting system requires an accurate table and constant attention to the positioning of the tools. A common error is to allow the triangles to push the top of the T-square down slightly, thereby throwing off all angles. Even tasks as simple as drawing two angled lines meeting at a point require a number of moves of the T-square and triangles and these machines often included the ability to change the angle, thereby removing the need for the triangles as well
7.
Raster graphics
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Raster images are stored in image files with varying formats. A raster is technically characterized by the width and height of the image in pixels, the printing and prepress industries know raster graphics as contones. The opposite to contones is line work, usually implemented as vector graphics in digital systems, the word raster has its origins in the Latin rastrum, which is derived from radere. It originates from the scan of cathode ray tube video monitors. By association, it can refer to a rectangular grid of pixels. The word rastrum is now used to refer to a device for drawing musical staff lines, most modern computers have bitmapped displays, where each on-screen pixel directly corresponds to a small number of bits in memory. The screen is refreshed simply by scanning through pixels and coloring them according to set of bits. The refresh procedure, being speed critical, is implemented by dedicated circuitry. Most computer images are stored in raster graphics formats or compressed variations, including GIF, JPEG, and PNG, three-dimensional voxel raster graphics are employed in video games and are also used in medical imaging such as MRI scanners. GIS programs commonly use rasters that encode geographic data in the values as well as the pixel locations. Raster graphics are resolution dependent, meaning they cannot scale up to a resolution without loss of apparent quality. This property contrasts with the capabilities of graphics, which easily scale up to the quality of the device rendering them. Raster graphics deal more practically than vector graphics with photographs and photo-realistic images, typically, a resolution of 150 to 300 PPI works well for 4-color process printing. However, for printing technologies that perform color mixing through dithering rather than through overprinting, printer DPI and image PPI have a different meaning. Thus, for instance, printing an image at 250 PPI may actually require a printer setting of 1200 DPI, when an image is rendered in a raster-based image editor, the image is composed of millions of pixels. At its core, an image editor works by manipulating each individual pixel. Most pixel-based image editors work using the RGB color model, and this article is based on material taken from the Free On-line Dictionary of Computing prior to 1 November 2008 and incorporated under the relicensing terms of the GFDL, version 1.3 or later
8.
Engineering drawing
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An engineering drawing, a type of technical drawing, is used to fully and clearly define requirements for engineered items. More than merely the drawing of pictures, it is also a language—a graphical language that communicates ideas, most especially, it communicates all needed information from the engineer, who designed a part, to the workers, who will make it. Engineering drawing and artistic drawing are both types of drawing, and either may be called simply drawing when the context is implicit, Engineering drawing shares some traits with artistic drawing in that both create pictures. But whereas the purpose of drawing is to convey emotion or artistic sensitivity in some way. Engineering drawing uses a set of conventions to convey information very precisely. Engineering drawing is a type of technique which is used to fully and clearly defined requirements for engineered items, Engineering drawing is one of the best ways to communicate one idea easily to other person. Persons employed in the trade of producing engineering drawings were called draftsmen in the past, although these terms are still in use, the non-gender-specific terms draftsperson and drafter are now more common. The various fields share many common conventions of drawing, while also having some field-specific conventions, each of these trades has some details that only specialists will have memorized. An engineering drawing is a document, because it communicates all the needed information about what is wanted to the people who will expend resources turning the idea into a reality. It is thus a part of a contract, the purchase order, thus, if the resulting product is wrong, the worker or manufacturer are protected from liability as long as they have faithfully executed the instructions conveyed by the drawing. If those instructions were wrong, it is the fault of the engineer and this is the biggest reason why the conventions of engineering drawing have evolved over the decades toward a very precise, unambiguous state. Engineering drawings specify requirements of a component or assembly which can be complicated, standards provide rules for their specification and interpretation. In 2011, a new revision of ISO8015 was published containing the Invocation Principle and this states that, Once a portion of the ISO geometric product specification system is invoked in a mechanical engineering product documentation, the entire ISO GPS system is invoked. It also goes on to state that marking a drawing Tolerancing ISO8015 is optional, the implication of this is that any drawing using ISO symbols can only be interpreted to ISO GPS rules. The only way not to invoke the ISO GPS system is to invoke a national or other standard, now in 2015 there is a new standardisation called BS8888, this is now used for all standard and technical drawings. Since there are two widely standardized definitions of size, there is only one real alternative to ISO GPS, i. e. ASME Y14.5. Standardization also aids internationalization, because people from different countries who speak different languages can read the same engineering drawing, to that end, drawings should be as free of notes and abbreviations as possible so that the meaning is conveyed graphically. The manufacturing of a technical drawing however is as difficult as the production of the design it describes
9.
Manufacturing
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Manufacturing is the value added to production of merchandise for use or sale using labour and machines, tools, chemical and biological processing, or formulation. Manufacturing engineering or manufacturing process are the steps through which raw materials are transformed into a final product, the manufacturing process begins with the product design, and materials specification from which the product is made. These materials are modified through manufacturing processes to become the required part. Manufacturing takes turns under all types of economic systems, in a free market economy, manufacturing is usually directed toward the mass production of products for sale to consumers at a profit. In a collectivist economy, manufacturing is more directed by the state to supply a centrally planned economy. In mixed market economies, manufacturing occurs under some degree of government regulation, modern manufacturing includes all intermediate processes required the production and integration of a products components. Some industries, such as semiconductor and steel manufacturers use the term fabrication instead, the manufacturing sector is closely connected with engineering and industrial design. Examples of major manufacturers in North America include General Motors Corporation, General Electric, Procter & Gamble, General Dynamics, Boeing, Pfizer, examples in Europe include Volkswagen Group, Siemens, and Michelin. Examples in Asia include Sony, Huawei, Lenovo, Toyota, Samsung, in its earliest form, manufacturing was usually carried out by a single skilled artisan with assistants. In much of the world, the guild system protected the privileges. Before the Industrial Revolution, most manufacturing occurred in rural areas, entrepreneurs organized a number of manufacturing households into a single enterprise through the putting-out system. Toll manufacturing is an arrangement whereby a first firm with specialized equipment processes raw materials or semi-finished goods for a second firm, manufacturing provides important material support for national infrastructure and for national defense. On the other hand, most manufacturing may involve significant social and environmental costs, the clean-up costs of hazardous waste, for example, may outweigh the benefits of a product that creates it. Hazardous materials may expose workers to health risks and these costs are now well known and there is effort to address them by improving efficiency, reducing waste, using industrial symbiosis, and eliminating harmful chemicals. The negative costs of manufacturing can also be addressed legally, developed countries regulate manufacturing activity with labor laws and environmental laws. Across the globe, manufacturers can be subject to regulations and pollution taxes to offset the costs of manufacturing activities. Labor unions and craft guilds have played a role in the negotiation of worker rights. Environment laws and labor protections that are available in developed nations may not be available in the third world, tort law and product liability impose additional costs on manufacturing
10.
Dimension
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In physics and mathematics, the dimension of a mathematical space is informally defined as the minimum number of coordinates needed to specify any point within it. Thus a line has a dimension of one only one coordinate is needed to specify a point on it – for example. The inside of a cube, a cylinder or a sphere is three-dimensional because three coordinates are needed to locate a point within these spaces, in classical mechanics, space and time are different categories and refer to absolute space and time. That conception of the world is a space but not the one that was found necessary to describe electromagnetism. The four dimensions of spacetime consist of events that are not absolutely defined spatially and temporally, Minkowski space first approximates the universe without gravity, the pseudo-Riemannian manifolds of general relativity describe spacetime with matter and gravity. Ten dimensions are used to string theory, and the state-space of quantum mechanics is an infinite-dimensional function space. The concept of dimension is not restricted to physical objects, high-dimensional spaces frequently occur in mathematics and the sciences. They may be parameter spaces or configuration spaces such as in Lagrangian or Hamiltonian mechanics, in mathematics, the dimension of an object is an intrinsic property independent of the space in which the object is embedded. This intrinsic notion of dimension is one of the ways the mathematical notion of dimension differs from its common usages. The dimension of Euclidean n-space En is n, when trying to generalize to other types of spaces, one is faced with the question what makes En n-dimensional. One answer is that to cover a ball in En by small balls of radius ε. This observation leads to the definition of the Minkowski dimension and its more sophisticated variant, the Hausdorff dimension, for example, the boundary of a ball in En looks locally like En-1 and this leads to the notion of the inductive dimension. While these notions agree on En, they turn out to be different when one looks at more general spaces, a tesseract is an example of a four-dimensional object. The rest of this section some of the more important mathematical definitions of the dimensions. A complex number has a real part x and an imaginary part y, a single complex coordinate system may be applied to an object having two real dimensions. For example, an ordinary two-dimensional spherical surface, when given a complex metric, complex dimensions appear in the study of complex manifolds and algebraic varieties. The dimension of a space is the number of vectors in any basis for the space. This notion of dimension is referred to as the Hamel dimension or algebraic dimension to distinguish it from other notions of dimension
11.
Engineering tolerance
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In engineering and safety, a physical distance or space, as in a truck, train or boat under a bridge as well as a train in a tunnel. In mechanical engineering the space between a bolt and a nut or a hole, etc, dimensions, properties, or conditions may have some variation without significantly affecting functioning of systems, machines, structures, etc. A variation beyond the tolerance is said to be noncompliant, rejected, a primary concern is to determine how wide the tolerances may be without affecting other factors or the outcome of a process. This can be by the use of principles, engineering knowledge. Experimental investigation is very useful to investigate the effects of tolerances, Design of experiments, formal engineering evaluations, a good set of engineering tolerances in a specification, by itself, does not imply that compliance with those tolerances will be achieved. Actual production of any product involves some inherent variation of input and output, measurement error and statistical uncertainty are also present in all measurements. With a normal distribution, the tails of measured values may extend well beyond plus and minus three standard deviations from the process average, appreciable portions of one tails might extend beyond the specified tolerance. The process capability of systems, materials, and products needs to be compatible with the engineering tolerances. Process controls must be in place and an effective Quality management system, such as Total Quality Management, a process capability index is used to indicate the relationship between tolerances and actual measured production. The choice of tolerances is also affected by the statistical sampling plan. This relates to the question of whether tolerances must be rigid or whether some small percentage of being out-of-tolerance may sometimes be acceptable. The alternative is that the best product has a measurement which is precisely on target, there is an increasing loss which is a function of the deviation or variability from the target value of any design parameter. The greater the deviation from target, the greater is the loss and this is described as the Taguchi loss function or quality loss function, and it is the key principle of an alternative system called inertial tolerancing. Research and development work conducted by M. Pillet and colleagues at the Savoy University has resulted in industry-specific adoption, recently the publishing of the French standard NFX 04-008 has allowed further consideration by the manufacturing community. Dimensional tolerance is related to, but different from fit in mechanical engineering, tolerances are assigned to parts for manufacturing purposes, as boundaries for acceptable build. No machine can hold dimensions precisely to the value, so there must be acceptable degrees of variation. If a part is manufactured, but has dimensions that are out of tolerance, tolerances can be applied to any dimension. The commonly used terms are, Basic size, the diameter of the shaft
12.
2D computer graphics
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2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them. The word may stand for the branch of science that comprises such techniques. This representation is more flexible since it can be rendered at different resolutions to suit different output devices. For these reasons, documents and illustrations are often stored or transmitted as 2D graphic files, 2D computer graphics started in the 1950s, based on vector graphics devices. These were largely supplanted by raster-based devices in the following decades, the PostScript language and the X Window System protocol were landmark developments in the field. 2D graphics models may combine geometric models, digital images, text to be typeset, mathematical functions and equations and these components can be modified and manipulated by two-dimensional geometric transformations such as translation, rotation, scaling. In object-oriented graphics, the image is described indirectly by an object endowed with a self-rendering method—a procedure which assigns colors to the pixels by an arbitrary algorithm. Complex models can be built by combining simpler objects, in the paradigms of object-oriented programming, in Euclidean geometry, a translation moves every point a constant distance in a specified direction. A translation can be described as a motion, other rigid motions include rotations and reflections. A translation can also be interpreted as the addition of a constant vector to every point, a translation operator is an operator T δ such that T δ f = f. If v is a vector, then the translation Tv will work as Tv = p + v. If T is a translation, then the image of a subset A under the function T is the translate of A by T, the translate of A by Tv is often written A + v. In a Euclidean space, any translation is an isometry, the set of all translations forms the translation group T, which is isomorphic to the space itself, and a normal subgroup of Euclidean group E. The quotient group of E by T is isomorphic to the orthogonal group O, E / T ≅ O, thus we write the 3-dimensional vector w = using 4 homogeneous coordinates as w =. Similarly, the product of matrices is given by adding the vectors. Because addition of vectors is commutative, multiplication of matrices is therefore also commutative. In linear algebra, a matrix is a matrix that is used to perform a rotation in Euclidean space. R = rotates points in the xy-Cartesian plane counterclockwise through an angle θ about the origin of the Cartesian coordinate system
13.
3D computer graphics
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Such images may be stored for viewing later or displayed in real-time. 3D computer graphics rely on many of the same algorithms as 2D computer vector graphics in the wire-frame model, 3D computer graphics are often referred to as 3D models. Apart from the graphic, the model is contained within the graphical data file. However, there are differences, a 3D model is the representation of any three-dimensional object. A model is not technically a graphic until it is displayed, a model can be displayed visually as a two-dimensional image through a process called 3D rendering or used in non-graphical computer simulations and calculations. With 3D printing, 3D models are rendered into a 3D physical representation of the model. William Fetter was credited with coining the term computer graphics in 1961 to describe his work at Boeing, 3D computer graphics software began appearing for home computers in the late 1970s. The earliest known example is 3D Art Graphics, a set of 3D computer graphics effects, written by Kazumasa Mitazawa, models can also be produced procedurally or via physical simulation. Basically, a 3D model is formed from points called vertices that define the shape, a polygon is an area formed from at least three vertexes. A polygon of n points is an n-gon, the overall integrity of the model and its suitability to use in animation depend on the structure of the polygons. Before rendering into an image, objects must be out in a scene. This defines spatial relationships between objects, including location and size, Animation refers to the temporal description of an object. These techniques are used in combination. As with animation, physical simulation also specifies motion, rendering converts a model into an image either by simulating light transport to get photo-realistic images, or by applying an art style as in non-photorealistic rendering. The two basic operations in realistic rendering are transport and scattering and this step is usually performed using 3D computer graphics software or a 3D graphics API. Altering the scene into a form for rendering also involves 3D projection. There are a multitude of websites designed to help, educate, some are managed by software developers and content providers, but there are standalone sites as well. These communities allow for members to seek advice, post tutorials, not all computer graphics that appear 3D are based on a wireframe model
14.
Automotive
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The automotive industry is a wide range of companies and organizations involved in the design, development, manufacturing, marketing, and selling of motor vehicles, some of them are called automakers. It is one of the worlds most important economic sectors by revenue, the term automotive was created from Greek autos, and Latin motivus to represent any form of self-powered vehicle. This term was proposed by Elmer Sperry, the automotive industry began in the 1890s with hundreds of manufacturers that pioneered the horseless carriage. For many decades, the United States led the world in automobile production. In 1929, before the Great Depression, the world had 32,028,500 automobiles in use, at that time the U. S. had one car per 4.87 persons. After World War II, the U. S. produced about 75 percent of auto production. In 1980, the U. S. was overtaken by Japan, in 2006, Japan narrowly passed the U. S. in production and held this rank until 2009, when China took the top spot with 13.8 million units. With 19.3 million units manufactured in 2012, China almost doubled the U. S. production, with 10.3 million units, from 1970 over 1998 to 2012, the number of automobile models in the U. S. has grown exponentially. Safety is a state that implies to be protected from any risk, danger, in the automotive industry, safety means that users, operators or manufacturers do not face any risk or danger coming from the motor vehicle or its spare parts. Safety for the automobiles themselves, implies there is no risk of damage. Safety in the industry is particularly important and therefore highly regulated. Automobiles and other vehicles have to comply with a certain number of norms and regulations, whether local or international. The standard ISO26262, is considered as one of the best practice framework for achieving automotive functional safety. In case of safety issues, danger, product defect or faulty procedure during the manufacturing of the motor vehicle and this procedure is called product recall. Product recalls happen in every industry and can be production-related or stem from the raw material, however, the automotive industry is still particularly concerned about product recalls, which cause considerable financial consequences. Around the world, there were about 806 million cars and light trucks on the road in 2007, consuming over 980 billion litres of gasoline, the automobile is a primary mode of transportation for many developed economies. The Detroit branch of Boston Consulting Group predicts that, by 2014, meanwhile, in the developed countries, the automotive industry has slowed down. It is also expected that this trend will continue, especially as the generations of people no longer want to own a car anymore
15.
Shipbuilding
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Shipbuilding is the construction of ships and other floating vessels. It normally takes place in a facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to before recorded history, Shipbuilding and ship repairs, both commercial and military, are referred to as naval engineering. The construction of boats is an activity called boat building. The dismantling of ships is called ship breaking, the ancestors of Australian Aborigines and New Guineans also went across the Lombok Strait to Sahul by boat over 50,000 years ago. Evidence from Ancient Egypt shows that the early Egyptians knew how to assemble planks of wood into a ship hull as early as 3000 BC, the Archaeological Institute of America reports that some of the oldest ships yet unearthed are known as the Abydos boats. These are a group of 14 ships discovered in Abydos that were constructed of wooden planks which were sewn together, the ship dating to 3000 BC was about 25 m,75 feet long and is now thought to perhaps have belonged to an earlier pharaoh. According to professor OConnor, the 5, 000-year-old ship may have belonged to Pharaoh Aha. Early Egyptians also knew how to assemble planks of wood with treenails to fasten them together, early Egyptians also knew how to fasten the planks of this ship together with mortise and tenon joints. The oldest known tidal dock in the world was built around 2500 BC during the Harappan civilisation at Lothal near the present day Mangrol harbour on the Gujarat coast in India, other ports were probably at Balakot and Dwarka. However, it is probable that many small-scale ports, and not massive ports, were used for the Harappan maritime trade, ships from the harbour at these ancient port cities established trade with Mesopotamia. Shipbuilding and boatmaking may have been prosperous industries in ancient India, native labourers may have manufactured the flotilla of boats used by Alexander the Great to navigate across the Hydaspes and even the Indus, under Nearchos. The Indians also exported teak for shipbuilding to ancient Persia, other references to Indian timber used for shipbuilding is noted in the works of Ibn Jubayr. The ships of Ancient Egypts Eighteenth Dynasty were typically about 25 meters in length and they mounted a single square sail on a yard, with an additional spar along the bottom of the sail. These ships could also be oar propelled, the ocean and sea going ships of Ancient Egypt were constructed with cedar wood, most likely hailing from Lebanon. The ships of Phoenicia seem to have been of a similar design, the naval history of China stems back to the Spring and Autumn period of the ancient Chinese Zhou Dynasty. The Chinese built large rectangular barges known as ships, which were essentially floating fortresses complete with multiple decks with guarded ramparts. There is considerable knowledge regarding shipbuilding and seafaring in the ancient Mediterranean and this was dually met with the introduction of the Han Dynasty junk ship design in the same century
16.
Aerospace
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Aerospace is the human effort in science, engineering and business to fly in the atmosphere of Earth and surrounding space. Aerospace organisations research, design, manufacture, operate, or maintain aircraft and/or spacecraft, Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace is not the same as airspace, which is the air space directly above a location on the ground. In most industrial countries, the industry is a cooperation of public. Along with these public space programs, many companies produce technical tools and components such as spaceships, some known companies involved in space programs include Boeing, Airbus Group, SpaceX, Lockheed Martin, MacDonald Dettwiler and Northrop Grumman. These companies are involved in other areas of aerospace such as the construction of aircraft. Modern aerospace began with George Cayley in 1799, Cayley proposed an aircraft with a fixed wing and a horizontal and vertical tail, defining characteristics of the modern airplane. Airmen like Otto Lilienthal, who introduced cambered airfoils in 1891, the Wright brothers were interested in Lilienthals work and read several of his publications. They also found inspiration in Octave Chanute, an airman and the author of Progress in Flying Machines, war and science fiction inspired great minds like Konstantin Tsiolkovsky and Wernher von Braun to achieve flight beyond the atmosphere. The launch of Sputnik 1 in October 1957 started the Space Age, in April 1981, the Space Shuttle Columbia launched, the start of regular manned access to orbital space. A sustained human presence in space started with Mir in 1986 and is continued by the International Space Station. Space commercialization and space tourism are more recent focuses in aerospace, Aerospace manufacturing is a high-technology industry that produces aircraft, guided missiles, space vehicles, aircraft engines, propulsion units, and related parts. Most of the industry is geared toward governmental work, for each original equipment manufacturer, the US government has assigned a Commercial and Government Entity code. These codes help to each manufacturer, repair facilities. In the United States, the Department of Defense and the National Aeronautics, others include the very large airline industry. The aerospace industry employed 472,000 wage and salary workers in 2006, most of those jobs were in Washington state and in California, with Missouri, New York and Texas also being important. The leading aerospace manufacturers in the U. S. are Boeing, United Technologies Corporation, SpaceX, Northrop Grumman and these manufacturers are facing an increasing labor shortage as skilled U. S. workers age and retire. In India, Bangalore is a center of the aerospace industry, where Hindustan Aeronautics Limited, the National Aerospace Laboratories
17.
Prosthesis
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In medicine, a prosthesis is an artificial device that replaces a missing body part, which may be lost through trauma, disease, or congenital conditions. A persons prosthetics should be designed and assembled according to the patients appearance, for instance, a patient may need a transradial prosthesis, but need to choose between an aesthetic functional device, a myoelectric device, a body-powered device, or an activity specific device. The patients future goals and economical capabilities may help choose between one or more devices. Craniofacial prostheses include intra-oral and extra-oral prostheses, extra-oral prostheses are further divided into hemifacial, auricular, nasal, orbital and ocular. Intra-oral prostheses include dental prostheses such as dentures, obturators, limb prostheses include both upper- and lower-extremity prostheses. A transradial prosthesis is a limb that replaces an arm missing below the elbow. Two main types of prosthetics are available, cable operated limbs work by attaching a harness and cable around the opposite shoulder of the damaged arm. The other form of prosthetics available are myoelectric arms and these work by sensing, via electrodes, when the muscles in the upper arm move, causing an artificial hand to open or close. In the prosthetic industry a trans-radial prosthetic arm is referred to as a BE or below elbow prosthesis. Lower-extremity prostheses provide replacements at varying levels of amputation and these include hip disarticulation, transfemoral prosthesis, knee disarticulation, transtibial prosthesis, Symes amputation, foot, partial foot, and toe. The two main subcategories of lower extremity prosthetic devices are trans-tibial and trans-femoral, a transfemoral prosthesis is an artificial limb that replaces a leg missing above the knee. Transfemoral amputees can have a difficult time regaining normal movement. In general, a transfemoral amputee must use approximately 80% more energy to walk than a person with two whole legs and this is due to the complexities in movement associated with the knee. In the prosthetic industry a trans-femoral prosthetic leg is often referred to as an AK or above the knee prosthesis, a transtibial prosthesis is an artificial limb that replaces a leg missing below the knee. A transtibial amputee is usually able to regain normal movement more readily than someone with an amputation, due in large part to retaining the knee. Lower extremity prosthetics describes artificially replaced limbs located at the hip level or lower, in the prosthetic industry a trans-tibial prosthetic leg is often referred to as a BK or below the knee prosthesis. Prosthetics have been mentioned throughout history, the earliest recorded mention is the warrior queen Vishpala in the Rigveda. The Egyptians were early pioneers of the idea, as shown by the wooden toe found on a body from the New Kingdom, roman bronze crowns have also been found, but their use could have been more aesthetic than medical
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Computer animation
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Computer animation is the process used for generating animated images. The more general term computer-generated imagery encompasses both static scenes and dynamic images, while computer animation refers to the moving images. Modern computer animation usually uses 3D computer graphics, although 2D computer graphics are used for stylistic, low bandwidth. Sometimes, the target of the animation is the computer itself, Computer animation is essentially a digital successor to the stop motion techniques used in traditional animation with 3D models and frame-by-frame animation of 2D illustrations. It can also allow a single graphic artist to such content without the use of actors, expensive set pieces. To create the illusion of movement, an image is displayed on the monitor and repeatedly replaced by a new image that is similar to it. This technique is identical to how the illusion of movement is achieved with television and motion pictures, for 3D animations, objects are built on the computer monitor and 3D figures are rigged with a virtual skeleton. For 2D figure animations, separate objects and separate transparent layers are used with or without that virtual skeleton, then the limbs, eyes, mouth, clothes, etc. of the figure are moved by the animator on key frames. The differences in appearance between key frames are calculated by the computer in a process known as tweening or morphing. For 3D animations, all frames must be rendered after the modeling is complete, for 2D vector animations, the rendering process is the key frame illustration process, while tweened frames are rendered as needed. For pre-recorded presentations, the frames are transferred to a different format or medium. The frames may also be rendered in real time as they are presented to the end-user audience, low bandwidth animations transmitted via the internet often use software on the end-users computer to render in real time as an alternative to streaming or pre-loaded high bandwidth animations. To trick the eye and the brain into thinking they are seeing a moving object. With rates above 75-120 frames per second, no improvement in realism or smoothness is perceivable due to the way the eye, at rates below 12 frames per second, most people can detect jerkiness associated with the drawing of new images that detracts from the illusion of realistic movement. Conventional hand-drawn cartoon animation often uses 15 frames per second in order to save on the number of drawings needed, to produce more realistic imagery, computer animation demands higher frame rates. Films seen in theaters in the United States run at 24 frames per second, for high resolution, adapters are used. Early digital computer animation was developed at Bell Telephone Laboratories in the 1960s by Edward E. Zajac, Frank W. Sinden, other digital animation was also practiced at the Lawrence Livermore National Laboratory. An early step in the history of animation was the sequel to the 1973 film Westworld
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Special effect
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Special effects are illusions or visual tricks used in the film, television, theatre, video game, and simulator industries to simulate the imagined events in a story or virtual world. Special effects are divided into the categories of optical effects. Mechanical effects are usually accomplished during the live-action shooting and this includes the use of mechanized props, scenery, scale models, animatronics, pyrotechnics and atmospheric effects, creating physical wind, rain, fog, snow, clouds, etc. Making a car appear to drive by itself and blowing up a building are examples of mechanical effects, mechanical effects are often incorporated into set design and makeup. For example, a set may be built with doors or walls to enhance a fight scene. An optical effect might be used to place actors or sets against a different background, since the 1990s, computer generated imagery has come to the forefront of special effects technologies. It gives filmmakers greater control, and allows many effects to be accomplished safely and convincingly and—as technology improves—at lower costs. As a result, many optical and mechanical effects techniques have been superseded by CGI, in 1857, Oscar Rejlander created the worlds first special effects movie by combining different sections of 30 negatives into a single image. In 1895, Alfred Clark created what is accepted as the first-ever motion picture special effect. While filming a reenactment of the beheading of Mary, Queen of Scots, as the executioner brought the axe above his head, Clark stopped the camera, had all of the actors freeze, and had the person playing Mary step off the set. He placed a Mary dummy in the place, restarted filming. Techniques like these would dominate the production of special effects for a century and it wasnt only the first use of trickery in cinema, it was also the first type of photographic trickery only possible in a motion picture, i. e. the stop trick. Georges Méliès accidentally discovered the same stop trick, according to Méliès, his camera jammed while filming a street scene in Paris. When he screened the film, he found that the trick had caused a truck to turn into a hearse, pedestrians to change direction. Because of his ability to manipulate and transform reality with the cinematograph. From 1910 to 1920, the innovations in special effects were the improvements on the matte shot by Norman Dawn. With the original matte shot, pieces of cardboard were placed to block the exposure of the film, Dawn combined this technique with the glass shot. Rather than using cardboard to block certain areas of the film exposure, from the partially exposed film, a single frame is then projected onto an easel, where the matte is then drawn
20.
Advertising
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Advertising is an audio or visual form of marketing communication that employs an openly sponsored, nonpersonal message to promote or sell a product, service or idea. Sponsors of advertising are often businesses who wish to promote their products or services, Advertising is differentiated from public relations in that an advertiser usually pays for and has control over the message. It is differentiated from personal selling in that the message is nonpersonal, the actual presentation of the message in a medium is referred to as an advertisement or ad. Commercial ads often seek to generate increased consumption of their products or services through branding, on the other hand, ads that intend to elicit an immediate sale are known as direct response advertising. Non-commercial advertisers who spend money to advertise items other than a product or service include political parties, interest groups, religious organizations. Non-profit organizations may use free modes of persuasion, such as a service announcement. Advertising may also be used to reassure employees or shareholders that a company is viable or successful, in 2015, the world spent an estimate of US$592.43 billion on advertising. Its projected distribution for 2017 is 40. 4% on TV,33. 3% on digital, internationally, the largest advertising conglomerates are Interpublic, Omnicom, Publicis, and WPP. In Latin, ad vertere means to turn toward, egyptians used papyrus to make sales messages and wall posters. Commercial messages and political campaign displays have been found in the ruins of Pompeii, lost and found advertising on papyrus was common in ancient Greece and ancient Rome. Wall or rock painting for commercial advertising is another manifestation of an ancient advertising form, which is present to this day in many parts of Asia, Africa, the tradition of wall painting can be traced back to Indian rock art paintings that date back to 4000 BC. In ancient China, the earliest advertising known was oral, as recorded in the Classic of Poetry of bamboo flutes played to sell candy, advertisement usually takes in the form of calligraphic signboards and inked papers. Fruits and vegetables were sold in the city square from the backs of carts and wagons, the first compilation of such advertisements was gathered in Les Crieries de Paris, a thirteenth-century poem by Guillaume de la Villeneuve. In the 18th century advertisements started to appear in newspapers in England. However, false advertising and so-called quack advertisements became a problem, thomas J. Barratt from London has been called the father of modern advertising. Working for the Pears Soap company, Barratt created an advertising campaign for the company products. One of his slogans, Good morning, have you used Pears soap. was famous in its day and into the 20th century. Barratt introduced many of the ideas that lie behind successful advertising
21.
Computer graphics
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Computer graphics are pictures and films created using computers. Usually, the term refers to computer-generated image data created with help from specialized hardware and software. It is a vast and recent area in computer science, the phrase was coined in 1960, by computer graphics researchers Verne Hudson and William Fetter of Boeing. It is often abbreviated as CG, though sometimes referred to as CGI. The overall methodology depends heavily on the sciences of geometry, optics. Computer graphics is responsible for displaying art and image data effectively and meaningfully to the user and it is also used for processing image data received from the physical world. Computer graphic development has had a significant impact on many types of media and has revolutionized animation, movies, advertising, video games, the term computer graphics has been used a broad sense to describe almost everything on computers that is not text or sound. Such imagery is found in and on television, newspapers, weather reports, a well-constructed graph can present complex statistics in a form that is easier to understand and interpret. In the media such graphs are used to illustrate papers, reports, thesis, many tools have been developed to visualize data. Computer generated imagery can be categorized into different types, two dimensional, three dimensional, and animated graphics. As technology has improved, 3D computer graphics have become more common, Computer graphics has emerged as a sub-field of computer science which studies methods for digitally synthesizing and manipulating visual content. Screens could display art since the Lumiere brothers use of mattes to create effects for the earliest films dating from 1895. New kinds of displays were needed to process the wealth of information resulting from such projects, early projects like the Whirlwind and SAGE Projects introduced the CRT as a viable display and interaction interface and introduced the light pen as an input device. Douglas T. Ross of the Whirlwind SAGE system performed an experiment in 1954 in which a small program he wrote captured the movement of his finger. Electronics pioneer Hewlett-Packard went public in 1957 after incorporating the decade prior, and established ties with Stanford University through its founders. This began the transformation of the southern San Francisco Bay Area into the worlds leading computer technology hub - now known as Silicon Valley. The field of computer graphics developed with the emergence of computer graphics hardware, further advances in computing led to greater advancements in interactive computer graphics. In 1959, the TX-2 computer was developed at MITs Lincoln Laboratory, the TX-2 integrated a number of new man-machine interfaces
22.
Integrated circuit
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An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material, normally silicon. The ICs mass production capability, reliability and building-block approach to circuit design ensured the rapid adoption of standardized ICs in place of using discrete transistors. ICs are now used in all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other home appliances are now inextricable parts of the structure of modern societies, made possible by the small size. These advances, roughly following Moores law, allow a computer chip of 2016 to have millions of times the capacity, ICs have two main advantages over discrete circuits, cost and performance. Cost is low because the chips, with all their components, are printed as a unit by photolithography rather than being constructed one transistor at a time, furthermore, packaged ICs use much less material than discrete circuits. Performance is high because the ICs components switch quickly and consume little power because of their small size, the main disadvantage of ICs is the high cost to design them and fabricate the required photomasks. This high initial cost means ICs are only practical when high production volumes are anticipated, Circuits meeting this definition can be constructed using many different technologies, including thin-film transistor, thick film technology, or hybrid integrated circuit. However, in general usage integrated circuit has come to refer to the single-piece circuit construction originally known as a integrated circuit. Jacobi disclosed small and cheap hearing aids as typical industrial applications of his patent, an immediate commercial use of his patent has not been reported. The idea of the circuit was conceived by Geoffrey Dummer. Dummer presented the idea to the public at the Symposium on Progress in Quality Electronic Components in Washington and he gave many symposia publicly to propagate his ideas, and unsuccessfully attempted to build such a circuit in 1956. A precursor idea to the IC was to create small ceramic squares, Components could then be integrated and wired into a bidimensional or tridimensional compact grid. This idea, which seemed very promising in 1957, was proposed to the US Army by Jack Kilby, however, as the project was gaining momentum, Kilby came up with a new, revolutionary design, the IC. In his patent application of 6 February 1959, Kilby described his new device as a body of semiconductor material … wherein all the components of the circuit are completely integrated. The first customer for the new invention was the US Air Force, Kilby won the 2000 Nobel Prize in Physics for his part in the invention of the integrated circuit. His work was named an IEEE Milestone in 2009, half a year after Kilby, Robert Noyce at Fairchild Semiconductor developed his own idea of an integrated circuit that solved many practical problems Kilbys had not. Noyces design was made of silicon, whereas Kilbys chip was made of germanium, Noyce credited Kurt Lehovec of Sprague Electric for the principle of p–n junction isolation, a key concept behind the IC
23.
Vector graphics
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Vector graphics is the use of polygons to represent images in computer graphics. Vector graphics are based on vectors, which lead through locations called control points or nodes, one of the first uses of vector graphic displays was the US SAGE air defense system. Vector graphics systems were retired from U. S. en route air traffic control in 1999. Vector graphics were used on the TX-2 at the MIT Lincoln Laboratory by computer graphics pioneer Ivan Sutherland to run his program Sketchpad in 1963. Subsequent vector graphics systems, most of which iterated through dynamically modifiable stored lists of drawing instructions, include the IBM2250, Imlac PDS-1, storage scope displays, such as the Tektronix 4014, could display vector images but not modify them without first erasing the display. In computer typography, modern outline fonts describe printable characters by cubic or quadratic mathematical curves with control points, nevertheless, bitmap fonts are still in use. Processing outline character data in sophisticated fashion to create satisfactory bitmaps for rendering is called hinting, although the term implies suggestion, the process is deterministic, and done by executable code, essentially a special-purpose computer language. While automatic hinting is possible, results can be inferior to that done by experts, although a typical plot might easily require a few thousand paper motions, back and forth, the paper doesnt slip. In a tiny roll-fed plotter made by Alps in Japan, teeth on thin sprockets indented the paper near its edges on the first pass, some Hewlett-Packard pen plotters had two-axis pen carriers and stationery paper. However, the moving-paper H-P plotters had grit wheels which, on the first pass, indented the paper surface, present-day vector graphic files such as engineering drawings are typically printed as bitmaps, after vector-to-raster conversion. The term vector graphics is used today in the context of two-dimensional computer graphics. It is one of several modes an artist can use to create an image on a raster display, Vector graphics can be uploaded to online databases for other designers to download and manipulate, speeding up the creative process. Other modes include text, multimedia, and 3D rendering, virtually all modern 3D rendering is done using extensions of 2D vector graphics techniques. Plotters used in technical drawing still draw vectors directly to paper, the World Wide Web Consortium standard for vector graphics is Scalable Vector Graphics. The standard is complex and has been slow to be established at least in part owing to commercial interests. Many web browsers now have support for rendering SVG data. In recent years, SVG has become a significant format that is independent of the resolution of the rendering device. SVG files are essentially printable text that describes both straight and curved paths, as well as other attributes, wikipedia prefers SVG for images such as simple maps, line illustrations, coats of arms, and flags, which generally are not like photographs or other continuous-tone images
24.
Solid modeling
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Solid modeling is a consistent set of principles for mathematical and computer modeling of three-dimensional solids. Solid modeling is distinguished from related areas of geometric modeling and computer graphics by its emphasis on physical fidelity, the use of solid modeling techniques allows for the automation of several difficult engineering calculations that are carried out as a part of the design process. Simulation, planning, and verification of such as machining. More recently, the range of supported manufacturing applications has greatly expanded to include sheet metal manufacturing, injection molding, welding. Solid modeling research and development has addressed many of these issues. The requirement implicitly recognizes the possibility of several representations of the same physical object as long as any two such representations are consistent. Such reasoning led to the development of the paradigm that has shaped the field of solid modeling as we know it today. These postulated properties can be translated into properties of subsets of three-dimensional Euclidean space, the two common approaches to define solidity rely on point-set topology and algebraic topology respectively. Both models specify how solids can be built from simple pieces or cells, according to the continuum point-set model of solidity, all the points of any X ⊂ ℝ3 can be classified according to their neighborhoods with respect to X as interior, exterior, or boundary points. Assuming ℝ3 is endowed with the typical Euclidean metric, a neighborhood of a point p ∈X takes the form of an open ball. For X to be considered solid, every neighborhood of any p ∈X must be three dimensional, points with lower-dimensional neighborhoods indicate a lack of solidity. Dimensional homogeneity of neighborhoods is guaranteed for the class of closed regular sets, in addition, solids are required to be closed under the Boolean operations of set union, intersection, and difference. The regularized set operations are denoted ∪∗, ∩∗, and −∗, a triangulation of a semi-analytic set into a collection of points, line segments, triangular faces, and tetrahedral elements is an example of a stratification that is commonly used. In particular this implies the Euler characteristic of the boundary of the polyhedron is 2. The key property that facilitates this consistency is that the class of closed subsets of ℝn coincides precisely with homogeneously n-dimensional topological polyhedra. Based on assumed mathematical properties, any scheme of representing solids is a method for capturing information about the class of subsets of Euclidean space. This means all representations are different ways of organizing the same geometric, all representation schemes are organized in terms of a finite number of operations on a set of primitives. Therefore, the space of any particular representation is finite
25.
Freeform surface modelling
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Freeform surface modelling is a technique for engineering Freeform Surfaces with a CAD or CAID system. The technology has encompassed two main fields, CAD software packages use two basic methods for the creation of surfaces. The first begins with construction curves from which the 3D surface is then swept or meshed through, the second method is direct creation of the surface with manipulation of the surface poles/control points. Freeform surface, or freeform surfacing, is used in CAD, Freeform surfaces do not have rigid radial dimensions, unlike regular surfaces such as planes, cylinders and conic surfaces. They are used to describe forms such as blades, car bodies. Initially developed for the automotive and aerospace industries, freeform surfacing is now used in all engineering design disciplines from consumer goods products to ships. Most systems today use nonuniform rational B-spline mathematics to describe the forms, however. The forms of freeform surfaces are not stored or defined in CAD software in terms of polynomial equations, but by their poles, degree, and number of patches. The degree of a surface determines its mathematical properties, and can be seen as representing the shape by a polynomial with variables to the power of the degree value, for example, a surface with a degree of 1 would be a flat cross section surface. A surface with degree 2 would be curved in one direction, some CAD systems use the term order instead of degree. The order of a polynomial is one greater than the degree, the poles of a surface define its shape. The natural surface edges are defined by the positions of the first and last poles, the intermediate poles act like magnets drawing the surface in their direction. The surface does not, however, go through these points, the second and third poles as well as defining shape, respectively determine the start and tangent angles and the curvature. In a single surface, there is one more pole than the degree values of the surface. Surface patches can be merged into a single NURBS surface, at these points are knot lines, the number of knots will determine the influence of the poles on either side and how smooth the transition is. These are values on the surface ranging from 0 to 1, used in the definition of the surface and for defining paths on the surface, for example. Note that they are not proportionally spaced along the surface, a curve of constant U or constant V is known as an isoperimetric curve, or U line. In CAD systems, surfaces are often displayed with their poles of constant U or constant V values connected together by lines, when defining a form, an important factor is the continuity between surfaces - how smoothly they connect to one another
26.
Systems development life cycle
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The systems development life-cycle concept applies to a range of hardware and software configurations, as a system can be composed of hardware only, software only, or a combination of both. Computer systems are complex and often link multiple traditional systems potentially supplied by different software vendors, SDLC can be described along a spectrum of agile to iterative to sequential. Agile methodologies, such as XP and Scrum, focus on processes which allow for rapid changes along the development cycle. Iterative methodologies, such as Rational Unified Process and dynamic systems development method, focus on limited project scope, sequential or big-design-up-front models, such as waterfall, focus on complete and correct planning to guide large projects and risks to successful and predictable results. Other models, such as development, tend to focus on a form of development that is guided by project scope. In project management a project can be defined both with a life cycle and an SDLC, during which slightly different activities occur. According to Taylor, the life cycle encompasses all the activities of the project. SDLC is used during the development of an IT project, it describes the different stages involved in the project from the drawing board, through the completion of the project. The product life cycle describes the process for building systems in a very deliberate, structured and methodical way. Information systems activities revolved around heavy data processing and number crunching routines, the system development life cycle framework provides a sequence of activities for system designers and developers to follow. It consists of a set of steps or phases in which phase of the SDLC uses the results of the previous one. The SDLC adheres to important phases that are essential for developers, such as planning, analysis, design, and implementation and it includes evaluation of present system, information gathering, feasibility study and request approval. A number of SDLC models have been created, waterfall, fountain, spiral, build and fix, rapid prototyping, incremental, synchronize and stabilize. The oldest of these, and the best known, is the waterfall model, conduct the preliminary analysis, in this step, you need to find out the organizations objectives and the nature and scope of the problem under study. Even if a problem only to a small segment of the organization itself. Then you need to see how the problem being studied fits in with them, propose alternative solutions, In digging into the organizations objectives and specific problems, you may have already covered some solutions. Alternate proposals may come from interviewing employees, clients, suppliers and you can also study what competitors are doing. With this data, you will have three choices, leave the system as is, improve it, or develop a new system, Systems analysis, requirements definition, Defines project goals into defined functions and operation of the intended application
27.
Product lifecycle
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PLM integrates people, data, processes and business systems and provides a product information backbone for companies and their extended enterprise. The inspiration for the business process now known as PLM came from American Motors Corporation. Lacking the massive budgets of General Motors, Ford, and foreign competitors … AMC placed R&D emphasis on bolstering the product cycle of its prime products. After introducing its compact Jeep Cherokee, the vehicle that launched the sport utility vehicle market, AMC began development of a new model. The first part in its quest for faster product development was computer-aided design software system that make engineers more productive. While an early adopter of PLM technology, Chrysler was able to become the auto industrys lowest-cost producer, during 1982-83, Rockwell International developed initial concepts of PDM and PLM for the B-1B bomber program. The system called Engineering Data System was augmented to interface with Computervision and CADAM systems to track part configurations and lifecycle of components, computervison later released implementing only the PDM aspects as the lifecycle model was specific to Rockwell and aerospace needs. PLM systems help organizations in coping with the complexity and engineering challenges of developing new products for the global competitive markets. Product lifecycle management should be distinguished from product life-cycle management, Product lifecycle management can be considered one of the four cornerstones of a manufacturing corporations information technology structure. All companies need to manage communications and information with their customers, their suppliers and fulfillment, their resources within the enterprise and their product planning, one form of PLM is called people-centric PLM. While traditional PLM tools have been deployed only on release or during the release phase and this has resulted in the extension of PLM into closed-loop lifecycle management. Systems engineering is focused on meeting all requirements, primarily meeting customer needs, an important aspect for life cycle management is a subset within Systems Engineering called Reliability Engineering. Product and portfolio management is focused on managing resource allocation, tracking progress vs. plan for new development projects that are in process. Manufacturing process management is a collection of technologies and methods used to define how products are to be manufactured, Product data management is focused on capturing and maintaining information on products and/or services through their development and useful life. Change management is an important part of PDM/PLM, the core of PLM is in the creation and central management of all product data and the technology used to access this information and knowledge. PLM as a discipline emerged from such as CAD, CAM and PDM, but can be viewed as the integration of these tools with methods, people. It is not just about technology but is also a business strategy. For simplicity the stages described are shown in a traditional sequential engineering workflow, design is an iterative process, often designs need to be modified due to manufacturing constraints or conflicting requirements
28.
Computer-aided engineering
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Computer-aided engineering is the broad usage of computer software to aid in engineering analysis tasks. It includes finite element analysis, computational fluid dynamics, multibody dynamics, software tools that have been developed to support these activities are considered CAE tools. CAE tools are being used, for example, to analyze the robustness and performance of components, the term encompasses simulation, validation, and optimization of products and manufacturing tools. In the future, CAE systems will be major providers of information to support design teams in decision making. Computer-aided engineering is used in fields such as automotive, aviation, space. In regard to information networks, CAE systems are considered a single node on a total information network. CAE systems can provide support to businesses and this is achieved by the use of reference architectures and their ability to place information views on the business process. Reference architecture is the basis from which information model, especially product, the term CAE has also been used by some in the past to describe the use of computer technology within engineering in a broader sense than just engineering analysis. It was in context that the term was coined by Jason Lemon. This definition is better known today by the terms CAx. Optimization of the product or process, in general, there are three phases in any computer-aided engineering task, Pre-processing – defining the model and environmental factors to be applied to it. Analysis solver Post-processing of results This cycle is iterated, often many times, CAE tools are very widely used in the automotive industry. In fact, their use has enabled the automakers to reduce development cost and time while improving the safety, comfort. The predictive capability of CAE tools has progressed to the point where much of the verification is now done using computer simulations rather than physical prototype testing. CAE dependability is based upon all proper assumptions as inputs and must identify critical inputs, even though there have been many advances in CAE, and it is widely used in the engineering field, physical testing is still a must. It is used for verification and model updating, to accurately define loads and boundary conditions and this can expected to become a problem as modern products become ever more complex. They include smart systems, which leads to an increased need for multi-physics analysis including controls, CAE software companies and manufacturers are constantly looking for tools and process improvements to change this situation. On the software side, they are looking to develop more powerful solvers, better use computer resources and include engineering knowledge in pre-
29.
Finite element method
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The finite element method is a numerical method for solving problems of engineering and mathematical physics. It is also referred to as finite element analysis, typical problem areas of interest include structural analysis, heat transfer, fluid flow, mass transport, and electromagnetic potential. The analytical solution of these problems generally require the solution to boundary value problems for partial differential equations, the finite element method formulation of the problem results in a system of algebraic equations. The method yields approximate values of the unknowns at discrete number of points over the domain, to solve the problem, it subdivides a large problem into smaller, simpler parts that are called finite elements. The simple equations that model these finite elements are assembled into a larger system of equations that models the entire problem. FEM then uses variational methods from the calculus of variations to approximate a solution by minimizing an associated error function, the global system of equations has known solution techniques, and can be calculated from the initial values of the original problem to obtain a numerical answer. To explain the approximation in this process, FEM is commonly introduced as a case of Galerkin method. The process, in language, is to construct an integral of the inner product of the residual. In simple terms, it is a procedure that minimizes the error of approximation by fitting trial functions into the PDE, the residual is the error caused by the trial functions, and the weight functions are polynomial approximation functions that project the residual. These equation sets are the element equations and they are linear if the underlying PDE is linear, and vice versa. In step above, a system of equations is generated from the element equations through a transformation of coordinates from the subdomains local nodes to the domains global nodes. This spatial transformation includes appropriate orientation adjustments as applied in relation to the coordinate system. The process is carried out by FEM software using coordinate data generated from the subdomains. FEM is best understood from its application, known as finite element analysis. FEA as applied in engineering is a tool for performing engineering analysis. It includes the use of mesh generation techniques for dividing a complex problem into small elements, FEA is a good choice for analyzing problems over complicated domains, when the domain changes, when the desired precision varies over the entire domain, or when the solution lacks smoothness. For instance, in a crash simulation it is possible to increase prediction accuracy in important areas like the front of the car. Another example would be in weather prediction, where it is more important to have accurate predictions over developing highly nonlinear phenomena rather than relatively calm areas
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Computer-aided manufacturing
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Computer-aided manufacturing is the use of software to control machine tools and related ones in the manufacturing of workpieces. CAM is now a used in schools and lower educational purposes. CAM is used in schools alongside computer-aided design to create objects. Historically, CAM software was seen to have shortcomings that necessitated an overly high level of involvement by skilled CNC machinists. Fallows created the first CAD software but this had severe shortcomings and was taken back into the developing stage. CAM software would output code for the least capable machine, as machine tool control added on to the standard G-code set for increased flexibility. In some cases, such as set up CAM software or specific tools. None of these issues were so insurmountable that an engineer or skilled machine operator could not overcome for prototyping or small production runs. In high production or high precision shops, a different set of problems were encountered where an experienced CNC machinist must both hand-code programs and run CAM software, integration of CAD with other components of CAD/CAM/CAE Product lifecycle management environment requires an effective CAD data exchange. CAM packages could not, and still cannot, reason as a machinist can and they could not optimize toolpaths to the extent required of mass production. Users would select the type of tool, machining process and paths to be used, while an engineer may have a working knowledge of G-code programming, small optimization and wear issues compound over time. Mass-produced items that require machining are often created through casting or some other non-machine method. This enables hand-written, short, and highly optimized G-code that could not be produced in a CAM package. At least in the United States, there is a shortage of young, skilled machinists entering the workforce able to perform at the extremes of manufacturing, high precision and mass production. User confidence is built on 3D visualization through a closer integration with the 3D CAD environment. Manufacturing complexity The manufacturing environment is increasingly complex, the need for CAM and PLM tools by buMs are NC programmer or machinist is similar to the need for computer assistance by the pilot of modern aircraft systems. The modern machinery cannot be used without this assistance. Todays CAM systems support the range of machine tools including, turning,5 axis machining
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Numerical control
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Computer numerical control is the automation of machine tools by means of computers executing pre-programmed sequences of machine control commands. This is in contrast to machines that are controlled by hand wheels or levers. In modern CNC systems, the design of a mechanical part, the parts mechanical dimensions are defined using computer-aided design software, and then translated into manufacturing directives by computer-aided manufacturing software. The resulting directives are transformed into the specific commands necessary for a machine to produce the component. Since any particular component might require the use of a number of different tools – drills, saws, in other installations, a number of different machines are used with an external controller and human or robotic operators that move the component from machine to machine. In either case, the series of steps needed to produce any part is highly automated and produces a part that closely matches the original CAD design. The first NC machines were built in the 1940s and 1950s and these early servomechanisms were rapidly augmented with analog and digital computers, creating the modern CNC machine tools that have revolutionized the machining processes. Motion is controlled along multiple axes, normally at least two, and a spindle that moves in the Z. The position of the tool is driven by direct-drive stepper motor or servo motors in order to provide highly accurate movements, or in older designs, open-loop control works as long as the forces are kept small enough and speeds are not too great. On commercial metalworking machines, closed loop controls are standard and required in order to provide the accuracy, speed, as the controller hardware evolved, the mills themselves also evolved. Most new CNC systems built today are 100% electronically controlled, cNC-like systems are now used for any process that can be described as a series of movements and operations. CNC mills use computer controls to cut different materials and they are able to translate programs consisting of specific numbers and letters to move the spindle to various locations and depths. Many use G-code, which is a programming language that many CNC machines understand. These proprietary languages, while often simpler than G-code, are not transferable to other machines, CNC mills have many functions including face milling, shoulder milling, tapping, drilling and some even offer turning. Standard linear CNC mills are limited to 3 axis, but others may also have one or more rotational axes, today, CNC mills can have 4 to 6 axes. Lathes are machines that cut workpieces while they are rotated, CNC lathes are able to make fast, precision cuts, generally using indexable tools and drills. They are particularly effective for complicated programs designed to make parts that would be infeasible to make on manual lathes, CNC lathes have similar control specifications to CNC mills and can often read G-code as well as the manufacturers proprietary programming language. CNC lathes generally have two axes, but newer models have more axes, allowing for more advanced jobs to be machined, plasma cutting involves cutting a material using a plasma torch
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Unbiased rendering
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In computer graphics, unbiased rendering refers to a rendering technique that does not introduce any systematic error, or bias, into the radiance approximation. Because of this, it is used to generate the reference image to which other rendering techniques are compared. Mathematically speaking, the value of the unbiased estimator will always be the population mean. Error found in an unbiased rendering will be due to variance, variance is reduced by n and standard deviation by n for n data points, meaning that four times as many data points are needed to halve the standard deviation of the error. This makes unbiased rendering techniques less attractive for realtime or interactive rate applications, conversely, an image produced by an unbiased renderer that appears smooth and noiseless is probabilistically correct. A biased rendering method is not necessarily wrong, and it can still converge to the answer if the estimator is consistent. It does, however, introduce a certain bias error, usually in the form of a blur and it is important to note that an unbiased technique may not consider all possible paths. Path tracing can not consistently handle caustics generated from a point light source, progressive photon mapping, a biased rendering technique, can handle caustics quite well. Although biased, PPM is provably consistent, meaning that as the number of samples goes to infinity, the error goes to zero
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Version control
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Changes are usually identified by a number or letter code, termed the revision number, revision level, or simply revision. For example, an set of files is revision 1. When the first change is made, the set is revision 2. Each revision is associated with a timestamp and the making the change. Revisions can be compared, restored, and with some types of files, the numbering of book editions and of specification revisions are examples that date back to the print-only era. Today, the most capable revision control systems are used in software development. Software tools for revision control are essential for the organization of multi-developer projects, in computer software engineering, revision control is any kind of practice that tracks and provides control over changes to source code. Software developers sometimes use revision control software to maintain documentation and configuration files as well as source code, bugs or features of the software are often only present in certain versions. Therefore, for the purposes of locating and fixing bugs, it is important to be able to retrieve. At the simplest level, developers could simply retain multiple copies of the different versions of the program and this simple approach has been used on many large software projects. While this method can work, it is inefficient as many copies of the program have to be maintained. This requires a lot of self-discipline on the part of developers, consequently, systems to automate some or all of the revision control process have been developed. This ensures that the majority of management of version control steps is hidden behind the scenes, sophisticated revision control that tracks and accounts for ownership of changes to documents and code may be extremely helpful or even indispensable in such situations. Revision control may also track changes to files, such as those typically stored in /etc or /usr/local/etc on Unix systems. This gives system administrators another way to track changes made. Revision control manages changes to a set of data over time and these changes can be structured in various ways. Often the data is thought of as a collection of individual items, such as files or documents. This accords with intuitions about separate files, but causes problems when identity changes, such as during renaming, splitting, or merging of files
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Wire-frame model
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A wire-frame model is a visual presentation of a 3-dimensional or physical object used in 3D computer graphics. It is created by specifying each edge of the object where two mathematically continuous smooth surfaces meet, or by connecting an objects constituent vertices using straight lines or curves. The object is projected into space by drawing lines at the location of each edge. The term wire frame comes from designers using metal wire to represent the shape of solid objects. 3D wire frame allows to construct and manipulate solids and solid surfaces, the 3D solid modeling technique efficiently draws higher quality representations of solids than the conventional line drawing. Using a wire-frame model allows visualization of the design structure of a 3D model. Traditional two-dimensional views and drawings can be created by appropriate rotation of the object, since wire-frame renderings are relatively simple and fast to calculate, they are often used in cases where a high screen frame rate is needed. When greater graphical detail is desired, surface textures can be added automatically after completion of the rendering of the wire frame. This allows the designer to quickly review solids or rotate the object to new desired views without long delays associated with more realistic rendering, the wire frame format is also well suited and widely used in programming tool paths for direct numerical control machine tools. Hand-drawn wire-frame-like illustrations date back as far as the Italian Renaissance, wire-frame models are also used as the input for computer-aided manufacturing. There are mainly three types of 3D CAD models, wire frame is one of them and it is the most abstract and least realistic. Other types of 3D CAD models are surface and solid and this method of modelling consists of only lines, points and curves defining the edges of an object. Wireframing is one of the used in geometric modelling systems. A wireframe model represents the shape of an object with its characteristic lines. There are two types of modelling, Pros and Cons. In Pros user gives a simple input to create a shape and it is useful in developing systems. While in Cons wireframe model, it does not include information about inside and outside boundary surfaces, today, wireframe models are used to define complex solid objects. The designer makes a model of a solid object, and then the CAD operator reconstructs the object
Learning materials related to Computer-aided Geometric Design at Wikiversity
Media related to Computer-aided design at Wikimedia Commons
The dictionary definition of computer-aided design at Wiktionary
