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46-764: In October 1942, the contract for two prototypes , designated "XP-75", was signed with the Fisher Body Division of GM. The design concept was to use the outer wing panels from the North American P-51 Mustang , the tail assembly from the Douglas A-24 (SBD) , and the undercarriage from the Vought F4U Corsair in a general layout much as in the Bell P-39 Airacobra with the engine located amidships with

92-639: A mockup , which is an inert representation of a machine's appearance, often made of some non-durable substance. An electronics designer often builds the first prototype from breadboard or stripboard or perfboard , typically using "DIP" packages. However, more and more often the first functional prototype is built on a "prototype PCB " almost identical to the production PCB, as PCB manufacturing prices fall and as many components are not available in DIP packages, but only available in SMT packages optimized for placing on

138-626: A second (thus defining the speed of light to be 299,792,458 meters per second). In many sciences, from pathology to taxonomy, prototype refers to a disease, species, etc. which sets a good example for the whole category. In biology, prototype is the ancestral or primitive form of a species or other group; an archetype. For example, the Senegal bichir is regarded as the prototypes of its genus, Polypterus . Formal specification In computer science , formal specifications are mathematically based techniques whose purpose are to help with

184-450: A specification , it is possible to use formal verification techniques to demonstrate that a system design is correct with respect to its specification. This allows incorrect system designs to be revised before any major investments have been made into an actual implementation. Another approach is to use probably correct refinement steps to transform a specification into a design, which is ultimately transformed into an implementation that

230-425: A PCB. Builders of military machines and aviation prefer the terms "experimental" and "service test". In electronics , prototyping means building an actual circuit to a theoretical design to verify that it works, and to provide a physical platform for debugging it if it does not. The prototype is often constructed using techniques such as wire wrapping or using a breadboard , stripboard or perfboard , with

276-596: A V-3420-23 engine that corrected most of the deficiencies by the time the first P-75A Eagles entered flight testing in September 1944. By this time, the Army Air Forces had decided to limit the number of combat aircraft types in production and not enter into large-scale production of new types that might not be available before the war ended. As the twin-engine Lockheed P-38 Lightning and North American P-51 Mustang demonstrated excellent long-range capabilities,

322-529: A favorite among US Military modelers), railroad equipment, motor trucks, motorcycles, and space-ships (real-world such as Apollo/Saturn Vs, or the ISS). As of 2014, basic rapid prototype machines (such as 3D printers ) cost about $ 2,000, but larger and more precise machines can cost as much as $ 500,000. In architecture , prototyping refers to either architectural model making (as form of scale modelling ) or as part of aesthetic or material experimentation , such as

368-469: A given specification”. Whether the formal specification correctly describes the problem to be solved is a separate issue. It is also a difficult issue to address since it ultimately concerns the problem constructing abstracted formal representations of an informal concrete problem domain , and such an abstraction step is not amenable to formal proof. However, it is possible to validate a specification by proving “challenge” theorems concerning properties that

414-492: A result, they have become more impactful to society. Because of this, better techniques are needed to assist in the design and implementation of reliable software. Established engineering disciplines use mathematical analysis as the foundation of creating and validating product design. Formal specifications are one such way to achieve this in software engineering reliability as once predicted. Other methods such as testing are more commonly used to enhance code quality. Given such

460-499: A time to the initial prototype. In many programming languages , a function prototype is the declaration of a subroutine or function (and should not be confused with software prototyping). This term is rather C / C++ -specific; other terms for this notion are signature , type and interface . In prototype-based programming (a form of object-oriented programming ), new objects are produced by cloning existing objects, which are called prototypes. The term may also refer to

506-429: A variety of reasons, some of which are: Other limitations: Formal specification techniques have existed in various domains and on various scales for quite some time. Implementations of formal specifications will differ depending on what kind of system they are attempting to model, how they are applied and at what point in the software life cycle they have been introduced. These types of models can be categorized into

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552-472: A way that the Planck constant h is prescribed a value of exactly 6.626 070 15 × 10  joule-second (J⋅s) Until 1960, the meter was defined by a platinum-iridium prototype bar with two marks on it (that were, by definition, spaced apart by one meter), the international prototype of the metre , and in 1983 the meter was redefined to be the distance in free space covered by light in 1/299,792,458 of

598-450: Is correct by construction . It is important to note that a formal specification is not an implementation, but rather it may be used to develop an implementation . Formal specifications describe what a system should do, not how the system should do it. A good specification must have some of the following attributes: adequate, internally consistent, unambiguous, complete, satisfied, minimal. A good specification will have: One of

644-518: Is a form of functional or working prototype. The justification for its creation is usually a data migration , data integration or application implementation project and the raw materials used as input are an instance of all the relevant data which exists at the start of the project. The objectives of data prototyping are to produce: To achieve this, a data architect uses a graphical interface to interactively develop and execute transformation and cleansing rules using raw data. The resultant data

690-517: Is becoming practical to eliminate the creation of a physical prototype (except possibly at greatly reduced scales for promotional purposes), instead modeling all aspects of the final product as a computer model . An example of such a development can be seen in Boeing 787 Dreamliner , in which the first full sized physical realization is made on the series production line. Computer modeling is now being extensively used in automotive design, both for form (in

736-421: Is generally used to evaluate a new design to enhance precision by system analysts and users. Prototyping serves to provide specifications for a real, working system rather than a theoretical one. Physical prototyping has a long history, and paper prototyping and virtual prototyping now extensively complement it. In some design workflow models, creating a prototype (a process sometimes called materialization )

782-431: Is possible that a prototype may fail to perform acceptably although the production design may have been sound. Conversely, prototypes may perform acceptably but the production design and outcome may prove unsuccessful. In general, it can be expected that individual prototype costs will be substantially greater than the final production costs due to inefficiencies in materials and processes. Prototypes are also used to revise

828-405: Is the step between the formalization and the evaluation of an idea. A prototype can also mean a typical example of something such as in the use of the derivation ' prototypical '. This is a useful term in identifying objects, behaviours and concepts which are considered the accepted norm and is analogous with terms such as stereotypes and archetypes . The word prototype derives from

874-414: Is then evaluated and the rules refined. Beyond the obvious visual checking of the data on-screen by the data architect, the usual evaluation and validation approaches are to use Data profiling software and then to insert the resultant data into a test version of the target application and trial its use. When developing software or digital tools that humans interact with, a prototype is an artifact that

920-499: Is used as the standard of measurement of some physical quantity to base all measurement of that physical quantity against. Sometimes this standard object is called an artifact . In the International System of Units ( SI ), there remains no prototype standard since May 20, 2019 . Before that date, the last prototype used was the international prototype of the kilogram , a solid platinum-iridium cylinder kept at

966-409: Is used to ask and answer a design question. Prototypes provide the means for examining design problems and evaluating solutions. HCI practitioners can employ several different types of prototypes: In the field of scale modeling (which includes model railroading , vehicle modeling, airplane modeling , military modeling, etc.), a prototype is the real-world basis or source for a scale model—such as

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1012-594: The Bureau International des Poids et Mesures (International Bureau of Weights and Measures) in Sèvres France (a suburb of Paris ) that by definition was the mass of exactly one kilogram . Copies of this prototype are fashioned and issued to many nations to represent the national standard of the kilogram and are periodically compared to the Paris prototype. Now the kilogram is redefined in such

1058-528: The Forty Wall House open source material prototyping centre in Australia. Architects prototype to test ideas structurally, aesthetically and technically. Whether the prototype works or not is not the primary focus: architectural prototyping is the revelatory process through which the architect gains insight. In the science and practice of metrology , a prototype is a human-made object that

1104-589: The Greek πρωτότυπον prototypon , "primitive form", neutral of πρωτότυπος prototypos , "original, primitive", from πρῶτος protos , "first" and τύπος typos , "impression" (originally in the sense of a mark left by a blow, then by a stamp struck by a die (note "typewriter"); by implication a scar or mark; by analogy a shape i.e. a statue, (figuratively) style, or resemblance; a model for imitation or illustrative example—note "typical"). Prototypes explore different aspects of an intended design: In general,

1150-536: The Prototype Javascript Framework . Additionally, the term may refer to the prototype design pattern. Continuous learning approaches within organizations or businesses may also use the concept of business or process prototypes through software models. The concept of prototypicality is used to describe how much a website deviates from the expected norm, and leads to a lowering of user preference for that site's design. A data prototype

1196-480: The contra-rotating propellers driven through extension shafts. At an early design stage, however, Curtiss P-40 Warhawk outer wing panels were substituted for the P-51 panels. In mid-1943, the need for long-range escort fighters became more urgent than fast climbing interceptors so a decision was made to order six more XP-75 airplanes modified for the long-range role. At this time, an order for 2,500 production aircraft

1242-421: The styling and aerodynamics of the vehicle) and in function—especially for improving vehicle crashworthiness and in weight reduction to improve mileage. The most common use of the word prototype is a functional, although experimental, version of a non-military machine (e.g., automobiles, domestic appliances, consumer electronics) whose designers would like to have built by mass production means, as opposed to

1288-592: The P-75 project being a "high-priority" project to help GM avoid the added strain of Superfortress production. The "Eagle" was given extensive media coverage prior to its first flight, being trumpeted as a "wonder plane". Powered by a V-3420-19 24-cylinder engine rated at 2,600 hp (1,900 kW) driving co-axial contra-rotating propellers , the XP-75 flew for the first time on 17 November 1943. The second XP-75 flew shortly thereafter, with all six long-range XP-75s entering

1334-572: The Second World War, Volume Four: Fighters and WW2 Aircraft Fact Files: US Army Air Force Fighters, Part 2 General characteristics Performance Armament Aircraft of comparable role, configuration, and era Related lists Prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics , design , electronics , and software programming . A prototype

1380-404: The creation of prototypes will differ from creation of the final product in some fundamental ways: Engineers and prototype specialists attempt to minimize the impact of these differences on the intended role for the prototype. For example, if a visual prototype is not able to use the same materials as the final product, they will attempt to substitute materials with properties that closely simulate

1426-407: The cycle returns to customer evaluation. The cycle starts by listening to the user, followed by building or revising a mock-up, and letting the user test the mock-up , then back. There is now a new generation of tools called Application Simulation Software which help quickly simulate application before their development. Extreme programming uses iterative design to gradually add one feature at

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1472-403: The design for the purposes of reducing costs through optimization and refinement. It is possible to use prototype testing to reduce the risk that a design may not perform as intended, however prototypes generally cannot eliminate all risk. Building the full design is often expensive and can be time-consuming, especially when repeated several times—building the full design, figuring out what

1518-415: The following specification paradigms: In addition to the above paradigms, there are ways to apply certain heuristics to help improve the creation of these specifications. The paper referenced here best discusses heuristics to use when designing a specification. They do so by applying a divide-and-conquer approach. The Z notation is an example of a leading formal specification language . Others include

1564-508: The full design. In technology research, a technology demonstrator is a prototype serving as proof-of-concept and demonstration model for a new technology or future product, proving its viability and illustrating conceivable applications. In large development projects, a testbed is a platform and prototype development environment for rigorous experimentation and testing of new technologies, components, scientific theories and computational tools. With recent advances in computer modeling it

1610-480: The implementation of systems and software. They are used to describe a system, to analyze its behavior, and to aid in its design by verifying key properties of interest through rigorous and effective reasoning tools. These specifications are formal in the sense that they have a syntax, their semantics fall within one domain, and they are able to be used to infer useful information. In each passing decade, computer systems have become increasingly more powerful and, as

1656-437: The intended final materials. Engineers and prototyping specialists seek to understand the limitations of prototypes to exactly simulate the characteristics of their intended design. Prototypes represent some compromise from the final production design. This is due to the skill and choices of the designer(s), and the inevitable inherent limitations of a prototype. Due to differences in materials, processes and design fidelity, it

1702-407: The main reasons there is interest in formal specifications is that they will provide an ability to perform proofs on software implementations. These proofs may be used to validate a specification, verify correctness of design, or to prove that a program satisfies a specification. A design (or implementation) cannot ever be declared “correct” on its own. It can only ever be “correct with respect to

1748-429: The problems are and how to solve them, then building another full design. As an alternative, rapid prototyping or rapid application development techniques are used for the initial prototypes, which implement part, but not all, of the complete design. This allows designers and manufacturers to rapidly and inexpensively test the parts of the design that are most likely to have problems, solve those problems, and then build

1794-585: The production run of the P-75A Eagle was subsequently terminated on 6 October 1944. It was decided to use the six completed production aircraft for experimental work and development of the V-3420 engine. As a result of those events, the P-75A did not complete formal performance trials due to termination of the production contract. Ultimately, only eight XP-75s and six P-75As were built. Data from War Planes of

1840-411: The prototyping platform, or replace it with only the microcontroller chip and the circuitry that is relevant to their product. Prototype software is often referred to as alpha grade , meaning it is the first version to run. Often only a few functions are implemented, the primary focus of the alpha is to have a functional base code on to which features may be added. Once alpha grade software has most of

1886-438: The real EMD GP38-2 locomotive—which is the prototype of Athearn 's (among other manufacturers) locomotive model. Technically, any non-living object can serve as a prototype for a model, including structures, equipment, and appliances, and so on, but generally prototypes have come to mean full-size real-world vehicles including automobiles (the prototype 1957 Chevy has spawned many models), military equipment (such as M4 Shermans,

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1932-463: The required features integrated into it, it becomes beta software for testing of the entire software and to adjust the program to respond correctly during situations unforeseen during development. Often the end users may not be able to provide a complete set of application objectives, detailed input, processing, or output requirements in the initial stage. After the user evaluation, another prototype will be built based on feedback from users, and again

1978-459: The result being a circuit that is electrically identical to the design but not physically identical to the final product. Open-source tools like Fritzing exist to document electronic prototypes (especially the breadboard-based ones) and move toward physical production. Prototyping platforms such as Arduino also simplify the task of programming and interacting with a microcontroller . The developer can choose to deploy their invention as-is using

2024-550: The specification is expected to exhibit. If correct, these theorems reinforce the specifier's understanding of the specification and its relationship with the underlying problem domain. If not, the specification probably needs to be changed to better reflect the domain understanding of those involved with producing (and implementing) the specification. Formal methods of software development are not widely used in industry. Most companies do not consider it cost-effective to apply them in their software development processes. This may be for

2070-416: The test program by the spring 1944. The test program brought up numerous teething problems, including miscalculation of the fighter's center of mass , failure of the engine to produce its expected power, inadequate engine cooling, high aileron forces at high speed, and poor spin characteristics. Redesigns were introduced into the long-range XP-75s including a modified tail assembly, new "bubble" canopy, and

2116-521: Was also let, but with the stipulation that if the first P-75A was not satisfactory the complete order might be canceled. At the time, General Motors was busy in several projects towards the war effort, including the mass production of several different aircraft types, among them the Grumman TBF Avenger . Some sources claim that the P-75 was the result of a scheme to get General Motors out of being forced to build Boeing B-29 Superfortresses ;

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