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35-474: It descends from the approach used in the System/360 mainframe family of computers, in which the members of the family were intended for use in many varied user applications. (This is expressed in the name: there are 4 π steradians in a sphere, just as there are 360 degrees in a circle.) Previously, custom computers had been designed for each aerospace application, which was extremely costly. In 1967,

70-656: A backwards compatible MMP with 158 instructions or the MIL-STD-1750A architecture with 243 instructions. It was based on the AP-101F used in the B-1B. The AP-101S/G was an interim processor. The AP-101B performance was 0.420 MIPS , while the AP-101S was 1.27 MIPS. James E. Tomayko, who was contracted by NASA to write a history of computers in spaceflight, has said: "It was available in basically its present form when NASA

105-613: A boiler, a cold reservoir (a stream of cold water), or a piston (on which the working body could do work by pushing on it). In 1850, the German physicist Rudolf Clausius generalized this picture to include the concept of the surroundings and began to use the term working body when referring to the system. The biologist Ludwig von Bertalanffy became one of the pioneers of the general systems theory . In 1945 he introduced models, principles, and laws that apply to generalized systems or their subclasses, irrespective of their particular kind,

140-612: A critical failure of the prime. A total of twelve were delivered to NASA by 1972. Two were flown on Skylab in 1973-1974; the others were used for testing and mission simulators. The software management effort was led by Harlan Mills and Fred Brooks . The Skylab flight software development process incorporated many lessons learned during the IBM System/360 Operating System project, as described in Brooks' 1975 book The Mythical Man-Month . The AP-101 , being

175-444: A major defect: they must be premised on one or more fundamental assumptions upon which additional knowledge is built. This is in strict alignment with Gödel's incompleteness theorems . The Artificial system can be defined as a "consistent formalized system which contains elementary arithmetic". These fundamental assumptions are not inherently deleterious, but they must by definition be assumed as true, and if they are actually false then

210-682: A single subsystem in order to test its Specific Application (SA). There are many kinds of systems that can be analyzed both quantitatively and qualitatively . For example, in an analysis of urban systems dynamics , A . W. Steiss defined five intersecting systems, including the physical subsystem and behavioral system. For sociological models influenced by systems theory, Kenneth D. Bailey defined systems in terms of conceptual , concrete , and abstract systems, either isolated , closed , or open . Walter F. Buckley defined systems in sociology in terms of mechanical , organic , and process models . Bela H. Banathy cautioned that for any inquiry into

245-670: A system is the Universe . An open system can also be viewed as a bounded transformation process, that is, a black box that is a process or collection of processes that transform inputs into outputs. Inputs are consumed; outputs are produced. The concept of input and output here is very broad. For example, an output of a passenger ship is the movement of people from departure to destination. A system comprises multiple views . Human-made systems may have such views as concept, analysis , design , implementation , deployment, structure, behavior, input data, and output data views. A system model

280-588: A system understanding its kind is crucial, and defined natural and designed , i. e. artificial, systems. For example, natural systems include subatomic systems, living systems , the Solar System , galaxies , and the Universe , while artificial systems include man-made physical structures, hybrids of natural and artificial systems, and conceptual knowledge. The human elements of organization and functions are emphasized with their relevant abstract systems and representations. Artificial systems inherently have

315-456: Is George Boole 's Boolean operators. Other examples relate specifically to philosophy, biology, or cognitive science. Maslow's hierarchy of needs applies psychology to biology by using pure logic. Numerous psychologists, including Carl Jung and Sigmund Freud developed systems that logically organize psychological domains, such as personalities, motivations, or intellect and desire. In 1988, military strategist, John A. Warden III introduced

350-546: Is a hardware system, software system , or combination, which has components as its structure and observable inter-process communications as its behavior. There are systems of counting, as with Roman numerals , and various systems for filing papers, or catalogs, and various library systems, of which the Dewey Decimal Classification is an example. This still fits with the definition of components that are connected together (in this case to facilitate

385-447: Is required to describe and represent all these views. A systems architecture, using one single integrated model for the description of multiple views, is a kind of system model. A subsystem is a set of elements, which is a system itself, and a component of a larger system. The IBM Mainframe Job Entry Subsystem family ( JES1 , JES2 , JES3 , and their HASP / ASP predecessors) are examples. The main elements they have in common are

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420-656: The Five Ring System model in his book, The Air Campaign , contending that any complex system could be broken down into five concentric rings. Each ring—leadership, processes, infrastructure, population and action units—could be used to isolate key elements of any system that needed change. The model was used effectively by Air Force planners in the Iran–Iraq War . In the late 1990s, Warden applied his model to business strategy. Guidance, navigation and control Too Many Requests If you report this error to

455-499: The environment . One can make simplified representations ( models ) of the system in order to understand it and to predict or impact its future behavior. These models may define the structure and behavior of the system. There are natural and human-made (designed) systems. Natural systems may not have an apparent objective but their behavior can be interpreted as purposeful by an observer. Human-made systems are made with various purposes that are achieved by some action performed by or with

490-512: The program status word register, allowing a directly addressable memory range of 1 M locations. This avionics computer has been used in the U.S. Space Shuttle , the B-52 and B-1B bombers, and other aircraft. It remained in service on the Space Shuttle because it worked, was flight-certified, and developing a new system would have been too expensive. There were a number of variants of

525-567: The AP101. The Offensive Avionics System, a retrofit update of the B-52, contains two AP-101C computers. The AP-101C prototypes were delivered in 1978. The B-1B employs a network of eight model AP-101F computers. The Space Shuttle used two variants of the AP-101: the earlier AP-101B and the upgraded AP-101S. The AP-101B was used for a series of Approach and Landing Tests in 1977. The first ascent to orbit

560-472: The French physicist Nicolas Léonard Sadi Carnot , who studied thermodynamics , pioneered the development of the concept of a system in the natural sciences . In 1824, he studied the system which he called the working substance (typically a body of water vapor) in steam engines , in regard to the system's ability to do work when heat is applied to it. The working substance could be put in contact with either

595-494: The Space Shuttle had magnetic-core memory . The upgrade to the AP-101S in the early 1990s replaced the core with semiconductor memory and reduced the size from two to one chassis. It was augmented by glass cockpit technology. Both variants use a microprogram to define the instruction set architecture. The early AP-101 variants used IBM'S Multipurpose Midline Processor (MMP) architecture. The AP-101B microprogram implemented MMP with 154 instructions. The AP101S could operate with

630-464: The System/4 Pi family consisted of these basic models: The Skylab space station employed the model TC-1, which had a 16-bit word length and 16,384 words of memory with a custom input/output assembly. Skylab had two, redundant, TC-1 computers: a prime (energized) and a backup (non energized.) There would be an automatic switchover (taking on the order of one second) to the backup in the event of

665-462: The allocation and scarcity of resources. The international sphere of interacting states is described and analyzed in systems terms by several international relations scholars, most notably in the neorealist school . This systems mode of international analysis has however been challenged by other schools of international relations thought, most notably the constructivist school , which argues that an over-large focus on systems and structures can obscure

700-461: The components that handle input, scheduling, spooling and output; they also have the ability to interact with local and remote operators. A subsystem description is a system object that contains information defining the characteristics of an operating environment controlled by the system. The data tests are performed to verify the correctness of the individual subsystem configuration data (e.g. MA Length, Static Speed Profile, …) and they are related to

735-399: The distinction between them is often elusive. An economic system is a social institution which deals with the production , distribution and consumption of goods and services in a particular society . The economic system is composed of people , institutions and their relationships to resources, such as the convention of property . It addresses the problems of economics , like

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770-404: The flow of information). System can also refer to a framework, aka platform , be it software or hardware, designed to allow software programs to run. A flaw in a component or system can cause the component itself or an entire system to fail to perform its required function, e.g., an incorrect statement or data definition . In engineering and physics , a physical system is the portion of

805-409: The nature of their component elements, and the relation or 'forces' between them. In the late 1940s and mid-50s, Norbert Wiener and Ross Ashby pioneered the use of mathematics to study systems of control and communication , calling it cybernetics . In the 1960s, Marshall McLuhan applied general systems theory in an approach that he called a field approach and figure/ground analysis , to

840-464: The notion of organizations as systems in his book The Fifth Discipline . Organizational theorists such as Margaret Wheatley have also described the workings of organizational systems in new metaphoric contexts, such as quantum physics , chaos theory , and the self-organization of systems . There is also such a thing as a logical system . An obvious example is the calculus developed simultaneously by Leibniz and Isaac Newton . Another example

875-405: The role of individual agency in social interactions. Systems-based models of international relations also underlie the vision of the international sphere held by the liberal institutionalist school of thought, which places more emphasis on systems generated by rules and interaction governance, particularly economic governance. In computer science and information science , an information system

910-407: The study of media theory . In the 1980s, John Henry Holland , Murray Gell-Mann and others coined the term complex adaptive system at the interdisciplinary Santa Fe Institute . Systems theory views the world as a complex system of interconnected parts. One scopes a system by defining its boundary ; this means choosing which entities are inside the system and which are outside—part of

945-459: The subjects of study of systems theory and other systems sciences . Systems have several common properties and characteristics, including structure, function(s), behavior and interconnectivity. The term system comes from the Latin word systēma , in turn from Greek σύστημα systēma : "whole concept made of several parts or members, system", literary "composition". In the 19th century,

980-1207: The system is not as structurally integral as is assumed (i.e. it is evident that if the initial expression is false, then the artificial system is not a "consistent formalized system"). For example, in geometry this is very evident in the postulation of theorems and extrapolation of proofs from them. George J. Klir maintained that no "classification is complete and perfect for all purposes", and defined systems as abstract, real, and conceptual physical systems , bounded and unbounded systems , discrete to continuous, pulse to hybrid systems , etc. The interactions between systems and their environments are categorized as relatively closed and open systems . Important distinctions have also been made between hard systems—–technical in nature and amenable to methods such as systems engineering , operations research, and quantitative systems analysis—and soft systems that involve people and organizations, commonly associated with concepts developed by Peter Checkland and Brian Wilson through soft systems methodology (SSM) involving methods such as action research and emphasis of participatory designs. Where hard systems might be identified as more scientific ,

1015-527: The system. The parts of a system must be related; they must be "designed to work as a coherent entity"—otherwise they would be two or more distinct systems. Most systems are open systems , exchanging matter and energy with their respective surroundings; like a car, a coffeemaker , or Earth . A closed system exchanges energy, but not matter, with its environment; like a computer or the project Biosphere 2 . An isolated system exchanges neither matter nor energy with its environment. A theoretical example of such

1050-593: The top-of-the-line of the System/4 Pi range, shares its general architecture with the System/360 mainframes . It is a repackaged version of the IBM Advanced Processor-1 (AP-1) used in the F-15 fighter. The AP-1 prototypes were delivered in 1971 and the AP-101 in 1973. It has 16 32-bit registers . Originally only 16 bits were available for addressing memory; later this was extended with four bits from

1085-1003: The universe that is being studied (of which a thermodynamic system is one major example). Engineering also has the concept of a system referring to all of the parts and interactions between parts of a complex project. Systems engineering is the branch of engineering that studies how this type of system should be planned, designed, implemented, built, and maintained. Social and cognitive sciences recognize systems in models of individual humans and in human societies. They include human brain functions and mental processes as well as normative ethics systems and social and cultural behavioral patterns. In management science , operations research and organizational development , human organizations are viewed as management systems of interacting components such as subsystems or system aggregates, which are carriers of numerous complex business processes ( organizational behaviors ) and organizational structures. Organizational development theorist Peter Senge developed

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1120-537: Was first used in the F-117A Stealth Fighter . It was upgraded to the AP-102A in the early 1990s. System A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment , is described by its boundaries, structure and purpose and is expressed in its functioning. Systems are

1155-508: Was in 1981. The AP-101S first launched in 2000 . Each AP-101 on the Shuttle was coupled with an input-output processor (IOP), consisting of one Master Sequence Controller (MSC) and 24 Bus Control Elements (BCEs). The MSC and BCEs executed programs from the same memory system as the main CPU, offloading control of the Shuttle's serial data bus system from the CPU. The AP-101B originally used in

1190-443: Was specifying requirements for the shuttle contracts in the 1970s. As such, it represents the first manned spacecraft computer system with hardware intentionally behind the state of the art." The Space Shuttle used five AP-101 computers as General-Purpose Computers (GPCs). Four operated in sync, for redundancy, while the fifth was a backup running software written independently. The Shuttle's guidance, navigation and control software

1225-563: Was written in HAL/S , a special-purpose high-level programming language , while much of the operating system and low-level utility software was written in assembly language . AP-101s used by the US Air Force are mostly programmed in JOVIAL , such as the system found on the B-1B bomber. The AP-102 variant design began in 1984. It is a MIL-STD-1750A standard instruction set architecture. It

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