|
Distributed Operating System
A distributed operating system is system software over a collection of independent software, networked, communicating, and physically separate computational nodes. They handle jobs which are serviced by multiple CPUs. Each individual node holds a specific software subset of the global aggregate operating system. Each subset is a composite of two distinct service provisioners. The first is a ubiquitous minimal kernel, or microkernel, that directly controls that node's hardware. Second is a higher-level collection of ''system management components'' that coordinate the node's individual and collaborative activities. These components abstract microkernel functions and support user applications. The microkernel and the management components collection work together. They support the system's goal of integrating multiple resources and processing functionality into an efficient and stable system. This seamless integration of individual nodes into a global system is referred to as ''trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies, based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies. The nodes of a computer network can include personal computers, servers, networking hardware, or other specialised or general-purpose hosts. They are identified by network addresses, and may have hostnames. Hostnames serve as memorable labels for the nodes, rarely changed after initial assignment. Network addresses serve for locating and identifying the nodes by communication protocols such as the Internet Protocol. Computer networks may be classified by many criteria, including the transmission medium used to carry signals, bandwidth, communications pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiprocessing
Multiprocessing is the use of two or more central processing units (CPUs) within a single computer system. The term also refers to the ability of a system to support more than one processor or the ability to allocate tasks between them. There are many variations on this basic theme, and the definition of multiprocessing can vary with context, mostly as a function of how CPUs are defined ( multiple cores on one die, multiple dies in one package, multiple packages in one system unit, etc.). According to some on-line dictionaries, a multiprocessor is a computer system having two or more processing units (multiple processors) each sharing main memory and peripherals, in order to simultaneously process programs. A 2009 textbook defined multiprocessor system similarly, but noting that the processors may share "some or all of the system’s memory and I/O facilities"; it also gave tightly coupled system as a synonymous term. At the operating system level, ''multiprocessing'' is somet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Program Counter
The program counter (PC), commonly called the instruction pointer (IP) in Intel x86 and Itanium microprocessors, and sometimes called the instruction address register (IAR), the instruction counter, or just part of the instruction sequencer, is a processor register that indicates where a computer is in its program sequence. Usually, the PC is incremented after fetching an instruction, and holds the memory address of ("points to") the next instruction that would be executed. Processors usually fetch instructions sequentially from memory, but ''control transfer'' instructions change the sequence by placing a new value in the PC. These include branches (sometimes called jumps), subroutine calls, and returns. A transfer that is conditional on the truth of some assertion lets the computer follow a different sequence under different conditions. A branch provides that the next instruction is fetched from elsewhere in memory. A subroutine call not only branches but saves the prece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiprogramming
In computing, multitasking is the concurrent execution of multiple tasks (also known as processes) over a certain period of time. New tasks can interrupt already started ones before they finish, instead of waiting for them to end. As a result, a computer executes segments of multiple tasks in an interleaved manner, while the tasks share common processing resources such as central processing units (CPUs) and main memory. Multitasking automatically interrupts the running program, saving its state (partial results, memory contents and computer register contents) and loading the saved state of another program and transferring control to it. This "context switch" may be initiated at fixed time intervals ( pre-emptive multitasking), or the running program may be coded to signal to the supervisory software when it can be interrupted ( cooperative multitasking). Multitasking does not require parallel execution of multiple tasks at exactly the same time; instead, it allows more than o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lincoln TX-2
The MIT Lincoln Laboratory TX-2 computer was the successor to the Lincoln TX-0 and was known for its role in advancing both artificial intelligence and human–computer interaction. Wesley A. Clark was the chief architect of the TX-2. Specifications The TX-2 was a transistor-based computer using the then-huge amount of 64 K 36-bit words of magnetic-core memory. The TX-2 became operational in 1958. Because of its powerful capabilities, Ivan Sutherland's revolutionary Sketchpad program was developed for and ran on the TX-2. One of its key features was the ability to directly interact with the computer through a graphical display. The compiler was developed by Lawrence Roberts while he was studying at the MIT Lincoln Laboratory. Relationship with DEC Digital Equipment Corporation was a spin-off of the TX-0 and TX-2 projects. The TX-2 Tape System was a block addressable 1/2" tape developed for the TX-2 by Tom Stockebrand which evolved into LINCtape and DECtape. Role ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refrigerator Truck
A refrigerator truck or chiller lorry (also called a Reefer), is a van or truck designed to carry perishable freight at low temperatures. Most long-distance refrigerated transport by truck is done in articulated trucks pulling refrigerated semi-trailers. Sometimes they are used to carry dead human beings. History The first successful mechanically refrigerated trucks were made for the ice cream industry in 1925. African American inventor Frederick McKinley Jones later contributed to the field. There were around 4 million refrigerated road vehicles in use in 2010 worldwide. Features Like refrigerator cars, refrigerated trucks differ from simple Thermal insulation, insulated and Ventilation (architecture), ventilated vans (commonly used for transporting fruit), neither of which are fitted with cooling apparatus. Refrigerator trucks can be ice-cooled, equipped with any one of a variety of mechanical refrigeration systems powered by small displacement diesel engines, or utiliz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tractor-trailer
A semi-trailer truck, also known as a semitruck, (or semi, eighteen-wheeler, big rig, tractor-trailer or, by synecdoche, a semitrailer) is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a type of hitch called a fifth wheel. Regional configurations Europe The noticeable difference between tractor units in Europe and North America is that almost all European models are cab over engine (called "forward control" in the UK), while the majority of North American trucks are "conventional" (called "normal control" or "bonneted" in the UK). European trucks, whether straight trucks or fully articulated, have a sheer face on the front. This allows shorter trucks with longer trailers (with larger freight capacity) within the legal maximum total length. Furthermore, it offers greater maneuverability in confined areas, a more balanced weight-distribution, and better overall view for the driver. The ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portable Computer
A portable computer is a computer designed to be easily moved from one place to another and included a display and keyboard together, with a single plug, much like later desktop computers called '' all-in-ones'' (AIO), that integrate the system's internal components into the same case as the display. The first commercially sold portable might be the MCM/70, released 1974. The next major portables were the IBM 5100 (1975), Osborne's CP/M-based Osborne 1 (1981) and Compaq's , advertised as 100% IBM PC compatible Compaq Portable (1983). These luggable computers still required a continuous connection to an external power source; this limitation was later overcome by the laptop. Laptops were followed by lighter models, so that in the 2000s mobile devices and by 2007 smartphones made the term almost meaningless. The 2010s introduced wearable computers such as smartwatches. Portable computers, by their nature, are generally microcomputers. Larger portable computers were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Department Of The Army
The United States Department of the Army (DA) is one of the three military departments within the Department of Defense of the U.S. The Department of the Army is the federal government agency within which the United States Army (U.S.) is organized, and it is led by the secretary of the Army, who has statutory authority under 10 United States Code § 7013 to conduct its affairs and to prescribe regulations for its government, subject to the limits of the law, and the directions of the secretary of defense and the president. The secretary of the army is a civilian official appointed by the president and confirmed by the Senate. The highest-ranking military officer in the department is the chief of staff of the Army, who is also a member of the Joint Chiefs of Staff. Other senior officials of the department are the under secretary of the Army (principal deputy to the secretary) and the vice chief of staff of the Army (principal deputy to the chief of staff.) The '' Depa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nist
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical science laboratory programs that include nanoscale science and technology, engineering, information technology, neutron research, material measurement, and physical measurement. From 1901 to 1988, the agency was named the National Bureau of Standards. History Background The Articles of Confederation, ratified by the colonies in 1781, provided: The United States in Congress assembled shall also have the sole and exclusive right and power of regulating the alloy and value of coin struck by their own authority, or by that of the respective states—fixing the standards of weights and measures throughout the United States. Article 1, section 8, of the Constitution of the United States, ratified in 1789, granted these powers to the new Congr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Bureau Of Standards
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical science laboratory programs that include nanoscale science and technology, engineering, information technology, neutron research, material measurement, and physical measurement. From 1901 to 1988, the agency was named the National Bureau of Standards. History Background The Articles of Confederation, ratified by the colonies in 1781, provided: The United States in Congress assembled shall also have the sole and exclusive right and power of regulating the alloy and value of coin struck by their own authority, or by that of the respective states—fixing the standards of weights and measures throughout the United States. Article 1, section 8, of the Constitution of the United States, ratified in 1789, granted these powers to the new Congre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Association For Computing Machinery
The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the world's largest scientific and educational computing society. The ACM is a non-profit professional membership group, claiming nearly 110,000 student and professional members . Its headquarters are in New York City. The ACM is an umbrella organization for academic and scholarly interests in computer science ( informatics). Its motto is "Advancing Computing as a Science & Profession". History In 1947, a notice was sent to various people: On January 10, 1947, at the Symposium on Large-Scale Digital Calculating Machinery at the Harvard computation Laboratory, Professor Samuel H. Caldwell of Massachusetts Institute of Technology spoke of the need for an association of those interested in computing machinery, and of the need for communication between them. ..After making some inquiries during May and June, we believe there is ample interest to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_pic2.JPG "Click for more on -> Tractor-trailer")
