Mathematical optimizationMathematical optimization (alternatively spelled optimisation) or mathematical programming is the selection of a best element, with regard to some criterion, from some set of available alternatives. It is generally divided into two subfields: discrete optimization and continuous optimization. Optimization problems arise in all quantitative disciplines from computer science and engineering to operations research and economics, and the development of solution methods has been of interest in mathematics for centuries.
Combinatorial optimizationCombinatorial optimization is a subfield of mathematical optimization that consists of finding an optimal object from a finite set of objects, where the set of feasible solutions is discrete or can be reduced to a discrete set. Typical combinatorial optimization problems are the travelling salesman problem ("TSP"), the minimum spanning tree problem ("MST"), and the knapsack problem. In many such problems, such as the ones previously mentioned, exhaustive search is not tractable, and so specialized algorithms that quickly rule out large parts of the search space or approximation algorithms must be resorted to instead.
Program optimizationIn computer science, program optimization, code optimization, or software optimization, is the process of modifying a software system to make some aspect of it work more efficiently or use fewer resources. In general, a computer program may be optimized so that it executes more rapidly, or to make it capable of operating with less memory storage or other resources, or draw less power. Although the word "optimization" shares the same root as "optimal", it is rare for the process of optimization to produce a truly optimal system.
Convex optimizationConvex optimization is a subfield of mathematical optimization that studies the problem of minimizing convex functions over convex sets (or, equivalently, maximizing concave functions over convex sets). Many classes of convex optimization problems admit polynomial-time algorithms, whereas mathematical optimization is in general NP-hard.
Optimizing compilerIn computing, an optimizing compiler is a compiler that tries to minimize or maximize some attributes of an executable computer program. Common requirements are to minimize a program's execution time, memory footprint, storage size, and power consumption (the last three being popular for portable computers). Compiler optimization is generally implemented using a sequence of optimizing transformations, algorithms which take a program and transform it to produce a semantically equivalent output program that uses fewer resources or executes faster.
Peephole optimizationPeephole optimization is an optimization technique performed on a small set of compiler-generated instructions; the small set is known as the peephole or window. Peephole optimization involves changing the small set of instructions to an equivalent set that has better performance.
Memory managementMemory management is a form of resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time. Several methods have been devised that increase the effectiveness of memory management.
PhraseIn grammar, a phrasecalled expression in some contextsis a group of words or singular word acting as a grammatical unit. For instance, the English expression "the very happy squirrel" is a noun phrase which contains the adjective phrase "very happy". Phrases can consist of a single word or a complete sentence. In theoretical linguistics, phrases are often analyzed as units of syntactic structure such as a constituent. There is a difference between the common use of the term phrase and its technical use in linguistics.
Memory segmentationMemory segmentation is an operating system memory management technique of dividing a computer's primary memory into segments or sections. In a computer system using segmentation, a reference to a memory location includes a value that identifies a segment and an offset (memory location) within that segment. Segments or sections are also used in s of compiled programs when they are linked together into a and when the image is loaded into memory.
Memory pagingIn computer operating systems, memory paging (or swapping on some Unix-like systems) is a memory management scheme by which a computer stores and retrieves data from secondary storage for use in main memory. In this scheme, the operating system retrieves data from secondary storage in same-size blocks called pages. Paging is an important part of virtual memory implementations in modern operating systems, using secondary storage to let programs exceed the size of available physical memory.
Verb phraseIn linguistics, a verb phrase (VP) is a syntactic unit composed of a verb and its arguments except the subject of an independent clause or coordinate clause. Thus, in the sentence A fat man quickly put the money into the box, the words quickly put the money into the box constitute a verb phrase; it consists of the verb put and its arguments, but not the subject a fat man. A verb phrase is similar to what is considered a predicate in traditional grammars.
Adpositional phraseAn adpositional phrase is a that includes prepositional phrases, postpositional phrases, and circumpositional phrases. Adpositional phrases contain an adposition (preposition, postposition, or circumposition) as head and usually a complement such as a noun phrase. Language syntax treats adpositional phrases as units that act as arguments or adjuncts. Prepositional and postpositional phrases differ by the order of the words used.
Adjective phraseAn adjective phrase (or adjectival phrase) is a phrase whose head is an adjective. Almost any grammar or syntax textbook or dictionary of linguistics terminology defines the adjective phrase in a similar way, e.g. Kesner Bland (1996:499), Crystal (1996:9), Greenbaum (1996:288ff.), Haegeman and Guéron (1999:70f.), Brinton (2000:172f.), Jurafsky and Martin (2000:362). The adjective can initiate the phrase (e.g. fond of steak), conclude the phrase (e.g. very happy), or appear in a medial position (e.g.
Adverbial phraseIn linguistics, an adverbial phrase ("AdvP") is a multi-word expression operating adverbially: its syntactic function is to modify other expressions, including verbs, adjectives, adverbs, adverbials, and sentences. Adverbial phrases can be divided into two types: complement adverbs and modifier adverbs. For example, in the sentence She sang very well, the expression very well is an adverbial phrase, as it modifies the verb to sing.
Memory leakIn computer science, a memory leak is a type of resource leak that occurs when a computer program incorrectly manages memory allocations in a way that memory which is no longer needed is not released. A memory leak may also happen when an object is stored in memory but cannot be accessed by the running code (i.e. unreachable memory). A memory leak has symptoms similar to a number of other problems and generally can only be diagnosed by a programmer with access to the program's source code.
Phrase structure rulesPhrase structure rules are a type of rewrite rule used to describe a given language's syntax and are closely associated with the early stages of transformational grammar, proposed by Noam Chomsky in 1957. They are used to break down a natural language sentence into its constituent parts, also known as , including both lexical categories (parts of speech) and phrasal categories. A grammar that uses phrase structure rules is a type of phrase structure grammar.
Plan (drawing)Plans are a set of drawings or two-dimensional diagrams used to describe a place or object, or to communicate building or fabrication instructions. Usually plans are drawn or printed on paper, but they can take the form of a digital file. Plans are used in a range of fields: architecture, urban planning, landscape architecture, mechanical engineering, civil engineering, industrial engineering to systems engineering. The term "plan" may casually be used to refer to a single view, sheet, or drawing in a set of plans.
COMMAND.COMCOMMAND.COM is the default command-line interpreter for MS-DOS, Windows 95, Windows 98 and Windows Me. In the case of DOS, it is the default user interface as well. It has an additional role as the usual first program run after boot (init process), hence being responsible for setting up the system by running the AUTOEXEC.BAT configuration file, and being the ancestor of all processes. COMMAND.COM's successor on OS/2 and Windows NT systems is cmd.exe, although COMMAND.
Dir (command)In computing, dir (directory) is a command in various computer operating systems used for and directory listing. It is one of the basic commands to help navigate the . The command is usually implemented as an internal command in the command-line interpreter (shell). On some systems, a more graphical representation of the directory structure can be displayed using the tree command.
Del (command)In computing, del (or erase) is a command in command-line interpreters (shells) such as COMMAND.COM, cmd.exe, 4DOS, NDOS, 4OS2, 4NT and Windows PowerShell. It is used to delete one or more or from a . The command is available for various operating systems including DOS, Microware OS-9, IBM OS/2, Microsoft Windows and ReactOS. It is analogous to the Unix rm command and to the Stratus OpenVOS delete_file and delete_dircommands. DEC RT-11, OS/8, RSX-11, and OpenVMS also provide the delete command which can be contracted to del.
