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External Data Representation
External Data Representation (XDR) is a standard data serialization format, for uses such as computer network protocols. It allows data to be transferred between different kinds of computer systems. Converting from the local representation to XDR is called ''encoding''. Converting from XDR to the local representation is called ''decoding''. XDR is implemented as a software library of functions which is portable between different operating systems and is also independent of the transport layer. XDR uses a base unit of 4 bytes, serialized in big-endian order; smaller data types still occupy four bytes each after encoding. Variable-length types such as string and opaque are padded to a total divisible by four bytes. Floating-point numbers are represented in IEEE 754 format. History XDR was developed in the mid 1980s at Sun Microsystems, and first widely published in 1987. XDR became an IETF standard in 1995. The XDR data format is in use by many systems, including: * Network File ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical Standard
A technical standard is an established norm or requirement for a repeatable technical task which is applied to a common and repeated use of rules, conditions, guidelines or characteristics for products or related processes and production methods, and related management systems practices. A technical standard includes definition of terms; classification of components; delineation of procedures; specification of dimensions, materials, performance, designs, or operations; measurement of quality and quantity in describing materials, processes, products, systems, services, or practices; test methods and sampling procedures; or descriptions of fit and measurements of size or strength. It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes, and practices. In contrast, a custom, convention, company product, corporate standard, and so forth that becomes generally accepted and dominant is often called a ''de facto'' standard. A techni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Wire Protocol
Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that takes two arguments * Binary relation, a relation involving two elements * Binary-coded decimal, a method for encoding for decimal digits in binary sequences * Finger binary, a system for counting in binary numbers on the fingers of human hands Computing * Binary code, the digital representation of text and data * Bit, or binary digit, the basic unit of information in computers * Binary file, composed of something other than human-readable text ** Executable, a type of binary file that contains machine code for the computer to execute * Binary tree, a computer tree data structure in which each node has at most two children Astronomy * Binary star, a star system with two stars in it * Binary planet, two planetary bodies of comparable mas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadruple Precision
In computing, quadruple precision (or quad precision) is a binary floating point–based computer number format that occupies 16 bytes (128 bits) with precision at least twice the 53-bit double precision. This 128-bit quadruple precision is designed not only for applications requiring results in higher than double precision, but also, as a primary function, to allow the computation of double precision results more reliably and accurately by minimising overflow and round-off errors in intermediate calculations and scratch variables. William Kahan, primary architect of the original IEEE-754 floating point standard noted, "For now the 10-byte Extended format is a tolerable compromise between the value of extra-precise arithmetic and the price of implementing it to run fast; very soon two more bytes of precision will become tolerable, and ultimately a 16-byte format ... That kind of gradual evolution towards wider precision was already in view when IEEE Standard 754 for Floating-Poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Precision
Double-precision floating-point format (sometimes called FP64 or float64) is a floating-point number format, usually occupying 64 bits in computer memory; it represents a wide dynamic range of numeric values by using a floating radix point. Floating point is used to represent fractional values, or when a wider range is needed than is provided by fixed point (of the same bit width), even if at the cost of precision. Double precision may be chosen when the range or precision of single precision would be insufficient. In the IEEE 754-2008 standard, the 64-bit base-2 format is officially referred to as binary64; it was called double in IEEE 754-1985. IEEE 754 specifies additional floating-point formats, including 32-bit base-2 ''single precision'' and, more recently, base-10 representations. One of the first programming languages to provide single- and double-precision floating-point data types was Fortran. Before the widespread adoption of IEEE 754-1985, the representation and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floating Point
In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can be represented as a base-ten floating-point number: 12.345 = \underbrace_\text \times \underbrace_\text\!\!\!\!\!\!^ In practice, most floating-point systems use base two, though base ten (decimal floating point) is also common. The term ''floating point'' refers to the fact that the number's radix point can "float" anywhere to the left, right, or between the significant digits of the number. This position is indicated by the exponent, so floating point can be considered a form of scientific notation. A floating-point system can be used to represent, with a fixed number of digits, numbers of very different orders of magnitude — such as the number of meters between galaxies or between protons in an atom. For this reason, floating-poin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integer (computer Science)
In computer science, an integer is a datum of integral data type, a data type that represents some range of mathematical integers. Integral data types may be of different sizes and may or may not be allowed to contain negative values. Integers are commonly represented in a computer as a group of binary digits (bits). The size of the grouping varies so the set of integer sizes available varies between different types of computers. Computer hardware nearly always provides a way to represent a processor register or memory address as an integer. Value and representation The ''value'' of an item with an integral type is the mathematical integer that it corresponds to. Integral types may be ''unsigned'' (capable of representing only non-negative integers) or ''signed'' (capable of representing negative integers as well). An integer value is typically specified in the source code of a program as a sequence of digits optionally prefixed with + or −. Some programming languages allow oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boolean Datatype
In computer science, the Boolean (sometimes shortened to Bool) is a data type that has one of two possible values (usually denoted ''true'' and ''false'') which is intended to represent the two truth values of logic and Boolean algebra. It is named after George Boole, who first defined an algebraic system of logic in the mid 19th century. The Boolean data type is primarily associated with conditional statements, which allow different actions by changing control flow depending on whether a programmer-specified Boolean ''condition'' evaluates to true or false. It is a special case of a more general ''logical data type—''logic does not always need to be Boolean (see probabilistic logic). Generalities In programming languages with a built-in Boolean data type, such as Pascal and Java, the comparison operators such as > and ≠ are usually defined to return a Boolean value. Conditional and iterative commands may be defined to test Boolean-valued expressions. Languages with no exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar (payment Network)
Stellar, or Stellar Lumens, is an open source, decentralized protocol for digital currency to fiat money low-cost transfers which allows cross-border transactions between any pair of currencies. The Stellar protocol is supported by a Delaware nonprofit corporation, the Stellar Development Foundation, though this organization does not enjoy 501(c)(3) tax-exempt status with the IRS. History In 2014, Jed McCaleb, founder of Mt. Gox and co-founder of Ripple, launched the network system Stellar with former lawyer Joyce Kim. Before the official launch, McCaleb formed a website called "Secret Bitcoin Project" seeking alpha testers. The nonprofit Stellar Development Foundation was created in collaboration with Stripe CEO Patrick Collison and the project officially launched that July. Stellar received $3 million in seed funding from Stripe. Stellar was released as a decentralized payment network and protocol with a native currency, stellar. At its launch, the network had 100 billion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firebird (database Server)
Firebird is an open-source SQL relational database management system that supports Linux, Microsoft Windows, macOS and other Unix platforms. The database forked from Borland's open source edition of InterBase in 2000 but the code has been largely rewritten since Firebird 1.5. History Within a week of the InterBase 6.0 source being released by Borland on 25 July 2000, the Firebird project was created on SourceForge. Firebird 1.0 was released for Linux, Microsoft Windows and Mac OS X on 11 March 2002, with ports to Solaris, FreeBSD 4, HP-UX over the next two months. Work on porting the codebase from C to C++ began in 2000. On 23 February 2004, Firebird 1.5 was released, which was the first stable release of the new codebase. Version 1.5 featured an improved query optimizer, SQL-92 conditional expressions, SQL:1999 savepoints and support for explicit locking. Firebird 2.0 was released on 12 November 2006, adding support for 64-bit architectures, tables nested in FROM claus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
User Interface
In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine from the human end, while the machine simultaneously feeds back information that aids the operators' decision-making process. Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls and process controls. The design considerations applicable when creating user interfaces are related to, or involve such disciplines as, ergonomics and psychology. Generally, the goal of user interface design is to produce a user interface that makes it easy, efficient, and enjoyable (user-friendly) to operate a machine in the way which produces the desired result (i.e. maximum usability). This generally means that the operator needs to provide minimal input ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Application Programming Interface
An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build or use such a connection or interface is called an ''API specification''. A computer system that meets this standard is said to ''implement'' or ''expose'' an API. The term API may refer either to the specification or to the implementation. In contrast to a user interface, which connects a computer to a person, an application programming interface connects computers or pieces of software to each other. It is not intended to be used directly by a person (the end user) other than a computer programmer who is incorporating it into the software. An API is often made up of different parts which act as tools or services that are available to the programmer. A program or a programmer that uses one of these parts is said to ''call'' that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Libvirt
libvirt is an open-source API, daemon and management tool for managing platform virtualization. It can be used to manage KVM, Xen, VMware ESXi, QEMU and other virtualization technologies. These APIs are widely used in the orchestration layer of hypervisors in the development of a cloud-based solution. Internals libvirt is a C library with bindings in other languages, notably in Python, Perl, OCaml, Ruby, Java, JavaScript (via Node.js) and PHP. libvirt for these programming languages is composed of wrappers around another class/package called libvirtmod. libvirtmod's implementation is closely associated with its counterpart in C/C++ in syntax and functionality. Supported Hypervisors * LXC – lightweight Linux container system * OpenVZ – lightweight Linux container system * Kernel-based Virtual Machine/QEMU (KVM) – open-source hypervisor for Linux and SmartOS * Xen – bare-metal hypervisor * User-mode Linux (UML) – paravirtualized kernel * VirtualBox – hyperviso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
