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Year 2038 Problem
The year 2038 problem (also known as Y2038, Y2K38, Y2K38 superbug or the Epochalypse) is a time computing problem that leaves some computer systems unable to represent times after 03:14:07 UTC on 19 January 2038. The problem exists in systems which measure Unix time—the number of seconds elapsed since the ''Unix epoch'' (00:00:00 UTC on 1 January 1970)—and store it in a signed 32-bit integer. The data type is only capable of representing integers between −(2) and 231 − 1, meaning the latest time that can be properly encoded is 2 − 1 seconds after epoch (03:14:07 UTC on 19 January 2038). Attempting to increment to the following second (03:14:08) will cause the integer to overflow, setting its value to −(2) which systems will interpret as 2 seconds ''before'' epoch (20:45:52 UTC on 13 December 1901). The problem is similar in nature to the year 2000 problem, the difference being the Y ... [...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 interval (mathematics), 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 word size, 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 −. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traction Control System
A traction control system (TCS), is typically (but not necessarily) a secondary function of the electronic stability control (ESC) on production motor vehicles, designed to prevent loss of traction (i.e., wheelspin) of the driven road wheels. TCS is activated when throttle input and engine power and torque transfer are mismatched to the road surface conditions. The intervention consists of one or more of the following: *Brake force applied to one or more wheels *Reduction or suppression of spark sequence to one or more cylinders *Reduction of fuel supply to one or more cylinders *Closing the throttle, if the vehicle is fitted with drive by wire throttle *In turbocharged vehicles, a boost control solenoid is actuated to reduce boost and therefore engine power. Typically, traction control systems share the electrohydraulic brake actuator (which does not use the conventional master cylinder and servo) and wheel-speed sensors with ABS. The basic idea behind the need for a tract ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Stability Control
Electronic stability control (ESC), also referred to as electronic stability program (ESP) or dynamic stability control (DSC), is a computerized technology that improves a car handling, vehicle's stability by detecting and reducing loss of Traction (engineering), traction (skid (automobile), skidding). When ESC detects loss of steering control, it automatically applies the brakes to help steer the vehicle where the driver intends to go. Braking is automatically applied to wheels individually, such as the outer front wheel to counter oversteer, or the inner rear wheel to counter understeer. Some ESC systems also reduce engine power until control is regained. ESC does not improve a vehicle's cornering performance; instead, it helps reduce the chance of the driver losing control of the vehicle on a slippery road. According to the U.S. National Highway Traffic Safety Administration and the Insurance Institute for Highway Safety in 2004 and 2006, one-third of fatal accidents could be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-lock Braking System
An anti-lock braking system (ABS) is a Automotive safety, safety anti-Skid (automobile), skid Brake, braking system used on aircraft and on land motor vehicle, vehicles, such as cars, motorcycles, trucks, and buses. ABS operates by preventing the wheels from locking up during braking, thereby maintaining Traction (mechanics), tractive contact with the road surface and allowing the driver to maintain more control over the vehicle. ABS is an automated system that uses the principles of threshold braking and cadence braking, techniques which were once practiced by skillful drivers before ABS was widespread. ABS operates at a much faster rate and more effectively than most drivers could manage. Although ABS generally offers improved vehicle control and decreases stopping distances on dry and some slippery surfaces, on loose gravel or snow-covered surfaces ABS may significantly increase braking distance, while still improving steering control. Since ABS was introduced in production v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moore's Law
Moore's law is the observation that the Transistor count, number of transistors in an integrated circuit (IC) doubles about every two years. Moore's law is an observation and Forecasting, projection of a historical trend. Rather than a law of physics, it is an empirical relationship. It is an experience-curve law, a type of law quantifying efficiency gains from experience in production. The observation is named after Gordon Moore, the co-founder of Fairchild Semiconductor and Intel and former CEO of the latter, who in 1965 noted that the number of components per integrated circuit had been exponential growth, doubling every year, and projected this rate of growth would continue for at least another decade. In 1975, looking forward to the next decade, he revised the forecast to doubling every two years, a compound annual growth rate (CAGR) of 41%. Moore's empirical evidence did not directly imply that the historical trend would continue, nevertheless, his prediction has held si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embedded System
An embedded system is a specialized computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is embedded as part of a complete device often including electrical or electronic hardware and mechanical parts. Because an embedded system typically controls physical operations of the machine that it is embedded within, it often has real-time computing constraints. Embedded systems control many devices in common use. , it was estimated that ninety-eight percent of all microprocessors manufactured were used in embedded systems. Modern embedded systems are often based on microcontrollers (i.e. microprocessors with integrated memory and peripheral interfaces), but ordinary microprocessors (using external chips for memory and peripheral interface circuits) are also common, especially in more complex systems. In either case, the processor(s) us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ReiserFS
ReiserFS is a general-purpose, journaling file system initially designed and implemented by a team at Namesys led by Hans Reiser and licensed under GPLv2. Introduced in version 2.4.1 of the Linux kernel, it was the first journaling file system to be included in the standard kernel. ReiserFS was the default file system in Novell's SUSE Linux Enterprise until Novell decided to move to ext3 for future releases on October 12, 2006. ReiserFS version 3.6, now occasionally referred to as Reiser3, introduced a new on-disk format allowing larger filesizes. Namesys considered ReiserFS stable and feature-complete and ceased development on it to concentrate on its successor, Reiser4, though it continued to release security updates and critical bug fixes. Namesys went out of business in 2008 after Reiser's conviction for murder. The product is now maintained as open source by volunteers. The reiserfsprogs 3.6.27 were released on 25 July 2017. As of Linux 6.12, ReiserFS is supported on L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ext3
ext3, or third extended filesystem, is a journaling file system, journaled file system that is commonly used with the Linux kernel. It used to be the default file system for many popular Linux distributions but generally has been supplanted by its successor version ext4. The main advantage of ext3 over its predecessor, ext2, is journaling file system, journaling, which improves reliability and eliminates the need to check the file system after an unclean or improper Shutdown (computing), shutdown. History Stephen Tweedie first revealed that he was working on extending ext2 in ''Journaling the Linux ext2fs Filesystem'' in a 1998 paper, and later in a February 1999 kernel mailing list posting. The filesystem was merged with the mainline Linux kernel in November 2001 from 2.4.15 onward. Advantages The speed performance of ext3 is less attractive than competing Linux filesystems, such as ext4, JFS (file system), JFS, ReiserFS, and XFS, but ext3 has a significant advantage in tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ext2
ext2, or second extended file system, is a file system for the Linux kernel (operating system), kernel. It was initially designed by French software developer Rémy Card as a replacement for the extended file system (ext). Having been designed according to the same principles as the Berkeley Fast File System from Berkeley Software Distribution, BSD, it was the first commercial-grade filesystem for Linux. The canonical implementation of ext2 is the "ext2fs" filesystem driver in the Linux kernel. Other implementations (of varying quality and completeness) exist in GNU Hurd, MINIX 3, some BSD kernels, in MiNT, Haiku (operating system), Haiku and as third-party Microsoft Windows and macOS (via Filesystem_in_Userspace, FUSE) drivers. This driver was deprecated in Linux version 6.9 in favor of the ext4 driver, as the ext4 driver works with ext2 filesystems. ext2 was the default filesystem in several Linux distributions, including Debian and Red Hat Linux, until supplanted by ext3, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inode
An inode (index node) is a data structure in a Unix-style file system that describes a file-system object such as a file or a directory. Each inode stores the attributes and disk block locations of the object's data. File-system object attributes may include metadata (times of last change, access, modification), as well as owner and permission data. A directory is a list of inodes with their assigned names. The list includes an entry for itself, its parent, and each of its children. Etymology There has been uncertainty on the Linux kernel mailing list about the reason for the "i" in "inode". In 2002, the question was brought to Unix pioneer Dennis Ritchie, who replied: A 1978 paper by Ritchie and Ken Thompson bolsters the notion of "index" being the etymological origin of inodes. They wrote: Additionally, Maurice J. Bach wrote that the word ''inode'' "is a contraction of the term index node and is commonly used in literature on the UNIX system". Details A file system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Structure
In computer science, a data structure is a data organization and storage format that is usually chosen for Efficiency, efficient Data access, access to data. More precisely, a data structure is a collection of data values, the relationships among them, and the Function (computer programming), functions or Operator (computer programming), operations that can be applied to the data, i.e., it is an algebraic structure about data. Usage Data structures serve as the basis for abstract data types (ADT). The ADT defines the logical form of the data type. The data structure implements the physical form of the data type. Different types of data structures are suited to different kinds of applications, and some are highly specialized to specific tasks. For example, Relational database, relational databases commonly use B-tree indexes for data retrieval, while compiler Implementation, implementations usually use hash tables to look up Identifier (computer languages), identifiers. Data s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
