- $749$881完美主義 電腦桌/書桌/NB桌/工作桌(胡桃色)-80x60x75cm購物中心折價券
- $3980DFhouse頂楓120CM工作桌+2抽屜+主機架-楓木色 120*60*76購物中心
- $1050$1280澄境 工業風附插座加粗鐵管電腦桌/工作桌/書桌110x60x75.5cm-DIY購物中心折價券
- $3499《DFhouse》巴菲特工作桌+羅德多功能大書架 150*60*76購物中心
- $839$986《HOPMA》DIY巧收圓腳工作桌/書桌-寬105 x深54 x高74.5cm購物中心折價券
- $799【日居良品】MIT 低甲醛工業風木感A字桌/工作桌/電腦桌(120公分寬)購物中心
- $902$1099EASY HOME 防潑水/耐磨加寬電腦工作桌(原木色)-120x60x75.5cm購物中心折價券
A sofa bed or sofa-bed (in the US often called a sofabed, hide-a-bed, bed-couch, sleeper-sofa, or pullout sofa) is typically a sofa or couch that, underneath its seating cushions, hides a metal frame and thin mattress that can be unfolded or ...
Products Ready-to-assemble furniture, homeware, food products Revenue €41.3 billion (FY 2019) Website about.ikea.com www.ingka.com Retail page www.ikea.com IKEA (Swedish: ) is a Swedish-origin Dutch (Netherlands)-headquartered multinational ...
- Building Blocks
- Further Reading
Flowcharts are used in designing and documenting simple processes or programs. Like other types of diagrams, they help visualize what is going on and thereby help understand a process, and perhaps also find less-obvious features within the process, like flaws and bottlenecks. There are different types of flowcharts: each type has its own set of boxes and notations. The two most common types of boxes in a flowchart are: 1. A processing step, usually called activity, and denoted as a rectangular box. 2. A decision, usually denoted as a diamond. A flowchart is described as "cross-functional" when the chart is divided into different vertical or horizontal parts, to describe the control of different organizational units. A symbol appearing in a particular part is within the control of that organizational unit. A cross-functional flowchart allows the author to correctly locate the responsibility for performing an action or making a decision, and to show the responsibility of each organiza...
The first structured method for documenting process flow, the "flow process chart", was introduced by Frank and Lillian Gilbreth in the presentation "Process Charts: First Steps in Finding the One Best Way to do Work", to members of the American Society of Mechanical Engineers (ASME) in 1921. The Gilbreths' tools quickly found their way into industrial engineering curricula. In the early 1930s, an industrial engineer, Allan H. Mogensen began to train business people in the use of some of the tools of industrial engineering at his Work Simplification Conferences in Lake Placid, New York. Art Spinanger, a 1944 graduate of Mogensen's class, took the tools back to Procter and Gamble where he developed their Deliberate Methods Change Program. Ben S. Graham, another 1944 graduate, Director of Formcraft Engineering at Standard Register Industrial, applied the flow process chart to information processing with his development of the multi-flow process chart, to present multiple documents and...
Sterneckert (2003) suggested that flowcharts can be modeled from the perspective of different user groups (such as managers, system analysts and clerks), and that there are four general types: 1. Document flowcharts, showing controls over a document-flow through a system 2. Data flowcharts, showing controls over a data-flow in a system 3. System flowcharts, showing controls at a physical or resource level 4. Program flowchart, showing the controls in a program within a system Notice that every type of flowchart focuses on some kind of control, rather than on the particular flow itself. However, there are some different classifications. For example, Andrew Veronis (1978) named three basic types of flowcharts: the system flowchart, the general flowchart, and the detailed flowchart. That same year Marilyn Bohl (1978) stated "in practice, two kinds of flowcharts are used in solution planning: system flowcharts and program flowcharts...".More recently, Mark A. Fryman (2001) identified mo...
The American National Standards Institute (ANSI) set standards for flowcharts and their symbols in the 1960s. The International Organization for Standardization (ISO) adopted the ANSI symbols in 1970. The current standard, ISO 5807, was revised in 1985.Generally, flowcharts flow from top to bottom and left to right.
The ANSI/ISO standards include symbols beyond the basic shapes. Some are:
1. Parallel Modeis represented by two horizontal lines at the beginning or ending of simultaneous operations For parallel and concurrent processing the Parallel Mode horizontal lines or a horizontal barindicate the start or end of a section of processes that can be done independently: 1. At a fork, the process creates one or more additional processes, indicated by a bar with one incoming path and two or more outgoing paths. 2. At a join, two or more processes continue as a single process, ind...
Any drawing program can be used to create flowchart diagrams, but these will have no underlying data model to share data with databases or other programs such as project management systems or spreadsheet. Many software packages exist that can create flowcharts automatically, either directly from a programming language source code, or from a flowchart description language. There are several applications and visual programming languages that use flowcharts to represent and execute programs. Gen...ISO 5807 (1985). Information processing – Documentation symbols and conventions for data, program and system flowcharts, program network charts and system resources charts. International Organizati...ECMA 4: Flowcharts (withdrawn – listof withdrawn standards)Schultheiss, Louis A., and Edward M. Heiliger. "Techniques of flow-charting." (1963); with introduction by Edward Heiliger.
- Structure and Implementation
- Virtual CPUs
- External Links
Early computers such as the ENIAC had to be physically rewired to perform different tasks, which caused these machines to be called "fixed-program computers". The "central processing unit" term has been in use since as early as 1955. Since the term "CPU" is generally defined as a device for software (computer program) execution, the earliest devices that could rightly be called CPUs came with the advent of the stored-program computer. The idea of a stored-program computer had been already present in the design of J. Presper Eckert and John William Mauchly's ENIAC, but was initially omitted so that it could be finished sooner. On June 30, 1945, before ENIAC was made, mathematician John von Neumann distributed the paper entitled First Draft of a Report on the EDVAC. It was the outline of a stored-program computer that would eventually be completed in August 1949. EDVAC was designed to perform a certain number of instructions (or operations) of various types. Significantly, the program...
The fundamental operation of most CPUs, regardless of the physical form they take, is to execute a sequence of stored instructions that is called a program. The instructions to be executed are kept in some kind of computer memory. Nearly all CPUs follow the fetch, decode and execute steps in their operation, which are collectively known as the instruction cycle. After the execution of an instruction, the entire process repeats, with the next instruction cycle normally fetching the next-in-sequence instruction because of the incremented value in the program counter. If a jump instruction was executed, the program counter will be modified to contain the address of the instruction that was jumped to and program execution continues normally. In more complex CPUs, multiple instructions can be fetched, decoded and executed simultaneously. This section describes what is generally referred to as the "classic RISC pipeline", which is quite common among the simple CPUs used in many electronic...
Hardwired into a CPU's circuitry is a set of basic operations it can perform, called an instruction set. Such operations may involve, for example, adding or subtracting two numbers, comparing two numbers, or jumping to a different part of a program. Each basic operation is represented by a particular combination of bits, known as the machine language opcode; while executing instructions in a machine language program, the CPU decides which operation to perform by "decoding" the opcode. A complete machine language instruction consists of an opcode and, in many cases, additional bits that specify arguments for the operation (for example, the numbers to be summed in the case of an addition operation). Going up the complexity scale, a machine language program is a collection of machine language instructions that the CPU executes. The actual mathematical operation for each instruction is performed by a combinational logic circuit within the CPU's processor known as the arithmetic logic un...
Cloud computing can involve subdividing CPU operation into virtual central processing units (vCPUs). A host is the virtual equivalent of a physical machine, on which a virtual system is operating. When there are several physical machines operating in tandem and managed as a whole, the grouped computing and memory resources form a cluster. In some systems, it is possible to dynamically add and remove from a cluster. Resources available at a host and cluster level can be partitioned out into resources pools with fine granularity.
The performance or speed of a processor depends on, among many other factors, the clock rate (generally given in multiples of hertz) and the instructions per clock (IPC), which together are the factors for the instructions per second (IPS) that the CPU can perform.Many reported IPS values have represented "peak" execution rates on artificial instruction sequences with few branches, whereas realistic workloads consist of a mix of instructions and applications, some of which take longer to execute than others. The performance of the memory hierarchy also greatly affects processor performance, an issue barely considered in MIPS calculations. Because of these problems, various standardized tests, often called "benchmarks" for this purpose—such as SPECint—have been developed to attempt to measure the real effective performance in commonly used applications. Processing performance of computers is increased by using multi-core processors, which essentially is plugging two or more indiv...How Microprocessors Work at HowStuffWorks.25 Microchips that shook the world – an article by the Institute of Electrical and Electronics Engineers.
Machine capable of carrying out a complex series of actions automatically. This article is about mechanical robots. For software agents, see Bot. For other uses of the term, see Robot (disambiguation). ASIMO (2000) at the Expo 2005. Articulated ...
- Interaction of The Solar Wind with Earth
- Auroral Particle Acceleration
- Historically-Significant Events
- Historical Views and Folklore
- on Other Planets
- See Also
- Further Reading
The word "aurora" is derived from the name of the Roman goddess of the dawn, Aurora, who travelled from east to west announcing the coming of the sun. Ancient Greek poets used the name metaphorically to refer to dawn, often mentioning its play of colours across the otherwise dark sky (e.g., "rosy-fingered dawn").
Most auroras occur in a band known as the "auroral zone", which is typically 3° to 6° wide in latitude and between 10° and 20° from the geomagnetic poles at all local times (or longitudes), most clearly seen at night against a dark sky. A region that currently displays an aurora is called the "auroral oval", a band displaced by the solar wind towards the night side of Earth. Early evidence for a geomagnetic connection comes from the statistics of auroral observations. Elias Loomis (1860), and later Hermann Fritz (1881) and Sophus Tromholt (1881)in more detail, established that the aurora appeared mainly in the auroral zone. In northern latitudes, the effect is known as the aurora borealis or the northern lights. The former term was coined by Galileo in 1619, from the Roman goddess of the dawn and the Greek name for the north wind. The southern counterpart, the aurora australis or the southern lights, has features almost identical to the aurora borealis and changes simultaneously wit...
A full understanding of the physical processes which lead to different types of auroras is still incomplete, but the basic cause involves the interaction of the solar wind with Earth's magnetosphere. The varying intensity of the solar wind produces effects of different magnitudes but includes one or more of the following physical scenarios. 1. A quiescent solar wind flowing past Earth's magnetosphere steadily interacts with it and can both inject solar wind particles directly onto the geomagnetic field lines that are 'open', as opposed to being 'closed' in the opposite hemisphere, and provide diffusion through the bow shock. It can also cause particles already trapped in the radiation belts to precipitate into the atmosphere. Once particles are lost to the atmosphere from the radiation belts, under quiet conditions, new ones replace them only slowly, and the loss-cone becomes depleted. In the magnetotail, however, particle trajectories seem constantly to reshuffle, probably when the...
Earth is constantly immersed in the solar wind, a rarefied flow of magnetized hot plasma (a gas of free electrons and positive ions) emitted by the Sun in all directions, a result of the two-million-degree temperature of the Sun's outermost layer, the corona. The quiescent solar wind reaches Earth with a velocity typically around 400 km/s, a density of around 5 ions/cm3 and a magnetic field intensity of around 2–5 nT (for comparison, Earth's surface field is typically 30,000–50,000 nT). During magnetic storms, in particular, flows can be several times faster; the interplanetary magnetic field (IMF) may also be much stronger. Joan Feynman deduced in the 1970s that the long-term averages of solar wind speed correlated with geomagnetic activity. Her work resulted from data collected by the Explorer 33spacecraft. The solar wind and magnetosphere consist of plasma (ionized gas), which conducts electricity. It is well known (since Michael Faraday's work around 1830) that when an electrica...
Just as there are many types of aurora, there are many different mechanisms that accelerate auroral particles into the atmosphere. Electron aurora in Earth's auroral zone (i.e. commonly visible aurora) can be split into two main categories with different immediate causes: diffuse and discrete aurora. Diffuse aurora appear relatively structureless to an observer on the ground, with indistinct edges and amorphous forms. Discrete aurora are structured into distinct features with well-defined edges such as arcs, rays and coronas; they also tend to be much brighter than the diffuse aurora. In both cases, the electrons that eventually cause the aurora start out as electrons trapped by the magnetic field in Earth's magnetosphere. These trapped particles bounce back and forth along magnetic field lines and are prevented from hitting the atmosphere by the magnetic mirror formed by the increasing magnetic field strength closer to Earth. The magnetic mirror's ability to trap a particle depends...
The discovery of a 1770 Japanese diary in 2017 depicting auroras above the ancient Japanese capital of Kyoto suggested that the storm may have been 7% larger than the Carrington event, which affected telegraph networks. The auroras that resulted from the "great geomagnetic storm" on both 28 August and 2 September 1859, however, are thought to be the most spectacular in recent recorded history. In a paper to the Royal Society on 21 November 1861, Balfour Stewart described both auroral events as documented by a self-recording magnetograph at the Kew Observatory and established the connection between the 2 September 1859 auroral storm and the Carrington–Hodgson flare event when he observed that "It is not impossible to suppose that in this case our luminary was taken in the act." The second auroral event, which occurred on 2 September 1859, as a result of the exceptionally intense Carrington–Hodgson white light solar flare on 1 September 1859, produced auroras, so widespread and extrao...
An aurora was described by the Greek explorer Pytheas in the 4th century BC. Seneca wrote about auroras in the first book of his Naturales Quaestiones, classifying them, for instance as pithaei ('barrel-like'); chasmata ('chasm'); pogoniae ('bearded'); cyparissae ('like cypress trees'), and describing their manifold colors. He wrote about whether they were above or below the clouds, and recalled that under Tiberius, an aurora formed above the port city of Ostia that was so intense and red that a cohort of the army, stationed nearby for fire duty, galloped to the rescue. It has been suggested that Pliny the Elder depicted the aurora borealis in his Natural History, when he refers to trabes, chasma, 'falling red flames' and 'daylight in the night'. The history of China has rich, and possibly the oldest, records of the aurora borealis. On an autumn around 2000 BC, according to a legend, a young woman named Fubao was sitting alone in the wilderness by a...
Both Jupiter and Saturn have magnetic fields that are stronger than Earth's (Jupiter's equatorial field strength is 4.3 Gauss, compared to 0.3 Gauss for Earth), and both have extensive radiation belts. Auroras have been observed on both gas planets, most clearly using the Hubble Space Telescope, and the Cassini and Galileo spacecraft, as well as on Uranus and Neptune. The aurorae on Saturn seem, like Earth's, to be powered by the solar wind. However, Jupiter's aurorae are more complex. Jupiter's main auroral oval is associated with the plasma produced by the volcanic moon Io, and the transport of this plasma within the planet's magnetosphere. An uncertain fraction of Jupiter's aurorae are powered by the solar wind. In addition, the moons, especially Io, are also powerful sources of aurora. These arise from electric currents along field lines ("field aligned currents"), generated by a dynamo mechanism due to the relative motion between the rotating planet and the moving moon. Io, whi...Chisholm, Hugh, ed. (1911). "Aurora Polaris" . Encyclopædia Britannica. 2 (11th ed.). Cambridge University Press. pp. 927–934.This includes a highly detailed description of historical observations...Baynes, T. S., ed. (1878). "Aurora Polaris" . Encyclopædia Britannica. 3(9th ed.). New York: Charles Scribner's Sons.Stern, David P. (1996). "A Brief History of Magnetospheric Physics During the Space Age". Reviews of Geophysics. 34 (1): 1–31. Bibcode:1996RvGeo..34....1S. doi:10.1029/95rg03508.Stern, David P.; Peredo, Mauricio. "The Exploration of the Earth's Magnetosphere". phy6.org.
Poly (methyl methacrylate) (PMMA), also known as acrylic, acrylic glass, perspex, or plexiglass, as well as by the trade names and brands Crylux, Plexiglas, Acrylite, Astariglas, Lucite, Perclax, and Perspex, among several others (), is a ...
Blackpink (Korean: 블랙핑크; commonly stylized as BLACKPINK or BLΛƆKPIИK) is a South Korean girl group formed by YG Entertainment, consisting of members Jisoo, Jennie, Rosé and Lisa.The group debuted in August 2016 with their single album Square ...
- External Links
The organization was created in 1955 by a ROC Presidential Directive from Chiang Kai-shek, to supervise and coordinate all security-related administrative organizations, military agencies and KMTorganizations in Taiwan. Earlier, the bureau was nicknamed "China's CIA" or "CCIA". The first Director-General of National Security Bureau was a three-star army general Cheng Jie-min[zh], with a background in military intelligence, who once was the deputy of the controversial Bureau of Investigation and Statistics of the National Military Council. (The "Military-Statistics Bureau" served under Dai Li, and even assumed command the "Military-Statistics Bureau" after the death of Dai Li in March 1946. As a result, the National Security Bureau is often seen as one of several successors to the Military-Statistics Bureau.) Initially, National Security Bureau did not have its own field officers or operatives. However, in order to strengthen its ability to guide and coordinate other intelligence age...
The National Security Bureau is subordinate to the National Security Council(NSC). Under the chain of command, the NSC is under the direct administration of the President. However, the Director-General of the National Security Bureau usually can and does report directly to the President, bypassing the NSC. The imagery also appears to be censored on google maps from satellite view. 25.107496°N 121.535756°ECheng Chieh-ming[zh](August 1954 – 11 December 1959)Hsia Chi-ping[zh](1 December 1962 – 30 June 1967)
Aluminium alloy. Welded aluminium alloy bicycle frame, made in the 1990s. Aluminium alloys (or aluminum alloys; see spelling differences) are alloys in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, ...