Crise économique mondiale des années 2008 et suivantes


Three different types of punch cards were used: The book IBM and the Holocaust by Edwin Black outlines the ways in which IBM's technology helped facilitate Nazi genocide through generation and tabulation of punch cards based upon national census data. Currently, CAMs or associative arrays in software are programming-language-specific. To be precise, EDSAC's first program printed a list of the squares of the integers from 0 to 99 inclusive.

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There were three separate readers for the three types of cards. The machine was about a century ahead of its time. However, the project was slowed by various problems including disputes with the chief machinist building parts for it.

All the parts for his machine had to be made by hand—this was a major problem for a machine with thousands of parts. Eventually, the project was dissolved with the decision of the British Government to cease funding. Babbage's failure to complete the analytical engine can be chiefly attributed to difficulties not only of politics and financing, but also to his desire to develop an increasingly sophisticated computer and to move ahead faster than anyone else could follow.

This appears to be the first published description of programming, so Ada Lovelace is widely regarded as the first computer programmer. Following Babbage, although unaware of his earlier work, was Percy Ludgate , an accountant from Dublin, Ireland. He independently designed a programmable mechanical computer, which he described in a work that was published in In the first half of the 20th century, analog computers were considered by many to be the future of computing.

These devices used the continuously changeable aspects of physical phenomena such as electrical , mechanical , or hydraulic quantities to model the problem being solved, in contrast to digital computers that represented varying quantities symbolically, as their numerical values change.

As an analog computer does not use discrete values, but rather continuous values, processes cannot be reliably repeated with exact equivalence, as they can with Turing machines. The first modern analog computer was a tide-predicting machine , invented by Sir William Thomson , later Lord Kelvin, in It used a system of pulleys and wires to automatically calculate predicted tide levels for a set period at a particular location and was of great utility to navigation in shallow waters.

His device was the foundation for further developments in analog computing. The differential analyser , a mechanical analog computer designed to solve differential equations by integration using wheel-and-disc mechanisms, was conceptualized in by James Thomson , the brother of the more famous Lord Kelvin.

He explored the possible construction of such calculators, but was stymied by the limited output torque of the ball-and-disk integrators. An important advance in analog computing was the development of the first fire-control systems for long range ship gunlaying. When gunnery ranges increased dramatically in the late 19th century it was no longer a simple matter of calculating the proper aim point, given the flight times of the shells.

Various spotters on board the ship would relay distance measures and observations to a central plotting station. There the fire direction teams fed in the location, speed and direction of the ship and its target, as well as various adjustments for Coriolis effect , weather effects on the air, and other adjustments; the computer would then output a firing solution, which would be fed to the turrets for laying. In , British engineer Arthur Pollen developed the first electrically powered mechanical analogue computer called at the time the Argo Clock.

Mechanical devices were also used to aid the accuracy of aerial bombing. Drift Sight was the first such aid, developed by Harry Wimperis in for the Royal Naval Air Service ; it measured the wind speed from the air, and used that measurement to calculate the wind's effects on the trajectory of the bombs.

The art of mechanical analog computing reached its zenith with the differential analyzer , [49] built by H. A dozen of these devices were built before their obsolescence became obvious; the most powerful was constructed at the University of Pennsylvania 's Moore School of Electrical Engineering , where the ENIAC was built. By the s the success of digital electronic computers had spelled the end for most analog computing machines, but hybrid analog computers , controlled by digital electronics, remained in substantial use into the s and s, and later in some specialized applications.

The principle of the modern computer was first described by computer scientist Alan Turing , who set out the idea in his seminal paper, [53] On Computable Numbers. Turing reformulated Kurt Gödel 's results on the limits of proof and computation, replacing Gödel's universal arithmetic-based formal language with the formal and simple hypothetical devices that became known as Turing machines.

He proved that some such machine would be capable of performing any conceivable mathematical computation if it were representable as an algorithm. He went on to prove that there was no solution to the Entscheidungsproblem by first showing that the halting problem for Turing machines is undecidable: He also introduced the notion of a 'Universal Machine' now known as a Universal Turing machine , with the idea that such a machine could perform the tasks of any other machine, or in other words, it is provably capable of computing anything that is computable by executing a program stored on tape, allowing the machine to be programmable.

Von Neumann acknowledged that the central concept of the modern computer was due to this paper. Except for the limitations imposed by their finite memory stores, modern computers are said to be Turing-complete , which is to say, they have algorithm execution capability equivalent to a universal Turing machine.

The era of modern computing began with a flurry of development before and during World War II. Most digital computers built in this period were electromechanical — electric switches drove mechanical relays to perform the calculation.

These devices had a low operating speed and were eventually superseded by much faster all-electric computers, originally using vacuum tubes. The Z2 was one of the earliest examples of an electromechanical relay computer , and was created by German engineer Konrad Zuse in It was an improvement on his earlier Z1 ; although it used the same mechanical memory , it replaced the arithmetic and control logic with electrical relay circuits.

In the same year, electro-mechanical devices called bombes were built by British cryptologists to help decipher German Enigma-machine -encrypted secret messages during World War II. It was a substantial development from a device that had been designed in by Polish Cipher Bureau cryptologist Marian Rejewski , and known as the " cryptologic bomb " Polish: In , Zuse followed his earlier machine up with the Z3 , [58] the world's first working electromechanical programmable , fully automatic digital computer.

It was quite similar to modern machines in some respects, pioneering numerous advances such as floating point numbers. Replacement of the hard-to-implement decimal system used in Charles Babbage 's earlier design by the simpler binary system meant that Zuse's machines were easier to build and potentially more reliable, given the technologies available at that time. In two patent applications, Zuse also anticipated that machine instructions could be stored in the same storage used for data—the key insight of what became known as the von Neumann architecture , first implemented in Britain in the Manchester Baby of Zuse suffered setbacks during World War II when some of his machines were destroyed in the course of Allied bombing campaigns.

Apparently his work remained largely unknown to engineers in the UK and US until much later, although at least IBM was aware of it as it financed his post-war startup company in in return for an option on Zuse's patents. In , the Harvard Mark I was constructed at IBM's Endicott laboratories; [63] it was a similar general purpose electro-mechanical computer to the Z3, but was not quite Turing-complete.

The term digital is suggested by George Stibitz and refers to all applications based on signals with two states — low 0 and high 1. That is why the decimal and binary computing are two ways to implement digital computing. A mathematical basis of digital computing is Boolean algebra , developed by the British mathematician George Boole in his work The Laws of Thought , published in In the s and working independently, American electronic engineer Claude Shannon and Soviet logician Victor Shestakov [66] both showed a one-to-one correspondence between the concepts of Boolean logic and certain electrical circuits, now called logic gates , which are now ubiquitous in digital computers.

This thesis essentially founded practical digital circuit design. Purely electronic circuit elements soon replaced their mechanical and electromechanical equivalents, at the same time that digital calculation replaced analog. Machines such as the Z3 , the Atanasoff—Berry Computer , the Colossus computers , and the ENIAC were built by hand, using circuits containing relays or valves vacuum tubes , and often used punched cards or punched paper tape for input and as the main non-volatile storage medium.

While working at the research station in Dollis Hill in the s, he began to explore the possible use of electronics for the telephone exchange. Experimental equipment that he built in went into operation 5 years later, converting a portion of the telephone exchange network into an electronic data processing system, using thousands of vacuum tubes. The machine's special-purpose nature and lack of changeable, stored program distinguish it from modern computers.

The German encryption machine, Enigma , was first attacked with the help of the electro-mechanical bombes. Most possibilities led to a contradiction, and the few remaining could be tested by hand. The Germans also developed a series of teleprinter encryption systems, quite different from Enigma.

The first intercepts of Lorenz messages began in As part of an attack on Tunny, Max Newman and his colleagues helped specify the Colossus. Tommy Flowers , still a senior engineer at the Post Office Research Station [77] was recommended to Max Newman by Alan Turing [78] and spent eleven months from early February designing and building the first Colossus which superseded the Heath Robinson.

Colossus was the world's first electronic digital programmable computer. It had paper-tape input and was capable of being configured to perform a variety of boolean logical operations on its data, but it was not Turing-complete. Colossus Mark I contained thermionic valves tubes , but Mark II with valves, was both 5 times faster and simpler to operate than Mark 1, greatly speeding the decoding process.

Mark 2 was designed while Mark 1 was being constructed. Allen Coombs took over leadership of the Colossus Mark 2 project when Tommy Flowers moved on to other projects.

Sometimes, two or more Colossus computers tried different possibilities simultaneously in what now is called parallel computing , speeding the decoding process by perhaps as much as double the rate of comparison. Colossus included the first ever use of shift registers and systolic arrays , enabling five simultaneous tests, each involving up to Boolean calculations , on each of the five channels on the punched tape although in normal operation only one or two channels were examined in any run.

Initially Colossus was only used to determine the initial wheel positions used for a particular message termed wheel setting. The Mark 2 included mechanisms intended to help determine pin patterns wheel breaking. Both models were programmable using switches and plug panels in a way their predecessors had not been. Without the use of these machines, the Allies would have been deprived of the very valuable intelligence that was obtained from reading the vast quantity of encrypted high-level telegraphic messages between the German High Command OKW and their army commands throughout occupied Europe.

Details of their existence, design, and use were kept secret well into the s. Winston Churchill personally issued an order for their destruction into pieces no larger than a man's hand, to keep secret that the British were capable of cracking Lorenz SZ cyphers from German rotor stream cipher machines during the oncoming Cold War. Two of the machines were transferred to the newly formed GCHQ and the others were destroyed. As a result, the machines were not included in many histories of computing.

It was unambiguously a Turing-complete device and could compute any problem that would fit into its memory. Like the Colossus, a "program" on the ENIAC was defined by the states of its patch cables and switches, a far cry from the stored program electronic machines that came later.

Once a program was written, it had to be mechanically set into the machine with manual resetting of plugs and switches. It combined the high speed of electronics with the ability to be programmed for many complex problems.

It could add or subtract times a second, a thousand times faster than any other machine. It also had modules to multiply, divide, and square root.

High-speed memory was limited to 20 words about 80 bytes. Built under the direction of John Mauchly and J. The machine was huge, weighing 30 tons, using kilowatts of electric power and contained over 18, vacuum tubes, 1, relays, and hundreds of thousands of resistors, capacitors, and inductors. The machine was in almost constant use for the next ten years.

Early computing machines had fixed programs. For example, a desk calculator is a fixed program computer. It can do basic mathematics , but it cannot be used as a word processor or a gaming console. Changing the program of a fixed-program machine requires re-wiring, re-structuring, or re-designing the machine. The earliest computers were not so much "programmed" as they were "designed". A stored-program computer includes by design an instruction set and can store in memory a set of instructions a program that details the computation.

The theoretical basis for the stored-program computer had been composed by Alan Turing in his paper. In Turing joined the National Physical Laboratory and began his work on developing an electronic stored-program digital computer. Although substantially similar to Turing's design and containing comparatively little engineering detail, the computer architecture it outlined became known as the " von Neumann architecture ".

However, the better-known EDVAC design of John von Neumann , who knew of Turing's theoretical work, received more publicity, despite its incomplete nature and questionable lack of attribution of the sources of some of the ideas.

Turing thought that the speed and the size of computer memory were crucial elements, so he proposed a high-speed memory of what would today be called 25 KB , accessed at a speed of 1 MHz. The Manchester Baby was the world's first electronic stored-program computer. The machine was not intended to be a practical computer but was instead designed as a testbed for the Williams tube , the first random-access digital storage device. Although the computer was considered "small and primitive" by the standards of its time, it was the first working machine to contain all of the elements essential to a modern electronic computer.

The Mark 1 in turn quickly became the prototype for the Ferranti Mark 1 , the world's first commercially available general-purpose computer. As it was designed to be the simplest possible stored-program computer, the only arithmetic operations implemented in hardware were subtraction and negation ; other arithmetic operations were implemented in software.

The Experimental machine led on to the development of the Manchester Mark 1 at the University of Manchester. The machine's successful operation was widely reported in the British press, which used the phrase "electronic brain" in describing it to their readers.

The computer is especially historically significant because of its pioneering inclusion of index registers , an innovation which made it easier for a program to read sequentially through an array of words in memory.

Thirty-four patents resulted from the machine's development, and many of the ideas behind its design were incorporated in subsequent commercial products such as the IBM and as well as the Ferranti Mark 1. The chief designers, Frederic C. The other contender for being the first recognizably modern digital stored-program computer [94] was the EDSAC , [95] designed and constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England at the University of Cambridge in But this is speculation and there is no sign of it so far.

The design implemented a number of important architectural and logical improvements conceived during the ENIAC's construction, and a high speed serial access memory. It was finally delivered to the U. Army 's Ballistics Research Laboratory at the Aberdeen Proving Ground in August , but due to a number of problems, the computer only began operation in , and then only on a limited basis.

The first commercial computer was the Ferranti Mark 1 , built by Ferranti and delivered to the University of Manchester in February It was based on the Manchester Mark 1. The main improvements over the Manchester Mark 1 were in the size of the primary storage using random access Williams tubes , secondary storage using a magnetic drum , a faster multiplier, and additional instructions.

The basic cycle time was 1. The multiplier used almost a quarter of the machine's 4, vacuum tubes valves. At least seven of these later machines were delivered between and , one of them to Shell labs in Amsterdam.

In October , the directors of J. The LEO I computer became operational in April [] and ran the world's first regular routine office computer job.

On 17 November , the J. This was the first business application to go live on a stored program computer. Its primary storage was serial-access mercury delay lines capable of storing 1, words of 11 decimal digits plus sign bit words. IBM introduced a smaller, more affordable computer in that proved very popular. Memory limitations such as this were to dominate programming for decades afterward.

The program instructions were fetched from the spinning drum as the code ran. Efficient execution using drum memory was provided by a combination of hardware architecture: Thus many instructions were, when needed, located in the next row of the drum to be read and additional wait time for drum rotation was not required. In , British scientist Maurice Wilkes developed the concept of microprogramming from the realisation that the central processing unit of a computer could be controlled by a miniature, highly specialised computer program in high-speed ROM.

Microprogramming allows the base instruction set to be defined or extended by built-in programs now called firmware or microcode. It was widely used in the CPUs and floating-point units of mainframe and other computers; it was implemented for the first time in EDSAC 2 , [] which also used multiple identical "bit slices" to simplify design. Interchangeable, replaceable tube assemblies were used for each bit of the processor.

ERA, then a part of Univac included a drum memory in its , announced in February The first mass-produced computer, the IBM , also announced in had about 8. The first use of magnetic core was demonstrated for the Whirlwind computer in August Magnetic core was used in peripherals of the IBM delivered in July , and later in the itself.

It went on to dominate the field through the mids. The bipolar transistor was invented in From onwards transistors replaced vacuum tubes in computer designs, [] giving rise to the "second generation" of computers. Initially the only devices available were germanium point-contact transistors. Silicon junction transistors were much more reliable than vacuum tubes and had longer, indefinite, service life.

Transistorized computers could contain tens of thousands of binary logic circuits in a relatively compact space. Transistors greatly reduced computers' size, initial cost, and operating cost. Typically, second-generation computers were composed of large numbers of printed circuit boards such as the IBM Standard Modular System [] each carrying one to four logic gates or flip-flops.

At the University of Manchester , a team under the leadership of Tom Kilburn designed and built a machine using the newly developed transistors instead of valves. Initially the only devices available were germanium point-contact transistors , less reliable than the valves they replaced but which consumed far less power. The design featured a kilobyte magnetic drum memory store with multiple moving heads that had been designed at the National Physical Laboratory, UK.

By this team had transistor circuits operating to read and write on a smaller magnetic drum from the Royal Radar Establishment. CADET used point-contact transistors provided by the UK company Standard Telephones and Cables ; 76 junction transistors were used for the first stage amplifiers for data read from the drum, since point-contact transistors were too noisy.

From August CADET was offering a regular computing service, during which it often executed continuous computing runs of 80 hours or more. The Manchester University Transistor Computer's design was adopted by the local engineering firm of Metropolitan-Vickers in their Metrovick , the first commercial transistor computer anywhere. They were successfully deployed within various departments of the company and were in use for about five years. IBM installed more than ten thousand s between and The second generation disk data storage units were able to store tens of millions of letters and digits.

Next to the fixed disk storage units, connected to the CPU via high-speed data transmission, were removable disk data storage units. A removable disk pack can be easily exchanged with another pack in a few seconds. Even if the removable disks' capacity is smaller than fixed disks, their interchangeability guarantees a nearly unlimited quantity of data close at hand.

Magnetic tape provided archival capability for this data, at a lower cost than disk. Many second-generation CPUs delegated peripheral device communications to a secondary processor. For example, while the communication processor controlled card reading and punching , the main CPU executed calculations and binary branch instructions. One databus would bear data between the main CPU and core memory at the CPU's fetch-execute cycle rate, and other databusses would typically serve the peripheral devices.

On the PDP-1 , the core memory's cycle time was 5 microseconds; consequently most arithmetic instructions took 10 microseconds , operations per second because most operations took at least two memory cycles; one for the instruction, one for the operand data fetch. During the second generation remote terminal units often in the form of Teleprinters like a Friden Flexowriter saw greatly increased use.

Eventually these stand-alone computer networks would be generalized into an interconnected network of networks —the Internet. The early s saw the advent of supercomputing. The Atlas Computer was a joint development between the University of Manchester , Ferranti , and Plessey , and was first installed at Manchester University and officially commissioned in as one of the world's first supercomputers — considered to be the most powerful computer in the world at that time.

Atlas also pioneered the Atlas Supervisor , "considered by many to be the first recognisable modern operating system ". In the US, a series of computers at Control Data Corporation CDC were designed by Seymour Cray to use innovative designs and parallelism to achieve superior computational peak performance.

The next great advance in computing power came with the advent of the integrated circuit. The idea of the integrated circuit was conceived by a radar scientist working for the Royal Radar Establishment of the Ministry of Defence , Geoffrey W.

Noyce also came up with his own idea of an integrated circuit half a year later than Kilby. Produced at Fairchild Semiconductor, it was made of silicon , whereas Kilby's chip was made of germanium. The explosion in the use of computers began with "third-generation" computers, making use of Jack St. Clair Kilby's and Robert Noyce's independent invention of the integrated circuit or microchip.

This led to the invention of the microprocessor. While the subject of exactly which device was the first microprocessor is contentious, partly due to lack of agreement on the exact definition of the term "microprocessor", it is largely undisputed that the first single-chip microprocessor was the Intel , [] designed and realized by Ted Hoff , Federico Faggin , and Stanley Mazor at Intel.

While the earliest microprocessor ICs literally contained only the processor, i. During the s there was considerable overlap between second and third generation technologies. The Burroughs large systems such as the B were stack machines , which allowed for simpler programming. These pushdown automatons were also implemented in minicomputers and microprocessors later, which influenced programming language design.

Minicomputers served as low-cost computer centers for industry, business and universities. The microprocessor led to the development of the microcomputer , small, low-cost computers that could be owned by individuals and small businesses. Microcomputers, the first of which appeared in the s, became ubiquitous in the s and beyond. While which specific system is considered the first microcomputer is a matter of debate, as there were several unique hobbyist systems developed based on the Intel and its successor, the Intel , the first commercially available microcomputer kit was the Intel -based Altair , which was announced in the January cover article of Popular Electronics.

However, this was an extremely limited system in its initial stages, having only bytes of DRAM in its initial package and no input-output except its toggle switches and LED register display. Despite this, it was initially surprisingly popular, with several hundred sales in the first year, and demand rapidly outstripped supply.

Several early third-party vendors such as Cromemco and Processor Technology soon began supplying additional S bus hardware for the Altair In April at the Hannover Fair , Olivetti presented the P , the world's first complete, pre-assembled personal computer system. As a complete system, this was a significant step from the Altair, though it never achieved the same success.

It was in competition with a similar product by IBM that had an external floppy disk drive. Computing has evolved with microcomputer architectures, with features added from their larger brethren, now dominant in most market segments. These facts, along with the close association with Steve Jobs, secure the NeXT a place in history as one of the most significant computers of all time. Systems as complicated as computers require very high reliability. In August Israeli police superintendent Rafi Biton said that the binary trading industry had "turned into a monster".

He told the Israeli Knesset that criminal investigations had begun. They arrested her for wire fraud and conspiracy to commit wire fraud. This required providers to obtain a category 3 Investment Services license and conform to MiFID's minimum capital requirements ; firms could previously operate from the jurisdiction with a valid Lottery and Gaming Authority license. In April , New Zealand 's Financial Markets Authority FMA announced that all brokers that offer short-term investment instruments that settle within three days are required to obtain a license from the agency.

Entrepreneur's goal is not to avoid complaints, but avoiding complaints that have nothing to do with the preferences of the complaining client. The Isle of Man , a self-governing Crown dependency for which the UK is responsible, has issued licenses to companies offering binary options as "games of skill" licensed and regulated under fixed odds betting by the Isle of Man Gambling Supervision Commission GSC.

On October 19, , London police raided 20 binary options firms in London. Fraud within the market is rife, with many binary options providers using the names of famous and respectable people without their knowledge.

In the United States, the Securities and Exchange Commission approved exchange-traded binary options in On the exchange binary options were called "fixed return options" FROs ; calls were named "finish high" and puts were named "finish low".

To reduce the threat of market manipulation of single stocks, FROs use a "settlement index" defined as a volume-weighted average of trades on the expiration day. Montanaro submitted a patent application for exchange-listed binary options using a volume-weighted settlement index in In Nadex , a U.

On June 6, , the U. Commodity Futures Trading Commission CFTC and the Securities and Exchange Commission jointly issued an Investor Alert to warn about fraudulent promotional schemes involving binary options and binary options trading platforms. The two agencies said that they had received numerous complaints of fraud about binary options trading sites, "including refusal to credit customer accounts or reimburse funds to customers; identity theft ; and manipulation of software to generate losing trades".

Other binary options operations were violating requirements to register with regulators. Regulators found the company used a "virtual office" in New York's Trump Tower in pursuit of its scheme, evading a ban on off-exchange binary option contracts. The company neither admitted nor denied the allegations.

In February the Times of Israel reported that the FBI was conducting an active international investigation of binary option fraud, emphasizing its international nature, saying that the agency was "not limited to the USA".

The investigation is not limited to the binary options brokers, but is comprehensive and could include companies that provide services that allow the industry to operate. Credit card issuers will be informed of the fraudulent nature of much of the industry, which could possibly allow victims to receive a chargeback , or refund, of fraudulently obtained money.

On March 13, , the FBI reiterated its warning, declaring that the "perpetrators behind many of the binary options websites, primarily criminals located overseas, are only interested in one thing—taking your money".

They also provide a checklist on how to avoid being victimized. From Wikipedia, the free encyclopedia. External video Simona Weinglass on prosecuting binary options firms , Times of Israel , 3: Retrieved January 26, Journal of Business , Retrieved 17 December Federal Bureau of Investigation.

Retrieved February 15, Retrieved March 15, Retrieved March 29, How Safe Is It? International Business Times AU. Retrieved March 4, Retrieved 18 May Israel's vast, amoral binary options scam exposed".

The Times of Israel. Here's how we fleece the clients". Retrieved October 24, Retrieved February 7, Retrieved 4 May Financial Market Authority Austria. Archived from the original on Commodity Futures Trading Commission. Options, Futures and Other Derivatives. Retrieved 20 November Retrieved June 19, Retrieved 5 September Retrieved April 26, Retrieved September 28, Retrieved 4 June Retrieved 27 March Commodities and Futures Trading Commission.

Retrieved May 16, Retrieved September 24, Finance Magnates Financial and business news. Retrieved 21 October Isle of Man Government. Retrieved September 20, Retrieved March 14, Energy derivative Freight derivative Inflation derivative Property derivative Weather derivative.

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