Thursday, December 20, 2012

Computer Crimes


Today, I write about "Computer Crimes".

 Nowadays, there are various computer crimes.
I cannot introduce all of them so I take up some themes.

The first theme is “Computer virus”. Computer virus is one of the most known computer problem. Computer virus defines a kind of the illegal program which brings damage to a computer. There are a number of kind of computer virus such as “Trojan horse”, “Warm virus” and “Logic bomb”, you computer may have damaged. The early virus which only reproduces its copy, is only infected between computers through a floppy disk etc., sometimes displays a message, and surprises a user was harmless. But After the second half of the 1980s, a virus evolved gradually and began to become the cause of bringing about realistic damage. The kind of computer virus is continuing increasing day by day and it is said that tens of thousands of sorts of computer viruses exist. On the other hand, development of the "vaccine" which remove a virus has also been furthered in parallel with evolution of a virus. In order to prevent infection of computer virus, introduction of anti-virus software is effective and the easiest. You should keep anti-virus software which install in your computer the newest thing because anti-virus software is often updated.

The next theme is “Online fraud”. Nowadays, the Internet spreads rapidly and is used all over the world. The Internet is very convenient but it is often abused. An online fraud is one of them. One of the online fraud has one-click fraud. One-click fraud means that if you click URL sent by email once, you are made to contract without your agreement. You may be blackmailed if you do not pay a charge. You may pay because you do not want it to be known. However, since the contract which has not obtained both consent is invalid, regardless of a click-through count at all, the contract is invalid. It can be considered that it is fraud to charge after they know to consent to the failure of a contract, so you do not have to pay.

The last theme is “Penny auction”. Penny auction is a new Internet problem. It is an Internet auction of the form that a commission is needed for every bid at each time. Although the upset price and contract price on a display are a small amount compared with the usual auction, the commission at the time of a bid becomes a large amount of money in many cases. Moreover, even when you are not able to make a successful bid as a result, it will be necessary to pay a commission. The number of consultation increased rapidly, so Consumer Affairs Agency urged the nudge to use in December, 2010. Penny auction site closing succeeded one another from the autumn of 2010 from the influence of a report of the trouble about such a penny auction.

Thursday, December 13, 2012

History of computers



Hello, thank you for watching my blog.
I will write about computers and introduce interesting things in this blog.
First blogging theme is “History”.

Do you know the origin of computers?
Generally speaking, it is “ENIAC(1946)” which was invented by John William Mauchly and John Presper Eckert. ENIAC contained eighty thousand vacuum tubes, weight is thirty ton and the power consumption was 150kW. But there was many problems. The life expectancy of the vacuum tube of was 2000 hours in those days. Therefore, if it calculates simply, a vacuum tube will break down in 6 minutes once. Since it was useless, Eckert made the filament of a vacuum tube turn on voltage lower than usual in order to improve reliability. The failure rate of ENIAC was lowness called two or three vacuums tube per week.

I introduce ENIAC is the first computer, but there was the computer appeared earlier than ENIAC. It is “ABC(1942)” which invented by John Vincent Atanasoff and Clifford Edward Berry. ABC contained three hundred vacuum tubes and the size was as large as a desk. And ABC adopted the binary number and the logic circuit, and had memory similar to DRAM (dynamic random access memory). It is a root of DRAM which is the memory which we are using for the personal computer.  But the memory was SAM (sequential access memory) correctly because the memory was a rotating drum.

There is one more computer called the first computer. It is “Colossus(1943)” was developed in order to use for World War in UK. Colossus used two thousand five hundred vacuum tubes and the power consumption was 4,5kW. Colossus gave the Allied Forces precious information in Normandy Landings in 1944. However, since Colossus was developed by military purposes, it was carried out in profound secrecy.

The modern computer is called the Neumman type. EDASC is the first computer which was invented by Maurice Vincent Wilkes (Cambridge University) in 1949. The name of EDSAC is an abbreviation of "Electronic Delay Storage Automatic Calculator". EDSAC had delay strage. The such type memory which reads and writes continuous data one by one is called sequential access memory. EDSAC contained three thousand vacuum tubes and the power consumption was 12kW. The power consumption of EDSAC was 1/10 less than of ENIAC.

Finally I would like to introduce WWW (world wide web). It is one of the most typical applications of the Internet in an E-mail in an information inspection system.  Nowadays, it is thanks to World Wide Web that we can browse a web page on the Internet. WWW was developed by CERN (European center for nuclear research) in 1989. The greatest feature of WWW is being able to embed the information for referring to other documents into a document. At the WWW server which offers the information on a web page, the file written in a language called HTML is saved, and it can see now freely from the outside. WWW was set to one of the factors through which the Internet spreads by leaps and bounds.