2. Have the ability to store and remember. The memory of a computer is similar to the human brain, and it can "memorize" (store) a large amount of data and computer programs.
3. Have the ability of logical judgment. Reliable logical judgment ability is an important reason why computers can realize information processing automation. Can make logical judgment, so that the computer can not only calculate numerical data, but also process non-numerical data, so that the computer can be widely used in non-numerical data processing fields, such as information retrieval, pattern recognition and various multimedia applications.
computer
1, commonly known as computer, is an electronic computer for high-speed calculation, which can be used for numerical calculation, logical calculation and memory storage. It is a modern intelligent electronic device that can automatically process massive data at high speed according to program execution. It consists of hardware system and software system, and a computer without any software is called bare metal. It can be divided into five categories: supercomputer, industrial control computer, network computer, personal computer and embedded computer. More advanced computers include biological computers, photonic computers and quantum computers.
2. Computer inventor john von neumann. Computer is one of the most advanced scientific and technological inventions in the 20th century, which has had an extremely important impact on human production and social activities, and has developed rapidly with strong vitality. Its application field has expanded from the initial military scientific research application package to all social fields, forming a huge computer industry, promoting the technological progress all over the world, thus triggering profound social changes. Computers have spread all over ordinary schools, enterprises and institutions, entered the homes of ordinary people and become an indispensable tool in the information society. The application of computers is becoming more and more common in China. After the reform and opening up, the number of computer users in China has been increasing, and the application level has been improving, especially in the fields of Internet, communication and multimedia. From 1996 to 2009, the number of computer users increased from 6.3 million to 6,765,438+million, and the number of networked computers increased from 29,000 to 59.4 million. The number of netizens has reached 30160,000, and there are 670 million mobile users of wireless Internet, among which1170,000 are mobile Internet users, ranking first in the world.
The main function of computer computer can replace people's mental work.
Computers can store a lot of information.
A computer is an information processor.
Computers can achieve high-speed operations.
Computers are usually tools for processing information.
What are the main features of computers? Computers have the following main features:
1, fast operation.
At present, the fastest supercomputer execution speed has reached more than 65.438+000 billion times per second, which is unmatched by traditional computing tools. With the progress of science and technology, the computing speed of computers is still increasing rapidly.
2, the calculation accuracy is high
The accuracy of a computer depends on the number of digits in the word length of the machine. The longer the word length, the higher the accuracy. Because the computer represents data in binary, it is easy to expand the word length of the machine. The word length of different types of computers is 8 bits, 16 bits, 32 bits, 64 bits and so on. In order to obtain higher precision, we can also double the word length or increase the space length several times, or even reach hundreds of binary numbers.
3. Large storage capacity
The memory of a computer can store original evidence, intermediate results and operation instructions for use. Memory can not only store a large amount of information, but also store or read information quickly and accurately.
4. Strong judgment
In addition to high-speed and high-precision computing power, computers also have the ability to logically reason and judge words, symbols and numbers. The emergence of artificial intelligence machine will further improve its ability of reasoning, judgment, thinking, learning, memory and accumulation, so that it can do more work instead of human brain.
5. Strong reliability
With the continuous development of science and technology, great changes have taken place in electronic technology, and the reliability of electronic devices is getting higher and higher. In the computer design process, the new structure can make it more reliable.
Computer applications:
1, scientific calculation
Scientific calculation, also known as numerical calculation, is the earliest application of computer, and its high-speed and high-precision operation is beyond the reach of manual operation. There are a lot of complicated numerical calculations in modern science and technology, such as earthquake prediction, meteorological prediction, engineering design, rocket and satellite launch, etc. These are inseparable from the accurate calculation of the computer, which greatly saves manpower, material resources and time.
2. Data processing
Data processing, also known as non-numerical calculation, is to process a large number of data and get useful data information. Data processing is widely used in office automation, transaction management, information analysis, enterprise management and other fields. Data processing has developed into a new computer application discipline.
3. Data processing
Data processing, also known as non-numerical calculation, is to process a large number of data and get useful data information. Data processing is widely used in office automation, transaction management, information analysis, enterprise management and other fields. Data processing has developed into a new computer application discipline.
Cai Sheng ebook answers for you!
What are the main functions of computer networks? It has two functions, mainly data communication and resource sharing. When realizing resource sharing, it is mainly manifested in two aspects: file sharing and print sharing.
Basic functions:
1,. data communication
2. Resource sharing
3. Decentralized treatment
4. Provide the reliability of the system
Computer network refers to a computer system that connects multiple computers with independent functions located in different geographical locations and their external devices through communication lines, and realizes resource sharing and information transmission under the management and coordination of network operating system, network management software and network communication protocol.
Color development method
The first generation computer network-remote terminal connection stage;
The second generation computer-computer network stage;
The third generation of computer networks-the interconnection stage of computer networks;
The fourth generation computer network-Internet and information superhighway stage;
primary network
Local area network (LAN; LAN) Usually our common "LAN" refers to the local area network, which is our most common and widely used network.
Schematic diagram of metropolitan area network (noerkMAN) This kind of network is generally the interconnection of computers in a city, not in the same geographical area.
Wide area map (wide area noerkWAN) This kind of network, also known as remote network, covers a wider area than people. Different cities are generally connected by local area network or metropolitan area network, and the geographical range can range from several hundred kilometers to several thousand kilometers.
Wireless Network With the increasing popularity and development of mobile computers such as notebook computers and personal digital assistant wireless networks (PDA), people often have to answer phones, send faxes and emails, read online information and log in to remote machines.
The main functions of computer network are data communication and resource sharing.
1, data communication means that the computer network can realize data transmission between computers.
2. Shared resources include shared hardware resources, software resources and data resources.
The functions of computer network are mainly embodied in three aspects: information exchange, resource sharing and distributed processing.
(1) information exchange
This is the most basic function of computer network, which mainly completes the system communication between nodes in computer network. Users can send emails, publish news messages, conduct e-shopping, e-commerce, distance e-education and so on.
⑵ Resource sharing
The so-called resources refer to all elements that constitute the system, including software and hardware resources, such as computing power, large-capacity disks, high-speed printers, plotters, communication lines, databases, files and other relevant information on computers. Due to economic and other factors, these resources are not (and cannot be) owned independently by all users, so computers on the network can not only use their own resources, but also share the resources on the network. Thereby enhancing the processing capacity of computers on the network and improving the utilization ratio of computer software and hardware.
(3) Decentralized treatment
A complex task can be divided into many parts, and the computers in the network cooperate with each other to complete the relevant parts in parallel, which greatly improves the efficiency of the whole system.
What are the main functions and characteristics of industrial portal crane? The all-in-one machine is a 1 electric lock device. Just replace the all-in-one access control with a multi-door controller and connect the controller to the computer for attendance management. If you want to increase the attendance function, you need a 485 conversion head; Multi-door access control and single-door access control need roughly the same things, but the number is different: 1 power box (transformer from 220V to 12V), 1 single-door access control machine, 1 exit button, which are all part of the access control system. If you are talking about the access control system, it is made up of several things. The simplest single door access control system includes