Computer Networks
Computer network, is a communication system that connects different computers together to achieve resource sharing through hardware devices and related communication protocols and software.
Simplex, half-duplex, duplex
Simplex means only one-way transmission. Half-duplex means that it cannot communicate in both directions at the same time, but only time-sharing, such as walkie-talkies, and duplex can communicate at the same time, such as cell phones.
Network topology
Star, mesh, linear, tree, half-mesh, ring. Principle and structure must be related, too complex to say
LAN, MAN, WAN
By coverage can be divided into LAN LAN, MAN WMAN WAN WAN
Frequency division multiplexing, time division multiplexing
Frequency division multiplexing is the frequency is divided into a number of segments, each communicating, time division multiplexing is similar to the time segments to transmit the information on each road
How to write a computer lab report summary?
Computer practical training summary example:
Computer application basic practical training practiced the operation of Windows_P, the operation of Word, the operation of the presentation PowerPoind, as well as the production of web pages, the use of e-mail, the organization and distribution of information resources. Practical training time of one semester.
Mainly introduces the office software we use and other commonly used several software in the application of skills to do a detailed explanation, and for everyone in the actual application of the process of the problems that often occur in the analysis, pointing, explanation. I believe that after this study, the future use of these software can certainly be handy.
In order to make the knowledge learned to life, I organized the students to establish a learning interest group, students together to exchange and discuss learning problems, experience, experience.
And the good learners lead the study, which can improve the learning efficiency. When you encounter problems and everyone to exchange, you can make your own better grasp of the knowledge points, and to help answer the question of the students can also deepen the understanding of the knowledge points. In addition to make full use of the online Q&A time, before the Q&A to do a good job of preparation, the study of the question beforehand to have a summary, so that in the Q&A can be targeted.
The practical training allows students to further understand the computer hardware and system software installation, maintenance knowledge. In the study of this part of the content of the King teacher in-depth explanation, and let us actively operate, combined with practice to improve their ability to operate.
Secondly, the study of several software application skills, but also learned some of the practical application process (such as downloading audio, picture data) often the problem of the method, through this study, will certainly allow me to work in the future will be the use of computers at ease.
In order to raise awareness, the teacher not only used physical demonstrations, but also provided us with hands-on opportunities to explain the knowledge, introduced some of the methods that we rarely use, which will help us in our future operations.
Through this semester of teaching practical training, students understand the need to learn more about the relevant knowledge, think more, ask more questions, ask more why, to learn to use, computer networks make learning, life, work, resource consumption is greatly reduced. We are a new generation of people using high-tech, but also with the current society is changing day by day, high-tech, the need for teachers to master a certain amount of computer knowledge in order to better help us.
But sometimes it is also necessary to move our brains, to personal experience, to practice, the location of the various commands, functions, usage to remember and do. Improve our overall knowledge and lay a good foundation. At the same time, we have learned a lot of computer knowledge, and more importantly, we have improved communication with other people.
We sit together and speak freely, discuss with each other, exchange, put their own do not understand, do not understand the place to put forward, let the teacher to help solve, so that each other have got to learn, consolidate the knowledge of the opportunity to improve the efficiency of learning. At the same time, I also hope that in the future we can organize more such training, because computer knowledge is updated very quickly, only continuous learning, in order to master the latest knowledge.
Computer basic knowledge points summarized in summary
With the development of information technology, computers are increasingly into people’s work, study and life. The following is a summary of the basic knowledge of computer points summarized for you, “only for reference, welcome to read.
Summary of basic computer knowledge points summarized
Hardware knowledge
1. The composition of the computer system, including the hardware system and software system hardware system is divided into three typical structures:
(1) a single-bus structure;
(2), dual bus structure;
(3), the use of the channel of the large system structure.
The central processor CPU contains the operator and controller.
2. Instruction system
Instructions consist of opcodes and address codes.
3. The storage system is divided into the main memory-secondary memory level and the main memory-Cache level.
The Cache serves as a copy of a localized area of the main memory and is used to store the most currently active programs and data. Representation of data in a computer
Basic structure of Cache: Cache consists of a storage body, an address image and a replacement mechanism.
4. A channel is a controller that manages I/O operations by executing a channel program, which allows the CPU to achieve a higher degree of parallelism with I/O operations.
5. Bus from the functional point of view, the system bus is divided into address bus (AB), data bus (DB), control bus (CB).
6. Disk capacity notation calculation.
Unformatted capacity = number of faces * (number of tracks/faces) * inner circumference * maximum bit density
Formatted capacity = number of faces * (number of tracks/faces) * (number of sectors/channels) * (number of bytes/sectors)
7. Representation of data in original and inverse code
[+0] original = 000…00 [ -0]original=100……00[+0]inverse=000…00[-0]inverse=111…11
The original code of a positive number=the complement of a positive number=the Inverse code of negative number: sign bit remains unchanged, rest of the bits become inverse.
Operating System
Definition of Operating System: a collection of programs used to control and manage system resources and to facilitate the use of computers by users.
Function: is the resource manager of a computer system. Characteristics: parallelism, sharing
Classification: multi-channel batch operating system, time-sharing operating system, real-time operating system, network operating system.
Process: a program with a certain independent function about a collection of data to run a single activity.
Processes are divided into three states: Running, Ready, and Blocked.
Virtual memory: is a false memory that does not actually exist in physical form.
Page Rack: divides the main memory into storage blocks of the same size.
Page: divides the user’s logical address space (virtual address space) into sections of the same size as the page shelf, each called a page.
Page replacement algorithms are:
1. Optimal replacement algorithm OPT
2. First-in, first-out replacement algorithm FIFO
3. Least recently used replacement algorithm LRU
4. Recently unused replacement algorithm NUR
To make an exclusive device into a shared device, thus improving device utilization and system efficiency.
SPOOL system: A hardware and software system that realizes the technology of virtual devices, and Spooling system, a pseudo-offline system.
Job scheduling algorithms:
1. First-come-first-served scheduling algorithm FIFO: according to the job arrives at the system or the process enters the ready queue. Priority order to choose.
2, priority scheduling algorithm: according to the priority size of the process scheduling, so that high-priority processes are prioritized scheduling strategy.
3. Highest Response Ratio Priority Scheduling Algorithm: Each job has a priority number, which is not only a function of the required service time, but also a function of the waiting time spent by the job to get service. All three of these are non-preemptive scheduling strategies.
Embedded system basics
Definition: application-centered, computer technology-based, hardware and software can be tailored to adapt to a particular application system, the function, reliability, cost, volume, power consumption of the computer system has strict requirements.
Characteristics: Hardware, small size, light weight, low cost, high reliability and other features, the use of specialized embedded CPU. software, small code size, high efficiency, the requirements of a fast response time, the ability to deal with asynchronous concurrent events, real-time processing capabilities.
Applications: from the space shuttle to home microwave ovens.
The sliding window protocol provides for retransmission of unacknowledged packets, the number of such packets can be at most equal to the size of the sliding window, and TCP uses the sliding window protocol to address end-to-end flow control.
Expanded reading: what are the computer class majors
1. Computer Science and Technology
Computer science and technology is the study of the design and manufacture of computers and the use of computers for information acquisition, representation, storage, processing, control, such as the theory, principles, methods and technology of the discipline.
The program is designed to cultivate computer professionals with good overall qualities and innovative abilities for the overall development of morality, intellectuality and physical fitness. Through the systematic learning to master the basic theory, basic knowledge and basic skills and methods of the specialty, can in science and technology, education and economic sectors engaged in research, teaching, application development and management.
2. Software Engineering
Software engineering is a study of engineering methods to build and maintain effective, practical and high-quality software discipline. It involves programming languages, databases, software development tools, system platforms, standards, design patterns and other aspects.
The goal of software engineering is to develop software products with applicability, effectiveness, modifiability, reliability, comprehensibility, maintainability, reusability, portability, traceability, interoperability, and fulfillment of users’ needs at a given cost and schedule. Pursuing these goals helps improve the quality and development efficiency of software products and reduces maintenance difficulties.
3. Network Engineering
Network engineering refers to the engineering of designing, developing, and solving network system problems by engineering ideas, ways, and methods as planned. Cultivate the basic theory and method of network engineering and computer technology and network technology knowledge, can use the knowledge and skills to analyze and solve related practical problems, can be in the information industry and other sectors of the national economy engaged in various types of network systems and computer communication systems research, teaching, design, development and other work of senior network technology personnel.
This specialty cultivates the overall development of moral, intellectual, physical and aesthetic development, mastering the basic knowledge of natural sciences and humanities and social sciences, basic theories of computer science, computer software and hardware systems and application knowledge, professional knowledge of network engineering and application knowledge, with a sense of creativity, with the ability to analyze and solve problems in this field of specialization, with a certain degree of practical skills, and have a good ability to apply foreign languages. Advanced research and application-oriented specialists.
4. Digital Media Technology Specialization
Digital Media Technology is an open platform that mainly contains scene design, character image design, game program design, multimedia post-processing, and human-computer interaction technology, and it is a specialization that is designed mainly for game development, web site artwork, and creative design jobs.
This program is designed to train professionals who are engaged in digital media development and digital communication for today’s informatization era with all-round development of morality, intelligence, physicality, and aesthetics. Graduates will have both information communication theory, digital media technology and design management capabilities, can be in the party and government agencies, news media, publishing, trade, education, information consulting and IT-related fields,
5. Electronic and Computer Engineering
Electronic and Computer Engineering is the Ministry of Education’s ad hoc specialties, combining electrical engineering and computer science, with a very good prospect for development. Electronic and computer engineering is the integration of software design and hardware design, and the combination of power electronics of a specialty.
Students in this program mainly study the basic theory and knowledge of electricity and computer technology, receive relevant training, and have the ability to solve practical problems and related work.