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Computer networks. Classification of computer networks. ……………4

Fast Ethernet network. …………………………………………………………..5

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Ensuring work safety in the Computer Center. ……….12

Computer networks. Classification of computer networks.

According to the principles of construction, computer networks are divided into local and remote (Figure 1).

Local networks are created, as a rule, in one organization or in one room.

The simplest version of such a network is to connect computers through parallel or serial ports. In this case, there is no need for any additional equipment. There should only be connecting conductors. This connection between computers is configured within the same room. It is used to transfer data from one computer to another. In this case, you can transfer data without using floppy disks. Any modern operating system shell has software that ensures such data transfer.

In local peer-to-peer computer networks, computers connect to the network through special network adapters, and the functioning of the network is supported by the network operating system. Examples of such operating systems are: Novell Personal Net Ware, Net Ware Line, Windows for Workgroups.

All computers and their operating systems in local peer-to-peer computer networks must be of the same type. Users of this network can transfer data to each other, use shared printers, magnetic and optical disks, etc.

In a local multi-rank computer network, one more powerful computer is used, which is called a server, and other, less powerful ones are called workstations. Servers use special system software that differs from workstation system software.

Remote computer networks are divided into regional and international. Regional ones are created in certain regions, for example, a state, and international ones ensure the connection of your computer with another computer on the World Wide Web. An example of such networks is Relcom (for CIS countries) and Internet (for the whole world). In principle, it is possible to access the Internet from regional computer networks.

Communication between computers in regional networks is provided by regular telephone networks or specially dedicated networks through special devices called modems. The modem converts binary code signals into language range audio signals, and vice versa.

Computers in a given area (city) are connected via modems and communication lines to a more powerful computer called a provider. There are currently more than 100 providers operating in Ukraine.

Each computer user that is connected to the network is assigned details (address). Providers, using the details, ensure communication between the corresponding user computers.

Communication between computers on different continents is carried out via satellite communication channels.

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Content

Introduction

Chapter 1 Concept and classification of computer networks

1.1 Purpose of a computer network

1.2 Classification of computer networks

Chapter 2. Main types of computer networks

2.1 Local area network (LAN)

2.2 Global Area Network (WAN)

Conclusion

List of used literature

Introduction

Russia's entry into the global information space entails the widespread use of the latest information technologies, and first of all, computer networks. At the same time, the user’s capabilities sharply increase and qualitatively change both in providing services to their clients and in solving their own organizational and economic problems.

It is appropriate to note that modern computer networks are a system whose capabilities and characteristics generally significantly exceed the corresponding indicators of the simple sum of the constituent elements of a network of personal computers in the absence of interaction between them.

The advantages of computer networks have led to their widespread use in information systems of the credit and financial sector, government and local governments, enterprises and organizations.

Computer networks and network information processing technologies have become the basis for building modern information systems. The computer should now be considered not as a separate processing device, but as a “window” into computer networks, a means of communication with network resources and other network users.

In recent years, the global Internet has become a global phenomenon. The network, which until recently was used by a limited number of scientists, government officials and employees of educational institutions in their professional activities, has become available to large and small corporations and even to individual users.

The purpose of this coursework is to familiarize yourself with the basics of the construction and operation of computer networks, to study the organization of computer networks. To achieve this goal, it is necessary to solve a number of problems:

Introduction to computer networks, highlighting their features and differences;

Characteristics of the main methods of constructing networks (network topology);

Studying scientific and methodological literature on this issue

Chapter 1 Concept and classification of computer networks

1.1 Purpose of a computer network

The main purpose of computer networks is to share resources and implement interactive communications both within one company and outside it. Resources are data, applications, and peripheral devices such as an external disk drive, printer, mouse, modem, or joystick.

Computers included in the network perform the following functions:

Organization of Internet access

Information transfer management

Providing computing resources and services to network users.

Currently, local computing (LAN) has become very widespread. This is due to several reasons:

Connecting computers into a network allows you to significantly save money by reducing the cost of maintaining computers (it is enough to have a certain disk space on the file server (the main computer of the network) with software products installed on it, used by several workstations);

Local networks allow you to use a mailbox to transfer messages to other computers, which allows you to transfer documents from one computer to another in the shortest possible time;

Local networks, with special software, are used to organize the sharing of files (for example, accountants on several machines can process transactions of the same ledger).

Among other things, in some areas of activity it is simply impossible to do without a LAN. These areas include: banking, warehouse operations of large companies, electronic archives of libraries, etc. In these areas, each individual workstation, in principle, cannot store all the information (mainly due to its too large volume).

A global computer network is a network connecting computers located geographically at great distances from each other. It differs from a local network in having longer communications (satellite, cable, etc.). The global network connects local networks.

The Internet, which once served exclusively research and academic groups whose interests ranged from access to supercomputers, is becoming increasingly popular in the business world.

1.2 Classification of computer networks

Based on the method of organization, networks are divided into real and artificial.

Artificial networks (pseudo-networks) allow you to connect computers together via serial or parallel ports and do not require additional devices. Sometimes communication in such a network is called communication via a null modem (no modem is used). Self-connection is called null-modem. Artificial networks are used when it is necessary to transfer information from one computer to another. MS-DOS and Windows are equipped with special programs for implementing a null modem connection.

Real networks allow computers to be connected using special switching devices and a physical data transmission medium.

/> The territorial distribution of networks can be local, global, regional and city.

Local Area Network (LAN) - Local Area Networks (LAN) is a group (communication system) of a relatively small number of computers united by a shared data transmission medium, located in a limited small area within one or more nearby buildings (usually within a radius of no more than 1 -2 km) in order to share the resources of all computers

A global computer network (WAN or WAN - World Area NetWork) is a network connecting computers that are geographically distant from each other. Differs from a local network in more extensive communications (satellite, cable, etc.). The global network connects local networks.

Metropolitan Area Network (MAN - Metropolitan Area NetWork) is a network that serves the information needs of a large city.

Regional - located on the territory of a city or region.

Also, recently experts have identified this type of network as a banking one, which is a special case of the corporate network of a large company. It is obvious that the specifics of banking activities impose strict requirements on information protection systems in the bank’s computer networks. An equally important role when building a corporate network is played by the need to ensure trouble-free and uninterrupted operation, since even a short-term failure in its operation can lead to huge losses.

There are departmental and state networks based on their affiliation. Departmental ones belong to one organization and are located on its territory.

Government networks are networks used in government agencies.

Based on the speed of information transfer, computer networks are divided into low-, medium- and high-speed.

low-speed (up to 10Mbit/s),

medium-speed (up to 100Mbit/s),

high-speed (over 100 Mbit/s);

Depending on the purpose and technical solutions, networks can have different configurations (or, as they also say, architecture, or topology).

In a ring topology, information is transmitted over a closed channel. Each subscriber is directly connected to its two closest neighbors, although in principle it is capable of contacting any subscriber in the network.

In a star-shaped (radial) system, in the center there is a central control computer that sequentially communicates with subscribers and connects them with each other.

In a bus configuration, computers are connected to a common channel (bus), through which they can exchange messages.

In a tree view, there is a “main” computer, to which the computers of the next level are subordinate, etc.

In addition, configurations without a distinct nature of connections are possible; The limit is a fully meshed configuration, where every computer on the network is directly connected to every other computer.

From the point of view of organizing the interaction of computers, networks are divided into peer-to-peer (Peer-to-Peer Network) and dedicated server (Dedicated Server Network).

All computers in a peer-to-peer network have equal rights. Any network user can access data stored on any computer.

Peer-to-peer networks can be organized using operating systems such as LANtastic, Windows "3.11, Novell Netware Lite. These programs work with both DOS and Windows. Peer-to-peer networks can also be organized on the basis of all modern 32-bit operating systems - Windows 9x \ME\2k, Windows NTworkstation versions, OS/2) and some others.

Advantages of peer-to-peer networks:

1) the easiest to install and operate.

2) the DOS and Windows operating systems have all the necessary functions that allow you to build a peer-to-peer network.

The disadvantage of peer-to-peer networks is that it is difficult to resolve information security issues. Therefore, this method of organizing a network is used for networks with a small number of computers and where the issue of data protection is not fundamental.

In a hierarchical network, when the network is installed, one or more computers are pre-allocated to manage data exchange over the network and resource distribution. Such a computer is called a server.

Any computer that has access to the server's services is called a network client or workstation.

A server in hierarchical networks is a permanent storage of shared resources. The server itself can only be a client of a server at a higher hierarchy level. Therefore, hierarchical networks are sometimes called dedicated server networks.

Servers are usually high-performance computers, possibly with several parallel processors, high-capacity hard drives, and a high-speed network card (100 Mbit/s or more).

The hierarchical network model is the most preferable, as it allows you to create the most stable network structure and more rationally distribute resources.

Another advantage of a hierarchical network is a higher level of data protection.

The disadvantages of a hierarchical network, compared to peer-to-peer networks, include:

1) the need for an additional OS for the server.

2) higher complexity of network installation and upgrading.

3) The need to allocate a separate computer as a server.

Chapter 2 Main types of computer networks

2.1 Local area network (LAN)

Local networks (LAN computers) connect a relatively small number of computers (usually from 10 to 100, although sometimes much larger ones are found) within one room (a computer classroom), building or institution (for example, a university). The traditional name is a local area network (LAN). ) - rather a tribute to the times when networks were mainly used to solve computing problems; today, in 99% of cases, we are talking exclusively about the exchange of information in the form of texts, graphic and video images, and numerical arrays. The usefulness of the LS is explained by the fact that from 60% to 90% of the information an institution needs circulates within it, without needing to go outside.

The development of drugs was greatly influenced by the creation of automated enterprise management systems (ACS). ACS include several automated workstations (AWS), measuring systems, and control points. Another important field of activity in which drugs have proven their effectiveness is the creation of classroom-based computer technology (KUTT).

Thanks to the relatively short lengths of communication lines (usually no more than 300 meters), information can be transmitted digitally over the LAN at a high transmission speed. Over long distances, this transmission method is unacceptable due to the inevitable attenuation of high-frequency signals; in these cases, it is necessary to resort to additional technical (digital-to-analog conversions) and software (error correction protocols, etc.) solutions.

A characteristic feature of the LAN is the presence of a high-speed communication channel connecting all subscribers for transmitting information in digital form.

There are wired and wireless channels. Each of them is characterized by certain values of parameters that are essential from the point of view of drug organization:

Data transfer rates;

Maximum line length;

Noise immunity;

Mechanical strength;

Convenience and ease of installation;

Cost.

Currently, four types of network cables are commonly used:

Coaxial cable;

Unprotected VitayaPara;

Protected twisted pair;

Fiber optic cable.

The first three types of cables transmit an electrical signal through copper conductors. Fiber optic cables transmit light along glass fibers.

Most networks allow several cable connection options.

Coaxial cables consist of two conductors surrounded by insulating layers. The first layer of insulation surrounds the central copper wire. This layer is braided from the outside with an external shielding conductor. The most common coaxial cables are thick and thin "Ethernet" cables. This design provides good noise immunity and low signal attenuation over distances.

There are thick (about 10 mm in diameter) and thin (about 4 mm) coaxial cables. Having advantages in noise immunity, strength, and league length, a thick coaxial cable is more expensive and more difficult to install (it is more difficult to pull through cable channels) than a thin one. Until recently, thin coaxial cable represented a reasonable compromise between the basic parameters of LAN communication lines and in Russian conditions is most often used for organizing large LANs of enterprises and institutions. However, thicker, more expensive cables provide better data transmission over longer distances and are less susceptible to electromagnetic interference.

Twisted pairs are two wires twisted together at six turns per inch to provide EMI protection and impedance matching. Another name commonly used for such wire is “IBM Type-3.” In the United States, such cables are installed during the construction of buildings to provide telephone communications. However, the use of telephone wire, especially when it is already located in the building, can create big problems. First, unprotected twisted pair cables are susceptible to electromagnetic interference, such as electrical noise generated by fluorescent lights and moving elevators. Interference can also be generated by signals transmitted in a closed loop on telephone lines along a LAN cable. In addition, poor quality twisted pair cables may have a variable number turns per inch, which distorts the calculated electrical resistance.

It is also important to note that telephone wires are not always laid in a straight line. A cable connecting two adjacent rooms can actually go around half the building. Underestimating the cable length in this case may result in it actually exceeding the maximum permissible length.

Protected twisted pairs are similar to unprotected twisted pairs, except that they use thicker wires and are protected from external influences by the neck of the insulator. The most common type of such cable used in local networks, “IBM type-1” is a secure cable with two twisted pairs of continuous wire. In new buildings, Type-2 cable may be the best option, since it includes, in addition to the data line, four unprotected pairs of continuous wire for transmitting telephone conversations. Thus, “type-2” allows you to use one cable to transmit both telephone conversations and data over a local network.

Protection and careful adherence to the number of twists per inch make rugged twisted pair cable a reliable alternative cabling connection.” However, this reliability comes at an increased cost.

Fiber optic cables transmit data in the form of pulses of light" to glass "wires". Most LAN systems today support fiber optic cabling. Fiber optic cable has significant advantages over any copper cable option. Fiber optic cables provide the highest transmission speeds; they are more reliable because they are not subject to loss of information packets due to electromagnetic interference. Optical cable is very thin and flexible, making it easier to transport than heavier copper cable. Most importantly, however, only optical cable has the bandwidth needed for faster networks in the future.

The price of fiber optic cable is still significantly higher than copper cable. Compared to copper cable, the installation of an optical cable is more labor-intensive, since its ends must be carefully polished and aligned to ensure a reliable connection. However, now there is a transition to fiber-optic lines, which are absolutely immune to interference and are unrivaled in terms of throughput. The cost of such lines is steadily decreasing, technological difficulties The junctions of optical fibers are successfully overcome.

Wireless communications over microwave radio waves can be used to organize networks within large premises such as hangars or pavilions, where the use of conventional communication lines is difficult or impractical. In addition, wireless lines can connect remote segments of local networks at distances of 3 - 5 km (with a wave channel antenna) and 25 km (with a directional parabolic antenna) subject to direct visibility. Organizing a wireless network is significantly more expensive than a conventional one.

To connect computers using LAN communication lines, network adapters (or, as they are sometimes called, network cards) are required. The most famous are: adapters of the following three types:

Of these, the latter have become overwhelmingly widespread in Russia. The network adapter is inserted directly into a free slot on the motherboard of a personal computer and a LAN communication line is connected to it on the rear panel of the system unit. The adapter, depending on its type, implements one or another access strategy from one computer to another.

To ensure coordinated operation in data networks, various communication protocols are used - sets of rules that the transmitting and receiving parties must adhere to for consistent data exchange. Protocols are sets of rules and procedures that govern how some communication occurs. Protocols are the rules and technical procedures that allow multiple computers, when networked, to communicate with each other.

There are many protocols. And although they all participate in the implementation of communication, each protocol has different goals, performs different tasks, and has its own advantages and limitations.

Protocols operate at different levels of the OSI/ISO open systems interconnection model. The functions of a protocol are determined by the level at which it operates. Several protocols can work together. This is the so-called stack, or set, of protocols.

Just as networking functions are distributed across all layers of the OSI model, protocols operate together at different layers of the protocol stack. Layers in the protocol stack correspond to layers of the OSI model. Taken together, the protocols provide a complete description of the functions and capabilities of the stack.

Data transmission over a network, from a technical point of view, must consist of sequential steps, each of which has its own procedures or protocol. Thus, a strict sequence in performing certain actions is maintained.

In addition, all these steps must be performed in the same sequence on each network computer. On the sending computer, actions are performed from top to bottom, and on the receiving computer, from bottom to top.

The sending computer, in accordance with the protocol, performs the following actions: breaks the data into small blocks called packets that the protocol can work with, adds address information to the packets so that the recipient computer can determine that this data is intended for it, prepares the data for transmission through the network adapter card and then via the network cable.

The recipient computer, in accordance with the protocol, performs the same actions, but only in reverse order: receives data packets from the network cable; transmits data to the computer through the network adapter card; removes from the packet all service information added by the sending computer, copies the data from the packet to a buffer - to combine it into the original block, transfers this block of data to the application in the format that it uses.

Both the sending computer and the receiving computer need to perform each action in the same way so that the data received over the network matches the data sent.

If, for example, the two protocols have different ways of breaking up data into packets and adding information (packet sequence, timing, and error checking), then a computer running one of those protocols will not be able to successfully communicate with a computer running the other protocol.

Until the mid-80s, most local networks were isolated. They served individual companies and were rarely combined into large systems. However, when local networks reached a high level of development and the volume of information transmitted by them increased, they became components of large networks. Data transmitted from one local network to another along one of the possible routes is called routed. Protocols that support data transfer between networks along multiple routes are called routed protocols.

Among the many protocols, the most common are the following:

· IPX/SPX and NWLmk;

· OSI protocol suite.

2.2 Wide Area Network (WAN)

WAN (World Area Network) is a global network covering large geographic regions, including both local networks and other telecommunication networks and devices. An example of a WAN is a packet-switched network (Frame relay), through which various computer networks can “talk” to each other.

Today, when the geographical boundaries of networks are expanding to connect users from different cities and states, LANs are turning into a global computer network [WAN], and the number of computers in the network can already vary from tens to several thousand.

Internet is a global computer network covering the whole world. Today the Internet has about 15 million subscribers in more than 150 countries. Every month the size of the network increases by 7-10%. The Internet forms a kind of core that connects various information networks belonging to various institutions around the world with one another.

If previously the network was used exclusively as a medium for transferring files and email messages, today more complex problems of distributed access to resources are being solved. About three years ago, shells were created that support network search functions and access to distributed information resources and electronic archives.

The Internet, which once served exclusively research and academic groups whose interests ranged from access to supercomputers, is becoming increasingly popular in the business world.

Companies are seduced by speed, cheap global communications, ease of collaboration, accessible programs, and a unique Internet database. They view the global network as a complement to their own local networks.

At a low cost (often just a flat monthly fee for the lines or telephone used), users can access commercial and non-commercial information services in the United States, Canada, Australia, and many European countries. In the archives of free access on the Internet you can find information on almost all areas of human activity, from new scientific discoveries to the weather forecast for tomorrow.

In addition, the Internet provides unique opportunities for low-cost, reliable and confidential global communications around the world. This turns out to be very convenient for companies with their branches around the world, transnational corporations and management structures. Typically, using the Internet infrastructure for international communication is much cheaper than direct computer communication via satellite or telephone.

E-mail is the most common Internet service. Currently, approximately 20 million people have an email address. Sending a letter by e-mail is much cheaper than sending a regular letter. In addition, a message sent by e-mail will reach the addressee in a few hours, while a regular letter can take several days, or even weeks, to reach the addressee.

Currently, the Internet uses almost all known communication lines from low-speed telephone lines to high-speed digital satellite channels.

In fact, the Internet consists of many local and global networks belonging to various companies and enterprises, interconnected by various communication lines. The Internet can be imagined as a mosaic made up of small networks of different sizes that actively interact with each other, sending files, messages, etc.

Like any other network on the Internet, there are 7 levels of interaction between computers: physical, logical, network, transport, session level, presentation and application level. Accordingly, each level of interaction corresponds to a set of protocols (i.e. rules of interaction).

Physical layer protocols determine the type and characteristics of communication lines between computers. The Internet uses almost all currently known communication methods, from a simple wire (twisted pair) to fiber-optic communication lines (FOCL).

For each type of communication line, a corresponding logical level protocol has been developed to control the transmission of information over the channel. Logical layer protocols for telephone lines include SLIP (Serial Line Interface Protocol) and PPP (Point to Point Protocol).

For communication over a cable local network, these are packet drivers for LAN cards.

Network layer protocols are responsible for transmitting data between devices on different networks, that is, they are responsible for routing packets in the network. Network layer protocols include IP (Internet Protocol) and ARP (Address Resolution Protocol).

Transport layer protocols control the transfer of data from one program to another. Transport layer protocols include TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).

Session-level protocols are responsible for establishing, maintaining and destroying the corresponding channels. On the Internet, this is done by the already mentioned TCP and UDP protocols, as well as the UUCP (Unix to Unix Copy Protocol).

Representative layer protocols are responsible for serving application programs. Executive-level programs include programs that run, for example, on a Unix server to provide various services to subscribers. These programs include: telnet server, FTP server, Gopher server, NFS server, NNTP (Net News Transfer Protocol), SMTP (Simple Mail Transfer Protocol), POP2 and POP3 (Post Office Protocol), etc.

Application layer protocols include network services and programs for providing them.

The Internet is a constantly developing network, which still has everything ahead, let’s hope that our country will not lag behind the progress.

/>/>/>/>/>/>/>/>/>/>/>/>Conclusion

A computer network is an association of several computers for the joint solution of information, computing, educational and other problems.

The main purpose of computer networks is to share resources and implement interactive communication both within one company and

and beyond.

A local computer network is a collection of computers connected by communication lines, providing network users with the potential opportunity to share the resources of all computers. On the other hand, simply put, a computer network is a collection of computers and various devices that provide information exchange between computers on the network without the use of any intermediate storage media.

A global computer network (WAN or WAN - World Area NetWork) is a network that connects computers that are geographically located at large distances from each other. It differs from a local network in more extensive communications (satellite, cable, etc.). The global network connects local networks.

Internet is a global computer network covering the whole world.

In fact, the Internet consists of many local and global networks belonging to various companies and enterprises, interconnected by various communication lines.

List of used literature

1. “Internet at your home”, S. V. Simonovich, V. I. Murakhovsky, LLC “AST-Press Book”, Moscow 2002.

2. Gerasimenko V.G., Nesterovsky I.P., Pentyukhov V.V. and others. Computer networks and means of their protection: Textbook / Gerasimenko V.G., Nesterovsky I.P., Pentyukhov V.V. and etc. – Voronezh: VSTU, 1998. – 124 p.

3. ComputerWeek Moscow, a weekly magazine for entrepreneurs and specialists in the field of information technology.

4. Magazine for personal computer users PC World.

5. Kamalyan A.K., Kulev S.A., Nazarenko K.N. and others. Computer networks and information security tools: Textbook / Kamalyan A.K., Kulev S.A., Nazarenko K.N. and others - Voronezh: VSAU, 2003.-119p.

6. Kurnosov A.P. Workshop on computer science/Ed. Kurnosova A.P. Voronezh: VSAU, 2001.- 173 p.

7. Malyshev R.A. Local computer networks: Textbook / RGATA. – Rybinsk, 2005. – 83 p.

8. Olifer V.G., Olifer N.A. Network operating systems/ V.G. Olifer, N.A. Olifer. – St. Petersburg: Peter, 2002. – 544 p.: ill.

9. Olifer V.G., Olifer N.A. Computer networks. Principles, technologies, protocols/V.G. Olifer, N.A. Olifer. - St. Petersburg: Peter, 2002.- 672 p.: ill.

10. Simonovich S.V. Informatics. Basic course/Simonovich S.V. and others - St. Petersburg: Peter Publishing House, 2000. - 640 pp.: ill.

(Graduate work)

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1 TPI Prilepo D.V.

Content

Page


	Introduction……………………………………………………………..	3

1.	a common part

1.1	Brief description of the object of practice……………………….	4

1.2	Characteristics of computer equipment………………………	6

1.2.1	Microsoft Word – text editor………………………………………………………	9

1.2.2	Microsoft Excel – editor for a set of formulas and plotting.	11

1.2.3	Microsoft Access – editor for creating databases……………	14

1.2.4	Microsoft Power Point – graphic editor (presentation design)………………………………………………………………………………….

2.	Special part

2.1	Stocks and bods market……………………………………………….	19

	Conclusion…………………………………………………………...	23

	Conclusion…………………………………………………………………	24

	Bibliography………………………………….	25

Introduction

Purpose practice is to consolidate theoretical knowledge and develop sustainable practical skills in collecting, storing, processing, analyzing and presenting information on personal computers.

To achieve the goal you need to do the following tasks:

preparation and execution of a report on the results of the work.

1. GENERAL PART
1.1 Brief description of the object of practice
Branch of the State Educational Institution of Higher Professional Education “Kostroma State University named after. ON THE. Nekrasova"

The branch is a structural subdivision of the state educational institution of professional higher education “Kostroma State University named after. ON THE. Nekrasova". The branch is endowed, by power of attorney issued by the rector of the University, with full or partial powers of a legal entity.

The branch was created on the basis of Order No. 259 of May 28, 1996 of the Ministry of Education of the Russian Federation, renamed into a branch of the state educational institution of professional higher education “Kostroma State University named after. ON THE. Nekrasov" in the city of Kirovsk, Murmansk region, on the basis of order No. 965 of 03/02/2004 of the Ministry of Education of the Russian Federation. The branch carries out its activities in accordance with the Constitution of the Russian Federation, the Law of the Russian Federation "On Education", the Law of the Russian Federation "On Higher and Postgraduate Professional Education", other federal laws of the state, the Charter of the State Educational Institution of Higher Professional Education "Kostroma State University named after. ON THE. Nekrasov”,_Regulations on the branch.

The director of the branch is appointed by order of the rector of the University. The director of the branch is Lyudmila Viktorovna Koptyaeva. If there is a power of attorney to grant the branch the powers of a legal entity, the director of the branch represents it in all bodies, institutions, and enterprises:

1 - opens branch accounts in the bank, issues orders and gives instructions mandatory for all employees and students;

2 - disposes of the property of the branch, including concluding agreements with subsequent notification of the Academic Council of the branch;

3 - carries out the hiring and dismissal of branch personnel, deputy directors and accountants, determines their specific duties and responsibilities

4 - determines the competence, level of responsibility, volume and forms of material financial incentives for branch employees

5 - bears personal responsibility for the results of the branch’s work.

The main objectives of the branch are:

satisfying the individual's needs for intellectual, cultural and moral development through higher education;
meeting the needs of society for highly qualified personnel, combining high general culture with professional competence;
conducting scientific research and development work;
increasing the general educational and cultural level of the population, expanding their knowledge.

Educational activities.

The branch implements basic and additional educational vocational training programs.
The content of education is determined by State standards, approved curricula of specialties and programs.

Research activities

The branch carries out scientific research, which is a necessary component of the training of specialists.
The subject and scope of scientific research is approved by the Academic Council of the University branch.

The director of the branch reports annually to the Academic Council on the activities of the branch.

The management of the department is carried out by the head, who is elected by the Academic Council of the university for a period of up to five years and confirmed in office by the rector of the university, and bears full responsibility for the results of work within the scope of his competence.

The department includes professors, associate professors, senior teachers, teaching assistants, educational and support staff.

The department provides methodologically and manages educational and production programs, coursework and diploma works (projects), independent studies for students, prepares and conducts coursework, exams and tests, and organizes practical training.

Today the branch has the following 4 departments.

The reorganization and liquidation of the branch is carried out by order of the Ministry of Education and Science of the Russian Federation in the prescribed manner.

The liquidation of a branch is carried out by the liquidation commission on the grounds provided for by the Laws of the Russian Federation in the prescribed manner.

1.2 Characteristics of computer equipment
The branch has 3 computer classes:
201 cab (XP):

9 Intel Pent-4 computers

9 LG monitors

Computer clock speed 2.4 megahertz

USB Model

A CD-ROM CCD-40 X3H is installed on one computer

RAM -256 MB

9 comps brand Sisg50-651-M 650-M652-740

9monitors

Clock frequency 1700mH

RAM 128 MB 7pcs

Hard drive 30GB-40GB

Operating system Wind-98

Their brand is Intel Pent-3

Clock frequency -602 mH

RAM - 12 MB

Hard disk - 10-20 GB

Wind-98 installation
Information and technical department:

3 computers:

1 set - Intel Celeron

T-frequency 667mG

RAM 128 MB

Hard disk - 120 GB

Operating system Wind-XP

Siver SAMSUNC

LG flatron LCD monitor

EPSH dot matrix printer

2nd ACEZ monitor

2 computer monitor AMD-k5

Clock frequency 100 mH

RAM 32 MB

Hard disk - 8 MB

Operating system Wind-98 network version

Siver –Beno

Intel Pent-4 Server

Clock frequency 2.66 mH

RAM 256 MB

Hard disk-20 MB

Operating system Winolows N1 Pzo

The photocopier oievelop 1300 is located

2nd LG LCD monitor

AMD Duzen computer

2 green manures

Scanner - Mustek

Model ACCUZA Hays

HD laser printer

Brief list of equipment:

Each department of the KSU branch is equipped with a PC and peripheral devices:

Printer

Xerox

Multifunctional devices:

Computer classes 102-201 are united into a local network for star topology communication.

In the future, it is planned to combine 3 branch buildings into one network for more efficient information exchange.

The branch's classes are designed to conduct practical classes in information disciplines.

Computers are equipped with server and software.

In practical classes, specialized packages are used, universal

Programs such as:

Accounting

Turbo Pockal

Mat Kat

As well as a text editor, graphics processor, spreadsheet processor and DBMS

Computer classes are equipped with legal reference systems:

Consultant + Guarantor

There is Internet access. Each computer is equipped with a parallel connection that protects against unauthorized access.
1.2.1 MicrosoftWord– text editor.
General information

The general name for software designed for creating, editing and formatting simple and complex text documents is word processors. Currently, the most widely used word processor is Microsoft Word.

Microsoft Word processor working window

Working window of the Microsoft Word 2000 processor Its main controls: menu bar, toolbar, work field and status bar, including indicators. Starting with the Microsoft Word 95 processor, the toolbar is customizable.

Document display modes

Starting with the sixth version of Microsoft Word, it supports several document presentation modes.

In normal mode, only the content part of the document is presented without requisite design elements that relate not to the text, but to the printed pages (headers, footers, subpage footnotes, etc.). This mode is convenient in the early stages of document development (text input, editing, reviewing), as well as in all cases when the content of the document is of higher importance than its external presentation. In this mode, operations with large documents are faster, which is important when working on low-performance computers.

In Web document mode, the screen representation does not match the printed one. This is a departure from the WYSIWYG principle, but it is typical for electronic publishing on the World Wide Web because it is not known in advance which viewer or equipment the document will be displayed on. The concept of a printed page is meaningless for electronic documents, so assigned page settings are not taken into account, and formatting of the document on screen is relative. Electronic publications are developed in this mode.

In markup mode, the screen representation of the document fully corresponds to the printed one, right down to the assigned parameters of the printed page. This mode is convenient for most work related to formatting text intended for printing.

In Outline view, you can only display document headings. The mode is useful in cases where the development of a document begins with the creation of a content plan. If the document is more than 5-7 printed pages in size, you should always start by creating a primary outline. The mode differs in that when it is turned on, the auxiliary Structure panel automatically opens on the toolbar, the controls of which allow you to edit the structure of the document.

Selecting one of the four above document presentation modes is done using the command buttons located in the lower left corner of the application window, or using the View menu commands.

A special view (fifth mode) is also available through the View menu. A document layout in which the application window has two working panels. The left panel shows the structure of the document, and the right panel shows the document itself. This mode, which combines the advantages of the markup mode and the structure mode, is useful when navigating through a voluminous document - it is convenient to use not when creating, but when viewing documents with a complex structure.

Two more document presentation modes are available through the File menu, used for previewing. For electronic documents, use the File command. Preview of the Web page, and for printed documents - the Preview file. In the first case, the created document is displayed as a Web page in the browser window registered by the operating system as the default one (preferably Microsoft Internet Explorer 5.0). In the second case, the document is presented in a special window

Techniques for working with texts in the Microsoft Word processor

Basic techniques for working with texts in the Microsoft Word word processor include the following:

creating a document;
text input;
text editing;
text review;
text formatting;
saving the document;
printing the document.

1.2.2 MicrosoftExcel– editor of a set of formulas, plotting.
MS Excel, being a leader in the market for spreadsheet processing programs, determines development trends in this area. Up until version 4.0, Excel was the de facto standard in terms of functionality and usability. Now version 5.0 has appeared on the market, which contains many improvements and pleasant surprises.

Significant achievements in the new version of Excel include the appearance of three-dimensional documents (notepads). Establishing links between files and tables has been greatly simplified compared to previous versions. Context menus have been significantly expanded, and additional software tools make it easier to solve complex application problems.

It is also worth mentioning the various assistants (Assistants), which help the user set functions and give recommendations if there is a simpler method for solving the current task. The Excel program has a built-in convenient help subsystem, which is ready to issue the necessary help at any time.

The innovations described so far relate mainly to ease of use and quick mastery of the program. One of the most important functional extensions of the program, intended for professionals, is the Visual Basic (VBA) programming environment built into Excel for solving applied problems. Thanks to VBA, Microsoft was able to not only expand the capabilities of the Excel 4.0 macro language, but also introduce a new level of application programming, since VBA allows you to create full-fledged application packages that, in their functions, go far beyond spreadsheet processing. In addition, the following important innovations of Excel 5.0 should be mentioned:

File manager, which provides detailed information about all files;

Dialog boxes-registers;

Separate icon for formatting;

The appearance of the Drag&Plot mechanism, designed to quickly activate diagrams.

All table data is recorded in so-called cells, which are located at the intersection of the rows and columns of the table. By default, the contents of a cell are presented by Excel in a standard format, which is installed when the program starts. For example, numbers and texts are set to a specific font type and size.

Excel has context menus that are called up with the right mouse button when a certain area of the table is marked. These menus contain many table processing and formatting directives.

The ability to use formulas and functions is one of the most important features of a spreadsheet program. This, in particular, allows for statistical analysis of the numerical values in the table.

The text of a formula that is entered into a table cell must begin with an equal sign so that Excel can distinguish the formula from text. After the equal sign, a mathematical expression containing arguments, arithmetic operations and functions is written into the cell.

Numbers and cell addresses are usually used as arguments in the formula. The following symbols can be used to denote arithmetic operations: + (addition); - (subtraction); * (multiplication); / (division).

The formula may contain references to cells that are located on another worksheet or even in a table in another file. Once entered, the formula can be modified at any time. The built-in Formula Manager helps the user find an error or incorrect link in a large table.

In addition, Excel allows you to work with complex formulas containing several operations. For clarity, you can turn on text mode, then Excel will display in the cell not the result of the formula calculation, but the formula itself.

Graphic charts enliven the dry columns of numbers in a table, which is why already in early versions of Excel the ability to create charts was provided. The fifth version of Excel includes a new Chart Designer that allows you to create "presentation-quality" charts.

A beautiful 3D diagram not only pleases the eye, but also improves the quality of the document. MS Excel 5.0 has introduced a new type of three-dimensional charts - the so-called donut charts, which complement the surface and grid three-dimensional charts of the fourth version.

It is fashionable to place the diagram next to the table or place it on a separate worksheet.

The Chart Builder is one of the most powerful tools in Excel. Constructing a diagram with its help is carried out in several steps. The designer is given the source area of the table, the type of chart, the labels and colors to use. The main panel has an icon for calling the Chart Designer.

To perform tabular calculations, you need formulas. Because some formulas and their combinations are very common, Excel offers more than 200 pre-programmed formulas called functions.

All functions are divided into categories to make them easier to navigate. The built-in Function Builder helps you use functions correctly at all stages of work. It allows you to construct and calculate most functions in two steps.

The program has a complete list of all functions, ordered alphabetically, in which you can easily find a function if you know its name; otherwise, you should search by category. Many functions vary very slightly, so when searching by category, it is useful to use the short descriptions of functions that the Function Builder provides. A function operates on some data called its arguments. A function argument can occupy a single cell or be placed in an entire group of cells. The function constructor provides assistance in specifying any type of arguments. Data exchange allows Excel users to import objects from other applications into their tables and transfer (export) their tables for embedding in other objects.

1.2.3 MicrosoftAccess– editor for creating databases.
Microsoft Access provides several tools for creating each of the main database objects. These remedies can be classified as;

manual (developing objects in Design mode);
automated (development using wizard programs);
automatic - means of accelerated development of simple objects.

1. When developing training tables and queries, it is recommended to use manual tools - work in Design mode. Using wizards speeds up work, but does not facilitate mastery of concepts and methods.

When developing educational forms, reports and access pages, on the contrary, it is better to use the automated tools provided by the wizards. This is due to the fact that appearance plays an important role for these objects. The design of these objects is very labor-intensive, so it is better to entrust it to the program, and the student to concentrate on the content of the work.

Working with tables

Creating tables. Working with any objects begins with the Database window. Its left panel contains controls for calling all seven types of program objects. Creating tables begins by selecting the Tables control.

The right panel provides a list of tables already included in the database and provides controls for creating a new table. To create a table manually, use the Create Table icon in Design view.

The lower part of the form contains a list of properties of the field highlighted in the upper part. Some of the properties are already set by default. Field properties are optional. They can be adjusted as desired, or left untouched.

When creating a table, it is advisable (though not required) to specify a key field. This will help later when organizing connections between tables. To set a key field, just right-click on its name and select Key Field in the context menu that opens.

We said above that if a primary key is needed to relate to other tables, but none of the fields is unique, then a primary key can be created based on two (or more fields). This operation is performed in exactly the same way, through the context menu, you just need to be able to select several fields at once

Having finished creating the table structure, close the form (the system prompts you to save the table), after which you give the table a name, and from that moment it is available among other tables in the main Database window. From there you can open it if necessary.

The created table is opened in the Database window by double-clicking on its icon. The new table has no records - only column names that characterize the structure of the table. Filling the table with data is done in the usual manner.

At the bottom of the table there is a Transition Button Panel. Its controls are convenient to use when navigating through a table that has a large number of records.

Beginner Microsoft Access users find it inconvenient that data does not always fit into table cells. The width of columns can be controlled by dragging their borders. It is convenient to use automatic formatting of columns “by content”. To do this, place the mouse pointer on the border between the columns (in the column header line), wait until the pointer changes shape, and double-click

After filling the table with data, there is no need to save it - everything is saved automatically. However, if, while working with a table, you edited its layout (for example, the width of the columns changed), the DBMS will ask you to confirm saving these changes.

If there is a need to change the structure of the table (the composition of the fields or their properties), the table must be opened in Design mode. To do this, select it in the Database window and click on the Design button.

Creating inter-table relationships. If the database structure is thought out in advance, and the relationships between tables are outlined, then creating relational relationships between tables is very simple. All necessary work takes place in a special Data Schema window and is performed using the mouse. The Data Schema window is opened with a button on the toolbar or with a command.

1.2.4 MicrosoftPowerPoint– graphic editor (design of presentations).
There are three main modes in Microsoft PowerPoint: Normal mode, Slide Sorter mode, and Slide Show. Based on these basic modes, you can select a default mode.

Creating presentations

The process of creating a presentation in Microsoft PowerPoint consists of such actions as choosing a general design, adding new slides and their content, selecting markings slides, changing the design of the slides if necessary, changing color scheme, the use of various design templates and creating effects such as slide show animations. The information below is about the tools available to start this process.

Task pane Creating a Presentation in Microsoft PowerPoint provides the following number of options for creating a new presentation.

Create. The slides have a minimum of design elements and no colors are applied to them.
From an existing presentation. A presentation is created based on an existing presentation with a given design. A copy of your existing presentation is created, allowing you to create a new presentation by making changes to the design and content of the original presentation.
From the design template. The presentation is created based on an existing Microsoft PowerPoint template containing basic design elements, fonts and a color scheme. In addition to standard Microsoft PowerPoint templates, you can use your own created templates.
From the Auto Content Wizard. Use the Auto Content Wizard to apply a design template that includes suggested text for your slides. Then the necessary changes are made to the proposed text.
Templates on the website. Create a presentation using a template located on the website.
Templates on Microsoft.com. Create a presentation using additional Microsoft PowerPoint templates from the Microsoft Office template library. These templates are organized by presentation type.

Create a presentation using blank slides

Create a presentation based on suggested content

If in task areas icon is not displayed Create a presentation, select from the menu File team Create.
On the list Create select item From Auto Content Wizard and follow the wizard's instructions.
Replace the suggested text with the new text in your presentation, and then make any changes to the presentation, such as adding or removing slides, adding artwork or animation effects, or inserting headers and footers.
When finished in the menu File select team Save, enter the name of the created presentation in the field File name and press the button Save.

Create a new presentation based on an existing one
Following the steps below will create a copy of your existing presentation, which will allow you to make changes to the design and content of the copy of the presentation without changing the original.

If in task areas icon is not displayed Create a presentation, select from the menu File team Create.
In chapter Create from an existing presentation select team Selecting a presentation.
In the list of files, select the desired presentation and click the button Create.
Make the necessary changes to the presentation and then to the menu File select team Cprotect as.
In field File name Enter a name for the new presentation.
Click the button Save.

2. GENERAL PART
Stocks and bods market.
General information:

In a modern market economy, the securities market occupies a special and very important place.

The history of the securities market goes back several centuries. 400 years ago, in 1592, a list of prices for securities sold on the local stock exchange was first published in Antwerp. This year is considered the year of the birth of stock exchanges as special organizations involved in the purchase and sale of securities.

In the regulated economy of the Soviet period, there were simply no securities. Only bonds of government loans were in circulation, which can be called a security only with great stretch due to the forced nature of the distribution of most issues of these loans and the lack of free circulation.

Securities - are documents that have legal force, drawn up in a certain form and giving their owner a unilateral standardized set of rights in relation to the persons who issued these documents, the ability to transfer these documents, subject to pre-agreed conditions, but without the consent of the issuers, to another person together with the whole range of rights contained in them.

The peculiarities of the formation of the Russian securities market include the issue of shares during the transformation of state-owned enterprises into joint-stock companies in the process of privatization. In Russia, mass privatization led to the appearance of a huge number of securities in circulation, but this way of expanding the stock market is not typical for world experience. Especially in countries with developed market economies, privatized enterprises are already joint-stock companies, the controlling stake of which belonged to the state before privatization.

Another feature of the formation of the securities market in Russia was the issue by federal authorities of part of government securities not to attract funds, but with the aim of giving a more civilized market form to government debts.

It was for this purpose that bonds of the Internal State Foreign Currency Loan, Treasury bills, rural bonds were issued, and here, with reservations, one can also include the Privatization Checks of the Russian Federation of the 1993 model. As with shares of privatized enterprises, these government securities laid the foundations for the modern Russian securities market.

In general, the securities market is a complex system with its own structure. Organizationally, the securities market includes several elements:

market regulatory framework;
market instrument – securities of all types;
methods of organizing securities trading;
market participants.

Types of securities:

1. bearer securities are securities that do not indicate the name of the owner. Most often they are issued in small denominations and are intended for investment by a wide range of people.

2. registered securities - the owner’s rights to such a security must be confirmed by entering the owner’s name in the text of the security itself and in the register maintained by the issuer.

Such securities can be sold on the secondary market, but in order to register the transfer of ownership it is necessary to register the transactions in the register, which complicates the circulation of registered securities compared to bearer ones. Most securities circulating in Russia are registered.

3. order securities – the rights of the owner of order securities are confirmed by transfer notes in the text of the paper and by presentation of the paper itself. This category primarily includes bills of exchange and checks.
Stock - a security issued by a joint-stock company (JSC), reflecting the investor's share in the authorized capital of the company and giving the owner the right to receive a certain income from the company's profits, that is, dividends.

The practice of attracting financial resources to joint-stock companies has developed a large number of types of shares that satisfy a wide variety of consumer needs.

The nominal price only shows what part of the value of the authorized capital in absolute terms is accounted for by a given share. Beyond this, at par value, only a minimum of information can be obtained, namely, if the par value of an ordinary share is divided by the size of the authorized capital of the enterprise, reduced by the volume of issued preferred shares, then the minimum share of votes per share at a meeting of shareholders will be obtained, and the share of profit that will be paid on this share from the total amount allocated for dividends on ordinary shares.

Bonds – this is the issuer’s obligation to pay certain amounts of money to the owner of this security within a certain period of time. Due to their debt-based nature, bonds are safer investments than stocks; being an analogue of a loan, they are “senior” securities in relation to shares, that is, they give a preferential right when paying income or returning invested funds in the event of bankruptcy or liquidation of the issuer.

The higher reliability of bonds makes them popular among investors, and bonds account for more than half of the turnover of most of the world's largest stock markets.

According to the status of the issuer, foreign issuers of bonds are sometimes classified into a separate category, which are also divided into private companies and government agencies.

Derivatives – An option is an obligation, written in the form of a security, conveying the right to buy or sell another security at a specified price up to or at a specified future payment.

Warrant is a security that gives the right to purchase other securities during their initial placement at a certain price and is sold by the issuer of these securities.

Certificates of Deposit and Savings – This is a bank certificate of deposit of funds, giving the right to receive the deposit and the agreed interest. In fact, certificates of deposit and savings certificates are a type of bank time deposits that can be resold.

The attractiveness of certificates of deposit for Russian investors is due to the peculiarities of tax legislation, according to which income from simple deposits of legal entities is subject to taxation at the income tax rate, and income from certificates of deposit is taxed as income from securities, the tax rate for which is much lower.

Bills – it is a promissory note drawn up in accordance with established laws, and giving its owner an unconditional right to claim a specified amount upon the expiration of a specified period.

To characterize the turnover of bills of exchange, you should become familiar with the special terminology used in this sector of the securities market:

promissory note - drawn up by the debtor and contains his obligations;
bill of exchange - drawn up by the creditor and contains an order to the debtor to pay the specified amount;
remittor – the person in whose favor the draft is drawn up;
endorsement – an endorsement on a bill of exchange that satisfies the transfer of the right of claim under the bill of exchange;
allonge – a sheet attached to the bill on which endorsements are made;
aval – a guarantee under which the person who committed it accepts responsibility for fulfilling the obligations of the debtor;
friendly bill is a bill that does not have any transaction behind it, but all participants in the bill transaction are real.

Other securities – Among other securities that are important for the Russian stock market, we can highlight units of mutual investment funds and depositary certificates. Securities include:

a check is a security document executed on a form established by the drawer in the form of an order from the drawer to the bank to pay the check holder the amount specified in the check.
A unit of a mutual fund is a security with unique properties. The uniqueness lies in the virtual absence of a specific element in this security. Units are issued by management companies.

Conclusion
As a result of educational and technological (computer) practice, I studied and mastered the following programs:

Microsoft Word;
Microsoft Excel;
Microsoft Access;
Microsoft Power Point.

During this internship, I learned how to fully work in these programs. These programs will help in the future, because... In our modern world, more and more the use of computer technology helps to increase labor productivity.

Personally, as a student, this will help me in writing coursework, practical work, as well as when writing diploma projects, namely, to feel more free in the above programs.

Conclusion
This practice contributed to the consolidation of theoretical knowledge and the formation of stable practical skills in collecting, storing, processing, analyzing and presenting information on personal computers.

During the practice the following were completed:

work in the Windows operating system environment;
work with service software (disk maintenance utilities, archivers, anti-virus programs);
creation of text documents (MS Word);
creation of functional spreadsheets and graphical display of data processing results (MS Excel);
creation and maintenance of relational databases (MS Access);
work with the integrated MS Office application package and create combined documents based on the MS Word word processor;
creation of a computer presentation (MS Power Point);
obtaining information from the Internet;
preparation and execution of a report on the results of the work.

As my suggestions, I would include in the program practice, working with a printer and scanner, allowing the opportunity to work (gain primary skills) working with the Internet.
Bibliography

Aleksunin V.A. Marketing in industries and fields of activity: textbook. – M.: Publishing house. "Dashkov and Co", 2005 - 716 p.
Weiskas J. Effective work with M. Access 2000. St. Petersburg - St. Petersburg, 2000 - 1040 p.
Gnidenko I.G., Merdina O.D., Ramin E.L. Access - 2000: Workshop. - St. Petersburg: Publishing house "Insight - Ch", 2002. - 192 p.; ill.
Dodge M., Stinson K. Effective work with M. Excel 2000, St. Petersburg: Peter.2000 - 1056 p.
Zhivotnova R.N., Ramin E.L., Shlenov V.V. Word-2000: Workshop. - St. Petersburg: Publishing house "Insight - Ch", 2001. - 176 p.; ill.
COMPUTER SCIENCE: Textbook / ed. N.V. Makarova M.: Finance and Statistics, 2003
COMPUTER SCIENCE: Workshop / ed. N.V. Makarova M.: Finance and Statistics, 2003.
Mogilev A.V. and others. Informatics: Proc. aid for students ped. Universities. - M.: Publishing house. Center "Academy", 2000. - 816 p.
Ramin E.L., Zhivotnova R.N. Power - Point 2000: Workshop. - St. Petersburg: Publishing house "Insight - Ch", 2002. - 26 p.; ill.
Khomonenko A.D., Tsyganokv V.M., Maltsev M.G., Databases: Textbook for higher educational institutions - 3rd Edition, additional. and processed – St. Petersburg: Crown print, 2003. - 672 p.

Content

Introduction

Chapter 1 Concept and classification of computer networks

1.1 Purpose of a computer network

1.2 Classification of computer networks

Chapter 2. Main types of computer networks

2.1 Local area network (LAN)

2.2 Global Area Network (WAN)

Conclusion

List of used literature

Introduction

The advantages of computer networks have led to their widespread use in information systems of the credit and financial sector, government and local governments, enterprises and organizations.

Introduction to computer networks, highlighting their features and differences;

Characteristics of the main methods of constructing networks (network topology);

Studying scientific and methodological literature on this issue

Chapter 1 Concept and classification of computer networks

1.1 Purpose of a computer network

Computers included in the network perform the following functions:

Organization of Internet access

Information transfer management

Providing computing resources and services to network users.

Currently, local computing (LAN) has become very widespread. This is due to several reasons:

Local networks allow you to use a mailbox to transfer messages to other computers, which allows you to transfer documents from one computer to another in the shortest possible time;

Local networks, with special software, are used to organize the sharing of files (for example, accountants on several machines can process transactions of the same ledger).

The Internet, which once served exclusively research and academic groups whose interests ranged from access to supercomputers, is becoming increasingly popular in the business world.

1.2 Classification of computer networks

Based on the method of organization, networks are divided into real and artificial.

Real networks allow computers to be connected using special switching devices and a physical data transmission medium.

/> The territorial distribution of networks can be local, global, regional and city.

Metropolitan Area Network (MAN - Metropolitan Area NetWork) is a network that serves the information needs of a large city.

Regional - located on the territory of a city or region.

There are departmental and state networks based on their affiliation. Departmental ones belong to one organization and are located on its territory.

Government networks are networks used in government agencies.

Based on the speed of information transfer, computer networks are divided into low-, medium- and high-speed.

low-speed (up to 10Mbit/s),

medium-speed (up to 100Mbit/s),

high-speed (over 100 Mbit/s);

Depending on the purpose and technical solutions, networks can have different configurations (or, as they also say, architecture, or topology).

In a star-shaped (radial) system, in the center there is a central control computer that sequentially communicates with subscribers and connects them with each other.

In a bus configuration, computers are connected to a common channel (bus), through which they can exchange messages.

In a tree view, there is a “main” computer, to which the computers of the next level are subordinate, etc.

From the point of view of organizing the interaction of computers, networks are divided into peer-to-peer (Peer-to-Peer Network) and dedicated server (Dedicated Server Network).

All computers in a peer-to-peer network have equal rights. Any network user can access data stored on any computer.

Advantages of peer-to-peer networks:

1) the easiest to install and operate.

2) the DOS and Windows operating systems have all the necessary functions that allow you to build a peer-to-peer network.

Any computer that has access to the server's services is called a network client or workstation.

Servers are usually high-performance computers, possibly with several parallel processors, high-capacity hard drives, and a high-speed network card (100 Mbit/s or more).

The hierarchical network model is the most preferable, as it allows you to create the most stable network structure and more rationally distribute resources.

Another advantage of a hierarchical network is a higher level of data protection.

The disadvantages of a hierarchical network, compared to peer-to-peer networks, include:

1) the need for an additional OS for the server.

2) higher complexity of network installation and upgrading.

3) The need to allocate a separate computer as a server.

Chapter 2 Main types of computer networks

2.1 Local area network (LAN)

A characteristic feature of the LAN is the presence of a high-speed communication channel connecting all subscribers for transmitting information in digital form.

There are wired and wireless channels. Each of them is characterized by certain values of parameters that are essential from the point of view of drug organization:

Data transfer rates;

Maximum line length;

Noise immunity;

Mechanical strength;

Convenience and ease of installation;

Cost.

Currently, four types of network cables are commonly used:

Coaxial cable;

Unprotected VitayaPara;

Protected twisted pair;

Fiber optic cable.

The first three types of cables transmit an electrical signal through copper conductors. Fiber optic cables transmit light along glass fibers.

Most networks allow several cable connection options.

Protection and careful adherence to the number of twists per inch make rugged twisted pair cable a reliable alternative cabling connection.” However, this reliability comes at an increased cost.

To connect computers using LAN communication lines, network adapters (or, as they are sometimes called, network cards) are required. The most famous are: adapters of the following three types:

Both the sending computer and the receiving computer need to perform each action in the same way so that the data received over the network matches the data sent.

Among the many protocols, the most common are the following:

· IPX/SPX and NWLmk;

· OSI protocol suite.

2.2 Wide Area Network (WAN)

The Internet, which once served exclusively research and academic groups whose interests ranged from access to supercomputers, is becoming increasingly popular in the business world.

Currently, the Internet uses almost all known communication lines from low-speed telephone lines to high-speed digital satellite channels.

For communication over a cable local network, these are packet drivers for LAN cards.

Transport layer protocols control the transfer of data from one program to another. Transport layer protocols include TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).

Application layer protocols include network services and programs for providing them.

The Internet is a constantly developing network, which still has everything ahead, let’s hope that our country will not lag behind the progress.

/>/>/>/>/>/>/>/>/>/>/>/>Conclusion

A computer network is an association of several computers for the joint solution of information, computing, educational and other problems.

The main purpose of computer networks is to share resources and implement interactive communication both within one company and

and beyond.

Internet is a global computer network covering the whole world.

In fact, the Internet consists of many local and global networks belonging to various companies and enterprises, interconnected by various communication lines.

List of used literature

1. “Internet at your home”, S. V. Simonovich, V. I. Murakhovsky, LLC “AST-Press Book”, Moscow 2002.

3. ComputerWeek Moscow, a weekly magazine for entrepreneurs and specialists in the field of information technology.

4. Magazine for personal computer users PC World.

6. Kurnosov A.P. Workshop on computer science/Ed. Kurnosova A.P. Voronezh: VSAU, 2001.- 173 p.

7. Malyshev R.A. Local computer networks: Textbook / RGATA. – Rybinsk, 2005. – 83 p.

8. Olifer V.G., Olifer N.A. Network operating systems/ V.G. Olifer, N.A. Olifer. – St. Petersburg: Peter, 2002. – 544 p.: ill.

9. Olifer V.G., Olifer N.A. Computer networks. Principles, technologies, protocols/V.G. Olifer, N.A. Olifer. - St. Petersburg: Peter, 2002.- 672 p.: ill.

10. Simonovich S.V. Informatics. Basic course/Simonovich S.V. and others - St. Petersburg: Peter Publishing House, 2000. - 640 pp.: ill.

Computer networks. Classification of computer networks. ……………4

Fast Ethernet network. …………………………………………………………..5

Network topology. ……………………………………………………...….8

Ensuring work safety in the Computer Center. ……….12

Computer networks. Classification of computer networks.

According to the principles of construction, computer networks are divided into local and remote (Figure 1).

Computer networks

Remote

Local

Peer-to-peer

Multi-rank

Regional

International

Local networks are created, as a rule, in one organization or in one room.

Computers in a given area (city) are connected via modems and communication lines to a more powerful computer called a provider. There are currently more than 100 providers operating in Ukraine.

Each computer user that is connected to the network is assigned details (address). Providers, using the details, ensure communication between the corresponding user computers.

Communication between computers on different continents is carried out via satellite communication channels.

Regional computer networks can operate in different modes. The simplest one is email mode. It is used to transfer letters, documents, etc. from one computer to another.

Fast Ethernet network

Fast Ethernet is a Local Area Network (LAN) technology used to connect computers in a small area, such as an office, building or group of buildings. Fast Ethernet is not intended for use in large regions, such as a large village or an entire city. This differs from wide area computing, which are systems designed to connect devices or LANs located at significant distances from each other.

A simple definition of a LAN is that it is a system for directly connecting many computers. One might say that this definition lacks academic precision, but it is practical and well suited to our purposes. Naturally, this definition requires some explanation. In particular, four words require clearer explanation: “system”, “immediate”, “connection” and “many”. Networks are systems because they are made up of components such as cable, repeaters, network interfaces, nodes, and protocols. You may already be familiar with the term hub. The terms hub and repeater are often used interchangeably, but in Fast Ethernet there are differences between the two. All these elements work together and function as a network. If at least one of them is missing, then there is no LAN.

The term “connection” is easy to explain. The network assumes the presence of a connection, i.e. the path through which computers exchange information and/or data. Creating a connection is the primary task of a LAN or any other network. It is very important that the LAN does not impose restrictions on the type of data that can be exchanged between nodes, except that the data must be digital. Most LANs are used for file and printer sharing. Almost every one of us encounters a similar local network. However, LANs and other networks are capable of transmitting video images, telephone conversations, and other information that can be presented in digital form.

The term “many” is also not difficult to explain. A network is not a network unless

contains two or more computers. Of course, it may contain other devices, such as printers. When referring to devices connected to a network, we use the general term nodes. The node communicates with the LAN using network interface. Thus, the local network directly connects many nodes.

The word “directly” has exceptional meaning in the definition of a LAN. It is the direct connection that makes the network local. “Directly” means that any LAN node can exchange information with any other node without the use of a third node or any device as an intermediary, as opposed to wide area networks that use local area networks or other devices for communication gateways.

Figure 2 shows three LANs connected via two wide area network (WAN) links. Nodes on each LAN can communicate with each other directly. When LAN node 1 communicates with LAN node 3, the data must pass through two gateways. Nodes on different LANs must have information about the presence of a gateway and, if necessary, interact with it. Another common name for a gateway is a router. However, when using this term, remember that every router is a gateway, but not every gateway is a router.

On a single Fast Ethernet LAN (or some other LAN), any two devices can communicate directly because they share a common transmission medium. Typically, this medium is a cable and/or other device that physically connects all the components on the network. In other words, Fast Ethernet is shared environment technology. All LAN nodes use the same transmission medium and the same data transfer rules. The main feature of a local network is that any two nodes that need to exchange data are not required to communicate through intermediate devices.

A LAN is local because all the computers on it are connected by a common environment. Each type of network has rules that determine

the physical connection of its components with each other is called topological

rules.

Rice. 2. Local and global networks

Network topology

There are three main types of network topology: hub and spoke (Hub and Spoke; often called simply “star”), ring and bus (Fig. 3). Computers in Fast Ethernet, like a 10Base-T Ethernet network, are physically connected using the first topology. We will use the term “star” to refer to the “hub and spoke” topology as it is more common.

Fast Ethernet and its predecessor Ethernet act as bus networks. In other words, Fast Ethernet physically uses a star topology, but logically acts as a bus network for historical reasons.

Hub and Beam Ring Fig. 3.

In the first Ethernet networks, from which Fast Ethernet derives, all nodes were connected to a single cable segment using T-connectors

(T-connector). In the first Ethernet networks, from which Fast Ethernet is derived. All nodes were connected to a single cable segment using T-connectors. Early Ethernet networks used thick coaxial cable. Both of its ends ended (Fig. 4) with a device called “terminator”. The configuration described is called 10Base-2 Ethernet or “thin” Ethernet. There are other Ethernet bus technologies, particularly 10Base5, often called “fat” Ethernet, which uses a thick yellow cable.

Rice. 4. Ethernet 10Base-2 bus network

It is easy to guess that such a connection scheme has certain limitations. The biggest challenge is running a single piece of cable throughout the entire building. The next problem is that if a break or other damage occurs anywhere in the cable, the entire LAN fails. The first Ethernet LANs could not be very large due to cable length limitations. To enable the network to grow larger, the concept of a repeater was introduced (Figure 5). The first repeaters were devices that connected two cable segments to form one LAN.

Rice. 5. First repeaters

Repeaters not only connected two pieces of cable, but also filtered the electrical signals passing between the segments. The first repeaters had another advantage: if problems occurred in any section of the cable (for example, a short circuit), then nodes connected to other segments could still communicate with each other. This technique is called splitting(partitioning) and is used in modern Ethernet and Fast Ethernet networks to isolate network components that may cause problems. Although repeaters are physically connected to cable segments, they are low-level electrical devices that are invisible to the nodes. Therefore, the entire system acts as a single LAN.

Newer technology (meaning 10Base-T) introduced the concept repeater hub, usually called simply a hub or repeaters. A hub is a device to which each node in the network is connected instead of being connected with a T-shaped connector to a common cable (Fig. 6).

Rice. 6. Basic repeater

The hub takes up the space allocated in the bus network for the cable and

T-shaped connections. Each node is connected to the hub with a separate cable (Fig. 4). Inside the hub there is a digital bus to which all nodes are connected through the repeater port. The internal digital bus takes up the space allocated for the coaxial cable in the bus network. Repeater ports are designed to perform the same functions as bus repeaters (Figure 5). The difference between them is that the hub has not two, but many (up to 32) ports. In the case of an Ethernet network, this technology is called 10Base-T, and in the case of Fast Ethernet, 100Base-T.

Using a hub offers some benefits and simplifies cable management. Moreover, installing a hub is much easier, since connections go from the center to each network node. All telephone systems are designed this way. In addition, inexpensive unshielded twisted pair cable is used to connect the nodes to the hub. 10Base-T technology used regular telephone cable for this purpose, which greatly simplified the installation of the network in older buildings. Often there was no need to lay a new cable at all, since the signals passed through the existing telephone cable. Twisted pair cable can also be used in Fast Ethernet.

Using cheap twisted pair cable actually reduces the cost of the network. However, the biggest advantage of hubs is that they are, to a certain extent, “smart” devices that control every connection on the network. In addition, Ethernet and Fast Ethernet repeaters offer many new capabilities. True, while Ethernet supports two physical topologies - bus and star, Fast Ethernet supports only star. A Fast Ethernet network cannot operate on coaxial cable.

One of the common features of Ethernet and Fast Ethernet is that nodes and repeaters are able to verify the integrity of the connection. When the cable is connected correctly, an indicator (usually an LED) turns on. Many hubs, as noted earlier, automatically disconnect nodes that are causing too many problems on the network.

When working with Ethernet and Fast Ethernet, these terms are used interchangeably. With other technologies they often mean different things. The hub is usually located in the center, and all connections from the nodes lead to it. Hubs are often simply mechanical devices for connecting cables and terminating them. For example, telephone risers are a form of wired hub.

In Ethernet and Fast Ethernet, a repeater is a device that copies (repeat) electrical signals passing between two or more devices. Early two-port repeaters simply connected two segments of coaxial cable. Fast Ethernet repeater hubs combine the functions of a hub and a repeater. For convenience, they are simply called repeaters, since this is the term specified in the Fast Ethernet specification. The repeater can be made in the form of a separate unit or a board built into a larger chassis. Sometimes it is assembled from separate devices called stackable hubs(stackable hubs).

Ensuring work safety in the Computer Center

The Computer Center widely uses digital computing technology (personal computers) to carry out various calculations, and therefore ensuring work safety is very important. Below are the basic safety regulations used during operation.

Safety precautions

when working with a personal computer

When starting to work with a personal computer, you must always remember that this is a very complex and expensive piece of equipment that requires careful and careful handling and high self-discipline at all stages of working with the computer.

The power supply voltage of a personal computer (220 V) is dangerous to human life. In this regard, the design of computer blocks and interblock connecting cables provide sufficiently reliable insulation from conductive areas. The user practically deals with several power switches and is seemingly protected from electric shock. However, in practical work, unforeseen situations occur, and to prevent them from becoming dangerous for the user, it is necessary to know and strictly follow a number of safety rules. This will not only help to avoid accidents and maintain health, but also guarantee the safety of the equipment.

Particular care must be taken when working with a display whose cathode ray tube uses high voltage and is a source of electromagnetic radiation. Improper handling of the display and other electronic equipment may result in severe electric shock or equipment fire. In this regard, strictly PROHIBITED:

If you notice a burning smell, unusual sounds, or the equipment turns off spontaneously, you must immediately turn off the computer and notify the appropriate personnel.

Working on a computer requires constant attention, clear actions and self-control. In this regard, you should not work on a computer in poor lighting, high noise levels, or touch the screen and back of the display, power wires and grounding devices, connecting cables;

violate the order of turning on and off hardware units, try to independently eliminate the identified malfunction in the operation of the equipment;

place foreign objects on the equipment;

work on a computer in wet clothes and with wet hands.

While working on the computer NECESSARY:

strictly follow the instructions for operating the equipment;

carefully monitor the serviceability of the main units and devices;

operate the keyboard with clean hands, do not press certain keys unnecessarily;

When working with floppy disks, protect them from shock, torsion, magnetic field or heat, do not touch the floppy disk, insert the floppy disk into the drive only after turning it on, making sure that the floppy disk is correctly oriented relative to the drive slot;

during a break in work, turn off the computer only if the processing of the current information is completed and the contents of the RAM are stored on magnetic disks (otherwise the information may be lost);

When working on a computer, the cathode ray tube of the display is a source of electromagnetic radiation, which, when working close to the screen, has a destructive effect on vision, causes fatigue and reduces performance. In this regard, it is necessary to work at a distance of 60–70 cm from the screen, maintain correct posture, without slouching or bending over.

Electrical hazards and protection against electric shock

In the process of setting up computer room equipment and laying network cables, there is a potential danger of electric shock.

Human activity today is unthinkable without the use of electric current. A unified energy system has been created in Ukraine, the capacity of power plants is enormous, the voltage of power lines reaches thousands of kilovolts.

The human body is a good conductor of electricity. When a person is accidentally (emergency) connected to an electrical circuit, the current has damaging effects of varying degrees of severity, including death. If we take the number of victims of electric current as 100%, then the number of people whose profession is related to electricity is about 50%.

An analysis of the causes of accidents shows that human contact with wires and live parts most often occurs by accident and is not caused by production needs. In addition, electric shocks occur when voltage is supplied incorrectly during repairs and inspections of electrical networks. From this we can conclude that the psychological factor plays a decisive role in ensuring electrical safety. When constantly working with live electrical installations, you should always remember the danger of electric shock.

The most severe injuries to humans are electric shock and electric shock. When an electric shock occurs, the body as a whole is damaged, accompanied by loss of consciousness and muscle cramps, and then cessation of breathing and heart function. With spasms of the motor muscles of the chest, suffocation can occur, and with fibrillation (random contraction) of the heart, death from acid starvation can occur.

The degree of electric shock to a person depends on many factors. These include: voltage and current strength, the time of its exposure, the paths along which the current passes through the human body when it is connected to a circuit, the type of current (direct or alternating), and the frequency of the alternating current.

The paths of current through the human body can be different: from hand to other hand, from hand to leg, from leg to leg. The most dangerous thing is the passage of current from hand to hand, when the heart and

human lungs; the danger of serious injury greatly increases.

The effect of current on a person as a biological system goes through four stages:

the onset of sensation (0.5–1.5 mA AC and 5–7 mA DC) – itching. burning, slight tingling;

convulsions (8–16 mA alternating current and 40–80 mA direct current), due to which a person cannot independently free himself from contact with live parts, and due to convulsions of the vocal cords, he cannot call for help;

clinical death (the damaging characteristics of the current depend on the path of its passage through the body and the individual data of the person) - there is no breathing and the heart stops working;

biological death, which occurs 3–7 minutes after clinical death as a result of the irreversible process of decay of cells of the cerebral cortex without an influx of oxygen.

To avoid electric shock, setting up computer equipment and laying network cables was carried out with the power supply turned off.

In the Computer Center, safety and fire safety precautions are observed during various types of work. The following are instructions on fire safety and safety precautions when working with computers in display classrooms, the main provisions of which guide the work.

Agreed with Approved

Madam Superintendent Vice-Rector for Frequency Responsibility

Shiryaev V.A.

INSTRUCTIONS

according to fire safety regime

Computing Center USMTU

Responsible persons for fire safety in educational institutions and laboratories are the heads of laboratories, workshops, and warehouses.

In accordance with the order, these persons are responsible for compliance with all fire safety rules and regulations at the facilities.

Responsible persons are obliged:

Clearly know the features of your facilities, the specifics of production, fire safety rules and exercise daily control over their implementation.

Know the location of fire extinguishing means, be able to use them and keep them ready for use.

Organize a fire safety minimum for workers and employees and demand strict compliance with fire safety.

The locations of heating electrical appliances should be equipped in accordance with fire safety rules: sheet metal, asbestos, ceramics.

Prohibited:

smoking in undesignated and unequipped areas, contaminating work tables, cabinets, sheds, floors with fuels and lubricants, using open flames from blowtorches;

leave operating installations, burners, electric stoves, irons, soldering irons, lamps unattended;

block entrances and exits from premises, as well as access to fire extinguishing equipment.

Persons responsible for the fire safety regime are required to develop evacuation plans for people and material assets in the event of a fire and familiarize workers with them.

In case of fire, call the fire brigade by phone No. 01 and meet them. Before the fire brigade arrives, take all measures to extinguish the fire. Workers who violate fire safety regulations are held accountable.

Agreed I approve

Head of SOT UGMTU Vice-Rector of the Academy of Arts and Sciences

Konstantinova L.V. Shiryaev V.Ya.

Safety instructions

when working with a computer in display classes

computer center of USMTU

When working with computers in display classes, it is necessary to remember that computers, displays and other electrical equipment are a source of increased danger. To avoid electric shock, it is strictly prohibited:

touch the screen and back of the display, power wires, grounding devices and connecting wires.

violate the order of turning on and off hardware units, independently eliminate the identified malfunction in the operation of the equipment.

place foreign objects on the equipment.

work on a computer in wet clothes and with wet hands.

If there is a burning smell, unusual sounds, or spontaneous shutdown of the equipment, you must turn off the computer and notify the teacher or maintenance personnel about the incident.

During computer operation, the cathode ray tube of the display is a source of electromagnetic radiation and negatively affects vision and performance, so it is necessary to work at a distance of 60–70 cm from the screen and maintain the correct position.

Head of VC Nor S.P.

Bibliography

Queen Laem, Russell Richard. Fast Ethernet. / Ed. K. Korolkova - Kyiv: BHV, 1998. - 444 p.

Rudenko V.D., Makarchuk A.M., Patlanzhoglu M.A.. / Under. ed. Academician of the Academy of Pedagogical Sciences of Ukraine Madzigon V.M.  Kyiv: Phoenix, 1997. – 304 p.

Figurnov V.E. IBM PC for the user.  Moscow, 1996. – 432 p.

SheetChange Sheet

Document no.

Signature Date

					8.092201.3362.

Ministry of Education and Science of Ukraine

UKRAINIAN STATE MARINE TECHNICAL UNIVERSITY

Department of Electrical Equipment of Ships

REPORT

on industrial practice

at the UGMTU Computing Center

Head from the department

Associate Professor ___________ Piskunov A.M.

(signature, date)

Head from

Computer center ___________ Nor S.P.

(signature, date)

Executor

student of group 3362 ___________ Kirichenko A.S.

(signature, date)

Nikolaev 2001

Ukrainian sovereign

Maritime Technical University

Individual assignments and practice protocol

Student specialty ___ 8.092201 ____

_________________Electrical systems and complexes _________________________

_______________________vehicles ___

Student ___________ KirichenkoAAlexander Sergeevich _____________________________

Group ___ 3362 ___ Type of practice __________ production _______________________

Place of practice __________ Computing center of USMTU ________________________

Term of practice ________ With _25.06.01 _to 07/15/01 _________________________

Kerivnyk at the University _________ Piskunov _A.M. ________________________________

Kerivnik as a business _________ Nor _S.P. ______________________________________

________________________________L i n i i v i d r i z u_ ________________________________

Individual design

1.1.Vivchiti

___________familiarize yourself with the classification of computer networks; study _____types of network topology, justify their advantages and disadvantages ___________

__________________________________________________________________________________________

1.2. Analyze (conduct an analysis, write a description)______ carry out analysispossibilities ___applicationsnetworksFast Ethernetin the computer room of the Computing Center, _justify its advantages and disadvantages_____________________________________

1.3.Incorporate safety precautions and safety equipment _________________________________ familiarize yourself with the technical rules ______safety at work and fire safety rules_____ ____ ____________________________________________________________________

“___”___________2001 p. Kerivnyk at the University _____________

CHARACTERISTICS

student internship

(Basics about a student’s work during practice: level of training, technical skills, moral and business standards, initiative, discipline, communication skills, forecast of professional activity) ___ _______________________________________________________________

___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

“___”___________2001 p. Kerivnik workshop, branch

laboratory _____________()

Place of signet Kerivnik practice in

enterprises____________()

__________________________________L i n i i v i d r i z u _______________________________

Practice protocol

2.1.Number of days missed per term of practice: ___ due to reasons

____ due to unimportant reasons.

2.2.Evaluation of the ceramics industry:

____________________________________________________________________

labor discipline ___________________________________________________

“___”______________2001 p. _____________________

2.3.Evaluation of the university project:

Vikonannya of the individual enterprise ____________________________________

____________________________________________________________________

labor discipline______________________________________________________________

“___”______________2001 p. _____________________

Practice report: Design of a training local computer network. Report on practice based on industrial premises "techol" Report on practice in production computer networks

n1.doc

Introduction

Hub and Beam Ring Fig. 3.

Rice. 6. Basic repeater

The hub takes up the space allocated in the bus network for the cable and

Electrical hazards and protection against electric shock

INSTRUCTIONS

Agreed I approve

Head of SOT UGMTU Vice-Rector of the Academy of Arts and Sciences

Safety instructions

Maritime Technical University

Individual assignments and practice protocol

CHARACTERISTICS

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