1.Basic concepts and definitions of computer science. Informatics, cybernetics, General systems theory and system analysis. Information system.
Information processing is an ordered process of its transformation in accordance with the algorithm for solving the problem.
Operations on information:
Collection, formalization (to a single view), filtering, sorting, archiving, protection, transportation, transformation.
BASIC DEFINITIONS OF COMPUTER SCIENCE
SYSTEM - a complex of interacting components (flexible and rigid - when a functionally important element is removed, it does not function - biological and technical, open and closed - in exchange with the external environment)
A PERSONAL COMPUTER (PC or IBM PC) is an electronic computer (ECM) designed to work in dialogue with a person (user).
COMPUTER SCIENCE is a science that studies the structure and most general properties of information, its search, storage, transmission and processing using a computer.
INFORMATION is information about objects and phenomena of the environment, their parameters, properties and state.
FILE is a named area of memory external media. Files can store texts, documents, programs themselves, drawings, etc.
A DIRECTORY is a named location on a disk where files are stored.
PROGRAMMING is the preparation of a problem for solving it on a computer.
ALGORITHM is a sequence of commands leading to some goal.
BRANCH is an algorithm command in which a choice is made: to execute or not to execute any group of commands, depending on the condition.
LOOP - these are algorithm commands that allow you to repeat the same group of commands several times.
Probably many people know or have heard about such a science as cybernetics. At one time, it was undeservedly hushed up for the reason that it was considered pseudoscience in official circles. This delusion, sad for our society, has now been completely overcome. However, the associated lag in the development of means computer science still takes place in our country. The foundations of this science were laid by the American scientist Norbert Wiener.
"Cybernetics. The science of the general laws of control and communication in nature and society (from the Greek word kybernetike - the art of managing). In a narrow sense - the doctrine of feedback in complex systems and organisms."
In the Dictionary of Cybernetics, edited (Kiev, 1989), we read the following: "Cybernetics ... is the science of managing, receiving, transmitting and transforming information in cybernetic systems ..." This is where the confusion begins. It is not possible to draw a clear line between these two disciplines. Nevertheless, it is widely believed that computer science is part of cybernetics. Informatics appeared thanks to advances in the development of computer technology and is completely unthinkable without it. Cybernetics, on the contrary, develops on its own, being interested in object management models using the information approach. Computer science is interested in the properties of information and hardware software tools its processing. Cybernetics and informatics are outwardly very similar disciplines, but most likely differ in the indicated arrangement of research topics. It should be noted that there is not a single word about cybernetics in the school informatics course. It is unlikely that this can be considered correct. Otherwise, in what other course could one mention cybernetics and introduce students to it, give the first concepts of cybernetic
System analysis is the process of obtaining an answer to the question: “Why is the general goal of the system being fulfilled (not being fulfilled?”).
The concept of "system analysis" includes two other concepts - "system" and "analysis". The concept of "system" is inextricably linked with the concept of "system goal". The concept of "analysis" means parsing and sorting into pieces (classification). Therefore, "system analysis" is the analysis of the goal of the system into its subgoals (classification or hierarchy of goals) and the analysis of the system itself into its subsystems (classification or hierarchy of systems) with the intention of finding out which subsystems and why can (cannot) fulfill the tasks assigned to them. goals (sub-goals).
System analysis can show that such and such an object "consists of ... for ..", i.e., to show for what purpose it was made given object what elements it consists of and what role each element plays in achieving this goal.
Organo-morphological analysis, in contrast to system analysis, can show that such and such an object "consists of ...", that is, it can only show what elements this object consists of.
System analysis is not carried out arbitrarily, but according to certain rules. The main conditions for system analysis are taking into account the complexity and hierarchy of goals and systems.
Systems theory (general systems theory) is a general scientific paradigm that offers a holistic approach to the study of systems.
The subject of research within this theory is the study of:
various classes, types and types of systems;
basic principles and patterns of behavior of systems (for example, the bottleneck principle);
processes of functioning and development of systems (for example, infraslow processes, transients).
General Systems Theory
Special-scientific and logical-methodological concept of the study of objects that are systems. O. t. s. is closely related to the systematic approach and is a concretization and logical and methodological expression of its principles and methods. The first option O. t. was nominated by Bertalanffy, but he had many predecessors (in particular, Bogdanov). Main idea O. t. Bertalanffy consists in the recognition of isomorphism (Isomorphism and homomorphism) of the laws governing the functioning of system objects. An important merit of Bertalanffy is the study of open systems, to-rye constantly exchanging matter and energy with the external environment. In the 50-70s. a number of other approaches to the construction of O. t. (M. Mesarovic, L. Zadeh, R. Ackoff, J. Clear, R. Kalman, E. Laszlo, etc.). Main At the same time, attention is paid to the development of a logical-conceptual and mathematical apparatus for system research. O. t. s. is important for the development of modern. science and technology: without replacing special system theories and concepts dealing with the analysis of certain classes of systems, it formulates the general methodological principles of system research.
IS architecture - centralized. Typically used batch processing tasks. The end user did not have direct contact with the IS, all pre-processing of information and input was carried out by the IS personnel.
Disadvantages of IS - information systems - of this generation:
a strong relationship between programs and data, that is, changes in the subject area led to a change in the data structure, and this forced the programs to be redone.
the complexity of developing and modifying systems.
the difficulty of harmonizing parts of the system developed by different people at different times.
In the 70s - early 80s. Business information systems are beginning to be used as a means of managing production, supporting and accelerating the process of preparing and making decisions. For the most part, ISs of this period were intended to solve established problems that were clearly defined at the stage of creating the system and then practically did not change. The appearance of personal computers leads to the correction of the idea of ACS; from CC and centralization of control to a distributed computing resource and decentralization of control. This approach has found its application in decision support systems (DSS), which characterize a new stage of computerized IT of organizational management. At the same time, the load on centralized computing resources and upper levels of management is reduced, which makes it possible to concentrate the solution of large long-term strategic tasks in them. The viability of any IT to a large extent depends on the operational access of users to centralized resources and the level of information links both "horizontally" and "vertically" within the organizational structure. At the same time, to ensure the effective management of large enterprises, the idea of creating integrated automated control systems has been developed and remains relevant.
By the end of the 80s. the concept of using IP is changing again. They become a strategic source of information and are used at all levels of an enterprise of any profile. IT of this period, providing the necessary information in time, helps the organization achieve success in its activities, create new products and services, find new markets, secure worthy partners for itself, and organize the release of products. High Quality and at a low price, etc. The desire to overcome the shortcomings of the previous generation of IS gave rise to the technology of creating and managing databases. The database is created for a group of interrelated tasks, for many users, and this allows you to partially solve the problems of previously created IS. Initially, DBMS were developed for large computers, and their number did not exceed a dozen. Thanks to the advent of the PC, database technology has become mass-produced, a large number of tools and DBMS for the development of IS, which in turn caused the emergence of a large number of applied IS in applied areas.
A big step forward was the development of the principle of "friendly interface" in relation to the user (both to the end user and to the IS developer). For example, it is commonly used GUI, advanced help systems and tips for the user, a variety of tools to simplify the development of IP: rapid application development systems (RAD-systems), computer-aided design of IP (CASE-tools).
It seems incredible that the punched card, the first information carrier in the form of a paper, cardboard or plastic rectangular plate with holes, appeared in the early 19th century. Of course, there was no talk of computers at that time, but the looms of the French inventor Joseph-Marie Jacquard were actively used, in which punched cards were used. With the help of them it was possible to control the pattern on the fabric. In the 30s of the nineteenth century, the technology began to be used in the first computers of Charles Babbage and in mechanical devices for classifying Semyon Korsakov's records. And in 1890, the American inventor Herman Hollerith came up with a device that used punched cards to process the results of the 1890 and 1900 American censuses. Of course, the punched card was destined to become the carrier of information in the first computers. Surely, many still remember these cards with dimensions of 187.325 × 82.55 mm and a thickness of 0.178 mm with rows of numbers and holes in certain positions - this is the most common format IBM introduced in 1928. Punched cards were widely used in computer technology until the early 80s, however, the inconvenience of their use and the need to store and process more information forced specialists to look for new solutions. Therefore, punched cards were gradually replaced by floppy disks.
It seems incredible that the floppy disk was a flexible disk that had a ferromagnetic coating and was hidden in a plastic case designed to protect against mechanical damage. In 1967, the IBM laboratory created the first floppy disk, which had a diameter of 8 inches, and in 1971 the first such floppy disk with a volume of 80 kilobytes was presented to a wide audience. The course of development of floppy disks was aimed at reducing the physical size and increasing the amount of memory, as a result of which the floppy disks first decreased to 5¼ inches, and then to 3½, and the amount of memory reached 2880 kilobytes by 1991, although the 3½-inch format remained the most popular format. 1.44 MB floppy. Unfortunately, floppy disks could not be called a reliable device for storing information due to the peculiarities of their device. They were easily demagnetized under the influence of magnetic fields of various nature, stuck in the drive, were subject to mechanical damage. As a result, when more reliable storage media began to appear, floppy disks began to disappear from everyday life and at the moment they have practically ceased to be used.
The next step in the development of storage media was optical discs- devices that read data using optical radiation. The first generation of such disks was used mainly for storing video files and music. These are well-known laser and compact disks, as well as magneto-optical disks, which combine the properties of both optical and magnetic information carriers. The first optical discs saw the light in the late 70s. The second generation of optical media includes, in particular, DVD format discs that appeared in the years. Having the same appearance as CDs, they could store much more information. It is worth noting the possibility of not only reading information, but also one-time or multiple (depending on the type of disc) recording it, which exists both in CD and DVD. Currently, along with second-generation optical discs, third-generation discs are widely used, and two formats have been fighting for leadership here for a long time - HD DVD and Blu-ray. However, manufacturers of the second type of discs still won. Currently, Blu-ray discs can hold between 23.3 and 128 gigabytes of information, depending on the number of layers. An undoubted disadvantage of all optical storage media is their susceptibility to various mechanical damages: even a small scratch on the disc surface can cause irreparable damage. In addition, the speed of writing information does not always satisfy the user, and the number of rewriting cycles is severely limited by physical parameters. That is why compact, fast and capable of withstanding about 100,000 rewrite cycles, devices that use flash memory to store information were born and became widespread.
Flash memory was invented in 1984 by Fujio Masuoka, a specialist at Toshiba. The first commercial flash chip was released in 1988 by Intel. Now flash cards of various types and volumes are actively used in mobile phones, cameras, mp3 players, as well as very popular USB flash drives or, in the people, flash drives that can be connected to a computer or laptop via a USB connector and quickly copy the necessary information. Currently, standard devices using flash memory can store tens of gigabytes of information.
The above devices are removable. Separately, it is worth talking about the built-in storage media - hard drives.
A hard disk (HDD, hard disk drive, hard drive), like a floppy disk, is based on the principles of magnetic recording, however, it records on hard plates coated with a layer of ferromagnet. Most often, the hard drive is initially built into system unit computer. The first prototype of the device, which had a memory capacity of 5 megabytes and incredible dimensions compared to today's hard drives, appeared in 1956 at Intel. The evolution of hard drives has led to a decrease in their physical size, an increase in the speed of reading / writing information and memory capacity. Modern hard drives store up to 3 terabytes of information and, for sure, this is not the limit.
3. Classification of software products according to the functional principle. Business applications, application programs in other subject areas and basic information technology, basic software.
Software products can be classified according to various criteria. The main feature by which all software products are classified is the scope (area) of their use. Therefore, the following classes of software products are distinguished:
1. System software
Designed to perform various auxiliary functions: computer resource management; creation of copies of used information; checking the operability of computer devices; extradition background information about the computer.
As part of the system software include: operating system; antivirus programs; archiving programs; network maintenance programs, etc.
2. Packages of application programs - directly provide the performance of the work required by the user.
Application Program Examples: text editors(Microsoft Word); computer graphics systems (educational, scientific, engineering, etc.); spreadsheets (Microsoft Excel); database management systems ( Microsoft Access); publishing systems; accounting programs (1C Accounting, Turbo Accountant, etc.); computer-aided design systems; expert systems; artificial intelligence systems (spell checker, translation, text recognition); browsers; training programs, etc.
3. Programming technology tools (facilitate the process of creating new computer programs in a specific programming language).
Examples of programming systems: Quck Basic; Turbo Basic; Visual Basic; Pascal; C++; Delphi etc.
The legal protection granted by this law extends to all types of computer programs. To recognize and exercise copyright in a computer program, it is not required to register it with any organization. Copyright in a computer program arises automatically when it is created.
Information technology (IT) - a set of means and methods for collecting, processing and transmitting data (primary information) to obtain information of a new quality about the state of an object, process or phenomenon (information product).
The purpose of information technology is the production of information for its analysis by a person and the adoption on its basis of a decision to perform an action.
The practical application of data processing methods and tools may be different, so it is advisable to single out the global basic and specific information Technology.
Basic information technology is designed for a specific application (manufacturing, research, teaching, etc.). Basic information technologies include the following technologies:
multimedia technologies
Office automation
Information technology of computer-aided design
Information technologies in industry and economy
Artificial intelligence technologies
CASE technologies
Geoinformation technologies
Statistical Information Technology
Management information technology
Information technologies in education
Accounting information systems (BUIS)
Applied programs in economics:
1C Accounting (enterprise)
Project Expear (planning)
CRM (Customer Relations)
Marketing Expert
Red director (financial organizer)
Applied programs in jurisprudence:
Consultant +
4.Software products and management levels in the company. Algorithmization and programming.
Algorithm - an exact instruction to the performer to perform a certain sequence of actions to achieve the goal in a finite number of steps.
The algorithm may be designed to be performed by a human or automatic device. Allows you to formalize the execution information process. Should be understandable by the computer.
Usually, several general properties of algorithms are formulated that make it possible to distinguish algorithms from other instructions.
Discreteness (discontinuity, separation) - the algorithm should represent the process of solving the problem as a sequential execution of simple (or previously defined) steps. Each action provided by the algorithm is executed only after the execution of the previous one has ended.
Certainty - each rule of the algorithm should be clear, unambiguous and leave no room for arbitrariness. Due to this property, the execution of the algorithm is mechanical in nature and does not require any additional instructions or information about the problem being solved.
Efficiency (finiteness) - the algorithm should lead to the solution of the problem in a finite number of steps.
Mass character - the algorithm for solving the problem is developed in general view, that is, it must be applicable to a certain class of problems that differ only in the initial data. In this case, the initial data can be selected from a certain area, which is called the area of applicability of the algorithm.
Based on these properties, sometimes a definition of an algorithm is given, for example: “An algorithm is a sequence of mathematical, logical, or combined operations that are deterministic, massive, directed, and lead to the solution of all problems of a given class in a finite number of steps.”
Types of algorithms
Mechanical algorithms, or otherwise deterministic, rigid (for example, the algorithm for the operation of a machine, engine, etc.);
Flexible algorithms, such as stochastic, i.e. probabilistic and heuristic. The mechanical algorithm sets certain actions, denoting them in a unique and reliable sequence, thereby providing an unambiguous required or desired result if the process conditions and tasks for which the algorithm is developed are met.
A probabilistic (stochastic) algorithm gives a program for solving a problem in several ways or ways that lead to the probable achievement of a result.
A heuristic algorithm (from the Greek word “eureka”) is an algorithm in which the achievement of the final result of the action program is not uniquely predetermined, just as the entire sequence of actions is not indicated, all the actions of the performer are not identified. Heuristic algorithms include, for example, instructions and prescriptions. These algorithms use universal logical procedures and decision-making methods based on analogies, associations and past experience in solving similar problems.
Alorhythmic structures
A linear algorithm is a set of commands (instructions) that are executed sequentially in time one after another.
A branching algorithm is an algorithm that contains at least one condition, as a result of checking which the computer provides a transition to one of two possible steps.
A cyclic algorithm is an algorithm that involves multiple repetitions of the same action (the same operations) on new initial data. Most of the calculation methods and enumeration of options are reduced to cyclic algorithms.
A program cycle is a sequence of commands (series, cycle body) that can be executed repeatedly (for new initial data) until a certain condition is satisfied.
An example of a block diagram: Structural (block-, graph-) diagram of an algorithm - a graphical representation of the algorithm in the form of a diagram of blocks interconnected with arrows (transition lines) - graphic symbols, each of which corresponds to one step of the algorithm. Inside the block, a description of the corresponding action is given.
The graphic representation of the algorithm is widely used before programming the problem due to its clarity, since visual perception usually facilitates the process of writing a program, its adjustments when possible mistakes, understanding the process of information processing.
Programming - in the usual sense, is the process of creating computer programs.
In a narrow sense (the so-called coding), programming is understood as writing instructions in a specific programming language, often according to an already existing algorithm (plan, method for solving a problem). Accordingly, people who do this are called programmers (in jargon - coders), and those who develop algorithms are called algorithmists, domain specialists, mathematicians.
In a broader sense, programming is understood as the whole range of activities related to the creation and maintenance of programs (computer software). A more accurate and modern term is software engineering, or software engineering. This includes analysis and problem setting, program design, algorithm building, data structure development, program text writing, program debugging and testing (program testing), documentation, tuning (configuration), refinement and maintenance.
Computer programming is based on the use of programming languages in which the program is written. In order for the program to be understood and executed by a computer, a special tool is required - a translator. The main types of translators are compiler and interpreter. Currently, the so-called integrated program development environments are actively used, which also include an editor for entering and editing program texts, a debugger for finding and eliminating errors in programs, a linker for assembling a program from several modules, and other service modules. The programming environment's text editor may have specific functionality such as name indexing, documentation display, visual creation tools. user interface. With the help of a text editor, the programmer produces a set of programs in the form of text, which is called the source code. The programming language defines the syntax and initial semantics of the source code, the semantics of the programming language can be extended by the program text, additional libraries, and the software and hardware environment in which the program is executed. The compiler converts program text into machine code that is directly executable. electronic components computer. The interpreter either does not explicitly convert the program text into machine code, or does such a conversion during program execution.
5 generations: 50s – accembler
60s accembler with variable
60s universal high-level languages
70s domain and object oriented languages
90s visual development systems
Languages: fortran, cobol (business), pascal, basic, prolog, subd
5. Display of computing and information processes. Graph - schemes of algorithms. General concepts.
As part of the graph diagram of the algorithm, large elements can be distinguished, represented by subsets of its vertices and arcs: branches (linear chains or sections of vertices) and fragments (initial, parallel, alternative, cyclic with pre-, post-condition and interruption). An equivalent representation of the graph-scheme of a correct algorithm is a tree of fragments, which reflects the nesting order of the fragments.
The graphical way of presenting algorithms is more compact and visual than the verbal way.
In a graphical representation, the algorithm is depicted as a sequence of interconnected functional blocks, each of which corresponds to the execution of one or more actions.
Such a graphical representation is called a flowchart or flowchart. In the flowchart, each type of action (inputting initial data, calculating expression values, checking conditions, controlling the repetition of actions, finishing processing, etc.) corresponds to a geometric figure represented as a block symbol. Block symbols are connected by transition lines (line or arrow), which determine the sequence of actions.
The table shows the most commonly used geometric shapes.
Terminator (start-stop). The element displays the input from the external environment or exit from it (the most common use is the beginning and end of the program). The corresponding action is written inside the figure.
Process. Performing one or more operations, processing data of any kind. Inside the figure, the operations themselves are written directly, for example, a: = a + SQRT (C).
Solution. Displays a switch type decision or function with one input and two or more alternative outputs, of which only one can be selected after evaluating the conditions defined within this element. The entrance to an element is indicated by a line that usually enters the top vertex of the element. If there are two or three exits, then usually each exit is indicated by a line coming out of the remaining vertices (side and bottom). In programming this block corresponds conditional operator if (two outputs: true, false) and case (multiple outputs).
Computer science - the science on methods of obtaining, accumulating, storing, transforming, transferring, protecting and using information. It includes disciplines related to information processing in computers and computer networks: how abstract like an analysis algorithms, and quite specific, for example, the development programming languages.
Informational resources- Various formalized knowledge (theories, ideas, inventions), data (including documents), technologies and means of their collection, processing, analysis, interpretation and application, as well as exchange between sources and consumers of information.
Information technology-1. A set of scientific disciplines involved in the study, creation and application of methods, methods, actions, processes, tools, rules, skills used to obtain new information (information, knowledge), collect, process, analyze, interpret, extract and apply data , content and information in order to meet the information needs of the national economy and society in the required volume and given quality.
Amount of Information can be considered as a measure to reduce the uncertainty of knowledge when receiving information messages.
The approach discussed above to information as a measure of reducing the uncertainty of knowledge makes it possible to measure information quantitatively. There is a formula that relates the number of possible information messages N and the amount of information I that the received message carries:
units of measurement of the amount of information. The minimum unit for measuring the amount of information is a bit, and the next largest unit is a byte, and:
1 byte = 8 bits = 2 3 bits.
In computer science, the system of education of multiple units of measurement is somewhat different from those accepted in most sciences. Traditional metric systems of units, such as the International System of Units SI, use a factor of 10 n as multiples of multiple units, where n \u003d 3, 6, 9, etc., which corresponds to the decimal prefixes "Kilo" (10 3), "Mega" (10 6), "Giga" (10 9), etc.
In a computer, information is encoded using a binary sign system, and therefore, in multiple units of measuring the amount of information, the coefficient 2 n is used
So, units of measurement of the amount of information that are multiples of a byte are entered as follows:
1 kilobyte (KB) = 2 10 bytes = 1024 bytes;
1 megabyte (MB) = 2 10 KB = 1024 KB;
1 gigabyte (GB) = 2 10 MB = 1024 MB.
Medical Informatics is a science that studies the processes of receiving, transmitting, processing, storing, distributing, presenting information using information technology in medicine and healthcare.
The object of study of medical informatics are information technologies implemented in healthcare.
The main goal of medical informatics is to optimize information processes in medicine and healthcare through the use of computer technology providing improvement of the quality of public health protection.
Tasks solved by medical informatics:
monitoring of the health status of different population groups, incl. patients of risk groups and persons with socially significant diseases
advisory support in clinical medicine (diagnosis, prognosis, treatment) based on computational procedures and (or) modeling of the logic of decision-making by doctors
transition to electronic medical records and outpatient medical records. cards, including payments for the treatment of insured patients (mandatory and voluntary insurance under various schemes)
automation of functional and laboratory diagnostics
Medical diagnostics
The development and implementation of information systems in the field of medical technology is a rather urgent task. An analysis of the use of personal computers in medical institutions shows that computers are mainly used for processing text documentation, storing and processing databases, and statistics. Part of the computer is used in conjunction with various diagnostic and therapeutic devices. In most of these areas of computer use, standard software is used - text editors, DBMS, etc. Therefore, the creation of an information organizational and technical system capable of timely and reliably establishing a patient's diagnosis and choosing an effective treatment strategy is an urgent task of informatization.
Treatment management systems
Treatment and rehabilitation process control systems include automated intensive care systems, biofeedback systems, as well as prostheses and artificial organs created on the basis of microprocessor technology.
In medical process control systems, the tasks of accurate dosing of quantitative parameters of work, stable retention of their set values in conditions of variability of the physiological characteristics of the patient's body come to the fore.
Under automated systems intensive care is understood as systems designed to control the state of the body for therapeutic purposes, as well as to normalize it, restore the natural functions of the organs and physiological systems of a sick person, and maintain them within the normal range. According to the structural configuration implemented in them, intensive care systems are divided into two classes - systems program control and closed control systems.
Program control systems include systems for the implementation of therapeutic effects. For example, various physiotherapy equipment equipped with computer technology, devices for infusion of drugs, equipment for artificial lung ventilation and inhalation anesthesia, heart-lung machines.
3. Network topologies. Examples. Specifications. Ethernet technology. Network topology is the geometric shape and physical arrangement of computers in relation to each other. Network topology allows you to compare and classify different networks. There are three main types of topology:
1) Star;
2) Ring;
BUS TOPOLOGY
When building a network according to a bus scheme, each computer is connected to a common cable, at the ends of which terminators are installed.
The signal passes through the network through all computers, reflecting from the end terminators.
The bus carries the signal from one end of the network to the other, with each workstation checking the address of the message, and if it matches the address of the workstation, it accepts it. If the address does not match, the signal goes further along the line. If one of the connected machines does not work, this does not affect the operation of the network as a whole, however, if the connection of any of the connected machines is disrupted due to a damaged contact in the connector or a cable break, a terminator malfunction, then the entire network segment (cable section between two terminators ) loses integrity, which leads to disruption of the entire network.
Advantages:
1) The failure of any of the workstations does not affect the operation of the entire network.
2) Simplicity and flexibility of connections.
3) Inexpensive cable and connectors.
4) A small amount of cable is needed.
5) Cable laying does not cause any particular difficulties.
Flaws
1) A broken cable, or other connection problems may prevent the normal operation of the entire network.
2) Limited cable length and number of workstations.
3) It is difficult to detect connection defects.
4) Low productivity.
5) When there is a large amount of data to be transmitted, the main cable may not be able to handle the information flow, resulting in delays.
TOPOLOGY "RING"
This topology is a series connection of computers, when the last is connected to the first. The signal travels around the ring from computer to computer in one direction. Each computer acts as a repeater, amplifying the signal and transmitting it further. Since the signal passes through each computer, the failure of one of them leads to the disruption of the entire network.
STAR TOPOLOGY
Star topology - a connection scheme in which each computer is connected to the network using a separate connecting cable. One end of the cable connects to the socket network adapter, the other is connected to a central device called a hub.
Installing a Zvezda topology network is easy and inexpensive. The number of nodes that can be connected to a hub is determined by the possible number of ports on the hub itself, however, there are limits on the number of nodes (maximum 1024). A working group created according to this scheme can function independently or can be associated with other working groups.
Advantages
1) Connecting new workstations does not cause any particular difficulties.
2) Ability to monitor the network and centrally manage the network
3) When using centralized network management, the localization of connection defects is simplified as much as possible.
4)Good extensibility and upgradeability.
Flaws
1) Failure of the hub leads to disconnection from the network of all workstations connected to it.
2) Sufficiently high cost of implementation, tk. a large amount of cable is required.
Ethernet local area network is a standard for organizing local computing systems used to connect devices located at a small distance from each other (in the same building, group of buildings).
An Ethernet network can have a bus or star topology. As a transmission medium, any type of cable can be used, as well as radio frequencies (radioEthernet).
The Ethernet specification provides several physical layer standards that define the type of cable systems and network topology in networking.
4. Open and closed source. Examples of OS open (OS) and closed source. List and characteristics of the advantages and disadvantages of OPS and proprietary operating systems Open source software (English open-source software) - open source software. The source code of such programs is available for viewing, studying and changing, which allows the user to take part in the finalization of the open program, use the code to create new programs and correct errors in them - by borrowing the source code, if license compatibility allows, or by studying the algorithms, data structures, technologies, techniques and interfaces used
Linux, Mozilla (Netscape browser engine), Apache (Web server), PERL (Web scripting language), and PNG (Format graphic files), there are many more examples of very popular open source software.
Closed source"- a program whose license does not fit the definition of open source software. As a rule, this means that only binary (compiled) versions of the program are distributed and the license implies no access to the source program code, which makes it difficult to create modifications to the program. Access to the source code to third parties is usually granted upon signing a non-disclosure agreement.
OS MS Windows, cons.
Relatively high cost. In the cheapest version, it is more than $ 50, despite the fact that such a "cheap" Windows, purchased with a new computer, is "tied" to this computer. And this means that when you change your computer, you will again have to spend money on Windows. Windows options computer-independent ones cost closer to $200 or more. And this is the cost of Windows for one computer. And if you need an OS, for example, for five computers that you already have (not new ones), you will have to pay for five copies of Windows about a thousand dollars.
A very large number malware(so-called computer viruses). For the Windows XP version, this is a particularly serious problem that imposes additional costs on the end user. Or to buy a good antivirus program or to contact specialists in cases where malware prevents the normal operation of Windows. This problem can be mitigated by expertly configuring Windows and using it carefully in risky situations, chief among them the Internet.
advantages and disadvantages of open source MS Windows, pros.
Support for a very large range of computer hardware. Whatever exotic piece of hardware you come across, you will almost certainly be able to use it under Windows. Although it may take you time to find the right driver program.
A huge number of application programs, today it is probably more than a hundred thousand titles. For any application task on the Windows platform, there are at least a few dozen; there are hundreds of programs for popular tasks. A large number of specialists who more or less well know the Windows OS family. That is, if you need help, you will find it easily and at a reasonable price.
GNU/Linux OS, pros.
Relatively low cost. In a more or less large city, it is quite possible to get a disk with any Linux distribution for the price of a blank CD / DVD by contacting Linux enthusiasts. You can also get a CD with an Ubuntu Linux distribution by mail for free. At the same time, having only one physical copy Linux distribution, you get the right to install it on any number of computers. So, going back to, say, five computers, if you buy one copy of a Linux distribution for $300 that's all your expenses for five computers - you don't have to buy five copies. So, on the one hand (Windows) about a thousand dollars, on the other hand (Linux) about 300 rubles (or even less than that).
The virtual absence, at least to date, of malware for this platform. This allows you to avoid additional costs for the prevention or elimination of damage from malware.
Developer Independence. If you need some functionality that is not available in the Linux OS, you can add it on your own. This possibility is due to the fact that the Linux OS is distributed not only in binary form, but also in source codes, and there are no prohibitions on modifying these source codes.
OS GNU/Linux, cons.
Significantly less than for the Windows platform, the number of applications. Moreover, if we are talking about some programs - the undisputed leaders in their application areas, then under Linux there are neither corresponding versions of these programs themselves, nor other programs comparable in functionality. Such application programs include Adobe products, 1C economic programs, AutoCAD engineering design program, text recognition programs (FineReader
Less than for the Windows platform, the number of good or decent specialists. That is, if you need help, then finding a person who is fairly well versed in Linux will not be so easy. It is quite possible that the cost of the services of such a specialist will be higher than in the case of Windows.
5. The concept of a software license, licensed and unlicensed software. Source. ishó this code(Also ishó one text) - text computer program in any language programming or markup language that can be read by a human. In a generalized sense, any input for translator.
Facé nzia on the prograḿ mmnoe obespé reading is a legal instrument governing the use and dissemination software, protected copyright. Typically, a software license permits the recipient to use one or more copies of the program, and without the license, such use would be considered legally an infringement of the publisher's copyright.
MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION
State educational institution of higher professional education
"SAINT PETERSBURG STATE UNIVERSITY
AEROSPACE INSTRUMENT MAKING»
Faculty N4 Faculty computing systems and programming
GRADE
TEACHER
WORK COMPLETED
Saint Petersburg 2011
The concept of information and informatics
Basic concepts of information
Most scientists today give up trying to give a strict definition of information and believe that information should be considered as a primary, indefinable concept, like a set in mathematics. Some textbook authors offer the following definitions of information:
Information is knowledge or information about someone or something.
Information- this is information that can be collected, stored, transmitted, processed, used.
Informatics - the science of information
or
is the science of the structure and properties of information, methods of collecting, processing and transmitting information
or
- computer science, studies the technology of collecting, storing and processing information, and the computer is the main tool in this technology.
The term information comes from the Latin word informatio, which means information, clarification, presentation. At present, science is trying to find common properties and patterns inherent in the multifaceted concept of information, but so far this concept remains largely intuitive and receives various semantic content in various branches of human activity:
1. In everyday life, information is any data, information, knowledge that interests someone. For example, a message about any events, about someone's activities, etc.;
2. in technology, information is understood as messages transmitted in the form of signs or signals (in this case, there is a source of messages, a recipient (receiver) of messages, a communication channel);
3. In cybernetics, information is understood as that part of knowledge that is used for orientation, active action, control, i.e. in order to preserve, improve, develop the system;
4. In information theory, information is understood as information about objects and phenomena of the environment, their parameters, properties and state, which reduce the degree of uncertainty and incompleteness of knowledge about them.
Information is a reflection of the outside world with the help of signs or signals.
The informational value of a message lies in the new information it contains (in the reduction of ignorance).
Information properties:
1. completeness - the property of information to exhaustively (for a given consumer) characterize the displayed object or process;
2. relevance - the ability of information to meet the needs of the consumer at the right time;
3. reliability - the property of information not to have hidden errors. Reliable information may become unreliable over time if it becomes outdated and no longer reflects the true state of affairs;
4. availability - a property of information that characterizes the possibility of its receipt by a given consumer;
5. relevance - the ability of information to meet the needs (requests) of the consumer;
6. security - a property that characterizes the impossibility of unauthorized use or change of information;
7. ergonomics - a property that characterizes the convenience of the form or amount of information from the point of view of a given consumer.
Information should be considered a special type of resource, meaning the interpretation of "resource" as a store of some knowledge of material objects or energy, structural or any other characteristics of an object. Unlike resources associated with material objects, information resources are inexhaustible and require significantly different methods of reproduction and updating than material resources.
From this point of view, we can consider the following properties of information:
1. memorability;
2. transferability;
3. reproducibility;
4. convertibility;
5. erasability.
memorability is one of the most important properties. The stored information will be called macroscopic (meaning the spatial scales of the storage cell and the storage time). It is with macroscopic information that we deal in real practice.
Transferability information using communication channels (including with interference) is well studied in the framework of K. Shannon's information theory. IN this case This refers to a slightly different aspect - the ability of information to be copied, i.e. to the fact that it can be "remembered" by another macroscopic system and at the same time remain identical to itself. Obviously, the amount of information should not increase when copying.
Reproducibility information is closely related to its transferability and is not its independent basic property. If transmissibility means that spatial relations between the parts of the system between which information is transmitted should not be considered significant, then reproducibility characterizes the inexhaustibility and inexhaustibility of information, i.e. that when copied, the information remains identical to itself.
The fundamental property of information is convertibility. It means that information can change the way and form of its existence. Copyability is a kind of information transformation in which its quantity does not change. In the general case, the amount of information in the transformation processes changes, but cannot increase.
Property erasure information is also not independent. It is associated with such a transformation of information (transmission), in which its amount decreases and becomes equal to zero.
· These properties of information are not enough to form its measure, since they refer to the physical level of information processes.
Information is always associated with a material carrier.
information carrier May be:
1) any material object (paper, stone, etc.);
waves of various nature: acoustic (sound), electromagnetic (light, radio wave), etc.;
2) a substance in a different state: the concentration of molecules in a liquid solution, temperature, etc.
Signal- a way of transferring information. This is a physical process that has information value. It can be continuous or discrete.
A signal is called discrete if it can take on only a finite number of values at a finite number of times.
analog signal- a signal that continuously varies in amplitude and time.
Signals that carry textual, symbolic information, discrete.
Analog signals are used in telephone communication, broadcasting, television.
It is pointless to talk about information in general, and not in relation to any of its specific types. You can classify it:
By means of perception (visual, tactile, etc.);
By the form of presentation (text, numerical, graphic, etc.);
by social significance (mass, special, personal).
Examples of getting information:
1) the computer speaker emits a specific sound familiar to Vasya - therefore, a new message has arrived via ICQ;
2) dense smoke was noticed from a fire department helicopter in the depths of the forest - a new forest fire was discovered;
3) all kinds of sensors located in a seismologically unstable area, fix the change in the situation, characteristic of an approaching earthquake.
The main directions in computer science: cybernetics, programming, computer technology, artificial intelligence, theoretical informatics, information systems. The concept of informatics is relatively new in the lexicon of modern man. Despite its widespread use, its content remains unclear due to its novelty. It is intuitively clear that it is connected with information, as well as with its processing on computers. This is confirmed by the existing legend about the origin of this word: it is believed that it is composed of two words - Information and automation (as a means of converting information).
Due to the widespread use of computers and the information boom that humanity is experiencing, every literate modern person should be familiar with the basics of computer science; that is why her teaching is included in the high school course and continues into high school.
Basic concepts of computer science
Computer science- the area of human activity associated with the processes of information transformation using computers and other computer technology. Computer science is often associated with one of the following concepts: it is either a set of certain means of information transformation, or a fundamental science, or a branch of production, or an applied discipline.
Informatics as a set of information transformation tools includes technical means (hardware), software products (software), mathematical methods, models and standard algorithms (brainware). The hardware includes computers and related peripherals (monitors, keyboards, printers and plotters, modems, etc.), communication lines, office equipment, etc., i.e. those material resources that provide the transformation of information, and the computer plays the leading role in this list. By its specificity, a computer is aimed at solving a very wide range of information conversion tasks, while the choice of a specific task when using a computer is determined by the software tool under which the computer operates. Software products include OS and their integrated shells, systems for programming and designing software products, various application packages, such as text and graphic editors, accounting and publishing systems, etc. The specific application of each software product specific and serves to solve a certain range of problems of an applied or systemic nature. Mathematical methods, models and standard algorithms are the basis that underlies the design and manufacture of software, hardware or other object due to the exceptional complexity of the latter and, as a result, the impossibility of a speculative approach to creation.
The word "information" comes from the Latin word information, which means clarification, statements, awareness. The very word information only relatively recently began to turn into an exact term. Prior to this, information was perceived as something that is present in the language, writing, or transmitted during communication. Now the meaning that is invested in this concept has changed and expanded greatly. A special mathematical discipline arose - information theory.
Although information theory introduces several of its specific definitions, they do not cover the entire scope of this concept. Let's look at some definitions.
Information - this is a reflection of the real (material, objective) world, which is expressed in the form of signals, signs.
Information is any set of signals, information (data) that any system perceives from the environment (input information), issues it into the environment (outgoing information) or is stored within a particular system (internal information).
Information exists in the form of documents, drawings, texts, sound and light signals, energy and nerve impulses, etc.
Information is understood as information about the objects of the surrounding world that are perceived by a person, animal, plant world or special devices and increase their level of awareness.
Information is transmitted through messages. Communication can be oral, written, in the form of drawings, gestures, special signs, or organized in some other way. Examples of messages are: indications of a measuring device, road signs, text of a telegram, oral story, and the like.
Information can be divided into types according to several criteria:
According to the way of perception
For a person, information is divided into types depending on the type of receptors that perceive it:
According to the form of presentation
According to the form of presentation, information is divided into the following types:
By appointment
Utility. The usefulness of information is evaluated by the tasks that can be solved with its use. Information that is important and useful to one person is useless to another if he cannot use it.
Relevance. Information is relevant (timely) if it is important in this moment time. If you are going to travel by train, then information about when this train leaves is important for you. However, this information loses its relevance after the train has started moving.
Probability (truthfulness). Information is considered reliable if it does not contradict reality, explains it correctly and is confirmed. If you learned about the flood from an information TV program, then this information is most likely reliable. At the same time, rumors about the arrival of aliens, which is expected next week, are unreliable.
Objectivity. Information can be objective or subjective (depend or not depend on whose judgment). For example, the message "water in the sea is cold" is subjective, while the message "temperature is +17 degrees Celsius" gives objective information.
Completeness. Information is complete if it is sufficient for correct conclusions and correct decision making. If a person has to decide something on the basis of some information, then he first evaluates whether this information is enough to make the right decision.
Clarity. Information is understandable if there is no need for additional messages during its perception (no questions arise). If a person is told something that he is not yet prepared to perceive, for example, they turn to English before the person has learned this language, then he will take out completely different information from the information he hears than it would be when the person learned English.
The environment in which the message is recorded is called the message carrier. In the “pre-computer” era, information was stored on paper, photographs, film, magnetic tape, etc. With the advent of the first computers, punched cards and punched tapes, magnetic disks, and CDs were widely used.
A punched card is a sheet of thin cardboard in standard sizes. In certain positions, punched cards punch holes. The presence of a hole in a certain position is considered one, and its absence is considered zero.
Perforated tape is a tape of thick paper of standard width, on which information is entered by punching holes in the appropriate positions on 5 or 8 parallel tracks.
Of course, there is quite definite information behind the holes printed on punched cards or punched tapes.
Magnetic tapes and magnetic disks for storing information began to be used with the development of computer technology. To record 1 (one), a small area was magnetized. The demagnetized (or oppositely magnetized) area meant 0 (zero).
Floppy disks, or FDDs, made it easy to transfer information from one computer to another, as well as to store information that is not constantly used on a computer. Floppy disks were produced, as a rule, with a disk with a diameter of 3.5 inches and had a capacity of only 1.44 MB.
Hard magnetic disks, or hard drives (HDD), are still the main type of storage media for long-term storage information. The drive includes a magnetic disk itself, a positioning system and a set of magnetic heads - all this is housed in a hermetically sealed case.
Magnetic cards contain coded information, this technology is used in credit, telephone and registration cards, as well as passes and "keys" for combination locks.
Compact discs (optical discs or CDs) are a special plastic disc with a mirror coating on the side from which information is written and read. Information is written to the disk in the following way: the disk rotates, and on its surface the laser inflicts “damage” to the surface in certain places in such a way that the laser beam does not reflect from them when reading. Thus 1 is written, "uncorrupted" places mean logical 0.
There are CD-R, DVD-R - optical discs that can be recorded once, as well as CD-RW, DVD-RW - optical discs that can be recorded multiple times.
The symbolic form of information representation is the simplest, in which each symbol has some meaning. For example: red traffic lights, turn indicators on vehicles, various gestures, abbreviations and symbols in formulas.
The textual form of information presentation is more complex. This form provides that the content of the message is transmitted not through individual characters (numbers, letters, signs), but by their combination, the order of placement. Sequentially arranged symbols form words, which in turn can form sentences. Text information is used in books, brochures, newspapers, magazines, etc.
The graphical form of information presentation, as a rule, has the largest volume. This form includes photographs, paintings, drawings, graphics and the like. The graphic form is more informative. Apparently, therefore, when we pick up a new book, the first thing we do is look for drawings in it in order to create the most complete impression of it.
Information can be presented in one of the ways: letters and signs, gestures, music notes, drawings, paintings, sculptures, sound recordings, video recordings, films, and the like.
Information can be in the form of continuous (analogue) and discrete (digital) signals.
Information in analog form changes its value gradually (indicators of a thermometer, a clock with arrows, a speedometer, etc.).
Information in a discrete form changes its value with a certain step (indicators electronic clock, scales with weights, counting the number of objects, etc.).
The term informatics comes from two words: information and automation. So computer science is “the science of information transformation”.
This term was first introduced into use in France in the mid-60s of the XX century, when the widespread use of computer technology began. Then, in English-speaking countries, the term "Computer Science" came into use to refer to the science of information transformation, which is based on computer technology. Now these terms are synonymous.
The basis of informatics - information technology - a set of tools and methods by which it is carried out in all spheres of human life and activity.
Information system — an interconnected set of means, methods and personnel used to store, process and issue information in order to achieve a specific task.
The modern understanding of the information system (IS) involves the use of a computer as the main technical means of information processing. As a rule, these are computers equipped with specialized software.
In the work of IS, in its technological process, the following stages can be distinguished:
The messages that are generated in the first step can be a regular paper document, an "electronic" message, or both. In modern information systems the message is mostly "electronic". The main components of information processes:
One of the most important conditions for the use of electronic computers (computers) for solving certain problems is the construction of an appropriate algorithm (program) containing information about the rules for obtaining the resulting (final) information from the given (input) information.
Programming is a discipline that studies methods for formulating and solving problems with the help of a computer, and is the main component of computer science.
So, information, computer, algorithm are three fundamental concepts of computer science.
Computer science is a complex scientific and engineering discipline that studies all aspects of design, creation, evaluation, operation computer systems information processing, its application and impact on various areas of social practice.
The founders of informatics are the sciences: documentary and cybernetics. Cybernetics - translates as "skillful in management."
In computer science, there are three main parts:
The subject of computer science is the concepts:
Methods and means of human interaction with hardware and software are called interface.
In colloquial speech, expressions such as information transfer, information compression, information processing are often found. In such cases, it is always about a certain message, which is encoded and transmitted in one way or another.
Most commonly used in computing binary form of information representation, based on the data presented by a sequence of two characters: 0 and 1
These characters are called binary digits, in English - binary digit, or, for short bit (bit).
The octal form of information representation is also used (based on the presented digit sequences 0, 1, ..., 7) and the hexadecimal form of information presentation (based on the presented sequence 0, 1, ..., 9, A, B, C, ..., F).
The information volume of the message is the number of bits in this message. The calculation of the information volume of a message is a purely technical task, since the content of the message does not play any role in such a calculation.
In modern computing, bits are usually combined into eights, which are called bytes: 1 byte \u003d 8 bits. Along with bits and bytes, large units of information are also used.
With two bits, four different values are encoded: 00, 01, 10, 11. Three bits can encode 8 states:
In general, with the help n bit can be encoded 2 n states.
Information transfer rate is measured by the number of bits transmitted in one second. The bit rate per second is called 1 baud. The derived units of bit rate are called Kbaud, Mbaud and Gbaud:
Example . Let the modem transmit information at 2400 baud. It takes about 10 bits to transmit one character of text. Thus, the modem is capable of transmitting about 2400/10 = 240 characters in 1 second.
On a computer, you can process not only numbers, but also texts. In this case, you need to encode about 200 different characters. In binary code, this requires at least 8 bits (28 = 256). This is enough to encode all characters of the English and Russian alphabets (lowercase and uppercase), punctuation marks, symbols of arithmetic operations of some generally accepted special characters.
Currently, there are several coding systems.
The most common are the following coding systems: ASCII, Windows-1251, KOI8, ISO.
ASCII (American Standard Code for Information Interchange)— standard information exchange code)
There are 2 coding tables fixed in the ASCII system: basic And extended. The base table fixes the values of codes from 0 to 127, extended from 128 to 255.
The first 32 codes (0-31) contain the so-called control codes, which do not correspond to any language characters, and, accordingly, the codes are not displayed either on the screen or on the printer.
Starting from code 32 to code 127, codes of characters of the English alphabet are placed.
The symbols of the national alphabet are placed in codes from 128 to 255.
Encoding Windows-1251 has become the standard in the Russian sector wold wide web .
KOI8(Information Interchange Code) is a standard encoding used in e-mail and teleconferencing messages.
ISO (International Standard Organization) is the international standard. This encoding is rarely used.
The emergence of informatics is due to the emergence and spread of new technology collection, processing and transmission of information related to the fixation of data on machine media. The main instrument of informatics is the computer.
The computer, which takes its name from its original purpose of performing calculations, has a second very important use. It has become an indispensable assistant to a person in his intellectual activity and the main technical means of information technology. And the rapid development in recent years of technical and software features personal computers, the spread of new types of information technologies create real opportunities for their use, opening up qualitatively new ways for the user to further develop and adapt to the needs of society.
Disinformation is deliberately false, false information provided to an opponent or adversary in order to more effectively conduct military operations, obtain any competitive advantages, to check for information leakage and identify the source of the leak, identify potentially unreliable customers or partners. Disinformation is also called the process of manipulating information, such as: misleading someone by providing incomplete information or complete, but no longer relevant information, distortion of the context, distortion of any part of the information.
Disinformation, as we see, is the result of human activity, the desire to create a false impression and, accordingly, push for the required actions and / or inaction.
Basic concepts of computer science Man is in the world of information. Help him not to get lost in this world, take on board as much as possible useful information, ignoring the unnecessary, to reduce the cost of searching and processing the necessary information - this is the main task of informatics.Under informatics it is customary to understand the branch of knowledge that studies the general properties and structure of information, as well as the patterns and principles of its creation, transformation, accumulation, transfer and use in various fields of human activity on the basis of modern means of computing and telecommunications technology.
Except France term Informatics used in several Eastern European countries. At the same time, in most countries of Western Europe and the USA, a different term is used - Computer Science (the science of computer technology).
Two sciences are usually called as sources of the concept of "informatics" - documentaries And cybernetics.
Documentary was formed at the end of the 19th century in connection with the rapid development of industrial relations. It flourished in the 20s and 30s. XX century, and the main subject was the study of rational means and methods for improving the efficiency of workflow.
Fundamentals of technical science close to informatics cybernetics were laid down by the works on mathematical logic of the American mathematician Norbert Wiener, published in 1948, and the name itself comes from the Greek word ( kybemeticos- skillful in management).
First time term cybernetics was introduced by the French physicist André Marie Ampère in the first half of the 19th century. He was engaged in the development of a unified classification system for all sciences and designated by this term the science of management, which at that time did not exist, but which, in his opinion, should have existed.
Today, in practice, cybernetics in many cases relies on the same computer software and hardware as computer science, and computer science, in turn, borrows from cybernetics the mathematical and logical basis for the development of these tools.
The main attention in informatics is given to determining the main most effective automated technologies for working with information.
The increase in the volume of information became especially noticeable in the middle of the 20th century. An avalanche-like flow of information poured over a person, not giving him the opportunity to fully perceive this information. In the daily emerging new stream of information, it became increasingly difficult to navigate. Sometimes it has become more profitable to create a new material or intellectual product than to search for an analogue made earlier. The formation of large flows of information is due to:
These reasons gave rise to a very paradoxical situation - the world has accumulated a huge information potential, but people cannot use it in full due to their limited capabilities. The information crisis has put society in front of the need to find ways out of the current situation. The introduction of computers, modern means of processing and transmitting information in various fields of activity was the beginning of a new evolutionary process, called informatization, in the development of human society, which is at the stage of industrial development.
Under informatization of society is commonly understood as an organized socio-economic and scientific-technical process of creating optimal conditions for meeting the information needs of citizens, public authorities, local governments, organizations, public associations based on the formation and use of information resources.
At computerization of society the main attention is paid to the development and implementation of the technical base of computers that ensure the prompt receipt of the results of information processing and its accumulation.
At informatization of society the main attention is paid to a set of measures aimed at ensuring the full use of reliable, comprehensive and timely knowledge in all types of human activity.
Informatization infrastructure includes:
Data carries information about events that have occurred in the material world, and is a registration of signals that have arisen as a result of these events. However, data is not the same as information. Whether data becomes information depends on whether the method of transforming the data into known concepts is known.
þ For example, we can hear the speech of a person addressing us, speaking in a foreign and unfamiliar language. On the one hand, we receive data from him in the form of sounds, but on the other hand, we could not receive any information from him, because. failed to understand the data transmitted to us. They were coded for us, but we did not know the decoding method.
The data that constitutes information has properties that unambiguously determine an adequate method for obtaining this information. Moreover, it is necessary to take into account the fact that information is not a static object - it changes dynamically and exists only at the moment of interaction between data and methods. At all other times it is in the data state. Information exists only at the time of the information process. The rest of the time it is contained in the form of data.
The same data may, at the time of consumption, represent different information depending on the degree of adequacy of the methods interacting with them.
By its nature, data is objective, as it is the result of registration of objectively existing signals caused by changes in material bodies or fields. Methods are subjective. Artificial methods are based on algorithms (ordered sequences of commands) compiled and prepared by people (subjects).
Data- represent the perceived facts of the surrounding world fixed in the form of certain signals.
where I is the amount of information;
p i - probability of occurrence of the i-th signal;
n is the number of possible signals.
The minus sign is put in order for the value of information to be positive, since the probabilities are always less than or equal to 1. The formula shows the dependence of the amount of information on the number of events and on the probability of these events. The information is zero when only one event is possible. As the number of events increases, it increases and reaches its maximum value when the events are equally probable. With this understanding, information is the result of a choice from a set of possible alternatives. However, the mathematical theory of information does not cover all the richness of the content of information, since it does not take into account the content side of the message.
Information- data organized in a certain way, having meaning, significance and value for its consumer and necessary for making decisions, as well as for the implementation of other functions and actions.
Knowledge- this is the awareness and interpretation of certain information, taking into account the ways of its best use to achieve specific goals. The characteristics of knowledge are: internal interpretability, structurability, coherence and activity.
Those objects or devices that can receive information are called receivers of information.
Basic requirements for the quality of information
Information requirements include the following:
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| Who is in the picture?
Hare? Duck? |
Who is in the picture? Hare? Duck? |
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| What information can be obtained from this picture? How many characters are shown here? Total 9 pcs. |
Information that is presented in the figure with visual distortions. ALL lines in the figure are PARALLEL |
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| Information that is presented in the figure with visual distortions. The figure is not a spiral, but a circle |
What is shown in this picture? What do you see - people look down from the balcony or do you see a fence near the lawn? |
That is why recently, consumer electronics (television, audio, video and other equipment), which is beginning to play an increasing role in the economic life of individual members, are also considered to be the main components of the means that facilitate information processing. information society, acting as the most important terminal devices for receiving / transmitting and accumulating data, information and knowledge.
Electronic computers (computers), or, as they are increasingly called, computers (from the English word COMPUTE - calculate, count), are one of the most amazing creations of man. The simplest devices for facilitating counting appeared in ancient times, several millennia ago. As human civilization developed, they slowly evolved, constantly improving.
However, it was only in the 1940s that the foundation was laid for the creation of computers of modern architecture and with modern logic - modern electronic computers. Since then, in a historically very short period of time, computers - thanks to the huge successes of electronics - have come a way in their technical improvement and the scale of application and impact on human society, which cannot be compared with any other invention of mankind, including atomic energy and space technology. And the latter could not have received such a powerful development without the use of the achievements of computer technology.
Briefly characterizing the pace of development of computer technology, one can refer to a figurative comparison in the journal Scientific American (December 1982): The 767 would cost $500, circle the globe in 20 minutes and use 5 gallons (about 20 liters) of fuel." These figures very clearly reflect the relative reduction in cost, the increase in speed and the increase in the efficiency of computers.
However, with the advent of computers, new problems arose, the existence of which was not previously known.
The computer is primarily a MACHINE - not existing in nature, but a man-made object designed to enhance the natural capabilities of a person. Unlike tools, devices and mechanisms, a computer, like any machine, does not use the physical strength (energy) of a person for its functioning. When working with any machine, a person performs only a control function.
A computer is a special - COMPUTING, information machine that enhances not the physical capabilities of a person, but his ability to calculate, accumulate and process information, perform various kinds of calculations or facilitate this process.
A computer is an ELECTRONIC computer, the main functional elements of which are made (implemented, built, implemented) on electronic devices, using the most modern advanced signal processing technology, based on the use of electronics achievements. Theoretically, it is possible to build computers on a different material basis: history knows mechanical ones, our contemporaries - electronic and optical ones, and futurists - biological computers.
According to the way information is presented, computers are divided into three groups:
With the development of networks since the early 70s, the list of services they provide is expanding and their intellectual level is increasing.
The most common services provided by modern networks include:
