Basic course in school computer science. Methodological recommendations for studying the subject “Informatics and ICT” in the basic course of computer science
Textbook “Informatics. 5-6 grade. Primary Course" is part of the new educational and methodological package for secondary schools. The purpose of the textbook is to give students basic knowledge and the field of computer science, train them to work on a computer and system Windows environment, Notepad text editor and graphical Paint editor, as well as in the LogoMira programming environment.
The course is designed for children aged 9-12 years and is focused not only on mastering technologies for working in various environments, but also on the development of algorithmic thinking and creative potential child. To this end, the main part of the textbook presents many practical tasks, and the appendix contains exercises for independent work.
The textbook can be used both for classroom work and for independent extracurricular activities.
Man and computer.
A person is able to receive information from the surrounding world using the senses in the form of sounds, visual images, smells. He can convey information by voice, gestures, notes and drawings. Man has learned to accumulate information and store it not only in his memory, but also in notebooks, books, audio and video cassettes and other media. And finally, man's ability to process information - to understand it and draw conclusions - distinguishes him from all other living beings on Earth.
When creating a computer, a person wanted to get an assistant who could work with information.
In Figure 1.1 you see the main devices that make up a computer: the system unit, keyboard, mouse and monitor. Each of them is designed to work with information.
Table of contents
Introduction
Section 1. Learning to work on a computer
§1.1. Man and computer
§1.2. Desktop in real and virtual world
§1.3. Computer assistant - mouse
§1.4. Menu: choice
§1.5. Get started by clicking the Start button
§1.6. Window to the computer world
§1.7. The keyboard is a writer's tool
§1.8. Typing and editing text
§1.9. What's Hidden in the Menu Bar
§1.10. Actions with a piece of text
§1.11. Calculator - assistant to mathematicians
§1.12. One assistant is good, but two are better
Control questions
Test tasks
Section 2. Computer graphics
§2.1. Drawing tools
§2.2. Computer graphics
§2.3. Creation computer drawing
§2.4. Setting up tools
§2.5. Editing a computer drawing
§2.6. Fragment of the drawing
§2.7. Assembling a drawing from parts
§2.8. How to save the created drawing
§2.9. How to open a drawing saved on disk
§2.10. Constructions using Shift keys
§2.11. Ellipse and circle
§2.12. What is a pixel
§2.13. What is a pictogram
§2.14. Algorithms in our lives
§2.15. Where does the word "algorithm" come from?
§2.16. Computer environment and algorithms
§2.17. What are the algorithms?
§2.18. Actions with a fragment of a picture
§2.19. Repetitive actions in algorithms
§2.20. Repeating elements around us
§2.21. Mosaic design
§2.22. Menu ready-made forms
§2.23. Construction from cubes
§2.24. Simulation of the surrounding world
§2.25. Training models
Control questions
Section 3. LogoWorlds programming environment
§3.1. Getting to know the LogoWorlds environment
§3.2. Pen samples
§3.3. First results
§3.4. The turtle changes appearance
§3.5. Teaching the Turtle to move
§3.6. The whole world is a theater
§3.7. The microworld is filled with inhabitants
§3.8. The turtle follows the compass
§3.9. The movement becomes more difficult
§3.10. First animation
§3.11. What can be modeled in LogoWorlds
§3.12. Turtle Student
§3.13. How to apply for the program
§3.14. Do you need a perpetual motion machine?
§3.15. What the sensors show
§3.16. Why does the Turtle need sensors?
§3.17. Learning to command “wisely”
§3.18. Dashboard
§3.19. Chance is the soul of the game
§3.20. We part to meet again
Control questions
Application. Tasks for independent work
Assignments for section 1
Assignments for section 2
Assignments for section 3
Recommendations for the teacher.
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Preface
The textbook offered to the reader's attention is written in accordance with the program of the discipline "Informatics", which is taught to first-year students at the department " Computer systems and networks" MSTU named after N.E. Bauman. Computer science as a subject is included in the natural science cycle of Russian disciplines. high school and is a basic component of the federal state educational standard for training plans for certified specialists in the field of “Informatics and Computer Science”.
Currently, teaching computer science in high school carried out with varying degrees of detail in the study of individual sections. Along with the different qualifications of teachers and the heterogeneous equipment of computer science classrooms, this leads to the fact that first-year students at technical universities are differently prepared for studying at such a university, although almost all of them have personal computers at home. Of course, when writing the textbook, this circumstance was taken into account, so each new topic is presented according to the principle “from simple to complex,” with a detailed explanation of the basic concepts and numerous examples. At the same time, the author hopes that this work will not seem too simple to the sophisticated reader, and that he will find quite a lot of interesting information in it.
The introduction analyzes the subject of computer science and determines its place among other scientific disciplines.
The first chapter is devoted to consideration of the basic concept of computer science, namely information. It specifies its properties and studies various approaches to measuring the amount of information. Enter here
the concept of entropy and its connection with information is explored. Finally, a distinction is made between the terms “information” and “data,” which we commonly consider synonymous, and different types of data are considered.
The second chapter examines number systems, their relationships, and ways to convert numbers from one number system to another. Are being considered machine codes numbers used to represent the latter and implement arithmetic operations in a computer. Methods for placing numbers in the bit grid of a computer are given, as well as basic methods for performing arithmetic operations.
IN The third chapter examines the basic concepts of logical algebra. As examples of the use of this mathematical apparatus, logical elements that implement Boolean functions are considered, and functional diagrams of some computer blocks are also given.
IN at the end of each chapter there are test questions that are correct
And confident answers to which will allow the reader to be convinced that he has firmly grasped the main content of the corresponding section. The author also hopes that this will be facilitated by the dictionary of basic terms given at the end of the textbook.
And automata theory - a mathematical apparatus with the help of which the functioning of the main blocks and the computer as a whole is described in a formalized form. Issues of presentation and processing of information will be considered in order to form in the reader a general understanding of the functioning of a computer, methods and devices for machine storage of information, as well as systems whose functioning is based on the use of large information storages. Special attention will be
focuses on problems of information transmission, as well as information networks, their types and the functioning of computer networks.
Introduction
The term “informatics” (informatique) arose in France in the late 60s of the twentieth century by merging two words: information (information) and automation (automatique) and implies computer processing of information. In the US and in English-speaking countries to indicate an area information activities With the help of human-machine information processing systems, the term “computer science” was adopted somewhat earlier. In our country, computer science was initially understood only as “ scientific discipline“, studying the structure and general properties of scientific information, as well as the patterns of all processes of scientific communication - from informal processes of exchange of scientific information through direct oral and written communication of scientists and specialists to formal processes of exchange through scientific literature.” (Dictionary of Cybernetics, 1979).
In a sense, the forerunner of computer science can be considered cybernetics - the science of managing, receiving, transforming and transmitting information in cybernetic systems, which are understood as systems of any nature: administrative, biological, social, technical, etc. It is possible to accurately indicate the time of the emergence of a new scientific direction in modern understanding - in 1948, the book of the American mathematician Norbert Wiener, “Cybernetics, or Control and Communication in the Animal and the Machine,” was published and immediately became a scientific bestseller. It talks about
the possibility of creating a general theory of control, and problems of control and communication for various systems are considered from a unified position.
Cybernetics is a word of Greek origin and can be translated as “the art of control.” However, this term in a scientific sense was first used in the first half of the 19th century by the French physicist Ampere, developing a unified system of classification of all sciences. He designated this way the then non-existent hypothetical science of managing people and society, which, in his opinion, was bound to appear.
It should be noted that the development of cybernetics in our country was artificially slowed down during almost the entire 50s of the twentieth century. For example, the first edition of the mentioned book by Wiener in Russian appeared only in 1958, and in the philosophical dictionary of the 1959 edition, cybernetics was still defined as “bourgeois pseudoscience.” This slowed down development computer technology in the USSR, although it was in those same years that we implemented projects that were advanced at that time to create computers under the leadership of S.A. Lebedeva.
The emergence of cybernetics coincided with the construction of first-generation electronic digital computers, which made it possible to solve very complex computing problems. The universality of computer computing made it possible to hope for the discovery of universal control schemes, but this did not fully happen. However, the knowledge gained from the cybernetic approach about various control systems general principles their functioning, which was partially revealed, turned out to be very productive. The ideas of cybernetics turned out to be fruitful for biology, chemistry and many other sciences.
Largely thanks to cybernetics, structural linguistics arose with the division of the latter into mathematical and applied linguistics.
It is worth highlighting such a direction as technical cybernetics, which includes the theory automatic control– theoretical foundation of automation. Research and practical work in this direction made it possible to obtain the most important results, without which technical progress would be impossible in modern society. Today cybernetics can be considered as applied computer science when creating various automatic and automated systems management, from the management of an autonomous object to powerful management systems for industries, teams of people, etc. Thus, the sources of modern computer science, first of all, are documentary science, which studies and optimizes documents and documentary systems, and cybernetics.
The formation of computer science coincided with the rapid development of computer technology, with the advent of increasingly powerful and sophisticated electronic computers, and then personal computers. Modern computer - powerful tool processing of heterogeneous information, and information, in turn, is the main object of study of computer science. This explains the positive impact of the constant rapid improvement of computing tools on the pace of development of modern computer science and on its content. On the other hand, advances in computer science have a beneficial effect on progress in the field of computer technology.
Computer science in its most general form can be defined as the science of methods of processing information using computers for its use in various fields human activity. Information processing means its collection,
storage, retrieval, transformation, transmission and retrieval. To date, the following components have been identified in computer science.
Theoretical computer science, using mathematical methods, studies the structure and general properties of information and the flow of information processes. It includes such disciplines as mathematical logic, computational methods, modeling, theory of automata, theory of algorithms, theory of information and its coding and transmission, theory of formal grammars and languages, operations research, artificial intelligence. The last of these sections deals with computational linguistics, machine translation, pattern recognition, reasoning modeling, creation expert systems and is at the intersection with psychology, physiology, linguistics and other sciences.
Hardware and software tools for informatization make it possible to implement the theoretical achievements of computer science at the applied level. These include computing devices, computing systems, as well as data processing and transmission systems. The software includes system, network, universal and professionally oriented tools with application program packages.
Information technologies and systems within the framework of the classification under consideration are quite universal. They deal with issues of analysis and optimization of information flows in various systems, implementation of the principles of structuring, storing and retrieving information. These include information reference, information retrieval systems, as well as global systems storage and retrieval of information, including the Internet.
Finally, we should mention social informatics, which relatively recently began to be allocated as a separate section
computer science. She studies information resources as factors in the socio-economic and cultural development of the modern information society.
From a consideration of the content of computer science, it becomes clear that it represents a very broad field of scientific knowledge and is located at the intersection of several fundamental and applied disciplines. It is connected:
- with mathematics - through mathematical logic, discrete mathematics, theory of algorithms, mathematical modeling;
- with physics, chemistry, biology, electronics, radio engineering - through the development of computer hardware;
- with cybernetics - through information theory and control theory;
- with linguistics – through the theory of formal languages and sign systems;
- with philosophy and psychology – through the theory of knowledge.
The important role of computer science lies in the fact that it is essentially the scientific foundation of the informatization process modern society. The need for it as an educational discipline lies in the social order for the training of specialists with a new worldview. It is based on an understanding of the role of information, knowledge of the latest and future information and computing technologies, systems and networks.
The proposed course will examine the main topics characterizing the content of computer science.
1. Basic concepts of information theory
1.1. The concept of information, its properties
Each of us comes across the word INFORMATION very often. A person lives among his own kind, the world around him is a constant source of various information for us, which we receive when communicating with other people, with animals, from various instruments, objects, from books and newspapers, observing ongoing phenomena and processes, etc. In this case, perception is carried out using five known senses: vision, hearing, taste, smell, touch; The main thing in this process is the eyes - over 80% of information comes to a person through them.
What is information? After all, there are people we will never meet, countries we will never visit, books we will never read. And these are all potential sources of information. Consequently, information does not exist on its own, but becomes such for us only after we receive it.
The term information comes from Latin word informatio, which means information, message, information about someone or something. It can be said that information is information or knowledge that living beings or devices exchange in the process of their functioning. It is necessary to take into account important aspect associated with receiving information: by perceiving it, we thereby learn something new about a specific subject area, in other words, we reduce the degree of incompleteness of our knowledge.
Information belongs to the original, undefined concepts of science. In the same way, for example, in planimetry such
basic concepts such as point, line and plane. Being a reflection of the processes of the real world, the essence of information is revealed in connection with the actions in which it takes a direct part: transmission, reception, storage, transformation, issuance. As part of our consideration, we will focus on the following formulation:
Information is information obtained about objects and phenomena that reduces the degree of incomplete knowledge about them.
With this approach, it is clear that very important are the ways of obtaining and processing diverse information that constantly accompanies our life. However, there are a number of properties that are inherent in any information, regardless of the means of obtaining it.
And representations, that is, they are universal. What are these properties that make information such?
Suppose you read the sentence: “Twice two is four.” It is unlikely that there is information here for any of you, because this fact is
And you've known that for a long time. Therefore, the information should be new
A Now there is another saying: “Twice two is five.” And there is no information here, since this is not true. Therefore, the information should be reliable
If now a first-year reader began to get acquainted in detail with the rules for calculating pensions, he would remember almost nothing - this information is completely uninteresting for him, since he is unlikely to need it now and in the foreseeable future. Therefore, information must be timely.
The sentence: “Ich wurde in Potsdam geboren” also does not contain any information for some of you, since without knowing German you will not understand what it is about. Therefore, the information must be understandable.
The fifth property of information is ideal, that is, one that one should strive for, but which cannot be achieved. Indeed, it is unlikely that any of us can learn everything about everything or even absolutely everything about something specific, but an inquisitive person always tries to find out as much as possible about the subject or phenomenon that interests him. Therefore, the information must be comprehensive or complete.
So, at the “everyday” level, we have identified five properties of information, namely: it must be new, reliable, timely, understandable and comprehensive. In fact, there are more of these properties; we present a list of them, which does not at all pretend to be complete.
Adequacy is a certain level of compliance of the image created on the basis of the information received with a real object or phenomenon.
Relevance is the degree to which information remains useful at the time of its use.
Sufficiency is the property of the received information to contain a minimal but sufficient set of indicators for its use.
Reliability is the property of information to reflect real objects or phenomena with a given accuracy.
Accessibility is the property of information to correspond to the level of its perception by the user.
Representativeness– a property of information associated with the correctness of its selection for a comprehensive reflection of the properties of an object or phenomenon.
Timeliness– the property of information to arrive at the time of its use.
Accuracy is the degree of closeness of the received information to the real state of an object or phenomenon.
Stability is the property of information to respond to changes in source data without reducing the required accuracy.
The listed properties of information require some clarification. Firstly, their set characterizes quality of information– a set of its consumer indicators that determine the possibility of effective use of information. Secondly, it is necessary to distinguish between such properties as adequacy, reliability, representativeness, accuracy and stability, relevance and timeliness, since the listed characteristics are determined both at the design stage and during the operation of information systems, that is, at different stages of use and processing of information. Thirdly, there is some terminological ambiguity associated with the inexhaustibility of the very concept of information, for example, instead of accessibility, the term clarity of information looks more accurate, since in the first case we can talk about the impossibility for some reason of obtaining the required information. Finally, fourthly, the proposed list of properties, as noted, is not complete; Thus, one can rightly assert that information, for example, should be useful and interesting, because if it seems so to a person, then he remembers it easier and more firmly.
1.2. Measuring information
We are accustomed to units of measurement of various quantities that we often encounter: kilometer, gram, hour, ruble, dollar, etc. How and in what units should knowledge be measured? After all, information is knowledge that...
Suppose the reader has two books in front of him, which obviously contain certain knowledge. Let the first book have three hundred pages, and the second – a hundred. Does this mean that a thicker book contains three times more for you? various information, than in the second? Hardly. For example, the first book is a collection of Russian folk tales, many of which are familiar to you from childhood, and the second book is a self-instruction manual for playing the guitar that you want to master. It is clear that in this case, the second book contains much more information for you, that is, when measuring the latter, you cannot act straightforwardly, but must take into account various parameters, for example, content.
Information is transmitted in space and time from source to recipient in the form of a message, which can be understood as some form of its representation using certain signs. Such a message can be expressed using natural or artificial languages. The first are languages of communication that arose naturally and are a combination of alphabet, vocabulary, grammar, and phonetics. The latter are specially created semiotic systems (semiotics is the science of the properties of signs and sign systems) and act as specialized sign systems for recording information.
From the point of view of semiotics, the information message is considered at three levels. At the syntactic level, the internal properties of messages are studied, namely the relationships that have developed between signs and reflect the structure of the existing sign system. (Syntactics is a section of semiotics that studies the syntax of sign systems). External properties are studied at the semantic and pragmatic levels. In the first case, the relationship between signs and the concepts they denote - objects, actions, qualities, etc. is analyzed. In other words, the role of the object of study at this stage is the semantic
the content of the information message, as well as its connection with the source of information. (Semantics is a branch of semiotics that studies the interpretation of statements of sign systems). In the second case, it is analyzed consumer the content of the message, that is, its connection with the recipient of the information. (Pragmatics is a section of semiotics that studies the perception of meaningful expressions of sign systems as a means of communication between the source and consumer of information).
In accordance with this, three directions are being formed for solving problems of presenting and transmitting information, as well as measuring its quantity. It should be noted that modern information theory mainly deals with problems syntactic level, abstracting from semantic content. In this case, the central concept is the “quantity of information,” which is understood as a measure of the frequency of using signs to form messages. We will also focus on this area, especially since it is much easier to formalize. However, first we present a classification of methods for measuring information (Figure 1.1) and give an overview of the other two levels of consideration external properties information messages in terms of measuring the amount of information contained in them.
In the modern world, studying this subject at school is already a necessity, because computerization has already penetrated almost all spheres of human life. That is why knowing at least the basics of computer literacy will allow children to feel confident in our time.
You can study computer science online by going to our website, which contains almost all computer science topics that make up the school curriculum in video format. Therefore, if you have enough time, a computer and access to the Internet, you can turn to video lessons and study the desired topic.
The discipline is based on the principles and methods of processing, storing and transmitting information using a computer and computer networks. One of the priority areas in modern teaching of computer science at school is the direction “ Global network Internet". This fact is determined by the popularization of Internet communications and the general informatization of society.
Computer Science Program
Computer science lessons in video format, presented on our portal, will help your child master the school course in this subject. In all schools, the study of the beginnings of computer science begins in the 5th grade, where it is explained how a computer works, how to use it, and the child also gets acquainted with the most common computer programs. In the 5th grade computer science section you can find interesting video lessons on all these topics. 6th grade computer science introduces schoolchildren to the basics of programming, which contributes to the development of logical thinking in the child; this is also helped by the study of theoretical questions about forms of thinking. The study of programming, in particular in the Basic language, continues in the next class. On our website, all the nuances of these difficult issues, which are presented in video lessons on computer science for 7th grade, are explained in an accessible form. In the 8th grade, schoolchildren learn about concepts such as information models, study computer architecture, learn what algorithms are, and become familiar with their properties. You can also find all this on our portal in the 8th grade computer science section.
Next in computer science lessons begins detailed study computer graphics, computer animation, processing tools and technologies numerical information, as well as three-dimensional modeling and information storage technologies, including databases. These complex topics may not be clear to a student the first time, which is why the site presents video lessons on computer science for grade 9 in a simple and visual form of presentation. With each grade, the course becomes more and more difficult: in computer science lessons of the 10th grade, schoolchildren will master the concepts of modeling living and inanimate nature, logical-mathematical models, as well as human information activities using computer technology. In computer science lessons of the 11th grade, schoolchildren continue to study issues of human information activity, and also repeat and deepen their knowledge regarding the features of operating systems and software.
The GIA in computer science is an optional exam for 9th grade students. The exam consists of three parts: part A (involves choosing the correct answer), part B (involves a short answer to the question) and part C (involves a detailed solution). When taking an exam in this discipline, the student must indicate in which programming language he will perform task C. This part is performed using a computer. To successfully pass the State Examination in Computer Science, you need to prepare systematically and approach the process of studying the material seriously, using textbooks, lectures and notes, as well as test materials on all topics of the course, and solve diagnostic and training tests.
In the process of studying topics within the framework of a computer science program, not only the theoretical component is important, but also the practical component. Because information technologies and processes cannot be fully comprehended and understood by studying only theory - as a rule, skills are acquired in practice. Proper use of a computer can turn an incredibly complex task into a simple algorithm of actions and thereby simplify the existing task.
The elementary computer science course is designed to broaden the horizons of elementary school students, develop the thinking process and introduce the basic concepts of the subject.
When teaching computer science in high school, the following goals should be achieved:
1. Acquiring skills in working with information tools communication technologies.
2. Getting to know various types information and the ability to work with them using a PC.
3. Implementation and development of projects of varying complexity.
4. Obtaining fundamental theoretical knowledge.
5. Development of creative abilities.
The role of computer technology in human life is growing every day. And at the moment, PCs are used in almost all areas of our everyday life. XXI century - era global informatization society, therefore the key to successful professional activity Every person is computer literate. Therefore, it is important that a student, studying computer science at school, fully master the basics of computer literacy.
You can study the material and repeat knowledge using our resource. It contains a large amount of materials that will help you study computer science online.
Plan:
Basic computer science course in middle school (grades 7-9). Objectives of the basic computer science course, which provides a mandatory minimum of general educational training for students in the field of computer science and information technology.
Computer science course at a foreign school (CIS countries and Western Europe, USA). The main components of the content of a basic computer science course, determined by the requirements of the standard for this subject. Analysis of the main existing programs basic course:
Continuous course in computer science (grades 1-11) of the Moscow Department of Education (authors A. L. Semenov, N. D. Ugrinovich);
Course “Information Culture” for grades 1-11 (authors Yu. A. Pervin and others);
Computer science course for grades 7-9 (A. G. Gein, V. F. Sholokhovich and others);
Basic computer science course for grades 7-9 (authors A. A. Kuznetsov and others);
Basic computer science course for grades 7-9 (authors N.V. Makarova and others)
Review of computer science textbooks: comparative analysis.
Analysis methodological manuals in computer science course.
Methodology and criteria for assessing the quality of school textbooks in computer science.
Lecture abstracts:
The main course in computer science and computer science serves as a source of topics for in-depth development of elective classes in the subject. The standard of general secondary education in computer science is based on highlighting three aspects in the computer science course:
1. custom, reflecting the goals and content of preparing students for the effective use of the capabilities of modern personal computers to satisfy information needs;
2. algorithmic, reflecting methods and means of formalized description of the performer’s actions, generally significant issues related to the development of students’ thinking through learning to program;
3. foundations of computer science, reflecting the mechanisms of information processes, information bases control processes in systems of various natures, modeling phenomena and processes on a computer and giving an idea of the methods of accumulation, processing and transmission of information.
The standard defines several stages in mastering the basics of computer science and the formation of an information culture during the learning process at school.
The first stage (grades I - VI) is a propaedeutic course “Informatics”. At this stage, schoolchildren become initially acquainted with the computer, the first elements of information culture are formed in the process of using educational game programs, simple computer simulators, etc.
The second stage (grades VII-IX) is the basic course “Computer Science and Information Technologies”, which provides a mandatory general education minimum for schoolchildren in computer science. It is aimed at students mastering methods and means of information technology for solving problems, developing skills in the conscious and rational use of computers in their educational and then professional activities. One of the results of students studying the course “Informatics and Information Technologies” is the opportunity to systematically use methods and tools of information technologies in the study of all school subjects. educational subjects.
The third stage (grades X-XI) is a pre-professional profile. It reflects the basic principle of constructing the senior level of a complete general school - the principle of profile differentiation and ensures the continuation of education in the field of computer science as specialized training, differentiated in volume and content depending on the interests and focus of pre-professional training of schoolchildren. The educational standard establishes the level of presentation of material to the learner, ensuring the implementation of learning objectives to the maximum extent. The set of requirements for the level of student preparation reflects the diversity and great variability in approaches and opportunities for teaching computer science in secondary general education institutions of various types, establishing minimum requirements for student training for each component and each stage of computer science education. At the final stage of each stage of training, standard tasks are offered to check whether students’ training meets the requirements of the standard.
7. Methodology for studying the information line of information processes: an idea of the essence of information processes, the structure and main elements of information systems, feedback functions, information transfer processes, communication lines, units of information quantity.
Regardless of the method of receiving and storing information, it has the same characteristics. Information, along with matter and energy, is now considered a fundamental concept. In this sense, information is the structure of the world around us, capable of influencing processes. Scientists have found that geometric structure has the ability to influence the human psyche by influencing his subconscious.
Information properties:
1. Information can accumulate.
2. Information does not have the property of being saved.
3. Information can self-organize, generating new information.
Understanding the structure and main elements of information systems
Structure of the information process. When transferring information in the form of a signal from a source to a consumer, it passes sequentially through the following phases (they say circulation phases), which make up the information process:
1. Perception (if the phase is implemented by a technical system) or collection (if the phase is implemented by a person) – maps the source of information into a signal. Here, the qualitative and quantitative characteristics of the source are determined, essential for solving the problems of the information consumer, for which purpose the information is collected or perceived. The combination of these characteristics creates an image of the source, which is recorded in the form of a signal on a medium of one nature or another (paper, electronic, etc.).
2. Transmission – transfer of information in the form of a signal in space through physical media of any nature. Included in the information process if the places where other phases of the information process are performed are geographically separated.
3. Processing – any transformation of information in order to solve certain functional problems (they are determined by the consumer of the information). This phase may include storing information as transferring it over time.
4. Presentation (if the consumer of information is a person) or impact (if the consumer is a technical system).
In the first case, information is prepared in a form convenient for the consumer (graphs, texts, diagrams, tables, etc.). In the second case, control actions are developed on technical means. This case is typical for graduates of the specialty "Control Automation" technological processes", and therefore is not considered here. The information process is shown schematically in the figure:
Rectangles depict procedures (phases), other figures indicate objects. The dotted boxes indicate that these phases may be missing. As can be seen from the figure, each phase in general case converts (or displays) input signal on a weekend. For example, during processing, signal S3 is converted to signal S4. This is done for the convenience of the next procedure or, in the latter case, for the convenience of the consumer.
Introduction to Feedback Functions
Control is the purposeful influence of the control object on the controlled object to organize its functioning in a given way. It turns out that a wide variety of control processes (in nature, society, technical devices) occur in a similar way and are based on the same principles. Any control action, no matter in what form it is performed, can be considered as information transmitted in the form of commands. As stated in the definition, commands are not given randomly, but purposefully. Sometimes the goal is achieved after executing one command; more often you have to use a sequence of commands. You already know that such a sequence is called an algorithm. Is one-way transmission of information (only from the control object to the controlled object) sufficient? Sometimes yes. But more often it is desirable (and often necessary) to be able to respond to changes in the real situation, that is, the control object must receive information from managed object and, depending on its condition, change the control action in one way or another. Feedback is used to transmit information about the state of the controlled object. Control systems containing a feedback branch are called closed, and those without it are called open. In the absence of feedback, the control algorithm can only contain an unambiguous linear sequence of commands.
Units of information quantity
A person receives information from the surrounding world with the help of his senses, analyzes it and identifies significant patterns with the help of thinking, and stores the received information in memory. The process of systematic scientific knowledge of the world around us leads to the accumulation of information in the form of knowledge (facts, scientific theories, and so on). Thus, from the point of view of the process of cognition, information can be considered as knowledge. If some message leads to a decrease in the uncertainty of our knowledge, then we can say that such a message contains information. The approach to information as a measure of reducing the uncertainty of knowledge makes it possible to quantitatively measure information, which is extremely important for computer science.
Units for measuring the amount of information
To quantify any quantity, it is necessary to determine the unit of measurement. So, to measure length, the meter is chosen as the unit, to measure mass - the kilogram, and so on. Similarly, to determine the amount of information, you must enter a unit of measurement. A unit of information is taken to be the amount of information that contains a message that reduces the uncertainty by half. This unit is called a “bit”. Minimum unit The measurement of the amount of information is a bit, and the next largest unit is a byte, with 1 byte = 23 bits = 8 bits. Traditional metric systems of units, such as the International System of Units SI, use a factor of 10n as multiples of units, where n = 3, 6, 9, and so on, which corresponds to decimal prefixes Kilo (103), Mega (106), Giga (109) and so on. The computer operates with numbers not in the decimal, but in the binary number system, therefore, in multiple units of measuring the amount of information, the coefficient 2n is used.
Thus, units of measurement of the amount of information that are multiples of a byte are entered as follows:
1 KB = 210 bytes = 1024 bytes;
1 MB = 210 KB = 1024 KB;
1 GB = 210 MB = 1024 MB.
Number of possible events and amount of information.
There is a formula that connects the number of possible events N and the amount of information I: N=2I.
Using this formula, you can easily determine the number of possible events if the amount of information is known. For example, if we received 4 bits of information, then the number of possible events was: N = 24 = 16.
On the contrary, to determine the amount of information, if the number of events is known, it is necessary to solve the exponential equation for I.
8. Language as a way of presenting information
A language that spontaneously arose in human society and is a developing system of discrete (articulate) sound signs intended for communication purposes and capable of expressing the entire body of human knowledge and ideas about the world. Being primarily a means of expressing and communicating thoughts, it is most directly related to thinking. It is no coincidence that units of language (words, sentences) served as the basis for establishing forms of thinking (concepts, judgments). The connection between language and thinking is interpreted in different ways in modern science. The most widespread point of view is that human thinking can only be accomplished on the basis of language, since thinking itself differs from all other types of mental activity in its abstractness (abstract concepts). There are two forms of existence of language, corresponding to the opposition of the concepts “language” and speech. Language as a system has the character of a kind of code; speech is the implementation of this code. Speech can be considered in a static aspect - as a text, and in a dynamic aspect - as speech activity, which is a form social activity person. language has special means and mechanisms for the formation of specific speech messages. Communicative goals, which are universal in nature, are heterogeneous (communicating a certain judgment, requesting information, inducing the addressee to action, assuming an obligation, etc., are carried out in the form of speech. With the participation of speech, the organization of work occurs, as well as many other types of social life of people.
Binary number system
A computer uses binary coding to represent information, since it has been possible to create reliably operating technical devices that can store and recognize no more than two different states (digits) with 100% reliability.
All types of information in a computer are encoded in machine language, in the form of logical sequences of zeros and ones. Information in a computer is presented in binary code, the alphabet of which consists of two digits (0 and 1).
A number system is a set of techniques and rules for naming and designating numbers. Conventional signs used to denote numbers are called numbers. Typically, all number systems are divided into two classes: non-positional and positional. A non-positional number system is a number system in which the value of each digit anywhere in the sequence of digits that represents the number does not change.
Historically, the first number systems were precisely non-positional systems. One of the main disadvantages is the difficulty of recording large numbers. Writing large numbers in such systems is either very cumbersome, or the alphabet of the system is extremely large.
Systems in which the meaning of each digit also depends on its place in the sequence of digits when writing a number are called positional. The positional number system is the usual one decimal system Reckoning. Translation decimal number into binary code can be done by sequentially dividing a number by 2. The remainders (0 or 1) resulting at each division step form the binary code of the number being converted, starting from its least significant digit.
9. The word “Algorithm” comes from algorithmi - the Latin spelling of the name of the greatest mathematician from Khorezm. Later, an algorithm began to be called a precise prescription that defines a sequence of actions that ensures obtaining the required result from the initial data. An algorithm may be designed to be executed by a human or automatic device. Each algorithm is created with a very specific performer in mind. Those actions that the performer can perform are called his permissible actions. The set of permissible actions forms a system of performer commands. The algorithm must contain only those actions that are acceptable for a given performer.
Properties of algorithms
The definition of an algorithm given above cannot be considered strict - it is not entirely clear what an “exact prescription” or “a sequence of actions ensuring the required result” is. Therefore, several general properties of algorithms are usually formulated to distinguish algorithms from other instructions. These properties are:
· Discreteness (discontinuity, separateness) - the algorithm must represent the process of solving a problem as a sequential execution of simple (or previously defined) steps. Each action provided by the algorithm is executed only after the previous one has completed execution.
· Certainty - each rule of the algorithm must 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 solving the problem in a finite number of steps.
· Mass scale - the algorithm for solving a problem is developed in a general form, that is, it should be applicable for 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.
The first rule is that when constructing an algorithm, you first need to specify a set of objects with which the algorithm will work. The formalized (coded) representation of these objects is called data. The algorithm begins to work with a certain set of data, which are called input, and as a result of its work produces data, which is called output. Thus, the algorithm converts input data into output data.
The second rule is that the algorithm requires memory to work. The memory stores the input data with which the algorithm begins to work, intermediate data and output data that are the result of the algorithm. Memory is discrete, i.e., consisting of individual cells. A named memory location is called a variable. In the theory of algorithms, memory sizes are not limited.
The third rule is discreteness. The algorithm is built from individual steps (actions, operations, commands). There are many steps that make up the algorithm, of course.
The fourth rule is determinism. After each step, you must indicate which step is performed next, or give a stop command.
The fifth rule is convergence. The algorithm must terminate after a finite number of steps. In this case, it is necessary to indicate what is considered the result of the algorithm.
So, an algorithm is an undefined concept in the theory of algorithms. Algorithm for everyone a certain set input data is associated with a certain set of output data, i.e. calculates (implements) a function. When considering specific issues in the theory of algorithms, we always have in mind some specific model of the algorithm.
Types of algorithms and their implementation
The types of algorithms as logical-mathematical tools reflect the indicated components of human activity and trends, and the algorithms themselves, depending on the purpose, initial conditions tasks, ways to solve them, and determination of the performer’s actions are divided as follows:
· Mechanical algorithms, or otherwise deterministic, rigid (for example, an algorithm for the operation of a machine, engine, etc.);
· Flexible algorithms, such as stochastic, i.e. probabilistic and heuristic.
A mechanical algorithm specifies certain actions, designating them in a single and reliable sequence, thereby providing an unambiguous required or desired result if the process conditions and tasks for which the algorithm was developed are met.
· A probabilistic (stochastic) algorithm provides a program for solving a problem in several ways or methods leading 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 clearly predetermined, just as the entire sequence of actions is not indicated, and 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.
· Linear algorithm– a set of commands (instructions) executed sequentially in time one after another.
· Branching algorithm – an algorithm containing at least one condition, as a result of checking which the computer provides a transition to one of two possible steps.
· Cyclic algorithm – an algorithm that involves repeated repetition of the same action (the same operations) on new initial data. Most methods of calculation 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 source data) until a certain condition is satisfied.
An auxiliary (subordinate) algorithm (procedure) is an algorithm previously developed and entirely used in the algorithmization of a specific task.
Algorithm flowchart
This method turned out to be very convenient means images of algorithms and has become widespread in the scientific and educational literature. Structural (block-, graph-) diagram of the algorithm - a graphical representation of the algorithm in the form of a diagram of blocks interconnected with the help of 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 “top-down” programming principle requires that the block diagram be specified step by step and each block be “described” down to elementary operations.
Algorithm flowcharts are convenient to use to explain the work of already ready-made algorithm, in this case, the actual blocks of the algorithm are taken as blocks, the operation of which does not require explanation.
The “process” block is used to denote an action or sequence of actions that changes the value, form of presentation or placement of data. The "decision" block is used to indicate conditional control transitions. Each "solution" block must identify the question, condition, or comparison it defines.
The “modification” block is used to organize cyclic structures.
The “predefined process” block is used to indicate calls to auxiliary algorithms that exist autonomously in the form of some independent modules, and for calls to library routines.
10. There are two types of computer software: software and hardware. The software includes system and application. Systemic software designed for the functioning of the computer itself as a single whole. This is, first of all, an operating system, as well as service programs for various purposes - drivers, utilities, etc. The system software includes network interface, which provides access to data on the server. Data entered into a computer is usually organized into a database, which, in turn, is controlled by a database management application (DBMS) and may contain, in particular, medical histories, digitized X-rays, and statistical reporting for the hospital. , Accounting. Application software represents programs for which, in fact, a computer is intended. Recently, the use of computers connected into computer networks using special cables or telephone channels. Such computer networks allow very efficient data exchange between computers remote from each other. Recently, computer hypertext systems have also become widespread, which make it possible to organize information in such a way that it becomes easily accessible to people who are not specialists in computer science. Such hypertext systems can include both text information, audio and graphics, including moving video images. These same systems, equipped with a subsystem for questioning and evaluating answers, can be used for training purposes.
A modern personal computer includes following devices:
processor that executes computer control,
· calculations;
· a keyboard that allows you to enter characters into the computer;
· monitor (display) for displaying text and graphic information;
· storage devices (disk drives) on floppy magnetic disks, used for reading and writing information;
· hard drive magnetic disk(hard drive), designed for writing and reading information;
To the system unit IBM computer A PC can be connected to various input/output devices, thereby expanding its functionality. Many devices are connected through special sockets (connectors) located
usually on the back wall of the computer system unit. In addition to the monitor and keyboard, such devices are:
· printer - for printing text and graphic information;
· mouse - a device that facilitates entering information into a computer;
· joystick - a manipulator in the form of a handle mounted on a hinge with a button, used mainly for computer games;
· plotter - connects to a computer to display drawings and other graphic information on paper;
· plotter - connects to print drawings on paper;
· scanner device for reading graphics and text information to the computer. Scanners can recognize letter fonts, which makes it possible to quickly enter printed (and sometimes handwritten) text into a computer;
· streamer - a device for quickly saving all information located on the hard drive. The streamer records information onto magnetic tape cassettes. The usual capacity of the streamer is 60 MB;
· Network adapter - allows you to connect your computer to a local network. In this case, the user can access data located on other computers.
RAM
Volume available random access memory- one of the most important parameters of any computer. Random access memory or random access memory (RAM or RAM) is a collection of chips on the system board that can accumulate and temporarily store programs and processed data. This information, as needed, can be quickly read from RAM by the processor and written there again. When the power is turned off, the contents of the RAM are completely erased and lost. Therefore, after turning on the computer, programs and data must be reloaded into RAM each time from sources of long-term storage of information. For long-term storage of information, magnetic and optical discs or other digital information storage devices. Modern computers mainly use dynamic random access memory. It is built on microcircuits that require periodic information updates to avoid losses. This process is called "memory regeneration". It is implemented by a special controller installed on motherboard. Periodic regeneration of data in dynamic random access memory chips takes some time. An attempt to read information from memory before the regeneration cycle has completed results in errors. Therefore, memory failures are often one of the most common problems in the operation of inexpensive personal computers of the “yellow” or “black” assembly, even if they use perfectly serviceable dynamic RAM chips. The volume of any computer memory, including RAM, is measured in kilobytes and megabytes. The smallest unit of measurement of information capacity and the smallest unit of division of computer memory is a byte. A byte itself is, in turn, a collection of eight smallest units of information called bits. The difference between the simplest stationary binary states, for example, “on”/“off” or between 0 and 1, is only one bit. The byte (or 8-bit) measurement structure was chosen because of the binary organization of computing technology. To transmit or store any one character - a letter, number or sign - a minimum of one byte is required. 1 kilobyte is equal to 1024 bytes, 1 megabyte is 1024 kilobytes, 1 gigabyte is 1024 megabytes.
11. Computer modeling is one of the effective methods studying complex systems. Computer models are often simpler and more convenient to study; they make it possible to carry out computational experiments, the real implementation of which is difficult or may give an unpredictable result. The logic and formalization of computer models makes it possible to identify the main factors that determine the properties of the objects under study and to study the response of a physical system to changes in its parameters and initial conditions. Computer modeling requires abstracting from the specific nature of phenomena, building first a qualitative and then a quantitative model. This is followed by a series of computational experiments on a computer, interpretation of the results, comparison of modeling results with the behavior of the object under study, subsequent refinement of the model, etc.
The main stages of computer modeling include:
· Statement of the problem, definition of the modeling object;
· Development of a conceptual model, identification of the main elements of the system and elementary acts of interaction;
· Formalization, that is, the transition to a mathematical model; creating an algorithm and writing a program;
· Planning and conducting computer experiments;
· Analysis and interpretation of results.
There are analytical and simulation modeling. Analytical models are called models of a real object that use algebraic, differential and other equations, and also provide for the implementation of an unambiguous computational procedure leading to their exact solution. Simulation models are mathematical models that reproduce the algorithm of functioning of the system under study by sequentially executing large quantity elementary operations.
Place of the “Computer Modeling” course in the computer science teacher training system
This course can become the most important connecting part between various types of computer science teacher training and perform the following functions:
· To promote awareness of modeling methodology in general as one of the leading ones in understanding the surrounding world;
· Develop interdisciplinary, integrative communication in relation to mathematical, natural science and highly specialized training in the field of computer science;
· Contribute to the development and deepening of skills in the field of programming and use of computers;
· Promote “building bridges” between specialized training in computer science and vocational pedagogical training.
The introductory part of the course examines the general concepts of modeling, the classification of types of abstract modeling - verbal, informational, mathematical, and the role of computers in their implementation. Some technological issues of computer modeling are discussed - organization of a dialog interface in modeling programs, scientific graphics techniques for displaying modeling results with maximum clarity, stages of computer mathematical modeling. Various approaches to classifying mathematical models are also discussed. The main block consists of models whose subject areas are physics, ecology, processes queuing; Other applications are also included. In an effort to give the course an integrative, interdisciplinary character, the authors deliberately limit themselves to this approach. This allows us to partially overcome some of the scholasticism traditionally inherent in mathematical education, to show in our work a number of mathematical structures and the capabilities of computers in solving applied problems. A significant role in the course is played by the laboratory and practical part - independent development, debugging, testing and trial use of several modeling programs. Leaving students the freedom to choose tools, we orient them towards a structural or object-oriented approach to programming. Finally, the course highlights that part that can later be a special course in schools with in-depth study of physics, mathematics and computer science. In 2005, a corresponding manual of a methodological nature was published, addressed to teachers of mathematics and computer science, as well as students. The total volume of the course in the curriculum for preparing a bachelor of education in the field of computer science is about 100 hours of classroom training (usually 1/4 of the time is allocated to lectures, the rest is laboratory and practical classes, mainly at the computer). “Computer modeling” (which, in particular, is preceded by a standard course of numerical methods) practically completes the physical, mathematical and general scientific education of students. By the end of the course, students have largely mastered the general methodology of working with a computer (most often mathematical) model, acquired practical skills in setting up a computational experiment and working with specialized literature.
13. Technology is a complex of scientific and engineering knowledge implemented in labor techniques, sets of material, technical, energy, labor factors of production, methods of combining them to create a product or service that meets certain requirements.. According to the definition adopted by UNESCO, information technology is a complex of interrelated scientific, technological, and engineering disciplines that study methods for effectively organizing the work of people involved in processing and storing information; computer technology and methods of organizing and interacting with people and production equipment, their practical applications, as well as the social, economic and cultural problems associated with all this. Information technologies themselves require complex training, large initial costs and high-tech technology. Information technology forms the cutting edge of scientific and technological progress, creates the information foundation for the development of science and all other technologies. Informatization of society is a global social process, the peculiarity of which is that the dominant type of activity in the sphere of social production is the collection, accumulation, production, processing, storage, transmission and use of information, carried out on the basis modern means microprocessor and computer technology, as well as based on various means information exchange. Informatization of society provides:
Active use the ever-expanding intellectual potential of society, concentrated in the printed fund, and the scientific, industrial and other activities of its members,
Integration of information technologies with scientific, production, initiating the development of all spheres of social production, intellectualization of labor activity;
High level of information services, accessibility of any member of society to sources of reliable information, visualization of the information presented, materiality of the data used.
Use of information technology in the learning process
Informatization of education, as a process of intellectualization of the activities of the teacher and student, developing, but based on the implementation of the capabilities of new information technologies, supports the integration tendencies of the process of cognition of patterns subject areas And environment(social, environmental, informational, etc.), combining them with the advantages of individualization and differentiation of learning, thereby ensuring a synergistic pedagogical impact.
Scientific information technologies play an important role, making it possible to implement in practice the real integration of educational subjects and the well-known idea of interdisciplinary connections at the level of research methods. Currently, there are many options for programs in any of the natural science subjects. They all have their advantages and disadvantages. In modern conditions, it is necessary to prepare a student to quickly perceive and process incoming information, successfully display and use it. The end result of the introduction of information technology into the process of teaching chemistry is the mastery of computers by students as a means of understanding the processes and phenomena occurring in nature and used in practical activities.
The pedagogical feasibility of using a computer in the educational process is determined by pedagogical goals, the achievement of which is possible only with the help of a computer, i.e., thanks to its capabilities. The use of information technology is the most actual problem in science education. Many schools already have a more or less modern computer lab, and some have even connected to the worldwide computer network The Internet, whose popularity among teachers around the world is constantly growing. In countries around the world, interest in the capabilities of software and pedagogical tools and the Internet in teaching is spreading. The process of a school’s entry into the global educational space requires improvement, as well as a serious reorientation of the computer and information component. The increasing use of computers makes it possible to automate, and thereby simplify, the complex procedure that teachers also use when creating teaching aids, thereby presenting various kinds of “ electronic textbooks", teaching aids on a computer has a number of advantages. Communication factors play a significant role in the development of society. Using new educational technologies opens up real opportunities for building an educational system based on the principles of open information space. Most promising technology in the open education system is distance learning technology.
Education system and new information and communication technologies
Application of information and communication technologies in higher education traditionally comes down to two main areas. The first is to use the capabilities of these technologies to increase the accessibility of education, which is done by including in the education system those individuals for whom another method may not be available at all. It must be said that this distance learning form encounters many objections. Its opponents rightly point out that future students are deprived of everything that is required to receive a truly high-quality education: work in laboratories, access to scientific libraries, communication with teachers and other students at seminars and in informal settings.
The second direction involves the use of information technology to change what is taught and how it is taught, that is, the content and methods of learning in the traditional classroom. But here a very sensitive problem arises due to the fact that the introduction of advanced technologies often creates additional advantages for the most successful, active and capable clients, without affecting the level of training of the majority. In the current structure, the question arises about the accessibility and quality of education. The transition to real informatization of general education is possible on the basis of a unified educational information environment formed by all participants in the information process. The creation of such an environment can begin with a school Internet library with a structured provision of information that is visual and accessible to students.
Another difficulty that cannot be ignored is the increase in responsibility of the student himself for the results of learning in a situation where he is given many opportunities to choose between different forms of training, an avalanche of necessary and extraneous information and extraneous information under time pressure. In these conditions, teachers must help students in the proper organization of their educational activities, taking into account their individual characteristics and capabilities.
