State budgetary professional educational institution

“Baikonur Electro-Radio Engineering College named after M.I. Nedelina"

Lesson 24 Development

on the 2015 / 2016 academic year

by discipline "Life Safety"

specialty: 09.02.03 "Programming in computer systems";

for 3 course, groups P-34; P-35; P-37

Topic: “Safe use of a computer. Protection during PC operation.

(practical lesson)

Developed

Niyazova Alisa Vadutovna

Baikonur

Lesson (lesson) No. 24

Section 3. Ecobioprotective technique.

Practical lesson.

Lesson Objectives:

educational – to acquaint students with the purpose and classification of eco-bioprotective equipment. General concepts.

To bring to the consciousness of students the urgency of the problem of the negative impact of the computer on the performance and health of a person;

Protection during PC operation.

The use of hygienic, practical and health-improving measures for PC users from the negative impact of computers, increase their efficiency and vitality.

Educational– to instill in students an understanding of the need to minimize the harmful effects of harmful and dangerous production factors, computers on the human body;

Development of interest and ability to correctly understand the basic rules and recommendations for the safe use of a computer.

Educational- to develop a competent attitude to preserve one's health.

Lesson type- practical lesson.

educational- visual aids- posters, cards - polls.

Technical means: TV, computer.

Structural elements of the lesson:

Organizational part:

Checking the presence of students;

Familiarization with a new topic;

Ecobioprotective technology. Safe use of a computer. Protection during PC operation -

a) can be considered as a “man-machine-environment” system, because real dangers affecting the environment through technological processes through technology, really at the moment or over any period of time have a negative impact on humans;

b) connection of the topic with other topics:

"Negative factors in the system" Man - environment "";

"Dangers, consequences of exposure to dangers".

c) the connection of the topic with other disciplines - with all the disciplines of the faculty, "Physical Education", "Fundamentals of Law", "Informatics", "Labor Protection", "Psychology".

d) connection with life - everywhere, not one enterprise, educational institution and other industries can do without a computer.

Checking the quality of knowledge.

Front poll:

Practical lesson. 1. Performing a military salute without weapons on the spot and on the move. Basic Rules.

2. Failure and commissioning, approach to the boss and departure from him Basic rules.

Practical part.

Performing a military salute without weapons on the spot and on the move. Basic Rules. Practicing actions for evaluation.

Failure and putting into operation, approach to the chief and departure from him. Practicing actions for evaluation.

Written survey

Define hazard.

Answer: Danger- these are processes, phenomena, objects that have a negative impact on human life and health.

Oral survey:

listening to messages, reports;

listening to the previous topic.

The study and development of new material.

Ecobioprotective technology.

Safe use of a computer. Protection during PC operation.

Purpose and classification of eco-bioprotective equipment. General concepts.

Positive factors when using a computer.

1. Negative factors of computer impact on human health.

Computer radiation.

Computer vision syndrome.

Problems related to muscles and joints.

Syndrome of computer stress.

Practical part. Protection during PC operation.

Improving and preventive exercises.

A set of exercises for the eyes and muscles of the body.

Sets of exercises to relieve symptoms of computer stress syndrome.
Conclusion.

Introduction

Computer (eng. Computer - “computer”), an electronic computer (computer) designed to transmit, store, and process information.

A computer

interactive tool

Intellectual Development Tool

Didactic material

Universal toy

The computer has long ceased to be a luxury, it has become an integral part of the life of modern people, like a TV or a watch. They have become commonplace in production, in the office, in transport, in educational institutions, in the classroom and even in kindergarten. However, we must not forget that this invention not only brings benefits, but also has an adverse effect on the human body.

Positive aspects of the computer:

Causes a positive interest in technology;

Develops creative abilities;

Eliminates fear of technology;

Forms psychological literacy to master the PC;

Develops imagination by modeling the future;

Cultivates attentiveness, concentration;

Helps to master reading, writing, etc. at a fast pace;

Trains memory, attention;

Develops speed of action and reaction;

Cultivates purposefulness.

1. Negative factors of computer impact on human health.

Many people who constantly work with a computer note that within a short time after the start of work, a headache, pain in the muscles of the face and neck, aching pain in the spine, pain in the eyes, tearing, impaired clear vision, pain when hand movement. The Russian Scientific Research Institute of Occupational Safety has conducted a biomedical study of the impact of PC on operators, which illustrates the fact that the degree of pain is proportional to the time spent on PC.

Strict norms for working with a PC should be established, especially for children and youth (20 minutes 2 times a week), and for an adult 3-4 hours a day, taking breaks every 45 minutes.

The negative impact of the computer on humans is complex. Only an integrated approach makes it possible to reliably assess the impact of a computer on a user's health.

Computer radiation.

Safe levels of radiation are regulated by the norms of the State Committee for Sanitary and Epidemiological Supervision “Hygienic requirements for video display terminals and PCs and organization of work. Sanitary norms and rules. 1996".

When all PC devices are turned on, an electromagnetic field with a complex structure is formed in the area of ​​the operator's workplace. Electromagnetic fields pose a real threat to the computer user. Their influence on the human body has not been studied enough, but it is clear that it is not without consequences. Studies of the functional state of PC users, conducted by the Center for Electromagnetic Security, showed that in the human body under the influence of electromagnetic radiation from the monitor, significant changes in the hormonal state, specific changes in brain biocurrents, and changes in metabolism occur. Low-frequency electromagnetic fields, when interacting with other negative factors, can initiate cancer and leukemia.

It has been established that frequent exposure to electromagnetic radiation from monitors leads to abnormal outcomes (fetal fading) at all stages of pregnancy, lactating mothers lose milk.

Article 254 of the Labor Code of the Russian Federation "Pregnant and lactating women are exempt from performing work related to the use of video display terminals and PCs."

You can not put computers in the bedroom because. can cause a violation of the reproductive (childbearing) function of a person. The computer must be at least 3 meters away from the bed.

IN exposure to dust and dirt.

Scientists came to the conclusion that there are many times more harmful microbes on the keyboard than on the toilet lid, so you can’t eat or drink at the computer, microbes, entering the body, cause diseases of the gastrointestinal tract (gastritis, ulcers, colitis, diarrhea and d.r.). And a sufficient amount of dust can accumulate in the system unit. Dust attracted by the electrostatic field of the monitor sometimes causes facial dermatitis, exacerbation of asthmatic symptoms, and irritation of the mucous membranes.

What to do:

- do not sit at the computer with dirty hands;

- about once a week, wipe the keyboard with alcohol or special wipes;

- Vacuum your computer once a month. (You can do this with an ordinary vacuum cleaner only carefully), but there are also special ones.

1.2. Computer vision syndrome.

Human vision is absolutely not adapted to the computer screen, we are used to seeing colors and objects in reflected light, which has been developed in the process of evolution.

Studies show that more than 90% of computer users complain of burning or pain in the eye area, a feeling of sand under the eyelids, blurred vision, etc. The complex of these and other characteristic ailments has recently been called "Computer Visual Syndrome". The impact of working with the monitor largely depends on the age of the user, on the state of vision, as well as on the intensity of work with the display and the organization of the workplace.

As a prophylacticuse of glasses specifically designed for PC use. Computer glasses protect the eyes from the negative effects of the monitor. They increase the clarity of perception, optimize color reproduction, reduce visual fatigue, increase comfort and performance.

1.3. Problems related to muscles and joints.

In people who earn a living working on computers, the largest number of health complaints are associated with diseases of the muscles and joints, there is a change in the shape of the spine. Intensive work with the keyboard causes pain in the elbow joints, forearms, wrists, hands and fingers.

Often there are complaints of neck numbness, pain in the shoulders and lower back, or tingling in the legs. But there are, however, more serious diseases. The most common is carpal tunnel syndrome, in which the nerves of the hand are damaged due to frequent and prolonged use of the computer. In its most severe form, this syndrome manifests itself in the form of excruciating pains that deprive a person of his ability to work.

1.4. Syndrome of computer stress.

There is evidence that regular PC users are more often and to a greater extent subjected to psychological stress, functional disorders of the central nervous system, diseases of the cardiovascular system. Based on the results of the research, conclusions can be drawn about the likelihood of hormonal changes and violations of the human immune status.

The influence of a computer on the nervous system is very diverse. Remember the situation when the computer freezes or loads very slowly the desired web page. And remember how you forgot to save the right file in time and several hours of fruitful work turned out to be wasted, worried when playing computer games. The game increases the state of nervousness and fear in the desire, by all means to achieve victory. The content of the games provokes the manifestation of aggression, cruelty. But there are cases when people had heart attacks because of this!

In addition, Internet addiction and gambling are becoming common phenomena. After working at the computer, refrain from watching TV for 2-3 hours.

Against this background, medical circles have identified a new type of disease - computer stress syndrome.

The symptoms of the disease are varied and numerous. Physical ailments: drowsiness, persistent fatigue; headaches after work; pain in the lower back, in the legs; feeling of tingling, numbness, pain in the hands; tension in the muscles of the upper body.

Eye diseases: a feeling of acute pain, burning, itching.

Visual impairment: blurred vision that increases during the day; occurrence of double vision.

Deterioration of concentration and performance: concentration is achieved with difficulty; irritability during and after work; loss of operating point on the screen; typing errors.

There is an opinion that by eliminating negative factors of influence, it is possible to reduce the likelihood of the Computer Stress Syndrome to a minimum.

Practical part

Protection during PC operation.

Workplace organization.

When working on a PC, organization of work is very important. The room in which the PCs are located should be spacious and well ventilated. The minimum area for one computer is 6 m 2 , the minimum volume is 20 m 3 .

Proper organization of lighting in the room is very important. A large contrast between the brightness of the screen and the surrounding space should be avoided. It is forbidden to work on the computer in a dark and semi-dark room. Lighting should be mixed: natural and artificial. Illumination on the surface of the table in the area where the working document is placed should be at least 300-500 lux. You can get rid of the glare of sunlight with the help of window curtains, curtains, blinds. It is advisable to install the PC so that, by raising your eyes from the screen, you can see the most distant object in the room, since shifting your gaze to a far distance is one of the most effective ways to unload the visual system when working on a PC. If there are several computers, the distance between the screen of one monitor and the back wall of another must be at least 2 m, and the distance between the side walls of adjacent monitors must be 1.2 m.

3. IMPROVING AND PREVENTIVE EXERCISES

The complexes of this part have a beneficial effect and help restore the normal functioning of the eyes and muscles of the body, as well as help relieve the symptoms of computer stress syndrome.

3.1. A set of exercises for the eyes and muscles of the body

Exercise 1. Sitting at the computer, take the most comfortable position: relax, do not strain; gently, slowly, straighten your back (do not slouch); closing your eyes, gently, without squeezing, close your eyelids; with your eyes closed, look only straight ahead - without straining your eyes, defocus; hold your head easily, without straining, without effort; do not strain the body and perform slight tilts of the head: to the chest, back; in turn to the left and right shoulder.

Exercise 2. Without opening your eyes, rotate them clockwise and counterclockwise, up and down.

Exercise 3. Take a break from work at least once every two hours, lean back in your chair, put your hands on your hips, relax your facial muscles and sit like this for 10-15 seconds.

Exercise 4. Close your eyes and massage with your fingers, making light circular stroking movements from the nose outward, the brow ridges and the lower part of the eye sockets for 20-30 seconds. Then sit with your eyes closed for 10-15 seconds.

Exercise 5. Slowly tilt your head forward, resting your chin on your chest, and move your head back. Do a series of head rotations. Repeat 4-6 times.

Exercise 6. Look into the distance for 2-3 seconds, then look at the tip of the nose, freeze for 2-3 seconds. Repeat 6-8 times.

Exercise 7. If possible, raise your hands up, spread your fingers tensely, strain all the muscles of the body, hold your breath for 7-8 seconds. With the rotation of the body, "drop" the hands and relax the whole body for 7-8 seconds. Repeat 3-5 times.

Exercise 8. Stretch and unclench your fingers so that you feel the tension. Relax, and then, slowly, squeeze your fingers.

Exercise 9. To relax your shoulders towards your upper back, interlace your fingers behind your head and move your shoulder blades until you feel tension in your upper back. Stay in this position for 5-10 seconds. Then relax. Repeat the exercise 5-10 times.

Exercise 10. Interlace your fingers behind your back with palms facing inward. Slowly try to raise and straighten your arms. Stay in this position for 5-10 seconds. Repeat 5-10 times.

Exercise 11. In a standing position, slowly raise your hands, while turning your head to the left, then to the right until you feel a slight tension.

Exercise 12. This exercise will help to neutralize the effects of a long stay in a forward-leaning position, when you look at the screen for a long time and carefully. Slowly lower your chin so that wrinkles form under it, stay in this position for 5 seconds. Repeat 5-10 times.

3.2. Sets of exercises to relieve symptoms of computer stress syndrome.

Symptom: drowsiness, fatigue.

Exercises: circular movements of the head; translation of the gaze from the near to the far distance - with one eye; translation of the gaze from the near to the far distance - with two eyes; palming.

Symptom: Headache after hard work.

Exercises: circular movements of the head; translation of the gaze from the nearest points to the far ones - with one eye; shifting gaze from corner to corner; palming; general sipping of the body; shrug (circular movements of the shoulders).

Symptom: Pain in the hips, legs, lower back.

Exercises: general sipping; sipping back muscles; tension in the lower back.

Symptom: tingling sensations and pain in the arms, wrists, palms.

Exercises: general sipping; tension of the fingers of the palm; spinal muscle tension; quick finger movements.

Symptom: Feeling of tension in the upper body.

Exercises: general sipping; spinal muscle tension; shrugging shoulders (circular movements); circular movements of the head.

Symptom: inflamed eyes.

Exercises: development of the correct blinking; fast blinking; eyelid closing exercise; circular movements of the head; shifting gaze from near to far distance with one eye; translation of sight from near to far with two eyes; focusing on the left and right corner of the room - with one eye;

Symptom: Irritability during or after work.

Exercise: eye strain; translation of the gaze from the near to the far distance - with one eye; translation of the gaze from the near to the far distance - with two eyes; alternate focusing of the gaze on the left and right corners of the room; palming.

Symptom: Typing errors.

Exercises: translation of the gaze from the near to the far distance - with two eyes; focusing on the left and right corners of the room; rotational movements with the thumbs; palming.

CONCLUSION

Recent studies by scientists have shown that not so much computer technology itself is a direct factor in the negative impact on the human body, but its incorrect location, non-compliance with elementary hygienic standards regarding work and rest.

Investigating the problem of the impact of a computer on human health, it becomes obvious that the means of modern information technology, of course, affect the user's body and "communication" with a computer requires strict regulation of working hours and the development of sanitary and hygienic measures to reduce and prevent such impacts.

Generalization and systematization.

It is important whether to be able to provide first aid for heart failure, stroke, respiratory arrest and cardiac activity.

Before proceeding with the provision of first aid, what is an important point to be observed.

Summarizing.

Homework 2 (277-283); 2 (261-262).

Lesson (lesson) No. 24

Safe use of a computer. Protection during PC operation.

Written survey

1. Define the hazard.

2. List factors harmful to health.

3. List the factors dangerous to health.

Lesson (lesson) No. 24

Practical lesson. Ecobioprotective technology.

Safe use of a computer. Protection during PC operation.

Written survey

2. List factors harmful to health.

3. List the factors dangerous to health.

___________________________________________________________________________________________

Lesson (lesson) No. 24

Practical lesson. Ecobioprotective technology.

Safe use of a computer. Protection during PC operation.

Written survey

1. Define the hazard.

2. List factors harmful to health.

3. List the factors dangerous to health.

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Federal State Autonomous Educational Institution

higher professional education

Belgorod State National Research University (NRU "BelSU")

Faculty of Computer Science and Telecommunications

Department of Applied Informatics

Computer security

11th grade student

MBOU secondary school №16

Panova Dmitry

Belgorod 2012

• Introduction
• 1. Computer crimes
• 2. Viruses and the fight against them
• 2.1 Choosing a protection system
• 2.2 Use of passwords
• 2.3 Email Security
• 2.5 Antivirus programs
• List of used literature

Introduction

Since the late 80s and early 90s, problems related to information security have been a concern for both computer security specialists and numerous ordinary users of personal computers. This is due to the profound changes that computer technology brings to our lives. The very approach to the concept of "information" has changed.

This term is now more used to refer to a special commodity that can be bought, sold, exchanged for something else, etc. At the same time, the cost of such a product often exceeds the cost of the computer technology itself, within which it functions, by tens or even hundreds of times. Naturally, there is a need to protect information from unauthorized access, theft, destruction and other criminal acts. However, most of the users do not realize that they constantly risk their security and personal secrets. And only a few protect their data in any way. Computer users regularly leave data such as tax and banking information, business correspondence and spreadsheets completely unprotected.

System administrators can increase security indefinitely, but there is always a way around it. Most people think and act in the same way. What one person thought of, another will think of, what one hid - the other will reveal. In Western literature, it is suggested to distinguish between the term hacker (hacker), which is proposed to designate a high-level computer professional who is not involved in illegal activities, and a cracker (cracker) - that is, a hacker who uses his abilities to hack computer systems for selfish purposes.

Anyone can be a computer criminal. The typical computer criminal is not a young hacker using his phone and home computer to gain access to large computers. The typical computer criminal is an employee who is allowed access to a system of which he is a non-technical user.

In the US, computer crimes committed by employees account for 70-80 percent of annual computer-related losses. The remaining 20 percent comes from the actions of dishonest and disgruntled employees.

And they do it for a number of reasons:

personal or financial gain

entertainment

Trying to win someone over

self-expression

· accident

vandalism.

1. Computer crimes

Computer crimes have become so widespread in countries with a developed telecommunications infrastructure that special offenses have been introduced into the criminal law to combat them. However, in all countries of the world there is an avalanche-like growth of computer crime. The annual economic damage from such crimes in the USA alone is about 100 billion dollars, and many losses are not detected or reported due to the high latency (secrecy) of these crimes (90%). The data on Russia published in the mass media are less "spectacular", but even they are alarming.

Thanks to the efforts of hackers, "electronic hacking" from the Internet is now a fairly typical precedent, although not always malicious.

In this regard, computer hackers are combined into several groups:

· "inquisitive" hackers are often students "traveling" on the Internet,

· Specialists, thirsting for professional self-affirmation - all sorts of experimenters and researchers.

People who have specific commercial, intelligence or other interests.

burglars and saboteurs. Their goal is to destroy databases, paralyze work, disable computer networks.

Computer crimes are divided into seven main categories, one way or another related to hacking: financial theft, sabotage, hardware theft, software theft, information theft and electronic espionage. And the seventh "crime" is computer hacking.

Money theft. Financial theft occurs when computer records are altered in order to embezzle someone else's money. This is often done through a program that directs money to a specific bank account, usually using the "salami" technique. "Salami" is a method that involves stealing small amounts over a long period of time in the hope that it will not be noticed. Thieves reprogram a bank or some other computer so that money goes into fake accounts. For example, the account can store 713.14863, where 863 are random numbers, since all signs are taken into account when multiplying. Usually the computer will show that the person has $713.15 in the pot by rounding 4 to 5. However, the computer programmed with "salami" separates these extra numbers and places them in separate accounts. And now the person has only $713.14, and hardly anyone will notice it.

The computer itself cannot produce money, it can only transfer legal money to an illegal account. Such thefts are quite difficult to detect. As soon as the thief accumulates a fairly large amount on the account, he withdraws the money from the account and, in most cases, is deleted along with them. Many thieves have tried this form of bank robbery and many have been caught, but now anyone can do it. You can identify the use of such a technique by creating a list of all accounts on the computer indicating how many times the account was accessed within one or several days. Then, any account that is requested too often is checked to determine how much money was withdrawn from it during each call. If this amount is small, then someone is lucky. But the mistake these thieves make is that instead of reprogramming the computer to transfer small amounts into an account, they should have simply subtracted that money and kept track of how much money accumulated in an area separate from the account files. Then the parts of the program that print out the total number of bank deposits are modified to account for the hidden amount so that this money does not appear to be lost. When the hidden number reaches a certain value, only then should it be transferred to the thief's account, and the transferred amounts should be equal to random values ​​in order to avoid suspicion. These steps require access to a computer. Usually they are made by bank employees. If such theft is committed by an employee with a limited access level or a non-bank employee, then hacking is necessary.

Sabotage. Computer sabotage is the physical destruction of hardware or software, or the distortion or destruction of information contained in a computer. The reason for sabotage may be the desire to get rid of a competitor or to obtain insurance. Computer hacking is only indirectly related to sabotage. Reverse social engineering uses something like sabotage, but it's really just a temporary and easily fixable computer crash. Computer vandals often sabotage information stored on computers by first using hacker methods to gain access to them. But don't confuse vandals and other data saboteurs with hackers. These people enter false information into computer systems, corrupting databases in one way or another.

Other types of theft. May include theft of hardware or the computer itself and peripherals, as well as theft of computer designs. They are classified as hacking insofar as a stolen computer can be used to obtain access codes. In the case of software piracy, a hacker may secretly read a developer's email or files in an attempt to steal new ideas. Software theft, or software piracy, is the illegal copying of copyrighted software. Hackers often make copies of programs found on a computer system for themselves in order to understand how they work. When it comes to hardware theft, there is a desire to catch up with the competition in software development. Information theft includes the theft of credit cards, lab results, patient or customer data, and generally any data of potential value. Electronic espionage is the sale of such information to a third party when the hacker starts spying on another company or country. In both cases, a hacker technician is installed to steal information and sometimes to contact the spy agency.

Hacking. Hackers are capable of committing any of the above crimes, but many people break into other people's computer systems out of a desire for knowledge - this is the so-called "pure" hacking. Yet many hackers, even the best of them. contributed to the bad reputation of hacking, as they were driven by other motives than gaining knowledge. There are also destructive hackers, and those who simply cannot stop and exit the game in time.

2. Viruses and the fight against them

The main difficulty that arises when trying to give a strict definition of a virus is that almost all the distinguishing features of a virus (introduction into other objects, secrecy, potential danger, etc.) are either inherent in other programs that are in no way viruses, or there are viruses. , which do not contain the above distinctive features (with the exception of the possibility of distribution). For example, if stealth is taken as the distinguishing characteristic of a virus, then it is easy to give an example of a virus that does not hide its spread. Such a virus, before infecting any file, displays a message stating that there is a virus in the computer and this virus is ready to infect the next file, then displays the name of this file and asks the user for permission to inject the virus into the file.

If the ability to destroy programs and data on disks is cited as a distinguishing feature of a virus, then dozens of completely harmless viruses can be cited as an example of this distinctive feature, which, apart from their distribution, do not differ in anything else.

The main feature of computer viruses - the possibility of their spontaneous introduction into various objects of the operating system - is inherent in many programs that are not viruses.

The second difficulty that arises when formulating a definition of a computer virus is that this definition must be tied to the specific operating system in which this virus is distributed. For example, theoretically, there may be operating systems in which the presence of a virus is simply impossible. An example of this would be a system where it is forbidden to create and modify areas of executable code, i.e. it is forbidden to modify objects that are either already running or can be run by the system under any conditions. Therefore, it seems possible to formulate only a mandatory condition for a certain sequence of executable code to be a virus.

A mandatory property of a computer virus is the ability to create duplicates of itself (not necessarily identical to the original) and inject them into computer networks and/or files, computer system areas and other executable objects. At the same time, duplicates retain the ability to further distribution.

Who writes viruses? Most of them are created by students and schoolchildren who have just learned assembly language, want to try their hand, but cannot find a more worthy application for them. It is gratifying that a significant part of such viruses is often not distributed by their authors, and the viruses "die" after a while along with the diskettes on which they are stored. Such viruses are most likely written only for self-affirmation.

The second group is also made up of young people (more often students) who have not yet fully mastered the art of programming, but have already decided to devote themselves to writing and distributing viruses. The only reason pushing such people to write viruses is an inferiority complex, which manifests itself in computer hooliganism. From the pen of such "craftsmen" often come either numerous modifications of "classical" viruses, or extremely primitive viruses with a large number of errors. The life of such virus writers has become much easier after the release of virus constructors, with which you can create new viruses even with minimal knowledge of the operating system and assembler, or even having no idea about it at all. Their life has become even easier after the advent of macro viruses, because instead of the complex Assembly language, it is enough to learn a fairly simple BASIC to write macro viruses. Having become older and more experienced, but never matured, many of these virus writers fall into the third, most dangerous group that creates and releases "professional" viruses into the world. These very carefully designed and polished programs are created by professional, often very talented programmers. Such viruses often use quite original algorithms, undocumented and little-known ways to penetrate system data areas.

"Professional" viruses are often made using stealth technology and (or) are polymorphic viruses that infect not only files, but also boot sectors of disks, and sometimes Windows and OS / 2 executable files.

The fourth group of virus authors - "researchers" - stands out somewhat separately. This group consists of quite smart programmers who are inventing fundamentally new methods of infecting, hiding, counteracting antiviruses, etc. They also come up with ways to introduce them into new operating systems, virus constructors and polymorphic generators. These programmers write viruses not for the sake of viruses themselves, but rather for the sake of "exploring" the potentials of the "computer fauna". Often the authors of such viruses do not put their creations into practice, but they actively promote their ideas through numerous electronic publications dedicated to the creation of viruses. At the same time, the danger from such "research" viruses does not fall - having fallen into the hands of "professionals" from the third group, new ideas are very quickly implemented in new viruses.

Where do viruses come from? The main source of viruses today is the global Internet. The greatest number of virus infections occurs when exchanging letters in Word/Office97 formats. The user of an editor infected with a macro virus, without suspecting it, sends infected messages to recipients, who in turn send new infected messages, and so on. Assume that a user is chatting with five recipients, each of whom is also corresponding with five recipients. After sending an infected email, all five computers that received it become infected. Then five more emails are sent from each newly infected computer. One goes back to an already infected computer, and four go to new recipients. Thus, 1+5+20=26 computers are already infected at the second distribution level. If network recipients exchange letters once a day, then by the end of the working week (in 5 days) at least 1+5+20+80+320=426 computers will be infected. It is easy to calculate that over a hundred thousand computers are infected in 10 days! And every day their number will be quadrupled. The described case of the spread of the virus is the most frequently reported by antivirus companies. It is not uncommon for an infected document file or Excel spreadsheet to be included in the mailing lists of commercial information of a large company due to an oversight. In this case, not five, but hundreds or even thousands of subscribers of such mailings suffer, who then send infected files to tens of thousands of their subscribers. Electronic conferences, ftp file servers and BBS "Public" file servers and electronic conferences are also one of the main sources of viruses. Almost every week there is a message that some user has infected his computer with a virus that was taken from a BBS, ftp server or from some electronic conference. In this case, the infected files are often "uploaded" by the virus author to several BBS/ftp or sent to several conferences at the same time, and these files are disguised as new versions of some software (sometimes - under new versions of antiviruses). In the case of a mass distribution of a virus to ftp/BBS file servers, thousands of computers can be affected almost simultaneously, but in most cases DOS or Windows viruses are "laid", the spread rate of which in modern conditions is much lower than macro viruses. For this reason, such incidents almost never end in mass epidemics, which cannot be said about macro viruses.

Local networks. The third way of "rapid infection" is local networks. If the necessary protection measures are not taken, then an infected workstation infects one or more service files on the server when entering the network (in the case of Novell NetWare, LOGIN.COM). The next day, users launch infected files when they enter the network. Instead of the LOGIN.COM service file, various software installed on the server, standard template documents or Excel spreadsheets used in the company, etc. can also act.

Pirated software. Illegal copies of software, as it has always been, is one of the main "risk areas". Often pirated copies on floppy disks and even on CDs contain files infected with various types of viruses. computer crime virus password

Personal computers "general use". Computers installed in educational institutions also pose a danger. If one of the students brought a virus on his floppy disks and infected any educational computer, then the floppy disks of all other students working on this computer will also receive another "infection". The same applies to home computers if more than one person works on them. It is not uncommon for a student son (or daughter), working on a multi-user computer at an institute, to drag a virus from there to a home computer, as a result of which the virus enters the computer network of the father's or mother's company.

Repair services. Rarely enough, but it is still quite possible to infect a computer with a virus during its repair or routine inspection.

Repairmen are people too, and some of them tend to give a damn about the elementary rules of computer security. Once forgetting to close the write protection on one of his floppy disks, such a "maestro" will quickly spread the infection on the machines of his clientele and, most likely, will lose it (the clientele).

2.1 Choosing a protection system

Any computer system is not perfect, that is, it cannot completely ensure the security of data on your PC. In order to 100% protect data from falling into the wrong hands, it is necessary to destroy it. And to keep the contents of your computer intact, you need to find a compromise between the importance of the data you protect and the inconvenience associated with the use of protection measures. Security measures are measures introduced by management to ensure the security of information - administrative guidance documents (orders, regulations, instructions), hardware devices or additional programs - the main purpose of which is to prevent crime and abuse from occurring.

Protective measures can also serve as a limitation, reducing the amount of damage from a crime. End-user awareness of security measures provides four levels of protection for computer and information resources:

· Detection - provides early detection of crimes and abuses, even if protection mechanisms have been bypassed.

Restriction - the amount of losses is reduced if the crime did occur, despite measures to prevent and detect it

· Recovery - Efficient recovery of information is ensured with documented and proven recovery plans.

The choice of means of protection should be based on providing sufficient security and at the same time not cause inconvenience. Each user must make their own risk analysis and decide which protection measures are most appropriate for their particular case.

Risk analysis for personal computers can be divided into three classes: analysis of autonomous systems, that is, a single computer, analysis of local systems and analysis of remote access systems connected to a global network (eg Internet).

2.2 Use of passwords

The idea behind using passwords is this: if someone tries to access your data or hardware, then passwords should create a lot of inconvenience. The more difficult it is to guess or "crack" the password you use, the more secure your data will be. The length of the password significantly affects the level of protection. Personal numbers are by far one of the least secure passwords in widespread use (eg credit cards for ATM cash registers or calling cards). In personal numbers, numbers from 0 to 9 can be used, that is, the number can have ten thousand variations. This is enough if we are talking about a person standing near the ATM and typing a code at random, but not much if we are talking about a computer using the frontal solution method.

In a "frontal" attack, all possible combinations of passwords are checked until one of them works. As the password length increases, the difficulty of a frontal attack increases, as it will take longer. Of course, many banks use not only a four-digit code (PIN), but also other methods to increase security, such as video cameras and ATMs that block cards. At the same time, the protection measures in each bank are very different. Most banks also provide the following service: you can call the bank, dial the card number and personal number and find out the status of the current account. This scenario makes your personal number (PIN) vulnerable - someone can sit down at the phone and try different options.

The four-digit password - your PIN - has a total of 9999 possible combinations. However, most computer passwords are longer and can contain characters in addition to the numbers 1-9. A four-digit password, which uses numbers and symbols, is more difficult to decipher - it can contain 1679616 unique combinations. Here is the formula for calculating the possible number of character combinations: c=xy, where c is the number of possible combinations, x is the number of different characters used in each position of the password, y is the number of characters in the password. For example, when using PIN c=104. Also, some passwords are case sensitive and include punctuation marks, so the number of possible combinations is even higher. In addition to the passwords used to access the local network, the Internet, etc., computer users have a number of security measures that include passwords. These include BIOS-based protection that requires you to enter a password when you boot your computer, special security software that blocks access to individual files, and password-protected ZIP archive files.

2.3 Email protection

The vast majority of e-mail is sent over the Internet or other wide area networks in plain text that can be read. The Electronic Communications Privacy Act treats your email as a regular phone call. You must understand that system administrators have all the necessary tools to read e-mail on their system. Sometimes they even need to check email to make sure the system is working properly.

Hackers and snoopers differ in that they have different ways of gaining access to your mail, but both of these categories cannot read your mail if it is encrypted. If you need to protect sensitive information, use PGP (Pretty Good Privacy) to encrypt mail before sending.

2.4 Use of encryption - cryptography

Cryptographic methods for protecting information in automated systems can be used both to protect information processed in a computer or stored in various types of memory, and to close information transmitted between various elements of the system via communication lines. But why has the problem of using cryptographic methods in information systems (IS) become particularly relevant at the moment? On the one hand, the use of computer networks has expanded, in particular the global Internet, through which large amounts of information of a state, military, commercial and private nature are transmitted, which does not allow unauthorized persons to access it. On the other hand, the emergence of new powerful computers, network and neural computing technologies made it possible to discredit cryptographic systems, which until recently were considered practically undisclosed. Cryptography makes it possible to transform information in such a way that its reading (restoration) is possible only if the key is known.

The process of cryptographic closing of data can be carried out both in software and in hardware. The hardware implementation is significantly more expensive, but it also has advantages: high performance, simplicity, security, etc. The software implementation is more practical and allows a certain flexibility in use.

For modern cryptographic information security systems, the following generally accepted requirements are formulated:

The encrypted message must be readable only if the key is present.

number of operations required to determine the used key

Encryption by a fragment of an encrypted message and the corresponding

The plain text must be no less than the total number of possible keys;

The number of operations required to decrypt information by searching through all possible keys must have a strict lower estimate and go beyond the capabilities of modern computers (taking into account the possibility of using network computing);

knowledge of the encryption algorithm should not affect the reliability of protection; a slight change in the key should lead to a significant change in the form of the encrypted message, even when using the same key;

Structural elements of the encryption algorithm must be unchanged;

additional bits introduced into the message during the encryption process must be completely and securely hidden in the ciphertext;

The length of the ciphertext must be equal to the length of the original text;

· there should be no simple and easily established dependence between the keys sequentially used in the encryption process;

any key from the set of possible ones must provide reliable protection of information;

The algorithm should allow both software and hardware implementation, while changing the key length should not lead to a qualitative deterioration of the encryption algorithm.

The simplest criterion for the effectiveness of cryptographic systems is the probability of revealing a key or the power of a set of keys. In essence, this is the same as cryptographic strength. For its numerical evaluation, one can also use the complexity of deciphering the cipher by enumeration of all keys.

2.5 Antivirus programs

Ways to counteract computer viruses can be divided into several groups: prevention of virus infection and reduction of the expected damage from such infection; methods of using anti-virus programs, including the neutralization and removal of a known virus; ways to detect and remove an unknown virus. Antivirus programs are the most effective in combating computer viruses. Modern anti-virus programs are multifunctional products that combine both preventive and prophylactic tools, as well as virus treatment and data recovery tools.

Classification of antiviruses.

The principle of operation of anti-virus scanners is based on scanning files, sectors and system memory and searching for known and new (unknown to the scanner) viruses in them. So-called "masks" are used to search for known viruses. A virus mask is some constant code sequence specific to that particular virus. If the virus does not contain a permanent mask, or the length of this mask is not large enough, then other methods are used. An example of such a method is an algorithmic language that describes all possible code variants that can be encountered when this type of virus is infected. This approach is used by some antiviruses to detect polymorphic viruses. Many scanners also use "heuristic scanning" algorithms, i. analyzing the sequence of commands in the object being scanned, collecting some statistics and making a decision ("possibly infected" or "not infected") for each object being scanned. Since heuristic scanning is largely a probabilistic method for detecting viruses, many laws of probability theory apply to it. For example, the higher the percentage of detected viruses, the greater the number of false positives.

Blockers. Anti-virus blockers are resident programs that intercept "virus-dangerous" situations and notify the user about it. "Virus-dangerous" calls include calls to open for writing to executable files, writing to the boot sectors of disks or the MBR of a hard drive, attempts by programs to remain resident, etc., that is, calls that are typical for viruses at the time of reproduction. The advantages of blockers include their ability to detect and stop the virus at the earliest stage of its reproduction, which, by the way, is very useful in cases where a well-known virus constantly "creeps out of nowhere". The disadvantages include the existence of ways to bypass blocker protection and a large number of false positives, which, apparently, was the reason for the almost complete refusal of users from this kind of anti-virus programs (for example, I am not aware of any blocker for Windows95 / NT - there is no demand, no offer).

Immunizers.

Immunizers are divided into two types: immunizers that report infection, and immunizers that block infection with any type of virus. The first ones are usually written to the end of files (according to the principle of a file virus) and each time the file is launched, it is checked for changes. The disadvantage of such immunizers is only one, but it is lethal: the absolute inability to report infection with a stealth virus. Therefore, such immunizers, as well as blockers, are practically not used at present. The second type of immunization protects the system from attack by a particular type of virus. The files on the disks are modified in such a way that the virus assumes they are already infected (for example, the infamous "MsDos" string that protects against the "Jerusalem" fossil virus). To protect against a resident virus, a program that imitates a copy of the virus is entered into the computer's memory. When launched, the virus stumbles upon it and believes that the system is already infected.

This type of immunization cannot be universal, since it is impossible to immunize files against all known viruses: some viruses consider files already infected if the file creation time contains a mark of 62 seconds, and others - 60 seconds. However, despite this, such immunizers as a half measure can quite reliably protect a computer from a new unknown virus until the moment when it is detected by anti-virus scanners.

If a virus is indeed found on the computer, then you need to do the following: if a file virus is detected, if the computer is connected to the network, you must disconnect it from the network and inform the system administrator. If the virus has not yet penetrated the network, this will protect the server and other workstations from the virus. If the virus has already hit the server, then disconnecting from the network will not allow it to re-enter the computer after it has been cured. Connection to the network is possible only after all servers and workstations are cured. If a boot virus is detected, the computer should not be disconnected from the network: viruses of this type do not spread over the network (naturally, except for file-boot viruses). If a macro-virus infection has occurred, instead of disconnecting from the network, it is enough to make sure that the corresponding editor (Word/Excel) is inactive on any computer for the period of treatment. If a file or boot virus is detected, you should make sure that the virus is either non-resident or the resident part of the virus is neutralized: when launched, some (but not all) antiviruses automatically neutralize the resident viruses in memory. Removing the virus from memory is necessary in order to stop its spread. When scanning files, antiviruses open them, many of the resident viruses intercept this event and infect the files being opened. As a result, most of the files will be infected, because the virus is not removed from memory. The same can happen in the case of boot viruses - all floppy disks being checked may be infected.), so you should also check the "boot sequence A: C:" item in the BIOS settings to ensure that DOS is loaded from the system floppy disk, and not from an infected hard drive . In addition to residency/non-residency, it is useful to familiarize yourself with other characteristics of a virus: the types of files infected by the virus, manifestations, and so on. The only source of detailed information of this kind known to me about almost all known viruses is the AVP Virus Encyclopedia.

Using an antivirus program, you need to restore infected files and then check their performance. Before disinfection or at the same time - create backup copies of infected files and print or save somewhere a list of infected files (antivirus log file). This is necessary in order to restore files if the disinfection fails due to an error in the anti-virus disinfection module or because the anti-virus is unable to disinfect the given virus. In this case, you will have to resort to the help of some other antivirus. It is much more reliable, of course, to restore infected files from a backup copy (if any), but you will still need antivirus services - in case not all copies of the virus are destroyed, or if the files in the backup copy are also infected. It should be noted that the quality of file recovery by many anti-virus programs leaves much to be desired. Many popular antiviruses often irreversibly damage files instead of curing them. Therefore, if the loss of files is undesirable, then the above points should be followed in full. In the case of a boot virus, all floppy disks must be scanned, whether they are bootable (that is, contain DOS files) or not. Even a completely empty floppy disk can become a source of virus spread - just forget it in the disk drive and restart the computer (unless, of course, the floppy disk is marked as the boot disk in BIOS Setup). LZEXE, PKLITE or DIET, files in archives (ZIP, ARC, ICE, ARJ, etc.) and data in self-extracting files created by utilities like ZIP2EXE. If you accidentally pack a file infected with a virus, then it is almost impossible to detect and remove such a virus without unpacking the file.

In this case, a typical situation will be when all anti-virus programs that are unable to scan inside packed files will report that all disks have been cleaned of viruses, but after a while the virus will appear again. Virus strains can also infiltrate backup copies of software when updating these copies. Moreover, archives and backup copies are the main suppliers of long-known viruses. A virus can "sit" in a distribution copy of a software product for years and suddenly appear when installing programs on a new computer. No one guarantees the complete destruction of all copies of a computer virus, since a file virus can infect not only executable files, but also overlay modules with name extensions other than COM or EXE. A boot virus can remain on a floppy disk and suddenly appear when you accidentally try to reboot from it. Therefore, it is advisable for some time after the removal of the virus to constantly use the resident anti-virus scanner (not to mention the fact that it is desirable to use it all the time).

List of used literature

1. Magazine "Home Computer" - No. 10, 2001.

2. S. Simonovich, G. Evseev "The latest tutorial on working on the Internet" - M: "DESS COM", 2000 - 528 p.

3. S. Simonovich "Computer science for lawyers and economists" M: "Infocom-Press", 2001.

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Computer technology is now used in almost all organizations. The use of this equipment by employees can have a negative impact on their health and even lead to emergencies and accidents at work. In order to avoid this, employees must observe safety precautions when working with a computer.

Negative factors when working at a computer

An employee who uses a computer in his work activity may experience the following negative factors:

• electromagnetic and infrared radiation;
• the noise of a running computer (or several computers);
• risk of electric shock in the event of a short circuit;
• the possibility of a fire.

Computer rules

Obliges the employer to develop and approve labor protection instructions and ensure that employees are familiarized with them. Thus, a special document can be approved in an organization that provides for the rules for performing labor operations with computer equipment, which can be called, for example, a safety instruction when working at a computer. Separate provisions on this issue may be contained in the instructions on labor protection for office workers.

In some branches of economic activity, standard instructions on labor protection are approved. For example, the Order of the Ministry of Communications of the Russian Federation of 02.07.2001 N 162 approved the Instruction on labor protection when working on a personal computer TOI R-45-084-01.

Consider the safety rules for each stage of working with a computer.

1. Before starting work: check the serviceability of the electrical wiring, sockets and plugs of the computer, the grounding of the PC.

2. During work:

• Wires must be handled with care.
• it is forbidden to work with a faulty computer;
• you can not clean the computer when it is energized;
• it is unacceptable to independently repair equipment in the absence of special skills;
• do not place liquids near the computer, as well as work with wet hands;
• do not touch other metal structures (for example, batteries) while working with a PC;
• smoking and eating food in the immediate vicinity of the PC, etc. is not allowed.

3. In emergency situations:

• in case of any problems, you must immediately disconnect the PC from the network;
• in case of detection of a bare wire, immediately notify all employees and exclude contact with the wire;
• in the event of a fire, take measures to extinguish it using fire extinguishers (workers must know where they are);
• in case of electric shock to a person, provide first aid and call an ambulance.

4. Upon completion of work:

• turn off computer;
• it is desirable to carry out wet cleaning of the workplace;
• turn off the power supply.

Workplace organization

Constant work at the computer causes deviations in the health of the employee, in particular:

• the load on vision leads to its deterioration, redness of the eyes, the occurrence of "dry eye syndrome";
• non-compliance with the standards of the organization of the workplace can lead to curvature of the spine, joint diseases and pain of a different nature;
• prolonged concentration of attention on the screen causes overwork.

The procedure for organizing work with a computer is determined by SanPiN 2.2.2 / 2.4.1340-03, entered into force on 06/30/2003.

Here are some of the requirements imposed by SanPiN on the workplace of a PC user:

• the distance from the monitor to the eyes should be from 600 to 700 mm, but not less than 500;
• the worker's chair must be adjustable in height and provide the ability to turn and change posture during work;
• table height - from 680 to 800 mm;
• the surface of the table should allow you to optimally place on it everything you need for work, etc.

Breaks at the computer

In order to avoid overworking the SanPiN employee, it is recommended to take breaks lasting from 10 to 15 minutes after 45 to 60 minutes of work. During a break, an employee should perform eye exercises and physical exercises provided for in Appendixes 8-10 to SanPiN.

Compliance with the rules of work at the computer will reduce the negative impact of the computer on the health of the employee. However, most often it is the employees who neglect these rules, and the task of the employer in this case is to constantly bring to the attention of their employees information about the consequences of non-compliance with the above requirements and organize mandatory work breaks with their orders.

The computer has long been an integral part of our lives. So integral that many of us now simply cannot imagine how we can communicate, search for the necessary information, relax and, of course, work without a keyboard with a mouse at hand and a display in front of our eyes. We spend eight hours at work staring at the monitor, and then go home to hunt on the Internet, kill monsters in an online game, or watch a freshly purchased movie.

Computer and security. How to protect yourself from the influence of computers.

According to statistics, the average time that a knowledge worker spends at a computer in developed countries reaches 12 hours a day. Is it a lot? “Dangerous, unacceptably much!” the researchers answer. Despite the apparent absence of physical stress, the body is subjected to enormous stress, the consequences of which, in addition, tend to accumulate. Literally everything suffers - vision, the musculoskeletal system, the nervous system, the psyche. Some of you, dear readers, may say: “Well, why are you frightening? I have been living like this for many years, and nothing, I’m healthy!” Do not rush to rejoice. Pathological processes occurring in the body in the initial stages may not be too noticeable, but one day there will definitely come a moment when they will declare themselves. But since the time of Hippocrates it has been known that the disease is easier to prevent than to cure.

So what should you pay attention to? How to reduce the risk of illness if professional activity inevitably chains you to a PC display? Let's try to figure it out. To do this, we need to consider the impact of prolonged work at the computer on various body systems.

Human vision and computer influence

We use our eyes to read information from a computer display; this process occurs almost continuously during the entire time of communication with the machine. Constant and long-term stress on vision causes a syndrome that has become known in medicine as CVS or "Computer Vision Syndrome". What pathological processes are its cause?

1 The dangerous factor of the computer is dehydration. Concentrating on the information displayed on the monitor, we simply forget to blink! Blinking is an important physiological process; at the moment when the eyelid slides over the eyeball, it is moistened and dust microparticles are washed off its surface. When we stop blinking, the surface of the cornea begins to dry out, and dust particles exacerbate irritation. In addition, with such a concentration of attention, we involuntarily open our eyes wider than usual, thereby increasing the area for moisture evaporation. The result is pain in the eyes, photophobia, weakening of the protective functions of the eye, and an increased risk of conjunctivitis.

2 Dangerous factor of the computer - disturbance of accommodation. Accommodation is the ability of the lens to change its shape, which ensures focusing on objects located at different distances from a person. During operation, the distance from the eyes to the display almost does not change, and the pupil is in the same position for a long time; muscles work only for “fine adjustment” of sharpness. Prolonged forced monotony in the work of accommodative muscles leads to their dysfunction; their ability to change the shape of the pupil is weakened, leading to nearsightedness or farsightedness (depending on the distance between the eyes and the monitor). If you already have problems with accommodation, prolonged exposure to the display can easily lead to their aggravation. It is also worth noting that focusing on the displayed information causes the lens muscles to continuously perform the “tuning” work mentioned above, which leads to their fatigue and subsequent pathology .

3 The risk factor is the "burnout" of the retina. This process is most pronounced in those who constantly work a lot with text. The image on the monitor in this mode of operation changes very little, and part of the light-sensitive cells of the retina - rods (rods) and cones (cones) constantly receives an unchanged illumination pattern. These cells, which receive a uniform and intense light for a long time, get tired, and the efficiency of the restoration of photopsin pigments (which decompose under the influence of light, forming the neurochemical response of the retina to light) decreases. The result is a decrease in the power of vision, a weakening of the ability to see in the dark.

How to protect yourself? Computer rules.

The first and most important method of dealing with CVS is rest! Studies have shown that every 30-40 work it is desirable to take short pauses, during which to perform the simplest exercises. Exercise 1 - “Closer-Further”: This exercise is best done near the window. Alternately focus your eyes on a close object (for example, your own finger) and a distant one (a window of a house in the distance). Try to position your finger so that it is almost in line with the distant object, so that you practically do not have to look away. Exercise 2 - “Rotate the eyes”: Look straight ahead. Then we make several movements with the eyeballs "left - down - right - down - right." Then - a series of similar movements back and forth along the upper arc. Exercise 3 - “Squinting”: We close our eyes tightly several times in a row. During the exercises, we, in fact, knead the accommodative and oculomotor muscles, as well as stimulate the blood supply to the eyes, and contribute to the normalization of intraocular pressure. Try it and you will feel how tired eyes feel better. Don't forget about blinking too. A piece of paper stuck on the monitor with the call: “Blink!” can be a good reminder. Important points are also the correct location of the monitor in relation to the eyes: the distance is at least 50 cm, the angle between the line of sight directed to its center and the normal (perpendicular) at the same point should be about 35 °. It is worth remembering about the right lighting. It should not be too bright - but you should not work in the dark either. When planning the location of the workplace, you should keep in mind the location of light sources, including windows: the monitor should not have glare and ambient light. Pay special attention to this aspect if your monitor has a "glossy" matrix. If you can’t completely get rid of glare and flare, you can try to make a hood from an ordinary drawing paper and fix it on the monitor with adhesive tape. The beauty of the workplace may suffer, but one's own health is usually noticeably more valuable than aesthetics.

Musculoskeletal system

The working day is not over yet - and already the neck and shoulders hurt, the wrists ache, the unbearable shoots in the arch of the brush lying on the back of the plastic rodent. No wonder; the body of the hero of the keyboard-display front requires no less attention than his eyes. What are the main problems in this area? Spine and back muscles. Too high or too low a table, as well as an uncomfortable chair, threaten your back and neck with serious trouble. If the monitor is not positioned correctly relative to the eyes, the person working behind it is forced to tilt the neck, bending the spine, which leads to an increase in the load on the muscles and intervertebral discs. Muscle fatigue leads to pain in them; the incorrect position of the spine leads, ultimately, to curvature of the spinal column, osteochondrosis, herniated discs. Another reason for the development of muscle pain and osteochondrosis is the non-ergonomic design of the work chair; very often, cheap office chairs purchased in bulk have too short or flimsy backs and seats, there is no lumbar support, and the possibilities for adjustment leave much to be desired.

Shoulders, arms, hands of a person - the influence of the PC.

Your chair doesn't have armrests and the table isn't deep enough to replace them with the ability to rest your forearms on it? So, after a while, you will probably notice discomfort in the shoulders and forearms. Wrists and hands also will not keep you waiting long.

The need to keep your hands on weight will quickly tire your muscles, turning your work from intellectual to physical. If you already have spinal problems, and you are constantly forced to consciously control the position of your own back and neck, fatigue of the arm muscles will inevitably make your task more difficult. What to do? First and most importantly - try to make it so that working at the computer is COMFORTABLE. If the table is too low and the chair is poorly adjusted in height, place something under the monitor; under the keyboard and mouse will also have to invent a stand. If the table is too high, raise the seat and don't forget the footrest; legs should not hang in the air. However, it is much better to demand a normal table from the authorities. What you sit on is just as important. A chair used for long-term work at a computer must necessarily have armrests and a wide backrest with a height of at least from the pelvis to the shoulder girdle; the relief of the back should provide for the presence of lumbar support (in the absence of a back, you should not work for more than a few minutes at all!). If the design of the chair provides for adjusting the inclination of the seat and back, as well as the height of the armrests, this is very good; the ability to change the working position will help you get tired less.

However, no matter how convenient the workplace is organized, you should never forget about rest. The recommendation of a five-minute rest every half hour is as true for the musculoskeletal system as it is for the eyes. 10 minutes every hour, or 15 minutes every hour - there are many options, everyone chooses for himself the optimal rhythm of work and rest. Get out of your chair and walk around the office. Stretch. Shake your hands so that they relax. If possible, do some simple exercises. Exercise 1: “The bird spreads its wings”: Stand with your feet together, arms hanging freely along the body. Rise on tiptoe, at the same time bending your back forward in the thoracic region and moving your arms slightly back, at the same time trying to turn your palms outward. Repeat several times. This exercise is intended primarily for those who tend to slouch; it stretches the muscles of the back and causes the spine to straighten. Exercise 2: "Pendulum in reverse": This exercise can be performed both while standing during a break, and sitting in a chair, looking away from working with the keyboard for a minute. Interlace your fingers in front of you so that your palms are facing outward. Raise your clasped hands above your head, stretch. Make tilts to the sides so that the torso deviates from the vertical, but the pelvic girdle remains motionless. This exercise fights scoliosis, but not only; part of the muscles being kneaded also works to maintain the back in a straightened position. Exercise 3: Shoulder Play: This exercise can also be done standing up or on the job. Move your shoulders. Raise each shoulder several times separately, then both together; the movement is similar to a normal shrug. Move first one, then the other shoulder back and forth. Try moving both shoulders at the same time (one forward, one back). Now, for those who wish - the most difficult: rotation of the shoulders. Try to rotate back and forth with each shoulder so that the elbow remains more or less stationary. Happened? If yes, then try rotating your shoulders in opposite directions: right - forward, left - back, and vice versa. I am sure that after several attempts to get your shoulders to work correctly, you will feel unprecedented relief after you return to work. If you can manage to control your shoulders, you have a great little set of exercises at your disposal to help your body withstand the hardships of hard mental work. It is easy to understand that this series of exercises kneads the stiff muscles of the shoulder girdle. By the way, it's not bad at the end of this series to shake your head deeply, but carefully - left-right and back and forth. This will help relax your neck muscles.

If you realized it too late, and the curvature of the spine has become a sad present for you, in no case start the process. The spine is the seat of the main conducting system of the body - the spinal cord, the roots of which provide innervation to most systems of the body. In the event of osteochondrosis or, even more so, disc herniation, these roots may be damaged, which can lead to irreversible health problems. Consult a doctor; He will prescribe you posture corrective measures, including exercise therapy, positioning and manual therapy (massage), and possibly wearing a special posture corrector.

The probability of negative consequences from using a personal computer is the same as when using other household appliances. After all, it is well known that it is important to observe safety measures with a microwave oven, iron or electric kettle.

Indirect harm that is not immediately noticeable is damage to health:

The danger of a PC as an electrical appliance lies in the occurrence of power failures and ignition of the entire system.

General safety rules

Safety precautions when working with a computer in an enterprise provides for the availability of a publicly available instruction, which indicates the mandatory requirements for the arrangement of the workplace and the process of using equipment. These rules are the same for all organizations, their implementation is controlled by the governing bodies.

Basic rules for organizing space around the workplace:

Safety requirements

For office workers, an oral basic briefing should be carried out, in the future, its printed text should be provided for detailed study. The organization shall place the information sheet in a conspicuous place without fail.

The briefing covers the full cycle of human contact with the computer. It starts with the installation of the equipment by the service department and ends with the disposal of the unusable device.

Before starting work

Even if we are talking about a workplace that is used every day and regularly checked by specialists (for example, in an office or educational institution), one should not lose vigilance.

Before turning on the computer, you need to take a couple of minutes to do the following:

When doing work

Since a personal computer has all the properties of an electrical device, the basic safety rules apply to it when interacting with current conductors:

As mentioned above, improper work with a personal computer is fraught with many threats to human health.

In order to minimize this influence even with a long stay at the monitor, it is worth remembering the following postulates forever:

In emergency situations

Timely vigilance will help to avoid dangerous situations for life and maintain the integrity of equipment.

Actions in emergency situations:

Upon completion of work

Close all programs and windows properly before finishing. Do not leave active storage media (disks and flash drives). It is worth noting that the order of turning off the constituent parts of the PC differs from the order of turning them on exactly the opposite. The computer starts up in a chain: general power supply - peripherals - system unit. Shutdown, respectively, begins with the system unit.

Pull out the power plug by firmly holding on to its body. You can not make sharp jerks and even more so pull the wire.

After completion of work, it is desirable to eliminate excess static voltage from the surface of electrical appliances and carry out wet cleaning of the workplace.

Video: How to sit at the computer

Monitor placement rules

1. The monitor is at a distance equal to the length of the user's arm. If the screen diagonal is more than twenty inches, then the distance is greater;
2. the eyes are at the level of the line, which is 5 centimeters below the top edge of the screen. To do this, the height of the chair and monitor is adjusted;
3. the screen is in the center so that it would not be necessary to hold the neck in an unnatural position;
4. windows in the room should not create glare on the screen. The light from the window is not brighter than the light from the PC;
5. excessive contrast and brightness of the image tire the eyesight, it is necessary to adjust these indicators;
6. in offices where computers are located in two rows, a protective intermediate screen should be installed to eliminate excess radiation.

Photo: correct placement of the monitor

If there is no such protection, then the minimum distance from the nearest screen is at least two meters.

Job Requirements

The minimum area of ​​the workplace for one person is 6 m2. Light must come from artificial and natural sources. Lamps do not glare from the screen, and excess sunlight must be restrained by fabric curtains. It is undesirable to illuminate the room exclusively with the help of a ceiling overhead light.

It is unacceptable to place computer wires near the heating system, their insulation must be intact. The system unit should not stand in a desk niche or other enclosed space where normal ventilation is impaired

Photo: Location of items in the workplace

To eliminate all kinds of risks, you need to responsibly treat all stages of using a computer. The user can and should control the entire cycle of interaction with the equipment. The process of complying with all these simple rules must be continuous and complex.