Information system. Information system software. Information technology and systems software
Information systems software is understood as a set of software and documentary tools for the creation and operation of data processing systems by means of computer technology.
Depending on the functions performed by the software, it can be divided into 2 groups: basic (system) software (Fig. 1) and application software (Fig. 2).
Basic (system) software organizes the process of information processing in a computer and provides a normal working environment for application programs. The underlying software is so closely related to the hardware that it is sometimes considered part of the computer.
Application software is designed to solve specific user tasks and organize the computing process information system generally.
The basic (system) software includes:
OS;
service programs;
programming language translators;
maintenance programs.
Operating systems (OS) provide control over the processing of information and interaction between hardware and the user. One of essential functions OS is the automation of the processes of input-output information, management of the execution applied tasks decided by the user. OS is loading desired program and computer memory and monitors the progress of its implementation; analyzes situations that interfere with normal calculations, and gives instructions on what needs to be done if difficulties arise.
Based on the functions performed, OS can be divided into three groups (see Fig. 1): single-tasking (single-user); multitasking (multi-user); network.
Rice. 1.
Single-tasking operating systems are designed for the work of one user at any given moment with one specific task. A typical representative of such operating systems is MS-DOS (developed by Microsoft). Multitasking operating systems provide for the collective use of computers in a multiprogram time-sharing mode (in the computer's memory there are several programs - tasks - and the processor distributes computer resources between tasks). Typical representatives of this class of OS are: UNIX, OS 2 of IBM Corporation, Microsoft Windows 95, Microsoft Windows NT and some others.
Network operating systems are associated with the advent of local and global networks 11 designed to provide user access to all resources computer network. Typical representatives of network operating systems are:
Novell NetWare, Microsoft Windows NT, Banyan Vines, IBM LAN, UNIX, Sun's Solaris.
Service software is a collection software products, providing the user with additional services in working with a computer and expanding the capabilities of operating systems.
By functionality, service tools can be divided into tools:
improving the user interface;
protecting data from destruction and unauthorized access;
recovery data;
accelerating data exchange between disk and RAM:
archiving-unzipping;
antiviral agents.
According to the method of organization and implementation, service tools can be represented by: shells, utilities and stand-alone programs. The difference between shells and utilities is often expressed only in the universality of the former and the specialization of the latter.
Rice. 2.
Shells that are an add-on to the OS are called operating shells. Shells are like settings above the operating system. Utilities and stand-alone programs have a highly specialized purpose and each perform its own function. But utilities, unlike standalone programs, are executed in the environment of the corresponding shells. At the same time, they compete in their functions with OS programs and other utilities. Therefore, the classification of service facilities according to their functions and methods of implementation is rather vague and very conditional.
Software (software) of information systems (IS) includes:
Basic software is operating systems (OS) and database management systems (DBMS);
· software modeling and design of IS;
means of implementing IS - programming languages;
· software application, which provides automated execution of domain tasks.
6.1 Comparative analysis of OS
The operating system is responsible for the efficiency of application execution; performance, degree of data protection, reliability of the network; the possibility of using equipment from different manufacturers; application of modern information technologies and their development.
OS selection is based on the following requirements:
1. Cost/performance ratio.
2. Functionality.
3. Reliability of functioning.
4. Data protection.
5. Ability to generate a kernel for a specific hardware structure.
6. Features of the functioning and modes of operation of the OS, allowing to solve the tasks.
7. All modern operating systems support network mode, but the requirements for the server and workstations may be different in the following parameters:
a) required volume random access memory;
b) required volume disk storage;
c) compatibility with other systems.
8. Support remote access to the terminals.
9. Prospects for the development of the entire computing system.
10. Support for standards.
11. Easy to administer and install.
Based on the above requirements, for comparative analysis includes currently popular Windows operating systems and Unix family operating systems designed for direct work V network mode and constituting two competing directions.
Conclusion.
For the organization of application servers (SQL servers), it is advisable to use the UNIX operating system, other operating systems are less effective as application servers.
Any file server can be used to implement modern system. But at the same time, Windows NT requires the most hardware resources. At a low bandwidth UNIX communication channels allow you to optimize access through packet routing.
To implement remote access servers, it is advisable to use UNIX, since it does not require the installation of any additional packages. Windows NT requires a lot of hardware resources at a very high cost and is not designed to provide remote access servers with a low number of connections.
The most efficient OS in terms of cost, performance, functionality, data protection and development prospects are the operating systems of the UNIX family.
Basic requirements for operating the OS in network mode
When it comes to the use of a multi-user database used not only in the workstations of one specialist, but also in the workstations of other specialists, the network OS must be able to organize a file server. In addition, network operating systems with a server must provide high performance for networks with a large number users.
When building a server-based LAN, reliability is a key factor, followed by factors such as workstation support and performance metrics. From the point of view of ensuring reliability, the most important thing is effective means memory management, because without it, with a large number of users, situations may arise when workstations lose contact with each other, and file servers turn out to be inoperable. The term reliability also covers the concept of compatibility: a network operating system should work well with all common multi-user applications and standard software. Reliability also means that the server and workstations operate smoothly on the network, application programs run correctly, and the network operating system protects data from hardware failures. A complete set of error protection tools, data protection at the level of individual database records, effective memory management tools and reliable mechanisms for organizing multitasking are required. Workstation support requirements are also important. If network drivers take up too much memory on each PC, it is possible that the workstation application software and utilities resident in RAM will not run.
Speed is especially important when operating multi-user software packages, as it determines the efficiency of SQL queries and how much additional users will be able to serve the system before it becomes necessary to purchase a second server.
After speed, the next most important factor is administration tools. Flexible administrative tools help you set up and configure your network in less time. The network OS should provide flexible options for sharing resources on the LAN - printers, modems, and external memory.
DBMS choice
The choice of a DBMS depends on the organization of a local and network database (DB), cost, the specifics of the tasks being solved, functional features(integrity support, data protection level, speed, efficiently processed amount of data in the database, network support, availability of a development environment, interaction with other applications, including Internet applications).
The following methodologies for organizing a network database should be considered:
1. The database is stored centrally on the server, and access from workstations is via the network;
2. The database is distributed among computers-workstations, but is rigidly fixed.
Selecting a network protocol(ODBC, Microsoft, Novell).
network protocol used to access data in a remote database. It allows you to integrate heterogeneous databases.
The choice is made in accordance with the international ISO standard (seven-level model) and is determined by the following criteria:
1. Performance and efficiency to ensure the necessary speed of processing requests and responses.
2. The possibility of its implementation by existing software using available system modules. The network can be set to the same SQL Server, then you can use the SQL server network protocol, and not use additional software to implement the standard protocol (ODBC).
The network protocol must comply with the international ISO standard. This protocol includes ODBC, which is universally suitable for interacting with any DBMS.
1. The ISO standard implies storing a list of users with prescribed rights along with the main database. Authorization is implemented by means of the DBMS.
2. The second option involves storing the list of users not directly in the database, but in the operating system. In this case, user authorization is network-based and is implemented at the OS level.
Database reservation.
To ensure the reliability of data storage, a copy of the database is necessarily created. Centralized databases are usually copied on the server. There are different strategies for distributed databases:
1) creation backup DB on the workstation itself, or on any workstation in the network;
2) creating a backup copy on the Backup server. By using special program Backup automatically creates a mirror copy of the database on any network computer sufficient power, which is the Backup server.
Software (SW) includes a set of programs that implement the functions and tasks of the system and ensure the stable operation of hardware complexes. Part software includes system-wide, instrumental and special (applied) programs, as well as instructive and methodological materials on the use of software tools.
General system software includes programs that organize the interaction of hardware and software of the system with each other and with the operator, allocate resources and organize the computing process, monitor and manage the data processing process, solve technological problems (operating systems, database management systems, antiviruses, diagnostics and so on.).
Tool software is used for writing, editing, documenting and debugging programs, allows you to automate the work of programmers (compilers, translators, interpreters, combined into packages with libraries standard programs and schedulers in CASE tools).
Special software is a set of application programs in the subject area of automation. It includes packages of application programs that organize data and process it when solving functional control problems.
The use of the software is associated with a number of legal and technological problems:
for installation and sharing programs on a PC must be approached very carefully, since all products, including the OS, are not free from errors, the effect of which can be summed up and lead to the destruction of the system;
announced by the manufacturer computing power in fact, the software may not be enough for the functioning, since the so-called. resident programs and a number of others, as well as part peripherals take up computing resources.
24. Basic concepts of artificial intelligence.
Artificial intelligence systems are focused on solving a large class of problems called non-formalizable (hard to formalize). Such tasks have the following properties:
algorithmic solution of the problem is unknown or unrealizable due to limited computer resources;
the task cannot be represented in numerical form;
the goals of solving the problem cannot be expressed in terms of a well-defined objective function;
large dimension of the solution space;
dynamically changing data and knowledge.
In research on artificial intelligence, two main areas can be distinguished.
1.Program-pragmatic - is engaged in the creation of programs with the help of which it is possible to solve those problems, the solution of which was previously considered exclusively the prerogative of a person. This direction is focused on the search for algorithms for solving intellectual problems on existing models computers.
2.Bionic - deals with the problems of artificial reproduction of those structures and processes that are characteristic of the human brain and which underlie the process of solving problems by a person. Within the framework of the bionic approach, a new science was formed - neuroinformatics, one of the results of which was the development of neurocomputers.
A significant breakthrough in the practical applications of artificial intelligence systems occurred in the mid-70s, when the search for a universal thinking algorithm was replaced by the idea of modeling the specific knowledge of expert experts. This is how knowledge-based systems appeared - expert systems. A new approach to solving intellectual problems has been formed - the representation and use of knowledge. It is interesting that the concept of "knowledge" does not have any exhaustive definition today.
Knowledge is the revealed patterns of the subject area (principles, connections, laws) that allow solving problems in this area. From the point of view of artificial intelligence, knowledge can be defined as formalized information that is referred to in the process of inference.
Let us give a number of definitions.
Knowledge base - it is a body of knowledge described using the chosen form of their presentation. The knowledge base is the foundation of any intelligent system. The knowledge base contains a description of abstract entities: objects, relationships, processes.
Knowledge can be divided into procedural And declarative. Historically, procedural knowledge, that is, the knowledge represented in algorithms, was the first to be used. Algorithms, in turn, were implemented in programs. However, the development of artificial intelligence systems has increased the priority of declarative knowledge, that is, knowledge concentrated in data structures.
Procedural knowledge is stored in the IS memory in the form of descriptions of procedures by which knowledge can be obtained. This is how methods for solving domain problems, various instructions, techniques, etc. are usually described. Procedural knowledge forms the core of the knowledge base.
Declarative knowledge is a collection of information about the qualitative and quantitative characteristics of objects, phenomena, presented in the form of facts and heuristics. Traditionally, such knowledge was accumulated in the form of various tables and directories, and with the advent of computers, it acquired the form of information arrays and databases. Declarative knowledge is often referred to simply as data.
One of the most important problems in the development of artificial intelligence systems is knowledge representation.
Representation of knowledge is their formalization and structuring, with the help of which characteristic features of knowledge are reflected: internal interpretability, structuredness, coherence, semantic metrics and activity.
There are the following main models of knowledge representation:
* logical models;
* production models;
* semantic networks;
* frame models;
* models based on fuzzy sets.
Information systems software
Software(English) software) is a set of programs that ensure the functioning of the information system (IS) and the solution of problems of subject areas with their help.
Modern IS software includes a wide variety of programs, which can be divided into three groups (Fig. 1):
- System software ( system programs);
- Application software (application programs);
- Instrumentation (instrumental systems).
· System software (SW) - these are programs that control the operation of the IS, and perform various secondary functions e.g. IP resource management, health check technical devices, issue background information on the status of IP, etc. They are intended for all categories of users, are used for effective work IP, as well as the effective execution of application programs.
The SPO includes operating systems (OS) and service systems (SS).
· Application software (PPO) designed to solve user problems. Its composition includes user applications and application packages(PPP) for various purposes .
operating system(OS) is a set of programs designed to manage the loading, launch and execution of other user programs, as well as to plan and manage IS computing resources. In a narrower sense, the OS is a program for managing the operation of a computer from the moment it is turned on to the moment the power is turned off.
The OS determines the performance of the system, the degree of data protection, the choice of programs with which you can work on a computer, and hardware requirements. Examples OS are MS DOS (practically not used), OS/2, Unix family, Windows family.
On the market of operating systems, developments of various companies are presented, which differ in their focus on hardware, solving a certain range of tasks, consumer needs, etc. It is possible to single out operating systems that have certain common features: one manufacturer, a single approach to organization and functioning, etc., which allows you to classify them by families and rulers. For example, families such as Windows ( Microsoft), Unix (various developers), Solaris ( Sun Microsystems) and others.
Currently the majority personal computers in the world are running one or another version of the operating Windows systems(firm Microsoft). Software products of this family have common features:
a single graphical user interface;
multitasking;
Support for work in a network environment;
· Availability universal system means of data exchange between applications (clipboard, dynamic data exchange - DDE, object linking and embedding - OLE).
On operating systems Windows families implemented open architecture(Windows Open Services Architecture– WOSA), which provides mechanisms for solving the problem of information transfer, regardless of its location and presentation format. With their help, a computer user can easily connect to any of the information services located on various networks or operating systems. Currently provided standard access to databases, mail, telephone networks and licensing systems network services and specialized services (financial systems and real-time data).
The Unix family is one of the very first operating systems and is currently one of the alternatives to the Windows OS family. Unix was created in Bell Telephone Laboratories in the 70s of the last century. The main difference and advantage of this family lies in the implementation for a wide range of hardware platforms - this is the first operating system that is truly portable to various hardware platforms. Unix is primarily focused on working in large local and global networks. It uses various options GUI. The versatility of the system is ensured by a variety of application programs.
Currently, there are versions of the Unix operating system from various manufacturers. Among them, the most famous commercial versions Sun And Solaris for Sun computers AIX for IBM minicomputers, IRIX for Silicon Graphics computers, freely redistributable FreeBSD and Linux for Intel platform computers.
Regardless of the version, common Unix features are:
· multi-user mode and the availability of powerful means of protecting data from unauthorized access;
multitasking;
portability of the system by writing its kernel in C;
The presence of a simple user interface;
Availability of built-in support computer networks, which makes the system one of the most popular server platforms on the Internet.
Unlike Windows, Unix is more demanding on computers and costs significantly more than Windows.
At present, the Linux operating system is becoming increasingly popular, which is a multitasking, multi-user operating system with support for national and standard keyboards, supports various types file systems, in particular, MS DOS, provides support for the full family of TCP / IP protocols for working on the Internet.
Software (software) of computer information systems (IS) is their necessary component. In general, software is a set of programs whose function is to solve certain tasks on a computer. Without the appropriate software, even an ideally designed system cannot function, since its meaning is completely lost.
Depending on the assigned functions, the compositions of the software are very different from each other. Typically, software includes application programs as well as translator programs. Thanks to this, it is possible to translate application programs from the language high level into machine language. They also include programs that provide automatic input of information through various devices input-output; programs that control the operation of equipment (including programs that control all devices of information systems in the process of information processing).
Functions of software products
There are two types of software: system software and application software.
System software includes ways of communicating with information systems and ways of organizing the calculation process, independent of the nature of the tasks. The main purpose of the first type is the protection function. In full is carried out only if the full software is available. Anti-virus and anti-spyware programs are mainly used as protection. There are other programs that are used as a means of protecting information, but they are not as popular as those listed above.
Speaking about the system software of information systems, it should be noted that both operating systems and programming systems can be distinguished in it. System programming includes products that protect information. Programming systems - a set of programs that provide automation of programming. They contain translators various languages programming and other programs that allow you to automate the design and adjustment of programs. special role in this case is assigned to translator programs, whose function is to translate the record of the solution of problems from a high-level language into a record, which, in turn, is suitable for direct implementation on a computer.
Types of translators used in information devices
Two types of translators are used in information systems computers: compilers and interpreters. The former broadcast the entire incoming record to work program, and then its execution in information systems is carried out. A program translated by a compiler is usually much faster because it is completely converted to machine code. At the same time, it needs more RAM, so compilers are used mainly in large computers. Such hardware can significantly save memory space and control the result of each operation. This is useful when using them in dialog mode.
The operating system (OS) is an important component of the software, since it has a protective function for the systems of any computer.
It manages the execution of work programs and human interaction with information systems. The OS consists of a set of management programs that provide access to them, manages files and schedules tasks for computing resources, controls the storage of programs and ensures their use.
Provision of information systems necessary means protection helps to create a coordinated work of computers and extend the life of the operating system.
The OS greatly simplifies user communication in relation to information systems by automatically performing a large number of intermediate operations, leaving the obligation of the user to only the most necessary operations. For this purpose, the corresponding commands are used, the address of which is specified by the user. Basically, all functions performed using the OS are divided into 3 groups:
- Organization of user interaction with computer information systems;
- Management of all information data entered into the IS;
- Use of OS applications.
The main thing to remember is that the third function will not have any problems if the application programs are compatible with the operating system. The number of application programs has a wide variety and does not cease to grow constantly. The most popular among them is the text editor, business graphics and integrated systems. It should be noted that the latter synthesize the possibilities of all the previous ones and therefore are expensive. With their help, the user has the ability to process different information (textual, tabular, graphic, and so on).
Service software, consisting of software tools that enable the use additional services, thereby expanding the functions of operating systems, includes not only various types of antiviruses and antispyware, but also WinRar archivers, WinZip.
Despite the fact that IPs can be used for various purposes, it should be noted that they do not differ too much from each other. The tasks that the software performs are also similar. Whether it is a single-tasking or multi-tasking software tool, the function is one - the protection of information, which takes place in several stages. First you need to determine the compatibility of programs and OS, then install these products, and then determine whether the software works correctly.
On video - detailed information about information systems software:
Data protection
Antivirus programs are used in cases where it becomes necessary to remove or cure a virus that has entered a computer in order to. Viruses tend to penetrate devices through various media, the Internet. Viruses can cause tremendous damage to both files and directly to the entire computer. Programs for protecting information perform a direct function of destroying viral pests, both harmless and very dangerous.
Based on the foregoing, we can summarize the importance of software for information devices. The initial purpose of software products is to protect information contained in computers and other electronic computing technology.
Information protection is very important for various organizations, institutions, since the loss of data can lead to the failure of enterprise networks.
This probability is undesirable, therefore, the installation of software products should be thoroughly thought out, checked for compatibility, and all possible errors that may occur during operation, as well as during their installation, should be calculated. That is why every serious enterprise, taking care of its reputation, carefully selects software tools. Archivers also play an important role, because they contribute to the compression of information without losing data, which helps in cases where there is a need to transfer large amounts of data.
Software products can expand functions and increase multitasking various types COMPUTER. This increases the user experience, expands functionality both the computer itself and the user. Software is a very important component of any IS, as it plays a major role in the commissioning of IS and helps to carry out various kinds of manipulations with files and databases.
On the video - information about the software with SDL: