Современные информационные технологии/1. Компьютерная инженерия

cand. tech. sci. Semakhin A.M.

student Мamontov R. I.

Kurgan State University, Russia

THE PROGRAM OF A CHOICE OF THE OPTIMUM PROJECT OF THE DISTRIBUTED COMPUTER NETWORK

Now the wide circulation of the distributed computer networks is observed. It speaks their advantages based on sharing of the information and a fast data access. The distributed computer networks solve problems in interests of corporation, its branches and the enterprises [1].

The choice of an effective variant of the distributed computer network is an actual problem. The mathematical model of a choice of an optimum variant of the distributed computer network is developed for the decision of a task in view, formalized on personal computer /PC/.

Statement of a problem of optimization of the distributed computer network is formulated as follows: from among alternative variants of the distributed computer network it is necessary to choose the best variant maximizing net present value and satisfying to financial restrictions.

The mathematical model of optimization includes two stages:

1. The method of expert estimations forms alternative variants of the distributed computer network.

2. The method of mathematical programming defines an optimum variant from among alternative, chosen on the first stage.

The mathematical model of linear programming looks like:

under restrictions

where – quantity of commissions of experts;

– number of experts in the group, projects estimating variants;

– quantity of the equipment chosen by the expert;

– the weight chosen of j experts for k equipment;

– the estimation given by j expert of i group for k equipment;

– average estimation of the project of i group;

– the net present value of v project;

– investment expenses of v project in w period of time;

– means of financing in w period of time;

– share of financing of v project;

– number of the investment project;

– number of the period of time [2].

The optimum decision is defined by method Gauss-Jordan.

The algorithm of method Gauss-Jordan includes stages:

1 Stage. Definition of the initial admissible decision.

2 Stage. Check on an optimality. If the decision optimum go to 5 stage.

3 Stage. A choice of included and excluded variables.

4 Stage. Definition of the new plan. Go to 2 stage.

5 Stage. A press of the optimum decision [3].

The mathematical model is formalized on PC. The developed program complex gives the automated choice of the best variant of the project of the distributed computer network.

In a basis of architecture of a program complex the three-level model of the application is used. The three-level model includes three levels: representation, business - logic, data.

Level of representation – the interface providing interaction of the user with the application.

Level business - logic – a rule of data processing.

Level of data – interaction with a database.

The program complex includes functions:

1. Input of initial data.

2. Realization of a method of expert estimations.

3. Definition of an optimum variant of the distributed computer network.

4. Search on a database.

5. Addition in a database.

6. Editing of characteristics of the equipment.

7. Viewing of the network equipment.

8. A conclusion of the list of the network equipment.

The program complex is realized in language Qt Creator C ++.

After start of the program, there is a prompt. Initial data according to the technical project are entered. After data input the first stage – formation of alternative projects with use of a method of expert estimations is realized (fig.1 – fig.2)

Fig.1 The First expert of the first group. A choice of the equipment

Fig.2 Result of a choice of the first expert of the first group

The quantity of groups and number of experts in groups can be changed in a program complex.

The result of work of experts is represented in a graphic kind (fig.3 – fig.4)

Fig.3 Result of work of experts of the first group

Fig.4 Results of work of commissions of experts

Total expenses for realization of projects are resulted on fig.5

Fig. 5 Total expenses for realization of projects

The second stage of mathematical model – a choice of an optimum variant of the project of the distributed computer network from among alternative variants of the first stage is realized (fig.6).

Fig.6 Data input for realization of the second stage of mathematical model

The optimum decision is resulted on fig.7

Fig.7 The Optimum decision

The program complex allows to look definition of the optimum decision on iterations and to deduce graphic representation of topology of a network.

Results of the lead researches have allowed to draw conclusions.

1. The mathematical model of a choice of an optimum variant of the project of the distributed computer network is developed.

2. The program complex of a choice of the optimum project of the distributed computer network is developed.

3. The developed mathematical model formalized on PC, allows to lower financial and time costs, to raise quality and validity of the made decision in designing the distributed computer network and to reduce a time of recovery of outlay.

4. Results of work can be used for the further research.

References:

1. Пятибратов А.П. Вычислительные системы, сети и телекоммуникации: Учебник. – 2-е изд, перераб. и доп./А.П. Пятибратов, Л.П. Гудыно, А.А. Кириченко; Под ред. А.П. Пятибратова. – М.: Финансы и статистика, 20025. – 512 c.

2. Семахин А. М. Математическая модель оптимизации информационной системы. Вестник Курганского государственного университета. – Серия «Технические науки». – Вып. 5. – Курган: Изд-во Курганского гос. ун-та, 2010. – 220 с.

3. Таха Хемди. Введение в исследование операций, 7 – издание.; Пер. с англ. – М.: Издательский дом “Вильямс”, 2005. – 912 с.