Turuta O. Methods and means to improve service requests in an information network

The object of study is the process of serving requests in an information network. Subject of research are the methods and means of assessing the priorities of serving requests and providing accessibility of resources in the information network. The aim of the thesis is to develop methods and means of improving the quality of requests service to help increase the efficiency of information networks. The thesis is devoted to solving a topical problem of improving the service of requests in the information network based on the developed methods of examining the usefulness of serving requests, assessing the priorities of serving requests and providing accessibility of resources in the information network. Research methods. In the course of dissertation research, probabilistic characteristics evaluation was made by the probabilities theory of and mathematical statistics methods. For evaluation of request service priority and load intensity, teletraffic theory methods and multivariable analysis methods were applied. Information network quality analysis was conducted by using a systems approach and general methods of the communication networks theory. To solve the problem of cluster decomposition of the information network, graph theory and set theory were applied. Evaluation of the efficiency of requests service priority and traffic control was carried out by simulation. Scientific novelty: 1. For the first time a method of assessing the usefulness of serving requests is proposed, which is based on the use of information resources needed to execute the request and on a comparison of probabilities of errors serving other requests in the process of serving the current request, and the records provided for possible losses resulting from denial of service for the current request, allowing to obtain effective estimates of necessary resources to service requests and on the basis of the obtained estimates to redistribute current service requests in an information network. 2. For the first time a method of evaluating the requests service priority in an information network is proposed, where, based on the estimates of usefulness of serving request, traffic marking is performed that contains the answer to the request, and the subsequent traffic service policy forming, which can reduce errors in serving requests in the information network. 3. Method to ensure the resources availability in the information network is further developed, which, unlike existing methods, forms the policy of providing access to services based on ratings usefulness of serving requests, information about requests being served and possible repeated requests, which allows to refuse to serving traffic that creates the problem situation in the service, the proposed method loses rejected traffic, but is able to continue serving all other traffic. 4. A model of the information network is improved based on agent-oriented approach, which describes the elements in view of real restrictions of the information network, in contrast to the existing graph models and models of queuing theory it allows to more fully take into account the real characteristics of the network during simulation. The degree of implementation: in practice of the Department of Information Technology of the Ministry of Internal Affairs and the Ukrainian Association of Distance Education, also in the educational process of the Kharkov National University of Internal Affairs.