Zygmunt Mazur

Models of a distributed information retrieval system based on thesauri with weights

Abstract problem of combining n local information systems S 1 , S 2 , …, S n based on thesauri with weights in one system S is considered. The distributed information retrieval system S may be assumed to be a network of the local systems S j . Both the generalization relation on the set of descriptors and weights of descriptors in descriptions of documents are taken into account. The fundamental properties of distributed systems are described. The inverted file structure is often used to organize data in the information retrieval system. Operations on inverted lists are modified in order to use them in the distributed information system. While retrieving the response to any query in a distributed system, we may use the existing inverted lists from local subsystems. In a distributed system the retrieval process follows almost in the same way as in the method of inverted files in conventional systems. It differs only due to use of the additional union operations on selected inverted lists from any local subsystems. The presented retrieval rules may be viewed as the logical approach in implementing a physical distributed information retrieval system.

On a model of distributed information retrieval systems based on thesauri

Abstract The properties of a global model consisting of n local information retrieval systems based on thesaurus are investigated.

Properties of a model of information retrieval system based on thesaurus with weights

Abstract This paper describes a model of information retrieval system based on thesaurus with weights. Definitions of the following terms: thesaurus, document description, information query, similarity of queries and descriptions of documents, similarity measure and accuracy of response are given. Inclusiveness and two other fundamental properties of the considered system are given.

Music Information Retrieval on the Internet

The chapter discusses selected issues in the field of music information retrieval on the Internet. Differences between music information retrieval and text based information retrieval are indicated. Ways of extracting information from audio files are discussed. ISMIR (Internet Systems of Music Information Retrieval) based on MIDI files, algorithms for identification of audio files based on so called fingerprints and ways of updating audio file metadata are discussed. New algorithms for positioning results of music files searches are proposed and essential elements of contemporary Internet Music Information Retrieval Systems are indicated.

Security of Internet Transactions

State-of-the-art IT facilities are ever more frequently applied in all areas of life. Nowadays, Internet connection, online resources and services are taken for granted. It is much quicker (almost immediate) and more convenient to access electronic information and use online services than to employ traditional methods. Therefore, more and more people take advantage of these options. Aware of the benefits, they often forget about network threats (that arise from inappropriate software protection and failure to follow necessary security rules) or simply underestimate them. This chapter deals with threats to Internet transactions with particular emphasis on new ways of obtaining information and data under false pretences and threats to services rendered in wireless networks.

Inverted File Organization in the Information Retrieval System Based on Thesaurus with Weights.

Abstract The inverted file structure is often used to organize data in the information retrieval system. When the hierarchy relation on the set descriptors and weights of descriptors in document description would be taken into account, the conventional concept of the inverted file may be extended. Properties and operations on inverted files, which are used in system based on thesaurus with weights, are studied in this paper.

Problem of network security threats

The development of computer networks is followed by a rapid evolution of threats to the security of their use. The phenomenon, though observed for years, has increased in the last period of time causing a growing problem to sustain an adequate level of security. New Internet threats utilize the latest techniques and Internet technologies. Computer crimes constitute a true challenge for software engineers and hardware producers as well as for users and all institutions responsible for the security of networks, including state institutions. Numerous world organizations supervise the issue of security. In the last period of time, the governments of many countries, including the European Parliament, have been working intensively on the laws concerning the network security.

Software Flaws as the Problem of Network Security

The software flaws give the possibility of attacking the IT systems, which may result in gaining remote control of them. The known vulnerabilities may be detected with the use of scanners and the threat is then removed through installing some patch or a new software version; however, when the tool does not have the updated threat database, the effect of its functioning may give illusory security. Furthermore, in practice, new vulnerabilities in the security systems are identified all the time, which indicates that obtaining high level of security is a significant problem.

Preconditions for Processing Electronic Medical Records

Due to the abundance and diversity of document types (both external and internal ones), the process of switching to electronic medical records requires a number of organizational, technical and legislative adjustments. The development of those processes and the current stage of works are described in this article. The first step in selecting documents that will become subject to electronic storage and processing in the first place was a survey in which respondents of nine Regional Project consortiums chose medical records most frequently used in business processes conducted by service providers. Based on the Pareto principle, 20% of medical records used in 80% of medical services provided were identified.

Threats to Wireless Technologies and Mobile Devices and Company Network Safety

The wireless technologies have become so attractive that more and more networks, including company ones, are created according to these standards. Mobile access to network resources is also becoming more and more common. Unfortunately, security mechanisms which are used nowadays show a number of faults and are prone to attacks, which, in the age of growing threats, including threats to mobile devices, raises concern about the future of wireless realizations. It is particularly significant in the case of industrial networks due to their frequent strategic importance. Management personnel should be aware of real threats whereas employees should strictly obey company safety policy principles assumed. The aim of this article is to show the importance of the problem and a scale of this phenomenon.