Tatjana Welzer - Academia.edu (original) (raw)

Papers by Tatjana Welzer

Traditional and industrial media (like newspapers and television) are today more and more exclude... more Traditional and industrial media (like newspapers and television) are today more and more excluded as important publishing techniques, while activities have been taken over by social media. Social media is usually understood as media that is designed for social interactions using highly accessible publishing technique. Among the benefits of social media is the inexpensiveness of use and easy access for almost anyone who would like to be a part of the community. This means that people from very different communities are participating and discussing the same topics across a shared medium (wikis, blogs and forums). Topics can very much differ from everyday life up to scientific conferences, project presentations and education. According to the last mentioned it seems that social media is more and more used also for purposes, that have not been expected from the beginning.

Software re-use has become a major issue in software engineering research to overcome the so call... more Software re-use has become a major issue in software engineering research to overcome the so called application backlog in software production. In this paper we introduce a meta data model as a tool to apply re-use concepts also to database design. The main idea is to provide a structured repository of data models such that a database designer can use models or submodels of previous projects in his actual design and thus accelerating the design process. In this meta data model objects are thus organized according to their similarity. In particular, the structure supports the search for similar objects.

Microprocessing and Microprogramming, 1989

Computer Standards & Interfaces, 2009

Many authenticated key agreement protocols based on identity information were published in recent... more Many authenticated key agreement protocols based on identity information were published in recent years. Hsieh et al. presented their protocol in 2002. However, Tseng et al. found a flaw in the protocol which resulted in a key compromise impersonation attack. Later, Tseng proposed his protocol conforming which conforms to all desirable security properties and is efficient. In this paper we propose two new two-party identity-based authenticated key agreement protocols. The first is based on Hsieh et al.'s protocol and makes it immune against Tseng et al.'s attack, while the second is an efficiently improved protocol based on Tseng's protocol.

Sigplan Notices, 1990

... (N) AC'IESS MODIY~ 1 (N) EA ~ created bY Figure 2. The idea of activation of the sys... more ... (N) AC'IESS MODIY~ 1 (N) EA ~ created bY Figure 2. The idea of activation of the system specifications. ... S ociety , IEEE Computer S ociety ; London, 1989. Harley,1987 DJ Hatley, IA Pirbhai, "Strategies for Real-Time System Specification", Dorset House Publ., NY, 1987. ...

The use of PROLOG for digital circuit simulation in the education process is discussed. It is not... more The use of PROLOG for digital circuit simulation in the education process is discussed. It is noted that the curriculum of the University of Maribor gives electrical engineering students some basic knowledge of computer techniques and FORTRAN or Pascal. On this basis, PROLOG can be presented to the students in order to acquaint them with some fundamentals of this fifth-generation language. The students who have acquired basic knowledge of PROLOG are able to define digital circuits specification programs as well as other simple PROLOG rules. The experience that students gain makes them capable of understanding similar models of conventional engineering as well as the basic working of expert systems

To compete successfully in the global information technology market, the localization and/or inte... more To compete successfully in the global information technology market, the localization and/or internationalization of software and web contents for disparate users is essential. More or less solutions are available by software producers as an underlying part of an application’s infrastructure and architecture. Things like date, time, currency symbols, and delimiters are handled seamlessly. More open are topics like quality assurance, standards, data modeling and intelligent systems. Nevertheless to ensure the progress and up to date solutions, integration of internationalization contents in development of intelligent systems are expected and have to be supported. Education of internationalization and localization-aware computer science professionals is so playing the key role. Experts and also students have to cope with local cultural conventions that influence applications solutions. Especially in the area of intelligent medical system is the problem of internationalization and understanding of different cultures very important. Not only, because in different social and cultural environments different parameters influence development and work of intelligent systems but, also because medical intelligent systems support critical decisions.

Informatica (slovenia), 2002

... Smetanova 17, Si-2000 Maribor, Slovenia. {bostjan.brumen | izidor.golob | welzer | i.rozman}@... more ... Smetanova 17, Si-2000 Maribor, Slovenia. {bostjan.brumen | izidor.golob | welzer | i.rozman}@uni-mb.si. AND. ... [Hedberg, 1995] Hedberg, Sara R.: The Data Gold Rush, Byte Magazine, 10-1995. [Helman, 1994] Helman, Paul: The Science of Database Management. ...

Computers & Security, 2010

The use of pairings has been shown promising for many two-party and three-party identity-based au... more The use of pairings has been shown promising for many two-party and three-party identity-based authenticated key agreement protocols. In recent years, several identity-based authenticated key agreement protocols have been proposed and most of them broken. In this paper, we propose two three-party identity-based authenticated key agreement protocols applying bilinear pairings. We show that the proposed protocols are secure (i.e. conform

Journal of Medical Systems, 2005

The spread of electronic use of data in various areas has put importance of data quality to highe... more The spread of electronic use of data in various areas has put importance of data quality to higher level. Data quality has syntactic and semantic component; the syntactic component is relatively easy to achieve if supported by tools (either off-the-shelf or our own), while semantic component requires more research. In many cases such data come from different sources, are distributed across enterprise and are at different quality levels. Special attention needs to be paid to data upon which critical decisions are met, such as medical data for example. The starting point for research is in our case the risk of the medical area. In the paper we will focus on the semantic component of medical data quality.

Informatica (lithuanian Academy of Sciences), 2003

In the paper, we present an algorithm that can be applied to protect data before a data mining pr... more In the paper, we present an algorithm that can be applied to protect data before a data mining process takes place. The data mining, a part of the knowledge discovery process, is mainly about building models from data. We address the following question: can we protect the data and still allow the data modelling process to take place? We consider the case where the distributions of original data values are preserved while the values themselves change, so that the resulting model is equivalent to the one built with original data. The presented formal approach is especially useful when the knowledge discovery process is outsourced. The application of the algorithm is demonstrated through an example.

Computer Communications, 2008

Remote authentication of users supported by passwords is a broadly adopted method of authenticati... more Remote authentication of users supported by passwords is a broadly adopted method of authentication within insecure network environments. Such protocols typically rely on pre-established secure cryptographic keys or public key infrastructure. Recently, Peyravian and Jeffries [M. Peyravian, C. Jeffries, Secure remote user access over insecure networks, Computer Communications 29 (5-6) (2006) 660-667] proposed a protocol for secure remote user access over insecure networks. Shortly after the protocol was published Shim [K.A. Shim, Security flaws of remote user access over insecure networks, Computer Communications 30 (1) (2006) 117-121] and Munilla et al. [J. Munilla, A. Peinado, Off-line password-guessing attack to Peyravian-Jeffries's remote user authentication protocol, Computer Communications 30 (1) (2006) 52-54] independently presented an off-line guessing attack on the protocol.

Accurate, efficient and predictable performance assessment of distributed object models is necess... more Accurate, efficient and predictable performance assessment of distributed object models is necessary to make a founded decision about which model to use in a given application domain. This article presents a performance assessment framework for distributed object models. It presents two contributions to the study of distributed object performances: it defines the performance criteria for all important aspects of distributed object computing, including single and multi-client scenarios, and, it presents the high and low-level design of the framework and gives insights into implementation details for several important distributed object models, like CORBA, RMI and RMI-IIOP.

The spread of electronic use of data in various areas has pushed the importance of data quality t... more The spread of electronic use of data in various areas has pushed the importance of data quality to a higher level. Data quality has syntactic and semantic components; the syntactic component is relatively easy to achieve if supported by tools (either off-the-shelf or our own), while the semantic component requires more research. In many cases such data come from different sources, are distributed across enterprises and are at different quality levels. Special attention needs to be paid to data upon which critical decisions are met, such as medical data for example. The starting point for research is in our case the risk of the medical area. We focus on the semantic component of medical data quality.

The adaptive incremental approach to classification task of data mining has a built-in feature to... more The adaptive incremental approach to classification task of data mining has a built-in feature to detect convergence of a classification algorithm. The feature is given in form of three equations, which must be all fulfilled. The equations are parametric and can be modified based on miner's personal experiences with the dataset at hand or similar datasets. The advantages of using the approach are potentially lower data preparation costs, lower algorithm execution times, good insight into the algorithm's behavior based on small subset of data, and possibility to predict algorithm's final error rate or based on the desired final error rate, to predict sample size to obtain it. In the future, the authors plan to validate their model on additional datasets and with several other data mining algorithms that build models and produce error rates. Additionally, they plan to incorporate the (run) time component into their framework

By using global communication systems, which are enabled by information and communication technol... more By using global communication systems, which are enabled by information and communication technology, the borders around the world are no longer important, and people are changing continents, countries, regions, cultures and languages with eases, without having to step out of the office or leave their room. Those changes also require and expect a new, different way of developing e-learning modules, which have to support the needs of users in different countries, who speak different languages and come from different cultural backgrounds. Different languages and cultural backgrounds are the reason why developers and producers have to be aware of the intercultural dialogue in global communication systems. But this is not enough. We also have to develop cultural awareness in students (scholars, learners, learning persons), who are using the developed and implemented e-learning modules. In the introduction, the ELLEIEC project and one of its most important outcomes, the Virtual Entrepreneurship Centre, will be described briefly. In the main part of the paper, our experiences with the implementation of the e-learning module with emphasis on the development of cultural awareness in students will be presented. In conclusion, first experiences of students with the e-learning module will be discussed.

Remote authentication schemes with smart cards have gained much attention in recent years. Recent... more Remote authentication schemes with smart cards have gained much attention in recent years. Recently Lee and Chiu proposed an improved remote authentication scheme with smart cards. It enables the user to freely choose his password and claim that their scheme is secure. Nevertheless, we present attacks and weaknesses of the scheme. Additionally, we propose a new improved scheme to counter these attacks.

Recent progress in hash functions analysis has led to collisions on reduced versions of SHA-256. ... more Recent progress in hash functions analysis has led to collisions on reduced versions of SHA-256. As in other hash functions, differential collision search methods of SHA-256 can be described by means of conditions on and between state and message bits. We describe a tool for efficient automatic searching of message pairs conforming to useful sets of conditions, i. e. stemming from (interleaved) local collisions. We not only considerably improve upon previous work [7], but also show the extendability of our approach to larger sets of conditions. Furthermore, we present the performance results of an actual implementation and pose an open problem in this context.