Program comprehension is important process in software maintenance, considering the lifetime of an industrial software. The first task for a developer is to understand the structure and the behaviour of the program without considering the type of the change - refactoring, bugfix - must be performed on the source code. Understanding and debugging the source code is not straightforward in case of a dynamically typed functional programming language, like Erlang. Thus RefactorErl supports code comprehension through a Semantic Query Language that helps the developers to query semantic relationships in their software product.

Nowadays complex software systems are designed and implemented with the help of the object-oriented paradigm principally. However, object-oriented languages support the object-oriented paradigm in different ways with different constructs. C++ has a sophisticated inheritence notation based on access modifiers. C++ distinguishes virtual, pure virtual and non-virtual methods. Java uses final classes and methods to disable inheritance. However, Java does not support multiple inheritance. Eiffel allows renaming inherited methods. In this paper we present some method utilites for C++ to create safer and more flexible object-oriented systems. We present how the method renaming can be implemented. We developed constructs to create final and unhidable methods. These constructs are implemented with the help of C++ template facilities. We present scenarios where one can write safer code with our constructs.

Open Document Format (ODF) is a popular office document format accepted by most of modern desktop office suites. The aim of our project is to create a software suite of specialized mobile ODF schemata and editors to provide support of editing ODF-based documents on mobile devices. Number of tests have been carried out with prototype tools focusing on the resource need of transferring, visualizing and editing simple ODF documents. Based on test results we have found that the limited capacity of mobile devices (compared to desktop computers) implies that documents in their original form cannot be handled on mobile devices. In this paper we investigate the methods and background of ODF-based document transfer and edition in a client-server model.

A novel zero-voltage and zero-current switching (ZVZCS) pulse-width modulation (PWM) converter is presented in this paper. An active energy recovery clamp in the secondary side provides conditions for zero-current switching (ZCS) of the transistors in the primary side of the DC/DC converter. Zero-voltage switching (ZVS) of the primary switches is achieved by the magnetizing current of the transformer. The active energy recovery clamp provides soft switching of the transistor located on the secondary side of the transformer. The principle of converter operation is explained and analyzed and experimental results obtained on the laboratory model are presented.

The characterization of high resolution Digital to Analog Converter (DAC) involves new problems caused by their high performance. This paper presents a new method for measuring the characteristics of high resolution DACs under dynamic condition. The main principle of the proposed method is the conversion of the DAC analog output voltage to a digital code. The one that is corresponding to the equality of the DAC output voltage and reference signal by using a fast comparator, a dithering DAC and an accurate dc voltmeter. The output of the comparator is used as the control signal to register the digital input code word of the DAC in a fast memory. After digital processing the registered record of digital code words is used to determine the Integral-nonlinearity (INL) and Differential-nonlinearity (DNL) of the DAC under test.

In this article, four free authoring tools have been selected. Following, the selected tools using benchmarking method have been compared. The benchmarking purpose is to show advantages and disadvantages of selected authoring tools and to provide recommendations for users with small experiences in multimedia technologies.

The paper deals with the problem of constructing the stable clustering structure for the uncertain data set. The problem of explaining of stability of the clustering structure in automatic classification of objects for varying attributes values is formulated. The proposed method of the uncertain data clustering is based on heuristic algorithms of possibilistic clustering. Basic concepts of the heuristic approach to possibilistic clustering based on the concept of allotment among fuzzy clusters, a validity measure and techniques of the data preprocessing are considered. A method of constructing the set of values of most possible number of fuzzy clusters for the uncertain data is provided and a technique of constructing the stable clustering structure is proposed. An illustrative example of the proposed technique application to the oil data set is carried out. An analysis of the experimental results is given and preliminary conclusions are formulated.

The problem of efficient computation of all second maximum path weights for a given square matrix A of dimension n in max-plus algebra is solved by computing so-called double power sequence of a specific extension ¯A of A. An algorithm using this method is presented, by which the second maximum cycle mean value l2(A) can be computed in O(n4) time.

The Semantic Web has reached the point where basic research is supposed to be replaced (at least partially) by research aiming at practical aspects of using the Semantic Web. Ontologies, as the essential technology in this area, have been under the spot light which produced some results, e.g. the semantic web search engines like Watson or Swoogle. These search engines help in finding and locating semantic information on the Web. However, they do not support users to quickly understand what an ontology is about, what information it contains. We argue in this paper that vector description, as a snapshot of data comprised in ontologies and therefore representing a vector-based gold standard of a domain, may help while trying to understand a particular ontology. In other words, instead of depicting a whole ontology all together, we prefer reduction of information given and therefore avoid users being overwhelmed and thus help with orienting in a wide offering of ontologies on the Web.

The Call Set up Success Rate (CSSR) is one of the most important Key Performance Indicators (KPIs) used by all mobile operators. The CSSR in general is a term in telecommunications denoting the fraction of the attempts to make a call which result in a connection to the dialled number. However there is no standard measurement possible for this parameter. Therefore the different operators can measure it differently. In this paper, a definition of a real data CSSR, possibility of its implementation using the current technologies in LTE (Long Term Evolution) is provided and the obtained formula proposal is discussed as well. The real in this case means that data CSSR is calculated as ratio of the assigned Evolved Packet System (EPS) bearers to the random access preamble requests related to data calls with excluded ghosts, signaling radio bearer drops during call set up caused by Evolved Packet Core (EPC) network problems. The data means that the LTE is only packet switched based network, i.e. there are not any circuit switched services as it is typical for example for GSM. The proposed modeling can help mobile operators to measure the data CSSR properly.

Systems with delays are a specific group of dynamic systems. The fact that some delays can be short and some can be long makes system analysis and control design much more complex. In this paper we present a proposal to solve the problem of stability and control design of continuous time systems with time-varying delays. Based on the Lyapunov-Krasovskii functional the stability condition is derived using the linear matrix inequality (LMI) techniques, and convex optimization principle to find LMI variables which simultaneously satisfies the limitations given by the theory of Lyapunov-Krasovskii functionals. Obtained solution is the feasible convex LMI problem for the static controller design. Finally the design method is demonstrated using a system model example.