Pavol Navrat

Kempelen Institute of Intelligent Technologies

While digital space is a place where users communicate increasingly, the recent threat of COVID-19 infection even more emphasised the necessity of effective and well-organised online environment. Therefore, it is nowadays, more whenever in the past, important to deal with various unhealthy phenomena, that prohibit effective communication and knowle...

Existing research in program comprehension has paid less attention to the coverage of programming concepts that were contained within the source codes used for studies. In this paper, we examine source codes covering four introductory programming concepts: branching, loops and arrays, sorting, and tail recursion. The diverse types of code fragments...

In this paper we present an approach to detection and tracking of currently unveiling news stories through analysis of news articles obtained from the Web. Articles are obtained using algorithm inspired by honey bees foraging for food. Due to the distributed dynamic nature of communication protocol utilized among bee workers when foraging for food,...

In this paper, we propose a new approach to visualization of software repositories that allow users to search and explore software projects in virtual reality. In provided environment, respective information structures are mapped to interactive 3D objects. We assume that such transformation of information space to its visible representation will en...

Block-based programming languages are successfully being used as an alternative way of teaching introductory programming concepts. The success is in part due to the low barrier of entry and the visual game-like appeal fostering experimentation and creativity. Virtual reality (VR) presents a step further to an even more immersive and engaging experi...

The main goal of the paper is to present the method of design pattern support based on principles of model driven development: the abstraction, semantics and model transformations. More specifically, the method is based on the principle of suggestion of design pattern instances via the semantic marking of model elements or source code fragments and...

In this paper, we discuss whether data collected from monitoring software developers' logs can be considered big. We hypothesize that it falls within the category of Big Data. The main topic of our paper however, is how to facilitate analysis of such data. Due to the specificity of the monitored activity, the analysis is at least partially explorat...

The efforts of the European Union (EU) in the energy supply domain aim to introduce intelligent grid management across the whole of the EU. The target intelligent grid is planned to contain 80% of all meters to be smart meters generating data every 15 minutes. Thus, the energy data of EU will grow rapidly in the very near future. Smart meters are s...

World Wide Web is undoubtedly a human creation. It was facilitated by a number of major inventions. Its continuous development results largely from innovative engineering efforts. The Web viewed as essentially a service provided on the Internet offers many different functions. We discuss information providing functionality offered as "Web search"....

World Wide Web is undoubtedly a human creation. It was facilitated by a number of major inventions. Its continuous development results largely from innovative engineering efforts. The Web viewed as essentially a service provided on the Internet offers many different functions. We discuss information providing functionality offered as "Web search"....

In this paper, we describe an approach to answering natural language questions that is based on knowledge acquired from the Web by a current search engine. Our system gradually builds a lightweight semantic knowledge base that is used to select the answer. Explicit feedback from the interested fellow helps readjust weights of the triplets in a lear...

A combination of several activities is required to solve a development task, but in the end, developer reports only part of it. It is difficult to understand whether all committed files were changed because of the reason in a given description. Software developers work on multiple tasks at once and often fail to distinguish them with separate commi...

Monitoring software developer's interactions in an integrated development environment is sought for revealing new information about developers and developed software. In this paper we present an approach for identifying potential source code dependencies solely from interaction data. We identify three kinds of potential dependencies and additionall...

While dynamically stabilized walking has many solutions already, new approaches are still possible. Described method shows combined techniques to reach efficient walk stabilization of Nao robot in RoboCup soccer simulation.

We have developed an approach to identification and tracking of currently unfolding news stories extracted from the news articles published on the Web. Our approach employs a set of agents to retrieve those articles from the Web that might refer to some developing news story. The set of agents is inspired by social insects, in particular by a bee c...

This paper presents an approach to personalised recommendation of who to follow on Twitter. It is based on a simple observation that following the same Twitter account could be considered a fact that contributes to a possible similarity of followers. We proposed a simple scheme to elicit gradually candidates to follow which are most likely sources...

Although interactive e-learning environments are increasingly used in university courses, traditional types of examination still dominate the way how students are assessed for grades. In this paper, we examined how student data from online interactive learning environment for programming exercises can be used for summative assessment at the end of...

In recent years, besides typical information retrieval, a broader concept of information exploration - exploratory search - is emerging into the foreground. In addition, more and more valuable information is presented in microblogs on social networks. We propose a new method for supporting the exploratory search on the Twitter social network. The m...

In this paper we present an approach to identification and tracking of currently unfolding news stories extracted from the news articles published on the Web. Our approach utilizes a set of social insect inspired agents to retrieve articles from the Web and identify popular terms, referred to as story words, relevant to the ongoing news stories. Th...

We present a view on the changes in software processes activated by the evolution of the World Wide Web, which shifts the software development more and more towards on-line practices. This includes not only the shift towards the use of web-based resources in software processes, but also and more importantly it opens a space for using approaches ori...

In this paper we present an approach, inspired by honey bees, that allows us to take a glance at current events by exploring a portion of the Web and extracting keywords, relevant to current news stories. Not unlike the bees, that cooperate together to retrieve little bits of food, our approach uses agents to select random keywords and carry them f...

Social networks, especially Facebook as currently the largest one, made the organization of events apparently simpler. Facebook offers the event service, which has greatly simplified the invitation process. Still, organizing an event is usually coupled with the risk of guest's no-show. We report an investigation designed to identify factors that mi...

In this paper we present an approach, inspired by honey bees, that allows us to take a glance at current events by exploring a portion of the Web and extracting keywords, relevant to current news stories. Not unlike the bees, that cooperate together to retrieve little bits of food, our approach uses agents to select random keywords and carry them f...

The issue of plagiarism is discussed in the context of university education in disciplines related to computing. The focus is therefore mainly on software plagiarism. First, however, a case is made for the claim that the most important reason that plagiarism cannot be tolerated lies in the essence of the concept of a university as it is rooted in t...

Nowadays there exist many approaches to support design pattern instantiation, evolution, etc., but most of the approaches focus mainly at the design level (i.e. model). By the transition to the source code level the pattern instances become almost invisible in the huge amount of source code lines. The goal of this paper is to present our method sup...

Adequate query formulation for web search is a very important prerequisite for successful retrieval of desired results. One productive way to improve it that is used in most popular search engines is query suggestion. Common search engines are quite good at suggesting words to general, highly popular queries, but their suggesting capability deterio...

Web environment gives us an opportunity to take broader aspects of textual information into account, for example information about behavior of web users, global web trends or social interactions between users. In this paper we present and evaluate method suitable for enhancing blog clustering using the information hidden in web comments. We found o...

The Guide to the Software Engineering Body of Knowledge (SWEBOK) provides a consensually validated characterization of the bounds of the software engineering discipline and to provide a topical access to the Body of Knowledge supporting that discipline. The topic “Notation for Process Definition” references selected notations appropriate for s...

Design patterns provide an especially effective way to improve the quality of a software system design as they provide abstracted, generalized and verified solutions of non-trivial design problems that occur repeatedly. The paper presents a method of design pattern instantiation support based on the key principles of both MDD and MDA. The method al...

This paper surveys principal concepts involved in various approaches to web search. There are many attempts to improve key word search. There is the concept of exploratory search, which represents a shift towards more complex view of the interested fellow's role, widening her options. There is proposed a more radical shift towards viewing informati...

The paper attempts to analyze current situation in plagiarism detection and to analyze existing methods and tools for checking the plagiarized programming code and natural language (particularly Slovak) text. Then, we describe our approach to plagiarism detection for two particular but important cases: texts in formal programming language and texts...

Currently, one can witness a growing mutual influence between the Model Driven Architecture (MDA) and the Semantic Web. MDA is an approach that uses models for system development, but its architecture limits usability of these models for knowledge empowered solutions. A lot of research tackles applicability of MDA standards in the technical space o...

Web content clustering is very important part of topic detection and tracking issue. In our paper we focus on pre-processing phase of web content clustering. We focus on blog articles published in Slovak language. We evaluate the impact of different data pre-processing methods on success of blog clustering. We found out that applying various text d...

This paper presents a novel method of designing selected aspects of messaging-based integration solutions. The method uses constraint programming to find appropriate communication channels, components’ deployment parameters and integration services in order to create a solution that meets specified functional and non-functional requirements. The me...

SPEM is metamodel based standard used to define software and systems development processes and their components. Unfortunately, its architecture is semiformal, thus it is not possible to make and to verify created language statements with formal techniques such as the consistency or satisfiability verification. Recently, the combination of MDA and...

In this paper we present a method that allows us to use a generic full text engine as a k-nearest neighbor-based recommendation system. Experiments on two real world datasets show that accuracy of recommendations yielded by such system are comparable to existing spreading activation recommendation techniques. Furthermore, our approach maintains lin...

Bee hive metaphor has recently been attracting researchers who investigate methods of problem solving, although early attempts can be traced one or even two decades ago. A bee hive is a complex system composed of bees whose behaviour in turn can by sufficiently approximately described in very simple terms. There are several approaches to do it. We...

A model of the bee hive that clearly separates the self-organizing decision-making behaviour of the bees in the hive and the problem-specific behaviour of the bees outside the hive is presented. This separation allows for the applications of the model for different problem domains. Results of the application to three problem domains are presented -...

In the article we concentrate on timing aspect of information propagation on social web. The aim of the information producer is to transfer the information to the broad audience via social web. Producer needs to identify interesting content and publish it to social web in the right time. Right timing of information publishing can increase the poten...

Nowadays e-commerce becomesmore and more popular and widespread. Being on the web opens many possibilities for both customers and service providers or goods merchants, thence there is a great potential and opportunity for all e-shops. For example, many e-shops provide discussion forum for every product they sell. Besides the primary role of any dis...

This paper presents a novel method of using action-based planning for construction of enterprise integration solutions that utilize messaging technologies. More specifically, the presented method is able to generate a sequence of processing steps needed to transform input message flow(s) to specified output message flow(s), taking into account requ...

Acquiring information from the Web is a demanding task and currently subject of a world-wide research. In this paper we focus on research of methods, and experience with development of software tools designed for retrieval, organization, presentation of information in heterogeneous data source spaces such as the Web. We see the Web as a unique evol...

There are various approaches to service composition - some of them mainly based on AI planning. Although they offer relatively good results, in some cases they are not sophisticated enough to solve real problems. We identified some problems with automatic composition. Our belief is that the natural way to improve these techniques is to include user...

This paper presents a method to automatically construct a sequence of mediation services needed to adapt an existing service interface into a required new form. The expected use of this method is mainly in heterogeneous service-oriented environments where Web Service and other technologies have to coexist. Unlike most other works in the area of Web...

In this paper we describe a framework dedicated to evolving methods supporting adaptability in e-learning applications with the use of current Semantic Web technologies. Adaptability based on user's characteristics (personalization) requires mechanisms that can work with meanings and uncover consequences based on the user's (learner's) behavior dur...

This work presents personalized web search using enhancing information extracted from context. Context reflects user profile, her interests, past searching experiences etc. It is represented by a set of weighted keywords. In our approach, we have to deal with keywords profile modeling and searching which respects users profile. Experiments on web s...

Information can change rapidly on the web. For example, news may hint some new story starts to develop. Many more news related to the original event begin to pour in the web. Imagine a person interested in how the story develops. It may be very difficult to trace it by trying to find the most relevant pages with most recent news on it. Our goal is...

Context search is based on gathering information about user’s sphere of interest before the search process. This information defines context and augments search query in subsequent phases of search to attain better search results. There are several basic methods for context enhanced searching. The main idea of them is to extract keywords of the fou...

An important role of a workflow system is to schedule and reschedule the workflow process and to allow the user to monitor and guide the overall progress of the workflow and its activities. This paper presents extensions of a rescheduling algorithm based on minimal graph cut. The initial approach allowed to find an optimal rescheduling, which chang...

A new approach to web search that is based on a bee hive metaphor is presented. We proposed a modified model of a bee hive. Our model comprises of a dance floor, an auditorium, and a dispatch room. We have shown that the model is a true model of a bee hive in the sense it simulates several kinds of its typical behaviour. However, more importantly i...

Optimization techniques are often viewed as implementation tricks that lower various software quality criteria. We analyze pooling and caching techniques and we show models that are based on known design patterns and allow incorporating optimization into abstract system models. We discuss specialization and code generation methods that have potenti...

The most popular development methodologies in the last decade are based on object-oriented techniques. The goal of this paper is to investigate the possibilities of extending the object-oriented methodology of information systems development with a service-oriented approach and to examine the benefits of this extension. We propose an augmentation t...

Context search is related to gathering information about user's sphere of interest before search process. This information defines context and augments search query in subsequent phases of search to attain better search results. There are several methods for searching with context. We took rank-biasing as a base and schemed out a modification hypot...

This paper discusses applying the social behaviour of bees to the Web search. We proposed an on-line search of the user's predefined group of pages. In particular, this approach is based on our model of a bee hive being augmented by a model of the behaviour of bees outside the hive and by the method of assigning the page quality. With regard to the...

The increasing number of Semantic Web applications that work with ontologies implies an increased need for building ontological knowledge bases. In order to improve ontologies during their development as well as to allow applications to be experimentally evaluated prior to their complete implementation and deployment, ontology bases must be filled...

It is widely believed, that the expressivity of STRIPS and STRIPS-like planning based on actions is generally lower than the expressivity of Hierarchical Task Network (HTN) and HTN-like planning, based on hierarchical decomposition. This would mean that a HTN-like planner can generally solve more domains than a STRIPS-like planner with the same ext...

This paper describes aims, progress and some results of a research conducted in a project that is aimed at devising ways of processing of information and knowledge in a heterogeneous environment, in particular at acquiring, organising and presenting information and knowledge from the web. Important part of the project are pilot applications. Their...

A new approach to Web search that is based on a bee hive metaphor is presented. We proposed a modified model of a bee hive. Our model comprises of a dance floor, an auditorium, and a dispatch room. We have shown that the model is a true model of a bee hive in the sense it simulates several kinds of its typical behaviour. However, more importantly i...

We propose a model of searching semantic web that allows to incorporate data semantics into the searching process.. We concentrated to devising a searching module. Its inputs are two ontologies, describing supply and demand. Its output are supply offers that correspond to demand requests, ordered by relevance to the request. In the next step, we at...

Patterns are used in different phases of software development, from analysis through architecture, from detailed design to implementation. By using patterns, some problems are identified. One of them is how to reuse parts of patterns at the source code level. This paper is concerned with design patterns especially with reusing general parts of patt...

A new approach to web search that is based on a bee hive metaphor is presented. We proposed a modified model of a bee hive. We have shown that the model is a true model of a bee hive in the sense it simulates several kinds of its typical behaviour. However, more importantly it is a simple model that describes some processes taking place in web sear...

In this paper we have attempted to contribute to the movement towards shifting more and more burden of managing the process, delivering the content and assessing the learning outcomes to the web-based tools. Among the tasks we attempted to support are for example: submission and checking of assignments, managing student projects, e-enrolment of...

In this paper, we tackle the problem of compression and decompression of PE-files (portable executable file format in MS Windows). We analyze decompression methods used in the PE-file unpackers. Based on that, we design a new decompression method, which however uses standard decompression algorithm s. Finally, we compare various standard decompress...

Team projects play an important role in the education of engineers. This paper describes a team project module that is part of a postgraduate course in Informatics. Its main objective is to give students a hands-on experience with difierent aspects of working in team on a problem. We discuss several issues that should be considered in designing suc...

Knowledge-capturing approaches cover a wide variety of software engineering activities, and this variety impedes to find relations and integration between them. One of movements towards knowledge reuse and integration is Model Driven Architecture, a model-centric approach based on platform-specific abstractions and model transformations. We attempt...

Aiming at a qualitatively new model of processing information in a heterogeneous environment such as the current and the future Web, it is desirable to focus among others on investigating new ways of working with information and knowledge in a heterogeneous environment, especially with imperfect and vague information from perhaps dubious sources. T...

Although the evolving field of software engineering introduces many methods and modelling techniques, we conjecture that the concepts of abstraction and generality are among the fundamentals of each such methodology. This study proposed a formal representation of these two concepts, along with a two-dimensional space for the representation of their...

Abstract The paper describes a rule - based query optimizer for object - oriented databases The originality of the approach is through a multi - level logic programming used to model the variety of knowledge contained in the query optimizer in an explicit, declarative and transparent way Our approach offers means of abstraction for expressing vario...

We review some of quantum algorithms for search problems: Grover's search algorithm, its generalization to amplitude amplification, the applications of amplitude amplification to various problems and the recent quantum algorithms based on quantum walks.

The paper describes a rule-based query optimizer for object-oriented databases. The originality of the approach is through a multi-level logic programming used to model the variety of knowledge contained in the query optimizer in an explicit, declarative and transparent way. Our approach offers means of abstraction for expressing various kinds of k...

The main goal of this research was to investigate means of intelligent support for retrieval of web documents. We have proposed the architecture of the web tool system - Trillian, which discovers the interests of users without their interaction and uses them for autonomous searching of related web content. Discovered pages are suggested to the user...

In content-based filtering systems, content of items is used to recommend newi tems to the users. It is usually represented by words in natural language where meanings of words are often ambiguous. We studied clustering of words based on their semantic similarity. Then we used word clusters to represent items for recommending new items by content-b...

The main goal of this research was to investigate the means of intelligent support for retrieval of web documents. We have proposed the architecture of the web tool system — Trillian, which discovers the interests of users without their interaction and uses them for autonomous searching of related web content. Discovered pages are suggested to the...

This book constitutes the refereed proceedings of the 6th East European Conference on Advances in Databases and Information Systems ADBIS 2002, held in Bratislava, Slovakia in September 2002. The 25 revised full papers and 4 short papers presented together with 3 invited papers were carefully reviewed and selected from 115 submissions. The papers a...

In the paper we discuss di#erent data representation formats used for EMG case collection and management. Data representation is described in the context of developed software tool called EMMA.

In the paper we discuss an approach to computer support of collecting EMG data, for the purpose of national normative EMG data determination. To find values that are as representative as possible (to become a true standard), we proposed to have several laboratories across the country collecting the data. We describe representation of both EMG data...

. Two possible approaches to reuse with design patterns (DPs) are described: pattern-based design and pattern-related code composition. For pattern-based design, a new representation of DPs similar to class diagrams as well as different modes for creating an instance of DP are proposed. # ,QWURGXFWLRQ Design patterns (DPs) [2] capture and communica...

In this paper we present a method for items recommendation. The proposed method uses estimated recommendations computed by Content-based filtering method in order to improve recommendations produced by Collaborative filtering method. By combining these two methods it is possible to alleviate the problem of lacking explicit ratings appearing in both...