Acta Cybernetica

Preface

2025-03-18T17:17:42+01:00

In today's dynamic and ever-evolving digital landscape, applied informatics plays a pivotal role in shaping the future of technology. From refining algorithms for enhanced data analysis to optimizing communication networks and advancing artificial intelligence, the realm of applied informatics continues to drive innovation and transformation across industries.

This current Special Issue features contributions from the 12th International Conference on Applied Informatics (ICAI 2023), which was held in Eger, Hungary on March 2-4, 2023. These research papers explore novel insights, innovative methodologies, and practical applications within the field of computer science and informatics. Each of them represents a valuable contribution to the applied informatics field and offers insights that bridge the gap between theory and practical application. They are a testament to the diversity and dynamism of our field, showcasing a wide range of research topics and applications.

Invariants and String Properties in the Analysis of the Knuth-Morris-Pratt Algorithm

2025-03-18T17:17:52+01:00

This paper is about the string-matching problem. We find the occurrences of a pattern inside a text. First, we formally define the problem and summarise its naive solution. Next, we analyse an efficient method, the Knuth-Morris-Pratt (KMP) algorithm. We prove the correctness of the KMP algorithm. We also analyse its efficiency. Our reasoning is based on the properties of the pattern and the text. It is also based on the invariant properties of KMP. In this way, we could develop an extremely compact and elegant proof. And the method of proving program correctness with the invariant properties of the program is already familiar to our students at our university.

How Egocentric Distance Estimation Changes in Virtual Environments by Using a Desktop Display or the Gear VR

2025-03-18T17:17:55+01:00

Due to the importance of depth perception in virtual spaces, the combined effects of display devices and human factors on egocentric distance estimation were investigated. We developed a virtual environment that can assess distance estimation skills of users at 10 various distances, starting from 25 cm and ending at 160 cm. Our results show that people are either accurate or overestimate distances on a desktop display, while underestimation occurs with the Gear VR in most cases. Combined with display devices, human factors also had effects on distance estimates. With the Gear VR, 35.73%-57.14% faster estimation times were obtained, and these can also be influenced by human factors and distances.

Effective Supervision of Students' Activity During Classroom Learning and Testing

2025-03-18T17:17:56+01:00

Due to the lockdowns caused by the COVID-19 pandemic, the majority of educational institutions worldwide have been forced to switch to online education, which has created a significant challenge for teachers and students alike. In order to communicate effectively in the online space, educational institutions had a wide range of tools to choose from (e.g. Adobe Connect, Cisco Webex, Google Meet, Microsoft Teams, Skype, Zoom, etc.). The challenge for teachers was to learn how to use them, to teach practical subjects effectively and to provide a supervised examination environment. The return to face-to-face (in-class) teaching after the end of the COVID-19 pandemic has allowed the online collaborative environments listed above to fade into the background, but the supervision of interactive, computer-based practical lessons (e.g. teaching programming languages, network programming etc.) and proctored examinations can still be a challenge for teachers. This article reviews some screen monitoring systems developed for both corporate and educational environments. We present one of them in more detail, namely Veyon, which is available free of charge\footnote{The basic version of Veyon is free, but you have to pay for the various desired add-on licenses.} and can be used on different operating systems, and whose applicability in both teaching and examination has been tested for almost a year at the Faculty of Informatics of the University of Debrecen.

P4 Specific Refactoring Steps

2025-03-18T17:17:58+01:00

P4 is a domain-specific programming language for programmable switches running inside next-generation computer networks. The language is designed to use the software defined networking (SDN) paradigm which separates the data plane and the control plane layers of the program. The paper introduces tool-supported refactoring steps for P4. The challenge in this task is that P4 has special domain-specific constructs that cannot be found in other languages and as such there is no existing methodology yet for refactoring these constructs. The proposed steps are implemented using P4Query, an analyzer framework dedicated to P4.

Co-reference, Thematic, and Network Analysis of a Selected Hungarian Poem and Its English Translation (Füst Milán: A szőlőműves / The Vine-Dresser)

2025-03-18T17:18:01+01:00

In our paper we present a parallel co-reference analysis of the Hungarian poem A szőlőműves (The Vine-Dresser) by Milán Füst and its English translation. We explore the textual world of the poem and compare the Hungarian and English texts using formal linguistic tools based on semiotic textology. We also reveal the possible differences between the original Hungarian text and its English translation. The results of the analysis prove that co-reference analysis devised and elaborated by János S. Petőfi can be effectively applied in a polyglot environment. We also introduce the hypertext implementation of the co-reference analy-sis of the selected poetic texts in a form of a web page. We would like to show that this has many practical advantages, for example, the analysis and its results can be transparent, accessible, and verifiable to everyone. In addition, the created web page provides additional aspects for the analysis. For example, considering the poetic text as a network, we can investigate whether the scale-free feature is also relevant in the textological environment – as it can be experienced in many other areas of reality.

Hungarian Sentence Analysis Learning Application with Transformer Models

2025-03-18T17:18:02+01:00

The purpose of our research is to present a project in which we started to develop an educational support tool that helps primary and high school students to use the correct techniques of sentence analysis based on the rules of Hungarian grammar taught in school. The aim was to create an application called LMEZZ that would help students of the Hungarian education system to practise tasks related to native language lessons. In this way, we expect them to have a more accurate understanding of the grammar rules. The application allows them to learn in the comfort of their own homes by providing immediate and accurate feedback on the solutions to various tasks. Natural language processing has made spectacular progress with the application of neural network technology, especially the contextual transformer model. In our research, Hungarian transformer-based BERT models were trained for our sentence analyser task. The results showed that the transformer models were much more condescending than the previously trained convolutional neural network based SpaCy models. This allowed us to increase the reliability of our software.

Scalix Mix Network

2025-03-18T17:18:03+01:00

Mix networks have now advanced to a level where they can compete in the domain of low-latency anonymous communication, owing to their "strong" anonymity design advantage. However, a few bottlenecks still exist, primarily because users are required to select the complete message path. This characteristic of mix networks hinders the implementation of load balancing and necessitates the use of an extensive shared database. To address this issue, we introduce Scalix, which presents a new topology featuring load balancers, modified path selection, and a mix package based on identity-based encryption and attribute-based encryption. Additionally, Scalix can serve as an anonymous return channel with minimal modifications.