Journal of Computer Sciences Institute

109-113

Authors: Bernadetta Michalik, Marek Miłosz

Artificial neural networks consist of many simple elements capable of processing data. These are tools inspired by the construction of the human brain, used in machine learning. The aim of the research was to analyze the occuracy of the created neural network in the process of handwriting recognition. The article presents the results obtained during the learning and testing of a convolution network with a different number of hidden layers. Each time learning and testing the network was carried out using the same set of images (taken from the publicly available IAM database) depicting handwritten words in English.

121-125

Authors: Dmytro Malenko

Most multi-user applications need an access system so that users can log in from different devices. To identify a user, at least one authentication method must be used. The article presents a comparison of the authentication method using NFC technology with other methods that are available for Android devices and differ in both implementation and specific usage.

133-138

Authors: Dominik Klej

The following article focuses on ilustrating the content of the master thesis with the same title. The methodology of developed by author digital indicator will be presented, as well as the results and conclusions based on the comparative analysis. The research concerns the comparative analysis between digital services in Poland, Japan and China, based on the IDI, WDC and ITC digital indicators. The analysis is based on publicly available data of digitization.

143-149

Authors: Mateusz Wlaź, Grzegorz Kozieł

The research work presents the study of the quality of telecommunications and satellite signals. For this purpose, a proprietary application for mobile devices has been designed, which allowed the collection data. The tests were performed on several models of cell phones and for different operators. The test checked the impact of such things as weather conditions, device architecture, device age, type of terrain. Based on the results, heat maps were created to visualize the research.

156-163

Authors: Agnieszka Dorota Wac, Tomasz Kamil Watras, Grzegorz Kozieł

The article presents a comparative analysis of tools supporting the production of automated tests for specific test scenarios. Within the framework of the research, the described tools were installed and then their functionalities were described. Using each of the tools, author's automatic tests were written and performed. The tool discussion was examined both in terms of the process of creating the tests and the speed of their execution. In addition, the selected tools were evaluated and subjective evaluations of the comfort of using the tool were taken into account, taking into account aspects such as the ease of installation and configuration of the tool, the need for programming skills, the simplicity of creating tests, additional functionalities and access to documentation. The summary includes the evaluation of the compared applications, and also discusses specific cases for which the tool will work better.

168-171

Authors: Andriy Dragni, Tomasz Szymczyk

This work presents the results research on interfaces enabling navigation in virtual reality. An original program presenting a typical museum gallery has been written. It implemented a number of different moving scenarios. The paper analyzes which of these methods is best for the user. The optimal speed was tested and determined, using the user feels comfortable and does not lose the sense of control over the program.

178-183

Authors: Michał Jusięga, Mariusz Dzieńkowski

This article is about research during which selected versions of the Symfony programming framework were compared in terms of their performance. The following versions of the framework were analysed: 3.0, 3.1, 3.2, 3.3, 3.4 LTS, 4.0, 4.1, 4.2, 4.3 and 4.4 LTS. For the purpose of the research, a simple test application in PHP was developed in ten variants corresponding to selected versions of the framework and consisting of 17 fragments of code – methods in the class, each of which operates on one basic component of Symfony. The application prepared in this manner was subject to performance tests in a two-stage experiment. After the experiment, the quantitative analyses were conducted in which the following aspects were taken into consideration: the average values of execution times and the average amounts of memory usage for specific code fragments for individual versions of the Symfony framework components and the average time of execution and demand for memory for the entire tested application. The obtained results for each code fragment representing a given component were visualized in the forms of graphs. The performed analyses showed that the best version of the Symfony programming framework in terms of performance is version 4.1.

189-195

Authors: Katarzyna Buszewicz

This article presents the results of a literature study related to the construction and operation of Java Virtual Machine, as well as performance tests of selected languages using the aforementioned runtime environment on the example of Java, Scala and Kotlin. Performance testing was carried out using two applications built using the Apache Maven archetype with the built-in Java Microbenchmark Harness library.

202-205

Authors: Monika Kaczorowska

The research paper contains a review and analysis of common programming mistakes made by first and second year students of Computer Science. The data were collected during the courses entitled “Algorithmics and Data Structures” and “Numerical Methods”, where students have to write programs in the C++ language. The article includes examples of three selected mistake types. A comparison of mistakes made by first and second year students is presented. The analysis carried out shows that the percentage of mistakes made decreases when the students are in the second year, but three types of mistakes demonstrate the opposite trend. It can be concluded that those three types of mistakes are related to the course of Numerical Methods, where students have to deal with a significant amount of mathematical expressions. The results show that the students have the most significant problems with memory management.

214-218

Authors: Martyna Wawrzyk

The paper is focused on application of the clustering algorithm and Decision Tress classifier (DTs) as a semi-supervised method for the task of cognitive workload level classification. The analyzed data were collected during examination of Digit Symbol Substitution Test (DSST) with use of eye-tracker device. 26 participants took part in examination as volunteers. There were conducted three parts of DSST test with different levels of difficulty. As a results there were obtained three versions of data: low, middle and high level of cognitive workload. The case study covered clustering of collected data by using k-means algorithm to detect three clusters or more. The obtained clusters were evaluated by three internal indices to measure the quality of clustering. The David-Boudin index detected the best results in case of four clusters. Based on this information it is possible to formulate the hypothesis of the existence of four clusters. The obtained clusters were adopted as classes in supervised learning and have been subjected to classification. The DTs was applied in classification. There were obtained the 0.85 mean accuracy for three-class classification and 0.73 mean accuracy for four-class classification.