Radoslava Stankova Kraleva

South-West University "Neofit Rilski" · Department of Informatics

This paper deals with an analysis of three algorithms for the graph vertex cover problem. Certain methods for solving this problem are analyzed. In addition, different studies on the problem and some approaches to its solution are discussed as well. An exact algorithm (based on the backtracking approach) is presented. Calculating the average time f...

This research focuses on an analysis of different algorithms for the graph vertex coloring problem. Some approaches to solving the problem are discussed. Moreover, some studies for the problem and several methods for its solution are analyzed as well. An exact algorithm (using the backtracking method) is presented. The complexity analysis of the al...

This study focuses on two heuristic algorithms for the graph vertex coloring problem: the sequential (greedy) coloring algorithm (SCA) and the Welsh–Powell algorithm (WPA). The code of the algorithms is presented and discussed. The methodology and conditions of the experiments are presented. The execution time of the algorithms was calculated as th...

This research focuses on a software application providing opportunities for the processing and analysis of data generated by a saccade sensor with human eye movements. The main functional opportunities of the developed application are presented as well. According to the methodology of the experiments, three experiments were prepared. The first was...

This research focuses on the k-center problem and its applications. Different methods for solving this problem are analyzed. The implementations of an exact algorithm and of an approximate algorithm are presented. The source code and the computation complexity of these algorithms are presented and analyzed. The multitasking mode of the operating sy...

This paper presents a study on the N-Queens Problem. Different approaches to its solution discussed in the scientific literature are analyzed. The implementation of an algorithm based on the backtracking method is also presented. The algorithm is optimized to find solutions in a specific subset of configurations among all possible ones. With this a...

Data modeling and data processing are important activities in any scientific research. This research focuses on the modeling of data and processing of data generated by a saccadometer. The approach used is based on the relational data model, but the processing and storage of the data is done with client datasets. The experiments were performed with...

Data analysis are important tasks in research. The present study focuses on the analysis of data sets from human eye movement experiments. The results of the experiments were analyzed according to two criteria – gender and age of the participants. The participants were divided into 3 groups, respectively group 1: between 20 and 35 years, group 2: b...

We have developed a hierarchical spike timing neural network model in NEST simulator aimed to reproduce human decision in simplified simulated visual navigation task. The model consists of the following layers: retinal photorecep-tors and ganglion cells (RGC); thalamic relay including lateral geniculate nucleus (LGN), thalamic reticular nucleus (TR...

We investigated age related synaptic plasticity in thalamic reticular nucleus (TRN) as a part of visual information processing system in the brain. Simulation experiments were performed using a hierarchical spike timing neural network model in NEST simulator. The model consists of multiple layers starting with retinal photoreceptors through thalami...

The paper develops a procedure for features extraction from eye movement’s time series aimed at age-related classification of humans. It exploits the properties of the echo state network (ESN) reservoir state achieved after its intrinsic plasticity tuning. A novel, recently proposed approach for ranking of dynamic data series using as single featur...

The new people generation Z can be viewed in terms of software engineering as specific users who have high requirements regarding the functions and interface of the software applications, connectivity to social networks and instant communication via the Internet. In recent years, the number of electronic learning systems increased, but students are...

In this study, deep neural networks are developed to evaluate its performance over wine data set from UCI repository. The data set consists of white and red wine samples from Portugal. Previous studies claimed that Support Vector Machine (SVM) outperformed the simple ANN and Multiple Regression (MR) on wine data set. We trained different neural net...

In this paper, three different methods for software visualization of large graph structures, respectively Rectangle, Intersection and Combined are presented. The basic concepts for using software development environments are outlined. Their capabilities for visual designing and event-oriented programming are discussed. A brief analysis of the basic...

The basic concepts of using application development environments are presented in this paper. The way of using the GraphAnalyser application and its basic functions is also presented. All results of the experiments conducted are generated with this application. According to the experimental methodology, they fall into two groups: the first one incl...

Настоящата книга съдържа откъси от дисертационния труд „АКУСТИЧНО-ФОНЕТИЧНО МОДЕЛИРАНЕ ЗА РАЗПОЗНАВАНЕ НА ДЕТСКА РЕЧ НА БЪЛГАРСКИ ЕЗИК“, разработен от д-р Радослава Кралева и защитен през 2014 година. Възпроизвеждането и разпознаването на реч е естествен процес, който се извършва от всеки човек още от първия ден на неговото съществуване. Речта е...

The use of modern information and communication technology as a means of training pupils and students has become a popular trend. For this purpose, a special type of web-based content management systems, called Learning Management Systems (LMSs), has been used. Due to their wide implemented, lots of LMSs have been developed in recent years. All tho...

Nowadays, software development methods have undergone a number of changes. The most preferred development environments proved to be rapid application development software and their application has been increasingly used in various software developments. However, developers not always have a clear idea of the requirements of the targeted users. They...

Journal of Computing Science and Engineering (JCSE), Volume 13, Number 1, March 2019, pp. 1-10 Abstract: Nowadays, the interest of young people in programming is decreasing steadily on a global scale. This, however, is becoming a problem for global economic development. The dynamic development of technologies requires the implementation of new tea...

This paper presents a study of a modified event grouping based algorithm (MEGB) for university course timetabling problem (UCTP). Multiple models to describe the problem and multiple approaches to solving it are pointed out. The main idea of the modification is that through reduction on the generated solutions the execution time of the standard eve...

Mobile apps can be used in various environments and at any time. People can use them for learning, communications, entertainment. Because of the ease use of technologies, the smart mobile devices can be used by everyone, including the children with special needs. In recent years, there has been an increase in the efforts of educational institutions...

span lang="EN-US">This paper presents the results obtained from a comparative analysis of two methods for experimental data sharing. Several works related to the topic and some approaches for processing data have been discussed. Different technolgoies related to the web services , ways of using them and the areas of their application are analyzed....

This book is a guide to the software development for storing and processing of multimedia information in C ++ Builder.

In this paper, the results of a comparative analysis between different approaches to experimental data storage and processing are presented. Several studies related to the problem and some methods for solving it have been discussed. Different types of databases, ways of using them and the areas of their application are analyzed. For the purposes of...

Designing applications adapted to the capabilities of each user is an important part of modern software engineering. Children with Autism spectrum disorder and/or intellectual disabilities are a special group of users where standard application design is not a good approach. Some of them have speech disorders, others have disorders of the musculosk...

Разглеждат се таговете за добавяне на мултимедийни обекти в уеб страниците. Представят се начините за използване на CSS шаблони към тях. Представяне на съвместимостта на мултимедийните обекти с различните видове уеб браузъри, проблемите, които възникват с тяхното използване и начините за тяхното разрешаване. Разглеждат се различните видове формат...

5. Въведение в езика HTML. Структуриране на HTML документ. Цели на темата: Да се разгледа историческото развитие на HTML. Да се посочат основните характеристики на езика. Да се представи конструкцията на HTML документа. Да се въведе основната терминология в изграждането на уеб страница с HTML. Да се посочат възможните текстови редактори и среди з...

Use case или приетият в българската литература Случай на употреба, е част от езика UML. В настоящата лекция ще бъде представени примери за начините на използване на use case, за представяне на основни идеи, свързани с функционалните възможности на софтуерен продукт; изчертаване на use case диаграми в Microsoft Visio и палитрата от компоненти UML Us...

This paper discusses the concept of rapid application development and some of its specific features. Also, the main stages based on this concept in the development of different types of applications are pointed out. These two stages are: application design – when creating the application outlook; and event-oriented programming – when the methods th...

Modern mobile devices are becoming more and more popular in children’s lives. Therefore, the development of appropriate applications for them is of crucial importance. This article focuses precisely on the design of interfaces for mobile application with the participation of children. An overview of contemporary research related to Child-Computer I...

This paper presents a study for a local search algorithm based on chromatic classes for the university course timetabling problem. Several models and approaches to resolving the problem are discussed. The main idea of the approach is through a heuristic algorithm to specify the chromatic classes of a graph in which the events of the timetable corre...

Този курс има за цел да запознае студентите с основите на визуалното про-ектиране и събитийно-ориентираното програмиране. Тъй като курсът е предназ-начен за неспециалисти, не е необходимо студентите да имат познания по някакви езици за програмиране. Тук те ще се запознаят с основите на езика C++ средата C++ Builder. В курсът ще се разгледат някои о...

В тази лекция се разглежда: * Секции и контейнери в уеб документите * Използване на различни стилови шаблони за създаване на различни дизайни за един и същи html документ. * Разглеждане на възможностите за подравняване на обекти в уеб страницата. * Представяне на правилата в изграждане на дизайн на уеб сайт. * Подбор на дизайн съобразно резолюци...

В настоящата тема ще бъдат разгледани:  Различните тагове и техните атрибути за създаване на форми в HTML;  Начини за форматиране на форми с CSS;  Разграничаване на методите Get и Post.  Валидиране на потребителски данни. Формата представлява съвкупност от елементи, чрез които потребителят може да въвежда информация и да я изпраща към сървъра...

The formation of creative and logical thinking in children is an important process that should begin in early childhood. However, the traditional approaches to learning and to the classical curricula cannot be always relied on for this purpose. This article considers some of the existing traditional programming languages and the possibility of thei...

This paper presents the study of an event grouping based algorithm for a university course timetabling problem. Several publications which discuss the problem and some approaches to its solution are analyzed. The grouping of events in groups with an equal number of events in each group is not applicable to all input data sets. For this reason, a un...

This article focuses on the possibilities of using mobile learning in the Bulgarian preschool education of young children. The state preschool educational regulations are presented and discussed. The problem concerning the children's safety when using mobile devices in terms of access to information on the Internet is revealed and analyzed. Two con...

This article considers the use of mobile learning in Bulgarian education by young children. The most used mobile operating systems are analyzed. Also some of the most used existing applications suitable for mobile learning of preschool children are presented and classified. Keywords: Mobile applications for preschool children, mobile learning.

Abstract: This article considers the use of mobile learning in Bulgarian education by young children. The most used mobile operating systems are analyzed. Also some of the most used existing applications suitable for mo-bile learning of preschool children are presented and classified. Keywords: Mobile applications for preschool children, mobile lea...

Abstract: This article presents an analysis of some of the existing software for working with graphs. It reveals a need for the development of such software. Also, the basic terminology of graph theory is described; further on, fundamental technologies for working with data are discussed. Some object-oriented integrated development environments (ID...

This paper provides an analysis of literature related to the use of mobile devices in teaching young children. For this purpose, the most popular mobile operating systems in Bulgaria are considered and the functionality of the existing mobile applications with Bulgarian interface is discussed. The results of a survey of parents' views regarding the...

The use of graphs is widely applied in modeling and solving problems in the field of computer science and bioinformatics.Therefore, it is essential to develop and improve algorithms reducing their computational complexity and increasing the precision of the solutions generated by them as well as the size of the input data.In this study two well-kno...

The use of graphs is widely applied in modeling and solving problems in the field of computer science and bioinformatics. Therefore, it is essential to develop and improve algorithms reducing their computational complexity and increasing the precision of the solutions generated by them as well as the size of the input data. In this study two well-k...

This dissertation focuses on modelling acoustic-phonetic characteristics of the speech of the Bulgarian language to children between 4 and 6 years. Developed a corpus of children's speech - ChildBG. Proposed is a multimedia information system for working with corpus ChildBG. Modern technologies for speech recognition are oriented mainly to the spe...

Abstract: The article discusses the speech of children with communicative disorders focusing from linguistic point of view on the number of the words they use that belong to the different parts of speech. The data are obtained from a project that aims at the development and approbation of a battery of tests that investigate the speech of children w...

The multimedia language corpus ChildBg, that contains child speech in Bulgarian, is presented in this article. The software architecture, user interface, and database are viewed. The ChildBG is appropriate for all scientists who are engaged in research of the children’s speech in Bulgarian. This system uses audio and image files. The used files are...

In this paper a variable neighborhood search approach as a method for solving combinatoric optimization problems is presented. A variable neighborhood search based algorithm for solving the problem concerning the university course timetable design has been developed. This algorithm is used to solve the real problem regarding the university course t...

The report presents the process of planning, designing and the development of a database of spoken children’s speech whose native language is Bulgar-ian. The proposed model is designed for children between the age of 4 and 6 without speech disorders, and reflects their specific capabilities. At this age most children cannot read, there is no sustai...

This article presents a survey of the existing corpora of children's speech. Some of the best-know corpora are discussed and a comparative analysis between them is made. Sample of spoken speech in Bulgarian, which contain only adults’ speech are presented. Keywords: Speech corpora, Children’s Speech Recognition,

This paper presents researches related to acoustic characteristics of children’s speech and adults’ speech. A comparative analysis of the speech of different age groups of speakers is made. The main factors affecting the degree of recognition of children’s speech are pointed out. The techniques used to adapt the children's speech to the speech of a...

This report presents a general model of the architecture of information systems for the children’s speech recognition. It presents a model of the speech data stream and how it works. The result of these studies and presented veins architectural model shows that research needs to be focused on acoustic-phonetic modeling in order to improve the quali...

In this article are discussed some problems in developing software related to the management of information flows. We presented the basic stages in their development. We bold a methodology for conceptual modeling and design of information systems of this type. In order to demonstrate the effectiveness of the proposed model is an information system...

In this paper has briefly examined the university course timetabling problem. Specified is the need to develop an information system to automate this process. Has described the methodology for drawing up the university course timetabling. It is a brief overview of technologies for developing distributed information systems. Described is an architec...

An integrated information system for university course timetabling is described in this paper. The functional requirements are formulated for this system. A new model of university course timetabling information system based on module organization is suggested. A scheme of relational database storing the necessary information used by the model is p...

This article deals with a three-layer architectural model of a distributed information system based on Web services, which will be used for automatic generation of sets of input data. The information system will be constructed of a client layer, a service layer and of a data layer. The web services as a tool of developing distributed software syste...

In the present paper one of the most popular classical self-organizing clustering methods – ISODATA (Iterative Self-Organizing Data Analysis Techniques Algorithm) is considered. It is proposed a modification implemented by changes in two of the restriction conditions of ISODATA algorithm. There are presented the received results of the work of the...