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Numerical Integration of Two-Dimensional Complex-Valued Functions for the needs of BIEM
Get PDFNumerical integration is a key problem with numerous applications, including the boundary integral equation method (BIEM). GSL [7] provides powerful implementations of a broad variety of well-known numerical methods and algorithms. However, its routines have certain limitations: the numerical integration based on QUADPACK library [2] is implemented only in the case of one-dimensional functions. In this paper we present an extension of the GSL numerical integration routines for the special case of two-dimensional complex-valued functions. The presented approach is part of our effort to build a BIEM software system for solving a 3D elastodynamics problem for wave propagation in a continuously inhomogeneous half-space
Theoretical Properties of a Neighborhood-based Approach for Widening
Get PDFMost of the research in parallel data mining and machine learning algorithms is focused on improving the efficiency of existing algorithms. However, our focus is the improvement of the solution quality, or model accuracy. We are looking for "smart" strategies to invest parallel compute resources in order to achieve a better exploration of the search space by exploring several solutions in parallel, referred to as Widening. In this paper, we discuss the theoretical properties of a neighborhood-based Widening using a type of neighborhoods, optimality neighborhoods and contrast this communicationless approach to the straightforward beam-like Top-k Widening approach, which requires communication. We show a bound on the number of parallel workers needed for the communicationless approach to guarantee that it has a solution of the same quality as the Top-k approach. In addition to the theoretical comparison, we experimentally compare these two approaches in terms of running time and quality of final solution, using a widened version of the greedy algorithm for set cover problem
Context-dependent Tools and Models in Cultural Heritage Education
No full textThis paper includes an overview of different tools and methods used to present cultural heritage resources in e-learning contexts - storytelling, serious games, digital libraries, and virtual museums. It introduces a model and several components for providing context-dependent education in cultural heritage topics. The model defines key criteria for the educational process - effective presentation of resources, different contexts, interaction, and the need for the environment to support interactivity between children in learning. The created instruments are based on the basic requirements identified and implemented in an online system for designing and providing educational content in e-learning. They include a component for 3D learning environments, allowing the creation and visualization of three-dimensional scenes in which users can examine cultural and historical artifacts in different settings
Диалекти и използване на чужда графична система в компютърно опосредстваната комуникация (Изследване на базата на примери в социалната мрежа "Фейсбук")
Get PDFДокладът разглежда използването на чужда графична система в неформалните комуникации в онлайн социалната мрежа "Фейсбук" и възможността за определяне на диалектната принадлежност на базата на чуждографичното изписване на ятовата гласна. Правят се изводи за тази възможност.The report shall consider the use of а foreign graphic system in the informal communication on the online social media Facebook and the possibility for determination of the dialectical affiliation, based on the graphic differences by the spelling of the jat vowel. Conclusions for this opportunity are drawn
Система от задачи по информатика с управление на физически системи – Lego робот
Get PDFMotivating students to study nowadays became harder, but an important task for the teacher. The most soughtafter way to show motivation is the direct practical use of knowledge most often in school. This can be achieved by carefully selecting examples and learning tasks. Proven motivating impact there is a possibility for training based on the management of physical systems. This paper presents a system of tasks with LEGO robot control, part of the new approach developed by the authors for training in informatics and IT, relying on strong motivation through the development of applications with modern interface in modern environment, solving everyday problems, demonstrations with robot and visualizations of algorithms. The proposed examples and tasks can serve to enrich the pedagogical practice of secondary school teachers
Развитие на информационните технологии и влиянието им върху образователните функции на музеите
Get PDFMuseums work to attract the interest of different types of museum audiences, including focusing on the youngest visitors – the children. Museums must strive to ensure accessibility at different levels: physical and intellectual, interactive, etc. Museums develop and follow policies for working with children, they take into account educational programs with educational and recreational character and adapt various socialization tools, including those related to the development of information technology
Фолклорните фестивали - съвременен метод за опазване на живото културно наследство
Get PDFСъвременната празничност очертава вижданията на модерното общество за начина на отбелязване и чествания на различни по мащаби и значение събития. Съвременните фолклорни фестивали са част от тази празничност, съчетаващи в себе си традиционни елементи и модерни компоненти. Облягайки се на тезата, че съществуването на песента, танца, традицията е позиционирано в момента на изпълнение и практикуване, то поставени в условията на презентиране елементите на живото – нематериалното културно наследство преминават през подготвителна фаза на трансмисия, носеща значимо влияние за неговото опазване.Contemporary festivity outlines the views of modern society on the way celebrations and celebrations of events of different magnitude and significance. Contemporary folk festivals are part of this celebration, combining traditional elements and modern components. Relying on the thesis that the existence of the song, dance, tradition is positioned at the moment of performance and practice, the elements put into the conditions of presentation - the intangible cultural heritage go through a preparatory phase of transmission, which has a significant impact on its preservation
Digitalization - a Tool for Modern Reading of the Craiova Agreement in Preserved Personal Collections of Evicted Bulgarians From Northern Dobrudja
No full textReport published in the Proceedings of the National Conference on "Education and Research in the Information Society", Plovdiv, November, 2020The report briefly presents the history of the conclusion of the Craiova Agreement
between Bulgaria and Romania 80 years ago, in the context of its impact on the fate of the
nearly 66,000 Bulgarians evicted from Northern Dobrudja and their settlement in Southern
Dobrudja. The documents and belongings stored in their personal collections show the other
face of this "greatest victory" of Bulgarian diplomacy in the last century. Digitizing these pages
of our history would help to create an objective and impartial assessment of the past generation
of the young generation and would support the disclosure of this long-held topic to our and the
world community.Association for the Development of the Information Society, Institute of Mathematics and Informatics Bulgarian Academy of Sciences, Plovdiv University "Paisii Hilendarski
Theory and Applications of Convex VSIO
Get PDFReport published in the Proceedings of the National Conference on "Education and Research in the Information Society", Plovdiv, November, 2020This presentation deals with vector semi-infinite optimization problems which are defined by finitely many objective functions whose variables belong to a finite-dimensional space and whose feasible sets are defined by infinitely many inequality constraints. The objective is to show several fields of applications of vector semi-infinite optimization as well as some theoretical results in convex vector semi-infinite optimization (characterization of solutions, necessary and sufficient optimality conditions).Association for the Development of the Information Society, Institute of Mathematics and Informatics Bulgarian Academy of Sciences, Plovdiv University "Paisii Hilendarski
The Impact of Sea-type Aerozols on the Climate Change and Ozone Layer Depletion
No full textReport published in the Proceedings of the National Conference on "Education and Research in the Information Society", Plovdiv, November, 2020Sea salts aerosols are highly hygroscopic and exhibit changes as a function of
relative humidity. Solid sea salt particles take up water in the atmosphere and form aqueous
droplets. Deliquescence is a process in which a soluble solid substance sorbs water vapor from
the air to form a very stable saturated aqueous solution on the particle’s surface. The uptake
of water by hygroscopic constituents of airborne particles significantly alters particle reactivity,
radiative properties, and cloud-droplet nucleation efficiency. This process is of interest in many
areas, such as chemistry of sea-salt aerosols in the marine boundary layer and clouds
formation in coastal areas, heterogeneous chemistry of inorganic salts, corrosion of metals in
atmosphere. The main purpose of this study is to develop a Pitzer approach based
thermodynamic model for stable (laboratory) and metastable (natural) equilibrium in extended
brine system and to build theoretically “solar evaporation diagram”. We apply the resulting
model for accurate thermodynamic description of highly non-ideal atmospheric aerosol system,
and an accurate estimation of solid-liquid phase change of sea type aerosols as function of
temperature (from 0оС to 75оС) and рН at wet natural conditions.Association for the Development of the Information Society, Institute of Mathematics and Informatics Bulgarian Academy of Sciences, Plovdiv University "Paisii Hilendarski