Now showing 1 - 10 of 18
  • Publication
    Konceptuālo un relāciju datu modeļu savietojamības noteikšanas metodoloģija
    Lai informācijas sistēmas varētu apmainīties ar datiem, to datu modeļiem jābūt saderīgiem. Bieži vien tas tā nav, jo sistēmas ir veidojuši dažādi izstrādātāji, vadoties pēc dažādiem mērķiem, kā rezultātā rodas atšķirības terminu lietojumā un datu vērtību skaidrojumos. Līdz ar to šo informācijas sistēmu datu modeļi var būt izteikti dažādās notācijās, kas apgrūtina saderības noteikšanu. Šajā promocijas darbā tiek risināta dažādās notācijās izteiktu datu modeļu savietojamības noteikšanas problēma. Datu modeļi tiek transformēti ontoloģijās, pielietojot transformācijas noteikumus. Vēlāk tiek veikta automātiska ontoloģiju savietošana, un iegūts datu modeļu saderības novērtējums. Datu modeļu savietošanas procesā lietoto metožu kopums ir apvienots metodoloģijā, ko var izmantot datu modeļu salīdzināšanai dažādās nozarēs. Metodoloģija ļauj nozares ekspertiem veikt savietošanas uzdevumus automātiskā veidā, ekonomējot šim uzdevumam atvēlēto laiku un resursus. Izstrādātā metodoloģija ir tikusi aprobēta, salīdzinot Latvijas Valsts zemes dienesta datu bāzes relāciju modeli ar ISO 19152 starptautiskā standarta konceptuālo datu modeli, lai noteiktu, cik lielā mērā viens datu modelis atbilst otram. Metodoloģijas nodrošināšanas un aprobācijas vajadzībām ir izstrādāts ontoloģiju savietošanas programmatūras rīks, kas ir viens no šī darba praktiskajiem rezultātiem. Rīks nodrošina automātisku datu modeļu transformāciju un ontoloģiju savietošanu, kā arī ļauj veikt manuālu savietošanu un entītiju anotāciju.
  • Publication
    Konceptuālo un relāciju datu modeļu savietojamības noteikšanas metodoloģija. Promocijas darba kopsavilkums
    Darba mērķis ir izstrādāt metodoloģiju konceptuālo datu modeļu un relāciju datu modeļu savietojamības noteikšanai, kas ļautu automatizēt savietošanas procesu un nodrošinātu nozares speciālistus ar rīkiem darbā ar dažādās notācijās izstrādātiem datu modeļiem. Izmantojot šo metodoloģiju, lietotājam tiek dota metožu kopa, kas ļauj risināt konceptuālo un relāciju datu modeļu savietojamības noteikšanas uzdevumu. Konceptuālo un relāciju datu modeļu savietojamības noteikšanai ir izstrādāts speciāls rīks, kas ļauj šo uzdevumu atrisināt atbilstoši metodoloģijai. Pateicoties tam, tiek ievērojami samazināts nozares speciālistu darba apjoms, kā rezultātā tiek ietaupīts laiks un resursi
  • Publication
    Automatic Transformation of Relational Database Schema into OWL Ontologies
    Ontology alignment, or ontology matching, is a technique to map different concepts between ontologies. For this purpose at least two ontologies are required. In certain scenarios, such as data integration, heterogeneous database integration and data model compatibility evaluation, a need to transform a relational database schema to an ontology can arise. To conduct a successful transformation it is necessary to identify the differences between relational database schema and ontology information representation methods, and then to define transformation rules. The most straight forward but time consuming way to carry out transformation is to do it manually. Often this is not an option due to the size of data to be transformed. For this reason there is a need for an automated solution. The automatic transformation of OWL ontology from relational database schema is presented in this paper; the data representation differences between relational database schema and OWL ontologies are described; the transformation rules are defined and the transformation tool’s prototype is developed to perform the described transformation.
    Scopus© Citations 2
  • Publication
    Apple and Pear Scab Expert System
    (2023)
    Apeināns, Ilmārs
    ;
    ;
    Lācis, Gunārs
    ;
    Litavniece, Lienīte
    Plant disease, such as apple and pear scab, control is a crucial issue of fruit-growing. Apple and pear are among the most widely grown (approximately 43% of all fruit tree area) and economically important fruit crops worldwide and in Latvia. Research projects have produced research data covering various aspects of plant-pathogen interactions, but there is no internal linkage analysis, as well as implementation of other types of data (such as environmental and meteorological data, etc.). Establishing such a data integration system would allow the identification of new regularities in plant-pathogen interactions, and provide mechanisms for disease control decisions. In this study an expert system was developed aimed to help professional fruit-growers evaluate the possible impact of apple and pear scab to the plant health and yield quality. The expert system is based on a previously developed apple and pear scab ontology and consists of a web based front-end and triplestore back-end.
  • Publication
    ENERGY AUDIT INFORMATION SYSTEM
    (2022)
    Arta Rozentale
    ;
    Inta Kotane
    ;
    The opportunities provided by energy audits to improve the competitiveness of companies by reducing energy consumption and introducing energy-efficient solutions also allow for achieving the environmental goals set by the European Union and Latvia in relation to climate neutrality. It is important to consider the results of energy audits in the development of both local and regional and national policies, thus setting more precise results to be achieved. At present, there is no unified energy audit development information system in Latvia, in which all audit stages and calculations could be performed; this would reduce clerical and calculation errors and allow data to be predicted and used in policy development, research. Within the framework of the work, the authors researched the concept of energy audit, its process and the results to be achieved by companies by implementing energy efficient measures, as well as the policy goals of the European Union and Latvia in environmental improvement programs. The paper summarizes and analyses the programs and methods available in Latvia, which are used to develop energy audits of companies, as well as the practices of other countries and their results.The research goal is to develop the specification of the energy audit information system, based on the analysis of the used energy audit information systems. Based on the findings, the authors developed a specification of the program's energy audit information system requirements, which is suitable for the Latvian market.
  • Publication
    The Analysis of Efficiency Dependence of the Shortest Path Finding Algorithms A* and HPA*
    (2012) ;
    Oleg Uzhga-Rebrov
    Many pathfinding problems in real-world applications require real-time computation of the shortest path between two points in a grid-based environment. It is not a trivial task. While some shortest path finding algorithms may perform admissibly in one condition, they may prove inadmissible in other conditions. HPA* pathfinding algorithm is faster and more memory efficient than the A*algorithm in relatively large twodimensional grids, but this advantage may not apply to very small or very large grids. The paper deals with the efficiency of A* and HPA*in two-dimensional grids of different sizes. For the sake of completeness of the analysis, HPA* efficiency is measured taking into consideration the number of hierarchy levels and different cluster sizes. Both algorithms have been implemented and tests conducted. Experimental evidence is proposed to demonstrate the algorithm efficiency in various conditions.
  • Publication
    ANALYSIS OF ARTIFICIAL INTELLIGENCE APPLICATIONS FOR AUTOMATED TESTING OF VIDEO GAMES
    Game testing is a software testing process for quality control in video games. Game environments, sometimes called levels or maps, are complex and interactive systems. These environments can include level geometry, interactive entities, player and non-player controllable characters etc. Depending on the number and complexity of levels, testing them by hand may take a considerable effort. This is especially true for video games with procedurally generated levels that are automatically created using a specifically designed algorithm. A single change in a procedural generation algorithm can alter all of the video game levels, and they will have to be retested to ensure they are still completable or meet any other requirements of the game. This task may be suitable for automation, in particular using Artificial Intelligence (AI). The goal of this paper is to explore the most promising and up-to-date research on AI applications for video game testing to serve as a reference for anyone starting in the field.
    Scopus© Citations 8
  • Publication
    Digital twin modelling for smart fruit-growing: eco-cyber-physical system 4+1 architecture
    (2023)
    Kodors, Sergejs
    ;
    ;
    Ginta Majore
    ;
    Edgars Rubauskis
    ;
    Lienite Litavniece
    The continuous evolution of technology and industrial revolutions provides new horizons for the application of smart solutions in every aspect of human lives. At the same time, it causes new social and engineering challenges, which require appropriate methodologies and solutions to overcome them. A smart orchard is an example of an eco-cyber-physical system. Modelling of an eco-cyber-physical system is more complex than simple software development because the complexity quickly grows together with the amount of interconnected components. The difficulties come together with various fruit tree species (in our case apples, pears, and cherries), related technologies and orchard systems. Such systems differ even in the frame of one species like apple trees (rootstocks effect on the tree size; planting density; tree canopy training systems, etc.) and some production risk-reducing technologies (rain and hail, against birds and insects protecting covering systems), as well as agricultural machinery movement in the site. An additional accelerator of complexity growth is the development of eco-cyber-physical and data-driven decision-making paradigms, which propose business-driven development considering ecological and technical aspects together within cyberspace. As a result, the product of synergy is a digital twin paradigm, which provides digital mirrors for artificial intelligence to monitor and manipulate the physical world considering environmental aspects. This article presents the digital twin “4 + 1” model of a smart orchard, which is described using modern visual notations like 4EM for project view, ARTSS for logical view, OPM for process view, IoT-adapted UML component diagram for physical view and spatial map for deployment view. The proposed methodology offers a roadmap for design and development of smart solutions in fruit-growing to predict the yield and potential of income generation in the early stages of the season.
  • Publication
    RISK ANALYSIS FOR APPLE ORCHARD SURVEY AND MONITORING USING UAV
    (2023)
    Lienīte Litavniece
    ;
    Kodors, Sergejs
    ;
    Juta Dekšne
    ;
    ;
    Gunārs Lācis
    ;
    Risk analysis is an integral part of modern business management because successful business largely depends on the effective implementation of risk analysis. Agriculture is an important sector in the national economy, therefore Industry 4.0 increasingly provides digital solutions in orchard management, which facilitate and simplify decision-making in daily tasks. Meanwhile, unmanned aerial vehicles are applied as the agriculture sector's main monitoring and data acquisition tool. However, this means that it is necessary to pay attention to risk analysis due to the process of managing the orchard, where not only a person and the mechanized equipment controlled by him, which moves on the ground but also flying automated equipment participates. The purpose of the article is to perform the risk analysis for the survey and monitoring of orchards for yield estimation using unmanned aerial vehicles by considering commercial apple orchards in Latvia. The main thing is that most risks are predictable, but planning is necessary to reduce the probability of their occurrence.  
  • Publication
    SIMULATION OF A SCHOOL CANTEEN TO UNDERSTAND MEAL DURATION IMPACT ON FOOD WASTE
    (2021)
    Kodors, Sergejs
    ;
    Zhukov, Vitaliy
    ;
    ;
    Litavniece, Lienīte
    ;
    ;
    Zvaigzne, Anda
    A system simulation is a one of the approaches to understand business processes or to explain them to other people. It is an excellent decision making solution to provide data-driven conclusions based on system modelling and experiments. This paper proposes simulation results of a school canteen. The aim of the research was to investigate the relation between a food waste amount and meal time duration. The proposed simulation was based on business process analysis, business process modelling, a Monte Carlo method and expert knowledge. The frequency distributions were constructed based on children meal duration observation completed by their mothers. It is a magnificent citizen science solution to involve mothers in the research because they can additionally better understand their children meal preferences and habits. Therefore, a questionnaire for citizens was developed, which can be applied to collect statistical data for model accuracy improvement and extension.
    Scopus© Citations 1