Promocijas darbs

Elektroniskā versija nesatur pielikumusDarba tēma ir saistīta ar biznesa procesu vadības sistēmu izstrādi. Šajā darbā biznesa procesu modelēšanas problēmas ir risinātas, izmantojot metamodelēšanas paņēmienus. Metamodelēšana ļauj dažādus biznesa modelēšanas aspektus aplūkot vienotā un vispārīgā formā, tai pat laikā nezaudējot precīzu jēdzienu nozīmi. Galvenie pētījumu rezultāti ir sekojoši: Izstrādāts vienots biznesa procesu un to apkārtnes metamodelis, kas parāda biznesa modelēšanas jēdzienus un to saistību. Izstrādāta biznesa modeļu jēdzienu kartēšanas metode jēdzienu kartēšanai no viena domēna uz vairākām modelēšanas valodām. Izstrādāta precīza Unified Modeling Language Aktivitāšu diagrammas (UML AD) izpildes semantika, izmantojot virtuālo mašīnu. Izstrādāti funkcionāli ekvivalenti UML AD apakškopas profila un BPMN apakškopu metamodeļi, un uz to bāzes izveidoti šo valodu redaktori. Izstrādātas transformācijas valodā MOLA, kas veic modeļu transformāciju no AD uz BPMN.The thesis discusses topics related to the development of business process management systems. Thesis proposes that business process modeling problems can be solved using a metamodeling approach, which allows analysis of different modeling aspects in a unified and comprehensive way, while retaining the exact semantics of concepts. The main results of the research are following: A notation independent business process metamodel is developed. A new approach is developed for mapping business concepts from one common domain to different modeling languages. Exact execution semantics for the UML activity diagram (AD) is developed using a virtual machine. Functionally equivalent metamodels are developed for the profile of the UML AD subset and a BPMN subset. Model transformations are developed in the MOdeling LAnguage (MOLA) to perform transformations from AD to BPMN

Biznesa procesu modelēšana, izmantojot metamodelēšanas paņēmienus

Darba tēma ir saistīta ar biznesa procesu vadības sistēmu izstrādi. Šajā darbā biznesa procesu modelēšanas problēmas ir risinātas, izmantojot metamodelēšanas paņēmienus. Metamodelēšana ļauj dažādus biznesa modelēšanas aspektus aplūkot vienotā un vispārīgā formā, tai pat laikā nezaudējot precīzu jēdzienu nozīmi. Galvenie pētījumu rezultāti ir sekojoši: Izstrādāts vienots biznesa procesu un to apkārtnes metamodelis, kas parāda biznesa modelēšanas jēdzienus un to saistību. Izstrādāta biznesa modeļu jēdzienu kartēšanas metode jēdzienu kartēšanai no viena domēna uz vairākām modelēšanas valodām. Izstrādāta precīza Unified Modeling Language Aktivitāšu diagrammas (UML AD) izpildes semantika, izmantojot virtuālo mašīnu. Izstrādāti funkcionāli ekvivalenti UML AD apakškopas profila un BPMN apakškopu metamodeļi, un uz to bāzes izveidoti šo valodu redaktori. Izstrādātas transformācijas valodā MOLA, kas veic modeļu transformāciju no AD uz BPMN.The thesis discusses topics related to the development of business process management systems. Thesis proposes that business process modeling problems can be solved using a metamodeling approach, which allows analysis of different modeling aspects in a unified and comprehensive way, while retaining the exact semantics of concepts. The main results of the research are following: A notation independent business process metamodel is developed. A new approach is developed for mapping business concepts from one common domain to different modeling languages. Exact execution semantics for the UML activity diagram (AD) is developed using a virtual machine. Functionally equivalent metamodels are developed for the profile of the UML AD subset and a BPMN subset. Model transformations are developed in the MOdeling LAnguage (MOLA) to perform transformations from AD to BPMN

Experimental Pilot Device for Thermal Analysis of Biomass Co-firing

The share of biomass in the transformation sector of Latvia accounts for only 15%, at the same time natural gas share in transformation sector is about 80%. Nonetheless, an ongoing natural gas price growth stimulates its full replacement with biomass. The goal of the research was to construct an experimental pilot device, where could be possible to combust biomass with gaseous fossil fuel. The pilot device was equipped with the following measurement instruments: thermocouples for local temperature measurements and gas analyzer for measurements of flue gas composition, temperature, and combustion efficiency

Energy Efficiency Results of Smart Metering, Pilot in a Context of Cost Benefit Analysis of Smart Meters in Latvia

This paper analyzes the results of providing smart meters and appropriate feedback on electricity consumption in a pilot study involving around 1000 households in Latvia. The findings from the study have shown response from feedback at 11.4% for an average and 8.6% for median of relative consumption reduction extrapolating the pilot results to all households in Latvia. Therefore, it can be suggested that a higher consumption saving level should be used in cost benefit analysis of rollout of smart meters at least in Latvia that would improve CBA and increase the size of the planned rollouts. It is additionally supported by the fact that for the households with annual consumption below 2500kWh the relative savings were found above the average level. This result would need additional study as in general there is expected that at low consumption levels there is also a low effect from provided feedback

Eco-intensity analysis for a chip-fuelled boiler house / Ekologinio intesyvumo namą šildant skiedromis analizė

The operational eco-intensity of a heat supply system is dependent upon the interaction of its elements and their common performance. It is of special importance to gain insight into possibilities to reduce chip fuel consumption in the case when an additional element – a gas condenser – is installed in a boiler house. The efficiency of a system's operation is estimated by its eco-intensity; such estimates concern the influence exerted by technological parameters on the reduction in natural resource consumption, allowing this problem to be thoroughly analysed by means of definite factors promoting the eco-intensity rise. Based on the results of commercial experiment, the authors have found the independent variables for the case of gas condenser without packing. The eco-intensity of a boiler house operation decreases as the outdoor temperature falls and therefore the boiler's load should be increased. This aspect could be due to several causes, among which the most important are: the deviations of the operating parameters of the gas condenser, the increase in the flue gas velocity, and temperature. Analytical treatment of the influence exerted by a boiler's specific load on the operational efficiency of its energy has shown that as this former grows, the efficiency decreases and therefore less heat energy could be derived from the gas condenser. This should be taken into account at simulation of the control over a gas condenser's operation. Santrauka Ekologinis intensyvumas priklauso nuo šilumos tiekimo sistemos elementų sąveikos ir jų bendro veikimo. Tai ypač svarbu tiriant galimybes sumažinti skiedrų kuro sąnaudas tuo atveju, kai šildomame name yra įdiegtas papildomas elementas – dujų kondensatorius. Sistemos veikimo efektyvumas įvertinamas pagal jos ekologinį intensyvumą; tokie vertinimai susiję su įtaka technologiniams parametrams mažinant gamtinių išteklių naudojimą. Remdamiesi tyrimo duomenimis, autoriai nustatė nepriklausomuosius dujų kondensatoriaus kintamuosius. Šildomo namo ekologinis intensyvumas susijęs su lauko temperatūra. Kai ji nukrinta, apkrova turėtų būti padidinama. Tai lemia kelios priežastys, iš jų svarbiausios: dujų kondensatoriaus darbinių parametrų nuokrypiai, išmetamųjų dujų greičio padidėjimas ir temperatūra. Atlikta analizė parodė, kad didinant katilo formą, sistemos efektyvumas mažėja, ir todėl mažiau šilumos energijos tiekiama iš dujų kondensatoriaus. Tai turėtų būti įtraukta į dujų kondensatoriaus veikimo kontrolės modeliavimo skaičiavimus. Reikšminiai žodžiai: dujų kondensatorius, skiedromis šildomas namas, šilumos tiekimo sistema, optimizacija, ekologinis intensyvumas, komerciniai tyrimai, aplinkos tausojima

Eco-Intensity Analysis for a Chip-Fuelled Boiler House

The operational eco-intensity of a heat supply system is dependent upon the interaction of its elements and their common performance. It is of special importance to gain insight into possibilities to reduce chip fuel consumption in the case when an additional element − a gas condenser – is installed in a boiler house. The efficiency of a system's operation is estimated by its eco-intensity; such estimates concern the influence exerted by technological parameters on the reduction in natural resource consumption, allowing this problem to be thoroughly analysed by means of definite factors promoting the eco-intensity rise. Based on the results of commercial experiment, the authors have found the independent variables for the case of gas condenser without packing. The eco-intensity of a boiler house operation decreases as the outdoor temperature falls and therefore the boiler’s load should be increased. This aspect could be due to several causes, among which the most important are: the deviations of the operating parameters of the gas condenser, the increase in the flue gas velocity, and temperature. Analytical treatment of the influence exerted by a boiler’s specific load on the operational efficiency of its energy has shown that as this former grows, the efficiency decreases and therefore less heat energy could be derived from the gas condenser. This should be taken into account at simulation of the control over a gas condenser’s operation