The purpose of this thesis is to validate generator models for dynamic studies of power systems using PSS/E (Power System Simulator for Engineering), EMTP (ElectroMagnetic Transient Program), and Hypersim. To thoroughly evaluate the behavior of a power system in the three specified software packages, it is necessary to have an accurate model for the power system, especially the generator which is of interest. The effect of generator modeling on system response under normal conditions and under faulted conditions is investigated in this work. A methodology based on sensitivity analysis of generator model parameters is proposed aiming to homogenize the behavior of the same power system that is modeled in three software packages. Standard IEEE 14-Bus system is used as a test case for this investigation. Necessary changes in the exciter parameters are made using the proposed methodology so that the system behaves identical across all three software platforms.

The Turkish TSO (TEIAS) has been leading a project that aims the synchronous interconnected operation of the Turkish Power System and the ENTSO-E CESA (former UCTE) System. For this purpose, this study concentrates on the specific problems related to the electromechanical systems of large size hydroelectric power plants regarding low frequency inter area oscillations, which are prone to occur once the interconnected operation is established. The expected frequency of inter area oscillations after interconnected operation is close to 0.15 Hz, which is in the frequency range of the speed governing structures of turbines, as explained in the first two sections of the thesis. In the third section, the nonlinear turbine governor model used throughout the study is explained. In the following part, the governor parameter tuning study with regard to the defined performance objectives is explained. Afterwards, the effect of the retuned governor settings of the sample hydroelectric power plants on a simple multi machine power system is shown. Following that, the system wide effect of removing the sources of negative damping, which are strongly dependent on the governor settings of the major hydroelectric power plants of the Turkish Power System, is shown. In the final part, conclusions are made on the operation of the hydroelectric power plants regarding the frequency stability of the system after synchronous interconnected operation of the Turkish Power System and the ENTSO-E CESA System.

The daily use of Internet services in the most diverse human activities creates in users the expectation of high availability of these services. Many of them have database systems as essential building block. Moreover, those services are subject outcomes such as errors and aging. An error-free software or a non-aging software which does not need innovations is an utopia. Thus, software updating is a required task. Currently, software-updating mechanisms are based on two different solutions: (i) using of additional hardware, an expensive and complex solution, or (ii) service interruption, which is trivial but inefficient. In this work, we explore the application of Dynamic Software Update (DSU) techniques as an alternative to update a Data Base Management System (DBMS) without requiring any additional hardware or service unavailability. Our solution was developed in a hypothetical DBMS architecture with the support of a software component model. A prototype was developed in accordance with this model using FRACTAL. Experimental evaluation confirmed the functional viability of this approach. The implementation overhead in a controlled environment was about 30%, which is acceptable. / O uso cotidiano da Internet nas mais diversas atividades humanas acaba por criar nos usuários a expectativa de serviços disponíveis a qualquer momento. Muitos destes serviços tem os Sistemas Gerenciadores de Banco de Dados (SGBDs) como ferramenta básica e essencial. Além disso, esses softwares estão sujeitos a erros e envelhecimento. Um software livre de erros ou que não precise de inovações é uma utopia. Assim, é necessário que o software sofra atualizações. Atualmente, os mecanismos para atualização de software utilizam hardware adicional, uma solução mais cara e complexa, ou optam pela indisponibilição do serviço para os clientes (parada do sistema), que é solução trivial mas ainda eficiente. O que este trabalho traz é a aplicação de técnicas de Atualização Dinâmica de Software (ADS) como uma alternativa para atualizar um SGBD sem o uso de hardware adicional e a indisponibilização do sistema. Para tanto, propõe-se o desenvolvimento de um SGBD em uma arquitetura hipotética com o suporte de componentes de software. Criou-se um protótipo de acordo com a solução proposta, utilizando o modelo de componentes FRACTAL. A avaliação experimental confirmou a viabilidade funcional da solução e que a sobrecarga da implementação em um ambiente controlado foi de aproximadamente 30%. Esta sobrecarga é aceitável, uma vez que se obtem a atualização do SGBD sem a parada total do mesmo.

[pt] A COVID-19 foi declarada como uma pandemia em março de 2020 pela OMS (Organização Mundial da Saúde) e até abril de 2022 infectou aproximadamente 490,7 milhões de pessoas, com pelo menos 6,17 milhões de mortes. A pandemia desafiou a segurança alimentar, agricultura e cadeias de alimentos frescos. Pesquisas sobre a análise de cadeias de suprimentos agroalimentares durante a COVID-19 indicam um maior impacto em pequenos fornecedores destas cadeias, principalmente as cadeias mais curtas, que são aquelas que possuem poucos elos. Neste contexto, esse trabalho analisa os efeitos da COVID-19 em cadeias de alimentos frescos. É desenvolvido, assim, um estudo de caso em uma organização de produtores do Rio de Janeiro. Esse estudo cobre uma revisão de escopo que identifica na literatura os principais impactos e políticas da pandemia nessa cadeia. Em seguida, os resultados são avaliados através de uma pesquisa de levantamento (survey) na organização para avaliar se as variáveis encontradas na literatura possuem aderência com as variáveis identificadas pelos respondentes da survey, que são pequenos produtores no estado do Rio de Janeiro. Por fim, o problema é modelado por meio de uma simulação por dinâmica de sistemas. Os resultados mostraram que a cadeia de suprimentos da organização é sensível a variáveis de impacto como aumento do custo de produção e não entrega de produtos, pois ao aumentar o custo de produção e a não entregar produtos, a taxa de vendas é impactada negativamente. A política de investimento em logística mostra que a taxa de vendas é impactada positivamente quando se aumenta o investimento. / [en] COVID-19 was declared a pandemic in March 2020 by the WHO (World Health Organization), and at the beginning of April 2022, it had infected approximately 490.7 million people, with at least 6.17 million deaths. The pandemic has challenged food security, agriculture, and fresh food chains. Research on the analysis of agri-food supply chains during COVID-19 indicates a more significant impact on small suppliers of these chains, especially the shorter chains, which are those with few links. In this context, this work analyzes the effects of COVID-19 on fresh food chains. Thus, a case study is developed in a producer organization in Rio de Janeiro. This study covers a scoping review that identifies in the literature the main impacts and policies of the pandemic in this chain. Then, the results are evaluated through a survey in the organization to assess whether the variables found in the literature match the variables identified by the survey respondents, who are small producers in the state of Rio de Janeiro. Finally, the problem is modeled through a system dynamics simulation. The results showed that the organization s supply chain is sensitive to impact variables such as increased production cost and non-delivery of products. As increasing production cost and not delivering products, the sales rate is negatively impacted. The investment policy in logistics shows that the sales rate is positively impacted when investment increases.

In order for a medication treatment to be considered successful, several roles and functions along the pharmacological treatment chain must function and cooperate effectively. The chain can most easily be described as five transitions; diagnosis, prescription treatment, dispensing, drug use and finally results and follow-up. Unfortunately, there are many problems and inefficiencies in the pharmacological drug chain. Unfortunately, those who study medication errors and their solutions have focused on individual parts of the pharmacological treatment system. However, for this reason, this study aims to develop a general framework for system analysis of inefficiencies along the pharmacological treatment chain. Due to the size of the problem, this project focused on medication adherence. Adherence can be defined as to what extent the patient follows the medication treatment plan. Adherence has many known problems and difficulties, among other things, it has major financial consequences. It can also be difficult to measure compliance, and there is no recognized perfect method. A system dynamic model is a theoretical image of a real system or object, which is a model used to understand the nonlinear behavior of complex systems. These models are useful when considering interventions and their effects when there are complex relationships. The project started with a literature study, and then went into data collection. Here, a search design and refinements were designed to find relevant articles. Once the articles were selected, the data was compiled from the articles and the analysis began. Here, factors and effects on adherence were identified as well as other interesting information from the articles. When the information was compiled and analyzed, the system dynamic model was created. The model was then sent via email to experts in the field to validation and revise the model. During the data collection, 23 relevant articles were found, compiled into 38 factors associated with compliance. In addition to these factors, 8 were excluded because they were too disease-specific or too ambiguous in their effect of adherence. The various articles studied many different chronic diseases, but hypertension was the most common. How adherence was measured in the articles also varied greatly, however, some form of self-report or questionnaire was most common method used. Three out of seven experts responded to the sent-out model and provided valuable comments. Although these are not sufficient to validate the model, their views showed that a validation can be designed in this way. The model would have to be sent to a larger set of experts and stakeholders, but because these experts are recognized in their fields, it gave weight to the results even though they were few reviewers. With the support of the literature and the experts’ statement, it was concluded that this model provides a good foundation and structure to continue to build upon. In addition, the model has proven to have many key relationships and cornerstones with important and relevant factors. It is also concluded that it is possible to translate the model into quantitative patterns, which is based on the fact that the factor itself can be translated quantitatively. Overall, it is also finally concluded that the model created in this project could be of great use in future projects when working towards a framework for system analysis of inefficiencies along the pharmacological treatment chain.

В рамках данной работы изучены особенности использования систем поддержки взаимодействия с клиентами в работе колл-центра. Рассмотрены возможности архитектурного подхода в разработке модели информационно-сервисной поддержки. Осуществлен анализ тенденций использования CRM-систем в колл-центрах. Осуществлена оценка результативности использования информационно-сервисной поддержки работы колл-центра. Построена полная модель архитектуры ООО «Нейтив Фарм». На основе процессного подхода детально рассмотрены все фазы проекта по информатизации колл-центра. Разработана и реализована имитационная модель управления проектом разработки и внедрения проекта информационно-сервисной поддержки работы колл-центра на основе различных сценарием. Осуществлена оценка эффективности внедрения новой CRM-системы в деятельность колл-центра. / Within the framework of this work, the features of using customer interaction support systems in the work of a call center were studied. The possibilities of the architectural approach in the development of the model of information and service support are considered. An analysis of trends in the use of CRM-systems in call centers was carried out. An assessment of the effectiveness of the use of information and service support for the work of the call center was carried out. A complete model of the architecture of Native Pharm LLC was built. Based on the process approach, all phases of the call center informatization project are considered in detail. A simulation model for project management for the development and implementation of a call center information and service support project based on various scenarios has been developed and implemented. An assessment was made of the effectiveness of introducing a new CRM system into the activities of the call center.

В диссертации были изучены особенности применения цифровых сервисов по управлению научной деятельностью образовательной организации. Рассмотрены возможности архитектурного подхода в разработке сервиса по управлению научной деятельностью. Осуществлен анализ текущего состояния научной деятельности ГОУ ВПО «Донецкого национального университета». Построена полная модель архитектуры ГОУ ВПО «Донецкий национальный университет». Разработан цифровой сервис «Scientific and information portal» с использованием веб-ориентированной среды Oracle APEX. Разработана и реализована имитационная модель управления затратами при внедрении цифрового сервиса в управление научной деятельностью образовательной организации. / In the dissertation, the features of the use of digital services for the management of scientific activities of an educational organization were studied. The possibilities of an architectural approach in the development of a service for the management of scientific activities are considered. The analysis of the current state of scientific activity of the Donetsk National University is carried out. A complete model of the architecture of the State Educational Institution of Higher Education "Donetsk National University" has been built. The digital service "Scientific and information portal" has been developed using the Oracle APEX web-oriented environment. A simulation model of cost management has been developed and implemented when implementing a digital service in the management of scientific activities of an educational organization.

Была рассмотрена инновационная деятельность технологических процессов на угледобывающих предприятиях, построена полная модель архитектуры деятельности угледобывающего предприятия ГП «Шахта Комсомолец Донбасса», отражающая полный анализ деятельности предприятия с теоретической и практической точки зрения данных. Разработана система мониторинга, с помощью использования данной системы диспетчер сможет контролировать отслеживания всех процессов, связанные с образованием метана, которые будут происходить в шахте для своевременного обнаружения большого количества газа на участках и его устранения. Разработана имитационная модель управления угледобывающего предприятия ГП «Шахта Комсомолец Донбасса», позволяющая проводить анализ эффективности предприятия, предопределять результаты других показателей деятельности компании, отражать конечные результаты, а также осуществлять прогноз и планирование на основе различных сценариев. / The innovative activity of technological processes at coal-mining enterprises was considered, a complete model of the architecture of the activity of the coal-mining enterprise SE Komsomolets Donbassa Mine was built, reflecting a complete analysis of the enterprise's activities from a theoretical and practical data point of view. A monitoring system has been developed, using this system, the dispatcher will be able to monitor the tracking of all processes associated with the formation of methane that will occur in the mine for the timely detection of large amounts of gas in the areas and its elimination. A simulation model for the management of a coal mining enterprise SE "Komsomolets Donbassa Mine" has been developed, which makes it possible to analyze the effectiveness of the enterprise, predetermine the results of other indicators of the company's performance, reflect the final results, and also carry out forecasting and planning based on various scenarios.

The recognition of nature in the resolution of societal challenges has been growing in relevance. This recognition has been associated with the development of new concepts from science and policy such as natural capital, ecosystem services, green infrastructure, and more recently Nature-Based Solutions (NBS). NBS intends to address societal challenges in an effective and adaptive form providing economic, social, and environmental benefits. The overall aim of this PhD thesis is to develop an environmental and economic assessment of NBS for highly urbanised territories based on rationales and models underpinning ecosystem services, urban/landscape ecology, and life cycle thinking approaches. This combined evaluation approach would help to better understand if NBS are cost-effective or not. The aim is developed according to four specific objectives. The first objective corresponds to the characterisation of NBS in relation to urban contexts and the problematics that they can help to address or mitigate. To achieve this objective a critical review on the study of the relationship between NBS, ecosystem services (ES) and urban challenges (UC) was developed. As a main output, a graph of plausible cause-effect relationships between NBS, ES and UC is obtained. The graph represents a first step to support sustainable urban planning, moving from problems (i.e. urban challenges) to actions (i.e. NBS) to resolutions (i.e. ES). The second objective corresponds to the definition of an adequate set of biophysical and monetary assessment methods and indicators to evaluate the value of NBS in urbanised contexts. To achieve this objective, a review of existing methods on ecosystem services valuation, life cycle cost analysis and life-cycle assessment are developed. The review takes into account specific constraints such as easiness to use and availability of data. At the end, potential methods and indicators were selected, which will be later integrated in the combined assessment framework. The third objective corresponds to the design of a combined assessment framework integrating methods from life cycle assessment, landscape/urban ecology and ecosystem services that quantifies the environmental and economic value of NBS informing about the cost-effectiveness of its entire life cycle. To achieve this objective, a conceptual framework is developed. From it, a system dynamics model of ecosystem (dis)services is developed and coupled with a life cycle assessment method. The combined evaluation is tested with a relevant NBS type (i.e. urban forest) in a case study in the metropolitan area of Madrid. The fourth objective is the development of a decision support (DSS) tool that integrates the assessment framework as part of iterative design processes in urban planning and landscape design. The DSS intends to enhance the interrelation between science, policy and planning/design. To achieve this objective a user-friendly web-based prototype DSS on NBS, called NBenefit$®, is developed. The prototype DSS provides the user a simple form of quantifying the provision of multiple ES and costs over the entire life cycle (implementation, operational life, and end-of-life) of NBS. This thesis contributed to the characterisation of NBS and its environmental and economic assessment to inform urban planning and landscape design processes, allowing decisions that are more informed. / Il riconoscimento della natura nella risoluzione delle sfide sociali è diventato sempre più importante. Questo riconoscimento è stato associato allo sviluppo di nuovi concetti provenienti dalla scienza e dalla politica, come il capitale naturale, i servizi ecosistemici, le infrastrutture verdi e, più recentemente, le soluzioni basate sulla natura (NBS). NBS intende affrontare le sfide della società in una forma efficace e adattabile fornendo benefici economici, sociali e ambientali. Lo scopo di ricerca di questa tesi di dottorato è quello di sviluppare una valutazione ambientale ed economica delle NBS per territori altamente urbanizzati basata su logiche e modelli che hanno alla base i servizi ecosistemici, l'ecologia urbana e paesaggistica e degli approcci di approcio life cycle. Questo quadro di valutazione combinato aiuterebbe a capire meglio se le NBS sono costo effetive e se contribuiscono a uno sviluppo resiliente e sostenibile. Questo scopo di ricerca è sviluppato secondo quattro obiettivi specifici. Il primo obiettivo corrisponde alla caratterizzazione delle NBS in relazione ai contesti urbani e alle problematiche che possono aiutare ad affrontare o mitigare. Per raggiungere questo obiettivo è stata sviluppata una revisione critica dell letteratura sullo studio della relazione tra NBS, servizi ecosistemici (ES) e sfide urbane (UC). Come risultato principale, si ottiene un grafico delle relazioni causa-effetto plausibili tra NBS, ES ed UC. Il grafico rappresenta un primo passo per supportare la pianificazione urbana sostenibile, passando dai problemi (es. UC) alle azioni (es. NBS) alle risoluzioni (es. ES). Il secondo obiettivo corrisponde alla definizione di un set di metodi e indicatori di valutazione biofisica e monetaria adeguate per valutare il valore della NBS in contesti urbanizzati. Per raggiungere questo obiettivo, viene sviluppata una revisione dei metodi esistenti sulla valutazione dei servizi ecosistemici, l'analisi dei costi del ciclo di vita e la valutazione del ciclo di vita. La revisione tiene conto di vincoli specifici come la facilità d'uso e la disponibilità dei dati. Alla fine, sono stati selezionati potenziali metodi e indicatori, che saranno successivamente integrati nel quadro di valutazione combinato. Il terzo obiettivo corrisponde alla progettazione del quadro di valutazione combinato, integrando metodi di valutazione del ciclo di vita, ecologia paesaggistica / urbana e servizi ecosistemici che quantifica il valore ambientale ed economico della NBS informando sull'efficacia in termini di costi del suo intero ciclo di vita. Per raggiungere questo obiettivo, prima viene sviluppato un quadro concettuale. Da esso, viene sviluppato un modello di dinamica di sistemi per calcolare i servizi (e disservici) ecosistemici, il quale è interrelazionato con un metodo di valutazione life cycle. Questa valutazione combinata viene testata con un tipo di NBS pertinente (foresta urbana) in un caso di studio nell'area metropolitana di Madrid. Il quarto obiettivo è lo sviluppo di uno strumento di supporto decisionale (DSS) che integri il quadro di valutazione come parte dei processi di progettazione iterativa nella pianificazione urbana e nella progettazione del paesaggio. Il DSS intende migliorare l'interrelazione tra scienza, politica e pianificazione / progettazione. Per raggiungere questo obiettivo è stato sviluppato Nbenefit$® un prototipo di DSS online per la valutazzione NBS di facile uso. Il prototipo DSS fornisce all'utente una forma semplice per quantificare multipli ES e costi (internalizatti o no) durante l'intero ciclo di vita (implementazione, vita operativa e fine vita) del NBS. In conclusione, questa tesi ha contribuito alla caratterizzazione di NBS e alla sua valutazione ambientale ed economica per informare i processi di pianificazione urbana e progettazione del paesaggio, consentendo decisioni più informate.

<p dir="ltr">The U.S. food supply chain, particularly the beef industry, faces growing demands for transparency and traceability due to increased consumer awareness of environmental and social impacts. A lack of transparency and access to information, along with misinformation, pose challenges to brand trust and supply chain efficiency. Emerging information technologies like RFID and blockchain are being explored to enhance traceability and information transparency, forming the topic of this dissertation.</p><p dir="ltr">This study aims to understand how the growing demand for transparency in the U.S. beef industry could reshape its supply chain structure and dynamics. It comprehensively examines the potential of information technologies like blockchain to enhance traceability, reduce transaction costs and information asymmetry and shift the supply chain structure to vertical coordination.</p><p dir="ltr">To achieve these objectives, we employed System Dynamics (SD) to model the U.S beef supply chain from 2013 to 2022, leveraging on existing literature and statistical data. This methodology was selected because of its unique ability to capture dynamic complexities and feedback among variables, allowing us to assess market dynamics and evaluate potential changes in the beef supply chain under different information technology scenarios. The model was evaluated through a series of tests and demonstrated its efficacy in simulating and analyzing the dynamics of the beef supply chain.</p><p dir="ltr">We simulated a wide range of key policy initiatives on both supply and demand sides of the beef supply chain. Our findings reveal that blockchain adoption is influenced by various factors such as market dynamics, consumer preferences, and existing power imbalances within the supply chain. Scenario analyses suggest that larger firms may be less incentivized to adopt blockchain if the market isn't ready for transparency, due to high implementation costs. Conversely, smaller firms could benefit from reduced transaction costs. Also, our results show an increased willingness to pay for transparent beef boosts the market for smaller firms and raises beef prices. Regulatory intervention may be necessary to balance the power dynamic within the supply chain, especially considering the market power held by packers.</p><p dir="ltr">This study fills existing knowledge gaps and provides valuable insights for beef supply chain stakeholders. It organizes complex data into clear, communicable causal loop diagrams and then introduces a comprehensive U.S. beef supply stock-and-flow diagram, grounded in literature, data, and trends. Finally, by synthesizing complex data and providing practical tools for decision-making, this research offers a foundation for future studies and policy recommendations in the field of supply chain transparency.</p>