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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Participation de parcs de production éolienne au réglage de la tension et de la puissance réactive dans les réseaux électriques / Wind farms participation at voltage and reactive power regulation in the power system network

Ahmidi, Amir 16 December 2010 (has links)
Nous proposons dans cette thèse, différents outils de réglage de tension et de gestion de la puissance réactive en fonction des conditions de raccordement des éoliennes au réseau électrique. Trois cas figure sont étudiés : raccordement direct sur un poste source de distribution, raccordement des éoliennes réparties dans un réseau de distribution et raccordement d’un ensemble de parcs éoliens au réseau de transport.Un algorithme de réglage basé sur l’asservissement de la puissance réactive est proposé pour le raccordement direct d'un parc sur un poste source. Un réglage coordonné de tension en présence de régleur en charge est proposé (D-RCT) pour le raccordement des éoliennes reparties dans un réseau de distribution. On propose aussi une version plus décentralisée du réglage coordonné (D2-RCT) qui pourrait être implantée sous forme de système multi-agents intelligents (SMA). Un system de control multi-niveaux est proposé pour le raccordement d’un ensemble de parcs éoliens au réseau de transport. Il permet de répondre de manière optimale à une demande puissance réactive envoyée par le gestionnaire du réseau de transport. Les différents types de réglages proposés sont basés sur des algorithmes d’optimisation multi-objectifs. Afin de valider en temps réel le bon fonctionnement des stratégies de réglages développées ainsi que leurs modes de communication, une implantation expérimentale sous simulateur temps réel RT-Lab a été effectuée. Enfin, les résultats des simulations montrent l’amélioration de l’intégration de la production décentralisée dans les réseaux électriques / In this PhD dissertation, we propose various voltage and reactive power regulation algorithms for different connection types of the wind farm to the power network. Three connection types are considered here: a wind farm connected directly to the distribution network, dispersed wind turbines connected to the distribution network and a set of wind farms connected to the transmission system.A closed loop controller (Wind Farm Controller) is proposed in case of a directly connected wind farm to the distribution network.A coordinated voltage control in the presence of on load tap changer (D-CVC) is proposed in case of dispersed wind turbines connected to the distribution network. We also propose a more decentralized version of D-CVC named D2-CVC; this version can be also implemented under multi-agent system (MAS).A multi-level control system is proposed in case of a set of wind farms connected to the transmission system. It allows the wind farms to optimally participate at reactive power balancing in transmission network. All the proposed voltage algorithms are based on a multi-objective optimization function. The experimental implementation of these regulation algorithms is run under RT-Lab real-time simulator. It allows validating their real-time operation and their communication modes before the implementation on a real site.The results of the current thesis show the improvement of distributed generation integration in the power system network
122

Posun k servisně orientované ekonomice a jeho dopad na strategii firmy / Shift to Service-Oriented Economy and Its Impact on Corporate Strategy

Šmerda, Jiří January 2008 (has links)
Práce představuje v širším kontextu paradigmata servisně orientované ekonomiky a ukazuje jejich vliv na podnikové a firemní strategie. Pokouší se dát dohromady tradiční modely podnikových a firemních strategií s nově vznikající vědou o službách. Práce ukazuje hlavní myšlenky servisně orientované ekonomiky v porovnání s tradiční produktovou ekonomikou. Jako výsledek srovnání práce poukazuje na potřebu nového přístupu k byznysu, který vychází z aktuálního dění ve světě. Práce přináší sadu doporučení pro formulace podnikových a firemních strategií v servisní ekonomice. V praktické části jsou výsledky demonstrovány a použity pro strategii ve vybrané firmě.
123

Rozvoj služeb z hlediska konkurenceschopnosti / Service Innovation as a Drive for Competitiveness

Kováčová, Petra January 2009 (has links)
Diplomová práce představuje paradigmata servisně orientované ekonomiky z hlediska konkurenceschopnosti firmy. Zaměřuje se na konkurenční výhody, kterých lze dosáhnout nebo podporovat rozvojem služeb. Teoretický základ prezentuje specifika a význam sektoru služeb v současných nejvyspělejších ekonomikách. Jmenuje hlavní konkurenční strategie používané v sektoru služeb a srovnává je se zažitými strategiemi známými z produktově orientované ekonomiky. Práce blíže analyzuje metody rozvoje služeb ve společnosti IBM GSDC Brno v oblasti globalních IT služeb. Pojednává o hlavních problémech spojených s jejich inovací a zároveň naznačuje současné a budoucí trendy v oblasti IT služeb. V praktické návrhové části jsou prezentovány nové přístupy k rozvoji služeb, které by mohly podpořit konkurenceschopnost firmy na globálním trhu služeb.
124

Dopady zavedení web scale discovery systémů v akademických knihovnách / Impact of Web Scale Discovery Services in Academic Libraries

Čejka, Marek January 2016 (has links)
This diploma thesis discusses a modern concept of information retrieval and search engines for libraries and other academic institutions. The concept named "web scale discovery" comprises of search engines, whose main characteristics lie in simplicity and user friendliness for the end users while maintaining all functional qualities of traditional research databases. Users can search in a wide variety of international research databases, and also in local sources of an institution that are combined within a large central index. The theoretical section presents definitions of web scale discovery, which conceptually set the new method of information retrieval within the field of information and library science. A graphic scheme of the basic functionality of a web scale discovery system is presented. Also discussed are requirements for a modern discovery system, an overview of the current situation in the Czech Republic, and a short characteristic of commercially available discovery systems. The theoretical part concludes with a literature review of selected foreign research, studying user satisfaction with the new solution, the impact on electronic and print resources in libraries, and usability testing. The practical part presents an original research study - usability testing of EBSCO Discovery...
125

Encouraging Recycling in Co-living : A Redesigning of Sorting Bins / Underlättning av återvinning i kollektiv bosättning : En ny design av källsorteringskärl

Chan, Eugene, Karuppasamy, Avinash Kumar January 2023 (has links)
There is an inefficiency of waste management in co-living spaces for students, emphasizing the importance of proper waste sorting. A multifaceted research methodology was initiated with a literature review to understand existing waste management solutions and how they work as a system, followed by attribute studies pivotal for co-living spaces. A potential of product-service systems was explored to facilitate collaboration between students and housing companies. Interviews with students and contextual studies further enriched the understanding of waste management practices. These research methods guided the development of innovative waste management solutions tailored to theunique dynamics of co-living spaces. Stakeholders in this endeavor include students, housing companies, municipalities, and waste management organizations. Instilling correct waste sorting habits, saving costs through reduced fines, more efficient waste processing, and streamlining operations. Our design specifications prioritize user-friendliness, adhering to Nordic sign norms, and a positive user experience. The bins feature designated openings, color coding, visual labels, transparency, and sealable dispensing. Collaborative value is enhanced through interactive elements and aesthetic graphics. We introduce a novel solution: specialized sorting bins with integrated behavioral nudges. Our primary goal is to foster a sense of collective responsibility among residents and promote sustainable waste practices. The final design utilizes recyclable materials. Sustainability is further promoted by encouraging bag reuse. The practical application of sustainability is achieved through nudges and educational graphics on the bins, while social cohesion is fostered through interactive placards. In conclusion, our innovative bin solution offers an effective approach to sustainable waste management in co-living and future work may involve adapting the solution to diverse needs and evolving waste management challenges in shared living environments. / Avfallshantering inom kollektiva (co-living) studentmiljöer saknar effektivisering och understryker vikten av korrekt avfallssortering. För att underlätta samarbetet mellan studenter och bostadsföretag undersöktes potentialen av ett produkt-tjänstesystem för utvecklingen av innovativa avfallshanteringslösningar; detta specifikt för den unika dynamiken i kollektiva utrymmen. Denna potential inkluderar intressenter som studenter, bostadsföretag, kommuner och avfallshanteringsorganisationer som kan leda till förbättringar i korrekta avfallssorteringsvanor, och dessutom spara kostnader genom minskade böter, effektivare avfallshantering och effektivisering av verksamheter. Metoderna som utfördes inkluderade en forskning med hjälp av litteratur, intervjuer och kontextuella studier med studenterna i centrum för att förstå de befintliga avfallshanteringslösningarna, de underliggande systemen, en ökad förståelsen av avfallshanteringsmetoder och relevanta egenskaper. Resultatet blev introduktionen av en lösning i form av specialiserade sorteringskärl som utnyttjar sig av puffning (nudging) för att utöka en känsla av kollektivt ansvar bland invånarna samt utförandet av hållbara avfallsmetoder. Vår designspecifikation prioriterar användarvänlighet, en bättre användarupplevelse och efterliknar de nordiska skyltnormerna. Detta uppnås med variation i former efter typer av förpackning, färgkoder, visuella beteckningar, transparens och förslutningsbar dispensering. För att förstärka samarbetsvärdet användes interaktiva element och estetisk grafik. Kärlen är konstruerade av återvinningsbara material och uppmuntrar därefter återanvändning av säckar tillsammans med kärlen. Den praktiska tillämpningen av hållbarhet uppnås genom puffar och grafiska illustrationer på kärlen, medan social sammanhållning främjas genom interaktiva skyltar. Sammanfattningsvis erbjuder vår innovation en lösning för källsortering på ett effektivt tillvägagångssätt för hållbar avfallshantering i kollektiva utrymmen med ett framtida arbete som kan innebära att anpassa lösningen till olika behov och utvecklande av avfallshanteringsutmaningar i delade livsmiljöer.

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