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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.
71

Méthode d’optimisation de procédés hybride associant une analyse thermodynamique et des méthodes algorithmiques / Process optimisation method based on a hybridation between thermodynamic analysis and algorithmic methods

Thibault, Fabien 22 October 2014 (has links)
La méthode du Pincement a été développée et utilisée dans le secteur de la pétrochimie. Le nombre de flux y est important et la consommation énergétique est un critère décisionnel fort. D'autres secteurs énergivores tels la métallurgie, la production de papier et de pâte à papier ou l'industrie agroalimentaire peuvent bénéficier de cette approche structurée. Par ailleurs, l'intégration d'utilités thermodynamiques complexes comme les pompes à chaleur ou les unités de cogénération peut réduire significativement la consommation d'énergie d'un procédé, sans avoir à en modifier la technologie.Un algorithme de conception d'un réseau d'échangeurs à partir de flux thermiques à été choisi dans la littérature, puis deux fonctionnalités lui ont été ajoutées : la différenciation des technologies d'échangeur et la prise en compte de flux "disponibilités" à température de sortie variable. Un module de présélection a été développé pour proposer et dimensionner des utilités thermodynamiques à partir de la grande courbe composite et d'un critère exergétique. Il est utilisé en amont de la conception du réseau d'échangeurs.Ces deux algorithmes ont été intégrés dans un logiciel dédié à l'intégration énergétique de procédés à partir des flux thermiques des opérations unitaires. Plusieurs validations ont été faites sur des cas théoriques de référence issus de la littérature ainsi que sur des cas industriels réels nécessitant la modélisation des procédés. L'enchainement des deux algorithmes débouche sur l'obtention de résultats concrets et technologiquement réalistes. L'amélioration apportée par les solutions est calculable à chaque étape. / The pinch analysis has been developed and exploited in the petrochemical sector. There are numerous heat fluxes and energy consumption is a strong decision criterion. Other energy-intensive sectors such as metallurgy, pulp and paper and food & drink industry can benefit from this systemic approach. Moreover, integration of complex thermodynamic utilities such heat pumps or Combined Heat and Power units can significantly reduce the energy consumption of a process, without having to interfere with the process technology.An algorithm for heat exchangers network design from heat fluxes was chosen in the literature and two features were added to it: Ability to pick different heat exchanger technology and creation of "availabilities" heat fluxes whose outlet temperature is variable. Preselection tool has been developed from grand composite curve and exergetic criterion to propose and pre-size thermodynamics utilities. It is used upstream of the heat exchangers network design step.These two algorithms have been integrated into a software for energy integration of process unit operations heat fluxes. Several validations were made on study cases from the literature as well as on industrial cases which require process modelling. The both algorithms sequence allows achieving practical and technologically feasible results. Improvement on energy consumption provided by the solutions can be calculated at each step.
72

Řízení změn IS v prostředí internetových obchodů / Change management for e-commerce IS

Brtník, David January 2009 (has links)
This thesis is an useful resource for small-sized and medium-sized companies struggling with the problem of out-dated information systems. Every rapidly-growing company will, sooner or later, reach a point where its information system no longer suits its requirements. In the thesis I analyze the case of a small outfit trying to expand to foreign markets, showing the uneven development of the individual parts of its information system. In this particular case, rapid partial changes in the functionality of the system were always preferred over a more systematic and thorough development. Eventually, the company found itself in a situation where it was no longer possible to further develop its system, and did not know what to do next. In accordance with the primary goal of improving the effectiveness of distribution processes, the thesis describes the project of unification of two different e-commerce solutions and their integration into other applications. In the second part, the thesis discusses the problem of choosing a suitable application that would bring all optimized distribution processes under one umbrella, describing various ways how to approach the problem.
73

Product Design Process Optimization at Small Business / Optimalizace procesu návrhu produktu v malé firmě

Jerkovič, Martin January 2013 (has links)
Thesis deals with design process optimization at Chute Corporation -- american startup that provides SaaS solutions for discovery, gathering, managing, publishing and analysis of multimedial user-generated content from social networks. The goal is to identify and analyze the processes, roles and tools of product design and propose an optimization. Thesis has two parts. First part describes the theoretical background for later application. Mainly a brief history of IT product design, design taxonomy and design workflow best practices are described. The other part provides a brief description of the company, especially its position on the market, business model, organizational structure, product portfolio, position of product team and also identifies the main processes, roles and tools that surround product design. The final part describes all optimized processes, roles and tools and summarizes all the facts as a set of recommendations. Thesis provides an overview of product design in the dynamic and complex world of startups. The specific recommendations and templates of optimized processes and tools enable immediate implementation into a company of a similar nature.
74

Integrated Business Planning / Integrované podnikové plánování

Jurečka, Peter January 2009 (has links)
Increasing competitive pressures on most markets force companies to continuously review the effectiveness and efficiencies of their operations. Traditional approach to business planning is becoming insufficient to cope with growing requirements on operational excellence. Concept of Integrated Business Planning (IBP) -- constituting the latest development stage of well-known Sales and Operations Planning (S&OP) -- is proposed as the right response on how to master the challenges of globalized economy in this field. The thesis combines theoretical analysis of inefficiencies of traditional S&OP with applied research realized on the case from real business environment. Microeconomic optimization models are employed to demonstrate the sub-optimal outcomes resulting from the lack of cross-functional integration and potentially antagonistic incentives in business planning. Overview of latest best practices in this area further complements the theoretical part of the thesis. Empirical part of the study summarizes author's experience from leading the large scale implementation of IBP concept in the multinational company. Theoretical assumptions of financial benefits of IBP implementation are tested against empirical observations via usage of statistical apparatus. This part may also be viewed as detailed guideline describing the project of IBP implementation. As a result, integrated approach to business planning proves to bring measurable financial as well as non-financial improvements for the company.
75

Změny procesů přijaté za účelem dosažení cílů finančního plánu 2015 -- 2017 společnosti prodávající úvěrové produkty / Optimization of selected business processes

Tupý, Marek January 2015 (has links)
The subject of my thesis is the optimization of selected business processes in the specific company. These are processes, which optimization will lead to save time, money and will generate additional income and increase the current level of profit significantly. In my thesis, I proposed several indicators of metrics and describe new information systems that will be part of optimized processes. In the first part I present the theoretical aspects and the transition from functional to process management, modeling based on different methodologies, standards and measuring the performance of individual processes. In the next chapter I am dealing with the practical application of theoretical knowledge on a specific company. First I briefly introduce this company, define its position in the market, and going through complex of strategic analysis. Next I give solution how to find out the problematic aspects of the most critical processes and then I suggest optimization. An important part of this thesis are suggested metrics and indicators for these metrics, which are monitored and evaluate targets of each individual process and thus his successful implementation. After incorporating the proposed optimization, the company has significantly shifted not only in monitored metrics, but will also increase its value. These ideas I will summarize in the end of the work.
76

Efeito do ácido lático adicionado sobre a produção de etanol em fermentações com reutilização de células a 34ºC. / Effects of the lactic acid added on ethanol production on fermentations with cell reuse at 34ºC.

Karen Fernanda de Oliveira 12 December 2008 (has links)
O ácido lático produzido por bactérias láticas constitui um sério problema nas fermentações industriais. Por este motivo, os efeitos deste ácido adicionado sobre a produção de etanol por levedura em meio sintético foi estudado no presente trabalho. Assim, foi possível evitar a interferências de um processo contendo uma cultura mista de bactérias láticas e levedura. Além disto, o meio sintético foi utilizado a fim de evitar as variações na composição da matéria-prima, no caso o melaço de cana-de-açúcar, durante a estocagem por um longo período de tempo. Inicialmente, dois planejamentos fatoriais foram realizados em batelada simples. Após a validação deste sistema, uma produção máxima de etanol (72,1 g.L-1) e uma boa retenção de viabilidade celular (86,4%) foram conseguidas utilizando-se inóculo bastante alto (40 g.L-1, massa seca) numa fermentação contendo 200 g.L-1 de sacarose inicial. Nestas condições, experimentos em batelada simples em mini-reatores foram realizados operando a 34 °C e em presença de 0 a 1,0 g.L-1 de ácido lático. Neste experimento, o pH do meio tornou-se bastante baixo (2,3 a 2,7). Por este motivo, outra fermentação em batelada simples foi realizada com o reajuste do pH inicial para 4,5 logo após adição de todos os componentes ao reator. O reajuste do pH inicial causou um aumento significativo tanto na produtividade e na velocidade específica máxima de etanol quanto na viabilidade final na batelada simples. Depois disto, comparações da batelada simples com a batelada alimentada continuamente e por pulsos também foram realizadas em presença de ácido lático. Observou-se que o processo de batelada com alimentação contínua consumiu açúcar mais lentamente, apresentou maior perda em viabilidade e maior produção de biomassa que a batelada simples enquanto que o processo de batelada alimentada por pulsos foi bem semelhante. A elevação da concentração do ácido lático (2,0 g.L-1 a 4,0 g.L-1) nos reatores permitiu a tamponagem do meio sintético logo após o reajuste inicial de pH para 4,5. Nestas condições, também houve semelhança entre os processos de batelada simples e batelada alimentada por pulsos. Em batelada alimentada por pulsos, verificou-se que a diminuição da quantidade de inóculo levou a perdas de viabilidade celular por causa do aumento do ácido externo em relação à quantidade de células no reator. De uma maneira geral, a presença de ácido lático causou aumentos no consumo de açúcar em todos os processos. Fermentações sucessivas foram realizadas, adicionado 3 pulsos de sacarose e 2,0 g.L-1 de ácido lático (em relação ao volume final do meio), a levedura 63M passou por um processo de adaptação até o terceiro ciclo. Além disto, houve uma redução na proteína intracelular final e um aumento na acidez total em presença ácido lático. No entanto, a produção de glicerol e a produção de trealose aumentaram e foram semelhantes tanto em presença quanto em ausência de pulsos de ácido lático. / Lactic acid produced by lactic bacteria is a problem serious in fermentation alcohol plants. For this reason, the effects of this added acid on ethanol by yeast in synthetic medium were studied in the present work. Thus, it was possible to avoiding interferences of a process containing a miscellaneous culture of lactic bacteria and yeast. Besides, synthetic medium was used to avoiding variations in raw material, sugar-cane molasses in this case, during the storage by a large period of time. Initially, two factorial planning were used in simple batch under agitation. After validation of these plannings, maximal ethanol production (72.1 g.L-1) with well retention of viability (86,4%) were obtained using high inoculum size (40 g.L-1, dry weight) in fermentation containing 200 g.L-1 initial sucrose. In these conditions, fermentations in simples batch in mini-reactors were carried out at 34 °C and in presence of 0 to 1,0 g.L-1 added lactic acid. In this experiment, the medium pH became very small (2.3 to 2.7). For this reason, another fermentation in simple batch was realized with initial pH readjusted for 4,5 after addition of all of medium compounds in the reactor. The readjusted of initial pH caused a significative increase as in productivity and maximal-specific rate of ethanol as in final viability in simple batch process. After this, comparisons among simple batch and continuous-fed batch and pulses-fed batch were made in the presence of lactic acid. In these experiments, continuous-fed batch process showed sugar uptake more slowly, showed more drops in viability and more biomass production than simple batch process, while the pulses-fed batch was similar than simple batch process. In addition, the elevation of lactic acid concentration for 2,0 g.L-1 to 4,0 g.L-1 in the reactors permitted the pH maintenance of synthetic medium after initial pH readjusted for 4,5. In these conditions, the simple batch and pulses-fed batch processes also were similar. In pulses-fed batch culture, the decrease of inoculum size caused drops in viability because of the increase of endogenous acid in relation to cell quantity in the reactor. Generally, the presence of lactic acid causes increases in sugar uptake in all of process. Fermentations with cell reuse were carried out in fed batch process with pulses of sucrose and 2,0 g.L-1 lactic acid (in relation to final medium volume), yeast 63M undertook to adaptation process until the third fermentation cycle. In adittion, a decrease of final intracellular protein and an increase of total acidity in presence of lactic acid. However, glycerol and trehalose productions increased with the fermentative cycles and were similar as in presence as in absence of added lactic acid.
77

Analýza opotřebení nástrojů při CNC obrábění diskovitých součástí / Wear of cutting tools at CNC production of the disc-shaped parts

Malý, Michal January 2019 (has links)
This diploma thesis evaluates two competitive cutting inserts for machining of disk-shaped blanks. The first part summarizes theoretical knowledge of turning, wear of cutting inserts and cost analysis of the cutting process. In the second part, the wear of two inserts from a different manufacturer is observed in two different cutting speeds. Wear is evaluated by electron microscope images. In the end, there is an economic evaluation of both VBD in different cutting speeds for serial production.
78

Návrh plánování a řízení projektu v softwarové společnosti / Design of a Project Planning and Management in the Software Company

Čtvrtlík, Miroslav January 2013 (has links)
The thesis is focused on analysis and optimization of processes in a company realizing software projects. Its aim is to find deficiencies in the process of realization of an individual customer requirement and to design improvements. According to the analysis of the process of requirement realization, the deficiencies were analysed from which the most important were selected and used for designing optimization of this process.
79

Optimalizace výrobního procesu / Production process optimization

Hejzlar, Aleš January 2008 (has links)
This diploma thesis deals with the production process optimization. The cutting operation and the lathe-turning issue is described in this thesis. In the practical part the production process is analyzed, the designed experiment (DOE) is suggested and evaluated. In the end of the practical part there is the evaluation of the machined material in the light of microstructure. On the basis of the partial findings the enclosures are done and the recommendations leading to the production optimization are suggested.
80

Beitrag zur Qualitätssicherung in Gießereien durch die Anwendung statistischer Methoden

Strehle, Matthias 15 November 2012 (has links)
Es werden die Voraussetzungen für die Anwendung statistischer Methoden in Seriengießereien dargestellt. Dazu wurde zunächst anhand einer umfangreichen Literaturrecherche aufgezeigt, dass der Stand der Technik deutliche Defizite aufweist. Für die Verwendung statistischer Methoden, mit dem Ziel der Ausschussreduktion oder Prozessoptimierung, ist eine Datenbank anzulegen, in der jedem Gussteil eindeutig alle qualitätsrelevanten Prozessparameter zugeordnet sind. In Gießereien werden eine Vielzahl von Prozessdaten gemessen und auf unterschiedlichen Computern gespeichert, jedoch ohne Zusammenhang zum Gussteil und dessen Qualität. Eine Zusammenführung der ungenutzten Daten im Nachhinein ist nicht möglich. Die Stoffströme (Sande, Kerne etc.) wurden vom Rohmaterial bis hin zur Gussteilqualität verfolgt (z. B. mit RFID, Infrarotpyrometer). Es wurde ein Ablaufplan über die Vorgehensweise erstellt und in mehreren Gießereien angewandt. Das Ergebnis war eine vollständige Datenbank der Prozessparameter und Gussteilqualitäten, an der mittels statistischer Methoden die Ursachen für Gussfehler identifiziert worden sind.

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