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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.
61

Μελέτη και υλοποίηση στρατηγικής διαχείρισης ενέργειας για τη βελτιωμένη οικονομική λειτουργία υβριδικού οχήματος με χρήση ψηφιακού μικροελεγκτή

Άννινος, Παναγιώτης 19 January 2010 (has links)
Στόχος της παρούσας διπλωματικής εργασίας ήταν η μελέτη και η υλοποίηση στρατηγικής διαχείρισης ενέργειας για τη βελτιωμένη οικονομική λειτουργία υβριδικού οχήματος με χρήση ψηφιακού μικροελεγκτή. Η προτεινόμενη στρατηγική, η οποία βασίζει τη λειτουργία της στην αρχή της ασαφούς λογικής αναπτύχθηκε και αρχικά δοκιμάστηκε, χρησιμοποιώντας το πρόγραμμα Matlab/Simulink. Για την επιβεβαίωση της ορθής λειτουργίας του συνολικού συστήματος αποτελούμενου από το ηλεκτρικό κινητήριο σύστημα, τη μηχανή εσωτερικής καύσης και το σύστημα διαχείρισης της ενέργειας, δημιουργήθηκε ένα μαθηματικό μοντέλο ενός υβριδικού οχήματος παράλληλης διάταξης, επίσης στο περιβάλλον Simulink,στο οποίο η διαχείριση της ενέργειας γίνεται μέσω του ανεπτυχθέντος ασαφούς ελεγκτή. Στόχος ήταν να ελεγχθεί η συμπεριφορά του ελεγκτή αυτού. Τέλος, κατασκευάστηκε το κύκλωμα υλοποίησης του ασαφούς ελεγκτή, χρησιμοποιώντας τον ψηφιακό μικροελεγκτή dsPIC30f4011 της εταιρίας Microchip. Για την υλοποίηση της λειτουργίας του ελεγκτή, αναπτύχθηκε ο αντίστοιχος κώδικας σε γλώσσα C, η λειτουργία του οποίου επιβεβαιώθηκε πειραματικά. / The objective of this master thesis was the study and the implementation of an energy management strategy, aiming for improved economic operation of hybrid vehicle using a digital microcontroller. The proposed strategy, based on the principles of fuzzy logic, was developed and initially tested using the environment Matlab/Simulink. To ascertain the correct operation of the system constituted by the electric motive system, the internal combustion machine and the energy management system, a mathematic model of hybrid vehicle of parallel provision was also created in Simulink. The energy management is implemented by the fuzzy controller. The main objective was to test the behavior of this controller. Finally, the electronic circuit of the fuzzy controller was manufactured. The digital microcontroller dsPIC30f4011 (Microchip company) was used. For the implementation of the operation of the controller, the corresponding code was developed in C language, the operation of which was experimentally confirmed.
62

Optimal energy management strategy for a fuel cell hybrid electric vehicle

Fletcher, Thomas P. January 2017 (has links)
The Energy Management Strategy (EMS) has a huge effect on the performance of any hybrid vehicle because it determines the operating point of almost every component associated with the powertrain. This means that its optimisation is an incredibly complex task which must consider a number of objectives including the fuel consumption, drive-ability, component degradation and straight-line performance. The EMS is of particular importance for Fuel Cell Hybrid Electric Vehicles (FCHEVs), not only to minimise the fuel consumption, but also to reduce the electrical stress on the fuel cell and maximise its useful lifetime. This is because the durability and cost of the fuel cell stack is one of the major obstacles preventing FCHEVs from being competitive with conventional vehicles. In this work, a novel EMS is developed, specifcally for Fuel Cell Hybrid Electric Vehicles (FCHEVs), which considers not only the fuel consumption, but also the degradation of the fuel cell in order to optimise the overall running cost of the vehicle. This work is believed to be the first of its kind to quantify effect of decisions made by the EMS on the fuel cell degradation, inclusive of multiple causes of voltage degradation. The performance of this new strategy is compared in simulation to a recent strategy from the literature designed solely to optimise the fuel consumption. It is found that the inclusion of the degradation metrics results in a 20% increase in fuel cell lifetime for only a 3.7% increase in the fuel consumption, meaning that the overall running cost is reduced by 9%. In addition to direct implementation on board a vehicle, this technique for optimising the degradation alongside the fuel consumption also allows alternative vehicle designs to be compared in an unbiased way. In order to demonstrate this, the novel optimisation technique is subsequently used to compare alternative system designs in order to identify the optimal economic sizing of the fuel cell and battery pack. It is found that the overall running cost can be minimised by using the smallest possible fuel cell stack that will satisfy the average power requirement of the duty cycle, and by using an oversized battery pack to maximise the fuel cell effciency and minimise the transient loading on the stack. This research was undertaken at Loughborough University as part of the Doctoral Training Centre (DTC) in Hydrogen, Fuel Cells and Their Applications in collaboration with the University of Birmingham and Nottingham University and with sponsorship from HORIBA-MIRA (Nuneaton, UK). A Microcab H4 test vehicle has been made available for use in testing for this research which was previously used for approximately 2 years at the University of Birmingham. The Microcab H4 is a small campus based vehicle designed for passenger transport and mail delivery at low speeds as seen on a university campus. It has a top speed of approximately 30mph, and is fitted with a 1.2kW fuel cell and a 2kWh battery pack.
63

Power Management Strategy of a Fuel Cell Hybrid Electric Vehicle with Integrated Ultra-Capacitor with Driving Pattern Recognition

January 2017 (has links)
abstract: The greenhouse gases in the atmosphere have reached a highest level due to high number of vehicles. A Fuel Cell Hybrid Electric Vehicle (FCHEV) has zero greenhouse gas emissions compared to conventional ICE vehicles or Hybrid Electric Vehicles and hence is a better alternative. All Electric Vehicle (AEVs) have longer charging time which is unfavorable. A fully charged battery gives less range compared to a FCHEV with a full hydrogen tank. So FCHEV has an advantage of a quick fuel up and more mileage than AEVs. A Proton Electron Membrane Fuel Cell (PEMFC) is the commonly used kind of fuel cell vehicles but it possesses slow current dynamics and hence not suitable to be the sole power source in a vehicle. Therefore, improving the transient power capabilities of fuel cell to satisfy the road load demand is critical. This research studies integration of Ultra-Capacitor (UC) to FCHEV. The objective is to analyze the effect of integrating UCs on the transient response of FCHEV powertrain. UCs has higher power density which can overcome slow dynamics of fuel cell. A power management strategy utilizing peak power shaving strategy is implemented. The goal is to decrease power load on batteries and operate fuel cell stack in it’s most efficient region. Complete model to simulate the physical behavior of UC-Integrated FCHEV (UC-FCHEV) is developed using Matlab/SIMULINK. The fuel cell polarization curve is utilized to devise operating points of the fuel cell to maintain its operation at most efficient region. Results show reduction of hydrogen consumption in aggressive US06 drive cycle from 0.29 kg per drive cycle to 0.12 kg. The maximum charge/discharge battery current was reduced from 286 amperes to 110 amperes in US06 drive cycle. Results for the FUDS drive cycle show a reduction in fuel consumption from 0.18 kg to 0.05 kg in one drive cycle. This reduction in current increases the life of the battery since its protected from overcurrent. The SOC profile of the battery also shows that the battery is not discharged to its minimum threshold which increasing the health of the battery based on number of charge/discharge cycles. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2017
64

ANÁLISE DA GESTÃO ESTRATÉGICA NAS UNIDADES RURAIS AGRÍCOLAS COM SISTEMA DE IRRIGAÇÃO POR PIVÔ CENTRAL DO MUNICÍPIO DE ORIZONA-GO / ANALYSIS OF STRATEGIC MANAGEMENT UNITS RURAL AGRICULTURAL IRRIGATION SYSTEM FOR PIVOT CENTRAL MUNICIPAL ORIZONIA-GO

TEIXEIRA, Luciana de Gois Aquino 11 March 2009 (has links)
Made available in DSpace on 2014-07-29T14:49:12Z (GMT). No. of bitstreams: 1 Dissertacao Luciana Gois .pdf: 1414281 bytes, checksum: 392042ee40ce53cfe3030b20d847d1d9 (MD5) Previous issue date: 2009-03-11 / This research raised the peculiarities in the strategic management of rural agricultural units that are based on the production irrigated by center pivot. Aimed to understand the main difficulties and potentials involved in the management of rural enterprise, raise difficulties for the adoption of strategic management in production, competitive scenario specify the units of irrigated agricultural production by central pivot the city of Orizona-GO, and finally , develop guidelines for the management of this strategic sector. The data collection instrument was the interview. The subjects of research were the landowners of the properties selected for this study. Concluded that strategic management in the units is important for rural development and improved performance properties, is essential for establishing a competitive position in the agribusiness market. / Esta pesquisa levantou as peculiaridades no processo de gestão estratégica das unidades rurais agrícolas que têm como base a produção irrigada por pivô central. Objetivou compreender as principais dificuldades e potencialidades que interferem na gestão da empresa rural, levantar as dificuldades para adoção da gestão estratégica nas unidades de produção, especificar cenário competitivo das unidades de produção agrícola irrigadas por pivô central da cidade de Orizona- GO e, por fim, elaborar orientações para a gestão estratégica deste setor. O instrumento de coleta de dados foi a entrevista. Os sujeitos de pesquisa foram os proprietários rurais das unidades selecionados para este estudo. Concluiu-se que a gestão estratégica nas unidades rurais é importante para o desenvolvimento e melhor desempenho das propriedades, sendo essencial para o estabelecimento de uma posição competitiva no mercado do agronegócio.
65

The role of management in the turnaround process

Roberts, Ian January 2015 (has links)
This thesis is entitled The Role of Management in the Turnaround Process and is presented for the degree of Doctor of Business Administration at the University of Manchester by Ian Roberts in April 2015. Inquiry into turnaround has largely has been carried forward in two broad areas of study: strategy and management. Strategy research has attempted to identify a single or limited number of strategies which apply in all turnaround situations, while management studies have concentrated on managers themselves or some of the techniques they employ. Neither school has systematically analysed how turnarounds are actually implemented in dysfunctional organisations and both schools are weak in extant theory. As a consequence, a holistic explanation of the process leading from crisis to viability is lacking. This thesis addresses these lacunae in three ways. Firstly, it provides a systematic study of how professional turnaround managers implement the turnaround process over time. Secondly, it applies a unique and complementary mix of extant theory which addresses both cognitive and organisational aspects of strategy formulation and implementation. Thirdly, it presents a holistic turnaround model based on six core constructs which are argued to be necessary and sufficient to explain the dynamics of the turnaround process. The thesis adopts a mixed-methods approach. A survey is used in order to gather data from turnaround professionals on implementation methods. This data is then subjected to statistical analysis in order to identify the most important factors for implementation. These concepts are then blended into a conceptual framework which is tested for its explanatory and predictive power on a matched pair of turnaround case studies of two mid-sized UK manufacturing companies in the household goods sector, one of which executed a successful turnaround and one of which failed in the attempt. The model is able to explain and predict the outcome in both cases. The thesis is one of only a handful of turnaround studies which employs a rigorous case study research protocol. Its principal contribution is that of a middle range turnaround theory of the causal factors leading from organisational crisis to dissolution or viability.
66

Aplikace Balanced Scorecard

Šimčíková, Eva January 2009 (has links)
Diplomová práce na téma Aplikace Balanced Scorecard se zabývá vytvořením systému měření a řízení výkonnosti samostatného podnikatele. Teoretická část je zaměřena na popis metody, jednotlivých perspektiv a vzájemných souvislostí. Praktická část se věnuje analýze dosavadní činnosti podnikatele a rozboru současné situace na trhu. V návaznosti na výsledky analýzy je vytvořen systém strategických cílů a měřítek, který je následně vyobrazen prostřednictvím strategické mapy.
67

Řízení vztahu se zákazníky / Customer Relationship Management

Otčenášková, Petra January 2015 (has links)
The Master's Thesis deals with Customer Relationship Management. The aim is to describe and analyze the CRM in a particular company and make suggestions for improvement. The Master's Thesis is divided into two parts, theoretical and practical. The theoretical part explains the theoretical knowledge of CRM. In the practical part is described and analyzed the mode of operation of the company T-Mobile with a focus on CRM. Theoretical basis is based on the available literature and other information sources. The practical part is based on interview with the company employee, customers and internal documents of the company.
68

Conflict in architectural projects : diagnosis and avoidance : a study based on Saudi Arabian construction industry

Alshehri, Abdullah Mohammed January 2013 (has links)
The main purpose of this research project was to bridge the existing knowledge gap inthe empirical identification and understanding of how conflict occurs between keyproject parties within Saudi Arabia’s public sector building projects. Such conflict hasbecome an increasingly endemic feature within the last 20 years, and this researchproject provides a contribution in knowledge terms which will help to overcome theobstacles and challenges impeding growth and development in the field. This wasachieved by conducting an investigation to provide the theoretical background aboutthe antecedents of conflict, and presenting a number of project management suggestions to avoid or minimise.Both qualitative and quantitative research approaches were utilised in this study. Thequalitative research data was obtained from 30 in-depth semi-structured interviewswith four types of key project party, namely, project owners, consultants, contractors,and sub-contractors. This was followed by two separate questionnaire surveys. The firstwas a means of validating conflict data obtained from the interviews, and the secondwas used to test Project Management - PM data, . In this part of the study, 672questionnaires were sent to various people engaged in the Saudi Arabian constructionindustry. The response rate was 46.1% (n = 310 ).In terms of the interview data, a total of 349 data items were derived and from these data items, 30 general themes emerged concerning various causes of conflict and the latent conditions of conflict, providing descriptions of what and how conflicts arise within Saudi Arabian public building projects. From these general themes, 31 recommendations for strategic project management processes are made, with the intention of preventing or at least minimising conflict. The quantitative survey conducted to test these project management strategies (recommendations) revealed that all of them were supported. The study subsequently produced a cyclical framework of conflict avoidance, derived from the research methodology used in the study, and this is outlined to enable project building participants, whether individuals, groups, or organisations, to improve their project management strategy from project to project.The research recommends that: generally, certain project management strategiesshould be implemented in the earlier phases of a project in order to promote conflictavoidance behaviours or at least to effect a reduction in these. Furthermore, strategicactions are required to deal with the latent condition-related issues in respect of building projects in the Saudi Arabian context. In this case, reforms to current practices are required to improve the performance within the building industry. It is also recommended that further research be undertaken to explore other latent conditions of conflict and conflicts themselves in order to develop additional project management strategies aimed at managing the causes of conflict.
69

Strategické podnikatelské aktivity vybraného podniku / Strategic business development of a company

Žďárská, Kristýna January 2012 (has links)
The subject of this thesis is to determine a business strategy, that will allow the company Farmet a.s. to increase its sales and to strengthen the position on the markets. The theoretical part describes methods and procedures that are further being referred to in the main part. The main part consists of the internal and the external environment analysis, as well as the SWOT analysis. Based on the actual accounting data and with regards to the current company position, there are several proposed strategies of possible business development. These strategic options are evaluated in terms of their individual profitability and risk. The final part of this thesis determines the optimum strategy and describes its implementation in more detail.
70

Intégration de diverses conditions de fonctionnement dans l'identification en temps réel et la gestion énergétique d'un véhicule à pile à combustible = Integrating various operating conditions into real-time identification and energy management of a fuel cell vehicle

Kandidayeni, Mohsen January 2020 (has links) (PDF)
No description available.

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