• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 95
  • 35
  • 29
  • 19
  • 6
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 226
  • 35
  • 30
  • 28
  • 28
  • 27
  • 26
  • 25
  • 21
  • 20
  • 19
  • 17
  • 16
  • 16
  • 16
  • 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.
51

Development of Test Equipment for Analysis of Camera Vision Systems Used in Car Industry : Printed Ciruit Board Design and Power Distribution Network Stability

Johansson, Jimmy, Odén, Martin January 2015 (has links)
The main purpose of this thesis was to develop a printed circuit board for Autoliv Electronics AB. This circuit board should be placed in their test equipment to support some of their camera vision systems used in cars. The main task was to combine the existing hardware into one module. To be able to achieve this, the most important factors in designing a printed circuit board was considered. A satisfying power distribution network is the most crucial one. This was accomplished by using decoupling capacitors to achieve low enough impedance for all circuits. Calculations and simulations were executed for all integrated circuits to find the correct size and numbers of capacitors. The impedance of the circuit board was tested with a network analyzer to confirm that the impedance were low enough, which was the case. System functionality was never tested completely, due to delivery problems with some external equipment.
52

New methodologies in solid state NMR

Heindrichs, Axel Stefan Dirk January 2000 (has links)
No description available.
53

MANAGEMENT CONSULTANCIES DISCURSIVE CONSTRUCTION OF WORK-LIFE BALANCE : A DISCOURSE ANALYSIS OF WEB PAGES

Bergqvist, Sofie, Vestin, Mikaela January 2014 (has links)
Academics, practitioners and media agree that the topic of work-life balance is on the agenda and valued by the new business generation. Although Sweden might be considered a working friendly country, the management consultancy industry is not recognized to be the same. With an institutional perspective we will through a discourse analysis investigate the communication on Swedish management consultancies web pages in order to explore how consultancies relate to the work-life balance discourse. In this study we look at work-life balance communication as a continuum with abstract and concrete as two opposites where the level of concreteness will decide the level of responsibility dedicated from the organizations regarding employees` work-life balance. Our findings suggest that the discourse is mostly composed of abstract descriptive talk, which indicates that the communication exists as a legitimizing result of institutional pressures, and might not be an essential matter for the concultancies` everyday practice. A big part of the responsibility to achieve a work-life balance is put upon the individual employee and even though initiatives are presented they are seldom followed up by concrete targets or supported with results.
54

Implementação das técnicas de overhauser e desacoplameto em espectroscopia por RMN / Implementation of overhauser and decoupling techniques bt NMR spectrocopy

Giannoni, Ricardo Alberto 23 May 1991 (has links)
A técnica de dupla ressonância unidimensional para alta resolução em líquidos constitui o objetivo deste trabalho. Para isso construiu-se uma sonda de dupla ressonância, apropriada para experiências heteronucleares do tipo 13C-{1H}. Empregam-se algumas sequências de pulsos para permitir as medidas do EON e do desacoplamento nuclear entre 1H e 13C. Emprega-se o EON com a finalidade de obter um aumento na intensidade do sinal de RMN do 13C; emprega-se o desacoplamento para eliminar a estrutura fina que surge devido ao acoplamento nuclear entre 1H e 13C. Inclui-se uma breve revisão sobre a teoria com a fmalidade de unificar o tratamento desta com as aplicações. As técnicas experimentais são discutidas e alguns espectros são mostrados para ilustrar os principais resultados / The one dimensional double resonance technique for high resolition in liquids is the main purpose of this work. For this we have built a double resonance probe, suitable for heteronuclear 13C-{1H} experiment. Some pulse sequences are employed to allow the NOE and decoupling between 1H e 13C to be measured. The NOE is employed in order to obtain a three-fold enhancement of the 13C NMR signal; decoupling is employed to eliminate the fme structW\'e arising from spin coupling between 1H e 13C. A short review about theory is included to provide unified treatment with applications. The experimental techniques are discussed and some spectra are shown to illustrate the main results.
55

The development of responsible management education in European business schools : responses to the 2013 EQUIS accreditation standards

Falkenstein, Mathias January 2017 (has links)
For the global business school community, the twenty-first century inaugurated a season of introspection. As global sustainability concerns grew in prominence, critical debate about the purpose of business and its role in society could not be left without an educational response. At the same time, however, it raised the question of whether business schools were at all ready to equip their students for leadership in a world faced by crucial economic, social, and environmental challenges. The answer is not self-evidently positive. Various authors grapple with questions on the purpose of business schools and their relationship with business and society. This empirical study examines the influence of EQUIS accreditation standards on business school practices in the areas of institutional strategies, programmes, faculty, research, and development, as well as in responsible management education at large. Although accreditation is not the only factor that determines what business schools believe, do, and become, it is an important shaper of the direction in which they will find their way forward in the face of twenty-first–century management education imperatives. This has especially become the case since the inclusion of ethics, responsibility, and sustainability (ERS) in the revised EQUIS standards. The analysis is drawn from a qualitative multi-case study where the author outlined a theoretical framework by developing an understanding of the organisational responses to EQUIS standards, using interviews and document review as the primary source of information. The case study included private, public, stand-alone, and university-embedded business schools. The findings show that business schools engage in a variety of ERS activities in their research and education portfolio. However, different stakeholder expectations pressure business schools to become more ethical, responsible, and sustainable, which leads to a decoupling of the schools’ “ERS talk” from their “ERS actions”. The decoupling can be seen as the consequence of a school’s translation, editing, and imitation activities in order to appear committed to society’s demands. Despite budget constraints and limited autonomy, public business schools seem to be more engaged in ERS education and research as compared to private institutions. Also, a multidisciplinary environment further supports ERS development as compared to stand-alone business schools. The research proposes core changes and developments that business schools may take into consideration to provide a systematic response to EQUIS ERS standards and criteria.
56

Evapotranspiração, transpiração e trocas gasosas em canavial irrigado / Evapotranspiration, transpiration and gas exchange on irrigated sugarcane crop

Nassif, Daniel Silveira Pinto 05 December 2014 (has links)
As mudanças climáticas globais e a expansão da cultura da cana-de-açúcar para regiões com menor suprimento hídrico elevaram a importância de estimativas consistentes das necessidades de água da cultura. Na tentativa de contribuir nesse campo, o presente trabalho buscou analisar o consumo hídrico da cana-de-açúcar em três diferentes escalas espaciais: folha, planta e dossel, além de uma ferramenta de simulação (DSSAT/CANEGRO) quanto ao seu desempenho na estimativa do consumo hídrico da cana-de-açúcar. Foram realizadas medidas de evapotranspiração do dossel pelo método do balanço de energia-razão de Bowen (MRB) e de transpiração das plantas por meio do balanço de calor nos colmos (BC) e das folhas com um analisador de gás à infravermelho (IRGA). Duas áreas experimentais foram utilizadas, sendo a primeira com a variedade CTC 12, na safra 2011/2012, irrigada por gotejamento subsuperficial; a segunda área com a variedade RB867515, irrigada por aspersão por meio de um pivô central, na safra 2012/2013. O acoplamento planta-atmosfera também foi avaliado. As análises do MRB indicaram um fluxo de calor latente médio de 70% da energia disponível no ambiente, com 25% de fluxo de calor sensível e 5% no fluxo de calor no solo. Com a mesma metodologia a evapotranspiração da cultura média (ETc) foi estimada em 3,92 e 3,25 mm dia-1 para as variedades CTC 12 e RB867515, respectivamente, resultando em um coeficiente de cultura (Kc) médio de 1,37, na fase de pleno desenvolvimento vegetativo. No período experimental, o canavial permaneceu mais acoplado à atmosfera (Ω médio=0,37) e a transpiração avaliada pelo BC chegou a 4,7 e 3,62 mm dia-1, respectivamente para CTC 12 e RB867515. A metodologia do IRGA resultou em perda de água ao nível foliar da faixa de até 1 mm h-1. Conforme a demanda atmosférica, o Kc da cultura apresentou-se variável em função da evapotranspiração de referência (ETo). O modelo DSSAT/CANEGRO mostrou-se eficiente na simulação da ETc e transpiração do canavial, com resultados mais satisfatórios (R2=0,59) quando utiliza-se a metodologia FAO 56 nas simulações. / Global climate change and the sugarcane crop expansion to regions with lower water supply became more important the real estimate of crop water requirements. This study aimed to contribute on this regard by analyzing the sugarcane water consumption at three different spatial scales: leaf, plant and canopy. The DSSAT/CANEGRO crop model was also evaluated with respect to sugarcane transpiration and evapotranspiration. Bowen ratio energy balance (BREB) method was performed to measure crop canopy evapotranspiration and the transpiration were measured with sap flow by stem heat balance for plant scale and infra-red gas analyzer (IRGA) for leaf scale. Two experimental sites were used: the first with CTC 12 cultivar and drip irrigation, on 2011/2012 season; in the second experiment the RB867515 variety was grown under sprinkler irrigation by a central pivot, on the 2012/2013 growing season. The plant-atmosphere decoupling factor was also evaluated. BREB method showed latent heat flux representing 70% of the available energy, 25% for sensible heat flux, and 5% for soil heat flux. BREB crop evapotranspiration (ETc) ranged from 3.92 to 3.25 mm day-1 for CTC 12 and RB867515, respectively, resulting in a mean crop coefficient (Kc) of 1.37 at the full vegetative growth stage. In the experimental period, sugarcane crop was coupled to the atmosphere (Ω=0.37) and transpiration assessed by HB reached 4.7 and 3.62 mm day-1 for CTC 12 and RB867515, respectively. IRGA method showed a leaf water loss up to 1 mm h-1. Kc varied with reference evapotranspiration (ETo) The DSSAT/CANEGRO crop model was efficient in the ETc and transpiration simulation, with better results (R2=0.59) when using FAO 56 ETo method in the simulations.
57

Control of an ultrahigh speed centrifugal compressor for the air management of fuel cell systems / Commande d'un compresseur centrifuge à vitesse ultra-haute pour la gestion de l'air du système de piles à combustible

Zhao, Dongdong 10 December 2013 (has links)
Le compresseur d'air alimentant en oxygène la pile est un élément important dans les systèmes pile à combustible. Le compresseur peut consommer jusqu'à 20% de l'électricité produite dans les cas les plus défavorables. Le choix et le dimensionnement du compresseur, ainsi que son système de contrôle associé, sont directement liés à la performance du système global. La taille et le poids du système de compression d'air doivent être réduits pour le rendre plus adapté aux applications automobiles. En outre, le contrôle du système de compression d'air est également une problématique importante car il affecte l'efficacité et la sécurité de fonctionnement de la pile à combustible. Pour éviter une sous-alimentation en oxygène de la pile, le débit massique d’air fourni doit être géré de façon appropriée en fonction de la demande de la charge électrique. Pendant ce temps, la pression ne doit pas montrer de trop grandes variations ou ondulations qui peuvent endommager la membrane de la pile.Un contrôle à découplage proposé récemment dans la littérature, nommé contrôle à découplage de perturbation (DDC), est utilisé pour le système de compression centrifuge. Le DDC traite les interactions internes comme une perturbation, puis les éliminent dans le contrôle. Les performances du DDC sont comparées à un dispositif de commande en mode glissant décentralisé. Grâce à la comparaison de ces deux contrôleurs, les résultats montrent que le DDC proposé est performant tant pour des cas stables que dynamiques. Le compresseur centrifuge est donc utilisable pour les systèmes pile à combustible automobiles. Sur un banc d'essai hardware-in-the-loop (HIL), le contrôleur proposé est validé avec un modèle de pile à combustible de 10 kW avec des demandes de charge variables. En outre, une méthode d'évitement d’instabilité, à savoir un limiteur de référence, est proposé pour empêcher le dépassement de la ligne de pompage du compresseur. Les résultats expérimentaux montrent que, dans tous les cas, la zone d’utilisation du compresseur est bien cantonnée à droite de la ligne de pompage. / Air compressor supplying the oxygen to the stack is an important component in the fuel cell systems. The compressor can consumes up to 20 % of the generated power in the most severe cases. The selecting of the compressor and corresponding control are directly related to the performance of the fuel cell. The size and weight of the air compressor has to be reduced to make them more feasible for automotive applications. Moreover, the control of the air compression system is also an important issue, which affects the efficiency and the safety of the fuel cell. To avoid oxygen starvation of the stack, the mass flow of the supplied air has to be controlled appropriately according to the load demand. Meanwhile, the pressure should not have large deviations or ripples which may damage the stack membrane.A recently proposed disturbance decoupling control (DDC) is used for the centrifugal compression system. DDC treats the internal interactions as a disturbance and then eliminates them in the control. The performance of the DDC is compared with a decentralized sliding mode controller. Through the comparison of those two controllers, the results show that the proposed DDC performs better in both the steady state and dynamic conditions, making the centrifugal compressor is capable of applying to the fuel cell in automotive applications. On a hardware-in-the-loop (HIL) testbench, the proposed controller is validated with a 10 kW fuel cell model under varied load demands. Moreover, a surge avoidance method, namely reference limiter, is proposed to prevent the compressor from surging. The experimental results show that the operation is restricted to the right of the surge line.
58

Postponement in Retailing Industry: A case study of SIBA

Ahmed, Kemal, Naqvi, Syed Mohammed January 2010 (has links)
Master’s Thesis in Logistics and Supply Chain Management _____________________________________________________ Title:                 Postponement in Retailing Industry- A case study of SIBA Authors:         Ahmed Kemal & Naqvi Syed Mohammad Tutor:               Helgi Valur Fredriksson, Dr. Date:               May, 2010 Key Words:   Speculation, Postponement, Customer Order Decoupling point, Retailing, Supply Chain Flexibility, Agility ______________________________________________________________ Abstract Problem: Today's business environment is characterized by changing customer demands, increasing cost pressures on retailers, shorter product life cycles and products becoming obsolete shortly after their introduction. The above factors make it difficult for electronics retailers to balance the costs of dealing with excessive inventory and not be out of stock. To be competitive, retailers should delay some of their activities until customer demand becomes visible. This brings us to the phenomenon of postponement. Electronics market in Sweden faces continuous growth, although at a declining rate. This is indicative of a saturation that this sector, as a whole, is approaching to. The above problems are due to the speculative approaches and standardized products policies that are in practice. Loss of sales and customers result from these practices. The current study analyses the importance of postponement strategy and the benefits it offers. This study also tries to explore the potential solutions for retailers that postponement may relate to.   Purpose: The scope of this study is to identify possible postponement strategies needed for SIBA. Method: A case study approach has been taken. The choice of the method is qualitative with an inductive approach. This involved personal communications during interviews with the managers of SIBA, using semi structured questions to collect data.   Results: The concepts of postponement, supply chain flexibility, agility and customer order decoupling points (CODP) are closely related to one another and it has been shown that as the depth of postponement increase from right to left in the CODP continuum, the CODP changes its position, moving along the CODP continuum from right to left and towards the upstream. With this movement, the flexibility and agility in the chain increases. Our finds suggest that postponement is rather underutilized and that wastes (by way of lost sales and customers, obsolete inventory costs and storage costs) in the retailing process occur due to speculative approaches in application at the retail level. We have suggested logistics postponement for two out of three product categories and enumerated the ensuing benefits that the retailer can derive by way of enhanced flexibility, agility and reductions in wastages and satisfied customers.
59

The Relation between Lean Manufacturing & Customer's Demand Uncertainty

Abid, Muhammad, Özkan, Senol January 2009 (has links)
Customer Demand Uncertainty is a big obstacle for companies to sustain their competitiveness in the market that responding customer requirements becomes essential. Besides companies need to consider also their cost structures which should have in high consistency to survive as well. Lean and Agile terminologies have been investigated so far in cost and responsiveness to customer manner within internal system perspective i.e. product volume and variety. This thesis aims to link lean manufacturing steps with customer demand uncertainty condition following information systems, marketing issues and human factor for management level in framework that firm’s (manufacturer) current condition can be tested according to answers from questionnaires and implementation of assessment tables since it is used as guideline and provides on which level firms are in demand uncertainty, lean and agile manufacturing. This support enables to firms to create their own flexible leagile decoupling point according to their interior characteristics and capabilities in the market.
60

Postponement, Mass Customization, Modularization and Customer Order Decoupling Point: Building the Model of Relationships

Can, Kemal Caglar January 2008 (has links)
This paper focuses on four interrelated strategies: postponement, mass customization, modularization and customer order decoupling point. The goal of the postponement is to delay the customization as late as possible in the supply chain. It is also known as delayed differentiation. Mass customization is a relatively new term, which began to gain attention in the industry a decade ago. It was an obligatory invention as a response to the global market which becomes more turbulent day by day for the last two decades. Its goal is to produce customized products at low costs. Modularization is a common term that is used in many areas. In this study, we will focus on product architecture modularity and process modularity. Customer order decoupling point, which is also known as order penetration point, is used to distinguish the point in the supply chain where a particular product is associated to a specific order. Our target is building a model that explains how these four concepts are related. In order to achieve this, we will, first, research every concept individually; we will state the definitions, levels, benefits, enablers, success factors, drivers, etc. of the concepts. Then we will study the pair-wise relationships of these strategies. We will build our model according to the findings we have found in the literature. After building our model, we will explore it in Autoliv Electronics to see how it works in practice. Briefly, our model states the following: Modularization is an enabler of customization and it is necessary for the success of mass customization where set-up costs are critical. Product architecture modularity provides rapid assembly and cost efficiency that is required for postponement and mass customization. In addition, it is used to measure the mass customization degree according to some others. Postponement requires process modularity, and it moves the customer order decoupling point downstream in the value added material flow. It contributes the mass customization by increasing both the leanness and agility. Customer order decoupling point uses the customer requirements and existing capabilities of the mass customization for optimizing the flexibility-productivity balance.

Page generated in 0.0785 seconds