Tesi: "Efficiency"

1

Bai, Guo. "Three Essays on Governance Designs in Digital Age". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLH011/document.

Testo completo

Abstract (sommario):

Le principal objectif de cette thèse est d'expliquer en quoi l’efficience statique (static efficiency), l’efficience de coordination (coordinative efficiency) et l’efficience créative (creative efficiency) jouent un rôle déterminant dans la conception de la gouvernance à l'ère numérique. Il s’agit également d’étudier des mécanismes originaux de gouvernance, au-delà de la traditionnelle dimension marché-hiérarchie, pouvant faciliter les processus de coordination intégrative (integrative coordination) ainsi que de création collective dans les organisations.La thèse comprend trois essais. Le premier est une contribution de nature théorique montrant que l’économie des coûts de transaction (Williamson 1979, 1991, 1996, 2002) ne permet pas de rendre compte de façon satisfaisante de la conception de la gouvernance à l’ère numérique. Le modèle conceptuel normatif proposé contribue à repenser celle-ci dans une perspective pluraliste intégrant complexité et variété. Les choix de gouvernance ne sont ainsi plus limités à la seule dimension marché-hiérarchie comme le laisse penser l’économie des coûts de transaction. Une perspective intégrant la construction sociale des modes d’organisation (Giddens, 1985; Greenwood et al. 2011) permet de définir une variété de formes de gouvernance. Il est possible de représenter, dans un espace à trois dimensions (efficience statique, efficience de coordination et efficience créative), les différentes configurations de gouvernance sous la forme d’un triangle. Cette représentation peut être appliquée afin de rendre compte des choix de gouvernance possibles à différents niveaux organisationnels.Les deux essais suivants sont à dominante empirique. Ils visent à prolonger le premier en étudiant le lien entre des configurations innovantes de gouvernance et la performance des organisations en matière d’efficacité de coordination et d’efficacité créative. Le deuxième essai se concentre sur la coordination d’intégration dans les organisations. Des structures organisationnelles distribuées à plusieurs couches ou layered distributed organizational structures (Simon, 1962), des plans définis ex ante de façon imprécise ou broad-brushed ex ante plans (Edmondson, Bohmer et Pisano, 2001), ainsi que des semi-structures (Brown et Eisenhardt, 1997) s’avèrent utiles au processus de coordination lorsque les interdépendances sont complexes et incertaines. Le troisième essai porte sur la performance des organisations en matière de créativité collective. Il s’intéresse notamment aux dispositifs organisationnels facilitant l’émergence d’une telle créativité tout en préservant stabilité et efficacité. Plusieurs formes de perturbation qualifiées d’ordonnées (ordered disruption), tant au niveau spatial (ordered spatial disruption) que temporel (ordered temporal disruption) et affectif (ordered affective disruption), contribuent à l'émergence de la créativité collective.Le matériel empirique utilisé dans les deuxième et troisième essais provient d’une étude des modes de gouvernance de différents projets de villes intelligentes (smart-cities) nécessitant une collaboration entre plusieurs organisations
The main objective of this dissertation is to explain why coordinative efficiency, creative efficiency, together with static efficiency are all critical goals of governance design in digital age, and to explore innovative governance arrangements, beyond the one-dimensional line defined by “market” and “hierarchy”, that can facilitate the processes of integrative coordination, and collective creation in organizations.The dissertation is composed of three essays. Essay 1 is a theory paper that provides the overall theoretical arguments about why transaction cost economics (Williamson 1979, 1991, 1996, 2002) is no longer a satisfactory theoretical framework for governance design in the digital age, and offers a normative model which suggest possibilities of much more nuanced, complicated and pluralistic governance choices than suggested by transaction cost economics. It is argued that potential governance choices are not solely situated on a one-dimensional line between hierarchy and market, as transaction cost economics asserts. The rich connotations of socially constructed agency (Giddens, 1985; Greenwood et al. 2011) provide diverse possibilities of governance arrangements, which spread across a triangular plane in a three-dimensional space defined by static efficiency, coordinative efficiency and creative efficiency (see Figure 1). This paper provides both graphic and mathematical presentations of this three-dimensional model for governance design, which can be applied to different levels of organizing.Essay 2 and 3 are two empirical papers that endeavor to extend Essay 1 by finding out the exact relationship between certain innovative governance arrangements with organizations’ performance in coordinative and creative efficiencies. Essay 2 focuses on the realization of integrative coordination in organizations. It found out that layered distributed organizational structure (Simon, 1962), broad-brushed ex ante plan (Edmondson, Bohmer and Pisano, 2001), and semi-structures (Brown and Eisenhardt, 1997) are beneficial in facilitating an ongoing coordination process when interdependencies are complex and uncertain. Essay 3 focuses on organizations’ performance in collective creativity (Shalley et al., 2004; George, 2007), especially on what governance arrangements can best allow collective creativity to emerge without overly sacrificing organizational stability and efficiency. It is discovered that “ordered disruption”, including ordered spatial disruption, ordered temporal disruption and ordered affective disruption, have positive effects on the emergence of collective creativity. Both Essay 2 and Essay 3 use collaborative organizations on smart city projects as the empirical setting. The findings of these two empirical papers are grounded on multiple case studies on those collaborative organizations

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Max, Talbak. "Efficient Households : Energy efficiency in small apartments in Stockholm". Thesis, KTH, Energiteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-175161.

Testo completo

Abstract (sommario):

The energy consumption of the first world has reached unexpected heights, and is increasing every day. Because of this, energy efficiency has become a hot subject, both on a small and large scale. Every individual has a possibility to improve their energy efficiency and energy use alike by substantial amounts, and should act on this for the sake of the environment. The report begins with a study of different regulations and standards regarding energy efficiency. After this, a literature study is conducted regarding the latest available technology in all areas of home appliances. Finally, a field study is conducted on an apartment in Stockholm to find out how much energy that actually can be saved, and what the economic results are from this. The result shows that in general, it isn’t economically viable to upgrade to the latest energy efficient technology within home appliances, but that one has to consider the environmental gains as incitement for action. Approximately 10% of the total annual energy consumption could be saved by changing all machinery and functions in the house, except the heating, ventilation and air conditioning part.
Västvärldens energianvändning har nått oanade höjder, och ökar varje dag. Därför har energieffektivitet blivit ett hett ämne, både på liten och stor skala. Varje enskild individ har möjlighet att förbättra sin energieffektivitet och därmed sin energianvändning med märkbara skillnader, och bör agera därefter för miljöns skull. Rapporten börjar med en studie av olika regleringar och bestämmelser om energieffektivitet. Efter det kommer en litteraturstudie om vilken teknik som finns tillgänglig inom alla delar av hemmets energianvändning. Slutligen utförs en fältstudie på en lägenhet i Stockholm för att avgöra hur mycket energi som kan sparas, och vilka ekonomiska följder detta har. Resultatet visar att det i allmänhet inte är ekonomiskt hållbart att byta till den senaste energieffektiva tekniken inom hemmets apparater, utan att man får avse de miljömässiga vinsterna som incitament för dessa uppgraderingar. Ungefär 10% av den totala årliga energianvändningen kunde sparas genom att åtgärda alla apparater och funktioner i huset, utan avseende på uppvärmning och isolering.

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Majiet, Ziyaad. "Impeding efficiency". Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/5595.

Testo completo

Abstract (sommario):

Includes abstract.
Includes bibliographical references.
Impeding Efficiency is based on my interest in the manner in which we experience space and in particular, the moment we become conscious of our surrounding built environment. The point of change between spaces, the threshold. Contemporary society lives in fast-forward; everything we do has been streamlined, developed in principles of efficiency. This phenomenon has caused a divide between user and the experience of architecture. We move rapidly, only with goal in mind, very rarely pausing, to adjust and reflect on our surroundings. This sparked a study of the threshold in architecture through the lens of four architects and the architectural strategies they have applied in a manner that impedes efficiency, hinders mobility, slows down time and allows for personal interpretation of the build environment.

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Chen, Ning. "Bandwidth Efficiency and Power Efficiency Issues for Wireless Transmissions". Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10484.

Testo completo

Abstract (sommario):

As wireless communication becomes an ever-more important and pervasive part of our everyday life, system capacity and quality of service issues are becoming more critical. In order to increase the system capacity and improve the quality of service, it is necessary that we pay closer attention to bandwidth and power efficiency issues. Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation technique for high speed data transmission and is generally regarded as bandwidth efficient. However, OFDM signals suffer from high peak-to-average power ratios (PARs) which lead to power inefficiency in the RF portion of the transmitter. Moreover, in OFDM, the well-known pilot tone assisted modulation (PTAM) technique utilizes a number of dedicated training pilots to acquire the channel state information (CSI), resulting in somewhat reduced bandwidth efficiency. In this dissertation, we will address the above mentioned bandwidth and power efficiency issues in wireless transmissions. To avoid bandwidth efficiency loss due to dedicated training, we will first develop a superimposed training framework that can be used to track the frequency selective as well as the Doppler shift characteristics of a channel. Later on, we will propose a generalized superimposed training framework that allows improved channel estimates. To improve the power efficiency, we adopt the selected mapping (SLM) framework to reduce the PARs for both OFDM and forward link Code Division Multiple Access (CDMA). We first propose a dynamic SLM algorithm to greatly reduce the computational requirement of SLM without sacrificing its PAR reducing capability. We propose a number of blind SLM techniques for OFDM and for forward link CDMA; they require no side information and are easy to implement. Our proposed blind SLM technique for OFDM is a novel joint channel estimation and PAR reduction algorithm, for which bandwidth efficiency power efficiency - complexity - bit error rate tradeoffs are carefully considered.

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Perakis, Georgia, e M. (Marina) Zaretsky. "On the Efficient Solution of Variational Inequalities; Complexity and Computational Efficiency". Massachusetts Institute of Technology, Operations Research Center, 2002. http://hdl.handle.net/1721.1/5099.

Testo completo

Abstract (sommario):

In this paper we combine ideas from cutting plane and interior point methods in order to solve variational inequality problems efficiently. In particular, we introduce a general framework that incorporates nonlinear as well as linear "smarter" cuts. These cuts utilize second order information on the problem through the use of a gap function. We establish convergence as well as complexity results for this framework. Moreover, in order to devise more practical methods, we consider an affine scaling method as it applies to symmetric, monotone variationalinequality problems and demonstrate its convergence. Finally, in order to further improve the computational efficiency of the methods in this paper, we combine the cutting plane approach with the affine scaling approach.

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Alam, Ahmad Mahbubul. "Energy efficiency-spectral efficiency tradeoff in interference-limited wireless networks". Thesis, Rennes, INSA, 2017. http://www.theses.fr/2017ISAR0028/document.

Testo completo

Abstract (sommario):

L'une des stratégies utilisée pour augmenter l'efficacité spectrale (ES) des réseaux cellulaires est de réutiliser la bande de fréquences sur des zones relativement petites. Le problème majeur dans ce cas est un plus grand niveau d'interférence, diminuant l'efficacité énergétique (EE). En plus d'une plus grande largeur de bande, la densification des réseaux (cellules de petite taille ou multi-utilisateur à entrées multiples et sortie unique, MU-EMSO), peut augmenter l'efficacité spectrale par unité de surface (ESuS). La consommation totale d'énergie des réseaux sans fil augmente en raison de la grande quantité de puissance de circuit consommée par les structures de réseau denses, réduisant l'EE. Dans cette thèse, la région EE-SE est caractérisé dans un réseau cellulaire hexagonal en considérant plusieurs facteurs de réutilisation de fréquences (FRF), ainsi que l'effet de masquage. La région EE-ESuS est étudiée avec des processus de Poisson ponctuels (PPP) pour modéliser un réseau MU-EMSO avec un précodeur à rapport signal sur fuite plus bruit (RSFB). Différentes densités de station de base (SB) et nombre d'antennes aux SB avec une consommation d'énergie statique sont considérées.Nous caractérisons d'abord la région EE-SE dans le réseau cellulaire hexagonal pour différentes FRF, avec et sans masquage. Avec le masquage en plus de la perte de propagation, la mesure de coupure ε-EE-ES est proposée pour évaluer les performances. Les courbes EE-ES présentent une grande partie linéaire, due à la consommation de puissance statique, suivie d'une forte diminution de l'EE, puisque le réseau est homogène et limité par les interférences. Les résultats montrent qu'un FRF de 1 pour les régions proches de la SB et des FRF plus élevés dans la région plus proche du bord de la cellule améliorent le point optimal du EE-ES. De plus, un meilleur compromis EE-ES peut être obtenu avec une valeur plus élevée de coupure. En outre, un FRF de 1 est le meilleur choix pour une valeur élevée de coupure en raison d'une réduction du rapport signal sur interférence plus bruit (RSIB).Les précodeurs sont utilisés en liaison descendante des réseaux cellulaires MU-EMSO à accès multiple par division spatiale (AMDS) pour améliorer le RSIB. La géométrie stochastique a été utilisée intensivement pour analyser de tels systèmes complexes. Nous obtenons une expression analytique de l'ESuS en régime asymptotique, c.-à-d. nombre d'antennes et d'utilisateurs infinis, en utilisant des résultats de matrices aléatoires et de géométrie stochastique. Les SBs et les utilisateurs sont modélisés par deux PPP indépendants et le précodage RSFB est utilisé. L'EE est dérivée d'un modèle de consommation de puissance linéaire. Les simulations de Monte Carlo montrent que les expressions analytiques sont précises même pour un nombre faible d'antennes et d'utilisateurs. De plus, les courbes d'EE-ESuS ont une grande partie linéaire avant une forte décroissante de l'EE, comme pour les réseaux hexagonaux. Les résultats montrent également que le précodeur RSFB offre de meilleurs performances que le précodeur forçage à zéro (FZ), qui est typiquement utilisé dans la literature. Les résultats numériques pour le précodeur RSFB montrent que déployer plus de SBs ou d'antennes aux BSs augmente l'ESuS, mais que le gain dépend du rapport des densités SB-utilisateurs et du nombre d'antennes lorsque la densité de l'utilisateur est fixe. L'EE augmente seulement lorsque l'augmentation de l'ESuS est plus importante que l'augmentation de la consommation d'énergie par unité de surface. D'autre part, lorsque la densité d'utilisateur augmente, l'ESuS dans la région limitée par les interférences peut être améliorée en déployant davantage de SB sans sacrifier l'EE et le débit ergodique des utilisateurs
One of the used strategies to increase the spectral efficiency (SE) of cellular network is to reuse the frequency bandwidth over relatively small areas. The major issue in this case is higher interference, decreasing the energy efficiency (EE). In addition to the higher bandwidth, densification of the networks (e.g. small cells or multi-user multiple input single output, MU-MISO) potentially increases the area spectral efficiency (ASE). The total energy consumption of the wireless networks increases due to the large amount of circuit power consumed by the dense network structures, leading to the decrease of EE. In this thesis, the EE-SE achievable region is characterized in a hexagonal cellular network considering several frequency reuse factors (FRF), as well as shadowing. The EE-ASE region is also studied using Poisson point processes (PPP) to model the MU-MISO network with signal-to-leakage-and-noise ratio (SLNR) precoder. Different base station (BS) densities and different number of BS antennas with static power consumption are considered.The EE-SE region in a hexagonal cellular network for different FRF, both with and without shadowing is first characterized. When shadowing is considered in addition to the path loss, the ε-SE-EE tradeoff is proposed as an outage measure for performance evaluation. The EE-SE curves have a large linear part, due to the static power consumption, followed by a sharp decreasing EE, since the network is homogeneous and interference-limited. The results show that FRF of 1 for regions close to BS and higher FRF for regions closer to the cell edge improve the EE-SE optimal point. Moreover, better EE-SE tradeoff can be achieved with higher outage values. Besides, FRF of 1 is the best choice for very high outage value due to the significant signal-to-interference-plus-noise ratio (SINR) decrease.In downlink, precoders are used in space division multiple access (SDMA) MU-MISO cellular networks to improve the SINR. Stochastic geometry has been intensively used to analyse such a complex system. A closed-form expression for ASE in asymptotic regime, i.e. number of antennas and number of users grow to infinity, has been derived using random matrix theory and stochastic geometry. BSs and users are modeled by two independent PPP and SLNR precoder is used at BS. EE is then derived from a linear power consumption model. Monte Carlo simulations show that the analytical expressions are tight even for moderate number of antennas and users. Moreover, the EE-ASE curves have a large linear part before a sharply decreasing EE, as observed for hexagonal network. The results also show that SLNR outperforms the zero-foring (ZF) precoder, which is typically used in literature. Numerical results for SLNR show that deploying more BS or a large number of BS antennas increase ASE, but the gain depends on the BS-user density ratio and on the number of antennas when user density is fixed. EE increases only when the increase in ASE dominates the increase of the power consumption per unit area. On the other hand, when the user density increases, ASE in interference-limited region can be improved by deploying more BS without sacrificing EE and the ergodic rate of the users

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Damak, Helmi. "Analyse de la relation entre productivité, profitabilité et création de la valeur : le cas des banques tunisiennes". Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0246.

Testo completo

Abstract (sommario):

Maintenir un accroissement soutenu de la valeur pour les actionnaires estaujourd'hui reconnu comme un des principaux objectifs stratégiques pour les institutions financières. Générer une croissance stable de la valeur pour les actionnaires nécessite une concentration intense sur une prestation de services de meilleure qualité aux clients, le recrutement, le maintien d'un effectif motivé, et l'entretien d'excellentes relations avec les différents partenaires de la firme bancaire.Cette thèse présente une évaluation analytique de la création de la valeur actionnariale dans le secteur bancaire. La première partie : Fournit un cadre pour l'analyse théorique de la valeur actionnariale en discutant comment la valeur actionnariale peut être définie, si elle peut être considérée comme un objectif valable et stratégique pour la banque, comment la valeur actionnariale peut être mesuré et comment elle peut être créé. La deuxième partie de la thèse présente des Investigations empiriques afin de mesurer la valeur actionnariale et certains de ses déterminants. La partie finale Analyses l'importance de Ces facteurs dans lacréation de valeur pour les actionnaires.L'échantillon utilisé comprend les dix banques tunisiennes cotées sur la bourse des valeurs mobilières de Tunisie entre 1995 et 2009. Nous utilisons un modèle de panel pour examiner les déterminants de la création de valeur pour les actionnaires (Mesuré par l'EVA et ses composante, c.-à-d. profits économiques et coût de capital) comme une fonction linéaire de variables spécifique aux banques et a l?industrie bancaire et des variables macro-économique. Nous trouvons que Divers facteurs semble être d'importants déterminants significatifs des profits économiques et de la valeur actionnariale créée par les banques. En cohérence avec la littérature antérieure, nous avons des efficiences coût et revenu qui sont liées positivement à la performance des banques: à savoir, les profits économiques ont eu un lien positif avec l'amélioration de l'efficience revenu, tandis que l'EVA est positivement liée a l'amélioration de l'efficience coût. Deuxièmement, nous trouvons une relation positive entre les pertes de crédit et la valeur actionnariale, ce qui explique que des pertes élevées inattendues impliquent un plus grand volume d'affaires et peut-être de moins bonne qualité du portefeuille de prêts. Troisièmement, nous avonsobservé un lien positif entre l'endettement bancaire et les profits économiques, mais non pas avec l'EVA. Cela est dû à la relation positive entre effet de levier financier et le coût du capital. Dans l'ensemble, plus le levier financier est important plus les profits économiques seront aussi importantes, mais cela est compensé par des coûts du capital plus élevés
Creating sustainable shareholder value is at this time accepted as one of the mostimportant strategic objectives for financial institutions. Generating stable shareholder value growth requires an intense focus on delivering benefits to customers in the most efficient way, hiring and retaining motivated personnel, maintaining excellent relationship with other firm stakeholders.This thesis provides an analytical assessment of shareholder value creation in banking. The first part of the text provides a framework for analysing shareholder value theory by discussing how shareholder value can be defined, if it can be considered a valid strategic objective for banks, how shareholder value can be measured and how it can be created.The second part of the text presents empirical investigations in order to measureshareholder value and some of it drivers. The final part analyses the importance of these drivers in creating shareholder value. In order to have a broad view of the sector, the sample analysed comprises commercial Tunisian banks listed on Tunisian stock exchange between 1995 and 2009. We use a panel model to examine the determinants of bank's shareholder value reaction (measured by EVA and its components) as a linear function of various bank-specific, industry-specific and macroeconomic. We find that various factors are found to be statistically significantdeterminants of economic profits and shareholder value created by banks. Consistently with the previous literature, we find that cost and revenue efficiency are positively related to bank performance: namely, economic profits are found to have a positive link with revenue efficiency improvements, while EVA is positively related to cost efficiency improvements. Secondly, we find a positive relationship between credit losses and shareholder value providing evidence that higher unexpected losses imply larger business volume and perhaps lower loan portfolio quality. Thirdly, we observe a positive link between bank's leverage and economic profits, but not with EVA. This is due to the positive relationship between financial leverage and the cost of capital, overall, greater financial leverage increase economic profits but this is compensate by higher costs of capital

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Kidd, Matthew Donald. "Bicycle chain efficiency". Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/1245.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Robbins, Peter. "Court Efficiency Rating". Thesis, Boston College, 2006. http://hdl.handle.net/2345/586.

Testo completo

Abstract (sommario):

Thesis advisor: Richard McGowan
Can statistical analysis of professional basketball players lead to a more efficient evaluation of a player's worth? Following the recent success of statistic-driven baseball franchises, many basketball executives and followers are beginning to mine the sport's production in search of an all-encompassing player value rating. Teams could thus exploit undervalued players, leading to increased team and fan welfare. My thesis addresses this ongoing debate by examining various player and team statistics in the National Basketball Association (NBA). While I find significant relationships between individual efficiency statistics and team success, I also discover the paramount importance of defensive statistics and balanced team payrolls. This paper proposes a model that would help team executives find players who promote team efficiency, rather than individual production
Thesis (BA) — Boston College, 2006
Submitted to: Boston College. College of Arts and Sciences
Discipline: Economics
Discipline: College Honors Program

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Bergkvist, Skoglund Jim, e Daniel Svensson. "Stock efficiency, Almroths". Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-122916.

Testo completo

Abstract (sommario):

Detta examensarbete har utförts på Almroths Åkeri AB i Norrköping. Almroths är ett tredjepartslogistikföretag som inriktar sig på service inom lager och transport såväl som helhetslösningar skräddarsydda för att erhålla en god servicenivå mot slutkund. Stora krav ställs därför på effektiva flöden och hantering av artiklar på lagret. Fokus i detta arbete har koncentrerats på Almroths kund Garden Girl, som säljer trädgårdsartiklar av varierat sortiment med en säsongsbetonad försäljning. Almroths lagerhåller Garden Girls artiklar innan vidare leverans sker mot slutkund. Syftet med detta examensarbete är att effektivisera Almroths verksamhet med hänsyn till plockning av artiklar genom en förbättrad artikelplacering för kunden Garden Girl. Utifrån Almroths affärssystem innehållande artikeldata över Garden Girls efterfråga har en ABC-klassificering genomförts. Denna klassificering ska generera en placering för Garden Girls artiklar som minskar plocktiden. Observationer av Almroths lager har utförts för att kartlägga hur plockningen genomförs i nuläget. En mätning av plockmetoder har genomförts för att jämföra nulägets plockmetod med orderplockning, artikelplockning och zonplockning. Resultatet av ABC-klassificeringen utformas av ett Excelark innehållande en klassificering för samtliga artiklar som förekommer i Garden Girls sortiment. Dessa artiklar delas in i A, B och C klass (A är den grupp med högst antal artiklar placerade i en order) beroende på hur många gånger en artikel plockas. Klass A i ABC-klassificeringen består av artiklar som lagts i en order mellan 36-24 gånger, klass B artiklar mellan 24-7 gånger och klass C artiklar mellan 7-1 gång. Med detta menas att artiklarna i klass A kommer placeras närmst plockcentralen, klass B artiklar därefter och längst ifrån plockcentralen placeras klass C artiklar. Resultatet för mätningen av plockmetoder visade på att orderplockning med två order är den metod som anses effektivast tidsmässigt för Garden Girls artiklar. Vid mätningen framkom att plockning med totalt 100 artiklar kunde generera en tidsbesparing på upp till sju minuter alternativt 30 % med plockmetoden orderplockning om två order plockas parallellt jämfört med en order åt gången. Rekommendationerna gruppen ger till Almroths är att utifrån ABC-klassificeringen, arrangera om Garden Girls artiklarna efter det resultat som tagits fram. Även trots att omplaceringen kräver mycket tid och kapacitet anser gruppen det kommer bli en besparing i framtiden. Avslutningsvis föreslår gruppen att Almroths ska bibehålla sin nuvarande plockmetod orderplockning, med två eller tre order.

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Sandberg, Maria. "Efficient treatment of forest industrial wastewaters : Energy efficiency and resilience during disturbances". Doctoral thesis, Karlstads universitet, Fakulteten för teknik- och naturvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-13031.

Testo completo

Abstract (sommario):

This work concerns the efficient treatment of wastewaters from pulp and paper mills by means of aerobic biological processes. For treatment processes there are many aspects of efficiency and the present study investigates both energy efficiency and purification efficiency during disturbances. Special focus is put on wood extractives, such as resin acids and fatty acids, since they can cause negative effects in fish and other organisms in the receiving waters. They can furthermore be toxic to microorganisms in a biological treatment plant. They also affect oxygen transfer, which is important for energy efficient aeration of aerobic biological treatment processes. This thesis includes five papers/studies and presents a strategy for efficient treatment of forest industrial wastewaters. The results should help creating resilient wastewater treatment strategies with efficient use of energy. One new strategy proposed here includes separation of extractives before the wastewater is treated biologically, and the use of the extra amount of sludge as an energy source, shifting the energy balance from negative to positive.

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Pesaresi, Filippo. "Recycling efficiency: a focus on single stream". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.

Cerca il testo completo

Abstract (sommario):

Nella tesi è stato sono state affrontate alcune delle problematiche legate al riciclo dei rifiuti, ponendo particolare enfasi al riutilizzo delle risorse provenienti da raccolta indifferenziata. Dopo un’introduzione legata all’evoluzione del riciclo, ho passato in rassegna parte della legislazione presente nel territorio dell’Unione Europea. Nei successivi due capitoli ho analizzato vantaggi e svantaggi portati dal riciclo di rifiuti indifferenziati e differenziati, anche grazie all’utilizzo di esempi provenienti sia da paesi europei, sia da stati d’oltreoceano. Nel capitolo finale della dissertazione ho, in primo luogo, introdotto Hera, ossia l’azienda che si occupa dei rifiuti sia a Bologna che nell’intera regione emiliano-romagnola; in fine ho provato a immaginare come come portare ad un riciclo più efficiente dei rifiuti presenti nel territorio in cui opera Hera.

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Sarin, Amit. "Equitable economic energy efficiency : creating good jobs in low-income efficiency programming". Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/55142.

Testo completo

Abstract (sommario):

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2009.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 95-100).
Energy efficiency is an important consideration in energy policy-making. So, a federal program aimed at funding "energy efficiency retrofits" for low-income households could be an important step in increasing the overall efficiency of energy use in America. If each eligible household reduces the amount of energy it currently wastes by weatherizing, the US could save 127 billion pounds of carbon dioxide. The Department of Energy's Weatherization Assistance Program, that performs energy efficiency retrofits for low-income households, has been funded by over a 20- fold increase due to Stimulus Funding (formally, the American Recovery and Reinvestment Act of 2009). This increase has caused a serious need for a labor ramp-up to meet the program implementation goals of 1 million to 2 million low-income homes weatherized per year, as compared with the previous level of 100,000 homes a year. This program will only work, however, if the necessary workers can be trained and deployed quickly. This need for labor ramp-up creates a puzzle though. The interests of expanding the weatherization effort quickly and effectively are often posed against the interest of creating quality jobs for marginalized workers. The stakeholders representing each interest-low-income energy efficiency advocates and Green Collar Job Advocates-are both working for the interests of the low-income people, creating some hope for a positive, mutually agreeable solution.
(cont.) This thesis attempts to bridge this gap by documenting how the need for thousands of weatherization workers might be handled in a way that not only stimulates the national economy-the primary goal of the current national economic stimulus effort--but also provides Auditor and Installer jobs for marginalized workers in a way that leads to fruitful long-term employment. Based on my review of ramp-up and weatherization efforts in Massachusetts, I find that collaborative efforts involving existing Community Action Programs, labor unions, Utility companies, neighborhood organizations and educational institutions that prioritize training for long-term skill development may well be possible to promote energy efficiency in a way that addresses both our long-term need to reduce the burning of fossil fuel and our urgent need to stimulate the US economy and improve the economic lot of the most marginalized in US society.
by Amit Sarin.
M.C.P.

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Onireti, Oluwakayode S. "Fundamental trade-off between energy efficiency and spectral efficiency in cellular networks". Thesis, University of Surrey, 2012. http://epubs.surrey.ac.uk/810838/.

Testo completo

Abstract (sommario):

In a context of energy saving and operational cost reduction, energy efficiency (EE) has emerged as an important performance metric in cellular networks. According to the famous Shannon’s capacity theorem, maximising the EE while maximising the spectral efficiency (SE) are conflicting objectives, hence, both metrics can be jointly studied via their trade-off, i.e. the EE-SE trade-off. In this context, the aim of this thesis is to investigate the fundamental trade-off between EE and SE in futuristic cellular networks where distributed multiple-input multiple output (DMIMO) or coordinated multi-point (CoMP) scheme is utilised for meeting the high data rate of the next generation wireless communication networks. Focusing on the DMIMO system, a novel tight closed-form approximation of its EE-SE trade-off is derived and its accuracy verified for both the uplink and downlink channels and for both the idealistic and realistic power consumption models (PCMs). In addition, the low and high-SE regime approximations of the DMIMO EE-SE trade-off are derived in the uplink and downlink channels. Furthermore, these approximations are utilised for assessing both the EE gain of the DMIMO over the co-located MIMO (CMIMO) and the incremental EE gain of DMIMO in the downlink channel. It is observed that DMIMO is more energy efficient than CMIMO for cell edge users in both PCMs; whereas the results for realistic incremental EE gain indicate that the optimal approach in terms of EE is to connect the user terminal to only one radio access unit. Focusing on the uplink of the CoMP system, a generic closed-form approximation of the EE-SE trade-off is derived and its accuracy is demonstrated for both the idealistic and realistic PCMs. Asymptotic approximations of this trade-off in both the low and high SE regimes are also presented. Furthermore, these approximations are utilised to compare the EE of the CoMP system with the EE of the traditional non-cooperative system with orthogonal multiple access scheme. It is observed that in the idealistic PCM, CoMP is more energy efficient than the non-cooperative system due to a reduction in power consumption; whereas in the realistic PCM, CoMP can also be more energy efficient but due to an improvement in SE and mainly for cell-edge communication and small cell deployment.

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Li, Xing. "Efficiency droop mitigation and quantum efficiency enhancement for nitride Light-Emitting Diodes". VCU Scholars Compass, 2012. http://scholarscompass.vcu.edu/etd/395.

Testo completo

Abstract (sommario):

In the past decade, GaN-based nitrides have had a considerable impact in solid state lighting and high speed high power devices. InGaN-based LEDs have been widely used for all types of displays in TVs, computers, cell phones, etc. More and more high power LEDs have also been introduced in general lighting market. Once widely used, such LEDs could lead to the decrease of worldwide electrical consumption for lighting by more than 50% and reduce total electricity consumption by > 10%. However, there are still challenges for current state-of-the art InGaN-based LEDs, including ‘efficiency droop’ issues that cause output power quenching at high current injection levels (> 100 A/cm2). In this dissertation, approaches were investigated to address the major issues related to state-of-the-art nitride LEDs, in particular related to (1) efficiency droop investigations on m-plane and c-plane LEDs: enhanced matrix elements in m-plane LEDs and smaller hole effective mass favors the hole transport across the active region so that m-plane LEDs exhibit 30% higher quantum efficiency and negligible efficiency droop at high injection levels compared to c-plane counterparts; (2) engineering of InGaN active layers for achieving high quantum efficiency and minimal efficiency droop: lower and thinner InGaN barrier enhance hole transport as well as improves the quantum efficiencies at injection levels; (3) double-heterostructure (DH) active regions: various thicknesses were also investigated in order to understand the electron and hole recombination mechanism. We also present that using multi-thin DH active regions is a superior approach to enhance the quantum efficiency compared with simply increasing the single DH thickness or the number of quantum wells (QWs, 2 nm-thick) in multi-QW (MQW) LED structures due to the better material quality and higher density of states. Additionally, increased thickness of stair-case electron injectors (SEIs) has been demonstrated to greatly mitigate electron overflow without sacrificing material quality of the active regions. Finally, approaches to enhance light extraction efficiency including using Ga doped ZnO as the p-GaN contact layer to improve light extraction as well as current spreading was introduced.

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Brodin, Nils, e Johan Hanberg. "Efficient Power : A discourse analysis of energy efficiency policies from Finland and Sweden". Thesis, Högskolan för lärande och kommunikation, Högskolan i Jönköping, HLK, Globala studier, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-36429.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Beita-Kiser, Gabriel. "Energy Efficient Homes in Tucson: How to Make Cost-Effective Energy Efficiency Retrofits". The University of Arizona, 2015. http://hdl.handle.net/10150/552896.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Beskow, Cecilia. "Towards a higher efficiency". Doctoral thesis, KTH, Machine Design, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-2938.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Naper, Linn Renée. "Educational efficiency and institutions". Doctoral thesis, Norwegian University of Science and Technology, Department of Economics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-2252.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Jansson, Gustav. "Industrialised housing design efficiency". Licentiate thesis, Luleå tekniska universitet, Byggkonstruktion och -produktion, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25688.

Testo completo

Abstract (sommario):

Industrialised housing has increased its Swedish market share the latest ten years from 2% to 15%. Prefabrication has developed into actual industrialisation, where factories produce not only elements for site assembly, but takes wholesale responsibility for the sales, design, factory production, and assembly of houses. A higher automation in housing production puts demands on the design department to become more efficient. Design is identified as a bottleneck to further increase the production rate. Information deliveries are not produced in the needed rate. With the change from drafting to modelling in building design, opportunities are given to work simultaneously for better efficiency. The focus on BIM-supported CAD-tools has lead ICT-developers to create systems that mainly support product modelling. But, in industrialised housing, support for process efficiency is just as important.In a case study at a Swedish industrialised housing company, during a three year period, interviews, observations and design activities at the company were recorded to study what components and functionality in the design support create business value. The results show that by defining design in stages with gates, by parallel planning of activities, and by using process visualisation methods, the efficiency increased about 41 % in information deliveries. Furthermore, the use of support systems has to create both internal value for efficiency in information deliveries and external value to meet and handle client requirements in a standardised way. By releasing time from project management activities to improvements and product development the focus on the product could increase. Product development theories with axiomatic design as the foundation for a support system combines product structures with BIM functionality and process support for planning, which secures quality between disciplines in a concurrent approach. Product life cycle management (PLM) is an umbrella that manages product development in a life-cycle perspective trough a defined framework that is applicable to industrialised housing design, both for software developers and industrialised builders.
Industriellt byggande har de senaste tio åren ökat sina marknadsandelar från 2% till 15% på den svenska bostadsmarknaden för flerfamiljshus. Prefabricering har utvecklats till industrialisering, där fabriker inte bara producerar komponenter för montering på byggplats, utan tar även helhetsansvar för försäljning, konstruktion, i fabrik och för montering av bostäder. Utvecklingen av en mer automatiserad produktion ställer högre krav på projekteringen. Som en definierad flaskhals måste tid frigöras från koordinering till kärnverksamhet för att skapa förbättringar och tillåta produktutveckling. Med förändringen från ritningsbaserad till modellbaserad byggprojektering, ges möjligheten att arbeta samtidigt för bättre effektivitet. Fokuseringen på BIM-stöd med CAD-verktyg har lett till att utvecklare skapar system som i huvudsak stödjer produktmodellering. För industriellt bostadsbyggande, är stöd för effektivitet i projekteringsprocessen lika viktig. Empiri har samlats genom intervjuer, observationer och dokumenterade aktiviteter i en fallstudie hos en svensk industriell bostadsbyggare för att analysera vilka komponenter och funktioner som ett stödsystem för projektering behöver för att skapa värde för företagen. Resultaten visar att en definition av projektering i steg med gater, aktiviteter för samplanering och användandet av metoder för att visualisera processen har ökat effektiviteten med omkring 41 % för informationsleveranser. Dessutom visar studien att stödsystem bör kunna skapa både internt värde för effektiva informationsleveranser och yttre värde för att möta och hantera kunders krav på ett standardiserat sätt. Ett stödsystem, baserat på produktutvecklingsteorier med axiomatisk design som grund, kan kombinera både produktstruktur med BIM- funktioner och processrelaterade funktioner för planering och därmed säkra kvaliteten mellan discipliner för samverkande arbete. Product life cycle management (PLM) är ett övergripande koncept för hantering av produktutveckling i ett livscykelperspektiv, vilket har ett definierat regelverk som är applicerbart på industriell byggprojektering, både för utvecklare av IT-system och för industriella husbyggare.
Godkänd; 2010; 20100914 (gusjan); LICENTIATSEMINARIUM Ämnesområde: Träbyggnad/Timber Structures Examinator: Docent lektor Helena Johnsson, Luleå tekniska universitet Diskutant: Tekn. Lic. Jerker Lessing, Tyréns, Malmö Tid: Onsdag den 20 oktober 2010 kl 10.00 Plats: F1031, Luleå tekniska universitet

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Moynihan, Muiris. "Material efficiency in construction". Thesis, University of Cambridge, 2014. https://www.repository.cam.ac.uk/handle/1810/246258.

Testo completo

Abstract (sommario):

Producing steel causes 6% of global anthropogenic carbon dioxide emissions. Experts recommend that these emissions are reduced by half by the year 2050 in order to avert the worst consequences of climate change. Demand for steel is predicted to double in the next 36 years, meaning that a 75% reduction in emissions per unit of steel produced is necessary to reach the recommended limit. Process efficiency improvements cannot deliver this magnitude of reduction; however if steel is used more efficiently so that less new material is required to deliver the same service - a concept termed 'material efficiency' - then this could allow demand to be satisfied whilst emissions targets are achieved. Construction is the single largest use of steel globally, therefore using steel more efficiently in construction will reduce emissions. Three material efficiency strategies are identified as having most potential for this industry: using less material, using products for longer, and reusing components. In order to prioritise areas for research, steel flows into construction are mapped, finding that industrial buildings and utility infrastructure are the largest users of steel, while superstructure is confirmed as the main use of steel in a typical building. To estimate the potential to use less steel in buildings, 23 steel-frame designs are studied, sourced from three leading design consultancies. The utilisation of each element is found and the building datasets are analysed to infer the amount of steel over-provided. The results suggest that such buildings contain almost twice as much steel as necessary for structural performance, and indicate that this amount of over-provision occurs to minimise labour costs, which are a larger proportion of total costs than materials. To investigate how buildings and infrastructure could be used for longer, reasons for their failure are reviewed. Based on interviews with industry professionals a set of strategies is proposed, tailored to each failure cause and distinguishing between cases where failure can and cannot be reasonably foreseen. Steel sections could be reclaimed from old buildings and reused in new buildings but this does not occur because they are damaged during demolition. Designing for deconstruction would facilitate reuse but is not practised due to its cost. Data from interviews and a commercial working group are analysed to identify three aspects of designing for deconstruction that provide financial and operational benefits to clients, thus encouraging their use. One remaining technical barrier to deconstruction is composite steel-concrete systems, where welded connectors make it impractical to separate the steel beam from the concrete slab without damage. A novel bolted composite connector is proposed and tested in three beam experiments. The bolted connector allows successful separation of the components, facilitating reuse. Its structural performance is similar to that of welded connectors and can be predicted using current design standards. Each of the investigations reveals significant opportunities to reduce steel use in construction by using material more efficiently. Achieving these savings would reduce demand for new steel production and thereby decrease carbon dioxide emissions.

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Brueggemann, Tobias. "Efficiency of local search". Enschede : University of Twente [Host], 2006. http://doc.utwente.nl/57144.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

23

Örn, Markus. "Towards Better Alternator Efficiency". Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-109098.

Testo completo

Abstract (sommario):

The requirements on vehicle industry are constantly getting stricter, especially when it comes to emissions. At the same time cars, trucks and buses are needed for our way of living. This have forced companies to be as ecient as possible in their way of using fossil fuels for travelling and transport. To increase the eciency companies investigate all possible fuel savings to decrease their carbon footprint as much as possible. One area of savings that is not that obvious to many people is the alternator. Several percent of the total energy used by a vehicle are needed to operate the alternator. With a typical alternator eciency of 70% considerable savings can be achieved. This thesis that concern alternator eciency was carried out at Scania in Södertälje, Sweden. The goal of the thesis is to construct a mathematical model of an alternator. The model is supposed to consider all losses in the alternator and together with the output power give an eciency model of the alternator at different speeds and loads. A great part of the project has been dealing with the magnetic losses. The magnetic losses have been modeled as an equivalent circuit with the load angle as a central piece. The equivalent circuit is built up by the fact that the alternator used in the vehicles is a salient pole alternator. The equivalent circuit describes a voltage equation where the voltage drop over the magnetic inductance is described. From that relations between the signals in the alternator and output signals can be written. The alternator model is then used together with data recorded from different buses all over the world, this to be able to investigate how the alternator contributes to the fuel consump- tion depending on the way that the buses are driven. The result of this thesis is a mathematical model that describes the losses in the alternator for different load cases and speeds.

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Wadud, Md Abdul. "Farm efficiency in Bangladesh". Thesis, University of Newcastle Upon Tyne, 1999. http://hdl.handle.net/10443/184.

Testo completo

Abstract (sommario):

This thesis examines farm-level efficiency of rice farmers in the High Barind region of Bangladesh by estimating technical, allocative and economic efficiency using farm level cross section survey data. Two contrasting methods for measuring efficiency are applied: the stochastic econometric frontier and Data Envelopment Analysis (DEA). These measures are used to investigate the factors associated with technical, allocative and economic inefficiency. First, technical efficiency is computed by estimating the translog stochastic frontier in which technical inefficiency effects are modelled as a function of socioeconomic, infrastructure and environmental degradation factors in a single stage estimation technique using maximum likelihood method. Technical and scale efficiency are calculated by solving output- and input-oriented constant returns to scale (CRS) and variable returns to scale (VRS) DEA frontiers. A Tobit model is used to evaluate factors associated with technical and scale inefficiency from both input-oriented and output-oriented CRS and VRS frontiers. Same factors are analyzed as in the translog stochastic frontier. The translog stochastic frontier results show that farm households are, on average, 79 per cent technically efficient. The output-oriented DEA frontier results show that the average technical efficiency estimates are 79 and 86 per cent under CRS and VRS assumptions and the average scale efficiency is 92 per cent. The average values for technical efficiency measures and scale efficiency from the input-oriented CRS and VRS frontiers are 79, 85 and 93 per cent respectively. The translog stochastic frontier exhibits decreasing returns to scale, whereas the DEA frontier exhibits decreasing, constant and increasing returns to scale. The technical inefficiency effects model in the translog stochastic frontier and Tobit analysis for DEA frontier show that irrigation infrastructure and environmental degradation are significant factors in determining technical inefficiency. We then measure technical, allocative and economic efficiency by estimating the Cobb- Douglas stochastic frontier following the Kopp and Diewert cost decomposition technique and by running input-oriented CRS and VRS DEA frontier models. We estimate the Tobit model to analyze the factors associated with technical, allocative and economic inefficiency from the DEA frontiers. In addition, we compare the results obtained from both the Cobb- Douglas stochastic frontier and DEA frontiers. The results from the Cobb-Douglas stochastic frontier shows that the average technical, allocative and economic efficiency of farm households are 80, 77, and 61 per cent respectively. The input-oriented CRS frontier results show that farm households have, on average, 86, 91 and 78 per cent technical, allocative and economic efficiency and the corresponding VRS frontier shows that farm households are, on average, 91, 87 and 79 per cent technically, allocatively and economically efficient. An evaluation of factors associated with technical, allocative and economic inefficiency from both the Cobb-Douglas stochastic frontier and DEA frontier reveals that irrigation infrastructure and environmental degradation are the most statistically significant factors affecting technical, allocative and economic inefficiency. This implies that diesel-operated pumps and environmental degradation are not only reducing output from given inputs but are also causing sub-optimal cost-minimizing input decisions. Assessing efficiency suggests that there is a considerable amount of inefficiency among farm households and there is room for enhancing rice production through the improvement of technical, allocative and economic efficiency without resort to technical improvements. Farm households could reduce their variable production costs, on average, between 21 - 31 per cent if they could utilize their inputs in a technically and allocatively efficient manner. An evaluation of factors associated with inefficiency concludes that government electrification programmes which convert diesel pumps into electricity-operated pumps for irrigation in rural areas and policies which lead to reduced environmental degradation would reduce inefficiency, thereby increasing rice production and the welfare of farm households.

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Chan, Walker R. "High efficiency thermophotovoltaic microgenerators". Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99773.

Testo completo

Abstract (sommario):

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 137-150).
We proposed, designed, and demonstrated a first-of-a-kind millimeter-scale thermophotovoltaic (TPV) system using a metallic microburner, photonic crystal (PhC) emitter, and low bandgap TPV cells. Many technologies (fuel cells, Stirling, thermoelectric, etc.) that potentially enable a portable millimeter-scale hydrocarbon microgenerator are under active investigation because conventional fuels offer energy densities fifty times that of batteries. In a TPV system, combustion heats an emitter to incandescence and the resulting thermal radiation is converted to electricity by photovoltaic cells. Our approach uses a moderate temperature (1000{1200°C) microburner coupled to a high emissivity, high selectivity PhC selective emitter and low bandgap TPV cells. The PhC emitter and low bandgap cells minimize total microgenerator mass by enabling simultaneous high eciency and high power density, even at moderate temperatures which allow ecient coupling to the combustion process by reducing undesired heat loss mechanisms. This approach is predicted to be capable of up to 30% ecient fuel-to-electricity conversion within a millimeter-scale form factor. Although considerable technological barriers need to be overcome to reach full performance, we have performed a robust experimental demonstration that validates the theoretical framework and the key system components. We first demonstrated a first-of-a-kind TPV system built from a 1010 mm catalytic silicon MEMS microburner with a Si/SiO₂ 1D PhC matched to the InGaAsSb (Eg = 0:55 eV) cells which achieved 2.7% fuel-to-electricity eciency, a millimeter-scale record, at a power of 344 mWe. We then proposed, designed, and demonstrated a highly robust metallic platform comprised of a 2020 mm Inconel microburner and a higher performance 2D tantalum PhC emitter. With the new system, we experimentally demonstrated a similar eciency but can achieve 5% with simple mechanical improvements. These two experimental demonstrations will pave the way for a lightweight, high energy density TPV microgenerator. We modeled a complete microgenerator based on the experimental system and found an energy density of 850 Wh/kg and power density of 40 W/kg are achievable.
by Walker R. Chan.
Ph. D.

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Дегтярьова, Ія Олександрівна, Ия Александровна Дегтярева, Iia Oleksandrivna Dehtiarova e D. Snitko. "Ecological-economic systems efficiency". Thesis, Видавництво СумДУ, 2009. http://essuir.sumdu.edu.ua/handle/123456789/7833.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Herrera-Restrepo, Oscar A. "Efficiency-Driven Enterprise Design". Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/80481.

Testo completo

Abstract (sommario):

This dissertation explores the use of the efficiency performance measurement paradigm (EM), in terms of its concepts and applications, as an ex-ante mechanism to evaluate enterprise performance and inform enterprise design. The design of an enterprise is driven by decisions that include, but not limit to, which strategies to implement, how to allocate resources, how to shift operating patterns, and how to boost coordination among enterprises, among others. Up to date, EM has been mainly used as a descriptive mechanism, but the fundamental reason for measuring performance in an ex-post fashion, i.e., how well an enterprise does, is also valid in the context of design decisions, i.e., ex-ante evaluation. The contrast between the ex-post and ex-ante use of EM relates to the measurement purpose, i.e., why to measure. Ex-post measurement focuses on evaluating 'what happened' (non-disruptive) while ex-ante measurement emphasizes in informing design decisions exploring changes in current settings (more disruptive). Within this context and to achieve the purpose above, this dissertation is supported by theoretical insights and complemented with three empirical studies. The theoretical insights relate to facts that support, connect to, and challenge (i.e., facilitate or impede) the ex-ante use of EM for enterprise evaluation and informing enterprise design. Those insights are based on the efficiency performance measurement, organizational design and enterprise systems engineering literature. Meanwhile, the three empirical studies situate the application of EM as an ex-ante mechanism to inform evacuation management, bank branch management, and power plants. The theoretical and empirical results indicate that EM is well suited for both evaluating enterprise performance and informing design decisions. The main contribution of this dissertation to enterprise stakeholders is that EM can be not only used to answer how well the enterprise did, but also how well it could do if certain design decisions are taken.
Ph. D.

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Prachýl, Lukáš. "Efficiency in Shared Services". Master's thesis, Vysoká škola ekonomická v Praze, 2010. http://www.nusl.cz/ntk/nusl-96416.

Testo completo

Abstract (sommario):

The thesis describes and analyzes shared services organizations as a management tool to achieve efficiency in the organizations' processes. Paper builds on established theoretical principles, enhance them with up-to-date insights on the current situation and development and create a valuable knowledge base on shared services organizations. Strong emphasis is put on concrete means on how exactly efficiency could be achieved. Major relevant topics such as reasons for shared services, people management, performance measurement, enabling technology, risks and so on are thoroughly covered. To demonstrate outlined principles a practical part at the end (in cooperation with Henkel AG, Germany) introduces a concrete controlling process and its possibility to be shifted into shared services center.

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Ludwig, Martijn. "Efficiency of Dutch hospitals". [Maastricht] : Maastricht : [Maastricht University] ; University Library, Universiteit Maastricht [host], 2008. http://arno.unimaas.nl/show.cgi?fid=14558.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Alexander, Jennifer Karns. "The meanings of efficiency /". Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/10426.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Al-Jarrah, Idries Mohammed Wanas. "Efficiency in Arabian banking". Thesis, Bangor University, 2002. https://research.bangor.ac.uk/portal/en/theses/efficiency-in-arabian-banking(06c8ee57-a0e4-4e63-bcf1-c6c028b59dda).html.

Testo completo

Abstract (sommario):

This thesis investigates the efficiency levels of the Jordanian, Egyptian, Saudi Arabian and Bahraini banking systems. The empirical evidence on bank efficiency in these markets aims to highlight the features associated with the role of economic and financial reforms that have taken place in these countries over the past decade. Our sample comprises information on 82 banks operating in Jordan, Egypt, Saudi Arabia and Bahrain over the 1992-2000 period. We use the stochastic frontier and Fourier-flexible form to estimate cost and profit efficiency levels in these banking systems. In addition, we also estimate the scale elasticity and scale efficiency levels in the banking sectors under study. The sample size represents 78% of the banking sector of Jordan, just under 90% of the Egyptian banking sector, 63% of that of Saudi Arabia and over 50% of the banking sector of Bahrain. To derive efficiency levels, we employ three distinct economic efficiency concepts (cost, standard profit and alternative profit efficiencies), using a number of different measurement methods (including the stochastic frontier approach, specification of the Fourier-flexible functional form versus the translog form, and inclusion of a banks' asset quality and financial capital in a number of different ways) to a single data set. In choosing the 'preferred' cost and profit models to estimate efficiency levels, we follow various contemporary methodologies that use a variety of hypotheses tests to arrive at preferred model specifications. Given cost efficiency, the preferred model is the Fourier-truncated form that excludes the control variables (capital adequacy, asset quality and the time trend) but includes all the environmental variables. Given the standard and alternative profit function, the preferred model is the Fourier-flexible that includes the control as well as the environmental variables. The technical cost efficiency averaged around 95%, based on our preferred model, over the 1992-2000 period. Standard and alternative profit functions estimates reveal technical efficiency on average around 66% and 58% respectively. Islamic banks are found to be the most cost and profit efficient while investment banks are the least (cost and profit efficient). This result perhaps reveals the fact that the cost of funds for Islamic banks is relatively cheaper than the cost of funds for other financial institutions. Large banks, in assets terms, appear to be relatively more cost and profit efficient. This possibly signals the ability of large banks to utilise more efficient technology with less cost, the ability of these banks to introduce more specialised staff for the most profitable activities and the ability of these banks to provide (presumably) better quality outputs for which they can charge higher prices. Geographically, Bahrain is the most cost and profit efficient while Jordan is the least (cost and profit efficient). The scale efficiency results reveal that, on average, banks in the countries under study are around 65% scale efficient in terms of cost. In terms of profit efficiency, estimates are around 60% for both standard and alternative profit function but with rather dissimilar movements overtime for scale efficiency scores using both sets of measures. Both cost and profit functions report Islamic and commercial banks as the most scale efficient types of banks. Based on asset size, the results of the alternative profit function estimates, in particular, indicate that large banks are more scale efficient than small banks. Geographically, Saudi Arabian and Egyptian banks appear to be the most cost and profit scale efficient. The derived efficiency levels for the banks operating in the countries under study, however, provide little evidence to suggest that the economic and financial reforms undertaken in Jordan, Egypt, Saudi Arabia and Bahrain over the last decade have had a noticeable impact on improvement in banking sector efficiency. The main policy recommendation from this study, therefore, is that these countries need to continue the reform process in order to enhance financial sector performance.

Gli stili APA, Harvard, Vancouver, ISO e altri

32

Wagner, Christina. "Dynamic efficiency under uncertainty". Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17242.

Testo completo

Abstract (sommario):

Der Milchsektor ist einer der bedeutendsten landwirtschaftlichen Sektoren in der Europäischen Union. Seit die Reformen der Gemeinsamen Agrarpolitik 2005 in Kraft traten, wurde der Markt stark liberalisiert und ist durch zunehmende Preisschwankungen gekennzeichnet. Für die Michviehbetriebe ist dies eine Herausforderung, denn Faktorpreisunsicherheit ist eng mit den betrieblichen Entscheidungsprozessen für die optimale langfristige Nutzung der Produktionsfaktoren verbunden. Ein weitreichender Teil der Literatur analysiert den Zusammenhang zwischen Betriebsgröße oder Betriebsführung und ökonomischer Effizienz. Die statische Effizienzmessung ist weitverbreitet, vernachlässigt jedoch die zeitliche Abhängigkeit und die Anpassungsprozesse der quasi-fixen Faktoren. Dies wird im Konzept der dynamischen Effizienzmessung aufgegriffen. Das verwendete Effizienzmodell berücksichtigt zudem Faktorpreisunsicherheit. Der Beitrag dieser Dissertation ist es, die dynamische Effizienz westdeutscher Milchviehbetriebe erstmals unter Unsicherheit zu analysieren. Es wird untersucht, ob die Produktionsfaktoren technisch und allokativ effizient einsetzen werden. Zudem wird die Rolle der Unsicherheit für die Faktornachfrage und die Effizienzmessung beleuchtet. Die Ergebnisse zeigen, dass die Milchviehbetriebe auf einem hohen technischen Effizienzniveau arbeiten im Vergleich zur allokativen Effizienz und dass die Futternachfrage negativ mit der Futterpreisvolatilität verbunden ist. Investitionen reagieren negativ auf die Volatilität des Milchpreises, wobei der Einfluss der Unsicherheit mit zunehmender Betriebsgröße steigt. Die Ergebnisse belegen, dass die Preisunsicherheit bei der (dynamischen) Effizienzmessung von entscheidender Bedeutung ist und die Vernachlässigung zu niedrigeren Effizienzwerten führt und die Betriebe ineffizient erscheinen. Diese Ergebnisse sind nicht nur für Milchviehbetriebe relevant, sondern auch für Sektoren, die durch volatile Marktbedingungen gekennzeichnet sind.
Dairy farming, the most important farming sector in the European Union, has been subject to considerable de-regulation since the 2005 EU Common Agricultural Policy came into effect and to increased commodity price volatility. This is a new challenge for dairy farms, since price volatility is related to farm-level decision-making with regard to the optimal factor allocation in the long run. A vast body of literature relates economic efficiency to dairy farm characteristics such as size or managerial ability. However, it is common for static approaches of efficiency which ignore the role of time and the adjustment processes of farms with respect to the quasi-fixed factors to be applied. The intertemporal linkages of production and investment decisions are emphasized by dynamic efficiency and an extended model incorporates factor price volatility. The contribution of this thesis is to analyze the dynamic efficiency of German dairy farms under uncertainty, which thus far has not been done. The application aims to investigate whether West German dairy farms use their production factors in a technically and allocative efficient way in the long run. Moreover, the application will explore the role of uncertainty for factor demand and efficiency measurement. The results show that the farms operate at high levels of technical efficiency in comparison to allocative efficiency and that feed demand is negatively related to the variance of the feed concentrate price. Investment is negatively related to the variance of the milk price and the effect increases with farm size. The results further show empirical evidence for considering uncertainty when deriving (dynamic) efficiency measures: neglecting uncertainty within the estimation procedure will underestimate the average efficiency score, and thus farms appear inefficient. This finding is not only interesting for dairy farms; it also applies to other sectors that operate in highly-volatile markets.

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Leon, Diego, e Viktor Meyer. "Efficiency evaluation of digitalization". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-258134.

Testo completo

Abstract (sommario):

The concept of digitalization has become more and more prevalent due to the unprecedented computational power of our current digital machines. Swedish healthcare has been focusing on digitalization in the form of e-health during the last decade and the amount of digital services is rapidly increasing. By using modern technology to create smarter and more efficient processes it is possible to improve quality for patients and users.There is a need for more reliable knowledge about digitalization and its potential for efficiency. This project seeks to investigate and discuss efficiency in digitalization. The purpose is to directly contribute with more data on the topic.This project implements a qualitative research method as well as a case-study to conduct efficiency tests and compare manual processes to digitalized ones.The research methodology consists of a literature study, the construction of a digitalized process, and two tests where each test involves executing a process both manually and digitally. The processes involve document generation and communication, within the healthcare sector.The test results show that digitalization achieves an overall efficiency increase of 333% when all results are summarized. Overall, it is clear from the results that digitalization leads to increased efficiency. The efficiency achieved varies from process to process. In the general case, an increase in efficiency is observed, but sometimes also a decrease.
Konceptet digitalisering har blivit allt mer utbrett på grund av den enorma datorkraft som finns i våra nuvarande digitala maskiner. Den svenska sjukvården har fokuserat på digitalisering i form av e-hälsa under det senaste decenniet och antalet digitala tjänster ökar snabbt. Genom att använda modern teknik för att skapa smartare och effektivare processer är det möjligt att förbättra kvaliteten för patienter och användare.Det finns ett behov av mer tillförlitlig kunskap om digitalisering och dess potential för effektivitet. Detta projekt har som mål att undersöka denna effektivitet. Syftet är att direkt bidra med mer data om ämnet digitalisering.Detta projekt bygger på en kvalitativ forskningsmetod samt en fallstudie för att genomföra effektivitetsprov och jämföra manuella med digitaliserade arbetsprocesser.Den använda forskningsmetodiken består av en litteraturstudie, konstruktion av en digitaliserad process, samt två tester där vardera test utvärderar både en manuell och digital process. Processerna innefattar dokumentgenerering och kommunikation, inom sjukvården.Testresultaten visar att digitalisering uppnår en total effektivitetsökning på 333% när alla resultat sammanställs. Överlag är det från resultaten uppenbart att digitalisering leder till ökad effektivitet. Effektiviteten som uppnås varierar från process till process. I det generella fallet observeras ökad effektivitet, men ibland även minskad.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Kohashi, Andrea Aya. "A question of efficiency". Thesis, University of Iowa, 2015. https://ir.uiowa.edu/etd/1666.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Bartelmess, Johan. "Compression efficiency of different picture coding structures in High Efficiency Video Coding (HEVC)". Thesis, Uppsala universitet, Avdelningen för systemteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-281926.

Testo completo

Abstract (sommario):

Video content is expected to account for 80 percent of all Internet traffic in 2019. There is therefore an increasing need for better video compression methods, to decrease the use of internet bandwidth. One way of achieving high video compression is to predict pixel values for a video frame based on prior and succeeding pictures in the video. The H.265 video compression standard supports this method, and in particular makes it possible to specify in which order pictures are coded, and which pictures are predicted from which. The coding order is specified for Groups Of Pictures (GOP), where a number of pictures are grouped together and predicted from each other in a specified order. This thesis evaluates how the GOPs should be structured, for instance in terms of sizing, to maximize the compression efficiency relative to the video quality. It also investigates the effect of multiple reference pictures, a functionality that enables the picture that renders the best prediction to be selected. The results show that the largest tested GOP size of 32 pictures is preferable for all tested video characteristics, and that support for multiple reference pictures renders a similar increase in compression efficiency for all GOP sizes.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Xu, Yiran. "Quality of Experience Aware Spectrum Efficiency and Energy Efficiency Over Wireless Heterogeneous Networks". DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4664.

Testo completo

Abstract (sommario):

Propelled by the explosive increases in mobile data traffic volume, existing wireless technologies are stretched to their capacity limits. There is a tremendous need for an expansion in system capacity and an improvement on energy efficiency. In addition, wireless network will support more and more multimedia services and applications, in which user experience has been always an important factor in evaluating the overall network performance. In order to keep pace with this explosion of data traffic and to meet the emerging quality of experience needs, wireless heterogeneous networks have been introduced as a promising network architecture evolution of the traditional cellular network. In this dissertation, we explore video quality-aware spectrum efficiency and energy efficiency in wireless heterogeneous networks|the potentials and the associated technical challenges. In particular, aiming to significantly enhance spectrum efficiency, we need to tackle the interference issue, which is exacerbated in heterogeneous network due to ultra dense node deployment as well as heterogeneity nature of various nodes. Specifically, werst study an optimal intra-cell inter-tier cooperation to mitigate interference between high power nodes and low power nodes. Together with cooperation, optimal mobile association and resource allocation schemes are also intensively investigated in heterogeneous network to achieve system load balancing so that bandwidth at high power and low power nodes can be utilized in the optimal way. The proposed scheme can greatly alleviate inter-tier interference and significantly increase overall system spectrum efficiency in a heterogeneous network. We then further apply advanced algorithms such as precoding, and non-orthogonal multiple access into intra-cell inter-tier cooperation so that the overall system spectrum efficiency and user experience are even more improved. When supporting a video type application in such a heterogeneous network, considering only spectrum efficiency is far from enough as video application is bandwidth consuming, battery consuming, and quality demanding. We develop a video quality-aware spectrum and energy efficiency resource allocation scheme in a wireless heterogeneous network and propose novel performance metrics to establish fundamental relationships among spectrum efficiency, energy efficiency, and quality of experience. Extensive simulations are conducted to evaluate the trade-o performance among three performance metrics.

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Nguyen, Thi Thanh Huyen. "Mesurer la performance des universités au Vietnam en termes d’efficience : Une application de la méthode DEA". Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1G016/document.

Testo completo

Abstract (sommario):

Avec l’apparition d’une économie basée sur les connaissances, le rôle de l’enseignement supérieur prend de plus en plus d’importance. Pour le Vietnam, ces dernières décennies ont été marquées par une explosion de la demande en études supérieures. Néanmoins, les lacunes actuelles des universités en matière de gestion et d’utilisation des ressources ont limité leur compétitivité, surtout à l’échelon régional et international. Un système de mesure de leur performance devient donc incontournable, plus précisément de l’efficience. Notre étude a pour objectif de construire ce système en utilisant trois techniques : l’analyse de sensibilité, l’approche DEA méta-frontière et les indices de Malmquist
With the emergence of a knowledge-based economy, the role of higher education is becoming increasingly important. For Vietnam, recent decades have seen an explosion in the demand for higher education. Nevertheless, the current deficiencies of universities in management and in using resources have limited their competitiveness, particularly at regional and international levels. A system of performance measurement becomes indispensable, especially the efficiency. Our study aims to build it, using three techniques: sensitivity analysis, DEA metafrontier and Malmquist index

Gli stili APA, Harvard, Vancouver, ISO e altri

38

He, Ya. "Energy efficiency and financing mechanisms : the case of energy efficient lighting retrofit in hotels". Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648468.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

39

Kimsey, Linda Gail. "HOW EFFICIENT ARE MILITARY HOSPITALS? A COMPARISON OF TECHNICAL EFFICIENCY USING STOCHASTIC FRONTIER ANALYSIS". Lexington, Ky. : [University of Kentucky Libraries], 2009. http://hdl.handle.net/10225/1093.

Testo completo

Abstract (sommario):

Thesis (Ph. D.)--University of Kentucky, 2009.
Title from document title page (viewed on October 29, 2009). Document formatted into pages; contains: ix, 153 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 143-152).

Gli stili APA, Harvard, Vancouver, ISO e altri

40

Brasier, Richard. "Efficient autonomy: Identifying energy efficiency opportunities with the introduction of autonomous and connected vehicles". Thesis, Brasier, Richard (2015) Efficient autonomy: Identifying energy efficiency opportunities with the introduction of autonomous and connected vehicles. Other thesis, Murdoch University, 2015. https://researchrepository.murdoch.edu.au/id/eprint/30759/.

Testo completo

Abstract (sommario):

Much of the scientific and policy analysis of autonomous vehicles advocates their safety and accessibility. This dissertation seeks to contribute to broadening academic discourse by examining the energy efficiency opportunities of the introduction of autonomous vehicles and vehicle communication technology. As the global market for autonomous vehicles develops, the impacts on society are beginning to be investigated including the impact on energy efficiency. This dissertation will contribute to this discourse by examining platooning and automated intersection management as techniques for improving efficiency as a result of the introduction of autonomous vehicles. In addition, this dissertation will analyse how society is likely to adapt to autonomous vehicles being introduced into the market and the how it may impact the energy efficiency of transportation networks. This examination demonstrates that there is great scope for energy efficiency as society and systems adapt to this technological change.

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Bunt, Christopher M. "Fishways for warmwater species, utilization patterns, attraction efficiency, passage efficiency, and relative physical output". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0028/NQ51183.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Al-Shamali, Mansour. "Weak form efficiency and factors leading to market efficiency in the Kuwait stock market". Thesis, Loughborough University, 1989. https://dspace.lboro.ac.uk/2134/6735.

Testo completo

Abstract (sommario):

A small stock market may be less efficient in the weak sense than a large one, because it is often less elaborately organised technically. Hence, information about stock price formation may spread only gradually through the financial community. Consequontly, stock prices may display e greeter degree of nonrandomness because traders are unable to eliminate this. The objective of the study is to test the weak form efficiency in Kuwait Stock Exchange, a segment of the Kuwait Long Term capital market. In addition, the study explores the impact of several. factors on market efficiency. In Chapter One the role of the stock market and its relationship to the economy will be discussed. The efficient market hypothesis is explored in Chapter Two. Chapter Three is devoted to surveying the empirical findings of other researchers in UK, USA and some other international markets. A number of authors have applied the efficient market hypothesis to actual stock market data, especially in the last twenty years. Some critical analyses are discussed in Chapter Four. The empirical question of the relations between market efficiency and stock valuation is explored in Chapter Five. An efficient market should price the security, so as to fully reflect the firms earning power. The uncertainty surrounding the stream of future income clouds this issue and has prompted debate among economists and financial analysts as to how the market values a given stock at any time. The characteristic of Kuwait Stock Exchange are the subject of Chapter Six. Chapter Seven presents empirical findings on the behaviour of Kuwait Stock Exchange in the context of efficient market theory. These findings will be compared with those related studies based on data from the United States and Europe. Chapter Eight will discuss the Kuwait Gulf Stock Exchange (over-the- counter market) or Al-Manakh. The 1982 crash of Al-Manakh is explored in depth in Chapter Nine and some of the important solutions will be discussed. In Chapter Ten the discussion Focusses on the three hypothesised Factors leading to market efficiency (market information, governmental rules and regulations, and market support facilities). Finally, in Chapter Eleven, general conclusions are drawn and recommendations presented with suggestions for further research.

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Cheung, Grace M. "Development of an automated efficiency and loss measurement system for high-efficiency power converters". Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61150.

Testo completo

Abstract (sommario):

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 105).
When building a high performance power converter system, characterization becomes a significant task in and of itself. This thesis addresses the development of an automated efficiency and loss measurement system for high-efficiency power converters. The design, construction, calibration, and evaluation of such a measurement setup is described, including development of software to control the system. Application of the setup to a solar high- efficiency grid-tie inverter system is also addressed.
by Grace M. Cheung.
M.Eng.

Gli stili APA, Harvard, Vancouver, ISO e altri

44

Örn, Tomas. "Energy efficiency in heritage buildings : Conservation approaches and their impact on energy efficiency measures". Licentiate thesis, Luleå tekniska universitet, Arkitektur och vatten, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68405.

Testo completo

Abstract (sommario):

The impeding climate change challenge urges for a reduction of energy use in the built environment. Buildings account for nearly 40% of the total energy use and about 35% of the greenhouse gas emissions in Europe. EU member states are required to improve the energy efficiency of the existing building stock, for example by sharpening building regulations and developing enforcement schemes. Since energy efficiency retrofits can affect irreplaceable values in heritage buildings, heritage buildings are often excluded from mandatory demands aiming at reducing the energy use in buildings. However, saving energy have gradually become embraced by the conservation community and heritage buildings with are seen as part of the solution. This licentiate thesis discusses the methods to identify heritage significance in a building and how the underlying theory determines different scenarios in a energy retrofitting process. The choice of conservation theory and conservation approach will affect the success the energy retrofitting process and determine how much the energy use that can be reduced. This thesis therefore suggests a framework to understand the different interpretation of the impacts that one could exert either by having an Objectivistic or Relative conservation value approach.. Based on this framework, a decision-support tool is developed to further detail the impacts of such approaches for different energy measures. Other results show that a majority of reviewed research publications focused on the operational energy in a building and only a few were concerned with energy use over the entire life- cycle of a building. These analyses are used to evaluate where most energy savings can be made, and often pinpoint weak spots in the building’s envelope or technical system. If it was mentioned at all, the influence of cultural and historical factors on energy efficiency measures as applied to heritage buildings tended to be assessed only briefly. Indeed, the majority does not describe conservation principles or even mention the methodology used – if any – for assessing or defining heritage values. Instead, researchers often show an explicit (sometimes an implicit) understanding of conservation as essentially something that is not destructive of original construction material and hence the authenticity of a building. This licentiate thesis is a compilation thesis, consisting of one separate sub-study, one literature review and an extended cover essay. The study is oriented towards a Swedish and European context, especially when it comes to climate conditions and discussions on building regulations and the theory and practice of architectural conservation. It addresses the growing research field of energy efficiency in heritage buildings and the thesis aims to contribute to an increased understanding on how the process of assessment and evaluation of heritage significance in buildings affects the making of heritage buildings more energy efficient. The main research question is: How do different approaches for assessing and evaluating heritage significance in buildings affect possible technical energy saving measures in heritage buildings?
Klimatförändringarna driver utvecklingen mot att energianvändningen i den byggda miljön behöver minska. Byggnader står för nästan 40% av den totala energianvändningen och cirka 35% av utsläppen av växthusgaser i Europa. EUs medlemsländer är bundna att förbättra energieffektiviteten hos befintliga byggnader, till exempel genom att skärpa byggreglerna och utveckla handlingsplaner. Eftersom energieffektiviseringar kan påverka värden i kulturhurhistoriska byggnader, är dessa ofta undantagna från krav som syftar till att minska energianvändningen i byggnader. Energibesparing och resurshushållning har gradvis blivit omfamnad av kulturmiljösektorn och kulturhistoriska byggnader betraktas allt mer som en del av lösningen på klimatförändringarna. I licentiatavhandlingen diskuteras metoderna för att identifiera kulturhistoriska värden i en byggnad och hur den underliggande teorin påverkar olika scenarier i en energieffektiviseringprocess. Valet av bevarandeteori och bevarandestrategi påverkar framgångsfaktorn i energieffektivseringen och hur mycket energianvändningen i en kulturhistorisk byggnad kan minskas. I denna avhandling föreslås därför ett teoretiskt ramverk för att förstå effekterna av de olika kulturhistoriska bedömningar som kan göras, antingen genom att använda ett objektivistiskt eller en relativ syn på hur en en byggnads kulturhistoriska värden skapas och bäst bevaras. Utifrån detta teoretiska ramverk har ett stöd för beslutsfattande utvecklats för att ytterligare beskriva effekterna av de olika bevarandestrategiernas påverkan på implementeringen av olika energieffektiviserande åtgärder. Andra resultat visar att en majoritet av de granskade forskningspublikationerna fokuserade på den operativa energin i en byggnad och bara ett fåtal gällde energianvändning under hela livscykeln i en byggnad. Dessa analyser används för att utvärdera var de flesta energibesparingar kan göras och ofta identifiera svaga punkter i byggnadens klimatskal eller tekniska system. Om det nämndes alls tenderade inflytandet av kulturella och historiska faktorer på energieffektivitetsåtgärder som tillämpas på arvsbyggnader endast att bedömas kortfattat. Faktum är att majoriteten av de genomgångna publikationerna inte beskriver bevarandeprinciper och inte nämner den metod som används för att bedöma eller definiera kulturhistoriska värden. Istället används ofta en explicit (ibland en implicit) förståelse för bevarande som i huvudsak något som inte förstör ursprungligt material och därmed autenticitet i en byggnad. Denna licentiatavhandling består av en separat undersökning, en litteraturöversikt och en utökad kappa. Studien är inriktad på ett svenskt och europeiskt sammanhang, särskilt när det gäller klimatförhållanden och diskussioner om byggregler och teori och praktik för kulturhistoriskt bevarande av byggnader. Den är en del av det växande forskningsområdet energieffektivisering i kulturhistoriska byggnader och avhandlingen syftar till att bidra till en ökad förståelse för hur utvärderingen av kulturhistoriska värden i byggnader påverkar arbetet med att göra dem mer energieffektiva. Huvudforskningsfrågan är: Hur påverkar olika metoder för bedömning och utvärdering av kulturhistoriska värden energibesparande åtgärder i kulturhistoriska byggnader?

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Pervaiz, Haris Bin. "Optimising energy efficiency and spectral efficiency in multi-tier heterogeneous networks : performance and tradeoffs". Thesis, Lancaster University, 2016. http://eprints.lancs.ac.uk/80695/.

Testo completo

Abstract (sommario):

The exponential growth in the number of cellular users along with their increasing demand of higher transmission rate and lower power consumption is a dilemma for the design of future generation networks. The spectral efficiency (SE) can be improved by better utilisation of the network resources at the cost of reduction in the energy efficiency (EE) due to the enormous increase in the network power expenditure arising from the densification of the network. One of the possible solutions is to deploy Heterogeneous Networks (HetNets) consisting of several tiers of small cell BSs overlaid within the coverage area of the macrocells. The HetNets can provide better coverage and data rate to the cell edge users in comparison to the macrocells only deployment. One of the key requirements for the next generation networks is to maintain acceptable levels of both EE and SE. In order to tackle these challenges, this thesis focuses on the analysis of the EE, SE and their tradeoff for different scenarios of HetNets. First, a joint network and user adaptive selection mechanism in two-tier HetNets is proposed to improve the SE using game theory to dynamically re-configure the network while satisfying the user's quality-of-service (QoS) requirements. In this work, the proposed scheme tries to offload the traffic from the heavily loaded small cells to the macrocell. The user can only be admitted to a network which satisfies the call admission control procedures for both the uplink and downlink transmission scheme. Second, an energy efficient resource allocation scheme is designed for a two-tier HetNets. The proposed scheme uses a low-complexity user association and power allocation algorithm to improve the uplink system EE performance in comparison to the traditional cellular systems. In addition, an opportunistic joint user association and power allocation algorithm is proposed in an uplink transmission scheme of device to device (D2D) enabled HetNets. In this scheme, each user tries to maximise its own Area Spectral Efficiency (ASE) subject to the required Area Energy Efficiency (AEE) requirements. Further, a near-optimal joint user association and power allocation approach is proposed to investigate the tradeoff between the two conflicting objectives such as achievable throughput and minimising the power consumption in two-tier HetNets for the downlink transmission scheme. Finally, a multi-objective optimization problem is formulated that jointly maximizes the EE and SE in two-tier HetNets. In this context, a joint user association and power allocation algorithm is proposed to analyse the tradeoff between the achievable EE and SE in two-tier HetNets. The formulated problem is solved using convex optimisation methods to obtain the Pareto-optimal solution for the various network parameters.

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Dahm, Matthias. "Coalitional stability and economic efficiency". Doctoral thesis, Universitat Autònoma de Barcelona, 2002. http://hdl.handle.net/10803/4030.

Testo completo

Abstract (sommario):

La tesis consta de tres capítulos que analizan la formación de países. El punto de partida es un artículo de Alesina y Spolaore (The Quart. J. of Econ. 112, 1997, 1027-1056) que propone un marco teórico para el análisis positivo y normativo de esta cuestión. El principal resultado de este trabajo es que en general en equilibrio se observa un número de países que es demasiado elevado. La tesis hace un "test de sensibilidad" de esta conclusión a variaciones de los supuestos del modelo utilizado. Los cambios en los supuestos están inspirados en conceptos de la literatura de la formación de coaliciones.
El primer capítulo estudia los efectos de cambios en el concepto de equilibrio utilizado. Por un lado se introduce el concepto del "strong Tiebout equilibrium" (Greenberg and Weber, J. of Econ. Th. 38, 1986, 101-117). Se muestra que el equilibrio de Alesina y Spolaore es robusto a este cambio ya que se puede entender como un "Strong Tiebout equilibrium" específico que se elige según las reglas de la formación de países utilizadas por Alesina y Spolaore. Esto implica propiedades adicionales para el equilibrio de Alesina y Spolaore que son deseables. Por otro lado se modifican las reglas de la formación de países para acercarlas a las reglas utilizadas en la realidad. Esto lleva al problema de la noexistencia del equilibrio.
En el segundo capítulo, se analiza el cambio de un modelo con una población que es un continuo a un modelo con un número finito de agentes. Un número finito es un supuesto tradicional de la literatura de la formación de coaliciones. Es deseable que las conclusiones que se derivan utilizando la herramienta poderosa de un continuo de agente se confirmen para un número elevado pero finito de agentes. El análisis utiliza conceptos de estabilidad básicos que son débiles. Por lo tanto se encuentra una multiplicidad de equilibrios. Algunos son eficientes en el sentido de Alesina y Spolaore mientras que otros no lo son.
Finalmente, el tercer capítulo extiende el análisis del segundo empleando nociones de estabilidad más fuertes. Como la aplicación de los conceptos de estabilidad de Alesina y Spolaore crea problemas en el modelo con un número finito de agentes, se utiliza la noción del "strong Tiebout equilibrium". Se encuentra una multiplicidad de equilibrios que aun siendo menor que en el segundo capítulo no permite confirmar la conclusión de Alesina y Spolaore.
The thesis consists of three Chapters that analyse the formation of countries. Starting point is a paper by Alesina y Spolaore (The Quart. J. of Econ. 112, 1997, 1027-1056) that proposes an analytical framework for the normative and positive analysis of this question. The fundamental result of this work is that in equilibrium one generally observes an inefficiently large number of countries. This thesis carries out a test of robustness of this result to changes in the assumptions of the model. These changes are motivated by the literature on coalition formation.
The first Chapter studies the effect of a change in the equilibrium concept. On one hand the concept of a strong Tiebout equilibrium (Greenberg and Weber, J. of Econ. Th. 38, 1986, 101-117) is introduced. It is shown that the equilibrium of Alesina y Spolaore is robust to this modification because it can be understood as the unique outcome of a selection among all strong Tiebout equilibria where the selection is driven by the specific rules of country formation. This implies additional desirable properties of the equilibrium of Alesina y Spolaore. On the other hand the rule of country formation are modified in order to make them closer to the rules used in reality. This leads to the problem of non-existence of an equilibrium.
The second Chapter analyses the change from a continuum of agents to a finite population. A finite number of agents is traditionally assumed in the literature on coalition formation. Moreover it is desirable that the conclusions derived using the logical construct of a continuum of agents are confirmed for a large but finite number of agents. Since the analysis employs weak stability concepts, a multiplicity of equilibria arises for some of which the inefficiency result is true while for others it is not.
Finally the third Chapter extends the investigation of the second using stronger stability notions. Since the stability concepts of Alesina and Spolaore lead to problems in the model with a finite number of agents, the notion of a strong Tiebout equilibrium is employed. Although this reduces the number of equilibria found in the second chapter, it does not allow to confirm the inefficiency result of Alesina and Spolaore.

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Keith, Islas Jorge Rubén. "Hospital efficiency analysis in México". Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/403769.

Testo completo

Abstract (sommario):

La tesis se estructura en tres capítulos, que se describen brevemente en esta sección: El capítulo II presenta una revisión de la literatura sobre los esquemas de financiamiento en varios países y se compara con el actual sistema de salud en México, principalmente integrado por el presupuesto global, capitativo y pagos directos. Un enfoque metafrontera se utiliza para identificar la eficiencia entre los hospitales bajo diferentes tecnologías de acuerdo con su esquema de financiamiento, en relación con la tecnología potencial disponible para todo el sistema de salud. Como parte de los resultados de eficiencia obtenidos previamente para los hospitales privados, el Capítulo III evalúa la eficiencia técnica y la presencia potencial de economías de escala y alcance para mejorar las decisiones de gestión, basándose en las teorías de la función de producción, escala y alcance. La metodología no paramétrica se utiliza para calcular los coeficientes de eficiencia para la valoración de las economías de escala. Posteriormente, se utilizó un modelo de dos etapas para hospitales diversificados y especializados para calcular la valoración de las economías de alcance. Este capítulo ha sido aceptado y publicado en la revista Salud Pública en México (año 2014, volumen 56, número 4, páginas 348-354). El Capítulo IV evalúa una alianza estratégica hospitalaria usando un concepto metafrontera para comparar la eficiencia entre los miembros de la alianza hospitalaria mexicana y un grupo control. Los índices de utilización de la capacidad hospitalaria se utilizan como la tasa máxima de producción posible de los insumos fijos en un entorno de frontera, utilizando funciones de distancia direccional. Finalmente, el Capítulo V presenta las conclusiones y principales aportaciones de la tesis, así como sugerencias para futuras investigaciones. La Tabla 1.1 indica un resumen de los principales elementos descritos anteriormente en cada capítulo.
The thesis is structured in three chapters, which are briefly described in this section: Chapter II presents a literature review on actual financing schemes in several countries, and is compared to the current health system in México mainly integrated by global budget, capitation and direct payments. A metafrontier approach is used to identify efficiency among hospitals under different technologies according to their financing scheme, relative to the potential technology available to all healthcare system. As part of the efficiency results previously obtained for private hospitals, Chapter III evaluates technical efficiency and potential presence of scale and scope economies to improve management decisions, based in the production function, scale and scope economies theories. Non-parametric methodology is used to calculate efficiency scores for scale economies valuation. Then a two-staged model for diversified and specialized hospitals was used to calculate the scope economies valuation. This chapter has been accepted and published in the journal Salud Pública en México (year 2014, volume 56, number 4, pages 348-354). Chapter IV evaluates a strategic hospital alliance by using a metafrontier concept to compare the efficiency between Mexican hospital alliance members and a control group. Hospital capacity utilization ratios are used as the maximum rate of output possible from fixed inputs in a frontier setting, using directional distance functions. Finally, Chapter V presents the conclusions and main contributions of the thesis, and suggestions for future research. Table 1.1 indicates a summary of the main elements described earlier in each chapter.

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Fredriksson, Robert, e Milovan Trkulja. "Fuel Efficiency in AWD-system". Thesis, Jönköping University, JTH, Mechanical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-1589.

Testo completo

Abstract (sommario):

This degree project has been made in cooperation with engineers working for GM Engineering/Saab Automobile AB in Trollhättan. The given name by Saab for the project is “Fuel efficiency improvements in All Wheel Drive(AWD)-system”. The main tasks of this thesis work were to investigate the size of the power losses in different parts on the propeller shaft, to design a computer program that calculates

coordinates and angles on a propeller shaft and to investigate the possibilities to put together a simplified formula that calculates the natural frequencies on a propeller shaft.

The main parts of this report are a compilation of the theory about AWD and mostly about the parts on the propeller shaft, and also a description of the developed computer program called Propeller Shaft Calculator. This report doesn’t concern power losses in the different joints because there were no such general equations to be found. The most common way to calculate the power losses inside a joint is to do tests were the power loss is measured at different angles, torque and speed and then use that data to put together an approximated equation.

Most of the work on this project has been on theory studies and on programming. The main result of the project is the program Propeller Shaft Calculator.

Propeller Shaft Calculator is a program that is designed in Microsoft Excel. All the menus are programmed in the visual basic editor in Excel. The program is supposed to be used as a help while designing new propeller shafts.

Propeller Shaft Calculator can calculate all the coordinates, lengths, angles and directions on a propeller shaft. It also calculates natural frequencies, plunge, estimated power loss on the second shaft and angles in the joints. In the program you can choose to do calculations on four different configurations of propeller shafts but can quite

easy upgrade the program with more choices.

Basically the program works like this:

First you choose the right propeller shaft in the main menu. Then you fill out the indata sheet with coordinates, lengths, material data and so on. As you type in the input data the output data will appear in the out-data sheet next to the in-data. Every propeller shaft has also a calculations sheet were more detailed calculations can be

found.

The program also has a built in help function and a warning function that lights a warning sign next to the values if they are outside the limits.

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Geske, Ulrich, e Hans-Joachim Goltz. "Efficiency of difference-list programming". Universität Potsdam, 2010. http://opus.kobv.de/ubp/volltexte/2010/4156/.

Testo completo

Abstract (sommario):

The difference-list technique is described in literature as effective method for extending lists to the right without using calls of append/3. There exist some proposals for automatic transformation of list programs into differencelist programs. However, we are interested in construction of difference-list programs by the programmer, avoiding the need of a transformation step. In [GG09] it was demonstrated, how left-recursive procedures with a dangling call of append/3 can be transformed into right-recursion using the unfolding technique. For simplification of writing difference-list programs using a new cons/2 procedure was introduced. In the present paper, we investigate how efficieny is influenced using cons/2. We measure the efficiency of procedures using accumulator technique, cons/2, DCG’s, and difference lists and compute the resulting speedup in respect to the simple procedure definition using append/3. Four Prolog systems were investigated and we found different behaviour concerning the speedup by difference lists. A result of our investigations is, that an often advice given in the literature for avoiding calls append/3 could not be confirmed in this strong formulation.

Gli stili APA, Harvard, Vancouver, ISO e altri

50

WANG, YI-NING, e 王翊寧. "Bandwidth-Efficient Fast Algorithm for High Efficiency Video Coding". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/bdp32g.

Testo completo

Abstract (sommario):

碩士
國立高雄第一科技大學
電腦與通訊工程系碩士班
106
Thanks to the fast developing high technology nowadays, mobile telecommunication 4G/LTE is popularized worldwide, and which makes a rapidly growing New Media related Industry.With the higher requirement for good quality an-d high resolution of Video/Webcam , the bandwidth and the amount of coding compressed data for transmitting Video have to be expanded. In order to keep high performance of video under efficient data compression, more complicated mathematical calculations is a must.In the newest HEVC, CU is quite diversified in order to match different resolution requirement as well as to support higher resolution. Since the bandwidth of audio and video on mobile internet device is limited, our major target is to settle bandwidth problem on high resolution video, that is , to narrow the bandwidth. This thesis puts forward the algorithm of Bandwidth-Rate-Distortion Optimization (BRDO), which is on basis of Rate-Distortion Optimization. The algorithm distributes bandwidth and search area by size of Rate-Distortion Cost (RDCost). It not only lowering the usage of bandwidth but maintaining quality and rate. On average, more than 56% of bandwidth's usages were saved and more than 60% of encoding time decrease largely. The hardware architecture was implemented by using Synopsys (Verilog, Verdi, Design Compiler, Synthesis, PrimeTime®, PrimePower®) and Cell Library (TSMC 90nm CLN90G). The speed of our design was 1.1GHz under the worst case simulation case, and the power consumption was 0.873mW.

Gli stili APA, Harvard, Vancouver, ISO e altri

Tesi sul tema "Efficiency"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili