• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 4
  • 1
  • 1
  • 1
  • Tagged with
  • 17
  • 17
  • 8
  • 4
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Uncertainty in life cycle costing for long-range infrastructure. Part II: guidance and suitability of applied methods to address uncertainty

Scope, Christoph, Ilg, Patrick, Muench, Stefan, Guenther, Edeltraud 25 August 2021 (has links)
Life cycle costing (LCC) is the state-of-the-art method to economically evaluate long-term projects over their life spans. However, uncertainty in long-range planning raises concerns about LCC results. In Part I of this series, we developed a holistic framework of the different types of uncertainty in infrastructure LCCs. We also collected methods to address these uncertainties. The aim of Part II is to evaluate the suitability of methods to cope with uncertainty in LCC. Part I addressed two research gaps. It presented a systematic collection of uncertainties and methods in LCC and, furthermore, provided a holistic categorization of both. However, Part I also raised new issues. First, a combined analysis of sources and methods is still outstanding. Such an investigation would reveal the suitability of different methods to address a certain type of uncertainty. Second, what has not been assessed so far is what types of uncertainty are insufficiently addressed in LCC. This would be a feature to improve accuracy of LCC results within LCC, by suggesting options to better cope with uncertainty. To address these research gaps, we conducted a systematic literature review. Part II analyzed the suitability of methods to address uncertainties. The suitability depends on data availability, type of data (tangible, intangible, random, non-random), screened hotspots, and tested modeling specifications. We identified types of uncertainties and methods that have been insufficiently addressed. The methods include probabilistic modeling such as design of experiment or subset simulation and evolutionary algorithm and Bayesian modeling such as the Bayesian latent Markov decision process. Subsequently, we evaluated learning potential from other life cycle assessment (LCA) and life cycle sustainability assessment (LCSA). This analysis revealed 28 possible applications that have not yet been used in LCC. Lastly, we developed best practices for LCC practitioners. This systematic review complements prior research on uncertainty in LCC for infrastructure, as laid out in Part I. Part II concludes that all relevant methods to address uncertainty are currently applied in LCC. Yet, the level of application is different. Moreover, not all methods are equally suited to address different categories of uncertainty. This review offers guidance on what to do for each source and type of uncertainty. It illustrates how methods can address both based on current practice in LCC, LCA, and LCSA. The findings of Part II encourage a dialog between practitioners of LCC, LCA, and LCSA to advance research and practice in uncertainty analysis.
2

Evolução da estrutura organizacional ao longo do ciclo de vida do projeto: um estudo de caso. / Evolution of the project organizational structure towards the cycle of life of the project.

Pinto, Ricardo Lopes 10 July 2002 (has links)
Esta pesquisa teve como objetivos revelar como se deu a evolução da estrutura da organização de projeto ao longo do ciclo de vida de um projeto considerado bem sucedido e possibilitar especulações sobre o porquê do fenômeno ter se dado daquela forma. Trata-se de um estudo de caso exploratório que focalizou o ciclo de vida de um projeto de otimização do chassi de um ônibus urbano feito em uma empresa com tradição em desenvolvimento de projetos. A investigação incluiu a descrição do ciclo de vida do projeto em termos de fases caracterizadas por suas deliverables, a caracterização da configuração adotada para a estrutura da organização de projeto em cada uma das fases do ciclo de vida do projeto e o relato das percepções do entrevistado sobre o uso de autoridade, sobre a atribuição de responsabilidades e sobre a comunicação. Foram empregadas múltiplas fontes de dados: entrevistas abertas, consulta a documentos e a registros de arquivos e observações diretas informais. Os resultados da pesquisa sugerem que o referencial teórico clássico desenvolvido para estruturas organizacionais de empresas pode ser muito útil para apoiar o processo de organizar na situação de projeto pois ficou claro que a situação descrita pôde ser explicada e prevista a partir da interpretação e adaptação dos conhecimentos a uma particular situação de projeto. Sendo assim, a pesquisa fornece uma contribuição à ampliação dos conhecimentos em Administração de Projetos já que oferece subsídios a futuras investigações no sentido de explorar em maior profundidade essa problemática. / The main goals of this research are to reveal the evolution of the project organizational framework, towards the cycle of life of a successful project and to enable some speculation about the development process itself. This study deals with the exploration process focusing the cycle of life of the developed project for an urban bus chassis by a traditional company. The research included the description of the cycle of life of the project, towards the phases characterized by its deliverables; the configuration set adopted for the project framework, in each phase of the cycle of life of the project and the report from the perception about authority, responsibility designation and communication of the person interviewed. Multiple data source was used: open interviews, consultation to documents and file records, and informal straight observations. The research results suggest that the classic theoretical reference developed for company organizational framework can be very helpful to support the organizational process on projects, because the reported situation could be explained and predicted from the interpretation and adaptation of the knowledge to a private project situation. Therefore, the research provides some contribution to the enlargement of reference on project administration, since it offers base to prospective researches in order to explore this matter in depth.
3

Life Cycle Thinking and Waste Policy : Between Science and Society

Lazarevic, David January 2012 (has links)
This study investigates the application of life cycle thinking (LCT) and life cycle assessment (LCA) in the field of waste management from perspectives based in the social sciences. LCT is explored through the theoretical construct of regimes, drawing theoretical resources from a combination of the ‘pragmatic turn’, the economics of conventions and transition theory.This work is based on eight papers treating theoretical arguments, qualitative and quantitative analysis, case studies and semi-structured interview data. LCT is placed in the context of contemporary societies. LCA is seen as an instrument of quantification and evaluation used by actors which have both similar and disparate objectives, and who offer justifications for its use through arguments embedded in conflicting pluralities of worth. Furthermore, this work analyses LCA as a tool for the qualification of the waste hierarchy; a waste management principle articulating a convention based on closed material cycles. This study argues that the technological trajectory of waste management regimes has been significantly influenced, inter alia, by actors’ institutional articulation of the waste hierarchy at national and territorial levels. It discusses the legitimacy of LCA, and the quantitative application of LCT, as an intermediary object used to qualify the waste hierarchy. Furthermore, LCT is placed in a prospective context which may be used to assist in the transition toward sustainable waste management. / <p>QC 20121127</p>
4

Housing histories : older women's experience of home across the life course.

Holland, Caroline Anne. January 2001 (has links)
Thesis (Ph. D.)--Open University. BLDSC no. DX215644.
5

Computational Fracture Prediction in Steel Moment Frame Structures with the Application of Artificial Neural Networks

Long, Xiao 2012 August 1900 (has links)
Damage to steel moment frames in the 1994 Northridge and 1995 Hyogken-Nanbu earthquakes subsequently motivated intensive research and testing efforts in the US, Japan, and elsewhere on moment frames. Despite extensive past research efforts, one important problem remains unresolved: the degree of panel zone participation that should be permitted in the inelastic seismic response of a steel moment frame. To date, a fundamental computational model has yet to be developed to assess the cyclic rupture performance of moment frames. Without such a model, the aforementioned problem can never be resolved. This dissertation develops an innovative way of predicting cyclic rupture in steel moment frames by employing artificial neural networks. First, finite element analyses of 30 notched round bar models are conducted, and the analytical results in the vicinity of the notch root are extracted to form the inputs for either a single neural network or a competitive neural array. After training the neural networks, the element with the highest potential to initiate a fatigue crack is identified, and the time elapsed up to the crack initiation is predicted and compared with its true synthetic answer. Following similar procedures, a competitive neural array comprising dynamic neural networks is established. Two types of steel-like materials are created so that material identification information can be added to the input vectors for neural networks. The time elapsed by the end of every stage in the fracture progression is evaluated based on the synthetic allocation of the total initiation life assigned to each model. Then, experimental results of eight beam-to-column moment joint specimens tested by four different programs are collected. The history of local field variables in the vicinity of the beam flange - column flange weld is extracted from hierarchical finite element models. Using the dynamic competitive neural array that has been established and trained, the time elapsed to initiate a low cycle fatigue crack is predicted and compared with lab observations. Finally, finite element analyses of newly designed specimens are performed, the strength of their panel zone is identified, and the fatigue performance of the specimens with a weak panel zone is predicted.
6

Evolução da estrutura organizacional ao longo do ciclo de vida do projeto: um estudo de caso. / Evolution of the project organizational structure towards the cycle of life of the project.

Ricardo Lopes Pinto 10 July 2002 (has links)
Esta pesquisa teve como objetivos revelar como se deu a evolução da estrutura da organização de projeto ao longo do ciclo de vida de um projeto considerado bem sucedido e possibilitar especulações sobre o porquê do fenômeno ter se dado daquela forma. Trata-se de um estudo de caso exploratório que focalizou o ciclo de vida de um projeto de otimização do chassi de um ônibus urbano feito em uma empresa com tradição em desenvolvimento de projetos. A investigação incluiu a descrição do ciclo de vida do projeto em termos de fases caracterizadas por suas deliverables, a caracterização da configuração adotada para a estrutura da organização de projeto em cada uma das fases do ciclo de vida do projeto e o relato das percepções do entrevistado sobre o uso de autoridade, sobre a atribuição de responsabilidades e sobre a comunicação. Foram empregadas múltiplas fontes de dados: entrevistas abertas, consulta a documentos e a registros de arquivos e observações diretas informais. Os resultados da pesquisa sugerem que o referencial teórico clássico desenvolvido para estruturas organizacionais de empresas pode ser muito útil para apoiar o processo de organizar na situação de projeto pois ficou claro que a situação descrita pôde ser explicada e prevista a partir da interpretação e adaptação dos conhecimentos a uma particular situação de projeto. Sendo assim, a pesquisa fornece uma contribuição à ampliação dos conhecimentos em Administração de Projetos já que oferece subsídios a futuras investigações no sentido de explorar em maior profundidade essa problemática. / The main goals of this research are to reveal the evolution of the project organizational framework, towards the cycle of life of a successful project and to enable some speculation about the development process itself. This study deals with the exploration process focusing the cycle of life of the developed project for an urban bus chassis by a traditional company. The research included the description of the cycle of life of the project, towards the phases characterized by its deliverables; the configuration set adopted for the project framework, in each phase of the cycle of life of the project and the report from the perception about authority, responsibility designation and communication of the person interviewed. Multiple data source was used: open interviews, consultation to documents and file records, and informal straight observations. The research results suggest that the classic theoretical reference developed for company organizational framework can be very helpful to support the organizational process on projects, because the reported situation could be explained and predicted from the interpretation and adaptation of the knowledge to a private project situation. Therefore, the research provides some contribution to the enlargement of reference on project administration, since it offers base to prospective researches in order to explore this matter in depth.
7

A living necropolis : the introduction of a necropolis to the inner city of Pretoria, focusing on the cycle of life

Erasmus, Jacobus Petrus 08 July 2011 (has links)
The proposed thesis design is a necropolis (city of the dead) in the form of a vertical park structure through which alternative methods of burial are investigated. The question of an architectural expression of consciousness to overcome cultural norms and challenge perceptions is researched through the theoretical exploration of the following: the cycle of life; the physical and meta-physical between; and collective dwelling. Through exploring ways of sensitively infusing urban environments with an awareness and acknowledgement of death, life is celebrated by exposing death through a physical manifestation of the whole cycle of life, which will transcend several generations of urban dwellers. In populating the between, these antimonument memorials would become accepted over time and a meta-physical awareness would be created to produce a new culture of urban life. / Dissertation (MArch(Prof))--University of Pretoria, 2011. / Architecture / unrestricted
8

Implementing Insect Production in Agricultural Value Chains: An ex-ante life cycle evaluation

Roffeis, Martin 01 April 2019 (has links) (PDF)
Résumé Une demande croissante sans cesse de produits alimentaires à base d’animaux influence la productivité des systèmes mondiaux de production alimentaire, et des mesures indispensables pour freiner la dégradation de l’environnement promettent des effets similaires. Si les scénarios de demande future peuvent être satisfaits de manière durable, cela dépend notamment de la possibilité de réduire de manière significative l'impact de l'aquaculture et de l'élevage sur l'environnement. Des recherches récentes suggèrent que l'utilisation d'aliments à base d'insectes (IBF) pourrait apporter une contribution significative à cet égard, et des arguments valables sont avancés pour soutenir cette hypothèse. Les larves de mouches, comme celles des mouches domestiques (Musca domestica) ou des mouches soldat noir (Hermetia illucens), sont en mesure de puiser des nutriments dans un large éventail de ressources organiques, y compris celles impropres à la consommation humaine. Cela crée la possibilité de convertir (et de réduire considérablement) les déchets organiques de faible valeur, tels que le fumier ou le sang animal, en protéines de haute qualité et en énergie alimentaire, qui se sont avérés appropriés pour nourrir différents poissons d'aquaculture et du bétail monogastrique.Bien que le concept IBF promet d’importants avantages et ait démontré sa faisabilité technique, il n’existe encore aucun système établi permettant de tester les avantages supposés en termes de durabilité. Dans cette thèse, nous avons essayé de surmonter cette lacune par la modélisation de tels systèmes. Notre objectif central était d'identifier les aspects influençant le potentiel d'application des IBF dans différents contextes géographiques et de définir des voies d'optimisation pour une mise en œuvre durable. En nous basant sur des données expérimentales recueillies lors d'essais d'élevage menés en Europe (Espagne et Slovaquie) et en Afrique de l'Ouest (Ghana et Mali), nous avons formulé la conception d'un ensemble de versions de systèmes améliorés élevant M. domestica et H. illucens sur différents substrats organiques de faible valeur. Les modèles de production génériques ont servi comme base d’une analyse du cycle de vie ex ante, dans laquelle nous avons exploré les performances des systèmes à l’aide d’analyse du cycle de vie environnementale (ACV) et de l’analyse des coûts du cycle de vie (ACCV).Les ACVs et ACCVs ont montré que les performances environnementales et économiques des IBF sont largement fonction de l’efficacité de conversion des systèmes, de l’organisation du processus de production (c’est-à-dire de l’apport de main-d’œuvre et d’équipements technologiques) et du contexte géographique. La combinaison de ces facteurs a fourni des avantages pour les configurations simplistes utilisées dans la production de M. domestica en Afrique occidentale tropicale dans des conditions de ponte naturelle (c'est-à-dire d'inoculation de substrat par le biais de mouches présentes à l'état naturel). L'inoculation artificielle (c'est-à-dire l'inoculation du substrat par le biais de larves nourries provenant d'une colonie d'adultes en captivité), utilisée dans la production de H. illucens en Afrique de l'Ouest et de M. domestica dans le sud de l'Espagne, a favorisé une efficacité de conversion élevée, mais a augmenté les impacts environnementaux et les coûts, parce que le système complexe et l'organisation de processus à forte intensité de main-d'œuvre ont considérablement accru les intrants de main-d'œuvre et d'infrastructures de production.Une comparaison avec des aliments conventionnels riches en protéines a mis en évidence des inconvénients environnementaux et économiques pour les modèles de production actuels des IBF, notamment en ce qui concerne les aliments végétaux (par exemple, le tourteau de soja). Les disparités entre les alimentations IBF et conventionnelles reflètent l’utilisation des capacités sub-optimaux des systèmes (effet d’économie d’échelle insuffisant), ainsi que la perte d’énergie et de biomasse le long de la chaîne trophique (producteurs autotrophes vs consommateurs hétérotrophes). Les résultats soulèvent des doutes légitimes sur les avantages en termes de durabilité d’une mise en œuvre d'insectes dans les chaînes de valeur agricoles actuelles. Le succès commercial dépend en grande partie du niveau de salaire spécifique au contexte, des prix des substrats d'élevage et de la manière dont les marchés évaluent les multiples fonctions que les insectes sont capables de fournir. S'agissant de la performance environnementale, nos résultats nous amènent à conclure que la production d'IBF ne présente aucun avantage par rapport aux aliments conventionnels.L’évaluation de systèmes de production encore hypothétiques impliquait une bonne quantité d’hypothèses et d’approximations. Étant donné ces multiples sources d'incertitude et compte tenu du fait que seul un nombre limité de conceptions de systèmes possibles sont prises en compte, les déclarations sur le potentiel d'application d'IBF n'ont aucune validité universelle et doivent être interprétées avec prudence. Cependant, nos résultats contribuent à une meilleure compréhension des facteurs influant sur le potentiel d’application des systèmes de production d’insectes et constituent un point de référence précieux pour les discussions scientifiques et les activités de recherche et développement futures visant à mettre en place des modes de production alimentaire durables.Bien que nos recherches n’apportent aucun soutien aux avantages environnementaux ou économiques supposés de l’utilisation d’insectes dans l’alimentation animale, il est possible que leur utilisation comme aliment destiné à la consommation humaine directe (c’est-à-dire comme substitut possible aux produits à base de poisson et de viande) constitue une solution durable aux problèmes actuels et futurs. Nous recommandons donc aux recherches futures de se concentrer sur les techniques permettant d'exploiter les insectes comme nourriture. / Doctorat en Sciences / There are a few details that I could not specify in the available input fields. I would like to ask you kindly to add the following information: (1) Prof. Erik Mathijs (KUL) is my second co-supervisor; (2) Next to the Jury members listed, there are Prof. Matthias Finkbeiner (TU Berlin) and Prof. Theo Niewold (KU Leuven), which I could not enter manually. / info:eu-repo/semantics/nonPublished
9

Environmental Life Cycle Costing (ELCC) für Produkte der Solarenergie: Die Verbindung von Life Cycle Assessment (LCA) und Life Cycle Costing (LCC) - from Cradle to Grave - angewandt auf die Photovoltaik. Anforderungen bei der Durchführung und aktueller Stand in der Praxis

Krause, Marcus January 2011 (has links)
Vor dem Hintergrund der zukünftigen Notwendigkeit einer nachhaltigen Energieversorgung beschäftigt sich die vorliegende Arbeit mit Technologien der regenerativen Energiequelle Solarenergie, insbesondere Photovoltaik (PV). Systeme zur Nutzung der unerschöpflich verfügbaren, sauberen und im Prinzip “frei Haus” gelieferten Energie der Sonne können eine bedeutsame Rolle in einer umweltverträglicheren Zukunft spielen. Allerdings ist die Herstellung der erforderlichen Komponenten heute i.d.R. noch energie- und kostenintensiv, weshalb für eine korrekte Bewertung dieser Technologien der gesamte Lebenszyklus betrachtet werden muss. Zur tieferen Analyse der PV wird die Methodik des Environmental Life Cycle Costing (ELCC) auf der Grundlage von drei Grundideen eingeführt. Konkret sind dies die Ausgangspunkte: Nachhaltigkeit, Lebenszyklusdenken und die Drei-Dimensionalität dieses Instrumentes durch die gemeinsame Betrachtung ökologischer, ökonomischer und technischer Aspekte in ihrem Zusammenspiel. Ausgehend von theoretischen Elementen der Ökobilanzierung (Life Cycle Assessment) und des Life Cycle Costings, verbunden mit den technischen Eigenschaften der Photovoltaik werden wichtigste Anforderungen und Schritte für die Durchführung eines ELCC für PV beschrieben. Mittels einer softwaregestützten Inhaltsanalyse wird im Anschluss der definierte Rahmen für ein ELCC für PV getestet (und modifiziert) gegen eine Auswahl von 135 bereits existierender Studien, die sich mit dem Lebenszyklus von PV-Technologien aus ökologischer und ökonomischer Sicht beschäftigen. Im Ergebnis hieraus können die wichtigsten Elemente eines ELCC für PV, wie beispielsweise ökologische Wirkungskategorien oder ökonomische Indikatoren, identifiziert werden (methodisches Feedback). In einem nächsten Schritt werden die Studien hinsichtlich ihrer “Qualität” bezogen auf ökologische, ökonomische und übergreifende Inhalte eines ELCC für PV bewertet. Auf diese Weise kann ein Inventar von Lebenszyklusanalysen für PV erstellt werden, das nach den Technologien und der inhaltlichen Qualität bezüglich eines ELCC strukturiert ist und für weitere Analysen als Grundlage dienen kann. Aus den bisherigen Ergebissen kann eine erste Einschätzung zum aktuellen Stand des ELCC für PV in der Literatur vorgenommen werden: Es existiert bereits ein großer Pool von Studien, die sich mit dem Lebenszyklus der PV beschäftigen. Mit Blick auf die Anforderungen eines ELCC für PV besteht jedoch Nachholbedarf in der Verbindung und gemeinsamen Betrachtung von hot spots und trade offs aus ökologischer und ökonomischer Perspektive. Der definierte theoretische Rahmen für ein ELCC für PV, die kodierten Studien sowie das erstellte Inventar von Lebenszyklusanalysen der PV können nun als Grundlage für weitere Analysen dienen. Insbesondere eine inhaltliche Auswertung der konkreten Ergebnisse von Studien kann so einen Benchmark und Orientierung für neue Lebenszyklusanalysen für PV-Technologien liefern. / The special need of a sustainable energy supply in mind the technologies of the renewable source solar energy, especially photovoltaics (PV) is main subject of the present thesis. Using the inexhaustible, clean and “freely delievered” power from the sun solar devices may play a major role in a cleaner future, but, on the other hand, they are still energy consuming and expensive in their production which consequently demands a whole life cycle perspective when assessing this technology. For a closer look at PV the methodology of Environmental Life Cycle Costing (ELCC) is introduced by following three theoretical points of view. Namely these are sustainability, life cycle thinking and the three dimensional nature of this tool by regarding environmental, economic and technical aspects in their interaction. Based on theoretical elements of Life Cycle Assessment and Life Cycle Costing in combination with the technical background of photovoltaics main requirements and steps for performing an ELCC for PV are described. By executing software based content analysis the defined framework is checked (and modified) against a choice of 135 existing studies analyzing the life cycle of PV technologies from an environmental or economic perspective. As a result the main elements of an ELCC for PV, e.g. environmental impact categories and economic indicators, are identified (methodological feedback). Within the next step the existing studies are rated by their “quality” regarding the environmental, economic and more general parts of an ELCC for PV in order to create an inventory of life cycle studies for PV. This inventory is structured by technologies as well as quality of content respecting ELCC and might be used for further analyses. At this stage the results propose the possibility of a first estimate of the present status of ELCC for PV: until now there is a good pool of existing analyses of the life cycle of PV systems. But from an ELCC perspective the examination of common hot spots and trade offs between economic and environmental aspects should be expanded. The theoretical framework of ELCC for PV, the encoded studies and the inventory of life cycle analyses for PV are now the starting point for further analyses, especially of the individual outcome within studies, which will then pose a benchmark for new life cycle studies of PV technology.
10

Revising the Gerotranscendence scale for use with older adults in the southern United States and establishing properties of the Reised Gerotranscendence scale

Cozort, Rachel W. January 1900 (has links)
Dissertation (Ph.D.)--The University of North Carolina at Greensboro, 2008. / Directed by Anita Tesh; submitted to the School of Nursing. Title from PDF t.p. (viewed Jan. 28, 2010). Includes bibliographical references (p. 119-130).

Page generated in 0.0659 seconds