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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The development of a prototype uniform for high school girls in Swaziland

Ndlangamandla, Sibongile Buyisile 24 June 2011 (has links)
A study was carried out to: <ul><li>Determine and describe all the stakeholders’ preferences and problems with regard to high school girls' uniform; and</li> <li>To make recommendations for the prototype uniform that could be tested amongst stakeholders.</li></ul> A survey was conducted through three questionnaires for the three different groups, namely the Form-3 girls, parents (represented by the mothers), and the teachers at the school, to determine the functional and aesthetic preferences and problems experienced with the current school uniform. Form-3 girls were selected because it was assumed they had passed the spurt of growth between the ages of 15 and 17 years. Their mothers had the experience of purchasing the family’s clothes, while the teachers spend most of the time with the girls observing the quality features of the uniform. Purposive sampling was used to select the girls, their mothers and five teachers from each school, resulting in a total sample of 150 girls, 150 mothers and 84 teachers. Fifteen (15) schools were selected from two highly populated urban areas, namely: the Hhohho region (Mbabane) and the Manzini region (Manzini). `The analysis starts with the descriptive characteristics of the demographic information of the stakeholders in the uniforms used in the school. Data was expressed in frequencies and percentages. Means and standard deviations were ranked in descending order, the most preferred functional and aesthetic features placed at the top. The functional and aesthetic performance problems were also ranked, with the feature giving most problems placed at the top. The study revealed that Swazi high school girls rated both their functional and aesthetic preferences high. Amongst the performance preferences, sensory-aesthetic dimensions were rated as very important, followed by durability (that the tunic should not fade in colour), comfort and ease of care. Performance preferences that were considered less important by the girls were the wearing of the tunic in summer and winter and using the tunic for class and sports. Mothers were not asked about comfort preferences because they do not wear the tunic; however, amongst the functional performance qualities tested on them, durability, care and cost were considered important. As was the case with the girls, mothers also considered symbolic preferences less important, for example that the tunic should show family and cultural values. The comparison of the combined functional dimensions to the combined aesthetic dimensions indicated that the girls and their mothers rated the functional performance preferences of the tunic higher than the aesthetic performance preferences. Teachers were only asked to respond on end-use and symbolic qualities of the tunic. Teachers considered the wearing of the tunic in winter and summer more important than the symbolic preferences. Symbolic preferences were also seen to be less important with the girls and their mothers. From the problems it can be concluded that the mothers and the girls did not experience major problems, except that the tunic fades. Mothers saw the cost of the tunic to be too expensive, as the same tunic could not be worn for sports. All the preferences relate to choice of style and fabric. Consumers preferred a panelled style of tunic with a waistline; however, in order to accommodate for growth, a semi-fitted princess style was recommended. / Dissertation (MConsumer Science)--University of Pretoria, 2010. / Consumer Science / unrestricted
22

Disaster Proof: The Ephemeralization of Prefabricated Architecture for Climate Resilience

Detroit, Ryan N. 09 July 2019 (has links)
No description available.
23

Prototype color graphic terminal

El-Saleh, Nabeel T. January 1983 (has links)
No description available.
24

Feasibility Study Into the Use of 3D Printed Materials in CubeSat Flight Missions

Fluitt, Daniel 01 June 2012 (has links) (PDF)
The CubeSat Program has provided access to space for many universities, private companies, and government institutions primarily due to the low cost of CubeSat satellite development. While these costs are orders of magnitude lower than similarly capable nano-satellite missions, they are still outside of the budgetary constraints of many potential developers including university and high school clubs. Using 3D printed plastics in the production of CubeSat structures and mechanisms presents a large cost savings opportunity that will allow these institutions to participate in the development of these satellites, expanding the educational and scientific impact of the CubeSat Program. Five rapid prototype plastics manufactured with four different 3D printing technologies were studied to determine their survivability when subjected to the required vibration testing and thermal bakeout that all CubeSats are must pass through before integration and launch. ASTM D638 Type V tensile bar samples of each plastic were procured and subjected to a thermal bakeout and tensile testing to determine the thermal and outgassing effects on their mechanical properties. This information was used to design a concept structure for use in a low budget CubeSat mission. Finite Element Analysis in Abaqus was then utilized to test the integrity of this structure under a worst case load condition derived from the ELaNa 6 launch vibration profile. Results from the analysis show that Objet FullCure720 photopolymer resin, DSM Somos Prototherm 12120 photopolymer resin, and Windform XT carbon fiber filled nylon all provide adequate strength to survive the environmental testing conditions required for this system to proceed through flight integration and launch.
25

Detection of pigments of halophilic endoliths from gypsum: Raman portable instrument and European Space Agency's prototype analysis

Culka, A., Osterrothova, K., Hutchinson, I.B., Ingley, R., McHugh, M., Oren, A., Edwards, Howell G.M., Jehlička, J. January 2014 (has links)
No / A prototype instrument, under development at the University of Leicester, for the future European Space Agency (ESA) ExoMars mission, was used for the analysis of microbial pigments within a stratified gypsum crust from a hypersaline saltern evaporation pond at Eilat (Israel). Additionally, the same samples were analysed using a miniaturized Raman spectrometer, featuring the same 532 nm excitation. The differences in the position of the specific bands, attributed to carotenoid pigments from different coloured layers, were minor when analysed by the ESA prototype instrument; therefore, making it difficult to distinguish among the different pigments. The portable Delta Nu Advantage instrument allowed for the discrimination of microbial carotenoids from the orange/green and purple layers. The purpose of this study was to complement previous laboratory results with new data and experience with portable or handheld Raman systems, even with a dedicated prototype Raman system for the exploration of Mars. The latter is equipped with an excitation wavelength falling within the carotenoid polyene resonance region. The ESA prototype Raman instrument detected the carotenoid pigments (biomarkers) with ease, although further detailed distinctions among them were not achieved.
26

A Framework for Integrating Pure Shadow Lines into Architectural Design Process

Sugati, Alsaleh Tariq 30 March 2022 (has links)
In light of today's technological developments, the world has become more interested in everything that is quantifiable. In the field of architecture, this phenomenon has affected the design process, in terms of neglect human requirements related to the lived experience. This research is concerned with studying the intersection between what is quantifiable and what could contribute to improve the living experience. Research in disciplines such as art, architecture, and psychology assert that geometries with pure mathematical expression are visually pleasing. The present research aims to integrate these geometric relationships with daylight when formed by the edge of light and shadow, resulting from direct sunlight entering a room through roof openings and presenting on a northern wall. The goal of this research is to develop an initial prototype for a proof of concept that enables architects to consider humanistic, aesthetic criteria for geometry and daylight. The research progresses through three stages. First, the researcher describes a method to assess the geometry of lines resulting from the boundary between light and shadow when falling on a sunlit wall. Second, the researcher applies the described method to a random sample of roof opening configurations using digital modeling and a simulation of the sun's movement. Thirdly, the researcher extracts a regression equation that describes the relationship between the resulting shadow lines on the walls and the configuration of the roof openings. This regression analysis will form an initial step to developing a decision-support tool that predicts the purity of shadow lines during the early stages of the design process. / Doctor of Philosophy / Many architects acknowledge that the buildings we design today lack beauty. This research discusses the possibility of creating a program that considers visual beauty in architectural design. Many disciplines have offered praise about pure geometric shapes. The aim of this research is to develop a prototype that helps architects use these geometric shapes in architectural design specifically in the use of daylight inside rooms. To elaborate, when the sun moves, in its rising and setting, lines of shadows appear within the space that belong to pure geometric shapes. These pure forms are a source of visual beauty because they are derived from nature; as a result, our bodies have a physiological and psychological response when seeing them. The study is based on testing a hypothesis that asserts the higher the degree of purity of the lines used in the design of a room, namely the north-facing wall and roof openings, the higher will be the purity of the shadow lines resulting from the movement of the sun.
27

Contextual Constraints: An Examination of Implicit Followership Theories

Snead, Kathleen Benton 22 April 2013 (has links)
This study was designed to assess follower prototypes as dynamic structures. Connectionist theory is a good framework to understand the process by which followership perceptions are altered by contextual factors. Organizational culture, change in immediate leader and follower prototypes were measured in an applied setting across time to assess the dynamism of the cognitive networks of implicit followership theories. Change in culture and immediate leader was measured at three time points, across six months, during the acquisition of one organization by a second. Change scores were created by computing difference scores from surveys completed at the first time point to the second time point, three months later, to the third and final time point, three months later. There were no significant effects of change in culture on reported follower networks. There was, however, a significant effect of leader change at time points two and three when regressed on individual's follower networks. The overall findings of this study suggest that IFT's like leadership prototypes remain fairly stable across time (Epitropaki, 2004), but are subject to organizational change. / Master of Science
28

Design Space Exploration : co-operative creation of proposals for desired interactions with future artefacts

Westerlund, Bo January 2009 (has links)
This thesis critically reflects on co-operative design workshops that I have conducted. The basic method used in these workshops draws on the participants’ embodied knowing. In the over twenty workshops that are analysed here a wide range of participants have been involved: family members, employees, persons with disabilities, and other stakeholders like manufacturers, service providers and civil servants. The topics have varied, but they have mostly been related to ICT products and services. Most of the workshops were conducted within various research projects. In order to analyse this diverse range of workshops I use several different theories and concepts. I articulate and analyse the design aspects of the activities by using established design theories and concepts. The conceptual tool design space, meaning all possible design proposals, is used for understanding the design process. I also use theories from other fields in order to analyse three different aspects of the workshops: the participants’ activities, the designers’ responsibility, and the process. To analyse the way that the participants co-operatively create knowledge, theories of interpersonal actions are used; to analyse the work done by the designer/conductor, theories of frames are used; and to analyse the process, the theory of actualisation and realisation is used. During the workshops the participants co-operatively make scenarios, props and video prototypes in order to create proposals for desired interactions with future artefacts. Contributions include accounts of critical situations during the workshops and suggested strategies for dealing with them. Some implications are relevant to the design field in general, for example the importance of a process where the participants trust each other, learn from each other and work effectively with difficult issues by creating multiple proposals that facilitate understanding of the design space. I also offer arguments about why it is better to see activities, props and prototypes as mainly constitutive rather than as only representative. Video prototypes on DVD and seven publications are included in the thesis.
29

La zone obscure du design : une pensée des pratiques de conception (d')après Gilbert Simondon / The dark zone of design : thinking design practices with and after Gilbert Simondon

Beaubois, Vincent 23 January 2019 (has links)
Cette thèse poursuit un double objectif. D’une part, montrer l’apport que constitue la philosophie de Gilbert Simondon à une compréhension renouvelée du design et des problématiques contemporaines qui l’habitent. D’autre part, renverser l’image communément attribuée au design : alors que celui-ci se présente majoritairement comme une force de résolution de problèmes, d’innovation et de progrès, l’anthropotechnologie déployée par Simondon interroge cette prétention démiurgique. La première partie de ce travail s’intéresse aux conditions historiques de ce dialogue entre la philosophie simondonienne et la pensée du design des années 1950. La deuxième partie problématise la pensée contemporaine du design : en centrant son activité sur la figure de l’« usager », celle-ci évacue la question de la matérialité de notre environnement et des relations écologiques que nous tissons avec elle. La pensée de Simondon ouvre, au contraire, la voie d’une « rematérialisation » de la pensée design. La troisième partie nous immerge dans le monde spécifique des pratiques de conception dans le but d’informer la logique propre au geste de design en train de se faire. Il s’agit alors de penser le design à partir de ce qu’il produit littéralement : non pas des biens de consommation, ni des services améliorant la qualité de vie des « usagers », mais une multitude de diagrammes, prototypes et maquettes donnant forme à un problème de conception. En suivant les pratiques de conception de ce point de vue endogène, il s’agit de rendre compte des conséquences politiques d’une telle opération. Le design se définit alors comme un lieu fragile d’exploration, d’expérimentation et d’invention de problématiques présentes ralentissant toute promesse de progrès futurs. / This thesis has a twofold objective. On the one hand, to examine the contribution of Gilbert Simondon’s philosophy to a renewed understanding of design and to the contemporary issues that inhabit it (relation to the user, to ecology). On the other hand, to invert the image commonly attributed to design: while this one presents itself mainly as a force for solving problems, innovation and progress, the anthropo-technology deployed by Gilbert Simondon questions this demiurgic claim. The first part of this work focuses on the historical conditions of this dialogue between the Simondonian philosophy and the thought of design in the 1950s. The second part problematizes the contemporary thinking of design: by focusing its activity on the figure of the “user”, it evacuates the question of our environment materiality and the ecological relations that we forge with it. Then, the thought of Simondon opens the way to a “rematerialization” of design thinking. The third part immerses us in the specific world of design practices to trace the logic of design in the making. It is then a question of thinking design from what it produces literally: not consumer goods, nor services improving the quality of life of “users”, but a multitude of diagrams, prototypes and models giving shape to a design problem. Thus, design first produces “designing” objects — questioning our ways of dwelling the world — before populating the world with “designed” objects. By following the design practices from this endogenous point of view, we account for the political consequences of such an operation. Design is then defined as a fragile place of exploration, experimentation and invention of current problems slowing down any promise of future progress.
30

Contribution to the sizing of the modular multilevel converter / Contribution au dimensionnement du convertisseur modulaire multiniveau

Džonlaga, Bogdan 25 September 2019 (has links)
Le convertisseur multiniveau modulaire (MMC) est une solution appropriée pour les réseaux HVDC grâce à sa modularité, sa faible fréquence de commutation et sa tension alternative quasi-sinusoïdale. En raison de sa topologie, son modèle mathématique est assez complexe et est donc souvent simplifié au stade de la conception. En particulier, la résistance équivalente au bras R, l'inductance du bras L et le courant circulant sont souvent négligés. Toutefois, les résultats expérimentaux obtenus avec notre prototype monophasé de MMC à pont complet à six niveaux ont montré que ces hypothèses ne sont pas toujours acceptables. Dans ce contexte, l'objectif de cette thèse est d'étudier l'impact de R, L et du courant de circulation sur la tension du condensateur du module et sur la zone de fonctionnement du MMC. Premièrement, nous avons étendu le modèle basé sur les intégrales communément utilisé et nous avons clarifié les hypothèses sur lesquelles il repose. Entre autres, des expressions pour les courants de circulation et courant DC ont été développées et comparées à celles que l’on trouve dans la littérature. Cela nous a permis d'analyser l'ondulation de la tension du condensateur du module en fonction de R et L, sans courant de circulation. Deuxièmement, pour surmonter les limites du modèle basé sur l'intégrale, nous avons proposé d'utiliser un modèle MMC invariant dans le temps en régime permanent dans le système dq0. Quelques hypothèses seulement sont nécessaires pour obtenir ce modèle, mais une évaluation numérique est requise. Cela nous a permis d'analyser la tension moyenne du condensateur du module et l'ondulation de tension du condensateur du module en fonction de R et L, avec et sans courant de circulation. Troisièmement, en utilisant le modèle invariant dans le temps en régime permanent, nous avons développé un diagramme PQ détaillé du MMC. Outre la limite de courant AC, la limite de courant DC et la limite d'indice de modulation classiques, nous avons ajouté plusieurs limites internes: courant de l'IGBT, courant efficace des bras et ondulation du courant et de la tension du condensateur du module. Les résultats ont été confirmés par simulation numérique à l'aide d'un modèle détaillé Matlab Simulink SimPowerSystems. Les résultats présentés dans cette thèse pourraient être utilisés pour optimiser le dimensionnement des composants de la MMC en fonction de sa zone d’exploitation et pour évaluer l’impact de différents paramètres sur les performances du MMC. / The modular multilevel converter is a suitable solution for HVDC grids thanks to its modularity, low switching frequency and quasi-sinusoidal AC voltage. However, due to its topology, its mathematical model is quite complex and is therefore often simplified at the design stage. In particular, the arm equivalent resistance R, the arm inductance L and the circulating current are often neglected. But experimental results obtained with our 1-ph 6-level full-bridge MMC prototype showed that these hypotheses are not always acceptable. In this context, the goal of this thesis is to study the impact of accounting for R, L and the circulating current on the module capacitor voltage and on the operating area of the converter. First, we extended the commonly used integral based model and we clarified the hypotheses behind it. Among others, expressions for the circulating and dc currents have been developed and compared with the one that can be found in the literature. It allowed us to analyze the module capacitor voltage ripple as a function of R and L, without circulating current only. Second, to overcome the limitations of the integral based model, we proposed to use a steady state time invariant (DeltaSiga) MMC model in dq0 frame. Only few hypotheses are required to obtain this model, but a numerical evaluation is required. It allowed us to analyze the module capacitor average voltage and the module capacitor voltage ripple as a function of R and L, with and without circulating current. Third, using the steady state time invariant model, we developed a detailed PQ diagram of the MMC. In addition to the conventional AC current limit, DC current limit and modulation index limit, we added several internal limits: IGBT current, arm rms current and module capacitor voltage and current ripple. The results have been confirmed by numerical simulation using a detailed Matlab Simulink SimPowerSystems model. The results presented in this thesis could be used to optimize the sizing of the components of the MMC considering its operating area, and to assess the impact of different parameters on the MMC performance.

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