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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.
51

Design of One-Story Hollow Structural Section (HSS) Columns Subjected to Large Seismic Drift

Kong, Hye-Eun 24 September 2019 (has links)
During an earthquake, columns in a one-story building must support vertical gravity loads while undergoing large lateral drifts associated with deflections of the vertical seismic force resisting system and deflections of the flexible roof diaphragm. Analyzing the behavior of these gravity columns is complex since not only is there an interaction between compression and bending, but also the boundary conditions are not perfectly pinned or fixed. In this research, the behavior of steel columns that are square hollow structural sections (HSS) is investigated for stability using three design methods: elastic design, plastic hinge design, and pinned base design. First, for elastic design, the compression and flexural strength of the HSS columns are calculated according to the AISC specifications, and the story drift ratio that causes the interaction equation to be violated for varying axial force demands is examined. Then, a simplified design procedure is proposed; this procedure includes a modified interaction equation applicable to HSS column design based on a parameter, Pnh/Mn, and a set of design charts are provided. Second, a plastic hinge design is grounded in the concept that a stable plastic hinge makes the column continue to resist the gravity load while undergoing large drifts. Based on the available test data and the analytical results from finite element models, three limits on the width to thickness ratios are developed for steel square HSS columns. Lastly, for pinned base design, the detailing of a column base connection is schematically described. Using FE modeling, it is shown that it is possible to create rotational stiffness below a limit such that negligible moment develops at the column base. All the design methods are demonstrated with a design example / Master of Science / One-story buildings are one of the most economical types of structures built for industrial, commercial, or recreational use. During an earthquake, columns in a one-story building must support vertical gravity loads while undergoing large lateral displacements, referred to as story drift. Vertical loads cause compression forces, and lateral drifts produce bending moments. The interaction between these forces makes it more complex to analyze the behavior of these gravity columns. Moreover, since the column base is not perfectly fixed to the ground, there are many boundary conditions applicable to the column base depending on the fixity condition. For these reasons, the design for columns subjected to lateral drifts while supporting axial compressive forces has been a growing interest of researchers in the field. However, many researchers have focused more on wide-flange section (I-shape) steel columns rather than on tube section columns, known as hollow structural section (HSS) steel columns. In this research, the behavior of steel square tube section columns is investigated for stability using three design methods: elastic design, plastic hinge design, and pinned base design. First, for elastic design, the compression and flexural strength of the HSS columns are calculated according to current code equations, and the story drift that causes failure for varying axial force demands is examined. Then, a simplified design procedure is proposed including design charts. Second, a plastic hinge design is grounded in the concept that controlled yielding at the column base makes the column continue to resist the gravity load while undergoing large drifts. Based on the available test data and results from computational models, three limits on the width to thickness ratios of the tubes are developed. Lastly, for pinned base design, concepts for detailing a column base connection with negligible bending resistance is schematically described. Using a computational model, it is shown that the column base can be detailed to be sufficiently flexible to allow rotation. All the design methods are demonstrated with a design example.
52

Maktstrukturer i gynekologin : Undersökning och kommentar på reproduktion av normer från 1800-talet i dagens patientupplevelse

Wilckens, Lina January 2017 (has links)
Stolar förhåller sig på ett mycket intimt sätt till våra kroppar och de kan även fungera som markörer i ett socialt maktspektrum. Gynekologstolen utvecklades under 1800-talet, den moderna medicinens glansdagar. Det var även en tid där kvinnor började begära större sociala och politiska rättigheter och det uppkom ett stort behov att biologiskt legitimera kvinnans underordning under mannen. Sedan dess har gynstolens strukturella utformning knappt förändrats. Den är en central symbol för den gynekologiska undersökningen och som jag kunde analysera i workshops och intervjuer kan den för patienter förknippas med känslor som utsatthet eller att ge upp bestämmelserätten över den egna kroppen. För vissa kvinnor är dessa känslor så starka att de skjuter upp kommande undersökningar eller undviker de helt. Som följd av det kan allvarliga sjukdomar förbli oupptäckta. I mitt kandidatarbete har jag undersökt patienters upplevelse av gynekologiska undersökningar idag och kopplat de till historiska erfarenheter. Huvudfokus av mitt arbete har som fysisk beröringspunkt varit gynekologstolen. Jag har vidare arbetat med formgivningen av en lounge chair som är lämpad för gynekologiska undersökningar. I framtagningen av stolen har jag valt att förhålla mig till design av sjukvårdsprodukter på ett icke-traditionellt sätt genom att lägga huvudfokus på patientupplevelsen. Genom detta har jag försökt att exemplifiera hur detta tillvägagångssätt i produktframtagning för vården kan leda till mer hållbara patientupplevelser. Mitt fokusområde har varit att förskjuta historiska maktförhållanden i gynekologin och att utveckla en stol för gynekologisk undersökning gemensamt med de som traditionellt inte har fått vara delaktiga i framtagningen av objekt som användes på deras kroppar: kvinnor. / <p>The full thesis contains copyrighted material which has been removed in the published version.</p>
53

New Perspectives on Analysis and Design of High-Speed Craft with Respect to Slamming

Razola, Mikael January 2016 (has links)
High-speed craft are in high demand in the maritime industry, for example, in maintenance operations for offshore structures, for search and rescue, for patrolling operations, or as leisure craft to deliver speed and excitement. Design and operation of high-speed craft are often governed by the hydrodynamic phenomena of slamming, which occur when the craft impact the wave surface. Slamming loads affect the high-speed craft system; the crew, the structure and various sub-systems and limit the operation. To meet the ever-increasing demands on safety, economy and reduced environmental impact, there is a need to develop more efficient high-speed craft. This progression is however limited by the prevailing semi-empirical design methods for high-speed planing craft structures. These methods provide only a basic description of the involved physics, and their validity has been questioned. This thesis contributes to improving the conditions for designing efficient highspeed craft by focusing on two key topics: evaluation and development of the prevailing design methods for high-speed craft structures, and development towards structural design based on first principles modeling of the slamming process. In particular a methodological framework that enables detailed studies of the slamming phenomena using numerical simulations and experimental measurements is synthesized and evaluated. The methodological framework involves modeling of the wave environment, the craft hydromechanics and structural mechanics, and statistical characterization of the response processes. The framework forms the foundation for an extensive evaluation and development of the prevailing semi-empirical design methods for high-speed planing craft. Through the work presented in this thesis the framework is also shown to be a viable approach in the introduction of simulation-based design methods based on first principles modeling of the involved physics. Summarizing, the presented methods and results provide important steppingstones towards designing more efficient high-speed planing craft. / <p>QC 20160907</p>
54

Innovation in the design of continuous flight auger and bored displacement piles

Baxter, David January 2009 (has links)
The field of pile design and construction in the United Kingdom is currently in a period of change. Not only are new processes and techniques being developed but also the legislative landscape is changing with the introduction of new Europe wide normative standards (BSI, 2004, 2007). This project sought to optimise pile design through better understanding and interpretation of ground conditions and of the pile-soil interaction for two pile types, continuous flight auger and bored displacement piles. Quantitative methods for interpreting and summarising previous knowledge and experience have been developed; the strata are divided into discrete bands and properties are represented with summary statistics. Experience and previous knowledge relating to the shear strength of London Clay have been quantified and presented using this approach. Furthermore, a straightforward tool has been provided for the implementation of such data into design; the previous knowledge and new site specific data are combined using Bayesian updating. Through use of this technique, the uncertainty associated with interpreting ground conditions from site data has been demonstrated to be reduced. The techniques described have been adopted into design practice within the sponsoring company. Bored displacement piles are a relatively new pile type. There is little published data or scientific understanding of the processes undergone by the soils during and after construction and the effect that these have on pile performance. This research identified the need for, and developed, a unified framework of descriptors for the various types of bored displacement pile and investigated the installation energy and performance of bored displacement piles in London Clay. The energy to construct the pile was observed to be highly variable and not directly related to capacity. Performance of bored displacement piles was observed to be similar to continuous flight auger piles of similar dimensions; typical values for the adhesion between bored displacement piles and the surrounding soil were established and these were comparable to those achieved by continuous flight auger piles. In addition, to enable the analysis of the probability of failure of a pile, the sources of variation have been investigated and the variability quantified. Besides the soil conditions, the dimensions of the pile, notably pile diameter, were found to be a significant source of variation.
55

Designing Context-Aware Applications for Complex Environments

Brett Campbell Unknown Date (has links)
Researchers have approached the problem of designing context-aware systems, computer systems that can react intelligently to the context in which they are used, from both software engineering and human-centred perspectives. While engineered context-aware systems have found successful application in optimising technical settings without requiring mundane and explicit interaction from humans, challenges remain in furthering their application to more complex environments. In particular, when technical decisions and human actions are intertwined in sophisticated work environments (rather than, for example, the simple act of transferring a mobile phone call to receive a signal from the nearest tower), the problem of designing context-aware systems demands further examination and calls for a new approach. A natural extension of the software engineering approach in more challenging environments is to try to implement increasingly sophisticated algorithms for managing context in the hope that this will lead to autonomous application behaviour. In contrast, research from a human-centred perspective, grounded in the social sciences and philosophy, demonstrates that context is not entirely objective and measurable but rather is dynamic and created through human action. It may not be easily detected through technical sensing systems, and therefore simply employing more sophisticated algorithms within the technical sphere may not be effective. While engineering approaches have continued to evolve, the problem of how to design interfaces to context-aware applications still remains. The research reported in this dissertation investigated the problem of designing context-aware systems for the complex environment of a dental surgery. I undertook, though a participatory design approach (a) to better characterise the problem of designing context-aware systems, and (b) to understand how design methods could be employed to bridge the human and software engineering approaches. The gap in existing research on context-aware systems is evident in the way that the methods applied to designing systems don't provide an insight into how people actively create the context in which they work (in a practical rather than theoretical sense) they don‘t closely examine the behaviours of people, the role and arrangement of artefacts, and the dynamic relationships between people and artefacts. I found that an understanding of how these features of work and human behaviour are realised in practice in a given environment is fundamental to being able to design an effective context-aware system for that environment. The challenge is to design at the boundary between the technical and the social. The contribution of this thesis is an approach that explores context-aware design through synthesis. The synthetic approach leads to design opportunities and guidelines based on an understanding of the processes through which people actively co-create the context in which they work. I have applied and built upon a number of existing user-centred design and participatory design methods, in addition to creating some new methods in order to develop an understanding of how designers can examine the human aspects surrounding the co-creation of context and apply these in a way that progressively informs the design process. The methods collectively represent a novel approach to designing context-aware applications and differ from the more traditional technical approaches of developing software frameworks and infrastructures, and formal models of context, tasks, users, and systems. The techniques presented have focused primarily on developing an understanding of how humans find meaning in their actions along with their interaction with other people and technology. Participatory design methods help participants to reveal potential implicit technical resources that can be presented explicitly in technologies in order to assist humans in managing their interactions with and amidst technical systems gracefully. The methods introduced and the design approach proposed complement existing research on context-awareness from both a human-centred and software engineering perspective. This research builds on the notion of providing resources which allow users to manage their own context and also manage shifts in control while interacting with other people and with a variety of technical artefacts. It does this by examining a complex work environment, in particular looking at the kinds of resources people use and expect to use (and the constraints around these), the form(s) it is appropriate for them to take, and the patterns of interaction they will ultimately be used within.
56

Functional and environmental factors in early phases of product development - Eco functional matrix

Lagerstedt, Jessica January 2003 (has links)
Interest in environmental issues has increased enormouslyover the last few decades and environmental problems areperceived to be on the increase. Due to the fact that thenumber of products on the market increases enormously, it isevident that we face a great challenge to overcome the problemconcerning our consumer society. An increasing barrage oflegislation accompanied by the public’s awareness of, andconcern for, the environment forcing the industry to respond.Products and their environmental impact have moved to thecentre stage and it is widely believed that designers have akey role in adapting products to a sustainable society. Threekey issues are identified in this development scenario: (a) theimportance of adapting products to a more sustainable society,(b) the specific situation facing the designer, especially inearly design phases, and (c) balancing environmental impactswith functional preferences. Research in this thesis presents a theoretical framework fordescribing environmental issues and the role of the designer inproduct development, as well as functional characteristics ofproducts in the early phases of design. Based on anengineering-design science foundation, theoretical models andconcepts have been developed describing how both functional andenvironmental preferences can be visualised in design forenvironment and product development. Case studies andinterviews have been performed and integrated into a coherenttheoretical model for identifying and evaluating functional andenvironmental preferences within ecodesign approach andreasoning. The overall concept proposed in this thesis is called theeco functional matrix, based on two parts: functional profileand environmental profile. The functional profile represent thefunctional characteristics and environmental profile theenvironmental characteristics respectively of a product in theearly phases of design. One of the objectives behind theconcept is to highlight the importance of balancing functionalrequirements and environmental impacts, presenting both theadvantages and disadvantages of the product. The basic idea isto account for user and societal preferences as well asenvironmental impact when assessing alternative productconcepts at early design stages. Balancing both the functionalrequirements and the negative environmental impacts of productsis the road to sustainable development. <b>KEYWORDS</b>Design for environment, life-cycle design,eco-design, eco-design methods, product environmentalcharacteristics, product functional characteristics, customerbenefit, value analysis, functional profile, environmentalprofile, eco functional matrix, product properties.
57

Functional and environmental factors in early phases of product development - Eco functional matrix

Lagerstedt, Jessica January 2003 (has links)
<p>Interest in environmental issues has increased enormouslyover the last few decades and environmental problems areperceived to be on the increase. Due to the fact that thenumber of products on the market increases enormously, it isevident that we face a great challenge to overcome the problemconcerning our consumer society. An increasing barrage oflegislation accompanied by the public’s awareness of, andconcern for, the environment forcing the industry to respond.Products and their environmental impact have moved to thecentre stage and it is widely believed that designers have akey role in adapting products to a sustainable society. Threekey issues are identified in this development scenario: (a) theimportance of adapting products to a more sustainable society,(b) the specific situation facing the designer, especially inearly design phases, and (c) balancing environmental impactswith functional preferences.</p><p>Research in this thesis presents a theoretical framework fordescribing environmental issues and the role of the designer inproduct development, as well as functional characteristics ofproducts in the early phases of design. Based on anengineering-design science foundation, theoretical models andconcepts have been developed describing how both functional andenvironmental preferences can be visualised in design forenvironment and product development. Case studies andinterviews have been performed and integrated into a coherenttheoretical model for identifying and evaluating functional andenvironmental preferences within ecodesign approach andreasoning.</p><p>The overall concept proposed in this thesis is called theeco functional matrix, based on two parts: functional profileand environmental profile. The functional profile represent thefunctional characteristics and environmental profile theenvironmental characteristics respectively of a product in theearly phases of design. One of the objectives behind theconcept is to highlight the importance of balancing functionalrequirements and environmental impacts, presenting both theadvantages and disadvantages of the product. The basic idea isto account for user and societal preferences as well asenvironmental impact when assessing alternative productconcepts at early design stages. Balancing both the functionalrequirements and the negative environmental impacts of productsis the road to sustainable development.</p><p><b>KEYWORDS</b>Design for environment, life-cycle design,eco-design, eco-design methods, product environmentalcharacteristics, product functional characteristics, customerbenefit, value analysis, functional profile, environmentalprofile, eco functional matrix, product properties.</p>
58

"E-Portfolio" projektavimas ir metodų tyrimas / Design and analysis of e-portfolio

Dovydaitis, Juozas 16 July 2008 (has links)
Šiame dokumente nagrinėjama tyrimo sritis susijusi su „E-Portfolio“ tipo sistemų projektavimu ir galimų projektavimo metodų parinkimu. Analitinėje darbo dalyje pristatomos „E-Portfolio“ sistemos, jos vėliau palyginamos. Projektinėje dalyje pateikiama suprojektuotos tokios sistemos – „ePortfelis“, - architektūra. Tiriamojoje darbo dalyje apžvelgiami skirtingi projektavimo metodai ir jų tinkamumas „E-Portfolio“ sistemų projektavimui. / The main objective of this project was to design and develop an e-portfolio system „ePortfelis”. During this process the analysis of alternative e-portfolio systems was performed, as well as gathering of e-portfolio requirements. The design of developed system was carried according to RUP process. There were reviewed three different software design methods during the software design methods analysis part: SSADM, Booch method and JSP. It was determined that of those three above mentioned methods JSP was most unsuitable for designing e-portfolio systems.
59

Supporting customer focused design in the assistive technology industry

Bamforth, Sarah E. January 2003 (has links)
Assistive technologies (AT) are the products provided to elderly and disabled people to enable them to live more independently. Despite their ability to help maintain independence and prevent injury, the literature discussed within this thesis indicates that assistive technologies are not meeting the needs of the end-user. In response, research has been undertaken with the following objectives: 1. To identify how and why assistive technology products are failing to satisfy the customer. 2. To establish if a design tool can be created that overcomes the issues identified in the inductive research and which enables companies to design customer-satisfying assistive technology products. In progressing these objectives, two phases of research were planned. The first comprised four parallel studies (focus groups, case studies, questionnaires and a literature study), which together examined the state of AT products and the product-development activities of AT manufacturers. The second phase of research examined four customer-focused product design methods for their suitability for utilisation by small companies within the AT sector. On finding that no method in its entirety was suitable, a customer-focused design tool for small AT companies was developed. The resulting tool comprises eight elements for application in the initial stages of the product development process. The tool was tested in four separate studies, which examined its usability and acceptability to AT companies and which gave further insights into the AT sector. The research both finds that AT products are failing the customer in five areas and that manufacturers are contributing to this failure through a lack of customer-focus in their design processes. In addition to identifying the market research and product development activities of small AT companies, a key contribution to knowledge resulting from the research is the concept of sectoral readiness for methods of design. In its conclusion the thesis finds that the two research objectives have been met.
60

A Search For Common Pleasures: CURATING THE CITY

Helsel, Sand, n/a January 2009 (has links)
The project-based research questions how professionals working in the built environment can engage a broader range of 'others' (students, client, users) in ways of seeing and acting in a meaningful way. It challenges the role of the expert in architecture and urban design and in particular their use of the masterplan, which is often an oversimplified reductive response, laden with generalisations and the ill-considered overlay of inappropriate models. Design methods are designed to enable us to see afresh and respond accordingly. These are demonstrated in three suites of projects that include urban installations such as Five Walks for the Melbourne International Arts Festival, war memorials, lectures, photographs and teaching practice such as Taipei Operations, a student workshop, architectural exhibition, and book. The design research is situated within an expanded field of cross-disciplinary practice that includes art, landscape architecture, urban design, architecture and geography. Tools are developed to enable us to understand the city at many spatial and temporal scales; observations made at a micro scale reveal systems at a macro scale - a bottom-up approach. The application of the methods explored implies that

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