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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.
171

Living alongside railways : a discursive psychological analysis of adapting to disruption and identities of place

Condie, J. January 2013 (has links)
The concepts of ‘place’ and ‘identity’ are increasingly being used to understand the relations between people and physical environments. This research utilised ‘place’ and ‘identity’ to examine how people negotiate environmental conditions such as vibration and noise within their talk around ‘place’ and ‘identity’. For the study context, living alongside railways was chosen as an ‘ordinary’ and ‘everyday’ physical feature within residential settings and also due to potential upcoming changes to the UK rail network such as new lines and increases in rail freight traffic. Ten qualitative interviews were generated with twelve residents living alongside the West Coast Main Line (WCML) railway in the North of England. Participants were recruited from the Defra-funded study ‘NANR209: Human Response to Vibration in Residential Environments’ (Defra, 2011). Using a discursive psychological approach, railways were portrayed as an insignificant aspect of ‘place’ in relation to the wider contexts of finding somewhere to live. Through the ‘lived ideologies’ of ‘the rural idyll’ and ‘a peaceful and quiet place’ that emerged within participants’ talk, railways could be considered as ‘disruptive’. Participants drew upon interpretative repertoires of adaptation to convey railways as initially ‘disruptive’ and as something ‘you get used to’ over time. Participants positioned themselves as being immune to the ‘disruption’ in that they no longer noticed the railways presence. Living alongside railways was presented as ‘commonplace’, which enabled participants to manage their identities of place and justify their continued residence within the context of ‘disruption’. ‘Place’ and ‘identity’ offer a way to examine how people make sense of living in places of ‘disruption’. Future research on how people make sense of continued residence alongside railways, particularly the role of adaptational repertoires, could assist in policy development.
172

A conceptual framework for project managers to improve projects performance

Kapogiannis, G. January 2013 (has links)
The Architecture, Engineering and Construction (AEC) sector often encounters difficulties in attaining satisfactory project performance. The secondary data in this research (literature review) clearly shows that an inability to pre-identify problems leads to projects becoming ‘risky’. This can be due to a lack of meeting certain project targets, i.e., a lack of predicting ‘accurate’ project time and costs, a failure to raise the project’s quality issues and failures in predicting a project’s return on investment. In addition, it has been shown that a major lack of anticipating problems within a construction project can occur because of a lack of providing accurate data/information and a lack of team collaboration between project stakeholders. Much research has been conducted in order to anticipate construction project problems and to attempt to offer technological solutions, including information maturity models. However, in spite of all this, research projects still run into risks. Therefore, this thesis aims to investigate a conceptual framework to support construction project managers in order to enhance project performance. This conceptual framework brings together three main entities: Integrated Collaborative Technologies, Team Collaboration and Proactive Behaviour. These three notable entities are used to support project managers’ strategies in order to successfully fulfil the project. In order for this to be achieved the researcher has met the following objectives: an investigation as to how proactive behaviour impacts on the progress of construction projects, an investigation into how team collaboration relates to proactive behaviour and an investigation into how team collaboration and integrated collaborative technologies can support proactive behaviour. The research design includes primary mixed data analysis and secondary data analysis from the literature review. In order to gather data, semi-structured interviews and a questionnaire have been undertaken by the researcher. The proposed conceptual framework was tested by asking professional experts whether the proposed framework was applicable within a construction project environment. The research shows that there is a relationship between integrated collaborative technologies and team collaboration, and team collaboration and proactive behaviour, and hence these factors impact on project performance. Moreover it has been proved that, in order to achieve a successful outcome, a project requires stakeholders to learn how to collaborate with the support of integrated collaborative technologies. Throughout this ‘iterative process’ construction project managers can enhance their proactive behaviour at an individual level and thus can enhance their ability to pre-identify construction related problems. Arguably, this behavioural change will impact positively on project performance indicators.
173

A generic approach to modelling individual behaviours in crowd simulation

Sun, Q. January 2014 (has links)
Crowd simulation has been widely used to simulate crowd dynamics and their behaviours. However, majority of existing studies can only simulate a specific scenario or behaviour. Although recent developments have attempted to integrate different individual behaviours in order to achieve a more realistic simulation result, it is still very complex and those crowd models often require significant modifications. This study is therefore aimed to develop a generic crowd model, which provides the flexibility to configure and represent different scenarios, as well as the ability to demonstrate individual differences on crowd behaviours. The theoretical principle of the proposed crowd model is based on the combination of force-based modelling and agent-based modelling. A unified core mathematical formula, which contains seven key parameters, is developed to represent the generic behaviour effects. In addition, a Behaviour Library is developed to present a set of basic behaviours by using the unified formula and subsequently, more complex behaviours could be formed by combining the basic behaviours. The proposed crowd model is implemented in a simulation environment by using Microsoft XNA framework. A number of well-known crowd behaviours are tested with the crowd model for validation. The proposed crowd model is further validated by simulating real life experiments and comparing its results. This research study presents a novel approach to simulate crowd behaviour at individual level by introducing a generic crowd model that can be configured into specific scenarios. It introduces a theoretical concept, through which different behaviour effects could be quantified by a unified mathematical formula. As a result, crowd modelling and simulation of different scenarios can be significantly simplified. For future work, the proposed crowd model can be tested under complex environment in order to fine-tune its theoretical model and to expand the Behaviour Library.
174

The analysis and improvement of focused source reproduction with wave field synthesis

Oldfield, R. G. January 2013 (has links)
This thesis presents a treatise on the rendering of focused sources using wave field synthesis (WFS). The thesis describes the fundamental theory of WFS and presents a thorough derivation of focused source driving functions including, monopoles, dipoles and pistonic sources. The principle characteristics of focused sources including, array truncation, spatial aliasing, pre-echo artefacts, colouration and amplitude errors are analysed in depth and a new spatial aliasing criterion is presented for focused sources. Additionally a new secondary source selection protocol is presented allowing for directed and symmetrically rendered sources. This thesis also describes how the low frequency rendering of focused sources is limited by the focusing ability of the loudspeaker array and thus derives a formula to predict the focusing limits and the corresponding focal shift that occurs at low frequencies and with short arrays. Subsequently a frequency dependent position correction is derived which increases the positional accuracy of the source. Other characteristics and issues with the rendering of focused sources are also described including the use of large arrays, rendering of moving focused sources, issues with multiple focused sources in the scene, the phase response, and the focal point size of focused sound field. The perceptual characteristics are also covered, with a review of the literature and a series of subjective tests into the localisation of focused sources. It is shown that an improvement in the localisation can be achieved by including the virtual first order images as point sources into the WFS rendering. Practical rendering of focused sources is generally done in compromised scenarios such as in non-anechoic, reverberant rooms which contain various scattering objects. These issues are also covered in this thesis with the aid of finite difference time domain models which allow the characterisation of room effects on the reproduced field, it is shown that room effects can actually even out spatial aliasing artefacts and therefore reduce the perception of colouration. Scattering objects can also be included in the model, thus the effects of scattering are also shown and a method of correcting for the scattering is suggested. Also covered is the rendering of focused sources using elevated arrays which can introduce position errors in the rendering.
175

Keep off the grass! : an exploration of how photographic practice may be used to develop alternative representations of the urban nature subject

Blazejewski, L. January 2013 (has links)
The relationship between people and nature has long been suffering from a cultural disconnect. In truth, nature is far more readily likened to travel than it is to everyday life; synonymous, as it is, with those faraway ideals beyond the everyday reach of an urban dweller. However, urban environments are teeming with a range of plants and animals, known as urban nature, thus providing the opportunity to shed these exotic associations in favour of a far more accessible experience. In order to do so, the form of contemporary urban nature photography will be examined in this thesis, where any representational trends found to be inhibiting its development will be identified, and ultimately challenged. A combination of photographic practice and reflective analysis was used to challenge these problematic trends. Five experiments were carried out. These served to yield a set of photographs which developed alternative representations of the urban nature subject. The resulting photographs of each experiment were subjected to a means of reflection; based on Gary Rolfe’s three stage method but refocused for compatibility with photographic practice, where observations were drawn from one experiment so as to guide the direction of the following experiment. These experiments culminated in a final project: a definitive body of photographs that served to fuse the findings of each experiment into an alternative aesthetic. Identity became a critical theme underlining the representations of the urban nature subject in this thesis, for the displacement of photographic information began to instil the subject with - to some extent - otherworldly sensibilities. This process challenged the active predisposition toward naturalism in urban nature photography, and began to direct such tendencies toward a much broader aesthetic landscape; engaging with unreserved artistic ideologies so as to develop exclusive representations of the urban nature subject.
176

High tensile steel as normal reinforcement in concrete

Attisha, H. P. January 1972 (has links)
The use of high tensile steel as normal reinforcement in concrete members necessitates the study of the behaviour of such members under the action of static, fatigue and sustained loading. The present state of knowledge of the effects of the type of steel and the type of loading on the serviceability and strength of concrete members has been reviewed. From a comparison of structures reinforced with ordinary and high tensile steels, it has been indicated that by increasing the permissible steel stresses great savings can be obtained, but the deflection and cracking become more pronounced, especially when the effects of long-term loading are considered. Limited information has been reported on the effect of the static cyoles, subsequent to the first cycle, on these two limit states. In view of the above, the applicability of the limit state design, and the study of the recommendations of codes of practice of several countries, it was felt that an experimental investigation was required to study the behaviour, in cracking and deflection, of concrete members reinforced with hiEýi tensile steel and subjected to static, fatigue and sustained loading. A programme of an experimental investigation was designed to study the behaviour of reinforced concrete beams.
177

Sustainable development in amenity-based communities of the Greater Yellowstone Ecosystem

Bergstrom, Ryan Dennis January 1900 (has links)
Doctor of Philosophy / Department of Geography / Lisa M.B. Harrington / The Greater Yellowstone Ecosystem (GYE) is a large, nearly intact ecosystem with significant protection that has often been considered an ideal location to examine coupled human-environment interactions due to the region’s complex mosaic of private and public lands, competing natural resource uses, and rapid population growth. A transition toward sustainability suggests that current societal and economic needs can be met while simultaneously maintaining the planet’s life support systems for future generations. To facilitate sustainability transitions it is imperative that the perceptions and experiences of local communities be documented. The objective of this study was to determine how residents of amenity-driven gateway communities (West Yellowstone and Red Lodge, Montana, and Jackson, Wyoming) surrounding Yellowstone and Grand Teton national parks perceive and experience their transition toward sustainability and the challenges inherent in that transition, how those perceptions inform locally produced and extra-local policies, and how institutions influence sustainability goals. Further, this study determined which factors contribute to these perceptions, and whether they differed spatially and temporally. To meet study objectives, a mixed methods approach was implemented, including the content analysis of local newspapers and key informant interviews. Content analysis of local newspapers was used to investigate decision maker and stakeholder priorities for the local and regional environment, economy, and communities, and to determine what actions had been taken to promote sustainability. A total of 193 articles from West Yellowstone News, 287 articles from Carbon County News, and 333 articles from Jackson Hole News & Guide for the ten year period 2000-2009, were analyzed. Specific focal topics varied among the newspapers/communities, but in general terms the most discussed topics in West Yellowstone during this time were focused on natural resources, economic development, community development, sustainability and conservation, and growth and development. The most discussed topics for Red Lodge were community development, government services, tourism and recreation, and growth and development. The most commonly discussed topics in Jackson were natural resources, growth and development, community development, and government services. A total of 35 semi-structured interviews were conducted with key informants in the three study communities during the summer of 2010 to allow for specific questioning and to gain additional information. Definitions of sustainability differed based on the key informant’s community, role in the community, and length of residence in the community. Overall, definitions of sustainability focused on the environment, the economy, and multi-generational or long-term thinking. The prioritization of the economy, environment, and society also differed based on community; however, there was overall recognition that each community was dependent upon the natural environment for economic vitality. In all three study communities, dependence on tourism and recreation-based industries, the lack of a diversified economy, and continued growth and development have resulted in a disconnect between perceptions, priorities, and goals as they relate to sustainability. In addition, each community was focused on multiple goals that further complicated the fulfillment of sustainability objectives. The multi-goal orientation of study communities is reflected in the multiple visions that various decision makers and stakeholders have for the community and their futures. What is needed most is a hierarchical approach to a sustainability transition, with each community setting its own, as well as ecosystem-wide, goals, objectives, and visions. Findings suggest that a transition toward sustainability is perceived and experienced differently based on local context. In the GYE, that context includes a tourism-based economy that is dependent upon the natural environment, a myriad of local, regional, national, and global stakeholders, and the presence of federal land agencies that are responsible for the sustainability of natural systems, freeing local communities to focus on the societal and economic dimensions of sustainability. A transition toward sustainability will be manifested differently in the Greater Yellowstone Ecosystem, and potentially other communities adjacent to protected lands, than it is other areas because of its unique milieu. While the close proximity of federal lands, including Yellowstone National Park, may complicate the sustainability discourse at times and may, in certain instances, add additional challenges through extra-local control of change, these same federal lands may also favor a transition toward sustainability in amenity-driven gateway communities. In addition, the disparate socio-economic conditions present in study communities, as well as extra-local institutions and agencies, directly influence, and may at times further complicate, a transition toward sustainability. This study is based on the theory that in order to successfully transition toward sustainability, a better understanding of coupled human and natural systems is critical, and because of the close couplings between human and natural systems in the Greater Yellowstone Ecosystem, and because of the unique challenges and conflicts present in the region, the GYE is an ideal location to study human-environment interactions. The use-inspired orientation of sustainability science aims to provide tangible, real-world, and place-based understanding of a transition toward sustainability. The contribution of this study to the field of sustainability science is the understanding that, while sustainability visions, goals, and objectives may be similar across a region, consideration of local contexts affecting goals and perceptions provides valuable insights that may inform sustainability pathways at local scales and, as a result, provide deeper understanding of global sustainability. One of these insights is that communities that seemingly have much in common due to their shared region, physical environmental surroundings, and history, the specific concerns to ensure place-based sustainability can show variability. Another important point from this research is that, while most depictions of sustainability are focused on three elements—the economy, society, and the environment—individuals also key in on multigenerational concerns.
178

A dialogue with nature : sacrificial offerings in Candomblé religion

Capponi, Giovanna January 2018 (has links)
The present work explores the relationships Candomblé followers interweave with the environment and with animals through ritual offerings and sacrificial practices. As a self-defined “religion of nature”, Afro-Brazilian Candomblé can be described as the cult of the orixás, deities whose origins can be traced to West Africa and who are connected with the natural elements in the landscape. The complex use of food items, other elements and animals in the rituals makes it necessary to investigate the role of these elements in Candomblé cosmology and to take into account emic perceptions of human-environment relations. Ritual practices develop around culturally determined ways of relating and perceiving the environment but they are also subjected to modifications and innovations. By presenting detailed ethnographic accounts of Candomblé rituals in Brazil but also in Italy (where a Candomblé house has been active for two decades), this thesis demonstrates how the ritual structure can be understood as a pattern that follows variations based on the needs of humans, but also on the tastes of the invisible entities and the agency of animals. The renegotiation of these elements takes the form of a dialogic process between the different parts. Ritual offerings and sacrifices can be understood not only as a form of feeding and exchanging favours with the orixás but also as a form of communication between the visible and the invisible world. Moreover, the constant correspondences and deferrals between humans, animals and orixás in the chants, in the mythology and the ritual proceedings allow the possibility of understanding animal sacrfice as being performed not only for the benefit, but also as a substitute, of a human life. Lastly, this thesis shows how ritual change is also expressed by the incorporation of contemporary notions of environmental ethics and pollution, allowing for new understandings of natural landscapes as a social and historical construct.
179

High strength steel reinforcement in ordinary reinforced and fibre reinforced cement composite lightweight concrete beams

Al-Sanjary, K. A. A. January 1975 (has links)
When high strength steel is used as reinforcement in lightweight concrete members, great economies can be achieved. However, because lightweight concrete has low tensile strength and modulus of elasticity, the working steel stresses hoped for may not be fully utilised due to the limit states of serviceability (cracking and deflection) not being satisfied. To control the amount of cracking and deflection in flexural concrete members, a new type of construction has been employed, whereby precast fibre reinforced cement (f. r. c) units in the form of thin channels are used as a surface reinforcement at the flexural tensile zone of the concrete members. The concrete in the tensile zone, confined by the f. r. c channel, will have a greater resistance to formation and extension of crack; consequently the rate of reduction in the flexural rigidity of the member will be decreased. A total of 27 ordinary reinforced and fibre reinforced cement composite lightweight concrete beams, 150mm wide, 300mm deep and 5m long were tested, 18 under static load test, 5 under fatigue load test and 4 under sustained load test. The composite beams were similar to the ordinary beams in every respect, except that f. r. c. channels (150mm width, 60mm length of upstands and 6mm thickness) were incorporated as integral parts on their flexural tensile sides. The main parameters employed for both beams were the type and amount of steel provided for the tension reinforcement. The various types of reinforcement with the corresponding nominal yield, or 0.2% proof stress employed were mild steel (275 N/mm2), Unisteel 410 (410 N/mm2), Unisteel 550 (550 N/mm2), "Kam 60" (590 N/mm2) and "Kam 90" (875 N/mm2). The flexural behaviour of both types of beams under static, fatigue and sustained types of loading has been studied, great emphasis being placed upon the limit states of ultimate strength, cracking and deflection with particular reference to the contribution of the f. r. c. channels in the composite beams. From the results, it is concluded that a considerable reduction in the amount of deflection and cracking can be achieved by using f. r. c. channels at the flexural tensile zone of concrete members, thus allowing a more efficient use of the highstrength steel.
180

Analysis and design of bolted connections in cold formed steel members

Zadanfarrokh, F. January 1991 (has links)
The purpose of this thesis has been to investigate, both analytically and experimentally, the behaviour of bolted joints in cold formed steel members. To this aim, the influences of all factors bearing a significant effect on behaviour of bolted connections in cold formed steel assemblies and structures have been investigated. Design expressions have been derived. With this information the moment capacity of bolted joints can be calculated with considerably more accuracy than the present existing expressionsin the current codeso f practice. The findings of the thesis have already influenced the design expressions for bearing strength of bolted connections in the European code of practice for design of cold formed steel sections, i. e. Eurocode No 3, Annex A. It is hoped that the conclusions drawn are further incorporated in the above mentioned code, and replace the existing guidelines in the British Standard, BS 5950 Part 5, for the design of such sections. Furthermore for the first time ever, as a result of the analyses and experiments carried out, designers are able to predict the moment-rotation relationship of such connections without having to resort to testing. It is intended to feed this information into design programmes to radically affect the elastic design of cold formed steel structures. It should then be possible to design optimum structures by specifying joints with appropriate characteristics.

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