published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

No description available.

The construction industry has a reputation for low productivity, waste, low use of new technologies, and poor quality (Egan, 1998; Wakefield & Damrienant, 1999). It is estimated that up to 30% of construction is rework, and recognised that site teams spend too much time and effort making designs work in practice (Egan, 1998). The aim of the research project was to develop a visualisation and communication environment that would assist design teams in communicating design details that may be problematic for construction teams. The investigation was based on the need for a tool that facilitates detail design information communication. The VISCON (computer visualisation support for buildability) environment provides support for general information sharing in the context of a collaborative building project. This prototype is Web based and can be accessed from any location. This will allow for construction information to be readily communicated and shared between head offices and construction sites and any other locations to provide better visualisation of design details. Three scenarios were developed as case studies for demonstration purposes based on real projects. These case studies used a paper factory, a bay barrage building and a swimming pool recently constructed at Loughborough University. In the development of the case studies, 3D models were produced using components from the selected prototype buildings that may inherently be difficult to assemble. The VISCON prototype demonstrates the various functionalities of the system in creating intricate design details that can be animated or interacted with in real time. The main achievements of the research are: The review of buildability problems and their causes during the construction stage of a facility; The development of an architecture for a computer visualisation tool for buildability (VISCON); Implementation and validation of the proposed system (VISCON) through the use of a number of case studies. The system was found to be useful and demonstrated that computer visualisation tools provide considerable potential in improving clarity of information and also a new way of visualising and solving design problems that arise during the construction stage of a project. It also demonstrated the ease of use of the proposed system, and its efficiency and application to the construction industry. The research concludes that the use of computer visualisation can improve the construction project delivery process by providing guidance on how components are assembled together and how buildability problems can be solved during the construction stage. Furthermore, the use of effective communication tools will improve collaboration between construction and design practitioners.

The technology and applications of evaporative cooling to provide human comfort in buildings is not new and has been used in different places based on different methods and materials. Conventional air conditioning systems overshadowed the application of evaporative cooling for buildings despite their ozone layer depletion. Evaporative cooling using porous ceramic evaporators were experimentally investigated. Encouraging results in terms of temperature reduction and cooling effectiveness were reported. In this work also thermoelectric unit was integrated in to the evaporative cooling system containing porous ceramic evaporators. The warm inlet air cooled in the evaporative cooling chamber was passed over the hot-side fins of the thermoelectric cooling device to act as a better heat sink. Typical test results showed that the cold side temperature of thermoelectric unit was 5Deg.C lower and the hot side was 10Deg.Clower, respectively when operated on the wet and dry porous ceramics evaporative cooling chamber. Direct evaporative cooling is often associated with the rise in relative humidity which may result in uncomfortable feeling due to unwanted increase in moisture. Indirect evaporative cooling offers a solution but still requires improvements in the effectiveness. There is also need for using cheap and readily available materials for the construction, requiring simple fabrication technology without very complex engineering infrastructure. Most widely used common fibrous materials have very limited capillary effect. So a periodic water spray system with an automatic control is required for running the cooler which adds to the power consumption, rise in operation costs as well as construction and operational difficulties. As a compromise using horizontal arrangement was considered. Use of pump for supplying water required to moisten the evaporative cooling surface was eliminated. The system was constructed and tested under varying temperature, relative humidity and air flow rates. Results showed significant temperature reduction accompanied with acceptable increase in relative humidity. Temperature drop of 6-10Deg.C between the inlet and outlet temperatures of the product or supply air was recorded. Increase in relative humidity of the supply air was 6 - 10% less than the working air. Application of this novel system was demonstrated in the parasol self-cooling arrangement. The fibre tube vaporative cooler has the potential of cooling a building space to the acceptable comfort limits. The application of porous ceramics for building space cooling, integrating the system to be used as a heat sink and the use of horizontal fibre tubes for evaporative cooling are all novel ideas in this field of research. Other novel features also include the ability to minimise energy consumption by eliminating common methods of continuous water circulation.

A construction project requires a multitude of people with different skills and interests and the coordination of a wide range of disparate, yet interrelated, activities. Such complexity is further compounded by the unique characteristics of a project and many other external uncertainties. As a result, construction is subject to more risk than other business activities. In a risky situation, individuals or organizations perceive the situation in their own ways and behave differently to meet their own interests. Many researchers have asserted that divergent risk attitudes are sources of mismatched risk perceptions and inconsistent behaviors among project participants in different organizations, which can disturb proactive and consistent organizational activities. The research on risk attitude has, therefore, been advocated to exploring ways to consistently arouse people‘s cognition, affection, and behavior among stakeholders. However, previous research has been a widely misunderstood concept and remains a fragmented focus in the construction field. Evidence on the construction of risk attitude and how it manifests itself is unavailable. To date, prior researchers have suffered from an issue-oriented focus that has resulted in simplified models by studying single level of antecedents of risk attitude and consequences of management performance, rather than multi-level. Moreover, previous studies only focused on the direct relationship between risk attitude and management performance instead of providing a profound conceptualization of the indirect relationship between risk attitude and management performance or empirically exploring risk attitude‘s antecedents and consequences. The current study seeks to bridge this research gap. Triangulation research is employed as an appropriate research methodology in which both qualitative and quantitative data collection are used to test the research propositions. The research plan draws upon ontology and methodological pluralism. By adopting the Critical Incident Technique (CIT), coupled with an intensive literature review, one can explore the manifestation of risk attitude and its antecedents by analyzing critical incidents derived from preliminary interviews. Cognitive Motivation Theory (CMT) and Social Cognitive Theory (SCT) provide rationales to combine a processed view of risk attitude and the antecedents and management performance of individuals and organizations into a multi-level model of risk attitude. Responses to a questionnaire survey of 239 individuals nested in 61organizations were analyzed with a blend of Confirmatory Factor Analysis (CFA) and Hierarchical Linear Modeling (HLM) to establish and examine the hypothesized relationships in the theoretical model. To capture the practical manifestation of risk attitude and its influence on management performance, case studies of two ongoing construction projects were performed. The findings summarized from both qualitative and quantitative studies indicated that risk attitude diverged due to the multi-level influences of its antecedents on project participants, resulting in inconsistent risk perception and risk inclinations. Risk attitude has two levels of manifestation – an individual and organization level. Individual risk attitude manifests itself as cognition, affection, and behavioral inclination, while organizational risk attitude mainly shows up as managerial trust, formalization, an ambiguity of goals and objectives, and a merit system. The findings confirmed that motivated individuals tend to present more consistent risk attitude and be more willing to and capable of exhibiting good management performance. The motivation behind this study is beyond the traditional motivational means. It extends from internal motivation with its locus of control and self-efficacy to external motivation with its interpersonal exchanges, external controls, and observational learning. The risk attitudes of motivated people to evoke better management performance, especially in the process of integrating risk management into a safety management system and the outcome performance of a stakeholder‘s satisfaction and potential to organizations. The research attempts to advance risk attitude theory by re-conceptualizing the antecedents of risk attitude and the consequences of management performance make the underlying theorizing mechanism explicit and testable. This study also provides practical indications of concrete interventions by managers to make risk attitudes converge and then strengthen safety risk management. The thesis contributes to multi-level analysis in the management research field and differentiates the different levels of participants in construction projects. Methodological pluralism and blended qualitative and quantitative research methods will be addressed to demonstrate the different and complementary perspectives of research. Due to limited samples, the generalizability of the findings in the different project types or across other levels needs to be further verified. / published_or_final_version / Real Estate and Construction / Doctoral / Doctor of Philosophy

No description available.

No description available.

No description available.

No description available.

No description available.