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Development of risk analysis models for decision-making in project managementGuo, Qiu Ling January 2001 (has links)
Risks and uncertainties are inherent in construction projects and if neglected these risks often lead to project cost and time overruns. Traditional methods of forecasting risks rely upon intuition and 'feel' which has proved inadequate for the needs of investors in modern construction projects. To cope with these recognised risks, a risk management framework, which consists four components (risk identification, risk classification, risk analysis and risk response), has been developed. The present research focuses on financial risks in construction management, and in particular, the development of enhanced quantitative, probabilistic methods for risk analysis. A comprehensive review of the treatment of risk and uncertainty in the construction industry is undertaken. Background knowledge of probability theory and Monte Carlo simulation is reviewed, as is previous investigations into construction network analysis and project economics. A comparison of the Programme Evaluation and Review Technique (PERT) and the Monte Carlo Simulation (MCS) methods in construction networks risk analysis is carried out. Two example projects are analysed by both methods. When applying the MCS method, a sensitivity analysis is carried out by investigating the effect of different probability distributions (Normal, Log-Normal, Beta, Triangular and Uniform) for individual activity durations, the number of simulations used and the effect of the manner of how the mean and standard deviations are set for the different probability distributions. A new analytical method, the Modified Stochastic Assignment Model (MSAM), is proposed for the prediction of project duration. Five example projects are used to demonstrate the validity of the MSAM and to illustrate its application in construction project evaluations. The accuracy of the MSAM method is assessed by comparison to the MCS method. A comparison of the MSAM with other analytical methods commonly used in construction network analysis, such as PERT and the Probabilistic Network Evaluation Technique (PNET), is also presented. The First Order Second Moment (FOSM) method, a methodology previously used solely in system reliability analysis is applied to project economics. The definition of the FOSM method is given and detailed mathematical treatments of these methods are described. The methodology of using the FOSM in construction economics is explained and ten examples are analysed using both the FOSM method and the MCS to show the applicability and the degree of accuracy of these methods. The current research shows that the MSAM method yields the probability of project completion within a prescribed target time, or the required project time at a specific probability. The research also shows that it is possible to use the FOSM methods for risk analysis in decision-making in construction economics in such areas as selection of project, elemental cost analysis, cash flow streams and setting of plant hire rates. Both methods require computational time that is significantly less than an equivalent MCS.
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The structural behaviour of timber joints made with fully overlapping nailsPorteous, Alexander January 2003 (has links)
An integrated programme of experimental and analytical work was carried out to evaluate the nonlinear semi-rigid characteristics of timber connections using fully overlapping nails subjected to short duration lateral loading and moment. The investigation is part of a continuing programme of research at Napier University into the behaviour of timberjoints using fully overlapping nails as the connecting Z -1 mechanism. The effects of the factors and material properties that influence the behaviour of nailed joints were addressed in a structured and controlled way allowing semi-empirical models to be developed for the lateral load behaviour of rnulti-nailed timber joints using steel and plywood gusset plates. A quality control procedure was established for the testing programme and consistent standards were applied to the preparation and testing work. The semi-empirical models that were developed included for the effect of timber density: crussept late material effect- nail strength; number of nails: nail diameter; row spacing and the effect of the moisture content in the timber. They covered joints assembled with and without a gap between the timber and the gusset plates and for joints assembled with steel gusset plates, the effect of the predrill size used in the gusset plate was also investigated. The model results compared very well with the results from tests, accurately predicting the non-linear behaviour of the joints up to failure. An extensive analytical and experimental study was carried out to investigate the moment-rotation behaviour of these types ofjoints. Two linear arýd four non-linear models were developed for each type of joint and the efficiencies of the models were compared to detennine the one that best simulated the joint behaviour. The linear models consistently underestimated the capacity of the joint, giving conservative results. The best solutions were obtained by applying the torsion formula used for steel connections and incorporating the nail behaviour models developed for the non-linear lateral load joints. Account was taken of the non-linear behaviour of the connection and alternative models using fixed and moveable centres of rotation were developed. Very good comparisons were achieved between these models and the test results. A detailed comparison was made between the behaviour of the joints using the lateral load displacement models and Eurocode 5 (EC5) and it was concluded that EC5 rules did not accurately simulate the behaviour of this type of joint. It was concluded that the nail spacing rules in the code did not apply to fully overlapping nails. A limit state design method based on the principles used in EC5 has been developed from the models for the design of joints using fully overlapping nails and subjected to lateral loading or moment. The semi-rigid behaviour of the joints was also investigated and it was concluded that to safely predict the response of structures assembled with fully, overlapping nails. the semi-rigid behaviour must be included for in the analysis procedure. Rigidity factors, end fixing moment reduction factors and the secant rotational stiffness coefficients for the joints were derived. It was also shown that where the analysis was limited to the serviceability limit state. a modified elastic method of analysis could be used and where it was beyond this state a non-linear method of analysis was required.
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Effectiveness of mergers and acquisitions and corporate financial performance in constructionDelaney, Frank T. January 2003 (has links)
In practice, construction firms are in business to achieve profitability. Construction companies operate in a highly competitive business environment characterised by low profit margins and high failure rates. At times firms will seek to grow in an attempt to increase profitability. At other times, firms will be concerned with survival and avoiding failure. Often firms plagued by poor performance seek to take higher risks. This may lead especially where resources exist to increased diversification. Against this background, the research focuses on the twin areas of corporate financial performance and the effects of merger activity. Prior studies in economics and accounting provide evidence that financial statement analysis can be utilised by possible investors or strategic planners to aid in the future plans and direction of the firm or to classify economic events such as mergers or failures. The present study examines the financial performance of the UK construction industry and the Global construction industry, and investigates the financial characteristics of merging construction companies. This research examines the financial performance of UK firms in different sectors of the construction industry. This analysis involves the use of descriptive statistics, which provides a valuable aid in the visual presentation of the range of the possible outcomes. In addition a probabilistic analysis of the distribution of profitability has been undertaken. This involves the use of inferential statistics which concentrates on the role of significance testing. The profitability performance of the plant hire sector was found to exceed that of contracting and materials sector. An examination of the impact of the national environment on international competitive performance and an assessment and comparison of the performance of global construction is also provided in the study. The research also investigates the financial profile of UX failed and solvent firms. The use of statistical models and accounting ratios in an effort to predict company failure for up to five years is examined. The results for the univariate analysis indicate that failing construction firms during the 1996-2001 period have low profitability and are highly geared. The testing of previous statistical failure prediction models provide little evidence of compatibility to the construction industry. The analysis on mergers and acquisition investigates the performance of construction companies involved in the acquisition process and examines the motives behind the merger process. Analysis of the relation between measures of costs and firm size in over 100 UK construction companies indicates the usefulness of scale economies. However, the evidence suggests that beyond a certain size the cost benefits appear to become exhausted. Large companies have to re-examine scale to ensure that they are employing it to their company's greater advantage. Abnormal share returns are also examined throughout a period surrounding the announcement of both successful and unsuccessful acquisition and merger bids. The overall results indicate that mergers in the construction industry create wealth for shareholders. The evidence shows significant increases in the performance of the target firms' shareholders over a 40 day event window surrounding the announcement. The results also show that bidding firms' experience no significant abnormal returns in a short period surrounding the announcement date.
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Performance measurement and mathematical modelling of integrated solar water heatersGarnier, Celine January 2009 (has links)
In a period of rapidly growing deployment of sustainable energy sources the exploitation of solar energy systems is imperative. Colder climates like those experienced in Scotland show a good potential in addressing the thermal energy requirement of buildings; particularly for hot water derived from solar energy. The result of many years of global research on solar water heating systems has outlined the promising approach of integrated collector storage solar water heaters (ICS-SWH) in cold climates. This calls for a need to estimate the potential of ICS-SWH for the Scottish climate. This research project aims to study and analyse the performance of a newly developed ICS-SWH for Scottish weather conditions, optimise its performance, model its laboratory and field performance together with its environmental impacts and analyse its integration into buildings and benefits of such a heating system, for the primary purpose of proposing a feasible ICS-SWH prototype. Laboratory and field experiments were performed to investigate the performance of the newly developed ICS-SWH and the parameters affecting it which were fundamental to modelling its performance. This was followed by developing a thermal macro-model able to compare the temperature variation in different ICS-SWH designs; including internal temperature and external weather conditions for a given aspect ratio and to evaluate the performance of this ICS-SWH for laboratory and field conditions. This was followed by a three-dimensional Computational Fluid Dynamic (CFD) analysis of the ICS-SWH in order to optimise the fin spacing as a means of improving its performance. A Life Cycle Assessment (LCA) and monetary analysis considering the whole life energy of the different ICS-SWH designs were carried out using a previously developed thermal model in order to establish the most viable ICS-SWH with the smallest carbon footprint. Finally, a study to show how the ICS-SWH could be integrated into buildings and its potential benefits to builders and households was undertaken. Through this work, important parameters for modelling laboratory and field performance of ICS-SWH are established. The innovative modelling tool developed can predict the bulk water temperature of the ICS-SWH for any orientation and location in the world with good accuracy. Improvements of the ICS-SWH fin design were suggested through the CFD analysis while keeping the costs to a minimum. The ICS-SWH prototype showed a high commercial potential due to its environmental and monetary benefits as well as its potential for integration into commonly used solar water heating installations and modern methods of construction such as roof panels which could result in a viable commercialisation of the prototype.
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Developing a performance measurement framework for municipal construction projects in Saudi ArabiaAlsulamy, Saleh January 2015 (has links)
Performance measurement has the main aim of helping organizations to realize how decision-making processes can be harnessed to improve success rate in past activities and how the understanding from the current and past can lead to future improvements. Specifically, a comprehensive performance measurement practise must enhance the achievement of the key aim of the project stakeholders, the objectives of the project itself, and the needs of the users all of which should be capable of being represented in raw data to be manipulated and measured by a performance measurement tool. The performance of a project is directly related to its potential for success, and on the other hand, the CSFs of a project have a direct bearing on the project's performance. In essence, the efficiency and effectiveness measures of a project are essential yardsticks for assessing project performance and success. The stakeholders in a project have needs and expectations which the project is being conceived to satisfy, therefore, these needs and expectations must be held paramount during the conceptual design, development execution, and operation stages of a project. This is applicable to the general construction industry and in particular, in construction projects implemented by municipal organisations. However, municipal construction project have been fraught with delays, cost overruns and failure in operational performance. Hence, the overall aim of this research is to develop a framework within which municipal construction project performance can be measured in the SA at any stage of the project, and specifically to increase its effectiveness and efficiency of the project in order to improve the project's performance to the satisfaction of stakeholders. This study was implemented through the administration of a questionnaire survey based on a hypothesis that requires the identification of the challenges and obstacles that are facing the implementation of municipal construction project in SA. The collected data is based on responses from three major organisations; government, contractors and consultants that are involved in the delivery of municipal construction projects in SA. Mean and analysis of variance (ANOVA statistic) was used to manipulate the data from the questionnaire within the SPSS v.20 software environment. The resulting framework was subjected to a validation procedure which involved a structured interview process based on a focus group consisting of experts that were specially selected for the purpose establishing the extent to which the framework is practical, clear, applicable and comprehensive. Also, the focus group was used to determine the significance of the CSFs, PMs, and success (efficiency and effectiveness) measures. Overall, this study found that a total absence of performance measurement concept process permeates the management of construction projects in SA and in the municipality construction projects in particular. To close this gap, this study was embarked upon to investigate and identify the various performance measurement approaches and frameworks that are used to support the guidance of project performance toward success. Notably, this study emphasises the importance of stakeholder needs and expectation forming the bases of municipality construction projects in SA. Specifically, this study suggests that the measurement of project performance in municipality construction projects in SA should be integrated in a holistic framework containing several elements that will help to guide construction projects toward success.
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Life cycle assessment of aluminium-clad timber windowsAsif, Muhammad January 2002 (has links)
Over the last century a temperature rise of 0.6 C m global climate and the affiliated greenhouse effects have inflicted enormous impacts in the form of natural catastrophes, economical losses, health problems and seasonal disorder. If human activities continue at existing pace, a further temperature rise of 2.5 C is being anticipated over the next hundred years, which may cause unimaginable damage to humanity and ecology of the planet. In such a prevailing global environmental scenario sustainability is the need of hour and should be given the prime importance in execution of activities in all sectors in order to keep future secure for coming generations. Windows are amongst the most sensitive elements in a building envelope, also, due to their multi-disciplinary role, they are important not only for their effects on interior environment but also for the energy performance of the building. Energy contents and environmental impacts of the materials involved, add up on to window significance in the ecology of buildings. Energy efficient windows with least possible environmental burden over their whole life cycle are thus very important in achieving desired levels of sustainability in general, particularly in buildings. The present work addresses the sustainability of double glazed aluminium clad timber windows adopting the life cycle assessment (LCA) approach. LCA of windows helps cutting down the associated ecological burdens at all stages, i.e. extraction/production of materials, operation, maintenance and disposal of windows at the end of their service life. Cost effectiveness and productivity, the important features of sustainability, have been evaluated for aluminium clad timber and timber windows on the basis of life cycle cost assessment (LCCA) approach. Value engineering (VE) of aluminium clad timber windows has also been addressed. Running and/or maintenance costs which largely determine the life cycle costing have been estimated and the most cost effective options are presented. Four different types of windows, made of aluminium, aluminium clad timber, PVC and timber frame, have also been compared with respect to the ecology of frame materials - covering energy contents and environmental loads, maintenance and durability, service life and costing. A survey has been carried out with the help of housing authorities, architects and surveyors within UK, to study the performance of these windows in real life. A series of accelerated tests have been carried out to study the weathering performance of the candidate windows. The results have revealed that aluminium clad timber windows have excellent resistance against weathering conditions and they perform better than aluminium, PVC and timber windows under any conditions. In an ongoing research project at Napier, copper (Cu) coated silicon carbide (SiC) reinforcement particles have been used in aluminium 6061 matrix to enhance the mechanical properties of the Al SiC metal matrix composite (MMC), which is a prospective material to be used in window hardware. Results have indicated that Cu coating does not bring any additional corrosion loads onto the MMC. Recommendations for further work have also been laid out.
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Sustainable urban developmentDeakin, Mark January 2011 (has links)
This submission for PhD by publication aims to capture, reflect upon, analyse and offer critical insights into how the use of land and exchange of property can help serve the search for sustainable urban development (SUD). This aim is subsequently met by: • hypothesising how the applicant's publications provide a representation of SUD able to get beyond the state-of-the-art and offer a conceptual framework capable of uncovering the positive role land and property can play in sustaining urban development; • reviewing the research undertaken by the applicant to define SUD and develop a framework for analysis, set of protocols and directory of assessment methods to evaluate the sustainability of urban development; • highlighting the possibility there is for the valuation methodologies and investment appraisal techniques underlying the use of land and exchange of property, to be constructive in terms of the relationship their corporate strategies and financial instruments have to the environment; • illustrating how it is possible to compute the informational basis of property management and draw upon the intelligence this offers cities to develop electronically-enhanced services underpinned by e-learning platforms, knowledge management systems and digital libraries, capable of supporting environmental improvements; • showing how the environmental improvements that surface from such developments in turn support the community-based approach to urban regeneration which underlies the UK government's socially-inclusive and participatory venture into ecological modernisation and democratic renewal; • providing examples of where the management of property by cities is intelligent, not only because the environmental improvement supporting their community-based approach to urban regeneration are socially-inclusive and participatory, but for the reason the ecological modernisation and process of democratic renewal underlying these developments meet the sustainability requirement; • reflecting on the contribution this representation of SUD as informational, intelligent, socially-inclusive, participatory, community-based, regenerative, ecological and democratic, makes to what is known and understood about the subject. Together these positive, analytical and constructive examinations of SUD augment into the informational basis of property management and surface as the corporate strategies and financial instruments of the electronically-enhanced service models needed for cities to be intelligent. In particular, the strategies, instruments and eGov(ernment) service models, cities need to be intelligent in valuing the environment and accounting for the socially-inclusive, participatory, community-based, regenerative, ecological and democratic qualities underlying their improvement programmes.
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The effects of drying on the dimensional stability of spruce woodCanavan, James W. January 2017 (has links)
Sitka spruce (Picea sitchensis (Bong.) Carr.) has been the most common forestry species in UK plantations for many decades. It is generally fast grown in short rotation, which has implications for quality. The harvested timber has a number of end-use applications. Of these, sawn construction grade timber is at the high end of market value. Currently, under one third of home grown sawn timber processed by sawmills achieves the required C16 or higher grading for construction class timber. Presently there is significant standing stock of 40 years old or under. Improvements in timber quality would create significant benefits for growers and processors. Distortion in kiln dried sawn timber is a considerable barrier to improving grading classification and marketability. Twist in particular accounts for around six percent of the rejections after kiln drying. Additional twist when timber dries further; in storage, at construction sites or in-service, is perceived as a marketing issue. The focus of this work was to better understand the evolution of twist during the drying process and seek to improve quality by examining the key properties in sawn timber that contribute to the formation of twist. Samples of regularly processed full size (3 m in length) sawn timber were kiln dried with no restraint to promote maximum twist. This was done in three stages to assess the impact of intermittent drying. Measurements of twist, moisture content, acoustic velocity and basic dimensions were taken before and after each drying cycle. The results showed highly significant differences between battens containing the pith and those that did not. Drying in stages did not seem to affect the linearity of the moisture content against twist relationship. Twist was seen to develop at a consistent rate throughout the process regardless of the final amount of twist accrued or the position from which the batten was sawn. Where timber is likely to dry to lower moisture content after sale it is therefore possible to predict the additional twist from the moisture content expected and allow for it by stricter grading than the twist standard demands. Twist was seen to decrease slightly during a lengthy period of storage in controlled conditions between drying cycles. This may allude to a relaxation effect which could have implications for timber distortion in-service but this would require a more extensive study before any such conclusions could be drawn. A second batch of unrelated samples, were kiln dried to 12% MC under restraint. All of these samples contained the pith along their length and all developed significant amounts of twist. This suggests that battens containing the pith will twist regardless of restraint. A method was developed to measure longitudinal shrinkage. This required the batten size to be reduced to fit the method and battens were sawn into 3 x 1 m sections. Battens were re-saturated and measured daily throughout air drying until an equilibrium moisture content was achieved. Measurements of transverse shrinkage were also taken concurrently. No relationship could be found between the longitudinal and transverse results. When plotted against the data for twist a positive relationship was found with longitudinal shrinkage. Acoustic tools were used to calculate dynamic stiffness. As the values for acoustic velocity squared correlated well with dynamic stiffness, other possible relationships were explored. Good agreement was found with twist and longitudinal shrinkage. This suggests it may be possible to predict twist in sawn timber directly or as a function of microfibril angle, using acoustic tools. A simple method for measuring grain angle was devised. Discs taken from the trees used in the drying experiment were measured for grain angle to compare with other measured properties. The measurement method worked well but the sample size was small and the discs too thin to provide good quality data quality. The results were not as instructive as expected. A vague relationship with twist was found. A repeat of the experiment with an improved method could yield more conclusive results. A method was developed to measure radial and tangential shrinkage in discs. Discs of Sitka spruce from a different source were used. Discs were saturated and allowed to dry with the expectation of cracks developing. The intention was to explore the nature of internal stresses present in intact discs and why tangential and radial shrinkage differs. As only one disc cracked the scope of comparison was limited but it was apparent that the greater shrinkage tendency in the tangential direction was responsible for radial cracking.
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ARGILE : a conceptual framework combining augmented reality with agile philosophy for the UK construction industryHussien, A. January 2017 (has links)
This research makes a significant contribution to knowledge in the area of agile project management and augmented reality visualisation technology. It enables an understanding on how the use of the proposed, designed, and developed ARGILE framework (integration of Agile and Augmented Reality) enhances the collaboration, communication, decision-making, and visual understanding within construction projects. ARGILE changes the current process buildings are designed and built, and consequently contributes to the improvement of the construction project outcomes. This research study seeks the best way to accomplish the research aim, and develops a conceptual framework, which implements a mixed convergent parallel approach in order to discover a rich coherence of the current situation in the design and construction industry; bridges the gap among decision-making, collaboration, communication; and finally facilitates the visual understanding. Consequently, to endorse the validation of the conceptual framework, the triangulation of mixed research methods including qualitative and quantitative to collect the data will be used, followed by a rich analysis and description of the data collected, leading to the design of the ARGILE framework, and ending with two focus groups’ workshops to effectively validate the proposed design and developed ARGILE framework. The main findings of this research are: the successful combination of agile and augmented reality achieved through the development of the ARGILE framework, which contributes to improving and augmenting the decision-making, collaboration, communications, and the visual understanding throughout the design and construction stages. Moreover, the most important outcome of this work is that it enabled the practices to obtain an overview of their current state of decision-making, collaboration, and the visual understanding, assisting in fundamentally changing the current way buildings are designed and constructed. As the design and construction are completely different tasks, but normally treated as one, using ARGILE will help breaking the link by allowing the design stage to spend enough time and conduct productive tests it needs before starting the construction stage on site. ARGILE contains all necessary mechanisms built-in to enable sufficient design, collaboration, decision-making, and client integration.
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Investigation of a novel thermochemical heat storage system for building applicationsMat Wajid, Norhayati January 2016 (has links)
Heating and cooling account nearly 60% of world total energy consumption and highly depending of conventional energy sources generated by fossils fuels. As the scarcity of oil reserves becomes the jargon issues in all part of the world today, researchers have to look into a robust investigation on finding the alternative energy to alleviate the dependency of conventional energy. Furthermore, if the phenomenon of using fossil fuel remain as the primary energy sources, it would affect adversely on the greenhouse gas emission. In 2008, The Climate Change Act by the UK Government had targeted that 34% cut in 1990 greenhouse gas emissions by 2020 and, at least, an 80% cut in emissions by 2050. Therefore, to achieve this target, more low carbon technology needed to realise the future reduction of emission. Renewable energy technologies such as solar, wind, geothermal and such thought to become the solution to reducing the demand for conventional energy. However, their instability considered as problematic for future energy demand. Thus, a more efficient management of energy demand, coupled with efficient energy storage systems is required. The aim of this study is to develop novel Thermochemical Heat Storage system (THSS) using off-peak power and renewable sources to minimise energy demands from fossil fuels and reducing GHG emissions. Thus, this could be achieved by developed and constructed a unique adsorption heat pipe using a high energy storage density of the nanocomposite Thermochemical material. Other than that, this unique adsorption heat pipe was integrated with a heat-pump circuit for desorption process. In this study, a Novel Thermochemical Heat Storage has been theoretically model, built and tested on a lab scale and a domestic-scale prototype. The chosen Thermochemical Material (Vermiculite + CaCl2) reacting with pure water vapour operates within a closed system. Other than that, result from thermal analysis shown that Vermiculite + CaCl2 could attain higher heat storage capacity of 374 kJ/kg. The heat storage system of this work based on reversible thermochemical reactions, such as adsorption and desorption of composite Thermochemical materials which exhibits very high energy storage density (up to 364 kWh·m3 of material storage). The small scale experimental investigation has found this THSS has the maximum adsorption temperature of 45.07°C to 71.12°C with the corresponding Coefficient of Performance (COP) of 0.53 to 1.34. Another investigation on Solar Heat Solar collector (SHSC) has carried out numerically and experimentally. The numerical study predicted that the temperature lift achieved at 42°C of using 10m2 of the solar collector. Hence, this SHSC has shown the possibility of integrating the TCM (Thermochemical material) with solar thermal energy. Lastly, a domestic scale THSS has revealed that the highest temperature uplift from the adsorption process at 57°C. The economic analysis of a domestic scale THSS has shown that this system will receive payback in 7.5 years with the internal rate of return (IRR) 15.25%. Furthermore, emission analysis demonstrated that this system would reduce 34% of CO2 in 20 years of its lifespans.
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