This study models the HVAC system of a power plant. It involved Computer simulations to study the energy demand by the HVAC system of the power plant as well as the energy demand of the system with modifications on the plant such as the building materials, use of energy efficient lighting, etc. Further studies on the energy demand of the system with the power plant located at different regions of the country were done to understand the effects of climate and locations. It is important to have an understanding of how a plant generating energy uses it for Heating, Ventilating and Air conditioning within the power plant building itself. This study has provided a better understanding of the energy use and how the HVAC system use in the offices and other areas located in the power plant building operates. The study included implementation of energy efficient measures in the choice of building materials for the building. The U.S. Department of Energy (DOE) EnergyPlus program was used to model the HVAC system of the power plant making use of the parameters and modified parameters of the power plant. The results of this study show that the energy demand of the HVAC system of a power plant is significantly affected by the choice of materials for the building. It was found that there is a reduction in the power demand of the HVAC system of the plant by about an average of about 21.7 % at the different the locations. It was also found that this resulted in the amount of energy saved per year of about 87,600 kWh. This gives an average cost savings per year of about $10,512.

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Absenteeism is a widely observed phenomenon that has received a great deal of attention from academics who argue that it is an excellent proxy for individuals' attitude to work and commitment to their jobs. Unfortunately, very little of this work has been done by economists. The little economics that has been done has tended to view absenteeism as a measure of the supply of effort. Given the paucity of economic analysis on absenteeism, the psychology, sociology and management literature is reviewed to examine the extent to which their approach and that of an economist have common ground. Upon careful reading, it becomes evident these disciplines offer similar perspectives. Probably the most researched area of absenteeism is the relationship between absence and turnover. Although there is much contention as to what the relationship between these two phenomena should be, most researchers view this as a means to test the hypothesis of withdrawal. This thesis examines the problem somewhat differently and suggests that the approach of much of the empirical work is misguided. An alternative methodology to examine these phenomena is suggested and tested using a very large and detailed database. The results suggest there is a positive correlation between absence and turnover, although the relationship is more complex than described in the literature. One area where economists have made a great deal of theoretical progress is in the examination of why absence might vary across firms. The key insight is that production technology may affect the shadow cost of absence and if the costs of absence differ across firms, then there will be different levels of motivation to reduce it. It is argued that not only will the shadow cost of absence vary across firms, it will also vary over time and a theoretical model is developed to demonstrate this. There is a presumption in the literature that absenteeism is inversely related with the business cycle. However, the empirical work on the subject only models absence as a supply side phenomenon. This introduces a significant identification problem. At the very time when individuals are least likely to go absent, firms' demand for reliable labour will be at its lowest. The empirical work in the chapter models absence from both the supply and the demand side and the findings confirm that both play a significant role in determining absence. The finding that firms' demand for reliable labour may vary through the business cycle is novel and receives further investigation. The data is dissaggregated to determine the robustness of the relationship between demand side factors and the business cycle. At broad levels of disaggregation, the results remain quite strong, although there does appear to be a difference between unionised and nonunionised workers. At finer levels of dissaggregation the results are not as conclusive. This is attributed to the relatively small samples used to derive the individual absence series and the resulting increased volatility that emerges due increased variability from the use of small samples.

Given the growth and outreach of new information, communication, computing and electronic technologies in various dimensions, the amount of data has explosively increased in the recent years. Centralised systems suffer some limitations to dealing with this issue due to all data is stored in central data centres. Thus, decentralised systems are getting more attention and increasing in popularity. Moreover, efficient service discovery mechanisms have naturally become an essential component in both large-scale and small-scale decentralised systems and. This research study is aimed at modelling a novel efficient indexing and searching model for service discovery in decentralised environments comprising numerous repositories with massive stored services. The main contributions of this research study can be summarised in three components: a novel distributed multilevel indexing model, an optimised searching algorithm and a new simulation environment. Indexing model has been widely used for efficient service discovery. For instance; the inverted index is one of the popular indexing models used for service retrieval in consistent repositories. However, redundancies are inevitable in the inverted index which is significantly time-consuming in the service discovery and retrieval process. This theeis proposes a novel distributed multilevel indexing model (DM-index), which offers an efficient solution for service discovery and retrieval in distributed service repositories comprising massive stored services. The architecture of the proposed indexing model encompasses four hierarchical levels to eliminate redundancy information in service repositories, to narrow the searching space and to reduce the number of traversed services whilst discovering services. Distributed Hash Tables have been widely used to provide data lookup services with logarithmic message costs which only require maintenance of limited amounts of routing states. This thesis develops an optimised searching algorithm, named Double-layer No-redundancy Enhanced Bi-direction Chord (DNEB-Chord), to handle retrieval requests in distributed destination repositories efficiently. This DNEB-Chord algorithm achieves faster routing performances with the double-layer routing mechanism and optimal routing index. The efficiency of the developed indexing and searching model is evaluated through theoretical analysis and experimental evaluation in a newly developed simulation environment, named Distributed Multilevel Bi-direction Simulator (DMBSim), which can be used as cost efficient tool for exploring various service configurations, user retrieval requirements and other parameter settings. Both the theoretical validation and experimental evaluations demonstrate that the service discovery efficiency of the DM-index outperforms the sequential index and inverted index configurations. Furthermore, the experimental evaluation results demostrate that the DNEB-Chord algorithm performs better than the Chord in terms of reducing the incurred hop counts. Finally, simulation results demonstrate that the proposed indexing and searching model can achieve better service discovery performances in large-scale decentralised environments comprising numerous repositories with massive stored services.

Resumo: O sistema LEED (Leadership in Energy and Environmental Design) consiste numa metodologia para avaliar o desempenho energético e ambiental de edificações ao longo de seu ciclo de vida, tendo como objetivo direcionar ações para o conceito de edificações sustentáveis (green buildings) e fornecer uma padronização para medir a dimensão ambiental relativa dos projetos. No Brasil, a Eletrobrás, através do Programa Nacional de Conservação de Energia Elétrica (Procel) e em parceria com o Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (Inmetro), lançaram a Etiqueta Nacional de Eficiência Energética em Edificações (ENCE), para edifícios comerciais, de serviços e públicos, reconhecendo edificações que reduzam o consumo de energia elétrica e água. Neste trabalho foi realizado um estudo de certificação energética e ambiental de edificações, bem como a identificação de alternativas técnicas para o enquadramento em níveis mais adequados e correspondente estudo de viabilidade econômica. Como estudo de caso, o edifício da Fundação existente no Campus de Guaratinguetá da UNESP foi analisado de acordo com os preceitos da avaliação de desempenho de ambas as metodologias. Com base nos resultados obtidos, foram realizadas sugestões de tecnologias e modificações possíveis de serem implantadas / Abstract: The LEED system (Leadership in Energy and Environmental Design) is a methodology for evaluating the energetic and environmental performance of buildings throughout their life cycle, aiming to guide actions for the concept of green building and provide a standard for measuring the size on environmental projects. In Brazil, Eletrobras, through the National Program for Energy Conservation (PROCEL) and in partnership with the National Institute of Metrology, Standardization and Industrial Quality (Inmetro), launched the Label National Energy Efficiency in Buildings (ENCE), for commercial buildings, and public service, recognizing buildings that reduce the consumption of electricity and water. In this research report it was presented an environmental and energetic certification of buildings study, as well as the analysis of technical solutions for the framework in more appropriate levels, and corresponding economic feasibility study. As a case study, the Foundation's existing building on the campus of UNESP at Guaratinguetá was analyzed in accordance with the principles of performance evaluation of both approaches. Based on these results, suggestions were made of possible technologies and changes being implemented / Orientador: José Antonio Perrella Balestieri / Coorientador: Rubens Alves Dias / Banca: Luiz Roberto Carrocci / Banca: Ricardo Dias Martins de Carvalho / Mestre

The economic and environmental benefits secured through the increased integration of photovoltaic (PV) technology into the built environment are undeniable and provide the principal motivation for this research. Present delays in the technology transfer of building integrated photovoltaics (BIPV) can be attributed to the following; material cost, performance guarantee, increased installation complexity and unfamiliar technology. It is well understood that the temperature of a PV material receiving solar irradiation, will increase with solar intensity, while reducing in electrical efficiency. It therefore makes economic sense to minimise the increase in PV material temperature and maximise electrical energy yield. Through the addition of a convecting fluid, flowing over the surface of heated PV material, heat transfer will be induced. With the added benefit of warm air capture from an integrated photovoltaic/thermal (PVT) collector, the economic benefits are increased. But, to ensure maximum utilisation of both thermal and electrical energy production, a significantly more complex control system has to be employed than that for a PV system on its own. Modelling the energy flows within a multifunctional PVT building facade presents a problem of considerable complexity. Previous work in this area has centred on performing finite element analysis of the system in order to find solutions to complex algorithms. It requires considerable computational power to perform these calculations and often the results produced are much more detailed than required. Within this thesis, a fully operational PVT facade model is presented, giving the potential for improved multifunctional facade design. This new model has been developed into a software program for use within the TRNSYS environment. By using the TRNSYS software, a detailed building model has been created and integrated with the new PVT facade model. Simulations were then undertaken to evaluate the energy transfers between internal and external environments and the electrical and thermal energy capturing capabilities of the facade. Simulated results have been evaluated against experimental data taken from a fully operational PVT facade. The results conclude that the presented model simulates the energy flows around, through and within the facade (radiative, conductive, convective and electrical) very well. Performance enhancing development work is due to take place on the operational facade analysed in this work, very soon. This new facade model will be used as a tool to evaluate the proposed changes to the building prior to this development work being undertaken.

Running economy (RE) is defined as the rate of oxygen consumption at a given submaximal running velocity. Whilst the concept of running economy is well documented, little information is available about the to daily variation in RE, variation in RE within prolonged running bouts and the effects on RE of exercise-induced dehydration. Thus, the principal aim of this research was to investigate these aspects and attempt to contribute further knowledge and understanding of RE. The purpose of the first study (Chapter 4), was to investigate the daily variation in RE in twenty one habitually active Singaporean men (V0₂max = 51.6 ± 5.8 ml.kg⁻¹ min⁻¹). The RE was measured over three consecutive days during treadmill running at 3.33 m.s⁻¹, and at running speeds representing relative exercise intensities of 60% and 85% V0₂max (randomly assigned in a counterbalanced design). The running bouts were of 10 min duration at each speed, with 5 min rest between each running bout. The group mean (±SD) VO₂ during submaximal running at 3.33 m.s⁻¹ (82 ± 5.7% V0₂max) was 44.5 (±2.1), 43.8 (±2) and 44.2 (±2) ml.kg⁻¹ min⁻¹ for days one, two and three respectively. The mean coefficient of variation (CV) for RE at 3.33 m.s⁻¹ was 2.54 % (range = 0.24 - 5.41%). The group mean VO₂ during submaximal running at 60% and 85% VO₂max was similarly invariant over the three consecutive days. The results showed no differences in daily RE for the group (p > 0.05). The results suggest that for the individuals in this study RE does not change on a daily basis.

The aim of this thesis was to examine the effects of exercise on gas mixing in the lung during exercise. There were four major stages. Firstly, the existing equipment used with resting subjects was applied to the exercising subject and was found to be inappropriate. Secondly, an in-line system of measuring flow and gas concentration was devised. Thirdly this system was validated with the aid of a physical model and resting subjects. Finally, nitrogen wash-out data were collected from 24 subjects at rest and during progressive exercise at three standard exercise intensities. The dynamic response characteristics of the bag-in-box spirometer at high breathing frequencies (50 min-1) were such that tidal volume was underestimated by almost 50%. The box was too small and its response too a linear for adequate correction factors to be applied. The in-line system, based on a linear relationship between flow and several argon, oxygen, carbon dioxide and nitrogen mixtures ( r = + 0.99, p < 0.01 , Y = 0.2687 FAr + 0.995 ), measured tidal volumes reliably ( CV < 1% ) when expired flow was maintained at 35&deg; C. Thirty-six wash-outs of a 2.4 litre bell jar produced a mean value of 2.461 litres ( SD. 0.034, CV. 1.4% ). The capacity of the in-line system to measure gas mixing efficiency reliably was tested on resting subjects ( six trials each on two days ). Mean values were 76.7% ( SD. 7-5% ) and 76.8% ( SD 4.7% ); mean CV for all trials was 8%. Progressive exercise resulted in significant reduction in lung volume as measured by recovered nitrogen; there was evidence that at the greatest exercise intensity all the nitrogen was not recovered. Decreased diffusion time as a result of greater respiratory frequency may have been responsible. The significantly greater tidal volumes and respiratory frequencies observed on exercise resulted in bigger minute volumes. Both series and alveolar deadspaces increased, but the greater minute volume more than compensated for the growing dead spaces, and so the inspired volume available for mixing was increased. Ventilatory and gas mixing efficiency improved significantly as exercise progressed, but the greatest improvement occurred at the first power output of 50W; thereafter, there was very little change in gas mixing efficiency in spite of three-fold increase in ventilation. It is possible that gas mixing efficiency functions optimally at FRC and that, unlike some other physiological measures, there is little reserve capacity. However, the possibility of gas mixing deficiencies at maximal exercise leading to a ventilatory limit to maximal oxygen uptake remains, and this issue still needs to be investigated.

A model for motor gasoline demand in Canada is developed by household. The model identifies and separates effects of several responses by the household to a change in gasoline prices such as driving fewer miles, purchasing fewer cars, and buying more fuel efficient cars. It also estimates the manufacturers' response of improving the technology of new automobiles. The size and the composition of the fleet according to the interior volume of four classes of automobiles rather than their natural weight is used. Furthermore, two components of the average fuel efficiency of new cars were identified and estimated. The first is the technical fuel efficiency set by the car manufacturers and the second is the sales ratio of four classes of new automobiles. The use of household expenditure survey data make it possible to experiment with some socio-economic variables such as the percentage of households living in urban areas, number of cars per household and the number of persons in the household who can drive. The relatively new technique of cointegration is also utilized. The results indicate that there are certain advantages associated with the elaborate treatment of the stock adjustment and the fuel economy of the fleet. In general, the estimated coefficients suggest that most of the adjustment after a gasoline price increase comes from miles driven in the short run and from miles per gallon, hence fuel efficiency improvements in the long run. The model gave the total short run (one year) price elasticity of gasoline consumption between 0.312 - 0.313 for the different provinces which is relatively small range. One of the more interesting results is that approximately 10 percent of the household response to a price change in the first year was due to a change in the composition of the fleet to a more fuel efficient vehicle. Approximately 75 percent was due to driving fewer miles while the remaining 15 percent was attributed to a change in the size of the fleet. The intermediate run (five year) price elasticities range from 0.689 to 0.7 09 and the long run price elasticities (ten year) range from 0.97 5 to 1.059. The long run price elasticities exceed unity which does not lend support to the belief that long run gasoline price elasticities are also inelastic. The short term household income elasticities range from 0.301 to 0.306, the intermediate term range from 0.655 to 0.679, and the long term range from 0.868 - 0.949.

Dans cette étude, nous utilisons des caractéristiques locales/globales en vue d’améliorer la chaîne de transmission des séquences de vidéos. Ce travail est divisé en quatre parties principales qui mettent à profit les caractéristiques de contenu vidéo. La première partie introduit un modèle de prédiction de paramètres d’un encodeur basé sur la complexité du contenu. Ce modèle utilise le débit, la distorsion, ainsi que la complexité de différentes configurations de paramètres afin d’obtenir des valeurs souhaitables (recommandées) de paramètres d’encodage. Nous identifions ensuite le lien en les caractéristiques du contenu et ces valeurs recommandées afin de construire le modèle de prédiction. La deuxième partie illustre le schéma de l’encodage à description multiple (Multiple Description Coding ou MDC, en anglais) que nous proposons dans ces travaux. Celui-ci est optimisé pour des MDC d’ordre-hauts. Le décodage correspondant et la procédure de récupération de l’erreur contenu-dépendant sont également étudiés et identifiés. La qualité de la vidéo reçue a été évaluée subjectivement. En analysant les résultats des expériences subjectives, nous introduisons alors un schéma adaptatif, c’est-à-dire adapté à la connaissance du contenu vidéo. Enfin, nous avons simulé un scénario d’application afin d’évaluer un taux de débit réaliste. Dans la troisième partie, nous utilisons une carte de déplacement, calculées au travers des propriétés de mouvement du contenu vidéo, comme entrée pour l’algorithme de masquage d’erreur par recouvrement (inpainting based error concealment algorithm). Une expérience subjective a été conduite afin d’évaluer l’algorithme et d’étudier la perturbation de l’observateur au visionnage de la vidéo traitée. La quatrième partie possèdent deux sous-parties. La première se penche sur les algorithmes de sélections par HRC pour les grandes bases de données de vidéos. La deuxième partie introduit l’évaluation de la qualité vidéo utilisant la connaissance du contenu global non-référencé. / In this work, the global/local content characteristics are utilized in order to improve the delivery chain of the video sequences. The work is divided into four main parts that take advantages of video content features. The first part introduces a joint content-complexity encoder parameters prediction model. This model uses bitrate, distortion, and complexity of different parameters configurations in order to get the recommended encoder parameters value. Then, the links between content features and the recommended values are identified. Finally, the prediction model is built using these features and the recommended encoder parameter values. The second part illustrates the proposed multiple description coding (MDC) scheme that is optimized for high-order MDC. The corresponding decoding and content-dependent error recovery procedures are also identified. The quality of the received videos is evaluated subjectively. By analyzing the subjective experiment results, an adaptive, i.e. content-aware, scheme is introduced. Finally, an application scenario is simulated to study the realistic bitrate consumption. The third part uses the motion properties of a content to introduce a motion map that will be used as an input for the modified state-of-the-art inpainting based error concealment algorithm. A subjective experiment was conducted to evaluate the algorithm and also to study the content-aware observer’s disturbance when perceiving the processed videos. The fourth part has two sub-parts, the first one is about HRC selection algorithms for the large-scale video database with an improved performance evaluation measures for video quality assessment algorithms using training and validation sets. The second part introduces global content aware no-reference video quality assessment.