The increasingly diverse nature of modern applications makes it critical for future systems to have dynamic resource scaling capabilities which enable them to adapt their resource usage to meet user requirements. Such mechanisms should be both fine-grained in nature for resource-efficient operation and also provide a high scaling range to support a variety of applications with diverse needs. To this end, heterogeneous platforms, consisting of components with varying characteristics, have been proposed to provide improved performance/efficiency than homogeneous configurations, by making it possible to execute applications on the most suitable component. However, introduction of such heterogeneous architectural components requires system software to embrace complexity associated with heterogeneity for managing them efficiently. Diversity across vendors and rapidly changing hardware make it difficult to incorporate heterogeneity-aware resource management mechanisms into mainstream systems, affecting the widespread adoption of these platforms. Addressing these issues, this dissertation presents novel abstractions and mechanisms for heterogeneous platforms which decouple heterogeneity from management operations by masking the differences due to heterogeneity from applications. By exporting a homogeneous interface over heterogeneous components, it proposes the scalable 'resource state' abstraction, allowing applications to express their resource requirements which then are dynamically and transparently mapped to heterogeneous resources underneath. The proposed approach is explored for both modern mobile devices where power is a key resource and for cloud computing environments where platform resource usage has monetary implications, resulting in HeteroMates and HeteroVisor solutions. In addition, it also highlights the need for hardware and system software to consider multiple resources together to obtain desirable gains from such scaling mechanisms. The solutions presented in this dissertation open ways for utilizing future heterogeneous platforms to provide on-demand performance, as well as resource-efficient operation, without disrupting the existing software stack.

<p> An emerging trend in computing is to use distributed heterogeneous computing (HC) systems to execute a set of tasks. Cluster computer systems, grids, and Desktop Grids are three popular kinds of HC systems. An important component of an HC system is its resource management system (RMS). The main responsibility of an RMS is assigning resources to tasks in order to satisfy certain performance requirements. </p> <p> For cluster computer systems, we propose a new mapping heuristic which requires less state information than current heuristics. For Desktop Grids, we propose a new scheduling policy that exploits knowledge of the effective computing power delivered by the machines and the distribution of their fault times in order to improve performance. Finally, for grids, we propose a new decentralized load balancing policy which dramatically cuts down the communication overhead incurred in state information update. </p> <p> The proposed resource management policies utilize the solution to a linear programming problem (LP) which maximizes the system capacity. Our simulation experiments show that these policies perform very competitively, especially in highly heterogeneous systems. </p> / Thesis / Doctor of Philosophy (PhD)

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Most irrigation schemes in India are performing poorly as seen from the average irrigation efficiency in the range of 30-40% for these projects. Hence it is necessary to study the performance assessment of these schemes to investigate the reasons and improve the performance subsequently. There are different kinds of performance measures that may vary spatially over the irrigation scheme. Hence it is necessary to use a framework for finding out the final performance index (FPI) that combines important performance measures. Hence this study was undertaken. Mula Irrigation Scheme in Ahmednagar District of Maharashtra State, India was identified after verifying that most of the needed data was available. The six performance indicators viz. Productivity, Equity, Adequacy Reliability, Flexibility and Sustainability were identified as the important one for obtaining the information on the relative preference from the farmers and first three were considered for obtaining the allocation plans. The performance of different irrigation schemes is assessed with the help of Area and Water Allocation Model (AWAM). The performance measures viz. productivity, equity, adequacy and excess were obtained by formulating the irrigation strategies based on 1. Irrigation amount: Full depth irrigation (FDI), Fixed depth irrigation (FxDI) and Variable depth irrigation (VDI), 2. Irrigation frequency (14 days, 21 days, 28 days and 35 days), 3. Water distribution: Free water distribution (FWD), Equitable distribution of seasonal water (EDSW) and Equitable distribution of intra-seasonal water (EDIW) and 4. Cropping distribution (Free cropping distribution and Fixed cropping distribution). The yield response of crops to different criteria such as soil, irrigation interval, irrigation strategy and irrigation depth, were analysed. It is found for wheat grown on all considered soils, the variable irrigation depth strategy provided better performance of irrigation scheme in terms of productivity and results in higher irrigation water use efficiency. It is concluded though that the application of water according to the variable irrigation depth strategy is operationally and from a management point of view not convenient and in current situation may not be adoptable. Though the fixed depth irrigation strategy is found to be less productive based on this research for Mula irrigation scheme, it is more convenient for operation compared to other strategies as it does not involve adoption of separate schedules for different crops. In general the area and net benefit productivity values are higher in fixed depth irrigation followed by variable depth and then full depth. The productivity values are higher in case of free cropping distribution compared to fixed cropping distribution. The equitable water distribution resulted in lower productivity compared to free water distribution. No specific trend of equity with the irrigation interval was found. Equity values are higher in case of fixed depth of irrigation compared to full depth. The equity values are higher in case of fixed cropping distribution compared to free cropping. The equity values are as expected higher or unity for equitable water distribution compared to free water distribution. The adequacy values are higher in full depth of irrigation followed by variable depth irrigation and fixed depth irrigation. It is observed that the productivity and equity are almost inversely proportional to each other. Hence the hypothesis that productivity and equity conflicts with each other holds true. Further, Analytic Hierarchy Process (AHP) was used to assign weights of different performance measures by determining the farmers relative preference of different performance measures. The average weights of different performance measures (monetary productivity, equity in water distribution and adequacy) were obtained for farmers from different reaches from the weights obtained from AHP analysis, and considerable differences were found between the weights for the head, middle and tail reaches. The values of the performance indicators were obtained from the simulation-optimization modeling (AWAM model). The different indicators were combined into a final overall performance indicator (FPI) of irrigation management in an irrigation scheme from the farmers perspective. The FPI was computed for head, middle and tail reach farmers using the weights obtained from AHP by compromise programming. It is interesting to note that the strategies that best met the farmers preferences (highest FPI), were same for middle reach and tail reach farmers however it is different for head reach. It is also interesting to note that the preferences of the head, middle and tail reach farmers, irrespective of their relative location in irrigation scheme, were best met by strategies which include the equitable distribution of water. For middle and tail reach farmers, full depth irrigation would give the highest FPI, while for head reach farmers optimised fixed depth would be best. It is also seen that for head and middle reach farmers a strategy with fixed cropping distribution and free water distribution would be worst for meeting the preferences of head and middle reach farmers while for tail reach farmers a strategy with free water and free cropping distribution would be worst. The mean values of the weights for head, middle and tail reach farmers were Productivity = 0.33, Equity = 0.31 and Adequacy = 0.36. With these weights, the highest FPI (0.85) was obtained with an irrigation strategy of Full depth irrigation with free cropping and annual equity at irrigation interval of 35 days in winter and 28 days in summer . Considering the different depth of irrigations (FxDI, VDI and FDI) the VDI and FDI are practically difficult to execute due to the data required for calculations and operational requirements of the irrigation canals. Using FxDI, a strategy with high FPI (0.83) was identified as the best feasible irrigation strategy to implement for the entire irrigation scheme: Fixed depth irrigation with free cropping and annual equity at irrigation interval of 35 days in winter and 28 days in summer . It was found that this best feasible irrigation strategy for the entire scheme was not sensitive to the weights assigned to the performance measures.

"January 2004" / Bibliography: leaves 183-198. / xv, 198 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / As no single specification or verification method is able to solve all classes of problems, especially with industrial-sized applications, a diversity of modelling languages and analysis techniques specialised and optimized for various domains is needed, along with the ability to use them in combination. The work presented in this thesis has concentrated on developing techniques to support the use of a combination of modelling languages, especially visual languages, for system specification. Also, in order to tackle the main obstacles of model checking and make it more accessible to and usable by practising engineers, this work has focused on providing lightweight but effective methods and tools to alleviate the state space explosion problem in model checking. / Thesis (Ph.D.)--University of Adelaide, School of Computer Science, 2004

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xi, 124 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 120-124).

In this study, I develop a Gaussian Closure method to simulate steady state unsaturated flow in randomly heterogeneous soils. I predict pressure heads and fluxes and evaluate uncertainties associated with these predictions, without resorting to Monte Carlo simulation, upscaling, or linearization of the governing flow equations and the constitutive relationship between unsaturated hydraulic conductivity and pressure head. Upon treating dimensionless pressure head as a multivariate Gaussian function in the manner of Amir and Neuman [2001], I obtain a closed system of coupled non-linear differential equations for the first and second moments of pressure head and flux for both spatially uncorrelated Y (log saturated hydraulic conductivity) and spatially correlated Y. Computational examples for unsaturated flow in a vertical plane, subject to deterministic forcing terms including a point source, show a good agreement between my Gaussian closure solution and a more general Monte Carlo solution. The computational examples include a uniform domain, eight subdomains, spatially uncorrelated non-uniform Y cases, spatially correlated Y cases, and conditional Y cases. Though the computational examples treat the random pore size parameter a as being uniform across the entire flow domain, I show theoretically that the Gaussian closure method could apply to spatially variable a statistics.

This thesis is based on experiments applying synchrotron based X-ray Absorption Spectroscopy(XAS) and Resonant Inelastic X-ray Scattering (RIXS) in the soft X-ray region to energy related systems. The main work of this thesis has been to develop a reaction cell that allowed for in situ XAS and RIXS investigations of the partial epoxidation of ethylene over a Ag catalyst at 1 atm and up to 250C. The developed in situ cell can be used in two sample modes: 1) the Ag catalyst is deposited directly onto the vacuum separating membrane with the reaction gases flowing beneath it or 2) a slightly compressed Ag powder sample is at a distance to the vacuum membrane with the reaction gases flowing between the Ag powder sample and the membrane.Both sample modes offers the total florescence yield, TFY, and the total electron yield, TEY, to be recorded simultaneously. By means of the developed in situ cell a number of oxygen species, residing in/on the Ag surface or in the Ag bulk, have been detected. We claim to detect adsorbed O2 under epoxidation conditions, as well as Ag–O–H groups. We are also able to monitor changes of the absorbed oxygen as we change the composition of the reaction gas feed. The first charging cycle of Li-ion batteries have been investigate by ex situ measurements on the cathode Li2-xMnSiO4 and the anode composite LixNi0:5TiOPO4/C . The initial crystalline material becomes amorphous due to lithiation during the first first charging. We find that the redox behaviors of these two states are significantly different. Sulfidation of natural copper oxides are is found to be strongly promoted when it is grown on the host metal by a disproportionation.

This dissertation consists of three essays about heterogeneous agents in the dynamic economy and how to deal with the asymmetric information arose by heterogeneity. Firstly, I consider the optimal taxation issue in a dynamic endogenous growth model with considering human capital accumulation, and agents ability is heterogeneous and private information. Moreover, the agents with higher ability have positive external effects on others. By using the two-sector endogenous model, I show that it is optimal to impose different income and capital income taxes on people with different abilities. Specifically, positive marginal income tax is adopted for people with lower ability while no tax is imposed for people with higher ability; marginal capital income tax is zero whatever the agent’s is low or high. As for people using the capital and labor for human capital accumulation, the government should subsidize them whatever their ability is. Secondly, I study the optimal monetary and fiscal policy with heterogeneous agents based on the search-theoretical environment where money is essential and consider the private information. I first solve the households’ problem in the centralized and decentralized market, and find out the optimal conditions. Then, in this section, I describe the problem that social planner faces by involving uncertainty and agents whose types are continuous. By comparing the optimal conditions in this generous setting, I show that the Friedman rule is no longer optimal when jointed with nonlinear taxation of income. Moreover, the capital income taxation is not zero. Moreover, I constructs a general theoretical model to consider two kinds of financial frictions in the economy with financial intermediaries. By quantitative analysis the model with three separate shocks which are a negative collateral shock, a negative productivity shock and a positive shock to bankers’ divert rate, I find that a negative collateral shock which tightens firms’ financing constraints on investment can generate an equity price boom which is different from what is observed in recessions. Therefore, the collateral shock is not the main reason for the business cycle, while the negative productivity shock and bankers’ moral hazard problem are more important aspects to explain current economy.

Wireless Sensor Networks (WSNs) are networks of small devices, called motes, designed to monitor resources and report to a server. Motes are battery-powered and have very little memory to store data. To conserve power, the motes usually form clusters to coordinate their activities. In heterogeneous WSNs, the motes have different resources available to them. For example, some motes might have more powerful radios, or larger power supplies. By exploiting heterogeneity within a WSN can allow the network to stay active for longer periods of time. In WSNs, the communications between motes draw the most power. By choosing better clusterheads in the clusters to control and route messages, all motes in the network will have longer lifespans. By leveraging heterogeneity to select better clusterheads, I have developed Heterogeneous Clustering Control Protocol (HCCP). HCCP is designed to be highly robust to change and to fully utilize the resources that are currently available.