This thesis examines two major issues associated with the long memory characteristics of Korean stock market return and return volatility: the presence of long memory; and possible origins of long memory. / Thesis (PhD)--University of South Australia, 2008.

Agriculture currently faces a number of environmental sustainability issues. Three key issues that are the focus of this study are greenhouse gas emissions, depletion of mineral phosphorus resources and cadmium contamination in agricultural soil. Biomass can potentially be used as a renewable energy source and can also be returned to improve the nutrient and drainage structure of agricultural soils. Sustainable management of biomass and agriculture can have significant impacts on reducing greenhouse gas emissions from a region. Moreover, it reduces the demand for external energy supply, phosphorous (P) based fertilizer, and it??s associated Cadmium (Cd) impurity which can contaminate the soil, plant and food chains. These three issues have typically been considered separately, and managed by different agencies or organisations. The aim of this thesis is to develop an integrated decision support tool that can be used for evaluating alternative options for management and resource recovery from biomass for enhancing recovery of energy, returning carbon (C) and phosphorus (P) from biomass back to soil, reducing greenhouse gas emissions and also cadmium (Cd) contamination in an agricultural region. This research employed a combination of the tools of Material Flow Analysis (MFA), Geographic Information System (GIS) and Cost-Benefit Analysis (CBA). MFA is used as the primary tool for this research. GIS and CBA are combined with MFA in later stages of the overall procedure to develop an integrated decision support tool. This integrated tool has been applied to the Murrumbidgee Irrigation Area (MIA) in Australia. Tracking the flow of essential substances using MFA has identified current resource management efficiency and substances accumulation across the region. Integrating a spatial analysis tool (GIS) with MFA has provided a feedback driven monitoring tool for evaluating trends of spatial accumulation of substances on agricultural land. This enables the time remaining before acceptable limits are exceeded to be estimated on a spatial basis. Integrated MFA and CBA has been applied to evaluate the tradeoffs and potential synergies of alternative biomass management options. Overall the tool can assist in evaluating the effectiveness of alternative scenarios and visualise the results to stakeholders in a systematic way.

Standard techniques for analysing sequential programs are severely constrained when applied to a concurrent program because they cannot take full advantage of the concurrent structure of the program. In this work, we overcome this limitation using a novel approach which ``lifts'' a sequential dataflow analysis to a concurrent analysis. First, we introduce concurrency primitives which abstract away from the details of how concurrency features are implemented in real programming languages. Using these primitives, we describe how sequential analyses can be made applicable to concurrent programs. Under some circumstances, there is no penalty for concurrency: our method produces results which are as precise as the sequential analysis. Our lifting is straightforward, and we illustrate it on some standard analyses -- available expressions, live variables and generalized constant propagation. Finally, we describe how concurrency features of real languages can be expressed using our abstract concurrency primitives, and present analyses for finding our concurrency primitives in real programs.

End products of society (e.g. sewage sludge and incineration ashes) can be used as indicators of the use of chemicals in consumer goods. Through upstream work the sources of substances released from goods may be identified before the emissions reach the end products. This thesis is a result of five studies, of which four were conducted using substance flow analyses (SFA) for silver (Ag), bismuth (Bi) and copper (Cu) reaching sewage sludge. The fifth is an SFA that explores the implications of the presence of As (from CCA-treated wood) in ashes. These studies helped fulfil the specific and overall aims of the thesis; to contribute to the general knowledge on diffuse emissions reflected in end products, by examining emissions of some heavy metals from various societal goods and the implications for end products, in this case sewage sludge and, to some extent, ashes. The results from the studies, of which four had Stockholm as a study object, show the urban flows and accumulated amounts (stocks) of the heavy metals. The largest sources of the metals Ag, Bi and Cu in sewage sludge were identified to be textiles (Ag), cosmetics (Bi) and brake linings (Cu). For As (in CCA-treated wood) and Cu updated SFAs were performed and compared with earlier studies in order to follow the development and changes in flows over time. The current use of the heavy metals studied can also be seen as a loss of resources, and as the metals should ideally be recovered as a part of a circular economy, urban and landfill mining as well as recycling are alternatives that need further exploring. The legislation of chemicals in consumer goods was identified as an important step in handling corresponding diffuse emissions.

Life cycle analysis is an appropriate way to clear obscure facts about an element. Gallium is a critical element which is used in many technologies these days and therefore quantification of main global cycles of gallium, production, consumption and end of life products, also investigation about recycled gallium content and potential recycling possibilities are investigated in this paper. First a qualitative substance flow for gallium is designed similar to other metal cycles with regards to exclusive characteristics of gallium flows itself. USGS and World Mining Data are mainly used to get information about gallium production, main gallium consumptions and end of life products. Subsequently a quantitative model in STAN should unlock many uncertainties. Substance flow analysis and material flow analysis give a better understanding of unknown gallium flows with their uncertainties and meanwhile major applications, concentration of gallium in different products, waste flows, landfills and present recycling technologies are detailed. Consequently STAN model asserts that main gallium flows are primary gallium production and refined gallium production in production process, Integrated Circuit board fabrication, Light Emitting Diodes, Photovoltaic and recycled new scrap flow in manufacturing process. A significant amount of gallium is collected as stock in consumption process. Also current gallium recycling facilities are limited as recycling is not economically justified. Moreover main part of recycled gallium content is collected from new scrap which is formed through manufacturing process. Finally gallium consumption in Photovoltaic and Light Emitting Diodes industry increases rapidly and sustainability demand cost efficient methods for gallium recycling from solar cells, diodes and other end of life products.

The aim of this study is to assess the current situation of energy and carbon flows through the waste sector in Jämtland. An energy flow analysis is performed by balancing the inflows and outflows of the lower heating value and embodied energy. A carbon flow analysis was made on the same principles although with the carbon content and embodied CO2eq.  The results are showing that over a period of one year, 75 000 tons of waste flows through the waste sector in Jämtland. Approximately 60 % of all the waste is incinerated. The energy analysis shows that 970TJ flows through the waste sector every year. Household waste is the category with most energy consumption and emissions in total. However, other materials like metal and electronics have higher energy and carbon content per ton than the household category. The results of the analyses can further be implemented in the Sustainable Jämtland model and it can then be used as a base when making strategies for a sustainable waste treatment.

Bounded Verification is an effective technique for finding subtle bugs in object-oriented programs. Given a program, its correctness specification and bounds on the input domain size, scope bounded checking translates bounded code segments into formulas in boolean logic and uses off the shelf satisfiability solvers to search for correctness violations. However, scalability is a key issue of the technique, since for non-trivial programs, the formulas are often complex and can choke the solvers. This thesis describes approaches which aim to scale scope bounded checking by utilizing syntactic and semantic information from the code to split a program into sub-programs which can be checked incrementally. It presents a thorough evaluation of the approaches and compares their performance with existing bounded verification techniques. Novel ideas for future work, specifically a specification slicing driven splitting approach, are proposed to further improve the scalability of bounded verification. / text

The development of an open pit phosphate mine in 1965 near Aurora, North Carolina, required groundwater withdrawals in excess of 50 million gallons per day for pressure relief from the underlying confined Castle Hayne aquifer. The effects of pumping from this limestone aquifer were widespread, extending over an area of more than 2,000 square miles in the first year before the pressure cone reached a stabilized condition. Salt water encroachment by lateral movement from downdip in the aquifer and by downward leakage from the Pamlico Estuary and Sound was possible if prolonged pumping were permitted. A joint project between state and industry in 1970-71 focused on analyzing the effects of five years of pumping for the purpose of making projections of future conditions of groundwater quality for continued and expanded groundwater development. The present study describes the method of flow net analysis used in the joint project to determine quantitatively the values of aquitard vertical permeability and aquifer transmissivity. These values provided the rational basis for making projections of groundwater movement and quality changes associated with this movement, A hydrologic projection model, developed in the present study, integrates the quality and volumetric flow of vertical leakage with that of lateral flow. Projection analyses are presented for two hypothetical cases of chloride distribution changed by continued pumping and for chloride changes associated with three different pumping regimes in the subject area.

Managing anthropogenic emissions in urban areas is a major challenge in sustainable environmental development for cities, and future changes and increasing urbanisation may increase this challenge. Systems perspectives have become increasingly important in helping urban managers understand how different changes may alter future emissions and whether current management strategies can efficiently manage these emissions. This thesis provides some systems perspectives that have been lacking in previous studies on modelling and managing future anthropogenic emissions in urban areas. The city of Stockholm, Sweden, was selected as the study site and studies about nitrogen, phosphorus and carbon were chosen, given world-wide urban eutrophication and global concerns about climate change. A substance flow analysis (SFA) structured model, comprising a source model coupled with a watershed model in an SFA structure, was developed to investigate future nutrient loading scenarios under various urban changes in small urban lake catchments. The results demonstrated that climate change potentially posed a greater threat to future nutrient loads to a selected lake catchment in Stockholm than the other scenarios examined. Another SFA-based study on future phosphorus flows through the city of Stockholm indicated that the best management option may depend on the perspective applied when comparing future scenarios of phosphorus flows and that both upstream and downstream measures need to be considered in managing urban phosphorus flows. An evaluation approach for examining current management plans and low-carbon city initiatives using the Driving forces-Pressure-States-Impact-Response (DPSIR) framework, was formulated. With such an evaluation approach, investigation of how well selected plans cover different aspects of the DPSIR framework and whether root causes and systematic measures are highlighted is possible. The results revealed that the current low-carbon city initiative in Stockholm falls within pressure-based, driver-orientated plans and that technical, institutional and cognitional measures are generally well covered. / <p>QC 20160510</p>

Abstract The development and advancement of microelectronics industry is very drastically. So, the key to create new technology of process and it's costs can be cut by simulating the performance of these equipments. The reactor of chemical vapor deposition (CVD) is important to semiconductor production process.. This research use numerical method to study the process parameters of low-pressure chemical vapor deposition (LPCVD) of Tungsten (W).In this simulation, the CVD reactor modeling are constructed and discreditzed by using the implicit finite volume method. The grids are arranged in a staggered manner for the discretization of the governing equations. Then, the SIMPLE-type algorithm will be used to solve all of the discretized algebra equations. In this research, the reactor is an single wafer and cold-wall system. The nozzle position is adjustable from 100 to 250mm.The nozzle-to-wafer distance is adjustable by changing the height from 30 to 120mm.The temperature and pressure in the reactor system can be setup with susceptor temperature 300~600 and pressure 0.5~8Torr. The results show that the flow in the reactor may depend on the flow rate and nozzle position. An effective means to avoid unstable is to reduce the susceptor temperature and system pressure due to the effects of buoyancy force and recirculation.