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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Avanços, impasses e desafios do trabalho social no âmbito dos programas federais de urbanização de favelas

Gomes, Raquel Paiva January 2013 (has links)
Orientador: Artur Zimerman / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Planejamento e Gestão de Território, 2013
72

The Public Accounts Committee: pursuing probity and effeciency in the Australian Public Service: the origins, work, nature and purpose of the Commonwealth's Public Accounts Committee

Laver, John Poynton, n/a January 1997 (has links)
The Commonwealth parliament's Public Accounts Committee (PAC) was established in 1913 and to the end of 1995 had produced 397 reports on government expenditure and administration, with almost all its recommendations implemented by government. However despite the Committee's prominence among the instruments parliament has used to oversight the executive, not only does it lack clear legislative authority for major areas of its activities but its specific purpose is not defined in its legislation. Among other things the latter omission renders proper evaluation of the PAC's effectiveness impossible, as objectives are a necessary prerequisite to assessment. This thesis establishes the de facto purpose of the Committee by tracing the development of standing public accounts committees generally, and by analysing the PAC's work as shown by its output of tabled reports. In that development, six evolutionary phases are identified: the PAC's roots in the move to a parliamentary control of the administration of government expenditure in Britain from the 1780s; its genesis in the 1850s with the concept of the standing public accounts committee, to be concerned with regularity and probity in government expenditure; its origins in the establishment of the British standing public accounts committee , in 1861, stressing high standards of government accounting, audit and reporting; its establishment in the Commonwealth, concentrating on information on departmental activities, efficient implementation of government programs and provision of policy advice; its re-establishment in 1951, stressing parliamentary control of government financial administration; and its operations from 1980, pressing for economic fundamentalist change in the public sector. Their output shows that in these phases the committees concerned displayed characteristic standing public accounts committee activism and independence in utilising the wording of their enabling documentation to adapt themselves to changes in their environment by pursuing a corresponding different mix of one or more of the following concurrent immediate aims: ensuring adequate systems of government accounting, audit and reporting; ensuring probity and regularity in departmental expenditure; obtaining and disseminating information on departmental activities; ensuring high standards of departmental administration and management; providing policy advice to executive government; and ensuring economic, efficient and effective government spending. Together these attributes and practices have made the PAC a parliamentary instrument of unequalled flexibility with a single continuing underlying aim - a purpose not concerning the public accounts per se, but directed at achieving high standards of management and administration in government by calling the Commonwealth's public service to account for its expenditure and activities.
73

Measurability Aspects of the Compactness Theorem for Sample Compression Schemes

Kalajdzievski, Damjan 31 July 2012 (has links)
In 1998, it was proved by Ben-David and Litman that a concept space has a sample compression scheme of size $d$ if and only if every finite subspace has a sample compression scheme of size $d$. In the compactness theorem, measurability of the hypotheses of the created sample compression scheme is not guaranteed; at the same time measurability of the hypotheses is a necessary condition for learnability. In this thesis we discuss when a sample compression scheme, created from compression schemes on finite subspaces via the compactness theorem, have measurable hypotheses. We show that if $X$ is a standard Borel space with a $d$-maximum and universally separable concept class $\m{C}$, then $(X,\CC)$ has a sample compression scheme of size $d$ with universally Borel measurable hypotheses. Additionally we introduce a new variant of compression scheme called a copy sample compression scheme.
74

PAC-Bayesian aggregation and multi-armed bandits

Audibert, Jean-Yves 14 October 2010 (has links) (PDF)
This habilitation thesis presents several contributions to (1) the PAC-Bayesian analysis of statistical learning, (2) the three aggregation problems: given d functions, how to predict as well as (i) the best of these d functions (model selection type aggregation), (ii) the best convex combination of these d functions, (iii) the best linear combination of these d functions, (3) the multi-armed bandit problems.
75

Treatment of leachate by combining PAC and UV/O3 processes / Kết hợp keo tụ với PAC và quá trình UV/O3 để xử lý nước rỉ rác phát sinh từ bãi chôn lấp chất thải rắn

Van, Huu Tap, Trinh, Van Tuyen, Dang, Xuan Hien 15 November 2012 (has links) (PDF)
The landfill leachate is commonly treated for non-biodegradable organic matters, ammonia and colour. Experimental investigations using polyaluminium chlorite (PAC) and UV/O3 have been conducted for the determination of optimal pH value, reaction time and PAC concentration for the removal of chemical oxygen demand (COD) and colour. In pre-treatment coagulation stages, the highest COD and colour removal efficiencies were observed at the concentration of PAC ≥ 3,000 mglG1 and pH values between 7 and 8. However, these experiments also indicated significant removal efficiency for PAC starting with concentrations of 1,500 mglG1. The efficiency of COD and colour removal were approximately 30% and 70%, respectively. Similar efficiencies have been observed also during the second treatment stage where UV/O3 processes were used to treat coagulated leachate. After UV/O3 application, the pH of leachate reached the optimum value of 7.5 whereas the highest COD and colour removal efficiency was 55% and 72%, respectively, and the optimal reaction time was achieved after 80 min. / Nước rỉ rác sinh ra từ bãi chôn lấp chất thải rắn cần được xử lý các thành phần chất hữu cơ khó phân hủy sinh học, xử lí amoni và độ màu. Một số kết quả thử nghiệm về xử lý COD và màu của nước rỉ rác bằng việc sử dụng phương pháp keo tụ với PAC và quá trình UV/O3 đã được thực hiện cùng với việc xác định các giá trị pH tối ưu, thời gian phản ứng và nồng độ PAC tối ưu. Hiệu suất xử lý cao nhất đạt được khi nồng độ của PAC ≥ 3.000 mg/l, pH trong khoảng từ 7 đển 8 trong giai đoạn tiền xử lý. Tuy nhiên, hiệu quả loại bỏ COD và màu bắt đầu tăng rõ khi nồng độ PAC từ 1.500 mg/l trở lên. Hiệu quả loại bỏ COD và màu tương ứng là khoảng 30% và 70%. Các giá trị pH này phù hợp cho quá trình phản ứng UV/O3 được sử dụng sau giai đoạn keo tụ. Sau quá trình xử lý bằng hệ UV/O3, pH của nước rỉ rác tối ưu được xác định là 7,5 (hiệu suất xử lý COD và màu cao nhất tương ứng là 55% và 72%), thời gian phản ứng tối ưu là 80 phút.
76

Removal of Assimilable Organic Carbon and Disinfection By-Products Formation Potential from Water Treatment Plant Using a Biological Activated Carbon Process

Hung, Pi-hsia 04 July 2010 (has links)
Taiwan Water Supply Cooperation (TWSC) has upgraded traditional purification processes into advanced treatment systems in south Taiwan for many years. The removal efficiency of assimilable organic carbon (AOC) by ultrafiltration (UF) with reverse osmosis (RO) systems was 47% was lower than that of 62% by ozone with biological activated carbon system (BAC). In this work, we investigate the removal of AOC and disinfection by products formation potential (DBPFP) of raw water took from a water treatment plant by using BAC and membrane treatment units. BAC system of granular activated carbon(GAC) and powder activated carbon (PAC) showed two kind carbons have certain efficiency for AOC removal. Results we found could reach above 50% (from 44.28¡Ó9.84£gg acetate-C/L reduce to 20.93¡Ó4.25£gg acetate-C/L for GAC and from 45.92¡Ó17.75£gg acetate-C/L reduce to 21.23¡Ó4.25£gg acetate-C/L for PAC), when hydraulic retention time (HRT) in BAC reactor was at 1 hour. When HRT raised to 6 hours the concentration of AOC in effluent of BAC systems were reduced under 15 £gg/L, and removal efficiency could reach above 70%. The suggested limit level of AOC is 50 £gg/L of drinking water. In removal of DBPFP, BAC of two carbons has showed certain efficiency on trihalomethanes formation potential (THMFP) and haloacetic acids formation potential (HAA5FP). The results were done in removal of THMFP (from 20.54¡Ó6.48£gg/L reduce to 14.21¡Ó4.47£gg/L for GAC and from 24.64¡Ó6.74£gg/L reduce to 14.75¡Ó4.04£gg/L for PAC) and HAA5FP (from 39.64¡Ó10.38£gg/L reduce to 17.35£gg/L for GAC and from 17.86¡Ó5.13£gg/L reduce to 11.76¡Ó3.76£gg/L for PAC) in BAC reactors. They were all lower than national standard of drinking water (THMs 80£gg/L, HAAs 60£gg/L). It is believed that two kind carbons in BAC system could all reduce effectively on AOC and DBPFP to obtain high quality of drinking water with biological stability at HRT of 6 hours.
77

Study of inactivation of microorganisms in water using ozone and chlorine on variation of AOC in advanced water treatment plant and correlations of cleaning frequency in reservoir and water tower

Chen, Bi-Hsiang 08 July 2012 (has links)
In response to organic contaminations pollutating water sources of drinking water, domestic water treatment plants (WTP) were transforming from traditional chlorination disinfecton method to advanced ozone-based disinfection processes. However, the effectiveness of water purification procedures n removing AOC (Assimilable Organic Carbon) and DBPsFP (Disinfection By-Products Formation Potential) can be improved. Additionally, the quality of clean water purified at WTP may deteriorate in the water distribution network for various reasons, primarily resulting from the regrowth of microorganisms in the water distribution pipelines. This study investigates and researches the essential water quality items of effluent before and after the advanced water purification treatment plants and water movement to end users through water distribution networks. The investigation proceeded in four directions: (1) the efficiency of removing AOC from raw water using powdered and granular activated carbon biological systems, and the development of an AOC prediction model based on water quality monitoring items using the AutoNet (6.03) method of the artificial neural network system; (2) removal of the byproducts of disinfection from raw water using powdered activated carbon biological systems; (3) examining the relationship between ozone-based and chlorination-based water disinfection methods by comparing the number of coliform bacteria and total bacteria population in traditional and advanced processing units; (4) regarding the water distribution storage facilities for users, water reservoir towers were examined for water quality sampling and analysis and water tower cleaning frequencies. Regression analysis was performed using SPSS ¡]Statistical Product and Service Solutions¡^ statistical software, with the correlation coefficient denoting the closeness of relationships. We anticipate understanding the water quality situation for current users of tap water, and demands for cleaning frequencies, thereby achieving the purpose of improving drinking water safety. Regarding the efficiency of removing AOC from raw water, the results showed powdered and granular activated carbon biological systems performed well, with the AOC removal rate reaching 53% and 54%, respectively, and the SUVA (Specific Ultraviolet Absorbance) value (showed by UV254/DOC) being reduced by 15-18% and 22-23%, respectively. The correlation analysis of the AOC prediction model shows that the GAC (Granular Activated Carbon) had high predictive and actual value R values (R2 = 0.772) after model regressing, and the PAC (Powder Activated Carbon) had higher predictive and actual value R values (R2 = 0.856) after model regressing as well. That the PAC system AOC prediction model has a slightly higher correlation that may be attributed to water contaminations resulting from domestic sewage, agricultural fertilizers, and livestock excretions. In the use of powdered activated carbon biological systems to remove disinfection byproducts, THMsFP (Trihalomethanes Formation Potential) and HAAsFP (Haloacetic acids Formation Potential) functioned with a certain removal efficiency, with the average effluent concentrations being under the regulatory standard of 80£gg/L, respectively, which reduces carcinogenic risks. Correlation analyses conducted using SUVA on the three water quality concentrations (HAA5FP, HAA9FP, and THMsFP) obtained R2 values of 0.805, 0.820, and 0.823, respectively, indicating high levels of correlation. For the results of microbial assessment using ozone and chlorine to process drinking water, the advanced and conventional WTP achieved a removal rate greater than 99% for microbial removal (coliform bacteria and total bacteria population). The correlation analysis between cleaning frequencies and water quality parameters showed the frequency at which the water reservoirs and towers were cleaned has a significant impact on tap water quality in residential compounds and schools that accommodated more than 100 households or less than 99 households. Higher cleaning frequency (more than four cleanings a year) results in better the water quality.
78

Modeling the User Interfaces: A Component-based Interface Research for Integrating the Net-PAC Model and UML

Tsai, Shuen-Jen 06 June 2002 (has links)
Graphical user interface (GUI) has become the key element of modern information systems and is commonly viewed as one of the decisive factors for the success of an information system project. To help develop effective GUIs, many tools have been introduced by software vendors to meet the needs of designing a variety of interfaces. Such modern design tools offer system developer vehicles to create sophisticated GUI with a few codes. However, the complicity of many GUIs and the varying expectations among users, designers and developers make the communication among them and the use of most prevailing design tools a real challenge. An integrated tool for better design and development of GUIs may help alleviate the problems caused by the mis-communication and the knowledge gaps existing among users, designers and developers. In this paper, a new design tool, which integrates the GUI design techniques embedded in Unified Modeling Language (UML) and the Presentation-Abstraction-Control (PAC) model in Web environment (Net-PAC) is proposed. The potential problems of using vendor-provided design methodology will be presented. Special features of the proposed integrated tool will then be discussed. Some real-world cases using the integrated techniques will be presented to illustrate the advantages of using proposed methodology.
79

Toughness-dominated hydraulic fractures in cohesionless particulate materials

Hurt, Robert S 03 April 2012 (has links)
This work shows that toughness (resistance) to fracture propagation is an inherent characteristic of cohesionless particulate materials, which is significant for understanding hydraulic fracturing in geotechnical, geological, and petroleum applications. We have developed experimental techniques to quantify the initiation and propagation of fluid-driven fractures in saturated particulate materials. The fracturing liquid is injected into particulate materials, where the fluid flow is localized in thin crack-like conduits. By analogy, we call them 'cracks' or 'hydraulic fractures'. Based on the laboratory observations and scale analysis, this work offers physical concepts to explain the observed phenomena. When a fracture propagates in a solid, new surfaces are created by breaking material bonds. Consequently, the material is in tension at the fracture tip. In contrast, all parts of the cohesionless particulate material (including the tip zone of hydraulic fracture) are likely to be in compression. In solid materials, the fluid front lags behind the front of the propagating fracture, while the lag zone is absent for fluid-driven fractures in cohesionless materials. The compressive stress state and the absence of the fluid lag are important characteristics of hydraulic fracturing in particulate materials with low, or no, cohesion. Our experimental results show that the primary factor affecting peak (initiation) pressure is the magnitude of the remote stresses. The morphology of fracture and fluid leak-off zone, however, changes significantly not only with stresses, but also with other parameters such as flow rate, fluid rheology, and permeability. Typical features of the observed fractures are multiple off-shots and the bluntness of the fracture tip. This suggests the importance of inelastic deformation in the process of fracture propagation in cohesionless materials. Similar to solid materials, fractures propagated perpendicular to the least compressive stress. However, peak injection pressures are significantly greater than the maximum principle stresses in the experiments. Further, by incorporating the dominate experimental parameters into dimensionless form; a reasonable power-law fit is achieved between a dimensionless peak injection pressure and dimensionless stress. Scaling indicates that there is a high pressure gradient in the leak-off zone in the direction normal to the fracture. Fluid pressure does not decrease considerably along the fracture, however, due to the relatively wide fracture aperture. This suggests that hydraulic fractures in unconsolidated materials propagate within the toughness-dominated regime. Furthermore, the theoretical model of toughness-dominated hydraulic fracturing can be matched to the experimental pressure-time dependences with only one fitting parameter. Scale analysis shows that large apertures at the fracture tip correspond to relatively large 'effective' fracture (surface) energy, which can be orders of magnitude greater than typical for hard rocks.
80

PAC investigations of ferromagnetic spinel semiconductors

Samohvalov, Veaceslav 10 December 2009 (has links) (PDF)
The ternary spinel-type compounds CdCr2Se4, CdCr2S4, HgCr2Se4, and CuCr2Se4 with Cr as transition metal form a special group of ferromagnetic semiconductors with Curie temperatures up to 430 K. They have particular perspectives in spintronics due to the coexistence of semiconducting and ferromagnetic properties. In this work the ferromagnetic semiconductors were investigated by the hyperfine interactions of implanted nuclear probes using the PAC (perturbed angular correlations) spectroscopy. In such compounds both magnetic hyperfine fields (Bhf) and electric field gradients (efg) allow a detailed study of the behavior of probes, which can additionally represent essential doping atoms in these substances. Besides the popular 111In(111Cd), also 111mCd, 111Ag(111Cd), 77Br(77Se), 117Cd(117In), 199mHg, and 100Pd(100Rh) probes were used exploiting the unique possibilities at the ISOLDE on-line separator and implanter (CERN, Geneva, Switzerland). The main objective of these investigations was to examine the lattice site occupation and the behavior of the implanted probes. In addition, the experimental hyperfine fields were used as test quantities for modern ab initio calculations of the electronic and spin structure (WIEN97).

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