Multi-objective design or extended design of Water Distribution Systems (WDSs) has received more attention in recent years. It is of particular interest for obtaining the trade-offs between cost and hydraulic benefit to support the decision-making process. The design problem is usually formulated as a multi-objective optimisation problem, featuring a huge search space associated with a great number of constraints. Multi-objective evolutionary algorithms (MOEAs) are popular tools for addressing this kind of problem because they are capable of approximating the Pareto-optimal front effectively in a single run. However, these methods are often held by the “No Free Lunch” theorem (Wolpert and Macready 1997) that there is no guarantee that they can perform well on a wide range of cases. To overcome this drawback, many hybrid optimisation methods have been proposed to take advantage of multiple search mechanisms which can synergistically facilitate optimisation. In this thesis, a novel hybrid algorithm, called Genetically Adaptive Leaping Algorithm for approXimation and diversitY (GALAXY), is proposed. It is a dedicated optimiser for solving the discrete two-objective design or extended design of WDSs, minimising the total cost and maximising the network resilience, which is a surrogate indicator of hydraulic benefit. GALAXY is developed using the general framework of MOEAs with substantial improvements and modifications tailored for WDS design. It features a generational framework, a hybrid use of the traditional Pareto-dominance and the epsilon-dominance concepts, an integer coding scheme, and six search operators organised in a high-level teamwork hybrid paradigm. In addition, several important strategies are implemented within GALAXY, including the genetically adaptive strategy, the global information sharing strategy, the duplicates handling strategy and the hybrid replacement strategy. One great advantage of GALAXY over other state-of-the-art MOEAs lies in the fact that it eliminates all the individual parameters of search operators, thus providing an effective and efficient tool to researchers and practitioners alike for dealing with real-world cases. To verify the capability of GALAXY, an archive of benchmark problems of WDS design collected from the literature is first established, ranging from small to large cases. GALAXY has been applied to solve these benchmark design problems and its achievements in terms of both ultimate and dynamic performances are compared with those obtained by two state-of-the-art hybrid algorithms and two baseline MOEAs. GALAXY generally outperforms these MOEAs according to various numerical indicators and a graphical comparison tool. For the largest problem considered in this thesis, GALAXY does not perform as well as its competitors due to the limited computational budget in terms of number of function evaluations. All the algorithms have also been applied to solve the challenging Anytown rehabilitation problem, which considers both the design and operation of a system from the extended period simulation perspective. The performance of each algorithm is sensitive to the quality of the initial population and the random seed used. GALAXY and the Pareto-dominance based MOEAs are superior to the epsilon-dominance based methods; however, there is a tie between GALAXY and the Pareto-dominance based approaches. At the end, a summary of this thesis is provided and relevant conclusions are drawn. Recommendations for future research work are also made.

This thesis examines the current situation on the electricity market in the Czech Republic. A particular emphasis is put on the regulation of distribution system operators (DSOs). The Czech regulator applies only general efficiency factors for all incumbents, and the efficiency of the incumbents is not taken into account in the regulatory formula. In many countries, the regulators apply benchmarking methods to assess the efficiency of operators. This thesis analyses the current regulatory formula in international comparison and considers the application of benchmarking methods to the regulation of DSOs. The first part provides a description of the theoretical approach to the regulation of network industries, relevant legal norms, the current situation on the Czech electricity market and practices of the regulatory bodies in selected European states. The second, empirical, part presents an international benchmarking study based on data of 15 regional DSOs including two Czech operators. The study examines the application of yardstick methods using data envelopment analysis (DEA) and stochastic frontier analysis (SFA). Based on our results, we find that the cost efficiency of each of the Czech DSOs is different. This suggests that introducing individual efficiency factors in the fourth regulatory...

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Nos processos industriais envolvendo eletrólise, como na produção de alumínio, cobre, zinco, níquel, manganês, carbeto de silício, cloro e seus derivados, as correntes envolvidas em geral atingem patamares que excedem o valor nominal de um único semicondutor, exigindo a associação de componentes em paralelo com uma distribuição de corrente equilibrada. Este trabalho apresenta uma análise comparativa da distribuição de corrente em associações de semicondutores em paralelo em vinte retificadores de alta potência com diferentes tipos de arquitetura física de barramentos. A particularidade deste estudo é a medição simultânea das correntes em todos os semicondutores de todos os ramos do retificador obtendo-se uma imagem da distribuição real de correntes do conversor. / The industrial electrolytic processes to produce, aluminum, cooper, zinc, nickel, manganese, silicon carbide, chlorine and its derivative, require current values which greatly exceed the capability of single rectifying devices and paralleled combinations of semiconductors or equipments are necessary. This study evaluated through a comparative analyzes twenty rectifiers, with different busbar geometries, in order to verify the current distribution in paralleled devices. The differential of this study is the simultaneous measurement of currents in all semiconductors of each branch in order to obtain a real representation of the rectifiers current distribution.

Spring water bottled and sold for human consumption can only be subjected to certain treatment processes such as separation from unstable constituents by decantation, filtration and aeration, ultraviolet irradiation and ozonation. A spring water distribution system in the Western Cape, South Africa was experiencing microbiological problems. The aim of the study was to investigate bacterial contamination in the spring water distribution system and the application of bioremediation as treatment technology. Sampling at various points in the spring water distribution bottling system started in February 2004 and continued until November 2004. The acceptable microbiological limits for bottled spring water clearly states that the total viable colony count should be < 100 organisms per ml of water. Analysis of samples by the heterotrophic plate count (HPC) technique indicated significantly (p < 0.05) high counts which did not conform to the microbiological limit. The heterotrophic plate counts recorded for weeks one, four, eight & 46 in the final bottled water (Site J) were 3.66 x 107 cfu/ml, 9.0 x 106cfu/ml, 2.35 x 107 cfu/ml and 5.00 x 104 cfu/ml, respectively. The total cell counts [Flow cytometry analyses (FCM)] recorded for week one, four, eight & 46 in the final bottled water (Site J) were 5.44 x 107 microorganisms/ml, 8.36 x 107 microorganisms/ml, 9.09 x 107 microorganisms/ml and 5.70 x 107 microorganisms/ml, respectively. The higher viable total cell counts(FCM) indicate that flow cytometry was able to detect cells in the water sample that enter a viable but not culturable state and that the heterotrophic plate count technique only allowed for the growth of the viable and culturable cells present in the water samples. This indicated that the HPC is not a clear indication of the actual microbial population in the water samples. It could be concluded that FCM technique was a more reliable technique for the enumeration of microbial populations in bottled water samples. Various organisms were identified by means of the Polymerase Chain Reaction (PCR) using 16S rRNA specific primers. Purified PCR amplicons were sequenced and Phylogenetic trees were constructed. Neighbour-joining phylogenetic tree analysis of the bacterial species present in the water samples was performed. The dominant bacterial isolates that were sequenced from the various water samples throughout weeks one, four, eight and 46 were Bacillus sp. and Enterobacteriaceae. The pathogenic species isolated throughout the sampling period included Escherichia sp., Pseudomonas sp., Shigella boydii, Bacillus and Staphylococcus sp. A laboratory-scale bioreactor was constructed and water samples were analysed over a period of two weeks. Water samples were analysed using FCM and Direct Acridine Orange Count (DAOC) in conjunction with epiflourescence microscopy (EM). The FCM counts ranged from 1.53 x 107 microorganisms/ml in the initial sample (Day 0) to 1.16 x 107 microorganisms/mℓ in the final sample (Day 13). The results indicated a 24% decrease in the microbial numbers however, it was still above the limit of < 100 organisms/ml as set out by the South African Standards of Bottled Water, (2003). The total cell counts obtained by the DAOC method ranged from 1.43 x 106 microorganisms/ml to 9.54 x 105 microorganism/ml on day 13 (final). The results indicated a 33% decrease in microbial numbers. The total cell counts analysed by flow cytometry fluctuated throughout the sampling period. The total cell counts obtained from the DAOC method were lower in all the water samples when compared to the total counts obtained by flow cytometric analyses. Even though the FCM counts fluctuated throughout the sampling period, results clearly show that the FCM method yielded more accurate data for total cell counts than the DAOC method. Due to external environmental conditions such as changes in the weather conditions the results fluctuated and the final results clearly indicated that further studies are required to optimise the bioreactor system for its application in the spring water industry.

by Lee Chi-ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 103-104). / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Three Underlying Distributions --- p.6 / Chapter 2.1 --- Exponential distribution --- p.8 / Chapter 2.1.1 --- Estimation of Thresholds --- p.8 / Chapter 2.1.2 --- Estimation of Parameter --- p.11 / Chapter 2.1.3 --- Simulation Study --- p.13 / Chapter 2.2 --- Normal distribution --- p.24 / Chapter 2.2.1 --- Estimation of Thresholds --- p.24 / Chapter 2.2.2 --- Estimation of Parameter --- p.26 / Chapter 2.2.3 --- Simulation Study --- p.29 / Chapter 2.3 --- Weibull distribution --- p.42 / Chapter 2.3.1 --- Estimation of Thresholds --- p.42 / Chapter 2.3.2 --- Estimation of Parameter --- p.44 / Chapter 2.3.3 --- Simulation Study --- p.46 / Chapter 3 --- Goodness-of-fit Test --- p.60 / Chapter 3.1 --- Test for the Exponential distribution --- p.63 / Chapter 3.2 --- Test for the Normal distribution --- p.66 / Chapter 3.3 --- Test for the Weibull distribution --- p.68 / Chapter 3.4 --- Implication --- p.70 / Chapter 3.5 --- An Artificial Example --- p.72 / Chapter 3.5.1 --- Case 1 (s= 3) --- p.72 / Chapter 3.5.2 --- Case 2 (s= 4) --- p.80 / Chapter 4 --- Real Data Illustration --- p.87 / Chapter 4.1 --- Test for the Exponential distribution --- p.90 / Chapter 4.2 --- Test for the Normal distribution --- p.91 / Chapter 4.3 --- Test for the Weibull distribution --- p.92 / Chapter 4.4 --- Inferences from the Exponential distribution --- p.94 / Chapter 4.5 --- Inferences from the Normal distribution --- p.95 / Chapter 4.6 --- Inferences from the Weibull distribution --- p.98 / Chapter 5 --- Conclusion --- p.101 / Bibliography --- p.103

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Thesis. 1976. Ph.D.--Massachusetts Institute of Technology. Dept. of Economics. / Microfiche copy available in Archives and Dewey. / Bibliography: leaves 92-95, 182-185. / A dynamic theory of racial income differences.--Intergenerational transfers and the equilibrium distribution of earnings. / Ph.D.

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Economics. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND DEWEY. / Bibliography: leaves 191-192. / Ph.D.