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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.
91

A contribution towards real-time forecasting of algal blooms in drinking water reservoirs by means of artificial neural networks and evolutionary algorithms.

Welk, Amber Lee January 2008 (has links)
Historical water quality databases from two South Australian drinking water reservoirs were used, in conjunction with various computational modelling methods for the ordination, clustering and forecasting of complex ecological data. Techniques used throughout the study were: Kohonen artificial neural networks (KANN) for data categorisation and the discovery of patterns and relationships, recurrent supervised artificial neural networks (RANN) for knowledge discovery and forecasting of algal dynamics and hybrid evolutionary algorithms (HEA) for rule-set discovery and optimisation for forecasting algal dynamics. These methods were combined to provide an integrated approach to the analysis of algal populations including interactions within the algal community and with other water quality factors, which results in improved understanding and forecasting of algal dynamics. The project initially focussed on KANN for the patternising and classification of the historical data to reveal links between the physical, chemical and biological components of the reservoirs. This offered some understanding of the system and relationships being considered for the construction of the forecasting models. Specific investigations were performed to examine past conditions and the impacts of different management regimes, as well as to discover sets of conditions that correspond with specific algal functional groups. RANN was then used to build models for forecasting both Chl-a and the main nuisance species, Anabaena, up to 7 days in advance. This method also provided sensitivity analyses to demonstrate the relationship between input and output variables by plotting the reaction of the output to variations in the inputs. Initially one year from the data set was selected for the testing of a model, as per the split-sample technique. To further test the models, it was later decided to select several years for testing to ensure the models were useful under changed conditions, and that test results were not misleading regarding the models true capabilities. RANN were firstly used to create reservoir specific or ad-hoc models. Later, the models were trained with the merged data sets of both reservoirs to create one model that could be applied to either reservoir. Another method of forecasting was trialled and compared to RANN. HEA was found to be equal or superior to RANN in predictive power, also allowed sensitivity analysis and provided an explicit, portable rule set. The HEA rule sets were initially tested on selected years of data, however to fully demonstrate the models potential, a process for k-fold cross-validation was developed to test the rule-set on all years of data. To further extend the applicability of the HEA rule-set; the idea of rule-based agents for specific lake ecosystem categories was examined. The generality of a rule-based agent means that, after successful validation on several lakes from one category, the agent could then be applied to other water bodies from within that category that had not been involved in the training process. The ultimate test of the rule-based agent for the warm monomictic and eutrophic lake ecosystem category was to be applied to a real-time monitoring and forecasting situation. The agent was fed with online, real-time data from a reservoir that belonged to the same ecosystem category but was not used in the training process. These preliminary experiments showed promising results. It can be concluded that the concept of rulebased agents will facilitate real-time forecasting of algal blooms in drinking water reservoirs provided on-line monitoring of relevant variables has been implemented. Contributions of this research include: (1) to offer insight into the capabilities of 3 kinds of computational modelling techniques applied to complex water quality data, (2) novel applications of KANN including the division of data into separate management periods for comparison of management efficiency, (3) to both qualitatively and quantitatively elucidate relationships between water quality parameters, (4) research toward the development of a forecasting tool for algal abundance 7 days in advance that could be generic for a particular lake ecosystem category and implemented in real-time, and (5) to suggest a thorough testing method for such models (k-fold cross validation). / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1331584 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008
92

Development of an expert system for irrigation and fertilization management in the Pacific Northwest

Cao, Weidong 23 October 1992 (has links)
Recent advances in computer technology have made possible the development of expert systems. Expert systems are computer programs that perform at the level of a human expert. Expert systems can help integrate and apply diverse sources of information and expertise to problems of integrated crop management. A prototype Crop Management eXpert (CMX) system has been developed. The primary goal of CMX is to provide recommendations on optimal irrigation and fertilization scheduling for wheat production in the Pacific Northwest. This system can be used by farmers and/or extension agents. OUS II Shell has been used as a implementation tool. To build this rule - based expert system, a development strategy, commonly used in the construction of expert systems, consisting of 1 ) identification; 2) conceptualization; 3) formalization; 4) implementation; and 5) testing was applied. CMX is composed of modules for irrigation and fertilization management. For irrigation management, CMX is mainly involved in the irrigation scheduling which is the major part of irrigation management. Irrigation strategies have been applied in irrigation decision making. For each strategy, timing criteria which generally consist of management allowed depletion, soil water potential, leaf water potential, and water stress indices have been used. The system provides farmers with irrigation scenarios which determine when and how much water to apply. CMX represents an integration of conventional computing and expert systems technology designed to provide expert recommendations enabling farmers to obtain the best return on their water and fertilizer investment. For fertilization management, a variety of variables have been taken into considered. Crop growth stages, soil moisture, nutrient analysis, protein requirement, and application methods are important factors for the fertilizer decision making. Several constraints have been used in optimal fertilizer advice. CMX can focus only on relevant information, thus reducing the problem space to a manageable size and significantly, improving the efficiency of the system. The facility of the expert system to explain the decision-making process enables users to better understand the underlying assumptions, facts, and reasoning used to generate recommendations. The CMX prototype demonstrates the feasibility of employing expert systems technology in agricultural applications. CMX has been validated and evaluated. The survey results showed that this prototype was successful in capturing domain experts' knowledge as rules and providing advice on the irrigation and fertilization management for wheat. / Graduation date: 1993
93

Optimising the renewal of natural gas reticulation pipes using GIS

Hobson, Alan George Cawood 04 1900 (has links)
Thesis (MA)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: A major concern for Energex, Australia's largest energy utility in South East Queensland, is the escape of natural gas out of their reticulation systems. Within many of the older areas in Brisbane, these networks operate primarily at low and medium pressure with a significant percentage of mains being cast iron or steel. Over many years pipes in these networks have been replaced, yet reports show that unaccounted for gas from the same networks remain high. Furthermore, operation and maintenance budgets for these networks are high with many of these pipes close to the end of their economic life. When operation and maintenance costs exceed the costs of replacement, the Energex gas utility initiates projects to renew reticulation networks with polyethylene pipes. Making decisions about pipe renewal requires an evaluation of historical records from a number of sources, namely: • gas consumption figures, • history of leaks, • maintenance and other related cost, and • the loss of revenue contributed by unaccounted for gas. Financial justification of capital expenditure has always been a requirement for renewal projects at the Energex gas utility, however the impact of a deregulation in the energy utility market has necessitated a review of their financial assessment for capital projects. The Energex gas utility has developed an application that evaluates the financial viability of renewal projects. This research will demonstrate the role of GIS integration with the Energex financial application. The results of this study showed that a GIS integrated renewal planning approach incorporates significant benefits including: • Efficient selection of a sub-network based on pipe connectivity, • Discovery of hidden relationships between spatially enabled alphanumeric data and environmental information that improves decision making, and • Enhanced testing of proposed renewal design options by scrutinizing the attributes of spatial data. / AFRIKAANSE OPSOMMING: 'n Groot bron van kommer vir Energex, Australië se grootste energieverskaffer in Suidoos- Queensland, is die verlies van natuurlike gas uit hul gasdistribusie netwerke. In 'n groot deel van ouer Brisbane opereer hierdie netwerke hoofsaaklik teen lae en medium druk, met 'n aansienlike persentasie van hoofpyplyne wat uit gietyster of staal bestaan. Al is sommige pyplyne in hierdie netwerke met verloop van tyd vervang, maak verslae dit duidelik dat 'n groot deel van die gas in hierdie netwerke steeds langs die pad verlore gaan. Die operasionele - en onderhoudsbegrotings vir hierdie netwerke is boonop hoog, met 'n groot persentasie van die pyplyne wat binnekort aan die einde van hulle ekonomiese leeftyd kom. Wanneer operasionele- en onderhoudsonkostes die koste van vervanging oorskry, beplan Energex se gasvoorsienings-afdeling projekte om verspreidingsnetwerke te hernu met poli-etileen pype. Om sinvolle besluite te neem tydens pyplynhernuwings, word verskeie historiese verslae geraadpleeg, insluitend: gasverbruikvlakke, lekplek geskiedenis rekords, onderhoud- en ander verwante onkostes, asook die verlies van inkomste weens verlore gas. Alhoewel finansiële stawing van kapitale uitgawes nog altyd 'n voorvereiste was tydens hernuwingsprojekte by Energex, het die impak van privatisering op die energieverskaffingsmark dit noodsaaklik gemaak om hulle finansiële goedkeuringsproses vir kapitaalprojekte te hersien. Energex het dus 'n sagteware toepassing ontwikkel wat die finansiële gangbaarheid van hernuwingsprojekte evalueer. Hierdie navorsing sal die moontlike integrasie van geografiese inligtingstelsels (GIS) met dié van Energex se finansiële evalueringspakket demonstreer. Die resultate van hierdie studie toon dat die integrasie van GIS in die hernuwingsproses aansienlike voordele inhou, insluitende: • die effektiewe seleksie van sub-netwerke, gebaseer op pyp konnektiwiteit, • die ontdekking van verskuilde verwantskappe tussen geografies-ruimtelike alfanumeriese data en omgewingsinligting, wat besluitneming vergemaklik, en • verbeterde toetsing van voorgestelde hernuwingsopsies deur die indiepte-nagaan van geografiesruimtelike elemente.
94

Networking the enterprise : a solution for HBR personnel

Honniger, Werner 12 1900 (has links)
Thesis (MPhil)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: This Extended Research Assignment discusses the information systems found in HBR Personnel. The discussion, based on the research problems, proposes steps in which the systems of HBR can be integrated so that they add the most value. Furthermore, a review of Corporate Portals is undertaken to show the potential impact it may have on organisational efficiencies and knowledge. The Assignment, according to the methodologies given, analyses the HBR information system for system incompatibilities and bottlenecks and proposes solutions for these problems. The solutions include changing core system databases and computer systems, together with a portal to fully integrate HBR Personnel’s information systems. / AFRIKAANSE OPSOMMING: Hierdie Uitgebreide Navorsingsopdrag bespreek die informasiestelsels gevind in HBR Personnel. Die bespreking, gebaseer op die navorsingsprobleme, stel stappe voor waardeur die stelsels van HBR geïntegreer kan word om die meeste waarde toe te voeg. Verder word ‘n oorsig gedoen van Korporatiewe Portale om te wys watter potensiële impak dit kan hê op organisatoriese doeltreffendheid en kennis. Na aanleiding van die gegewe metodologieë analiseer die opdrag HBR se informasiestelsel vir sistemiese probleme en bottelnekke en stel oplossings voor vir hierdie probleme. Die oplossings sluit in ‘n verandering van kern-sisteem databasisse en rekenaarstelsels, tesame met ‘n portaal om HBR Personnel se informasiestelsels ten volle te integreer.
95

Towards a comprehensive knowledge management system architecture

Smuts, Johanna Louisa 11 1900 (has links)
Knowledge management has roots in a variety of disciplines, such as philosophy, psychology, social sciences, management sciences and computing. As a result, a wide variety of theories and definitions of knowledge and knowledge management is used in the literature. Irrespective of the theory or definition used, is it recognised that expert knowledge and insight are gained through experience and practice and that it is a key differentiator as an organisational asset. This shift to knowledge as the primary source of value results in the new economy being led by those who manage knowledge effectively. Today’s organisations are creating and leveraging knowledge, data and information at an unprecedented pace – a phenomenon that makes the use of technology not an option, but a necessity. It enables employees to deal with multifaceted environments and problems and make it possible for organisations to expand their knowledge creation capacity. Software tools in knowledge management are a collection of technologies and are not necessarily acquired as a single software solution. Furthermore, these knowledge management software tools have the advantage of using the organisation’s existing information technology infrastructure. Organisations and business decision makers spend a great deal of resources and make significant investments in the latest technology, systems and infrastructure to support knowledge management. It is imperative that these investments are validated properly, made wisely and that the most appropriate technologies and software tools are selected or combined to facilitate knowledge management. The purpose of this interpretive case study is to consider these issues and to focus on an understanding of the key characteristics of a knowledge management system architecture by exploring and describing the nature of knowledge management. Based on the findings of this study, a list of key characteristics that a knowledge management solution must comply with was collated, which expanded the existing knowledge management model towards describing a knowledge management system architecture. / Computing / M.Sc. (Information Systems)
96

Assessment of Computer Uses in Texas University and College Foodservice

Sahba, Afsaneh 08 1900 (has links)
The purposes of this study were. to identify current uses of computers by university foodservice operations and to determine if there.are any differences in computer use among university foodservice operations. The twelve university foodservice directors who responded to the research questionnaire varied significantly in their computer usage and computer characteristics. Institutions serving more than 1,000 meals per day represented 91% of the sample using computers. Chi Square analysis found a significant use of menu-costing programs. The computers were used more than six hours a day by 75% of the sample. The.problems relating to hardware and software selection indicate a lack of assessment of operational needs for foodservice operations. Guidelines to assist foodservice directors in computerization are needed.
97

The Use of Computers in the Administration of Non-Public Schools

Beyer, Stephen 12 1900 (has links)
The purposes of this study were (1) to identify the uses of computers in non-public school administration and (2) to determine what factors affect the usage of computers in non-public school administration. An eight per cent (1525 schools) sampling of all nonpublic secondary and elementary in the United States was sent questionnaires. Eight hundred and seventy two (57 per cent) were returned. Some major findings of this study were that 36 per cent of all non-public schools use computers for administrative purposes. Non-public secondary schools use computers significantly more for administration than do non-public elementary schools. Independent schools, those not associated with any religious body, use computers significantly more for administration than do Parochial schools, those affiliated with some religious body. Within the Parochial classification, there is no significant difference in administrative computer usage between Catholic and Other Parochial schools. Schools with an enrollment larger than 500 students use administrative computers more frequently than do smaller schools. Administrators not using administrative computers perceived that the expense of computers and the lack of trained computer personnel were the major reasons they were not using computers. Administrators using computers for administrative functions listed word processing, general accounting, payroll, grading, attendance monitering and budgeting as the most common uses of the computer. Administrators using computers for administrative purposes noticed more time for curriculum development tasks and for supervisory tasks. Additionally, these principals noticed that more office work was done faster with the aid of computers. Seventy-three per cent of the respondents noted that computers are important to administrators for administrative functions.
98

Decision support systems design: a nursing scheduling application

Ceccucci, Wendy A. 10 November 2005 (has links)
The systems development life cycle (SDLC) has been the traditional method of decision support systems design. However, in the last decade several methodologies have been introduced to address the limitations arising in the use of the traditional method. These approaches include Courban's iterative design, Keen's adaptive design, prototyping and a number of mixed methodologies incorporating prototyping into the SDLC. Each of the previously established design methodologies has a number of differing characteristics that make each of them a more suitable strategy for certain environments. However, in some environments the current methodologies present certain limitations or unnecessary expenditures. These limitations suggest the need for an alternative methodology. This dissertation develops a new methodology, priority design, to meet this need. To determine what methodology would be most effective in a given situation, an analysis of the operating environment must be performed. Such issues as project complexity, project uncertainty, and limited user involvement must be addressed. This dissertation develops a set of guidelines to assist in this analysis. For clarity, the guidelines are applied to three, well-documented case studies. As an application of the priority design methodology, a decision support system for nurse scheduling is developed. The development of a useful DSS for nurse scheduling requires that projected staff requirements and issues of both coverage and differential assignment of personnel be addressed. / Ph. D.
99

As capacidades din??micas e a sustenta????o do ERPII: uma proposta de Framework anal??tico

POLO, Antonio Cesar 27 May 2015 (has links)
Submitted by Elba Lopes (elba.lopes@fecap.br) on 2017-08-23T15:38:52Z No. of bitstreams: 2 Antonio_Cesar_Polo.pdf: 2722503 bytes, checksum: e2d32aeb4ecefc90cc5bdb5c422e9ed3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-08-23T15:38:52Z (GMT). No. of bitstreams: 2 Antonio_Cesar_Polo.pdf: 2722503 bytes, checksum: e2d32aeb4ecefc90cc5bdb5c422e9ed3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-05-27 / The 1990s demonstrated a growth of ERP (enterprise resource planning) adoption amongst organizations, and among scholars it has been studied in a series of aca-demic publications, that defined ERPs as a contributor to obtain competitive advan-tage and organizational performance. The present study encompasses the new ERP configuration, dedicated to support companies in its front end operations and value chain integration, so called ERPII model, and investigates the relationship with the Dynamic Capabilities during the post-implementation phase. In order to ac-complish this objectives, a conceptual Framework is developed, to articulate the construct variables with the level of market turbulence. Furthermore, a quantitative field research is executed, based on a survey, and the research results are interpreted under the Framework perspective, where the results are validated through statistical tests such as Spearman correlation, Mann-Withney and Kruskal-Wallis, in order to obtain an explicative analysis of the Dynamic Capabilities role in the sustenance of ERPII. The results, evidenced Dynamic Capabilities in all presuppositions articulated by the Framework, with positive impacts in reconfiguration of routines responsible for ERPII sustenance and its organizational performance contribution. In this sense, the major effects were identified in sensing and seizing of market opportunities focused on evolving ERPII, management initiatives to encourage tacit and explicit learning processes, coordination of ERPII quality and performance metrics, and level of uncertain of business market related to ERPII context. / Os anos de 1990 apresentaram um crescimento na ado????o dos sistemas de gest??o empresarial (ERPs) pelas organiza????es, e o tema foi estudado em um grande n??me-ro de publica????es acad??micas, que apontaram o mesmo como um impulsionador da obten????o da vantagem competitiva e desempenho empresarial. A presente disserta-????o aborda a configura????o contempor??nea dos sistemas ERPs, dedicada a suportar as empresas em suas opera????es de linha de frente e integra????o com a cadeia de valor, dentro do modelo conceitual chamado ERPII, e analisa suas rela????es com as Capacidades Din??micas em sua fase de p??s-implementa????o. Para tanto, um Fra-mework conceitual ?? proposto, com o objetivo de articular as vari??veis relativas aos constructos, agregando-as a indicadores concernentes ao n??vel de incerteza do am-biente. Em continuidade, o trabalho apresenta uma pesquisa de campo, executada por meio de um instrumento de pesquisa de natureza quantitativa. Por fim, sob a ??ti-ca do Framework desenvolvido, os resultados da pesquisa s??o validados estatisti-camente por meio de testes de correla????o de Spearman, Mann-Withney e Kruskal-Wallis, visando obter uma an??lise explicativa do papel das Capacidades Din??micas na sustenta????o do ERPII. Como resultados, observou-se a presen??a das Capacida-des Din??micas em todos os pressupostos articulados por meio do Framework, com impacto positivo na reconfigura????o de rotinas respons??veis pela sustenta????o do ERPII e consequente contribui????o para o desempenho organizacional. Nesse senti-do, os fatores que exerceram maior influ??ncia foram os relacionados a mecanismos de prospec????o e tratamento de oportunidades e atualiza????es do ERPII, seguidos por a????es gerenciais de incentivo ?? aprendizagem t??cita e expl??cita, coordena????o de in-dicadores de qualidade e desempenho, e n??vel de dinamicidade do mercado de ne-g??cios no contexto do ERPII.
100

An infrastructure management support system for Western Cape Nature Conservation Board

Van Zyl, Nicolaas Milne 03 1900 (has links)
Thesis (MA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: This thesis investigates the use of GIS (Geographical Information Systems) to develop an infrastructure management support system for the Western Cape Nature Conservation Board (WCNCB). The primary goal was to design a system to help the managers with their task of managing the infrastructure of a reserve. It involved the development and description, of a system in ArcView with the programming language Avenue in conjunction with an Access application developed in Visual Basic for Applications. The end result was a system that can create maps of all the different infrastructure features with ArcView and use an open-ended Access application to input data. The data are stored in an Access database. The thesis describes the user functionality of the system. Basic reporting facilities are provided and the data and system have the potential to provide essential reporting in future development. The conclusion of this thesis is that GIS could fulfil the role of an Infrastructure Management Support System for WCNCB. / AFRIKAANSE OPSOMMING: Die tesis ondersoek die gebruik van GIS (Geografiese Inligting Stelsels) in die ontwikkeling van 'n infrastruktuur bestuurshulpmiddel VIT Wes-Kaap Natuurbewaringsraad. Die primêre doel van hierdie studie is om 'n sisteem te ontwikkel wat die bestuurders van die verskillende natuurreservate kan bystaan in die bestuur van hul reservate. Die tesis beskryf die ontwikkeling van 'n infrastruktuur bestuurshulpmiddel met ArcView se programmeringstaal Avenue. Tesame hiermee is 'n Access applikasie wat in Visual Basic for Applications ontwikkel is geïntegreer. Die eind-resultaat is 'n sisteem wat kaarte met ArcView vanaf gestoorde data in 'n Access databasis kan produseer en ook datainvordering kan hanteer. Die tesis beskryf die ontwikkeling en funksionaliteit van die sisteem. Daar word voorsiening gemaak vir basiese verslaglewerende funksies en vir toekomstige meer gevorderde analises in die data samestelling. Die gevolgtrekking wat in die tesis gemaak word is dat GIS die rol van 'n infrastruktuur bestuurshulpmiddel kan vervul VIT Wes-Kaap Natuurbewaringsraad.

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