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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.

Supporting library interface changes in open system software evolution /

Chow, Kingsum. January 1996 (has links)
Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (p. [140]-149).

Comprehensive forecasting of software integrity in C I systems /

Hirschman, Edward, January 1992 (has links)
Report (M.S.)--Virginia Polytechnic Institute and State University. M.S. 1992. / Vita. Abstract. Includes bibliographical references (leaves 93-94). Also available via the Internet.

Path-based dynamic impact analysis /

Law, James January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 187-208). Also available on the World Wide Web.

Preventative maintenance optimisation in a capital-constrained environment

Marsden, Iain January 2019 (has links)
Due to the recognition of the importance of maintenance from an organisational perspective, a number of different maintenance-related approaches have been developed. These approaches include reliability centred maintenance, business-centred maintenance, total productive maintenance and life cycle costing. They consider maintenance from specific different viewpoints and no single approach can be applied to all circumstances. Common to all these approaches are techniques to optimise the maintenance strategies using mathematical models. A variety of mathematical approaches are described in the literature, all of which involve the minimisation of the total costs incurred in relation to the required maintenance activities. This study focuses on data-driven optimisation models that consider costs and the reliability performance of equipment. The practical implementation of these optimising maintenance models presents two main challenges. First, the decision on when to use which model would depend on the type of system/equipment under consideration, as well as on available data. Different models based on analysing the historical failure data of the system or component are considered in order to optimise the maintenance strategies to be applied to these two types of individual systems. In the case of having a number of identical components or systems in series, where a shutdown of one of the systems results in the shutdown of the entire series, models are considered to allow for analysis with the correct maintenance technique of components or systems showing these trends. A major limitation of these maintenance optimisation models is that they all require failure data for their implementation, which is not always obtainable. Historical maintenance cost data, however, is mostly available, therefore forecasting techniques and life cycle cost modelling are also considered. Second, the successful implementation of optimised maintenance strategies will be dependent on informed budgetary decisions being made. Therefore, the challenge of integrating the outputs from the variety of optimisation models utilised into a cohesive compilation and sensible presentation of an overall maintenance budget for a complex plant needs to be addressed. This study presents an integrated maintenance optimisation model that uses the appropriate sub-models described individually in the literature to enable the integrated compilation and sound presentation of an overall maintenance budget for a complex plant for appropriate decision-making. iii The use of the case study validates this methodology. It illustrates that a concise, integrated overall budgetary maintenance decision model is highly beneficial in communicating the budgetary requirements for an organisation. It was found that the outcome resulted in an effective decision-making tool with significant potential for implementation in a variety of organisations in search of optimal maintenance planning and budgetary requirements. / Dissertation (Msc)--University of Pretoria, 2019. / Mechanical and Aeronautical Engineering / MSc / Unrestricted

The maintenance of adult but dependent offspring

Da Silva Pfafferott, Toyah Leigh January 2019 (has links)
Parenthood automatically gives rise to the obligation of a parent to support his or her child. This common-law duty arises upon the birth of a child and it is furthermore provided for in the Maintenance Act. The Maintenance Act addresses the maintenance of both minor and major offspring. The problem, however, arises when a study of the practical execution of this right is conducted. This dissertation specifically focuses on the practicality in respect of major/adult dependent ‘children’. This dissertation examines the laws that enact the common-law duty and the right to support. A study of how the courts have interpreted the law and directed the enforcement of this right for major/adult dependent children/offspring reveals the impracticality of the prescribed enforcement methods and a failure to understand this group’s particular needs. This study explores alternative approaches to implementing the right of adult dependent offspring to maintenance and offers solutions to the limitations that are revealed. / Mini Dissertation (LLM)--University of Pretoria, 2019. / NONE / Private Law / LLM Child Law / Unrestricted

Do not let bad maintenance ruin your day : A case study of coordinating turnaround maintenance in a continuous flow process industry.

Hlebnikovs, Andrew, Kövamees, Axel January 2022 (has links)
The uptime of machinery in continuous flow process industries such as steel manufacturing plants puts pressure on the maintenance function. This in turn contributes to sustaining reliable physical assets. As absence of reliable physical assets highly affects the competitive advantage. Turnaround maintenance is a common practice in such production setups and requires top-of-the-line managerial attention to be planned,executed and assessed in an efficient manner. By applying an abductive approach and combining the qualitative and quantitative research approaches, this thesis aims to explore the managerial issue of coordinating turnaround maintenance within a continuous flow process industry. The research questions that guide this thesis consist of describing how turnaround maintenance can be coordinated and its associated challenges. By comparing publicly available literature and empirical evidence provided by performing a case study, it is confirmed that the main challenges for conducting efficient turnaround maintenance comes down to the management in all stages associated with the turnaround. To coordinate turnaround maintenance activities in the most efficient manner, several challenges must be overcome. Aligning organisational goals and generating management commitment is the first prerequisite before any improvements can be done. It is necessary to define a common scope that strives for creating reliable physical assets to enhance the competitive advantage. The defined challenges in coordination are related to before, during and after the turnaround execution. These relate to creating a cyclical process for the turnaround where previously acquired knowledge is used for improving future turnarounds. While detailed planning is necessary for each turnaround, a high level of contingency is also necessary. To achieve this and succeed, it is argued that a high level of visibility during the turnarounds and the use of standardised methods is required. / Drifttiden för maskiner i industrier med kontinuerligt flöde, såsom ståltillverkningsanläggningar, sätter press på underhållsverksamenheten. Detta för att i sin tur bidra till att upprätthålla tillförlitliga fysiska tillgångar. Eftersom avsaknad av tillförlitliga fysiska tillgångar påverkar konkurrensfördelen i hög grad. Storaunderhållstopp där den kontinuerliga produktionslinan stoppas, är en vanligt förekommande praxis i sådana produktionsanläggningar vilket kräver ledningens uppmärksamhet för att planera och utvärdera på ett effektivt sätt. Genom att tillämpa ett abduktivt tillvägagångssätt och kombinera kvalitativ och kvantitativ forskningsmetodik, syftar detta examensarbete till att utforska den ledarskapsrelaterade frågan om att koordinera underhållsaktiviteter för stora underhållstopp inom processindustrier med kontinuerligt flöde. Forskningsfrågorna som vägleder detta examensarbete består av att beskriva hur större underhållstopp kan koordineras och dess associerade utmaningar. Genom att jämföra offentligt tillgänglig litteratur och empiriska bevis från en fallstudie, bekräftas att de största utmaningarna för att genomföra ett effektivt underhållstopp beror på ledningen i alla steg som är förknippade med underhållstoppet. För att samordna underhållsaktiviteterna på ett så effektivt sätt som möjligt måste flera utmaningar övervinnas. Att anpassa organisationens mål och skapa engagemang hos ledningen är den första förutsättningen innan fler förbättringar kan utföras. Det är nödvändigt att definiera gemensamma mål som strävar efter att skapa tillförlitliga fysiska tillgångar för att i sin tur öka konkurrensfördelen. De definierademanagementutmaningarna sammankopplas till före, under och efter underhållsstoppet. Utmaningarnahandlar om att skapa en cyklisk process för underhållsstoppen där tidigare förvärvad kunskap nyttjas för att förbättra framtida stopp. Även om detaljerad planering är nödvändig för varje underhållstopp, är en hög nivå av beredskap också nödvändig. För att uppnå och lyckas med detta krävs en hög grad av visibilitet under underhållsstoppen och användning av standardiserade metoder.

An Optimised instrument for designing a maintenance plan - A sequel to reliability centred maintenance

Coetzee, Jasper Lodewikus 01 December 2005 (has links)
Reliability Centred Maintenance (RCM) started a new chapter in the history of preventive maintenance strategy setting. It was now possible to develop a scientifically based, highly successful maintenance program for complex systems. It developed as a result of the reliability problems and cost of maintenance of aircraft during the late 50’s and early 60’s. The result was a methodology called MSG-1, followed by the improved MSG-2. When MSG-2 was used contractually for the United States Department of Defence, it led to the present definition of RCM. In academic circles there developed a growing dissatisfaction with the technique [Pintelon et al (1999], of which part stems from watering down its scientific basis to make RCM more marketable [Moubray (2000)], while at least part is based on perceived inherent scientific weaknesses in the methodology itself. This thesis, in setting out to solve these limitations, makes several important contributions to the RCM methodology. The first of these is a method of concentrating the RCM analysis effort on the most important failure modes encountered by the organisation. Secondly, it introduces a Quality Improvement task in the RCM task selection tree, based on a limitation identified by Harris (1985). The third contribution is the addition of a formal task packaging methodology, following Gits (1984). The thesisalso combines the use of RCM for the most important failure modes with conventional maintenance tasks for the remaining failure modes, to form a total methodology for the typical industrial concern. It furthermore introduces the application of sound management principles in the implementation of RCM and lastly, blends concepts from different RCM authors, together with the innovations listed above, into one logical whole. In summary, the proposed revised methodology can play a very important part to achieve the goal of World Class manufacturing standards, including ensuring that the organisation’s maintenance effort is as proactive as possible. D13/4/90 / Thesis (PhD (Industrial Engineering))--University of Pretoria, 2002. / Industrial and Systems Engineering / unrestricted

Selective maintenance for multi-state systems considering the benefits of repairing multiple components simultaneously

Dao, Cuong D., Zuo, M.J. 06 August 2020 (has links)
No / Many industrial systems such as aircrafts, ships, manufacturing systems, etc. are required to perform several missions with finite breaks between missions. Maintenance is only available within the breaks. Due to the limitation of resources, all components in the system may not be maintained as desired. The selective maintenance problem helps the decision makers figure out what critical components to select and how to perform maintenance on these components. This paper studies the selective maintenance for multi-state series-parallel systems with the benefit of repairing multiple components simultaneously. Both time and cost savings can be acquired when several components are simultaneously repaired in a selective maintenance strategy. As the number of repaired components increases, the saved time and cost will also increase due to the share of setting up between components and another additional reduction amount from the repair of multiple identical components. A non-linear optimization model is developed to find the most reliable system subjected to time and cost constraints. Genetic algorithm is used to solve the optimization model. An illustrative example will be provided. / Natural Sciences and Engineering Research Council of Canada (NSERC) and Vietnam International Education Development (VIED)

Teaching of the operation and repair of the gasoline engine, tractor, and automobile in the vocational agriculture farm shop

Bergsma, Silas Solomon January 2011 (has links)
Typescript, etc. / Digitized by Kansas State University Libraries

Strengthening of concrete beams with composite plastic plates

An, Wei, 1963- January 1990 (has links)
This study investigates the feasibility of strengthening reinforced concrete beams with epoxy-bonded Glass-Fiber-Reinforced-Plastic (GFRP) plates. The composite plate is epoxy-bonded to the tension flange of the beam to increase its stiffness and strength. Seven rectangular and one T-beam, retrofitted with composite plates, were tested to failure under symmetrical 4-point bending. The load versus deflection and the load versus strain in the composite plate, steel rebar and the extreme compression fiber of concrete were measured and plotted for the midspan section throughout the entire range of loading up to failure. Analytical models based on the equilibrium of forces and compatibility of deformations were developed to predict the stresses and deformations of the beam in the linear and nonlinear regions. The predicted and measured results correlated well. The analytical models were used in a parametric study to investigate the effects of design variables such as, plate area, plate strength and stiffness, reinforcement ratio, etc., on the moment-curvature relationships of typical rectangular and T cross sections.

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