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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.
141

Factors influencing the quality of building maintenance services in the Department Of Cooperative Governance And Traditional Affairs.

Moela, Mmamashita Paulina. January 2014 (has links)
M. Tech. Business Administration / Quality management was initially applied as a management philosophy in the manufacturing sector in the 1920s. Following its success, it is increasingly being applied within the services sector also in the management of public buildings. The purpose of the study was to investigate the factors influencing the quality of building maintenance services within the Department of Cooperative Governance and Traditional Affairs buildings. The study determined the extent of commitment to quality standards by service providers in managing building maintenance services.
142

A decision support model to improve rolling stock maintenance scheduling based on reliability and cost

Asekun, Olabanji Olumuyiwa 12 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The demand for rail travel has increased over the years. As a result, it is becoming mandatory for railway industries to maintain very high availability of their assets to ensure that service levels are high. Railway industries require both their infrastructure and rolling stock assets maintained efficiently to sustain reliability. There has been on-going research on how maintenance can be carried out in a cost effective manner. However, the majority of this research has been done for infrastructure and the rolling stock maintenance has not been properly covered. The purpose of this research is to contribute to the maintenance sector of rolling stock for railway industries by developing a decision support model for rolling stock based on reliability and cost. The model is developed as an optimization problem of a system containing several components dependent on each other with different reliability characteristics. In this model, a mixed integer nonlinear problem is developed and solved using an exact method and metaheuristics methods. The Metrorail facility in Cape Town was chosen as a case study. Failure history and cost data were gathered from the facility and the information was applied to the model developed. The case study was investigated and different results were achieved using both exact and metaheuristics methods. The final result from the study is an optimal maintenance schedule based on reliability and cost. The developed model serves as a practical tool railway companies can adopt to schedule rolling stock maintenance to achieve a high level of reliability and at the same time maintaining minimum cost expenditure. / AFRIKAANSE OPSOMMING: Die vraag na spoorvervoer het oor die jare toegeneem. Dus het dit belangrik geword dat die spoorweg se bates hoogs toeganklik moet wees om te verseker dat die vlak van dienslewering hoog bly. Die spoorweg industrie besef dat hulle infrastruktuur, lokomotiewe, waens ens. effektief in stand gehou moet word sodat dit betroubaar kan wees. Navorsing word nog steeds gedoen oor hoe instandhouding op ’n koste-effektiewe wyse gedoen kan word. Die meeste van hierdie navorsing gaan egter oor infrastruktuur en instandhouding word nie ordentlik gedek nie. Die doel met hierdie navorsing is om by te dra tot die instandhoudingsektor van die spoorweg deur om ’n besluit-ondersteunende model vir lokomotiewe, waens, ens wat op betroubaarheid en koste gegrond is, te ontwikkel. Die model is ontwikkel as ’n optimasie probleem van ’n sisteem wat verskillende komponente wat van mekaar afhanklik is maar oor verskillende betroubaarheidskenmerke beskik, inluit. In hierdie model word ’n gemengde, heeltal nie-lineêre probleem ontwikkel en met ’n eksakte metode en metaheuristiese metodes opgelos. Die Metrorail fasiliteit in Kaapstad is vir die gevalle studie gekies. Die geskiedenis van mislukkings en koste data is by die fasiliteit versamel en die inligting is op die model wat ontwikkel is, toegepas. Die gevalle studie is ondersoek, en verskillende resultate is met eksakte en metaheuristiese metodes bereik. Die finale uitkomste van die studie is ’n optimale instandhoudingskedule wat op betroubaarheid en koste gegrond is. Die model wat ontwikkel is dien as ’n praktiese instrument wat spoormaatskappye kan gebruik om die instandhouding van lokomotiewe, waens ens. te reël sodat ’n hoë vlak van betroubaarheid bereik kan word en kostes terselfdertyd tot ’n minimum beperk kan word.
143

Reliability centered maintenance implementation on the eThekwini electricity network for system maintenance process optimisation

Lokothwayo, Musawenkosi Phillemon January 2017 (has links)
Submitted in fulfillment of the requirements for the degree of Master of Engineering, Durban University of Technology, Durban, South Africa, 2017. / Much equipment in the eThekwini Electricity network has been in use for several decades. Failure of this equipment could critically impact electricity supply to customers, and result in high costs associated with loss of load and/or component replacement. The fundamental motive for any power utility is to plan, operate, and maintain power infrastructure such that customers receive reliable electric services at the minimum expense possible. For this dissertation, the Reliability Centered Maintenance (RCM) model was implemented in the eThekwini Electricity network. This model emphasises the importance of long-term planning and allocation of resources over the life time of a transformer, or any other component. RCM is an ongoing process that entails gathering data from operating systems performance, and using this data to improve design, operation, and maintenance of the system. The eThekwini Power network failure statistics for the previous five years were collected and thoroughly analysed to identify critical components associated with higher failure rates, and associated consequences. Upon examination, it was determined that the power transformer is a critical component of the system. The transformer plays a significant role in the power system due to its remarkable effect on overall reliability, in addition to the fact that it is a major cost factor in the power grid. Transformer management comprises of identifying the appropriate type and frequency of maintenance, and the appropriate time to replace the transformer in a cost-effective manner. The Markov model for ascertaining the transformer’s remaining service life was applied on the identified critical transformer. The transformer deterioration process is modelled by representing the oil insulation by discrete stages. Using the Institute of Electrical and Electronics Engineers (IEEE) standard for interpreting the transformer insulation, the transformer under review was found to be at stage two. Further analysis was performed on system unavailability rates versus mean time to first failure (MTTFF). The analyses indicated that the higher the MTTFF, the longer the system availability whereas the lower the MTTFF, the more reduced the system availability. Improving the MTTFF rates of a system will enhance reliability. The effective application of RCM will optimise the maintenance processes with reasonable expenditures. / M
144

Integrated Apartment Management System

Hu, Feng-Ming 01 January 2006 (has links)
The Integrated Apartment Management System (IAMS) is a web-based system that allows tenants to make appointments with repairmen on line and notify both apartment managers and repairmen of appointments through an email directly from IAMS. IAMS also keeps a database of appointments, repairs, and payments that can be accessed by tenants, repairmen, and apartment managers.
145

Optimal design, procurement and support of multiple repairable equipment and logistic systems

Moore, Thomas P. January 1986 (has links)
A concept for the mathematical modeling of multiple repairable equipment and logistic systems (MREAL systems) is developed; These systems consist of multiple populations of repairable equipment, and their associated design, procurement, maintenance, and supply support. MREAL systems present management and design problems which parallel the·management and design of multiple, consumable item inventory systems. However, the MREAL system is more complex since it has a repair component. The MREAL system concept is described in a classification hierarchy which attempts to categorize the components of such systems. A specific mathematical model (MREAL1) is developed for a subset of these components. Included in MREAL1 are representations of the equipment reliability and maintainability design problem, the maintenance capacity problem, the retirement age problem, and the population size problem, for each of the multiple populations. MREAL1 models the steady state stochastic behavior of the equipment repair facilities using an approximation which is based upon the finite source, multiple server queuing system. System performance measures included in MREAL1 are: the expected MREAL total system life cycle cost (including a shortage cost penalty); the steady state expected number of shortages; the probability of catastrophic failure in each equipment population; and two budget based measures of effectiveness. Two optimization methods are described for a test problem developed for MREAL1. The first method computes values of the objective function and the constraints for a specified subset of the solution space. The best feasible solution found is recorded. This method can also examine all possible solutions, or can be used in a manual search. The second optimization method performs an exhaustive enumeration. of the combinatorial programming portion of MREAL1, which represents equipment design. For each enumerated design combination, an attempt is made to find the optimal solution to the remaining nonlinear discrete programming problem. A sequential unconstrained minimization technique is used which is based on an augmented Lagrangian penalty function adapted to the integer nature of MREAL1. The unconstrained minimization is performed by a combination of Rosenbrock's search technique, the steepest descent method, and Fibonacci line searches, adapted to the integer nature of the search. Since the model contains many discrete local minima, the sequential unconstrained minimization is repeated from different starting solutions, based upon a heuristic selection procedure. A gradient projection method provides the termination criteria for each unconstrained minimization. / Ph. D.
146

A tractor maintenance and operation program for schools of agriculture in Nigeria

Keswet, Andrew D January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
147

The formulation and application of a gravel loss model in management of gravel roads in Iringa region, Tanzania

Mwaipungu, Richard Robert January 2015 (has links)
Submitted in fulfillment of the academic requirements for the degree of Doctor of Engineering: Civil Engineering and Surveying, Durban University of Technology. Durban. South Africa, 2015. / Among various gravel roads distress prediction models in existence, a gravel loss prediction model is considered critical in selecting the optimal re-gravelling schedule for effective maintenance management of gravel roads. However, due to the number of variables contributing to deterioration of gravel roads and hence gravel loss, gravel loss prediction models are not readily transferable from one geographical location to another, particularly if the locations in question differ in climatic condition, gravel material characteristics, quality of construction and maintenance, terrain, traffic characteristics and driver behaviours. Addressing the aforementioned local characteristics pose a challenge to existing international gravel loss prediction models when employed locally, resulting in inaccurate prediction of gravel loss. Hence the need for a gravel loss prediction model to be formulated locally so as to address local characteristics influencing gravel roads deterioration. The main objective of this study was to formulate locally, a statistically accurate gravel loss prediction model for marginal gravel materials employed to surface gravel roads in Iringa region. The intention was to address local characteristics influencing gravel roads deterioration in the region. To promote research on gravel roads management, the author has published seven papers and presented ten papers in established journals and conferences respectively, as indicated in the Appendix 13. It is author expectation that, given the right impetus, locally formulated gravel loss prediction models can be incorporated, as one of a tool, in gravel roads management systems (GRMS). The literature review focused on the gravel road condition surveys, modelling exercises, gravel loss, and a review of existing gravel loss prediction models. The literature review also examined the version of GRMS currently practiced in Tanzania by its road organizations. The study used factorial experimental design. Parameters which are deemed to influence the gravel loss were collected and studied. A questionnaire was used to study the status of gravel road MMS in Tanzania. The data obtained from the questionnaire responses were analysed with the aid of Statistical Package for Social Sciences (SPSS) and Microsoft Excel. A detailed gravel road condition survey of each 300 m long test section was carried out during site visits. The measurement of gravel loss through the change in average height loss formed a crucial part of the study. The modelling of a gravel loss prediction model was performed using pavemetric principles, the term coined by this study, which is principally based on econometric principles. From the analysis of questionnaire responses, it was evident that each Tanzania Roads Agency (TANROADS) regional office and district council works department needs to have a unique MMS and GRMS which reflect their operating capacity. The results of the condition survey led to the formulation of a new range of grading coefficient (GC) to suit the local marginal materials. The gravel loss survey results assisted in establishing gravel loss thresholds. The thresholds were based on the rate of gravel loss noted in the study. These thresholds can be employed to enhance the quality control of gravel roads construction and maintenance practices. The study formulated a gravel loss prediction model for Iringa region. The process utilized average daily traffic, climate, and derivatives of sieve analysis and Atterberg limits. The model is statistically significant at 1 % level. The model gives a constant gravel loss of 0.1 mm per annum regardless the state of the six variables in the model. This was attributed to autonomous loss that is the amount of gravel material lost through mechanical and chemical weathering. Recommendations include the need for gravel loss prediction models to reflect local characteristics influencing the deterioration of the gravel roads in question and the modelling capacity of local road agencies. Areas for further studies are highlighted.
148

Effect of service-quality dimensions on customer patronage at Jaguar Land Rover dealerships in Gauteng

Theron, Daniell. January 2015 (has links)
M. Tech. Business Administration / The study assesses the dimensions of service quality within a Jaguar Land Rover dealership in Gauteng. The first objective is to determine the importance of each service quality and the second is to measure the effect of the service quality at the dealerships.
149

Performance Characterization of Cement Treated Sand Base Material of Mozambique

De Vos, Ebenhaezer Roux 03 1900 (has links)
Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2007. / Mozambique is investing heavily in rehabilitating and upgrading the current roadway infrastructure. Investigation by the Mozambican roads authority found that some consulting engineers and contractors were not familiar with Mozambican conditions and materials. The World Bank sponsored a research project to support the roadway infrastructure preservation and maintenance efforts. The thesis work presented forms an integral part of the work conducted by the World Bank project research team. The objective of the thesis is to characterise cement stabilized sand bases in Mozambique under Accelerated Pavement Testing (APT) in terms of stiffness and deflection responses under load trafficking. This work forms the basis for developing guidelines for a mechanistic-empirical design method for Mozambican conditions and materials. Reported findings from initial MMLS3 testing conducted for the World Bank project were used to scope the full-scale research study and provided guidelines for the selection and construction of full scale test sections on natural subgrade. The APT presented encompass full-scale pavement testing including wet trafficking cycles to emulate environmental effects.
150

Scheduling algorithms for routine maintenance of roads in maintenance wards of a gravel road network

Burger, A. F. (Adriaan Francois) 04 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: The study reported in this thesis focuses on the development of algorithms that can be used to schedule routine maintenance work in maintenance wards of a gravel road network, This was undertaken as part of the development of the Blading Optimisation Module of the Gravel Management System of the Provincial Government: Western Cape. Two scheduling algorithms were developed and mapped to a pilot object model on the computer. The algorithms and application interface takes account of the constraints and variables of routine maintenance that were identified through interviews with personnel of the five District Municipalities contained in the Western Cape. The algorithms are tested and evaluated using the pilot application. Based on the evaluation of the algorithms conclusions are drawn and recommendations are made. / AFRIKAANSE OPSOMMING: Die studie beskryf in hierdie tesis fokus op die ontwikkeling van algoritmes vir die skedulering van roetine instandhoudingswerk in instandhoudingswyke van 'n gruispadnetwerk. Dit is ondemeem tydens die ontwikkeling van die "Blading Optimisation Module" van die "Gravel Management System" van die Provinsiale Regering: Wes Kaap. Twee algoritmes is ontwikkel en afgebeeld op 'n loods-objekmodel op die rekenaar. Die algoritmes en toepassingskoppelvlak maak voorsiening vir die beperkings en veranderlikes wat geidentifiseer is tydens onderhoude met personeel van die distrikmunisipaliteite in die Wes Kaap. Die algoritmes is getoets en geevalueer met behulp van die loodstoepassing. Gevolgtrekkings en aanbevelings word gemaak op grond van die resultate van die evaluasie van die algoritmes.

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