• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 36
  • 5
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 53
  • 53
  • 53
  • 27
  • 12
  • 10
  • 8
  • 7
  • 7
  • 7
  • 6
  • 5
  • 5
  • 5
  • 5
  • 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.
51

Development of a reconfigurable assembly system with enhanced control capabilities and virtual commissioning

Niemann, Johan January 2013 (has links)
Thesis (M. Tech. (Engineering: Electrical)) -- Central University of technology, Free State, 2013 / The South African (SA) manufacturing industry requires developing similar levels of sophistication and expertise in automation as its international rivals to compete for global markets. To achieve this, manufacturing plants need to be managed extremely efficiently to ensure the quality of manufactured products and these plants must also have the relevant infrastructure. Furthermore, this industry must also compensate for rapid product introduction, product changes and short product lifespan. To support this need, this industry must engage in the current trend in automation known as reconfigurable manufacturing. The aim of the study is to develop a reconfigurable assembly system with enhanced control capabilities by utilizing virtual commissioning. In addition, this system must be capable of assembling multiple different products of a product range; reconfigure to accommodate the requirements of these products; autonomously reroute the product flow and distribute workload among assembly cells; handle erroneous products; and implement enhanced control methods. To achieve this, a literature study was done to confirm the type of components to be used, reveal design issues and what characteristics such a system must adhere to. Software named DELMIA was used to create a virtual simulation environment to verify the system and simultaneously scrutinize the methods of verification. On completion, simulations were conducted to verify software functions, device movements and operations, and the control software of the system. Based on simulation results, the physical system was built, and then verified with a multi agent system as overhead control to validate the entire system. The final results showed that the project objectives are achievable and it was also found that DELMIA is an excellent tool for system verification and will expedite the design of a system. By obtaining these results it is indicated that companies can design and verify their systems earlier through virtual commissioning. In addition, their systems will be more flexible, new products or product changes can be introduced more frequently, with minimum cost and downtime. This will enable SA manufacturing companies to be more competitive, ensure increased productivity, save time and so ensure them an advantage over their international competition.
52

An implementation of the parallelism, distribution and nondeterminism of membrane computing models on reconfigurable hardware

Nguyen, Van-Tuong January 2010 (has links)
Membrane computing investigates models of computation inspired by certain features of biological cells, especially features arising because of the presence of membranes. Because of their inherent large-scale parallelism, membrane computing models (called P systems) can be fully exploited only through the use of a parallel computing platform. However, it is an open question whether it is feasible to develop an efficient and useful parallel computing platform for membrane computing applications. Such a computing platform would significantly outperform equivalent sequential computing platforms while still achieving acceptable scalability, flexibility and extensibility. To move closer to an answer to this question, I have investigated a novel approach to the development of a parallel computing platform for membrane computing applications that has the potential to deliver a good balance between performance, flexibility, scalability and extensibility. This approach involves the use of reconfigurable hardware and an intelligent software component that is able to configure the hardware to suit the specific properties of the P system to be executed. As part of my investigations, I have created a prototype computing platform called Reconfig-P based on the proposed development approach. Reconfig-P is the only existing computing platform for membrane computing applications able to support both system-level and region-level parallelism. Using an intelligent hardware source code generator called P Builder, Reconfig-P is able to realise an input P system as a hardware circuit in various ways, depending on which aspects of P systems the user wishes to emphasise at the implementation level. For example, Reconfig-P can realise a P system in a rule-oriented manner or in a region-oriented manner. P Builder provides a unified implementation framework within which the various implementation strategies can be supported. The basic principles of this framework conform to a novel design pattern called Content-Form-Strategy. The framework seamlessly integrates the currently supported implementation approaches, and facilitates the inclusion of additional implementation strategies and additional P system features. Theoretical and empirical results regarding the execution time performance and hardware resource consumption of Reconfig-P suggest that the proposed development approach is a viable means of attaining a good balance between performance, scalability, flexibility and extensibility. Most of the existing computing platforms for membrane computing applications fail to support nondeterministic object distribution, a key aspect of P systems that presents several interesting implementation challenges. I have devised an efficient algorithm for nondeterministic object distribution that is suitable for implementation in hardware. Experimental results suggest that this algorithm could be incorporated into Reconfig-P without too significantly reducing its performance or efficiency. / Thesis (PhDInformationTechnology)--University of South Australia, 2010
53

Enhancing small business through mobile apps: a case study from Lagos, Nigeria

Owoseni, Adebowale Oluropo 02 1900 (has links)
This thesis draws on the framework of dynamic capability (DC) in an effort to make sense of how small and medium scale enterprises (SMEs) use mobile apps in Lagos, Nigeria. There exists significant knowledge regarding the application of the DC framework in large firms but its application in smaller organisations has scarcely been researched. The knowledge of how SMEs use mobile apps is important at this time because it could help these SMEs compete favourably, despite unpredictable environments. Based on pragmatic philosophy and a mixed-methods research approach, the research was conducted in two phases. The first phase of the research used qualitative methods to identify the absorptive, adaptive and innovative capabilities of SMEs in Lagos with a view to discover the extent to which mobile apps are used as enablers and/or drivers of these capabilities. The findings from 20 SMEs identified 15 DC constructs whose impact on SMEs could be enhanced using appropriated mobile apps. The SMEs manifest adaptive capabilities, mainly through using appropriated mobile apps. The SMEs manifest adaptive capabilities, mainly through customer feedback and referrals, and demonstrate absorptive capabilities through the repackaging and repricing of their goods and/or service offerings. The innovative capabilities of SMEs became evident through the imitation and adaptation of offerings. The second phase of this research surveyed 1 162 SMEs in Lagos in an effort to validate the identified constructs through quantitative methods. Descriptive statistics of survey responses affirm the use of mobile apps by SMEs and it also indicated the underutilisation of mobile apps as a DC enabler. Further analysis, using covariance-based structural equation modelling (SEM) techniques and confirmatory factor analysis (CFA), explored the fitness of a conceptual SME model. The model assembled seven latent variables namely: mobile app usage, adaptive capability, absorptive capability, innovative capability, opportunity sensing ability, opportunity shaping ability and opportunity seizing ability. Subsequently, 15 hypotheses aimed at understanding the relationships between the variables were developed. The findings from the quantitative analysis revealed that mobile app usage increases the adaptive, absorptive and innovative capabilities of SMEs. The results failed to establish a direct relationship between mobile app usage and opportunity sensing, shaping and seizing abilities. Furthermore, the use of the adaptive capability in taking advantage of opportunities could not be generalised in SMEs’ context. The research findings imply the existence of an untapped potential as far as the use of mobile apps by SMEs in Lagos is concerned. The findings suggest that SMEs in Lagos respond to opportunities by becoming innovative and they seldom exhibit innovation in order to create opportunities. Based on the heterogeneous nature of SMEs, it is difficult to suggest a clear-cut narrative as to how all SMEs should employ mobile apps to create and maximise opportunities. However, mobile apps could induce creativity when developed and applied to the contextual requirements of SMEs. The outcome of this research reflects a multidisciplined research experience. The study contributed to IS through the creation of a model for investigating mobile app usage by organisations from a DC perspective. The conceptual model designed in this study could be adapted to investigate the way in which mobile app usage influences organisations in other contexts. The study contributed to the area of Information Systems by revealing the application of the DC framework to SMEs in contrast to the usual practice of researching DC with large organisations in mind. This research work suggests implicit ways of enhancing SMEs which could aid policy makers. This study was limited in that it gathered data from SMEs in Lagos alone as Lagos represents the commercial centre of Nigeria. Considerations for future research include the comparison of DC of large and small organisations in Lagos to examine if similarities and/or contrasts exist. Furthermore, due to the evasive and heterogeneous nature of SMEs, it would be beneficial to delimit future research on SMEs along specific domains of interest. / Iqoqa Lolu cwaningo lususelwa ohlakeni lokuthiwa ngamandla aphilayo (dynamic capability [DC]) emzameni wokuba umuntu aqonde ukuthi amabhizinisi amancane namaphakathi (ama-SME) awasebenzisa kanjani ama-apps ahanjiswayo eLagos, eNigeria. Lolu lwazi lubalulekile ngoba lungasiza la mabhizinisi ukuba ancintisane namanye ngokunempumelelo, noma izimo akuzo wona zingaqondakali kahle. Ucwaningo lwenziwa ngezigaba ezimbili. Isigaba sokuqala sahlonza ama-DC ama-SMSE eLagos, ngenhloso yokuthola ukuthi ngabe ama-apps ahanjiswayo asetshenziswa kangakanani ukukhuthaza kanye/noma ukuqhubela phambili la mandla aphilayo. Okwatholakala kuma-SME angama-20 kwaba ukuhlonzwa kwezinhlelo zama-DC ithonya lazo kuma-SME elalingase liphakame ngokusebenzisa ama-apps ahanjiswayo afanele. Ama-SME afakazela ama-DC ikakhulu ngokushiwo ngamakhasimende nalabo abathintiwe, nokuba kubonakale ngokuba impahla ekhishwayo ipakishwe kabusha, ifakelwe intengo entsha, noma kube yimpahla engukulingisa eyokuqala noma ilungiswe ifane neyokuqala. Ibanga lesibili lalolu cwaningo lwahlola ama-SME ayi-1 162 eLagos ukuzama ukuqinisekisa ngezinga lezinhlaka ezihlonziweyo. Izimpendulo ezavezwa ucwaningo zakwesekela ukusetshenziswa ngama-SME kwama-apps ahanjiswayo, zakhomba nokuthi awasetshenziswa ngokugcwele ama-apps ahanjiswayo njengokunika i-DC amandla. Okunye ukuhlaziya kwakhombiisa ukuthi ukusebenzisa ama-apps ahanjiswayo kwakungasiza ama-SME ngokwandisa amathuba awo. Nokho phela ukusebenzisa amathuba avelayo kwakungeke kwenzeke yonke indawo kuma-SME. Okuvezwa ucwaningo kukhombisa ukuthi kukhona ukusizakala okukhulu okungakafinyelelwa kukho mayelana nokusetshenziswa ngama-SME kwama-apps ahanjiswayo eLagos. Ucwaningo luphonsa itshe esivivaneni enkundleni yezinhlelo zokusebenza ngezolwazi ngokwembula ukusetshenziswa kohlaka lwe-DC kuma-SME uma kuqhathaniswa ngokuphambene nalokhu, okungukucwaninga okwejwayelekile nge-DC ezinhlanganweni ezinkulu. Lolu cwaningo luveza izindlela ezingekho obala zokuthuthukisa ama-SME, okungaba usizo kulabo ababhekene nokusungula imigomo yezwe. / School of Computing / Ph. D. (Information Systems)

Page generated in 0.0737 seconds