934 resultados para engineering and maintenance enterprises


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thesis is developed from a real life application of performance evaluation of small and medium-sized enterprises (SMEs) in Vietnam. The thesis presents two main methodological developments on evaluation of dichotomous environment variable impacts on technical efficiency. Taking into account the selection bias the thesis proposes a revised frontier separation approach for the seminal Data Envelopment Analysis (DEA) model which was developed by Charnes, Cooper, and Rhodes (1981). The revised frontier separation approach is based on a nearest neighbour propensity score matching pairing treated SMEs with their counterfactuals on the propensity score. The thesis develops order-m frontier conditioning on propensity score from the conditional order-m approach proposed by Cazals, Florens, and Simar (2002), advocated by Daraio and Simar (2005). By this development, the thesis allows the application of the conditional order-m approach with a dichotomous environment variable taking into account the existence of the self-selection problem of impact evaluation. Monte Carlo style simulations have been built to examine the effectiveness of the aforementioned developments. Methodological developments of the thesis are applied in empirical studies to evaluate the impact of training programmes on the performance of food processing SMEs and the impact of exporting on technical efficiency of textile and garment SMEs of Vietnam. The analysis shows that training programmes have no significant impact on the technical efficiency of food processing SMEs. Moreover, the analysis confirms the conclusion of the export literature that exporters are self selected into the sector. The thesis finds no significant impact from exporting activities on technical efficiency of textile and garment SMEs. However, large bias has been eliminated by the proposed approach. Results of empirical studies contribute to the understanding of the impact of different environmental variables on the performance of SMEs. It helps policy makers to design proper policy supporting the development of Vietnamese SMEs.

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The preparation and characterisation of novel biodegradable polymer fibres for application in tissue engineering and drug delivery are reported. Poly(e-caprolactone) (PCL) fibres were produced by wet spinning from solutions in acetone under low shear (gravity flow) conditions. The tensile strength and stiffness of as-spun fibres were highly dependent on the concentration of the spinning solution. Use of a 6% w/v solution resulted in fibres having strength and stiffness of 1.8 MPa and 0.01 GPa respectively, whereas these values increased to 9.9 MPa and 0.1 GPa when fibres were produced from 20% w/v solutions. Cold drawing to an extension of 500% resulted in further increases in fibre strength (up to 50 MPa) and stiffness (0.3 GPa). Hot drawing to 500% further increased the fibre strength (up to 81 MPa) and stiffness (0.5 GPa). The surface morphology of as-spun fibres was modified, to yield a directional grooved pattern by drying in contact with a mandrel having a machined topography characterised by a peak-peak separation of 91 mm and a peak height of 30 mm. Differential scanning calorimetery (DSC) analysis of as-spun fibres revealed the characteristic melting point of PCL at around 58°C and a % crystallinity of approximately 60%. The biocompatibility of as-spun fibres was assessed using cell culture. The number of attached 3T3 Swiss mouse fibroblasts, C2C12 mouse myoblasts and human umbilical vein endothelial cells (HUVECs) on as-spun, 500% cold drawn, and gelatin coated PCL fibres were observed. The results showed that the fibres promoted cell proliferation for 9 days in cell culture and was slightly lower than on tissue culture plastic. The morphology of all cell lines was assessed on the various PCL fibres using scanning electron microscopy. The cell function of HUVECs growing on the as-spun PCL fibres was evaluated. The ability HUVECs to induce an immune response when stimulated with lipopolysaccaride (LPS) and thereby to increase the amount of cell surface receptors was assessed by flow cytometry and reverse transcription-polymerase chain reaction (RT-PCR). The results showed that PCL fibres did not inhibit this function compared to TCP. As-spun PCL fibres were loaded with 1 % ovine albumin (OVA) powder, 1% OVA nanoparticles and 5% OVA nanoparticles by weight and the protein release was assessed in vitro. PCL fibres loaded with 1 % OVA powder released 70%, 1% OVA nanoparticle released 60% and the 5% OVA nanoparticle released 25% of their protein content over 28 days. These release figures did not alter when the fibres were subjected to lipase enzymatic degradation. The OVA released was examined for structural integrity by SDS-PAGE. This showed that the protein molecular weight was not altered after incorporation into the fibres. The bioactivity of progesterone was assessed following incorporation into PCL fibres. Results showed that the progesterone released had a pronounced effect on MCF-7 breast epithelial cells, inhibiting their proliferation. The PCL fibres display high fibre compliance, a potential for controlling the fibre surface architecture to promote contact guidance effects, favorable proliferation rate of fibroblasts, myoblasts and HUVECs and the ability to release pharmaceuticals. These properties recommended their use for 3-D scaffold production in soft tissue engineering and the fibres could also be exploited for controlled presentation and release of biopharmaceuticals such as growth factors.

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DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY WITH PRIOR ARRANGEMENT

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Students at Cranfield Manufacturing Systems Centre helped Brompton Bikes formulate a strategy to meet rapid sales growth. The students took up Operations Excellence MSc, a two-year part-time programme based on the Cranfield MSc in Engineering and Management of Manufacturing Systems, include the Realising Competitive Manufacture module, which is set out to consolidate and embed the knowledge and skills developed throughout the two-year programme. Guided by StratNav process, the students analysed the product families of Brompton, established the basis on which they compete in the market place, and then benchmarked against key competitors. The top five developments identified to be needed by Brompton are: the formation of group technology cells, creation of a robotic brazing facility, and training and recruitment initiatives for production staff.

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Saudi Arabian Small and Medium Enterprises (SMEs) will face fierce competition from new entrants to local markets as a result of their accession to the Word Trade Organisation (WTO), and electronic commerce (e-commerce) technologies can reinforce SME’s competitive edge. This study investigates the state of e-commerce adoption and analyses the factors that determine the extent to which SMEs in Saudi Arabia are inclined towards deploying e-commerce technologies. This could assist future firms in designing effective implementation projects. Seven SMEs’ e-commerce adoption levels are studied as a case. The Technology-Organization-Environment (TOE) framework was used as the major source of inspiration in our analysis of e-commerce adoption amongst Saudi SMEs. In addition to advancing research on e-commerce in Saudi Arabia, this chapter also highlights several directions for future inquiry and implications for managers and policymakers.

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The objective of Total Productive Maintenance (TPM) is to maximise plant and equipment effectiveness, to create a sense of ownership for operators, and promote continuous improvement through small group activities involving production, engineering and maintenance personnel. This paper describes and analyses a case study of TPM implementation at a newspaper printing house in Singapore. However, rather than adopting more conventional implementation methods such as employing consultants or through a project using external training, a unique approach was adopted based on Action Research using a spiral of cycles of planning, acting observing and reflecting. An Action Research team of company personnel was specially formed to undertake the necessary fieldwork. The team subsequently assisted with administering the resulting action plan. The main sources of maintenance and operational data were from interviews with shop floor workers, participative observation and reviews conducted with members of the team. Content analysis using appropriate statistical techniques was used to test the significance of changes in performance between the start and completion of the TPM programme. The paper identifies the characteristics associated with the Action Research method when used to implement TPM and discusses the applicability of the approach in related industries and processes.