41,716 research outputs found

    Kompetensi pembimbing syarikat bertauliah Sistem Latihan Dual Nasional (SLDN)

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    Sistem Latihan Dual Nasional (SLDN) merupakan satu sistem latihan dan usahasama antara sektor awam dan sektor swasta dilaksanakan untuk melahirkan tenaga mahir k-worker selari dengan keperluan industri masa kini untuk membangunkan ekonomi negara. Pihak kerajaan dan syarikat swasta menaja pekerja pilihan mereka sebagai pelatih dalam sistem latihan ini bagi mempertingkatkan kebolehan pekerja mereka. Selain itu, pelatih juga terdiri daripada pelajar yang tidak dapat melanjutkan pelajaran ke mana-mana institusi pengajian tinggi awam mahupun swasta. Sistem ini menjalankan pendekatan day release iaitu pelatih menjalani latihan selama empat hari di industri dan satu hari di institusi latihan atau block release iaitu pelatih menjalani latihan kemahiran di industri empat bulan dan satu bulan di institusi latihan mengikut kesesuaian industri tersebut. Kajian berbentuk deskriptif dijalankan untuk melihat melihat tahap kompetensi pembimbing SLDN. Selain itu juga, kajian ini dijalankan bagi melihat perbezaan terhadap tahap pengetahuan, kemahiran dan sikap pembimbing SLDN berdasarkan jantina. Kajian ini juga dibuat bagi menentukan hubungan kompetensi pembimbing berdasarkan pengalaman bekerja. Penyelidikan tinjauan deskriptif ini menggunakan borang soal selidik sebagai instrumen kajian berskala Likert. Seramai 84 orang responden yang terdiri daripada pembimbing syarikat bertauliah SLDN terlibat di dalam kajian ini. Data dianalisis menggunakan SPSS versi 16.0. Hasil analisis mendapati pembimbing mempunyai pengetahuan yang tinggi di samping kemahiran dan sikap. Keputusan inferensi pula menunjukkan tidak terdapat perbezaan antara tahap pengetahuan, kemahiran dan sikap pembimbing berdasarkan jantina manakala analisis korelasi Pearson menunjukkan tidak terdapat hubungan antara kompetensi pembimbing berdasarkan pengalaman bekerja

    Kompetensi pembimbing syarikat bertauliah Sistem Latihan Dual Nasional (SLDN)

    Get PDF
    Sistem Latihan Dual Nasional (SLDN) merupakan satu sistem latihan dan usahasama antara sektor awam dan sektor swasta dilaksanakan untuk melahirkan tenaga mahir k-worker selari dengan keperluan industri masa kini untuk membangunkan ekonomi negara. Pihak kerajaan dan syarikat swasta menaja pekerja pilihan mereka sebagai pelatih dalam sistem latihan ini bagi mempertingkatkan kebolehan pekerja mereka. Selain itu, pelatih juga terdiri daripada pelajar yang tidak dapat melanjutkan pelajaran ke mana-mana institusi pengajian tinggi awam mahupun swasta. Sistem ini menjalankan pendekatan day release iaitu pelatih menjalani latihan selama empat hari di industri dan satu hari di institusi latihan atau block release iaitu pelatih menjalani latihan kemahiran di industri empat bulan dan satu bulan di institusi latihan mengikut kesesuaian industri tersebut. Kajian berbentuk deskriptif dijalankan untuk melihat melihat tahap kompetensi pembimbing SLDN. Selain itu juga, kajian ini dijalankan bagi melihat perbezaan terhadap tahap pengetahuan, kemahiran dan sikap pembimbing SLDN berdasarkan jantina. Kajian ini juga dibuat bagi menentukan hubungan kompetensi pembimbing berdasarkan pengalaman bekerja. Penyelidikan tinjauan deskriptif ini menggunakan borang soal selidik sebagai instrumen kajian berskala Likert. Seramai 84 orang responden yang terdiri daripada pembimbing syarikat bertauliah SLDN terlibat di dalam kajian ini. Data dianalisis menggunakan SPSS versi 16.0. Hasil analisis mendapati pembimbing mempunyai pengetahuan yang tinggi di samping kemahiran dan sikap. Keputusan inferensi pula menunjukkan tidak terdapat perbezaan antara tahap pengetahuan, kemahiran dan sikap pembimbing berdasarkan jantina manakala analisis korelasi Pearson menunjukkan tidak terdapat hubungan antara kompetensi pembimbing berdasarkan pengalaman bekerja

    The XDEM Multi-physics and Multi-scale Simulation Technology: Review on DEM-CFD Coupling, Methodology and Engineering Applications

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    The XDEM multi-physics and multi-scale simulation platform roots in the Ex- tended Discrete Element Method (XDEM) and is being developed at the In- stitute of Computational Engineering at the University of Luxembourg. The platform is an advanced multi- physics simulation technology that combines flexibility and versatility to establish the next generation of multi-physics and multi-scale simulation tools. For this purpose the simulation framework relies on coupling various predictive tools based on both an Eulerian and Lagrangian approach. Eulerian approaches represent the wide field of continuum models while the Lagrange approach is perfectly suited to characterise discrete phases. Thus, continuum models include classical simulation tools such as Computa- tional Fluid Dynamics (CFD) or Finite Element Analysis (FEA) while an ex- tended configuration of the classical Discrete Element Method (DEM) addresses the discrete e.g. particulate phase. Apart from predicting the trajectories of individual particles, XDEM extends the application to estimating the thermo- dynamic state of each particle by advanced and optimised algorithms. The thermodynamic state may include temperature and species distributions due to chemical reaction and external heat sources. Hence, coupling these extended features with either CFD or FEA opens up a wide range of applications as diverse as pharmaceutical industry e.g. drug production, agriculture food and processing industry, mining, construction and agricultural machinery, metals manufacturing, energy production and systems biology

    A new approach to modelling process and building energy flows in manufacturing industry.

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    Global conservation of energy and material has become a key topic among governments, businesses, local societies and academics. A point made by many on the subject of energy begin by stating the importance of conserving the earth’s natural resources, and the need to reduce greenhouse gas emissions in a bid to reduce global warming. This research is no exception, concentrating on an energy and material intensive sector of the global economy; manufacturing industry. This research formulates a methodology for modelling energy flows between a factory building, its manufacturing process systems and the materials used. The need for such an approach arises from the gap in knowledge between the understanding of energy consumed by factory buildings and process systems in manufacturing industry. Factory buildings are purpose built environments that house manufacturing processes, manufacturing plant, materials and occupants. Modern production lines are designed to optimise the flow of materials throughout a factory; to and from storage, production, assembly and distribution. Manufacturing production systems dictate the shape and size of factory buildings. This can lead to a high proportion of the overall energy consumption to be attributed to building services. The coupling of factory energy flows assists energy managers at both the facility and process levels, in order to identify efficiency improvements and reduce energy use and associated carbon emissions. A better understanding of the overall energy balance of a factory environment will allow energy to be used in a more sustainable manner. Simulation tools are widely used in the disciplines of building design and manufacturing systems engineering. Traditional building energy flow paths are well documented and are handled within dynamic building modelling tools. Globally, manufacturing activities cover a wide field of industrial practice and use a range of simulation software packages such as flow diagramming packages, computational fluid dynamics, discrete event tools, direct coding, optimisation tools etc. The increasing use of simulation makes it difficult for a manufacturing systems analyst to choose a suitable approach for energy modelling. An important aspect of the methodology described in this thesis is the coupling of energy flows that occur internally (within a factory boundary) and externally (outside a factory boundary e.g. weather) in relation to time and location within and around a factory environment. Building modelling tools provide a structured and well defined approach to monitoring energy flows within traditional built environments. The methodology extends the framework of an existing building modelling tool; the International Building Physics Toolbox (IBPT), to include the simulation of manufacturing process systems and material flow within a factory. There is a wide range of manufacturing processes used in industry so the scope of this research is reduced to thermal and electrical processes only. A thermal process is considered to be an extension of a thermal zone (such as a room), as defined in building modelling tools. Two thermal processes are considered; processes that act on a volume of gas (i.e. air) and those that act on a volume of liquid. Material flow is represented in the model by time series. The lumped capacitance method is used to approximate the change in surface temperature of a material in relation to its stored energy, long wave radiation between the material and its surroundings, and convective heat transfer. To validate the use of the IBPT algorithms to model building physics, the results derived by using the IBPT are compared with those derived by using an industry standard trusted building modelling tool called ‘Integrated Environmental Solutions Virtual Environment’ (IES VE), in comparable areas of building modelling. Three industrial case studies have been analysed, and these represent real scenarios from the automotive and aerospace manufacturing industry sectors. Two out of the three case studies include the simulation of the building (fabric and heating system), material flow and manufacturing process systems (air and liquid based). The third case study focuses on process modelling only, with future scope to include the factory building. Data obtained from industrial practice is used to validate the results of energy modelling using the proposed method. Results from the case studies demonstrate the capabilities of the proposed method of modelling factory energy flows and associated energy consumption at both facility and process level. Opportunities to reduce energy use and associated carbon emissions are also identified. The methodology does have some limitations in the form of the number of manufacturing process types represented and the complex nature of modelling real energy flows that occur within factory buildings. However the findings of the research show that an integrated approach to modelling factory energy flows through development of a building modelling framework has real benefits for manufacturing industry. These benefits are very unlikely to be realised by modelling processes and buildings separately, as is the way current modelling methods are carried out by the separate discipline areas of building design and manufacturing systems. Factory energy managers and future factory designs are example areas in which the presented integrated tool would be most beneficial used. Future research within this area could include an extension of the framework to model moisture transfer, the inclusion of further types of manufacturing process systems and further investigation into the coupling of time-driven and event-driven hybrid modelling techniques to simulate material flow both in terms of locality and thermal behaviour.Technology Strategy Board (reference number BD479L

    A dynamics-driven approach to precision machines design for micro-manufacturing and its implementation perspectives

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    Precision machines are essential elements in fabricating high quality micro products or micro features and directly affect the machining accuracy, repeatability and efficiency. There are a number of literatures on the design of industrial machine elements and a couple of precision machines commercially available. However, few researchers have systematically addressed the design of precision machines from the dynamics point of view. In this paper, the design issues of precision machines are presented with particular emphasis on the dynamics aspects as the major factors affecting the performance of the precision machines and machining processes. This paper begins with a brief review of the design principles of precision machines with emphasis on machining dynamics. Then design processes of precision machines are discussed, and followed by a practical modelling and simulation approaches. Two case studies are provided including the design and analysis of a fast tool servo system and a 5-axis bench-top micro-milling machine respectively. The design and analysis used in the two case studies are formulated based on the design methodology and guidelines

    Thermophysical Phenomena in Metal Additive Manufacturing by Selective Laser Melting: Fundamentals, Modeling, Simulation and Experimentation

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    Among the many additive manufacturing (AM) processes for metallic materials, selective laser melting (SLM) is arguably the most versatile in terms of its potential to realize complex geometries along with tailored microstructure. However, the complexity of the SLM process, and the need for predictive relation of powder and process parameters to the part properties, demands further development of computational and experimental methods. This review addresses the fundamental physical phenomena of SLM, with a special emphasis on the associated thermal behavior. Simulation and experimental methods are discussed according to three primary categories. First, macroscopic approaches aim to answer questions at the component level and consider for example the determination of residual stresses or dimensional distortion effects prevalent in SLM. Second, mesoscopic approaches focus on the detection of defects such as excessive surface roughness, residual porosity or inclusions that occur at the mesoscopic length scale of individual powder particles. Third, microscopic approaches investigate the metallurgical microstructure evolution resulting from the high temperature gradients and extreme heating and cooling rates induced by the SLM process. Consideration of physical phenomena on all of these three length scales is mandatory to establish the understanding needed to realize high part quality in many applications, and to fully exploit the potential of SLM and related metal AM processes

    Energy efficiency in discrete-manufacturing systems: insights, trends, and control strategies

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    Since the depletion of fossil energy sources, rising energy prices, and governmental regulation restrictions, the current manufacturing industry is shifting towards more efficient and sustainable systems. This transformation has promoted the identification of energy saving opportunities and the development of new technologies and strategies oriented to improve the energy efficiency of such systems. This paper outlines and discusses most of the research reported during the last decade regarding energy efficiency in manufacturing systems, the current technologies and strategies to improve that efficiency, identifying and remarking those related to the design of management/control strategies. Based on this fact, this paper aims to provide a review of strategies for reducing energy consumption and optimizing the use of resources within a plant into the context of discrete manufacturing. The review performed concerning the current context of manufacturing systems, control systems implemented, and their transformation towards Industry 4.0 might be useful in both the academic and industrial dimension to identify trends and critical points and suggest further research lines.Peer ReviewedPreprin
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