This paper presents the use of factorial experiments and response surface methodology to determine the best workstation design configuration of an existing electronic industry. The aim is to find the value of physical dimensions that gives the best performance for the workstation. Four performance measures are selected; the cycle time, the metabolic energy expenditure, worker’s posture during the task and lifting limitations. The methodology used in this study consists of two parts. The first part is based on factorial experiments and handles discrete search over combinations of factor-levels for improving the initial solution. In the second part, the solution that was obtained earlier is further refined by changing the continuous factors by using response surface methodology. The result of this optimization study shows that the optimum value of physical dimensions gives a significant improvement for the performance measures of the workstation.
Kaedah unsur terhingga (FEM) berdasarkan pemodelan dan simulasi proses pemotongan telah menarik minat ramai penyelidik secara berterusan untuk mengkaji lebih mendalam terutamanya mengenai penjanaan daya dan suhu di dalam zon pemotongan yang sebelum ini tegasan tidak boleh diukur secara langsung. Dalam kajian ini, simulasi proses pemotongan ortogon besi tuang mulur (FCD 500) menggunakan mata pemotong karbida pada pelbagai keadaan angin sejuk telah dikaji. Perisian DEFORM digunakan untuk menjalankan simulasi proses pemotongan ortogon dengan laju pemotongan (100-300 m/min), kadar suapan (0.15-0.35 mm/pus), kedalaman pemotongan (0.2-0.8 mm) dan suhu angin sejuk (2o -25oC). Mata pemotong mempunyai jejari hidung mata pemotong 0.4 mm, sudut sadak, α =5o dan sudut kelegaan, β = 7o. Reka bentuk uji kaji adalah menggunakan kaedah Taguchi dalam tatasusunan ortogon L9, nisbah S/N dan analisis Pareto ANOVA digunakan untuk menganalisis kesan parameter pemotongan terhadap hasil pemesinan iaitu daya, tegasan dan suhu semasa pemesinan. Keputusan menunjukkan kadar suapan memberikan pengaruh yang paling tinggi (96.12%) terhadap daya pemotongan. Tegasan pemotongan paling dipengaruhi oleh kadar suapan iaitu 78.87%. Kajian ini telah membuktikan, banyak masa, kos dan tenaga dapat dijimatkan dalam mengkaji kebolehmesinan sesuatu bahan secara simulasi berbanding dengan kaedah eksperimen, di samping keputusan yang tepat diperoleh.
Tool life of the cutting tools is considered as one of the factors which has effects on machining costs and the quality of machined parts. The topic of tool life prediction has been an interesting and important research topic attracting the attention of a wide number of researchers in this particular area. In terms of the suitable methods used in this research topic, it is stated that both statistical and artificial intelligence (AI) approaches can be employed to model tool life. For further justifying the capability of the ANN model in predicting tool life, the current study was based on conducting experimental work for collecting the experimental data. After carrying out the experiment, 17 data sets were collected and they were divided into two subsets; the first one for training and the second for testing. Since the data sets seemed to be lower than the number of data sets used in previous studies, we attempted to make verification of the ability of the ANN model in learning and adapting with low training and testing data. Diverse topologies accompanied with single and two hidden layers were created for modeling the tool life. For choosing the best and most effective network, the study adopted the mean square error function as criteria for the evaluation of the network selection. Thus, based on the data generated from the same experiment, a regression model (RM) was constructed employing the SPSS software. A comparison between the ANN model and RMs in terms of their accuracy was carried out and the findings revealed that the accuracy of the ANN was higher than that of the RM.
Kertas kerja ini membincangkan pendekatan dalam mengintegrasikan Java dan persekitaran VRML yang telah diaplikasikan dalam mensimulasi masa nyata bagi proses kisar hujung maya. Pendekatan yang menggunakan Routing ini adalah sangat penting untuk komunikasi dan penghantaran mesej antara VRML dan Java. Dalam pendekatan ini, nod Script digunakan bagi memanggil dan menghubungkan kelas Java dengan entiti-entiti yang sepatutnya di dalam persekitaran VRML. Simulasi bahan termesin bagi proses kisar hujung dalam sistem ini dilaksanakan melalui satu kaedah baru iaitu dengan penggunaan nod penaikan bagi penjanaan objek 3D dan nod PositionInterpolator serta CoordinateInterpolator bagi animasi bahan termesin. Melalui kaedah ini simulasi bagi proses kisar hujung dapat dipaparkan secara maya dan pada masa yang sama graf haus rusuk bagi perkakas pemotong melawan masa pemotongan dapat dijana serentak.
Kertas ini membincangkan pembangunan suatu alat sokongan pembuat keputusan dalam mereka bentuk produk berasaskan teori baris-gilir yang dikaitkan dengan maklumat masa kitar pembuatan. Dengan penggunaan alat sokongan ini, kesan reka bentuk sesuatu produk terhadap parameter kapasiti dan masa kitar pembuatan sesuatu sistem pembuatan sedia ada dapat ditentukan. Aplikasi alat sokongan ini membolehkan kumpulan pembangunan produk membangunkan produk sebenar pada masa yang singkat, meminimumkan kos pembangunan serta mengurangkan keperluan untuk mereka
bentuk semula produk. Alat sokongan ini telah diaplikasikan pada sebuah industri automotif tempatan dan hasil kajian menunjukkan bahawa alat sokongan tersebut telah berjaya melakukan analisis masa kitar dan tahap penggunaan pada sistem pembuatan sedia ada. Pada jumlah keluaran 44 komponen/jam dan saiz sesekumpul 80, hasil analisis menunjukkan tahap penggunaan pada 98% dengan masa kitar 17.8 jam bagi pemprosesan gabungan produk yang terdiri daripada komponen dengan reka bentuk baru dan reka bentuk sedia ada.
Composite materials have increasingly become crucial in manufacturing engineering products and producing commodity
materials in the major industries including; automotive, aerospace, marine, construction, agriculture and health science.
However, several improvements regarding the strength, dimensional stability and the cost of production are required.
In this study, composite of Kenaf, multi-wall carbon nanotube (MWCNT) and polypropylene (PP) with maleic anhydridegrafted
polypropylene (MAPP) are examined. The results highlight that increasing MAPP loading, in turn, increases the
value of the mechanical properties. The composites are produced by blending kenaf/MWCNT/PP using a Sigma blade
mixer and injection moulding. Injection moulding is a significant operation used to produce plastic products. In the
study, Kenaf core fibre was mixed with MWCNT and polypropylene, in addition to MAPP. The MAPP is added by applying
different percentage (1, 2, 3 and 4 wt. %) during the blending process. The main objective of the study was to analyse the
effects of MAPP concentrations on the mechanical properties of the Kenaf/MWCNT/PP composite. The results of the study
established that MAPP 3 wt. % concentration with MWCNT 3 wt. % loading and Kenaf 30 wt. % filler provide optimum
results for the composites. There was approximately, a 21% enhance in tensile strength of Kenaf 30 wt. %/MWCNT, 3 wt.
%/MAPP, 3 wt. %/PP observed compared to the (without) MAPP composite. The composites with coupling agent stimulate
better filler dispersion between Kenaf, MWCNT and PP observed using a scanning electron microscope (SEM) and fieldemission
scanning electron microscope (FESEM).