• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.567-574
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• 1991

In this study thermal stress generated in three ingot moulds(GC25) during the solidification process of aluminum were analyzed by the two-dimensional thermo-elasto-plastic theory. In temperature analysis, all of the three models are shown steep temperature rising each case in initial stage of cooling. In thermal stress analysis, all of three models took compressible stress on inside wall of the mould, and tensible along with on out side. Model 2 take place less compressible, tensible stress then model 1. But model 3. have similar as thermal stress as model 2. The analysis will made one possible to calculate an optimum mould shape whose thermal stress gradient becomes minimum.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.1 no.1
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• pp.48-54
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• 2002

In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, new machining technologies which take environmental aspects into consideration are being developed Industry and research institutions established applications for dry, semi-dry, oil-mist and compressed cold air machining. This paper investigates the performance of new compressed cold air system for environmentally conscious machining and evaluates machinability of dry and new compressed cold air machining. A series of tests are carried out using measuring eqipments under dry and compressed cold air machining.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.141-146
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• 2003

This paper calculates the elapsed time to go down a straight as a function of the corner exit speed and considers air resistance, rolling resistance, and slope resistance to figure out the force for forward acceleration. In a car racing, the most critical comer in a course is the one before the longest straight. A driver can lose a quite amount of time by taking a bad line in a corner. Taking a bad line also causes poor comer exit speed which in turn costs more elapsed time to go down a straight. The results are not so dramatic as in the case of cornering but are showing why one should take the correct corner racing line to get the maximum exit speed. Also, for the case of drag race, the elapsed time to go 1/4 mile is calculated.

• International Journal of Quality Innovation
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• v.5 no.2
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• pp.26-44
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• 2004

Distance Education is a non-traditional mode of training and can take many forms, one of which is the use of Computer Based Training (CBT). This paper reviews various quality assurance models for designing the delivery of programmes at the universities and other training institutions. It presents the findings of a CBT research that is currently being carried out at the Department of Mechanical and Manufacturing Engineering, University of the West Indies, Trinidad. The significance of the research is discussed with particular emphasis on the influence of curricula sequencing on knowledge acquisition in learners of varying cognitive styles. The paper concludes that adherence to quality assurance principles could result in the enhanced performance of users of the CBT.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.104-107
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• 2002

Direct Metal Manufacturing (DMM) is a new additive process that aims to take die making and metalworking in an entirely new direction. It is the blending of five common technologies : lasers, computer-aided design (CAD), computer-aided manufacturing (CAM), sensors and powder metallurgy. The resulting process creates parts by focusing an industrial laser beam onto a tool-steel work piece or platform to create a molten pool of metal. A small stream of powdered tool-steel metal is then injected into the melt pool to increase the size of the molten pool. By moving the laser beam back and forth, under CNC control, and tracing out a pattern determined by a computerized CAD design, the solid metal part is built line-by-line, one layer at a time. DMM produces improved material properties in less time and at a lower cast than is possible with traditional fabrication.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.230-234
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• 2006

This study review about input data needing for noise mapping through the process for noise mapping to the Cheong-Ju on a middle-small scale city. Typically a technician know a input data in noise mapping but it is difficult to get the data. Even if we get the data, it is not regular type. So it take a long time to work out. This study is presented the guideline to solve this problems and indicate about getting data a scheme. and as it make a comparative study of the Europe case.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.401-406
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• 1998

This study aimed at the technique for the construction control in braced excavation works. Selecting a case of Kwangju subway works, field observational values were compared with prediction using Plaxis's. Maximum observational values relevant to both horizontal and vertical proved satisfactory in that they were within the criteria. Numerical results by used Plaxis were overestimated greater than observational values, which meant the prediction were safe tendency. .It must be emphasized that displacement measurement for neighboring important structures should be carried out in order to take countermeasure charge for construction methods, in case that the risk or failure was previewed.

• Journal of the Ergonomics Society of Korea
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• v.23 no.3
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• pp.53-72
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• 2004

Today we are observing a lot of injuries, casualties, and property losses that are mainly caused by the defects of products. In order to derive safety designs, which minimize the possibility of such product liability-related accidents, we need to take into account the user-product interaction as an important part of the danger factor analysis. Existing risk analysis techniques, however, have some limitations in detecting comprehensive danger factors that are peculiarly involved in human errors and the functional defects of products. Researches on danger factor analysis regarding the user-product interaction have been carried out actively in ergonomics. In this paper, we suggest a novel product risk analysis technique, which is more objective and systematic compared to the previous ones, by combining a modified TAFEI (Task Analysis For Error Identification) technique with SASA (Systematic Approach to Accident Scenario Analysis) technique. By applying this technique to the product design practice in industry, corporations will be able to improve the product safety, consequently strengthening the competitiveness.

• Applied Biological Chemistry
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• v.2
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• pp.9-14
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• 1961

The formation of sulfide from sulfate has been discussed from the thermodynamic principles. No mechanism of the reaction has been presented. From the stoichiometric and Nernst equations for the conversion of sulfate into sulfide, it was concluded that the formation of sulfide from sulfate can take place more readily if pH of a medium is low. The difficulty of this conversion increases with increasing pH. As pH of a medium increases, the degree of dissociation of H₂S into S= increases and this, in turn, renders the chance of precipitation of sulfide as FeS easier. Higher the pH of a soil or medium, greater is the S= concentration. The concentration of ferrous ion required to remove dissolved sulfide in a medium by forming insoluble FeS decreases with increasing pH. From the theory it was pointed out that an application of lime and iron rich foreign substances to a soil may be effective in causing the removal of dissolved sulfide from solution.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.211-214
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• 2009

Edge detection always influenced by noise belong to the original image, therefore need use some methods to sort this issue, mean shift algorithm has the smooth function which suit for the edge detection purpose, so adopted to fade out the unimportant information, and the sensitive noise portions. After this section, use the Canny algorithm to pick up the contour of the objects we focus on, meanwhile select the Soble operator that has the orientation attribute to support the method work well. In final, take experiment and get the perfect result we wanted, make sure this method make sense and better than the sole Edge detection algorithm,