• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1479-1485
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• 2010

In recent times, due to wire drawing of high carbon steel at a high speed to ensure a high productivity and high strength, axial residual stress are generated because of rapid increase in surface temperature. In the process, the temperatures of the wires increased because of the deformation of the wires and the friction between the die and wire. In particular, in the case of the wire drawing at a high speed, friction leads to a large temperature gradient so that considerable axial residual stress is generated on the surface. In this study, the relationship between axial residual stress and increase in the surface temperature was investigated, and a prediction model of uniform temperature was proposed. Then, a prediction model for residual stress was developed. The proposed model was verified by measuring the residual stress by X-ray diffraction on drawn wires.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.8
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• pp.70-75
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• 2010

The aim of this study is to evaluate the axial residual stress in multi-pass drawn high carbon steel wire by using FE analysis and XRD. When FE analysis is applied to evaluate the residual stress in drawn wire of multi-pass drawing process, obtaining the reliable effective stress-strain curve at high strain is very important. In this study, a model, which can express the reliable effective stress-strain curve at high strain, is introduced based on the Bridgman correction and tensile test for multi-pass drawn high carbon steel wires. By using the introduced model, FE analysis was carried out to evaluate the axial residual stress in the drawn wires. Finally, the effectiveness of the FE analysis with the introduced stress-strain relation was verified by the measurement of residual stress in the drawn wires through XRD. As a result, the evaluated residual stress of FE analysis shows good agreement with the measured residual stress.

• Transactions of Materials Processing
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• v.26 no.3
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• pp.162-167
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• 2017

The tensile surface residual stress in the multi-pass drawn wire deteriorates the mechanical properties of the wire. Therefore, the evaluation of the residual stress is very important. Especially, the axial residual stress on the wire surface is the highest. Therefore, the objective of this study was to propose an axial surface residual stress prediction model of the multi-pass drawn steel wire. In order to achieve this objective, an elastoplastic finite element (FE) analysis was carried out to investigate the effect of semi-die angle and reduction ratio of the axial surface residual stress. By using the results of the FE analysis, a surface residual stress prediction model was proposed. In order to verify the effectiveness of the prediction model, the predicted residual stress was compared to that of a wire drawing experiment.

• Transactions of Materials Processing
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• v.28 no.5
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• pp.275-280
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• 2019

The aim of this study is to fabricate an ultra-fine pure rhodium wire using multi-pass wire drawing process. To manufacture $30{\mu}m$ ultra-fine rhodium wire from the initial $50{\mu}m$ wire, a multi-pass wire drawing process was designed based on the uniform reduction ratio theory. The elastic-plastic finite element analysis was then conducted to validate the efficacy of the designed process. The drawing load, drawing stress, and the distribution of the effective strain were evaluated using the finite element analysis. Finally, the wire drawing experiment was performed to validate the designed wire drawing process. From the results of the experiment, the diameter of the final drawn wire was found to be $29.85{\mu}m$.

• Transactions of Materials Processing
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• v.19 no.4
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• pp.224-229
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• 2010

During the multi-pass wire drawing process, wires suffer a great amount of plastic deformation that is through the cross-section. This generates tensile residual stress at surface of drawn wires. The generated residual stress on surface is one of the problems for quality of wires so that prediction and reduction of residual stresses is important to avoid unexpected fracture. Therefore, in this study, the effect of process variables such as semi-die angle, bearing length and reduction ratio on the residual stress was evaluated through Finite Element Analysis. Based on the results of the Analysis, a prediction model was established for predicting residual stress on the surface of high carbon steel(AISI1072, AISI1082). To identify the effectiveness of the proposed model, X-ray diffraction is used to measure the residual stresses on the surface. As the result of the comparison between calculated residual stresses and measured residual stresses, the model could be used to predict residual stresses in cold drawn wire.

• Journal of Nutrition and Health
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• v.9 no.1
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• pp.76-83
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• 1976

The aims of this study are, 1) to describe the attitudes of the community towards each food item and 2) to provide the information necessary for the solution of nutritional problems due to the different food intake of the community. This study is based on the Food Consumption Survey conducted by the Ministry of Health and Social Affairs in a series of National Nutrition Survey in August, 1973. The sample included 8 communities, in which 160 households were selected at random for this study. The procedures and methods used in this study to compute the acceptability index were adopted from the study of H. Toyokawa, University of Tokyo. Food attitudes of the sample communities are clear in terms of the mean acceptability index which is presented in Table 3. The following order is indicative of the relative strength of acceptability of the respective food items: 1. Seasonings (-1.20) 2. Oils and fats (-1.12) 3. Pulses(- .60) 4. Processed vegetables (- .45) 5. Seaweeds (- .32) 6. Sugars (- .19) 7. Fresh vegetables (- .15) 8. Rice (- .13) 9. Cereals and grain products (- .07) 10. Starchy roots (- .06) 11. Fresh fish and shells (.44) 12. Processed fish and shells (.56) 13. Eggs (1.06) 14. Fruits (1.26) 15. Meats and poultry (1.33) 16. Milk and milk products (2.87) There are highly significant difference in the acceptability index between food items and the mean intake of rice, cereals and grain products, pulses, starchy roots, processed vegetables, fruits, sugars, seaweeds, seasonings, meats and poultry, eggs, fresh and shells, and oils and fats between the communities at the .01 level of significance.