• 소성∙가공
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• 제16권8호
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• pp.575-581
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• 2007

The high dimensional accuracy of the cold forged part could be acquired by the accurate dimensional modification for the die, which is, the dimensional changes from the die through forged part to final part after heat treatment were considered. The experimental and FEM analysis are performed to investigate the dimensional changes from the die to final part on cold forged part, comparing with the machined gear. The dimension of forged part is compared with the die dimension at each stage, such as, machined die, cold forged part, and heat-treated-part. The elastic characteristics and thermal influences on forging stage are analyzed numerically by the $DEFORM-3D^{TM}$. The analyzed residual stress of forged part is considered into the FE-analysis for heat treatment using the $DEFORM-HT^{TM}$. The effects of residual stress affected into the dimensional changes could be investigated by the FEA. Each residual stress of gears was measured practically by laser beam type measurement.

• 동의생리병리학회지
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• 제24권6호
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• pp.1082-1086
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• 2010

This study reports two cases of patients with cold hypersensitivity on hands and feet who were typed as the Soyangin. Although the two patients were experiencing the same symptom of cold hypersensitivity on hands and feet, we diagnosed one as a Soyangin Kyel-Hyung syndrome(結胸證) and the other as a Mang-eum syndrome(亡陰證). So we prescribed them Medications for Soyangin. And we used D.I.T.I.(Digital Infrared Thermal Imaging) to prove the improvement for cold hypersensitivity on hands and feet. The temperature change of D.I.T.I. after treatment showed that the main symptom After treatment, their symptoms were improved and the patients' D.I.T.I results also showed their improvement.

• 농업과학연구
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• 제48권4호
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• pp.753-760
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• 2021

This study was carried out to discover suitable packaging methods during the cold or frozen storage of sawtooth oak and Japanese larch seedlings, which are major afforestation tree species in Korea. The weight loss rate of sawtooth oak was lower under frozen storage at -2℃ (maximum, 33.7%) than under cold storage at 2℃ (maximum, 61.0%). A film liner treatment inside the packaging box effectively suppressed the increase in the weight loss rate. For the sawtooth oak containerized seedlings, when stored at -2℃, the rate of weight loss was 17.9 to 25.4% in the untreated group and less than 1% in the film liner treatment group. Similar results were observed with Japanese larch. After two months of freezing at -2℃, both species maintained a low index of 1.0 - 1.1 with regard to the degree of shoot desiccation of containerized seedlings, and there was no significant difference between the treatments. On the other hand, the chlorine dioxide treatment could more effectively reduce the occurrence of mold and shoot desiccation than a PE single treatment in bare-root seedlings. According to these results, it was concluded that frozen storage is generally suitable as a means of long-term storage compared to cold storage of sawtooth oak and Japanese larch. A chlorine dioxide treatment at 20 ppm was effective for maintaining seedling quality levels during storage, demonstrating the good effect of suppressing the occurrence of shoot desiccation and the occurrence of mold.

• 대한한의정보학회지
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• 제19권1호
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• pp.1-34
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• 2013

Objectives : A common cold is a viral disease. There exists only allopathy for it depending on symptoms because of no cure. Korean medicine has taken a serious view of common cold patients with digestive problems as well as patients of the common cold. Accordingly, this study is aimed at finding out the traits of patients with digestive problems among common cold patients. Methods : A survey was conducted with 62 cold patients who got medical treatment in Korean medicine clinics located in small cities and towns including metropolitan cities. The SPSS for Windows( 19.0 Version) was used for statistical analysis. Results : Depending on which clinic common cold patients decided to go to, there was a significant difference in the number of sick days. The group of patients who decided to go straight to oriental medicine clinics had fewer sick days. Only 9.7% of the group of patients who got treatment in Koean medicine clinics had more than 6 sick days. The group of common cold patients with digestive problems had more sick days than the group with no digestive problems, which showed that there was a significant correlation between digestive problems and sick days. When it came to digestive problems depending which clinic common cold patients decided to go to, there was no significant value because of little data collection. However, while 41.9% of the group who went to hospital at first and then to Koean medicine clinic had digestive problems, 24.2% of the group who directly went to Koean medicine clinic had digestive problems. On the whole, 66.1% of the entire common cold patients were shown to have digestive problems. Conclusion : There are relatively many patients with digestive problems among common cold patients, and there is a significant correlation between digestive problems and sick days on common cold.

• 대한한의학방제학회지
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• 제15권1호
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• pp.1-19
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• 2007

This study was investigated to make sure the range of Gypsum treatment, the nature of disease, the pathology and the dosage of it in Dongeuybogam. The following conclusions were reached through investigations on the prescriptions that use Gypsum as a key ingredient. The Gypsum blended prescriptions are utilized in 23 fields of treatment such as cold, head. ect. Prescriptions that use Gypsum as the main ingredient are used commonly in the treatment of cold, head disease, fever, skin disease, diabetes, stroke, ophthalmic disease, jaundice, ENT disease and dental disease. The Gypsum is used for nature of disease which of cold, heat(fever), summer heat, phlegm, malfunction of liver, malfunction of liver and kidney, heat of stomach, malfunction of spleen and fever of stomach. The clinical dosage of Gypsum has ranged at a wide variety of amount from 1.6g to 16g per dose with 4g ${\sim}$ 8g being the typical dose for most treatment. The Gypsum is applied as a fundamental prescription with several herb remedies for the pathology.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.87-90
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• 2004

In this paper, net-shape forming of an automobile gear is investigated. Barrel, a component of automobile start motor, is adopted as a net-shape forming. In order to accomplish the goal of net-shape forming without cutting of tooth and cam after forming, forming ability is raised through billet treatment and die design. As a technique of billet treatment spheroidizing annealing of billet to get low hardness and molybdenum disulphide coating to get low contact friction between billet and die is carried out. One of critical points of die design, fillet radii variation of tooth of die is applied to get smooth surface of barrel after cold forging. As a measurement of tooth accuracy, distance between two pins and lead-tooth alignments are investigated. Cam profile accuracy is checked with a 3D measuring instrument. Results obtained from the tests revealed reasonable result with respect to design goal. By these results, the paper shows that reasonable results can be obtained by billet treatment and die design for net-shape forming.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 The 8th Asian Symposium on Precision Forging ASPF
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• pp.73-79
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• 2003

Recently many kinds of gears have been produced by forging in order to enhance the mechanical properties of the gears and the productivity of the process. Developments in forging technology are the reason for the increased usage. However, a critical problem of the forged gears is the dimensional change or distortion caused by elastic recovery after forging, and relief of the residual stresses during subsequent heat treatments. Distortion is of great concern to the manufacturers of precision parts, because it influences directly the dimensional accuracy and the grade of carburized bevel gears. In the present paper, distortion due to cold forging and heat treatment of bevel gears is investigated. Distortions of forged gears, machined gears and die are measured and compared. Numerical analysis is used to simulate the complete cold forging process and heat treatment process for the machined gears and shows good agreement with the experimental measurements.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.125-126
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• 2006

The characteristics of the tool system give many effects into the costs and qualities for the finished components. Therefore, a tool life is one of the important issues on cold forging industry. However, since variables related with tool life are many complicated, the studies for solution should be investigated by the systematic research approach. In this study, heat-treatment of tool material is investigated to improve the tool life. Deep cryogenic treatment of tool steel is very efficient to improve the wear resistance due to the fine carbide. And, it is investigated that the shape and dimension of tool give effect into both tool life and quality of forged product.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.102-105
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• 2008

To investigate the evolution of deformation texture during cold rolling deformation, cold rolling process on a commercial Al-5% Mg sheet was carried out at different rolling reduction ratio. The evolution of annealing texture in cold-rolled Al-5% Mg sheet was also investigated. The evolution of recrystallization texture during annealing process strongly depends on the rolling reduction ratio before heat treatment. Visco-plastic self-consistent (VPSC) polycrystal model was used to predict r-value anisotropy of the cold-rolled and annealed Al-5% Mg sheets. The change of volume fraction for the major texture components was also analyzed.

• 대한기계학회논문집A
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• 제26권8호
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• pp.1615-1622
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• 2002

The purpose of this study is comparing cold expansion method with interference fit. Cold expansion method and interference fit of fastener hole is using in the aerospace industry. These treatment lead to an improvement of fatigue life to the compressive residual stresses developed on the hole surface. But Research is nothing to about difference effect of between cold expansion method and interference fit. So, this paper, it is shown that Comparing cold expansion method with interference fit using the finite element method. It is further shown that residual stress distribution according to plate thickness and clamping force.