• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.171-177
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• 2000

It is essential to understand the creep behavior, which shows how long the characteristics of material maintains because press joined molding GMT-Sheet for recycle is usually used in the severe environment. In this study, we predict joining strength of GMT-Sheet for recycle, when lap length was changed. and we will investigate how compression ratio have an effect on creep behavior in press joined molding. The result of experiment of forming condition concerned with joining problem of GMT-Sheet is as followings joining efficiency. of GMT-Sheet, increases as lap joint length I, increases. Increase of compression ratio causes decrease o f joining efficiency after of GMT-Sheet joining. As the result of creep test, GMT-Sheet is easily damaged in high temperature range, because it is sensitive to the temperature

• The Journal of Korean Medicine
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• v.15 no.2 s.28
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• pp.373-396
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• 1994

The studies look at the causes, pathology, symptom, diagnosis, treatment of rheumatoid arthritis in the sight of east-western medicine. Following are the results : 1. Rheumatoid arthritis korean-medically belongs to symptom such as Bi(痺), Poung Bi(風痺), Tong Poung(痛風), Youk Jeol Poung(歷節風), Bak Hoe Poung(白虎風), Bak Hoe Youk Jeol Poung(白虎歷節風), etc. 2. The causes of Rheumatoid arthritis are endopathic and exopathic : endopathically it tis related to Chil Jeong(七情) and visceral imbalance, and exopathically it is related to Euk Eum (六淫) and environmental factors. 3. To figure out rheumatoid arthritis, we need to diagnose first the joint symptom and the general body condition, we need about 6 weeks to get the exact decision after the serologic test, the immune and inheritance test, the synovium test. 4. There are four kinds of treatments for rheumatoid arthritis : medicin, acupucture and moxibustion, suction cup and purging away the blood, physical therapy. Cheong Eol So Bi(淸熱消痺) can be used for the acute stage and Jang Bu Seong Shai(臟腑盛衰) is to be considered for the chronic stage. 5. Rheumatoid arthritis should be constantly treated to prevent the patient from the deformity of joint complication.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.14
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• pp.323-348
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• 2000

Facing the current difficulties of fisheries industry nationally and internationally, economic cooperations between South and North Korea are needed urgently. Applying the process of economic integration to fisheries sector of separated nation, cooperation processes are divided as follows; (1) indirect and direct fisheries trade, (2) reciprocal use of fishing grounds, (3) joint venture in fisheries sector, (4) free movement of production factors and common fisheries policy. Here, fisheries trade falls under economic interchange stage. Reciprocal use of fishing ground and fisheries joint venture come in economic cooperation stage. Finally. free factor movement and common fisheries policy are related with economic integration stage. This paper investigates the schemes for fisheries cooperation between South and North Korea in preparation for a unified Korea, focusing on fisheries trade. The paper is composed of 5 chapters. Chapter 2 discusses structure and characteristics of North Korea trade, and trade situation between South and North Korea. Then, the present condition of North Korea fisheries industry and fisheries trade trend between South and North Korea are presented in chapter 3. Next, chapter 4 tackles the most common problems encountered in fisheries trade between South and North Korea, and the devices and schemes to raise fisheries trade between South and North Korea. Finally, chapter 5 summarizes and concludes the research results.

• Journal of Korean Foot and Ankle Society
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• v.17 no.1
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• pp.64-67
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• 2013

Pigmented villonodular synovitis (PVNS) is a slowly, progressive, proliferative disorder of synovial tissue characterized by villous or nodular changes of synovial-lined joints, bursae, and tendon sheaths and most frequently affects the large joints, with the knee and hip. A few studies have been reported that occurred PVNS in small joint, but mainly in hands. It is a very rare condition that occurs in the small joints of the forefoot. We have experienced the case, which developed in small joint of the forefoot, and performed total synovectomy. After the operation, there was no recurrence. We report a case of PVNS in forefoot with a review of the literature.

• Journal of Power System Engineering
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• v.7 no.3
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• pp.74-79
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• 2003

Alumina($Al_2O_3$) and Al 6061 were brazed by using Al-12wt% Si filler metal in a high vacuum environment. The interfacial microstructure and mechanical properties of the joints were investigated. The results obtained were as follows. (1) The maximum tensile strength of 54Mpa was acquired at the processing conditions of high vacuum ($3{\times}10^{-6}Torr$), $620^{\circ}C$ and 10min, but this condition will not be used in the industrial area due to high evaporation of Al alloy composition. (2) Reaction products for holding time and brazing temperature worked as stress relieve layer and the fractures after the mechanical properties test were occurred to the ceramic side or reaction layer. (3) The glancing angle X-ray diffraction analysis for the reaction product of $Al_2O_3/Al$ 6061 were processed. the joint strengths were low due to existed $Al_2Si_5\;and\;SiO_2$.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.2
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• pp.187-192
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• 2011

UBM(Under Bump Metallurgy) is very important for successful realization of Flip-Chip technology. In this study, it is investigated the interfacial reactions between various Sn-Ag solder alloys and Ni-P/Au UBM and Cu plate finish. It is also evaluated the shear strength by using the micro shear-punch test method for Sn-37Pb alloy, binary and ternary alloys of environment-friendly Pb-free solder alloys which are applied in the electronic packages. In terms of interfacial microstructure, the Pb-free solder joints have thicker IMCs than the Sn-Pb solder joints. The thickness of IMC is related to Reflow time. The IMC has been observed to grow with the increase in Reflow time. As a result of the shear test, in case of Max. shear strength, Pb-free solder showed the highest strength value and Sn-37Pb showed the lowest strength value 10 be generally condition of Reflow time.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.5
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• pp.329-337
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• 2016

The demand for the eco-friendly vehicles is skyrocketing because of the increasing $CO_2$ emissions and global warming. In the industrial field, the battery process, a core part of an eco-friendly vehicle, is drawing increased attention; its weight lightening as well as high energy density are becoming increasingly important. In this study, pure Ni plates that were used as the battery pole plate were welded using the laser. The lab joint welding was conducted on ten pure Ni plates at a laser power of 1900 W and a feed speed of 2.8-3.4 m/min. As observed in the experiment, a faster feed speed reduced the bead width, but the laser did not penetrate all ten specimen plates. In addition, pores were trapped when protective gas was used, but they were not trapped when the welding was conducted in atmospheric condition.

• Archives of Reconstructive Microsurgery
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• v.17 no.1
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• pp.7-13
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• 2008

Popliteal artery injury in blunt trauma of knee joint is not common but poses high rate of amputation due to anatomical characteristics or delayed diagnosis and treatment. The aim of the present study is to review the authors' experiences with this condition and identify factors contributing to disability. We reviewed 7 cases of popliteal artery injury in trauma around knee. Injury mechanism, type of vessel damage, associated injuries, mangled extremity severity scores (MESS), ischemic time and additional treatments were analyzed. Tibial fracture, distal femoral fracture and serious soft tissue defect were combined. Mean MESS was 9.9 point and mean time of revascularization was 7.1 hours. Transfemoral amputation was performed in 2 cases due to vascular insufficiency and devastating infection, and 4 patients were able to walk without any support at the last follow up. Age, the severity of soft tissue injury, ischemic time and MESS are thought to be related to prognosis, and young patients with short ischemic time show best results, but authors experienced one exceptional case. We have to consider multiple factors related to the prognosis in popliteal artery injury with fractures around knee, and careful decision is needed regarding to early amputation.

• Transactions of Materials Processing
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• v.19 no.5
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• pp.277-282
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• 2010

Magnesium alloy has been known as lightweight material in automobile and electronic industry with aluminum alloy, titanium alloy and plastic material. Friction welding is useful to join various metals and nonferrous metals that are difficult to join by such as gas welding, resistance welding and electronic beam welding. In this study, friction joining was performed to investigate mechanical properties of Mg alloy with 20mm diameter solid bar. Also the optimal joining conditions for its application were determined on the basis of tensile test, and hardness survey. The joining parameters were chosen as heating pressure, heating time, upsetting pressure, and upsetting time. Heating and upsetting pressure were executed under the range of 10~40MPa and 20~80MPa, respectively. From the experimental results, optimal joining conditions were determined as follows; rotating speed=2000rpm, heating pressure=35MPa, upsetting pressure=70MPa, heating time=1sec, upsetting time=5sec. Also the hardness of jointed boundary showed as HV50 which was similar to that of base metal at the optimal condition, and it was supposed that zone of HAZ was 8mm. Finally two materials were strongly mixed at interface part to show a well-combined microstructure without particle growth or any defect.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.82-84
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• 2005

Fatigue assessment of welded structure is very sensitive to the method of local stress determination. Normally, hot spot stress which is surface stress extracted from 0.5t, 1.5t away from weld toe is widely used to obtain local stress. However, this method has a lot of limitation in the evaluation of fatigue strength. Therefore, mesh has to comply with strict requirements since stress extracted from this method strongly rely on mesh size and element types. And that method does not cover the stress gradient through thickness direction since only surface stress is considered. Recently, new method to obtain local stress is proposed, which is structural stress. This method has an advantage, which is mesh intransitiveness and covering the effect of both bending and axial stress in local area. In this paper, fatigue test data for various welded joints was analyzed to review the reliability of structural stress. As a result, it is verified that S-N curve using structural stress guaranteed single master curve for various joint type and testing condition.