• 구강회복응용과학지
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• 제30권3호
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• pp.206-214
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• 2014

목적: 내부 원추형 연결형태 임플란트에서 지대주 나사의 좌면각도가 연결부의 기계적 안정성에 미치는 영향을 알아보기 위함이다. 연구 재료 및 방법: 원추형 연결구조 티타늄 임플란트와 시멘트 유지형 지대주, 텅스텐 카바이드 코팅된 티타늄 합금 지대주 나사를 사용하였다. 좌면각도가 $45^{\circ}$와 $90^{\circ}$를 갖는 지대주와 지대주 나사를 제작하여 30 Ncm 조임회전력으로 지대주를 체결한 후 하중을 가하고 체결 및 하중 부여에 따른 침하량을 측정하였다(n = 5). 유압식 피로시험기에 임플란트를 고정하고 스테인리스 스틸 금속관을 지대주에 합착하였다. 이 후 반복 하중을 가한 후 풀림토크 변화량을 측정하고, 압축굽힘강도와 피로강도를 측정하였다(n = 5). 결과: 지대주 침하량은 지대주나사 체결 시 가장 크게 나타났으며(P < 0.05), 나사체결과 하중부여에 따른 총 침하량은 $45^{\circ}$군보다 $90^{\circ}$군에서 더 크게 측정되었다(P < 0.05). 반복하중 부여 후 풀림 토크, 그리고 최대 압축굽힘강도와 피로강도는 통계적으로 유의한 차이를 보이지 않았다(P > 0.05). 결론: 본 실험조건하에서 지대주 나사머리의 원추형 설계가 지대주의 총 침하량을 약간 감소시키는 효과를 나타냈으나, 연결부의 전체적인 기계적 안정성에 미치는 영향은 크지 않을 것으로 판단된다.

• Composites Research
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• 제13권4호
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• pp.42-53
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• 2000

차세대 항공기소재로 관심을 가지고 있는 Al 7075/CFRP 적층 복합재인 CARALL(CARbon ALuminum Laminates)하이브리드 복합소재 제조를 위한 중요조건중의 하나인 Al 표면처리조건과 경화방법에 대해 조사하였다. 항공기용 Al 전처리 중 대표적인 것으로 증기탈지, 크롬산 양극산화 피막처리, 황산-중크롬산 나트륨 에칭처리 및 인산 양극산화 피막처리공정이 있다. 본 실험에서는 상기 전처리 공정을 모두 항공 규격에 준해서 실시하여 Lap shear 및 Bell peel strength를 비교함으로써 효과적인 접착강도를 나타내는 표면처리 공정을 찾아내고, 시편의 자연표면상태를 그대로 관찰할 수 있는 AFM(Atomic Force Microscope)장비를 이용하여 각 전처리 시편의 표면형상을 측정함으로써 표면형상과 접착강도와의 상관관계를 고찰 하였다. 그리고 Al 표면처리와 별도로 Al과 접착제 및 탄소섬유 프리프레그를 동시에 경화시키는 방법과 탄소섬유 프리프레그를 미리 경화시킨후 다시 Al과 탄소섬유 라미네이트를 접착필름을 이용하여 재 접착시키는 이차 경화법을 적용하여 상호 접착강도 및 물성을 비교하였다. 또한 이차경화법에서의 오토클레이브 압력 변화와 DMA(Dynamic Mechanical Analysis) 장비를 이용한 접착필름의 유리전이온도($T_g$) 측정을 통해 효과적인 공정압력 및 접착내구성 유지에 필요한 최소 경화시간을 파악하였다. 상기 결과로부터 정밀 치수관리가 필요하며 고접착강도, 내구성 항공기 부품을 제작하기 위한 알루미늄 표면처리 공정과 복합재 경화공정 조건을 제시하고자 하였다.

• 한방안이비인후피부과학회지
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• 제13권2호
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• pp.20-50
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• 2000

This paper was written into condsideration records about the definition of "Ong-Jeo", the difference between "Ong" and "Jeo", the Western medical approach to "Ong-Jeo", and the etiology and pathologic mechanism of "Ong-Jeo". After this study, I report the following results from it. 1. "Ong" is an acute diapyesis disease which is found is in our skin and muscle and flesh. The chrateristics of this disease is that the affacted site is shine, no head, and the size is 3-4 chon. The prossess of the diesease shows that it is very quick, and very easily swell, and becomes pus easily, easily become to ulcer, easily converge. But this don't damage to the muscle and bone. 2. "Jeo" is the disease which damages bone-skeleton, muscle and flesh, and even destroy the stationary tissue. Jeo can be divided into two. One is called "Yudujeo" and it is acute diapydesis disease. The characteriscs of this disease is the miliary abscess, swell, has fever, and has an ache which is feeled spaned. And this is diffused into periphrey tissue and is diffused into deep site. After the ulcer, this becomes to shape the cellula. The size is more than 3-4 chon and this disease goes into chuk if this is serious. The other one is called "Mudujeo" and this disease is the ulcerative one in our joint and skeleton. The characteristic of this disease shows that the color of skin be not changed, and swell diffusely, and is not easily vanished, not easily becomes ulcerative, and not easily becomes converged. 3. "Ong-Jeo" is caused by the bacteriunm named by the "Golden and Yeollw Staphylococcus" in the Western medicine. "Ong" can be applicable to the carbuncle, acute diapyesis lymphadenitis, and some of cellulitis. "Jeo" can belong to cellulitis, and Mudujeo can belong to suppurative arthritis, suppurative osteomyelitis, tuberculous arthritis and osteomyelitis, and tuberculous lymphadenitis. 4. The etiologies of "Ong-Jeo" can be divided three, which are internal, external and other etiology which can not be clasiffied by two etiologies above. The internal etiology is seven emotion, and the external etiology is the six eumsa, unki, chunhang and so on. Other etiology is inadequate absorption of food, and excessive bang-sa. 5. The etiology of "Ong" is suppurative one which is choked between our skin and muscle and flesh, and is congested, become to hot, and finally erodes the muscle and flesh because of the inbalance of cirrculation in the enegy and blood. "Jeo" is the same as the Ong, but this is the suppurative disease which damages the muscle, flesh, and skeleton, and even damages into five Zang, the internal intestine.

• Journal of Welding and Joining
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• 제30권2호
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• pp.59-64
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• 2012

Welding is an essential process in the automotive industry. Most welding processes that are used for auto body are spot welding and $CO_2$ welding are used in a small part. In production field, $CO_2$ welding process is decreased and spot welding process is increased due to welding quality is poor and defects are occurred in $CO_2$ welding process frequently. But $CO_2$ welding process should be used at robot interference parts and closed parts where spot welding couldn't. Because of the 0.65mm ~ 2.0mm thickness steel sheet were used in the automotive industry, poor quality of welding area such as burn through and under fill were happened frequently in $CO_2$ process. In this paper, we will study about the penetration depth which gives a huge impact on burn through changing a degree of base metal, welding position and torch angle. Voltage, current and welding speed were fixed but degree of base metal, welding position and torch angle were changed. And Cold- Rolled(CR) steel sheet was used. Penetration depth was analysed by multiple regression analysis to derive approximate calculations. And reliability of approximate calculations were confirmed through additional experiments. As the results of this research, we confirmed the effect of torch and plate angle to bead shape. And we present a possibility that can simulate more accurate to weld geometry, as deduced the verification equations that has tolerance of less than 21.69%.

• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.172-182
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• 2002

Objectives: We did research in the cause of the Pitchers' injury and their recovery process to make a detailed injury list for the purpose of finding the cause of the Korean professional pitchers' injury and its classification. We drew the conclusion through the results as following. Methods: We posed a question to the 80 pitchers playing in the first team of the eight Korean professional baseball team and analyzed the 62 pieces of question paper except the paper having a mistake. We used SAS/PC statistical package in analyzing the data. Results: In the frequency of the pitchers' shoulder injury in the last three years, the injured of all the players were 61.3$\%$ and the injury free players were 28.7$\%$. The cause of the injury was 45.2$\%$ wrong pitching motion, which was the highest value. For the shape of a pain when injured, the reverberation ache feeling when he is hit in the weight commanded an absolute majority as 19.4$\%$. Those who had muscular pain were 17.7$\%$, which was felt mostly at the pitching motion. The most trouble name of the injured shoulder was bicepstendinitis as 16.1$\%$ while the injury of shoulder joint was the lowest as 1.6$\%$. As the most widely used treatment, 25.8 percent of all the players had taken an electronical thraphy after injury. 14.5 percent of the players who had an injury to the shoulder told that they have an operation and 85 percent of them didn't. As a sort of the operation, a repairing of labrum was 44.4 percent, which is the highest value and the 77.8 percent pitchers are performing a normal pitching through rehabilitation after the operation and 22.2 percent of them are undergoing rehabilitation training. Conclusion: The research have shown that the main cause of the injury, concerning the Korean professional pitchers throwing lots of ball in both matches and practices, is overuse syndrome, bad mechanism, muscle weakness and instability of balance. I think that the role of trainer, physical therapy, and team physician taking charge of the players' injury must learn physical test method by heart exactly to check up the state of the injury definitely at the initial phase. Moreover, when the cause of the injury part after a close examination is discovered, the scientific and good surgery is essential to the rehabilitation success and making a classification of shoulder instability is useful to make a operation plan as well as the players' rehabilitation, treatment.

• 대한정형외과스포츠의학회지
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• 제8권1호
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• pp.33-38
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• 2009

목적: 중년 이후에서 흔히 일어나는 내측 반월상 연골판 후각 부착 부에 발생하는 방사상 파열의 임상적 특성과 관절경적 소견을 문헌 고찰과 함께 보고하고자 한다. 대상 및 방법: 2005년 1월부터 2007년 4월까지 본원 정형외과에 내원하여 슬관절 내시경 수술을 시행 받은 환자 중 관절경상 내측 반월상 연골판 후각 부착 부 파열이 관찰되었던 환자 40명, 40례에 대해 의무 기록을 통한 후향적인 검사를 시행하였다. 남자 7명, 여자 33명이고, 평균 연령61(47~80)세이며, 외상 병력의 유무, 동반된 관절염의 등급 및 통증 발생 후부터 수술까지의 기간(유병기간), 자기공명영상 소견, 임상 증상 및 파열단의 모양과 치료법 등을 검토하였다. 결과: 외상 병력이 있었던 경우가 6례며, 34례는 외상 병력이 없었다. 단순 방사선 사진상 Kellgren-Lawrence 분류는 0-II형이 31례, III형은 9례 였으며, 관절경상 대퇴골 내과의 관절 연골 상태는 Outerbridge grade IV 형이 17례, III 형이 4례, II 형이 9례, I 형이 9례이었다. 유병기간은 평균 5.3개월이었으며, MRI 소견으로는 전례에서 축상면 또는 관상면에서 틈(cleft)나 시상면에서 유령 징후(ghost sign) 중 1개 이상이 관찰되었다. 파열단의 모양은 18례가 뭉툭한 형태, 12례가 수평 파열, 10례가 퇴행성 파열이었으며 수술법으로는 연골판 아전 절제술을 16례, 부분 절제술을 10례, 봉합술을 14례에서 시행하였다. 결론: 중년 이후의 연령에서 반월상 연골판 후각 부착부 파열은 외상 병력이 드물게 발생하며 심한 기계적 증상을 호소하며, 관절염을 동반하는 경우가 많다. 치료로 절제술 뿐만 아니라 봉합술을 시도해 볼만한 파열이 있었으며, 추후 그 치료 결과에 대한 연구가 필요하다.