• Current Industrial and Technological Trends in Aerospace
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• v.5 no.1
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• pp.104-111
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• 2007

내충돌성(crashworthiness)은 항공기 추락시 탑승객을 보호할 수 있는 항공기와 그 내부 시스템 및 구성품의 성능으로 정의할 수 있다. 민간 항공 분야에서 내충돌성에 대한 체계적인 연구가 시작된 것은 1980년대로서 90년대에 이르러서야 감항 기준으로서 완성되게 된다. 항공기의 안전성과 관련된 주요 설계 요건들이 이미 50-60년대에 기본적인 틀을 갖추었다는 점을 감안하면 내충돌성과 관련된 설계 요구조건은 상대적으로 새로 운 설계 개념으로 생각할 수 있다. 본 논문에서는 회전익 항공기를 중심으로 내충돌성 확보를 위해 고려해야 할 사항을 살펴보고, 현재 민간 회전익 항공기에 적용되고 있는 주요한 내충돌성 설계기준을 소개하도록 한다.

• Journal of radiological science and technology
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• v.33 no.1
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• pp.19-24
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• 2010

The aim of this study was to evaluate the change of bone mineral density according to distal radius rotation and the correlations of the lowest BMD measured by DXA at the lumba versus distal radius. The eleven males were projected distal radius by DR X-ray and the measurement of BMD by DXA of the appropriate position of the forearm were performed on 21 males. The healthy 11 and 21 volunteers without any history of operations, anomalies, or trauma were enrolled. The experiment was performed by two methods. First, The DR X-ray was measured distal radius of 11 males in pronation and supination with three, six and nine degrees, including a neutral position. The ROI was measured by the m-view program on the PACS monitor. Second, The DXA was measured distal radius of 21 males in pronation and supination with five and ten degrees, including a neutral position to evaluate the changes of BMD according to the rotation. A correlation of the BMD in the distal radius with BMD that lumbar spine was performed, along with analysis of the data by SPSS 12.0v. The mean rotation angle of the distal radius about eleven males DR X-ray measured $7^{\circ}$ of pronation (82%, n = 9), $6^{\circ}$ of supination and $0^{\circ}$ of neutral of (9%, n = 1), The total average rotation angle in 11 male was $5.1^{\circ}$ of pronation. The rotation angle of the distal radius about twenty one males on DXA measured $7.2^{\circ}$ of pronation (43%, n = 9), $7^{\circ}$ of supination (24%, n = 5), and $0^{\circ}$ of neutral (33%, n = 7), The total average rotation angle in 21 people was $4.1^{\circ}$ of pronation. The correlation of the analysis of lumba and distal radius were r = 3.0, p = 0.18. consequently, The correlation was not significance. Because BMD of lumba was not coverd for BMD of the distal radius, with a neutral position, Pronation is needed for BMD in the distal radius with the rotation angle measuring at the lowest BMD. the rotation angle about five degrees of pronation of the distal radius is recommended.

• Journal of the Korean Arthroscopy Society
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• v.8 no.2
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• pp.115-118
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• 2004

Purpose: The purpose of this study is to measure the internal and external rotation of shoulder and compare with normal volunteer and patients diagnosed as SLAP lesion. Materials and Methods: Thirty-eight cases (group 1) who had SLAP lesions at shoulder arthroscopy and fourty young volunteers(group 2) were analyzed retrogradely with medical record, intra-operative arthroscopic photo & video for SLAP lesions and the ROM of shoulder Under the interscalene anesthesia, the range of motion of internal rotation and external rotation were measured on flxed scapula and 90 degree abduction of shoulder, and the same method for group 2. We analyzed the results with two sample T-test and Wisconsin signed ranks test. Results: There was a significant difference between group 1 and group 2 for the ROM of shoulder. (IR; p<0.001,ER; p<0.001).For the group 1, internal and external rotation with the arm abducted 90 averaged 50 and 64 degrees and for the group 2, internal and external rotation averaged 77 and 90 degrees with significant difference(IR; p<0.001,ER; p<0.001).Conclusion: The range of motion of shoulder, especially internal and external rotation significantly decreased in SLAP lesions. Our results suggest that a limited rotational motion of shoulder closely related with SLAP lesion.

• Journal of Korean Orthopaedic Sports Medicine
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• v.12 no.1
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• pp.29-36
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• 2013

Purpose: Proprioceptive function has been known to be important to shoulder stability. However, the function in rotator cuff tear patients is rarely investigated. The purpose of current study is to report the proprioceptive function in rotator cuff tear patients and to analyze the proprioceptive function regarding the tear size and the presence of subscapularis tear. Materials and Methods: Between 2011 and 2012, total 76 patients (male 28 and female 48) were recruited and average age was 61.7 years old (range, 38~76). Preoperatively, joint position senses in internal and external rotation were measured for proprioceptive function testing by method of active re-positioning technique. The absolute difference from set point was measured. Proprioceptive function was further analyzed according to tear size of rotator cuff, the presence of subscapularis tear, visual analogue scale of pain, shoulder functional score (American society of elbow and shoulder score), and ranges of motion in shoulder. Results: The absolute difference for external rotation was $4.9^{\circ}{\pm}2.9^{\circ}$, in normal joint and $4.9^{\circ}{\pm}3.0^{\circ}$for involved joint in rotator cuff tear patients. This difference was not significant statistically (p=0.87). The absolute difference for internal rotation was $4.0^{\circ}{\pm}2.7^{\circ}$in normal joint whereas $4.8^{\circ}{\pm}3.7^{\circ}$ for involved joint showing statistically significant difference (p=0.043). There was some trend that the proprioceptive function of internal rotation was more impaired in the bigger tear size group (more than medium tear) compared to the smaller tear size group (partial thickness and small tear, 5.0 vs. 4.0, p=0.061). The impairment of internal rotation proprioception was also accentuated in patients with subscapularis tear (4.8 vs. 4.0, p=0.065). The proprioceptive function of internal rotation was decreased when the pain visual analogue scale was increased (5.2 vs. 4.0 p=0.04), shoulder functional score was decreased (6.1 vs. 4.2, p=0.005), or range of motion in shoulder joint was restricted (5.3 vs. 3.7, p=0.041). Conclusion: The deficit of proprioceptive function was observed in rotator cuff tear patients. Proprioception for internal rotation was impaired in patients with the bigger tear size and subscapularis tear. Pain, shoulder function score, and range of motion were also shown to be related with the deficit in proprioceptive function.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.601-603
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• 2002

MRI 스캔중 촬상 대상물의 화강평면내에서의 회전은 MRI 신호에 위상오차와 불균일 표본화를 일으킨다. 따라서, 아티팩트가 포함된 MR 화상의 화질열화를 개선하기 위하여 다음과 같은 방법들을 제안한다. 우선, 미리 주어진 회전파라메타써 쌍일처 보간과 중첩 특성을 이용해서 k 공간 불균일 표본화 데이터를 수정하는 알고리즘과, 2차원 회전운동의 회전각은 이미 알려져 있고, 회전중심 위치가 미지인 경우에 대해 위상보정에 기초한 아티팩트를 보정하는 알고리즘 및 회전중심과 각도가 모두 미지인 2차원 회전운동에 대해 아티팩느를 보정하는 알고리즘을 제안한다. 이 때, 미지운동 파라메타를 예측하기 위해 찰상대상물의 경계바깥쪽에서 이상적인 MR 화상의 에너지는 최소가 되고, 활상 대상물의 회전이 존재할 때 측정된 에너지가 증가한다는 성질을 이용했다. 이러만 성질을 이용해서 시뮬레이션 화상에 적용한 결과 제안한 방법에 대한 유효성을 확인하였다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2005.11a
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• pp.155-158
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• 2005

MRI 스캔시 화상평면내에서 촬상대상물체의 회전은 MRI 신호에 위상오차와 불균일 표본화를 일으킨다. MRI 신호의 위상오차와 불균일 표본화에 대한 문제의 모델은 화상평면내 임의 중심과 원점에 관한 회전운동에 의해 열화된 MRI 신호들사이에 위상차가 존재함을 나타낸다. 이에 아티팩트가 포함된 MR 화상의 화질을 개선하기위해서 다음과 같은 방법을 제안한다. 우선, 2차원 회전운동의 회전각은 이미 알려져 있고, 회전중심의 위치가 미지인 경우에 대해 위상보정에 기초한 아티팩트를 보정하는 알고리즘과, 다음으로, 회전중심과 각도가 모두 미지인 2차원 회전운동에 대해 아티팩트를 보정하는 알고리즘을 제안한다. 이때, 미지 운동 파라메타를 예측하기위해 촬상대상물체의 경계바깥쪽에서 이상적인 MR 화상의 에너지는 최소가 되고, 촬상대상물체의 회전이 존재할 때 측정된 에너지는 증가한다는 성질을 이용한다. 이러한 성질을 이용해서 각 위상부호화 단계에서 미지의 회전각 크기를 추정하기위한 평가함수가 도입된다. 최종적으로 시뮬레이션 화상 및 실제화상에 적용해서 제안한 본 방법의 유효성을 확인한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.839-842
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• 2005

본 논문은 스테레오 카메라를 통해 얻은 변이 정보를 이용하여, 3 차원으로 머리의 회전 각도를 추정하는 방법을 제안한다. 머리 회전에 의한 주시 방향은 사람이 관심을 가지는 방향이므로 이동을 추정하는 것에 비해 많은 중요성을 갖는다. 본 논문에서는 얼굴 영역 내의 여러 특징점들 중 3 개의 특징점들을 포함하는 여러 평면(Plane)이 머리가 이동하더라도, 그 평면들 사이의 각은 변하지 않으므로, 회전 각도 추정에 영향을 주지 않는 점을 이용하여 회전 각도를 추정하였다. 또한, 기존 논문이 카메라 보정을 통해 3 차원 위치를 측정하지만, 제안하는 방법은 변이 공간에서 회전 각도를 추정하기 때문에 카메라 보정 과정이 필요하지 않다. 변이 정보를 얻기 위한 스테레오 장비는 평행 카메라 모델로 가정하며, 얼굴 내의 특징점은 KLT(Kanade-Lucas-Tomasi) 특징 추적 알고리즘을 이용하였다. 실험결과는 기준 영상에 대하여 추정된 3 차원 각도를 나타낸다.

• Clinics in Shoulder and Elbow
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• v.15 no.2
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• pp.86-90
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• 2012

Purpose: We studied the need for distal clavicle resection by comparing rotator cuff tear patients who underwent non-surgical treatment with and without acromioclavicular joint pathology. Materials and Methods: 45 cases that had been under follow up care for at least 9 months after receiving rotator cuff repair in our hospital between Jan. 2005 and Jun. 2011 had been studied. Acromioclavicular joint pathology group and control group were classified by physical examination and MRI findings. The temporal changes in shoulder joint abduction, internal and external rotation strength, ASES and KSS score of the two groups were measured and analyzed. Results: The acromioclavicular joint pathology complicated rotator cuff injury group's strength measurements for abduction, internal rotation, external rotation were each 8.05 (${\pm}4.54$), 11.33 (${\pm}6.05$), 10.24 (${\pm}5.27$) preoperatively and improved to 13.26 (${\pm}5.50$), 17.51 (${\pm}6.80$), 15.60 (${\pm}5.37$) post operatively while the KSS score and ASES score were each 49.07 (${\pm}15.28$) and 48.65 (${\pm}13.27$) preoperatively, improving to 84.48 (${\pm}10.96$) and 84.65. (${\pm}9.86$). The measurements for the group without complicating acromioclavicular pathology are as follows. The strength for abduction, internal rotation, external rotation was each 6.42 (${\pm}3.11$), 7.59 (${\pm}4.81$) and 7.93 (${\pm}4.49$) preoperatively, improving to 15.85 (${\pm}7.35$), 19.18 (${\pm}9.14$), 16.95 (${\pm}5.70$) post operatively, while the KSS score and ASES score each went from 42.12 (${\pm}6.43$) and 41.37 (${\pm}7.42$) to 83.44 (${\pm}6.30$) and 83.17 (${\pm}7.01$) respectively. The measurements for the two groups, however, did not show a statistically significant difference (p>0.05). Conclusion: Analysis of the rotator cuff injury groups with and without AC joint pathology showed that both groups had improved strength, ASES and KSS scores with no statistical difference difference among the groups. As such, it thought that conservative treatment is an acceptable alternative to distal clavicle resection.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.2 no.2
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• pp.62-67
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• 2009

Purpose: The purpose of this study is to find out the accuracy and usability of the three dimensional ultrasonography in measuring the size of the rotator cuff tear, especially before and after the injection of normal saline into the glenohumeral joint. Materials and Methods: 14 patients of rotator cuff tear who were diagnosed and operated from August 2007 to September 2008 were included in this study and authors compared the size of rotator cuff tear measured with three dimensional ultrasonography with the real size measured intraoperatively. In preoperative ultrasonographic evaluation, horizontal and longitudinal length of rotator cuff tear before and after injection of normal saline intraarticularly. During the arthroscopic operation the size of tear was measured by passing a Kirschner wire through a spinal needle and direct measure was performed in open surgery. Results: The average difference was 8 mm in horizontal and 1.9 mm in longitudinal length of tear without saline injection between ultrasonographic and intraoperative measure. The average difference was 4.1 mm in horizontal and 1.6 mm in longitudinal length of tear after the normal saline injection. Conclusion: In three dimensional ultrasonographic evaluation in rotator cuff tear, intraarticular normal saline injection would produce more accurate results.

• Clinics in Shoulder and Elbow
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• v.11 no.1
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• pp.53-56
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• 2008

Periarticular cysts in the shoulder joint are relatively rare. The most common are paralabral cysts, which can cause suprascapular nerve entrapment syndrome. Acromioclavicular juxtaarticular cysts have been described in association with full-thickness rotator cuff tears and a degenerated acromioclavicular joint. Intramuscular cysts of the rotator cuff are a relatively rare and unknown type of periarticular cyst. We report a case of an intramuscular cyst of the rotator cuff that was associated with a tear of the rotator cuff.