• Smart Structures and Systems
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• 제30권1호
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• pp.49-62
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• 2022

Experimental and discrete element methods were used to investigate the effects of triple joints lengths and triple joint angle on the failure behavior of rock mass under uniaxial compressive test. Concrete samples with dimension of 20 cm × 20 cm × 5 cm were prepared. Within the specimen, three imbedded joint were provided. The joint lengths were 2 cm, 4cm and 6 cm. In constant joint lengths, the angle between middle joint and other joints were 30°, 60°, 90°, 120° and 150°. Totally 15 different models were tested under compression test. The axial load rate on the model was 0.05 mm/min. Concurrent with experimental tests, the models containing triple joints, length and joint angle are similar to the experiments, were numerical by Particle flow code in two dimensions (PFC2D). Loading rate in numerical modelling was 0.05 mm/min. Tensile strength of material was 1 MPa. The results show that the failure behaviors of rock samples containing triple joints were governed by both of the angle and the length of the triple joints. The uniaxial compressive strengths (UCS) of the specimens were related to the fracture pattern and failure mechanism of the discontinuities. Furthermore, it was shown that the compressive behavior of discontinuities is related to the number of the induced tensile cracks which are increased by decreasing the joint length. Along with the damage failure of the samples, the acoustic emission (AE) activities are excited. There were only a few AE hits in the initial stage of loading, then AE hits rapidly grow before the applied stress reached its peak. In addition, every stress drop was accompanied by a large number of AE hits. Finally, the failure pattern and failure strength are similar in both methods i.e., the experimental testing and the numerical simulation methods.

• 한국운동역학회지
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• 제16권4호
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• pp.105-113
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• 2006

The purpose of this study was to analyze the joint torque of triple segmental system in golf driver swing. For this purpose, joint torque were calculated. In order to determine the load on the lumbar region, a triple segmental system was set for wrist, left shoulder and lumbar, torque working on the lumbar region were estimated. For this study, a total of 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular's equation was used to produce some kinematic data, which were used to calculate joint torque with Newton's function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint torque was generated in the direction opposite the target on wrist and shoulder during down swing, while in the direction towards the target on the lumbar region. During impact and release, the torque on the wrist joint was converted from the direction opposite the target to the direction towards the target, while the torque on the lumbar region was generated vice versa. The joints on the club-arm-shoulder were generated in the opposite direction at the beginning of down swing when the torque on the thorax-pelvis began to be generated, and then, the torque on the thorax-pelvis began to lower, while that on the club-arm-shoulder began to increase. Thus, a rapid decrease of the torque on the lumbar region linked to the low trunk acted to increase moment and joint torque on the arm-club region.

• 한국운동역학회지
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• 제15권2호
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• pp.57-67
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• 2005

The purpose of this study was to analyze the kinetic factors of the golf driver swing using the Inverse Dynamics function. For this purpose, joint force were calculated. In order to test the possibility of Inverse Dynamics function(motion-dependent interaction), a triple segmental system was set for wrist, left shoulder and lumbar and joint force working on the anatomical joint region was estimated. For this study, 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular's equation was used to produce some kinematic data, which were used to calculate joint force and torque with Newton's function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint force was generated on wrist, shoulder and lumbar joints in the direction of the target, and that the joint force was stronger in the direction of target immediately before impact. The joint force was generated towards the target to activate the nodes, and then, it was generated in the reverse direction to increase the speed during impact.

• 대한족부족관절학회지
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• 제1권1호
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• pp.38-42
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• 1997

It was well known that arthrodesis of the tarsal joint is an exellent procedure to correct the flatfoot deformity for relieving pain. Recently, concept of the selective tarsal joint fusion instead of the triple fusion was developedto preserve the joint motion. To investigate and compare the effect of the each different tarsal fusion, we measured the strain at the spring ligament, medial roof of the medial longitudianl arch. Five fresh frozen cadevar foot specimens, with distal half of the tibia were utilized. The superomedial portion of the spring ligament complex was dissected from the origin to the insertion. For each specimen, a calibrated open liquid metal strain guage was secured along the length of the superomedial portion. Under the specially devised test rig, measurement of the strain was taken at each test condition from the tare weight 18.2 lb followed by 38.2 lb., 82.2 lb and a maximum loads of 134.6 lb. : 1) unfused condition, 2) isolated subtalar fusion 3) isolated talonavicular fusion 4) combined subtalar and talonavicular fusion 5) triple fusion. Statistics showed that siginificant reduction in strain following the triple fusion, and from the subtalar fusion to triple fusion.

• 한국임상수의학회지
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• 제34권6호
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• pp.463-466
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• 2017

A 3-year-old, 26 kg, castrated male Chow Chow was presented for assessment of weight-bearing lameness of the left hind limb. The patient had a history of triple pelvic osteotomy on the left side to correct hip dysplasia 2 years prior to his presentation of clinical signs and underwent total hip replacement on the right coxofemoral joint 1 year later. Upon physical examination, pain and crepitus were noted on the left hip joint during extension. Radiological examination revealed coxofemoral joint subluxation and moderate degenerative bone changes on the left hip joint and pelvic axis, which relates to acetabular angles that were changed after triple pelvic osteotomy (TPO). Preoperative computed tomography was used for 3-dimensional printing to establish an accurate surgical plan. The changed angles of the acetabulum after TPO were evaluated, and rehearsal surgery was performed using a 3-demensional printing bone model. Three months after the THR surgery, the function of the affected limb had improved, with no lameness. Complications, such as luxation and implant failure, were not observed until 6 months after the operation. Accurate evaluation of acetabulum angles and rehearsal surgery using a 3D-printed bone model is effective for total hip replacement after unsuccessful TPO.

• 대한기계학회논문집 C: 기술과 교육
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• 제1권2호
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• pp.153-165
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• 2013

기존의 보행분석 연구들은 하지를 하나의 스프링으로 간주하였다. 만약 슬관절 신전을 보조할 수 있는 슬관절 액추에이팅 메커니즘을 개발할 수 있다면 보행에 필요한 탄성-변형률에너지를 혁신적으로 저장-방출할 수 있고, 그 결과 보행 중 하지강성은 더욱 증가할 것이다. 게다가 족관절 액추에이팅 메커니즘까지 추가되어 있다면 슬관절 액추에이터에 의한 과도한 인공하지강성을 능동적이고 적절한 수준으로 보상해주는 기전으로 작동할 것이다. 만약 가속도에 의한 보행속도 증가를 방지하기 위해 인위적 감속통제를 작동시킨다면 불필요한 운동에너지의 방출이 발생되고 하지강성 액추에이터의 실효성은 의심을 받게 된다. 따라서 본 저자는 보행속도를 2개의 세그먼트에 의한 상대 각속도 조절기법을 이용하여 하지강성을 증가시킨다는 기본개념으로 슬-족관절 액추에이터 시스템을 개발하였다. 또한 족관절에 슬관절 액추에이팅에 대한 보상기전이 존재하는 경우, 족관절의 보상기전이 중족지절관절 경사각 및 보행속도 변화에 미치는 상호영향을 연구하였다.

• 대한족부족관절학회지
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• 제6권2호
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• pp.156-160
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• 2002

Purpose: To analyze the clinical outcome of triple arthrodesis for the posttraumatic arthritis after calcaneal fractures. Materials and Methods: We retrospectively reviewed 22 posttraumatic arthritis patients who underwent a triple arthrodesis from March 1991 to May 1998. The mean duration of follow up was 74 months(range, 36-123 months). The pain, function and alignment were evaluated by the modified ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society(AOFAS) clinically and the union rate, the duration of union and the degenerative change of adjacent joints radiographically were evaluated. Results: The mean duration from injury to arthrodesis was 33 months (range, 12-132 months). The AOFAS score improved from 36.4 points(range, 14-64) preoperatively to 67.6(range, 25-90) postoperatively. The union rate was 90.1% radiographically, the mean duration of union was 14.3 weeks(range, 12-21 weeks) and the degenerative change in the adjacent joint was showed in 12 patients(54.5%). There were 2 cases of talonavicular nonunion, one superficial wound infection and one partial skin necrosis. Conclusion: Triple arthrodesis for posttraumatic arthritis after calcaneal fractures is a useful method for relief of pain and correction of posttraumatic hindfoot deformity, as an evidenced by the satisfactory clinical outcome. Although a high prevalence of subsequent arthritis of the ankle and midtarsal joint was noted radiographically, we found that it was not clinically relevant.

• Clinics in Shoulder and Elbow
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• 제12권1호
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• pp.80-83
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• 2009

목적: 삼중 관절와 순 병변(triple labral lesion)은 전방, 후방, 상방 관절와 순의 파열이 동시에 발생한 경우를 말한다. 문헌 보고가 드물어서, 수상 기전과 증상에 대하여 아직 정립되지는 않았다. 대상 및 방법: 본 저자들은, 교통 사고 후 우측 견관절의 동통과 능동적 외전 장애를 보인 39세 남자에서 삼중 관절와 순 병변을 경험하였다. 내원 시에 관절와 상완 관절의 불안정에 대한 증상을 호소하지는 않았다. 흡수성 봉합 나사못과 봉합 갈고리를 사용하여 관절와 순에 대한 봉합술을 시행하였다. 결과: 수술 후 18개월 추시에서, 능동적 운동범위는 정상으로 호전되었으며 일상 생활 중에는 어려움이 없었다.

• Journal of Contemporary Eastern Asia
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• 제13권1호
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• pp.19-37
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• 2014

In an attempt to develop comprehensive evidence-based methods for evaluation of the R&D performance of cross-disciplinary projects, a joint bibliometric analysis of patents and publications was performed for two industry-university-government collaborative projects aimed at commercialization: Hokkaido University Research & Business Park Project (2003-2007; 63 inventors; 176 patents; 853 papers), and Matching Program for Innovations in Future Drug Discovery and Medical Care - phase I (2006-2010; 46 inventors; 235 patents; 733 papers). Besides the simple output indicators (for five years period), and citations (from the publication date to the end of 2012), science maps based on the network analysis of words and co-authorship relations were generated to identify the prominent research themes and teams. Our joint analysis of publications and patents yields objective and mutually complementing information, which provides better insights on research and commercialization performance of the large-scale projects. Hence, such analysis has potential for use in the industry-university project's performance evaluation.

• 한국임상수의학회지
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• 제14권2호
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• pp.370-375
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• 1997

8개월령의 체중이 40.4kg인 로트와일러 수컷 어린개와 9개월령의 체중 34.6kg인 골 든 레트리버 수컷 어린개가 각각 2주령과 1개월령부터 파행 및 통증을 주중으로 머독대학 동물 병원에 내원 하였다. 내원 했을 때 호흡과 심박수 및 체온은 정상이었다. 일반 보행 및 신경검사 와 방사선 사진을 촬영하여 확인한 결과 양측 고관절 이형성(Hip displasia)과 퇴행성 관절질환 (Degenerative joint disease)을 확인 할 수 있었으며, 그 증상의 정도는 우측에 비하여 좌측이 더 심하게 나타냈다. 외과적 치료는 Slocum과 Devine에 의한 3중 고관절 절단술(Triple pelvic osteotomy)를 실시하였으며 특별한 외부 고정은 하지 않았다. 수술 후 5개월 동안 지켜본 결과 증 상은 매우 좋아졌으며 골반골의 완벽한 고정 유지에 따른 교정된 고관절을 확인 할 수 있었다.