• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.789-795
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• 2008

Slope stability is affected by various factors. For safety management of slopes, monitoring systems have been widely constructed along railway lines. The representative data from the systems are variations of ground profile such like ground water level and pore water pressure etc. and direct displacement measured by ground clinometer and tension wire sensor. Slopes are mainly effected by rainfall and rainfall causes the decrease of factor of safety(FOS). Because FOS varies linearly by the variation of ground water level and pore pressure, it has a weak point that could not define the time and proper warning sign to secure the safety of the train. In this study, alternative of FOS such as reliability index and probability of failure is applied to slope stability analysis introducing the reliability concept. FOS, reliability index, probability of failure and velocity of probability of failure of the slopes by variation of ground water level are investigated for setting up the specification of safety management of slopes. By executing case study of a slope(ILLO-IMSUNGLI), it is showed to be applied to specification of safety management.

• Ocean and Polar Research
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• 제41권1호
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• pp.19-34
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• 2019

The present study obtained universal mathematical models of all elements and characteristics regarding hook and line fishing systems. To describe the hook and line fishing systems on site we used three kinds of coordinate systems: the earth based coordinate system, natural coordinate system, and flow (velocity) coordinate system. Mathematical models presented in this article allow us to define the shape of the fishing gear, the tension of the rope at different points, hydrodynamic resistance, diameter of the hook's wire, immersion depth of the fishing hooks, distance from hooks to the ground and the required lifting force of the floats. These models allow for the performance of computer simulations regarding any kinds of hook and line gears in still water or water where flow occurs.

• 대한치과교정학회지
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• 제27권5호
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• pp.825-837
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• 1997

실험적 치아이동 후 보정기간 동안 고정방법이 치주인대 섬유의 재배열에 미치는 영향을 알아보기 위하여, 체중 20kg 내외의 성견에서 상악 제 3절치와 견치 사이에 견인 스프링을 이용하여 120 gm의 교정력을 3주간 가한 후 좌측에는 유연성 고정장치로 0.0215 인치 multistrand wire를, 우측에는 견고성 고정장치로 폴리 에틸렌 리본을 레진 접착제로 각각 장착한 다음 4주, 8주, 또는 12주 후 희생시켜 치주조직의 변화를 방사선 사진, 광학 현미경 관찰을 통하여 분석한 바 다음과 같은 결과를 얻었다. 1. 치아이동 후 압박측에서는 치주인대 공간의 압축과 함께 치주인대섬유가 굵어진 소견을 보였으며 인장측의 치주인대섬유는 신장되어 보였다. 2. 보정 4주 후 유연성 고정군에서는 치주인대섬유의 재배열이 관찰되었으나 견고성 고정군에서는 관찰되지 않았다. 3. 보정 8주 후부터는 두 군 모두에서 치주인대섬유의 재배열 소견이 관찰되었으며, 두 군간 치주인대섬유의 재배열 차이는 보이지 않았다. 4. 보정기간 동안 치주인대섬유의 재배열은 압박측 보다 인장측에서 빠른 소견을 보였다. 이상의 결과는 치아이동 후 견고하게 고정한 보정방법에서도 치주인대섬유의 재배열이 일어남을 보여주었고, 치아 보정시 폴리에틸렌 리본으로 고정한 보정장치도 유용하게 사용될 수 있음을 시사하였다.

• 수산해양기술연구
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• 제51권1호
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• pp.50-60
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• 2015

This paper conducted research on identifying the process of change in fishing gear and organizing the function of periodically-used fishing gear types through net plan and computer simulation by selecting the design of the four types of fishing gear used for the Korea tuna purse seiner in the Western and Central Pacific Ocean, which 1,000 G/T class and whose length over all 60 m class. In the late 1980s, the length of the tuna purse gear was 1,939 m and the design depth was 160 m, but currently, the length and the design depth are 2,515 m and 230 m, respectively. As a result of the simulation, the expansion of the fishing gear increased buoyance, sinking force, sinking depth, surrounded area, and purse wire continuously. Recently, the maximum tension of the currently used purse wire of tuna purse seiner is 23.5 tons and is close to 25.4 tons which is the maximum lift capacity of WS454 winch. The way to improve fishing gear should be proceeded to increase sinking speed rather than expand the size of fishing gear.

• 대한조선학회논문집
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• 제46권5호
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• pp.527-535
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• 2009

This paper describes the control system to suppress the load pendulation using tagline for the floating crane. Dynamic equation of motion of the floating crane and the load is derived using Newton's 2nd law and free body model. The floating crane and the load are assumed that they move in center plane. Each rigid body has 3 DOF (surge, heave, pitch), because it moves in two directions and rotates. Then, this system, which is composed of two rigid bodies, has 6 DOF. The gravitational force, the hydrostatic force, the hydrodynamic force and the tension of the wire rope are considered as external forces, which affect to the floating crane. To suppress the pendulation of the load, the tagline, which connects between the load and the float crane, is applied to the system. The tagline is composed of the spring and the wire rope. Proportional and Derivative control is used as a linear control algorithm. The results of the numerical analysis of the 3,600 ton floating crane show that the tagline system is effective to suppress the load pendulation.

• 콘크리트학회논문집
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• 제27권1호
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• pp.11-20
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• 2015

본 연구에서는 유한요소해석을 통하여 직경 15.2 mm의 비부착식 강연선을 위한 포스트텐션 1구 정착구를 개발하였고 이에 대한 성능시험을 수행하였다. 정착장치에 대한 성능시험으로 콘크리트 표준시방서에 따라 KCI-PS101에 제시된 정하중시험과 하중전달시험 방법이 사용되었다. 정하중시험과 강연선 인장시험을 통하여 개발된 정착구가 강연선 공칭인장강도에도 손상 및 파괴되지 않음을 확인하였다. 하중전달시험을 통해서는 각종 철근보강에 따른 실험체의 압축성능을 확인하였고, 무보강 실험체가 강연선 인장강도의 1.64배까지 저항할 수 있다는 결과를 얻었다.

• Archives of Plastic Surgery
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• 제35권6호
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• pp.723-728
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• 2008

Purpose: The disinsertion of the phalangeal tendon distal insertion has difficulties in ordinary tenorrhaphy operation for the anatomical features, and still has controversy between non-surgical and surgical management. The purpose of this study is to select treatment for the injury of the phalangeal tendon distal insertion, as we've had a good results from operation treatment with Pull-in suture technique. Methods: We reviewed the hospital records of 12 patients treated with Pull-in suture technique with disinsertion of the phalangeal extensor or flexor tendon distal insertion from June 2006 to June 2007. Eight patients were involved with the tendon disinsertion without bone fracture, and 4 patients were involved with the fracture of the phalangeal tendon distal insertion site. After removal of the K-wire in week 6, active physical exercises were commenced immediately. The mean follow-up period was 12.4 months. Results: All the patients who had tendon disinsertion with bone fracture had IIB, by Wehbe and Schneider's classification 2, and we evaluated the results comparing the same finger of the other hand according to Crawford's evaluation criteria 5. The nine excellent and three good results were obtained and there were no limitation of motor for the patient who had operation for the rupture of flexor tendon as well. There were no particular complications during the follow-up period. Conclusion: The most important thing for the disinsertion of the phalangeal tendon distal insertion is to maintain an accurate and durable reduction state keeping the tension of tendon. At this point, after removal of the K-wire, the Pull-in suture technique allows accurate realignment of the tendon-bone unit without any specific instrumentation under the more stable state. The Pull-in suture technique seems to be a strong alternative for the treatment of disinsertion of the phalangeal tendon distal insertion, with successful treatment outcome(rapid functional recovery and high patient satisfaction).

• 반도체디스플레이기술학회지
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• 제21권1호
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• pp.27-32
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• 2022

There has always been a demand for orthodontic treatment. Orthodontic treatment allows tooth to be arranged by flexible arch wire fixed with tooth-attached brackets. Arch wire generate constant pressure to tooth brackets which moves the teeth to proper place. When the bracket transmits force, the braced wing of the bracket may deform. Deformed tie wing will lead to lost tension of elastic ligature. Then, lacking grip between tie wing and ligature might delay the tooth movement. Furthermore, tooth brackets used for orthodontic treatment make contact with in direct oral surface and this cause feeling of irritation that comes from height of tooth braces. This study suggests an optimal teethe bracket design to make up for inconvenience by shorten the height of bracket and complement the shape of bracket to reduce strain rate using finite element analysis. As a result, new optimal design of teethe bracket indicates lower strain rate of the bracket wing and takes good effects of shorten body height in terms of convenience.

• Smart Structures and Systems
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• 제31권1호
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• pp.89-100
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• 2023

This paper conducts a parametric study of a new tuned mass damper with pre-strained superelastic SMA helical springs (SMAS-TMD) on the vibration reduction effect. First, a force-displacement relation model of superelastic SMA helical spring is presented based on the multilinear constitutive model of SMA material, and the tension tests of the six SMA springs fabricated are implemented to validate the mechanical model. Then, a dynamic model of a single floor steel frame with the SMAS-TMD damper is set up to simulate the seismic responses of the frame, which are testified by the shaking table tests. The wire diameter, initial coil diameter, number of coils and pre-strain length of SMA springs are extracted to investigate their influences on the seismic response reduction of the frame. The numerical and experimental results show that, under different earthquakes, when the wire diameter, initial coil diameter and number of coils are set to the appropriate values so that the initial elastic stiffness of the SMA spring is between 0.37 and 0.58 times of classic TMD stiffness, the maximum reduction ratios of the proposed damper can reach 40% as the mass ratio is 2.34%. Meanwhile, when the pre-strain length of SMA spring is in a suitable range, the SMAS-TMD damper can also achieve very good vibration reduction performance. The vibration reduction performance of the SMAS-TMD damper is generally equal to or better than that of the classic optimal TMD, and the proposed damper effectively suppresses the detuning phenomena that often occurs in the classic TMD.

• Clinics in Shoulder and Elbow
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• 제1권1호
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• pp.66-71
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• 1998

The fractures of lateral end of clavicle can be treated by conservative or operative treatment, but many authors report the higher rate of non-union with conservative treatment and that the operative treatment is more effective for the type II fractures. The authors reviewed and analysed 15 cases of lateral end fracture of clavicle which had been treated at Department of Orthopedic Surgery, Kyungpook National University Hospital from 1991 to 1996. The results were as follows; 1. Among the 15 patients, male was 6,female 9 and the average age was 46.2 years ranged from 21 to 72 years. 2. According to the classification by Rockwood, type II a was 8 cases and II b was 7 cases. 3. We treated operatively 12 cases, 9 cases with tension band wiring and 3 cases with intramedul-Iary K-wire fixation. And we treated conservatively 3 cases with Velpeau cast, but I case of nonunion was treated with tension band wiring. 4. The average follow-up was 3.2 years ranged from 2.1 to 4.7 years. 5. The functional results were evaluated with Weitzman's classification. 6. In the operatively treated cases, there were 4 cases(30.7%) in excellent, 7 cases(53.8%) in good and 2 cases(15.3%) in fair result. But, in the conservatively treated cases, there were 2 cases in good and I case in poor result, and the poor case did not united and had open reduction and internal fixation. 7. In conclusion, the operative treatment revealed good functional results in most cases (10/12) and early open reduction and internal fixation was better method than conservative treatment.