• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1995.10a
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• pp.117-119
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• 1995

입사파의 파장에 비교하여 그 대표 길이가 작은 소형 구조물에 작용하는 파력을 산정하는 경우에는 통상적으로 Morison식이 이용되고 있다. 원주나 판 등의 단순한 구조물에 관한 Morison식 중 유체력 계수(관성력 및 항력계수)에 관해서는 이미 많은 연구가 나와 있어 이들에 작용하는 파력을 고정도로 추정하는 것이 가능하다. 한편 이들 중에는 어초의 경우에서와 같이, 단순한 부재가 여러개로 조합되어 복잡한 구조물을 형성하고 있는 경우를 많이 볼 수 있다. (중략)

• The Optical Journal
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• s.99
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• pp.52-56
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• 2005

본 고는 지난 8월 25일과 26일 양일간에 걸쳐 산업기술대학교에서 주최한 제3회 초정밀 광학클러스터 기술세미나에서 일본 (株)岡本工作機械製作所(Okamoto Kazuo Watanabe)가 발표한‘도광판 금형의 초정밀 · 고능률 가공기술 동향’에 관한 내용이다. 액정 Display의 고정도화, 대형화, 경량화, 박막화, 저소비전력화 등 기술적 발전의 한 부분을 담당하고 있는 도광판과 관련하여 현재 도광판 가공기 분야에서 독보적인 기술적 위치를 차지하고 있는 이 회사의「도광판 금형 가공기 LCD Series」의 기본 특징 및 최신 기능에 대한 소개를 통해 도광판 가공기술에 대한 기술 및 시장 상황을 가늠해 볼 수 있으리라 예상된다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2247-2248
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• 2008

비접촉 터치식 조명 스위치의 감도에 관한 실험을 하였다. 유리, 목재(파티클 보드), 플라스틱의 세 종류 재질에 대해 다양한 두께의 판을 이용하여 스위치 전극을 고정한 후, 스위치가 안정적으로 동작하는 커패시턴스를 실험적으로 찾아보았다.

• Journal of Chest Surgery
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• v.26 no.1
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• pp.64-66
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• 1993

We experienced 2 cases of surgical immobilization with Judet`s strut for flail chest with multiple rib fractures. The patients were undertaken explorative thoracotomy for unevacuated hematoma and chest wall fixation for paradoxically moving segments of ribs after initial trials of internal fixation, i.e. mechanical ventilation with endotracheal intubation. Immediately after operation, the patient`s general condition and respiratory status were improved remarkably. Mechanical ventilation and endotracheal intubtion were removed on postoperative second day without any events.

• Journal of the Microelectronics and Packaging Society
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• v.4 no.2
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• pp.17-24
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• 1997

Spacer가 없는 Field Emission Display 정보표시소자의 진공 패키징시 패널 유리 두 께에 따른 패널 유리가 받는 응력과 패널의 중앙 부위에서의 변위를 계산하였다. 판의 각 모서리가 고정된 상태에서 일정한 압력을 받는 경우의 bending moment로부터 우리가 받는 압력을 계산하였으며 3.7"와 5.7"크기의 두가지 경우를 실험하여 계산값과 파괴양상 및 중앙 에서의 변위를 비교하였다.변위를 비교하였다.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06d
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• pp.5-8
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• 1998

본 논문에서는 지향성이 좋고, 대역폭이 넓은 초음파 스피커를 설계, 제작하는 것을 목표로 하였다. 이를 구현하기 위하여 초음파를 발생시키는데 널리 이용되고 있는 압전 세라믹인 PZT를 사용하였다. 먼저 스피커 제작을 위하여 금속진동판의 종류와 크기, 감도, 대역폭등의 최적값을 도출하여 주변고정, 마디지지, 주변지지의 형태로 스피커를 1차로 제작하여 음압을 측정하였고, 큰 음압을 구현하기 위해 동일한 성능을 가지는 마디지지의 스피커를 60개 배열하여 스피커로서 사용을 검증하였다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.533-549
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• 2017

In this study, drainage systems were proposed to drain the leakage of groundwater in the existing underground concrete structures. The system consists of drainage board, wire mesh, fixed nail, and mortar with mineral. In order to increase constructability, the drainage board and wire mesh were attached on the surface of cement concrete using the air nailer and fixed nail. The mortar with 30% of blast furnace slag was sprayed on the drainage board and wire mesh using the spray mortar equipment. The field test construction was carried out in a conventional concrete lining tunnel and concrete retaining wall for performance verification of the drainage system in the field. There was no problem with performance degradation in the drainage system for three years after construction. The bond strength tests were performed on the sprayed mortar at 14 days and about 3 years after field test construction. In case of attaching the wire mesh on the drainage board, the bond strengths of the sprayed mortar were 1.04 MPa at 14 days and 1.46 MPa about 3 years. In case of the drainage board without the wire mesh, the bond strengths of the sprayed mortar were 1.13 MPa at 14 days and 0.89 MPa, less than 1 MPa of bond strength criteria, about 3 years.

• Journal of the Korean Arthroscopy Society
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• v.13 no.1
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• pp.46-52
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• 2009

Purpose: To evaluate the usefulness of minimally invasive arthroscopy-assisted plate removal of a laterally inserted periarticular distal femur plate used for the treatment of AO type-C distal femur fractures. Materials and Methods: From October 2002 to November 2005, we evaluated 17 patients whose plates were removed through minimally invasive arthroscopy-assisted plate-removal technique and 15 patients who got their plates removed through conventional method without using arthroscopy, 32 patients in total. All these patients included in this study initially underwent open reduction and internal fixation of the distal femoral fractures with a lateral plate, and complained of continued pain over the lateral femoral condyle after the fracture fixation. The average age was 42.6 (ranges: 20~66) and initial fracture types included 16 cases of C1, 11 cases of C2, and 5 cases of C3 following AO/ASIF classification guidelines. Measured outcomes included: associated intra-articular pathologies, time needed to return to activities of daily living, patients' overall satisfaction, complications following the removal of hardware, and pain before and 6 months after the operation. Results: The distal-most end of the plate was placed in the knee joint in all cases and damage of the lateral articular capsule was found in 23 cases. Continuous wound discharge after surgery was found in one case who underwent arthroscopy-assisted plate removal, and it was treated by irrigation and re-suture. Average time needed to return to activities of daily living was 7 days in arthroscopy assisted group and 7.6 days in conventionally removed group. Fourteen patients (82.4%) who underwent arthroscopyassisted plate-removal reported above 'fair' satisfaction and the Visual analog scale pain score decreased from 4.9 to 1.9, six months after the plate removal. Thirteen patients(86.7%) who underwent conventional plate removal reported above 'fair' satisfaction and the Visual analog scale pain score decreased from 5.2 to 2.5, six months after the operation. Conclusion: Through minimally invasive arthroscopic-assisted plate removal, intrarticular pathology of the knee joint was able to be simultaneously identified and treated at the time of hardware removal. Damage of lateral capsule of the knee joint caused by the inserted plate for the treatment of type C distal femoral fracture was very frequently found and following the plate removal, patients experienced an improvement in pain score. We therefore recommend routine lateral distal femoral plate removal if the bony union is attained in such cases as type C distal femoral fractures whose distal most end of the plates are located in the joint.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.1-7
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• 2022

Recently, satellites equipped with high-performance electronics have required higher power consumption because of the advancement of satellite missions. For this reason, the size of the solar panel is gradually increasing to meet the required power budget. Increasing the size and weight of the solar panel is one of the factors that induce the elastic vibration of the flexible solar panel during the highly agile maneuvering of the satellite or the mode of vibration coupling to the satellite or the mode of vibration coupling to the micro-jitter from the on-board appendages. Previously, an additional damper system was applied to reduce the elastic vibration of the solar panel, but the increase in size and mass of system was inevitable. In this study, to overcome the abovementioned limitations, we proposed a high -damping yoke structure consisting of a superplastic SMA(Shape Memory Alloy) laminating a thin FR4 layer with viscoelastic tape on both sides. Therefore, this advantage contributes to system simplicity by reducing vibrations with small volume and mass without additional system. The effectiveness of the proposed superelastic SMA multilayer solar panel yoke was validated through free vibration testing and temperature testing using a solar panel dummy.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.1999-2010
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• 1992

The fixed slab analogy device which can measure stress intensity factors(S.I.F) experimentally by slab analogy theory is developed in this paper. The margin of errors resulted from the new testing apparatus are between 0.02% and 8.25%. Therefore, it is assured that this one can be effectively used for the more accurate measurement of S.I.F.( $k_{I}$, $k_{I I}$) than conventional apparatus. The pitch of master grating used in this experiment is 0.1mm It is known that the ratio of the distance from crack tip to the crack length on obtaining the accurate stress intensity factor is between 0.4 and 0.7. The optimum curvature radius of slab is about 125mm. The thickness of slab(plate) used in the fixed slab analogy device is 0.05mm(P.V.C. ; E = 64 MN/ $m^{2}$, .nu.=0.38), which is proved to be suitable for the test. The optimum material for the frame(slab`s external boundary) is a alloy tool steel(SKS 5) plate and its thickness is 1mm. In this research, the rigid cracks are directly bonded to the slab surface by cyanoacrylate adhesive for the easiness of slab making and conformity to the practical crack figure. The material of rigid crack is thin steel plate. It is expected that the developed method can be used effectively for the analysis of $k_{I}$ and $k_{I I}$ of arbitrary shaped or distributed cracks.cks.