• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권8호
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• pp.373-380
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• 2003

This paper consists of a study in post-assembly magnetization of LSPM (Line Start Permanent Magnet Motor). Recently, LSPM is noted as an alternative to the induction motor because it offers a very high efficiency and unity power factor, And it is necessary for permanent magnets to be magnetized by means of post-assembly magnetization in LSPMS because of the manufacturing cost involved. The manufacturing process is also simpler in post-assembly magnetization than in pre-assembly magnetization. Generally, permanent magnet motors are magnetized by their own stator coil or by magnetizing fixtures. However, the permanent magnet in a LSPM is scarcely magnetized by using them because of the eddy current of the rotor bar. Hence, it is necessary to design a magnetizing fixture that overcomes this problem. In this paper, the author analyses the post-assembly magnetization of a LSPM and proposes a method for designing the magnetizing fixture. The method that the author proposes is to make the number of coil turns greater in order to reduce the effect of the eddy current of the rotor bars.

• 대한치과보철학회지
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• 제54권2호
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• pp.110-119
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• 2016

목적: 본 연구는 임플란트 지대주의 체결부 길이와 골정에 대한 고정체 상단의 위치에 따라서, 하중 적용 시 고정체, 지대주, 나사 및 골에서의 응력 분포에 어떤 변화가 나타나는지 평가해 보고자 하였다. 재료 및 방법: 원추형 사면과 육각 기둥 형태의 회전저항구조를 갖는 내측 연결형 임플란트에서 지대주의 체결부 길이가 2.5 mm, 3.5 mm, 4.5 mm인 경우와 각 경우에서 고정체 상단이 골정과 같거나 골정보다 2 mm 상방에 위치할 때를 상정하여, 유한요소분석을 위한 모델을 총 6개 형성하였다. 각 경우에서 170 N의 30도 경사하중을 적용하였다. 결과: 6개의 유한요소분석 모델 모두에서, 임플란트는 고정체와 지대주의 체결 상단 부위에서, 주위 골에서는 골정 부근에서 최대 응력 값을 나타냈다. 지대주의 체결부 길이가 길어질수록, 주어진 하중에서 발생되는 고정체, 지대주, 나사 및 골에서의 최대 응력 값은 줄어들었다. 고정체 상단이 골정과 동일한 높이에 있는 경우보다 골정 2 mm 상방에 위치하는 경우에서 지대주의 체결부 길이가 길어질수록 모든 부위에서 더 큰 비율로 최대 응력 값의 감소를 나타내었다. 결론: 지대주의 체결부 길이가 길어질수록 모든 부위에서 주어진 하중에 따른 최대 응력 값이 줄어드는 것을 알 수 있었고, 임플란트의 기계적 및 생물학적 합병증 예방에 도움이 될 수 있을 것으로 판단된다.

• 대한치과보철학회지
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• 제43권1호
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• pp.105-119
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• 2005

Statement of problem. As the effects of the various diameters of fixture and abutment screw on stress distribution was not yet examined, this study focused on the different design of single implant restoration using three dimensional finite element analysis. Purpose. This study was to compare five different fixture-abutment combinations for single implant supported restorations with different fixture and abutment screw diameters. Material of methods. The five kinds of finite element models were designed by 3 diameter fixtures ($\oslash$3.3, 3.75, 5.0 mm) with 3 different abutment screws $\oslash$1.5, 1.7, 2.0 mm). The crown for mandibular first molar was made using UCLA abutment according to Wheeler's anatomy. 244 N was applied at the central fossa with two different loading directions, vertically and obliquely (30$^{\circ}$) and at the buccal cusp vertically. Maximum von Mises stresses were recorded and compared in the supporting bone, crowns, fixtures, and abutment screws. Results. 1. The stresses in supporting bone and implant-abutment structure under oblique loading were greater than those under vertical or offset loading. The stresses under vertical loading were the least among 3 loading conditions regardless of the implant and abutment screw diameters. 2. The stresses in the narrow implants were greater than the wider implants. The narrow implant with narrow abutment screw showed highest stresses in the lingual crest, but the narrow implant with standard abutment screw showed highest stress in abutment screw. 3. The stresses of abutment screws were influenced by the diameter of fixtures and loading conditions. The wide implants showed least difference between two different abutment screw diameters. Conclusions. The wide implants showed lesser stresses than the narrow implants and affected least by the different abutment screw diameters. The narrow implants with standard abutment screw showed highest stresses in the lingual bony crest under oblique loading.

• 한국융합학회논문지
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• 제11권11호
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• pp.183-187
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• 2020

LCD BLU의 CCFL 전극에 사용되는 몰리브덴 전극의 주요소재인 몰리브덴 컵과 몰리브덴 핀은 국내 가공기술이 개발되지 못하여 전량 일본에서 수입하여 사용되고 있어 CCFL 제조업체들의 납기 및 경쟁력에 부담을 주고 있다. 본 연구에서는 LCD BLU의 CCFL 전극에 사용되는 몰리브덴 핀의 제조 기술을 개발하는 연구로 직선처리 기술개발, 몰리브덴 와이어 표면처리 기술개발, 와이어 절단기술 개발, 몰리브덴 핀의 제작, 검사용 JIG와 Fixture 설계 및 제작, 몰리브덴 핀 시제작 및 해석, 몰리브덴 핀 전수검사 기술개발에 관한 연구를 수행하였으며 본 논문에서는 몰리브덴 핀 제작에 있어 전수검사기 융합설계에 대한 연구를 다루고자 한다.

• 한국안전학회지
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• 제37권5호
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• pp.1-6
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• 2022

In this study, to confirm the effects of the mixed load of normal and shear forces acting on a fixing bolt, fatigue design criteria were developed by varying the loading angle and conducting tensile and fatigue tests. After evaluating and comparing the test results under different loading angles, the evaluation criteria were selected. These evaluation criteria were then applied to develop the design criteria. An Arcan fixture was designed and manufactured to simultaneously apply a mixed load of normal and shear forces to the fixing bolt of a turntable, and a fatigue test was conducted. S-N diagrams for various loading angles were obtained, and a 1% P-S-N diagram of failure probability was determined using statistical processing techniques. Our results show that failures of the fixing bolt can be prevented using these diagrams as a basis for developing fatigue design criteria.

• 대한치과보철학회지
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• 제44권2호
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• pp.185-196
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• 2006

Statement of problem: The researches on the influence of design variables on the stress distribution in cortical and trabecular bones and on optimal design for implant system were limited. Purpose: The purpose of this study is to identify the sensitivities of design parameters and to suggest the optimal parameters for designing the onebody type implant system. Material and methods: Stresses arising in the implant system were obtained by finite element analysis using a three dimensional model. An onebody type implant system[Oneplant (Warrantec. Co. Ltd., Korea)] was considered in this study. Vortical load(150 N) was applied on the top of the abutment along the axial direction. The initial design variables set for sensitivity analysis were radius of fixture, numbers of micro thread, numbers of power thread, height of micro thread, future length, tapered angle of future, inclined angle of thread, width of micro thread and width of power thread. The statistical technique of Design of Experiments(DOE) was applied tn the simulation model to deduce effective design parameters on stress distributions in bones. The deduced design parameters were incorporated into a fully automated design tool which is coupled with the finite element analysis and numerical optimization to determine the optimal design parameters. Results: 1. The result of sensitivity analysis showed six design variables - radius of future, tapered angle of fixture, inclined angle of thread, numbers of power thread, numbers of micro thread and height of micro thread - were more influential than the others. 2. The optimal values of design variables can be deduced by coupling finite element analysis (FEA) and design optimization tool(DOT).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권4호
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• pp.240-247
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• 2009

Purpose: The purpose of this study was to evaluate marginal bone loss to the bone crest functionally loaded for up to eighteen months and also with regard to other variables of interest. Material and Methods: 135 endosseous implants(GS II, Osstem, South Korea) were placed in 35 patients. The design of GS II implant is straight with the microthread. Radiographic examinations were conducted at baseline (implant loading) and 3, 6, 9, 12 and 18 months after loading. Marginal bone level measurement was made from the reference point to the lowest observed point of contact of the marginal bone with the fixture. The reference point of the fixture was the border between the blasted surface and machined surface of the fixture. Results: Implants were on function for a mean 12.7 months(range, 3?18 months). For the 56 maxillary and 79 mandibular implants, mean marginal bone loss was 0.68 mm and 0.70 mm. Implants placed maxillary posterior area displayed more crestal bone loss than the other position. The difference between mesial and distal bone levels was statistically significant (p<0.05) with respective means of 0.51 mm and 0.62 mm. Also, The difference between bone graft group and no-bone graft group was statistically significant(p<0.05) with respective means of 0.38 mm and 0.66 mm. But no statistically significant influence of sex, type of surgery(one or two stage surgery), the implant length was observed(p>0.05). Conclusion: This study indicates the amount of marginal bone loss around implant has maintained a relative stable during follow-up periods.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2008년도 춘계학술발표논문집
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• pp.170-172
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• 2008

본 논문은 LED조명기구의 상용화에 문제가 되고 있는 방열설계에 관한 논문으로서, CF-design을 이용한 방열해석을 통하여 문제해결의 방법을 제시한다. 해석 결과 시뮬레이션 값과 시작품 제작 후 측정 온도와의 차이가 6[$^{\circ}C$]이하로 도출되었으며 주어진 제 요소들을 잘 활용하면 실제작품의 목표치에 근접하는 결과를 얻을 수 있다.

• International Journal of Aeronautical and Space Sciences
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• 제18권1호
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• pp.63-69
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• 2017

In this paper, composite laminate pull-through resistance was analyzed using the FEM method and compared with test results. 2D and 3D simplified FEM models, a nonlinear analysis, and a progressive failure analysis utilizing three composite laminate failure theories Maximum Stress, Maximum Strain, and Tsai-Wu were used to predict the FEM results with the test results. The load and boundary conditions of the test were applied to the FEM to simulate the test. A composite laminate pull-through test (ASTM D7332 Proc. B) was designed with a special fixture to collect more precise data. The test results were compared with the FEM analysis results.

• 스마트미디어저널
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• 제5권4호
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• pp.103-110
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• 2016

본 연구는 유사 목적을 가진 제품들을 형태적 특성에 따라 분류하고, 기능적 유사성을 기반으로 범주화하여 전형성 추출함으로써 기구디자인 개발 시, 개발방향의 기준 마련에 목적을 둔다. 전형성 추출을 위한 본 연구의 표본영역은 선험 사례연구와 전문가자문을 통해 팬던트형과 천정부착형으로 제한을 두고, 한국과 일본에 출시된 2015년 12월 이전 출시 제품을 표본으로 국내 주요 6개 도시 관련업무 종사자 및 전공자를 대상으로 조사를 실시하였다. 조사는 형태적 분류를 위한 1차 조사와 전형성 추출에 관한 2차 조사, 형태적 디자인속성 분류에 관한 3차 조사로 이루어졌으며, 기능 및 형태적 분류와 조형원리를 기준으로 디자인 속성을 도출하고 개별 요소를 추출함으로써 디자인 가중치 측정에 대한 향후 연구의 기반을 마련하고자 하였다. 연구결과의 산업적 적용으로 광원 대체로 인한 조명기구 시장변화에 디자인기술의 효율적 역할 정립과 기업의 연구개발 및 조명기구관련 제품디자인 타입 변화 가속화에 신속한 대응방향 제시 효과를 기대할 수 있다.