• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.951-955
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• 2007

Recently, drywall's demand is increasing by interest about spread of remodeling house and separated wall structure. This research evaluated panel's SRI and found out panel properties using material of small size. Conclusion of this research is as following. First, we confirmed the effectiveness of small-scale material. Measuring results appeared equally about 400 ${\sim}$ 500 Hz that is fc frequency. Second,, it is no big difference in SRI that use CRC or magnesium board that is used for protection of panel surface. Third, it is compared SRI by used junction to make wall that become disjointing assembly. By the result, sealed wall secures resemblant SRI performance almost with normal wall. Therefore, using joint materials and sealing junction became wall that is detached with high SRI.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.813-816
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• 1991

Direct-drive SCARA-type industrial robots are increasingly used in the assembly process of small mechanical parts as well as electronic components, which uses direct-drive (DD) motors instead of reduction gear-type conventional motors for the actuators of manipulator arms. There are many advantages in using DD motors for robots, such as no backlash, low friction, high mechanical stiffness capability for fast and precise arm control, and high repeatability of positioning. However, there exist a number of difficulties which must be overcome to ensure proper construction and operation; increasing effects of load veriation and nonlinear and coupling dynamics, severe vibration caused by resonance of the manipulator components and low mechanical damping, etc. In order to handle these difficulties, lots of efforts have been made such as reduction of the arm inertia and elimination of the resonance, Performance evaluation of a recently developed, domestic DD robot shows that it works excellently compared with conventional robots. It, however, requires proved reliability and price competitiveness against its foreign counterparts.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.377-380
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• 2000

본 연구에서는 자동차의 차체조립공정설계를 위하여 FACTOR/AIM 및 자체 개발한 생산시스템 성능평가를 위한 시뮬레이션 프로그램을 이용하여 비교 연구하였다. 이를 위하여 먼저 자체에서 개발한 시스템성능 산정 방법으로 초기 해를 구하고 세부 생산라인의 고장 Data와 조립라인의 구성, 운반장비 등의 다양한 여건을 고려하기 위하여 FACTOR/AIM을 사용하였다. Data의 분석을 위하여 Expert Fit를 사용하였으며 초기 시스템 모델링 및 Data로부터 목표 생산시스템을 만족하는 시스템을 단계별로 찾아가는 과정을 사용하여 최적 해를 구하였다. 본 연구에서 분석한 K회사의 경우 목표 생산량 70대/시간을 만족하기 위하여 4 차의 개선을 통하여 71.57대/시간의 생산라인을 구하였다. 본 연구에서 생산조립라인의 공정설계를 위한 시뮬레이션 과정을 실 예를 들어 제시하였으며 다른 제품의 생산공정분석에도 활용 가능하리라 생각된다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.741-743
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• 2003

A surface mount machine operation policy to assemble printed circuit boards is being developed in this research. The policy includes how to assign electronic components to slots on a component rack, and how to determine placement sequences on printed circuit board. The suggested heuristic uses information about component types and closeness relationships in each component on the board to assemble. First, the size of components and closeness ratings are used to divide them into two different size groups. Then rack assignment and placement routes are developed using component type and quantity information for a small size group, and followed by a large size group. Simulation models are developed using Visual C++ for performance evaluation of the heuristic. Necessary statistical analyses are provided to show the effectiveness of the suggested heuristic.

• 한국생산제조학회지
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• 제21권5호
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• pp.830-835
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• 2012

A research for application of LDSMC(Low Density Sheet Molding Compound) composite is in progress for lightening the weight. This paper has performed fatigue test and simulation of external panel for Korean commercial vehicle. Before the fatigue test, static test was carried out. From the test, the structural safety was investigated using Goodman diagram. After the static test performance, the fatigue test was conducted at a range of load frequency 5Hz, a stress ratio(R) of 0.05 and an endurance limit of $10^6$ to obtain the S-N curve. The S-N curve is applied to the fatigue analysis of the external panel assembly. The result of FEM analysis was in accord with the experimental result within 83% confidence. It showed that the process to set up the safety range of allowable error is required in process of the design and simulation verification.

• 소음진동
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• 제10권4호
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• pp.584-595
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• 2000

We design a new actuator for high density optical device in order to control the radial tilting motion. The newly designed actuator makes it possible to control the tilting motion actively, while the coventional actuator compress tilting motion with passive spring. First of all, We present 3-dimensional modeling of actuator and accomplish the modal analysis and magnetic analysis of actuator. Due to these results, a new designed actuator has performance of high sensitivity and high second resonance frequency. Secondly, We present the 3-DOF dynamic modeling of the 4-wire spring type actuator. sensitivity analysis is performed to consider the assembling error, such as the difference of mass center and force center. From these results, the sensitivities of rotation due to the assembly error are revealed and design criteria of rotation is presented. And experimental results of a newly designed actuator are presented and compared with theoretical results. Finally, We propose a dynamic tilt compensation and high acceleration actuator for high density optical storage devices.

• 마이크로전자및패키징학회지
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• 제21권2호
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• pp.13-21
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• 2014

Technology for high power devices has made impressive progress in increasing the current density of power semiconductor, system module, and design optimization, which realize high power systems with heterogeneous functional integration. Depending on the performance development of high power semiconductor, packaging technology of high power device is urgently required for efficiency improvement of the device. Power device packaging must provide superior thermal management due to high operating temperature of power modules. Here we, therefore, review critical challenges of typical power electronics packaging today including core assembly processes, component materials, and reliability evaluation regulations.

• 한국정밀공학회지
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• 제20권3호
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• pp.165-171
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• 2003

In a structure, many components are fastened together using bolts, nuts and rivets through drilled holes. Not only do these fastened joints enable easy assembly and dismantling, they are also able to transfer as well as to distribute loads applied onto the structures. The major drawback of such connections, however, is that the fatigue life of the components is reduced by the presence of the hole since the stress concentration around the hole is increased. In addition, the hole drilling process itself may introduce defects or roughness at the surfaces of the hole that may cause further decrease in fatigue performance of the components. For applications where fatigue loadings are important, one way to compensate the decrease in fatigue life of the components is by introduction of beneficial compressive residual stress around the hole using cold working. The material used for this research were A12024-T351 and A17050-T7451 using the primary member of aircraft. We present, In this paper, the characteristics of coldworking by evaluation of the hole expansion ratio, residual stress distribution, and fatigue properties.

• 한국기계가공학회지
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• 제20권11호
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• pp.60-66
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• 2021

The antenna transmits and receives signals has a number of electronics that generate heat. For cooling, four fans and airways circulate air inside the antenna-equipped housing to exchange heat from the cooling plate assembly. In this study, fluid analysis was conducted to assess the suitability of the cooling system. The electronic components of the antenna exhibited temperature values lower than the maximum operating temperature of the components, which showed that the cooling system for the antenna had sufficient performance.

• 전기전자학회논문지
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• 제18권1호
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• pp.152-158
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• 2014

본 연구에서는 저온유동성 성능검사 시스템 구현을 통해 디젤 차량용 통합형 연료히터의 성능을 평가한다. 저온 유동성 시험장치에서 $+20{\sim}-30^{\circ}C$ 온도범위에 따라 분리형과 통합형 연료히터 성능을 비교하고, 필터 전후에 따라 유압과 시동시간, 히터의 소모전력을 측정한다. 이때 다양한 종류의 필터면적을 사용함으로써 통합형 연료히터와 분리형을 비교한 결과 시동 시간이 23% 향상되었고, 저온시동성능은 19% 정도 향상된다.