• Proceedings of the KSME Conference
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• 2003.04a
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• pp.468-472
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• 2003

MRE-1 dual thruster module(DTM) which will be installed to the present under development KOMPSAT(Korea Multi-Purpose Satellite) can provide reliable and cost-effective means of propulsive control for attitude and maneuvering control system. Thruster heat shield, one of the main components of DTM, is designed to intercept the radiative heat exchange between thruster and satellite during firing. The inside diameter of the current configuration will be decreased a little compared with that of the previous one due to manufacturing method change. Therefore, the possibility of interference between thruster and heat shield due to configuration change is investigated through structural analysis and their results are described in this paper.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.142-150
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• 2003

MDO is one of the efficient methods for huge and multi -functional system design. This paper describes a design collaboration framework with MDO in networked design environment. A prototype of web -based integrated design system was implemented to show sharing and exchange of models and analysis information between MDO modules and collaborative design stations. Server System consists of MDO modules for optimization and modeling module for 3D modeling operation. Client system provide user with graphic interface for shape modeling and system operation. We believe that the proposed approach can be extended to solve real complex multidisciplinary design problems.

• Journal of Applied Reliability
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• v.17 no.1
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• pp.28-37
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• 2017

Purpose: This paper proposes a procedure that may infer and identify interaction failures in a module. Methods: In design FMEA, we defined an interaction model between components and proposed a method for selecting a single component by using the standard specification classification table and four methods for choosing the related components. We also introduced the function tree for function and requirement characteristic analysis and proposed utilization of standard stress lists and 1st and 2nd stress analysis tables to determine the effect the stress analysis has on interactions. Finally, the interaction mechanism diagram was proposed and used to infer the failure mechanism. Process FMEA also established procedures in a similar way. Results: We established a procedure for predicting the failure mode due to interaction between components based on Company A's multi-step FMEA procedure. Conclusion: By applying the proposed interaction FMEA procedure to the development model, we were able to confirm the effect of the new derivation on the failure mode of interaction, which was not predicted by the existing FMEA.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.04a
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• pp.69-72
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• 2000

기판과의 동시소성에 의한 고주파 MCM-C(Multi-Chip-Module-Cofired)용 저항을 제작하고 6 GHz 까지의 RF 특성을 측정하였다. 기판은 저온 소성용 기판으로서 총 8층으로 구성하였으며, 7층에 저항체 및 전극을 인쇄하고 Via를 통하여 기판의 최상부까지 연결되도록 하였다 저항체 Pastes, 저항체의 크기, Via의 길이 변화에 따라서 저항의 RF 특성은 고주파일수록 더욱 DC 저항값에서부터 변화되는 양상을 보였다. 내부저항의 등가회로를 구현한 결과, 저항은 전송선로, Capacitance 성분이 혼재되어 있는 것으로 나타났으며 전극의 형태에 따라 Capacitance 성분이 많은 차이를 나타내었다.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.11a
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• pp.81-85
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• 2000

마이크로파대역에서 우수한 유전적 특성을 가지며 소결이 90$0^{\circ}C$ 이하에서 가능하여 Ag와 동시 소결이 가능한 유전체 조성을 개발하여 RF MCM-C(Multi-chip Module on Ceramic) 제조를 위한 유전체 테잎 제조에 대한 기초적인 실험과 Ag 전극과 동시소성에 대한 반응성 실험을 하였다. 본 실험에 앞서 개발된 유전체 조성의 마이크로대역에서의 유전특성은 유전율 24, 품질계수 30,000 이상, 공진주파수 온도계수 37 ppm/$^{\circ}C$ 이었고 소결온도는 85$0^{\circ}C$이었다. 이 유전체를 이용결함 없는 테잎 제조를 위한 유기용매의 선택, 바인더 및 가소제의 량 및 비에 따른 테잎의 소결 전 .후의 상태를 비교.분석하여 최적의 조성비를 결정하였다. 테잎과 은전극과의 반응성 실험결과 은과 유전체의 상호확산은 거의 이루어지지 않음을 확인하였다.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.83-86
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• 2002

This paper intends to provide convenience to the disabled, losing the use of their limbs, through voice recognition technology. The voice recognition part of this system recognizes voice by DTW (Dynamic Time Warping) Which is most Widely used in Speaker dependent system. Specially, S/N rate was improved through Wiener filter in the pre-treatment phase while considering real environmental conditions; the result values of 12th order feature pattern per frame are extracted by DTW algorithm using LPC and Cepsturm in feature extraction process. Furthermore, miniaturization is pursued using TMS320C32, 71's the floating-point DSP, for the hardware part. Currently, 90% of hardware porting has been completed, but we can confirm that the recognition rate was 96% as a result of performing the DTW algorithm in PC.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.107-112
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• 2009

This paper describes design and fabrication issues of the SiP(System in Package) one-chip for a portable digital broadcasting receiver. It includes RF tuner chip, demodulator chip and passive components for the receiver system. When we apply the SiP one-chip technology to the broadcasting receiver, the system board size can be reduced from $776mm^2$ to $144mm^2$. SiP one-chip has an advantage that the area reduces more 81% than separated chips. Also the sensitivity performance advances -1dBm about 36 channels in the RF weak electric field, the power consumption reduces about 2mW and the C/N keeps on the same level.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.536-541
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• 2000

A low cost PC based simulator for excavator manipulation has been developed using virtual reality technology. The simulator consists of two joystick input devices, server and client PCs, an excavator kinematics module, and a graphic rendering program Open Inventor. In order to use two joysticks in the PC window environment multi-thread programing with network protocol TCP/IP has been used. To provide realistic view to the operator, CAD program Pro/Engineer and 3D modeller have been employed to create 3D part geometry of tile manipulator and virtual environmental geometries. Those geometries also have been transformed and imported to the Open Inventor. The Simulator developed is to be improved for more realistic excavator operational training.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.4
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• pp.17-23
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• 2008

Development of die technology for holder and barrel dies is necessary according to minimization of lens assembly, image sensor, and connectors. In these cases, there are two technical problems arising from die design. One is determination of knock-out pin location in die set. Minimization of lens assembly size make it difficult to obtain ejecting space. The other is whether or not high-precision die technology is possible to reduce torque variation when holer and barrel products is assembled. In this study, multi-cavity die set was developed taking advantage of gear-driven ejecting method. In the developed technology, die manufacturing technology was guaranteed with a high-precision level.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.908-910
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• 2013

현재 지능형 자동차와 관련된 연구들은 끊임없이 발전되고 지속되고 있다. 차량에는 다양한 통신모듈이 장착되어 내/외부로 통신이 가능하며, 송수신된 데이터를 처리하기 위한 모듈은 모든 데이터에 대한 병목현상이 발생하지 않도록 정보를 제공하는 연구도 활발하게 진행되고 있다. 하지만 이러한 스케줄링 된 센서 정보는 내부에서만 사용이 가능하며, 외부로 센서 정보를 제공하기 위한 인터페이스 모듈에 대한 연구는 현재 진행되고 있지 않다. 본 연구에서는 차량에 부착된 다중 센서의 데이터를 외부와 연결하여 데이터를 송수신할 수 있는 인터페이스 모듈을 설계하는 것에 목적을 둔다.