• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.5-8
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• 2002

The use of the co-cured joining method for composite structures is attractive due to several benefits. However, since the design stress level in cyclic loads is often smaller than the joint strength obtained from the static tensile load test, it is important to establish proper fatigue design criteria. Although some researchers have reported on co-cured joints, there are only a few papers published on the fatigue characteristics of co-cured joints. In this paper, the effect of bond parameters on the fatigue characteristics of a steel-composite co-cured double lap joint under cyclic tensile loads was experimentally investigated. We considered the surface roughness of the steel adherend and the stacking sequence of the composite adherend as bond parameters. A fatigue failure mechanism of the co-cured double lap joint was explained systematically by investigating the surfaces of failed specimens.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2017년도 춘계학술대회 논문집
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• pp.219-219
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• 2017

This study aims at examining each firm's decision-makings of complex product and system (hereafter CoPS) innovation strategy, so that it tries to reveal the nature and role of CoPS innovations strategy. And it designed a comparative case study along with qualitative methods, by having two mobile operators' digital rights management (hereafter DRM) innovation in South Korea's digital music service industry. Through literature review, this study formulated three research propositions: (i) Each firm's decision-makings of CoPS innovations strategy are analytical negotiation process among economic actors in an industry; (ii) Each firm's market power originated from its market share from the installed base through network effect and switching cost influence decision-makings of CoPS innovation strategies; (iii) Each firm's decision-makings of different CoPS innovation strategies are related to their intension of achieving better market power, consequently dominant design. Through empirical examination of two mobile operators' decision-makings of DRM innovation strategy, this study empirically verified three research propositions.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.295-298
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• 2008

We developed a novel PVA pixel design for mobile application with excellent off-axis image quality and optical performance by introducing Active Level Shift technology and optimizing pixel structure. Our new pixel design enables better off-axis image quality without sacrificing other optical properties compared with a conventional mPVA structure.

• Corrosion Science and Technology
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• 제6권3호
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• pp.90-95
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• 2007

Cathodic protection technology has been widely used on ship's outer hull and inner side of ballast water tanks as a supplementary corrosion protection measure in combination with protective organic coatings. Impressed current cathodic protection system is typically opted for the ship's hull and, sacrificial anode system, for ballast water tanks. The anticipation and interest in cathodic protection system for ships has been surprisingly low-eyed to date in comparison with protective coatings. Computational analysis for the verification of cathodic protection design has been tried sometimes for offshore marine structures, however, in commercial shipbuilding section, decades old design practice is still applied, and no systematic or analytical verification work has been done for that. In this respect, over-rotection from un-erified initial design protocol has been also concerned by several experts. Especially, it was frequently reported in sacrificial anode system that even after full design life time, anode was remaining nearly intact. Another issue for impressed current system, for example, is that the anode shield area design for ship's outer hull should be compromised with actual application situation, because the state-of-the-art design equation is quite impractical from the applicator's stand. Besides that, in this study, some other critical design issues for sacrificial anode and impressed current cathodic protection system were discussed.

• Journal of Mechanical Science and Technology
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• 제20권1호
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• pp.133-146
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• 2006

Collaborative optimization (CO) is a multi-level decomposed methodology for a large-scale multidisciplinary design optimization (MDO). CO is known to have computational and organizational advantages. Its decomposed architecture removes a necessity of direct communication among disciplines, guaranteeing their autonomy. However, CO has several problems at convergence characteristics and computation time. In this study, such features are discussed and some suggestions are made to improve the performance of CO. Only for the system level optimization, genetic algorithm is used and gradient-based method is used for subspace optimizers. Moreover, response surface models are replaced as analyses in subspaces. In this manner, CO is applied to aero-structural design problems of the aircraft wing and its results are compared with the multidisciplinary feasible (MDF) method and the original CO. Through these results, it is verified that the suggested approach improves convergence characteristics and offers a proper solution.

• 한국정밀공학회지
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• 제32권8호
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• pp.719-726
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• 2015

This paper presents a velocity-synchronizing control for the multiple axes of an injection unit; based on MBS, a virtual design model has been developed for the multiple-axes servomechanism. Prior to the design of the controller, a linear plant model was derived via open-loop response simulations. To synchronize the motions of the multiple axes, a cross-type synchronizing controller was designed and combined with the PID control to accommodate any parameter mismatches among the multiple axes. From the tracking control simulations, a significant reduction of both velocity-tracking and position-tracking errors was achieved through the use of the proposed control scheme.

• 한국항공우주학회지
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• 제39권9호
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• pp.896-903
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• 2011

본 논문에서는 차세대 영상 압축 표준으로 주목받고 있는 JPEG2000 알고리즘을 유도탄 원격측정용 영상압축모듈 임베디드 시스템(embedded system)에서 효율적으로 구현하기 위한 DSP와 FPGA co-design 방법을 제안한다. DSP와 함께 FPGA에서 co-processing할 부분은 JPEG2000 알고리즘 가운데서 계산량이 많으면서도 FPGA 상에 구현하기 적합한 알고리즘인 MQ-코더 부분을 소프트웨어 profiling 작업을 거쳐 선정하였고 VHDL 언어를 사용해서 병렬 처리에 적합하도록 설계하였다. 구현한 MQ-코더의 성능을 검증하기 위하여 JBIG2 표준 테스트 벡터 및 실제 영상을 사용하였다. 실험결과 본 논문에서 제안한 MQ-코더는 기존 소프트웨어 코더보다 약 3배 정도의 압축속도를 향상 시켰다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1251-1253
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• 2001

This paper presents on capacity design of DC-fed-traction system. The system is introduced including a characteristics of train, feeding network configuration, and design method of substation arrangements. Optimal design procedures is described, and program for capacity computation of the system is presented using the nodal equation, K.C.L, K.V.L, Ohm's law and superposition theory. For the proof of the proposed algorithm, we accomplished the simulation of DC traction system for HA-Nam LRT. By considering whole component in DC traction system the conclusion will be much precise.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 춘계 학술대회논문집
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• pp.59-63
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• 2007

With the recent increasing demand on the high-performance buildings, there has been a rapid growth in the application of the Computational Fluid Dynamics to the Building design. The conceptual ventilation design of the underground parking area currently under construction is validated using the CFD-ACE+. It has been found that the conceptual ventilation design quantitively satisfies the legal standards. However, the highly concentrated region of CO is predicted. The positions and blowing directions of ventilating lane are changed based on the previously predicted concentration distributions. The highly concentrated region of CO is slightly reduced, but not much change has been observed. Two more fang are installed and the positions and blowing directions of the fans are modified so that the highly concentrated region of CO is minimized.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1057-1064
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• 2009

Since the global warming causes debris flow damage has increased in Kangwon Area, Sediment control dam have increasingly founded to protect the damage. In spite of the realities design methods are well not established to determine type of the dam, design parameters and maintenance. Through comparison for design methods to sediment control dam in Korea, it raised some points to improve to correspond with realities. In addition, it pointed that some issues for the sediment control dams in Kangwon Area. Those are shown that unclear positions of the dams, unremoval of sediment, occurrence of seepage under the dams and uninstallation of roads to remove sediment. In addition, the countermeasure for the issues are proposed.