• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.5
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• pp.779-787
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• 2001

The multi degree of freedom system using magnetic levitation has been implemented successfully. Differently from another noncontact systems, the developed system was focused on the maximization of the system stiffness under the constraint of a limited input. The variation of a relative adopting point between the magnetic pair, its location on the fixed base, and the selection of optimal specifications for the main active magnetic elements give us another chance to realize the increased robustness against external disturbances with the less control inputs. In this paper, the overall development procedures are given including the optimal design, the dynamic modeling, the various control tests, and the main issues to be solved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.232-232
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• 2004

최근 초고속 광통신 시스템이 발달함에 따라, 광통신 시스템 및 초고속 광통신 시스템의 핵심 부품인 평면도파로형 분배기(Splitter) 및 결합기(Coupler), 파장분할 다중화소자(WDM), AWG(Arrayed Wave Guide) 필터와 같은 소자부품 수요가 급격히 늘고 있다. 그러나 이러한 소자를 생산하는 공정은 수공적인 방법에 의존하여 생산성 향상을 위한 자동화에 대한 요구가 시급하다 특히 소자(Devices)와 광섬유(Optical fiber) 사이의 광학적인 정렬(Alignment)과 접속(Attachment) 공정은 부품 성능 및 생산성 향상, 그리고 비용절감을 위한 가장 핵심적인 문제로 대두되고 있다.(중략)

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.473-480
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• 1998

The substructuring pseudodynamic test is a hybrid testing method consisting of a numerical simulation of the earthquake response of an analytical model and a loading test of a specimen. The substructuring pseudodynamic testing technique has been applied to various seismic experiments since it has advantages over the shaking table test to study dynamic behaviors of relatively large scale structures. However, experimental errors are inevitable in substructuring pseudodynamic testing. Some of these errors can be monitored during the test, but, due to limitations in control system, they cannot be eliminated. For example, one cannot control exactly the displacements that are actually imposed on the structures at each time step. This paper focuses on a technique to minimize the cumulative effect of such control errors for MDOF system. For this purpose, the modified posterior adjustment of the time increment from a target value $\Delta$t$_{n}$ to an adjusted value is performed to minimize the effect of the control errors for MDOF system.for MDOF system.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.61
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• pp.303-325
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• 2014

As the development of information and globalization of world economy enters new condition, the stake of every nation's makes more complwx, and multilateral negotiation lead by WTO is seriously delayed. But the number of agreement about FTA increase exponentially. In this study we aim to consider whether Korean FTA affects the relation of the trade of Korea and Japan or not, especially Automobile industry. The composition of this paper is as follows. Chap. 1 is Introduction. In Chap. 2, we consider the change of the Trade Policy of Korea focusing in FTA. In Chap. 3, we consider how Korean FTA affect the structure of Japan's Trade, especially the automobile industry of Korea and Japan. In Chap. 4, we have conclusion. As the conclusion, the impact to the automobile industry of Korea and Japan is that Korean FTA works to Korean automobile industry advantageously in micro level, but in macro level, the competition of world automobile industry move into a next generation technology market.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.923-928
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• 2004

AFM tip has been used for surface profiling with a fine resolution, but there is a barrier to improve its performance because of the low aspect ratio. Many researchers have solved this problem with attaching carbon nanotube (CNT) to Si-tip. In this paper, we proposed the aligner system that composed of dual type stage system, and these stages could attach a carbon nanotube to tungsten-tip in vacuum condition. We used tungsten tip instead of Si-tip because of its conductivity. The aligner system proposed in this paper has 10 degree-of-freedom that 3 in the first stage and 7 in the second stage. With picomotors and piezotube, the first stage has the resolution about several tens of nm and the second stage has a resolution about a nm. We experimented on characterization of Nano Aligner System and operated picomotors in SEM environment.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.150-155
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• 2005

In recent years, as the demands of VBNS(Very high speed Backbone Network Service) and VDSL(Very high-data rate Digital Subscriber Line) increase, the development of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, WDM elements increase. The alignment and the attachment technology are very important to fabricate the optical elements for communication. In this paper, the mechanism of rotational stage are studied. with the three different method and the results of them are applied to the design of the system. The performance test of resolution and travel is performed.

• Annual Conference on Human and Language Technology
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• 2015.10a
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• pp.213-215
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• 2015

국립국어원 온라인가나다에서 제공되는 질의응답 문서를 이용한 국어정보에 대한 Q&A시스템은 언어 자체에 대한 질문과 답변의 특성으로 조사나 어미로 끝나는 표현이 주어로 등장하는 등의 특이한 문장이 자주 나타난다. 이러한 이유로 형태소 분석을 거쳐 명사를 키워드로 추출하는 일반적인 키워드 추출 방식은 좋은 성능을 얻기 어렵다. 본 논문에서는 국어정보 질의응답 문서의 특징에 맞는 키워드 추출 방법을 제안한다. 제안하는 방식에서는 문장 단위로 분할된 결과에서 연결어미로 문장을 추가로 분할한 뒤에 조사 앞에 나타나는 단어열을 키워드로 추출한다. 덧붙여 다자비교형 질의에서의 키워드 추출을 위해 편집거리를 이용한 키워드 추출 방법을 제안한다.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.11
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• pp.492-497
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• 2006

Nash Equilibrium (NE) is essential to investigate a participant's bidding strategy in a competitive electricity market. The transmission line constraints make it difficult to compute the NE due to causing a mixed strategy NE instead of a pure strategy NE. Computing a mixed strategy is more complicated in a multi-player game. The competition among multi-participants is modeled by a two-level hierarchical optimization problem. A mathematical programming approach is widely used in finding this equilibrium. However, there are difficulties to solving a mixed strategy NE. This paper presents two propositions to add heuristics to the mathematical programming method. The propositions are based on empirical studies on mixed strategies in numerous sample systems. Based on the propositions a new formulation is provided with a set of linear and nonlinear equations, and an algorithm is suggested for using the prepositions and the newly-formulated equations.

• The Journal of Korea Robotics Society
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• v.12 no.1
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• pp.11-18
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• 2017

Static balance of an articulated robot arm at various configurations requires a torque compensating for the gravitational torque of each joint due to the robot mass. Such compensation torque can be provided by a spring-based counterbalance mechanism. However, simple installation of a counterbalance mechanism at each pitch joint does not work because the gravitational torque at each joint is dependent on other joints. In this paper, a 6 DOF industrial robot arm based on the parallelogram for multi-DOF counterbalancing is proposed to cope with this problem. Two passive counterbalance mechanisms are applied to pitch joints, which reduces the required torque at each joint by compensating the gravitational torque. The performance of this mechanism is evaluated experimentally.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.447-449
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• 2017

리그 오브 레전드, 히어로즈 오브 더 스톰 등으로 대변되는 다자 온라인 전투 게임(MOBA)은 PC 버전에서 우리 게이머가 아주 많이 플레이하는 장르이다. 본 논문은 이 장르의 모바일 버전인 2017년작 펜타스톰의 사용자 인터페이스를 PC 버전의 인터페이스와 물리적 구조 및 기능성에 대해 비교 분석하고 코호넨의 휴리스틱에 기초한 사용자 인터페이스의 조작 편의성에 집중한 설문 조사를 통해 펜타스톰 사용자 인터페이스의 만족도와 개선 방향을 살펴보았다. 4점 척도로 적극적 평가를 요구한 8개의 설문에서 펜타스톰 사용자 인터페이스는 5개 부문에서 80% 이상의 긍정률을 보였지만 아이템 구매 관련은 호불호가 갈렸고 캐릭터 동선과 상대 지정 부분은 상대적으로 낮은 긍정률을 보여 개선의 필요성을 나타냈다.