• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.108.4-108
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• 2002

This paper aims to derive a mathematical model of the dynamics of handling tasks in robot fingers which stably grasps and manipulates a rigid object with some dexterity. Firstly, a set of differential equation describing dynamics of the manipulators and object together with geometric constraint of tight area-contacts is formulated by Lagrange's equation. Secondly, problems of controlling both the internal force and the rotation angle of the grasped object under the constraints of tight area-contacts are discussed. The effect of geometric constraints of area-contacts on motion of the overall system is analyzed and a method of computer simulation for differential-algebraic equations of overall...

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1989년도 가을 학술발표회 논문집
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• pp.51-58
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• 1989

Through a series of analyses of specific structures it is shown that incremental collapse may be the critical design criterion and that shakedown analysis can be used as a design tool. Using shakedown analysis technique, a nonlinear structural optimization program has been developed. This incorporates : (ⅰ) design constraints on elastic stresses and deflections ; (ⅱ) constraints for the prevention of incremental collapse and soft story failure ; and (ⅲ) the constraint on the fundamental period of structure. A five-step design procedure is proposed by using this program to obtain the optimum design that satisfies all the requirements of comprehensive earthquake-resistant design.

• 전산구조공학
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• 제2권4호
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• pp.99-109
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• 1989

몇 가지의 예를 들어 점진적 붕괴가 내진설계의 중요한 설계기준이 될 수 있다는 것과 이와 관련하여 Shakedown 해석이 한 구조설계 도구로 사용될 수 있다는 사실이 밝혀진다. 이 Shakedown 해석기법을 사용하여 비선형 계획에 의한 최적 구조설계 프로그램이 개발되었는데, 이것은: (i) 탄성응력과 처짐에 대한 제약조건: (ii) 점진적 붕괴와 약충붕괴의 방지를 위한 제약조건: 그리고 (iii) 구조물의 기본주기에 대한 제약조건을 수용하고 있다. 마지막으로 내진설계의 모든 요구조건을 만족시키는 최적설계를 얻기 위하여, 이 개발된 프로그램을 이용한 5-단계 설계방법론이 제시되고 있다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.887-890
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• 1993

By introducing the notion of constraint-oriented fuzzy inference, we will show that it provides us ways of fuzzy control methods that has abilities of adaptation, learning and self-organization. The basic supporting techniques behind these abilities are“hard”processing by Artificial Intelligence or traditional computational framework and“soft”processing by Neural Network or Genetic Algorithm techniques. The reason that these techniques can be incorporated to fuzzy control systems is that the notion of“constraint”itself has two fundamental properties, that is, the“modularity”property due to its declarativeness and the“logicality”property due to its two-valuedness. From the former property, the modularity property, decomposing and integrating constraints can be done easily and efficiently, which enables us to carry out the above“soft”processing. From the latter property, the logicality property, Qualitative Reasoning and Instance Generalization by Symbolic Reasoning an be carried out, thus enabling the“hard”processing.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1060-1067
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• 2005

This paper attempts to derive and analyze the dynamic system of pinching a rigid object by means of two multi-degrees-of-freedom robot fingers with soft and deformable tips. It is shown firstly that a set of differential equation describing dynamics system of the manipulators and object together with geometric constraint of tight area-contacts is formulated by Lagrange's equation. It is shown secondly that the problems of controlling both the forces of pressing object and the rotation angle of the object under the geometric constraints are discussed. In this paper, the control method for dynamic stable grasping and enhancing dexterity in manipulating things is proposed. It is illustrated by computer simulation that the control system gives the performance improvement in the dynamic stable grasping of the dual fingers robot with soft tips.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.467-472
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• 2010

Individual vacuum pressure method is soft ground improvement technique, in which a vacuum pressure can be directly applied to the vertical drain board to promote consolidation and strengthening the soft ground. This method does not require a surcharge load, different to embankment or pre-loading method. In this study, given the inner displacement of the ground where the individual vacuum pressure is applied, this dissertation aimed to reproduce the state of stress in the ground that is subject to the constraints created by the depth of improvement area. Modified Cam Clay theory which made it possible to take into account the isotropic displacement of the ground was applied to the NAP-IVP used simulation; the conception of equivalent permeability proposed by Hird was also applied so that the 3-dimensional real construction effect of drain materials could be reflected in the analysis.

• 전력전자학회논문지
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• 제18권5호
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• pp.458-465
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• 2013

This paper proposes a novel soft-switched auxiliary resonant circuit to provide a Zero-Voltage-Transition at turn-on for a conventional PWM boost converter in a PFC application. The proposed auxiliary circuit enables a main switch of the boost converter to turn on under a zero voltage switching condition and simultaneously achieves both soft-switched turn-on and turn-off. Moreover, for the purpose of an intelligent multi-chip power module fabrication, the proposed circuit is designed to satisfy several design constraints including space saving, low cost, and easy fabrication. As a result, the circuit is easily realized by a low rated MOSFET and a small inductor. Detail operation and the circuit waveform are theoretically explained and then simulation and experimental results are provided based on a 1.8 kW prototype PFC converter in order to verify the effectiveness of the proposed circuit.

• 한국음향학회지
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• 제29권4호
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• pp.286-293
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• 2010

기존 데이터 압축 방식에는 크게 resolution-constrained quantization (RCQ) 방식과entropy-constrained quantization (ECQ) 방식이 있다. RCQ 방식은 고정 비트율 전송을 가능하게 하지만 셀 크기의 변화에 따른 이상 신호왜곡이 발생하며, ECQ 방식은 셀 크기가 고정된 대신에 이상 비트율 할당 문제가 발생한다. 본 논문에서는 기존 RCQ 방식의 대표적인 학습기법인 generalized Lloyd algorithm (GLA)을 개선한 cell-size constrained vector quantization (CCVQ) 방식을 제안한다. CCVQ 알고리즘은 셀 크기에 따라 유동적으로 패널티 척도를 주는 방식으로 기존의 RCQ와 ECQ 사이의 soft-decision을 가능하게 한다. 제안 알고리즘을 사용할 경우 기존의 GLA에 비해 약간의 평균왜곡 증가는 발생하나 이상 신호왜곡을 줄일 수 있다.

• 무역학회지
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• 제45권5호
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• pp.1-22
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• 2020

This study explores the role of relationship banking for the exports of SMEs (small and medium sized enterprises) in Korea. Using a sample of SMEs listed on the Korean stock markets between 2004 and 2018, I find that relationship banking has a positive impact on exporting behaviors of SMEs. This result indicates that relationship banking is suitable for SMEs to raise their funds in the export decision-making since the incentive for banks to obtain soft information enhances SMEs' access to external finance. In particular, through further analysis considering financial constraints, I find that the positive impact of relationship banking on exports is amplified for financially constrained SMEs. In addition, the positive impact on exports is also amplified for export starters. Finally, relationship banking provides benefits for SMEs' export decision-making regardless of the financial crisis. To sum up, relationship banking may be useful means of financing for Korean SMEs whose creditworthiness cannot be assessed only by hard information. As the role of finance in international trade has recently been highlighted, this study provides insightful evidence that relationship banking may enhance exports of SMEs as a source of trade finance.

• 지질공학
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• 제28권3호
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• pp.367-377
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• 2018

이 연구는 전기비저항 역산의 해상도를 높이기 위한 구조제약과 부등식 제약조건을 적용한 전기비저항역산법을 소개하고 적용한 결과를 보여준다. 이들 역산에서는 지하투과레이다와 표면파 탐사자료로부터 사전 해석된 층서구조를 전기비저항 참조모델로 도입하고 구조제약과 부등식 제약의 유용성을 합성모델을 이용한 역산실험으로 확인하였다. 연약지반 조건을 가정한 실험모델에 대한 구조제약과 부등식 제약 역산실험 모두 일반적인 전기비저항 역산보다 향상된 역산결과를 보여주었으나, 부등식제약 역산에서는 참조모델이 다소 부정확한 경우에도 배경층서구조를 정확히 재구성하는 동시에 천부(약 10 m 심도)의 전도성 이상체들도 정확히 나타내는 역산결과를 보여주었다.