• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1218-1227
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• 2004

Multi-domain engineering systems include electrical, mechanical, hydraulic, pneumatic, and thermal components, making it difficult to design a system because of their complexity and inter domain nature. In order to obtain an optimal design, a unified design approach for each domain and an automated search method are required. This paper suggests a method for automatically synthesizing designs for multi-domain systems using the combination of bond graph that is domain independent and genetic programming that is well recognized as a powerful tool for open-ended search. To investigate the effect of proposed approach, an eigenvalue design problem is tested for some sample target sets of eigenvalues with different embryos.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.1
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• pp.1-6
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• 2016

Domain analysis is an important component for reliability of development project. Domain analysis error have an effect in the whole system. As a result, the system reliability will be deteriorated. Therefore, we need a methodology to analyze domain characteristic for a reliable analysis in the domain analysis phase. In this paper, we propose a methodology for domain categorization and estimation of complexity for reliability improvement of domain analysis.

• Smart Structures and Systems
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• v.14 no.6
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• pp.1197-1220
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• 2014

Accurate actuator tracking is critical to achieve reliable real-time hybrid simulation results for earthquake engineering research. The frequency-domain evaluation approach provides an innovative way for more quantitative post-simulation evaluation of actuator tracking errors compared with existing time domain based techniques. Utilizing the Fast Fourier Transform the approach analyzes the actuator error in terms of amplitude and phrase errors. Existing application of the approach requires using the complete length of the experimental data. To improve the computational efficiency, two techniques including data decimation and frequency decimation are analyzed to reduce the amount of data involved in the frequency-domain evaluation. The presented study aims to enhance the computational efficiency of the approach in order to utilize it for future on-line actuator tracking evaluation. Both computational simulation and laboratory experimental results are analyzed and recommendations on the two decimation factors are provided based on the findings from this study.

• Structural Engineering and Mechanics
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• v.32 no.1
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• pp.37-53
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• 2009

In this paper the problem of calculating the probability that the responses of a wind-excited structure exceed specified thresholds within a given time interval is considered. The failure domain of the problem can be expressed as a union of elementary failure domains whose boundaries are of quadratic form. The Domain Decomposition Method (DDM) is employed, after being appropriately extended, to solve this problem. The probability estimate of the overall failure domain is given by the sum of the probabilities of the elementary failure domains multiplied by a reduction factor accounting for the overlapping degree of the different elementary failure domains. The DDM is extended with the help of Line Sampling (LS), from its original presentation where the boundary of the elementary failure domains are of linear form, to the current case involving quadratic elementary failure domains. An example involving an along-wind excited steel building shows the accuracy and efficiency of the proposed methodology as compared with that obtained using standard Monte Carlo simulations (MCS).

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.3
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• pp.266-281
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• 2017

Hydroelastic interactions of a deformable floating body with random waves are investigated in time domain. Both hydroelastic motion and structural dynamics are solved by expansion of elastic modes and Fourier transform for the random waves. A direct and efficient structural analysis in time domain is developed. In particular, an efficient way of obtaining distributive loads for the hydrodynamic integral terms including convolution integral by using Fubini theory is explained. After confirming correctness of respective loading components, calculations of full distributions of loads in random waves are expedited by reformulating all the body loading terms into distributed forms. The method is validated by extensive convergence tests and comparisons against the counterparts of the frequency-domain analysis. Characteristics of motion/deformation responses and stress resultants are investigated through a parametric study with varying bending rigidity and types of random waves. Relative contributions of componential loads are identified. The consequence of elastic-mode resonance is underscored.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.8
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• pp.883-888
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• 1999

To obtain high positioning auccuracy for a long, flex bleman Ipulator, residual vibration must be removed from the tip motion. But it is difficult to control the vibration of low frequency. There are open-loop and closed loop methods in the elimination of the residual vibration. We inroduce input shaping technique has been used as a simple open-loop method of controlling the residual vibration of a flexible manipulator. Design of input shaper in the continuous time domain is complicated. This paper presents a new technique that designs input shaper in the z-domain and analyzes input shaping method in the z-domain. This technique is simple and easy to design input shaper.

• Structural Engineering and Mechanics
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• v.20 no.3
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• pp.347-362
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• 2005

The input energy to a base-isolated (BI) building during an earthquake is considered and formulated in the frequency domain. The frequency-domain approach for input energy computation has some notable advantages over the conventional time-domain approach. Sensitivities of the input energy to the BI building are derived with respect to uncertain parameters in the base-isolation system. It is demonstrated that the input energy can be of a compact form via the frequency integration of the product between the input component (Fourier amplitude spectrum of acceleration) and the structural model component (so-called energy transfer function). With the help of this compact form, it is shown that the formulation of earthquake input energy in the frequency domain is essential for deriving the sensitivities of the input energy to the BI building with respect to uncertain parameters. The sensitivity expressions provide us with information on the most unfavorable combination of the uncertain parameters which leads to the maximum energy input.

• 한국HCI학회:학술대회논문집
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• 2006.02b
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• pp.76-82
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• 2006

본 연구는 항공기 관제사의 관제디스플레이에 대한 생태학적 인터페이스 디자인을 적용하기 위한 초기작업으로써 항공기 관제영역에 대한 Work Domain Analysis 를 실시하여 Work Domain Model 을 개발하고 모델에 대한 테스트를 통해 모델의 타당성을 검증하였다. 또한, 완성된 모델을 바탕으로 디자인을 위한 Information Requirement 를 추출함으로써 지금까지 적용해보지 않은 항공기 관제영역에 대한 생태학적 인터페이스 디자인 툴(Tool)의 새로운 적용가능성을 확인하여 추후, 구체적인 관제 디스플레이의 생태학적 개발에 기본 틀을 제공하고자 한다.

• Earthquakes and Structures
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• v.6 no.3
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• pp.251-266
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• 2014

Dynamic analyses for a suite of ground of motions were conducted on concrete gravity dam sections to examine the earthquake induced stresses and effective damping. For this purpose, frequency domain methods that rigorously incorporate dam-reservoir-foundation interaction and time domain methods with approximate hydrodynamic foundation interaction effects were employed. The maximum principal tensile stresses and their distribution at the dam base, which are important parameters for concrete dam design, were obtained using the frequency domain approach. Prediction equations were proposed for these stresses and their distribution at the dam base. Comparisons of the stress results obtained using frequency and time domain methods revealed that the dam height and ratio of modulus of elasticity of foundation rock to concrete are significant parameters that may influence earthquake induced stresses. A new effective damping prediction equation was proposed in order to estimate earthquake stresses accurately with the approximate time domain approach.

• Annual Conference on Human and Language Technology
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• 2010.10a
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• pp.152-154
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• 2010

다 영역 대화 시스템 개발에서는 영역 확장이 쉬워야 하며 처리하는 대화 영역이 늘어나더라도 대화 과정에서 사용자 편의성을 유지해야 하는 점이 중요하다. 본 논문에서는 이런 특성을 가지는 다 영역 대화 시스템을 작성하기 위한 프레임워크를 제안한다. 이 프레임워크는 공통의 인터페이스를 구현하는 영역 전문가(Domain Expert) 기반으로 동작하므로 영역 확장이 용이하다. 또한 진행 중이던 대화를 종료하지 않은 채 타 대화 영역으로 이동하는 영역 전환(Domain Switching) 현상은 다 영역 대화를 복잡하게 만드는 주요한 원인 중 하나로써 이를 효과적으로 관리할 수 있는 영역 전환 전략을 사용하여 사용자 편의성을 확보하였다.