• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.1
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• pp.20-27
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• 2002

Aircraft design requires the intergration of several disciplines, inculding aerodynamics, structures, controls. To achieves advances in performance, each technology, or discipline must be more accurate in analysis and must be more highly intergrated. One of the important interdisciplinary interactions in mordern aircraft design is that of aerodynamics and structures. In this study, for increasing accuracy in each discipline's analysis, CFD for aerodynamic analysis and FEM for structurral analysis was used and, for considering important interdisciplinary interactions, aeroelastic effect was considered. As optimization algorithm, PBIL algorithm was used for global optima and was parallelized to alleviate the computational burden. The efficiency and accuracy of the present method was assesed by range maximiziation of reference of reference wing.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.1056-1064
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• 2010

This paper presents the approximate analysis method for the symmetric transmission line crossing the aperture in an backplane. The method of moments is used to determine the aperture impedance for the construction of the equivalent transmission line that the aperture impedance apply to the transmission line as the shunt impedance. As the results, the insertion loss increases at the specific frequency range for the impedance matching. In the case of the mismatching, we are confirmed to the insertion gain at the specific frequency. Also the horizontal length of the aperture affects to the transmission line better than vertical length. The measurement of the insertion loss is performed to verify the theoretical analysis.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.1
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• pp.59-78
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• 2024

In tunnel construction, the stability is evaluated by the settlement of adjacent structures and ground, but the shear strain of the ground is the main factor that determines the failure mechanism of the ground due to the tunnel excavation and the change of the operating load, and can be used to review the stability of the tunnel excavation and to calculate the reinforcement area. In this study, a twin tunnel excavation was simulated on a soft ground in an urban area through a laboratory model test to analyze the behavior of the twin tunnel excavation on the adjacent pile grouped foundation and adjacent ground. Both the displacement and the shear strain of ground were obtained using a close-range photogrammetry during laboratory model test. In addition, two-dimensional finite element numerical analysis was performed based on the model test. The results of a back-analysis showed that the maximum shear strain rate tends to decrease as the horizontal distance between the pillars of the twin tunnel and the vertical distance between the toe of the pile group and the crown of the tunnel were decreased. The impact of the second tunnel on the first tunnel and pile group was decreased as the horizontal distance between the pillars of the twin tunnel was increased. In addition, the vertical distance between the toe of the pile group and the crown of the tunnel had a relatively greater impact on the shear strain results than the horizontal distance of the pillars between the twin tunnels. According to the results of the close-range photogrammetry and numerical analysis, the settlement of adjacent pile group and adjacent ground was measured within the design criteria, but the shear strain of the ground was judged to be outside the range of small strain in all cases and required reinforcement.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.257-262
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• 2015

In this paper, the split-ring DGS resonator is proposed and its equivalent circuit are analyzed to design the low pass filter. Compared with the conventional dumbell DGS cell, this structure has a flat fluctuation in low frequency range and a sharp slop at edge frequency. The out-band suppression of the SRR-DGS cell can be improved by placing the open stubs on the conductor line which operates as parallel capacitances. Making use of equivalent circuit analytical method, the characteristics of the improved SRR DGS cell are investigated and applied to design compact low pass filter, which has a low in-band loss, sharp slop and high suppression of more than 35dB within a wide out-band frequency range. The dependence of the transmission characteristic on the dimension of a split ring, such as side-length and split-gap, is analyzed in detail. In addition, an improved SRR DGS cell model with open stubs loaded on the conductor line is then presented to improve the out-band suppression. By using the equivalent-circuit analytical method, an S-band microstrip low-pass filter with perfect low-pass characteristic and high out-band suppression is designed and fabricated.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1011-1018
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• 2006

멀티모달 인터페이스는 인간의 제스처, 시선, 손의 움직임, 행동의 패턴, 음성, 물리적인 위치 등 인간의 자연스러운 행동들에 대한 정보를 해석하고 부호화하는 인지기반 기술이다. 본 논문에서는 제스처와 음성, 터치를 이용한 3D 오브젝트 기반의 멀티모달 인터페이스를 설계, 구현한다. 서비스 도메인은 스마트 홈이며 사용자는 3D 오브젝트 직접조작을 통해 원격으로 가정의 오브젝트들을 모니터링하고 제어할 수 있다. 멀티모달 인터랙션 입출력 과정에서는 여러 개의 모달리티를 병렬적으로 인지하고 처리해야 하기 때문에 입출력 과정에서 각 모달리티의 조합과 부호화 방법, 입출력 형식 등이 문제시된다. 본 연구에서는 모달리티들의 특징과 인간의 인지구조 분석을 바탕으로 제스처, 음성, 터치 모달리티 간의 입력조합방식을 제시하고 멀티모달을 이용한 효율적인 3D Object 인터랙션 프로토타입을 설계한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.52-54
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• 2011

In this paper, efficient framework design to construct electromagnetic simulator is proposed and examined. Especially computing time for example problem is enhanced to be shorted than computed time for single task corresponding to increasing the number of network PCs. As a result, design and analysis for antenna, cavity, and waveguide problems with large scale complex structure can be applied.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.5
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• pp.738-746
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• 1999

In this paper, a microstrip $18\times2$ dual beam array antenna is designed at 10 GHz. The radiating element is an aperture-coupled patch, and it is analyzed by the transmission line model. The feed is a tapered parallel-series type to reduce the side lobe level. To obtain dual beam at $\pm45^{\circ}$, The difference in phase excitation between the elements is $180^{\circ}$. In conclusion, the side lobe level is 25 dB, and the beam width $8^{\circ}$with two main lobes at $\pm44.5^{\circ}$.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.156-162
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• 1999

원자력교육원 2회기 기준발전소인 영광 1호기 발전소의 디지털 경보설비 (IAS : Intelligent Annunciator System) 는 MPU, SSU, ACU 및 ADU로 구성되어 있으며, 특히 MPU에서는 SSU 로부터 수신된 Scan Data를 해석하고 경보를 저장하고, 경보의 내용을 프린터 및 CRT를 비롯하여 다양한 형태로 병렬출력이 가능하도록 하고 있다. 본 논문에서는 전력연구원에서 수행중인 '원자력 교육원 시뮬레이터 성능개선' 과제의 일부로 IAS의 구조와 이를 시뮬레이터 주컴퓨터 (Host Computer)상의 다이나믹 모델과 연동시켜 구현하는 방법론을 다루고 있다. 특히, 시뮬레이터에 대한 규제기관의 인허가가 중요한 현안으로 대두될 전망임에 따라 ANSI/ANS-3.5, Regulatory Guide 1.149 등 규제요건에서 제시하는 성능기준 및 검사기준을 만족하도록 설계함으로 향후 규제기관에 대한 인허가 획득에서 대비할 예정이다.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.9
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• pp.952-958
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• 2009

This article presents a combined structure of serial and parallel mechanisms for a humanoid robot. The 3 DOF parallel structure is designed and added to the waist of the humanoid robot arm to give flexible bending and rotating motions. Forward and inverse kinematics of a serial and parallel robot have been analyzed to generate motions. Simulation studies of verifying kinematics solutions of the parallel robot have been done. Experimental studies of mimicking shake-hands motion have been conducted to show the feasibility and usability of the combined structure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.10
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• pp.1109-1116
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• 1992

Mathematical morphology, theoretical foundation for morphological filter, is very efficient for the analysis of the geometrical characteristics of signals and systems and is used as a predominant tool for smoothing the data with noise. In this study, H/W design of morphological filter is implemented to process the gray scale dilation and the erosion in the same circuit and to choose the maximum and minimum value by a selector, resulting in their education of the complexity of the circuit and an architecture for parallel processing. The structure of morphological filter consists of the structuring-element block, the image data block, the control block, the ADD block, the MIN/MAX block, etc, and is designed on an one-chip for real time operation.