• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2009.06a
• /
• pp.89-90
• /
• 2009

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.5B
• /
• pp.591-594
• /
• 2008

Present study aims at the development of a reasonable boundary condition for a structure over inclined seabed in case of the numerical model with quadrilateral mesh system. The technique for the inclined impermeable/permeable boundary in the quadrilateral mesh is newly proposed. The new technique and LES-WASS-3D model (Hur and Lee, 2007) have been used for the investigation of the dynamics of fluid field, and validated through the comparison with a typical stair-type boundary condition. 3-Dimensional numerical model with Large Eddy Simulation is called LES-WASS-3D, and is able to simulate directly interaction of WAve Structure Sea bed/Sandy beach.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1991.04a
• /
• pp.57-61
• /
• 1991

최근 차량의 고급화에 따라 차실 소음 저감에 대한 연구가 많이 수행되고 있다. 차실의 소음은 주로 엔진 또는 동력전달 장치의 진동과 도로의 요철로 생기는 차체의 진동으로부터 발생된다. 차실에서 20-200Hz의 저주파수대의 소음은 주로 차체 진동과의 연성 효과로 기인한다. 따라서 이 주파수영역에 있어서 소음의 특성을 파악하기 위해서는 차실의 음향 모우드 해석과 차체 구조물의 진동과 차실 음향 모우드의 상호관계를 고려한 구조-음향 연성 해 석이 필요하다. 차실의 음향 모우드 해석을 위해서는 실험적 방법과 유한 요 소법을 이용하는 방법이 있다. 유한 요소법을 이용하여 음향 특성을 결정하 는 경우, 큰 어려움은 없으나 밀폐된 공동에서 경계면을 이루는 구조물의 진 동에 의해 음이 발생되는 경우 단순히 공간의 음향 특성만으로는 음향 응답 을 예측할 수 없게 된다. 즉, 경계면에서 반사되는 반사파는 경계면의 탄성 변위에 의해 운동 특성이 변화되어 반사되므로 입사파와 다른 특성을 가지 게 된다. 따라서 이러한 구조 진동 특성과 음향 특성을 모두 고려한 연성 해 석을 수행하여야 하며, 음향 모우드와 구조 진동 모우드와의 연성에 의한 음 향 응답 특성을 결정하기 위한 수치 해석 프로그램을 개발하게 되었다. 본 연구에서는 전.후 처리 및 사용자 편의성을 염두에 두고 차실소음해석 전용 프로그램(ACSTAP: Acoustical and structural, coupling analysis program) 을 작성하고 이를 실차에 적용하여 유용성을 보였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.35 no.5
• /
• pp.404-411
• /
• 2007

new domain/boundary decomposition method is suggested to perform efficient finite element analyses of contact problems. A penalty method is used for connecting an interface or contact interfaces with neighboring subdomains that satisfy continuity conditions. As a result, the derived effective stiffness matrices are always positive definite, and computational efficiency can be improved to a considerable degree. Moreover, any complex-shaped domain can be divided into independently modeled subdomains without considering the conformity of meshes along the interface. Using a computer code based on the present method, these advantageous features are confirmed through a set of numerical examples.

• The KIPS Transactions:PartA
• /
• v.16A no.2
• /
• pp.79-88
• /
• 2009

In boundary scan architecture, test stimuli are shifted in one at a time and applied to the on-chip system logic. The test results are captured into the BSR and are examined by subsequent shifting. In this paper, we developed a continuous capture test architecture and test procedure using TPG based on boundary scan is used to performance test. In this architecture, test patterns of TPG are applied to CUT with system clock rate, and response of CUT is continuously captured by CBSR(Continuous Capture Boundary Scan Register) at the same rate and the captured results is shifted to TDO at the same rate. The suggested a continuous capture test architecture and test procedure is simulated by Altera Max+Plus 10.0. The simulation results shows the accurate operation and effectiveness of the proposed test architecture and procedure.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.36 no.1
• /
• pp.39-47
• /
• 2016

Repair methods of aging concrete pavement are generally used composite structure pavements, such a composite structure is subjected to a large impact on the mechanical behavior and ensure long-term commonality integrated under vehicle loads, environmental loads of the public in accordance with the bond strength between old and new concrete. A common of bonded concrete overlays that are currently available is Interface arrangements using a variety of equipment to ensure the excellent bond strength between old and new concrete than standard concrete, mixed with a material such as a polymer in order to improve the adhesion with the material itself. However, these method of constructions are being applied, depending on the developer site presents no special specifications apply when a specific application criteria objectively, this is due to the situation of each individual method, which is based on the difficulty in quality control of the site manager. In this study by performing a field test for polymer content via the variables that contribute most significantly to ensure bond strength and the field element core of the interface processing method and materials to ensure bond strength between the old and the new concrete, it was to derive the construction site construction method that can improve the performance of the bond strength through a review of the construction around the correlations and the bond strength according to the effective performance analysis of the conventional surface treatment process and variation of polymer volume fraction.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.1
• /
• pp.78-84
• /
• 2015

Depth estimation is often required for robot vision, 3D modeling, and motion control. Previous method is based on the focus measures which are calculated for a series of image by a single camera at different distance between and object. This method, however, has disadvantage of taking a long time for calculating the focus measure since the mask operation is performed for every pixel in the image. In this paper, we estimates the depth by using the focus measure of the boundary pixels located between the objects in order to minimize the depth estimate time. To detect the boundary of an object consisting of a straight line and a circle, we use the Hough transform and estimate the depth by using the focus measure. We performed various experiments for PCB images and obtained more effective depth estimation results than previous ones.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.12
• /
• pp.1165-1172
• /
• 2009

The laminar boundary layer along a streamwise corner formed by two flat plates intersecting at right angle is measured by using Particle Image Velocimetry(PIV) technique. The free stream velocity ranges from 2.96m/s to 3.0m/s. The angle of incidence of the corner is set to 1.2 degree providing slightly favourable pressure gradient to ensure a laminar flow in the corner region. A round shape leading edge is used and the length of the model is about 1000mm. In the bisector plane, the measurement data show separation type velocity profiles having an inflection point which is a typical characteristic of laminar corner boundary layers. As the distance away from the bisector plane increases, velocity profiles are found to change into the Blasius profile. The change completes around half length of the boundary layer thickness in the bisector plane away from the bisector plane along the plate. In the bisector plane, the growth characteristic of the boundary layer thickness and the approximate similarity of velocity profiles are confirmed from the measurement data.

• The KIPS Transactions:PartB
• /
• v.11B no.7 s.96
• /
• pp.841-848
• /
• 2004

Evolutionary a1gorithms are well-suited for multi-objective optimization problems involving several, often conflicting objectives. Pareto-based evolutionary algorithms, in particular, have shown better performance than other multi-objective evolutionary algorithms in comparison. However, generalized evolutionary multi-objective optimization algorithms have a weak point, in which the distribution of solutions are not uni-formly distributed onto Pareto optimal front. In this paper, we propose an evolutionary a1gorithm for multi-objective optimization which uses seed individuals in order to overcome weakness of algorithms Published. Seed individual means a solution which is not located in the crowded region on Pareto front. And the idea of our algorithm uses seed individuals for reproducing individuals for next generation. Thus, proposed a1go-rithm takes advantage of local searching effect because new individuals are produced near the seed individual with high probability, and is able to produce comparatively uniform distributed pareto optimal solutions. Simulation results on five testbed problems show that the proposed algo-rithm could produce uniform distributed solutions onto pareto optimal front, and is able to show better convergence compared to NSGA-II on all testbed problems except multi-modal problem.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.3
• /
• pp.862-872
• /
• 1998

In this paper, we developed a delay test architecture and test procedure for clocked sequential circuit. In addition, we analyze the problems of conventional and previous method on delay test for clocked sequential circuit in IEEE 1149.1. This paper discusses several problems of Delay test on IEEE 1149.1 for clocked sequential circuit. Previous method has some problems of improper capture timing, of same pattern insertion, of increase of test time. We suggest a method called ARCH-S, is based on a clock counting technique to generate continuous clocks for clocked input of CUT. A 4-bit counter is selected for the circuit under test. The simulation results ascertain the aecurate operation and effectiveness of the proposed architecture.