• 전자공학회논문지B
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• 제31B권7호
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• pp.129-140
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• 1994

In this paper we investigate the hardware implementation of block matching algorithms (BMAs) for moving sequences. Using systolic arrays we propose a hardware architecture of a two-stage BMA using integral projections which reduces greatly computational complexity with its performance comparable to that of the full search (FS). Proposed hardware architecture is faster than hardware architecture of the FS by 2~15 times. For realization of the FS and two stage BMA modeling and simulation results using SPW and VHDL are also shown.

• 산업기술연구
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• 제16권
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• pp.197-205
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• 1996

In this paper, we propose a new neural architecture. We synthesize the architecture from a combination of structures known as MRCCN (Multi-resolution Radial-basis Competitive and Cooperative Network) and BPN (Backpropagation Network). The proposed neural network is able to improve the learning speed of MRCCN and the mapping capability of BPN. The ability and effectiveness of identifying a ninlinear dynamic system using the proposed architecture will be demonstrated by computer simulation.

• 한국군사과학기술학회지
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• 제15권4호
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• pp.404-409
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• 2012

In order to detect and track target, submarine gather the target information(bearing, range, frequency and so on) with using multiple sensors. And submarine can estimate target states with target information. In this paper, we suggest the target motion analysis(TMA) filter architecture of submarine and the proposed TMA filter architecture is tested by a series of computer simulation runs and the results are analyzed and verified.

• Wind and Structures
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• 제14권5호
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• pp.465-480
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• 2011

In this paper, a stabilized large eddy simulation technique is developed to predict turbulent flow with high Reynolds number. Streamline Upwind Petrov-Galerkin (SUPG) stabilized method and three-step technique are both implemented for the finite element formulation of Smagorinsky sub-grid scale (SGS) model. Temporal discretization is performed using three-step technique with viscous term treated implicitly. And the pressure is computed from Poisson equation derived from the incompressible condition. Then two numerical examples of turbulent flow with high Reynolds number are discussed. One is lid driven flow at Re = $10^5$ in a triangular cavity, the other is turbulent flow past a square cylinder at Re = 22000. Results show that the present technique can effectively suppress the instabilities of turbulent flow caused by traditional FEM and well predict the unsteady flow even with coarse mesh.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.157-162
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• 2005

컴퓨터 시뮬레이션이라는 개념이 세상에 소개되고 널리 사용된 것은 이미 오랜 전의 일이다. 또한 이러한 방법론이 여러 방면으로 제조/생산 분야 기업의 이윤을 증대시키는 데 기여할 수 있다고 알려져 있고 실제로 일부 영역에서는 기여를 하고 있다. 하지만, 냉정하게 현실을 판단해보면 컴퓨터 시뮬레이션이 좀 더 넓은 제조 영역에서 그 자체의 가치를 향상시키기 위해서는 아직 부족한 점이 존재한다. 예를 들어, 적용하고자 하는 분야에서 컴퓨터 시뮬레이션의 효용 가치를 발견하지 못한다거나, 시뮬레이션 모델링 업무 자체가 하나의 새로운 부담으로 다가오는 일, 또는 기업의 입장에서 시뮬레이션 소프트웨어의 가격이 너무 높기 때문에 컴퓨터 시뮬레이션을 도입하고 싶어도 비용적인 측면에서 벽에 부딪치는 일이 빈번하게 발생을 하고 있다. 본 논문에서는 이러한 문제점들을 해결할 수 있는 방법론들에 대한 분석 및 사례들을 보이고자 한다. 컴퓨터 시뮬레이션 모델링을 기존의 라이브러리를 활용하여 좀 더 쉬운 방법으로 재활용 할 수 있는 방법론, 제조 현장 어디서나 컴퓨터 시뮬레이터에 접속하여 시뮬레이션을 수행 할 수 있는 방법론 그리고, 이러한 방법론들이 실제로 기업의 업무에서 어떠한 기여를 할 수 있는지에 대한 분석을 수행하고자 한다.

• 한국전산유체공학회지
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• 제17권2호
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• pp.35-41
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• 2012

This paper presents incompressible Navier-Stokes solution algorithm for 2D Free-surface flow problems on the Cartesian mesh, which was implemented to run on Graphics Processing Units(GPU). The INS solver utilizes the variable arrangement on the Cartesian mesh, Finite Volume discretization along Constrained Interpolation Profile-Conservative Semi-Lagrangian(CIP-CSL). Solution procedure of incompressible Navier-Stokes equations for free-surface flow takes considerable amount of computation time and memory space even in modern multi-core computing architecture based on Central Processing Units(CPUs). By the recent development of computer architecture technology, Graphics Processing Unit(GPU)'s scientific computing performance outperforms that of CPU's. This paper focus on the utilization of GPU's high performance computing capability, and presents an efficient solution algorithm for free surface flow simulation. The performance of the GPU implementations with double precision accuracy is compared to that of the CPU code using an representative free-surface flow problem, namely. dam-break problem.

• 한국정보과학회논문지:시스템및이론
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• 제36권2호
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• pp.53-59
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• 2009

국방 획득업무에 있어 통합적 협력에 의한 M&S의 활용을 지향하는 SBA가 적용 중에 있다. 이를 효율적으로 수행하기 위해서는 공통하부기반을 통해 M&S 구성요소의 재사용성, 재구성, 확장성 등의 제고가 요구된다. PlugIn-Based Architecture(PBA)는 컴포넌트 간 상호독립적인 인터페이스 및 상호작용이 가능함으로써 기존 아키텍처에 비해 컴포넌트의 추가 및 조합이 용이하고 재사용을 높일 수 있는 공통하부기반을 제공할 수 있도록 설계되었다. 또한, 이러한 PBA를 적용한 시뮬레이터 개발을 지원할 수 있도록 PBA Framework을 구현하였다. PBA Framework은 공통하부기반으로서 M&S 업무 적용 시 효율성을 제고시킬 수 있을 것으로 기대된다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권6호
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• pp.577-588
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• 2016

Due to the uncertainties related to the flaw assessment parameters, such as flaw size, fracture toughness, loading spectrum and so on, the probability concept is preferred over deterministic one in flaw assessment. In this study, efforts have been made to develop the reliability based flaw assessment procedure which combines the flaw assessment procedure of BS7910 and first-and second-order reliability methods (FORM/SORM). Both crack length and depth of semi-elliptical surface crack at weld toe were handled as random variable whose probability distribution was defined as Gaussian with certain means and standard deviations. Then the limit state functions from static rupture and fatigue perspective were estimated using FORM and SORM in joint probability space of crack depth and length. The validity of predicted limit state functions were checked by comparing it with those obtained by Monte Carlo simulation. It was confirmed that the developed methodology worked perfectly in predicting the limit state functions without time-consuming Monte Carlo simulation.

• Journal of the Korean Wood Science and Technology
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• 제44권2호
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• pp.283-293
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• 2016

Owing to an increase in the air tightness of recent buildings, the natural ventilation rate was significantly lowered and the removal of accumulated moisture became difficult in these buildings. The hygrothermal performance of these buildings should be carefully considered to provide comfortable indoor environment by removing the moisture condensation risk and the mold growth potential. In this study, hygrothermal performance of two selected wall structures was investigated based on WUFI simulation program. The results displayed that the indoor temperature had impact on the moisture accumulation in the insulation layer for both modeled walls, showing that lower indoor temperature resulted in higher moisture accumulation, especially in the wood frame structure. Also, the yearly moisture accumulation profile exhibited a downward shift throughout the year by adding a vapour retarder with a lower sd-value. In addition, both of the two walls have condensation risk in winter, due to low temperature level. The wood frame structure has a bigger fluctuation and higher condensation risk than the concrete structure.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권2호
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• pp.899-913
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• 2019

In order to provide a complementary perspective to the effects of the maneuvering motions on the unsteady propeller performance, the numerical simulation of the flow field of the hull-rudder- propeller system is performed by Unsteady Reynolds-averaged Naiver-Stokes (URANS) method. Firstly, the flow fields around the submarine model without the presence of propeller in straight ahead motion and the steady diving maneuvers with submergence rudder deflections of 4°, 8° and 12° are predicted numerically. The non-uniformity characteristic of the nominal wake field is exacerbated with the increase submergence rudder angle. Then the flow field around the SUBOFF-G submarine fitted with the 4381 propeller is simulated. The axial, transverse and vertical unsteady propeller forces in different maneuvering conditions are compared. In general, as the submarine maneuvers more violently, the harmonic amplitudes of the unsteady force at the 2BPF and 3BPF increased more significantly than that at BPF.