• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 학술대회 논문집
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• pp.92-94
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• 2003

In superconductive digital logic circuits, D2 cells can be used to compose a decoder an important component of an Arithmetic Logic Unit (ALU). In this wor, we simulated D2 cell by using WRspice. D2 cell has one input, one switch input, and two outputs (output1 and output2). D2 cell functions in such way that output1 follows the input and output2 is the complement of the input data, when the switch input is "0, ". However, when there is a switch input "1, " the opposite output signals are generated. In this paper, we optimized a D2 cell by using WRspice, and obtained the minimum margin of 26%. Our optimized D2 cell will play a key role in the ALU fabrication.the ALU fabrication.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.46-47
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• 2009

In this paper, a power combiner using IPD process for SK Telecom 3-Generation (2.13 ~ 2.15 GHz) application. The Integrated Passive Device (IPD) Wilkinson power Combiner shows compact size and high performance. It is simulated by 3D Electro Magnetic (EM) simulation because of more accurate measurement result wire-bonding effects. This combiner exhibit size of $1.2mm^2$ the insertion loss of 3.6 dB, and the return loss of 10.1 dB, and isolation of more than -7.7 dB.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.30-43
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• 2021

In the 2D/1D method, a global adjoint CMFD based on the generalized equivalence theory is built to synthesize the 2D radial MOC adjoint and 1D axial NEM adjoint calculation and also to accelerate the iteration convergence of 3D whole-core adjoint transport calculation. Even more important, an advanced yet accurate two-level (TL) CMFD acceleration technique is proposed, in which an equivalent one-group adjoint CMFD is established to accelerate the multi-group adjoint CMFD and then to accelerate the 3D whole-core adjoint transport calculation efficiently. Based on these method, a new code is developed to perform 3D adjoint neutron flux calculation. Then a set of VERA and C5G7 benchmark problems are chosen to verify the capability of the 3D adjoint calculations and the effectiveness of TL CMFD acceleration. The numerical results demonstrate that acceptable accuracy of 2D/1D adjoint calculations and superior acceleration of TL CMFD are achievable.

• 한국시뮬레이션학회논문지
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• 제19권2호
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• pp.1-8
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• 2010

최근 컴퓨터 하드웨어 및 3D 그래픽의 기술 발전으로 많은 사용자들이 실제와 유사한 3D 그래픽으로 표현되는 것에 관심을 가지고 있다. 이러한 사용자들의 요구가 증대됨에 따라 많은 분야에서 3D 시뮬레이션이 개발 보급되고 있다. 본 논문에서는 3D 그래픽 기술을 활용하여 화재시의 건물 내에서 사람들이 대피하는 시뮬레이션 시스템을 설계하고 구현한다. 본 논문에서는 사람이 화재 시 건물을 탈출할 때 인공지능을 갖기 위해 A* 알고리즘을 사용하였으며, 화재 시에 사람의 탈출에 영향을 미치는 열과 연기를 고려하여 각 사람의 탈출 속도를 계산한다. 본 논문에서 제안하는 대피 시뮬레이션의 효과를 입증하기 위해 실제 건물환경을 모델링하여 적용하였다. 실험결과들을 통해서 본 논문에서 제안한 방법을 통하여 연기의 농도가 짙어질수록 사람의 탈출속도가 감소하는 것과 온도와 연기 농도에 의해 사람이 피해를 입고 사망하는 것을 확인할 수 있다.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2002년도 추계학술대회 논문집
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• pp.125-130
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• 2002

본 연구는 DEVS를 기반으로 개발된 교통류 시뮬레이션 시스템인 $\ulcorner$I$^3$D$^2$ 교통류 시뮬레이션 시스템$\lrcorner$(이하 I$^3$D$^2$)의 검증을 그 목적으로 한다. I$^3$D$^2$는 본 연구진이 DEVS를 기반으로 개발한 범용 시뮬레이션 도구로써, 이미 서울시 강남 신호교차로와 내부순환로를 대상으로 하여 개발된 내용을 발표한 바 있다. I$^3$D$^2$는 헌재 단속류에서의 최적신호 생성 및 대기행렬 예측 문제, 그리고 연속류 시설의 용량 산정 문제등을 시뮬레이션 할 수 있다. 하지만 아직 문헌자료나 현장 데이터를 토대로 한 충분한 검증이 수행되지 못한 문제가 있다. 따라서 본 연구에서는 문헌자료를 토대로, I$^3$D$^2$를 검증한다. 이를 위하여 고속도로 또는 도시고속도로와 같은 연속 교통류의 대표적인 효과척도인 $\ulcorner$교통량 - 밀도 - 평균주행속도 (시간)$\lrcorner$ 간의 상관관계를 이용하여 미국 HCM과 우리나라의 도로용량편람에 정의되어 있는 기준을 토대로 I$^3$D$^2$ 검증을 수행하였다. 모델링은 서울시 올림픽대로의 양화대교 - 성산대교 - 가양대교 구간을 대상으로 했으며, 검증은 교통량에 따라 크게 3가지 교통류 상태(random, intermediate, constant)를 기준으로 시뮬레이션이 각각의 교통상태에서 예측한 평균주행시간의 정확도를 측정하면서 수행하였다. 검증 결과 random 상태에서는 문헌자료에 부합되는 예측결과를 보여주었으나, intermediate와 constant 상태에서는 문헌보다 다소 낮은 속도를 보여주었다 이러한 속도차는 추후 현장 데이터를 수집하여 보다 실질적인 검증을 통하여 조정되어야 할 것으로 판단된다.

• 한국전산유체공학회지
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• 제18권4호
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• pp.47-52
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• 2013

In the present study, the turbulent flow from an annular jet is investigated by using large eddy simulation. Particularly, the effect of the ratio of the inner and outer diameters is one of the main interests of this study. The instantaneous fields presented in this paper showed that behind the jet exit the backflow region, as well known in literatures, exists, and its detailed behavior depends on the ratio of the inner and outer diameters ($D_1/D_2$). The dependence on $D_1/D_2$ is attributed to the different shear layer development according to $D_1/D_2$. At small $D_1/D_2$, the development of the outer shear layer is similar to that from the circular jet. However, with increasing $D_1/D_2$, the interaction between the outer and inner shear layers becomes strong, resulting in fast transition to turbulence.

• 농업과학연구
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• 제48권4호
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• pp.1027-1037
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• 2021

This study aims to evaluate the performance of an electric multi-purpose cultivator through a simulation analysis. The simulation model was developed using commercial software, Simulation X, by applying the specifications of certain parts, such as an electric motor, a battery, and so on. The input parameter of the simulation was the engine load data according to the rotary tillage level using a conventional multi-purpose cultivator. The data were collected by configuring a load measurement system, and the load cycle was developed by repeating the data collection process under the most severe conditions. The average output engine torque values of conventional multi-purpose cultivator were 10.7, 13.0, 9.4, and 11.2 Nm in the D1P1, D1P2, D2P1, and D2P2 conditions, respectively. As a result of the simulation, the maximum values of the motor torque, rotational speed, and power of the electric multi-purpose cultivator were 16.8 Nm, 2,033.3 rpm, and 3.3 kW, respectively, and the motor was driven in sections within 70, 68, and 45% of the maximum output range. The rate of decrease of the battery state of charge (SOC) level per minute was approximately 0.6%, and it was possible to supply electric power to the motor for 9,550 sec. In the future study, research to verify and improve simulation models of electric multi-purpose cultivators should be conducted.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 춘계 학술대회논문집
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• pp.114-118
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• 2005

CFD simulation was peformed for 2D and 3D flying and rotating frisbees. Multiple reference method(MRF) was utilized to consider the rotation of 3D model. Geometry change of 2D model shows dramatic increase of lift, but 3D simulation results for geometry change show decrease of lift and drag. Ground effect increases the lift of the frisbee being close to ground.

• 복식문화연구
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• 제19권2호
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• pp.245-254
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• 2011

The purpose of this study was to develop uniform pattern of obese junior-high school girls by using the virtual twin and 3D virtual garment simulation system. The results were as follows; first, by using 3D virtual garment simulation, new uniform pattern considered obese junior-high school girls was development. The basic numerical formula were as follows; bust girth=B/2+2.5, armhole depth=B/4, front waist girth=W/4+1.8, back waist girth=W/4+1, front hip girth=H/4+1, back hip girth=H/4+1, chest width=chest width+1.5, back width=back width+1 and back neck width 8cm. Second, according to the results of the new uniform pattern's appearance evaluation, it estimated more highly than existing pattern in silhouette and ease amount, confirming that new uniform pattern is appropriate for the obese junior-high school girls. Also, new uniform pattern was evaluated to allow proper space length of bust, waist, abdomen and hip. Virtual models production through 3D body scan data, pattern draft and virtual garment digital program were applied to prototypic design method so as to enhance the fitness of ready-made garments. This study is expected to serve as one of important basic data for ensuing studies that may utilize 3D virtual garment simulation system with 2D patterns, and also for future 3D pattern production program development.

• 한국자동차공학회논문집
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• 제24권2호
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• pp.161-168
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• 2016

CNG engine has been used as a transportation because of higher thermal efficiency and lower CO2 and particulate matter. However its out put power is decreased due to cylinder-to-cylinder variation during the supply of air-fuel mixture to the each cylinder. It also causes noise and vibration. So in this study, 1D engine simulation model was validated by comparison with experiment data and 3D CFD simulation was conducted to steady-state flow analysis about each manifold geometry. Then, the effects of various intake manifold geometries on variation were evaluated by using 1D-3D coupling analysis at engine speed of 2100 rpm range in 12 L CNG engine. As a result, variation was improved about 4 % though 3D CFD analysis and there was a variation within 3 % using 1D-3D coupling analysis.