• 한국산업융합학회 논문집
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• 제20권2호
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• pp.133-140
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• 2017

This paper is a study of the central structural unit model of the sandwich core structure. The applied model is based on the honeycomb structure formed by the truss, the H-shaped honeycomb structure formed by adding the truss of H shape to the space of the center portion, and the honeycomb structure formed by the plate. Applied material property is AISI 304 stainless steel, which has cost effectiveness and easy to get near place. The truss diameter of the model is three different type: 1mm, 2mm and 3mm. ABAQUS software is obtained to do the analysis and applied test is quasi-static loading. Boundary conditions for the analysis are that vertical direction loading at top place without any rotation and bottom surface is fixed. The test results show that the H-truss model has the highest stiffness and yield strength. Therefore, it is hoped that more and more researching for the development of a unit model in sandwich core structure has been investigating and that the developed sandwich core model can be applied into various industrial fields such as mechanical or aerospace industries.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.525-526
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• 2006

A macro model for Savtchenko switching mode MRAM (toggling MRAM) cells which can be utilized to develop the core architecture and the peripheral circuitry is proposed, and a writing scheme suitable to the toggling characteristic is developed. The sensing and writing operations of the toggling MRAM adopting the macro model are verified by Spectre simulations.

• 문화기술의 융합
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• 제8권6호
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• pp.389-395
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• 2022

본 연구는 성인대학생의 핵심역량모형을 개발하는 것을 목적으로 한다. 이를 위해 국내외 문헌연구를 분석하여 성인대학생의 핵심역량을 도출하였으며, 핵심역량의 타당성을 위하여 델파이 조사를 하였다. 이를 위해 SPSS 18.0 프로그램을 이용하여 분석하였다. 연구결과는 의사소통, 문제해결 및 메타, 대인관계, 자기관리·개발, 디지털 정보 문해, 전공지식, 시민의식, 융합, 인성, 전문직업과 글로벌로 총 11개의 성인대학생 핵심역량이 도출되었다. 성인대학생의 핵심역량모형은 델파이 조사의 결과를 바탕으로 01~11의 번호를 부여하여 개발하였다. 성인대학생의 핵심역량은 서로 유기적으로 연계되어 있어 하나의 핵심역량의 함양은 다른 핵심역량에도 영향을 미치는 것으로 나타났다.

• 한국산학기술학회논문지
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• 제13권7호
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• pp.3194-3200
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• 2012

본 연구의 목적은 금융IT 발전과정의 역사적 사실들을 체계적으로 정리하고 다양한 추적 과정을 통해 입증된 교훈을 통해 조만간 가시화될 2020년대를 준비하는 신 차세대 시스템에서의 코어뱅킹 모델의 새로운 발전 모형과 방향성을 제시하는데 있다. 이를 위해 금융IT 발전과정 40년 동안 중요한 영향을 미쳤던 의미있는 패턴들을 도출 및 분석하고 코어뱅킹 모델의 라이프사이클을 역 추적하여 코어뱅킹 모델의 새로운 모형을 제시하였으며, 이를 활용하게 될 신 차세대 시스템의 발전방향도 함께 제시하였다. 연구결과 우리나라 금융IT 시스템과 코어뱅킹 모델의 라이프사이클은 각각 약 10년으로 분석되었으며, 최장기 모델의 라이프사이클은 33년으로 추정되었다. 향후 코어뱅킹 모델의 발전 모형은 기존 모델의 기본 구조에 비즈니스 허브 기능과 상품수명 주기관리 기능을 추가시키는 것이 바람직한 것으로 나타났다. 또한 신 차세대 시스템의 개발방식으로 빅뱅 방식은 지양해야 하며 IT기술 측면보다는 업무지향 측면에서 추진되어야 한다. 아울러 금융IT 분야는 융합산업 분야로 성장시켜 나가야 하며, 이를위해 코어뱅킹 모델연구의 체계화와 전문인력 양성이 필요하다. 본 연구는 우리나라 금융IT 발전과정을 처음으로 체계적으로 정리하였다는 점과 최초로 코어뱅킹 모델의 집중 분석을 통해 새로운 모형을 제시함으로써 향후 전개될 신 차세대 시스템 발전 방향의 가이드 라인을 제시하였다는데 의의가 있다.

• 한국CDE학회논문집
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• 제16권2호
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• pp.156-164
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• 2011

The automation technology is able to enhance the business process more rapidly and effective. Open BIM technology which supports automation technology of building overcomes the limitations of two dimensions drawings system. The purpose of this study is on the development of open BIM based modules for creating and verifying the core model for super-tall building in the schematic design phase. The module is expected to create cases of core models automatically and it is expected to verify the requirement of building model. This module is anticipated to utilize for creating the core model rapidly in order to create the alternative plan and to make the model accurate by its verification.

• Nuclear Engineering and Technology
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• 제51권6호
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• pp.1487-1503
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• 2019

The methods and performance of a pin-level nuclear reactor core thermal-hydraulics (T/H) code ESCOT employing the drift-flux model are presented. This code aims at providing an accurate yet fast core thermal-hydraulics solution capability to high-fidelity multiphysics core analysis systems targeting massively parallel computing platforms. The four equation drift-flux model is adopted for two-phase calculations, and numerical solutions are obtained by applying the Finite Volume Method (FVM) and the Semi-Implicit Method for Pressure-Linked Equation (SIMPLE)-like algorithm in a staggered grid system. Constitutive models involving turbulent mixing, pressure drop, and vapor generation are employed to simulate key phenomena in subchannel-scale analyses. ESCOT is parallelized by a domain decomposition scheme that involves both radial and axial decomposition to enable highly parallelized execution. The ESCOT solutions are validated through the applications to various experiments which include CNEN $4{\times}4$, Weiss et al. two assemblies, PNNL $2{\times}6$, RPI $2{\times}2$ air-water, and PSBT covering single/two-phase and unheated/heated conditions. The parameters of interest for validation include various flow characteristics such as turbulent mixing, spacer grid pressure drop, cross-flow, reverse flow, buoyancy effect, void drift, and bubble generation. For all the validation tests, ESCOT shows good agreements with measured data in the extent comparable to those of other subchannel-scale codes: COBRA-TF, MATRA and/or CUPID. The execution performance is examined with a mini-sized whole core consisting of 89 fuel assemblies and for an OPR1000 core. It turns out that it is about 1.5 times faster than a subchannel code based on the two-fluid three field model and the axial domain decomposition scheme works as well as the radial one yielding a steady-state solution for the OPR1000 core within 30 s with 104 processors.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.2343-2351
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• 2024

Accurately predicting the thermal hydraulic parameters of a transient reactor core under different working conditions is the first step toward reactor safety. Mass flow rate and temperature are important parameters of core thermal hydraulics, which have often been modeled as time series prediction problems. This study aims to achieve accurate and continuous prediction of core thermal hydraulic parameters under instantaneous conditions, as well as test the feasibility of a newly constructed gated recurrent unit (GRU) model based on the soft attention mechanism for core parameter predictions. Herein, the China Experimental Fast Reactor (CEFR) is used as the research object, and CEFR 1/2 core was taken as subject to carry out continuous predictive analysis of thermal parameters under transient conditions., while the subchannel analysis code named SUBCHANFLOW is used to generate the time series of core thermal-hydraulic parameters. The GRU model is used to predict the mass flow and temperature time series of the core. The results show that compared to the adaptive radial basis function neural network, the GRU network model produces better prediction results. The average relative error for temperature is less than 0.5 % when the step size is 3, and the prediction effect is better within 15 s. The average relative error of mass flow rate is less than 5 % when the step size is 10, and the prediction effect is better in the subsequent 12 s. The GRU model not only shows a higher prediction accuracy, but also captures the trends of the dynamic time series, which is useful for maintaining reactor safety and preventing nuclear power plant accidents. Furthermore, it can provide long-term continuous predictions under transient reactor conditions, which is useful for engineering applications and improving reactor safety.

• 정보처리학회논문지D
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• 제19D권1호
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• pp.95-104
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• 2012

본 연구의 목적은 금융IT 발전의 거시적 관점에서 방향성을 제안하고, 국내 금융IT 환경의 변화과정에 대한 경험적 모델을 바탕으로 향후 진행될 금융IT 시스템의 이론적 근거를 제시하는데 있다. 이를 위해 금융IT 발전과정 40년 동안 중요한 영향을 미쳤던 의미있는 패턴들을 도출 및 분석하고 코어뱅킹 모델의 라이프사이클을 역 추적하였다. 연구결과 첫째, 우리나라 금융IT 시스템의 라이프사이클은 10년으로 분석되었다. 둘째, 코어뱅킹 모델의 라이프사이클은 평균11년으로 분석되었으며 최장기 모델의 라이프사이클은 33년으로 분석되었다. 셋째, 장기 생존 코어뱅킹 모델들은 초기부터 철저한 객관적 분석과 벤치마킹을 통해 설계되고 발전시켜 왔다. 넷째, 금융IT 분야는 융합산업 분야로 성장시켜 나가야 하며, 이를 위해 코어뱅킹 모델연구의 체계화와 전문인력 양성이 필요하다. 본 연구는 그동안 명확하게 정리되지 않았던 코어뱅킹 모델의 분석을 통해 새로운 방향성을 제시하였다는데 의의가 있다. 전반부에는 코어뱅킹 모델의 역추적 의미와 금융IT 경영전략 차원의 핵심요소들을 중심으로 조사하였고, 후반부에는 이를 근거로 본격적인 코어뱅킹 모델의 라이프사이클을 분석하였다.

• 천문학회보
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• 제35권2호
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• pp.73.2-73.2
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• 2010

In order to understand internal dynamics of starless cores, molecular line emissions are usually observed. From profiles of the molecular lines, internal motions of starless cores have been deduced using a simple radiative transfer model such as the two-layer model (Myers et al.1996). This brings complexities arising from the chemical evolution. The motivation of this study is to follow the chemical evolution of a starless core that goes through gravitational contraction. For this purpose, we have performed hydrodynamical simulations with a marginally unstable Bonnor-Ebert sphere as an initial condition. We follow the chemical evolution of this core with changing conditions such as the chemical reaction rate at the dust surface and the strength of radiation field that penetrate into the core. At the core center, the molecules suffer from a higher degree of molecular depletion on the dust covered by ice rather than on the bare silicate dust. The stronger radiation field dissociates more molecules at the core envelope. From analysis on the line profile using the two-layer model, we found that the speed of inward motion deduced from the HCN F = 2-1 line adequately traces the true infall speed, when the dust is covered by ice and the core is exposed to the diffuse interstellar radiation field. Under different conditions, the two-layer model significantly underestimate the infall speed.

• Nuclear Engineering and Technology
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• 제36권1호
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• pp.36-46
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• 2004

The ISAAC fission product release calculation is based on detailed FPRAT models developed by Jaycor. For volatile fission product release calculations, either the Cubicciotti steam oxidation correlation or the NUREG-0772 correlation is used. In this study, evaluation is carried out for these volatile fission product release models. As a result, in the case of early release, the IDCOR model with an in-vessel Te release option shows the most conservative results and for the late release case, the NUREG-0772 model shows the most conservative results. Considering both early and late release, the IDCOR model with an in-vessel Te bound option is evaluated to show mitigated conservative results. In addition, a sensitivity study on detailed core nodalization is performed. In the study, 380 horizontal fuel channels in the Wolsong plant are nodalized into 12 (6 channels per loop, $3{\times}3$ Core Pass) representative channels and detailed by 16/20/24 channels. For reference accidents, LOAH and large LOCA are selected as representing high and low pressure sequences, respectively. According to the results, the original 12 channel approach with $3{\times}3$ core passes is evaluated to be sufficient as an optimal scheme.