• Nuclear Engineering and Technology
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• 제43권6호
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• pp.489-498
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• 2011

UK National Nuclear Laboratory's (NNL's) version of the ENIGMA fuel performance code is described, including details of the development history, the system modelled, the key assumptions, the thermo-mechanical solution scheme, and the various incorporated models. The recent development of ENIGMA in the areas of whole core analysis and dry storage applications is then discussed. With respect to the former, the NEXUS code has been developed by NNL to automate whole core fuel performance modelling for an LWR core, using ENIGMA as the underlying fuel performance engine. NEXUS runs on NNL's GEMSTONE high performance computing cluster and utilises 3-D core power distribution data obtained from the output of Studsvik Scandpower's SIMULATE code. With respect to the latter, ENIGMA has been developed such that it can model the thermo-mechanical behaviour of a given LWR fuel rod during irradiation, pond cooling, drying, and dry storage - this involved: (a) incorporating an out-of-pile clad creep model for irradiated Zircaloy-4; (b) including the ability to simulate annealing out of the clad irradiation damage; (c) writing of additional post-irradiation output; (d) several other minor modifications to allow modelling of post-irradiation conditions.

• 정보처리학회논문지D
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• 제13D권1호
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• pp.117-124
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• 2006

UML(Unified Modeling Language)은 객체지향 모델링을 위한 언어이다 UML에 포함되어 있는 AD(Activity Diagram; 활동 다이어그램)는 워크플로우 시스템의 모델링에 적합하지만 수행 과정의 평가가 수학적이지 못하므로 수행 과정을 직관적으로 파악해야 하는 단점이 있다. 그러나 EMFG(Extended Mark Flow Graph)는 이산적인 시스템의 모델링에 적합할 뿐 아니라 수행 과정을 수학적으로 평가할 수 있다. 따라서 본 연구에서는 EMFG를 사용하여 모델링된 AD의 수행 동작을 평가하려고 한다. 우선 AD를 EMFG로 변환하는 방법에 대하여 제안하고, 변환된 EMFG의 수행을 평가함으로써 모델링된 AD의 수행완료 가능성을 평가한다. 그리고 컴퓨터 시뮬레이션을 통하여 이를 입증한다. 제안한 알고리듬은 대규모 워크플로우 시스템을 모델링한 AD의 수행완료 가능성도 쉽게 평가할 수 있는 장점이 있다.

• 대한간호학회지
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• 제41권3호
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• pp.423-431
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• 2011

Purpose: The study was designed to determine the discriminating ability of a Bayesian network (BN) for predicting risk for pressure ulcers. Methods: Analysis was done using a retrospective cohort, nursing records representing 21,114 hospital days, 3,348 patients at risk for ulcers, admitted to the intensive care unit of a tertiary teaching hospital between January 2004 and January 2007. A BN model and two logistic regression (LR) versions, model-I and .II, were compared, varying the nature, number and quality of input variables. Classification competence and case coverage of the models were tested and compared using a threefold cross validation method. Results: Average incidence of ulcers was 6.12%. Of the two LR models, model-I demonstrated better indexes of statistical model fits. The BN model had a sensitivity of 81.95%, specificity of 75.63%, positive and negative predictive values of 35.62% and 96.22% respectively. The area under the receiver operating characteristic (AUROC) was 85.01% implying moderate to good overall performance, which was similar to LR model-I. However, regarding case coverage, the BN model was 100% compared to 15.88% of LR. Conclusion: Discriminating ability of the BN model was found to be acceptable and case coverage proved to be excellent for clinical use.

• 정보학연구
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• 제7권2호
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• pp.7-17
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• 2004

학업 성취는 긍정적인 측면에서 설명하면 학습 목표달성과 연관되어 이루어지는 교육적 기대치를 향상시킬 수 있다. 본 연구의 목적은 학업 성취에 관련된 여러 가지의 변수 관계와 관련된 요인을 분석하고 탐색하는 데 있다. 즉 과거의 성취도, 정보기술 활용 능력, 학업 수행자의 성과 기대치, 학업성취 목표 달성에 관한 발전단계를 연구한다. 본 연구는 정보기술에 기반하여 학업 성취도를 확인하는 발전단계에 있어서의 효과분석에 초점을 두고 있으며 본 연구에 참가한 참가자들에게 본인들의 기대치 척도, 정보기술 활용능력, 정보기술 능력시험, 기초지식 설문지를 작성케 하여 그 결과를 분석하였다. 경로 모형 결과를 기반으로 하여 학생들의 학업 성취도가 지난 과거의 성취도와 관련이 있다는 것에 연구의 초점을 두었다. 학업성취를 위한 발전단계에 관한 연구결과는 학업성취가 학업의 달성 수준을 등급화 하여 목표 달성의 정도를 파악하고 정보기술 능력이 학업성취도에 영향이 있다는 것을 제시한다. 현재의 연구 결과에 의하면, 과거 성취도에 대한 변수가 성과 기대치에 영향을 미친다는 것에 초점을 맞추어 조사하였으나 학업성취도를 예측하는 데에는 성공하지 못하였다.

• The Journal of Asian Finance, Economics and Business
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• 제8권7호
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• pp.295-302
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• 2021

In the context of economic growth, the banking system has greatly contributed to a substantial rise in living conditions, connecting savings and investment, and economic growth. Since economic reform in 1986, Vietnam's banking system has increasingly expanded in quality and quantity of banks including state-owned, private-owned, and foreign banks. The aim of this study is to evaluate the main factors affecting employee's performance in the banking system in the case of an emerging economy of Vietnam. Using the pilot study by investigating three experts in a few banks in order to correct the questionnaires, and a mega sample data of 170 observations conducted from bank's staffs, and managers in Hanoi capital of Vietnam, empirical results demonstrate that the independent variables included in the model can explain 67% of the change of the dependent variable of employee's performance, and the rest (31%) can be explained by other reasons. Further, motivation (MO), and working ability (WA) have a positive and insignificant impact on employee's performance, reflecting that motivation, and working ability have insignificantly affected employee's performance. In contrast, four factors, namely, welfare, working environment, cooperation, and education have a positive and significant impact on employee's performance in the case of Hanoi, Vietnam.

• 컴퓨터교육학회논문지
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• 제23권3호
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• pp.41-47
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• 2020

21세기 미래 인재에게 필요한 핵심 역량으로 컴퓨팅 사고력이 주목받고 있다. 국내외적으로 컴퓨팅 사고력 향상을 위한 소프트웨어 교육이 한창이다. 그중에서 문제해결 프로그래밍 교육은 컴퓨팅 사고력 향상에 도움이 된다. CT-TDPS 학습 모형은 복잡한 문제들을 모듈화하는 분해, 추상화 사고 과정과 이를 구현하는 반복적·점증적 프로그래밍 방식인 애자일(Agile) 개발 방식을 따른다. 본 연구에서는 스크래치를 이용한 문제해결 프로그래밍 교육에 CT-TDPS 학습 모형을 적용하여 컴퓨팅 사고력 향상을 확인하고자 하였다. 연구 결과, CT-TDPS 학습 모형을 적용한 문제해결 프로그래밍 교육에서 컴퓨팅 사고력의 하위 요인인 컴퓨팅 개념, 컴퓨팅 수행, 컴퓨팅 관점에서 모두 향상이 되었음을 확인할 수 있었다. 그리고, Dr.Scratch 자동 평가 결과에 대한 t 검정 결과 실험집단에서 유의한 차이가 있음을 확인하였다.

• 한국생산제조학회지
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• 제23권2호
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• pp.157-163
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• 2014

In this paper, a robust MRAC (model reference adaptive control) scheme is applied to control an electrohydraulic positioning system under various loads. The inverse dead-zone compensator in the control system cancels out the dead-zone response, and an integrator added to the controller provides good position-tracking ability. LQG/LTR (linear quadratic Gaussian control with loop transfer recovery) closed-loop model is used as the reference model for learning the MRAC system. LQG/LTR provides a systematic technique to design the linear controller that optimizes the objective function using some compromise between the control effort and the system performance in the frequency domain. Different external load tests are performed to investigate the effectiveness of the designed MRAC system in real time. The experimental results show that the tracking performance of the proposed system is highly accurate, which offers considerable robustness even with a large change in the load.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.125.4-125
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• 2001

The problem of recongurable ight control is investigated, focusing on model reference adaptive control(MRAC) through imprecise fault diagnosis. The method integrates the fault detection and isolation(FDI) scheme with the model reference adaptive control, and can be implemented on-line and in real-time. The algorithm can cope with the fast varying parameters. The Simulation results demonstrate the ability of reconguration to maintain the stability and acceptable performance after a failure.

• 전자통신동향분석
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• 제32권6호
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• pp.105-115
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• 2017

This paper describes a project - based quality management model that identifies development technologies and codes while at the same time verifying the ability to implement processes that are essential in R & D projects. In order to verify the process implemented in the R & D project implementation, there are review, checking points, and evaluating methods the process performance levels for five processes such as defining requirements which is the beginning stage of system development, testing process which is the completion stage of system development, and project management and peer review process for project management and support in the proposed project-based quality management model. For development technology and code validation, the model included the documented test cases for each requirement by the developer in the requirements definition stage, debugging and testing in the design and implementation stages, static analysis and open source licence verification procedure, and system environment. After applying the model in SW development R&D project for evaluating the process performance, and verifying the development technology and the code, the developers responded that the improvement in the development technique and the code, and upgrade of process performance level for project are more than 10%.

• Journal of Power Electronics
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• 제7권2호
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• pp.159-173
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• 2007

In this paper, an intelligent sliding-mode position controller (ISMC) for achieving favorable decoupling control and high precision position tracking performance of permanent-magnet synchronous motor (PMSM) servo drives is proposed. The intelligent position controller consists of a sliding-mode position controller (SMC) in the position feed-back loop in addition to an on-line trained fuzzy-neural-network model-following controller (FNNMFC) in the feedforward loop. The intelligent position controller combines the merits of the SMC with robust characteristics and the FNNMFC with on-line learning ability for periodic command tracking of a PMSM servo drive. The theoretical analyses of the sliding-mode position controller are described with a second order switching surface (PID) which is insensitive to parameter uncertainties and external load disturbances. To realize high dynamic performance in disturbance rejection and tracking characteristics, an on-line trained FNNMFC is proposed. The connective weights and membership functions of the FNNMFC are trained on-line according to the model-following error between the outputs of the reference model and the PMSM servo drive system. The FNNMFC generates an adaptive control signal which is added to the SMC output to attain robust model-following characteristics under different operating conditions regardless of parameter uncertainties and load disturbances. A computer simulation is developed to demonstrate the effectiveness of the proposed intelligent sliding mode position controller. The results confirm that the proposed ISMC grants robust performance and precise response to the reference model regardless of load disturbances and PMSM parameter uncertainties.