• Nuclear Engineering and Technology
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• 제31권2호
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• pp.192-201
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• 1999

This paper proposes an improved signal processing strategy for accurate feedwater flowrate estimation in nuclear power plants. It is generally known that ∼2% thermal power errors occur due to fouling Phenomena in feedwater flowmeters. In the strategy Proposed, the noises included in feedwater flowrate signal are classified into rapidly varying noises and gradually varying noises according to the characteristics in a frequency domain. The estimation precision is enhanced by introducing a low pass filter with the wavelet analysis against rapidly varying noises, and an autoassociative neural network which takes charge of the correction of only gradually varying noises. The modified multivariate stratification sampling using the concept of time stratification and MAXIMIN criteria is developed to overcome the shortcoming of a general random sampling. In addition the multi-stage robust training method is developed to increase the quality and reliability of training signals. Some validations using the simulated data from a micro-simulator were carried out. In the validation tests, the proposed methodology removed both rapidly varying noises and gradually varying noises respectively in each de-noising step, and 5.54% root mean square errors of initial noisy signals were decreased to 0.674% after de-noising. These results indicate that it is possible to estimate the reactor thermal power more elaborately by adopting this strategy.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제24권4호
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• pp.331-350
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• 2020

Exploding gradient is a widely known problem in training recurrent neural networks. The explosion problem has often been coped with cutting off the gradient norm by some fixed value. However, this strategy, commonly referred to norm clipping, is an ad hoc approach to attenuate the explosion. In this research, we opt to view the problem from a different perspective, the discrete-time optimal control with infinite horizon for a better understanding of the problem. Through this perspective, we fathom the region at which gradient explosion occurs. Based on the analysis, we introduce a gradient-explosion-free algorithm that keeps the training process away from the region. Numerical tests show that this algorithm is at least three times faster than the clipping strategy.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.864-868
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• 2009

Fire safety management on any construction site should start with recognizing fire risks in the workplace, understanding the extent of the risks, and proper assessment of the controls necessary to reduce the risks. However, the most important step to prevent fire-related accidents on jobsites is the constant review and monitoring of processes and controls by all individuals involved. This study was conducted to analyze the effectiveness of using computer simulation as an addition to maps or floor plans in safety training and management. Simulex was used on a real project to model various egress routes and to identify potential problem areas of the evacuation strategy. This study highlights the efficacy of simulated emergency evacuation as a training tool that visually shows constantly altering means of egress.

• 대한안전경영과학회지
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• 제10권3호
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• pp.127-135
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• 2008

In this study, we offered a way that is to make warehouse industry clustered in Incheon port for getting competitive and high end value added activities like advanced port logistics center considering trend that is changing functions of port and importance of port-hinterland. For this, we studied the existing research about port cluster, the present condition of warehouse industry in Incheon port and importance of value-added logistics activities. Also, we offered needs to build a high value-added and integrated logistics center by examples of advanced port logistics center in Singapore, Netherlands(Rotterdam) and Hongkong. We get the questionnaires for gathering ideas of port logistics industry about to set integrated logistics centers by strategy we offered that is making warehouse logistics clustered.

• Asian Journal of Innovation and Policy
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• 제6권2호
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• pp.138-151
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• 2017

This aim of the study is to show the necessity of implementing an industrial innovation strategy with consideration given to characteristics of the industrial technology. The relationship between industrial technological characteristics and innovation performance is analyzed by using an innovation survey as well as a human capital corporate panel (HCCP). The time-lag effect is also examined. Findings of the analysis show that high-tech industries have entered the post catch-up technology innovation stage in the mid-2000s, but low-tech industries still seem to stay in the catch-up stage. In terms of technology policy, the additional technology innovation support policy should focus on enhancing the innovation capability of the middle and low technology industries, since high technology industries are already developing their own innovation capability. It is necessary to strengthen capacity building through technical cooperation with technology consulting, rather than providing technical support through suppliers.

• 공학교육연구
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• 제24권4호
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• pp.52-60
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• 2021

This study designed and developed a class using review games as a way to enhance students' interest, class participation, and class comprehension in engineering theory classes, and explored their educational effectiveness. To this end, a review game strategy based on the Creative Training Technique was established and applied to three engineering theory subjects. The types of review games include Jin-jin-ga, Bingo, Challenge Golden Bell, Finding hidden terms, and Completing initial sentences. As a result of applying this review game strategy to the classes over the past decade, students' satisfaction and lecture evaluation scores significantly increased compared to before application, and it was confirmed that students' interest in and understanding of the class increased significantly. Furthermore, this gamification class strategy can be a way to increase students' participation in theory classes regardless of their major, and can be applied to non-face-to-face online classes.

• 지능정보연구
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• 제20권2호
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• pp.59-71
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• 2014

KOSPI200 선물 트레이딩을 위해 업계에서는 여러 전략으로 포트폴리오를 구성해서 운용한다. 동일한 전략 모음을 갖고 있더라도 포트폴리오를 어떻게 구성하느냐에 따라 수익은 크게 차이가 난다. 시장 상황에 맞는 전략들로 포트폴리오를 구성하는 것은 오랜 경험과 탁월한 노하우가 있어야하는 어려운 작업이다. 본 논문에서는 SVM을 활용하여 쉽고 빠르게 적절한 전략 포트폴리오를 구성하는 방법을 제시하였다. 본 논문에서 제안한 시스템의 성과는 벤치마킹의 성과와 비교하여 2배 이상의 수익을 내는 것을 확인하였다. 1990.01.03~2011.11.04 동안의 KOSPI200 데이터 중 이전 80%의 데이터로 학습을 하고 최근 20%의 데이터로 성능을 시험하였다. 각 전략별로 선택여부를 판별하는 SVM모델을 만들고 그 결과를 바탕으로 포트폴리오를 구성하였다. 벤치마킹을 위해 KOSPI200 선물을 2계약 매수한 경우의 수익, 시험 시작 직전 30일간 최고 수익을 낸 2개 전략의 수익, 실제 최고 수익을 낸 전략 2개를 보유했을 때의 수익과 비교하였다. 매매 비용을 반영하지 않을 때는 벤치마킹은 132.2~510.37pt의 수익을 냈고, 본 시스템은 1072.36~1140.91pt의 수익을 보여주었다. 그리고 거래비용을 감안하면 벤치마킹은 130.44~502.41pt의 수익을 냈고, 본 시스템은 706.22pt~768.95pt의 수익을 나타내었다. 본 논문은 기계학습을 통한 전략 포트폴리오를 구성하는 방안이 유의미하며 실전에 활용할 수 있음을 보여주었다. 이를 바탕으로 여러 전략과 다양한 시장에 적용해서 안정성을 검증하면 견고한 상용 솔루션으로 발전시킬 수 있을 것이다. 그리고 자금관리 기법을 더 반영한다면 수익을 더욱 크게 향상시킬 수 있을 것이다.

• 한국공간정보시스템학회 논문지
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• 제10권4호
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• pp.67-75
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• 2008

본 연구에서는 u-City 인력양성 현황을 토대로 국토해양부의 u-City 관련 인력양성에 대한 실천 계획이 효율적으로 실행될 수 있는 방안을 제시하였다. u-City를 추진하는 지자체, 개발사업자마다 공통적으로 제기하는 문제점은 u-City 관련 고급 및 산업 인력의 절대적인 부족이다. u-City 전문 인력은 u-City건설의 특성상 도시계획.개발, 정보통신망, IT 등 다양한 분야에 대한 전문지식을 갖추어야하나 이러한 고급인력이 배출되고 있지 않다. 따라서 본 연구에서는 인력양성방안의 목표를 'u-City의 성공적인 추진에 부합하는 전문 인력 양성'으로 설정하였으며, 수요자 중심의 교육, 지역 균형적인 전문 인력 양성, u-City 관련분야의 융.복합교육, u-City 관련 교육인프라 구축을 추진전략으로 수립하였다. u-City 인력양성의 추진목표 및 전략을 실행하기 위한 중점추진과제로는 'u-City건설 전문 인력 교육 관련 수요전망', '지역별 거점대학 선정을 통한 전문 인력의 양성', 'u-City 인력양성센터 건립추진', '교육포탈을 통한 온라인 교육', '교육인프라 구축' 등 5개를 선정하였다. u-City 인력양성을 위한 추진전략의 성공적 실행을 위해서는 중점 추진과제들 간의 유기적인 연계가 필수적이다.

• The Journal of Korean Physical Therapy
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• 제32권5호
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• pp.283-289
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• 2020

Objective: The purpose of this study was to determine the force of lower extremities, the change in walking ability on the ground by applying a walking training program based on perceptual learning to improve gait capacity of chronic stroke patients. Method: This study included Twenty-four patients with chronic stroke. Using a perceptual-based gait training, the experimental group trained twice a day for 30 minutes each time, 5 times a week, for a total of 8 weeks. The control group underwent ground gait training that excluded the element of a perceptual training for 30 minutes, 5 times a week for 8 weeks. Results: In the two groups, the maximum forefoot pressure after intervention was significantly different in both the LEPGT and GGT (p<0.05). The maximum midfoot pressure was significantly different in LEPGT (p<0.05). There was a significant difference in the maximum heel pressure after intervention between the two groups (p<0.05). As a result of comparing the change in step length and stride length after intervention in the two groups, there was a significant difference between the two groups (p<0.05). Conclusion: Both gait training programs was found that gait training based on perceptual learning and ground gait training were the training for improving the functional gait of stroke patient. Perceptual learning gait training utilizing intensive perceptual awareness was the training for improving gait capacity within the period than ground gait training.

• 영어어문교육
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• 제17권1호
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• pp.165-190
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• 2011

This research investigates listening strategies and the relationship between the employment of strategy and listening proficiency of Korean EFL middle school students. One hundred and four middle school students (N = 104) participated in this study and their strategy use was assessed through a questionnaire adapted from Oxford's (1990) SILL and O'Malley and Chamot (1990). To measure listening proficiency, the English Listening Ability Test designed by 15 city and provincial offices of education in Korea was used. The results show that students employed a moderate use of strategies; compensation strategies were used most frequently and metacognitive strategies were used the least frequently. Significant differences were found in the use of implicit strategy among different listening proficiency groups, but not in their use of behavioral strategy. Furthermore, there were significant differences in the use of implicit memory, cognitive and compensation strategies among groups of students with different listening proficiencies, but not in their use of metacognitive strategy. The results from multiple regression analysis indicate that implicit strategy use could play an important role in listening comprehension. The findings suggest the need for additional research to explore the effect of listening strategy training for English language learners.