• Earthquakes and Structures
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• 제25권1호
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• pp.15-26
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• 2023

It is of great importance to assess the residual displacement demand in the performance-based seismic design. In this paper, a hybrid deep learning model for predicting the residual displacement spectra under near-fault (NF) ground motions is proposed by combining the long short-term memory network (LSTM) and back-propagation (BP) network. The model is featured by its capacity of predicting the residual displacement spectrum under a given NF ground motion while considering the effects of structural parameters. To construct this model, 315 natural and artificial NF ground motions were employed to compute the residual displacement spectra through elastoplastic time history analysis considering different structural parameters. Based on the resulted dataset with a total of 9,450 samples, the proposed model was finally trained and tested. The results show that the proposed model has a satisfactory accuracy as well as a high efficiency in predicting residual displacement spectra under given NF ground motions while considering the impacts of structural parameters.

• Journal of Positioning, Navigation, and Timing
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• 제13권2호
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• pp.137-147
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• 2024

This paper presents a novel Long Short-Term Memory (LSTM) network architecture for the integration of an Inertial Measurement Unit (IMU) and Global Navigation Satellite Systems (GNSS). The proposed algorithm consists of two independent LSTM networks and the LSTM networks are trained to predict attitudes and velocities from the sequence of IMU measurements and mechanization solutions. In this paper, three GNSS receivers are used to provide Real Time Kinematic (RTK) GNSS attitude and position information of a vehicle, and the information is used as a target output while training the network. The performance of the proposed method was evaluated with both experimental and simulation data using a lowcost IMU and three RTK-GNSS receivers. The test results showed that the proposed LSTM network could improve positioning accuracy by more than 90% compared to the position solutions obtained using a conventional Kalman filter based IMU/GNSS integration for more than 30 seconds of GNSS outages.

• 한국축산식품학회지
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• 제23권2호
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• pp.137-144
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• 2003

본 연구에서는 IGFs를 다양한 기능성 유제품에 적용하기 전에 먼저 상업용 IGFs 및 초유로부터 분리.정제된 IGFs의 안전성을 평가하여 새로운 기능성 소재로서의 IGFs의 가능성을 검토해 보고자 하였다. 이를 위하여 독성평가에서 기본적으로 수행되고 있는 단회투여독성시험과 반복투여독성시험을 실시하였다. 단회투여독성시험에서는 R&D Systems사의 Recombinant Human IGF- I 을 시험물질로 하고 생후 4주된 Sprague-Dawley계(♂) 흰쥐(rat)를 실험동물로 하여 개체당 0, 10, 20, 50 $\mu\textrm{g}$씩 투여하는 시험군을 설정한 후, 꼬리정 꼬리정맥에 주사하여 20일간 관찰하면서 체중변화, 식이섭취변화를 측정하고 최종적으로 부검하여 육안검사 및 간장, 신장, 비장에 대한 병리조직검사를 실시한 결과, 명확한 이상소견이 나타나지 않아 모든 시험군에서 급성독성이 확인되지 않았다. 반복투여독성시험에서는 초유로부터 분리.정제된 IGF- I 을 시험물질로 하고 생후 4주된 Sprague-Dawley계(♂) 흰쥐(rat)를 실험동물로 하여 개체당 0, 5, 10, 15 $\mu\textrm{g}$씩 투여하는 시험군을 설정한 후, 14일간 반복적으로 강제경구투여하면서 임상증상을 관찰하면서 체중변화, 식이섭취변화를 측정하였고 최종적으로 부검하여 육안검사 및 간장, 신장, 비장에 대한 병리조직검사를 실시한 결과, 명확한 이상소견이 나타나지 않아 모든 투여농도에서 반복투여독성시험을 비롯한 기본적인 독성평가에 있어서 초유 내 IGF-I의 안전성에는 명확한 이상소견이 없는 것으로 판단되었다.

• 한국초전도ㆍ저온공학회논문지
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• 제6권2호
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• pp.25-28
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• 2004

Three-phase inductive superconducting fault current limiter (SFCL) with DC reactor rated on 6.6 $KV_{rms}/200 A_{rms}$ has been developed in Korea. This system consists of one DC reactor, AC/DC power converter, and a three-phase transformer, which is called magnetic core reactor (MCR). This paper deals with the short-circuit analysis of the SFCL. The DC reactor was the HTS solenoid coil whose inductance was 84mH. The power converter was performed as the dual-mode operation for dividing voltage between the rectifying devices. The short-term normal operation (1 see) and short-circuit tests (2∼3 cycles) of this SFCL were performed successfully. In regular short-circuit test, the fault current was limited as 30% of rated short-circuit current at 2 cycles after the fault. The experimental results have a very similar tendency to the simulation results. Using the technique for the fault detection and SCR firing control, the fault current limiting rate of the SFCL was improved. From this research, the parameters for design and manufacture of large-scale SFCL were obtained.

• 의학교육논단
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• 제25권2호
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• pp.126-131
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• 2023

The aim of this study was to systematically collect data for evaluating short- and long-term outcomes using Kirkpatrick's four-level evaluation model, Chonnam National Medical School has established plans for developing and managing a database of student and graduate cohorts. The Education Evaluation Committee, with assistance from the Medical Education Office, manages the development and maintenance of cohort data. Data collection began in the 2022 academic year with first- through fourth-year medical students and graduates of the year 2022. The collected data include sociodemographic characteristics, admission information, psychological test results, academic performance data, extracurricular activity data, scholarship records, national medical licensing exam results, and post-graduation career paths. The Education Evaluation Committee and the Medical Education Office analyze the annually updated student and graduate cohort data and report the results to the dean and relevant committees. These results are used for admissions processes, curriculum improvement, and the development of educational programs. Applicants interested in using the student and graduate cohort data to evaluate the curriculum or conduct academic research must undergo review by the Educational Evaluation Committee before being granted access to the data. It is expected that the collected data from student and graduate cohorts will provide a sound and scientific basis for evaluating short- and long-term achievements based on student, school, and other characteristics, thereby supporting medical education policies, innovation, and implementation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.271-274
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• 2005

Under competitive power markets, various long-term and short-term contracts based on spot price are used by producers and consumers. So an accurate forecasting for spot price allow market participants to develop bidding strategies in order to maximize their benefit. Artificial Neural Network is a powerful method in forecasting problem. In this paper we used Radial Basis Function(RBF) network to forecast spot price. To learn ANN, in addition to price history, we used some other effective inputs such as load level, fuel price, generation and transmission facilities situation. Results indicate that this forecasting method is accurate and useful.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.138-147
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• 2002

This paper describes the present research status and plan of transmission & substation technology fields in KEPCO. The details are below: the overview of research environment in KEPCOC(KEPRI), the research results in 2001, the research items in 2002, and the long-term and short-term research plans in the field of transmission & substation technology, etc.

• The Journal of Asian Finance, Economics and Business
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• 제8권7호
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• pp.469-476
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• 2021

This study aims to examine and measure the impact of capital structure on the profitability of companies in emerging markets. The research sample includes eighteen rubber companies listed on the Vietnam stock exchange from 2015-2019. After collecting the research data, it was imported into excel to calculate the criteria for the research model. By using Stata 16 software, the study selected a data processing model and evaluated the relevance of the regression analysis model. The research results show that the profitability of listed rubber companies in Vietnam (measured by return on equity (ROE) has a positive relationship with the debt-to-asset ratio but has a negative relationship with the long-term debt-to-asset ratio. The results also show a positive impact of firm size and revenue growth on profitability while liquidity and the ratio of tangible fixed assets to total assets do not affect significantly. These results are consistent with most of the previously published studies. However, in contrast to many previous studies, our study shows that the long-term debt-to-assets ratio has a negative effect on profitability while the debt-to-asset ratio has a positive effect. This is entirely consistent with the characteristics of long-term debt use in emerging markets.

• Pediatric Infection and Vaccine
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• 제30권2호
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• pp.55-61
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• 2023

목적: 소아에서 요로감염은 높은 질병부담을 갖는다. 본 연구의 목적은 합병증이 없고 균혈증이 없는 소아 요로감염에서 단기 항생제 요법이 기존의 표준치료 방법과 비교해 비열등한지 평가하고자 한다. 방법: PubMed, Embase 및 Cochrane 데이터베이스에서 2021년 4월까지 출간된 연구에 대한 신속 체계적 문헌고찰(Rapid Systematic Review)을 시행했다. 비교군으로는 소아 요로감염 환자를 대상으로 단기 항생제 치료(≤4일)를 한 군과 표준 항생제 치료(≥5-7일)를 한 군 간의 임상결과를 비교한 연구를 선정하였다. 결과: 신속 체계적 문헌고찰 결과, 단기 치료 방법은 표준 치료 방법에 비해 비열등한 치료 효과를 가지며, 임상 완치율 및 재발률이 유사한 것으로 측정되었다. 단기 치료와 표준 치료 방법의 임상적 치료율을 비교한 10개의 연구 모두 유사한 결과를 보고하였다. 신장 합병증을 평가를 한 연구는 단기 치료 방법이 표준 치료 방법과 비교해 비열등하지 않음을 보여주었다. 요로감염 재발에 대해서는 10개 중 8개의 연구에서 단기 치료와 표준 치료 방법 간 결과에 유의미한 차이가 없다고 보고하였다. 결론: 본 연구를 통해 결과는 균혈증이 없는 소아 요로감염 환자에서 단기 치료 방법이 표준 치료 방법에 준하는 효과성을 나타났었다. 본 연구결과를 바탕으로 일부 선택된 환자에 대한 치료 의사결정 시 참고할 수 있을 것이다.

• 한국산학기술학회논문지
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• 제17권6호
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• pp.676-686
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• 2016

본 연구는 국내 리츠가 운용된 2002년부터 2015년까지의 리츠사의 타인자본에 대한 차입이자율을 월별 자료로 구축하여 차입이자율의 흐름과 금리변수와의 관계를 분석하였다. 선행연구를 검토한 결과 리츠사의 차입이자율은 리츠 내부의 고유요인에 의해 결정되기도 하지만 거시경제변수 중 금리변수와 연계성이 높게 나타났다. 이에 본 연구는 K-REITs 차입이자율과 금리 변수 간에 ARDL(autoregressive distributed lag: 자기회귀시차) 모형을 설정하여 장기관계를 분석하였으며, ARDL-ECM 모형을 기반하여 단기 관계도 검토하였다. 실증분석 결과 K-REITs 차입이자율과 국고채 3년, 국고채 5년, 회사채(AA-,3년), 기업일반자금 대출금리에서 장기 공적분 관계가 형성되었으며, 이는 K-REITs 차입이자율이 장기금리 변수와 동조하고 있음을 보여준다. 또한, 기업일반자금 대출금리는 장기 관계와 단기 조정 과정에서도 K-REITs 차입이자율과의 연계성이 높게 나타났다. REITs가 금융권 차입에 관한 사항과 경영계획 수립 시에 기업일반자금 대출금리와 같은 장기금리 변수의 동향 등을 고려하여 의사결정 한다면 K-REITs 발전에 실질적인 도움이 될 수 있을 것이다.