• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.328-329
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• 2000

This research is to estimate population parameters of the Korean horse mackerel stock and to determine the status of the stock. Considering the linkage of recruitment with the variation of environmental conditions in the early life history, acceptable biological catch (ABC) of horse mackerel was estimated. (omitted)

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.628-633
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• 2003

Recently, the electronic circuit with microprocessor based control system instead of conventional analog circuit is widely used for rolling stock, and also these circuits are widely adopted for train control and monitoring in modem rapid transit system. Noise, distortion and attenuation are always present in electronic equipments and strictly limit performance. The purpose of this paper is to propose noise reduction technology for electronic equipments in rolling stock.

• Current Research on Agriculture and Life Sciences
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• 제11권
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• pp.1-9
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• 1993

신문 용지용(用) 지료(紙料)의 조성조건(調成條件)에 따른 보류(保留)의 변화를 연구(硏究)한 결과 다음과 같은 사실을 알수가 있었다. 1. 온도(溫度)의 상승(上昇)에 따라 보류(保留)는 지료(紙料)의 종류 및 배합비(配合比)에 관계없이 감소(減少)하였으며 GP보다 DIP가 온도(溫度)변화에 민감(敏感)하였다. 2. pH변화에 따른 보류(保留)의 변화는 GP와 DIP 및 GP/DIP=50/50 모두 pH5에서 보류(保留)가 가장 높았으며 pH 5보다 높거나 낮으면 감소(減少)하였고 DIP가 GP보다 감소(減少)가 적었다. 3. Alum첨가(添加)에 따른 보류(保留)의 변화는 GP와 GP/DIP=50/50의 경우 2% 첨가(添加)에서 보류(保留)가 가장 높았고 DIP는 3% 첨가(添加)에서 가장 높았다. 4. 보류(保留)는 지료(紙料)의 응집작용(凝集作用)과 밀접한 관련이 있었다.

• 한국자동차공학회논문집
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• 제21권3호
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• pp.1-14
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• 2013

In this paper, a finite element analysis technique of rolling stock models for collision-induced derailments was suggested using rolling contacts for wheel-rail interaction. The collision-induced derailments of rolling stock can be categorized into two patterns of wheel-climb and wheel-lift according to the friction direction between wheel flange and rail. The wheel-climb derailment types are classified as Climb-up, Climb/roll-over and Roll-over-C types, and the wheel-lift derailment types as Slip-up, Slip/roll-over and Roll-over-L types. To verify the rolling contact simulations for wheel-rail interaction, dynamic simulations of a single wheelset using Recurdyn of Functionbay and Ls-Dyna of LSTC were performed and compared for the 6-typical derailments. The collision-induced derailment simulation of the finite element model of KHST (Korean High Speed Train) was conducted and verified using the theoretical predictions of a simplified wheel-set model proposed for each derailment type.

• 한국자동차공학회논문집
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• 제18권3호
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• pp.116-126
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• 2010

The Korean rolling stock safety regulation stipulates that the collision deceleration of a car body should be maintained under average 5g and maximum 7.5g during train collisions. One-dimensional dynamic model of a full rake train, which is made up of nonlinear springs/bars-dampers-masses, is often used to estimate the collision decelerations of car bodies in a basic design stage. By the way, the previous studies have often used some average force-deformation curve for energy absorbing structures in rolling stock. Through this study, we intended to analyse how much the collision deceleration levels are influenced by the initial peak force modeling in the one-dimensional force-deformation curve. The numerical results of the one-dimensional dynamic model for the Korean High-Speed Train show that the initial peak force modeling gives significant effect on the collision deceleration levels. Therefore the peak force modeling of the force-deformation curve should be considered in one-dimensional dynamic model of a full rake train to evaluate the article 16 of the domestic rolling stock safety regulations.

• The Journal of Asian Finance, Economics and Business
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• 제9권7호
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• pp.53-62
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• 2022

Commercial banks have a significant impact on the economy of Vietnam because they provide the majority of transactional capital. Therefore, the operational efficiency of commercial banks is a viral topic for the study of the Vietnamese banking system. The research aims to examine the efficiency and inefficiency of joint-stock commercial banks in Vietnam from 2016 to 2020 and then classify them into the efficient group and inefficient group. The study employs the time series data of 29 joint-stock commercial banks during the period 2016-2020. Based on the data collected from the annual audited financial statements of 29 Vietnamese joint-stock commercial banks, the authors select input and output variables for the standard DEA models and anti-efficient DEA models. This research uses two stages, first, by applying the standard DEA model, we investigate the efficient banks; second, by employing the anti-efficient DEA model, we find out the inefficient banks. The results reveal that the average efficiency score of 29 joint-stock commercial banks tends to increase in the period 2016-2018 and decrease gradually in the period 2019-2020. The findings of this study suggest that several small and medium-sized banks in the Vietnamese banking sector have both promising and risky performances and the efficiency of state-owned commercial banks has also improved significantly during the study period.

• 반도체디스플레이기술학회지
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• 제22권2호
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• pp.104-111
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• 2023

The semiconductor industry, which relies on global supply chains, has recently been facing longer lead time for material procurement due to supply chain uncertainties. Moreover, since increasing customer satisfaction and reducing inventory costs are in a trade-off relationship, it is challenging to determine the appropriate safety stock level under demand and lead time uncertainties. In this paper, we propose a framework for determining safety stock levels by utilizing the optimization method to determine the optimal safety stock level. Additionally, we employ a linear regression method to analyze customer satisfaction scores and inventory costs based on variations in lead time and demand. To verify the effectiveness of the proposed framework, we compared safety stock levels obtained by the regression equations with those of the conventional method. The numerical experiments demonstrated that the proposed method successfully reduces inventory costs while maintaining the same level of customer satisfaction when lead time increases.

• The Journal of Asian Finance, Economics and Business
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• 제7권8호
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• pp.185-195
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• 2020

This study examines the association between governance quality at country level and stock market performance. Specifically, the study investigates the influence of control of corruption, government effectiveness, political stability and absence of violence, rule of law, regulatory quality, and voice and accountability on all-share index of the stock markets of the six Gulf Cooperation Council (GCC) countries. This study is anchored on two theories - the Efficient Market Hypothesis (EMH) and Institutional Theory. The study employs panel data spanning from 2006 to 2017. The findings show that political stability and absence of violence and rule of law exhibit a significant positive impact on stock market performance, while regulatory quality and voice and accountability have a significant, but negative relationship with stock market performance. The results imply that quality of governance in terms of rule of law and political stability devoid of violence have strong impact on stock market returns. Similarly, improved stock market returns are largely dependent on the efficiency of the institutional environment of market as investors are always wary of the inherent risks associated with the uncertainty of the market. This study has crucial policy implications for the government of the GCC countries and stock market participants.

• 산업경영시스템학회지
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• 제41권3호
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• pp.154-161
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• 2018

This study conducted to predict the stock market prices based on the assumption that internet news articles might have an impact and effect on the rise and fall of stock market prices. The internet news articles were tested to evaluate the accuracy by comparing predicted values of the actual stock index and the forecasting models of the companies. This paper collected stock news from the internet, and analyzed and identified the relationship with the stock price index. Since the internet news contents consist mainly of unstructured texts, this study used text mining technique and multiple regression analysis technique to analyze news articles. A company H as a representative automobile manufacturing company was selected, and prediction models for the stock price index of company H was presented. Thus two prediction models for forecasting the upturn and decline of H stock index is derived and presented. Among the two prediction models, the error value of the prediction model (1) is low, and so the prediction performance of the model (1) is relatively better than that of the prediction model (2). As the further research, if the contents of this study are supplemented by real artificial intelligent investment decision system and applied to real investment, more practical research results will be able to be developed.

• 기술혁신학회지
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• 제13권2호
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• pp.231-251
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• 2010

과학기술 R&D 활동의 대표적 성과인 SCI 논문과 특허의 생산에 영향을 미치는 요인은 연구비, 연구원수, 지식스톡(R&D스톡, 논문스톡, 특허스톡 등), 연구환경, 개방화 정도, 인적자본, GDP 등 다양하다. 일반적인 회귀모형을 이용하여 논문 또는 특허의 생산에 영향을 미치는 요인을 추정하면 생산요인들 간에 다중공선성 문제가 발생하여 추정의 오류가 발생한다. 본 논문에서는 과학기술 지식생산에 영향을 미치는 요인들 간의 다중공선성 문제를 해결하기 위해 주성분 회귀모형을 이용하였다. SCI 논문을 산출로 가정한 과학생산성과와 특허를 산출로 가정한 기술생산성과에 영향을 미치는 요인을 회귀모형과 주성분 회귀모형을 이용하여 3가지 사례를 대상으로 비교 분석하였다. 일반 회귀모형을 이용하여 SCI 논문과 특허의 생산에 영향을 미치는 요인들을 분석한 결과, 요인들간에 다중공선성이 매우 높게 나타났고, 그 결과 회귀계수와 추정과 검정에 오류가 발생되었다. 반면 주성분 회귀모형을 이용하여 분석한 결과 다중공선성문제가 해결되어, 개별 생산요인에 대한 효과를 적절하게 추정할 수 있었다. 본 논문에서 제안한 주성분 회귀모형을 이용한 과학기술 지식생산함수 추정방법은 다중공선성이 강한 소수의 생산요소를 포함한 회귀분석에서 유용하게 적용될 수 있을 것이다.