• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 추계학술대회 논문집(I)
• /
• pp.150-155
• /
• 2002

En case of the fatigue life evaluation of rolling stock structures, mainly deterministic fatigue life evaluation has been carried out. But most of the parameters influencing on the fatigue life have a probabilistic distribution such as normal, log-normal, Weibull, etc. Therefore, to take probabilistic factors into fatigue life evaluation, probabilistic methods are being applied to the fatigue life evaluation of rolling stock. In this paper, probabilistic S-N analysis and methods using limit state functions are introduced. And some results of fatigue life evaluation obtained with these methods for rolling stock structures are shown.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.1418-1425
• /
• 2011

Subway operators in the country have their own heavy maintenance facilities for maintaining rolling stock(EMU). However, it is true that the heavy maintenance facilities are not utilized 100% with the recent trend of lengthening maintenance cycle(intervals). With the fact, this enabled the existing maintenance facilities to be utilized for other purposes. By taking advantage of spare facilities and the maintenance staff with rolling stock assembly abilities, subway operators can assemble rolling stock by procuring parts for the assembly instead of purchasing trains from other companies. It is estimated that this will enhance the operator's technology and have a great impact on the management skill as well. This study attempts to find out how the heavy maintenance factory can be utilized for rolling stock assembly.

• 정보기술과데이타베이스저널
• /
• 제6권1호
• /
• pp.73-88
• /
• 1999

There have been a series of debates to determine whether it would be possible to forecast dynamic systems such as stock markets. Recently the introduction of chaos theory has allowed many researchers to bring back this issue. Their main concern was whether the behavior of stock markets is chaotic or not. These studies, however, present divergent opinions on this question, depending upon the method applied and the data used. And the issue of predictability based on the nonlinear, chaotic nature was not dealt extensively. This paper is to test the nonlinear nature of the Korea stock market and accordingly attempts to predict its behavior. The result indicates that our stock market represents a chaotic behavior. We also found out based on our simulation that executing buy/sell transactions based upon forecasts which were derived using the local approximation method outperforms the decision of holding without a buy/sell transaction.

• 지능정보연구
• /
• 제18권2호
• /
• pp.143-156
• /
• 2012

누구나 뉴스와 주가 사이에는 밀접한 관계를 있을 것이라 생각한다. 그래서 뉴스를 통해 투자기회를 찾고, 투자이익을 얻을 수 있을 것으로 기대한다. 그렇지만 너무나 많은 뉴스들이 실시간으로 생성 전파되며, 정작 어떤 뉴스가 중요한지, 뉴스가 주가에 미치는 영향은 얼마나 되는지를 알아내기는 쉽지 않다. 본 연구는 이러한 뉴스들을 수집 분석하여 주가와 어떠한 관련이 있는지 분석하였다. 뉴스는 그 속성상 특정한 양식을 갖지 않는 비정형 텍스트로 구성되어있다. 이러한 뉴스 컨텐츠를 분석하기 위해 오피니언 마이닝이라는 빅데이터 감성분석 기법을 적용하였고, 이를 통해 주가지수의 등락을 예측하는 지능형 투자의사결정 모형을 제시하였다. 그리고, 모형의 유효성을 검증하기 위하여 마이닝 결과와 주가지수 등락 간의 관계를 통계 분석하였다. 그 결과 뉴스 컨텐츠의 감성분석 결과값과 주가지수 등락과는 유의한 관계를 가지고 있었으며, 좀 더 세부적으로는 주식시장 개장 전 뉴스들과 주가지수의 등락과의 관계 또한 통계적으로 유의하여, 뉴스의 감성분석 결과를 이용해 주가지수의 변동성 예측이 가능할 것으로 판단되었다. 이렇게 도출된 투자의사결정 모형은 여러 유형의 뉴스 중에서 시황 전망 해외 뉴스가 주가지수 변동을 가장 잘 예측하는 것으로 나타났고 로지스틱 회귀분석결과 분류정확도는 주가하락 시 70.0%, 주가상승 시 78.8%이며 전체평균은 74.6%로 나타났다.

• 수산경영론집
• /
• 제41권1호
• /
• pp.1-24
• /
• 2010

The main goal of the study is to propose an objective and standardized evaluation system of stock enhancement programs. In order to achieve this goal, the study first suggested the need for stock enhancement program evaluation system through the review of current status and problems. Second, the study identified possible problems of the existing stock enhancement program evaluation by reviewing domestic and foreign evaluation systems. Finally the study proposed a new evaluation system and implementation plan of it. This study also classified the program evaluation criteria into ex-ante evaluation and ex-post evaluation according to the evaluation point in time, and applied the economic, political and technical feasibility tests into the evaluation of the stock enhancement program in order to solve the current problems of the evaluation. The evaluation process of the stock enhancement program is composed of an evaluation system design, estimation of weights using the analytical hierarchy process, design of estimation standard, conversion of scores and final summary of the evaluation. The central government takes the lead in the evaluation of the regional (metropolitan city or province) projects and the regional government is in charge of the evaluation of the local (city or county) projects. For the implementation of the ex-ante evaluation, either the regional or local governments ask for the evaluation and then submit an evaluation plan and other necessary documents to the upper level governments. The ex-post evaluation is then carried out by the upper level governments.

• 한국철도학회논문집
• /
• 제13권3호
• /
• pp.251-256
• /
• 2010

본 연구에서는 충돌해석 프로그램의 해석 결과와 실제 시험결과에 대한 비교를 통하여 충돌해석 프로그램의 신뢰성에 대한 검증을 진행하였으며, 충돌해석 프로그램을 이용하여 도시철도차량에서 요구하는 차량 편성에 대한 충돌 해석 결과를 제시하였다.

• 동아시아경상학회지
• /
• 제8권1호
• /
• pp.57-69
• /
• 2020

Purpose - This study examines what are the asset market fluctuations in Europe and how each economic variable affects major variables, and explore the dynamics of housing and stock market through Greece. The variables under consideration are balance on current account (BCA), index of stock (STOCK), gross domestic product (GDP), housing price indices (HOUSING), M3, real rate of interest (IR_REAL) and household credits (LOAN). We investigate the functional and causal relationships between housing and stock market. Research design, data, and methodology - Vector error correction model (VECM) is used to figure out the dynamic relationships among variables. This study also contains the augmented Dickey-Fuller unit root, cointegration, Granger causality test, and impulse response function and variance decomposition analysis by EViews 11.0. Results - The statistical tests show that all variables under consideration have one unit root and there is a longterm equilibrium relationship among variables for Greece. GDP, IR_REAL, M3, STOCK and LOAN can be considered as causal factors to affect real estate market, while GDP, LOAN, M3, BCA and HOUSING can bring direct effects to stock market in Greece. Conclusions - It can be judged that the policy that affects the lending policy of financial institutions may be more effective than the indirect variable such as monetary interest rate.

• Journal of the Korean Data Analysis Society
• /
• 제20권6호
• /
• pp.2759-2769
• /
• 2018

The behavioral finance view on the existence of asset pricing anomalies is based on two factors: investors' sentiment and limits to arbitrage. This paper tries to examine the effect of investors' sentiment on the stock price in the Korean stock market. In order to measure investors' sentiment, we constructed the sentiment index using principal component of five sentiment variables. By using sentiment index as an additional independent variable to three risk factors, impacts of the sentiment index on individual stocks and 25 portfolios sorted by BM-size are examined. Main results found are as follows: 1) not only all three risk factors show positive impacts on the return of individual stock, but also the sentiment index has a positive impact. SI alone explains 15% of individual return variation. 2) among four independent variables, the most important factor turned out to be the market risk factor and investors' sentiment has better explanatory power on stock price than the size effect. 3) after controlling the market risk factor, the coefficient of the sentiment index for the smallest size and highest book/market value portfolios is significantly positive. 4) all the coefficients of the sentiment index for 25 portfolios sorted by BM-size have significant positive value after controlling size or (and) value.

• 한국조리학회지
• /
• 제16권5호
• /
• pp.287-298
• /
• 2010

본 연구에서는 소스나 스프 등의 모체가 되는 닭 육수의 제조에 닭뼈를 이용하여 각종 영양 성분이 적절하게 이용되기 위한 닭 육수를 만들고자 했다. 닭 육수의 맛과 영양을 향상시키고 국물을 이용하는 요리의 품질 개선과 최상의 육수개발의 기초 자료로 이용하기 위하여 토마토를 이용한 닭 육수를 제조하였다. 따라서 토마토의 첨가량에 따른 수분, 회분, 색도, 당도, pH, 유리 아미노산, 관능적 특성 및 기호도 분석을 통하여 육수 제조 시 첨가되는 토마토에 함유된 유기산을 이용하여 닭뼈에서 용출되는 유리 아미노산과 각종 영양성분에 따른 관능적 특성을 알아 보고자 했다. 총 유리 아미노산의 함유량과 종합적인 기호도는 7.4%의 토마토를 첨가하였을 때 가장 높았다. 이상의 연구 결과를 통해 적절한 토마토의 첨가는 전체적인 기호도에 긍정적인 영향을 미치며, 닭 육수의 제조에 있어서 토마토 7.4% 첨가가 가장 적절한 것으로 평가되었다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.836-842
• /
• 2007

Recently it is a tendency that Diesel rolling stock is committing in the commuter's train route of the suburb for solving commuting traffic congestion. It has advantage which expense of diesel rolling stock is relatively cheaper than electric rail car or high-speed train. In addition, it can be using the exist route without large-scale facility investment. Because of this advantage, the demand of diesel rolling stock occupy regular portion from overseas railway car market. GM/RT 2100 specifies the loads vehicle bodies shall be capable of withstanding, identifies how material data shall be used and presents the principles to be used for design verification by analysis. Therefore, in order to fulfill the structural requirements, Rotem Company has carried out Finite Element Analysis (FEA) to verify whether the carbody structure has enough strength to withstand the loads specified by GM/RT 2100. This research contains the results obtained by the analysis. The analysis was carried out using I-DEAS 12 NX Series