• 한국안전학회지
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• 제32권3호
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• pp.117-122
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• 2017

In this study, we studied the ride quality considering the deterioration effects of the three type couplers (single, double, and ring types) for EMUs. In order to know the impact occurred when an urban transit vehicle is under breaking, we tested the conditions of the service brake and the emergency brake. Normal coupler models without any slack showed similar dynamic performance results under all breaking conditions. But if the couplers become old, the initial pre-stresses are removed because of permanent compressive deformation in rubber. For three types of the old coupler models without the initial pre-stress, we evaluated dynamic performances of each type. As the results, the maximum and average acceleration levels of the double type and the ring type were similarly low in all conditions. But the accelerations of the single type coupler was high when compared to those of the double and ring types. In addition, Jerk value of the single type model associated with ride quality was high up to 15 times to the ring type in condition of the service braking in empty vehicle weight. Jerk value of the double type model was high up to 6 times to the ring type.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.160-169
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• 2003

Pantograph of high speed rolling stock is one of the key components that transfer of associated technologies was blocked fundamentally from advanced nations. In this study, main technologies related to development of prototype pantograph installed on prototype test train developed according to the project "Development of high speed railway technology" are presented. Status of current korean technologies is explained by presenting developed technologies and applications during the past 6 years from concept design to test and evaluation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.423-430
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• 2002

This study was started to develop maintenance technology for wheel tread suitable domestic railway environment. As a pre-study to develop optima] wheel tread, we analyzed the wear characteristics of wheel tread that is being applied to railway rolling-stock in KNR. To analyze wheel wear characteristics. we have conducted the simulation and experiment for passenger rolling-stock and obtained useful datum. Here, we describe some results.

• 한국식품조리과학회지
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• 제26권5호
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• pp.665-675
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• 2010

This study applied high-pressure extraction cooking, which has been proven superior in processibility and stock extraction, for the preparation of stock, which is widely used as a basic material of dishes, and examined the physicochemical and sensory properties of the extracted stock by adding salt. We observed changes in the chromaticity of brown stock according to salt content, and pH decreased with increased the salt content, suggesting that stock was acidified. Regarding the mineral content, Na was the highest, followed by K and P. Regarding total free amino acid content, the content of essential amino acids, enhancing free amino acids, and other amino acids also showed the highest level in S2, which contented 0.3% salt. In the sensory test, saltiness grew stronger with an increase in salt content, and overall palatability was highest in S2. Regarding ranking, preference was highest for S2. Utilize to data that study finding of above is actual in development for mass production of brown stock product licensed cooks' traditional mesh dipper technology quality that make mass production direction that change and normalizes product that can keep excellent taste and improve conservative property develop. Culture formation and our country foodservice industry development that reduce damage of informed people ashes through development of brown stock product that is changed in large quantity, and improve quality of food more positively contributing to reappear diversification of menu, systematization and taste of specialty store as well as can contribute in rationalization of informed people ashes purchase, personnel expense (labor power) curtailment, waste decrease etc. but is developed still more being utilized.

• 한국컴퓨터정보학회논문지
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• 제16권2호
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• pp.279-288
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• 2011

본 연구는 자동차부품제조업의 전사적 자원관리(ERP : Enterprise Resource Planning)시스템 전체 모듈중 가용재고관리 프로세스에 대한 표준화 모델을 개발한다. 표준화 모델은 중소기업청 및 중소기업기술정보진흥원에서 제시한 정보화구축 개발 방법론에 준하여 단계별 방법론에 따라 시스템이 구축되게 된다. 표준화 모델은 가용 재고관리 프로세스를 위한 발주관리, 입고관리, 출고관리, 재고관리의 프로세스를 표준화 시키고 표준모듈을 개발한다. 본 연구로 ERP시스템 하에서 가용재고관리 프로세스를 구축하고자 하는 제조기업 및 관련 전문 IT업체 들이 표준화된 모듈을 적용하여 시스템을 보다 효과적으로 구축 할 수 있으며, 시스템에 대한 구축 용이성과 신뢰성을 제공한다. 본 연구 결과를 적용함으로써 기업의 원자재 및 제품의 과다보유를 방지하고 적정, 안전재고를 항시 보유할 수 있으며 실시간 재고파악, 고객납기 준수, 과다제품 생산 방지 및 재고비용 절감 등이 가능하다.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.1005-1015
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• 2020

This paper aims to propose a Comprehensive Decision Support Model to evaluate retail companies' financial performance traded on the Vietnam Stock Exchange Market. The financial performance has been examined in terms of the valuations ratios, profitability ratios, growth rates, liquidity ratios, efficiency ratios, and leverage ratios. The data of twelve companies from the first quarter to the fourth quarter of 2019 and the first quarter of 2020 were employed. The weights of 18 chosen financial ratios are calculated by using the Standard Deviation method (SD). Grey Relational Analysis technique was applied to obtain the final ranking of each company in each quarter. The results showed that leverage ratios have the most significant impact on the retail companies' financial performance and gives some long-term investment recommendations for stakeholders and indicated that the Taseco Air Services Joint Stock Company (AST), Mobile World Investment Corporation (MWG), and Cam Ranh International Airport Services Joint Stock Company (CIA) are three of the top efficient companies. The three of the worst companies are Viglacera Corporation (VGC), Saigon General Service Corporation (SVC), and HocMon Trade Joint Stock Company (HTC). Furthermore, this study suggests that the GRA model could be implemented effectively to ranking companies of other industries in the future research.

• 펄프종이기술
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• 제38권1호통권113호
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• pp.16-20
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• 2006

The effect of the freeness of pulp slurries on turbidity and transmittance of papermaking stocks was investigated using beaten bleached hardwood pulp stocks with freeness ranging from 651 mL to 403 mL CSF. Also the influence of fiber length on the turbidity and transmittance was examined with fractionated pulp stocks. Increases in stock consistency increased the turbidity. Transmittance of stock samples decreased, however, with the increase of stock consistency. Second order equations and exponential equations have been obtained as regression equations for the turbidity and transmittance of these stock samples, respectively.

• 펄프종이기술
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• 제40권3호
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• pp.15-22
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• 2008

Properties of pulp fibers can be modified by LbL multilayering technology. We evaluated the effect of stock composition on the polyelectrolyte multilayering performance of pulp fibers in this study. Stock composition was varied with pulp type and fines content. Three types of pulp-Hw-BKP, BCTMP and KOCC-were treated with polyelectrolytes of poly-DADMAC and PSS. Fines content of stock were controlled at 0, 10, 20, 30, and 40%. Zeta potential of pulp fibers and charge demand of filtrate were evaluated. The highest adsorption ratio was obtained for BCTMP because of its shortest fiber length and highest specific surface area. Higher fines content in the stock increased the adsorption ratio of polyelectrolyte onto pulp fiber and it required a higher amount of polyelectrolyte for charge neutralization. For the pulp stock with higher fines content, a higher level of polyelectrolyte and the increased layer number were required to modify and stabilize the electrochemical properties of pulp fibers.

• The Journal of Asian Finance, Economics and Business
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• 제8권7호
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• pp.91-101
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• 2021

The paper examines the impact of the COVID-19 pandemic on the stock market prices. The vector autoregression model (VAR) has been used in this analysis to survey 341 stocks on the Ho Chi Minh City Stock Exchange (HOSE) for the period from January 23, 2020 to December 31, 2020. The empirical results obtained from the analysis of 11 economic sectors suggest that there is a statistically significant impact relationship between COVID-19 and the healthcare and utility industries. Additional findings show a statistically significant negative impact of COVID-19 on the utility share price at lag 1. Analysis of impulse response function (IRF) and forecast error variance decomposition (FEVD) show an inverse reaction of utility stock prices to the impact of COVID-19 and a gradual disappearing shock after two steps. Major findings show that there is a clear negative effect of the COVID-19 pandemic on share prices, and the daily increase in the number of confirmed cases, indicate that, in future disease outbreaks, early containment measures and positive responses are necessary conditions for governments and nations to protect stock markets from excessive depreciation. Utility stocks are among the most severely impacted shares on financial exchanges during a pandemic due to the high risk of immediate or irreversible closure of manufacturing lines and poor demand for basic amenities.

• 경영과정보연구
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• 제31권3호
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• pp.307-321
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• 2012

본 연구는 중국 경제의 성장에 따른 중국 주식시장과 한국 주식시장간의 동조화에 대한 연구의 일환이다. 저자가 관심을 가지는 부분은 한국과 중국의 1시간 30분의 시차에 따라 발생하는 중국시장의 개장충격 즉, 시가갭에 대한 한국시장의 장중반응이다. 금융위기 이후 중국 주식시장에서 발생하는 충격은 이전보다는 크게 영향을 주고 있는 것으로 체감됨에 따라 실제 한국 시장의 10시 30분 이후의 수익률과 변동성을 살펴봄으로써 중국시장의 시가갭의 영향이 증가해오고 있는지를 실증적으로 분석하고자 하였다. 분석기간은 2008년 1월부터 2010년 4월까지 총 28개월이며, 수익률 전이 및 변동성 전이를 연속회귀에 의해 분석함으로써 시간의 흐름에 따라 계수의 크기와 유의성의 변화를 관찰하였다. 그 결과, 중국 시장의 시가갭은 한국 시장의 10시 30분 이후 5분내외의 누적수익률 및 변동성에 유의적인 양의 영향을 미치고 있으며, 이러한 경향은 최근에 들어서야 크게 증가하고 있는 것으로 분석되었다. 그리고 10분이후의 누적수익률 및 변동성에 미치는 영향은 거의 없는 것으로 보여 중국시장의 개장충격은 한국시장에 약 5분정도 상당한 영향을 줄 수 있는 것으로 파악된다. 무엇보다 중요한 점은 이러한 장중의 영향이 최근에 들어 일관되게 증가하고 있다는 점이며, 중국의 성장에 따른 영향력이 커지고 있음을 실증적으로 알 수 있게 되었다는 점에서 다양한 후속 연구가 기대된다. 특히 아시아 지역의 개장시차의 차이에 따른 수익률 및 변동성 전이의 흐름으로 확장될 수 있기를 바란다.