• 펄프종이기술
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• 제31권1호
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• pp.52-60
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• 1999

Drainage rate in wet-end, which has significant influences on the production capacity, product quality and process economics in papermaking, becomes an important factor in the modern high speed papermaking processes owing to increased level of fines contained in today's pulp materials and increased papermaking system closure. A study was carred out to investigate the influence of beating and fines content on natural and vacuum dewatering using a vacuum drainage tester. Increase in beating and accumulation of fines in the stock decreased natural dewatering, Vacuum dewatering effect, however, increased substantially as beating and fines content were increased. But this increase in vacuum dewatering decreased again when a stock is severely beaten or fines content is greater than 35%. Above this level of fines content, mobile fines migrates to the interstices of the forming web to cause sealing or plugging which restrict fluid movement through the web.

• 한국식품영양학회지
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• 제4권2호
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• pp.133-140
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• 1991

This study was designed to investigate age-related changes in body composition and cell mediated immunity. Male Sprague-Dawley rats were fed stock diet ad libitum and 12 rats were sacrified at 1, 4, 6, 12 months of age. Body weight Increased sharply from 1 to 4 months. and Increased steadily thereafter. The weights of liver, epididymal fat pads, and kidney increased in similar pattern as body weight, but their relative ratio to body weight decreased with age. The ratio of epididymal fat pads to body weight increased with age. The weight of extensor digitorium longus, coleus and plantaris increased from 1 to 4 months, but it decreased at 6, 12 months. The protein content of muscles decreased or increased through- out 12 months. The T cell proliferation response to Con A stimulation was significantly lower at 6 months than 1 month and lower at 12 months than 6 months.

• Communications for Statistical Applications and Methods
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• 제10권1호
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• pp.89-99
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• 2003

The primary purpose of this paper is to estimate the wealth effect. We establish a linear relationships between household consumption, labor income, and stock price index. Each variable is nonstationary. And so, it contains a unit root. However, as the result of the test about cointegrating relations, the variables are cointegrated which implies the error term is stationary. The cointegrating parameter that the marginal propensity to consume out of stock price is 0.08%. The result of estimation shows the error correction is -0.62 and the significant level is also high. The error correction term indicates a rather rapid adjustment to deviations from the long run equilibrium relations.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1486-1493
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• 2008

In this paper, we performed analysis and comparison on emergency response action for passengers, drivers, workers and controllers in case of failure occurrence on rail infrastructure and rolling stock. In general, the subjects of emergency response action perform the response action with following emergency response procedures when accidents occurred. In reality, however, no matter how well the subjects are trained, it is hard to follow the emergency response procedures precisely without making any mistakes. As for emergency response action, the most significant factor for the subjects is to follow the emergency response procedures as learned, without any hesitation. In this paper, therefore, we analyzed the emergency response actions that should be performed by passengers and railway workers when emergency accidents occurred. We also examined the communication facilities for emergency response among train, wayside and station in order to provide the emergency reporting system for passenger and the method for cleaning out the accident area.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.472-476
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• 2004

In this study, we investigate the change characteristic of friction coefficient of disk brake lining for rolling stock according to disk type, The actual brake tests were carried out under constant brake force and operating sequence by using dynamo-tester. Test results showed that instant friction coefficient was higher in the case of devided disk type rather than single body disk type, Also, averge friction coefficient was appeared similer to the above result. It is thought that ,in the case of devided disk type, friction resistance was increased due to the gap between both side of half disk.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.483-488
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• 2004

The inter-laboratory comparison test which is demanded on the authorized test of ISO/IEC 17025 is the program to guarantee the confidence of test result. This paper, as a part of the inter-laboratory comparison test between South Korea and China, is refered to the characteristic of friction coefficient of disk brake lining for rolling stock according to disk type. Brake tests were carried out under constant brake force and operating sequence by using dynamo-tester according to disk and disk lining types. To establishing the confidence of test result, we calculated A type uncertainty about friction coefficient and investigated the factors about the variation of friction coefficient.

• Advances in Energy Research
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• 제3권3호
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• pp.181-194
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• 2015

In this work, an experimental study of the gasification on wood was carried out in downdraft type fixed bed Gasifier attached with 10 kW duel fuel diesel engine. The main objective of the study was to use wood as the biomass fuel for downdraft Gasifier and to evaluate the operating parameter of gasifier unit to predict its performance in terms of gas yield and cold gas efficiency. The influence of different biomass on fuel consumption rate, gas yield and cold gas efficiency was studied. Composition of producer gas was also detected for measuring the lower heating value of producer gas to select the feed stock so that optimum performance in the existing gasifier unit can be achieved. Under the experimental conditions, Lower heating value, of producer gas, cold gas efficiency and gas yields, using wood as a feed stock, are $4.85MJ/m^3$, 46.57% and $0.519m^3/kg$.

• Communications for Statistical Applications and Methods
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• 제25권6호
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• pp.659-671
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• 2018

In this study, we consider the extension of the heterogeneous autoregressive (HAR) model for realized volatility by incorporating a neural network (NN) structure. Since HAR is a linear model, we expect that adding a neural network term would explain the delicate nonlinearity of the realized volatility. Three neural network-based HAR models, namely HAR-NN, $HAR({\infty})-NN$, and HAR-AR(22)-NN are considered with performance measured by evaluating out-of-sample forecasting errors. The results of the study show that HAR-NN provides a slightly wider interval than traditional HAR as well as shows more peaks and valleys on the turning points. It implies that the HAR-NN model can capture sharper changes due to higher volatility than the traditional HAR model. The HAR-NN model for prediction interval is therefore recommended to account for higher volatility in the stock market. An empirical analysis on the multinational realized volatility of stock indexes shows that the HAR-NN that adds daily, weekly, and monthly volatility averages to the neural network model exhibits the best performance.

• 한국가금학회지
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• 제2권1호
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• pp.4-6
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• 1975

Field trials and research works have shown that the sexually retarded pullets are better equipped to lay larger eggs at the commencement of lay than the pullets grown under the natural conditions with no control over the rate of maturity. The method of delaying the sexual maturity by restricting the nutrient intake is receiving a considerable attention from the research workers, since the nutrient restriction can be a method of reducing the rearing cost. Many experiments were carried out to study the effect of different methods of restricting the nutrient intake of the chicken. But the comparisons between these experiments are difficult because of the differences in the environment, management, type of breed and feed, and in the length of the time during which the feed intake was restricted. In addition the comparisons were not made on an economic basis in these experiments. This experiment was designed to provide information on the reproductive responses to three different methods of restricting the nutrient intake in a egg type stock and to establish which methods are economically profitable. (omitted)

• 경영과정보연구
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• 제29권1호
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• pp.1-23
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• 2010

본 연구는 국내와 미국 IPO기업을 대상으로 이사회내의 사외이사의 특성, 사외이사에 대한 보상 등이 기업공개 후 누적비정상 수익률에 어떠한 영향을 미치는지를 실증분석하고 있다. 본 연구를 통해 아래의 흥미로운 결과를 도출할 수 있었다. 첫째, KOSDAQ기업의 사외이사의 연령과 누적비정상수익률(CAR)간에는 유의한 관계가 나타나지 않은 반면 NASDAQ 기업에서는 유의한 양의 관계를 도출할 수 있었다. 또한 50대 초과 사외이사 그룹은 50대 이하 그룹보다 기업가치에 긍정적인 영향을 미친다는 것을 도출할 수 있었다. 둘째, 사외이사의 학력과 국내 KOSDAQ기업의 CAR간에는 통계적으로 유의한 결과는 도출할 수 없었다. 그러나 미국기업의 경우에는 대체로 학력이 높을수록 기업가치에 긍정적인 영향을 미침을 발견할 수 있었다. 셋째, 사외이사의 경력과 관련해서는 전문성과 대표이사 경험을 보유한 사외이사가 회색이사 그룹 군에 비해 기업가치에 긍정적인 영향을 준다는 것을 살펴볼 수 있었다. 마지막으로, 사외이사의 보수와 기업가치 간의 관계에 있어서는 한국기업의 경우 유의하지 않은 음(-)의 관계를 보였으나 미국기업의 경우에는 양(+)의 유의한 관계를 도출할 수 있었다. 특히, 미국기업의 경우 사외이사의 Stock Option과 누적비정상 수익률 간에는 유의한 양(+)의 관계를 보이고 있어 이러한 결과로 유추해 볼 때 사외이사의 Stock Option이 기업가치 상승에 긍정적인 영향을 미치고 있음을 살펴볼 수 있었다.