• 한국산학기술학회논문지
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• 제16권11호
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• pp.7781-7787
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• 2015

본 논문은 국내 양식 넙치 중장기 시장 규모 추정을 위해 구축된 수급전망모형을 개발한 내용과 이 모형을 이용하여 2015년-2017년 기간에 대해 시장 규모(수급 및 가격)를 예측한 내용을 소개하고 있다. 양식 넙치 수급전망모형은 단일품목 부분균형모형이며 동태 축차적 시뮬레이션 모형으로 개발되었고, 모형내 각 행태방정식은 계량경제학 방법을 이용하여 추정되었다. 중 장기 시장 규모 전망에 앞서 모형의 예측정확도는 RMSPE, MAPE, Theil의 불균등계수를 기준으로 검토되었다. 예측력 검토결과, 양식면적, 양성물량, 출하량, 도매가격은 모두 4% 이내의 양호한 오차율을 보였다. 국내 양식 넙치 시장 규모 전망결과, 생산량은 2015년 37,445톤, 2017년 42,561톤에 이를 것으로 전망되었고, 산지가격은 2015년 9,226원(1kg 기준), 2017년 10,191원될 것으로 전망되었다.

• 한국경영과학회지
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• 제26권3호
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• pp.105-117
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• 2001

This paper models supply uncertainty in the dynamic Newsboy problem context. The system consists of one supplier and one retailer who places an order to the supplier every period to meet stochastic demand. Supply uncertainty is modeled as the uncertainty in quantities delivered by the supplier. That is, the supplier delivers exactly the amount ordered by the retailer with probability of $\beta$ and the amount minus K with probability of (1-$\beta$). We formulate the problem as a dynamic programming problem and prove that retailer’s optimal replenishment policy is a stationary base-stock policy. Through a numerical study, we found that the cost increase due to supply uncertainty is significant and that the costs increase more rapidly as supply uncertainty increases. We also identified the effects of various system parameters. One of the interesting results is that as retailer’s demand uncertainty, the other uncertainty in our model, increases, the cost increase due to supply uncertainty becomes less significant.

• 자원ㆍ환경경제연구
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• 제19권2호
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• pp.283-301
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• 2010

이 논문은 벡터자기회귀모형을 사용하여 종이 공급에 펄프 가격이 미치는 영향의 정도와 지속기간을 추정하고, 종이 수요에 국내총생산이 미치는 영향의 정도와 지속기간을 추정하였다. 종이 공급을 분석한 결과에 의하면 펄프 가격의 변화가 종이 공급 변화의 약 12%를 설명하고, 종이 가격의 변화가 종이 공급 변화의 약 29%를 설명하였다. 즉, 펄프 가격이 종이 공급에 큰 영향을 미치지 않는다. 그리고 펄프 가격의 변화에 대한 종이 공급의 반응은 약 6개월간 지속되며, 종이 가격의 변화에 대한 종이 공급의 반응도 약 6개월간 지속되었다. 펄프 가격이 상승하는 경우에 펄프 가격의 상승분을 종이 가격에 반영하지 못하면 일시적으로 수익률이 감소할 수 있다. 즉, 종이 가격이 펄프 가격의 상승 속도를 따라가지 못하면 수익률이 하락한다. 이와 같은 경우에 수익률을 회복시키기 위해서는 제품단가를 인상하여야 한다. 종이가 과잉 공급되면 펄프 가격의 인상을 종이 가격에 반영할 수 없다. 그러나 우리나라의 종이 공급은 과잉 상태가 아니어서 펄프 가격의 상승을 종이 가격에 반영할 수 있다. 즉, 원료 가격이 상승하면 제품 가격도 인상되고 있다. 이 연구 결과에 의하면 펄프 가격의 변동이 종이 공급에 영향을 미치는 기간은 6개월이다. 즉, 펄프 가격의 인상이 종이 가격에 반영되어 종이 생산의 수익률 하락을 회복하기까지 6개월이 소요된다고 해석할 수 있다. 종이 수요를 분석한 결과에 의하면 국내총생산의 변화가 종이 수요 변화의 약 28%를 설명하고, 종이 가격의 변화가 종이 수요 변화의 약 17%를 설명하였다. 즉, 국내 총생산이 종이 수요에 상당한 영향을 미친다. 그리고 국내총생산의 변화에 대한 종이 수요의 반응은 약 6개월간 지속되며, 종이 가격의 변화에 대한 종이 수요의 반응도 약 6개월간 지속되었다.

• 지역연구
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• 제12권2호
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• pp.37-57
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• 1996

Intra-metropolitan spatial segmentation of the labor marker requires barriers of mobility on both supply and demand side of the local labor marker. The phenomena of spatial segmentation of the labor market are particularly applied to the secondary workers rather than to the primary workers. Supply side barriers include the costs of obtaining job information regarding jobs outside of the immediate area, commuting costs, and barriers to residential mobility. Demand side barriers include site-specific technology and product demand, and discrimination. In this paper, I discuss these barriers and examine their implications for differences in segmentation by demographic and skill groups at the intra-metropolitan scale. In particular, I apply a job search model to examine supply side barriers such as information and commuting costs, and an implicit contract model to explain demand side barriers such as dual/internal labor market and firms' (re) location strategies.

• Industrial Engineering and Management Systems
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• 제8권1호
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• pp.1-13
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• 2009

This paper presents a coordinated planning model of price-dependent demand for a single-manufacturer and a single-retailer. The demand is assumed to be normally distributed, with its mean being price dependent. The manufacturer and retailer coordinate with each other to jointly and simultaneously determine the retail selling price and the retailer order quantity to maximize the joint expected total profit. This model is then compared to a 'returns' policy model where manufacturer buys back unsold items from the retailers. It is shown that the optimal total profit is higher for coordinated planning model than that for the returns policy model, in which the retail price is set by the retailer. A compensation or profit sharing scheme is then suggested and it is shown that the coordinated model with profit sharing yields a 'win-win' situation. Numerical results are presented to illustrate the profit patterns for both linear and nonlinear demand functions. The coordinated planning model, in addition, has a lower optimal price than for a returns policy model, which would result in higher sales, thus expanding the markets for the whole supply chain.

• 전기학회논문지P
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• 제64권2호
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• pp.74-78
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• 2015

With the improvement of living standards and economic development, electricity consumption continues to grow. The electricity is a special energy which is hard to store, so its supply must be consistent with the demand. The objective of electricity demand forecasting is to make best use of electricity energy and provide balance between supply and demand. Hence, it is very important work to forecast electricity demand with higher precision. So, various forecasting methods have been developed. They can be divided into five broad categories such as time series models, regression based model, artificial intelligence techniques and fuzzy logic method without considering special-day effects. Electricity demand patterns on holidays can be often idiosyncratic and cause significant forecasting errors. Such effects are known as special-day effects and are recognized as an important issue in determining electricity demand data. In this research, we developed the power demand forecasting method using ELM(Extreme Learning Machine) for special day, particularly, lunar new year and Chuseok holiday.

• 전기학회논문지
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• 제57권1호
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• pp.20-24
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• 2008

A bid-based pool(BBP) model is representative of energy market structure in a number of restructured electricity markets. Supply function equilibrium(SFE) models of interaction better match what is explicitly required in the bid formats of typical BBP markets. Many of the results in the SFE literature involve restrictive parametrization of the bid cost functions. In the SFE models, two parameters, intercept and slope, are available for strategic bidding. This paper addresses the realistic competition format that players can choose both parameters arbitrarily. In a fixed demand function, equilibrium conditions for generation company's profit maximization have a degree of freedom, which induces multi-equilibrium. So it is hard to choose a convergent equilibrium. However, consideration of stochastic demand function makes the equilibrium conditions independent each other based on the amount of variance of stochastic demand function. This variance provides the bidding players with incentives to change the slope parameter from an equilibrium for a fixed demand function until the slope parameter equilibrium.

• 한국정보시스템학회지:정보시스템연구
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• 제15권3호
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• pp.159-174
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• 2006

Employment rate of graduating students has been one of the most important issues at universities. Recently interest on internship abroad has been increased significantly due to globalization of the society In particular, central and local governments have developed policies and encouraged university students to participate in internships abroad. However, activities and resources for internships abroad are very limited to a few organizations. This paper investigated the current status of internship in the U.S. and Korea. Then, this paper analyzed differences in demand and supply of the internship and matching mechanism of the internship between the U.S. and Korea. From the results of those analyses, this paper developed an international network model which can help effective and efficient increase in the demand and supply of the internship as well as the internship matching mechanism in Korea. This network model utilizes international NGOs in order to develop internationally cooperative environment. This model provides mechanism for (1) effectively identifying intern applicants who like to work abroad and evaluating thent (2) effectively identifying new internship positions and evaluating companies which plan to hire interns, (3) efficiently matching demand for and supply of internship by identifying appropriate candidates, (4) monitoring companies for their quality of working conditions and interns for their qualities of work This model for internship has been applied for a NGO which is International CBMC (Christian Businessman Committee International)

• 한국수자원학회논문집
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• 제30권1호
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• pp.45-54
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• 1997

수돗물, 송배수펌프의 운전 등 상수도시설을 합리적인 운용을 위해서는 일, 또는 시간 단위의 급수량 사용량의 추정이 필수적이다고 할 수 있다. 급수량의 추정방식은 회귀모형식 및 시계열 분석방법이 있는데, 본 연구에서는 시계열 분석방법인 ARIMA모형을 이용하여 일일 급수량을 추정하였으며 연구대상 지역으로는 광주광역시를 선정하였다. 일일 급수량을 추정하는데 있어서 시계열장을 15, 30. 60, 90일로 나누어 각각의 시계열장에 대해 시행착오법으로 각 모형에 적용하여 최적의 시계열장을 결정하여, 상수도 일일 급수량을 추정할 수 있는 모형을 제안하고 그 유효성을 잔차분석을 통해 검증하였다. 제안된 모형식은 사고 등의 인위적인 조작(단수 등)이 가해지는 시기를 제외하고는 실측치와 모형의 추정치와의 오차율이 최대 약 12%, 평균 3% 이내로 나타나, 모형의 결과는 상수도 일일 급수량의 추정에 필요한 시설에 적용 가능하다고 판단된다.

• 대한한의학회지
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• 제20권2호
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• pp.27-36
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• 1999

This study was performed to investigate the supply and demand of the oriental medical doctor(OMD) based on the supply and demand analysis of OMD up to the year 1997. The baseline projection and demographic methods were considered to examine the supply of OMD. On the contrary, for the demand analysis, two different approaches were conducted with the nonlinear regression model. The findings of this study indicate that the OMD will be oversupplied before the year 2012 with decreasing rate. However, when we consider the demand of OMD in the future. it is anticipated that the demand of oriental medicine will be increased rapidly with two major aspects. The first is the expansion of insurance benefits. The second is the increasing number of adult diseases because of the aging of the population structure. Therefore, the effective cooperation system and mutual exchange between western and oriental medicine is required for the future. Also. it is necessary to make the oriental medicine of the pharmaceutical services in more scientific way for the appropriate policy of the demand and supply of OMD. For the future study, the students who study abroad, especially China should be considered. These students will be the key element for the future supply of OMD.