• Journal of Energy Engineering
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• v.22 no.3
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• pp.245-249
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• 2013

This paper attempts to estimate the kerosene demand function in Korea over the period 1981-2012. As the kerosene demand function provides us information on the pattern of consumer's kerosene consumption, it can be usefully utilized in predicting the impact of policy variables such as kerosene price and forecasting the demand for kerosene. We apply least absolute deviations and least median squares estimation methods as a robust approach to estimating the parameters of the kerosene demand function. The results show that short-run price and income elasticities of the kerosene demand are estimated to be -0.468 and 0.409, respectively. They are statisitically significant at the 1% level. The short-run price and income elasticities portray that demand for kerosene is price- and income-inelastic. This implies that the kerosene is indispensable goods to human-being's life, thus the kerosene demand would not be promptly adjusted to responding to price and/or income change. However, long-run price and income elasticities reveal that the demand for kerosene is price- and income-elastic in the long-run.

• Review of Culture and Economy
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• v.21 no.3
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• pp.59-88
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• 2018

This study examines demand of the Korean TV VOD using monthly aggregate data and time series analysis models. In particular, the impact of box office attendance, number of IPTV subscribers, income and price of substitutes on TV VOD market is analyzed. Data on TV VOD download during the period 2013 January to 2018 June are used for the empirical analysis. TV VOD demand shows lower level of seasonality than box office attendance and the share of monthly top1 movie in TV VOD platform is also lower than that of box office attendance. The relationship between a movie's holdback and box office performance does not seem consistent. The empirical result of ARDL model reveals that in the short-run box office attendance, number of IPTV subscribers and price of substitutes have significant impact on TV VOD demand. The result on the long-term relation shows that income is the only determinant of TV VOD demand. The impact of box office attendance on TV VOD is not shown to be robust both for the short-term and long-term.

• Digital Contents
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• no.4 s.71
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• pp.32-33
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• 1999

리누스 토발즈에 의해 개발된 리눅스가 DBMS 시장의 새로운 변수로 자리잡고 있다. 한국 IBM을 비롯해 한국인포믹스, 한국오라클, 한국사이베이스 등 주요 DBMS 벤더들은 리눅스용 데이터베이스를 무료 배포하는 등 하반기 이후 본격적인 수요가 예상되는 리눅스용 DBMS시장을 겨냥해 업체별 전략을 내놓고 있다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.2
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• pp.125-130
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• 2014

Forest recreation is done outdoor, so weather has impact on forest recreation. Impact of temperature on forest recreation has been studied. However, impact of precipitation on forest recreation has not been studied yet. This article paid attention to rainfall and rainy day among the variables explaining the visitor number of national park. We analyzed whether rainfall and rainy day have impact on visitor number. As the result of analysis, rainy day had impact on the visitor number of national park in Korea, and the degree of the impact was inelastic. However, rainfall could not explain the visitor number of national park. It is needed to monitor the impact of precipitation on forest recreation demand.

• Monthly Korean Chicken
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• v.18 no.1
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• pp.58-62
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• 2012

큰 어려움이 예상되었던 2011년 육계산업은 여러 변수들로 인해 예상 밖의 선전을 보였다. 2010년 하반기 종계도태 증가와 맞물려 HPAI로 종계가 일부 매몰처분 되면서 공급과잉이 아닌 공급부족현상이 나타났고, 구제역으로 인한 대체수요, 방사능 유출로 인한 대체수요 등으로 4월까지 산지가격이 폭등했다. 이후 공급량 증가와 수입량 증가가 맞물리면서 가격이 폭락하는 상황이 발생했다. 폭등과 폭락을 경험했던 상반기와 달리 하반기에는 일시적 공급 감소는 있었으나, 꾸준히 공급량이 증가했다. 다사다난했던 2011년 육계산업을 정리하면서 2012년 산업을 전망하고자 한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.28
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• pp.109-112
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• 1993

본 논문은 품절기간 중 수요의 일부는 부재고되고 나머지 일부는 유실되는 재고 모형을 제시한다. 부재고되는 수요량은 불확실하다. 따라서 부재고되는 수요의 양을 확률변수로 놓고, 부재고되는 수요량의 표준편차가 누적품절량의 크기에 비례하는 경우를 다루었다. 투영에 의한 분해법(decomposition by projection)을 사용하여 최적 재고 정책을 도출하였다.

• Journal of the Korean Data and Information Science Society
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• v.6 no.1
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• pp.23-30
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• 1995

이동전화 서비스에 대한 가입자수는 중단기적으로 급격히 증가하지만 장기적으로는 대체서비스의 개발 등의 영향으로 그 증가율이 감소하는 특징을 가지고 있다. 본 연구에서는 이동전화 수요에 영향을 미치는 사회 경제 및 기술적 변수들에 대한 통계분석과 아울러 우리나라의 이동전화 가입자수를 예측하였다. 수요의 특성에 따라 로지스틱모형과 이동평균모형을 적용하여 예측한 결과 2001년에는 660만명에 달하여 이동전화의 대중화 시대가 본격적으로 전개될 전망이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6B
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• pp.390-401
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• 2007

This paper is to estimate and analyze the price elasticities of demand for mobile calls. We used the data for the period from January 2000 to December 2005 on a monthly basis. Data used are call minutes to mobile-originating(ML+MM), tariff for dispatch of fixed and mobile calls($P_L,P_M$), income(Y), and subscriber for mobile(N). In order to provide robust estimates of price elasticities, we have used two different econometric models. One is a Dynamic model which includes a lagged dependent variable and so can differentiate between long-un and short-run price elasticities using the Generalized Method of Moments(GMM). The other is a Box-Cox transformation model which is one of the most useful methods. Box-Cox transformation model shows that elasticity changes with the lapse of time. The results are as follow : Not including the price indices for land-originating, the estimate is overestimated otherwise. In Box-Cox transformation case, price elasticity had been steadily declining. And this result shows that mobile services had been changed necessities increasingly in Korea.

• Journal of Energy Engineering
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• v.22 no.1
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• pp.1-7
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• 2013

This paper attempts to estimate the residential electricity demand function, using survey data of 521 households in Korea. As the residential electricity demand function provides us information on the pattern of consumer's electricity consumption, it can be usefully utilized in predicting the impact of policy variables such as electricity price and forecasting electricity demands. We apply least absolute deviation(LAD) estimation as a robust approach to estimating parameters. The results showed that price and income elasticities are -0.68 and 0.14 respectively, and statistically significant at the 10% levels. The price and income elasticities portray that residential electricity is price- and income-inelastic. This implies that the residential electricity is indispensable goods to human-being's life, thus the residential electricity demand would not be promptly adjusted to responding to price and/or income change.

• Journal of Korean Society of Transportation
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• v.19 no.1
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• pp.89-99
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• 2001

The conventional studies on equilibrium network design problem(ENDP) with fixed travel demand models assume that the future OD travel demand might not be changed even if the structure and the capacity of the network are improved. But this fixed demand assumption may loose its validity in the long-range network design because OD travel demand actually shifts with the network service level. Thus, it is desirable to involve the variable travel demand which is determined endogenously in the model in the optimal network design. In this paper a hi-level model formulation and solution procedure for ENDP with variable travel demand are presented. Firstly It is considered how to measure the net user benefits to be derived from the improved in link capacities, and the equilibrium network design problem considered here is to maximize the increase of net user benefit which results from a set of lift capacity enhancements within the budget constraints, while the OD travel demands and link travel times are obtained by solving the lower level network equilibrium problem with variable demand. And secondly sensitivity analysis is carried out to find the links to which the network equilibrium flow pattern is the most sensitive. Finally numerical example with simple network is carried out to test the validity of the model.