• Title/Summary/Keyword: Box-Cox 변화

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The Smoothing of Rainfall Intensity - Duration - frequency Relationships curve by the Box-Cox Transformation (Box-Cox 변환에 의한 I-D-F 곡선의 평활화)

  • Lee, Hee-Chan;Seong, Kee-Won
    • Journal of Korea Water Resources Association
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    • v.36 no.2
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    • pp.153-159
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    • 2003
  • When available rainfall data is not sufficient, a rough tendency of I-D-F relationship appeared frequently. In fact, rainfall intensity on the curve shows abnormally higher value the longer rainfall duration is applied that gives rise to great confusion to apply a rainfall I-D-F relationships curve to a practical work, however, the research work will present a way to solve above mentioned problem by the use of the Box-Cox transformation formula for a given rainfall data. The study came to a conclusion that the Box-Cox transformation formula is satisfied to utilize in a practical work on the ground of analysis for rainfall data of Sancheong and Yeongcheon.

Study on analysis of initial Data on 6 Sigma application in real fields (6 Sigma 현장적용 적용 시 초기 데이터 분석에 대한 고찰)

  • Lee, Sang-Bok;Choe, Eun-Hyang
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2009.10a
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    • pp.33-39
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    • 2009
  • 본 연구에서는 현장에서 6 시그마를 활용 시 통계분석의 기초가 되는 초기 데이터 분석에 대한 고찰이다. 통계의 가장 기본이 되는 데이터가 잘못되었으면 나머지 모두 문제가 된다. 이에 데이터 초기에 발생할 수 있는 여러 오류의 가능성을 살펴보고 각각에 대해 해결책을 제시하였다. 여기서 활용하는 방법들은 계측기 선정, Gage R&R, Histogram, Box-plot, PDF, Box-Cox 변화 등이다.

  • PDF

A Study on Price Elasticities of mobile telephone Demand in Korea (국내 이동전화 통화수요의 요금탄력성 추정에 관한 연구)

  • Jeong, Woo-Soo;Cho, Byung-Sun
    • 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.

Estimating WTP for the reduction of disamenity in the Seoul Metropolitan Area Landfill site using the Hedonic Pricing Model (헤도닉가격모형을 이용한 수도권매립지 유발 비효용(disamenity) 감소에 대한 지불의사액 추정)

  • Kang, Heechan
    • Environmental and Resource Economics Review
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    • v.29 no.3
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    • pp.335-362
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    • 2020
  • Using the Hedonic pricing model using Box-Cox transformation, this paper estimated the marginal effect (implicit price) of odors from landfill in the metropolitan area on housing prices and the willingness to pay for changes in certain odor conditions. This paper utilized the proximity from the landfill in the metropolitan area as a environmental variable, and analyzed the effect of various housing characteristic variables on the sale price of apartments within a radius of 5 km from the landfill. In particular, because odors factor have various heterogeneity, we applied hedonic price models instead of stated-preference methods with various types of functional forms through Box-Cox transformation, considering the heterogeneity of each region. Estimates show that the marginal value (implicit price) for the distance from the odor source was 0.227 to 0.533 depending on the function type of the estimated model. In addition, when other house factors are the same, the marginal willingness to pay for a distance of 1km from the odor source was calculated to be 16.79 to 51.76 thousand dollar depending on the type of function. Finally for the general Box-Cox model, the annual WTP was estimated to be 3,229dollar.

An Analysis of the Effects of WTI on Korean Stock Market Using HAR Model (국내 주식시장 변동성에 대한 국제유가의 영향: 이질적 자기회귀(HAR) 모형을 사용하여)

  • Kim, Hyung-Gun
    • Environmental and Resource Economics Review
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    • v.30 no.4
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    • pp.535-555
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    • 2021
  • This study empirically analyzes the effects of international oil prices on domestic stock market volatility. The data used for the analysis are 10-minute high-frequency data of the KOSPI index and WTI futures price from January 2, 2015, to July 30, 2021. For using the high-frequency data, a heterogeneous autoregression (HAR) model is employed. The analysis model utilizes the advantages of high frequency data to observe the impact of international oil prices through realized volatility, realized skewness, and kurtosis as well as oil price return. In the estimation, the Box-Cox transformation is applied in consideration of the distribution of realized volatility with high skewness. As a result, it finds that the daily return fluctuation of the WTI price has a statistically significant positive (+) effect on the volatility of the KOSPI return. However, the volatility, skewness, and kurtosis of the WTI return do not appear to affect the volatility of the KOSPI return. This result is believed to be because the volatility of the KOSPI return reflects the daily change in the WTI return, but does not reflect the intraday trading behavior of investors.

An Analysis on Productivity Change in Environment-Friendly Farming of Fruit Vegetables (과채류 친환경 실천 농가의 생산성 변화 분석)

  • Choi, Don-Woo;Kim, Tae-Kyun
    • Korean Journal of Organic Agriculture
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    • v.22 no.2
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    • pp.335-345
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    • 2014
  • The productivity decrease in environment-friendly farming is the biggest obstacle for the development of environment-friendly food market. This paper aimed to analyze the productivity change in environment-friendly farming of fruit vegetables (oriental melon, watermelon, and strawberry). Box-Cox transformation model was used to infer the functional form of productivity change. The results showed that the periods of productivity restoration to 90% level in oriental melon, strawberry, and watermelon were 14.1 years, 11.4 years, and 6.0 years, respectively. The forms of productivity restoration of fruit vegetables showed differences due to their growth characteristics, incidences of crop pests, preference for the environment- friendly agricultural products, cultivation period and so on. Because the form and period of productivity restoration were different depending on kinds of fruit vegetable, the government policy should be established considering this point of view.