• Title/Summary/Keyword: Maximum Entropy

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Sustainable Production Strategy of Pine Mushroom (Tricholoma matsutake) using the Maximum Entropy Technique (최대 엔트로피 기법으로 도출한 지속 가능한 송이 생산 전략)

  • Choi, Junyeong;Koo, Ja-Choon;Youn, Yeo-Chang
    • Journal of Korean Society of Forest Science
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    • v.102 no.3
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    • pp.365-371
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    • 2013
  • Pine mushroom (Tricholoma matsutake) is one of the most profitable forest products in Korea. We postulated a hypothesis that a high rate of returns to labor input could make the harvest of pine mushroom off the optimum level. In the view of developing a sustainable production strategy for pine mushroom producers, production of pine mushroom collectors and pine mushroom growth function were estimated using maximum entropy method. Annual pine mushroom production and labor input were the data used in the estimation of production function of pine mushroom collectors and pine mushroom growth function. The level of sustainable maximum production derived from the estimated function. The production function estimated shows that production of pine mushroom is affected more by the resource of pine mushroom stocked in the forests than by labor that households put in forestry business. The production function of mushroom collectors and the estimated growth function indicate that pine mushroom harvests for the period of 2005-2011 did not reach the potential level of maximum sustainable production. Therefore, we suggest that pine mushroom harvest should be controlled until the resource stock of pine mushroom in the forests increases to the level of maximum sustainable production.

A Comparative Analysis of Maximum Entropy and Analytical Models for Assessing Kapenta (Limnothrissa miodon) Stock in Lake Kariba (카리브호수 카펜타 자원량 추정을 위한 최대엔트피모델과 분석적 모델의 비교분석)

  • Tendaupenyu, Itai Hilary;Pyo, Hee-Dong
    • Environmental and Resource Economics Review
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    • v.26 no.4
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    • pp.613-639
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    • 2017
  • A Maximum Entropy (ME) Model and an Analytical Model are analyzed in assessing Kapenta stock in Lake Kariba. The ME model estimates a Maximum Sustainable Yield (MSY) of 25,372 tons and a corresponding effort of 109,731 fishing nights suggesting overcapacity in the lake at current effort level. The model estimates a declining stock from 1988 to 2009. The Analytical Model estimates an Acceptable Biological Catch (ABC) annually and a corresponding fishing mortality (F) of 1.210/year which is higher than the prevailing fishing mortality of 0.927/year. The ME and Analytical Models estimate a similar biomass in the reference year 1982 confirming that both models are applicable to the stock. The ME model estimates annual biomass which has been gradually declining until less than one third of maximum biomass (156,047 tons) in 1988. It implies that the stock has been overexploited due to yieldings over the level of ABC compared to variations in annual catch, even if the recent prevailing catch levels were not up to the level of MSY. In comparison, the Analytical Model provides a more conservative value of ABC compared to the MSY value estimated by the ME model. Conservative management policies should be taken to reduce the aggregate amount of annual catch employing the total allowable catch system and effort reduction program.

Estimation for scale parameter of type-I extreme value distribution

  • Choi, Byungjin
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.2
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    • pp.535-545
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    • 2015
  • In a various range of applications including hydrology, the type-I extreme value distribution has been extensively used as a probabilistic model for analyzing extreme events. In this paper, we introduce methods for estimating the scale parameter of the type-I extreme value distribution. A simulation study is performed to compare the estimators in terms of mean-squared error and bias, and the obtained results are provided.

Characteristics of Heat Transfer in Three-Phase Swirling Fluidized Beds (삼상 Swirling 유동층에서 열전달 특성)

  • Son, Sung-Mo;Shin, Ik-Sang;Kang, Yong;Cho, Yong-Jun;Yang, Hee-Chun
    • Korean Chemical Engineering Research
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    • v.46 no.1
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    • pp.56-62
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    • 2008
  • Characteristics of heat transfer were investigated in a three-phase swirling fluidized bed whose diameter was 0.102 m and 2.5 m in height. Effects of gas and liquid velocities, particle size and liquid swirling ratio ($R_S$) on the immersed heater-to-bed overall heat transfer coefficient were examined. The heat transfer characteristics between the immersed heater and the bed was well analyzed by means of phase space portraits and Kolmogorov entropy(K) of the time series of temperature difference fluctuations. The phase space portraits of temperature difference fluctuations became stable and periodic and the value of Kolmogorov entropy tended to decrease with increasing the value of liquid swirling ratio from 0.1 to 0.4. The value of Kolmogorov entropy exhibited its minimum with increasing liquid swirling ratio. The value of overall heat transfer coefficient (h) showed its maximum with the variation of liquid velocity, bed porosity or liquid swirling ratio, but it increased with increasing gas velocity and particle size. The value of K exhibited its maximum at the liquid velocity at which the h value attained its maximum. The overall heat transfer coefficient and Kolmogorov entropy were well correlated in terms of dimensionless groups and operating variables.

Estimation of Rivers Discharge by Probabilistic Velocity Function Considering Hydraulic Characteristics (하천 수리특성을 고려한 확률론적 유속공식에 의한 하천유량 산정)

  • Choo, Tai Ho;Lee, Sang Jin;Park, Sang Woo;Oh, Ryun Su
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.6B
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    • pp.537-542
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    • 2009
  • To improve stage-discharge curve equation considering water level's function, this study suggested the method that can efficiently compute rivers discharge based on hydraulic characteristics such as river width, area, channel bed slope and entropy concept adopting probabilistic approach. This scheme is proposed to estimate discharge from the velocity formulation based on the entropy function in the equilibrium state derived from the relation between mean and maximum flow velocity. It has been tested using field and laboratory hydraulic data collected from the Alberta university in Canada. As a result it was found that the method proposed in this study was more efficient and accurate comparing with the traditional stage-discharge curve equation.

On the Least Squared Ordered Weighted Averaging (LSOWA) Operator Weights

  • Ahn Byeong-Seok
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.05a
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    • pp.1788-1792
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    • 2006
  • The ordered weighted averaging (OWA) operator by Yager has received more and more attention since its appearance. One key point in the OWA operator is to determine its associated weights. Among numerous methods that have appeared in the literature, we notice the maximum entropy OWA (MEOWA) weights that are determined by taking into account two appealing measures characterizing the OWA weights. Instead of maximizing the entropy in the formulation for determining the MEOWA weights, the new method in the article tries to obtain the OWA weights which are evenly spread out around equal weights as much as possible while strictly satisfying the orness value provided in the program. This consideration leads to the least squared OWA (LSOWA) weighting method in which the program tries to obtain the weights that minimize the sum of deviations from the equal weights since entropy is maximized when the weights are equal. Above all, the LSOWA weights display symmetric allocations of weights on the basis of equal weights. The positive or negative allocations of weights from the median as a basis depend on the magnitude of orness specified. Further interval LSOWA weights are constructed when a decision-maker specifies his or her value of orness in uncertain numerical bounds.

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Improving a Test for Normality Based on Kullback-Leibler Discrimination Information (쿨백-라이블러 판별정보에 기반을 둔 정규성 검정의 개선)

  • Choi, Byung-Jin
    • The Korean Journal of Applied Statistics
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    • v.20 no.1
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    • pp.79-89
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    • 2007
  • A test for normality introduced by Arizono and Ohta(1989) is based on fullback-Leibler discrimination information. The test statistic is derived from the discrimination information estimated using sample entropy of Vasicek(1976) and the maximum likelihood estimator of the variance. However, these estimators are biased and so it is reasonable to make use of unbiased estimators to accurately estimate the discrimination information. In this paper, Arizono-Ohta test for normality is improved. The derived test statistic is based on the bias-corrected entropy estimator and the uniformly minimum variance unbiased estimator of the variance. The properties of the improved KL test are investigated and Monte Carlo simulation is performed for power comparison.