• Title/Summary/Keyword: Empirical approach

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CVM에 의한 유류유출 해양환경 복원기술 가치측정에 관한 연구 (The Study on the Value of Restoration Technology for the Marine Environmental Damage Caused by Oil Spill Using CVM)

  • 홍성표;조상섭;권석재;백민희
    • Ocean and Polar Research
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    • 제33권1호
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    • pp.77-83
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    • 2011
  • In this study we examined the economic value of restoration technology for oil spill using contingent value methods. One and one half approach to questionnaires can be taken when analyzing tax payer situations as well as single bound approach. The results of the empirical analysis suggest three conclusions. First, the economic value of the restoration technology considered are estimated to be between 8,439 won to 11,867 won per month. Second, the WTP is estimated differently depending on the approaches, OOHB and SB, and the degrees of difference are very sensitive to the model specifications. This empirical result supports the argument for using interval for the economic value when using CVM. Third, the empirical results may provide useful input to policy authorities attempting to estimate the economic justification of the R&D investment for developing an ocean environmental restoration technology.

Prediction of Physicochemical Properties of Organic Molecules Using Semi-Empirical Methods

  • Kim, Chan Kyung;Cho, Soo Gyeong;Kim, Chang Kon;Kim, Mi-Ri;Lee, Hai Whang
    • Bulletin of the Korean Chemical Society
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    • 제34권4호
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    • pp.1043-1046
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    • 2013
  • Prediction of physicochemical properties of organic molecules is an important process in chemistry and chemical engineering. The MSEP approach developed in our lab calculates the molecular surface electrostatic potential (ESP) on van der Waals (vdW) surfaces of molecules. This approach includes geometry optimization and frequency calculation using hybrid density functional theory, B3LYP, at the 6-31G(d) basis set to find minima on the potential energy surface, and is known to give satisfactory QSPR results for various properties of organic molecules. However, this MSEP method is not applicable to screen large database because geometry optimization and frequency calculation require considerable computing time. To develop a fast but yet reliable approach, we have re-examined our previous work on organic molecules using two semi-empirical methods, AM1 and PM3. This new approach can be an efficient protocol in designing new molecules with improved properties.

New Empirical Approach to Enhance The Accuracy of Cannon Tube Erosion Rate

  • Chung, Dong-Yoon;Oh, Myoung-Ho
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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    • pp.231-232
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    • 2002
  • Various methods that utilize erosion rate measurement of standard cannon, 155mm Howitzer M185, as reference, are being used to calculate erosion rate of an interested unknown cannon tubes. We know ten measured erosion values of the standard cannon from 391 rounds to 4.000. An approximate function fitting these value s is derived. The new erosion equation is also suggested and computer simulations arc presented.

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A simulation/analytic approach for queueing network analysis

  • Yoon, Bok-Sik
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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    • pp.359-364
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    • 2001
  • In this study, we try to improve the accuracy of QN-GPH by the help of simulation approach. We first establish an estimation method for GPH distributions with sufficient accuracy based on empirical distribution, and then perform a brief trial run to find appropriate empirical distributions. After getting GPH form of distributions, we continue the QN-GPH analytic steps and compute necessary performance measures. We apply the method to find sojourn time distributions in a 8-node queueing system and compare the results with the whole simulation and the original two-parametric approximation.

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Non-Conservatism of Bonferroni-Adjusted Test

  • Jeon, Cyeong-Bae;Lee, Sung-Duck
    • Communications for Statistical Applications and Methods
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    • 제8권1호
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    • pp.219-227
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    • 2001
  • Another approach (multi-parameter measurement method) of interlaboratory studies of test methods is presented. When the unrestricted normal likelihood for the fixed latent variable model is unbounded, we propose a me쇙 of restricting the parameter space by formulating realistic alternative hypothesis under which the likelihood is bounded. A simulation study verified the claim of conservatism of level of significance based on assumptions about central chi-square distributed test statistics and on Bonferroni approximations. We showed a randomization approach that furnished empirical significance levels would be better than a Bonferroni adjustment.

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이동장벽으로써 인사관리변수와 경영전략군 유형과의 관계에 대한 실증연구 (An Empirical Study of The Relationship Between Personnel Variables and Strategic Groups)

  • 양화섭;유병남
    • 산업경영시스템학회지
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    • 제16권28호
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    • pp.59-67
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    • 1993
  • Recently, The concept of strategic groups is recognized as a basic unit of understanding framework in strategic management research. Researchers have consistently approached the relationship between strategic groups and organizational variables(organization structure vs strategies, management process vs strategies, management systems vs strategies, environment vs strategies, strategies vs performance). However the relationship between strategic groups and human resources has been neglected in theortical approach and empirical approach. Therefore this study explores the relationship between strategic groups and human resources management.

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Microfinance and Poverty Alleviation: An Empirical Reflection

  • Mago, Stephen
    • The Journal of Asian Finance, Economics and Business
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    • 제1권2호
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    • pp.5-13
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    • 2014
  • The purpose of this paper is to carry out an empirical analysis of the link that exists between microfinance and poverty alleviation. The analysis is driven by literature searches on empirical works done by different researchers in different contexts. Qualitative research methodology was adopted, following a desktop approach. An empirical literature review took a centre stage in this investigation. An analysis of empirical works shows that microfinance enhances poverty alleviation despite the challenges such as the Indian Andhra Pradesh crisis. The paper is limited to a review of empirical sources of literature. A field survey, supported by an econometric analysis would have helped to generate robust results. This paper attempts to bring together the empirical works that were done in different contexts to shed light on the important relationship between microfinance and poverty. Many research works on microfinance depend upon personal anecdotes, thus this present paper attempts to compile the scattered empirical findings on microfinance and poverty alleviation.

AN EMPIRICAL BAYESIAN ESTIMATION OF MONTHLY LEVEL AND CHANGE IN TWO-WAY BALANCED ROTATION SAMPLING

  • Lee, Seung-Chun;Park, Yoo-Sung
    • Journal of the Korean Statistical Society
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    • 제32권2호
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    • pp.175-191
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    • 2003
  • An empirical Bayesian approach is discussed for estimation of characteristics from the two-way balanced rotation sampling design which includes U.S. Current Population Survey and Canadian Labor Force Survey as special cases. An empirical Bayesian estimator is derived for monthly effect under presence of two types of biases and correlations It is shown that the marginal distribution of observation provides more general correlation structure than that frequentist has assumed. Consistent estimators are derived for hyper-parameters in Normal priors.

Empirical Bayes Pproblems with Dependent and Nonidentical Components

  • Inha Jung;Jee-Chang Hong;Kang Sup Lee
    • Communications for Statistical Applications and Methods
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    • 제2권1호
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    • pp.145-154
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    • 1995
  • Empirical Bayes approach is applied to estimation of the binomial parameter when there is a cost for observations. Both the sample size and the decision rule for estimating the parameter are determined stochastically by the data, making the result more useful in applications. Our empirical Bayes problems with non-iid components are compared to the usual empirical Bayes problems with iid components. The asymptotic optimal procedure with a computer simulation is given.

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An empirical study on the material distribution decision making

  • Ko, Je-Suk
    • Journal of the Korean Data and Information Science Society
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    • 제21권2호
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    • pp.355-361
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    • 2010
  • This paper addresses a mathematical approach to decision making in a real-world material distribution situation. The problem is characterized by a low-volume and highly-varied mix of products, therefore there is a lot of material movement between the facilities. This study focuses especially on the transportation scheduler with a tool that can be used to quantitatively analyze the volume of material moved, the type of truck to be used, production schedules, and due dates. In this research, we have developed a mixed integer programming problem using the minimum cost, multiperiod, multi-commodity network flow approach that minimizes the overall material movement costs. The results suggest that the optimization approach provides a set of feasible solution routes with the objective of reducing the overall fleet cost.