• Title/Summary/Keyword: logistic function

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Distribution Functions Describing the Microbiological Contamination of Seasoned Soybean Sprouts

  • Park, Jin-Pyo;Lee, Dong-Sun;Paik, Hyun-Dong
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.659-663
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    • 2008
  • Different statistical distribution functions were examined to find an adequate distribution function to describe the microbial contamination behavior of a Korean side dish product, seasoned soybean sprouts for different seasons and market groups. The triang distribution was the best for any market groups in winter, while the logistic distribution could describe the microbial contamination in log CFU/g for all the market groups in spring and summer. From parametric bootstrapping based on the fitted distributions, it was found that a normal distribution could describe the distribution of mean microbial count in log CFU/g for all the seasons and market groups. Statistical parameters for each season/market group are presented to estimate the confidence interval.

Effects and Batch Kinetics of Agitation and Aeration on Submerged Cultivation of Ganoderma Iucidum (영지의 액체배양에 미치는 통기.교반의 효과와 동력학적 특성)

  • 이학수;정재현;이신영
    • KSBB Journal
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    • v.16 no.3
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    • pp.307-313
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    • 2001
  • The effects of agitaion and aeration on mycelial growth, exo-polysaccharide (EPS) production, and substrate consumption upon the submerged cultivation of G. lucidum were investigated, and the batch kinetics of the EPS fermentation of G. lucidum were interpreted as function of agitation speed and aeration rate. In a 2.6 L jar fermenter system, the optimum agitation speed and aeration rate for EPS production were determined to be 400 rpm and 1.0 vvm, respectively. The maximum production of EPS obtained was 15 g/L. The logistic model for mycelial growth fitted the experimental data better than that determined by the Monod and the two-thirds power models. The Luedeking-Piret equation adequately modelled the kinetic data obtained for product and substrate.

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Empirical Analysis of Shipper Requirement for E-logistics : The Case of International Shipping (E-logistics에 있어서 화주의 평가체계에 관한 실증적 연구 : 국제 해운분야를 중심으로)

  • Cho, Chan-Hyouk;Strohmaier, James G.
    • Journal of Korea Port Economic Association
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    • v.20 no.2
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    • pp.217-234
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    • 2004
  • Information technology has been transforming the relationship between shippers and carriers, but an unresolved question remains: what is the relative importance to shippers of service versus cost benefits of e-logistics solutions? This research develops and empirically tests a model to determine how Internet-based logistical operations in international shipping impact on the relative importance of cost versus service benefits to shippers. Contrary to expectations, results show that shippers perceived cost benefits from well-designed web sites, undoubtedly a consequence of perceptions that multi-function portals with ease of access contributed to savings in time and money. Another result was the confirmation of the positive effects of cargo tracing and bill of lading issuance on service-related factors. Finally, this study draws attention to the need for improvements in on-line booking capabilities and development of a comprehensive common portal; issues that must be addressed for shipping lines to succeed in an increasingly competitive e-logistics market.

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Measurement Error Variance Estimation Based on Complex Survey Data with Subsample Re-Measurements

  • Heo, Sunyeong;Eltinge, John L.
    • Communications for Statistical Applications and Methods
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    • v.10 no.2
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    • pp.553-566
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    • 2003
  • In many cases, the measurement error variances may be functions of the unknown true values or related covariates. This paper considers design-based estimators of the parameters of these variance functions based on the within-unit sample variances. This paper devotes to: (1) define an error scale factor $\delta$; (2) develop estimators of the parameters of the linear measurement error variance function of the true values under large-sample and small-error conditions; (3) use propensity methods to adjust survey weights to account for possible selection effects at the replicate level. The proposed methods are applied to medical examination data from the U.S. Third National Health and Nutrition Examination Survey (NHANES III).

An Experimental Study on the Prediction Model for the Compressive Strength of Concrete with Blast Furnace Slag by Maturity Method (고로슬래그미분말 혼입 콘크리트의 적산온도를 이용한 강도예측모델에 관한 실험적 연구)

  • Yang, Hyun-Min;Cho, Myung-Won;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.107-108
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    • 2012
  • The study on the strength prediction using Maturity is mainly focused on, but the study on the concrete mixing blast furnace slag powder is insufficient. The purpose of this study is to investigate the relationships between compressive strength and equivalent age by Maturity function and is to compare and examine the strength prediction of concrete mixing Blast Furnace Slag Power using ACI and Logistic Curve prediction equation. So it is intended that fundamental data are presented for quality management and process management of concrete mixing Blast Furnace Slag Power in the construction field.

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A Study of the Factors Influencing Alcohol Use Disorder in Elders (재가노인의 알코올 사용장애에 영향을 미치는 요인)

  • Jang, In-Sun
    • Journal of Korean Public Health Nursing
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    • v.22 no.2
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    • pp.165-176
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    • 2008
  • Purpose: This study was conducted in order to analyze the factors that influence alcohol use disorder in elders in KyongBuk province. The results of the study will provide basic information for the development of nursing interventions to promote proper alcohol use in elders. Methods: The subjects were 626 elderly individuals. Alcohol use disorder was defined as a score of more than 15 point on the AUDIT-K(Korean version of Alcohol Use Identification Test). Descriptive statistics, chi-square test, ANOVA and logistic regression were utilized to analyze the data. Results: Overall incidence of alcohol use disorder level; normal 73.2%, problem drinking 7.5% and alcohol use disorder 19.3%. Significant factors affecting alcohol use disorder were sex (OR=6.897), religious belief (OR=1.836), smoking (OR=2.948), liver disease (OR=4.753) and depression (OR=1.779). Conclusion: Community health care nurses perform a crucial function in the screening of elderly alcoholics. Early detection and treatment of depression in elders may help to prevent alcoholism.

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Study on the Comparison and Analysis of Data Mining Models for the Efficient Customer Credit Evaluation (효율적인 신용평가를 위한 데이터마이닝 모형의 비교.분석에 관한 연구)

  • 김갑식
    • Journal of Information Technology Applications and Management
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    • v.11 no.1
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    • pp.161-174
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    • 2004
  • This study is intended to suggest1 the optimized data mining model for the efficient customer credit evaluation in the capital finance industry. To accomplish the research objective, various data mining models for the customer credit evaluation are compared and analyzed. Furthermore, existing models such as Multi-Layered Perceptrons, Multivariate Discrimination Analysis, Radial Basis Function, Decision Tree, and Logistic Regression are employed for analyzing the customer information in the capital finance market and the detailed data of capital financing transactions. Finally, the data from the integrated model utilizing a genetic algorithm is compared with those of each individual model mentioned above. The results reveals that the integrated model is superior to other existing models.

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Toddler's Compliance as a Function of Gender, Temperament, and Inhibition of the Child, and Maternal Child-Rearing Attitudes (아동의 성, 기질, 행동억제 및 어머니의 양육행동과 아동의 순종행동간의 관계)

  • Park, Seong Yeon;Rubin, Kenneth H.;Chung, Ock Boon;Yoon, Chong Hee;Doh, Hyun Sim
    • Korean Journal of Child Studies
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    • v.28 no.4
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    • pp.1-17
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    • 2007
  • Participants in this study on links between toddlers' compliance and variables were 97 toddlers and their mothers. Instruments were the Toddler Behavior Assessment Questionnaire (Goldsmith, 1988) and the Child Rearing Practice Report-Q Sort (Block, 1981). Toddlers' compliance was observed on clean-up and behavior-delay tasks. Data analysis was by logistic and regression analyses. Results on the clean-up task indicated lower compliance by difficult children and higher compliance by girls. On the behavior-delay task, boys with less difficult temperament showed higher compliance by mother's higher punishment attitudes, whereas highly difficult boys were more compliant by mother's lower punishment attitudes. Girls' compliance was higher than boys in the low inhibition group whereas boys' compliance was higher than girls in the high inhibition group.

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NONSELECTIVE HARVESTING OF A PREY-PREDATOR COMMUNITY WITH INFECTED PREY

  • Chattopadhyay, J.;Ghosal, G.;Chaudhuri, K.S.
    • Journal of applied mathematics & informatics
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    • v.6 no.3
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    • pp.835-850
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    • 1999
  • The present paper deals with the problem of nonselective harvesting in a partly infected prey and predator system in which both the susceptible prey and the predator follow the law of logistic growth and some preys avoid predation by hiding. The dynamical behaviour of the system has been studied in both the local and global sense. The optimal policy of exploitation has been derived by using Pontraygin's maximal principle. Numerical analysis and computer simulation of the results have been performed to investigate the golbal properties of the system.

Effective Computation for Odds Ratio Estimation in Nonparametric Logistic Regression

  • Kim, Young-Ju
    • Communications for Statistical Applications and Methods
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    • v.16 no.4
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    • pp.713-722
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    • 2009
  • The estimation of odds ratio and corresponding confidence intervals for case-control data have been done by traditional generalized linear models which assumed that the logarithm of odds ratio is linearly related to risk factors. We adapt a lower-dimensional approximation of Gu and Kim (2002) to provide a faster computation in nonparametric method for the estimation of odds ratio by allowing flexibility of the estimating function and its Bayesian confidence interval under the Bayes model for the lower-dimensional approximations. Simulation studies showed that taking larger samples with the lower-dimensional approximations help to improve the smoothing spline estimates of odds ratio in this settings. The proposed method can be used to analyze case-control data in medical studies.