• 제목/요약/키워드: poisson model

검색결과 942건 처리시간 0.027초

Genetic Parameter Estimation with Normal and Poisson Error Mixed Models for Teat Number of Swine

  • Lee, C.;Wang, C.D.
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권7호
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    • pp.910-914
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    • 2001
  • The teat number of a sow plays an important role for weaning pigs and has been utilized in selection of swine breeding stock. Various linear models have been employed for genetic analyses of teat number although the teat number can be considered as a count trait. Theoretically, Poisson error mixed models are more appropriate for count traits than Normal error mixed models. In this study, the two models were compared by analyzing data simulated with Poisson error. Considering the mean square errors and correlation coefficients between observed and fitted values, the Poisson generalized linear mixed model (PGLMM) fit the data better than the Normal error mixed model. Also these two models were applied to analyzing teat numbers in four breeds of swine (Landrace, Yorkshire, crossbred of Landrace and Yorkshire, crossbred of Landrace, Yorkshire, and Chinese indigenous Min pig) collected in China. However, when analyzed with the field data, the Normal error mixed model, on the contrary, fit better for all the breeds than the PGLMM. The results from both simulated and field data indicate that teat numbers of swine might not have variance equal to mean and thus not have a Poisson distribution.

Application of the Weibull-Poisson long-term survival model

  • Vigas, Valdemiro Piedade;Mazucheli, Josmar;Louzada, Francisco
    • Communications for Statistical Applications and Methods
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    • 제24권4호
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    • pp.325-337
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    • 2017
  • In this paper, we proposed a new long-term lifetime distribution with four parameters inserted in a risk competitive scenario with decreasing, increasing and unimodal hazard rate functions, namely the Weibull-Poisson long-term distribution. This new distribution arises from a scenario of competitive latent risk, in which the lifetime associated to the particular risk is not observable, and where only the minimum lifetime value among all risks is noticed in a long-term context. However, it can also be used in any other situation as long as it fits the data well. The Weibull-Poisson long-term distribution is presented as a particular case for the new exponential-Poisson long-term distribution and Weibull long-term distribution. The properties of the proposed distribution were discussed, including its probability density, survival and hazard functions and explicit algebraic formulas for its order statistics. Assuming censored data, we considered the maximum likelihood approach for parameter estimation. For different parameter settings, sample sizes, and censoring percentages various simulation studies were performed to study the mean square error of the maximum likelihood estimative, and compare the performance of the model proposed with the particular cases. The selection criteria Akaike information criterion, Bayesian information criterion, and likelihood ratio test were used for the model selection. The relevance of the approach was illustrated on two real datasets of where the new model was compared with its particular cases observing its potential and competitiveness.

여행비용모형을 이용한 전남 바다목장 해역 유어활동의 경제적 가치 추정 (Estimating the Economic Value of Recreational Fishing in the Jeonnam Marine Ranching Area)

  • 서주남;김도훈;강성경
    • 수산경영론집
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    • 제43권2호
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    • pp.41-49
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    • 2012
  • This study aimed to estimate the economic value of the recreational fishing in the Jeonnam marine ranching area as a part of the total socioeconomic evaluation of the Jeonnam marine ranching program. A travel cost method was applied to the estimation of economic value of the recreational fishing in the Jeonnam marine ranching area and input variables included annual fishing trip days, average travel cost per trip, average catch amount, monthly income, marriage, age, and personal perception on the marine ranching program. In the analysis, due to its characteristic of count data, both poisson model and negative binomial model were used. Model results indicated that a negative binomial model was statistically more suitable than the poisson model as the overdispersion problem occurred in the poisson model. All signs of the estimated parameters were estimated as previous studies showed. Based on the results, the economic value per trip of the recreational fishing in the Jeonnam marine ranching area was estimated to be 145,000 won and the annual total economic value of the recreational fishing in the Jeonnam marine ranching area was analyzed to be 2,514,000 won. In addition, the change of total value by catch rate showed that the economic value could be increased by 180,900 won as the catch increased by one kilogram.

정부 품질보증활동 데이터 활용을 위한 Zero-Inflated 포아송 분포 적용 (Application of Zero-Inflated Poisson Distribution to Utilize Government Quality Assurance Activity Data)

  • 김지훈;이창우
    • 품질경영학회지
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    • 제46권3호
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    • pp.509-522
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    • 2018
  • Purpose: The purpose of this study was to propose more accurate mathematical model which can represent result of government quality assurance activity, especially corrective action and flaw. Methods: The collected data during government quality assurance activity was represented through histogram. To find out which distributions (Poisson distribution, Zero-Inflated Poisson distribution) could represent the histogram better, this study applied Pearson's correlation coefficient. Results: The result of this study is as follows; Histogram of corrective action during past 3 years and Zero-Inflated Poisson distribution had strong relationship that their correlation coefficients was over 0.94. Flaw data could not re-parameterize to Zero-Inflated Poisson distribution because its frequency of flaw occurrence was too small. However, histogram of flaw data during past 3 years and Poisson distribution showed strong relationship that their correlation coefficients was 0.99. Conclusion: Zero-Inflated Poisson distribution represented better than Poisson distribution to demonstrate corrective action histogram. However, in the case of flaw data histogram, Poisson distribution was more accurate than Zero-Inflated Poisson distribution.

Poisson Effect on Electromechanical Impedance of Unconstrained Piezoelectric Patch

  • Shin, Sung-Woo;Kwon, Oh-Heon
    • International Journal of Safety
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    • 제8권2호
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    • pp.26-30
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    • 2009
  • In this study, the Poisson effect on resonant frequency behaviors of the unconstrained piezoelectric patch is investigated. The electromechanical impedance models for the un-bonded patch are derived from the two existing bonded patch models and numerical analysis for a given piezoelectric material is performed. From the analysis, it is found that the Poisson effect is not important as long as the electromechanical impedance model is used to predict the locations of resonant frequencies. However, Poisson effect should be considered when predicting the location of the largest resonant frequency of the patch since the amplitude responses are different with the model used.

A Study on the Determinants of Drinking Demand and Expenditure of College Students

  • Lee, Seung-gil
    • International journal of advanced smart convergence
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    • 제10권4호
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    • pp.215-224
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    • 2021
  • The purpose of this study is to estimate the factors that affect college students' drinking needs and spending. An analysis model to estimate the determinants affecting drinking needs was applied with a truncated Poisson model and a truncated negative binomial model. Tests to select more appropriate models of the two types were made using the comparison of log-likelihood function and the over-dispersion test. The analysis result was interpreted by applying the truncated negative binomial model as the truncated Poisson model showed over-dispersion. We also applied the Tobit model to analyze the determinantsthat affect college students' expenditure on drinking. According to the analysis, gender, grade, allowance and parental occupation were the factors influencing statistics, and gender, type of household income, and student religion were the factors influencing expenditure.

A Bayesian Approach for Record Value Statistics Model Using Nonhomogeneous Poisson Process

  • Kiheon Choi;Hee chual Kim
    • Communications for Statistical Applications and Methods
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    • 제4권1호
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    • pp.259-269
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    • 1997
  • Bayesian inference for a record value statistics(RVS) model of nonhomogeneous Poisson process is considered. We seal with Bayesian inference for double exponential, Gamma, Rayleigh, Gumble RVS models using Gibbs sampling and Metropolis algorithm and also explore Bayesian computation and model selection.

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2-포아송 모형의 전문검색시스템 응용에 관한 연구 (Application of the 2-Poisson Model to Full-Text Information Retrieval System)

  • 문성빈
    • 정보관리학회지
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    • 제16권3호
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    • pp.49-63
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    • 1999
  • 본 연구는 질문용어의 분포가 초록/표제 및 전문으로 표현된 문헌 내에서 2-포아송 분포를 따르고 있는지를 조사하였으며 질문용어의 2-포아송 분포여부가 확률이론에 기반을 둔 이진독립모형과 2-포아송 독립모형에서 초록/표제 및 전문의 검색효율성에 미치는 영향을 비교 분석하였다.

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Structural detection of variation in Poisson's ratio: Monitoring system for zigzag double walled carbon nanotubes

  • Hussain, Muzamal;Asghar, Sehar;Ayed, Hamdi;Khadimallah, Mohamed A.;Alshoaibi, Adil;Tounsi, Abdelouahed
    • Advances in nano research
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    • 제12권4호
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    • pp.345-352
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    • 2022
  • In this paper, natural frequency curves are presented for three specific end supports considering distinct values of nonlocal parameter. The vibrational behavior of zigzag double walled carbon nanotubes is investigated using wave propagation with nonlocal effect. Frequency spectra of zigzag (12, 0) double walled carbon nanotubes have been analyzed with proposed model. Effects of nonlocal parameters have been fully investigated on the natural frequency against against variation of Poisson's ratio. A slow increase in frequencies against variation of Poisson's ratio also indicates insensitivity of it for suggested nonlocal model. Moreover, decrease in frequencies with increase in nonlocal parameter authenticates the applicability of nonlocal Love shell model. Also the frequency curves for C-F are lower throughout the computation than that of C-C curves.