• 제목/요약/키워드: Growth curve model

검색결과 264건 처리시간 0.026초

성장곡선모형의 판별분석에서 균형이차분류법의 적용 (An Application of the Balanced Quadratic Classification Rule on the Discriminant Analysis in Growth Curve Model)

  • 심규박
    • 품질경영학회지
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    • 제23권2호
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    • pp.53-67
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    • 1995
  • The problem considered here is to find the optimal discriminant analysis method in growth curve model. It has been studied how to find correct prior probability for the effective classification in discriminant analysis. We use the balanced condition to calculate prior probability. From the informative simulation study, new classification rule for the growth curve model is suggested. The suggested classification rule has better classification result than the other previously suggested method in terms of error rate criterion.

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Estimation of genetic relationships between growth curve parameters in Guilan sheep

  • Hossein-Zadeh, Navid Ghavi
    • Journal of Animal Science and Technology
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    • 제57권5호
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    • pp.19.1-19.6
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    • 2015
  • The objective of this study was to estimate variance components and genetic parameters for growth curve parameters in Guilan sheep. Studied traits were parameters of Brody growth model which included A (asymptotic mature weight), B (initial animal weight) and K (maturation rate). The data set and pedigree information used in this study were obtained from the Agricultural Organization of Guilan province (Rasht, Iran) and comprised 8647 growth curve records of lambs from birth to 240 days of age during 1994 to 2014. Marginal posterior distributions of parameters and variance components were estimated using TM program. The Gibbs sampler was run 300000 rounds and the first 60000 rounds were discarded as a burn-in period. Posterior mean estimates of direct heritabilities for A, B and K were 0.39, 0.23 and 0.039, respectively. Estimates of direct genetic correlation between growth curve parameters were 0.57, 0.03 and -0.01 between A-B, A-K and B-K, respectively. Estimates of direct genetic trends for A, B and K were positive and their corresponding values were $0.014{\pm}0.003$ (P < 0.001), $0.0012{\pm}0.0009$ (P > 0.05) and $0.000002{\pm}0.0001$ (P > 0.05), respectively. Residual correlations between growth curve parameters varied form -0.52 (between A-K) to 0.48 (between A-B). Also, phenotypic correlations between growth curve parameters varied form -0.49 (between A-K) to 0.47 (between A-B). The results of this study indicated that improvement of growth curve parameters of Guilan sheep seems feasible in selection programs. It is worthwhile to develop a selection strategy to obtain an appropriate shape of growth curve through changing genetically the parameters of growth model.

BASS 확산 모형을 이용한 국내 자동차 외장 램프 LED 수요예측 분석 (Domestic Automotive Exterior Lamp-LEDs Demand and Forecasting using BASS Diffusion Model)

  • 이재흔
    • 품질경영학회지
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    • 제50권3호
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    • pp.349-371
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    • 2022
  • Purpose: Compared to the rapid growth rate of the domestic automotive LED industry so far, the predictive analysis method for demand forecasting or market outlook was insufficient. Accordingly, product characteristics are analyzed through the life trend of LEDs for automotive exterior lamps and the relative strengths of p and q using the Bass model. Also, future demands are predicted. Methods: We used sales data of a leading company in domestic market of automotive LEDs. Considering the autocorrelation error term of this data, parameters m, p, and q were estimated through the modified estimation method of OLS and the NLS(Nonlinear Least Squares) method, and the optimal method was selected by comparing prediction error performance such as RMSE. Future annual demands and cumulative demands were predicted through the growth curve obtained from Bass-NLS model. In addition, various nonlinear growth curve models were applied to the data to compare the Bass-NLS model with potential market demand, and an optimal model was derived. Results: From the analysis, the parameter estimation results by Bass-NLS obtained m=1338.13, p=0.0026, q=0.3003. If the current trend continues, domestic automotive LED market is predicted to reach its maximum peak in 2021 and the maximum demand is $102.23M. Potential market demand was $1338.13M. In the nonlinear growth curve model analysis, the Gompertz model was selected as the optimal model, and the potential market size was $2864.018M. Conclusion: It is expected that the Bass-NLS method will be applied to LED sales data for automotive to find out the characteristics of the relative strength of q/p of products and to be used to predict current demand and future cumulative demand.

담배의 생장반응에 관한 수리해석적 연구 제2보 담배생장곡선의 신모형에 관하여 (Mathematical Analysis of Growth of Tobacco (Nicotiana tabaccum L.) II. A New Model for Growth Curve)

  • 김용암;반유선
    • 한국작물학회지
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    • 제27권1호
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    • pp.84-86
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    • 1982
  • 담배의 품종과 재배형별 주당 건물중의 경시적 변화를 보다 더 정밀하게 표현할 수 있는 생장곡선방정식을 수식화하기 위하여 3가지의 생장모형을 만들어서 그 타당성을 분석한 결과는 다음과 같다. 1. 담배의 건물중에 가장 적합한 생장곡선은 C형이며 이 생장곡선은Y = A + (1-$\sqrt{4AK+1}$)/2이다. 2. 이 곡선은 이식후 35-55일의 편차가 Logistic curve보다 더 작으며 정밀하다.

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Analysis of Growth in Intersubspecific Crossing of Mice Using Gompertz Model

  • Kurnianto, E.;Shinjo, A.;Suga, D.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권1호
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    • pp.84-88
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    • 1998
  • The aim of this study was to describe growth patterns of mice using Gompertz model. Two distinct types of mice, laboratory mouse $CF_{\sharp1}$ (Mus musculus domesticus) and Yonakuni wild mouse (Yk, Mus musculus molossinus yonakuni) were used. From all possible crosses, there were two parental types and two reciprocal $F_1$ crosses obtained. Individual body weights were measured weekly from birth to ten weeks of age on 321 mice. Standardization to six mice was conducted and only first litters were used. Growth curve parameters were estimated to fit growth data. The results showed that growth among genetic groups were significantly different (p < 0.05) for both sexes, in which parental type of $CF_{\sharp1}$ and Yk had the highest and the smallest values, respectively. Meanwhile, reciprocal $F_1$ crosses were intermediate between parental types. It was concluded that Gompertz model provided and excellent fit for the growth data with a high coefficient determination $(R^2 = 0.999)$.

SAS JMP를 이용한 S형 소프트웨어 신뢰도 성장모델에서의 모수 추정에 관한 연구 (A study on the parameter estimation of S-Shaped Software Reliability Growth Models Using SAS JMP)

  • 문숙경
    • 품질경영학회지
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    • 제26권3호
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    • pp.130-140
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    • 1998
  • Studies present a guide to parameter estimation of software reliability models using SAS JMP. In this paper, we consider only software reliability growth model(SRGM), where mean value function has a S-shaped growth curve, such as Yamada et al. model, and ohba inflection model. Besides these stochastic SRGM, deterministic SRGM's, by fitting Logistic and Gompertz growth curve, have been widely used to estimate the error content of software systems. Introductions or guide lines of JMP are concerned. Estimation of parameters of Yamada et al. model and Logistic model is accomplished by using JMP. The differences between Yamada et al. model and Logistic model is accomplished by using JMP. The differences between Yamada et al. model and Logistic model is discussed, along with the variability in the estimates or error sum of squares. This paper have shown that JMP can be an effective tool I these research.

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원샷시스템의 신뢰도 성장 계획 설정 방안 (A Study on the Establishment of Reliability Growth Planning for One-shot System)

  • 서양우;전동주;김소정;김용근
    • 시스템엔지니어링학술지
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    • 제16권1호
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    • pp.1-8
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    • 2020
  • In this paper we proposed to develop the reliability growth planning for the One-shot system using the PM2-Discrete model. The PM2-Discrete is the methodology specifically developed for discrete systems and is the first quantitative method available for formulating detailed plans in the discrete usage domain. First, the parameters RG, RI, T, MS and d of the PM2-Discrete model are set. Second, the case analysis was performed on One-shot system A. Third, the input parameter values were applied to drive the R(t) equation. Finally, using RGA 11 Software, the reliability Growth Planning Curve of One-shot system A was constructed. Also, the sensitivity analyses are performed for the changes of model parameters. The results of this study can be usefully used in establishing the reliability growth planning curve of the One-shot system.

금융산업에서 IT투자와 경영성과의 상관관계에 관한 실증적 연구 (An Empirical Study on the Correlation of IT Investment and Management Performance in the Financial Industry)

  • 박상국;김종배
    • 한국IT서비스학회지
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    • 제11권3호
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    • pp.89-101
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    • 2012
  • The study investigated if IT investment in Korean financial markets for the past 18 years has grown following the s-curve pattern based on Nolan's growth model in order to find the correlation between IT investment and management performance in the financial industry. According to the research finding it can be said that the overall financial markets maintain s-curve pattern, and IT investment is related to management performance, particularly increase in total assets and net profit. However, each sector has defining features of growth patterns. The banking industry has grown similarly to the s-curve, and the insurance industry also shows the s-curve but it looks more like linear pattern. In terms of securities industry, its growth patterns can hardly be considered s-curve due to the irregular changes. his research outcome illustrates the analysis of IT growth patterns in the financial industry and thus, it is expected to be a useful reference when deciding the appropriate time for IT investment in the financial industry.

M-추정을 사용한 국방과학기술 수준조사 기술성장모형의 이상치 제거 (Elimination of Outlier from Technology Growth Curve using M-estimator for Defense Science and Technology Survey)

  • 김장헌
    • 한국군사과학기술학회지
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    • 제23권1호
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    • pp.76-86
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    • 2020
  • Technology growth curve methodology is commonly used in technology forecasting. A technology growth curve represents the paths of product performance in relation to time or investment in R&D. It is a useful tool to compare the technological performances between Korea and advanced nations and to describe the inflection points, the limit of improvement of a technology and their technology innovation strategies, etc. However, the curve fitting to a set of survey data often leads to model mis-specification, biased parameter estimation and incorrect result since data through survey with experts frequently contain outlier in process of curve fitting due to the subjective response characteristics. This paper propose a method to eliminate of outlier from a technology growth curve using M-estimator. The experimental results prove the overall improvement in technology growth curves by several pilot tests using real-data in Defense Science and Technology Survey reports.