• Journal of the Korean Statistical Society
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• 제25권1호
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• pp.81-94
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• 1996

This paper suggests a new criterion for testing the general linear hypothesis about coefficients in multivariate growth curve model. It is developed from a Bayesian point of view using the highest posterior density region methodology. Likelihood ratio test criterion(LRTC) by Khatri(1966) results as an approximate special case. It is shown that under the simple case of vague prior distribution for the multivariate normal parameters a LRTC-like criterion results; but the degrees of freedom are lower, so the suggested test criterion yields more conservative test than is warranted by the classical LRTC, a result analogous to that of Berger and Sellke(1987). Moreover, more general(non-vague) prior distributions will generate a richer class of tests than were previously available.

• Asian-Australasian Journal of Animal Sciences
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• 제28권9호
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• pp.1252-1258
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• 2015

The Liangshan pig is a traditional Chinese small-sized breed; it has a relatively long feeding period and low meat production ability but superior meat quality. This study utilized three non-linear growth models (Von Bertalanffy, Gompertz, and logistic) to fit the growth curve of Liangshan pigs from an unselected, random-bred pig population and estimate the pigs most suitable slaughter weight. The growth development data at 20 time points of 275 Liangshan pigs (from birth to 250 d) were collected. To analyze the relative gene expression related to development, seven slaughter weight phases (50, 58, 66, 74, 82, 90, and 98 kg) (20 pigs per phase) were examined. We found that the Liangshan pig growth curve fit the typical S-curve well and that their growth turning point was 193.4 days at a weight of 62.5 kg, according to the best fit Von Bertalanffy model based on the goodness of fit criteria. Furthermore, we estimated that the most suitable slaughter weight was 62.5 to 74.9 kg based on the growth curve and the relative expression levels of growth-related genes.

• 한국산림과학회지
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• 제57권1호
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• pp.1-7
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• 1982

원래 인구증가곡선(人口增加曲線)으로 알려진 단순(單純) logistic 곡선(曲線)은 초본식물(草本植物)의 성장표현(成長表現)에도 이용(利用)되어 왔다. 초본(草本)의 경우 이론치(理論値)와 실측치(實測値) 사이의 적합도(適合度)는 만족(滿足)스러운 것으로 알려져 있다. 그러나 초본(草本)과는 특성(特性)이 상이(相異)한 목본식물(木本植物)의 성장(成長)에 단순(單純) logistic 곡선(曲線)이 적용(適用)된 예는 극히 드물다. 따라서 그에 대한 적합성(適合性) 여부는 아직 의문시 되고 있다. 본연구(本硏究)에서는 임분밀도관리(林分密度管理)의 기초(基礎)가 되고 있는 단순(單純) logistic 곡선(曲線)의 적합성(適合性)을 조사하기 위하여 이것을 소나무임분(林分)에 적용(適用)시켜 보았다. 적합성검정(適合性檢定)을 위해서는 Chi-square test가 채용되었다.

• 응용통계연구
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• 제14권2호
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• pp.233-243
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• 2001

중장기 수요예측을 위해 자주 사용되는 방법으로 확산모형과 성장곡선모형을 들 수 있다. 본 논문에서는 이들 방법론의 성격 및 실제 적용에 있어 모수추정에 따른 문제점들을 살펴보고, 모수추정을 효율적으로 수행하기 위한 전략을 제시한다. 또한 실제 자료에 각 방법론들을 적용하여 예측결과를 비교한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.702-709
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• 2004

Modified Gurson model (Gurson-Tvergaard-Needleman model) was used to analyze crack growth in M(T) and C(T) specimens. A commercial finite element code ABAQUS/Explicit is used to account for total failure of material point by cavity coalescence, and crack growth was simulated by finite element extinction. Crack growth resistance curve was obtained by calculating J-integral. Crack growth under residual stress was investigated.

• 한국산림과학회지
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• 제83권1호
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• pp.63-74
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• 1994

단목(單木) 또는 임분(林分)의 생장파악 및 예측을 위해서는 수간형태(樹幹形態)의 파악이 선행되어야 한다. 또한 임분의 생장을 동적(動的)으로 파악하기 위해서는 수간형태(樹幹形態)를 수식화(數式化)할 필요가 있다. 그러나 수간(樹幹)은 전체적으로는 원추형(圓錐型)에 가깝지만 그 가늘어지는 정도가 부분적으로 다르기 때문에 하나의 식(式)으로 표현하기엔 어려움이 있으므로, 부분적으로 상이한 계수를 갖는 구간추정식(區間推定式)으로 표현하는 것이 이상적이다. 본 논문에서는 spline함수로부터 유도된 단목간곡선의 집합으로부터, 선형관계식을 이용하여 임분간곡선(林分幹曲線)을 수식화하는 방법을 소개하였다. 이와 같이 수간형태(樹幹形態)를 수식화(數式化) 한 단목 및 임분의 간곡선식(幹曲線式)은 임분(林分)의 발달과정을 동적(動的)으로 파악할 수 있게 하여 임분생장연구의 다양성 및 합리적 산림계획모델의 기초를 제공한다.

• Journal of Information Technology Applications and Management
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• 제12권2호
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• pp.1-13
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• 2005

This paper proposes a software-reliability growth model incoporating the amount of testing effort expended during the software testing phase after developing it. The time-dependent behavior of testing effort expenditures is described by a Logistic curve. Assuming that the error detection rate to the amount of testing effort spent during the testing phase is proportional to the current error content, a software-reliability growth model is formulated by a nonhomogeneous Poisson process. Using this model the method of data analysis for software reliability measurement is developed. After defining a software reliability, This paper discusses the relations between testing time and reliability and between duration following failure fixing and reliability are studied. SRGM in several literatures has used the exponential curve, Railleigh curve or Weibull curve as an amount of testing effort during software testing phase. However, it might not be appropriate to represent the consumption curve for testing effort by one of already proposed curves in some software development environments. Therefore, this paper shows that a logistic testing-effort function can be adequately expressed as a software development/testing effort curve and that it gives a good predictive capability based on real failure data.

• 산업경영시스템학회지
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• 제33권4호
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• pp.167-177
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• 2010

Recent competitive and technological changes during the past decade have accelerated the need for better capital recovery methods. Competition and technology have together shortened the expected lives of property which could not have been forecasted several years ago. Since the usage of technological growth models has been prevalent in various technological forecasting environments, the various forms of growth models have become numerous. Of six such models studied, some models do significantly better than others, especially at low penetration levels in predicting future levels of growth. A set of criteria for choosing an appropriate model for technological growth models was developed. Two major characteristics of an S-shaped curve were elected which differentiate the various models; they are the skewness of the curve and underlying assumptions regarding the variance of error structure of the model.

• Journal of Animal Science and Technology
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• 제45권6호
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• pp.885-890
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• 2003

본 연구는 재래돼지와 랜드레이스 품종을 기초축으로 조성한 F2 집단의 일령별 체중 자료를 이용하여 비선형 회귀에 의해 추정한 개체별 성장곡선 모수 및 성장 특성치에 대한 LEPR 관련 초위성체 표지인자의 다형성에 따른 효과를 추정함으로써 Leptine 수준에 따른 성장 형질의 특성을 규명하고자 실시하였다. 조사된 F2 집단에 대해 개체별 성숙체중(A)과 성숙률(k)의 평균은 각각 179.69${\pm}$4.40kg 및 0.3103${\pm}$0.0043으로 추정되었으며, 성장 특성에 대한 성의 효과는 통계적 유의성이 없었으며 (p〉.05), 성숙체중(A) 및 최대 증체 속도($\partial$W$_{t1}$/$\partial$t)는 분만 그룹에 따른 유의적인 차이를 보였다(p〈.05). 조사된 모든 성장특성에 대해 LEPR 표지인자의 다형성 효과는 유의적으로 나타났으며(p〈.05), AA 유전자형을 가지는 개체는 만숙성이며, 반면 유전자형이 DD인 경우, 조사된 유전자형들 가운데 초기 성장이 빠른 조숙성의 성장 특성으로 가지지만, 성장률의 증가추세가 일찍 감소하며, 성숙체중의 최대치는 낮을 것을 추정되었다. 따라서 조사된 LEPR 관련 표지인자 유전자형의 다형성에 따른 성장 특성의 해석 및 예측이 가능하며, 그 범위는 생애 전반에 걸쳐 적용해야 할 것으로 사료된다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2016년도 춘계 종합학술대회 논문집
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• pp.383-384
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• 2016

The Special Needs Education Assessment Tool (SNEAT) were verified of reliability and validity. However, the reliability and validity has been verified is only Okinawa Prefecture, the national data has not been analyzed. Therefore, this study aimed to verify the reliability and construct validity of SNEAT in Miyagi Prefecture as part of the national survey. SNEAT using 55 children collected from the classes on independent activities of daily living for children with disabilities in Miyagi Prefecture between November and December 2015. Survey data were collected in a longitudinal prospective cohort study. The reliability of SNEAT was verified via the internal consistency method; the coefficient of Cronbach's ${\alpha}$ were over 0.7. The validity of SNEAT was also verified via the latent growth curve model. SNEAT is valid based on its goodness-of-fit values obtained using the latent growth curve model, where the values of comparative fit index (0.997), tucker-lewis index (0.996) and root mean square error of approximation (0.025) were within the goodness-of-fit range. These results indicate that SNEAT has high reliability and construct validity.