• Journal of Animal Science and Technology
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• 제48권2호
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• pp.151-160
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• 2006

본 연구는 유전능력의 검정자료로서 뿐만 아니라 농가에서 편리하게 체중을 추정할 수 있도록 하여 관리 경영상 뚜렷한 개선을 제공하기 위하여 한우의 성장 단계별 발육 특성을 조사하였다. 자료의 구성은 1980～2004년의 남원, 대관령, 서산과 핵군농가의 자료로 암소 27,647개 비거세우 14,744개 거세우 1,290개를 이용하였다. 암소의 경우 시그모이드(sigmoid)의 형태를 나타내고 있으며, 비거세우의 경우에도 거의 비슷한 분포를 보여주고 있으나 거세우의 경우에는 직선 회귀식의 형태를 보여주고 있다. Gompertz 모형을 이용하여 년도별로 분석한 성장곡선은 암, 수소 모두 1990～1994년의 잔차값이 68.49와 54.29로 낮게 나타났으며, 모수 A, b, k의 경우 암소에서 각각 423.6±5.8, 2.387±0.064, 0.0908±0.0033로 추정되었고 수소에서 823.3±15.3, 3.584±0.070, 0.1139±0.0032로 추정되었다. 적합도가 Logistic 모형보다 좋은 Gompertz 모형을 이용하여 곡선추정을 하였으며, 추정된 암소의 월별추정값과 일별추정값은 379.3±7.509, 2.499±0.057, 0.114±0.0045와 367.1±1.9003, 2.3983±0.012, 0.004±0.00003이며, 오차의 평균 제곱합(Residual mean square)은 31.85, 998.4으로 추정되었다. 수소의 월별추정값과 일별추정값은 834.6±22.00, 3.319±0.062, 0.104±0.0037과 796.0±6.128, 3.184±0.014, 0.003±0.00003으로 오차의 평균 제곱합은 66.18, 2106.5로 추정되었으며, 거세우의 경우 1049.1±144.2, 3.024±0.008, 0.067±0.0096와 1505.1±176.6, 2.997±0.067, 0.001±0.0001이며, 오차의 평균 제곱합은 186.0, 1119.1이었다. 성장의 특성을 살펴보면 Gompertz 모형으로 추정할 때 암소의 변곡점(Inflection point)에서의 체중은 139.53kg 이었으며, 변곡점에서의 일당증체율은 0.52kg으로 추정되었다. 수소의 변곡점에서의 체중은 307.03kg 이었으며, 일당증체율은 1.04kg 이었다. 거세우의 경우 변곡점 체중은 385.94kg 이었고 성장속도가 최대인 지점의 순간적인 증체율은 두 모형에서 0.84kg을 나타내었다. 암소가 수소나 거세우에 비하여 성숙체중이 작고 변곡점까지의 도달일령이 빠르며 일당증체량도 작은 성장특성을 보였다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권2호
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• pp.162-170
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• 2016

Purpose: The purpose of this study was to analyze the failure modes of an auto transfer switch (ATS), determine the most common failure mechanisms, and iterate the design to improve reliability. Methods: We carried out failure mode and effect analysis (FMEA) to determine the failure modes and mechanisms. We identified the parts or modules that required improvement via two-stage quality function deployment based on FMEA, and improvements to reliability were monitored using the Gomperz growth model. Results: The main failure modes of the ATS were damage to, and deformation of, the stator / movable element due to repetitive movements. Five iterations of design modification were carried out, and the mean time to failure (MTTF) increased to 14,539 cycles, corresponding to 85% of the target MTTF. The Gompertz growth model indicates that the 10th iteration of design modification is expected to achieve the target MTTF. Conclusion: We improved the reliability of mechanical parts via failure mode analysis, and characterized the iterative improvements in the MTTF using the Gompertz growth model.

• 수산경영론집
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• 제46권3호
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• pp.103-118
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• 2015

The purpose of this paper is to discuss possibilities of applying growth curve models, such as Logistic, Log-Logistic, Log-Normal, Gompertz and Weibull, to three specific technology areas of Fishery Science and Technology in the process of measuring their technology level between Korea and countries with the state-of-the art level. Technology areas of hazard control of organism, environment restoration, and fish cluster detect were selected for this study. Expert panel survey was conducted to construct relevant panel data for years of 2013, 2016, and a future time of approaching the theoretical maximum technology level. The size of data was 70, 70 and 40 respectively. First finding is that estimation of shape and location parameters of each model was statistically significant, and lack-of-fit test using estimated parameters was statistically rejected for each model, meaning all models were good enough to apply for measuring technology levels. Second, three models other than Pearl and Gompertz seemed very appropriate to apply despite the fact that previous case studies have used only Gompertz and Pearl. This study suggests that Weibull model would be a very valid candidate for the purpose. Third, fish cluster detect technology level is relatively higher for both Korea and a country with the state-of-the-art among three areas as of 2013. However, all three areas seem to be approaching their limits(highest technology level point) until 2020 for countries with the state-of-the-art. This implies that Korea might have to speed up her research activities in order to catch up them prior to 2020. Final suggestion is that future study may better apply various and more appropriate models respectively considering each technology characteristics and other factors.

• 한국농공학회논문집
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• 제62권1호
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• pp.61-70
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• 2020

To estimate the ventilation volume of mechanically ventilated swine farms, various regression models were applied, and errors were compared to select the regression model that can best simulate actual data. Linear regression, linear spline, polynomial regression (degrees 2 and 3), logistic curve, generalized additive model (GAM), and gompertz curve were compared. Overfitting models were excluded even when the error rate was small. The evaluation criteria were root mean square error (RMSE) and mean absolute percentage error (MAPE). The evaluation results indicated that degree 3 exhibited the lowest error rate; however, an overestimation contradiction was observed in a certain section. The logistic curve was the most stable and superior to all the models. In the estimation of ventilation volume by all of the models, the estimated ventilation volume of the logistic curve was the smallest except for the model with a large error rate and the overestimated model.

• 산업경영시스템학회지
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• 제32권4호
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• pp.184-191
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• 2009

In a technological driven environment, a depreciation estimate which is based on traditional life analysis results in a decelerated rate of capital recovery. This time pattern of technological growths models needs to be incorporated into life analysis framework especially in those industries experiencing fast technological changes. The approximation technique for calculating the variance can be applied to the six growth models that were selected by the degree of skewness and the transformation of the functions. For the Pearl growth model, the Gompertz growth model, and the Weibull growth model, the errors have zero mean and a constant variance over time. However, transformed models like the linearized Fisher-Pry model, the linearized Gompertz growth model, and the linearized Weibull growth model have increasing variance from zero to that point at which inflection occurs. It can be recommended that if the variance of error over time is increasing, then a transformation of observed data is appropriate.

• 농업과학연구
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• 제48권4호
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• pp.987-1001
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• 2021

One of the most critical issues in the dairy industry, alongside the low birth rate and the aging population, is the decrease in demand for milk. In this study, the consumption trends of 12 major dairy products distributed in Korea were predicted using a logistic model, the Gompertz model, and the Bass diffusion model, which are representative S-shaped growth models. The 12 dairy products are fermented milk (liquid type, cream type), butter, milk powder (modified, whole, skim), liquid milk (market, flavored), condensed milk, cheese (natural, processed), and cream. As a result of the analysis, the growth potential of butter, condensed milk, natural cheese, processed cheese, and cream consumption among the 12 dairy products is relatively high, whereas the growth of the remaining dairy product consumption is expected to stagnate or decrease. However, butter and cream are by-products of the skim milk powder manufacturing process. Therefore, even if the consumption of butter and cream grows, it is difficult to increase the demand of domestic milk unless the production of skim milk powder produced from domestic milk is also increased. Therefore, in order to support the domestic dairy industry, policy support should be focused on increasing domestic milk usage for the production of condensed milk, natural cheese, and processed cheese.

• 한국가금학회지
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• 제43권1호
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• pp.1-14
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• 2016

Prediction of growth patterns of commercial chicken strains is important. It can provide visual assessment of growth as function of time and prediction body weight (BW) at a specific age. The aim of current study is to compare the three nonlinear functions (i.e., Logistic, Gompertz, and von Betalanffy) for modeling the growth of twenty five commercial Korean native chicken (KNC) strains reared under a battery cage system until 32 weeks of age and to evaluate the three models with regard to their ability to describe the relationship between BW and age. A clear difference in growth pattern among 25 strains were observed and classified in to the groups according to their growth patterns. The highest and lowest estimated values for asymptotic body weight (C) for 3H and 5W were given by von Bertalanffy and Logistic model 4629.7 g for 2197.8 g respectively. The highest estimated parameter for maturating rate (b) was given by Logistic model 0.249 corresponds to the 2F and lowest in von Bertalanffy model 0.094 for 4Y. According to the coefficient of determination ($R^2$) and mean square of error (MSE), Gompertz and von Bertalanffy models were suitable to describe the growth of Korean native chicken. Moreover, von Bertalannfy model was well described the most of KNC growth with biologically meaningful parameter compared to Gompertz model.

• 전기전자학회논문지
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• 제9권2호
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• pp.143-151
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• 2005

본 연구에서는 유한고장 비동질적인 포아송 과정 모형에서 결함당 고장 발생률이 상수이거나, 단조 증가 또는 단조 감소하는 패턴을 가질수 있다. 감마족 분포를 적용하여 고장발생률에 대한 특징을 알아보았고 감마족 분포는 형상 모수의 선택에 따라 다양한 모형으로 유도 될 수 있다. 따라서 본 연구는 형상모형에 근거한 감마 또는 와이블 그리고 곰페르츠 모형을 제시하여 신뢰도 분석 결과를 나열하였고 모형 선택 및 자료 분석을 위하여 산술과 라플라스 검정과 편차 자승합 등을 이용하였다.

• 한국건설순환자원학회논문집
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• 제7권4호
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• pp.121-127
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• 2012

본 연구에서는 플라이애시를 치환한 시멘트 모르터의 양생온도에 따른 강도증진을 검토하기 위하여 등가재령방법에 의한 강도증진해석을 실시하였다. 플라이애시를 30% 치환한 시멘트모르터의 겉보기활성화에너지를 ASTM C 1074 방법에 의하여 산정한 결과 34.75KJ/mol로 산정되었고, 이를 토대로 Plowman 모델과 Gompertz 모델을 이용하여 해석한 결과 해석치가 측정치를 양호하게 추정함을 알 수 있었고 특히 Gompertz 모델식이 보다 양호한 추정 정밀도를 갖는 것으로 확인되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.953-954
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• 2012