• 제목/요약/키워드: GROWTH PREDICTION MODEL

검색결과 446건 처리시간 0.03초

A Study on Growth and Development Information and Growth Prediction Model Development Influencing on the Production of Citrus Fruits

  • Kang, Heejoo;Lee, Inseok;Goh, Sangwook;Kang, Seokbeom
    • Agribusiness and Information Management
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    • 제6권1호
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    • pp.1-11
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    • 2014
  • The purpose of this study is to develop the growth prediction model that can predict growth and development information influencing on the production of citrus fruits. The growth model was developed to predict the floral leaf ratio, number of fruit sets, fruit width, and overweight fruits depending on the main period of growth and development by considering the weather factors because the fruit production is influenced by weather depending on the growth and development period. To predict the outdoor-grown citrus fruit production, the investigation result for the standard farms is used as the basic data; in this study, we also understood that the influence of weather factors on the citrus fruit production based on the data from 2004 to 2013 of the outdoor-grown citrus fruit observation report in which the standard farms were targeted by the Agricultural Research Service and suggested the growth and development information prediction model with the weather information as an independent variable to build the observation model. The growth and development model for outdoor-grown citrus fruits was assumed by using the Ordinary Least Square method (OLS), and the developed growth prediction model can make a prediction in advance with the weather factors prior to the observation investigation for the citrus fruit production. To predict the growth and development information of the production of citrus fruits having a great ripple effect as a representative crop in Jeju agriculture, the prediction result regarding the production applying the weather factors depending on growth and development period could be applied usefully.

시스템다이내믹스를 이용한 저출생체중아의 성장예측모형 (A System Dynamics Model for Growth Prediction of Low Birth Weight Infants)

  • 이영희
    • 한국시스템다이내믹스연구
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    • 제11권3호
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    • pp.5-31
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    • 2010
  • The purpose of this study is to develop a system dynamics model for growth prediction of low birth weight infants(LBWIs) based on nutrition. This growth prediction model consists of 9 modules; body weight, height, carbohydrate, protein, lipid, micronutrient, water, activity and energy module. The results of the model simulation match well with the percentiles of weights and heights of the Korean infants, also with the growth records of 55 LBWIs, under 37 weeks of gestational age, whose weights are appropriate for their gestational age. This model can be used to understand the current growth mode of LBWIs, predict the future growth of LBWIs, and be utilized as a tool for controlling the nutrient intake for the optimal growth of LBWIs in actual practice.

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비행하중하에서 2124-T851 알루미늄합금의 피로균열진전 예측 (Prediction of Crack Growth in 2124-7851 Al-Alloy Under Flight-Simulation Loading)

  • 심동석;황돈영;김정규
    • 대한기계학회논문집A
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    • 제26권8호
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    • pp.1487-1494
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    • 2002
  • In this study, to propose the prediction method of the crack growth under flight-simulation loading, crack growth tests are conducted on 2124-7851 aluminum alloy specimens. The prediction of crack growth under flight-simulation loading is performed by the stochastic crack growth model which was developed in previous study. First of all, to reduce the complex load history into a number of constant amplitude events, rainflow counting is applied to the flight-simulation loading wave. The crack growth, then, is predicted by the stochastic crack growth model that can describe the load interaction effect as well as the variability in crack growth process. The material constants required in this model are obtained from crack growth tests under constant amplitude loading and single tensile overload. The curves predicted by the proposed model well describe the crack growth behavior under flight-simulation loading and agree with experimental data. In addition, this model well predicts the variability of fatigue lives.

단일 과대 하중에 의한 균열 성장 지연 거동 예측 (Prediction of Crack Growth Retardation Behavior by Single Overload)

  • 송삼흥;최진호;김기석
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.928-932
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    • 1996
  • Single overload fatigue tests with overload sizes ranging from 50% and 100% have been performed to investing ate the fatigue crack growth retardation behavior. A modified and experimental method of Willenborg's model for prediction of crack growth retardation behavior has been developed, based on evaluations of equivalent plastic zone size (EPZS) changing its size along the overload plastic zone boundary. The minimum crack growth rates of each overload size are linearly decreased with overload size increasing, but fatigue lives extended by single overload are increasing much more unlike the crack growth rates. Comparisons of crack growth behavior predicted by EPZS model and Willenborg model have shown that the EPZS model accounts for overload effects better than Willenborg model. These effects include delayed retardation, large retardation region, minimum crack growth rate, and the increase rate of crack growth rate in the region crack growth rate recovered.

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Crack growth prediction and cohesive zone modeling of single crystal aluminum-a molecular dynamics study

  • Sutrakar, Vijay Kumar;Subramanya, N.;Mahapatra, D. Roy
    • Advances in nano research
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    • 제3권3호
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    • pp.143-168
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    • 2015
  • Initiation of crack and its growth simulation requires accurate model of traction - separation law. Accurate modeling of traction-separation law remains always a great challenge. Atomistic simulations based prediction has great potential in arriving at accurate traction-separation law. The present paper is aimed at establishing a method to address the above problem. A method for traction-separation law prediction via utilizing atomistic simulations data has been proposed. In this direction, firstly, a simpler approach of common neighbor analysis (CNA) for the prediction of crack growth has been proposed and results have been compared with previously used approach of threshold potential energy. Next, a scheme for prediction of crack speed has been demonstrated based on the stable crack growth criteria. Also, an algorithm has been proposed that utilizes a variable relaxation time period for the computation of crack growth, accurate stress behavior, and traction-separation atomistic law. An understanding has been established for the generation of smoother traction-separation law (including the effect of free surface) from a huge amount of raw atomistic data. A new curve fit has also been proposed for predicting traction-separation data generated from the molecular dynamics simulations. The proposed traction-separation law has also been compared with the polynomial and exponential model used earlier for the prediction of traction-separation law for the bulk materials.

시계열 분석 모형 및 머신 러닝 분석을 이용한 수출 증가율 장기예측 성능 비교 (Comparison of long-term forecasting performance of export growth rate using time series analysis models and machine learning analysis)

  • 남성휘
    • 무역학회지
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    • 제46권6호
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    • pp.191-209
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    • 2021
  • In this paper, various time series analysis models and machine learning models are presented for long-term prediction of export growth rate, and the prediction performance is compared and reviewed by RMSE and MAE. Export growth rate is one of the major economic indicators to evaluate the economic status. And It is also used to predict economic forecast. The export growth rate may have a negative (-) value as well as a positive (+) value. Therefore, Instead of using the ReLU function, which is often used for time series prediction of deep learning models, the PReLU function, which can have a negative (-) value as an output value, was used as the activation function of deep learning models. The time series prediction performance of each model for three types of data was compared and reviewed. The forecast data of long-term prediction of export growth rate was deduced by three forecast methods such as a fixed forecast method, a recursive forecast method and a rolling forecast method. As a result of the forecast, the traditional time series analysis model, ARDL, showed excellent performance, but as the time period of learning data increases, the performance of machine learning models including LSTM was relatively improved.

동일평면상에 존재하는 복수표면균열의 피로성장수명예측 (Fatigue Growth Life Prediction for Collinear Multiple Surface Cracks)

  • 이진호;최용식;김영진
    • 대한기계학회논문집
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    • 제17권7호
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    • pp.1668-1677
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    • 1993
  • The objective of this paper is to develop a computational model for predicting the fatigue propagation of collinear multiple surface cracks under constant amplitude and variable amplitude loadings. After examining fatigue crack growth behavior for CT specimens and single surface crack specimens, empirical equations of(11) and(12) are proposed for the prediction of fatigue life in a multiple surface crack geometry. The accuracy of the proposed model is verified using a life prediction computer program. Several case studies were performed to check the accuracy of the proposed model and to verify the usefulness of the developed program. Good agreement is observed between the numerical results based on the proposed model and the published experimental data.

정기평균생장을 이용한 잣나무 임분의 흉고직경 생장예측모델 및 고사예측모델의 개발 (Development of Diameter Growth and Mortality Prediction Models of Pinus Koraiensis Based on Periodic Annual Increment)

  • 김선영;설아라;정주상
    • 한국산림과학회지
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    • 제100권1호
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    • pp.1-7
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    • 2011
  • 본 연구는 기존의 잣나무임분 거리독립 개체목 생장모델을 개선하기 위해 수행되었다. 직경생장함수 및 고사율함수의 매개변수들을 고정표본점의 정기평균생장량을 토대로 추정하고, 이 함수들의 특성을 기존의 총평균생장량을 토대로 추정한 모델과 비교하였다. 여기서 생장함수는 수관율함수, 잠재직경생장함수 및 임분을 구성하는 임목간 경쟁효과를 고려하기 위한 수정율함수를 의미한다. 고사율예측함수의 경우에는 고정표본점 자료의 한계로 인해 정기평균생장량 측정값을 구할 수 없어 대신 총평균생장량과의 관계식을 추정하여 대체하여 적용하였다. 연구결과 정기평균생장량을 토대로 하는 직경생장함수가 총평균생장량을 토대로 추정한 함수에 비해 개체목의 생장특성을 보다 현실적으로 반영하는 것을 보여주었다. 고사율함수의 경우, 총평균생장량을 적용하여 개발한 경우 고사율이 과대한 것으로 나타나는 문제가 있었으나 새로운 모델에서는 이 문제가 개선된 것으로 나타났다.

랜덤하중 하에서 피로균열진전예측 방법들의 비교 (A comparative study of methods to predict fatigue crack growth under random loading)

  • 최병익;강재윤;이학주;김정엽
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.235-240
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    • 2003
  • Methods to predict fatigue crack growth are compared in a quantitative manner for crack growth test data of 2024-T351 aluminum alloy under narrow and wide band random loading. In order to account for the effect of load ratio, crack closure model, Hater's equation and NASGRO's equation have been employed. Load interaction effect under random loading has been considered by crack closure model, Willenborg's model and Wheeler's model. The prediction method using the measured crack opening results provides the best result among the prediction methods discussed for narrow and wide band random loading data.

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