• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1212-1214
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• 2012

생장예측모델이란 작물의 생장 시스템 내에서 일어나는 기작이나 생산과정을 수식으로 묘사하는 것이다. 신뢰성 있는 생장예측모델을 만들기 위해서는 생장과 관련된 대량의 데이터가 필요하다. 본 논문에서는 IT와 농업을 융합한 시설 원예작물 생장예측모델을 위한 생장 및 생장환경 데이터 수집 시스템 설계사례를 소개하고자 한다.

• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.1-7
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• 2011

The objective of this study was to improve the performance of the existing individual-tree/distantindependent stand growth model in predicting the growth of Pinus koraiensis forest stands. The parameters of diameter growth and mortality prediction models were estimated using periodic annual increment (PAI) of permanent plots and the performance of the models were compared with that of the existing ones using mean anuual increment (MAI). The diameter growth model includes crown ratio, potential diameter growth and modifier to compute for competitions of trees of a stand. In deriving the mortality prediction model, the parameters were estimated based on PAI which was also estimated as the function of MAI due to the lacking of permanent plot data. The results of this study showed that the newly-estimated functions based on PAI provide more realistic patterns in diameter growth of individual trees. The new approach using PAI in mortality model seems to overcome the over-estimate problem by the MAI-based model in estimating mortality of stand trees.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.351-356
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• 2009

This study purposed to judge potential possibility of building highly precise empirical model using environmental variables. Environmental variables such as altitude, mean annual rainfall, mean annual temperature and organic matter ratio of soil were added to height and diameter model for Chamaecyparis obtusa, and examined accuracy and residuals of prediction model. Improvement in precision was found for the Gompertz polymorphic height model by including mean temperature and altitude as independent variables, while the Gompertz diameter model with annual rainfall and altitude was showed improvement of precision and accuracy. Comparing the improvement of precision between the model before adding environmental variables and the model after adding them, an improvement or some ratio was obtained though it is not obvious. Therefore, there is enough proof that adding environmental variables, which can be easily acquired relatively when considering the difficulties of measurement and budget, into the model as independent variables would improve the accuracy and precision of growth models.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.11a
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• pp.293-297
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• 2002

폐쇄형 식물 생산 시스템에서 생산되는 식물은 생장속도가 빠르기 때문에 생장속도를 제어하거나 예측할 수 없어 수확적기를 놓치면 품질이 현저히 떨어져 상품성이 저하된다. 이를 해결하기 위해서는 식물생장기간 동안 식물에 따라 적절한 생장환경을 조성하여 생장정도를 균일하게 할 수 있는 최적 환경제어가 필요하다. 본 연구에서는 폐쇄형 식물 생산시스템의 최적 환경제어를 위하여 엽록소형광분석법을 이용하여 상추를 중심으로 광합성효율 모델(photosynthesis efficiency model ; PEM)을 개발하였다. (중략)

• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.62-69
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• 2011

Six commonly used non-linear growth functions were fitted to individual tree height-dbh data of eight major tree species measured by the $5^{th}$ National Forest Inventory in Chungcheong province. A total of 2,681 trees were collected from permanent sample plots across Chungcheong province. The available data for each species were randomly splitted into two sets: the majority (90%) was used to estimate model parameters and the remaining data (10%) were reserved to validate the models. The performance of the models was compared and evaluated by $R^2$, RMSE, mean difference (MD), absolute mean difference (AMD) and mean difference(MD) for diameter classes. The combined data (100%) were used for final model fitting. The results showed that these six sigmoidal models were able to capture the height-diameter relationships and fit the data equally well, but produced different asymptote estimates. Sigmoidal growth models such as Chapman-Richards, Weibull functions provided the most satisfactory height predictions. The effect of model performance on stem volume estimation was also investigated. Tree volumes of different species were computed by the Forest Resources Evaluation and Prediction Program using observed range of diameter and the predicted tree total height from the six models. For trees with diameter less than 30 cm, the six height-dbh models produced very similar results for all species, while more differentiation among the models was observed for large-sized trees.

• Food Science and Preservation
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• v.24 no.6
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• pp.778-785
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• 2017

This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and $30^{\circ}C$). Baranyi model was used as a primary order model for growth data. The maximum growth rate (${\mu}max$) and lag-phase duration (LPD) for each temperature (except for $10^{\circ}C$ LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.

• Journal of agriculture & life science
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• v.45 no.5
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• pp.25-31
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• 2011

This study was conducted to develop the growth model for diameter at breast height (DBH) and basal area (BA) of Larix leptolepis stands grown in eastern mountain areas, Jeollabuk-do and to enhance the precision of the models by adding regional and climatal factors, such as altitude, mean annual rainfall, and mean annual temperature. In results, it was analyzed that Schumacher polymorphic equation might be the best model to estimate DBH and BA growth. In case of the DBH growth model, precision was improved by adding altitude and mean annual rainfall. Moreover, in case of the BA growth model, precision was improved by adding mean annual rainfall. Meanwhile, it would be necessary for more precise model to add various factors, such as stand density, mortality, thinning ratio, and edaphic status along with regional and climatal factors.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.725-733
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• 2001

In this study, the relationship between growth factors for Pinus densiflora stands in Anmyun-Island was analyzed and dynamic growth model was prepared. A total of 96 sample plots was investigated in which dbh and height of individual trees were measured. From these plot data, quadratic mean dbh, mean height, dominant tree height, stem number per ha, basal area per ha and volume per ha were estimated. Several regression equations between growth factors were derived using NLIN and REG procedure of SAS. And dynamic growth model, in which the equations were interactively linked, was prepared for the prediction of stand growth and yield under different management regime. The predictions of dynamic growth model were found to be coincided with general growth principles. The dynamic growth model was considered as adequate for predicting growth and yield of Pinus densiflora stand in Anmyun-Island. In practice, the dynamic growth model can be applied for predicting the growth and development of stand for various forest treatments and for decision-making in forest management.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.446-453
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• 1999

In this study, the effects of stand planting density on parameters of stand height and basal area growth models were investigated. We used the Korf equation as the base model in estimating the parameters of the growth models for cryptomeria plantation forest stands. Then, in order to investigate the effects of the change in plantation density on the parameter estimates, the "extra sums of square" principle, which provided a reasonable statistical procedure for a performance test, was used. The results of the test coincide with the understandings that stand height growth is not affected significantly by the planting density and the growth curves of stand basal area approaches a common asymptote regardless of the stand density for a given site. However, the shapes of the basal area growth curves were affected significantly by the planting density. Based on the results of the test, we developed a basal area growth model to account for the effects of initial planting density in cryptomeria plantation forest stands.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.362-363
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• 2012

본 논문에서는 한 장의 실제 나무 영상이 주어졌을 시, 사실적인 3차원 나무 모델링(modeling) 및 자가생장(self-growth) 표현을 위한 방법을 소개하도록 한다. 스켈레톤기반의 간략화(skeleton-based abstraction)를 이용하여 동일한 나무 몸통(trunk)을 갖는 다양한 나무 모델생성과 함께 나무의 다면체구조(manifold structure)를 고려한 지오데식 커널(geodesic kernel)을 이용하여 나무의 자가생장을 표현한다. 나무의 자가생장은 사전 정의된 나무 굵기, 전체 크기, 그리고 가지증식 순서정보와 같은 상대적 성장정보(allometric information)를 동시 이용하여 상대적인 나무 생장(allometric tree growth)을 표현하도록한다. 한편, 보여지지않는 나무 가지와 잎들에 대해선, 나무구조는 로컬하게 자기유사성(local self-similarity)을 갖는다라는 고전적인 절차적(conventional procedural) 가정을 이용하여 자동적으로 생성토록한다. 실제영상을 이용한 몇몇들의 실험을 통해 보다 효과적으로 나무 모델 및 생장 표현이 가능함을 보여주도록한다.