• Title/Summary/Keyword: stand growth model

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Development and Validation of the Stand Density Management Diagram for Pinus densiflora Forests in Korea (소나무 임분밀도관리도 작성 및 실용성 검정)

  • Park, Joon Hyung;Lee, Kwang Soo;Yoo, Byung Oh;Park, Yong Bae;Jung, Su Young
    • Journal of Korean Society of Forest Science
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    • v.105 no.3
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    • pp.342-350
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    • 2016
  • This study aims to make the stand density management diagram which is very useful for establishing systematic management plan and obtaining management goal in Pinus densiflora forest. To estimate 5 models mainly composed of stand density management diagram, we used total of 1,886 sample plots having more than 75% of the total basal area of the pine trees in each stand. To test the goodness of fit, $X^2$ was computed with a significance level of 5%, and the acceptable error range as 20%. Also standard deviation of the model was $34.59m^3{\cdot}ha^{-1}$, minimum acceptable error range was 16.59% and coefficient of variation was 22.11%. If we use the stand density management diagram, it would be useful to establish the timber yield and thinning plan understanding the pathway of stand density management.

Localizing Growth Model of Chamaecyparis obtusa Stands Using Dummy Variables in a Single Equation

  • Lee, Sang-Hyun;Kim, Hyun
    • Journal of Korean Society of Forest Science
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    • v.94 no.2 s.159
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    • pp.121-126
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    • 2005
  • This study was carried out to construct a single diameter and a single height model that could localize Chamaecyparis obtusa stand grown in 3 Southern regions of Korea. Dummy variables, which convert qualitative information such as geographical regions into quantitative information by means of a coding scheme (0 or 1), were used to localize growth models. In results, modified form of Gompertz equation, $Y_2={\exp}({\ln}(Y_1){\exp}(-{\beta}(T_2-T_1)+{\gamma}({T_2}^2-{T_1}^2))+({\alpha}+{\alpha}_1Al+{\beta}_1k_1+{\beta}_2k_2)(1-{\exp}(-{\beta}(T_2-T_1)+{\gamma}({T_2}^2-{T_1}^2))$, for diameter and height was successfully disaggregated to provide different projection equation for each of the 3 regions individually. The use of dummy variables on a single equation, therefore, provides potential capabilities for testing the justification of having different models for different sub-populations, where a number of site variables such as altitude, annual rainfall and soil type can be considered as possible variables to explain growth variation across regions.

Crown Ratio Models for Tectona grandis (Linn. f) Stands in Osho Forest Reserve, Oyo State, Nigeria

  • Popoola, F.S.;Adesoye, P.O.
    • Journal of Forest and Environmental Science
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    • v.28 no.2
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    • pp.63-67
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    • 2012
  • Crown ratio is the ratio of live crown length to tree height. It is often used as an important predictor variable for tree growth equation. It indicates tree vigor and is a useful parameter in forest health assessment. The objective of the study was to develop crown ratio prediction models for Tectona grandis. Based on the data set from the temporary sample plots, several non linear equations including logistics, Chapman Richard and exponential functions were tested. These functions were evaluated in terms of coefficient of determination ($R^2$) and standard error of the estimate (SEE). The significance of the estimated parameters was also verified. Plot of residuals against estimated crown ratios were observed. Although the logistic model had the highest $R^2$ and the least SEE, Chapman-Richard and Exponential functions were observed to be more consistent in their predictive ability; and were therefore recommended for predicting crown ratio in the stand.

Forest Management Planning by Linear Programming - Timber Harvest Scheduling of a Korean Pine stand - (Linear Programming에 의한 삼림경영계획(森林經營計劃) - 잣나무임분(林分)의 삼림수확계획(森林收穫計劃)을 중심으로 -)

  • Woo, Jong Choon
    • Journal of Korean Society of Forest Science
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    • v.80 no.4
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    • pp.427-435
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    • 1991
  • Linear programming(LP) is a well-known method in optimizing timber harvest schedules. This paper describes a linear programming formulation of korean pine stands for timber harvest scheduling problems. Simulation technique and LP were applied to optimize the time and space distribution of the sustained yield for the 10-year forest management planning horizon. Growthfunction of korean pine stands in study area was derived with the yield table. This growthfunction was contained to the simulation model in estimating of changing stand volume conditions for the planning horizon. These estimated values were served as the basic data of LP model, and LP model was formulated with the maximum of periodical harvest volume calculated by the classical yield regulation method (Paulsen-Hundeshagen formula) and the maximum of periodical harvest area calculated for the normal age distribution. The timber harvest schedule was established periodically for each subcompartment of korean pine stands in experiment forest of College of Forestry in Kangweon National University with the here developed LP model.

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Establishing a marketing strategy model for academic-industrial cooperation between companies and universities (기업과 대학간의 산학협력마케팅 전략모델 구축에 관한 연구)

  • Yun, Jeong-Keun
    • Journal of Distribution Science
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    • v.12 no.4
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    • pp.65-72
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    • 2014
  • Purpose - Because of the emphasis on the necessity of academic-industrial cooperation between companies and universities, there are various ongoing academic-industrial cooperation programs led by the government. As government actively supports such cooperation as policy,and universities vitalize new technology development, academic-industrial cooperation between companies and universities is being recognized as an important growth engine for companies the competitiveness of academic-industrial cooperation is also attracting more interest. The government has vitalized human resource fostering, practical R&D, and technology transfer to companies since 2012 by executing a "leading university fostering project for academic-industrial cooperation." Based on an organic interlink among universities, industry, and research institutes, the government also created and is promoting several models of such cooperation between companies and universities to support shared growth of industry and local universities. The purpose of academic-industrial cooperation is growth and benefit fromtechnology development, technical cooperation, and technology transfer between companies and universities. Research design, data, and methodology - As more academic-industrial cooperation efforts are ledby companies due to the limitation in technology-focused commercialization cooperation, the academic-industrial cooperation system became fragmented and it is losing the potential for future advancement. Specifically, as differences between universities grow, academic-industrial cooperation between companies and universities based on new technology from universities is finding difficulty advancing,while systematic support from companies to enhance the performance of businesses created by academic-industrial cooperation is also insufficient. Accordingly, this study established a growth model for the advancement of academic-industrial cooperation between companies and universities and suggested a plan to strengthen the competitiveness and promote the future advancementof academic-industrial cooperation between companies and universities by analyzing the current situation of such cooperation and diagnosing its issues. Results - This study explored the concept and current status of academic-industrial cooperation relationships and analyzed related issues. For such cooperative organizations to be competitive, the employment environment of professional human resources for academic-industrial cooperation should be improved and measures to secure professional resources should be taken as early as possible. Though the academic-industrial cooperation now is being led by government, there is a limitation based on business models, which require creation of profit; however, an academic-industrial cooperation model still cannot stand alone without the support of government. This study also pointed out that a having only a plan to build competitiveness of companies and universities for academic-industrial cooperation is not sufficient. Conclusions - In order to increase the competitiveness of academic-industrial cooperation, a detailed growth-sharing model for academic-industrial cooperation should be developed, and there should be more joint development processes for the advancement of such cooperation in which the need for technology development can be verified in advance. In addition, beyond focusing on technology-focused academic-industrial cooperation, a network between companies and universities searching for ideas for academic-industrial cooperation in the fields of human and social aspects should be created. A new academic-industrial model linking current cooperation between companies and universities to the local area should be built based on such academic-industrial cooperation in human and social fields.

Economic Analysis of Snow Damage on Sugi (Cryptomeria japonica) Forest Stands in Japan Within the Forest Stand Optimization Framework

  • Yoshimoto, Atsushi;Kato, Akio;Yanagihara, Hirokazu
    • Journal of Forest and Environmental Science
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    • v.24 no.3
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    • pp.143-149
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    • 2008
  • We conduct economic analysis of the snow damage on sugi (Cryptomeria japonica) forest stands in Toyama Prefecture, Japan. We utilize a single tree and distant independent growth simulator called "Silv-Forest." With this growth simulator, we developed an optimization model by dynamic programming, called DP-Silv (Dynamic Programming Silv-Forest). The MS-PATH (multiple stage projection alternative technique) algorithm was embedded as a searching algorithm of dynamic programming. The height / DBH ratio was used to constrain the thinning regime for snow damage protection. The optimal rotation age turned out to be 65 years for the non-restricted case, while it was 50 years for the restricted case. The difference in NPV of these two cases as the induced costs ranged from 179,867 to 1,910,713yen/ha over the rotation age of 20 to 75 years. Under the optimal rotation of 65 years, the cost became 914,226 yen/ha. The estimated annual payment based on the difference in NPV, was from 9,869 yen/ha/yr to 85,900 yen/ha/yr. All in all, 10,000 yen/ha/yr to 20,000 yen/ha/yr seems to cover the payment from the rotation age of 35 to 75 years.

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Development of Diameter Distribution Change and Site Index in a Stand of Robinia pseudoacacia, a Major Honey Plant (꿀샘식물 아까시나무의 지위지수 도출 및 직경분포 변화)

  • Kim, Sora;Song, Jungeun;Park, Chunhee;Min, Suhui;Hong, Sunghee;Yun, Junhyuk;Son, Yeongmo
    • Journal of Korean Society of Forest Science
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    • v.111 no.2
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    • pp.311-318
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    • 2022
  • We conducted this study to derive the site index, which is a criterion for the planting of Robinia pseudoacacia, a honey plant, and to investigate the diameter distribution change by derived site index. We applied the Chapman-Richards equation model to estimate the site index of the Robinia pseudoacacia stand. The site index was distributed within the range of 16-22 when the base age was 30 years. The fitness index of the site index estimation model was low, but we judged that there was no problem in the application because the residual distribution of the equation had not shifted to one side. We used the Weibull diameter distribution function to determine the diameter distribution of the Robinia pseudoacacia stand by site index. We used the mean diameter and the dominant tree height as independent variables to present the diameter distribution, and our analysis procedure was to estimate and recover the parameters of the Weibull diameter distribution function. We used the mean diameter and the dominant tree height of the Robinia pseudoacacia stand to show distribution by diameter class, and the fitness index for dbh distribution estimation was about 80.5%. As a result of schematizing the diameter distribution by site indices as a 30-year-old, we found that the higher the site index, the more the curve of the diameter distribution moved to the right. This suggests that if the plantation were to be established in a high site index stand, considering the suitable trees on the site, the growth of Robinia pseudoacacia woul d become active, and not onl y the production of wood but al so the production of honey would increase. We therefore anticipate that the site index classification table and curve of this Robinia pseudoacacia stand will become the standard for decision making in the plantation and management of this tree.

The Relationship between Stand Mean DBH and Temperature at a Watershed Scale: The Case of Andong-dam Basin (유역단위에서의 임목평균흉고직경과 기온 간의 관계: 안동댐 유역을 중심으로)

  • Moon, Jooyeon;Kim, Moonil;Lim, Yoonjin;Piao, Dongfan;Lim, Chul-Hee;Kim, Seajin;Song, Cholho;Lee, Woo-Kyun
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.287-297
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    • 2016
  • This study aims to identify the relationship between climatic factors and stand mean Diameter at Breast Height (DBH) for two major tree species; Pinus densiflora and Quercus mongolica in Andong-dam basin. Forest variables such as age, diameter distribution and number of trees per hectare from the $5^{th}$ and $6^{th}$ National Forest Inventory data were used to develop a DBH estimation model. Climate data were collected from six meteorological observatory station and twelve Automatic Weather System provided by Korea Meteorological Administration to produce interpolated daily average temperature map with Inverse Distance Weighting (IDW) method. Andong-dam basin reflects rugged mountainous terrain, so temperature were adjusted by lapse rate based correction. As a result, predictions of model were consistent with the previous studies; that the rising temperature is negatively related to the growth of Pinus densiflora whereas opposing trend is observed for Quercus mongolica.

Cooperation Strategy in the Business Ecosystem and Its Healthiness: Case of Win - Win Growth of Samsung Electronics and Partnering Companies (기업생태계 상생전략과 기업건강성효과: 삼성전자와 협력업체의 상생경영사례를 중심으로)

  • Sung, Changyong;Kim, Ki-Chan;In, Sungyong
    • The Journal of Small Business Innovation
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    • v.19 no.4
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    • pp.19-39
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    • 2016
  • With increasing adoption of smart products and complexity, companies have shifted their strategies from stand alone and competitive strategies to business ecosystem oriented and cooperative strategies. The win-win growth of business refers to corporate efforts undertaken by companies to pursue the healthiness of business between conglomerates and partnering companies such as suppliers for mutual prosperity and a long-term corporate soundness based on their business ecosystem and cooperative strategies. This study is designed to validate a theoretical proposition that the win-win growth strategy of Samsung Electronics and cooperative efforts among companies can create a healthy business ecosystem, based on results of case studies and surveys. In this study, a level of global market access of small and mid-sized companies is adopted as the key achievement index. The foreign market entry is considered as one of vulnerabilities in the ecosystem of small and mid-sized enterprises (SMEs). For SMEs, the global market access based on the research and development (R&D) has become the critical component in the process of transforming them into global small giants. The results of case studies and surveys are analyzed mainly based on a model of a virtuous cycle of Creativity, Opportunity, Productivity, and Proactivity (the COPP model) that features the characteristics of the healthiness of a business ecosystem. In the COPP model, a virtuous circle of profits made by the first three factors and Proactivity, which is the manifestation of entrepreneurship that proactively invests and reacts to the changing business environment of the future, enhances the healthiness of a given business ecosystem. With the application of the COPP model, this study finds major achievements of the win-win growth of Samsung Electronics as follows. First, Opportunity plays a role as a parameter in the relations of Creativity, Productivity, and creating profits. Namely, as companies export more (with more Opportunity), they are more likely to link their R&D efforts to Productivity and profitability. However, companies that do not export tend to fail to link their R&D investment to profitability. Second, this study finds that companies with huge investment on R&D for the future, which is the result of Proactivity, tend to hold a large number of patents (Creativity). And companies with significant numbers of patents tend to be large exporters as well (Opportunity), and companies with a large amount of exports tend to record high profitability (Productivity and profitability), and thus forms the virtuous cycle of the COPP model. In addition, to access global markets for sustainable growth, SMEs need to build and strengthen their competitiveness. This study concludes that companies with a high level of proactivity to invest for the future can create a virtuous circle of Creativity, Opportunity, Productivity, and Proactivity, thereby providing a strategic implication that SMEs should invest time and resources in forming such a virtuous cycle which is a sure way for the SMEs to grow into global small giants.

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Assessment of Forest Vegetation Effect on Water Balance in a Watershed (산림식생에 따른 유역 물수지 영향 평가)

  • Kim, Chu- Gyum;Kim, Nam-Won
    • Journal of Korea Water Resources Association
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    • v.37 no.9
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    • pp.737-744
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    • 2004
  • In this study, to evaluate the effect of forest vegetation on the long-term water balance in a watershed, semi-distributed and physically based parameter model, SWAT was applied to the Bocheong watershed, and the variation of hydrological components such as evapotranspiration, surface flow, lateral flow, base flow, and total runoff was investigated with coniferous and deciduous forests, respectively. First, SWAT model was modified to simulate the actual plant growth pattern of coniferous trees which have the uniform value of leaf area index all the seasons of the year. The modified model was applied to the watershed that is assumed to have only one land cover in the whole watershed, and the variation of the water balance components was investigated for each land cover. It was found that coniferous forest affected the increase in evapotranspiration and decrease in runoff more than deciduous forest. However, the age and the density of stand, the location, and soil characteristics and meteorological conditions including the tree species should be also considered to examine the effect more quantitatively and to reduce the uncertainties in simulated output from the hydrological model.