• Title/Summary/Keyword: simple logistic growth curve

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Stand Density Management Studies on Pine Stands in Korea (I) - The Simple Logistic Growth Curve and Its Application to Pine Stands - (소나무림(林)의 밀도관리(密度管理)에 관(關)한 연구(硏究)(I) - 단순(單純) logistic 곡선(曲線)과 소나무림(林)에 대한 그의 적용(適用) -)

  • Kwon, O Bok;Lee, Heung Kyun;Woo, Chong Chun
    • Journal of Korean Society of Forest Science
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    • v.57 no.1
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    • pp.1-7
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    • 1982
  • The simple logistic growth model on the logistic curve, being originally a kind of population growth curve has also been sometimes utilized to describe growth curves in herbaceous plants such as duckweed and sun-flowers. It has already been recognized that the agreement between the theoretical calculations and the empirical observations is quite satisfactory form a practical point of view. It remains, however, still doubtful whether the logistic curve could be applied to the growth or ordinary woody plants which is quite different in its character from that of herbaceous plants. In this study, the simple logistic model, being a basic tool of stand density management, is applied to yield data from pine stands in order to test the adequacy of the model An attempt of testing the significance of the fit is made by applying the Chi-square test.

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On the estimation of parameters for the growth curve of the Korean Population (한국의 인구곡선 추정에 관한 연구)

  • 구자흥
    • The Korean Journal of Applied Statistics
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    • v.7 no.2
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    • pp.249-261
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    • 1994
  • The purpose of this research is to obtain a Simple Logistic Curve for the curve fitting of Korean total Population. Based on the population census data from 1949 to 1990, the parameters are estimated by 3-group method. As the results, intercensal populations of Korea from 1950 to 190 are estimated, and Korean total populations from 1991 to 2010 A.D. are projected. And we also can suggest the upper asymptote 58, 616 thousands of Korean total population.

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A theoretical approach and its application for a dynamic method of estimating and analyzing science and technology levels : case application to ten core technologies for the next generation growth engine (동태적 기술수준 측정 방법에 대한 이론적 접근 : 차세대성장동력 기술의 사례분석)

  • Bark, Pyeng-Mu
    • Journal of Korea Technology Innovation Society
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    • v.10 no.4
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    • pp.654-686
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    • 2007
  • To estimate and analyze an interested science and technology level in any case requires three basic informations: (1) relative positions of our technology level, (2) other relevant technology level of the world best country holding the state of the art technology, and (3) its theoretical or practical maximum level within a certain period of time. Further, additional information from analyzing its respective rate of technology changes is necessary. It seems that most previous empirical or case studies on technology level have not considered third and fourth informations seriously, and thus critically have missed important findings from a dynamic point of view on the matter. A dynamic approach considering types of development processes and paths as well as current position needs an application of a concept of technology development stages and respective growth curves. This paper proposes a new method of approach and application by implementing relatively simple types of the growth curve(S-curve) such as logistic and Comports curves and applying estimation results of these curves to ten core technologies of the growth engines for the next future generation in Korea. The study implies that Korean science and technology level in general clearly gets higher as it approaches to a recent time of period, but relative technology gap from the world best in terms of catching-up period does not get better or narrower in case of at least part of the concerned technologies such as bio new drugs and human organs, and intelligence robots. The possibility does exist that some of our concerned technologies shooting for the next future generation may not come to the world highest level in the near future. The purpose of this study is to propose possibilities of catching-up, if any, by estimating its relevant type of growth pattern by way of measuring and analyzing technology level and by analyzing the technology development process through a position analysis. At this stage this study tries to introduce a new theoretical approach of estimating technology level and its application to existing case study results(data) from Korea Institute of Science and Technology Planning and Evaluation(KISTEP) and Korea Institute of Industrial Technology Evaluation and Planing(ITEP), for years of 2004 and 2006 respectively. The study has some limitations in terms of accuracy of measuring(estimating) a relevant growth curve to a particular technology, feasibility of applying estimated results, accessing and analyzing panel experts opinions. Hence, it is recommended that further study would follow soon enough to verify practical applicability and possible expansion of the study results.

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