• Title/Summary/Keyword: Function model

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Family of floral homeotic genes (MADS-box genes) expressed in early flower Panax genseng

  • Yoon, Sunha;Yoon, Euisoo
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2002년도 제9차 국제심포지움 및 추계정기학술발표회
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    • pp.15-15
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    • 2002
  • In higher dicotyledonous plants, the floral organs are arranged in four different whorls, containing sepals, petals, stamens and carpels. petals, stamens and carpels. The specification of floral organ identity is explained by the ABC model (Weigel and Meyerowitz 1994). Expression of an A-function gene specifies sepal formation in whorl 1. the combination of A-and B-function genes specifies the formation of petals in whorl 2, B-and C-function genes spesify stamen formation in whorl 3, and expression of the C-function alone determines the formation of carpels in whorl 4. A-. B-, C-function genes have been isolated from many plant species and most of them belong to the family of MADS-box genes encoding transcription factor. In contrast to the flower of higher dicots, the perianths of genseng plants have three whorls of almost identical petaloid organs. van Tunen et al. (1993) proposed a modified ABC model, exemplified with tulip. In this model, B-function genes are expressed in whorl 1 as well as whorl 2 and 3, theefore the organs of whorl 1 and whorl 2 have the same petaloid structure. They proposed this model with the molphological data of wild type and mutant flowers of tulip, however, there are no molecular data.(중략)

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산림자원 및 산림의 공익기능량 추정을 위한 시스템다이내믹스 모형 개발 (Development of a System Dynamics Model For Estimating the Volume of Forest Resources and Function of Public Benefit)

  • 조윤숙
    • 한국시스템다이내믹스연구
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    • 제15권3호
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    • pp.5-36
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    • 2014
  • The purpose of this paper is to develop a System Dynamics model for estimating the volume of forest resources in the future and simulating the volume of function of public benefit linked to forest resources in dynamic manner. Also it is to analyze the impact when the volume of forest land conversion is controlled by policy using the SD model. The analysis was done at nation-wide for the simulation period 2000 to 2040. Estimated forest area was 6.2 million ha and estimated growing stock was $4.7\;billion\;m^3$ in 2040 from the future forecast without policies. Changing of forest resources, 13.9 billion tons of forest-ground-water storage was estimated, $1.8\;million\;m^3$ of erosion control of forest was estimated and 377 million tons of $CO_2$ absorption was estimated. As a result of simulation with two alternatives, forest area was less reduced and growing stock was bigger than do nothing policy. Also, function of public benefit reflected by changes of forest resources was enhanced. This study contributes to estimate the quantitatively measured volume of forest resources and function of public benefit over the 30 years in Korean forest land in scientific way. Using this SD model, decision maker would develop forest land policies more delicately for deserving forest resources and increasing the volume of function of public.

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유동 섭동에 의한 난류예혼합화염의 열발생 모델에 관한 연구 (A Heat Release Model of Turbulent Premixed Flame Response to Acoustic Perturbations)

  • 조주형;백승욱
    • 대한기계학회논문집B
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    • 제32권6호
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    • pp.413-420
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    • 2008
  • The unsteady heat release characteristics play a significant role in combustion instabilities observed in low emissions gas turbine combustors. Such combustion instabilities are often caused by coupling mechanisms between unsteady heat release rates and acoustic perturbations. A generalized model of the turbulent flame response to acoustic perturbations is analytically formulated by considering a distributed heat release along a curved mean flame front and using the flame's kinematic model that incorporates the turbulent flame development. The effects of the development of flame speed on the flame transfer functions are examined by calculating the transfer functions with a constant or developing flame speed. The flame transfer function due to velocity fluctuation shows that, when a developing flame speed is used, the transfer function magnitude decreases faster with Strouhal number than the results with a constant flame speed at low Strouhal numbers. The flame transfer function due to mixture ratio fluctuation, however, exhibits the opposite results: the transfer function magnitude with a developing flame speed increases faster than that with a constant flame speed at low Strouhal numbers. Oscillatory behaviors of both transfer function magnitudes are shown to be damped when a developing flame speed is used. Both transfer functions also show similar behaviors in the phase characteristics: The phases of both transfer functions with a developing flame speed increase more rapidly than those with a constant flame speed.

Non-linear modelling to describe lactation curve in Gir crossbred cows

  • Bangar, Yogesh C.;Verma, Med Ram
    • Journal of Animal Science and Technology
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    • 제59권2호
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    • pp.3.1-3.7
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    • 2017
  • Background: The modelling of lactation curve provides guidelines in formulating farm managerial practices in dairy cows. The aim of the present study was to determine the suitable non-linear model which most accurately fitted to lactation curves of five lactations in 134 Gir crossbred cows reared in Research-CumDevelopment Project (RCDP) on Cattle farm, MPKV (Maharashtra). Four models viz. gamma-type function, quadratic model, mixed log function and Wilmink model were fitted to each lactation separately and then compared on the basis of goodness of fit measures viz. adjusted $R^2$, root mean square error (RMSE), Akaike's Informaion Criteria (AIC) and Bayesian Information Criteria (BIC). Results: In general, highest milk yield was observed in fourth lactation whereas it was lowest in first lactation. Among the models investigated, mixed log function and gamma-type function provided best fit of the lactation curve of first and remaining lactations, respectively. Quadratic model gave least fit to lactation curve in almost all lactations. Peak yield was observed as highest and lowest in fourth and first lactation, respectively. Further, first lactation showed highest persistency but relatively higher time to achieve peak yield than other lactations. Conclusion: Lactation curve modelling using gamma-type function may be helpful to setting the management strategies at farm level, however, modelling must be optimized regularly before implementing them to enhance productivity in Gir crossbred cows.

다중 목적 입자 군집 최적화 알고리즘 이용한 방사형 기저 함수 기반 다항식 신경회로망 구조 설계 (Structural Design of Radial Basis Function-based Polynomial Neural Networks by Using Multiobjective Particle Swarm Optimization)

  • 김욱동;오성권
    • 전기학회논문지
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    • 제61권1호
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    • pp.135-142
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    • 2012
  • In this paper, we proposed a new architecture called radial basis function-based polynomial neural networks classifier that consists of heterogeneous neural networks such as radial basis function neural networks and polynomial neural networks. The underlying architecture of the proposed model equals to polynomial neural networks(PNNs) while polynomial neurons in PNNs are composed of Fuzzy-c means-based radial basis function neural networks(FCM-based RBFNNs) instead of the conventional polynomial function. We consider PNNs to find the optimal local models and use RBFNNs to cover the high dimensionality problems. Also, in the hidden layer of RBFNNs, FCM algorithm is used to produce some clusters based on the similarity of given dataset. The proposed model depends on some parameters such as the number of input variables in PNNs, the number of clusters and fuzzification coefficient in FCM and polynomial type in RBFNNs. A multiobjective particle swarm optimization using crowding distance (MoPSO-CD) is exploited in order to carry out both structural and parametric optimization of the proposed networks. MoPSO is introduced for not only the performance of model but also complexity and interpretability. The usefulness of the proposed model as a classifier is evaluated with the aid of some benchmark datasets such as iris and liver.

확률프런티어 모형하에서 단조증가하는 매끄러운 프런티어 함수 추정 (Estimation of smooth monotone frontier function under stochastic frontier model)

  • 윤단비;노호석
    • 응용통계연구
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    • 제30권5호
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    • pp.665-679
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    • 2017
  • 생산성 평가를 위해서는 주어진 생산 자료를 기반으로 투입 대비 최대산출량을 나타내는 최대산출량을 나타내는 생산 프런티어 곡선에 대한 정보가 필요한 경우가 많다. 이러한 프런티어 함수를 확률프런티어 모형하에서 추정하는 경우에 초기에는 프런티어 함수의 특정한 모수적 형테를 가정하는 경우가 많았다. 그러나 최근에는 프런티어 함수를 프런티어 함수가 기본적으로 만족해야 하는 단조성이나 오목성등을 만족하도록 하면서 비모수적 방법으로 추정하는 방법들이 많이 이루어졌다. 하지만, 이러한 방법들에서 얻어지는 추정량들은 프런티어 함수를 조각적 선형함수 또는 계단함수로 추정하는 특징 때문에 추정의 효율이 떨어지나가 프런티어 함수가 해석이 용이하지 않은 불연속점을 가지는 문제를 가지게 된다. 본 논문에서는 이러한 문제를 해결하기 위해 확률프런티어 모형에서 단조증가하는 매끄러운 프런티어 함수 추정법을 제시하고 제안된 추정방법이 기존의 추정방법에 비해서 가지는 추정 효율의 장점을 시뮬레이션를 통해 예시하였다.

An Adaptive Failure Rate Change-Point Model for Software Reliability

  • Jeong, Kwang-Mo
    • International Journal of Reliability and Applications
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    • 제2권3호
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    • pp.199-207
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    • 2001
  • The failure rate functions between successive failures are of concatenated form. We allow the parameters of failure rate function change after a certain failure and its fixing. We confine out attention to a model wherein the interfailure times are described by its failure rate function. We suggest an adaptive failure rate function with a change-point under the assumption that interfailure times are record value statistics from a Weibull distribution. The proposed model will be applied through a practical example of software failure data.

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Nonparametric Estimation of the Bivariate Survival Function under Koziol-Green Model I

  • Ahn, Choon-Mo;Park, Sang-Gue
    • Journal of the Korean Data and Information Science Society
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    • 제14권4호
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    • pp.975-982
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    • 2003
  • In this paper we considered the problem of estimating the bivariate survival distribution of the random vector (X, Y) when Y may be subject to random censoring but X is always uncensored. Adapting conditional Koziol-Green model, simplified estimator for bivariate survival function is proposed. We perform simulation to compare the proposed estimator with popular estimators and discussed the performance of it.

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The Asymptotic Properties of Mean Residual Life Function on Left Truncated and Right Censoring Model

  • Moon, Kyoung-Ae;Shin, Im-Hee
    • Journal of the Korean Data and Information Science Society
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    • 제8권1호
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    • pp.99-109
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    • 1997
  • The estimation procedure of mean residual life function has been placed an important role in the study of survival analysis. In this paper, the product limit estimator on left truncated and right censoring model is proposed with asymptotic properties. Also, the small sample properties are investigated through the Monte Carlo study and the proposed product limit type estimator is compared with ordinary Kaplan-Meier type estimator.

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대체함수에 의한 수문 시계열 모형 (Hydrologic Time Series Model by Transfer Function)

  • 강관원;김주환
    • 물과 미래
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    • 제24권3호
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    • pp.61-70
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    • 1991
  • 본 연구는 이산형 선형 대체함수(discrete linear transfer function)를 이용하여 수문시스템의 입력과 출력으로 나타낼 수 있는 강우와 유출의 관계를 통계학적으로 분석하고 모형화 하는 것이다. 모형의 설정 및 특정(identification), 추정(estimation) 및 검토(diagnostic checking) 과정이 제시되었으며 모형에 대한 적합성은 시계열 분석에서 이용되고 있는 통계량으로 판정하였다.

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