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Predator Population Dynamics Involving Exponential Integral Function When Prey Follows Gompertz Model
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作者 Ayele Taye Goshu Purnachandra Rao Koya 《Open Journal of Modelling and Simulation》 2015年第3期70-80,共11页
The current study investigates the predator-prey problem with assumptions that interaction of predation has a little or no effect on prey population growth and the prey’s grow rate is time dependent. The prey is assu... The current study investigates the predator-prey problem with assumptions that interaction of predation has a little or no effect on prey population growth and the prey’s grow rate is time dependent. The prey is assumed to follow the Gompertz growth model and the respective predator growth function is constructed by solving ordinary differential equations. The results show that the predator population model is found to be a function of the well known exponential integral function. The solution is also given in Taylor’s series. Simulation study shows that the predator population size eventually converges either to a finite positive limit or zero or diverges to positive infinity. Under certain conditions, the predator population converges to the asymptotic limit of the prey model. More results are included in the paper. 展开更多
关键词 EXPONENTIAL INTEGRAL function gompertz Model POPULATION Growth PREDATOR PREY
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Gompertz PSO variants for Knapsack and Multi-Knapsack Problems
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作者 Pinkey Chauhan Millie Pant Kusum Deep 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2021年第4期611-630,共20页
Particle Swarm Optimization,a potential swarm intelligence heuristic,has been recognized as a global optimizer for solving various continuous as well as discrete optimization problems.Encourged by the performance of G... Particle Swarm Optimization,a potential swarm intelligence heuristic,has been recognized as a global optimizer for solving various continuous as well as discrete optimization problems.Encourged by the performance of Gompertz PSO on a set of continuous problems,this works extends the application of Gompertz PSO for solving binary optimization problems.Moreover,a new chaotic variant of Gompertz PSO namely Chaotic Gompertz Binary Particle Swarm Optimization(CGBPSO)has also been proposed.The new variant is further analysed for solving binary optimization problems.The new chaotic variant embeds the notion of chaos into GBPSO in later stages of searching process to avoid stagnation phenomena.The efficiency of both the Binary PSO variants has been tested on different sets of Knapsack Problems(KPs):0-1 Knapsack Problem(0-1 KP)and Multidimensional Knapsack Problems(MKP).The concluding remarks have made on the basis of detailed analysis of results,which comprises the comparison of results for Knapsack and Multidimensional Knapsack problems obtained using BPSO,GBPSO and CGBPSO. 展开更多
关键词 Binary PSO Knapsack Problems Multi Knapsack Problems gompertz function CHAOS
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采用Gompertz函数的水稻土压缩特性研究 被引量:6
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作者 霍连飞 Belal Eisa Adam +2 位作者 丁启朔 何瑞银 汪小旵 《农业工程学报》 EI CAS CSCD 北大核心 2020年第12期136-142,共7页
土壤压实模型是预测压实破坏的常用方法,但土壤压实模型的应用常因输入参数(土壤压缩特性及其与不同土壤物理性质之间的关系)的缺乏而受到限制。为定量地评价土壤水力学性质和土壤结构对土壤压缩特性的影响,该文利用土壤固结仪对25种不... 土壤压实模型是预测压实破坏的常用方法,但土壤压实模型的应用常因输入参数(土壤压缩特性及其与不同土壤物理性质之间的关系)的缺乏而受到限制。为定量地评价土壤水力学性质和土壤结构对土壤压缩特性的影响,该文利用土壤固结仪对25种不同含水率和容重的重塑土样进行单轴压缩试验,并采用Gompertz函数对试验数据进行拟合以获取土样的回弹指数、压缩指数和先期固结压力。试验结果表明,Gompertz函数对水稻土试验数据的拟合效果较优,决定系数为0.991~0.999。水稻土回弹指数为0.003~0.138,与容重呈负相关,与含水率呈正相关。水稻土压缩指数为0.115~0.839,与容重呈负相关,与含水率呈二次多项式关系。水稻土先期固结压力为33~127 kPa,与容重呈正相关,与含水率呈负相关。该研究建立的土壤压缩特性与含水率和容重之间的传递函数,可用于大尺度范围内水稻土压缩特性的预测;同时这些传递函数可作为土壤压实模型的输入参数,用于农业机械作业引起的压实破坏的量化和土壤压实风险的评估。 展开更多
关键词 土壤 含水率 容重 压实模型 压缩特性 gompertz函数
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一类具有时滞和Gompertz增长率的捕食系统的全局稳定性
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作者 李梁晨 徐瑞 《军械工程学院学报》 2015年第2期74-78,共5页
研究一类具有时滞和Gopmertz增长率的捕食系统.通过分析相应特征方程根的分布,讨论可行平衡点的局部稳定性,得到系统出现Hopf分支的条件.通过构造Lyapunov泛函和应用LaSalle不变原理,给出正平衡点全局渐近稳定的充分条件.
关键词 时滞 功能性反应 gompertz增长率 全局稳定性
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The Odd Generalized Exponential Gompertz Distribution
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作者 M. A. El-Damcese Abdelfattah Mustafa +1 位作者 B. S. El-Desouky M. E. Mustafa 《Applied Mathematics》 2015年第14期2340-2353,共14页
In this paper we propose a new lifetime model, called the odd generalized exponential gompertz distribution. We obtained some of its mathematical properties. Some structural properties of the new distribution are stud... In this paper we propose a new lifetime model, called the odd generalized exponential gompertz distribution. We obtained some of its mathematical properties. Some structural properties of the new distribution are studied. The method of maximum likelihood is used for estimating the model parameters and the observed Fisher’s information matrix is derived. We illustrate the usefulness of the proposed model by applications to real data. 展开更多
关键词 gompertz Distribution HAZARD function MOMENTS Maximum LIKELIHOOD Estimation Odds function T-X Family of Distributions
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On the Application of Nadarajah Haghighi Gompertz Distribution as a Life Time Distribution
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作者 Adebisi Ade Ogunde Isaac Oluwaseyi Ajao Gbenga Adelekan Olalude 《Open Journal of Statistics》 2020年第5期850-862,共13页
The convolution of Nadarajah-Haghighi-G family of distributions will result <span style="font-family:Verdana;">into a more flexible distribution (Nadarajah-Haghighi Gompertz distribution) </span>... The convolution of Nadarajah-Haghighi-G family of distributions will result <span style="font-family:Verdana;">into a more flexible distribution (Nadarajah-Haghighi Gompertz distribution) </span><span style="font-family:Verdana;">than each of them individually in terms of the estimate of the characteristics in there parameters. The combination was done using Nadarajah-Haghighi </span><span style="font-family:Verdana;">(NH) generator. We investigated in the newly developed distribution some basic </span><span style="font-family:Verdana;">properties including moment, moment generating function, survival rate function, hazard rate function asymptotic behaviour and estimation of parameters. The proposed model is much more flexible and has a better representation of data than Gompertz distribution and some other model considered. A real data set was used to illustrate the applicability of the new model.</span> 展开更多
关键词 Moment Generating function Nadarajah-Haghighi Generator gompertz Distribution Survival Rate function MOMENT
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连续日称重杜洛克公猪的生长曲线分析 被引量:7
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作者 徐如海 胡锦平 +2 位作者 翁经强 褚晓红 黄少珍 《浙江农业学报》 CSCD 2007年第5期343-345,共3页
利用14头杜洛克公猪1 596条连续日称重记录,进行了Logistic方程和Compertz方程的生长曲线拟合分析。结果表明:两种方程的拟合度(R2)在0.99以上,拐点体重和日龄差别不显著。但综合杜洛克公猪实际成熟体重考虑,用Compertz方程对杜洛克公... 利用14头杜洛克公猪1 596条连续日称重记录,进行了Logistic方程和Compertz方程的生长曲线拟合分析。结果表明:两种方程的拟合度(R2)在0.99以上,拐点体重和日龄差别不显著。但综合杜洛克公猪实际成熟体重考虑,用Compertz方程对杜洛克公猪进行生长曲线的拟合效果更好,更接近实际。 展开更多
关键词 杜洛克公猪 生长曲线 LOGISTIC方程 Compertz方程
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不同品种公猪连续日称重记录的生长曲线拟合 被引量:10
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作者 郑华 刘小红 +1 位作者 吴常信 张福权 《安徽农业科学》 CAS 北大核心 2006年第11期2406-2407,2409,共3页
利用农业部种猪质量监督检验测试中心(广州)的杜洛克公猪45头4 072条日称重记录,长白公猪49头4 545条日称重记录,大约克公猪50头4 614条日称重记录,进行了Logistic方程、Gompertz方程和Polynomials函数的生长曲线拟合。结果表明,不进行... 利用农业部种猪质量监督检验测试中心(广州)的杜洛克公猪45头4 072条日称重记录,长白公猪49头4 545条日称重记录,大约克公猪50头4 614条日称重记录,进行了Logistic方程、Gompertz方程和Polynomials函数的生长曲线拟合。结果表明,不进行任何数据前处理只有0.8左右的拟合度(R2),按剔除法或Lowess方法数据处理后,R2可分别提高到0.9以上和0.99左右。不同品种公猪比较而言,杜洛克长势不如长白和大约克品种,其Gompertz方程得出的成熟体重(216.2 kg)比长白(234.7 kg)和大约克(235.7 kg)低,生长拐点(141.60 d,79.54 kg)比长白(145.01 d,86.34 kg)和大约克(146.90 d,86.71 kg)早。Logistic方程的趋势相同,但拐点更早。 展开更多
关键词 生长曲线 LOGISTIC方程 gompertz方程
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On modeling with multiplicative differential equations 被引量:9
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作者 Agamirza E.Bashirov Emine Misirli +1 位作者 Ycel Tandogdu Ali zyapici 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2011年第4期425-438,共14页
This work is aimed to show that various problems from different fields can be modeled more efficiently using multiplicative calculus, in place of Newtonian calculus. Since multiplicative calculus is still in its infan... This work is aimed to show that various problems from different fields can be modeled more efficiently using multiplicative calculus, in place of Newtonian calculus. Since multiplicative calculus is still in its infancy, some effort is put to explain its basic principles such as exponential arithmetic, multiplicative calculus, and multiplicative differential equations. Examples from finance, actuarial science, economics, and social sciences are presented with solutions using multiplicative calculus concepts. Based on the encouraging results obtained it is recommended that further research into this field be vested to exploit the applicability of multiplicative calculus in different fields as well as the development of multiplicative calculus concepts. 展开更多
关键词 gompertz function ELASTICITY exponential arithmetic multiplicative calculus growth.
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新美系大约克猪的生长规律及上市屠宰体重的优化 被引量:4
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作者 郑华 骆建才 +2 位作者 唐仕强 赵祖凯 吴常信 《畜牧与兽医》 北大核心 2007年第1期11-13,共3页
以66头2005年底引进的新美系大约克猪纯繁一代为对象,分析了从初生到120 kg体重间不同性别不同体重阶段的增重、耗料情况和饲料报酬,进行了Logistic方程、Gompertz方程和Polynomials函数的生长曲线拟合。不同性别间生长规律差异分析表明... 以66头2005年底引进的新美系大约克猪纯繁一代为对象,分析了从初生到120 kg体重间不同性别不同体重阶段的增重、耗料情况和饲料报酬,进行了Logistic方程、Gompertz方程和Polynomials函数的生长曲线拟合。不同性别间生长规律差异分析表明,母猪成熟体重稍大,达到拐点的日龄和体重也最大,公猪次之,阉猪则最早达到生长拐点。利用经济学平衡原理,分析出其新美系大约克猪的最佳上市体重为125 kg,最佳上市日龄为193.6 d。 展开更多
关键词 上市屠宰体重 生长曲线 LOGISTIC方程 gompertz方程
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KOSTELEC地区西黄松林木个体胸高断面积生长分析(英文) 被引量:6
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作者 廖超英 PODRA ZSKY Vile m 《西北林学院学报》 CSCD 北大核心 2001年第4期1-5,12,共6页
用 Mitscherlich、Logistic、Gompertz和 Korf4个理论生长方程分别对引种到捷克 Kostelec地区的西黄松林木个体胸高断面积生长过程进行了拟合 ,由最佳生长方程分别得出了胸高断面连年生长量、平均生长量和相对生长率随时间变化的函数 ,... 用 Mitscherlich、Logistic、Gompertz和 Korf4个理论生长方程分别对引种到捷克 Kostelec地区的西黄松林木个体胸高断面积生长过程进行了拟合 ,由最佳生长方程分别得出了胸高断面连年生长量、平均生长量和相对生长率随时间变化的函数 ,并对生长过程进行了分析。结果表明 :Korf方程具有最高的拟合精度 ,能很好地描述西黄松胸高断面积生长过程 ;西黄松胸高断面积连年生长量和平均生长量最大值分别出现在第 7a和第 1 5 a(胸高年龄 ) ;1~ 2 6a的平均相对生长率为 0 .2 4 3;速生期 ( 3~ 1 1 a)内胸高断面积平均生长量为 0 .0 0 1 474m2。 展开更多
关键词 KOSTELEC地区 西黄松 胸高断面积 生长分析
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Predictive Models for Cumulative Confirmed COVID-19 Cases by Day in Southeast Asia 被引量:2
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作者 Yupaporn Areepong Rapin Sunthornwat 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第12期927-942,共16页
Coronavirus disease 2019 outbreak has spread as a pandemic since the end of year 2019.This situation has been causing a lot of problems of human beings such as economic problems,health problems.The forecasting of the ... Coronavirus disease 2019 outbreak has spread as a pandemic since the end of year 2019.This situation has been causing a lot of problems of human beings such as economic problems,health problems.The forecasting of the number of infectious people is required by the authorities of all countries including Southeast Asian countries to make a decision and control the outbreak.This research is to investigate the suitable forecasting model for the number of infectious people in Southeast Asian countries.A comparison of forecasting models between logistic growth curve which is symmetric and Gompertz growth curve which is asymmetric based on the maximumof Coefficient of Determination and theminimumof RootMean Squared Percentage Error is also proposed.The estimation of parameters of the forecasting models is evaluated by the least square method.In addition,spreading of the outbreak is estimated by the derivative of the number of cumulative cases.The findings show that Gompertz growth curve is a suitable forecasting model for Indonesia,Philippines,andMalaysia and logistic growth curve suits the other countries in South Asia. 展开更多
关键词 Coronavirus disease 2019 gompertz function least square estimation logistic function
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SARS流行预测分析 被引量:15
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作者 王建锋 《中国工程科学》 2003年第8期23-29,共7页
表面上突如其来的SARS本质上却有极规律的内在发展演化机制 ,遵从初始缓慢增长、加速、减速和稳定终止四个阶段总体道路 ,自然和社会生活领域众多事件演化都符合这一规律 ,因而可以运用广义的Logistic生长模型进行描述。基于先期流行的... 表面上突如其来的SARS本质上却有极规律的内在发展演化机制 ,遵从初始缓慢增长、加速、减速和稳定终止四个阶段总体道路 ,自然和社会生活领域众多事件演化都符合这一规律 ,因而可以运用广义的Logistic生长模型进行描述。基于先期流行的广东SARS感染病例数据 ,以及尚未结束的北京、全国 2 0 0 3年SARS流行统计数据 ,借助于最优化分析技术 ,运用广义的Logistic生长模型对该事件演化特征参量进行了辨识 ;在此基础上 ,又借助于广义生长模型的特例———Gompertz函数进行了演化过程的预测 ,并与其他生长模型结果进行了比较。研究表明 ,生长模型模拟结果均与实际数据有很好的一致性 ,可以用来预测事件的发生演化过程 ,此次SARS事件堪称生长模型的经典实例。 展开更多
关键词 SARS 广义的Logistic生长模型 gompertz分布 预测 最优化
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基于Gompertz函数的矿区地表下沉预测方法
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作者 李国平 谷海静 郭冬冬 《陕西煤炭》 2024年第11期156-161,共6页
煤炭开采所引起的地表沉陷对生态环境极具危害,造成的经济损失也相当巨大,因此开展矿区地表下沉预测十分必要。通过对开采沉陷动态预计的改进分段Knothe时间函数和分段Weibull时间函数进行分析,以时间、空间相一致的建模思路,构建出一... 煤炭开采所引起的地表沉陷对生态环境极具危害,造成的经济损失也相当巨大,因此开展矿区地表下沉预测十分必要。通过对开采沉陷动态预计的改进分段Knothe时间函数和分段Weibull时间函数进行分析,以时间、空间相一致的建模思路,构建出一种适用于充填长壁开采工艺的开采沉陷动态预计的时间函数模型,即Gompertz时间函数模型。在给出参数求取方法及全盆地动态移动变形预计算法的基础上,认为该时间函数与地表点下沉特征具有非常高的一致性,对开采沉陷动态预计具有良好适用性。以陕西某矿22302工作面地表移动观测站实测数据进行Gompertz函数参数反演,与实测数据进行对比并分析其拟合精度,验证了该方法能够满足沉陷预测的要求。 展开更多
关键词 煤炭开采 地表沉陷 沉陷预测 动态预计 gompertz函数
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灰色分离建模方法的改进
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作者 黄秀花 田海军 《咸阳师范学院学报》 2014年第6期7-10,共4页
结合灰色GM(1,1)模型的3种改进方法:平滑原始序列、分离建模、灰色Gompertz模型,提出一种改进的灰色分离建模方法。通过实例和对比分析,证明新的方法能够提高预测精度。
关键词 平滑原始序列 分离建模 灰色gompertz模型 融合函数
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Generalized Mathematical Model for Biological Growths 被引量:1
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作者 Purnachandra Rao Koya Ayele Taye Goshu 《Open Journal of Modelling and Simulation》 2013年第4期42-53,共12页
In this paper, we present a generalization of the commonly used growth models. We introduce Koya-Goshu biological growth model, as a more general solution of the rate-state ordinary differential equation. It is shown ... In this paper, we present a generalization of the commonly used growth models. We introduce Koya-Goshu biological growth model, as a more general solution of the rate-state ordinary differential equation. It is shown that the commonly used growth models such as Brody, Von Bertalanffy, Richards, Weibull, Monomolecular, Mitscherlich, Gompertz, Logistic, and generalized Logistic functions are its special cases. We have constructed growth and relative growth functions as solutions of the rate-state equation. The generalized growth function is the most flexible so that it can be useful in model selection problems. It is also capable of generating new useful models that have never been used so far. The function incorporates two parameters with one influencing growth pattern and the other influencing asymptotic behaviors. The relationships among these growth models are studies in details and provided in a flow chart. 展开更多
关键词 Growth Model Koya-Goshu function gompertz LOGISTIC RICHARDS Weibull
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Modeling Motorization Development in China
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作者 Junlei Wang Xiaoduan Sun +1 位作者 Yulong He Shuzhan Hou 《Journal of Transportation Technologies》 2012年第3期267-276,共10页
Entering the 21st century, China’s economic development has reached new heights and the country has ascended to the world’s second largest economy. The 20 year unrelenting development in China also stimulates income... Entering the 21st century, China’s economic development has reached new heights and the country has ascended to the world’s second largest economy. The 20 year unrelenting development in China also stimulates income growth. The increased disposable income enables an ordinary Chinese family vehicle ownership which was unthinkable two decades ago. The most populous country has started a love affair with automobile just like in the United States. Annual automobile sales in China rose from 2.1 million in 2000 to 18.1 million in 2010 with a yearly growth rate of 24.3%, which spurs the vehicle ownership increase from 18.1 million in 2000 to 78.8 million in 2010, a growth rate of 15.9% The unprecedented motorization development in China is making a huge impact on all aspects of society, including negative consequences that cannot be ignored. Traffic congestion, air pollution, and dependency on imported oil are huge emerging problems threatening Chinese sustainable development. Although these problems occurred and still exist in many other developed and developing countries, they are more acute in China today. By collecting and analyzing the massive data from various sources, this paper explores the relationship between economic development and level of mobility by studying the historical developments from several developed counties and discusses the key issues in Chinese motorization development. The objective of the study is to predict the future level of motorization and its potential impacts. 展开更多
关键词 Motor and SOCIETY MOTORIZATION gompertz Growth function Vehicle OWNERSHIP Per Capita GDP GDP ELASTICITY Forecast
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Gompertz模型在高龄阶段的修正及模拟 被引量:4
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作者 张志强 张润楚 《数学的实践与认识》 CSCD 北大核心 2004年第1期36-40,共5页
近年来我国人口老龄化呈加快之势 ,精确估计高龄老人的年龄别死亡概率对人寿保险公司计算年金显得尤为重要 .本文针对观察年龄别死亡概率在高龄阶段不再呈现指数增长的事实 ,对 Gompertz模型进行了修正 ,以使模型更好地拟合观察年龄别... 近年来我国人口老龄化呈加快之势 ,精确估计高龄老人的年龄别死亡概率对人寿保险公司计算年金显得尤为重要 .本文针对观察年龄别死亡概率在高龄阶段不再呈现指数增长的事实 ,对 Gompertz模型进行了修正 ,以使模型更好地拟合观察年龄别死亡概率 . 展开更多
关键词 gompertz模型 人口老龄化 中国 人寿保险 年龄别死亡概率
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基于GOMPERTZ函数的上证综合指数预测的实证研究
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作者 陶永宏 《数学的实践与认识》 CSCD 北大核心 2005年第12期51-56,共6页
对基于G om pertz函数的上证综合指数进行预测的可行性进行了分析,同时,在对上证综合指数的具体走势及实际数据进行研判的基础上,对牛市行情下上证综合指数的运行进行了预测的实证研究,得出了相应的结论,并提出了该预测方法进一步完善... 对基于G om pertz函数的上证综合指数进行预测的可行性进行了分析,同时,在对上证综合指数的具体走势及实际数据进行研判的基础上,对牛市行情下上证综合指数的运行进行了预测的实证研究,得出了相应的结论,并提出了该预测方法进一步完善之处和可进一步深入研究的问题. 展开更多
关键词 gompertz函数 上证综合指数 预测 实证研究
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长爪沙鼠体质量生长模式特征 被引量:3
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作者 刘伟 宛新荣 钟文勤 《生态学杂志》 CAS CSCD 北大核心 2009年第9期1853-1856,共4页
通过Gompertz方程拟合分析了野外围栏条件下当年春季出生的长爪沙鼠(Merio-nes unguiculatus)体质量生长模式。结果表明:雌、雄鼠体质量生长系数相近,该结果支持生长系数具有种的特异性,反映物种固有特征的结论;但雄鼠的当年稳定体质量... 通过Gompertz方程拟合分析了野外围栏条件下当年春季出生的长爪沙鼠(Merio-nes unguiculatus)体质量生长模式。结果表明:雌、雄鼠体质量生长系数相近,该结果支持生长系数具有种的特异性,反映物种固有特征的结论;但雄鼠的当年稳定体质量和体质量日瞬时增长率高于雌鼠,雄鼠的体质量增长的拐点时间、生长速率降低到起始值的时间以及达到稳定体质量90%的时间均较雌鼠的晚,这些指标呈现的性别差异提示了长爪沙鼠婚配策略中的多配倾向。 展开更多
关键词 长爪沙鼠 gompertz方程 年龄 婚配策略
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