基于非线性混合模型的杉木优势木平均高

从理论上介绍一阶线性化算法和一阶条件期望线性化算法求解非线性混合效应模型参数,并利用这2种算法分别对杉木优势木平均高进行拟合(选用常用的Logistic模型作为基础模型,把区组作为随机效应因子)。结果表明:2种算法对杉木优势木平均高进行拟合时精度都很高。通过对2种线性化算法进一步比较可得,在分析单木水平非线性混合效应优势木平均高模型时,2种算法拟合效果非常接近,因此在实际应用中可以选择其中任意一种算法对杉木优势木平均高进行拟合。     

A financial analysis of a silvopasture system in southern Mississippi

Silvopasture is reemerging as a land use in the southern US. Alternate land use treatments based on field trials for timber and pasture for beef cattle production were financially evaluated. Multiple-use management aspects of these systems were further illustrated by the addition of fee hunting. Land Expectation Values (LEVs) were lower when silvopasture treatments were compared to steer grazing only. However, silvopasture treatments compared favorably to some grazing treatments. LEVs were higher when silvopasture treatments were compared to commercial forest plantation applications on similar sites. Silvopasture systems promote multiple-use management of the land under an environmentally friendly cropping system whereby certain types of wildlife can thrive. This is particularly relevant in light of recent increases in fee hunting in the South. LEVs were reduced by $289, $200, and $151 ha⁻¹ at discount rates of 5%, 7%, and 9% respectively, when fee hunting was excluded in the recommended silvopasture treatment. The monetary value of a wildlife component in this system can be interpreted as the expected value gained per hectare per rotation in perpetuity when fee hunting is part of the management plan. On average, it represented an 8.6% gain in LEVs for this treatment. Results from this study support the potential for silvopasture applications in the South for private landowners. Cattle grazing of improved forage in commercially productive loblolly pine (Pinus taeda) stands can relieve annual cash flow problems inherent in tree production. This revised version was published online in June 2006 with corrections to the Cover Date.     

应用GIS推进海南热带农业信息化的探讨

首先阐述了GIS和农业信息化概念,通过分析海南省热带农业的发展现状,提出应用GIS推进海南热带农业信息化的意义和可行性,进而对GIS技术在海南热带农业信息化的应用进行展望。     

城乡居民年人均蔬菜消费量长期趋势分析

将中国城乡居民年人均蔬菜消费量序列转化为不同的状态和状态的转移概率.用Markov链遍历性原理,得到经过长期变化之后年增减率的数学期望.对城乡居民年人均蔬菜消费量趋势进行了分析.     

西藏高原巨柏的研究进展与展望

巨柏（Cupressus gigantean）是藏东南雅鲁藏布江流域特有的国家一级濒危保护植物，寿命达2 000 余年，是高原地区重要的水土保持和园林绿化树种。通过阅读和实地调查研究，简要论述了巨柏的生物学特性、起源、地理分布、群落特性、苗木培育、引种驯化、濒危机制与物种保护等方面的研究进展，分析其中的问题，提出未来巨柏研究的科学与技术问题。     

农村文化建设调查与分析——基于河北省农民问卷调查

在2009、2010年对农村文化建设调查分析的基础上,通过更加细致、广泛的调查,充分利用最新的调查数据,从农民角度分析了对农村文化建设的认知与期望,尤其是重点调查分析了农村文化中的文化资源、农民旅游、乡村游以及非物质文化遗产部分等。结果发现,当前农村文化建设在以上几方面取得了进展,但也存在不少问题。进一步分析发现：农村文化建设主要受到了农民、政府、社会3方面因素的影响,最后有针对性的提出了相应的对策建议。     

前景判别的局部模型匹配目标跟踪

目的 在复杂背景下,传统模型匹配的跟踪方法只考虑了目标自身特征,没有充分考虑与其所处图像的关系,尤其是目标发生遮挡时,易发生跟踪漂移,甚至丢失目标。针对上述问题,提出一种前景判别的局部模型匹配(FDLM)跟踪算法。方法 首先选取图像帧序列前m帧进行跟踪训练,将每帧图像分割成若干超像素块。然后,将所有的超像素块组建向量簇,利用判别外观模型建立包含超像素块的目标模型。最后,将建立的目标模型作为匹配模板,采用期望最大化(EM)估计图像的前景信息,通过前景判别进行局部模型匹配,确定跟踪目标。结果 本文算法在前景判别和模型匹配等方面能准确有效地适应视频场景中目标状态的复杂变化,较好地解决各种不确定因素干扰下的跟踪漂移问题,和一些优秀的跟踪算法相比,可以达到相同甚至更高的跟踪精度,在Girl、Lemming、Liquor、Shop、Woman、Bolt、CarDark、David以及Basketball视频序列下的平均中心误差分别为9.76、28.65、19.41、5.22、8.26、7.69、8.13、11.36、7.66,跟踪重叠率分别为0.69、0.61、0.77、0.74、0.80、0.79、0.79、0.75、0.69。结论 实验结果表明,本文算法能够自适应地实时更新噪声模型参数并较准确估计图像的前景信息,排除背景信息干扰,在部分遮挡、目标形变、光照变化、复杂背景等条件下具有跟踪准确、适应性强的特点。     

Bayesian Estimation of the Censored Life-span Experiment

The censored life-span experiment is very popular. To estimate the expectation of the random variable that only has imperfection samples based on Bayesian method is a method that utilize prior information, and the estimator has a recursive formula, when samples added it is very convenient in calculation. This method is a fusion method of dynamic discrete data. It is more effective than routine estimators.     

The Causes and Countermeasures of Customer Satisfaction Trap

The article deals with the guidance of Two-Factor Theory. There are two kinds of customer expectations, which are basic expectation and potential expectation. Basic expectation is similar to dissatisfiers and potential expectation is similar to satisfiers. Basic expectation and potential expectation are different in different stage of customer lifecycle, therefore, corresponding measures are supposed to be taken to meet their different stages.     

种群及瓜螟种群存亡规律的探讨

采用数学方法分析了自然条件下某生物种群的寿命分布 ,得到了种群寿命分布函数和种群内禀死亡常数 ,并由此推导出了种群寿命的数学期望和方差。并以瓜螟种群试验资料 ,拟合了瓜螟第二、三代寿命分布函数 ,拟合效果较好。