Analysis of information used in the management of plant genetic resources: a case study from northwestern Mato Grosso,Brazil     

Jorge L. Vivan  Peter H. May  Luís H. H. da Cunha  Walter S. de Boef  Charles R. Clement 《Agroforestry Systems》2009,76(3):591-604

Evaluation and monitoring are critical to agroforestry (AFS) project management, especially if they aim to contribute to use and conservation of biodiversity and plant genetic resources. A methodology to analyze information used in decision-making processes was developed and applied in a biodiversity conservation project in the Brazilian Amazon. Quality of information gathered at landscape, AFS, species (Bactris gasipaes Kunth, both wild and cultivated varieties) and genetic diversity levels in three dimensions was analyzed. The information at the landscape level was good, while that in the organizational-institutional and socio-economic dimensions was acceptable; information gaps were serious in the genetic-ecological dimension. Ecological and economic functionality assessment based on indicators built upon reported administrative actions suggests that information related to conservation played a greater role in decision-making and management than information associated with use and development. The application of the methodology proved instrumental for enhancing efficacy of decision-making within an adaptive management approach to plant genetic resources use and conservation.  相似文献   

用于可靠性评测的优化检测方法     

仉俊峰  王昉  苏永涛 《东北林业大学学报》2009,37(8)

在最小方差检测策略基础上,提出了用于可靠性估计的自适应检测算法.通过比较可知,自适应检测算法对可靠性估计的方差值小于操作框架均匀分布的随机检测方法和操作框架指定分布的一般检测方法的值.结果表明了自适应检测算法是有效的.  相似文献   

基于稳定性的并联机构自适应控制     

鲁开讲  师俊平  淡卜绸 《农业机械学报》2012,43(1):202-207

针对并联机构存在参数变化及不可预测的未建模误差的特点,提出一种基于模型的参考自适应控制策略。将机构系统的参数变化及未建模误差看成对实际系统的扰动,建立理想的参考模型,依靠系统状态及其误差构造自适应反馈律,利用稳定性理论推导自适应控制律,使得实际机构与参数模型具有相同的动态特性。实例显示,自适应控制器对参数变化及未建模误差引起的运动误差具有很好的抑制作用,保证机构对规划的目标运动具有很高的跟踪精度。  相似文献   

基于自适应导航参数的智能车辆视觉导航     

李进  陈无畏 《农业机械学报》2012,43(6):19-24,152

为提高导航路径识别的鲁棒性和实时性,采用了分区阈值二值化、噪声点搜索及滤波等图像处理方法,并对导航路径进行分区逐段识别;在路径跟踪方面,在获取的导航路径图像中选取远端路径和近端路径,以远端路径和近端路径的方位偏差量作为确定目标路径的依据,使提取的导航参数能适应导航路径的变化。根据四轮智能车辆模型进行路径跟踪仿真计算。在此基础上,采用两块数字信号处理器,对基于路径导航的视觉智能车辆进行了设计和试验验证。试验结果表明采用该方法设计的智能车辆具有较好的路径识别和跟踪控制效果。  相似文献   

玛纳斯河流域绿洲盐漠带适生植物筛选及物种多样性研究          下载免费PDF全文

潘旭东  吴英翔  张凤华 《农学学报》2011,(5)

通过筛选适生植物,为退化盐漠带生态系统恢复与重建提供参考物种,达到提高绿洲生态系统稳定性的目的。在盐漠带植物种群结构组成、物种多样性及生态位宽度方面进行了综合分析。结果表明,猪毛菜,柽柳,盐爪爪,骆驼蓬在植物种群生态特征方面优势明显,在盐渍化环境下适应能力较强;结合生态位宽度综合分析,得出土壤盐分维最大,为0.5832,其次是有机质、全氮、水分,综合值分别为0.4800、0.4379与0.2201。由此得出,骆驼蓬、柽柳、猪毛菜、盐爪爪为优势适生种;盐漠带植物物种多样性不高,主要受到盐分与水分限制。  相似文献   

生态系统管理的原则——以美国黄石国家公园为例   总被引：2，自引：1，他引：1  

毕艳玲  冯源 《安徽农业科学》2017,45(8)

讨论了生态系统管理的定义及原则,以美国黄石公园为例,阐述了黄石公园现状及管理目标,分析在建设过程中运用的生态系统管理原则,总结黄石公园目前存在的问题以及未来发展方向,为我国生态系统管理提供参考。  相似文献   

干旱气候变化对西南干旱河谷农业的影响及适应性对策研究   总被引：2，自引：0，他引：2  

鲍文 《农业科学与技术》2011,(5):737-740

在干旱气候变化情境下,西南干旱河谷生态环境的脆弱性和发展滞后,会进一步强化其农业不利的发展环境。为改变干旱河谷农业资源独特但利用粗放的现实,需妥善处理好资源开发与生态环境的关系,明确干旱河谷农业适应干旱气候变化的原则。文章最后提出发展现代草地畜牧业、加强特色农业与农业产业化建设、注重生态农业开发、构建现代农业节水技术推广体系、大力发展服务＂三农＂的第三产业和因地制宜,进行水利设施基础建设和可再生能源开发的西南干旱河谷农业适应性对策建议。  相似文献   

一种新的TS模型辨识算法     

林妹娇  陈水利 《厦门水产学院学报》2013,(3):219-224

提出一种新的TS模型辨识算法.该算法思想：首先采用MCR算法（Mountain C-Regressionmethod）自动确定聚类数目和初始聚类中心,然后采用改进的GK（Gustafon-Kessl）聚类算法得到最优的划分矩阵,再根据最优划分矩阵计算系统前件参数的最优值,最后用自适应粒子群优化算法（Adaptive Parti-cle Swarm Optimization,APSO）对后件参数进行优化.此辨识算法能够用较少的规则数描述给定的未知系统,并且容易实现.仿真实验表明该算法能够实现非线性系统的辨识,并且可获得相对高的精度.  相似文献   

Estimation of Soil Cation Exchange Capacity using Multiple Regression,Artificial Neural Networks,and Adaptive Neuro-fuzzy Inference System Models in Golestan Province,Iran     

《Communications in Soil Science and Plant Analysis》2012,43(6):763-780

Artificial neural networks (ANN) and adaptive neuro-fuzzy inference systems (ANFIS) provide an alternative by estimating soil parameters from more readily available data. In this article, multilayer perceptron (MLP) and radial basis function (RBF) of ANN and ANFIS models were described to estimate soil cation exchange capacity and compared to traditional multiple regression (MR). Moreover, to test the accuracy of previous functions that estimate cation exchange capacity (CEC), five pedotransfer functions (PTFs) were surveyed. The results showed that the accuracies of ANN and ANFIS models were similar in relation to their statistical parameters. It was also found that ANFIS model exhibited greater performance than RBF, MLP, MR, and PTFs to estimate soil CEC, respectively. Finally, sensitivity analysis was conducted to determine the most and the least influential variables affecting soil CEC. The performance comparisons of used models showed that the soft computing system is a good tool to predict soil characteristics.  相似文献   

Managing and learning with multiple models: Objectives and optimization algorithms     

William J.M. Probert  Cindy E. Hauser  Eve McDonald-Madden  Michael C. Runge  Peter W.J. Baxter  Hugh P. Possingham 《Biological conservation》2011,(4):1237-1245

The quality of environmental decisions should be gauged according to managers’ objectives. Management objectives generally seek to maximize quantifiable measures of system benefit, for instance population growth rate. Reaching these goals often requires a certain degree of learning about the system. Learning can occur by using management action in combination with a monitoring system. Furthermore, actions can be chosen strategically to obtain specific kinds of information. Formal decision making tools can choose actions to favor such learning in two ways: implicitly via the optimization algorithm that is used when there is a management objective (for instance, when using adaptive management), or explicitly by quantifying knowledge and using it as the fundamental project objective, an approach new to conservation.This paper outlines three conservation project objectives – a pure management objective, a pure learning objective, and an objective that is a weighted mixture of these two. We use eight optimization algorithms to choose actions that meet project objectives and illustrate them in a simulated conservation project. The algorithms provide a taxonomy of decision making tools in conservation management when there is uncertainty surrounding competing models of system function. The algorithms build upon each other such that their differences are highlighted and practitioners may see where their decision making tools can be improved.  相似文献