五道河林场次生用材林龄级结构调整及评价

龄级结构是森林结构中最重要的结构之一 .该文对河北省五道河林场的次生用材林的龄级结构用数学规划方法进行了调整 ,并用欧氏距离和平衡率 2方法对龄级结构调整的结果进行了评价 ,效果良好     

APPLICATION OF A CONVEX NETWORK FLOW PROGRAMMING TO THE ECONOMIC POWER DISPATCH

Analyses the characteristics of convex network flow programming of the economic power dispatch with security and presents a rapid algorithm. The numerical examples are given to demonstrate the effectiveness of the algorithm.     

Descending Dimension Algorithm of Nolinear Programming Problem with Linear Inequality Constraints

The general nonlinear programming with linear constraints was investigated. In the algorithm, the method of contributing set was used. Comparing with the general contributing set method, the descending dimension method was used to solve the sub-problem with equality constraints in iterative procedure and the problem with inequality constraints. The algorithm is effective by the numerical test. Finally, it was proved that the iteration points are descending, when the objective functions are convex.     

农业工程规划及农业工程项目

针对国家开展农业大规模建设的需要,提出了制订农业工程规划及农业工程项目的问题;阐述了地区经济发展战略与农业工程规划、农业工程项目的关系,农业工程规划与项目的内容和特点以及规划、计划与项目的联系和区别;最后讨论了几种系统工程方法在制订规划工作中的应用问题。     

单井滴灌干管管网的优化设计

为解决单井运行滴灌干管管网的优化设计问题，提出了干管管网优化设计的数学模型，并采用动态规划法对该问题进行求解。所提出的方法，不仅能得出一个优化的干管管网，而且还能确定出所需水泵扬程及流量，并确定水泵型号。     

车辆行驶的表层沙土非线性弹性本构模型的试验研究

以车辆行驶的表层沙土为研究对象，用土壤动态三轴仪对车辆行驶的表层沙土的力学特性进行了试验研究，建立了适于车辆行驶的表层沙土的非线性弹性邓肯（Ｄｕｎｃａｎ）本构模型。研究结果表明它能够较好地反映车辆行驶的表层沙土的本构关系，为车辆行走机构与表层沙土相互作用的力学计算分析和研制沙漠运输车辆奠定了基础     

Locating and protecting critical reserve sites to minimize expected and worst-case losses

There has been much recent interest in the development of systematic reserve selection methods that are capable of incorporating uncertainty associated with site destruction. This paper makes a contribution to this line of research by presenting two different optimization models for minimizing species losses within a planning region. Given limited acquisition budgets, the first minimizes expected species losses over all possible site loss patterns outside the reserve network while the second minimizes maximum species losses following the worst-case loss of a restricted subset of nonreserve sites. By incorporating the uncertainty of site destruction directly into the decision planning process, these models allow a conservation planner to take a less defensive and more strategic view of reserve selection that seeks to minimize species losses through the targeted acquisition of high-value/high-risk sites. We compare both of these methods to a more standard approach, which simply maximizes within reserve representation without regard for the varied level of threat faced by different sites and species. Results on a realistic dataset show that significant reductions in species losses can be achieved using either of these more intelligent modeling frameworks.     

目标规划在国营林业局生产管理中的应用

本文采用目标规划的数学方法,针对林业生产经济效益、生态效益和社会效益的综合要求,本着以林为主多种经营、森林资源永续利用的原则,建立了国营林业局生产管理系统的规划模型。实例论证表明,所建模型具有整体性、动态性、灵活性和可分析性等优点,可以统筹林业生产管理活动,适用于国营林业局制定科学的生产管理方案。     

人工用材林最优密度控制模型

以抛物线型密度效应模型为前提，针对人工用材林生长系统的特点，用最优控制方法建模，以动态规划方法求解，导出最优密度控制模型。模型具有幂次数可变、适应性较强、疏伐间隔期可变和实际应用较方便等特点。模型在贵州马尾松人工用材林中的应用结果表明，模型计算结果符合人工用材林生长规律，并与实地试验吻合，表2参11。     

约束优化问题的遗传算法求解

应用遗传算法基本原理,采用锦标赛选择、算术交叉、均匀交叉、均匀变异和非均匀变异算子,设计了一般非线性规划和整数规划问题的通用求解算法,应用Matlab6.0编制了相应的求解软件。实例测试结果表明,该算法可以应用于一般的非线性规划和整数规划问题。