基于BP神经网络隧道施工岩爆预测研究

通过综合分析和对以往岩爆判据的研究,将影响岩爆的因素分为三类:围岩岩性、初始地应力、开挖扰动。选取能反映以上三类岩爆因素的4种指标作为岩爆的预测参数,实现了岩爆的多因素预测:利用BP神经网络方法对信息进行大规模处理的能力及很强的鲁棒性和容错性,解决隧道岩爆及其多种影响因素之间关系复杂难以表达、各因素权重的分配不合理问题,实现了根据先验岩爆案例预测未来岩爆情况的目的。在预测模型计算方法的实现上,利用已相当完善的数学软件——Matlab及其神经网络工具箱。计算结果与施工实践对比表明:用该方法及模型进行岩爆预测是可行有效的。     

基于Matlab的数学可视化问题研究及实践*

可视化是同理论、实验、计算一样的重要的科学研究方法。通过对二元函数泰勒公式近似计算中误差控制及计算区域的确定问题进行可视化求解,展示了利用 Matlab的符号可视化及数值可视化进行数学可视化的方法。利用 Matlab非数 nan等实现了曲面的裁剪,可广泛应用于曲面的可视化问题中。     

基于SOM神经网络的民用机场分类方法

机场是综合交通运输的重要节点,是航空运输的重要基础设施。科学地进行机场分类研究对于机场的国家布局规划、机场自身定位和运行策略选择等都具有重要的现实与理论研究价值。利用神经网络技术中的自组织映射（SOM）网络并结合MATLAB软件进行编程对我国主要机场进行聚类分析评价,得出我国主要机场分为8层的主要结论。结果表明,自组织特征映射（SOM）能很好用于我国机场分类,是一种新颖、有效的分类方法。     

Implementing coastal zone management: 1972–1990

Abstract

The implementation history of the Coastal Zone Management Act offers insights into the process of long‐term intergovernmental policy implementation. This five‐stage history is explained as a coproduction process, in which coastal state, environmental, and development advocacy coalitions interacted with congressional committees and the federal coastal office to shape coastal policy and manage coastal development. The coproduction approach proved invaluable during the Reagan assault on the coastal program, when the states and Congress assumed responsibility for keeping the program alive. Acknowledging underlying stakeholder dynamics as the basis for coastal program evaluation could strengthen future coastal management implementation.     

Perceptions of the performance of state coastal zone management programs in the United States. II. Regional and state comparisons

A mail survey of coastal user groups, academics, and state coastal zone management program managers was conducted to determine the perceptions of the performance of state coastal zone management programs relative to the protection of coastal resources, the management of coastal development, the improvement of public access, and the management of coastal hazards. Information on the perceived importance of the selected issues to each of the 24 states being studied was also solicited. Findings on the perceptions of various categories of interest groups, academics, and program managers with respect to the overall performance of state coastal zone management programs in the four issue areas were presented in an earlier article, “Perceptions of the Performance of State Coastal Zone Management Programs in the United States”; (Knecht et al., 1996). The present article draws on a subset of these data—the responses from the coastal user groups and the academics—and presents the findings at the regional and individual state level. In terms of perceived performance of state coastal zone management programs on a regional basis relative to the selected issue areas, the highest rating went to the Great Lakes region for its management of public access. However, the North Atlantic region received the highest performance rating for the three other issue areas: protection of coastal resources, management of coastal development, and management of coastal hazards. Looking at state performance with regard to the coastal issues judged to be of most importance to the states—the protection of coastal resources and the management of coastal development—respondents indicated that states should improve their performance in both areas, with the greatest need related to the management of coastal development. Overall, the states of the North Atlantic, Great Lakes, and South Atlantic regions were perceived to be performing somewhat better relative to the four issue areas than the states in the Pacific and Gulf of Mexico regions. While the data do not shed light on the reasons for these regional differences, we suggest that, in the case of the Pacific region at least, the differences could be associated with higher expectations among the resident population with regard to environmental quality in general and coastal management in particular.     

高速油缸的缓冲结构设计

高速油缸的运行速度极快,需要在行程末端进行缓冲,因此设计一种合理的缓冲结构十分重要。本文参考了4种经典的油缸缓冲结构,借鉴其优点,采用压力补偿方法保证缓冲过程中压力的稳定性,提出了一种通用的缓冲冲头设计方法,并采用Matlab仿真输出了油缸缓冲结构的冲头形线。     

Cargo Container Loading Plan Model and Solution Method for International Air Express Carriers

Abstract

In this article, a cargo container loading plan model is developed based on the operations of FedEx, the international air express carrier. The objective is to minimize total container handling cost, subject to related operating constraints. The model is expected to be a useful planning tool whereby international air express carriers such as FedEx can decide on container loading plans that will lead to lower operating costs, thus enhancing profits and market competitiveness. The model is formulated as a non-linear mixed integer program that is characterized as NP-hard. A solution method is then developed, with the use of the mathematical programming solver, CPLEX, to solve the problem efficiently. To evaluate the model and the solution method, we perform a case study using data from FedEx. The preliminary results indicate that the model and the solution method are both efficient and effective.     

一种基于调用链的Java程序数据竞争静态检测算法

多线程并发程序的广泛使用引发了更多的数据竞争问题,竞争检测对于提高软件质量具有重要意义。论文将竞争静态检测和静态切片分析结合起来,提出了一种类层次的Java数据竞争静态检测算法,该算法利用函数调用层次获得函数调用链,对类域进行分析,找出可能数据竞争,通过静态切片缩小程序分析范围,并结合数据竞争的必要条件,去掉不可能数据竞争。实例表明,该算法可用于指导修复程序中的竞争缺陷。     

定时、定线路上下班拼车方案实现与评价——以淮安为试点

因信息不畅、费用不统一、违法犯罪时有发生和法律界定不明确等问题,导致私家车拼车市场发展缓慢.设计了以淮安为试点的定时、定线路上下班拼车方案,搭建了拼车信息平台,实现了拼车的信息检索、信息配对、双方互选、双方互评等功能,并利用时间费用阻抗评价模型和Vissim仿真对该实施后的方案进行评价,结果表明该方案可使时间费用阻抗减少65%~86%,拼车路网中平均车速提高17.83%、总停车延误时间减少34.84%、总行驶时间减少28.29%、总延误时间减少40.89%、平均延误时间减少29.23%.方案在淮安试点表明,该方案能较大地减少拼车过程中的出行时间和出行费用,改善拼车区域路网交通拥堵状况,提高拼车过程的安全性和经济性.      

梁格体系简支梁桥静载试验应用研究

以沈阳市内某桥为例,介绍桥梁静载试验方案的选择和设计,将有限元引入桥梁检测的理论计算中,使实测结果和理论分析有机结合,可为同类桥梁的检测提供一定的参考和借鉴。