RFID技术在国防工程安全管理系统中的应用

结合国防工程安全管理的现状和建设信息化部队的要求,考虑到现有的安全管理模式对人员和装备的精确化管理程度低和实时性差的特点,采用RFID技术、超声波技术和现场总线技术,设计了国防工程安全管理系统.在介绍了系统架构的基础上,详细阐述了系统的软硬件设计,并对管理系统的软件进行了模块和功能的分析.试验结果表明,该系统能实时显示国防工程中的人员和装备信息,在提高国防工程安全管理的精确化水平方面具有广阔的应用前景.     

基于主动学习的模式类别挖掘模型

在实际应用问题中,由于客观世界物质的多样性、模糊性和复杂性,经常会遇到大量未知样本类别信息的数据挖掘问题,而传统方法往往都依赖于已知样本类别信息才能对数据进行有效挖掘,对于未知模式类别信息的多类数据目前还没有有效的处理方法.针对未知类别信息的多类样本挖掘问题,提出了一种基于主动学习的模式类别挖掘模型(pattern class mining model based on active learning,PM_AL)来解决未知类别信息的模式类别挖掘问题.该模型通过衡量已得到的模式类别与未标记样本间的关系,引入样本差异度的方法来抽取最有价值样本,通过主动学习方式以较小的标记代价快速挖掘无标记样本所蕴含的可能模式类别,从而有助于将无类别标记的多分类问题转化成有类别标记的多分类问题.实验结果表明,PM_AL算法能够以较小的标记代价处理无类别信息的模式类别挖掘问题.     

数据采集系统在中间试验工厂的开发与应用

基于中间试验工厂设备多而杂的特点,为了提升中间试验工厂的管理能力和设备利用率,对中间试验工厂的设备功能进行了研究,提出了基于Framework的分布式系统方案。在方案实施中,对与Framework系统不兼容的设备进行了改造升级,成功实现了各种不同接口设备生产数据的采集。并在此基础上开发出了专用的数据采集系统,为中间试验工厂的设备运行、科研调度提供了有力的技术支撑,同时也为其他钢厂设备的引进和数据采集系统的建立提供了可以借鉴的经验。     

Differential geometry based active fault tolerant control for aircraft

This work shows how to use a differential geometry tool to design a novel nonlinear active fault tolerant flight control system for aircraft. The proposed control scheme consists of two main subsystems: a controller, which is designed for the nominal plant, and a fault detection and diagnosis module, which provides fault estimation. A further feedback loop exploits the fault estimation to accommodate faults affecting the system. The estimate convergence and the stability of the active fault tolerant flight controller are theoretically proved. Finally, high fidelity simulations show the effectiveness of the scheme.     

Pricing strategies with reference effects in competitive industries

This paper examines the effect of reference prices on companies operating within competitive industries. We confirm that even with competition, firms optimally price high in the short term to generate a high reference price and then decrease this price over time. Competitors' prices converge toward each other over time, emphasizing the short‐term nature of reference prices. We then show that pricing optimally to take advantage of reference prices generates a positive externality for other firms in an industry, such that competitors may generate higher profit. The longer the focus of a given firm, the more profit the firm generates, but less relative to its competitors. This arises because the externalities created through pricing high to increase reference prices outweigh the benefits of the higher reference prices themselves. If pricing managers are compensated relative to their competition, this suggests that short‐termism may be implicitly encouraged to the detriment of profit.     

Formulations for an inventory routing problem

In this paper, we present and compare formulations for the inventory routing problem (IRP) where the demand of customers has to be served, over a discrete time horizon, by capacitated vehicles starting and ending their routes at a depot. The objective of the IRP is the minimization of the sum of inventory and transportation costs. The formulations include known and new mathematical programming formulations. Valid inequalities are also presented. The formulations are tested on a large set of benchmark instances. One of the most significant conclusions is that the formulations that use vehicle‐indexed variables are superior to the more compact, aggregate formulations.     

Coordination between strategic forest management and tactical logistic and production planning in the forestry supply chain

In this paper, we study the coordination mechanism in the forestry supply chain between strategic forest management and tactical production planning. We first formulate an integrated model to establish a theoretical benchmark for performance of the entire supply chain. It is a mixed integer programming model that involves harvesting, bucking, transportation, production, and sales decisions for both tactical and strategic planning levels. We then present two sequential approaches S‐A and S‐B where the coordination is done through internal pricing. S‐A is the approach currently used in practice where harvesting in the forest is the main driver of the supply chain activities and internal pricing is introduced to control bucking decision in a separate stage. In contrast, S‐B takes downstream demand information into consideration and internal pricing directly influences harvesting decision in the first stage. In order to find the appropriate setting of internal pricing that leads to the system optimum, we suggest two heuristics H‐I and H‐II. The internal pricing in H‐I is based on dual values and in H‐II, it is derived from a Lagrangian decomposition. A real‐life case study in the Chilean forestry industry is used to compare the results of different approaches. It is shown that the new sequential approach S‐B generates as good feasible solution as that obtained from the integrated approach but in much less time. Both heuristics H‐I and H‐II bring about near‐optimal feasible solutions. H‐II also provides optimistic bound of the optimal objective function value, which can be used as a measure of the solution quality.     

基于多尺寸网格的LEACH协议改进

针对低功耗自适应集簇分层型(LEACH)协议中节点采集的数据存在大量冗余和能量消耗不均衡问题,提出一种能量高效路由协议MDG-LEACH。该协议基于虚拟网格和多尺寸网格选取活跃节点,采用综合考虑节点剩余能量和空间分布情况的簇头选择机制,簇头与基站之间根据动态规划方法建立最短传输路由树进行数据传输。仿真结果表明,与LEACH协议以及单剑锋的LEACH改进协议(计算机技术与发展,2013年第2期)相比,MDGLEACH协议在均衡节点能量消耗和延长无线传感器网络寿命方面有了较大提高。     

基于同态哈希函数的云数据完整性验证算法

云存储已经成为未来存储发展的一种趋势,但也带来新的安全挑战,如云服务提供商可能出于某种目的篡改数据。为确保云数据的完整性,提出一种基于同态哈希函数的云数据完整性检查算法。该算法在可信第三方的审计下,通过聚合多个RSA签名,对云数据进行完整性验证。为不泄露用户数据信息,采用同态线性认证与随机掩蔽技术,实现隐私保护。分析结果表明,该算法不仅能有效地抵抗服务器的恶意攻击,而且支持数据更新,与现有审计算法相比,该算法在验证过程中能减少计算代价,在批量审计中降低通信量,从而提高验证的效率。     

供应链环境下安全的RFID认证方案

供应链环境下RFID安全认证方案不仅要保证各节点的隐私安全,还应该满足供应链管理需求。针对现有方案存在不能同时兼顾两者的不足,提出一种基于"双重签名"的认证方案。标签的认证信息先后采用访问密钥和认证密钥进行双重签名生成,只有同时具备这两个密钥才能识别标签身份。该方案既可以实现标签在供应链内的安全传递,又能方便供应链的管理。分析表明,该方案较现有方案优势明显。