Tiered bandwidth reservation scheme for multimedia wireless networks

It is important to provide quality of service (QoS) guarantees if we want to support multimedia applications over wireless networks. In this paper, considering the features of tiering in sectored cellular networks, we propose a novel scheme for bandwidth reservation to approach QoS provisioning. By predicting the movement of each connection, the reserving of bandwidth is only required in needful neighboring cells instead of in all neighboring cells. In addition, an admission control mechanism incorporated with bandwidth borrowing assists in distributing scarce wireless bandwidth in more adaptive way. Through mathematical analysis, we proof the advantages of tier‐based approach and the bound for the selection of tiered boundary. The simulation results also verify that our scheme can achieve superior performance than traditional schemes regarding no bandwidth reserving, fixed bandwidth reserving, and bandwidth borrowing in sectored cellular networks when performance metrics are measured in terms of the connection dropping probability (CDP), connection blocking probability (CBP), and bandwidth utilization (BU). Copyright © 2008 John Wiley & Sons, Ltd.     

系统仿真技术在车用燃气定价决策中的应用

按照系统分析的思路及程序对出租车和加气站所构成的车一站系统进行分析,结合西安市燃气汽车发展的具体情况构建了系统动力学模型,对车用燃气定价问题及外界环境对价格的影响进行了系统仿真,得出了相关政策建议。     

现代名优白酒市场营销策略选择的研究

市场是白酒企业得以生存的根本保障,成功开发市场,不断扩大市场份额,提高市场占有率是白酒企业得以发展的前提和基础。白酒市场营销策略是占有市场的基础,市场营销策略决定着企业的兴衰成败,白酒企业在实施市场营销的过程中,必须采取科学全面的营销策略。     

RWCE算法中采用单元重构策略激励换热网络结构优化

应用强制进化随机游走算法优化换热网络的过程中,通过监测最优结构中换热单元优化进程,探究总体结构进化特点,发现存在换热单元先入为主的现象,主体结构稳固难以被突破,导致换热网络优化进入“停滞”状态。基于此,提出了换热单元重构策略,该策略旨在增强结构变异能力,经过一定阶段概率性消除结构中既有换热单元,腾出结构进化空间,再依据约束条件重新构建换热单元,既丰富了结构多样性又扩大了搜索域。此外建立优化状态监测指标,维持结构较高的变异活性,增强算法全局寻优能力。最后将该策略加入算法流程优化多个换热网络实例,总结分析其作用机理,所得结果均优于现有文献结果,证实了该策略的有效性。     

基于XML技术的通用数据采集解决方案研究

对于行业中心数据库来说,数据的采集是其提供决策支持的根本。本文详细分析了目前存在的一些数据采集的方法,指出了这些方法存在的不足。然后提出一种完全基于XML技术的通用数据采集解决方案。该方案具有通用性,可以较大程度地提高信息采集的效率,同时较好地降低了采集系统的维护成本。     

‘To Go Beyond or Not to Be’ Unsolicited Architecture: An Interview with Ole Bourman

The complex dynamics of today's architecture require a deep intellectual freedom. This is something that Dutch architectural critic Ole Bouman espouses through his provocative writings and lectures and his advocacy of ‘unsolicited architecture’. Luca Guido invited Bouman to reflect on what it means to be an architect today and how it might be possible to pursue critical practice beyond the conventional construction processes. Copyright © 2009 John Wiley & Sons, Ltd.     

一种新型低存储二维离散小波变换架构

由于现有二维离散小波变换硬件结构通常存在输入图像存储空间较大和硬件资源消耗较高的问题,制约了系统的硬件效率提升．为此,调整了输入数据的时序,设计了一种基于提升算法的新型二维离散小波变换架构．采用了横向并行、数据错位的三输入扫描方法,降低了处理模块的硬件资源消耗,同时消除了片外存储的需求．对于一幅长宽为N×N的输入图像,系统的总存储需求缩减为9N字节．经过硬件分析,对比其他现有结构,本架构的硬件效率提升了8％以上．     

无人机中继广播通信系统航迹优化方法

为了提高固定翼无人机中继广播通信系统链路传输的连通性,提出中继无人机航迹优化方法．首先分析了无人机中继广播通信系统单用户节点的中断概率近似计算公式,并以此为基础推导出了服务区域内所有用户节点平均中断概率的近似计算公式; 然后基于服务区域内用户节点平均中断概率最小化准则提出了中继无人机的航迹优化方法,并进一步给出了最优航迹下单个用户节点的精确中断概率计算公式;最后通过计算机仿真验证了所提出方法的有效性．     

生命周期大数据驱动的复杂产品智能制造服务新模式研究

在分析当前制造企业产品生命周期管理面临的挑战与现有制造服务模式不足的基础上,针对复杂产品生命周期数据呈现的大数据特性,提出一种生命周期大数据驱动的复杂产品智能制造服务新模式,并设计了一种体系构架。以产品生命周期为主线,提出并详细阐述了生命周期大数据驱动的智能制造服务新模式的关键技术体系与实现框架,包括制造和运维动态数据驱动的产品与服务设计、实时多源数据驱动的生产过程分析与优化、面向服务的运维数据故障演化分析与预测等。通过上述体系构架及关键技术的实施,可有效促进生命周期各阶段数据和知识的集成应用,进而构建一种产品设计闭环创新、生产过程实时优化、运维服务动态预测的产品生命周期管理与运作机制,以提升全制造流程和全生命周期管理的智能决策能力。所提体系和框架可为生命周期大数据驱动的智能制造服务研究和应用提供一种参考模型。     

Data-driven intelligent monitoring system for key variables in wastewater treatment process

In wastewater treatment process (WWTP), the accurate and real-time monitoring values of key variables are crucial for the operational strategies. However, most of the existing methods have difficulty in obtaining the real-time values of some key variables in the process. In order to handle this issue, a data-driven intelligent monitoring system, using the soft sensor technique and data distribution service, is developed to monitor the concentrations of effluent total phosphorous (TP) and ammonia nitrogen (NH₄-N). In this intelligent monitoring system, a fuzzy neural network (FNN) is applied for designing the soft sensor model, and a principal component analysis (PCA) method is used to select the input variables of the soft sensor model. Moreover, data transfer software is exploited to insert the soft sensor technique to the supervisory control and data acquisition (SCADA) system. Finally, this proposed intelligent monitoring system is tested in several real plants to demonstrate the reliability and effectiveness of the monitoring performance.