Dynamic Waveband Switching in WDM Mesh Networks Based on a Generic Auxiliary Graph Model

Waveband switching (WBS) is a promising technique to reduce the switching and transmission costs in the optical domain of a wavelength-division multiplexing (WDM) network. This paper considers the problem of provisioning dynamic traffic using WBS in a WDM mesh network. The network of interest is a homogeneous WBS network, where each node has the functionality of WBS. The problem is called the dynamic WBS problem, which involves searching waveband-routes or wavelength-routes for the dynamically arriving traffic requests. The objective is to minimize the total switching and transmission costs in the optical domain. To solve the dynamic WBS problem, an auxiliary graph model capturing the network state is proposed. Based on the auxiliary graph, two heuristic on-line WBS algorithms with different waveband grouping policies are proposed, namely the wavelength-first WBS algorithm based on the auxiliary graph (WFAUG) and the waveband-first WBS algorithm based on the auxiliary graph (BFAUG). Simulation results indicate that WBS is an attractive technique which reduces the overall switching and transmission costs by up to 30% in the network. The results also show that the WFAUG algorithm outperforms the BFAUG algorithm in terms of port savings and cost savings.     

Perceived risk and trust associated with purchasing at electronic marketplaces

Understanding consumer behaviour is of vital importance to consumer-oriented e-business models today. In this paper, we study the relationships between consumer perceptions of risk and trust and the attitude towards purchasing at a consumer-to-consumer electronic marketplace (EM). Typical for EM settings is that consumer behaviour is subject to perceptions of the selling party as well as of the institutional structures of the intermediary that is operating the EM. Building upon the well-established literature of trust, we consider the concepts of intermediary trust and seller trust. We extend this categorisation by introducing the concepts of intermediary risk and seller risk. We developed measurement instruments for intermediary risk and seller risk. All measurement scales have acceptable alphas and are unidimensional. An empirical study is conducted to explore the relationships between the risk and trust types and consumer purchase attitude. The results reveal significant, direct effects of seller trust and seller risk. Second-order effects of intermediary trust and intermediary risk are investigated and reported. The paper concludes with general observations and recommendations for research and practice.     

关于S盒的几点注记

分析了Ｓ盒的平衡性，相关免疫性，严格雪崩性和非线性度的各种可能定义及它们之间的相互关系，提出了要Ｓ盒采用这些准则的定义。     

液罐汽车转弯制动稳定性的研究

该文研究罐装部分液体汽车在转弯制动工况下，由于液体货物质心位置的变化对行驶稳 定性的影响。文中建立了有关力学模型和数学模型，分析研究了罐体内装载不同量液体对汽车转弯制动时横摆角速度的影响规律。     

纳米碳管的电子衍射及其螺旋度测量

本文对电弧放电和催化剂热解碳氢气法制备的多层直形纳米碳管的倒空间及其螺旋度，采用电子衍射进行了研究。结果表明：尽管制备方法不同，两类多层管的结构相似，皆由螺旋和非螺旋的单层石墨管组成；对其倒空间的分析以及系列倾转电子衍射实验证明，衍射图中测得的表观螺旋度值随和射条件而改变，只有在垂直入射条件下该值才代表碳管的真实螺旋度；     

采用模数转换技术提高脉冲激光测距的测时精度

针对脉冲激光测距中计数量化误差影响测时精度的问题,本文提出了采用模数转换技术提高测时精度的方法,并进行了可行性与精度分析,理论与实践结果均表明,该方法易于实现,能够容易地将计数量化误差减少若干个数量级。     

激光熔敷合金层组织及腐蚀磨损特性研究

利用ＣＯ＿２连续激光器在４５钢表面进行了激光熔敷镍基合金、镍基Ｃｒ＿２Ｏ＿３合金和镍基ＷＣ合金，以２Ｃｒ１３不锈钢为对比材料，系统地研究了激光熔敷层在不同冲击速度和腐蚀介质浓度下的腐蚀磨损特性，并根据组织分析、显微硬度测试及腐蚀磨损后的表面形貌观察，探讨了激光熔敷层的腐蚀磨损过程。结果表明：激光熔敷层的腐蚀磨损性能均比２Ｃｒ１３不锈钢好。     

烧成及热处理工艺对钛酸锶铅基热敏材料性能及显微结构的影响

研究了烧成及热处理工艺对钛酸锶铅基热敏材料的阻温特性及显微结构的影响。通过扫描电镜（ＳＥＭ）和能量分散仪（ＥＤＡＸ）分析了材料的显微结构及不同形貌晶粒的成份。通过对组成、烧成及热处理工艺的控制，可得到具有Ｖ型ＰＴＣＲ特性的热敏材料。