摘要：本文研究了两种新型极化和模式分集玻璃介质谐振器天线(DRAs),用于三频段(2.4 GHz、5.2 GHz和5.8 GHz)无线保真(WiFi)应用。研究比较了这两种DRAs以及一种新型空间分集玻璃DRA,以确定哪种分集天线最适合WiFi路由器应用。同时,将这三种分集玻璃DRAs与一个商业空间分集单极对进行比较,以评估玻璃DRA在WiFi路由器应用中的性能。在极化分集天线中,采用双端口馈电方案来激发不同的DRA模式,并通过使用阶梯形DRA来调节DRA模式的频率。对于模式分集设计,引入堆叠式DRA来扩展圆锥和正侧向辐射模的带宽。所有三种新型分集天线均得到了实验验证。在实验中,还测量了三种玻璃分集天线和参考空间分集单极子天线的误码率(BER),并对结果进行了比较和讨论。实验结果表明,在三种天线中,极化分集全向DRA具有最稳定的BER。

摘要：In this paper,we present the design of a new photonic crystal fiber(PCF)gas sensor for evanescent-field sensing in terahertz(THz)wave *** sensor can be used to identify the gas,and its size is very large,so that it is beneficial to fill it with the test *** on simulation,we demonstrate that the gas sensor using PCFs with four noncircular large holes in the cladding has high sensitivity and low loss,the confinement loss is less than 0.007 dB/m,and the bending loss is very *** new PCF gas sensor can detect kinds of gases,for example,if test gas is water vapor,it has obvious absorption peaks in THz band,and the sensitivities of gas sensor are 64%and 73%at 1.097 THz and 0.752 THz,*** to the ultra-low loss and high sensitivity of the model,the novel steering-wheel structured fiber is very suitable for evanescent-field sensing and the detection of chemical and biological products.

摘要：为了针对不同的应用和流量提供服务质量保障和差异化服务,负载均衡和多优先级队列技术被广泛地应用于网络中。在传统网络中,网络管理员经常使用"traceroute"和"ping"工具来检测负载均衡机制或者服务质量策略是否正常工作。然而,由于这些工具并不被现有的OpenFlow交换机所支持,所以还不能够应用于软件定义网络中。此外,traceroute和ping依靠主动发送探测包来探测路径。然而,当负载均衡机制把探测包和所需追踪流的数据包均衡到不同路径时,这些工具将无法探测出流的真实转发路径,更无法测量出真实的路径时延。因此,为了准确的测量链路时延,测量工具必须能够提前找出数据包的真实转发路径。基于此发现,我们提出了一套新的软件定义网络中的流追踪机制"FlowTrace",利用它来追踪任意流量的转发路径以及测量数据流所经历的链路时延。该工具通过收集交换机的流表来计算流的转发路径。然而,如果直接从交换机中查询流表会产生很大的数据平面流量,从而带来巨大的开销。因此,我们提出了一种被动的零开销的流表收集方法来解决该问题。在获得流的真实转发路径后,我们提出了一种新的测量方法来测量不同流的网络时延。最后,实验结果显示我们设计的方法可以准确的找出流的真实转发路径并测量出不同种类流所经历的时延。

摘要：The development of software as a service represents a great advantage for the users of cloud computing, such as users of small, medium or large organizations. All these users possess different characteristics, which must be taken into account as reference for the interface development of a software product. This paper considers the element of a user experience model, with the purpose of getting to know the different features that must be taken into account during the development of software as a service. This also involves the participation of different types of users of the SaaS layer model together with the users’ interaction skills level. This paper offers a framework of the involvement actors in the design of a software interface as a service, with the objective of identifying their participation outside and within the organization. The purpose is to create an interface centered on the user, involving clients and experts to work collaboratively;and get usable software as a service application.

摘要：In 3D models retrieval, feature description and retrieval of non-rigid model face more complex problems due to the isometry transformation of itself. We introduce the hierarchical combination matching into the feature comparison, and build a map between the divided regions of two models, and then achieve accurate feature matching based on patch-by-patch, which successfully introduces the spatial information into feature matching. Verified by experiment, the 3D model retrieval method proposed in this paper based on hierarchical combination matching can make sure more accurate feature matching, so as to enhance the precision of retrieval.