摘要：提出了在飞秒锁模钛宝石激光器腔内产生太赫兹辐射的新设计方案,并给出了太赫兹产生器件的结构参数以及器件的设计原理。新设计的器件把光电导太赫兹偶极天线发射器与飞秒钛宝石激光器的可饱和Bragg反射镜结合在一起,不仅可以提高太赫兹辐射的产生效率,而且可以使飞秒钛宝石激光器自启动锁模.

摘要：为了研究火箭发动机点火过程中动态冲击对固体推进剂的影响,设计了一个基于中止燃烧的模拟点火冲击装置。该装置由点火螺栓、燃烧室和泄压螺栓组成。金属爆破片安装在泄压螺栓的剪切口处,在点火冲击过程中准确控制泄压压力。模拟点火冲击试验的研究对象是圆环柱体形状的poly(BAMO-THF)/AP/Al固体推进剂试样。p-t曲线表明爆破片的泄压压力与测得的压力一致,其误差在±6%。根据p-t曲线计算增压速率,10 MPa下增压速率达到7000 MPa·s^-1,15 MPa下增压速率达到12000 MPa·s^-1,这远远大于固体火箭实际点火过程中的增压速率。在模拟点火冲击试验后,推进剂试样端面(受损表面)镶嵌的粒子受损,而内侧表面(未损表面)仍保持完整的状态。点火冲击试验后,推进剂试样的压缩强度增加,而压缩强度开始增加时的形变值降低。这说明在模拟点火冲击试验后,推进剂受损表面会进一步受损,力学性能也会发生改变。

摘要：This paper presents a scheme to perform QoS management and assure network security by using the trustedrouter based on the Trust Management System. In this trustedrouter, every IP packet is forwarded and queued by its trust value, which is the quantification of the networks expectation for this packets and its owners behavior in the network. We outline the algorithms to calculate the trust value of the trustedrouter and the IP packet. We also introduce the trustbased QoS management algorithm and the deployment of the trustedrouters which carry out this algorithm. The simulation results show that the least trusted IP packets will be dropped to save resources for those highly trusted IP packets. This will ecourage all the elements in the network to keep a good trust record.

摘要：This paper proposes novel multiple-mobile-robot collision avoidance path planning based on cooperative co-evolution,which can be executed fully distributed and in parallel. A real valued co-evolutionary algorithm is developed to coordinate the movement of multiple robots in 2D world, avoiding C-space or grid net searching. The collision avoidance is achieved by cooperatively co-evolving segments of paths and the time interval to pass them. Methods for constraint handling, which are developed for evolutionary algorithm, make the path planning easier. The effectiveness of the algorithm is demonstrated on a number of 2Dpath planning problems.

摘要：提出一种基于频域滤波的城市河道信息提取方法。首先对高分辨率遥感图像进行傅里叶变换得到频谱图,并利用径向和角向分布图分析城市河道的频谱特征。其次,基于城市河道的双线型特点,将其分为边缘特征和低频信息两个部分,并根据周期性纹理的频谱模型和地物频谱能量分布规律确定两个部分的频域识别标志。然后设计相应的扇环形带通log Butterworth滤波器和低通Butterworth滤波器分别对城市河道的边缘特征和低频信息进行提取,并根据该两部分信息实现城市河道信息提取。最后对城市河道信息提取结果进行定量评价,结果表明,本文方法可以有效地实现城市河道的信息提取。

摘要：为了控制碳纳米管阴极发射电子束的形状,设计了4种电子通道来控制电子束轨迹.在设计结构中,其基本结构是一倒置的内壁涂有绝缘材料的漏斗状通道.当初始电子碰撞绝缘壁时,会产生二次电子,而二次电子能改善电子在通道出口处的电子能量分布的均匀性.通过分析和比较电子在通道出口处的状态,得到了一种理想的通道结构.在该结构中,电子在通道出口处的分布更加均匀,电子束的束径较小.而且通过在慢波线外部加磁场的方法来控制电子束在慢波线中的扩散,所加的磁场越大,电子在慢波线中的通过率则越大.通过分析4种不同的结构,在所得到的一种理想的通道结构中,需要较小的磁场就能使得电子在慢波线中的通过率较高.

摘要：The concurrent presence of different types of traffic in multimedia applications might aggravate a burden on the underlying data network, which is bound to affect the transmission quality of the specified traffic. Recently, several proposals for fulfilling the quality of service(QoS) guarantees have been presented. However, they can only support coarse-grained QoS with no guarantee of throughput, jitter, delay or loss rate for different applications. To address these more challenging problems, an adaptive scheduling algorithm for Parallel data Processing with Multiple Feedback(PPMF) queues based on software defined networks(SDN) is proposed in this paper, which can guarantee the quality of service of high priority traffic in multimedia applications. PPMF combines the queue bandwidth feedback mechanism to realise the automatic adjustment of the queue bandwidth according to the priority of the packet and network conditions, which can effectively solve the problem of network congestion that has been experienced by some queues for a long time. Experimental results show PPMF significantly outperforms other existing scheduling approaches in achieving 35--80% improvement on average time delay by adjusting the bandwidth adaptively, thus ensuring the transmission quality of the specified traffic and avoiding effectively network congestion.

摘要：Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

摘要：Gelman and Bloom found that adults and children's object naming was sensitive to how an object was created (man-made or not), but they did not reveal on which specific level of conceptual system this effect was. Using a free-naming task and a force-choice task, two experiments were conducted to test a hypothesis that this effect was specifically on domain level ("artifact/non-artifact" distinction). In Experiment 1, participants were asked to name shortly-depicted objects, rate their confidence, and report their reasons for each naming response. Results showed that most of the naming responses in "man-made" condition were in artifact domain, and most in "natural" condition were in non-artifact domain, although in both conditions names were very divergent on basic level. In Experiment 2, another group of participants were asked to choose one from two names (one in artifact domain and the other in non-artifact domain) to match the same shortly-depicted objects presented in the first experiment. Re-sults of Experiment 1 on domain level were replicated in Experiment 2. These convergent findings supported the hypothesis that the effect of object's origin is specifically on domain level of conceptual system of objects. Reasons explicitly reported for naming responses in Experiment 1 suggested that participants might automatically infer objects' functions in "man-made" condition but not in "natural" condition. Here the function-based hypothesis of artifacts classification is discussed.

摘要：Localization is one of the substantial issues in wireless sensor networks. The key problem for the mobile beacon localization is how to choose the appropriate beacon trajectory. However, little research has been done on it. In this paper, firstly, we deduce the number of positions for a beacon to send a packet according to the acreage of ROI (region of interest); and next we present a novel method based on virtual force to arrange the positions in arbitrary ROI; then we apply TSP (travelling salesman problem) algorithm to the positions sequence to obtain the optimal touring path, i.e. the reduced beacon trajectory. When a mobile beacon moves along the touring path, sending RF signals at every position, the sensors in ROI can work out their position with trilateration. Experimental results demonstrate that the localization method, based on the beacon reduced path, is efficient and has flexible accuracy.