市政道路施工的有效管理措施

本文对市政工程道路建设管理存在的弊端和遇到的问题进行了简要分析,建议市政道路建设加强监督管理措施,可以有效地提高工作效率,并对市政道路施工后的质量施工管理进行了阐述。     

Effects of sheet thickness and material on the mechanical properties of flat clinched joint

Frontiers of Mechanical Engineering - The flat clinching process is attracting a growing attention in the joining field of lightweight materials because it avoids the geometric protrusion that...     

机械臂的改进固定时间滑模控制方法设计

当机械臂末端对给定轨迹进行跟踪控制时,跟踪误差收敛速度容易受初始跟踪误差大小的影响,针对这一问题设计了一种适用于机械臂模型的改进固定时间滑模轨迹跟踪控制策略.在快速终端滑模面的基础上,设计了一种固定时间滑模面,从而使得控制器具有固定时间收敛特性并给与证明;针对滑模控制伴随抖震的特性,对滑模控制器的趋近律进行了抑制抖振的改进,使得趋近律具有一定的自适应性.通过对二自由度机械臂的仿真实验,验证了在系统含有未知扰动的情况下,设计的改进固定时间滑模控制器能够在固定时间内使得机械臂末端轨迹跟踪误差快速收敛,且通过控制器参数的调整能够达到更快的收敛速率.通过仿真对比,验证了论文设计方法的收敛速率要快于快速终端滑模控制方法.     

无人艇群协同作业功能测试与评估系统设计

针对无人艇群协同作业能力的评价缺少有效测评方法问题,设计了一种无人艇群协同作业测评系统.采用信息优势度量法作为测评方法,根据无人艇群协同作业的特点,提出包含5个不同评价指标、将无人艇群协同作业能力水平评价转变为可以细分度量的数据值.采用MatlabGUI可视化面板构建可与用户交互的测评系统面板并进行验证实验.结果表明,测评系统能够对测试数据给出符合预期的处理结果,对无人艇群协同作业能力提升具有指导价值.     

大功率压接式功率器件用水冷基板研究

针对大功率压接式功率器件的散热需求,进行用于其冷却的水冷基板设计与研究.根据压接式功率器件用水冷基板结构特点和技术要求,设计内部冷却流道为螺旋线结构,使用UG软件建立三维模型,应用仿真软件计算得出其温度场分布云图和压力分布云图,并对产品进行热性能试验和压接试验.结果显示,表面研制的水冷基板仿真计算结果与试验结果相近,热阻和流阻参数指标满足技术条件要求,功率模块区域均温性良好,且产品可靠性满足设计及实际运用要求.该研究内容为类似结构水冷基板设计提供参考.     

堆用中子探测器校验装置设计

本文采用MCNP4c程序,对影响堆用中子探测器校验装置的各项参数进行计算,确定了装置慢化体厚度、引出孔径等一系列参数。对装置的屏蔽性能进行了计算,结果表明装置屏蔽性能满足标准要求。     

TFSM‐based dialogue management model framework for affective dialogue systems

A new dialogue management model for affective dialogue system, which aims to provide a service of information inquiry and affective interaction, is proposed in this paper. First, we construct two finite state machines (TFSM) to model the user and the system, respectively, and simulate the dialogue process as an information exchange between the two state machines. All possible state transitions in dialogue and its probabilities of the user are summarized as a user model, which is helpful for the system to inference and predict the user's internal states. Second, we further discuss the implementation methods of information inquiry and emotional response modules. Finally, we employ the return function of partially observable Markov decision processes (POMDP) model to analyze and evaluate the TFSM‐based dialogue management model. The experimental results not only show the relationships between the average returns, recognition error rates, and state transition probabilities but also confirm that our TFSM‐based dialogue management model outperforms the conventional FSM model. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Self‐adaptive 3D pairwise view registration by surface‐fitting and hill‐climbing method

A self‐adaptive 3D pairwise view registration method is presented. Coarse registration of neighboring views is achieved according to their common continuous nonflat areas. These areas are calculated by local least‐square (LS) surface fitting. Then, the principle of point‐to‐surface projection is used to search for the corresponding points, where the local moving least‐square (MLS) surface is employed. Finally, multidimensional optimization based on the technique of hill‐climbing is performed to refine the coarse registration. Experimental results show that this method gives good noise immunity and requires simple computation process and very few manual interventions. Thus it is suitable for large‐scale free‐form surfaces lacking obvious geometric characteristics. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Exploiting opinion distribution for topic recommendation in Twitter

The popular social networking service Twitter provides rapidly updated information and online trends, which enriches and benefits people's daily life. At the same time, how to find out the really interesting and relevant topics from the massive streams of tweets, to provide precise topic recommendation for users, becomes a challenging problem in the real world. Previous collaborative filtering methods give solutions to traditional recommendation tasks considering users' positive reviews to help recommend items. However, to the problem ‘what is interesting to whom’ in Twitter, positive opinions toward a topic do not imply that the user will be interested in it with high probability, for the user probably prefers to know those controversial topics or hot events with a large number of negative posts. In this paper, we exploit the characteristics of topical opinion distribution for improving the performance of recommendation. The experimental results on a real‐world Twitter dataset show that the proposed opinion‐distribution‐aware topic recommendation (ODA‐TR) approach outperforms the state‐of‐the‐art collaborative recommendation methods. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A dynamic paging scheme for long‐term evolution mobility management

In long‐term evolution, the service area is partitioned into several tracking areas (TAs), which comprise one or more cells (the radio coverages of base stations). The TAs are grouped into TA list (TAL). When an incoming call arrives, the network attempts to connect to the user equipment (UE) by paging the cells in the UE's TAL, which may incur large paging traffic that significantly consumes the limited radio resources. To resolve this issue, this paper proposes a dynamic paging scheme that determines the paging sequence of cells in real time according to the UE movement and call behavior. We compare the performance of the dynamic paging with that of the previously proposed Cell‐TA‐TAL (CTT) paging. Our study indicates that the dynamic paging outperforms the CTT paging when movement pattern is regular and the UE moves frequently. Copyright © 2013 John Wiley & Sons, Ltd.