基于模型分析的城市环境下车载移动Ad hoc网络路由协议改进策略

在Manhattan移动模型的基础上,深入分析了车载移动Ad hoc网络路由协议的性能问题.结合AODV路由协议,提出了一种可以量化分析车载Ad hoc网络路由断链率和路由负载的模型.模型分析指出,传统的移动Ad hoc网络路由协议应用于车载Ad hoc网络时性能会严重下降.针对这一问题,提出了一种基于车辆运动方向信息的类AODV路由协议DBAP,将车辆的运动方向信息作为其路由发现过程中的辅助参数,从而显著地增强了路由稳定性.仿真结果验证了模型的正确性,同时证明了本文所提出的DBAP路由协议在城市车载环境中具有较低的路由负载和路由断链率,在协议性能等方面相对于AODV协议具有显著提高.     

基于正态隶属度—属性区间识别模型的岩爆倾向等级预测

岩爆是地下工程开挖面临的关键问题之一,为了准确预测深埋隧洞中岩爆烈度倾向等级,提出了正态隶属度—属性区间识别模型的岩爆预测方法。针对岩爆倾向等级属于典型的多属性有序分割类问题,构建了属性区间识别模型,并将岩爆倾向等级划分为4个等级进行预测。根据岩爆发生的成因和机理,选取应力系数、脆性系数、弹性应变指数和岩石完整性系数作为预测指标,考虑各指标之间、指标与标准等级之间的交互关系,采用正态隶属度函数和Jousselme距离计算评价指标权重。结合13个深埋隧洞工程对该预测模型进行准确性测试,并以双江口水电站SPD9厂房为例进行工程实例验证,该模型预测结果与实际相吻合,证明该模型用于具体工程实践中是可行且有效的,研究结果可为类似深埋隧洞岩爆倾向等级预测提供新的思路。     

铁路宽带移动通信网络规划技术研究

提出了一种铁路宽带移动通信网络的规划方法.该方法参照通用WiMAX网络规划步骤,分析了典型铁路移动通信业务的通信速率和服务质量(QoS)需求,结合铁路使用环境进行了各类业务的链路预算并得出网络覆盖能力,就覆盖能力数据提出了典型铁路设定情况下的容量规划算法原则,最后基于OPNET软件对典型铁路WiMAX网络的规划方案进行了仿真.     

The social network in marijuana-using groups

Three ongoing marijuana-using groups were studied in their natural environments. Group characteristics and the relationship of each member to individuals within the group were assessed, in addition to the members' primary social roles outside the group. The relationship of sociometric data to user characteristics was determined. The social and drug histories of the three groups were highly similar. Despite high levels of drug use, the most frequent reason for group participation was friendship, and diverse social activities occurred in the group. Social resources outside the group were minimal, whereas enduring, positive relationships characterized each group. Popularity was related to frequency of group participation, but not to extent of drug use. The function of marijuana-using groups in fulfilling interpersonal needs is discussed.     

车载通信网中基于DSR分层机制的移动代理路由策略研究

分析了现有动态源路由(dynamic source routing,DSR)协议机制以及在车载通信网路由发现中存在的问题,提出一种基于DSR分层机制的移动代理路由策略(cluster mobile agent-dynamic source routing,CM-DSR),并对设计的算法进行仿真实验.结果表明,所提出的CM-DSR协议与DSR路由协议相比较,较大幅度地降低了端到端的传输延迟,减少了路由请求次数,包的提交率也有一定程度的提高.     

The social network of the psychotherapy patient.

Examined the social networks of psychotherapy patients to find factors that affected the patients' contributions to the therapeutic process and the effectiveness of treatment. 265 outpatients (aged 18–61 yrs) completed measures of their individual ties, their collective networks, and their network support. Ss were neither interpersonally bereft nor socially isolated. Most Ss had close friends, and most had an ongoing romantic relationship. Most had at least 1 confidant with whom they discussed entering therapy, and most experienced nurturing support from their significant others. Ss were embedded in a network of significant and meaningful ties that could potentially influence their participation in the therapeutic process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social roles as mechanism for psychological need satisfaction within social groups.

The authors explored ways in which needs for autonomy and relatedness can be simultaneously met within the context of group life. Specifically, it was hypothesized that social role performances provide means of both expressing the self and connecting with group members. Consistent with the assumption that autonomy and relatedness are complementary rather than conflictual, these needs were positively correlated in all 5 studies. Consistent with the authors' assumption that these needs are both important, feelings of autonomy and relatedness in social roles independently predicted subjective well-being, as measured by concurrent (Studies 1 and 3), peer-report (Study 2), and longitudinal (Studies 4 and 5) methodologies. Study 5 showed that participants whose characteristics matched an assigned role experienced more autonomy and relatedness and thus more positive mood during a group task. Implications for optimal functioning in group contexts are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-construal moderates age differences in social network characteristics.

In this study, the authors examined age differences in social network characteristics (SNC) among Hong Kong Chinese. The sample consisted of 596 Chinese adults, ranging from 18 to 91 years old. Age was positively associated with close social partners and negatively associated with peripheral social partners. For individuals who were more likely to define the self as interconnected with others (i.e., interdependent self-construal), increasing age was associated with a greater number of close social partners. The negative association between age and the number of peripheral social partners, well-documented in the Western literature, was found only among Chinese adults with lower interdependence but not among those with higher interdependence. These findings highlight the importance of examining the underlying mechanism rather than a particular pattern of SNC across cultures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Community intervention with the elderly: a social network approach

A technique is described for using the advantages of a social systems approach when working with elderly persons in psychiatric distress. The technique is based on the assumption that the solution to a variety of human predicaments lies within the collective instrumental and affective resources of the client's social network. The vehicle for accomplishing this objective is the "Network Session" during which a mental health professional meets with the elderly person and members of his/her social network to help resolve the difficulty. A case report demonstrating use of the technique is included.     

Gender differences in predicting loneliness from social network characteristics.

Examined gender differences in predicting loneliness from measures of social network structure and a measure of perceived social support. Study 1 (including 179 undergraduates and 124 students [mean age 29 yrs]) used the traditional measure of network density in which the number of relationships among network members was determined. Study 2 (including 143 undergraduates [17–46 yrs]) used an index of density that assessed the extent of closeness of relationships between pairs of network members. Uniformly, male Ss with more highly interconnected, cohesive sets of friends reported themselves to be less lonely, whereas density had little relation to loneliness in females. Results are discussed as possibly indicating that men and women use different standards in evaluating whether they are lonely. It is suggested that men may use more group-oriented criteria in evaluating loneliness, whereas women focus more on the qualities of dyadic relationships. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于手机移动传感网络的矿震群智定位方法

为提高矿震监测系统定位精度,减少监测盲区,降低监测成本,基于分布式的思想,提出一种基于手机移动传感网络的矿震定位方法。首先以矿区附近工人及家属等使用的智能手机建立手机移动传感网络,其次对模拟震源点网格化,构建基于标准差的目标函数,提出改进的萤火虫寻优策略,并使用拐点回溯法以及手机移动传感网络排除离散点策略(EDPS)降低定位误差,最后通过矿震模拟实验进行验证。实验结果表明:在手机移动传感网络无到时误差理想情况下,所有模拟震源点都能够准确收敛至震源位置,定位误差小于1 m。但手机相较于检波器到时误差较高,且定位误差与到时误差具有相关性,当手机到时误差为?1.0～1.0 s时,传统算法定位误差为216 m,无法实现高精度定位。通过研究目标函数值与定位误差间的关系,提出并使用拐点回溯法以及EDPS两种优化方法,算法绝对定位误差降低至73 m,当到时误差为?0.2～0.2 s时,绝对定位误差降低至17 m,定位精度提高76.1%。基于手机移动传感网络的矿震群智定位方法,为矿震监测提供了一种新方法,未来可考虑与井下微震系统联合,在节省监测成本、提高定位精度方面具有重要意义。      

Real-time neural network based camera localization and its extension to mobile robot control

The feasibility of using neural networks for camera localization and mobile robot control is investigated here. This approach has the advantages of eliminating the laborious and error-prone process of imaging system modeling and calibration procedures. Basically, two different approaches of using neural networks are introduced of which one is a hybrid approach combining neural networks and the pinhole-based analytic solution while the other is purely neural network based. These techniques have been tested and compared through both simulation and real-time experiments and are shown to yield more precise localization than analytic approaches. Furthermore, this neural localization method is also shown to be directly applicable to the navigation control of an experimental mobile robot along the hallway purely guided by a dark wall strip. It also facilitates multi-sensor fusion through the use of multiple sensors of different types for control due to the network's capability of learning without models.