A probabilistic approach to stability and stabilization of networked control systems

In this paper, a probabilistic approach is proposed to study the modeling, stability, and stabilization problems for networked control systems (NCSs) with simultaneous random network communication delay and data dropout. Different from existing modeling approaches, the proposed NCSs model naturally captures the stochastic characteristics of the considered NCSs by taking into account the effects of the random network communication delay and data dropout. Based on the developed NCSs model, necessary and sufficient conditions of stability analysis, state, and output feedback stabilization problems are tackled. Moreover, necessary and sufficient stability and stabilization conditions are also presented for the case when the occurrence probabilities of delay and data dropout are partially known. Finally, three numerical examples are provided to demonstrate the effectiveness and the reduced conservatism of the proposed method. Copyright © 2014 John Wiley & Sons, Ltd.     

基准信号的低相噪声长距离光纤传输设计

介绍了基准光传输设备的基本组成和原理,指出低相噪长距离光纤传输中的问题所在,并提供了解决问题的方法,即数模混合器件的选择及改进滤波器设计.     

WIDESTARII卫星移动通信方案研究

WIDESTAR II系统为了更好的满足用户需求,在WIDESTAR系统的基础之上对移动终端、基站设备以及核心网节点进行了再次开发,从而实现了更高的传输速率以及与IMS或其他通用IP技术的灵活兼容。本文中,将首先对WIDESTAR II系统进行简要的介绍与分析,然后,对此系统所采用频谱效率提高方法、IP兼容技术以及时延降低策略等卫星移动通信机制进行研究与验证。     

An efficient utilization of intermittent surface–satellite optical links by using mass storage device embedded in satellites

Recently, earth observation system by using satellite network has attracted much attention due to its wide coverage and disaster resistance. Although the system is useful for collecting various data, which have an effect on a natural disaster, ecology and so forth, earth observation satellite hardly send the collected observation data to the ground station. This is because that the earth observation satellite needs to orbit near surface of the earth to get high-precision data, and it limited the time that can be used to send the observed data traffic to the ground station. Additionally, the amount of the observed data drastically increase in these days. Thus, we focus on the data relay satellite using optical communication in this network. By relaying observed data to traffic to the relay satellite, which has geostationary orbit, it is possible to increase the chance of sending data for the observation satellite due to the wide coverage of the relay satellite. In addition, laser light that is used in optical communication in satellite network has high frequency and it can deliver large data compared with radio wave. However, laser light is greatly influenced by atmosphere, and optical link capacity between satellite and ground station drastically changes according to weather condition. Therefore, we propose a new data traffic control method to use the network constructed by satellites which has mass storage device effectively according to the condition of optical downlink between satellite and optical ground station. The effectiveness of the proposed method is evaluated with numerical result.     

Virtual shopping and unconscious persuasion: The priming effects of avatar age and consumers’ age discrimination on purchasing and prosocial behaviors

This study examined how operating elderly or young avatars affected shoppers’ product perceptions and purchasing behaviors. It also investigated how virtual shopping experiences translated into prosocial behavior regarding a nonprofit organization supporting the elderly. Operating elderly avatars influenced shoppers’ product choice and walking speed while shopping compared to operating younger avatars. In addition, operating elderly avatars positively affected participants’ attitudes and willingness to donate to and volunteer for a nonprofit organization supporting the elderly. Statistical interactions between avatar age and a shopper’s ageism on behavioral and persuasion outcomes were also confirmed, and these findings implied an assimilation/contrast effect influenced by a shopper’s preexisting prejudices toward the elderly.     

REST API技术及在移动通信网络管理中的应用

介绍了目前最炙手可热的REST架构风格，该风格顺应Web2.0的兴起，完美的匹配了云计算时代来临的可扩展要求，在各种应用场景中都得到了充分的表现。根据其技术特点，分析了该风格的API在移动通信网络管理中的应用，从网管系统内部、网管系统之间以及网管系统与上层APP应用之间等多方面对是否适用于REST风格以及如何在合适的位置使用REST API进行了分析。     

一种实用的多数据库量子信息检索协议

针对目前量子私有信息检索不能适用与云存储的多数据库问题,基于现在成熟的量子密钥分发方法,提出了一种适合在多数据库环境下,实用的量子私有信息检索协议。对于不同大小的数据库,协议可通过调节参数θ和k,在保证数据库安全及用户隐私的情况下,完成信息的检索。性能分析结果表明,协议的通信复杂度低,检索成功率高、易于实施。     

In vivo Kinetic Biodistribution of Nano‐Sized Outer Membrane Vesicles Derived from Bacteria

Evaluation of kinetic distribution and behaviors of nanoparticles in vivo provides crucial clues into their roles in living organisms. Extracellular vesicles are evolutionary conserved nanoparticles, known to play important biological functions in intercellular, inter‐species, and inter‐kingdom communication. In this study, the first kinetic analysis of the biodistribution of outer membrane vesicles (OMVs)—bacterial extracellular vesicles—with immune‐modulatory functions is performed. OMVs, injected intraperitoneally, spread to the whole mouse body and accumulate in the liver, lung, spleen, and kidney within 3 h of administration. As an early systemic inflammation response, increased levels of TNF‐α and IL‐6 are observed in serum and bronchoalveolar lavage fluid. In addition, the number of leukocytes and platelets in the blood is decreased. OMVs and cytokine concentrations, as well as body temperature are gradually decreased 6 h after OMV injection, in concomitance with the formation of eye exudates, and of an increase in ICAM‐1 levels in the lung. Following OMV elimination, most of the inflammatory signs are reverted, 12 h post‐injection. However, leukocytes in bronchoalveolar lavage fluid are increased as a late reaction. Taken together, these results suggest that OMVs are effective mediators of long distance communication in vivo.     

Secondary school educators' perceptions and practices in handling cyberbullying among adolescents: A cluster analysis

School educators play an important role in cyberbullying management. Since scarce earlier research indicated low perceived competence of school educators in handling cyberbullying, more insight is needed in what determines their actions and how to improve these practices. This study assessed school educator practices, their perceptions and context factors from a behavior change theoretical framework, and investigated educator clusters related to this. An online survey was conducted among 451 secondary school educators (teachers, principals, school counselors). School educators mostly used recommended actions (i.e. conversations with pupils, enlisting professionals for support, parental involvement, providing supportive victim advice). Four educator clusters were identified: ‘referrers’ (65%), ‘disengaged’ educators (14%), ‘concerned’ educators (12%) and ‘use all means’ educators (9%). The first two clusters were less adept at handling cyberbullying and comprised mostly teachers, particularly indicating a need for training teachers. Our findings show a need for tailored educator training, e.g. by job position, gender, school size and grade. The behavior change theoretical framework can help target educators' particular needs.     

Event-triggered controller design of nonlinear discrete-time networked control systems in T-S fuzzy model

This article is concerned with event-triggered fuzzy control design for a class of discrete-time nonlinear networked control systems (NCSs) with time-varying communication delays. Firstly, a more general mixed event-triggering scheme (ETS) is proposed. Secondly, considering the effects of the ETS and communication delays, based on the T-S fuzzy model scheme and time delay system approach, the original nonlinear NCSs is reformulated as a new event-triggered networked T-S fuzzy systems with interval time-varying delays. Sufficient conditions for uniform ultimately bound (UUB) stability are established in terms of linear matrix inequalities (LMIs). In particular, the quantitative relation between the boundness of the stability region and the triggering parameters are studied in detail. Thirdly, a relative ETS is also provided, which can be seen as a special case of the above proposed mixed ETS. As a difference from the preceding results, sufficient conditions on the existence of desired fuzzy controller are derived to ensure the asymptotic stability of the closed-loop system with reduced communication frequency between sensors and controllers. Moreover, a co-design algorithm for simultaneously determining the gain matrices of the fuzzy controller and the triggering parameters is developed. Finally, two illustrative examples are presented to demonstrate the advantage of the proposed ETS and the effectiveness of the controller design method.