A Reconfiguration Trial on the Platform of Allied Information for Wireless Converged Networks

PAl （platform of allied information） promotes persistent innovation and application of the wireless technologies among different institutes, based on open, safe and controllable network architecture. The platform architecture, unified interface, security mechanism, and reconfiguration are designed to achieve the convergence of various wireless experimental resources. In this paper, the reconfiguration mechanism is designed and a reconfiguration trial is implemented based on the PAI, to verify the ability of integrating experimental resources in the related units.     

A genetic algorithm for finding a path subject to two constraints

Multi-constrained routing (MCR) aims to find the feasible path in the network that satisfies multiple independent constraints, it is usually used for routing multimedia traffic with quality-of-service (QoS) guarantees. It is well known that MCR is NP-complete. Heuristic and approximate algorithms for MCR are not effective in dynamic network environment for real-time applications when the state information of the network is out of date. This paper presents a genetic algorithm to solve the MCR problem subject to transmission delay and transmission success ratio. Three key design problems are investigated for this new algorithm, i.e., how to encode the problem in genetic representation, how to avoid the illegal chromosomes in the process of population initialization and genetic operation, and how to design effective genetic operator. We propose the gene structure (GS) to deal with the first problem, and the gene structure algorithm (GSA) to generate the GS. Based on the GS, we provide the heuristic chromosome initialization and mutation operator to solve the last two problems. Computer simulations show that the proposed GA exhibits much faster computation speed so as to satisfy the real-time requirement, and much higher rate of convergence than other algorithms. The results are relatively independent of problem types (network scales and topologies). Furthermore, simulation results show that the proposed GA is effective and efficient in dynamic network environment.     

Improving trust modeling through the limit of advisor network size and use of referrals

This paper explores potential improvements to the trust modeling of agents in multi-agent systems when a social network of advisors is employed as part of the trust modeling, and in particular, examines means of optimizing the number of advisors that should be maintained in the social network. We propose three such improvements, two directly relating to the limit of advisor network size by either setting a maximum size for a buyer’s advisor network or setting a minimum trustworthiness threshold for agents to be accepted into that advisor network, and a third which uses an advisor referral system in combination with one of the first two network-limiting techniques. We provide experimental results in defence of our approach for two distinct trust modeling systems, and show how these optimizations can improve, sometimes significantly, the accuracy of different trust models (in the context of electronic marketplaces). We believe that the proposed techniques will be very useful for trust researchers seeking to improve the accuracy of their own trust models by setting the size and composition of advisor networks.     

Effective protocol for generation of multiple atoms entangled states in two coupled cavities via adiabatic passage

A scheme is proposed to deterministically generate a two atoms entangled state and a multiple atoms W state in two coupled cavities by one step. In the scheme, the populations of cavities and atoms excited are negligible under certain conditions with an adiabatic passage along a dark state. Furthermore, the interaction time needs not to be controlled exactly and keeps unchanged with the increasing of the number of qubits. In consideration that only one of the atoms needs to be operated, the realization in experiment can be relatively easier.     

Oscillating bubbles in teardrop cavities for microflow control

Microstreaming generated from oscillating microbubbles has great potential in microfluidic applications for localized flow control. In this study, we explore the use of teardrop-shaped cavities for trapping microbubbles. Upon acoustic actuation, these microbubbles confined in teardrop cavities can be utilized to generate a directional microstreaming flow. We further show that by altering the acoustic excitation frequency, a flow-switch for altering flow direction in microfluidic environments can be achieved using two oppositely arranged teardrop cavities with different sizes. In the end, we show that an array of such bubble-filled teardrop cavities can act as a fixated microfluidic transport system allowing for on-chip particle manipulation in complex flow patterns. This inexpensive method to create flows to switch and transport elements based on teardrop cavities can be widely employed for microfluidic applications such as drug delivery systems.     

基于冗余链路的校园网流量管理设计与实现

分析了目前校园网用户体验宽带不宽的主要因素,针对校园网出口冗余链路提出基于时间策略的负载均衡方案,并对校园网骨干架构做出相应调整,经过实际应用测试,保障了用户办公学习网络应用带宽,提高了校园网用户满意度。     

Statistically uniform intra-block refresh algorithm for very low delay video communication

This paper focuses on the mechanism underlying the overall delay of a real-time video communication system from the time of capture at the encoder to the time of display at the decoder. A detailed analysis is presented to illustrate the delay problem. We then describe a statistically uniform intra-block refresh scheme for very low delay video communication. By scattering intra-blocks uniformly into continuous frames, the overall delay is significantly decreased, and object changes in the scene could be presented to the end user instantly. For comparison, the overall delay and the peak signal-to-noise ratio (PSNR) performance are tested. The experiment results show that an average of approximately 0.1 dB PSNR gain on average is obtained relative to random intra-macroblock refresh algorithm in H.264 JM, and the end-to-end delay performance is significantly improved.     

Self-sensing active magnetic bearing using real-time duty cycle

In a self-sensing active magnetic bearing (AMB) system driven by pulse width modulation (PWM) switching power amplifiers, the rotor position information can be extracted from coil current and voltage signals by a specific signal demodulation process. In this study, to reduce the complexity of hardware, the coil voltage signal was not filtered but measured in the form of a duty cycle by the eCAP port of DSP (TMS320F28335). A mathematical model was established to provide the relationship between rotor position, current ripple, and duty cycle. Theoretical analysis of the amplitude-frequency characteristic of the coil current at the switching frequency was presented using Fourier series, Jacobi-Anger identity, and Bessel function. Experimental results showed that the time-varying duty cycle causes infinite side frequencies around the switching frequency. The side frequency interval depends on the varying frequency of the duty cycle. Rotor position can be calculated by measuring the duty cycle and demodulating the coil current ripple. With this self-sensing strategy, the rotor system supported by AMBs can steadily rotate at a speed of 3000 r/min.     

智能水电厂现地控制单元发展趋势

介绍了智能水电厂概念的提出对水电厂计算机监控系统现地控制单元(LCU)的影响,从LCU的结构模式、智能可编程逻辑控制器、LCU的安全稳定3个方面总结了目前水电厂LCU的现状和不足,并着重探讨了未来的智能水电厂LCU的发展趋势.     

黄土类地层综合降水试验及优化设计

根据南水北调中线穿黄工程Ⅰ标渠道及进口段场地水文地质条件,通过单井降水试验和生产性群井降水试验的降水资料,采取以管井为主,井点及明排为辅的综合性降水施工方法,成功地将渠道内地下水位降至基础设计标高以下.保证了渠道边坡稳定,达到了黄土类弱透水、高地下水位地层降水、渠道高边坡开挖和衬砌施工的目的.所得降水试验及设计成果为今...