网络控制机制的运行状况及其对大学生网络失范行为的影响

对四川省8所高校1414名大学生抽样调查表明,大学生网络失范行为比较普遍,对网络法律法规的知晓度与认同度以及对网络道德的认同度都较高,但网络思想政治教育和网络知识教育还比较滞后,社会资本还不够丰富。多元线性回归分析表明,网络法律法规、网络道德、思想政治教育、网络知识以及社会资本都有助于防范大学生的网络失范行为。

可编程网络技术提供开放的网络控制机制

根据用户需要,快速的产生、利用和管理新的服务是推动可编程网络研究的一个关键因素。这个研究领域所取得的结果,对客户、服务提供商、设备提供者甚至对整个电信部门,如宽带、移动、IP网络都有很大的影响。现在的ISPs(Internet Service Providers)和将来的ISPs之间竞争的关键是对市场需求的反应速度。引进新的服务种类是一项富有挑战性的工作,这需要在产生服务的方法和工具上有很大的提高和进步;需要大量具体的服务的计算、数据处理和交换;并且必须提供新的网络编程环境来使将来的网络基础是开放的、可扩展的、可编程的。在网络发展的推动下,可编程网络(Programmable Network)应运而生。

网络拥塞控制机制简析及一种预侦型算法

分析了网络拥塞产生原因和常见拥塞控制策略,提出了一种适于局域网使用的基于虚电路的预侦型源端控制算法,该算法属开环控制,易实现,能以小代价获得较理想的拥塞控制效果,拥有较好的性价比。

产业集群技术创新风险控制机制研究

以往的研究忽视了由于产业集群特殊的产业组织形态而导致集群的技术创新本身隐藏着巨大风险这一事实。论证了集群面临着3种技术创新风险。为了有效控制风险,除了进一步完善契约等正式风险控制机制外,还应重点探索和建立以网络为基础的非正式风险控制机制。最后,论证了区域创新平台控制集群技术创新风险的可行性。

基于事件触发机制的NCS主被动混合鲁棒H∞容错控制

研究了在离散事件触发机制(DETCS)条件下,网络化控制系统(NCS)的主被动混合鲁棒H_∞容错控制设计方法.针对具有时变时延的不确定线性NCS,在受到外部有限能量扰动的影响下,基于离散事件触发通讯机制,分别设计了正常控制器和被动鲁棒H_∞容错控制器:正常控制器使系统正常运行时能具备良好的动态性能;而当系统发生故障时,通过瞬态切换函数切换至被动鲁棒H_∞容错控制器,确保系统在已知故障发生时不仅稳定而且具有一定的H_∞扰动抑制性能,未知故障发生初期减缓系统性能下降速度.同时,设计了鲁棒H_∞故障检测观测器,实时检测故障,利用自适应补偿控制消除未知故障对系统的影响.最后通过仿真算例验证了所提方法的可行性.

Time-stamped predictive functional control for networked control systems with random delays

The random delays in a networked control system (NCS) degrade control performance and can even destabilize the control system.To deal with this problem,the time-stamped predictive functional control (PFC) algorithm is proposed,which generalizes the standard PFC algorithm to networked control systems with random delays.The algorithm uses the time-stamp method to estimate the control delay,predicts the future outputs based on a discrete time delay state space model,and drives the control law that applies to an NCS from the idea of a PFC algorithm.A networked control system was constructed based on TrueTime simulator,with which the time-stamped PFC algorithm was compared with the standard PFC algorithm.The response curves show that the proposed algorithm has better control performance.

A TCP Performance Enhancement Scheme in Infrastructure based Vehicular Networks

Transmission Control Protocol （TCP） in infrastructure based vehicular net- works is dedicated to support reliable Intemet services for mobile users. However, an end-to- end TCP flow not only experiences some com- mon challenges in wireless mobile networks, such as high packet loss rate, medium access competition, unstable wireless bandwidth, and dynamic topology, etc., but also suffers from performance degradation due to traffic congestion at the Road-Side Units （RSUs） that connect the wireline and wireless networks. In order to address the challenging issues related to reliable TCP transmissions in infrastruc- ture based vehicular networks, we propose an RSU based TCP （R-TCP） scheme. For wireline source nodes, R-TCP adopts a novel flow control mechanism to adjust transmission rates according to the status of bottleneck link. Specifically, during the short wireless connec- tion time in Infrastructure based vehicular net- works, R-TCP quickly chooses an ideal trans- mission rate for data transmissions instead of activating the slow start algorithm after the connection is established, and successfully avoids the oscillation of the transmission rate. Simulation results show that R-TCP achieves great advantages than some relate proposals in terms of throughput, end-to-end delay, and packet loss rate.

Autonomic QoS Management Mechanism in Software Defined Network

With the increase of network complexity,the flexibility of network control and management becomes a nontrivial problem.Both Software Defined Network(SDN) and Autonomic Network technologies are sophisticated technologies for the network control and management.These two technologies could be combined together to construct a software defined self-managing solution for the future network.An autonomic QoS management mechanism in Software Defined Network(AQSDN) is proposed in this paper.In AQSDN,the various QoS features can be configured autonomically in an OpenFlow switch through extending the OpenFlow and OF-Config protocols.Based on AQSDN,a novel packet context-aware QoS model(PCaQoS) is also introduced for improving the network QoS.PCaQoS takes packet context into account when packet is marked and managed into forwarding queues.The implementation of a video application's prototype which evaluates the self-configuration feature of the AQSDN and the enhancement ability of the PCaQoS is presented in order to validate this design.

Data Distribution Mechanism over Opportunistic Networks with Limited Epidemic

Most of data distribution mechanism in Opportunistic Networks is derived by Epidemic data distribution,and Epidemic data distribution means that when each node meets another node,it may copy its own messages and transfer to another node.On the one hand,the copies improve the forwarding rate,and reduce the transmission delay.However,on the other hand,energy consumption increases and network survival time is reduced because the copies consume transmission resource.Therefore,copy number should be under control.In this paper,we first introduce the existing routing strategy based on Epidemic briefly,and present the Epidemic routing protocol analysis model and copy control mechanism based on the limited Epidemic in Opportunistic Networks.Then based on the limited copies scheme(LCS),we propose an energy balance scheme(EBS),the results show that EBS can improve the network survival time.

State feedback control for Lurie networked control systems

The problem of the stability analysis and controller design which the network-induced delays and data dropout problems network-induced delays are assumed to be time-varying and bounded, for Lurie networked control systems （NCSs） is investigated, in are simultaneously considered. By considering that the and analyzing the relationship between the delay and its upper bound, employing a Lyapunov-Krasovskii function and an integral inequality approach, an improved stability criterion for NCSs is proposed. Furthermore, the resulting condition is extended to design a less conservative state feedback controller by employing an improved cone complementary linearization （ICCL） algorithm. Numerical examples are provided to show the effectiveness of the method.

Leadership, Control Mechanisms and Networks for Sustainable Fishing

The purpose of this article was to analyse how fisheries governance can be improved when there is low enforcement capacity by state＇s institutions. Based on the theoretical arguments from the neo-institutionalism and the social capital approaches, the findings of this research point to the role of fishing cooperatives＇ structural organization on the attitude of individuals to comply with regulations. Using a most similar comparative method, it was found that fishers with higher scores of compliance belong to cooperatives that have an outstanding leader, control mechanisms, as well as multi-actor external networks which connect the organization with other networks and thus facilitate the access to knowledge, technology and activities related to conservation and sustainable fishing. The findings of the research coincide with other studies about the importance of leadership that enable good fishing management. This may help in the design of different strategies to address situations with low state capacity to ensure compliance and contribute to solve problems of commons, such as the one in marine fisheries.

A Combined Admission and Priority Control Mechanism for Assuring Communication Quality in VANETs integrated with Wireless Mesh Networks

In this paper, we introduce a new combined priority and admission control mechanism applying in the VCN （Vehicular Communication Network） which is designed with an integration of the Vehicular Ad-hoc Networks （VANETs） based on standard IEEE 802.11 p and IEEE 802.11 s WMNs （Wireless Mesh Networks）. Simulation experiments are intensively investigated to evaluate the novel combined priority and admission control mechanism to assure quality of the I2V （Infrastructure to Vehicle） emergency services occurred during the time video flows are being delivered between content servers and cars. The simulation results show effectiveness of proposed priority and admission control schemes in term of the minimized end-to-end delay as well as the increase of throughput and PDR （Packet Delivery Ratio） of the emergency data flow.

A Study of Maneuvering Control for an Air Cushion Vehicle Based on Back Propagation Neural Network

A back propagation （BP） neural network mathematical model was established to investigate the maneuvering control of an air cushion vehicle （ACV）. The calculation was based on four-freedom-degree model experiments of hydrodynamics and aerodynamics. It is necessary for the ACV to control the velocity and the yaw rate as well as the velocity angle at the same time. The yaw rate and the velocity angle must be controlled correspondingly because of the whipping, which is a special characteristic for the ACV. The calculation results show that it is an efficient way for the ACV＇s maneuvering control by using a BP neural network to adjust PID parameters online.