Fault-aware Communication Mapping for NoCs with Guaranteed Latency

As feature sizes shrink, transient failures of on-chip network links become a critical problem. At the same time, many applications require guarantees on both message arrival probability and response time. We address the problem of transient link failures by means of temporally and spatially redundant transmission of messages, such that designer-imposed message arrival probabilities are guaranteed. Response time minimisation is achieved by a heuristic that statically assigns multiple copies of each message to network links, intelligently combining temporal and spatial redundancy. Concerns regarding energy consumption are addressed in two ways. First, we reduce the total amount of transmitted messages, and, second, we minimise the application response time such that the resulted time slack can be exploited for energy savings through voltage reduction. The advantages of the proposed approach are guaranteed message arrival probability and guaranteed worst case application response time.     

Trace,failure and testing equivalences for communicating processes

A basic question in the theory of communicating processes is “When should two processes be considered equivalent?”. Attempts to answer this question have led to the concepts of observation equivalence, bisimulations, testing equivalence, failure equivalence, etc. The main point of this paper is to increase the understanding and motivation for two of these equivalences, namely failure and testing equivalences. The approach starts with the idea that the equivalence of processes should be reducible to the visible sequences of actions which a process performs in various contexts. This idea is implemented by a string-based semantic order for communicating processes where divergence is catastrophic. Under some assumptions about contexts, the resulting semantics is shown to be equivalent to theimproved failure semantics of Brookes and Roscoe⁽¹⁾ and also to themust testing-semantics of Hennessy and DeNicola.^(2–4) This characterization gives independent support for the appropriateness of failures and testing.     

针对任意传感器失效的反馈设计新方法

本文针对任意传感器的失效，给出了一种反馈设计方法，通过解Ｌｙａｐｕｎｏｖ方程及判定一个不等式的成立，即可给出反馈增益阵的设计，最后用这种方法研究了一个例子。     

Stochastically resilient extended Kalman filtering for discrete-time nonlinear systems with sensor failures

Missing sensor data is a common problem, which severely influences the overall performance of modern data-intensive control and computing applications. In order to address this important issue, a novel resilient extended Kalman filter is proposed for discrete-time nonlinear stochastic systems with sensor failures and random observer gain perturbations. The failure mechanisms of multiple sensors are assumed to be independent of each other with different failure rates. The locally unbiased robust minimum mean square filter is designed for state estimation under these conditions. The performance of the proposed estimation method is verified by means of numerical Monte Carlo simulation of two different nonlinear stochastic systems, involving a sinusoidal system and a Lorenz oscillator system.     

指挥信息系统双层耦合网络模型级联失效研究

针对指挥信息系统级联失效研究中存在的结构建模简单和攻击方式单一的不足,提出指挥信息系统双层耦合网络模型,在此基础上设置不同的攻击方式,分析系统的级联失效特性.首先,根据指挥信息系统体系结构和层级网络理论,构建了由通信网络和功能网络构成的双层耦合网络模型,并提出节点重要度指标;其次,设置实体打击、赛博攻击和混合攻击三种攻击方式,以及不同的攻击强度对指挥信息系统进行攻击,分析其级联失效机理;最后,仿真分析表明,双层耦合网络模型能够反映指挥信息系统的结构特征,基于该模型能够分析指挥信息系统在多种攻击方式和攻击强度下的级联失效特性.     

人工肺-嗅觉系统集成与混合气体识别方法

针对仿人机器人的嗅觉及多种混合气体识别问题,提出一种人工肺-嗅觉系统(HALOS-I)及基于主动呼吸的气体识别方法.该系统硬件主要集成了微型真空泵、酒精/硫化氢/氨气/烟雾/甲烷5种气体传感器、单片机以及信号采集与处理电路;分别用K-均值聚类分析法、遗传算法结合神经网络(GA+BP)、三级级联神经网络(GA+3BP)进行了5种单一气体及4种混合气体的识别实验,结果表明:GA+BP算法仅对5种单一气体识别率达到90%以上,加入混合气体后识别率较低;GA+3BP算法除对硫化氢和烟雾的混合气体识别率为70%以外,对其余8种气体识别率均在90%以上,表明GA与多级级联BP神经网络相结合方法对多种单一及混合气体具有较高的识别率.     

制冷系统隐性故障分析

制冷系统中,隐性故障因故障现象不是十分明显而难以及时被发现,致使系统带故运行,造成能源的浪费。从热力学角度分析了制冷系统极易发生的5种隐性故障,总结出5种隐性故障的压力、温度变化特征,提供了判断隐性故障的途径。     

Endurance: A new robustness measure for complex networks under multiple failure scenarios

Society is now, more than ever, highly dependent on the large-scale networks that underpin its functions. In relatively recent times, significant failures have occurred on large-scale networks that have a considerable impact upon sizable proportions of the world’s inhabitants. The failure of infrastructure has, in turn, begot a subsequent loss of services supported by that network. Consequently, it is now vitally important to evaluate the robustness of such networks in terms of the services supported by the network in question. Evaluating network robustness is integral to service provisioning and thus any network should include explicit indication of the impact upon service performance. Traditionally, network robustness metrics focused solely on topological characteristics, although some new approaches have considered, to a degree, the services supported by such networks. Several shortcomings of these new metrics have been identified. With the purpose of solving the drawbacks of these metrics, this paper presents a new measure called endurance, which quantifies the level of robustness supported by a specific topology under different types of multiple failure scenarios, giving higher importance to perturbations affecting low percentages of elements of a network. In this paper, endurance of six synthetic complex networks is computed for a range of defined multiple failure scenarios, taking into account the connection requests that cannot be satisfied. It is demonstrated that our proposal is able to quantify the robustness of a network under given multiple failure scenarios. Finally, results show that different types of networks react differently depending on the type of multiple failure.