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In this paper, we introduce a new property for graphs called bounded fragmentation, by which we mean after removing any set of at most k vertices the number of connected components is bounded only by a function of k. We demonstrate how bounded fragmentation can be used to measure the reliability of a network and introduce several classes of bounded fragmentation graphs. Finally, we pose some open problems related to this concept. © 2003 Elsevier Ltd. All rights reserved  

This paper presents an FPGA-based fault injection tool, called FITO that supports several synthesizable fault models for dependability analysis of digital systems modeled by Verilog HDL. Using the FITO, experiments can be performed in real-time with good controllability and observability. As a case study, an OpenRISC 1200 microprocessor was evaluated using an FPGA circuit. About 4000 permanent, transient, and SEU faults were injected into this microprocessor. The results show that the FITO tool is more than 79 times faster than a pure simulation-based fault injection with only 2.5% FPGA area overhead. © 2008 IEEE  

Demand response (DR) as a key integral part of the future smart grid is gaining a great and still growing focus of attention in nowadays electric power industries. However, many potential benefits of DR, although they have been envisioned to be significant, have not been yet thoroughly and quantitatively investigated. DR provides network operators with the opportunity to mitigate operational limit violations by load modification in place of load shedding when network reliability is jeopardised. This paper aims to comprehensively assess the potential impacts of DR on major attributes of service reliability in a residential distribution network. For doing so, firstly, load profiles for major... 

In recent decades, multistate two-terminal reliability problem has attracted several researchers, and accordingly many exact and approximation approaches have been proposed in the literature in terms of minimal cuts (MCs) or minimal paths (MPs) to address this problem. Here, an MP-based approximation approach is developed based on exact algorithms. With all the MPs at hand, the approach rearranges the MPs ascendingly with respect to their lengths and then sets the flow on some MPs to be zero which turns to reduce the computing cost in solving the problem. We provide the complexity results, and by employing some benchmarks and one thousand randomly generated networks illustrate that not only... 

Automation can greatly enhance distribution-network reliability by speeding up service restoration and thus significantly reduce customer-outage time. The paper presents an approach to assess quantitatively the adequacy of a particular automated distribution scheme designated as the 'low interruption system' (LIS). Owing to the use of a high-speed communication system and line sensors, this automated scheme can reduce drastically the number of interruptions, the service interruption time and also the area affected by the fault. This scheme provides a simple and cost-effective way to automate distribution systems in which the remotely controlled switches speed up isolation of faulted sections... 

This paper proposes an efficient mechanism that mitigates crosstalk faults in Network-on-Chips (NoCs). This is done by using a Packet Manipulating mechanism called PAM for reliable data transfer of NoCs. PAM investigates the transitions of a packet to minimize the forbidden transition patterns appearing during the flit traversal in NoCs. To do this, the content of a packet is manipulated using three different manipulating mechanisms. In other words, PAM manipulates the content of packet in three manipulating modes including: vertical, horizontal and diagonal modes. Then, comparing the transitions of these manipulating mechanisms, a packet with minimum numbers of transitions is selected to be... 

The d-MinCut (d-MC) problem has been extensively studied in the past decades and various algorithms have been proposed. The existing algorithms often consist of two general stages, finding all the d-MC candidates and testing each candidate for being a d-MC. To find all the d-MC candidates, a system of equations and inequalities should be solved. Here, we propose a novel efficient algorithm to solve the system. Then, using our new results, an improved algorithm is proposed for the d-MC problem. Computing its complexity, we show the proposed algorithm to be more efficient than the other existing algorithms with respect to the number of minimal cuts. A medium-size network example is worked... 

Localization and quantification of structural damage and estimating the failure probability are key outputs in the reliability assessment of structures. In this study, an Artificial Neural Network (ANN) is used to reduce the computational effort required for reliability analysis and damage detection. Toward this end, one demonstrative structure is modeled and then several damage scenarios are defined. These scenarios are considered as training data sets for establishing an ANN model. In this regard, the relationship between structural response (input) and structural stiffness (output) is established using ANN models. The established ANN is more economical and achieves reasonable accuracy in... 

Reliability cost is considered as an inevitable criterion in expansion planning studies of distribution systems. However, nonlinear expressions of reliability indices aggravate complexity of planning studies. To address this issue, this letter proposes a novel method to linearize mathematical model of the reliability-based distribution expansion planning problem. Using this variant of reliability indices, reliability costs can easily be involved in mixed-integer linear programming model of distribution expansion planning. Validity of the derived expressions is tested by simulation results. © 1969-2012 IEEE  

Network reliability measures the probability that a target node is reachable from a source node in an uncertain graph, i.e., a graph where every edge is associated with a probability of existence. In this paper, we investigate the novel and fundamental problem of adding a small number of edges in the uncertain network for maximizing the reliability between a given pair of nodes. We study the mathbf {NP}NP-hardness and the approximation hardness of our problem, and design effective, scalable solutions. Furthermore, we consider extended versions of our problem (e.g., multiple source and target nodes can be provided as input) to support and demonstrate a wider family of queries and... 

In this paper, Bayesian Network (BN) is used for reliability assessment of composite power systems with emphasis on the importance of system components. A simple approach is presented to construct the BN associated with a given power system. The approach is based on the capability of the BN to learn from data which makes it possible to be applied to large power systems. The required training data is provided by state sampling using the Monte Carlo simulation. The constructed BN is then used to perform different probabilistic assessments such as ranking the criticality and importance of system components from reliability perspective. The BN is also used to compute the frequency and... 

The different characteristics of UWSN and trade off between UWSN and WSN, have been discussed in many researches. Here, we aim to propose a new architecture for very large scale underwater sensor network. In deployment part of sensors, topology plays a crucial role in issues like communication performance, power consumption, network reliability and fault tolerance capabilities. Hence, it is so critical and should be analyzed how we deploy sensors in targets environment. For instance, to improve reliability of our networks in harsh conditions, it is so important to avoid deploying underwater sensors with single point of failure and bottleneck. For this purpose, we present enhanced clustering... 

Abstract Several researchers have worked on transmitting a given amount of flow through a network flow within fastest possible time, allowing flow to be transmitted through one or more paths. Extending this problem to the system reliability problem, the quickest path reliability problem has been introduced. The problem evaluates the probability of transmitting some given amount of flow from a source node to a sink node through a single minimal path in a stochastic-flow network within some specified units of time. Later, the problem has been extended to allow flow to be transmitted through two or more separate minimal paths (SMPs). Here, we consider the problem of sending flow through two... 

High reliability against noise, high performance, and low energy consumption are key objectives in the design of on-chip networks. Recently some researchers have considered the impact of various error-control schemes on these objectives and on the tradeoff between them. In all these works performance and reliability are measured separately. However, we will argue in this paper that the use of error-control schemes in on-chip networks results in degradable systems, hence, performance and reliability must be measured jointly using a unified measure, i.e., performability. Based on the traditional concept of performability, we provide a definition for the "Interconnect Performability".... 

This paper develops a reliability-based model for distribution network expansion planning (DNEP) studies. It incorporates the effects of distribution line maintenance in the planning studies to be considered as an alternative for the installation of feeders. To that end, at first, some models are introduced to effectively estimate the effects of maintenance activities budget on distribution lines' failure and repair rates. Therefore, the reliability data of distribution lines are updated in the reliability evaluation studies of distribution networks. Then, these models are involved in the formulation of DNEP problem which is introduced as a multi-objective optimization model. The developed... 

In this paper the reliability of distribution network is modeled in joint multistage expansion planning of distribution network assets and distributed generations (DGs). The imposed costs due to network reliability weakness are considerable in the distribution level. Therefore in the proposed model distribution network operator (DNO) considers the costs associated with load interruptions in the planning problem. In this regard, reliability evaluation of the network is modeled in the joint multistage distribution network expansion planning (MDNEP) problem in an integrated manner while the network topology is unknown until the planning problem is not solved. In the proposed joint MDNEP problem...