Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Some key technologies of deploying high availability redundant cluster system and dependability analysis

HAO Li-rui,XUE Hong-ye,CHEN Yan,

计算机应用 , 2009,
Abstract: Some key technologies for deploying high availability cluster system were discussed in this paper. An adaptive fault-tolerance method based on task table was presented. The designing idea of the adaptive fault-tolerance algorithm and the implementation of the algorithm were described in detail. Finally, the dependability model with Petri-net was also presented. According to the dependability analysis of the high availability cluster, it shows that the cluster system in this paper has high availability to be used in critical application field.
Software dependability modeling using an industry-standard architecture description language  [PDF]
Ana-Elena Rugina,Peter H. Feiler,Karama Kanoun,Mohamed Kaaniche
Computer Science , 2008,
Abstract: Performing dependability evaluation along with other analyses at architectural level allows both making architectural tradeoffs and predicting the effects of architectural decisions on the dependability of an application. This paper gives guidelines for building architectural dependability models for software systems using the AADL (Architecture Analysis and Design Language). It presents reusable modeling patterns for fault-tolerant applications and shows how the presented patterns can be used in the context of a subsystem of a real-life application.
Dependability Considerations in Wireless Sensor Networks Applications  [cached]
Amirhosein Taherkordi,Majid Alkaee Taleghan,Mohsen Sharifi
Journal of Networks , 2006, DOI: 10.4304/jnw.1.6.28-35
Abstract: Recently, the use of wireless sensor networks has spread to applications areas that are not viable or costefficient to be run on other types of networks. Due to some critical tasks done in these types of networks, the majority of sensor networks applications should be dependable and should be run continuously and reliably without interruption. Hence, the two more significant dependability factors that should be nowadays taken into account in developing wireless sensor networks applications are ‘availability’ and ‘reliability’ of application services. The specific characteristics and constraints of wireless sensor networks require a different interpretation of these two factors when developing applications for such networks. In this paper, we propose a middleware layer mechanism for satisfying these two factors as more important dependability issues in sensor networks applications. We propose an event-based middleware service that is specifically designed for wireless sensor networks in which a group of sensor nodes forms a cluster and a replicated service is run on each cluster head. The communication model among cluster members and cluster head is based on the publish/subscribe scheme. We show how the replicated services and communication model in cluster nodes satisfy dependability issues and increase the availability and reliability of applications running under the proposed middleware.
An architecture-based dependability modeling framework using AADL  [PDF]
Ana-Elena Rugina,Karama Kanoun,Mohamed Kaaniche
Computer Science , 2007,
Abstract: For efficiency reasons, the software system designers' will is to use an integrated set of methods and tools to describe specifications and designs, and also to perform analyses such as dependability, schedulability and performance. AADL (Architecture Analysis and Design Language) has proved to be efficient for software architecture modeling. In addition, AADL was designed to accommodate several types of analyses. This paper presents an iterative dependency-driven approach for dependability modeling using AADL. It is illustrated on a small example. This approach is part of a complete framework that allows the generation of dependability analysis and evaluation models from AADL models to support the analysis of software and system architectures, in critical application domains.
Dependability Analysis of Control Systems using SystemC and Statistical Model Checking  [PDF]
Van Chan Ngo,Axel Legay,Jean Quilbeuf
Computer Science , 2015,
Abstract: Stochastic Petri nets are commonly used for modeling distributed systems in order to study their performance and dependability. This paper proposes a realization of stochastic Petri nets in SystemC for modeling large embedded control systems. Then statistical model checking is used to analyze the dependability of the constructed model. Our verification framework allows users to express a wide range of useful properties to be verified which is illustrated through a case study.
Bayesian Networks for Dependability Analysis: an Application to Digital Control Reliability  [PDF]
Luigi Portinale,Andrea Bobbio
Computer Science , 2013,
Abstract: Bayesian Networks (BN) provide robust probabilistic methods of reasoning under uncertainty, but despite their formal grounds are strictly based on the notion of conditional dependence, not much attention has been paid so far to their use in dependability analysis. The aim of this paper is to propose BN as a suitable tool for dependability analysis, by challenging the formalism with basic issues arising in dependability tasks. We will discuss how both modeling and analysis issues can be naturally dealt with by BN. Moreover, we will show how some limitations intrinsic to combinatorial dependability methods such as Fault Trees can be overcome using BN. This will be pursued through the study of a real-world example concerning the reliability analysis of a redundant digital Programmable Logic Controller (PLC) with majority voting 2:3
Parametric Dependability Analysis through Probabilistic Horn Abduction  [PDF]
Andrea Bobbio,Stefania Montani,Luigi Portinale
Computer Science , 2012,
Abstract: Dependability modeling and evaluation is aimed at investigating that a system performs its function correctly in time. A usual way to achieve a high reliability, is to design redundant systems that contain several replicas of the same subsystem or component. State space methods for dependability analysis may suffer of the state space explosion problem in such a kind of situation. Combinatorial models, on the other hand, require the simplified assumption of statistical independence; however, in case of redundant systems, this does not guarantee a reduced number of modeled elements. In order to provide a more compact system representation, parametric system modeling has been investigated in the literature, in such a way that a set of replicas of a given subsystem is parameterized so that only one representative instance is explicitly included. While modeling aspects can be suitably addressed by these approaches, analytical tools working on parametric characterizations are often more difficult to be defined and the standard approach is to 'unfold' the parametric model, in order to exploit standard analysis algorithms working at the unfolded 'ground' level. Moreover, parameterized combinatorial methods still require the statistical independence assumption. In the present paper we consider the formalism of Parametric Fault Tree (PFT) and we show how it can be related to Probabilistic Horn Abduction (PHA). Since PHA is a framework where both modeling and analysis can be performed in a restricted first-order language, we aim at showing that converting a PFT into a PHA knowledge base will allow an approach to dependability analysis directly exploiting parametric representation. We will show that classical qualitative and quantitative dependability measures can be characterized within PHA. Furthermore, additional modeling aspects (such as noisy gates and local dependencies) as well as additional reliability measures (such as posterior probability analysis) can be naturally addressed by this conversion. A simple example of a multi-processor system with several replicated units is used to illustrate the approach.
On Dependability of Computing Systems
XU Shiyi,

计算机科学技术学报 , 1999,
Abstract: With the rapid development and wide applicatioos of computing systems on which more reliance hu been put, a dependable syatem will be much more important than ever. This paper is hrst aimed at giving informal but precise definitions characterizing the various attributes of dependability of computing sys- tems and then the importance of (and the relationshipa among) all the attributes are explained . Dependability is first introduced as a global concept which subsumes the usual attributea of reliability, availabilityt maintainability, safety and securit. The basic definitions given bere are then commended and supplemented by detailed material and additional explanations in the subsequent sections . The presentation has been structured as follows so as to attract the reader's atteation to the important attributions of dependability. Search for a few number of concise concepts enabling the dependability at- tributes to be expressed as clearly as possible. Use of terms which are identical or as close as possible to those commonly used mowadays . This paper is also intended to provoke people's interest in designing a dependable computing system.
Intelligent Transportation Systems Using Short Range Wireless Technologies  [PDF]
Razi Iqbal, Kenichi Yukimatsu
Journal of Transportation Technologies (JTTs) , 2011, DOI: 10.4236/jtts.2011.14017
Abstract: In this paper, we propose using ZigBee for Intelligent Transportation System (ITS). Most of the accidents these days are caused because of drivers not knowing the upcoming traffic hurdles like curves, traffic signals, railway lines and etc. If drivers come to know about the upcoming signals, curves, and railways lines etc the accidents can be avoided. The aim is to provide drivers with intelligent roads so that they can receive the information about the curves and the traffic signals ahead. After receiving the information about the signals ahead, drivers will be careful; this will help avoid the road accidents. Many researches are taking place in the world in the field of ITS and many useful systems are also built but no system is built using this remarkable ZigBee technology. ZigBee is low cost as compared to other short range wireless technologies which will help reduce the total cost of the system, enabling this system to be deployed in developing countries as well.
Dependability in Aggregation by Averaging  [PDF]
Paulo Jesus,Carlos Baquero,Paulo Sérgio Almeida
Computer Science , 2010,
Abstract: Aggregation is an important building block of modern distributed applications, allowing the determination of meaningful properties (e.g. network size, total storage capacity, average load, majorities, etc.) that are used to direct the execution of the system. However, the majority of the existing aggregation algorithms exhibit relevant dependability issues, when prospecting their use in real application environments. In this paper, we reveal some dependability issues of aggregation algorithms based on iterative averaging techniques, giving some directions to solve them. This class of algorithms is considered robust (when compared to common tree-based approaches), being independent from the used routing topology and providing an aggregation result at all nodes. However, their robustness is strongly challenged and their correctness often compromised, when changing the assumptions of their working environment to more realistic ones. The correctness of this class of algorithms relies on the maintenance of a fundamental invariant, commonly designated as "mass conservation". We will argue that this main invariant is often broken in practical settings, and that additional mechanisms and modifications are required to maintain it, incurring in some degradation of the algorithms performance. In particular, we discuss the behavior of three representative algorithms Push-Sum Protocol, Push-Pull Gossip protocol and Distributed Random Grouping under asynchronous and faulty (with message loss and node crashes) environments. More specifically, we propose and evaluate two new versions of the Push-Pull Gossip protocol, which solve its message interleaving problem (evidenced even in a synchronous operation mode).
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.