Network Availability and Reliability Research Papers (original) (raw)

In this paper we present a novel approach for the specification of access rights in a service oriented architecture. Being part of the SECTET framework for model driven security for B2B-workflows, our specification language SECTET-PL for... more

In this paper we present a novel approach for the specification of access rights in a service oriented architecture. Being part of the SECTET framework for model driven security for B2B-workflows, our specification language SECTET-PL for permissions is influenced by the OCL specification language and is interpreted in the context of UML models. Concerning the technological side, SECTET-PL specifications are translated into platform independent XACML permissions interpreted by a security gateway.

Abstract: This letter presents an approach to determining the impact of supplemental reserve and high-MVA-capacity transmission lines on optimal maintenance and repair time. The impact of the supplemental reserve and high-capacity... more

Abstract: This letter presents an approach to determining the impact
of supplemental reserve and high-MVA-capacity transmission lines on optimal maintenance and repair time. The impact of the supplemental reserve and high-capacity transmission lines is determined by including the availability and costs characteristics. Availability is calculated by taking into account successfully supplied consumer areas, and costs are calculated bytaking into account costs of maintenance, repair, and undelivered electric energy. The optimal maintenance and repair time is determined by considering the balance between availability and the costs. The results obtained show that the supplemental reserve and high-capacity transmission lines prolong the maintenance and repair period and reduce the costs.
Keywords: Availability, costs, maintenance, repair, undelivered energy,
supplemental reserve, transmission, power system.

The purpose of the paper is to present a metric for availability based on the design of the information system. The availability metric proposed in this paper is twofold, based on the operating program and network delay metric of the... more

The purpose of the paper is to present a metric for availability based on the design of the information system. The availability metric proposed in this paper is twofold, based on the operating program and network delay metric of the information system (For the local bound component composition the availability metric is purely based on the software/operating program, for the remote bound component composition the metric incorporates the delay metric of the network). The aim of the paper is to present a quantitative availability metric derived from the component composition of an Information System, based on the dependencies among the individual measurable components of the system. The metric is used for measuring and evaluating availability of an information system from the security perspective, the measurements may be done during the design phase or may also be done after the system is fully functional. The work in the paper provides a platform for further research regarding the quantitative security metric (based on the components of an information system i.e. user, hardware, operating program and the network.) for an information system that addresses all the attributes of information and network security.

Cloudavailabilityisamajorperformanceparameterforcloud platforms, but there are very few measurements on commercial plat- forms, and most of them rely on outage reports as appeared on special- ized sites, providers’ dashboards, or the... more

Cloudavailabilityisamajorperformanceparameterforcloud platforms, but there are very few measurements on commercial plat- forms, and most of them rely on outage reports as appeared on special- ized sites, providers’ dashboards, or the general press. A paper recently presented at the PAM 2014 conference by Hu et alii reports the results of a measurement campaign. In this note, the results of that paper are summarized, highlighting sources of inaccuracy and some possible im- provements. In particular, the use of a low probing frequency could lead to non detection of short outages, as well as to an inaccurate estima- tion of the outage duration statistics. Overcoming this lack of accuracy is relevant to properly assess SLA violations and establish the basis for insurance claims.

In this paper, we propose a novel privacy-preserving location assurance protocol for secure location-aware services over vehicular ad hoc networks (VANETs). In particular, we introduce the notion of location-aware credentials based on... more

In this paper, we propose a novel privacy-preserving location assurance protocol for secure location-aware services over vehicular ad hoc networks (VANETs). In particular, we introduce the notion of location-aware credentials based on “hash-sign-switch” paradigm so as to guarantee the trustworthiness of location in location-aware services while providing conditional privacy preservation which is a desirable property for secure vehicular communications. Furthermore, the proposed protocol provides efficient procedures that alleviate a burden of computation for location-aware signature generation and verification on vehicles in VANETs. In order to achieve these goals, we consider online/offline signature scheme and identity-based aggregate signature scheme as our building blocks. Finally, we demonstrate experimental results to confirm the efficiency and effectiveness of the proposed protocol.

In the case of failing equipment in industrial plants, the replacement time and effort must be kept at a minimum to increase the overall system availability. A well-designed Faulty Device Replacement (FDR) concept is therefore a central... more

In the case of failing equipment in industrial plants, the replacement time and effort must be kept at a minimum to increase the overall system availability. A well-designed Faulty Device Replacement (FDR) concept is therefore a central issue to the effective operation of industrial plants. Network enabled devices supporting FDR with minimum subsequent manual device configuration after replacement form a key requirement to improve repairability. To achieve this, several FDR techniques have been proposed and implemented by different vendors and organizations. In this work, a performance model for the time to repair and a taxonomy for existing FDR methods is provided. This can be used as a basis for comparative performance measurements to derive the most suitable method during the planning phase of an industrial network.