223,028 research outputs found

    On Usage Control for GRID Systems

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    This paper introduces a formal model, an architecture and a prototype implementation for usage control on GRID systems. The usage control model (UCON) is a new access control paradigm proposed by Park and Sandhu that encompasses and extends several existing models (e.g. MAC, DAC, Bell-Lapadula, RBAC, etc). Its main novelty is based on continuity of the access monitoring and mutability of attributes of subjects and objects. We identified this model as a perfect candidate for managing access/usage control in GRID systems due to their peculiarities, where continuity of control is a central issue. Here we adapt the original UCON model to develop a full model for usage control in GRID systems. We use as policy specification language a process description language and show how this is suitable to model the usage policy models of the original UCON model. We also describe a possible architecture to implement the usage control model. Moreover, we describe a prototype implementation for usage control of GRID computational services, and we show how our language can be used to define a security policy that regulates the usage of network communications to protect the local computational service from the applications that are executed on behalf of remote GRID users

    Energy Network Communications and Expandable Control Mechanisms

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    A modular, expandable network requiring little or no calibration is something that is well sought after and would offer great benefits when used for distributed energy generation. Intelligent and adaptive control of such a network offers stability of supply from intermittent sources which, to date, has been hard to achieve. Key to the effective use of such control systems is communications, specifically the exchange of commands and status information between the control systems and the attached devices. Power-line communications has been used in various applications for years and would offer a good mechanism for interconnecting devices on a power grid without the expense of laying new cabling. By using clusters of devices managed by an IEMS (Intelligent Energy Management System) in a branching network fashion (not unlike the grid itself) it would be possible to manage large numbers of devices and high speed with relatively low bandwidth usage increasing the usable range of transmission. Implications of this include improving network efficiency through managed power distribution and increased security of supply

    Usage Control, Risk and Trust

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    Abstract. In this paper we describe our general framework for usage control (UCON) enforcement on GRID systems. It allows both GRID services level enforcement of UCON as well as fine-grained one at the level of local GRID node resources. In addition, next to the classical checks for usage control: checks of conditions, authorizations, and obligations, the framework also includes trust and risk management functionalities. Indeed, we show how trust and risk issues naturally arise when considering usage control in GRID systems and services and how our architecture is flexible enough to accommodate both notions in a pretty uniform way

    On Usage Control for Data Grids: Models, Architectures, and Specifications

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    This thesis reasons on usage control in Data Grids, by presenting models, architectures and specifications. This work is a step toward a continuous monitoring and control of the data access and usage in a Data Grid. First, the thesis presents a background on Grids, security, and security for Grids, by making an abstraction to the current Grid implementations. We argue that usage control in Data Grids should be considered as a process composed by two black boxes. We analysed the requirements for Grid security, and propose a distributed usage control model suitable for Grids and distributed systems alike. Then, we apply such model to a Data Grid abstraction, and present a usage control architecture for Data Grids that uses the functional components of the currents Grids. We also present an abstract specification for an enforcing mechanism for usage control policies. To do so, we use a formal requirement engineering methodology with a bottom-up approach, that proves that the specification is sound and complete. With the methodology, we show formally that such abstract specification can enforce all the different typologies of usage control policies. Finally, we consider how existing prototypes can fit in the proposed architecture, and the advantages derived from using Semantic Grid techologies for the specification of policies subjects and objects

    Adaptive Electricity Scheduling in Microgrids

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    Microgrid (MG) is a promising component for future smart grid (SG) deployment. The balance of supply and demand of electric energy is one of the most important requirements of MG management. In this paper, we present a novel framework for smart energy management based on the concept of quality-of-service in electricity (QoSE). Specifically, the resident electricity demand is classified into basic usage and quality usage. The basic usage is always guaranteed by the MG, while the quality usage is controlled based on the MG state. The microgrid control center (MGCC) aims to minimize the MG operation cost and maintain the outage probability of quality usage, i.e., QoSE, below a target value, by scheduling electricity among renewable energy resources, energy storage systems, and macrogrid. The problem is formulated as a constrained stochastic programming problem. The Lyapunov optimization technique is then applied to derive an adaptive electricity scheduling algorithm by introducing the QoSE virtual queues and energy storage virtual queues. The proposed algorithm is an online algorithm since it does not require any statistics and future knowledge of the electricity supply, demand and price processes. We derive several "hard" performance bounds for the proposed algorithm, and evaluate its performance with trace-driven simulations. The simulation results demonstrate the efficacy of the proposed electricity scheduling algorithm.Comment: 12 pages, extended technical repor

    A dependable model for attaining maximum authetication security procedure in a grid based environment

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    Grid computing is an emergent computing innovation which offers endless access to computing infrastructure across various organizations (academia and industry). Since this technology allows aggregation of various computer systems for usage by different users to run applications, the information stored on it which may be sensitive and private, remains vulnerable. According to related research on the attribute based access control for grid computing there is no adequate and appropriate security mechanism to authorize and authenticate users before accessing information on a grid system. The issue of security in grid technology has not been fully addressed even though it is a precondition for optimizing grid usability. Having realized the paucity of security guarantees, this research work focuses on developing a model for securing data and applications deployed on a grid on the basis of double identity authentication and public key. The implementation of the model has undoubtedly guaranteed the security of sensitive information on a grid vis-α-vis strict adherence to security policies and protocols

    Evaluation of Single Phase Smart PV Inverter Functions in Unbalanced Residential Distribution Systems

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    In the United States, smart PV inverters integrated with residential distribution systems are becoming a more common occurrence. With integration of smart PV inverters, power utilities are experiencing an increase of number of operations with regards to switched capacitor banks, voltage regulators and on load tap changers. These increases can lead to excess wear and tear on the devices causing power utilities to perform unwanted replacement and maintenance. However, smart PV inverters when controlled under specific functions can enable these inverters to provide reactive power and voltage control which in turn lowers the number of operations for switched capacitor banks, voltage regulators and on load tap changers. Furthermore, the standard basis is that when implementing Unbalanced Residential Distribution Systems into the grid, centralized control is a well-known choice, however, decentralized control provides a strong case for usage when using smart PV inverters in residential distribution systems. The objective of this thesis is to provide a better understanding of Unbalanced Residential Distribution Systems tied into the distribution side of the power grid when using control functions. Furthermore, better understand and prove the theory of using decentralize control for smart PV inverters in a residential distribution system. The future work will be analyzing the role of restoration practices and islanded mode with control algorithms that are used in grid connected mode. The specific areas below will be discussed in this thesi

    A Dependable Model for Attaining Maximum Authentication Security Procedure in a Grid Based Environment

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    Grid computing is an emergent computing innovation which offers endless access to computing infrastructure across various organizations (academia and industry). Since this technology allows aggregation of various computer systems for usage by different users to run applications, the information stored on it which may be sensitive and private, remains vulnerable. According to related research on the attribute based access control for grid computing there is no adequate and appropriate security mechanism to authorize and authenticate users before accessing information on a grid system. The issue of security in grid technology has not been fully addressed even though it is a precondition for optimizing grid usability. Having realized the paucity of security guarantees, this research work focuses on developing a model for securing data and applications deployed on a grid on the basis of double identity authentication and public key. The implementation of the model has undoubtedly guaranteed the security of sensitive information on a grid vis-a-vis strict adherence to security policies and protocols

    Measures to Reduce Concerns Related to Smart Meter Data_x000D_ Are detailed Consumer data needed for Smart Grid Operations?

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    Intelligent information systems are necessary to improve power grid operations. The current trend reveals the deployment of smart meter at consumer sites as the energy provider’s starting point to grid modernisation. Smart meters are considered as a core element in most of the smart grid projects. The smart metering system is designed to collect and transmit detailed consumption data. This data could profile the consumer’s lifestyle and this is among the reasons for consumer’s resistance to smart meters. It is also not clear how the power grid will benefit from individual consumer’s detailed power usage data. This article attempts to investigate this issue by analysing if detailed end-user data is required for the operation of other control systems in the grid. Further an analysis is conducted to identify which stakeholders will benefit from the detailed smart meter data. Based on the analysis remedial measures are proposed
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