75,954 research outputs found
On Usage Control for Data Grids: Models, Architectures, and Specifications
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
Impact of IEC 61850 GOOSE Communication Quality on Decentralized Reactive Power Control in Smart Distribution Grids – a Co-simulation Study
International audienceSmart grids are expected to increase efficiency, reliability and sustainability of future energy usage. Employing state-of-the-art information and communication technologies, within power grids, is defining for smart grids; therefore interaction between energy grids and communication networks requires thorough study. Combined simulation of the behaviour of the electrical and communication network would allow to analyse their influences on one each other.In this paper, the results of a MATLAB® /Simulink® cosimulation of an electrical distribution grid containing two renewable sources in interaction with its communication network are presented. Communication between different nodes is based on the IEC 61850 GOOSE protocol, whose simulation model incorporates its different efficiency and reliability features. Communication network and electrical grid are modelled using SimEvents® blocks and SimPowerSystems® blocks, respectively. The effect of perturbations on the reliability of the data transfer links, while information to perform decentralised reactive power control is flowing on them, is examined
A solution for secure use of Kibana and Elasticsearch in multi-user environment
Monitoring is indispensable to check status, activities, or resource usage of
IT services. A combination of Kibana and Elasticsearch is used for monitoring
in many places such as KEK, CC-IN2P3, CERN, and also non-HEP communities.
Kibana provides a web interface for rich visualization, and Elasticsearch is a
scalable distributed search engine. However, these tools do not support
authentication and authorization features by default. In the case of single
Kibana and Elasticsearch services shared among many users, any user who can
access Kibana can retrieve other's information from Elasticsearch. In
multi-user environment, in order to protect own data from others or share part
of data among a group, fine-grained access control is necessary.
The CERN cloud service group had provided cloud utilization dashboard to each
user by Elasticsearch and Kibana. They had deployed a homemade Elasticsearch
plugin to restrict data access based on a user authenticated by the CERN Single
Sign On system. It enabled each user to have a separated Kibana dashboard for
cloud usage, and the user could not access to other's one. Based on the
solution, we propose an alternative one which enables user/group based
Elasticsearch access control and Kibana objects separation. It is more flexible
and can be applied to not only the cloud service but also the other various
situations. We confirmed our solution works fine in CC-IN2P3. Moreover, a
pre-production platform for CC-IN2P3 has been under construction.
We will describe our solution for the secure use of Kibana and Elasticsearch
including integration of Kerberos authentication, development of a Kibana
plugin which allows Kibana objects to be separated based on user/group, and
contribution to Search Guard which is an Elasticsearch plugin enabling
user/group based access control. We will also describe the effect on
performance from using Search Guard.Comment: International Symposium on Grids and Clouds 2017 (ISGC 2017
Smart Grid Communications: Overview of Research Challenges, Solutions, and Standardization Activities
Optimization of energy consumption in future intelligent energy networks (or
Smart Grids) will be based on grid-integrated near-real-time communications
between various grid elements in generation, transmission, distribution and
loads. This paper discusses some of the challenges and opportunities of
communications research in the areas of smart grid and smart metering. In
particular, we focus on some of the key communications challenges for realizing
interoperable and future-proof smart grid/metering networks, smart grid
security and privacy, and how some of the existing networking technologies can
be applied to energy management. Finally, we also discuss the coordinated
standardization efforts in Europe to harmonize communications standards and
protocols.Comment: To be published in IEEE Communications Surveys and Tutorial
Smart Grid Technologies in Europe: An Overview
The old electricity network infrastructure has proven to be inadequate, with respect to modern challenges such as alternative energy sources, electricity demand and energy saving policies. Moreover, Information and Communication Technologies (ICT) seem to have reached an adequate level of reliability and flexibility in order to support a new concept of electricity network—the smart grid. In this work, we will analyse the state-of-the-art of smart grids, in their technical, management, security, and optimization aspects. We will also provide a brief overview of the regulatory aspects involved in the development of a smart grid, mainly from the viewpoint of the European Unio
A Taxonomy of Data Grids for Distributed Data Sharing, Management and Processing
Data Grids have been adopted as the platform for scientific communities that
need to share, access, transport, process and manage large data collections
distributed worldwide. They combine high-end computing technologies with
high-performance networking and wide-area storage management techniques. In
this paper, we discuss the key concepts behind Data Grids and compare them with
other data sharing and distribution paradigms such as content delivery
networks, peer-to-peer networks and distributed databases. We then provide
comprehensive taxonomies that cover various aspects of architecture, data
transportation, data replication and resource allocation and scheduling.
Finally, we map the proposed taxonomy to various Data Grid systems not only to
validate the taxonomy but also to identify areas for future exploration.
Through this taxonomy, we aim to categorise existing systems to better
understand their goals and their methodology. This would help evaluate their
applicability for solving similar problems. This taxonomy also provides a "gap
analysis" of this area through which researchers can potentially identify new
issues for investigation. Finally, we hope that the proposed taxonomy and
mapping also helps to provide an easy way for new practitioners to understand
this complex area of research.Comment: 46 pages, 16 figures, Technical Repor
Efficient ICT for efficient smart grids
In this extended abstract the need for efficient and reliable ICT is discussed. Efficiency of ICT not only deals with energy-efficient ICT hardware, but also deals with efficient algorithms, efficient design methods, efficient networking infrastructures, etc. Efficient and reliable ICT is a prerequisite for efficient Smart Grids. Unfortunately, efficiency and reliability have not always received the proper attention in the ICT domain in the past
Dynamic Trust Federation in Grids
Grids are becoming economically viable and productive tools. Grids provide a way of utilizing a vast array of linked resources such as computing systems, databases and services online within Virtual Organizations (VO). However, today’s Grid architectures are not capable of supporting dynamic, agile federation across multiple administrative domains and the main barrier, which hinders dynamic federation over short time scales is security. Federating security and trust is one of the most significant architectural issues in Grids. Existing relevant standards and specifications can be used to federate security services, but do not directly address the dynamic extension of business trust relationships into the digital domain. In this paper we describe an experiment in which we highlight those challenging architectural issues and we will further describe how the approach that combines dynamic trust federation and dynamic authorization mechanism can address dynamic security trust federation in Grids. The experiment made with the prototype described in this paper is used in the NextGRID project for the definition of requirements for next generation Grid architectures adapted to business application need
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