107,376 research outputs found
The CERN Detector Safety System for the LHC Experiments
The Detector Safety System (DSS), currently being developed at CERN under the
auspices of the Joint Controls Project (JCOP), will be responsible for assuring
the protection of equipment for the four LHC experiments. Thus, the DSS will
require a high degree of both availability and reliability. After evaluation of
various possible solutions, a prototype is being built based on a redundant
Siemens PLC front-end, to which the safety-critical part of the DSS task is
delegated. This is then supervised by a PVSS SCADA system via an OPC server.
The PLC front-end is capable of running autonomously and of automatically
taking predefined protective actions whenever required. The supervisory layer
provides the operator with a status display and with limited online
reconfiguration capabilities. Configuration of the code running in the PLCs
will be completely data driven via the contents of a "Configuration Database".
Thus, the DSS can easily adapt to the different and constantly evolving
requirements of the LHC experiments during their construction, commissioning
and exploitation phases.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 5 pages, PDF. PSN THGT00
A genetic-inspired joint multicast routing and channel assignment algorithm in wireless mesh networks
Copyright @ 2008 IEEEThis paper proposes a genetic algorithm (GA) based optimization approach to search a minimum-interference multicast tree which satisÂŻes the end-to-end delay constraint and optimizes the usage of the scarce radio network resource in wireless mesh networks. The path-oriented en- coding method is used and each chromosome is represented by a tree data structure (i.e., a set of paths). Since we expect the multicast trees on which the minimum-interference channel assignment can be produced, a fitness function that returns the total channel conflict is devised. Crossover and mutation are well designed to adapt to the tree structure. A simple yet effective channel assignment algorithm is proposed to reduce the channel conflict. Simulation results show that the proposed GA based multicast algorithm achieves better performance in terms of both the total channel conflict and the tree cost than that of a well known algorithm
Optimal network topologies for information transmission in active networks
This work clarifies the relation between network circuit (topology) and
behavior (information transmission and synchronization) in active networks,
e.g. neural networks. As an application, we show how to determine a network
topology that is optimal for information transmission. By optimal, we mean that
the network is able to transmit a large amount of information, it possesses a
large number of communication channels, and it is robust under large variations
of the network coupling configuration. This theoretical approach is general and
does not depend on the particular dynamic of the elements forming the network,
since the network topology can be determined by finding a Laplacian matrix (the
matrix that describes the connections and the coupling strengths among the
elements) whose eigenvalues satisfy some special conditions. To illustrate our
ideas and theoretical approaches, we use neural networks of electrically
connected chaotic Hindmarsh-Rose neurons.Comment: 20 pages, 12 figure
Discovering Communication
What kind of motivation drives child language development? This
article presents a computational model and a robotic experiment to articulate
the hypothesis that children discover communication as a result
of exploring and playing with their environment. The considered
robotic agent is intrinsically motivated towards situations in which
it optimally progresses in learning. To experience optimal learning
progress, it must avoid situations already familiar but also situations
where nothing can be learnt. The robot is placed in an environment in
which both communicating and non-communicating objects are present.
As a consequence of its intrinsic motivation, the robot explores this environment
in an organized manner focusing first on non-communicative
activities and then discovering the learning potential of certain types of
interactive behaviour. In this experiment, the agent ends up being interested
by communication through vocal interactions without having
a specific drive for communication
Cycle-accurate evaluation of reconfigurable photonic networks-on-chip
There is little doubt that the most important limiting factors of the performance of next-generation Chip Multiprocessors (CMPs) will be the power efficiency and the available communication speed between cores. Photonic Networks-on-Chip (NoCs) have been suggested as a viable route to relieve the off- and on-chip interconnection bottleneck. Low-loss integrated optical waveguides can transport very high-speed data signals over longer distances as compared to on-chip electrical signaling. In addition, with the development of silicon microrings, photonic switches can be integrated to route signals in a data-transparent way. Although several photonic NoC proposals exist, their use is often limited to the communication of large data messages due to a relatively long set-up time of the photonic channels. In this work, we evaluate a reconfigurable photonic NoC in which the topology is adapted automatically (on a microsecond scale) to the evolving traffic situation by use of silicon microrings. To evaluate this system's performance, the proposed architecture has been implemented in a detailed full-system cycle-accurate simulator which is capable of generating realistic workloads and traffic patterns. In addition, a model was developed to estimate the power consumption of the full interconnection network which was compared with other photonic and electrical NoC solutions. We find that our proposed network architecture significantly lowers the average memory access latency (35% reduction) while only generating a modest increase in power consumption (20%), compared to a conventional concentrated mesh electrical signaling approach. When comparing our solution to high-speed circuit-switched photonic NoCs, long photonic channel set-up times can be tolerated which makes our approach directly applicable to current shared-memory CMPs
The evolution of retail banking services in United Kingdom: a retrospective analysis
The purpose of this paper is to assess the sequence of technological changes occurred in the retail banking sector of the United Kingdom against the emergence of customer services by developing an evolutionary argument. The historical paradigm of Information Technology provides useful insights into the âlearning opportunitiesâ that opened the way to endogenous changes in the banking activity such as the reconfiguration of its organizational structure and the diversification of the product line. The central idea of this paper is that innovation never occurs without simultaneous structural change. Thus, a defining property of the banking activity is the diachronic adaptation of formal and informal practices to an evolving technological dimension reflecting the extent to which the diffusion of innovation (re)generates variety of micro level processes and induces industry evolution.Information Technology; Retail Banking; History of Technology; Innovation Systems.
Towards the Model-Driven Engineering of Secure yet Safe Embedded Systems
We introduce SysML-Sec, a SysML-based Model-Driven Engineering environment
aimed at fostering the collaboration between system designers and security
experts at all methodological stages of the development of an embedded system.
A central issue in the design of an embedded system is the definition of the
hardware/software partitioning of the architecture of the system, which should
take place as early as possible. SysML-Sec aims to extend the relevance of this
analysis through the integration of security requirements and threats. In
particular, we propose an agile methodology whose aim is to assess early on the
impact of the security requirements and of the security mechanisms designed to
satisfy them over the safety of the system. Security concerns are captured in a
component-centric manner through existing SysML diagrams with only minimal
extensions. After the requirements captured are derived into security and
cryptographic mechanisms, security properties can be formally verified over
this design. To perform the latter, model transformation techniques are
implemented in the SysML-Sec toolchain in order to derive a ProVerif
specification from the SysML models. An automotive firmware flashing procedure
serves as a guiding example throughout our presentation.Comment: In Proceedings GraMSec 2014, arXiv:1404.163
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