7,736 research outputs found
Status Report of the DPHEP Study Group: Towards a Global Effort for Sustainable Data Preservation in High Energy Physics
Data from high-energy physics (HEP) experiments are collected with
significant financial and human effort and are mostly unique. An
inter-experimental study group on HEP data preservation and long-term analysis
was convened as a panel of the International Committee for Future Accelerators
(ICFA). The group was formed by large collider-based experiments and
investigated the technical and organisational aspects of HEP data preservation.
An intermediate report was released in November 2009 addressing the general
issues of data preservation in HEP. This paper includes and extends the
intermediate report. It provides an analysis of the research case for data
preservation and a detailed description of the various projects at experiment,
laboratory and international levels. In addition, the paper provides a concrete
proposal for an international organisation in charge of the data management and
policies in high-energy physics
An agent-based architecture for managing the provision of community care - the INCA (Intelligent Community Alarm) experience
Community Care is an area that requires extensive cooperation
between independent agencies, each of which needs to meet its own objectives and targets. None are engaged solely in the delivery of community care, and need to integrate the service with their other responsibilities in a coherent and efficient manner. Agent technology provides the means by which effective cooperation can take place without compromising the essential security of both the client and the
agencies involved as the appropriate set of responses can be generated through negotiation between the parties without the need for access to the main information repositories that would be necessary with conventional collaboration models. The autonomous nature of agents also means that a variety of agents can cooperate
together with various local capabilities, so long as they conform to the relevant messaging requirements. This allows a variety of agents, with capabilities tailored to the carers to which they are attached to be developed so that cost-effective solutions can be provided.
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On-sky multi-wavelength phasing of segmented telescopes with the Zernike phase contrast sensor
Future Extremely Large Telescopes will adopt segmented primary mirrors with
several hundreds of segments. Cophasing of the segments together is essential
to reach high wavefront quality. The phasing sensor must be able to maintain
very high phasing accuracy during the observations, while being able to phase
segments dephased by several micrometers. The Zernike phase contrast sensor has
been demonstrated on-sky at the Very Large Telescope. We present the
multi-wavelength scheme that has been implemented to extend the capture range
from \pmlambda/2 on the wavefront to many micrometers, demonstrating that it is
successful at phasing mirrors with piston errors up to \pm4.0 micron on the
wavefront. We discuss the results at different levels and conclude with a
phasing strategy for a future Extremely Large Telescope.Comment: 17 pages, 8 figures, 2 tables. Accepted for publication in Applied
Optics; he final publised version is available on the OSA website:
http://www.opticsinfobase.org/abstract.cfm?msid=13671
Simulating Radiating and Magnetized Flows in Multi-Dimensions with ZEUS-MP
This paper describes ZEUS-MP, a multi-physics, massively parallel, message-
passing implementation of the ZEUS code. ZEUS-MP differs significantly from the
ZEUS-2D code, the ZEUS-3D code, and an early "version 1" of ZEUS-MP distributed
publicly in 1999. ZEUS-MP offers an MHD algorithm better suited for
multidimensional flows than the ZEUS-2D module by virtue of modifications to
the Method of Characteristics scheme first suggested by Hawley and Stone
(1995), and is shown to compare quite favorably to the TVD scheme described by
Ryu et. al (1998). ZEUS-MP is the first publicly-available ZEUS code to allow
the advection of multiple chemical (or nuclear) species. Radiation hydrodynamic
simulations are enabled via an implicit flux-limited radiation diffusion (FLD)
module. The hydrodynamic, MHD, and FLD modules may be used in one, two, or
three space dimensions. Self gravity may be included either through the
assumption of a GM/r potential or a solution of Poisson's equation using one of
three linear solver packages (conjugate-gradient, multigrid, and FFT) provided
for that purpose. Point-mass potentials are also supported. Because ZEUS-MP is
designed for simulations on parallel computing platforms, considerable
attention is paid to the parallel performance characteristics of each module.
Strong-scaling tests involving pure hydrodynamics (with and without
self-gravity), MHD, and RHD are performed in which large problems (256^3 zones)
are distributed among as many as 1024 processors of an IBM SP3. Parallel
efficiency is a strong function of the amount of communication required between
processors in a given algorithm, but all modules are shown to scale well on up
to 1024 processors for the chosen fixed problem size.Comment: Accepted for publication in the ApJ Supplement. 42 pages with 29
inlined figures; uses emulateapj.sty. Discussions in sections 2 - 4 improved
per referee comments; several figures modified to illustrate grid resolution.
ZEUS-MP source code and documentation available from the Laboratory for
Computational Astrophysics at http://lca.ucsd.edu/codes/currentcodes/zeusmp2
Managing healthcare workflows in a multi-agent system environment
Whilst Multi-Agent System (MAS) architectures appear to offer a more flexible model for designers and developers of complex, collaborative information systems, implementing real-world business processes that can be delegated to autonomous agents is still a relatively difficult task. Although a range of agent tools and toolkits exist, there still
remains the need to move the creation of models nearer to code generation, in order that the development path be more rigorous and repeatable. In particular, it is essential that complex organisational
process workflows are captured and expressed in a way that MAS can successfully interpret. Using a complex social care system as an exemplar, we describe a technique whereby a business process is
captured, expressed, verified and specified in a suitable format for a healthcare MAS.</p
Tools of the Trade: A Survey of Various Agent Based Modeling Platforms
Agent Based Modeling (ABM) toolkits are as diverse as the community of people who use them. With so many toolkits available, the choice of which one is best suited for a project is left to word of mouth, past experiences in using particular toolkits and toolkit publicity. This is especially troublesome for projects that require specialization. Rather than using toolkits that are the most publicized but are designed for general projects, using this paper, one will be able to choose a toolkit that already exists and that may be built especially for one's particular domain and specialized needs. In this paper, we examine the entire continuum of agent based toolkits. We characterize each based on 5 important characteristics users consider when choosing a toolkit, and then we categorize the characteristics into user-friendly taxonomies that aid in rapid indexing and easy reference.Agent Based Modeling, Individual Based Model, Multi Agent Systems
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