346,855 research outputs found
A Model-Driven Architecture Approach to the Efficient Identification of Services on Service-oriented Enterprise Architecture
Service-Oriented Enterprise Architecture requires the efficient development of loosely-coupled and interoperable sets of services. Existing design approaches do not always take full advantage of the value and importance of the engineering invested in existing legacy systems. This paper proposes an approach to define the key services from such legacy systems effectively. The approach focuses on identifying these services based on a Model-Driven Architecture approach supported by guidelines over a wide range of possible service types
Caustic Skeleton & Cosmic Web
We present a general formalism for identifying the caustic structure of an
evolving mass distribution in an arbitrary dimensional space. For the class of
Hamiltonian fluids the identification corresponds to the classification of
singularities in Lagrangian catastrophe theory. Based on this we develop a
theoretical framework for the formation of the cosmic web, and specifically
those aspects that characterize its unique nature: its complex topological
connectivity and multiscale spinal structure of sheetlike membranes, elongated
filaments and compact cluster nodes. The present work represents an extension
of the work by Arnol'd et al., who classified the caustics for the 1- and
2-dimensional Zel'dovich approximation. His seminal work established the role
of emerging singularities in the formation of nonlinear structures in the
universe. At the transition from the linear to nonlinear structure evolution,
the first complex features emerge at locations where different fluid elements
cross to establish multistream regions. The classification and characterization
of these mass element foldings can be encapsulated in caustic conditions on the
eigenvalue and eigenvector fields of the deformation tensor field. We introduce
an alternative and transparent proof for Lagrangian catastrophe theory, and
derive the caustic conditions for general Lagrangian fluids, with arbitrary
dynamics, including dissipative terms and vorticity. The new proof allows us to
describe the full 3-dimensional complexity of the gravitationally evolving
cosmic matter field. One of our key findings is the significance of the
eigenvector field of the deformation field for outlining the spatial structure
of the caustic skeleton. We consider the caustic conditions for the
3-dimensional Zel'dovich approximation, extending earlier work on those for 1-
and 2-dimensional fluids towards the full spatial richness of the cosmic web
The Zeldovich approximation: key to understanding Cosmic Web complexity
We describe how the dynamics of cosmic structure formation defines the
intricate geometric structure of the spine of the cosmic web. The Zeldovich
approximation is used to model the backbone of the cosmic web in terms of its
singularity structure. The description by Arnold et al. (1982) in terms of
catastrophe theory forms the basis of our analysis.
This two-dimensional analysis involves a profound assessment of the
Lagrangian and Eulerian projections of the gravitationally evolving
four-dimensional phase-space manifold. It involves the identification of the
complete family of singularity classes, and the corresponding caustics that we
see emerging as structure in Eulerian space evolves. In particular, as it is
instrumental in outlining the spatial network of the cosmic web, we investigate
the nature of spatial connections between these singularities.
The major finding of our study is that all singularities are located on a set
of lines in Lagrangian space. All dynamical processes related to the caustics
are concentrated near these lines. We demonstrate and discuss extensively how
all 2D singularities are to be found on these lines. When mapping this spatial
pattern of lines to Eulerian space, we find a growing connectedness between
initially disjoint lines, resulting in a percolating network. In other words,
the lines form the blueprint for the global geometric evolution of the cosmic
web.Comment: 37 pages, 21 figures, accepted for publication in MNRA
Analysing I/O bottlenecks in LHC data analysis on grid storage resources
We describe recent I/O testing frameworks that we have developed and applied within the UK GridPP Collaboration, the ATLAS experiment and the DPM team, for a variety of distinct purposes. These include benchmarking vendor supplied storage products, discovering scaling limits of SRM solutions, tuning of storage systems for experiment data analysis, evaluating file access protocols, and exploring I/O read patterns of experiment software and their underlying event data models. With multiple grid sites now dealing with petabytes of data, such studies are becoming essential. We describe how the tests build, and improve, on previous work and contrast how the use-cases differ. We also detail the results obtained and the implications for storage hardware, middleware and experiment software
Abmash: Mashing Up Legacy Web Applications by Automated Imitation of Human Actions
Many business web-based applications do not offer applications programming
interfaces (APIs) to enable other applications to access their data and
functions in a programmatic manner. This makes their composition difficult (for
instance to synchronize data between two applications). To address this
challenge, this paper presents Abmash, an approach to facilitate the
integration of such legacy web applications by automatically imitating human
interactions with them. By automatically interacting with the graphical user
interface (GUI) of web applications, the system supports all forms of
integrations including bi-directional interactions and is able to interact with
AJAX-based applications. Furthermore, the integration programs are easy to
write since they deal with end-user, visual user-interface elements. The
integration code is simple enough to be called a "mashup".Comment: Software: Practice and Experience (2013)
HILT IV : subject interoperability through building and embedding pilot terminology web services
A report of work carried out within the JISC-funded HILT Phase IV project, the paper looks at the project's context against the background of other recent and ongoing terminologies work, describes its outcome and conclusions, including technical outcomes and terminological characteristics, and considers possible future research and development directions. The Phase IV project has taken HILT to the point where the launch of an operational support service in the area of subject interoperability is a feasible option and where both investigation of specific needs in this area and practical collaborative work are sensible and feasible next steps. Moving forward requires detailed work, not only on terminology interoperability and associated service delivery issues, but also on service and end user needs and engagement, service sustainability issues, and the practicalities of interworking with other terminology services and projects in UK, Europe, and global contexts
The internet milieu: individualization within a globalised community
Communication technologies have become deeply embedded in our lives, mediating the ways in which information is presented. Due to the global nature of this channel of communication, the world has shrunk and members of the internet may share similar cultural norms of thinking and
behaving. Yet, paradoxically, the Internet is personal in that each individual has an interactive opportunity in choosing the options that can expand the breadth and depth of the information they are reading, who they interact with, and the means to achieve that interaction. These options can be expressed through a variety of media techniques. This paper is based on a study of selected websites hosted in English. It looks at language use in the Internet and illustrates the paradoxes between global and individual mediations of meanin
BlogForever: D3.1 Preservation Strategy Report
This report describes preservation planning approaches and strategies recommended by the BlogForever project as a core component of a weblog repository design. More specifically, we start by discussing why we would want to preserve weblogs in the first place and what it is exactly that we are trying to preserve. We further present a review of past and present work and highlight why current practices in web archiving do not address the needs of weblog preservation adequately. We make three distinctive contributions in this volume: a) we propose transferable practical workflows for applying a combination of established metadata and repository standards in developing a weblog repository, b) we provide an automated approach to identifying significant properties of weblog content that uses the notion of communities and how this affects previous strategies, c) we propose a sustainability plan that draws upon community knowledge through innovative repository design
Lattice QCD input for nuclear structure and reactions
Explorations of the properties of light nuclear systems beyond their
lowest-lying spectra have begun with Lattice Quantum Chromodynamics. While
progress has been made in the past year in pursuing calculations with physical
quark masses, studies of the simplest nuclear matrix elements and nuclear
reactions at heavier quark masses have been conducted, and several interesting
results have been obtained. A community effort has been devoted to investigate
the impact of such Quantum Chromodynamics input on the nuclear many-body
calculations. Systems involving hyperons and their interactions have been the
focus of intense investigations in the field, with new results and deeper
insights emerging. While the validity of some of the previous multi-nucleon
studies has been questioned during the past year, controversy remains as
whether such concerns are relevant to a given result. In an effort to summarize
the newest developments in the field, this talk will touch on most of these
topics.Comment: Plenary talk presented at the "35th International Symposium on
Lattice Field Theory", Granada, Spain, June 2017. 26 pages, 14 figure
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