37,975 research outputs found
IMP Science Gateway: from the Portal to the Hub of Virtual Experimental Labs in Materials Science
"Science gateway" (SG) ideology means a user-friendly intuitive interface
between scientists (or scientific communities) and different software
components + various distributed computing infrastructures (DCIs) (like grids,
clouds, clusters), where researchers can focus on their scientific goals and
less on peculiarities of software/DCI. "IMP Science Gateway Portal"
(http://scigate.imp.kiev.ua) for complex workflow management and integration of
distributed computing resources (like clusters, service grids, desktop grids,
clouds) is presented. It is created on the basis of WS-PGRADE and gUSE
technologies, where WS-PGRADE is designed for science workflow operation and
gUSE - for smooth integration of available resources for parallel and
distributed computing in various heterogeneous distributed computing
infrastructures (DCI). The typical scientific workflows with possible scenarios
of its preparation and usage are presented. Several typical use cases for these
science applications (scientific workflows) are considered for molecular
dynamics (MD) simulations of complex behavior of various nanostructures
(nanoindentation of graphene layers, defect system relaxation in metal
nanocrystals, thermal stability of boron nitride nanotubes, etc.). The user
experience is analyzed in the context of its practical applications for MD
simulations in materials science, physics and nanotechnologies with available
heterogeneous DCIs. In conclusion, the "science gateway" approach - workflow
manager (like WS-PGRADE) + DCI resources manager (like gUSE)- gives opportunity
to use the SG portal (like "IMP Science Gateway Portal") in a very promising
way, namely, as a hub of various virtual experimental labs (different software
components + various requirements to resources) in the context of its practical
MD applications in materials science, physics, chemistry, biology, and
nanotechnologies.Comment: 6 pages, 5 figures, 3 tables; 6th International Workshop on Science
Gateways, IWSG-2014 (Dublin, Ireland, 3-5 June, 2014). arXiv admin note:
substantial text overlap with arXiv:1404.545
Are Delayed Issues Harder to Resolve? Revisiting Cost-to-Fix of Defects throughout the Lifecycle
Many practitioners and academics believe in a delayed issue effect (DIE);
i.e. the longer an issue lingers in the system, the more effort it requires to
resolve. This belief is often used to justify major investments in new
development processes that promise to retire more issues sooner.
This paper tests for the delayed issue effect in 171 software projects
conducted around the world in the period from 2006--2014. To the best of our
knowledge, this is the largest study yet published on this effect. We found no
evidence for the delayed issue effect; i.e. the effort to resolve issues in a
later phase was not consistently or substantially greater than when issues were
resolved soon after their introduction.
This paper documents the above study and explores reasons for this mismatch
between this common rule of thumb and empirical data. In summary, DIE is not
some constant across all projects. Rather, DIE might be an historical relic
that occurs intermittently only in certain kinds of projects. This is a
significant result since it predicts that new development processes that
promise to faster retire more issues will not have a guaranteed return on
investment (depending on the context where applied), and that a long-held truth
in software engineering should not be considered a global truism.Comment: 31 pages. Accepted with minor revisions to Journal of Empirical
Software Engineering. Keywords: software economics, phase delay, cost to fi
Data-Driven Application Maintenance: Views from the Trenches
In this paper we present our experience during design, development, and pilot
deployments of a data-driven machine learning based application maintenance
solution. We implemented a proof of concept to address a spectrum of
interrelated problems encountered in application maintenance projects including
duplicate incident ticket identification, assignee recommendation, theme
mining, and mapping of incidents to business processes. In the context of IT
services, these problems are frequently encountered, yet there is a gap in
bringing automation and optimization. Despite long-standing research around
mining and analysis of software repositories, such research outputs are not
adopted well in practice due to the constraints these solutions impose on the
users. We discuss need for designing pragmatic solutions with low barriers to
adoption and addressing right level of complexity of problems with respect to
underlying business constraints and nature of data.Comment: Earlier version of paper appearing in proceedings of the 4th
International Workshop on Software Engineering Research and Industrial
Practice (SER&IP), IEEE Press, pp. 48-54, 201
Incorporating stakeholdersâ knowledge in group decision-making
International audienc
Myths and Realities about Online Forums in Open Source Software Development: An Empirical Study
The use of free and open source software (OSS) is gaining momentum due to the
ever increasing availability and use of the Internet. Organizations are also
now adopting open source software, despite some reservations, in particular
regarding the provision and availability of support. Some of the biggest
concerns about free and open source software are post release software defects
and their rectification, management of dynamic requirements and support to the
users. A common belief is that there is no appropriate support available for
this class of software. A contradictory argument is that due to the active
involvement of Internet users in online forums, there is in fact a large
resource available that communicates and manages the provision of support. The
research model of this empirical investigation examines the evidence available
to assess whether this commonly held belief is based on facts given the current
developments in OSS or simply a myth, which has developed around OSS
development. We analyzed a dataset consisting of 1880 open source software
projects covering a broad range of categories in this investigation. The
results show that online forums play a significant role in managing software
defects, implementation of new requirements and providing support to the users
in open source software and have become a major source of assistance in
maintenance of the open source projects
Effective Governance of Global Financial Markets:An Evolutionary Plan for Reform
Runaway electrons, which are generated in a plasma where the induced electric field exceeds a certain critical value, can reach very high energies in the MeV range. For such energetic electrons, radiative losses will contribute significantly to the momentum space dynamics. Under certain conditions, due to radiative momentum losses, a non-monotonic feature - a âbump' - can form in the runaway electron tail, creating a potential for bump-on-tail-type instabilities to arise. Here, we study the conditions for the existence of the bump. We derive an analytical threshold condition for bump appearance and give an approximate expression for the minimum energy at which the bump can appear. Numerical calculations are performed to support the analytical derivation
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