11,142 research outputs found
Agile preference models based on soft constraints
An accurate model of the user’s preferences is a crucial element of most decision support systems. It is often assumed that users have a well-defined and stable set of preferences that can be elicited through a set of questions. However, recent research has shown that people very often construct their preferences on the fly depending on the available decision options. Thus, their answers to a series of questions before seeing decision options are likely to be inconsistent and often lead to erroneous models. To accurately capture preference expressions as people make them, it is necessary for the preference model to be agile: it should allow decision making with an incomplete preference model, and it should let users add, retract or revise individual preferences easily. We show how constraint satisfaction and in particular soft constraints provide the right formalism to do this, and give examples of its implementation in a travel planning tool
Agile preference models based on soft constraints
An accurate model of the user's preferences is a crucial element of most decision support systems. It is often assumed that users have a well-defined and stable set of preferences that can be elicited through a set of questions. However, recent research has shown that people very often construct their preferences on the fly depending on the available decision options. Thus, their answers to a series of questions before seeing decision options are likely to be inconsistent and often lead to erroneous models. To accurately capture preference expressions as people make them, it is necessary for the preference model to be agile: it should allow decision making with an incomplete preference model, and it should let users add, retract or revise individual preferences easily. We show how constraint satisfaction and in particular soft constraints provide the right formalism to do this, and give examples of its implementation in a travel planning tool. Copyright © 2005, American Association for Artificial Intelligence (www.aaai.org). All rights reserved
The relativistic jet of Cygnus X-3 in gamma rays
High energy gamma-rays have been detected from Cygnus X-3, a system composed
of a Wolf-Rayet star and a black hole or neutron star. The gamma-ray emission
is linked to the radio emission from the jet launched in the system. The flux
is modulated with the 4.8 hr orbital period, as expected if high energy
electrons are upscattering photons emitted by the Wolf-Rayet star to gamma-ray
energies. This modulation is computed assuming that high energy electrons are
located at some distance along a relativistic jet of arbitrary orientation.
Modeling shows that the jet must be inclined and that the gamma ray emitting
electrons cannot be located within the system. This is consistent with the idea
that the electrons gain energy where the jet is recollimated by the stellar
wind pressure and forms a shock. Jet precession should strongly affect the
gamma-ray modulation shape at different epochs. The power in non-thermal
electrons represents a small fraction of the Eddington luminosity only if the
inclination is low i.e. if the compact object is a black hole.Comment: 5 pages, 4 figures, accepted for publication in MNRAS Letter
Formalising responsibility modelling for automatic analysis
Modelling the structure of social-technical systems as a basis for informing software system design is a difficult compromise. Formal methods struggle to capture the scale and complexity of the heterogeneous organisations that use technical systems. Conversely, informal approaches lack the rigour needed to inform the software design and
construction process or enable automated analysis.
We revisit the concept of responsibility modelling, which models social technical systems as a collection of actors who discharge their responsibilities, whilst using and producing resources in the process. Responsibility modelling is formalised as a structured approach for socio-technical system requirements specification and modelling, with well-defined semantics and support for automated structure and validity analysis. The
effectiveness of the approach is demonstrated by two case studies of software engineering methodologies
The Agile Alert System For Gamma-Ray Transients
In recent years, a new generation of space missions offered great
opportunities of discovery in high-energy astrophysics. In this article we
focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID)
onboard the AGILE space mission. The AGILE-GRID, sensitive in the energy range
of 30 MeV-30 GeV, has detected many gamma-ray transients of galactic and
extragalactic origins. This work presents the AGILE innovative approach to fast
gamma-ray transient detection, which is a challenging task and a crucial part
of the AGILE scientific program. The goals are to describe: (1) the AGILE
Gamma-Ray Alert System, (2) a new algorithm for blind search identification of
transients within a short processing time, (3) the AGILE procedure for
gamma-ray transient alert management, and (4) the likelihood of ratio tests
that are necessary to evaluate the post-trial statistical significance of the
results. Special algorithms and an optimized sequence of tasks are necessary to
reach our goal. Data are automatically analyzed at every orbital downlink by an
alert pipeline operating on different timescales. As proper flux thresholds are
exceeded, alerts are automatically generated and sent as SMS messages to
cellular telephones, e-mails, and push notifications of an application for
smartphones and tablets. These alerts are crosschecked with the results of two
pipelines, and a manual analysis is performed. Being a small scientific-class
mission, AGILE is characterized by optimization of both scientific analysis and
ground-segment resources. The system is capable of generating alerts within two
to three hours of a data downlink, an unprecedented reaction time in gamma-ray
astrophysics.Comment: 34 pages, 9 figures, 5 table
The Real World Software Process
The industry-wide demand for rapid development in concert with greater process maturity has seen many software development firms adopt tightly structured iterative processes. While a number of commercial vendors offer suitable process infrastructure and tool support, the cost of licensing, configuration and staff training may be prohibitive for the small and medium size enterprises (SMEs) which dominate the Asia-Pacific software industry. This work addresses these problems through the introduction of the Real World Software Process (RWSP), a freely available, Web-based iterative scheme designed specifically for small teams and organisations. RWSP provides a detailed process description, high quality document templates - including code review and inspection guidelines - and the integrated tutorial support necessary for successful usage by inexperienced developers and teams. In particular it is intended that the process be readily usable by software houses which at present do not follow a formal process, and that the free RWSP process infrastructure should be a vehicle for improving industry standards
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