1,559,915 research outputs found
Event Data Definition in LHCb
We present the approach used for defining the event object model for the LHCb
experiment. This approach is based on a high level modelling language, which is
independent of the programming language used in the current implementation of
the event data processing software. The different possibilities of object
modelling languages are evaluated, and the advantages of a dedicated model
based on XML over other possible candidates are shown. After a description of
the language itself, we explain the benefits obtained by applying this approach
in the description of the event model of an experiment such as LHCb. Examples
of these benefits are uniform and coherent mapping of the object model to the
implementation language across the experiment software development teams, easy
maintenance of the event model, conformance to experiment coding rules, etc.
The description of the object model is parsed by means of a so called
front-end which allows to feed several back-ends. We give an introduction to
the model itself and to the currently implemented back-ends which produce
information like programming language specific implementations of event objects
or meta information about these objects. Meta information can be used for
introspection of objects at run-time which is essential for functionalities
like object persistency or interactive analysis. This object introspection
package for C++ has been adopted by the LCG project as the starting point for
the LCG object dictionary that is going to be developed in common for the LHC
experiments.
The current status of the event object modelling and its usage in LHCb are
presented and the prospects of further developments are discussed.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, LaTeX, 2 eps figures. PSN
MOJT00
Underlying Event Studies for LHC Energies
Underlying event was originally defined by the CDF collaboration decades ago.
Here we improve the original definition to extend our analysis for events with
multiple-jets. We introduce a definition for surrounding rings/belts and based
on this definition the jet- and surrounding-belt-excluded areas will provide a
good underlying event definition. We inverstigate our definition via the
multiplicity in the defined geometry. In parallel, mean transverse momenta of
these areas also studied in proton-proton collisions at TeV LHC
energy.Comment: 6 pages and 4 figure
Language and tool support for event refinement structures in Event-B
Event-B is a formal method for modelling and verifying the consistency of chains of model refinements. The event refinement structure (ERS) approach augments Event-B with a graphical notation which is capable of explicit representation of control flows and refinement relationships. In previous work, the ERS approach has been evaluated manually in the development of two large case studies, a multimedia protocol and a spacecraft sub-system. The evaluation results helped us to extend the ERS constructors, to develop a systematic definition of ERS, and to develop a tool supporting ERS. We propose the ERS language which systematically defines the semantics of the ERS graphical notation including the constructors. The ERS tool supports automatic construction of the Event-B models in terms of control flows and refinement relationships. In this paper we outline the systematic definition of ERS including the presentation of constructors, the tool that supports it and evaluate the contribution that ERS and its tool make. Also we present how the systematic definition of ERS and the corresponding tool can ensure a consistent encoding of the ERS diagrams in the Event-B models
Event notification services: analysis and transformation of profile definition languages
The integration of event information from diverse event notification sources is, as with meta-searching over heterogeneous search engines, a challenging task. Due to the complexity of profile definition languages, known solutions for heterogeneous searching cannot be applied for event notification.
In this technical report, we propose transformation rules for profile rewriting. We transform each profile defined at a meta-service into a profile expressed in the language of each event notification source. Due to unavoidable asymmetry in the semantics of different languages, some superfluous information may be delivered to the meta-service. These notifications are then post-processed to reduce the number of spurious messages. We present a survey and classification of profile definition languages for event notification, which serves as basis for the transformation rules. The proposed rules are implemented in a prototype transformation module for a Meta-Service for event notification
Influence of the definition of dissipative events on their statistics
A convenient and widely used way to study the turbulent plasma in the solar
corona is to do statistics of properties of events (or structures), associated
with flares, that can be found in observations or in numerical simulations.
Numerous papers have followed such a methodology, using different definitions
of an event, but the reasons behind the choice of a particular definition (and
not another one) is very rarely discussed. We give here a comprehensive set of
possible event definitions starting from a one-dimensional data set such as a
time-series of energy dissipation. Each definition is then applied to a
time-series of energy dissipation issued from simulations of a shell-model of
magnetohydrodynamic turbulence as defined in Giuliani and Carbone (1998), or
from a new model of coupled shell-models designed to represent a magnetic loop
in the solar corona. We obtain distributions of the peak dissipation power,
total energy, duration and waiting-time associated to each definition. These
distributions are then investigated and compared, and the influence of the
definition of an event on statistics is discussed. In particular, power-law
distributions are more likely to appear when using a threshold. The sensitivity
of the distributions to the definition of an event seems also to be weaker for
events found in a highly intermittent time series. Some implications on
statistical results obtained from observations are discussed.Comment: 8 pages, 13 figures. Submitted to Astronomy&Astrophysic
A systematic approach to atomicity decomposition in Event-B
Event-B is a state-based formal method that supports a refinement process in which an abstract model is elaborated towards an implementation in a step-wise manner. One weakness of Event-B is that control flow between events is typically modelled implicitly via variables and event guards. While this fits well with Event-B refinement, it can make models involving sequencing of events more difficult to specify and understand than if control flow was explicitly specified. New events may be introduced in Event-B refinement and these are often used to decompose the atomicity of an abstract event into a series of steps. A second weakness of Event-B is that there is no explicit link between such new events that represent a step in the decomposition of atomicity and the abstract event to which they contribute. To address these weaknesses, atomicity decomposition diagrams support the explicit modelling of control flow and refinement relationships for new events. In previous work,the atomicity decomposition approach has been evaluated manually in the development of two large case studies, a multi media protocol and a spacecraft sub-system. The evaluation results helped us to develop a systematic definition of the atomicity decomposition approach, and to develop a tool supporting the approach. In this paper we outline this systematic definition of the approach, the tool that supports it and evaluate the contribution that the tool makes
Topology of event distribution as a generalized definition of phase transitions in finite systems
We propose a definition of phase transitions in finite systems based on
topology anomalies of the event distribution in the space of observations. This
generalizes all the definitions based on the curvature anomalies of
thermodynamical potentials and provides a natural definition of order
parameters. The proposed definition is directly operational from the
experimental point of view. It allows to study phase transitions in Gibbs
equilibria as well as in other ensembles such as the Tsallis ensemble.Comment: 4 pages, 3 figure
Topology of event distribution as a generalized definition of phase transitions in finite systems
We propose a definition of phase transitions in finite systems based on
topology anomalies of the event distribution in the space of observations. This
generalizes all the definitions based on the curvature anomalies of
thermodynamical potentials and provides a natural definition of order
parameters. The proposed definition is directly operational from the
experimental point of view. It allows to study phase transitions in Gibbs
equilibria as well as in other ensembles such as the Tsallis ensemble.Comment: 4 pages, 3 figure
Extracting sigma_effective from the CDF gamma+3jets measurement
In their 1997 paper, CDF measured sigma_effective, the normalization factor
that relates the cross section for double parton scattering to the product of
the inclusive cross sections of the two individual scatters, in a model in
which they are assumed to be independent. In his 2007 paper, Treleani pointed
out that CDF used a non-standard definition, in which the double parton
scattering cross section corresponds to exactly two scatters, rather than the
more conventional one in which it is the inclusive two-scatter cross section.
He also estimated the correction from one definition to the other, to give a
corrected value of sigma_effective. Treleani's form would be correct under the
assumption that CDF were able to uniquely identify and count the number of
scatters in an event, which is certainly not the case. In this publication we
consider CDF's event definition in more detail to provide an improved
correction.Comment: 19 page
Super-spreading Events and Contribution to Transmission of MERS, SARS, and COVID-19
There is no clear definition for the term âsuper-spreaderâ or âsuper-spreading eventâ. The World Health Organization refers to a super-spreader as a patient (or an event) that may transmit infection to a larger number of individuals than is usual by one individual (or event). In the severe acute respiratory syndrome (SARS) situation, a super-spreading event was defined as the transmission of SARS to at â„8 contacts, and other authors defined this as individuals infecting an unusually large number of secondary cases [ 1 , 2 ]. A super-spreading event could merely be defined as an event in which one patient infects far more people than an average patient does, which is estimated by the basic reproduction number (R0)
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