103 research outputs found
Vehicles Recognition Using Fuzzy Descriptors of Image Segments
In this paper a vision-based vehicles recognition method is presented.
Proposed method uses fuzzy description of image segments for automatic
recognition of vehicles recorded in image data. The description takes into
account selected geometrical properties and shape coefficients determined for
segments of reference image (vehicle model). The proposed method was
implemented using reasoning system with fuzzy rules. A vehicles recognition
algorithm was developed based on the fuzzy rules describing shape and
arrangement of the image segments that correspond to visible parts of a
vehicle. An extension of the algorithm with set of fuzzy rules defined for
different reference images (and various vehicle shapes) enables vehicles
classification in traffic scenes. The devised method is suitable for
application in video sensors for road traffic control and surveillance systems.Comment: The final publication is available at http://www.springerlink.co
Performance Evaluation of Road Traffic Control Using a Fuzzy Cellular Model
In this paper a method is proposed for performance evaluation of road traffic
control systems. The method is designed to be implemented in an on-line
simulation environment, which enables optimisation of adaptive traffic control
strategies. Performance measures are computed using a fuzzy cellular traffic
model, formulated as a hybrid system combining cellular automata and fuzzy
calculus. Experimental results show that the introduced method allows the
performance to be evaluated using imprecise traffic measurements. Moreover, the
fuzzy definitions of performance measures are convenient for uncertainty
determination in traffic control decisions.Comment: The final publication is available at http://www.springerlink.co
Precision Predictions for (Un)Stable WW/4f Production in e +e- Annihilation: YFSWW3/KoralW-1.42/YFSZZ
We present precision calculations of the processes e+ e- -> 4-fermions in
which the double resonant W+ W- and ZZ intermediate states occur. Referring to
these latter intermediate states as the 'signal processes', we show that, by
using the YFS Monte Carlo event generators YFSWW3-1.14 and KoralW-1.42 in an
appropriate combination, we achieve a physical precision on the WW signal
process, as isolated with LEP2 MC Workshop cuts, below 0.5 per cent. We stress
the full gauge invariance of our calculations and we compare our results with
those of other authors where appropriate. In particular, sample Monte Carlo
data are explicitly illustrated and compared with the results of the program
RacoonWW of Denner et al. In this way, we cross check that the total (physical
oplus technical) precision tag for the WW signal process cross section is 0.4
per cent for 200 GeV, for example. Results are also given for 500 GeV with an
eye toward the LC. For the analogous ZZ case, we cross check that our YFSZZ
calculation yields a total precision tag of 2 per cent, when it is compared to
the results of ZZTO and GENTLE of Passarino and Bardin et al., respectively.Comment: 14 pages, 1 figure, 4 tables, presented at RADCOR2000 by B.F.L. War
Coherent Exclusive Exponentiation for Precision Monte Carlo Calculations of Fermion Pair Production / Precision Predictions for (Un)stable W+W- Pairs
We present the new Coherent Exclusive Exponentiation (CEEX), in comparison to
the older Exclusive Exponentiation (EEX) and the semi-analytical Inclusive
Exponentiation (IEX), for the process e+e- -> f-bar f + n(gamma),
f=mu,tau,d,u,s,c,b, with validity for centre of mass energies from tau lepton
threshold to 1 TeV. We analyse 2f numerical results at the Z-peak, 189 GeV and
500 GeV. We also present precision calculations of the signal processes e+e- ->
4f in which the double resonant W+W- intermediate state occurs using our
YFSWW3-1.14 MC. Sample 4f Monte Carlo data are explicitly illustrated in
comparison to the literature at LEP2 energies. These comparisons show that a TU
for the signal process cross section of 0.4 percent is valid for the LEP2 200
GeV energy. LC energy results are also shown.Comment: 5 pages, 4 figures, Presented at ICHEP200
QED Exponentiation for quasi-stable charged particles: the process
All real and virtual infrared singularities in the standard analysis of the
perturbative Quantum Electrodynamics (like that of Yennie-Frautschi-Suura) are
associated with photon emissions from the external legs in the scattering
process. External particles are stable, with the zero decay width. Such
singularities are well understood at any perturbative order and are resummed.
The case of production and decay of the semi-stable {\em neutral} particles
like boson or lepton, with the narrow decay width, ,
is also well understood at any perturbative order and soft photon resummation
can be done. For the absent or loose upper cut-off on the total photon energy
the production and decay process of the semi-stable (neutral)
particles decouples approximately and can be considered quasi-independently. In
particular soft photon resummation can be done separately for the production
and decay process treating semi-stable (neutral) particle as stable. So far,
consistent treatment of the soft photon resummation for semi-stable {\em
charged} particles like boson is not available in the literature and
the aim of this work is to present a solution for this problem. Generally, it
should be feasible because the underlying physics is the same as in the case of
the neutral semi-stable resonances -- in the limit production
and decay processes for charged particles also necessarily decouple due to long
lifetime of the particles. The technical problems to be solved in this work are
related to the fact that semi-stable charged particle are able to emit photons.Comment: Short version has appeared in conference materials, Symmetry 11, 1389
(2019
Inclusion of the QCD next-to-leading order corrections in the quark-gluon Monte Carlo shower
Methodology of including QCD NLO corrections in the quark--gluon Monte Carlo
shower is outlined. The work concentrates on two issues: (i) constructing
leading order (LO) parton shower Monte Carlo from scratch, such that it
rigorously extends collinear factorization into the exclusive (fully
unintegrated) one which we call the Monte Carlo factorization scheme; (ii)
introducing next-to-leading-order (NLO) corrections to the hard process in this
new environment. The presented solution is designed to be extended to the full
NLO level Monte Carlo, including NLO corrections not only in the hard process
but in the whole shower. The issue of the difference between the factorization
scheme implemented in the Monte Carlo (MC) solution and the standard MSbar
scheme is addressed. The principal MC implementation is designed for the
electroweak boson production process at the LHC, but in order to discuss
universality -- process independence, the deep inelastic lepton--hadron
scaterring is also brought into the MC framework.Comment: 28 pages, 6 figures, updated to match journal versio
Z-boson as "the standard candle" for high precision W-boson physics at LHC
In this paper we propose a strategy for measuring the inclusive W-boson
production processes at LHC. This strategy exploits simultaneously the unique
flexibility of the LHC collider in running variable beam particle species at
variable beam energies, and the configuration flexibility of the LHC detectors.
We propose their concrete settings for a precision measurement of the Standard
Model parameters. These dedicated settings optimise the use of the Z boson and
Drell-Yan pair production processes as ``the standard reference candles''. The
presented strategy allows to factorise and to directly measure those of the QCD
effects which affect differently the W and Z production processes. It reduces
to a level of 10^{-4} the impact of uncertainties in the partonic distribution
functions (PDFs) and in the transverse momentum of the quarks on the
measurement precision. Last but not the least, it reduces by a factor of 10 an
impact of systematic measurement errors, such as the energy scale and the
measurement resolution, on the W-boson production observables.Comment: 20 pages, 4 figure
How QCD evolution kernels depend on the type of evolution variable
We show that by changing the upper phase space limit in calculation of an evolution kernel, one can change its functional form. This happens already at the NLO level, e.g. when the upper phase space limit is defined in terms of maximum of transverse momenta. The upper phase space limit of the evolution kernel corresponds to the evolution variable used in a Parton Shower, and this dependence means that the different kernels need to be used depending on the ordering of the Parton Shower
Overview of theoretical precision of the luminosity at future electron-positron colliders
For both the FCC-ee and the ILC, to exploit properly the respective precision physics program, the theoretical precision tag on the respective luminosity will need to be improved from the analogs of the 0.054%(0.061%) results at LEP at , where the former (latter) LEP result has (does not have) the pairs correction. At the FCC-ee at one needs improvement to 0.01%, for example. We present an overview of the roads one may take to reach the required 0.01% precision tag at the FCC-ee and of what the corresponding precision expectations would be for the FCC-ee, ILC, ILC and CLIC setups
NLO corrections to hard process in QCD shower : proof of concept
The concept of new methodology of adding QCD NLO corrections in the initial state Monte Carlo parton shower (hard process part) is tested numerically using, as an example, the process of the heavy boson production at hadron–hadron colliders such as LHC. In spite of the use of a simplified model of the process, all presented numerical results prove convincingly that the basic concept of the new methodology works correctly in practice, that is, in the numerical environment of the Monte Carlo parton shower event generator. The differences with the other well established methods, like MC@NLO and POWHEG, are briefly discussed and future refinements of the implementation of the new method are also outlined
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