5,361 research outputs found
Totem: a case study in HEP
It is being proved that the neurochip \Totem{} is a viable solution for high
quality and real time computational tasks in HEP, including event
classification, triggering and signal processing. The architecture of the chip
is based on a "derivative free" algorithm called Reactive Tabu Search (RTS),
highly performing even for low precision weights. ISA, VME or PCI boards
integrate the chip as a coprocessor in a host computer. This paper presents: 1)
the state of the art and the next evolution of the design of \Totem{}; 2) its
ability in the Higgs search at LHC as an example.Comment: Latex, elsart.sty, 5 pages, talk presented by I.Lazzizzera at CHEP97
(Berlin, April 1997
Detailed analysis of quantum phase transitions within the algebra
We analyze in detail the quantum phase transitions that arise in models based
on the algebraic description for bosonic systems with two types of
scalar bosons. First we discuss the quantum phase transition that occurs in
hamiltonians that admix the two dynamical symmetry chains
and by diagonalizing the problem exactly in the
basis. Then we apply the coherent state formalism to determine the energy
functional. Finally we show that a quantum phase transition of a different
nature, but displaying similar characteristics, may arise also within a single
chain just by including higher order terms in the hamiltonian.Comment: 5 figure
Cross-cultural validation and measurement invariance of the Short Grit scale (Grit-S): preliminary results.
Preliminary results of a cross-cultural validation of the Grit -
Modified Profile Likelihood for Fixed-Effects Panel Data Models
We show how modified profile likelihood methods, developed in the statistical literature, may be effectively applied to estimate the structural parameters of econometric models for panel data, with a remarkable reduction of bias with respect to ordinary likelihood methods. Initially, the implementation of these methods is illustrated for general models for panel data including individual-specific fixed effects and then, in more detail, for the truncated linear regression model and dynamic regression models for binary data formulated along with different specifications. Simulation studies show the good behavior of the inference based on the modified profile likelihood, even when compared to an ideal, although infeasible, procedure (in which the fixed effects are known) and also to alternative estimators existing in the econometric literature. The proposed estimation methods are implemented in an R package that we make available to the reader
Twin reversed arterial perfusion sequence: current treatment options
Twin reversed arterial perfusion (TRAP) sequence is a specific and severe complication of monochorionic multiple pregnancy, characterized by vascular anastomosis and partial or complete lack of cardiac development in one twin. Despite its rarity, interest in the international literature is rising, and we aimed to review its pathogenesis, prenatal diagnostic features and treatment options. Due to the parasitic hemodynamic dependence of the acardiac twin on the pump twin, the management of these pregnancies aims to maximize the pump twinâs chances of survival. If treatment is needed, the best timing of intervention is still debated, although the latest studies encourage intervention in the first trimester of pregnancy. As for the technique of choice to interrupt the vascular supply to the acardiac twin, ultrasound-guided laser coagulation and radiofrequency ablation of the intrafetal vessels are usually the preferred approaches
Ammonia and Greenhouse Gas emissions from slatted dairy barn floors cleaned by Robotic Scrapers
The design of animal housing and manure management systems are key factors in livestock farming. Frequent removal
methods, in fact, allow for the reduction of gasses produced from fermentations of the organic matter contained in
manure, that affect animal welfare and farmer health and are emitted from animal housings into the atmosphere as a
consequence of ventilation. The present study aims to evaluate the performance of a Robotic Scraper (RS) operating on
the floors in a full-scale, operative free-stall dairy barn. The research is focused on the evaluation of gaseous emissions
from the two types of floors (concrete and rubber mat coated), and with and without RS operation. The floors with
rubber coating demonstrated higher emission rates of ammonia (NH3), carbon dioxide (CO2), nitrous oxide (N2O), and
methane (CH4) compared to the uncovered concrete floors, both before and after RS operations. The operation of RS,
furthermore, determined significant reduction of greenhouse gasses (GHG) but did not have relevant effect in terms
of NH3 emission, which reduced only of 1.4% from concrete floors, but increase of 12.7% from rubber coated floors
A time-variable, phase-dependent emission line in the X-ray spectrum of the isolated neutron star RXJ0822â4300
RX J0822â4300 is the central compact object associated with the Puppis A supernova remnant. Previous X-ray observations suggested RX J0822â4300 to be a young neutron star with a weak dipole field and a peculiar surface temperature distribution dominated by two antipodal spots with different temperatures and sizes. An emission line at 0.8 keV was also detected. We performed a very deep (130-ks) observation with XMMâNewton, which allowed us to study in detail the phase-resolved properties of RX J0822â4300. Our new data confirm the existence of a narrow spectral feature, best modelled as an emission line, only seen in the âsoftâ-phase interval â when the cooler region is best aligned to the line of sight. Surprisingly, comparison of our recent observations to the older ones yields evidence for a variation in the emission-line component, which can be modelled as a decrease in the central energy from âŒ0.80 keV in 2001 to âŒ0.73 keV in 2009â10. The line could be generated via cyclotron scattering of thermal photons in an optically-thin layer of gas, or, alternatively, it could originate in low-rate accretion by a debris disc. In any case, a variation in energy, pointing to a variation of the magnetic field in the line-emitting region, cannot be easily accounted for
Cultivares de trigo Embrapa - comportamento nas unidades demonstrativas de Passo Fundo, safra 1999.
bitstream/item/84167/1/CNPT-COM.-TEC.-19-00.pd
Searching the Higgs with the Neurochip TOTEM
We show that neural network classifiers can be helpful in discriminating
Higgs production events from the huge background at LHC, assuming the case of a
mass value GeV. We use the high performance neurochip TOTEM,
trained by the Reactive Tabu Search algorithm (RTS), which could be used for
on-line purposes. Two different sets of input variables are compared.Comment: 4 pages,1 figure, requres espcrc2.sty and epsfig.sty. Work prsented
in The 5th Topical Seminar on ``The irresistible rise of the Standard
Model'', San Miniato, Tuscany, Italy, April 21-25 199
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