Search results for "PPM"

showing 10 items of 20 documents

Optimum Design and Performance of an Electron Gun for a Ka-Band TWT

2019

This paper deals with optimum design and development of a thermionic electron gun to meet specified beam requirements within defined electric and geometric constraints for a Ka -band traveling wave tube (TWT) for space applications. The electron gun design is based on the Pierce method and carried out according to the iterative process indicated by Vaughan. The design of a periodic permanent magnet (PPM) beam focusing system for the stability of the beam is also required. A sensitivity analysis, by varying electric parameters and geometric parameters, is presented and taken into account as a fundamental role to the aim of optimizing the design of the Pierce gun. A cathode current value of 5…

010302 applied physicsBeam diameterMaterials sciencebusiness.industryTraveling-wave tubeSettore ING-INF/01 - Elettronica01 natural sciencesCathodeElectronic Optical and Magnetic Materialslaw.inventionSettore ING-IND/31 - ElettrotecnicaOpticslawcontrol grid electron gun PPM focusing system sensitivity analysis shadow grid TWTMagnet0103 physical sciencesKa bandElectrical and Electronic EngineeringbusinessBeam (structure)VoltageElectron gunIEEE Transactions on Electron Devices
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Does the GATT/WTO promote trade? After all, Rose was right

2019

This paper re-examines the effect of the GATT/WTO on trade using recent econometric developments that allow us estimating structural gravity equations with the Poisson pseudo-maximum likelihood (PPML) estimator on a large dataset that requires computing high-dimensional fixed effects. By doing so, we overcome computational limitations that are present in previous studies. In line with Rose’s (Am Econ Rev 94:98–114, 2004) seminal work, we find that, unlike regional trade agreements and currency unions, the GATT/WTO accession has not generated positive trade effects. This result is robust to the use of alternative measures of trade flows, across periods and country groups, to changes in the p…

Comerç RegulacióVariablesmedia_common.quotation_subject05 social sciencesInternational economicsPPMLAccessionRegional tradeGravity model of tradeCurrency0502 economics and businessEuropean integrationEconomicsEconomia Mètodes estadístics050207 economicsGeneral Economics Econometrics and Finance050205 econometrics media_common
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EMU and trade: A PPML re‐assessment with intra‐national trade flows

2020

This paper examines the EMU effect on trade for the eleven early joiners and Greece relying for the first time on data that include both international and intra‐national trade flows, in line with all the microfoundations of the structural gravity model of trade. We find that the overall EMU impact on trade is positive between its members and, specially, for trade between members and non‐members. Interestingly, we further show that the effect of the EMU on bilateral trade remarkably differs across countries. For Ireland, Belgium–Luxembourg, Spain, Portugal and Austria, we find robust evidence that EMU has boosted trade both with other members and with third countries, while for Finland, Fran…

Economics and Econometrics050208 finance05 social sciencesInternational economicsPPMLBilateral tradeGravity model of tradeAccounting0502 economics and businessPolitical Science and International RelationsEconomicsGravity equation050207 economicsFinanceMicrofoundationsThe World Economy
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A Novel Method of Distance Measurement Based on Pulse Position Modulation and Synchronization of Chaotic Signals Using Ultrasonic Radar Systems

2009

This paper deals with a novel method of transmission and receipt of a signal based on both the property of two chaotic systems generating the same chaotic signal when they are synchronized and the property of pulse position modulation (PPM) to be insensitive to the distortions of the transmission channel. The method is discussed in the context of ultrasonic radar systems, in which the transmitter and receiver, which consist of ultrasonic sensors, are near each other, and the received signal consists of the transmitted signal reflected by an obstacle. A reference sinusoidal signal is superimposed to a chaotic signal generated by a master chaotic system, and the whole signal is modulated acco…

Engineeringanimal structuresSignal generatorbusiness.industrySignal edgeSignalSignal transitionAnalog signalTransmission (telecommunications)Settore ING-INF/04 - AutomaticaChaotic pulse position modulation (CPPM) chaotic system synchronization crosstalk distance measurement multipath fading ultrasonic sensors.Electronic engineeringDemodulationComputerSystemsOrganization_SPECIAL-PURPOSEANDAPPLICATION-BASEDSYSTEMSElectrical and Electronic EngineeringSignal transfer functionbusinessInstrumentationComputer Science::Information Theory
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Is the Serum N Terminal Pro-Brain Natriuretic Peptide the Best Candidate Biomarker for Long-term Prognosis in Patients with Prosthesis-patient Mismat…

2014

AGE8. Is the Serum N Terminal Pro-Brain Natriuretic Peptide the Best Candidate Biomarker for Long-term Prognosis in Patients with Prosthesis-patient Mismatch after Mitral Valve Replacement? C. R. Balistreri1, C. Pisano1, R. Franchino1, S.R. Vacirca1, F. Crapanzano1, O. F. Triolo1, C. Palmeri1, G. Ruvolo1 1University Of Palermo, Palermo, Italy Background: Natriuretic peptides (NPs) are released from the heart in response to pressure and volume overload. Among these, B-NP and Nterminal- proBNP (NT-proBNP) have become important diagnostic tools for the management of heart failure. However, B-NP and NT-proBNP levels reflect complications of systolic and diastolic function as well as alteration …

Natriuretic peptides (NPs) B-NP and Nterminal- proBNP (NT-proBNP) prosthesis patient mismatch (PPM) mitral valve replacement (MVR)
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The Positive Personality Model (PPM): Exploring a New Conceptual Framework for Personality Assessment.

2018

The aim of this paper is to explore a new framework for personality assessment that may function as sanity nosology of personality traits: the Positive Personality Model. The recent publication of DSM-5 created the opportunity to assess personality traits as dimensional constructs (American Psychiatric Association, 2013). In Section III, five maladaptive personality traits are proposed as the maladaptive versions of Five Factor Model (FFM) traits (Costa and McCrae, 1985). This approach draws on the existing idea of conceptualizing pathological and typical personality traits as part of a continuum. It places DSM-5’s maladaptive traits in a sickness pole and FFM’s traits in a “typical” pole. …

PPMmedia_common.quotation_subjectassessmentlcsh:BF1-990Population050109 social psychology050105 experimental psychologyDSM-5DSM-5PersonalityPsychology0501 psychology and cognitive sciencesBig Five personality traitseducationGeneral Psychologymedia_commonOriginal Researcheducation.field_of_studypositive personalitypositive traits05 social sciencesModerationlcsh:PsychologyConvergent validitypersonalityTraitPersonality Assessment InventoryPsychologyClinical psychologyFrontiers in psychology
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Couplings in coupled channels versus wave functions in the case of resonances: Application to the twoΛ(1405)states

2011

In this paper we develop a formalism to evaluate wave functions in momentum and coordinate space for the resonant states dynamically generated in a unitary coupled channel approach. The on-shell approach for the scattering matrix, commonly used, is also obtained in quantum mechanics with a separable potential, which allows one to write wave functions in a trivial way. We develop useful relationships among the couplings of the dynamically generated resonances to the different channels and the wave functions at the origin. The formalism provides an intuitive picture of the resonances in the coupled channel approach, as bound states of one bound channel, which decays into open ones. It also pr…

PhysicsNuclear and High Energy Physics010308 nuclear & particles physicsFísica01 natural sciencesSchrödinger equationSeparable spaceLippmann–Schwinger equationMany-body problemsymbols.namesakeQuantum mechanics0103 physical sciencesBound statesymbolsCoordinate space010306 general physicsWave functionS-matrixPhysical Review D
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Doubly charmed exotic mesons: A gift of nature?

2011

Article history: We study doubly charmed exotic states by solving the scattering problem of two D mesons. Our results point to the existence of a stable isoscalar doubly charmed meson with quantum numbers (I) J P = (0)1 + . We perform a thorough comparison to the results obtained within the hyperspherical harmonic formalism. Such exotic states could be measured at LHC and RHIC. Their experimental observation would,

PhysicsNuclear and High Energy PhysicsParticle physicsLarge Hadron ColliderMesonIsoscalarNuclear TheoryHigh Energy Physics::PhenomenologyQuark modelHadronQuantum numberLippmann–Schwinger equationNuclear physicsHadron spectroscopyHigh Energy Physics::ExperimentNuclear ExperimentPhysics Letters B
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Study of meson production in nuclei near threshold

2009

We present a study of the η production at low energies in pd collision with 3He and pd nuclear systems in the final state. The η production mechanism is described by a two-step model and the final state interactions are included fully. The η - d and η - 3He final state interactions are incorporated through the solution of the Lippmann Schwinger equation for a half off-shell η - AT-matrix. For η - d this t -matrix is written in a factorized form, with an off-shell form factor multiplying an on-shell part having the scattering length representation. The p - d final state interaction is included by multiplying the production matrix element by the inverse of the Jost function which includes th…

PhysicsNuclear and High Energy PhysicsRank (linear algebra)Quantum mechanicsCoulombForm factor (quantum field theory)General Physics and AstronomyInverseScattering lengthProduction (computer science)State (functional analysis)Atomic physicsLippmann–Schwinger equation
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Two pion decay of the Roper resonance

2002

We evaluate the two pion decay of the Roper resonance in a model where explicit re-scattering of the two final pions is accounted for by the use of unitarized chiral perturbation theory. Our model does not include an explicit $\epsilon$ or $\sigma$ scalar-isoscalar meson decay mode, instead it generates it dynamically by means of the pion re-scattering. The two ways, explicit or dynamically generated, of introducing this decay channel have very different amplitudes. Nevertheless, through interference with the other terms of the model we are able to reproduce the same phenomenology as models with explicit consideration of the $\epsilon$ meson.

PhysicsNuclear and High Energy PhysicsRoper resonanceParticle physicsChiral perturbation theoryNuclear TheoryUnitarityMesonHigh Energy Physics::LatticeNuclear TheoryFOS: Physical sciencesFísicaSigmaLippmann–Schwinger equationNuclear Theory (nucl-th)PionHigh Energy Physics::ExperimentNuclear ExperimentPhenomenology (particle physics)Physical Review C
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