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Search Results: 1 - 10 of 38717 matches for " Francisco Tiago Lima "
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Optical Bistability in an Acousto-Optic Tunable Filter (AOTF) Operating with Short Optical Pulses  [PDF]
Karlo David Alves Sabóia, Alex Sander Barros Queiroz, Francisco Tiago Lima, Cícero Saraiva Sobrinho, Jose Wally Mendon?a Menezes, Antonio Sergio Bezerra Sombra
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2012, DOI: 10.4236/jemaa.2012.43015
Abstract: In this paper we report for the first time the presence of bistability in an acoustic-optic tunable filter (AOTF) operating with ultrashort (2 ps) optical light pulses. The results for the study of bistability has shown the dependence of the hysteresis curve with the product of the coupling constant (κ) by the length of the device (ξL) and the conversion power-coupling constant factor (G). The range of bistability varies significantly with both G and with κξL parameters. The variation of κξL directly increases the size of the range of bistability hysteresis while the increase in G causes the bistability to occur at low powers. The phenomenon of optical bistability (OB) is the object of increasing interest due to its possibilities for important device applications. A bistable device is a device with a capability to generate two different outputs for a given input and the physical requirements for this are an intensity-dependence refractive index and an optical feedback mechanism.
Perfus?o miocárdica dinamica por tomografia computadorizada de dupla fonte de raio X
Parga Filho, José Rodrigues;Lima, Cintia Souza Lima Moraes;Lima, Felipe Gallego;Jaques, Tiago da Silveira;ávila, Luiz Francisco Rodrigues de;Kalil Filho, Roberto;
Arquivos Brasileiros de Cardiologia , 2012, DOI: 10.1590/S0066-782X2012000300014
Abstract: we report a dual-source computed tomography study of dynamic and quantitative myocardial perfusion in a 44-year-old patient with previous documented coronary artery disease. quantitatively, the tomography showed myocardial perfusion deficit in the territories with significant coronary stenosis, confirmed by computed tomography angiography and conventional angiography. dual-source computed tomography allowed dynamic perfusion and anatomic evaluation in a single study during the follow-up of this patient.
Tiago da Silva Teófilo,Matheus Balduíno Moreira,Jo?o Chysostomo de Resende Júnior,Ronaldo Francisco de Lima
Ciência Animal Brasileira , 2009,
Fast Fading Channel Neural Equalization Using Levenberg-Marquardt Training Algorithm and Pulse Shaping Filters  [PDF]
Tiago Mota, Jorgean Leal, Ant?nio Lima
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2014, DOI: 10.4236/ijcns.2014.72008

Artificial Neural Network (ANN) equalizers have been successfully applied to mitigate Inter symbolic Interference (ISI) due to distortions introduced by linear or nonlinear communication channels. The ANN architecture is chosen according to the type of ISI produced by fixed, fast or slow fading channels. In this work, we propose a combination of two techniques in order to minimize ISI yield by fast fading channels, i.e., pulse shape filtering and ANN equalizer. Levenberg-Marquardt algorithm is used to update the synaptic weights of an ANN comprise only by two recurrent perceptrons. The proposed system outperformed more complex structures such as those based on Kalman filtering approach.

Controlling the Tax Evasion Dynamics via Majority-Vote Model on Various Topologies  [PDF]
Francisco W. S. Lima
Theoretical Economics Letters (TEL) , 2012, DOI: 10.4236/tel.2012.21017
Abstract: Within the context of agent-based Monte-Carlo simulations, we study the well-known majority-vote model (MVM) with noise applied to tax evasion on simple square lattices (LS), Honisch-Stauffer (SH), directed and undirected Bara-basi-Albert (BAD, BAU) networks. In to control the fluctuations for tax evasion in the economics model proposed by Zaklan, MVM is applied in the neighborhod of the noise critical qc to evolve the Zaklan model. The Zaklan model had been studied recently using the equilibrium Ising model. Here we show that the Zaklan model is robust because this can be studied using equilibrium dynamics of Ising model also through the nonequilibrium MVM and on various topologies cited above giving the same behavior regardless of dynamic or topology used here.
The Dog as a Risk Factor in Transmission of Visceral Leishmaniasis: A Review  [PDF]
Francisco Assis Lima Costa
Advances in Infectious Diseases (AID) , 2012, DOI: 10.4236/aid.2012.22006
Abstract: Visceral leishmaniasis (VL) is a serious public health problem in Brazil and worldwide. Despite the euthanasia of dogs serologically positive, such action has not solved the endemic in Brazil. A risk area for VL involves the presence of the vector, the occurrence of canines and the record of human cases. The factors that have favored the persistence and spread of VL in Brazil are related to the predatory action of man on the environment, to the migratory movements and rural exodus, and a close coexistence of man and animals. Thus considering the epidemiological chain of VL, one fact seems clear: we do not know yet the true extent of the participation of the dog in the infectious cycle of VL. The clinical disease is an important indicator of the extent of the problem in an endemic area. The immunological events are complex and involve resistance and susceptibility to canine visceral leishmaniasis (CVL). One aspect in CVL is that many symptomatic dogs underwent xenodiagnosis not infect the vector. In such cases the pattern recognition receptors CD11b+, TLR2+, and NO present higher values for dogs with results in immunohistochemistry of skin and xenodiagnosis negative (IMH-/XENO-) than dogs with immunohistochemistry in skin and xenodiagnosis positive (IMH+/XENO+), suggesting that innate immunity modulates the competence of the dog to infect the vector. The organic response in CVL varies from individual to individual and within the same individual, with a strong evidence of being organ-specific. Only 20% of asymptomatic dogs have parasites in the skin and 15% are able to recover from clinical signs and eliminate the parasites spontaneously. In this review, we analyze the epidemiology of visceral leishmaniasis and clinical, immunological and pathological conditions that can contribute to understanding the role of dogs in transmission of visceral leishmaniasis.
Tax Evasion Dynamics via Non-Equilibrium Model on Complex Networks  [PDF]
Francisco W. S. Lima
Theoretical Economics Letters (TEL) , 2015, DOI: 10.4236/tel.2015.56089
Abstract: The Zaklan model has become an excellent mechanism to control the tax evasion fluctuations (TEF) in a people- or agent-based community. Initially, the equilibrium Ising model (IM) had been used as a dynamic of temporal evolution of the Zaklan model near the critical point of the IM. On some complex network the IM presents no critical points or well-defined phase transitions. Then, through Monte Carlo simulations we study the recurring problem of the TEF control using the version of non-equilibrium Zaklan model as a control mechanism for TEF via agent-based non-equilibrium majority-vote model (MVM). Here we study the TEF on directed Barabási-Albert (BAD) and Apollonian (ANs) networks where the IM is not applied. We show that the Zaklan model can be also studied using non-equilibrium dynamics through of the non-equilibrium MVM on complex topologies cited above, giving the behavior of the TEF regardless of dynamic or topology used here.
Tax Evasion Dynamics via Non-Equilibrium Model on Directed Small-World Networks  [PDF]
Francisco W. S. Lima
Theoretical Economics Letters (TEL) , 2016, DOI: 10.4236/tel.2016.64086
Abstract: Based on people or agent community, we use the Zaklan model as a mechanism to control the tax evasion fluctuations. Here, we use the non-equilibrium Sánchez-López-Rodríguez model (SLR), i.e. directed Watts-Strogatz networks, as a dynamics of the temporal evolution of the Zaklan model. We simulate the response of tax cheaters to punishment by an auditing authority as well as to the behavior of their neighbors. The higher the punishment is, the smaller is the simulated probability to cheat. This reasonable result shows that our model is qualitatively good.
Open Access and Multilingual Approach to Communication Journals – The case and the editor’s perspective of Observatorio (OBS*) Journal and the importance of Open Science for the Knowledge Society
Rita Espanha,Tiago Lima Quintanilha
Online Journal of Communication and Media Technologies , 2011,
Abstract: This paper is about the contribution of the network society to a more open and cross-cultural way of making and publishing science. Basically, and speaking of Observatorio (OBS*) e-journal that has been published by OberCom-Lisbon, we believe that it might be relevant to note the tendency that science, in relation to its distribution model, has been showing lately. We think more traditional ways of publishing science in closed platforms (as paper format), where legitimacy was only dependent on the strict editorial team, has definitely lost its space in scientific publications on open online platforms, where legitimacy is now managed from the contribution of several experts: a model named Open Science. The open science movement replaces the traditional, hierarchical and centralized logic with more dynamic horizontal collaboration among peers: a form of community production, decentralized and self-selective. One can say that the growth of the OBS* e-journal in Portugal, rather than other scientific journals in the same areas, but in more traditional formats, clearly demonstrates that a self-centred science with fewer users and whose distribution of produced knowledge implies bigger reliance on funding, is giving rise to a more open science with more users, for whom the transmission of produced knowledge is more autonomous, effective, cheaper, etc.
Tableaux for Dynamic Logic of Propositional Assignments
Tiago de Lima,Andreas Herzig
Computer Science , 2014,
Abstract: The Dynamic Logic for Propositional Assignments (DL-PA) has recently been studied as an alternative to Propositional Dynamic Logic (PDL). In DL-PA, the abstract atomic programs of PDL are replaced by assignments of propositional variables to truth values. This makes DL-PA enjoy some interesting meta-logical properties that PDL does not, such as eliminability of the Kleene star, compactness and interpolation. We define and analytic tableaux calculus for DL-PA and show that it matches the known complexity results.
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