The Physics Graduate Program invites everyone to:
Qualifying Examination for Doctoral Thesis
William Martarello
INFLUÊNCIA DO ESPAÇO-TEMPO CURVO NO CÁLCULO DO LIVRE CAMINHO MÉDIO DE NEUTRINOS EM UM GÁS INTERAGENTE
FORMADO POR PRÓTONS, NÊUTRONS E ELÉTRONS
Defense Committee:
Prof. Dr. Celso de Camargo Barros Junior – (president) – UFSC/FSC
Prof. Dr. José Ricardo Marinelli – (local member) – UFSC/FSC
Prof. Dr. Marcus Emmanuel Benghi Pinto – (local member) – UFSC/FSC
Prof. Dr. Luis Guilherme de Carvalho Rego – (local member) – UFSC/FSC
Date: 22/December/2016 – thursday – Time: 9:00 am – Place: Sala 212 – Auditório do Departamento de Física
THE PHYSICS GRADUATE PROGRAM invites everyone to the seminar:
Phase transitions and self-organized criticality in networks of stochastic spiking neurons.
Prof. Dr. Osame Kinouchi
Departamento de Física – FFCLRP – USP
Abstract:
Phase transitions and critical behavior are crucial issues both in theoretical and experimental neuroscience. We report analytic and computational results about phase transitions and self-organized criticality (SOC) in networks with general stochastic neurons. The stochastic neuron has a firing probability given by a smooth monotonic function Phi(V) of the membrane potential V, rather than a sharp firing threshold. We find that such networks can operate in several dynamic regimes (phases) depending on the average synaptic weight and the shape of the firing function Phi. In particular, we encounter both continuous and discontinuous phase transitions to absorbing states. At the continuous transition critical boundary, neuronal avalanches occur whose distributions of size and duration are given by power laws, as observed in biological neural networks. We also propose and test a new mechanism to produce SOC: the use of dynamic neuronal gains — a form of short-term plasticity probably in the axon initial segment (AIS) — instead of depressing synapses at the dendrites (as previously studied in the literature). The new self-organization mechanism produces a slightly supercritical state, that we called SOSC, in accord to some intuitions of Alan Turing.
Date: 19/December/2016 – (monday) – Place: Sala 212 – Auditório do Departamento de Física- Time: 10h30min
The Physics Graduate Program invites everyone to:
Qualifying Examination for Doctoral Thesis
William Rafael Tavares
Matéria de quarks e mésons magnetizada sob influência de temperaturas e densidades finitas
Defense Committee:
Prof. Dr. Sidney dos Santos Avancini – (president) – UFSC/FSC
Prof. Dr. Ricardo Luciano Sonego Farias – (external member) – UFSM
Prof. Dr. Marcus Emmanuel Benghi Pinto – (local member) – UFSC/FSC
Prof. Dr. Celso de Camargo Barros Junior – (local member) – UFSC/FSC
Date: 16/December/2016 – friday – Time: 2:00 pm – Place: Sala 212 – Auditório do Departamento de Física
The Physics Graduate Program invites everyone to:
Qualifying Examination for Doctoral Thesis
Sérgio Souto Rocha
ESTRUTURAS DEFORMADAS NA PASTA NUCLEAR 3D NA APROXIMAÇÃO DE THOMAS FERMI
Defense Committee:
Prof. Dr. Sidney dos Santos Avancini – (president) – UFSC/FSC
Prof. Dr. Eduardo Inacio Duzzioni – (external member) – UFSC/FSC
Prof. Dr. José Ricardo Marinelli – (Local member) – UFSC/FSC
Prof. Dr. Celso de Camargo Barros Junior – (local member) – UFSC/FSC
Date: 16/December/2016 – friday – Time: 10:00am – Place: Sala 212 – Auditório do Departamento de Física
THE PHYSICS GRADUATE PROGRAM invites everyone to the seminar:
Kelvin: past, present and future.
Prof. Felix Sharipov
Departamento de Física/UFPR
Abstract:
Four basic physical units of SI, viz., kilogram, ampere, mole, and kelvin will be redefined in 2018. Their definitions will be related to universal physical constants such as Planck constant, elementary charge, number of Avogadro and Boltzmann constant. At the moment, great efforts are being done to measure these constants with a high accuracy. The lecture gives a brief history of the kelvin definition. Its future definition via the Boltzmann constant will be presented. Experimental and theoretical results related to the future definition of kelvin are reviewed.
Date: 06/December/2016 – (tuesday) – Place: Sala 212 – Auditório do Departamento de Física- Time: 14 horas
