Oscillator Network
Mostrando 1-12 de 17 artigos, teses e dissertações.
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1. Multicolor Quantum Correlations in the Optical Parametric Oscillator / Correlações quânticas multicolores no oscilador paramétrico ótico
We have investigated the collective quantum properties of the three bright light beams produced by an optical parametric oscillator (OPO) operating above threshold, named pump, signal, and idler. We have analyzed experimentally their intensity and phase quantum fluctuations, and how they are correlated. For the first time, we have observed the existence of p
Publicado em: 2008
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2. Modelagem ambiental de uma casa de vegetação utilizando rede de osciladores de Van Der Pol. / Greenhouse environmental modeling using Van Der Pol oscillator network.
Agricultural automation is an important area in the development of Brazilian production in recent years. Often, measurement and control of the internal conditions of greenhouses are not easy to implement at a reasonable cost. Researches in this area look for models using computational theory, foreseeing the behavior of internal variables of a greenhouse from
Publicado em: 2007
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3. ONNIS-GI: uma rede neural oscilatória para segmentação de imagens implementada em arquitetura maciçamente paralela
A presente tese apresenta a concepção de uma rede neural oscilatória e sua realização em arquitetura maciçamente paralela, a qual é adequada à implementação de chips de visão digitais para segmentação de imagens. A rede proposta, em sua versão final, foi denominada ONNIS-GI (Oscillatory Neural Network for Image Segmentation with Global Inhibiti
Publicado em: 2007
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4. Extração de contornos de figuras via sincronismo em redes de osciladores com acoplamento dinâmico
Uma variante do modelo de Kuramoto para osciladores de fase com acoplamento dinâmico é estudada. A intensidade do acoplamento é ajustada pela diferença de fases dos osciladores, de forma que a conexão é reforçada para osciladores sincronizados e enfraquecida para osciladores não sincronizados. As soluções de equilíbrio e suas estabilidades são ap
Publicado em: 2006
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5. Locally excitatory chaotic oscillator network for scene segmentation.
A aplicaÃÃo de sistemas dinÃmicos para processamento de informaÃÃes à um tÃpico promissor de pesquisa. Um excelente exemplo sÃo as redes neurais caÃticas. Em geral, o caos tem duas caracterÃsticas marcantes, quais sÃo: complexidade dinÃmica e grande regularidade. Estas caracterÃsticas geram propriedades de sistemas caÃticos muito ricas e, ao me
Publicado em: 1998
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6. Synaptic depression creates a switch that controls the frequency of an oscillatory circuit
Synaptic depression is a form of short-term plasticity exhibited by many synapses. Nonetheless, the functional significance of synaptic depression in oscillatory networks is not well understood. We show that, in a recurrent inhibitory network that includes an intrinsic oscillator, synaptic depression can give rise to two distinct modes of network operation.
The National Academy of Sciences.
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7. Integration of circadian and phototransduction pathways in the network controlling CAB gene transcription in Arabidopsis
The transcription of CAB genes, encoding the chlorophyll a/b-binding proteins, is rapidly induced in dark-grown Arabidopsis seedlings following a light pulse. The transient induction is followed by several cycles of a circadian rhythm. Seedlings transferred to continuous light are known to exhibit a robust circadian rhythm of CAB expression. The precis
The National Academy of Sciences of the USA.
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8. Global processing of visual stimuli in a neural network of coupled oscillators.
An oscillator neural network model is presented that is capable of processing local and global attributes of sensory input. Local features in the input are encoded in the average firing rate of the neurons while the relationships between these features can modulate the temporal structure of the neuronal output. Neurons that share the same receptive field int
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9. Robustness properties of circadian clock architectures
Robustness, a relative insensitivity to perturbations, is a key characteristic of living cells. However, the specific structural characteristics that are responsible for robust performance are not clear, even in genetic circuits of moderate complexity. Formal sensitivity analysis allows the investigation of robustness and fragility properties of mathematical
National Academy of Sciences.
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10. Fast synaptic inhibition promotes synchronized gamma oscillations in hippocampal interneuron networks
Networks of GABAergic interneurons are of critical importance for the generation of gamma frequency oscillations in the brain. To examine the underlying synaptic mechanisms, we made paired recordings from “basket cells” (BCs) in different subfields of hippocampal slices, using transgenic mice that express enhanced green fluorescent protein (EGFP) under t
The National Academy of Sciences.
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11. Light-Dark Cycle Memory in the Mammalian Suprachiasmatic Nucleus
The mammalian circadian oscillator, or suprachiasmatic nucleus (SCN), contains several thousand clock neurons in its ventrolateral division, many of which are spontaneous oscillators with period lengths that range from 22 to 28 h. In complete darkness, this network synchronizes through the exchange of action potentials that release vasoactive intestinal poly
The Biophysical Society.
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12. Synchronizing genetic relaxation oscillators by intercell signaling
The ability to design and construct synthetic gene regulatory networks offers the prospect of studying issues related to cellular function in a simplified context; such networks also have many potential applications in biotechnology. A synthetic network exhibiting oscillatory behavior has recently been constructed [Elowitz, M. B. & Leibler, S. (2000) Nature
The National Academy of Sciences.