6688376
Frequency sensitivity in Hodgkin–Huxley systems
Abstract. The frequency sensitivity of weak periodic signal detection has been studied via numerical simulations for both a single neuron and a neuronal network. The dependence of the critical amplitude of the signal upon its frequency and a resonance between the intrinsic oscillations of a neuron and the signal could account for the frequency sensitivity. In the presence of both a subthreshold periodic signal and noise, the signal-to-noise ratio (SNR) of the output of either a single neuron or a neuronal network present the typical characteristics of stochastic resonance. In particular, there exists a frequency-sensitive range of 30–100 Hz, and for signals with frequencies within this range the SNRs have large values. This implies that the system under consideration (a single neuron or a neuronal network) is more sensitive to the detection of periodic signals, and the frequency sensitivity may be of a functional significance to signal processing.
7396266
Dynamics of the noisy neural network
Abstract. The dynamic features of interspike interval sequences and structures of spatiotemporal patterns of firing in a coupled noisy neural network are investigated. The system displays complex dynamics under periodic external stimuli. The dynamics is modulated by a periodic impulse-like synaptic current which relates to a global coupling interaction between neurons. The firings of the stimulated neurons are phase-locked to this current. In addition, the interspike interval histograms are studied for the case of frozen noise which does not change its value within a time interval once it has been distributed onto the network. It is found that the peaks in these histograms are located at integer multiples of the period of the external stimulus, and the heights of these peaks decay exponentially, which corresponds to the experimental results.
62166223
Study on the Si-Ge Nanowire MOSFETs with the Core-Shell Structure
This paper investigates the transport properties of the silicon-germanium nanowire MOSFETs with core-shell structure by using a finite element numerical method for electronic structure, energy level, and channel current computation. Coupled Poisson's equation to Schrodinger's equation for electrostatics calculation and electron structure to current transport equation for channel current computation, the electronic structure, quantized energy levels, relevant wave functions and charge distribution are solved selfconsistently for the core-shell structure MOSFETs. Furthermore, based on these findings, the transistor performances, including the capacitance characteristics and drain current, are also predicted.
13252008
Anode-ALM: An Aggregation-Based Application Level Multicast for Media Streaming
Building application level multicast (ALM) for media streaming, we had better keep the invariability of source to-end delay (S2EDelay) of any node on the tree, so as to avoid delay jitter problem. In this paper, we proposed an aggregation-based ALM architecture, which aggregates the unstable nodes within a local area into a relative stable aggregation node Anode, and then builds tree by Anodes. Anode shields node’s dynamicity inside and behaves as a stable one outside. To build the architecture, we first proposed an Anode structure by n-dimension anti-cube, and proposed a distributed algorithm to bind the logic view and physical view of an Anode dynamically by the differentiation and assimilation operations, which maintain the integrality of the logic view while the physical view changes dynamically. Experiment results indicate that our algorithm can keep theS2EDelay invariability of the built ALM tree effectively.
14281509
A Quick Group Search Optimizer with Passive Congregation and its Convergence Analysis
This paper presents a quick group search optimizer with passive congregation (QGSOPC) for optimum design of pin connected structure. The algorithm is based on the quick group search optimizer (QGSO). The QGSOPC algorithm is verified and compared with the HPSO, GSO and QGSO algorithm used for the designs of two planar and spatial truss structures. The results show that the QGSOPC algorithm not only has preferable convergence rate and accuracy, but also it has the best stability of convergence rate and accuracy. It is desired for QGSOPC to be used more effectively for practical structural optimal design problems.
27479532
Subspace-Based Blind Detection of Space-Time Coding
Space-time coding (STC) schemes for communication systems employing multiple transmit and receive antennas have received considerable interest recently. On space-time coding, some algorithms with perfect channel state information (CSI) have been proposed. In certain fast varying situation, however, it may be difficult to estimate the channel accurately and it is natural to study the blind detection algorithm without CSI. In this paper, based on subspace, a new blind detection algorithm without CSI is proposed. Using singular value decomposition (SVD) on output signal, noise subspace and signal subspace, which keep orthogonal to each other, are obtained. By searching the intersection of the signal subspace and the limited symbol vector set, symbol detection is achieved. The simulations illustrate that the proposed algorithm significantly improves system performance by receiving more output signals relative to transmit symbols. Furthermore, the presented algorithm is robust to the fading channel that changes between two successive blocks.
41632859
A Novel Frequency Offset Estimator over Frequency Selective Fading Channels by Using Correlative Coding
A new data-aided carrier frequency offset (CFO) estimation technique is presented for correlative coded OFDM systems in the presence of strong multipath. Different from traditional data-aided estimation techniques, the technique estimates CFO by detecting amplitude of pilots rather than their phase shift and removes effects on CFO estimation due to intercarrier interference by an iterative compensation method. A theoretical analysis of its performance has been derived and simulation results comparing the new technique with a traditional data-aided estimation technique are presented.