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PHARMACOLOGICAL STUDY OF THE ONE SPIKE SPHERICAL NEURON PHENOTYPE IN GYMNOTUS OMARORUM

NEUROSCIENCE 2014年 258卷 347-354页

作者： Nogueira, J. Caputi, A. A. Inst Invest Biol Clemente Estable Dept Integrat & Computat Neurosci Montevideo Uruguay Univ Republica Fac Med Dept Histol & Embriol Montevideo Uruguay

The intrinsic properties of spherical neurons play a fundamental role in the sensory processing of self-generated signals along a fast electrosensory pathway in electric fish. Previous results indicate that the spherical neuron's intrinsic properties depend mainly on the presence of two resonant currents that tend to clamp the voltage near the resting potential. Here we show that these are: a low-threshold potassium current blocked by 4-aminopyridine and a mixed cationic current blocked by cesium chloride. We also show that the low-threshold potassium current also causes the long refractory period, explaining the necessary properties that implement the dynamic filtering of the self-generated signals previously described. Comparative data from other fish and from the auditory system indicate that other single spiking onset neurons might differ in the channel repertoire observed in the spherical neurons of Gymnotus omarorum. (C) 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

关键词： intrinsic properties electroreception time coding low responsiveness window onset neuron single spiking

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Near In Place Linear time Minimum Redundancy coding

Near In Place Linear Time Minimum Redundancy Coding

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Data Compression Conference (DCC)

作者： Karkkainen, Juha Tischler, German Univ Helsinki Dept Comp Sci FI-00014 Helsinki Finland

ISBN: (纸本)9781467360371

In this paper we discuss data structures and algorithms for linear time encoding and decoding of minimum redundancy codes. We show that a text of length n over an alphabet of cardinality sigma can be encoded to minimum redundancy code and decoded from minimum redundancy code in time O(n) using only an additional space of O(sigma) words (O(sigma log n) bits) for handling the auxiliary data structures. The encoding process can replace the given block code by the corresponding minimum redundancy code in place. The decoding process is able to replace the minimum redundancy code given in sufficient space to store the block code by the corresponding block code.

关键词： Block codes time coding minimum NATIONAL EMERGENCY ALARM REPEATER Codes DEcoding Data structures ancillary data

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A new design criterion for spherically-shaped division algebra-based space-time codes

A new design criterion for spherically-shaped division algeb...

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IEEE Information Theory Workshop (ITW)

作者： Luzzi, Laura Vehkalahti, Roope CNRS ENSEA UCP Lab ETIS Cergy Pontoise France Univ Turku Dept Mat Turku Finland

ISBN: (纸本)9781479913213

This work considers normalized inverse determinant sums as a tool for analyzing the performance of division algebra based space-time codes for multiple antenna wireless systems. A general union bound based code design criterion is obtained as a main result. In our previous work, the behavior of inverse determinant sums was analyzed using point counting techniques for Lie groups;it was shown that the asymptotic growth exponents of these sums correctly describe the diversity-multiplexing gain trade-off of the space-time code for some multiplexing gain ranges. This paper focuses on the constant terms of the inverse determinant sums, which capture the coding gain behavior. Pursuing the Lie group approach, a tighter asymptotic bound is derived, allowing to compute the constant terms for several classes of space-time codes appearing in the literature. The resulting design criterion suggests that the performance of division algebra based codes depends on several fundamental algebraic invariants of the underlying algebra.

关键词： space-time codes time coding division algebra sums Constant term Determinants Lie group DESIGN CRITERIA CARRIER SYSTEM arithmetic

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time disparity sensitive behavior and its neural substrates of a pulse-type gymnotiform electric fish, Brachyhypopomus gauderio

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JOURNAL OF COMPARATIVE PHYSIOLOGY A-NEUROETHOLOGY SENSORY NEURAL AND BEHAVIORAL PHYSIOLOGY 2013年第7期199卷 583-599页

作者： Matsushita, Atsuko Pyon, Grace Kawasaki, Masashi Sokendai Dept Evolutionary Studies Biosyst Hayama 2400193 Japan Univ Virginia Dept Biol Charlottesville VA 22904 USA

Roles of the time coding electrosensory system in the novelty responses of a pulse-type gymnotiform electric fish, Brachyhypopomus, were examined behaviorally, physiologically, and anatomically. Brachyhypopomus responded with the novelty responses to small changes (100 mu s) in time difference between electrosensory stimulus pulses applied to different parts of the body, as long as these pulses were given within a time period of similar to 500 mu s. Physiological recording revealed neurons in the hindbrain and midbrain that fire action potentials time-locked to stimulus pulses with short latency (500-900 mu s). These time-locked neurons, along with other types of neurons, were labeled with intracellular and extracellular marker injection techniques. Light and electron microscopy of the labeled materials revealed neural connectivity within the time coding system. Two types of time-locked neurons, the pear-shaped cells and the large cells converge onto the small cells in a hypertrophied structure, the mesencephalic magnocellular nucleus. The small cells receive a calyx synapse from a large cell at their somata and an input from a pear-shaped cell at the tip of their dendrites via synaptic islands. The small cells project to the torus semicircularis. We hypothesized that the time-locked neural signals conveyed by the pear-shaped cells and the large cells are decoded by the small cells for detection of time shifts occurring across body areas.

关键词： Electrosensory system Phase comparison Phase-locked neurons Temporal coding time coding

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A Fast Fractional Motion Estimation Algorithm and Architecture for H.264/AVC Multiview Video coding

A Fast Fractional Motion Estimation Algorithm and Architectu...

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55th IEEE International Midwest Symposium on Circuits and Systems (MWSCAS)

作者： Chang, Yuan-Teng Chung, Wen-Hao Ind Technol Res Inst Informat & Commun Res Labs Hsinchu Taiwan

ISBN: (纸本)9781467325271

This paper presents a fast fractional motion estimation (FME) and the associated VLSI architecture for H.264/AVC multiview video coding. The proposed FME automatically turns off the mode P8x8 by exploiting the results of integer motion estimation and similarity between views. In addition, the fraction-pel refinement of integer motion or disparity vector in any partition may be skipped according to the difference of their rate-distortion cost. This algorithm accelerates the FME by nearly 50% with negligible PSNR degradation and bitrate increase. The resultant FME can process a macroblock within 612 clock cycles, enough to achieve real-time coding for the stereoscopic HD1080p video sequences operating at frequency of 300 MHz.

关键词： motion estimation ARCHITECTURE Building construction Bit rate Video coding Rate distortion real-time coding time coding Integer Fasting

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Novel 64QAM Space-time Codes Using a Large Number of Receive Antennas

Novel 64QAM Space-Time Codes Using a Large Number of Receive...

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International Symposium on Information Theory and its Applications (ISITA)

作者： Konishi, Tatsumi Aichi Inst Technol Toyota Aichi 4700392 Japan

ISBN: (纸本)9784885522673

Most space-time codes have been designed so that they have full-rank. However, when the number of receive antennas is large, the minimum trace plays a more important role in performance. In this paper, we propose new space-time codes using the 64QAM signal constellations that are suitable for the situation. The proposed codes are compared the bit error probability to the quasi-orthogonal space-time block codes (QOSTBC) and the Alamouti code. The results show the proposed codes have a small rank, however, significant performance gain when the number of receive antennas is large.

关键词： time coding Receiving antennas space-time codes 64QAM role performance bit error probability ANTENNA Codes

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Generalization of Lu's Linear time Encoding Algorithm for LDPC Codes

Generalization of Lu's Linear Time Encoding Algorithm for LD...

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International Symposium on Information Theory and its Applications (ISITA)

作者： Kobayashi, Kazuki Shibuya, Tomoharu Sophia Univ Dept Informat & Commun Sci Tokyo Japan

ISBN: (纸本)9784885522673

In this paper, we propose a new encoding algorithm applicable to any linear codes over arbitrary finite field whose computational complexity is O(w(H)) where w(H) denotes the number of non-zero elements in a parity check matrix H of a code. The proposed algorithm is essentially equivalent to the linear time encoding algorithm presented by Lu et al. when the maximum column weight delta* of H is less than or equal to 3, and is regarded as a natural generalization of the algorithm when delta* > 3. Moreover, the proposed algorithm can encode any linear codes defined by sparse parity check matrices, such as LDPC codes, with O(n) complexity where n denotes the code length.

关键词： check matrix low density parity check codes time coding linear codes code length Generalization Galois fields Additive identity algorithms Less than or equal to Lutetium

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Network-based multi-channel signal processing using the precision time protocol

Network-based multi-channel signal processing using the prec...

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Annual Summit and Conference of the Asia-Pacific-Signal-and-Information-Processing-Association (APSIPA)

作者： Chisaki, Yoshifumi Murakami, Dan Usagawa, Tsuyoshi Kumamoto Univ Kumamoto Japan

ISBN: (纸本)9781467348638

A conventional microphone array system uses a conductor to wire from a microphone to an input via an amplifier. While, a wireless transmission for an array system makes the configuration flexible, and it is expected to provide novel applications widely, such as measuring of impulse response in wide area. Not only in acoustic research field but also in research area of remote sensing of body motion and so on, data acquisition with a precise time synchronization is essential. When a signal received at distributed microphone's position is sent over a computer network, the data is packetized and can include some information at receiving point. When a time is included as information at data acquisition position, the time depends on each data acquisition client device. Since it is possible to use network time protocol or precision time protocol, multichannel signal processing can be achieved with ease. This paper proposes multiple signals transmission system over a computer network with a time code embedding to synchronize those signals. The signal from a client is reconstructed at a server with the time code. Since the time differences between clients affects to performance of the multichannel signal processing, smaller error in time at a client is preferred. This paper discusses how the error in time between channels affects to performance of the distributed microphone array system.

关键词： computer network time coding customers Clients precision time microphone arrays clock recovery Data Collection Methods signal processing Network time Protocol Microphone Device Component WIRELESS TRANSMISSION timeDif IMPULSE RESPONSE

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Performance of cooperative space time coding with spatially correlated fading and imperfect channel estimation

Performance of cooperative space time coding with spatially ...

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作者： Wan, Derrick Che-Yu University of British Columbia

学位级别：master

A performance evaluation of CSTC (Cooperative Space time coding) with spatially cor-related fading and imperfect channel estimation in Gaussian as well as impulsive noise is presented. Closed form expressions for the pairwise error probability conditioned on the estimated channel gains are derived by assuming the components of the received vector are independent given the estimated channel gains. An expurgated union bound using the limiting before averaging technique given the estimated channel gains is then obtained. Although this assumption is not strictly valid, simulation results show that the bound is accurate in estimating the diversity order as long the channel estimation is not very poor. It is found that CSTC with block fading channels can reduce the frame error rate (FER) relative to SUSTC (Single User Space time coding) with quasi-static fading channels, even when the channel gains for each user are strongly correlated and when the channel estimations are very poor.A decision metric for CSTC with spatially correlated fading, imperfect channel estimation, and impulsive mixture Gaussian noise is derived which yields lower FERs than the Gaussian noise decision metric. Simulation results show that the FER performance of CSTC with mixture Gaussian noise outperforms CSTC with Gaussian noise at low SNR. At high SNR, the FER performance of CSTC with Gaussian noise is better than the FER performance of CSTC with mixture Gaussian noise due to the heavy tail of the mixture Gaussian noise

关键词： Cooperative space time coding

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Design of IRIG-B Code Encoder Based on SOPC

Design of IRIG-B Code Encoder Based on SOPC

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2012年计算机应用与系统建模国际会议

作者： Xu Qiaoyu Wang Xing School of Electromechanical Engineering Henan University of Science and Technology

Aiming at the complexity of time unified hardware architecture, this paper presents the design scheme of IRIG-B encoder and system control based on SOPC. The NIOSII processor is configured with NIOSII IDE. Firstly, the design of IRIG-B(DC) coding module is accomplished to realize with Verilog HDL, and then IRIG-B(AC) coding module is completed successfully through the D\A conversion on the basis of IRIG-B(DC) code. The experiment result shows that the encoder can stably and reliably produce a standard IRIG-B code, and satisfy the application requirements.

关键词： IRIG-B code SOPC NIOSII time coding

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