• Title/Summary/Keyword: Neural Circuit

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Integrated Circuit Implementation and Characteristic Analysis of a CMOS Chaotic Neuron for Chaotic Neural Networks (카오스 신경망을 위한 CMOS 혼돈 뉴런의 집적회로 구현 및 특성 해석)

  • Song, Han-Jeong;Gwak, Gye-Dal
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.37 no.5
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    • pp.45-53
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    • 2000
  • This paper presents an analysis of the dynamical behavor in the chaotic neuron fabricated using 0.8${\mu}{\textrm}{m}$ single poly CMOS technology. An approximated empirical equation models for the sigmoid output function and chaos generative block of the chaotic neuron are extracted from the measurement data. Then the dynamical responses of the chaotic neuron such as biurcation diagram, frequency responses, Lyapunov exponent, and average firing rate are calculated with numerical analysis. In addition, we construct the chaotic neural networks which are composed of two chaotic neurons with four synapses and obtain bifurcation diagram according to synaptic weight variation. And results of experiments in the single chaotic neuron and chaotic neural networks by two neurons with the $\pm$2.5V power supply and sampling clock frequency of 10KHz are shown and compared with the simulated results.

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Neuroglial Cells : An Overview of Their Physiological Roles and Abnormalities in Mental Disorders (신경아교세포의 정상 기능과 정신장애에서 나타나는 신경아교세포 이상에 대한 고찰)

  • Lee, Kyungmin
    • Korean Journal of Biological Psychiatry
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    • v.22 no.2
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    • pp.29-33
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    • 2015
  • The brain maintains homeostasis and normal microenvironment through dynamic interactions of neurons and neuroglial cells to perform the proper information processing and normal cognitive functions. Recent post-mortem investigations and animal model studies demonstrated that the various brain areas such as cerebral cortex, hippocampus and amygdala have abnormalities in neuroglial numbers and functions in subjects with mental illnesses including schizophrenia, dementia and mood disorders like major depression and bipolar disorder. These findings highlight the putative role and involvement of neuroglial cells in mental disorders. Herein I discuss the physiological roles of neuroglial cells such as astrocytes, oligodendrocytes, and microglia in maintaining normal brain functions and their abnormalities in relation to mental disorders. Finally, all these findings could serve as a useful starting point for potential therapeutic concept and drug development to cure unnatural behaviors and abnormal cognitive functions observed in mental disorders.

Noninvasive measuring;Detections of materials and quantities on eddy current testing

  • Obayashi, Koji;Tamura, Muneyoshi;Zhang, X.;Aoyama, T.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1555-1560
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    • 2004
  • We made a simplified eddy-current-tester, and observed some materials for the ingredients and mass and locations. The tester detects the current as frequency shifts of a LC-resonance circuit, which are caused by the eddy currents. Using air-wick coil and a multi-piled ceramic capacitor, we made a resonance system whose frequency was 100KHz. The shift quantity is few; so, to detect it, we used a frequency counter, and counted the shift. We can detect 10Hz order's shift.

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Modulation of Neural Circuit Actvity by Ethanol in Basolateral Amygdala

  • Chung, Leeyup
    • Development and Reproduction
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    • v.16 no.4
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    • pp.265-270
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    • 2012
  • Ethanol actions in the amygdala formation may underlie in part the reinforcing effects of ethanol consumption. Previously a physiological phenomenon in the basolateral amygdala (BLA) that is dependent on neuronal network activity, compound postsynaptic potentials (cPSPs) were characterized. Effects of acute ethanol application on the frequency of cPSPs were subsequently investigated. Whole cell patch clamp recordings were performed from identified projection neurons in a rat brain slice preparation containing the amygdala formation. Acute ethanol exposure had complex effects on cPSP frequency, with both increases and decreases dependent on concentration, duration of exposure and age of the animal. Ethanol produces complex biphasic effects on synaptically-driven network activity in the BLA. These findings may relate to subjective effects of ethanol on arousal and anxiolysis in humans.

High Efficiency drive of SRM using GN/NN (GA/NN을 이용한 SRM의 고효율 구동)

  • Kim Bong-Chul;Oh Seok-Gyu;Ahn Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2004.07b
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    • pp.963-966
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    • 2004
  • The torque of SRM depends on the level of phase current and the derivative of phase inductance. But the phase inductance of SRM is not linearly changed according to rotor position angle because of saturation in magnetic circuit. Therefor it is difficult to control the desired torque. This paper proposes a model of control system for high efficiency drive of SRM. The GA-Neural Network is used to simulate the reasonable switching angle which is nonlinearly varied with rotor speed and load.

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A Study on the Characteristics of Synaptic Multiplication for SONOSFET Memory Devices (SONOSFET 기억소자의 시랩스 승적특성에 관한 연구)

  • 이성배;김병철;김주연;이상배;서광열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1991.10a
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    • pp.1-4
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    • 1991
  • EEPROM technology has been used for storing analog weights as charge in a nitride layer between gate and channel of a field effect transistor. In the view of integrity and fabrication process, it is essentially required that SONOSFET is capable of performing synapse function as a basic element in an artificial neural networks. This work has introduced the VLSI implementation for synapses including current study and also investigated physical characteristics to implement synapse circuit using SONOSFET memories. Simulation results are shown in this work. It is proposed that multiplication of synapse element using SONOSFET memories will be developed more compact implementation under Present fabrication processes.

Pattern Recognition of Dynamic Resistance and Real Time Quality Estimation (동저항 패턴 인식 및 실시간 품질 평가)

  • 조용준;이세헌
    • Proceedings of the KWS Conference
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    • 2000.04a
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    • pp.303-306
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    • 2000
  • Quality estimation of the weld has been one of the important issues in RSW which is a main process of the sheep metal fabrication in auto-body industry, It was well known that among the various welding process variables, dynamic resistance has a close relation with nugget formation. With this variable, it is possible to estimate the weld quality in real time. In this study, a new quality estimation algorithm is developed with the primary dynamic resistance measured at welding machine timer. For this, feature recognition method of Hopfield neural network is used. Primary resistance patterns are vectorized and classified with five patterns. The network trained by these patterns recognizes the dynamic resistance pattern and estimates the weld quality Because the process variable monitored at the primary circuit is used, it is possible to apply this system to real time application without any consideration of electrode wear or shunt effect.

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Synchronization in Complex Systems

  • Bae, Young-Chul;Kim, Chun-Suk;Koo, Young-Duk
    • Journal of information and communication convergence engineering
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    • v.2 no.4
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    • pp.237-242
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    • 2004
  • In this paper, we introduce a complex systems synchronization method using hyper-chaos circuit consist of State-Controlled Cellular Neural Network (SC-CNN). We make a complex systems using SC-CNN with the n-double scroll. A complex system is created by applying identical n-double scroll or non-identical n-double scroll and Chua's oscillator with weak coupled method to each cell. Complex systems synchronization were achieved using GS(Generalized Synchronization) method between the transmitter and receiver about each state variable in the SC-CNN.

Improvement of Current Controller Characteristics of Interior Permanent Magnet Synchronous Motor for Electric Vehicle (전기자동차용 매입형 영구자석 동기전동기의 전류제어기 특성 개선)

  • Park, Jung-Woo;Kim, Jong-Moo;Ku, Dae-Hyun;Kim, Heung-Geun
    • Proceedings of the KIEE Conference
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    • 1999.07f
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    • pp.2526-2528
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    • 1999
  • Parameters of equivalent circuit of IPMSM are varied according to current magnitude and current phase angle. Especially, Parameter variation of IPMSM for an electric vehicle(EV) is critical. Because current magnitude is very large. and current phase angle range also is wide. So, variation characteristics of $L_d$ and $L_q$ of the IPMSM are analyzed and verified through experiments. And then new parameter estimator of $L_d$ and $L_q$ that is constructed by neural network technique is suggested Using numerical method, the advanced characteristics of current controller of vector control algorithm is verified.

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Dopamine signaling in food addiction: role of dopamine D2 receptors

  • Baik, Ja-Hyun
    • BMB Reports
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    • v.46 no.11
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    • pp.519-526
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    • 2013
  • Dopamine (DA) regulates emotional and motivational behavior through the mesolimbic dopaminergic pathway. Changes in DA signaling in mesolimbic neurotransmission are widely believed to modify reward-related behaviors and are therefore closely associated with drug addiction. Recent evidence now suggests that as with drug addiction, obesity with compulsive eating behaviors involves reward circuitry of the brain, particularly the circuitry involving dopaminergic neural substrates. Increasing amounts of data from human imaging studies, together with genetic analysis, have demonstrated that obese people and drug addicts tend to show altered expression of DA D2 receptors in specific brain areas, and that similar brain areas are activated by food-related and drug-related cues. This review focuses on the functions of the DA system, with specific focus on the physiological interpretation and the role of DA D2 receptor signaling in food addiction.