• 제목/요약/키워드: Neural Circuit

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Neural circuit remodeling and structural plasticity in the cortex during chronic pain

  • Kim, Woojin;Kim, Sun Kwang
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권1호
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    • pp.1-8
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    • 2016
  • Damage in the periphery or spinal cord induces maladaptive plastic changes along the somatosensory nervous system from the periphery to the cortex, often leading to chronic pain. Although the role of neural circuit remodeling and structural synaptic plasticity in the 'pain matrix' cortices in chronic pain has been thought as a secondary epiphenomenon to altered nociceptive signaling in the spinal cord, progress in whole brain imaging studies on human patients and animal models has suggested a possibility that plastic changes in cortical neural circuits may actively contribute to chronic pain symptoms. Furthermore, recent development in two-photon microscopy and fluorescence labeling techniques have enabled us to longitudinally trace the structural and functional changes in local circuits, single neurons and even individual synapses in the brain of living animals. These technical advances has started to reveal that cortical structural remodeling following tissue or nerve damage could rapidly occur within days, which are temporally correlated with functional plasticity of cortical circuits as well as the development and maintenance of chronic pain behavior, thereby modifying the previous concept that it takes much longer periods (e.g. months or years). In this review, we discuss the relation of neural circuit plasticity in the 'pain matrix' cortices, such as the anterior cingulate cortex, prefrontal cortex and primary somatosensory cortex, with chronic pain. We also introduce how to apply long-term in vivo two-photon imaging approaches for the study of pathophysiological mechanisms of chronic pain.

반사방지막 태양전지의 I-V특성에 대한 인공신경망 모델링 (I-V Modeling Based on Artificial Neural Network in Anti-Reflective Coated Solar Cells)

  • 홍다인;이종환
    • 반도체디스플레이기술학회지
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    • 제21권3호
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    • pp.130-134
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    • 2022
  • An anti-reflective coating is used to improve the performance of the solar cell. The anti-reflective coating changes the value of the short-circuit current about the thickness. However, the current-voltage characteristics about the anti-reflective coating are difficult to calculate without simulation tool. In this paper, a modeling technique to determine the short-circuit current value and the current-voltage characteristics in accordance with the thickness is proposed. In addition, artificial neural network is used to predict the short-circuit current with the dependence of temperature and thickness. Simulation results incorporating the artificial neural network model are obtained using MATLAB/Simulink and show the current-voltage characteristic according to the thickness of the anti-reflective coating.

The Digital Fuzzy Inference System Using Neural Networks

  • Ryeo, Ji-Hwan;Chung, Ho-Sun
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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    • pp.968-971
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    • 1993
  • Fuzzy inference system which inferences and processes the Fuzzy information is designed using digital voltage mode neural circuits. The digital fuzzification circuit is designed to MIN,MAX circuit using CMOS neural comparator. A new defuzzification method which uses the center of area of the resultant fuzzy set as a defuzzified output is suggested. The method of the center of area(C. O. A) search for a crisp value which is correspond to a half of the area enclosed with inferenced membership function. The center of area defuzzification circuit is proposed. It is a simple circuit without divider and multiflier. The proposed circuits are verified by implementing with conventional digital chips.

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영어 수계를 이용한 디지털 신경망회로의 실현 (An Implementation of Digital Neural Network Using Systolic Array Processor)

  • 윤현식;조원경
    • 전자공학회논문지B
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    • 제30B권2호
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    • pp.44-50
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    • 1993
  • In this paper, we will present an array processor for implementation of digital neural networks. Back-propagation model can be formulated as a consecutive matrix-vector multiplication problem with some prespecified thresholding operation. This operation procedure is suited for the design of an array processor, because it can be recursively and repeatedly executed. Systolic array circuit architecture with Residue Number System is suggested to realize the efficient arithmetic circuit for matrix-vector multiplication and compute sigmoid function. The proposed design method would expect to adopt for the application field of neural networks, because it can be realized to currently developed VLSI technology.

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Hopfield 신령회로망의 VLSI 구현에 관한 연구 (VLSI Implementation of Hopfield Neural Network)

  • 박성범;오재혁;이창호
    • 전자공학회논문지B
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    • 제30B권11호
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    • pp.66-73
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    • 1993
  • This paper presents an analog circuit implementation and experimental resuls of the Hopfield type neural network. The proposed architecture enables the reconfiguration betwewn feedback and feedforward networks and employs new circuit designs for the weight supply and storage, analog multilier, nd current-voltage converter, in order to achieve area efficiency as well as function al versatility. The layout design of the eight-neuron neural network is tested as an associative memory to verify its applicability to real world.

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양안 입체시에 의한 3차원 표면의 복원 (Restoration of 3-Dimensional Surface Based on Binocular Stereo Vision)

  • 정남채
    • 융합신호처리학회논문지
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    • 제6권3호
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    • pp.112-119
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    • 2005
  • 본 논문에서는 심리학 생리학적 지식을 기초로 하여 좌우 망막을 양안 입체시로 대응시켜 얻은 2매의 화상으로부터 깊이 정보를 추출하는 신경회로 모델을 제안하고 3차원 표면의 복원법을 검토한다. 화상의 특징을 근거로 하여 시차를 추출할 경우, 경계 부분에 유사한 특징이 반복된다면 경우 올바른 깊이 정보를 검출할 수 없다. 본 논문에서 제안된 신경회로 모델은 시차의 추출, 시차의 통합, 시차의 보간에 의하여 시차를 결정한다. 또한, 깊이 정보를 보간하여 3차원 형상을 복원하고 그 복원된 3차원 형상에 좌입력 화상을 투영하여 3차원 표면을 복원하는 법을 제안하고, 실험을 통하여 시차 추출 시간을 대폭 줄일 수 있음을 확인하였다.

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Molecular Mechanisms of Synaptic Specificity: Spotlight on Hippocampal and Cerebellar Synapse Organizers

  • Park, Dongseok;Bae, Sungwon;Yoon, Taek Han;Ko, Jaewon
    • Molecules and Cells
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    • 제41권5호
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    • pp.373-380
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    • 2018
  • Synapses and neural circuits form with exquisite specificity during brain development to allow the precise and appropriate flow of neural information. Although this property of synapses and neural circuits has been extensively investigated for more than a century, molecular mechanisms underlying this property are only recently being unveiled. Recent studies highlight several classes of cell-surface proteins as organizing hubs in building structural and functional architectures of specific synapses and neural circuits. In the present minireview, we discuss recent findings on various synapse organizers that confer the distinct properties of specific synapse types and neural circuit architectures in mammalian brains, with a particular focus on the hippocampus and cerebellum.

MFSFET의 신경회로망 응용을 위한 CUJT와 PUT 소자를 이용한 발진 회로에 관한 연구 (Study on Oscillation Circuit Using CUJT and PUT Device for Application of MFSFET′s Neural Network)

  • 강이구;장원준;장석민;성만영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.55-58
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    • 1998
  • Recently, neural networks with self-adaptability like human brain have attracted much attention. It is desirable for the neuron-function to be implemented by exclusive hardware system on account of huge quantity in calculation. We have proposed a novel neuro-device composed of a MFSFET(ferroelectric gate FET) and oscillation circuit with CUJT(complimentary unijuction transistor) and PUT(programmable unijuction transistor). However, it is difficult to preserve ferroelectricity on Si due to existence of interfacial traps and/or interdiffusion of the constitutent elements, although there are a few reports on good MFS devices. In this paper, we have simulated CUJT and PUT devices instead of fabricating them and composed oscillation circuit. Finally, we have resented, as an approach to the MFSFET neuron circuit, adaptive learning function and characterized the elementary operation properties of the pulse oscillation circuit.

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An Artificial Neural Networks Application for the Automatic Detection of Severity of Stator Inter Coil Fault in Three Phase Induction Motor

  • Rajamany, Gayatridevi;Srinivasan, Sekar
    • Journal of Electrical Engineering and Technology
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    • 제12권6호
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    • pp.2219-2226
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    • 2017
  • This paper deals with artificial neural network approach for automatic detection of severity level of stator winding fault in induction motor. The problem is faced through modelling and simulation of induction motor with inter coil shorting in stator winding. The sum of the absolute values of difference in the peak values of phase currents from each half cycle has been chosen as the main input to the classifier. Sample values from workspace of Simulink model, which are verified with experiment setup practically, have been imported to neural network architecture. Consideration of a single input extracted from time domain simplifies and advances the fault detection technique. The output of the feed forward back propagation neural network classifies the short circuit fault level of the stator winding.

확률신경회로망을 이용한 전력계통의 고장진단에 관한 연구 (A study on Fault Diagnosis in Power systems Using Probabilistic Neural Network)

  • 이화석;김정택;문경준;이경홍;박준호
    • 대한전기학회논문지:전력기술부문A
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    • 제50권2호
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    • pp.53-57
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    • 2001
  • This paper presents the new methods of fault diagnosis through multiple alarm processing of protective relays and circuit breakers in power systems using probabilistic neural networks. In this paper, fault section detection neural network (FSDNN) for fault diagnosis is designed using the alarm information of relays or circuit breakers. In contrast to conventional methods, the proposed FSDNN determines the fault section directly and fast. To show the possibility of the proposed method, it is simulated through simulation panel for Sinyangsan substation system in KEPCO (Korea Electric Power Corporation) and the case studies show the effectiveness of the probabilistic neural network mehtod for the fault diagnosis.

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