• Title/Summary/Keyword: Activation Functions

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Algorithm for Classifiation of Alzheimer's Dementia based on MRI Image (MRI 이미지 기반의 알츠하이머 치매분류 알고리즘)

  • Lee, Jae-kyung;Seo, Jin-beom;Cho, Young-bok
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.97-99
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    • 2021
  • As the aging society continues in recent years, interest in dementia is increasing. Among them, Alzheimer's disease is a degenerative brain disease that accounts for the largest percentage of all dementia patients, with the medical community currently not offering clear prevention and treatment for Alzheimer's disease, and the importance of early treatment and early prevention is emphasized. In this paper, we intend to find the most efficient activation function by combining various activation functions centering on convolutional neural networks using MRI datasets of normal people and patients with Alzheimer's disease. In addition, it is intended to be used as a dementia classification modeling suitable for the medical field in the future through Alzheimer's dementia classification modeling.

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APPROXIMATION ORDER TO A FUNCTION IN Lp SPACE BY GENERALIZED TRANSLATION NETWORKS

  • HAHM, NAHMWOO;HONG, BUM IL
    • Honam Mathematical Journal
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    • v.28 no.1
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    • pp.125-133
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    • 2006
  • We investigate the approximation order to a function in $L_p$[-1, 1] for $0{\leq}p<{\infty}$ by generalized translation networks. In most papers related to neural network approximation, sigmoidal functions are adapted as an activation function. In our research, we choose an infinitely many times continuously differentiable function as an activation function. Using the integral modulus of continuity and the divided difference formula, we get the approximation order to a function in $L_p$[-1, 1].

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The Biofeedback Scapular Stabilization Exercise in Stroke Patients Effect of Muscle Activity and Function of the Upper Extremity

  • Yang, Dae-Jung;Uhm, Yo-Han;Kim, Je-Ho
    • The Journal of Korean Physical Therapy
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    • v.27 no.5
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    • pp.325-331
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    • 2015
  • Purpose: This study attempts to understand the effect of stabilization exercise of biofeedback scapular on muscle activity and functional evaluation of the upper extremity in stroke patients. Methods: Patients were divided into two groups; a biofeedback scapular stabilization exercise group comprised of 8 patients and a task-oriented training group including another 8 patients, and 30-minute exercise was performed 5 times a week for 8 weeks. Electromyogram was used to measure muscular activity of lower trapezius, deltoid middle, and serratus anterior. Fugl-Meyer Assessment and Manual Function Test were used to evaluate functions of the muscles mentioned. Results: Significant difference was observed in the comparison group before and after exercise in muscular activity of lower trapezius, deltoid middle, and serratus anterior, Fugl-Meyer Assessment, and Manual Function Test. Conclusion: Therefore, we could see that biofeedback scapular stabilization exercise is more effective than task-oriented training in facilitating muscle activation and functional capacity of upper limb.

Formation Kinetic Study of Thermal Products of Tocopherols

  • Chung, Hae-Young
    • Preventive Nutrition and Food Science
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    • v.12 no.3
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    • pp.131-134
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    • 2007
  • The kinetic analyses for thermal products of alpha-, gamma- and delta-tocopherols during heating as functions of temperature and time were studied. Alpha-, gamma- and delta-tocopherols dissolved in glycerol were heated at $100{\sim}200^{\circ}C$ for $5{\sim}60$ min. The thermal products were separated by hexane extraction and analyzed by HPLC using a reversed phase ${\mu}-Bondapak$ $C_{18}-column$ with two kinds of elution solvents in a gradient mode. The formation kinetics of thermal products of tocopherols followed a first-order kinetic model. The formation rate of thermal products of tocopherols was dependent on heating temperatures and heating times. The activation energy and enthalpy for the thermal products of ${\gamma}-and$ ${\delta}-tocopherols$ were higher than those for ${\alpha}-tocopherol$ as in the case of the oxidative degradation kinetics of tocopherol. The magnitude order of the activation energy was ${\gamma}->{\delta}->{\alpha}-tocopherol$.

The Role of Nrf2 in Cellular Innate Immune Response to Inflammatory Injury

  • Kim, Ji-Young;Surh, Young-Joon
    • Toxicological Research
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    • v.25 no.4
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    • pp.159-173
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    • 2009
  • Nuclear factor erythroid derived 2-related factor-2 (Nrf2) is a master transcription regulator of antioxidant and cytoprotective proteins that mediate cellular defense against oxidative and inflammatory stresses. Disruption of cellular stress response by Nrf2 deficiency causes enhanced susceptibility to infection and related inflammatory diseases as a consequence of exacerbated immune-mediated hypersensitivity and autoimmunity. The cellular defense capacity potentiated by Nrf2 activation appears to balance the population of $CD4^+$ and $CD8^+$ of lymph node cells for proper innate immune responses. Nrf2 can negatively regulate the activation of pro-inflammatory signaling molecules such as p38 MAPK, NF-${\kappa}B$, and AP-1. Nrf2 subsequently functions to inhibit the production of pro-inflammatory mediators including cytokines, chemokines, cell adhesion molecules, matrix metalloproteinases, COX-2 and iNOS. Although not clearly elucidated, the antioxidative function of genes targeted by Nrf2 may cooperatively regulate the innate immune response and also repress the expression of pro-inflammatory mediators.

EXISTENCE AND GLOBAL EXPONENTIAL STABILITY OF A PERIODIC SOLUTION TO DISCRETE-TIME COHEN-GROSSBERG BAM NEURAL NETWORKS WITH DELAYS

  • Zhang, Zhengqiu;Wang, Liping
    • Journal of the Korean Mathematical Society
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    • v.48 no.4
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    • pp.727-747
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    • 2011
  • By employing coincidence degree theory and using Halanay-type inequality technique, a sufficient condition is given to guarantee the existence and global exponential stability of periodic solutions for the two-dimensional discrete-time Cohen-Grossberg BAM neural networks. Compared with the results in existing papers, in our result on the existence of periodic solution, the boundedness conditions on the activation are replaced with global Lipschitz conditions. In our result on the existence and global exponential stability of periodic solution, the assumptions in existing papers that the value of activation functions at zero is zero are removed.

Design of Self-Organizing Networks with Competitive Fuzzy Polynomial Neuron (경쟁적 퍼지 다항식 뉴론을 가진 자기 구성 네트워크의 설계)

  • Park, Ho-Sung;Oh, Sung-Kwun;Kim, Hyun-Ki
    • Proceedings of the KIEE Conference
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    • 2000.11d
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    • pp.800-802
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    • 2000
  • In this paper, we propose the Self-Organizing Networks(SON) based on competitive Fuzzy Polynomial Neuron(FPN) for the optimal design of nonlinear process system. The SON architectures consist of layers with activation nodes based on fuzzy inference rules. Here each activation node is presented as FPN which includes either the simplified or regression Polynomial fuzzy inference rules. The proposed SON is a network resulting from the fusion of the Polynomial Neural Networks(PNN) and a fuzzy inference system. The conclusion part of the rules, especially the regression polynomial uses several types of high-order polynomials such as liner, quadratic and modified quadratic. As the premise part of the rules, both triangular and Gaussian-like membership functions are studied. Chaotic time series data used to evaluate the performance of our proposed model.

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Maternal effect genes: Findings and effects on mouse embryo development

  • Kim, Kyeoung-Hwa;Lee, Kyung-Ah
    • Clinical and Experimental Reproductive Medicine
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    • v.41 no.2
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    • pp.47-61
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    • 2014
  • Stored maternal factors in oocytes regulate oocyte differentiation into embryos during early embryonic development. Before zygotic gene activation (ZGA), these early embryos are mainly dependent on maternal factors for survival, such as macromolecules and subcellular organelles in oocytes. The genes encoding these essential maternal products are referred to as maternal effect genes (MEGs). MEGs accumulate maternal factors during oogenesis and enable ZGA, progression of early embryo development, and the initial establishment of embryonic cell lineages. Disruption of MEGs results in defective embryogenesis. Despite their important functions, only a few mammalian MEGs have been identified. In this review we summarize the roles of known MEGs in mouse fertility, with a particular emphasis on oocytes and early embryonic development. An increased knowledge of the working mechanism of MEGs could ultimately provide a means to regulate oocyte maturation and subsequent early embryonic development.

The Effect of Hydrogen Plasma on Surface Roughness and Activation in SOI Wafer Fabrication

  • Park, Woo-Beom;Kang, Ho-Cheol;Sung, Man-Young
    • Transactions on Electrical and Electronic Materials
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    • v.1 no.1
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    • pp.6-11
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    • 2000
  • The hydrogen plasma treatment of silicon wafers in the reactive ion-etching mode was studied for the application to silicon-on-insulator wafers which were prepared using the wafer bonding technique. The chemical reactions of hydrogen plasma with surface were used for both surface activation and removal of surface contaminants. As a result of exposure of silicon wafers to the plasma, an active oxide layer was found on the surface. This layer was rendered hydrophilic. The surface roughness and morphology were examined as functions of the plasma exposing time and power. In addition, the surface became smoother with the shorter plasma exposing time and power. The value of initial surface energy estimated by the crack propagation method was 506 mJ/㎡, which was up to about three times higher as compared to the case of conventional direct using the wet RCA cleaning method.

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GLOBAL ROBUST STABILITY OF TIME-DELAY SYSTEMS WITH DISCONTINUOUS ACTIVATION FUNCTIONS UNDER POLYTOPIC PARAMETER UNCERTAINTIES

  • Wang, Zengyun;Huang, Lihong;Zuo, Yi;Zhang, Lingling
    • Bulletin of the Korean Mathematical Society
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    • v.47 no.1
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    • pp.89-102
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    • 2010
  • This paper concerns the problem of global robust stability of a time-delay discontinuous system with a positive-defined connection matrix under polytopic-type uncertainty. In order to give the stability condition, we firstly address the existence of solution and equilibrium point based on the properties of M-matrix, Lyapunov-like approach and the theories of differential equations with discontinuous right-hand side as introduced by Filippov. Second, we give the delay-independent and delay-dependent stability condition in terms of linear matrix inequalities (LMIs), and based on Lyapunov function and the properties of the convex sets. One numerical example demonstrate the validity of the proposed criteria.