• Title/Summary/Keyword: Activation Functions

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Optimization of Sigmoid Activation Function Parameters using Genetic Algorithms and Pattern Recognition Analysis in Input Space of Two Spirals Problem (유전자알고리즘을 이용한 시그모이드 활성화 함수 파라미터의 최적화와 이중나선 문제의 입력공간 패턴인식 분석)

  • Lee, Sang-Wha
    • The Journal of the Korea Contents Association
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    • v.10 no.4
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    • pp.10-18
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    • 2010
  • This paper presents a optimization of sigmoid activation function parameter using genetic algorithms and pattern recognition analysis in input space of two spirals benchmark problem. To experiment, cascade correlation learning algorithm is used. In the first experiment, normal sigmoid activation function is used to analyze the pattern classification in input space of the two spirals problem. In the second experiment, sigmoid activation functions using different fixed values of the parameters are composed of 8 pools. In the third experiment, displacement of the sigmoid function to determine the value of the three parameters is obtained using genetic algorithms. The parameter values applied to the sigmoid activation functions for candidate neurons are used. To evaluate the performance of these algorithms, each step of the training input pattern classification shows the shape of the two spirals.

Analyzing Effective of Activation Functions on Recurrent Neural Networks for Intrusion Detection

  • Le, Thi-Thu-Huong;Kim, Jihyun;Kim, Howon
    • Journal of Multimedia Information System
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    • v.3 no.3
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    • pp.91-96
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    • 2016
  • Network security is an interesting area in Information Technology. It has an important role for the manager monitor and control operating of the network. There are many techniques to help us prevent anomaly or malicious activities such as firewall configuration etc. Intrusion Detection System (IDS) is one of effective method help us reduce the cost to build. The more attacks occur, the more necessary intrusion detection needs. IDS is a software or hardware systems, even though is a combination of them. Its major role is detecting malicious activity. In recently, there are many researchers proposed techniques or algorithms to build a tool in this field. In this paper, we improve the performance of IDS. We explore and analyze the impact of activation functions applying to recurrent neural network model. We use to KDD cup dataset for our experiment. By our experimental results, we verify that our new tool of IDS is really significant in this field.

CHARACTERISTICS OF A NEW PNEUMATIC TRANSFER SYSTEM FOR A NEUTRON ACTIVATION ANALYSIS AT THE HANARO RESEARCH REACTOR

  • Chung, Yong-Sam;Kim, Sun-Ha;Moon, Jong-Hwa;Baek, Sung-Yeol;Kim, Hark-Rho;Kim, Young-Jin
    • Nuclear Engineering and Technology
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    • v.41 no.6
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    • pp.813-820
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    • 2009
  • A rapid pneumatic transfer system (PTS) for an instrumental neutron activation analysis (INAA) is developed as an automatic irradiation facility involving the measurement of a short half-life nuclide and a delayed neutron counting system. Three new PTS designs with improved functions were constructed at the HANARO research reactor in 2006. The new system is composed of a manual system and an automatic system for both an INAA and a delayed neutron activation analysis (DNAA). The design and basic conception of a modified PTS are described, and the functions of system operation and control, radiation protection and emissions of radioactive gas are improved. In addition, a form of capsule transportation of these systems is tested. The experimental results pertaining to the irradiation characteristics with variation of the neutron flux and the temperature of the irradiation position with the irradiation time are presented, as is an analysis of the reference material for analytical quality control and uncertainty assessments.

Activation Energy for the Decapsulation of Small Molecules from A-Type Zeolites

  • 김정섭;황계정;홍석봉;노경태
    • Bulletin of the Korean Chemical Society
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    • v.18 no.3
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    • pp.280-286
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    • 1997
  • Potential energy function sets for some ion-exchanged A-type zeolites, K-A and Rb11Na1-A, were determined by introducing the X-ray crystal structures as constraints. The potential functions reproduced well the X-ray crystal structures of the monovalent ion-exchanged zeolites. The activation energies for the en- or de-capsulation of small molecules (H2, O2, N2, and CH4) and inert gases from the α-cage of model zeolites (Na-A, K-A, Rb11Na1-A, and Cs3Na9-A) were obtained by the molecular mechanical calculations. The calculated activation energies agreed well with experimental results.

Generalization of Recurrent Cascade Correlation Algorithm and Morse Signal Experiments using new Activation Functions (순환 케스케이드 코릴레이션 알고리즘의 일반화와 새로운 활성화함수를 사용한 모스 신호 실험)

  • Song Hae-Sang;Lee Sang-Wha
    • Journal of Intelligence and Information Systems
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    • v.10 no.2
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    • pp.53-63
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    • 2004
  • Recurrent-Cascade-Correlation(RCC) is a supervised teaming algorithm that automatically determines the size and topology of the network. RCC adds new hidden neurons one by one and creates a multi-layer structure in which each hidden layer has only one neuron. By second order RCC, new hidden neurons are added to only one hidden layer. These created neurons are not connected to each other. We present a generalization of the RCC Architecture by combining the standard RCC Architecture and the second order RCC Architecture. Whenever a hidden neuron has to be added, the new RCC teaming algorithm automatically determines whether the network topology grows vertically or horizontally. This new algorithm using sigmoid, tanh and new activation functions was tested with the morse-benchmark-problem. Therefore we recognized that the number of hidden neurons was decreased by the experiments of the RCC network generalization which used the activation functions.

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Evaluation of Response Functions for Activation Foil-based Bonner Spheres (중성자 방사화 포일 기반 보너구 반응함수 계산 방법)

  • Kim, Jung-Ho;Park, Hyeon-Seo
    • Journal of Radiation Protection and Research
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    • v.36 no.1
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    • pp.44-51
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    • 2011
  • Activation foil-based Bonner sphere spheres are used to obtain neutron energy spectra of nuclear power plants or accelerator-produced neutrons. The position and the foil mass dependence of response functions should be studied carefully before measurement of Bonner spheres. This study showed that the normal incidence to the foil surface made a large shift of responses while parallel and isotropic incidence made no position dependence. The correlation between foil mass and response was not linear. Therefore, the response functions of activation-foil based Bonner spheres should be calculated for every different foil mass and the direction of Bonner spheres for parallel incidence will be preferred for radioactive neutron source or accelerator target produced neutrons.

Signaling for Synergistic Activation of Natural Killer Cells

  • Kwon, Hyung-Joon;Kim, Hun Sik
    • IMMUNE NETWORK
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    • v.12 no.6
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    • pp.240-246
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    • 2012
  • Natural killer (NK) cells play a pivotal role in early surveillance against virus infection and cellular transformation, and are also implicated in the control of inflammatory response through their effector functions of direct lysis of target cells and cytokine secretion. NK cell activation toward target cell is determined by the net balance of signals transmitted from diverse activating and inhibitory receptors. A distinct feature of NK cell activation is that stimulation of resting NK cells with single activating receptor on its own cannot mount natural cytotoxicity. Instead, specific pairs of co-activation receptors are required to unleash NK cell activation via synergy- dependent mechanism. Because each co-activation receptor uses distinct signaling modules, NK cell synergy relies on the integration of such disparate signals. This explains why the study of the mechanism underlying NK cell synergy is important and necessary. Recent studies revealed that NK cell synergy depends on the integration of complementary signals converged at a critical checkpoint element but not on simple amplification of the individual signaling to overcome intrinsic activation threshold. This review focuses on the signaling events during NK cells activation and recent advances in the study of NK cell synergy.

Characterization of the NF-$textsc{k}$B Activation Induced by TR8, an Osteoclastogenic Tumor Necrosis Factor Receptor Family Member

  • Kim, Hong-Hee
    • Archives of Pharmacal Research
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    • v.22 no.5
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    • pp.454-458
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    • 1999
  • TR8 is a recently identified member of the tumor necrosis factor (TNF) receptor superfamily. TR8 seems to play important roles in bone metabolism as stimulation of this receptor with its ligand, TL8 or osteoclast differentiation factor (ODF), induced the differentiation and activation of osteoclasts. Despite its important biological functions, the biochemcial events ensuing form TR8 activation have not been revealed in detail. Most of TNF receptor family proteins provoke the activation of the NF-$textsc{k}$B transcription factor. In the present study, we examined the signaling potential of TR8 to induce NF-B activation. When overexpressed in a human embryonic kidney cell line by transient transfection, TR8 caused a strong activation of NF-$textsc{k}$B, which was further increased upon stimulation with TL8. The TR8-induced NF-B activation was abrogated by the co-expression of the TRAF6 mutnat lacking the Ring and zinc finger domains and that of the kinase-inactive mutant NIK. Taken together, our study suggests that the presence of intact TRAF6 and the kiase activity of NIK may be essential for TR8 to induce NF-$textsc{k}$B activation.

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The Methods of Value Management to Support Decision-Making of Urban Regeneration Projects

  • Kang, Hyun-Koo;Yu, Jung-Ho;Kim, Chang-Duk;Son, Bo-Sik
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1503-1508
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    • 2009
  • The paradigm of urban generation does not lie in physical development/maintenance such as urban redevelopment any more. The paradigm is shifting to balanced activation of administration / management functions including central commerce/business functions, broad culture/tourism functions, international functions and adequate level of residence functions. The urban regeneration project aims to restore functions of cities by physical/environmental, living/cultural and industrial/economical regeneration and is managed differently from existing projects in that it includes multiple sub-projects in it. The overall projects management should be by managing the value sought by the urban regeneration project and multiple other sub-projects. The objective of this study is to present various methods of value management in order to avoid conflicts between various objectives within the said project. It aims to provide the value management methods for decision making by understanding correlatedness between values of various projects and prioritizing them.

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Regulatory Role of CD29 $({\beta}1-integrins)$ in Monocytic Cell Functions (단핵구 기능 수행에서의 $CD29({\beta}1-integrins)$ 조절 역할)

  • Kim, Byung-Hun;Cho, Jae-Youl
    • YAKHAK HOEJI
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    • v.52 no.1
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    • pp.48-55
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    • 2008
  • CD29 $({\beta}1-integrins)$ is one of major adhesion molecules involved in regulating cell adhesion, migration and morphological changes. In this study, we investigated the regulatory role of CD29 in monocytic functions using monocytic cell line U937 cells. CD29 was found to be one of highly expressed membrane proteins in U937 cells, according to flow cytometric analysis. The activation of CD29 by agonistic antibody MEM101A and extracellular matrix protein (ECM) fibronectin strongly induced cell-cell and cell-fibronectin adhesions. However, blocking antibodies to CD98 and CD147 showed different inhibitory features in these two adhesion events. Furthermore, U0126, an ERK inhibitor, only blocked cell-cell adhesion but not cell-fibronectin adhesion, indicating that cell-cell or cell-fibronectin adhesion events may be regulated by different molecular mechanisms. Meanwhile, CD29 activation also enhanced ROS generation but not phagocytic ability, and similarly radical scavenger N-acetyl-L-cysteine strongly blocked CD29-mediated cell-cell adhesion, implying that ROS may play a critical role in up-regulating cell-cell adhesion. Therefore, our data suggest that the activation of CD29 may be critically involved in regulating monocytic cell-mediated cell-cell adhesion and ROS generation.