• Title/Summary/Keyword: RBF (Radial-Basis Function)

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An Improved Learning Approach for the Resource- Allocating Network (RAN) (RAN을 위한 개선된 학습 방법)

  • 최종수;권오신;김현석
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.35C no.11
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    • pp.89-98
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    • 1998
  • The enhanced resource-allocating network(ERAN) that adaptively generates hidden units of radial basis function(RBF) network for systems modeling has been proposed. The ERAN is an improved version of the resource-allocating network(RAN) that allocates new hidden units based on the novelty of observation data. The learning process of the ERAN involves allocation of new hidden units and adjusting the network parameters. The network starts with no hidden units. As observation data are received, the network adds a hidden units only if the three network growth criteria are satisfied. The network parameters are adjusted by the LMS algorithm. The performance of the ERAN is compared with the RAN for nonlinear static systems modeling problem with sequential and random learning. For two simulations, the ERAN has been shown to realize RBF networks with better accuracy with fewer hidden units.

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Artificial neural network reconstructs core power distribution

  • Li, Wenhuai;Ding, Peng;Xia, Wenqing;Chen, Shu;Yu, Fengwan;Duan, Chengjie;Cui, Dawei;Chen, Chen
    • Nuclear Engineering and Technology
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    • v.54 no.2
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    • pp.617-626
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    • 2022
  • To effectively monitor the variety of distributions of neutron flux, fuel power or temperatures in the reactor core, usually the ex-core and in-core neutron detectors are employed. The thermocouples for temperature measurement are installed in the coolant inlet or outlet of the respective fuel assemblies. It is necessary to reconstruct the measurement information of the whole reactor position. However, the reading of different types of detector in the core reflects different aspects of the 3D power distribution. The feasibility of reconstruction the core three-dimension power distribution by using different combinations of in-core, ex-core and thermocouples detectors is analyzed in this paper to synthesize the useful information of various detectors. A comparison of multilayer perceptron (MLP) network and radial basis function (RBF) network is performed. RBF results are more extreme precision but also more sensitivity to detector failure and uncertainty, compare to MLP networks. This is because that localized neural network could offer conservative regression in RBF. Adding random disturbance in training dataset is helpful to reduce the influence of detector failure and uncertainty. Some convolution neural networks seem to be helpful to get more accurate results by use more spatial layout information, though relative researches are still under way.

Design of Supersonic Impulse Turbine Nozzle with Asymmetric Configuration using the Optimal Method (최적화기법을 이용한 초음속 충동형 터빈 노즐의 비대칭 설계)

  • Jeong, Soo-In;Choi, Byoung-Ik;Jeong, Eun-Hwan;Kim, Kui-Soon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.04a
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    • pp.61-65
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    • 2011
  • In this paper, the nozzle design with asymmetric configuration using the optimal method is used in order to improve the under- and over-expansion problem of the flow at the supersonic turbine nozzle. For the design of nozzle contour, 8 design variables are selected and the total-to-static efficiency from the nozzle inlet to the wake outlet is considered as the objective function to be maximized. The Fluent6.3 and the iSIGHT-FD program are used for calculation of nozzle flow and design optimization respectively. RBF(Radial Basis Function) method is chosen for approximate optimization algorithm. It is shown that the static efficiency of improved nozzle design increases 1.35% and loss coefficient decreases 19.85% as compared to baseline design.

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Enhancing Security Gaps in Smart Grid Communication

  • Lee, Sang-Hyun;Jeong, Heon;Moon, Kyung-Il
    • International Journal of Advanced Culture Technology
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    • v.2 no.2
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    • pp.7-10
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    • 2014
  • In order to develop smart grid communications infrastructure, a high level of interconnectivity and reliability among its nodes is required. Sensors, advanced metering devices, electrical appliances, and monitoring devices, just to mention a few, will be highly interconnected allowing for the seamless flow of data. Reliability and security in this flow of data between nodes is crucial due to the low latency and cyber-attacks resilience requirements of the Smart Grid. In particular, Artificial Intelligence techniques such as Fuzzy Logic, Bayesian Inference, Neural Networks, and other methods can be employed to enhance the security gaps in conventional IDSs. A distributed FPGA-based network with adaptive and cooperative capabilities can be used to study several security and communication aspects of the smart grid infrastructure both from the attackers and defensive point of view. In this paper, the vital issue of security in the smart grid is discussed, along with a possible approach to achieve this by employing FPGA based Radial Basis Function (RBF) network intrusion.

Artificial Neural Network Models in Prediction of the Moisture Content of a Spray Drying Process

  • Taylan, Osman;Haydar, Ali
    • Journal of the Korean Ceramic Society
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    • v.41 no.5
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    • pp.353-358
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    • 2004
  • Spray drying is a unique drying process for powder production. Spray dried product must be free-flowing in order to fill the pressing dies rapidly, especially in the ceramic production. The important powder characteristics are; the particle size distribu-tion and moisture content of the finished product that can be estimated and adjusted by the spray dryer operation, within limits, through regulation of atomizer and drying conditions. In order to estimate the moisture content of the resultant dried product, we modeled the control system of the drying process using two different Artificial Neural Network (ANN) approaches, namely the Back-Propagation Multiplayer Perceptron (BPMLP) algorithm and the Radial Basis Function (RBF) network. It was found out that the performance of both of the artificial neural network models were quite significant and the total testing error for the 100 data was 0.8 and 0.7 for the BPMLP algorithm and the RBF network respectively.

Neural Network Compensation for Improvement of Real-Time Moving Object Tracking Performance of the ROBOKER Head with a Virtual Link (가상링크 기반의 ROBOKER 머리의 실시간 대상체 추종 성능 향상을 위한 신경망 제어)

  • Kim, Dong-Min;Choi, Ho-Jin;Lee, Geun-Hyung;Jung, Seul
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.7
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    • pp.694-699
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    • 2009
  • This paper presents the implementation of the real-time object tracking control of the ROBOKER head. The visual servoing technique is used to track the moving object, but suffers from ill-estimated Jacobian of the virtual link design. To improve the tracking performance, the RBF(Radial Basis Function) network is used to compensate for uncertainties in the kinematics of the robot head in on-line fashion. The reference compensation technique is employed as a neural network control scheme. Performances of three schemes, the kinematic based scheme, the Jacobian based scheme, and the neural network compensation scheme are verified by experimental studies. The neural compensation scheme performs best.

Design of Incremental FCM-based RBF Neural Networks Pattern Classifier for Processing Big Data (빅 데이터 처리를 위한 증분형 FCM 기반 RBF Neural Networks 패턴 분류기 설계)

  • Lee, Seung-Cheol;Oh, Sung-Kwun;Roh, Seok-Beom
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1343-1344
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    • 2015
  • 본 연구에서는 증분형 FCM(Incremental Fuzzy C-Means: Incremental FCM) 클러스터링 알고리즘을 기반으로 방사형 기저함수 신경회로망(Radial Basis Function Neural Networks: RBFNN) 패턴 분류기를 설계한다. 방사형 기저함수 신경회로망은 조건부에서 가우시안 함수 또는 FCM을 사용하여 적합도를 구하였지만, 제안된 분류기에서는 빅 데이터간의 적합도를 구하기 위해 증분형 FCM을 사용한다. 또한, 빅 데이터를 학습하기 위해 결론부에서 재귀최소자승법(Recursive Least Square Estimation: RLSE)을 사용하여 다항식 계수를 추정한다. 마지막으로 추론부에서는 증분형 FCM에서 구한 적합도와 재귀최소자승법으로 구한 다항식을 이용하여 최종 출력을 구한다.

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A Study on Channel Compensation Algorithm for Robust Speaker Recognition (화자인식 성능 향상을 위한 채널 보상 알고리즘에 관한 연구)

  • Kim Jung Ho;Jung Hui Seok;Kang Chul Ho
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.131-134
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    • 2002
  • 화자 확인시스템에서 화자 변이, 잡음환경, 그리고 학습환경과 인식환경의 불일치등이 화자확인에 어려움을 가져다 준다. 본 논문에서는 유무선 전화망에서 화자 확인의 성능을 개선하기 위한 채널 보상 알고리즘을 제안한다. 화자 확인시스템에서 유무선 전화망의 채널 왜곡을 보상하기 위한 방법으로 RBF(Radial Basis Function) 신경망을 이용하여 특징 벡터를 사상하는 알고리즘을 이용하며 유선과 무선의 채널 왜곡을 감소시킨다. 동일한 화자의 유무선의 벡터 영역이 서로 다르므로 등록단계에서 RBF 신경망을 사용하여 화자의 특징 벡터를 유선과 무선의 비슷한 벡터 영역으로 사상하고, 인식단계에서는 유무선의 우도비를 비교하여 결정규칙에 의해 판별한다. 켑스트럼 평균 차감법(CMS) 보다 제안한 채널 보상 알고리즘이 인식율이 향상을 실험에 의해 확인하였다.

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Neural network with audit data reduction algorithm for IDsystem (원시데이터 축약 알고리즘을 이용한 신경망의 침입탐지시스템으로의 접근)

  • 박일곤;문종섭
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10c
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    • pp.595-597
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    • 2002
  • 현재 인터넷의 발달에 인한 다양한 공격의 가능성의 이유로 침입 탐지 시스템(IDsystem, IDS)의 중요성은 날로 커지고 있으며 네트워크의 보안을 보장하기 위한 방안으로서 널리 이용되고 있다. 그러나 작은 네트워크 환경에서도 IDsystem에 적용되는 audit data의 양이 많아짐으로서 시간당 처리속도와 IDsystem의 설정을 위한 시간이 더욱더 요구되며 전체적인 효율성이 감소하게 된다. 본 연구에서는 IDsystem으로 빠른 훈련과정과 일반화 능력, 구조적인 단순함으로 다양한 분야에서 연구가 진행 중인 신경망 모델 중 하나인 Radial Basis Function(RBF)를 사용하였으며, 효율성 제고를 위하여 RBF에 적용 할 입력 간들의 중요성을 선 처리 단계에서 판별하여 불필요한 입력 값들을 축약하기 위해 결정계수(R-square)같을 측정, 알려지지 않은 공격과 알려진 공격들을 판별 할 수 있는 IDsystem을 제안하였다.

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A Decision Support Model for Sustainable Collaboration Level on Supply Chain Management using Support Vector Machines (Support Vector Machines을 이용한 공급사슬관리의 지속적 협업 수준에 대한 의사결정모델)

  • Lim, Se-Hun
    • Journal of Distribution Research
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    • v.10 no.3
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    • pp.1-14
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    • 2005
  • It is important to control performance and a Sustainable Collaboration (SC) for the successful Supply Chain Management (SCM). This research developed a control model which analyzed SCM performances based on a Balanced Scorecard (ESC) and an SC using Support Vector Machine (SVM). 108 specialists of an SCM completed the questionnaires. We analyzed experimental data set using SVM. This research compared the forecasting accuracy of an SCMSC through four types of SVM kernels: (1) linear, (2) polynomial (3) Radial Basis Function (REF), and (4) sigmoid kernel (linear > RBF > Sigmoid > Polynomial). Then, this study compares the prediction performance of SVM linear kernel with Artificial Neural Network. (ANN). The research findings show that using SVM linear kernel to forecast an SCMSC is the most outstanding. Thus SVM linear kernel provides a promising alternative to an SC control level. A company which pursues an SCM can use the information of an SC in the SVM model.

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