• Title/Summary/Keyword: Complex adaptive system

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MPPT of photovoltaic system with duty ratio of DC-DC converter considered load (부하를 고려한 DC-DC 컨버터의 듀티비에 따른 태양광 발전 시스템의 최대전력점 추적)

  • Jun, Young-Sun;Ko, Jae-Sub;Choi, Jung-Sik;Jung, Chul-Ho;Kim, Do-Yeon;Jung, Byung-Jin;Chung, Dong-Hwa
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.05a
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    • pp.407-410
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    • 2008
  • This paper presents a maximum power point tracking(MPPT) of photovoltaic system with duty ratio of DC-DC converter considered load. A variation of solar irradiation is most important factor in the MPPT of PV system That is nonlinear, aperiodic and complicated. NN was widely used due to easily solving a complex math problem. The paper consists of solar radiation source, DC-DC converter, DC motor and load(cf, pump). NN algorithm apply to DC-DC converter through an adaptive control of neural network, calculates converter-duty ratio using an adaptive control of NN. The results of an adaptive control of NN compared with the results of converter-duty ratio which are calculated mathematical modeling and evaluate the proposed algorithm. The experimental data show that an adequacy of the algorithm was established through the compared data.

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On the Adaptive 3-dimensional Transform Coding Technique Employing the Variable Length Coding Scheme (가변 길이 부호화를 이용한 적응 3차원 변환 부호화 기법)

  • 김종원;이신호;이상욱
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.7
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    • pp.70-82
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    • 1993
  • In this paper, employing the 3-dimensional discrete cosine transform (DCT) for the utilization of the temporal correlation, an adaptive motion sequence coding technique is proposed. The energy distribution in a 3-D DCT block, due to the nonstationary nature of the image data, varies along the veritical, horizontal and temporal directions. Thus, aiming an adaptive system to local variations, adaptive procedures, such as the 3-D classification, the classified linear scanning technique and the VLC table selection scheme, have been implemented in our approach. Also, a hybrid structure which adaptively combines inter-frame coding is presented, and it is found that the adaptive hybrid frame coding technique shows a significant performance gain for a moving sequence which contains a relatively small moving area. Through an intensive computer simulation, it is demonstrated that, the performance of the proposed 3-D transform coding technique shows a close relation with the temporal variation of the sequence to be code. And the proposed technique has the advantages of skipping the computationally complex motion compensation procedure and improving the performance over the 2-D motion compensated transform coding technique for rates in the range of 0.5 ~ 1.0 bpp.

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Neuro-Fuzzy Modeling of Complex Nonlinear System Using a mGA (mGA를 사용한 복잡한 비선형 시스템의 뉴로-퍼지 모델링)

  • Choi, Jong-Il;Lee, Yeun-Woo;Joo, Young-Hoon;Park, Jin-Bae
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2305-2307
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    • 2000
  • In this paper we propose a Neuro-Fuzzy modeling method using mGA for complex nonlinear system. mGA has more effective and adaptive structure than sGA with respect to using the changeable-length string. This paper suggest a new coding method for applying the model's input and output data to the number of optimul rules of fuzzy models and the structure and parameter identifications of membership function simultaneously. The proposed method realize optimal fuzzy inference system using the learning ability of Neural network. For fine-tune of the identified parameter by mGA, back-propagation algorithm used for optimulize the parameter of fuzzy set. The proposed fuzzy modeling method is applied to a nonlinear system to prove the superiority of the proposed approach through compare with ANFIS.

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Performance Improvement of Frequence Sharing of DS-CDMA/TDMA System (DS-CDMA/TDMA 주파수 공유 시스템의 성능 개선)

  • 백승선;강희조
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.4
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    • pp.639-644
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    • 2001
  • Sequence Code Division Multiple Access) and TDMA(Time Division Multiple Access) system. In this system, the narrowband TDMA signals can cause intolerant interferences to CDMA signals. In this paper, DS-CDMA/TDMA frequency sharing system have been analyzed in AWGN(Additive white Gaussian Noise), MAI (Multi Access Interference) and NI(Narrowband Interference) environment. Also, performance improvement has been obtained by adopting an adaptive notch filtering scheme using complex filter bank and CCI canceller.

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Adaptive Predistortion for High Power Amplifier by Exact Model Matching Approach

  • Ding, Yuanming;Pei, Bingnan;Nilkhamhang, Itthisek;Sano, Akira
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.401-406
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    • 2004
  • In this paper, a new time-domain adaptive predistortion scheme is proposed to compensate for the nonlinearity of high power amplifiers (HPA) in OFDM systems. A complex Wiener-Hammerstein model (WHM) is adopted to describe the input-output relationship of unknown HPA with linear dynamics, and a power series model with memory (PSMWM) is used to approximate the HPA expressed by WHM. By using the PSMWM, the compensation input to HPA is calculated in a real-time manner so that the linearization from the predistorter input to the HPA output can be attained even if the nonlinear input-output relation of HPA is uncertain and changeable. In numerical example, the effectiveness of the proposed method is confirmed and compared with the identification method based on PSMWM.

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Dental Impression Measurement Based on an Adaptive Measuring Process Plan (적응형 측정계획 기반 치과인상 측정)

  • Park, Sang Chul;Chung, Yong Ho;Hwam, Won Kyung
    • Korean Journal of Computational Design and Engineering
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    • v.18 no.4
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    • pp.283-289
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    • 2013
  • Presented in this paper is an adaptive measuring procedure of dental impression using the Structured Light System. While measuring a complex object, such as dental impression, in the reverse engineering, it is not possible to acquire all parts of the scanned surface. Missing scanned data is resulted in holes in a created triangular mesh. The focus of this paper is to introduce an algorithm for automatic identification of additional scanning orientations to fill holes that are created by a default scan. The proposed algorithm was developed by the three major technological requirements: camera visibility, projector visibility, data reliability. In order to satisfy the requirements, the proposed algorithm determines additional scanning orientation from the orientation of a projection plane derived from the average normal vector of boundary triangles.

On the Synthesis of Robot Manipulator using Adaptive Control (적용제어에 의한 로보트매니퓰레이터 설계)

  • Lee, Si-Bok;Lee, Man-Hyung;Park, Jong-Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.3 no.1
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    • pp.50-59
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    • 1986
  • Adaptive Model Following Control (AMFC) technique is applied to develop a robot manipulator control system, which can deal successfully with the complex dvnamics of the manipulator. Main concerns of this study are put on the problem reducing the chatter amplitude of control signal yielded by the unit vector control law that was proposed [10] previously for AMFC of the manipulatro, and the effect- iveness of the algorithm when implemented practically. To see the effectiveness of modified method, computer simulations using new and old control law are carried out and compared, and the modified one id implemented in RHINO XR-II robot system recon- structed partially to enable torque control.

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Direct-band spread system for neural network with interference signal control (직접 대역 확산 시스템에서 신경망을 이용한 간섭 신호 제어)

  • Cho, Hyun-Seob
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.3
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    • pp.1372-1377
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    • 2013
  • In this Paper, a back propagation neural network learning algorithm based on the complex multilayer perceptron is represented for controling and detecting interference of the received signals in cellular mobile communication system. We proposed neural network adaptive correlator which has fast convergence rate and good performance with combining back propagation neural network and the receiver of cellular. We analyzed and proved that NNAC has lower bit error probability than that of traditional RAKE receiver through results of computer simulation in the presence of the tone and narrow-band interference and the co-channel interference.

Generation of Tolerogenic Dendritic Cells and Their Therapeutic Applications

  • Seungbo Yoo;Sang-Jun Ha
    • IMMUNE NETWORK
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    • v.16 no.1
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    • pp.52-60
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    • 2016
  • Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that bridge innate and adaptive immune responses, thereby leading to immune activation. DCs have been known to recognize pathogen-associated molecular patterns such as lipopolysaccharides (LPS) and nucleic acids via their pattern recognition receptors, which trigger signaling of their maturation and effector functions. Furthermore, DCs take up and process antigens as a form of peptide loaded on the major histocompatibility complex (MHC) and present them to T cells, which are responsible for the adaptive immune response. Conversely, DCs can also play a role in inducing immune suppression under specific circumstances. From this perspective, the role of DCs is related to tolerance rather than immunity. Immunologists refer to these special DCs as tolerogenic DCs (tolDCs). However, the definition of tolDCs is controversial, and there is limited information on their development and characteristics. In this review, we discuss the current concept of tolDCs, cutting-edge methods for generating tolDCs in vitro, and future applications of tolDCs, including clinical use.

A search-based high resolution frequency estimation providing improved convergence characteristics in power system (전력계통에서 수렴성 향상을 위한 탐색기반 고분해능 주파수 추정기법)

  • An, Gi-Sung;Seo, Young-Duk;Chang, Tae-Gyu;Kang, Sang-Hee
    • Journal of IKEEE
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    • v.22 no.4
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    • pp.999-1005
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    • 2018
  • This paper proposed a search-based high resolution frequency estimation method in power systme. The proposed frequency estimation method adopts a slope-based adaptive search as a base of adaptive estimation structure. The architectural and operational parameters in this adaptive algorithm are changed using the information from context layer analysis of the signals including a localized full-search of spectral peak. The convergence rate of the proposed algorithm becomes much faster than those of other conventional slope-based adaptive algorithms by effectively reducing search range with the application of the localized full-search of spectrum peak. The improvements in accuracy and convergence rate of the proposed algorithm are confirmed through the performance comparison with other representative frequency estimation methods, such as, DFT(discrete Fourier transform) method, ECKF(extended complex Kalman filter), and MV(minimum variable) method.