• Title/Summary/Keyword: Adaptive response

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A direct adaptive control using generalized predictive control (일반형 예측제어를 이용한 직접 적응 제어)

  • Lee, Young-Il;Kwon, Wook-Hyun
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.376-379
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    • 1989
  • In this paper a direct adaptive control scheme which minimizes N-step cost function is proposed. It is derived via GPC control algorithm under the assumption that we know N-step unit step response of the given system. The proposed adaptive scheme is shown to have the same stability properties with the RHTC control, and require very small amount of calculation compared with other adaptive algorithms which minimize N-step cost function. And it is shown through simulations that the proposed adaptive algorithm is robust to the variation of the unit step response which is assumed to be known.

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Subband Sparse Adaptive Filter for Echo Cancellation in Digital Hearing Aid Vent (디지털 보청기 벤트 반향제거를 위한 부밴드 성긴 적응필터)

  • Bae, Hyeonl-Deok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.5
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    • pp.538-542
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    • 2018
  • Echo generated in digital hearing aid vent give rise to user's discomfort. For cancelling feedback echo in vent, it is required to estimate vent impulse response exactly. The vent impulse response has time varying and sparse characteristics. The IPNLMS has been known a useful adaptive algorithm to estimate vent impulse response with these characteristics. In this paper, subband sparse adaptive filter which applying IPNLMS to subband hearing aid structure is proposed to cancel echo of vent by estimating sparse vent impulse response. In the propose method, the decomposition of input signal to subband can pre-whiten each subband signal, so adaptive filter convergence speed can be improved. And the poly phase component decomposition of adaptive filter increases sparsity of each components, and the better echo cancellation can be possible without additional computation. To derive coefficients update equation of the adaptive filter, by defining the cost function based weight NLMS is defined, and the coefficient update equation of each subband is derived. For verifying performances of the adaptive filter, convergence speed, and steady state error by white signal input, and echo cancelling results by real speech input are evaluated by comparing conventional adaptive filters.

Prophylactic and Therapeutic Modulation of Innate and Adaptive Immunity Against Mucosal Infection of Herpes Simplex Virus

  • Uyangaa, Erdenebileg;Patil, Ajit Mahadev;Eo, Seong Kug
    • IMMUNE NETWORK
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    • v.14 no.4
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    • pp.187-200
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    • 2014
  • Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are the most common cause of genital ulceration in humans worldwide. Typically, HSV-1 and 2 infections via mucosal route result in a lifelong latent infection after peripheral replication in mucosal tissues, thereby providing potential transmission to neighbor hosts in response to reactivation. To break the transmission cycle, immunoprophylactics and therapeutic strategies must be focused on prevention of infection or reduction of infectivity at mucosal sites. Currently, our understanding of the immune responses against mucosal infection of HSV remains intricate and involves a balance between innate signaling pathways and the adaptive immune responses. Numerous studies have demonstrated that HSV mucosal infection induces type I interferons (IFN) via recognition of Toll-like receptors (TLRs) and activates multiple immune cell populations, including NK cells, conventional dendritic cells (DCs), and plasmacytoid DCs. This innate immune response is required not only for the early control of viral replication at mucosal sites, but also for establishing adaptive immune responses against HSV antigens. Although the contribution of humoral immune response is controversial, $CD4^+$ Th1 T cells producing IFN-${\gamma}$ are believed to play an important role in eradicating virus from the hosts. In addition, the recent experimental successes of immunoprophylactic and therapeutic compounds that enhance resistance and/or reduce viral burden at mucosal sites have accumulated. This review focuses on attempts to modulate innate and adaptive immunity against HSV mucosal infection for the development of prophylactic and therapeutic strategies. Notably, cells involved in innate immune regulations appear to shape adaptive immune responses. Thus, we summarized the current evidence of various immune mediators in response to mucosal HSV infection, focusing on the importance of innate immune responses.

A Study on the Change of Adaptive Response Through the Sensory Integration Intervention : Case Study (감각통합치료를 통한 적응반응의 변화 : 사례보고)

  • Kim, Eun-Young;Kim, Kyeong-Mi
    • The Journal of Korean Academy of Sensory Integration
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    • v.6 no.1
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    • pp.63-69
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    • 2008
  • Introduction : This study presents a case report of a child with sensory integration dysfunction(mixed sensory modulation disorder and dyspraxia), and describes strategy of the sensory integration intervention to encourage child's inner drive and the change of adaptive response. Main Subject : The subject was a boy, age 5 years and 10 months, who participated in short-term intensive sensory integration therapy program which was provided in a 2008 sensory integration treatment course. Based on results of assessment to the child, This study identifies the treatment goals, contents of treatment and analyze adaptive response' change of four therapy sessions. Conclusion : This case report demonstrates improvement of the adaptive response by sensory integration intervention and impotent to encourage the child's inner drive. However, subjective date, which is sensory integration may produce an effect that is evident during treatment sessions and in home environment have suggested.

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Pretreatment of Low Dose Radiation Reduces Radiation-Induced Apoptosis in Mouse Lymphoma (EL4) cells

  • Kim, Jeong-Hee;Hyun, Soo-Jin;Yoon, Moon-Young;Jioon, Young-Hoon;Cho, Chul-Koo;Yoo, Seong-Yul
    • Archives of Pharmacal Research
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    • v.20 no.3
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    • pp.212-217
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    • 1997
  • Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of ${\gamma}$-rays (0.01 Gy) 4 or 20 hrs prior to high dose ${\gamma}$-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose .gamma.-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-.betha.-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose ${\gamma}$-ray irradiation to high dose ${\gamma}$-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.

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Adaptive Response to ionizing Radiation Induced by Low Doses of Gamma Rays in Human Lymphoblastoid Cell Lines (인체임파양세포에서 저선량의 감마선에 의해서 유도되는 적응 반응)

  • Seong, Jin-Sil;Suh, Chang-Ok;Kim, Gwi-Eon
    • Radiation Oncology Journal
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    • v.12 no.1
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    • pp.1-8
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    • 1994
  • When cells are exposed to low doses of a mutagenic or clastogenic agents. they often become less sensitive to the effects of a higher dose administered subsequently. Such adaptive responses were first described in Escherichia coli and mammalian cells to low doses of an alkylating agent. Since most of the studies have been carried out with human lymphocytes, it is urgently necessary to study this effect in different cellular systems. Its relation with inherent cellular radiosensitivity and underlying mechanism also remain to be answered. In this study, adaptive response by 1 cGy of gamma rays was investigated in three human lymphoblastoid cell lines which were derived from ataxia telangiectasia homozygote, ataxia telangiectasia heterozygote, and normal individual. Experiments were carried out by delivering 1 cGy followed by 50 cGy of gamma radiation and chromatid breaks were scored as an endpoint. The results indicate that prior exposure to 1 cGy of gamma rays reduces the number of chromatid breaks induced by subsequent higher dose (50 cGy), The expression of this adaptive response was similar among three cell lines despite of their different radiosensitivity. When 3-aminobenzamide, an inhibitor of poly (ADP-ribose) polymerase, was added after 50 cGy, adaptive responses were abolished in all the tested cell lines. Therefore it is suggested that the adaptive response can be observed in human lymphoblastoid cell lines, which was first documented through this study. The expression of adaptive response was similar among the cell lines regardless of their radiosensitivity. The elimination of the adaptive response by 3-aminobenzamide is consistent with the proposal that this adaptive response is the result of the induction of a certain chromosomal repair mechanism.

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Adaptive control for linear systems with parameter uncertainty using switching

  • Maki, Midori;Hagino, Kojiro
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.173-176
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    • 1996
  • This paper deals with the problem of designing an adaptive regulator in order to improve transient performance in time-response when the linear state-space model of the plant contains unknown parameters which vary within prescribed bounds. The whole possible parameter space is divided into some subspaces and multiple models and controllers are established from the view point that each controller gives satisfactory transient behavior for systems corresponding to each parameter subspace. Based on time-response and an associated cost function, an appropriate controller is selected on-line out of multiple controllers.

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A convergence analysis of a PLL for a digital recording channel with an adaptive partial response equalizer (적응 부분응답 등화기를 갖는 디지탈 기록 채널의 PLL 수렴 특성 분석)

  • 오대선;양원영;조용수
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.6
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    • pp.45-53
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    • 1996
  • In this paper, the convergence behavior of timing phase when an adaptive partial response equalizer and decision-directed type of a PLL work together in a digital recording channel is described. The phenomena of getting biased in timing phase when the convergence parameter of an adaptive partial response equalizer and timing recovery constant of a PLL are not selected properly is introduced. The phenomena, occurring due to perturbation of timing phase, are analyzed, by computer simulation and the region of ocnvergence for timing phase is discussed. Also, a method to overcome the phenomena using a variable step-size parameter is described.

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A Permanent Magnet Pole Shape Optimization for a 6MW BLDC Motor by using Response Surface Method (I) (RSM을 이용한 6MW BLDC용 영구자석의 형상 최적화 연구 (I))

  • Woo, Sung-Hyun;Chung, Hyun-Koo;Shin, Pan-Seok
    • Proceedings of the KIEE Conference
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    • 2008.04c
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    • pp.65-67
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    • 2008
  • An adaptive response surface method with Latin Hypercube sampling strategy is employed to optimize a magnet pole shape of large scale BLDC motor to minimize the cogging torque. The proposed algorithm consists of the multi-objective Pareto optimization and ($1+{\lambda}$) evolution strategy to find the global optimal points with relatively fewer sampling data. In the adaptive RSM, an adaptive sampling point insertion method is developed utilizing the design sensitivities computed by using finite element method to set a reasonable response surface with a relatively small number of sampling points. The developed algorithm is applied to the shape optimization of PM poles for 6MW BLDC motor.

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