• Title/Summary/Keyword: adaptive response

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Low-dose of Ultraviolet radiation-, Ethyl methanesulfonateor Bleomycin-lnduced Adaptive Response in Chinese hamster ovary Cells

  • Lee, Dong-Wook;Shin, Eun-Joo;Um, Kyung-Il
    • Environmental Mutagens and Carcinogens
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    • v.15 no.2
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    • pp.94-99
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    • 1995
  • The adaptive response and cross-adaptive response to sister chromatid exchanges (SCEs) and DNA single-strand breaks (SSBs) in Chinese hamster ovary (CHO)-K$_1$ cells treated with ultraviolet radiation (UV), ethyl methanesuffonate (EMS), or bleomycin (BLM) were investigated. Two assays were used in this study; SCEs and alkaline elution. The pretreatment with low conditioning dose of 2 mM EMS or 1 J/m$^2$ UV decreased the yield of SCEs induced by subsequent treatment with 8 mM EMS, 5 J/m$^2$ UV or 5 $\mu$g/ml BLM. And the pretreatment with low conditioning dose of 1 $\mu$g/ml BLM decreased the yield of SCEs induced by subsequent treatment with 5 $\mu$g/ml BLM or 5 J/m$^2$ UV. The rejoining of DNA SSBs in cells subsequently treated with 2 J/m$^2$ UV, 50 mM EMS or 400 $\mu$g/ml BLM is higher than that only treated with 2 J/m$^2$ UV, 50 mM EMS or 400 $\mu$g/ml BLM. These results suggest that there are the adaptive response and cross-adaptive response to SCEs, and is the adaptive response to the rejoining of DNA SSBs in CHO cells.

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Adaptive Response in Chinese Hamster lung Cells by Benzidine Dihydrochloride (Benzidine dihydrochloride에 의한 Chinese hamster lung 세포의 적응반응)

  • 맹승희;정해원;이권섭;이용묵;정호근;유일재
    • Environmental Mutagens and Carcinogens
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    • v.21 no.2
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    • pp.142-148
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    • 2001
  • We studied adaptive response in CHL cells by benzidine dihydrochloride, a derivative of benzidine, which was a major mutagenic agent in dye industry. Chromosome aberration analysis was used for the identification of adaptive response to this mutagen. Adaptive and reactive doses were confirmed by cell proliferation rate curve. Cell proliferation rate curve was obtained from the mitotic indices of cells treated with various concentrations of benzidine dihydrochloride for 24 hours. Marked adaptive responses to benzidine dihydrochloride in the induction of chromosome aberration were observed in CHL cells by pre-treatment with low concentrations of benzidine dihydrochloride (0.0047 mg/$m\ell$ or 0.0094 mg/$m\ell$) for 24 hours following post-treatment with high concentrations (0.0187, 0.0375, 0.075, 0.15 mg/$m\ell$) for 24 hours. These adaptive responses were found mostly in the type of chromatid breaks and chromatid exchanges. There is no difference in these results between two adaptive doses, 0.0047 mg/$m\ell$ and 0.0094 mg/$m\ell$. The amount of adaptive response, however, was dependent on post-treatment doses.

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Adaptive control with multiple model (using genetic algorithm)

  • Kwon, Seong-Chul;Park, Juhyun;Won, Sangchul
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.331-334
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    • 1996
  • It is a well-known problem that the adaptive control has a poor transient response. In order to improve this problem, the scheme that model-reference adaptive control (MRAC) uses the genetic algorithm (GA) in the search for parameters is proposed. Use genetic algorithm (GA) in the searching for controller's parameters set and conventional gradient method for fine tuning. And show the reduction of the oscillations in transient response comparing with the conventional MRAC.

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How Did South Korean Governments Respond during 2015 MERS Outbreak?: Application of the Adaptive Governance Framework

  • Kim, KyungWoo
    • Journal of Contemporary Eastern Asia
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    • v.16 no.1
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    • pp.69-81
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    • 2017
  • This study examines how South Korean governments responded to the outbreak of Middle East Respiratory Syndrome Coronavirus (MERS) using the adaptive governance framework. As of November 24, 2015, the MERS outbreak in South Korea resulted in the quarantine of about 17,000 people, 186 cases confirmed, and a death of 38. Although the national government had overall responsibility for MERS response, there is no clear understanding of how the ministries, agencies, and subnational governments take an adaptive response to the public health crisis. The paper uses the adaptive governance framework to understand how South Korean governments respond to the unexpected event regarding the following aspects: responsiveness, public learning, scientific learning, and representativeness of the decision mechanisms. The framework helps understand how joint efforts of the national and subnational governments were coordinated to the unexpected conditions. The study highlights the importance of adaptive governance for an effective response to a public-health related extreme event.

New Echo Canceller using Adaptive Cascaded System Identification Algorithm (적응 다단 시스템 식별 알고리듬을 이용한 새로운 반향제거기)

  • Kwon, Oh Sang
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.1
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    • pp.113-120
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    • 2014
  • In this paper, I present a new echo canceller using the adaptive cascade system identification (CSI) method, which a system response is divided into several responses so that each response is adaptively estimated and combined. Echo cancellation is required for a dual-duplex DSL, in order to allow each individual loop to operate in a full duplex fashion. Echo cancellation was one of the most difficult aspects of DSL design, requiring high linearity and total echo return loss in excess of 70 dB. Especially, for a fickle response, if the response is estimated by an adaptive filter, the filter needs more taps and the performance is decreased. But the response is divided into several responses, the computation complexities are decreased and the performance is increased. For the stage constant n, which represents the number of stages, if the response is not divided (n=1), the computation complexity of multiply is $2N^2$. And if the response is divided into two responses (n=2), the computation complexity of multiply is $2N^2$. Also, if n=3, the computation complexity is ${\frac{2}{3}}N^2$. Therefore, it is known that the computation complexity is decreased as n is increased. Finally, this proposed method is verified through simulation of echo canceller for digital subscriber line (DSL) application.

Effects of Inhibitors on Cross-Adaptive Response to Ultraviolet Radiation or Ethyl methanesulfonate in Chinese Hamster Ovary Cells

  • Lee, Dong-Wook;Shin, Eun-Joo;Kim, Seon-Young;Um, Kyung-Il
    • Environmental Mutagens and Carcinogens
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    • v.16 no.2
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    • pp.83-87
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    • 1996
  • This study was performed by the sister chromatid exchanges (SCEs) to investigate the effects of Aphidicolin (APC) or 2, 4-dinitrophenoi (DNP) on cross-adaptive response to ultraviolet radiation (UV) or ethyl methanesulfonate (EMS) in Chinese hamster ovary (CHO) cells. The pretreatment with 1 J/m$^2$ UV decreased the yield of SCEs induced by subsequent treatment with 8 mM EMS in CHO cells. And the treatment with 10 $\mu$g/ml APC or 50 $\mu$M DNP during incubation after pretreatment with 1 J/m$^2$ UV increased the yield of SCEs induced by 8 mM EMS. The pretreatment with 2 mM EMS decreased the yield of SCEs induced by subsequent treatment with 5 J/m$^2$ UV. The treatment with 10 $\mu$g/ml APC during incubation after 2 mM EMS increased the yield of SCEs induced by 5 J/m$^2$ UV. These results suggest that APC and DNP inhibit cross-adaptive response to pretreatment with UV and subsequent treatment with EMS, and also cross-adaptive response to pretreatment with EMS and subsequent treatment with UV is inhibited by APC in CHO cells.

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A novel reliability analysis method based on Gaussian process classification for structures with discontinuous response

  • Zhang, Yibo;Sun, Zhili;Yan, Yutao;Yu, Zhenliang;Wang, Jian
    • Structural Engineering and Mechanics
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    • v.75 no.6
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    • pp.771-784
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    • 2020
  • Reliability analysis techniques combining with various surrogate models have attracted increasing attention because of their accuracy and great efficiency. However, they primarily focus on the structures with continuous response, while very rare researches on the reliability analysis for structures with discontinuous response are carried out. Furthermore, existing adaptive reliability analysis methods based on importance sampling (IS) still have some intractable defects when dealing with small failure probability, and there is no related research on reliability analysis for structures involving discontinuous response and small failure probability. Therefore, this paper proposes a novel reliability analysis method called AGPC-IS for such structures, which combines adaptive Gaussian process classification (GPC) and adaptive-kernel-density-estimation-based IS. In AGPC-IS, an efficient adaptive strategy for design of experiments (DoE), taking into consideration the classification uncertainty, the sampling uniformity and the regional classification accuracy improvement, is developed with the purpose of improving the accuracy of Gaussian process classifier. The adaptive kernel density estimation is introduced for constructing the quasi-optimal density function of IS. In addition, a novel and more precise stopping criterion is also developed from the perspective of the stability of failure probability estimation. The efficiency, superiority and practicability of AGPC-IS are verified by three examples.

T-S Fuzzy Model-Based Adaptive Synchronization of Chaotic System with Unknown Parameters (T-S 퍼지 모델을 이용한 불확실한 카오스 시스템의 적응동기화)

  • Kim, Jae-Hun;Park, Chang-Woo;Kim, Eun-Tai;Park, Mignon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.2
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    • pp.270-275
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    • 2005
  • This paper presents a fuzzy model-based adaptive approach for synchronization of chaotic systems which consist of the drive and response systems. Takagi-Sugeno (T-S) fuzzy model is employed to represent the chaotic drive and response systems. Since the parameters of the drive system are assumed unknown, we design the response system that estimates the parameters of the drive system by adaptive strategy. The adaptive law is derived to estimate the unknown parameters and its stability is guaranteed by Lyapunov stability theory. In addition, the controller in the response system contains two parts: one part that can stabilize the synchronization error dynamics and the other part that estimates the unknown parameters. Numerical examples, including Doffing oscillator and Lorenz attractor, are given to demonstrate the validity of the proposed adaptive synchronization approach.

Comparison of sequential estimation in response-adaptive designs with and without covariate-adjustment

  • Park, Eunsik
    • Communications for Statistical Applications and Methods
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    • v.23 no.4
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    • pp.287-296
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    • 2016
  • Subjects on one side of the covariate population can be allocated to the inferior treatment when there is interaction between the covariate and treatment along with a response-adaptive (RA) design without covariate adjustment. An RA design allows a newly entered subject to have a better chance so that the subject is treated by a superior treatment based on cumulative information from previous subjects. A covariate-adjusted response-adaptive (CARA) is the same as RA design and additionally adjusts the allocation based on individual covariate information. A comparison has been made for the sequential estimation procedure with and without covariate adjustment to see how ignoring significantly interactive covariate affects the correct treatment allocation. Using logistic models, we present simulation results regarding the coverage probability of treatment effect, correct allocation, and stopping time.

A Robust and Computationally Efficient Optimal Design Algorithm of Electromagnetic Devices Using Adaptive Response Surface Method

  • Zhang, Yanli;Yoon, Hee-Sung;Shin, Pan-Seok;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • v.3 no.2
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    • pp.207-212
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    • 2008
  • This paper presents a robust and computationally efficient optimal design algorithm for electromagnetic devices by combining an adaptive response surface approximation of the objective function and($1+{\lambda}$) evolution strategy. In the adaptive response surface approximation, the design space is successively reduced with the iteration, and Pareto-optimal sampling points are generated by using Latin hypercube design with the Max Distance and Min Distance criteria. The proposed algorithm is applied to an analytic example and TEAM problem 22, and its robustness and computational efficiency are investigated.