35 resultados para System Identification
Resumo:
The paper proposes the identification method of linear and non-linear chromatographic system. The non-linear isotherms and lumped mass transfer coefficients of chromatography separating sorbitol and mannitol are determined. And the theoretical elution curves calculated by non-linear chromatographic model are more accurate than those calculated by linear chromatographic model.
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根据小型自治遥控水下机器人SARV的运动特性,研制了光纤微缆收放的控制系统。设计使用了嵌入式QNX软件开发技术,系统稳定可靠。采用系统辨识的方法,获得被控对象的等效数学模型。采用单神经元自适应PID控制器对控制参数进行在线自调节,实现了SARV在水中运动时光纤收放的恒张力控制,满足光纤收放装置的设计要求。
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本论文的研究内容分为两方面:AUV的建模和控制。 建模方面,主要对当前用于AUV的建模方法进行了分类及对比,给出了水动力机理建模、水动力辨识、面向目标的系统辨识三类方法的优缺点。 根据可辨识性理论,对AUV闭环系统进行分析,给出了AUV闭环系统可辨识的充分条件。为了提高辨识算法的实时性,解决辨识过程中的“数据饱和”问题,给出了改进的变步长增广卡尔曼滤波辨识算法。利用小型AUV湖上试验数据辨识出航向回路、深度回路的系统模型,通过不同的试验数据与模型预测值的相关性验证模型,试验结果表明了该算法应用于AUV闭环系统建模的可行性。 控制方面,在传统PID控制、S面控制方法基础上,借鉴单神经元PID控制思想,将积分环节加入S面控制中来简化S面PID控制算法,并通过仿真验证了算法的可行性。上述方法参数调节依赖工程经验,而广义预测控制具有对模型要求低、算法鲁棒性强、参数调节简单等优点。因此,本文对输入输出约束的广义预测控制快速算法应用于AUV系统进行仿真,通过小型AUV水池试验验证了算法的有效性。
Resumo:
提出了求解某武器系统导弹弹道轨迹的两种方法:计算机仿真和系统辨识方法.详细介绍了导弹系统的计算机仿真模型,并利用控制理论和数值分析的方法对仿真模型求解;根据系统辨识理论,将整个系统看作“黑箱”,建立与输入、输出数据等价的模型,引入折息因子对模型进行辨识.最后分别给出了计算机仿真试验曲线和系统辨识试验曲线,证明了两种求解方法的有效性。
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本文用双线性系统的辨识方法对海洋机器人航向与侧推的控制系统建模,并对所得模型进行了计算机仿真,仿真结果表明了模型的有效性。
Resumo:
This paper describes a special-purpose neural computing system for face identification. The system architecture and hardware implementation are introduced in detail. An algorithm based on biomimetic pattern recognition has been embedded. For the total 1200 tests for face identification, the false rejection rate is 3.7% and the false acceptance rate is 0.7%.
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Edwardsielia tarda is one of the leading marine pathogens that can infect a wide range of cultured marine species. In this study, the acrR-acrAB cluster was cloned from TX1, a pathogenic E. tarda strain isolated from diseased fish. AcrR and AcrAB were found to be involved in resistance against acriflavine and methyl viologen, which positively regulate the expression of acrAB. AcrR negatively regulates its own expression and the expression of the acrAB operon, most likely by interacting with a 24-bp operator site that overlaps the putative promoter of acrA (PacrA). The repressive effect of AcrR on PacrA could be relieved by acriflavine, methyl viologen, and ethidium bromide, the presence of each of which enhanced transcription from PacrA. Interruption of the regulated expression of acrR by introducing into TX1 a plasmid that overexpresses acrR affected growth under stress conditions, AI-2 production, and bacterial virulence. In addition, mutational analyses identified a constitutively active AcrR mutant (named N215), which exhibits full repressor activity but is impaired in its ability to interact with the inducer. Overexpression of N215 produced the same kind of but moderately stronger effect on TX1 compared to that produced by overexpression of the wild-type acrR.
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Large-insert bacterial artificial chromosome (BAC) libraries are necessary for advanced genetics and genomics research. To facilitate gene cloning and characterization, genome analysis, and physical mapping of scallop, two BAC libraries were constructed from nuclear DNA of Zhikong scallop, Chlamys farreri Jones et Preston. The libraries were constructed in the BamHI and MboI sites of the vector pECBAC1, respectively. The BamHI library consists of 73,728 clones, and approximately 99% of the clones contain scallop nuclear DNA inserts with an average size of 110 kb, covering 8.0x haploid genome equivalents. Similarly, the MboI library consists of 7680 clones, with an average insert of 145 kb and no insert-empty clones, thus providing a genome coverage of 1.1x. The combined libraries collectively contain a total of 81,408 BAC clones arrayed in 212 384-well microtiter plates, representing 9.1x haploid genome equivalents and having a probability of greater than 99% of discovering at least one positive clone with a single-copy sequence. High-density clone filters prepared from a subset of the two libraries were screened with nine pairs of Overgos designed from the cDNA or DNA sequences of six genes involved in the innate immune system of mollusks. Positive clones were identified for every gene, with an average of 5.3 BAC clones per gene probe. These results suggest that the two scallop BAC libraries provide useful tools for gene cloning, genome physical mapping, and large-scale sequencing in the species.
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The nonlinear behavior varying with the instantaneous response was analyzed through the joint time-frequency analysis method for a class of S. D. O. F nonlinear system. A masking operator an definite regions is defined and two theorems are presented. Based on these, the nonlinear system is modeled with a special time-varying linear one, called the generalized skeleton linear system (GSLS). The frequency skeleton curve and the damping skeleton curve are defined to describe the main feature of the non-linearity as well. Moreover, an identification method is proposed through the skeleton curves and the time-frequency filtering technique.
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In the previous paper, a class of nonlinear system is mapped to a so-called skeleton linear model (SLM) based on the joint time-frequency analysis method. Behavior of the nonlinear system may be indicated quantitatively by the variance of the coefficients of SLM versus its response. Using this model we propose an identification method for nonlinear systems based on nonstationary vibration data in this paper. The key technique in the identification procedure is a time-frequency filtering method by which solution of the SLM is extracted from the response data of the corresponding nonlinear system. Two time-frequency filtering methods are discussed here. One is based on the quadratic time-frequency distribution and its inverse transform, the other is based on the quadratic time-frequency distribution and the wavelet transform. Both numerical examples and an experimental application are given to illustrate the validity of the technique.
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Micro-fabrication technology has substantial potential for identifying molecular markers expressed on the surfaces of tissue cells and viruses. It has been found in several conceptual prototypes that cells with such markers are able to be captured by their antibodies immobilized on microchannel substrates and unbound cells are flushed out by a driven flow. The feasibility and reliability of such a microfluidic-based assay, however, remains to be further tested. In the current work, we developed a microfluidic-based system consisting of a microfluidic chip, an image grabbing unit, data acquisition and analysis software, as well as a supporting base. Specific binding of CD59-expressed or BSA-coupled human red blood cells (RBCs) to anti-CD59 or anti-BSA antibody-immobilized chip surfaces was quantified by capture efficiency and by the fraction of bound cells. Impacts of respective flow rate, cell concentration, antibody concentration and site density were tested systematically. The measured data indicated that the assay was robust. The robustness was further confirmed by capture efficiencies measured from an independent ELISA-based cell binding assay. These results demonstrated that the system developed provided a new platform to effectively quantify cellular surface markers effectively, which promoted the potential applications in both biological studies and clinical diagnoses.
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We propose an efficient scheme to build an arbitrary multipartite Greenberger-Horne-Zeilinger state and discriminate all the universal Greenberger-Horne-Zeilinger states using parity measurement based on dipole-induced transparency in a cavity-waveguide system. A prominent advantage is that initial entangled states remain after nondetective identification and they can be used for successive tasks. We analyze the performance and possible errors of the required single-qubit rotations and emphasize that the scheme is reliable and can satisfy the current experimental technology.
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Gibel carp ( Carassius auratus gibelio) is a uniquely gynogenetic species with a minor ratio of males in natural habitats, but its male origin and sex determination mechanisms have been unknown. In this study, a male-biased mutant family was discovered from the gynogenetic gibel carp, and a male-specific SCAR marker was identified from the mutant family. Normal spermatogenesis was observed in the male testes by immuno. fluorescence histochemistry. Nearly identical AFLP profiles were observed between males and females, but a male-specific 86 bp AFLP fragment was screened by sex-pool bulked segregant analysis and individual screening. Based on the male-specific AFLP fragment, a total of 579 bp sequences were cloned by genome walking. Subsequently, a male-specific SCAR marker was designed, and the male-specific DNA fragment was confirmed to be steadily transmitted to the next generation and consistently detected only in males. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.
Resumo:
Background: Cytochrome P450 monooxygenases play key roles in the metabolism of a wide variety of substrates and they are closely associated with endocellular physiological processes or detoxification metabolism under environmental exposure. To date, however, none has been systematically characterized in the phylum Ciliophora. T. thermophila possess many advantages as a eukaryotic model organism and it exhibits rapid and sensitive responses to xenobiotics, making it an ideal model system to study the evolutionary and functional diversity of the P450 monooxygenase gene family. Results: A total of 44 putative functional cytochrome P450 genes were identified and could be classified into 13 families and 21 sub-families according to standard nomenclature. The characteristics of both the conserved intron-exon organization and scaffold localization of tandem repeats within each P450 family clade suggested that the enlargement of T. thermophila P450 families probably resulted from recent separate small duplication events. Gene expression patterns of all T. thermophila P450s during three important cell physiological stages (vegetative growth, starvation and conjugation) were analyzed based on EST and microarray data, and three main categories of expression patterns were postulated. Evolutionary analysis including codon usage preference, sit-especific selection and gene-expression evolution patterns were investigated and the results indicated remarkable divergences among the T. thermophila P450 genes. Conclusion: The characterization, expression and evolutionary analysis of T. thermophila P450 monooxygenase genes in the current study provides useful information for understanding the characteristics and diversities of the P450 genes in the Ciliophora, and provides the baseline for functional analyses of individual P450 isoforms in this model ciliate species.