NSTL联合数据加工系统的功能框架设计   总被引：1，自引：1，他引：0  

张建勇  孟连生  刘筱敏  曾燕  刘小兵  董智鹏 《图书情报工作》2011,55(3):64-69

论述NSTL联合数据加工系统建设的目标、设计原则,构建系统的总体功能框架,重点分析在分布式的文献数据加工管理环境中,文献数据从生产、处理、管理、仓储到服务的全过程的工作流管理和数据加工管理的流程。探讨联合目录系统、数据仓储系统、联合数据加工中心系统和分中心系统间基于OAI-PMH协议的元数据共享和交换过程,分析数据资源的特点和各类数据资源的数据结构,描述联合数据加工系统的中心和分中心两级系统的管理框架和各模块的功能。  相似文献   

档案资源整合视角下的数字档案资源公共服务能力评价指标构建     

董宇  安小米  白文琳  钟文睿  孙舒扬  郝春红 《档案学研究》2015,29(4):58-63

本文分析了档案资源整合对公共服务能力提升所起的作用,并通过构建基于“公共价值理论”的公共服务能力概念框架选取评价指标。与经典的“公共价值理论”相比,结合数字档案资源的特点,创新性地将“工作人员的素质”、“数字档案资源整合”和“档案管理机构协同”增加到“公共价值理论”的指标体系中,丰富了“公共价值理论”在此领域中的内涵。为了验证评价指标,本文采用面对面访谈和座谈会交流的形式对9个市级、3个省级的相关档案管理机构展开调研活动,从档案管理机构的角度论证了本概念模型中各个评价指标的合理性、实用性和有效性。  相似文献   

Fe–Mn/MCM-41: Preparation,Characterization,and Catalytic Activity for Methyl Orange in the Process of Heterogeneous Fenton Reaction     

Xubin Zhang  Jianxin Dong  Zhencheng Hao  Wangfeng Cai  Fumin Wang 《天津大学学报(英文版)》2018,(4)

Active Fe-and Mn-loaded MCM-41(Fe–Mn/MCM-41),which was synthesized via a hydrothermal reaction followed by impregnation,is used in the heterogeneous Fenton reaction to degrade methyl orange(MO) in aqueous solution. The synthesized samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,N_2 adsorption–desorption isotherm analysis,Fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy. Compared with Fe/MCM-41 and Mn/MCM-41,Fe–Mn/MCM-41 showed higher activity for MO degradation and mineralization. Effects of various operating parameters,such as pH,Mn content,and H_2O_2 dosage,on the degradation process were subsequently investigated. Results of experiments on the effect of radical scavengers revealed that the degradation of MO could be attributed to oxidation by HO_·. The synergy of Fe and Mn species in the Fenton oxidation process was also explained.  相似文献   

Centralized security-guaranteed filtering in multirate-sensor fusion under deception attacks     

Zidong Wang  Dong Wang  Bo Shen  Fuad E. Alsaadi 《Journal of The Franklin Institute》2018,355(1):406-420

In this paper, the centralized security-guaranteed filtering problem is studied for linear time-invariant stochastic systems with multirate-sensor fusion under deception attacks. The underlying system includes a number of sensor nodes with a centralized filter, where each sensor is allowed to be sampled at different rate. A new measurement output model is proposed to characterize both the multiple rates and the deception attacks. By exploiting the lifting technique, the multi-rate sensor system is cast into a single-rate discrete-time system. With a new concept of security level, the aim of this paper is to design a filter such that the filtering error dynamics achieves the prescribed level of the security under deception attacks. By using the stochastic analysis techniques, sufficient conditions are first derived such that the filtering error system is guaranteed to have the desired security level, and then the filter gain is parameterized by using the semi-definite programme method with certain nonlinear constraints. Finally, a numerical simulation example is provided to demonstrate the feasibility of the proposed filtering scheme.  相似文献   

Optimal residual generation for fault detection in linear discrete time-varying systems with uncertain observations     

Yueyang Li  Hamid Reza Karimi  Choon Ki Ahn  Yuan Xu  Dong Zhao 《Journal of The Franklin Institute》2018,355(7):3330-3353

This work deals with the problem of optimal residual generation for fault detection (FD) in linear discrete time-varying (LDTV) systems subject to uncertain observations. By introducing a generalized fault detection filter (FDF) with four parameter matrices as the residual generator, a novel FDF design scheme is formulated as two bi-objective optimization problems such that the sensitivity of residual to fault is enhanced and the robustness of residual to unknown input is simultaneously strengthened. A generalized operator based optimization approach is proposed to deduce solutions to the corresponding optimization problems in operator forms, where the related H_∞/H_∞ or $H_{?}/H_{\infty }$ FD performance index is maximized. With the aid of the addressed methods, the connections among the derived solutions are explicitly announced. The parameter matrices of the FDF are analytically derived via solving simple matrix equations recursively. It is revealed that our proposed results establish an operator-based framework of optimal residual generation for some kinds of linear discrete-time systems. Illustrative examples are given to show the applicability and effectiveness of the proposed methods.  相似文献   

Fractional-order follower observer design for tracking consensus in second-order leader multi-agent systems: Periodic sampled-based event-triggered control     

Aijuan Wang  Xiaofeng Liao  Tao Dong 《Journal of The Franklin Institute》2018,355(11):4618-4628

This paper investigates the tracking consensus problem for the second-order leader systems by designing fractional-order observer, where a periodic sampled-based data event-triggered control is employed. In order to track the position information of leader, observers for followers are designed by fractional-order system, where only the relative position information is available. Furthermore, in the process of observers design, a sampled-based event-triggered strategy is proposed so that observers use the event-triggered sampled-data, to reduce the overall load of the network. In our proposed event-triggered strategy, the event detection only works at every sampling time instant which determines whether the sampled-data should be discarded or used. Under this control strategy, the Zeno-behavior is absolutely excluded since the minimum of inter-event times is inherently lower bounded by one sampling period. It is found that the followers can track state of the leader if fractional-order observers are appropriately designed and relevant parameters are properly selected. By using the generalized Nyquist stability criterion, a necessary and sufficient condition for the observer tracking consensus of the second-order leader systems is derived. The results show that the real and imaginary parts of the eigenvalues of the augmented Laplacian matrix, and fractional-order α of observer play a vital role in reaching consensus.  相似文献   

Error-driven nonlinear feedback-based fuzzy adaptive output dynamic surface control for nonlinear systems with partially constrained tracking errors     

Shigen Gao  Hairong Dong  Bin Ning  Hongwei Wang 《Journal of The Franklin Institute》2018,355(13):5452-5474

In this paper, a novel error-driven nonlinear feedback technique is designed for partially constrained errors fuzzy adaptive observer-based dynamic surface control of a class of multiple-input-multiple-output nonlinear systems in the presence of uncertainties and interconnections. There is no requirements that the states are available for the controller design by constructing fuzzy adaptive observer, which can online identify the unmeasurable states using available output information only. By transforming partial tracking errors into new error variables, partially constrained tracking errors can be guaranteed to be confined in pre-specified performance regions. The feature of the error-driven nonlinear feedback technique is that the feedback gain self-adjusts with varying tracking errors, which prevents high-gain chattering with large errors and guarantees disturbance attenuation with small errors. Based on a new non-quadratic Lyapunov function, it is proved that the signals in the resulted closed-loop system are kept bounded. Simulation and comparative results are given to demonstrate the effectiveness of the proposed method.  相似文献   

Terminal iterative learning control for discrete-time nonlinear systems based on neural networks     

Jian Han  Dong Shen  Chiang-Ju Chien 《Journal of The Franklin Institute》2018,355(8):3641-3658

The terminal iterative learning control is designed for nonlinear systems based on neural networks. A terminal output tracking error model is obtained by using a system input and output algebraic function as well as the differential mean value theorem. The radial basis function neural network is utilized to construct the input for the system. The weights are updated by optimizing an objective function and an auxiliary error is introduced to compensate the approximation error from the neural network. Both time-invariant input case and time-varying input case are discussed in the note. Strict convergence analysis of proposed algorithm is proved by the Lyapunov like method. Simulations based on train station control problem and batch reactor are provided to demonstrate the effectiveness of the proposed algorithms.  相似文献   

A decentralized control method for frequency restoration and accurate reactive power sharing in islanded microgrids     

Zhanqiang Zhang  Chunxia Dou  Dong Yue  Bo Zhang  Wei Luo 《Journal of The Franklin Institute》2018,355(17):8874-8890

To achieve the frequency restoration (FR) and accurate reactive power sharing (RPS) in islanded microgrids (MGs), an improved P-f droop control is proposed. Firstly, the inverter impedance, whose value is set by the virtual impedance method, is used to minimize the impact of line resistance on powers coupling and RPS. Then, in order to restore the frequency of distributed generations (DGs) to the rated value, the reference is changed for compensating the frequency deviation (FD) caused by loads change. And the fast FR rate is achieved under a large constant k. Besides, in order to eliminate the inaccuracy of RPS caused by voltages difference (VD), the line voltage drop (LVD) is used to compensate the voltage droop characteristics. The use of voltage feedback ensures that the obtained voltage is desired after the LVD compensation. Finally, the simulation in RT-LAB indicates the effectiveness of proposed method in an islanded MG model.  相似文献   

Correction to: Do Teachers’ Instructional Practices Moderate Equity in Mathematical and Scientific Literacy?: An Investigation of the PISA 2012 and 2015     

Jihyun Hwang  Kyong Mi Choi  Yejun Bae  Dong Hoon Shin 《International Journal of Science and Mathematics Education》2018,16(8):1629-1631

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