CONTROL CHAOS IN TRANSITION SYSTEM USING SAMPLED-DATA FEEDBACK

The method for controlling chaotic transition system was investigated using sampled- data . The output of chaotic transition system was sampled at a given sampling rate , then the sampled output was used by a feedbacks subsystem to construct a control signal for controlling chaotic transition system to the origin . Numerical simulations are presented to show the effectiveness and feasibility of the developed controller.

Impulsive effect on exponential synchronization of neural networks with leakage delay under sampled-data feedback control

We consider the impulsive effect on the exponential synchronization of neural networks with leakage delay under the sampled-data feedback control. We use an appropriate Lyapunov-Krasovskii functional combined with the input delay approach and some inequality techniques to derive sufficient conditions that ensure the exponential synchronization of the delayed neural network. The conditions are formulated in terms of the leakage delay, the sampling period, and the exponential convergence rate. Numerical examples are given to demonstrate the usefulness and the effectiveness of the results.

Improving Diabetes Care by Data Feedback and Diabetes Templates

Importance: Health information technology has been used to improve diabetes care and outcomes. With the implementation of our diabetes registry, we discovered several flaws in the data. Objective: The aim of this paper is to demonstrate whether improving diabetes templates in electronic medical records associated with data feedback, improves process and quality outcomes for patients with diabetes. Methods: We redesigned our chronic diseases templates and clinical flow, built a diabetes registry and used the data for feedback to educate providers, staff and address inconsistencies. A total of 724 active diabetic patients were identified in October 2009 (pre-implementation) and 731 active diabetic patients were identified in June 2011 (post-implementation). Results: The results showed an improvement in the process outcomes of ordering hemoglobin A1C every 6 months and a microalbumin every 12 months (p-value 0.05). Discussion: Data feedback and lessons learned were instrumental to our practice change.

BFM:A Bus-Like Data Feedback Mechanism Between Graphics Processor and Host CPU

Graphics processors have received an increasing attention with the growing demand for gaming,video streaming,and many other applications.During the graphics rendering with OpenGL,host CPU needs the runtime attributes to move on to the next procedure of rendering,which covers almost all the function units of graphics pipeline.Current methods suffer from the memory capacity issues to hold the variables or huge amount of data parsing paths which can cause congestion on the interface between graphics processor and host CPU.This paper refers to the operation principle of commuting bus,and proposes a bus-like data feedback mechanism(BFM)to traverse all the pipeline stages and collect the run-time status data or execution error of graphics rendering,then send them back to the host CPU.BFM can work in parallel with the graphics rendering logic.This method can complete the data feedback ta.sk easily with only 0.6%increase of resource utilization and has no negative impact on performance,which also obtains 1.3 times speed enhancement compared with a traditional approach.

Metadata Feedback and Utilization for Data Deduplication Across WAN

Data deduplication for file communication across wide area network （WAN） in the applications such as file synchronization and mirroring of cloud environments usually achieves significant bandwidth saving at the cost of significant time overheads of data deduplication. The time overheads include the time required for data deduplication at two geographi- cally distributed nodes （e.g., disk access bottleneck） and the duplication query/answer operations between the sender and the receiver, since each query or answer introduces at least one round-trip time （RTT） of latency. In this paper, we present a data deduplication system across WAN with metadata feedback and metadata utilization （MFMU）, in order to harness the data deduplication related time overheads. In the proposed MFMU system, selective metadata feedbacks from the receiver to the sender are introduced to reduce the number of duplication query/answer operations. In addition, to harness the metadata related disk I/O operations at the receiver, as well as the bandwidth overhead introduced by the metadata feedbacks, a hysteresis hash re-chunking mechanism based metadata utilization component is introduced. Our experimental results demonstrated that MFMU achieved an average of 20%~40% deduplication acceleration with the bandwidth saving ratio not reduced by the metadata feedbacks, as compared with the ＂baseline＂ content defined chunking （CDC） used in LBFS （Low-bandwith Network File system） and exiting state-of-the-art Bimodal chunking algorithms based data deduplication solutions.

An Improvement on Data-Driven Pole Placement for State Feedback Control and Model Identification

The recently proposed data-driven pole placement method is able to make use of measurement data to simultaneously identify a state space model and derive pole placement state feedback gain. It can achieve this precisely for systems that are linear time-invariant and for which noiseless measurement datasets are available. However, for nonlinear systems, and/or when the only noisy measurement datasets available contain noise, this approach is unable to yield satisfactory results. In this study, we investigated the effect on data-driven pole placement performance of introducing a prefilter to reduce the noise present in datasets. Using numerical simulations of a self-balancing robot, we demonstrated the important role that prefiltering can play in reducing the interference caused by noise.

ROBUST CONTROL WITH COVARIANCE CONSTRAINT FOR UNCERTAIN SAMPLED-DATA FEEDBACK CONTROL SYSTEMS

The problem of robust controller design with covariance constraint for uncertain sampled data feedback control systems was considered in this paper. The goal of this problem is to design controllers such that the closed loop system meets the prespecified covariance constraint. This problem can be reduced to a controller design problem for an equivalent uncertain discrete time system. Sufficient conditions were given for the existence of the desired controllers. The analytical expression of the set of desired controllers was also presented. An illustrative example was given to show the applicability of the proposed design procedure.

Load Shedding Strategy Based on Combined Feed-Forward Plus Feedback Control over Data Streams

In data stream management systems (DSMSs), how to maintain the quality of queries is a difficult problem because both the processing cost and data arrival rates are highly unpredictable. When the system is overloaded, quality degrades significantly and thus load shedding becomes necessary. Unlike processing overloading in the general way which is only by a feedback control (FB) loop to obtain a good and stable performance over data streams, a feedback plus feed-forward control (FFC) strategy is introduced in DSMSs, which have a good quality of service (QoS) in the aspects of miss ratio and processing delay. In this paper, a quality adaptation framework is proposed, in which the control-theory-based techniques are leveraged to adjust the application behavior with the considerations of the current system status. Compared to previous solutions, the FFC strategy achieves a good quality with a waste of fewer resources.

Suboptimal distributed Kalman filtering fusion with feedback

In order to improve the accuracy of fusion algorithm, feedback is introduced into Kalman filtering fusion. Fusion center broadcasts its latest estimated states to the local sensors, which can improve the performance of local tracking error through reducing the oovariance of each local error, and only needs calculating the trace of error variance matrices without calculating the inverse of error variance matrices. Simulation results show that it can reduce the ecmputational complexity and the oovariance of error, and it is oonvenient for engineering applications.

Relationship Between Track Fusion Solutions with and without Feedback Information

In distributed multisensor data fusion systems, there are two types of track fusion approaches. One is sensor track fusion with feedback information, the other is without feedback information. This paper proves that the solutions of sensor track fusion with and without feedback information are both optimal and equal.

Some Additional Moment Conditions for a Dynamic Count Panel Data Model with Predetermined Explanatory Variables

This paper proposes some additional moment conditions for the linear feedback model with explanatory variables being predetermined, which is proposed by [1] for the purpose of dealing with count panel data. The newly proposed moment conditions include those associated with the equidispersion, the Negbin I-type model and the stationarity. The GMM estimators are constructed incorporating the additional moment conditions. Some Monte Carlo experiments indicate that the GMM estimators incorporating the additional moment conditions perform well, compared to that using only the conventional moment conditions proposed by [2,3].

Lift fin stabilizers based on data fusion with wavelet denoising technology

Fin stabilizers with fin-lift feedback control can shield the mapping error of calculation between the fin angle and fin lift force,which is in the fin stabilizer with fin-angle feedback control.In practice,there are some technical difficulties in lift fin stabilizers,such as lift force detection and lift force sensor installation,so it cannot achieve the good antirolling performance.Therefore,a fin stabilizer system with fin-lift/fin-angle integrated control is brought forward.Data fusion based on wavelet denoising technology is employed in the system,which combines lift with fin angle local information from two sensors with different frequency ranges in order to eliminate redundant and contradictory information,and using complementary information to obtain the relative integrity of the lift force signal.The system model is established in this paper,and the fusion signal and the antirolling performance of this model are simulated respectively.The result shows that the control system can meet the antirolling need in different sea situations.

Quantized dynamic output feedback control for networked control systems

The problem of the quantized dynamic output feedback controller design for networked control systems is mainly discussed. By using the quantized information of the system measurement output and the control input, a novel networked control system model is described. This model includes many networkinduced features, such as multi-rate sampled-data, quantized signal, time-varying delay and packet dropout. By constructing suitable Lyapunov-Krasovskii functional, a less conservative stabilization criterion is established in terms of linear matrix inequalities. The quantized control strategy involves the updating values of the quantizer parameters μi（i = 1, 2）（μi take on countable sets of values which dependent on the information of the system measurement outputs and the control inputs）. Furthermore, a numerical example is given to illustrate the effectiveness of the proposed method.

非仿射非线性系统控制综述

作为仿射非线性系统更一般化的描述,非仿射非线性系统所对应的实际应用更加广泛,也更贴近实际。因此,研究非仿射非线性系统的控制问题十分重要。然而,非线性系统的非仿射特性会使控制信号以非线性函数形式出现在闭环系统中,从而带来诸如控制方向未知、奇异、过零等问题。由此,解决非仿射非线性系统的控制问题面临着巨大的挑战。基于此,介绍了仿射、严格反馈和高阶系统的相关背景知识,总结和分析了解决非仿射非线性系统控制的3种解决思路,包括函数变换法、参考模型法和数据驱动法。在已有的研究成果基础上,指出非仿射非线性系统研究领域所面临的挑战和发展趋势。

含有输入时滞的非线性系统的输出反馈采样控制

针对含有输入时滞和低阶非线性项的非线性系统,提出一种基于采样机制的无记忆输出反馈控制方法.该方法移除了传统预测控制方法预测映射难以确定的限制,同时避免了时滞依赖方法对过去时刻状态信息的依赖性,在实际中更易实现.首先,根据系统输出在采样时刻的信息,利用加幂积分技术和齐次占优思想设计了无记忆输出反馈采样控制器.然后,利用齐次系统理论提出了闭环系统的稳定性条件.最后,仿真结果验证了所提方法的有效性和优越性.

可视化反馈促进自我调节学习的实验研究

建设终身学习型社会要求学习者具备更高的自我调节学习能力。这就要求教育不仅要教会学生知识,更要教会学生学习。然而,当前关于促进基础教育中学习者自我调节学习的研究较少,并且缺乏可以应用于线下课堂的实用工具,导致测评数据无法被深入解读。立足于基础教育课堂教学,设计开发促进学习者自我调节学习的可视化反馈工具,深入分析测评数据,挖掘其中蕴藏的有效信息。该工具提供包括自我认识、学习动机、学习策略三个维度的可视化反馈报告,将知识掌握情况、错题归因、试题定位等信息呈现给学习者,助力其自我调节学习的发生。为检验该工具的效果,在两个班级开展对比实验,对两组学生的自我调节学习能力和学习成绩进行差异性检验。独立样本T检验结果显示,实验班和对照班在自我调节学习能力和学习成绩之间均存在显著性差异,并且均呈现出0.4左右的效应量。证明该工具提供的可视化反馈报告能够有效促进学习者的自我调节学习,同时能够促进学业表现。

工程图学课程的数字化转型实践探索

随着信息技术和智能制造技术的飞速发展,工程图学课程正迎来数字化转型的重大机遇。文章聚焦课程内容、教学模式、数据分析与反馈三个维度,探索工程图学课程的数字化转型。具体措施包括:引入前沿数字化技术,整合数字化教学内容;丰富数字化资源,创新数字化教学组织模式;引入数字化评估工具,对学生的学习进行精准干预和全面评价。实践表明,工程图学课程的教学质量和效果得到显著提升,为同类课程深入开展数字化转型实践积累了经验。

Evaluation of Ocean Data Assimilation in CAS-ESM-C:Constraining the SST Field

A weakly coupled assimilation system, in which SST observations are assimilated into a coupled climate model （CAS- ESM-C） through an ensemble optimal interpolation scheme, was established. This system is a useful tool for historical climate simulation, showing substantial advantages, including maintaining the atmospheric feedback, and keeping the oceanic tields from drifting far away from the observation, among others. During the coupled model integration, the bias of both surface and subsurface oceanic fields in the analysis can be reduced compared to unassimilated fields. Based on 30 model years of ot.tput fiom the system, the climatology and imerannual variability of the climate system were evaluated. The results showed that the system can reasonably reproduce the climatological global precipitation and SLP, bul it still sutters from the double ITCZ problem. Besides, the ENSO footprint, which is revealed by ENSO-related surface air temperature, geopotential height and precipitation during El Nifio evolution, is basically reproduced by the system. The system can also simulate the observed SST-rainfall relationships well on both interannual and intraseasonal timescales in the western North Pacific region, in which atmospheric feedback is crucial for climate simulation.

数据要素乘数效应的内涵与实现逻辑

数据是数字经济时代的关键生产要素,国家高度重视发挥数据要素乘数效应、赋能经济社会发展。基于凯恩斯主义经济学框架分析数据要素乘数效应的内涵,结合数据要素乘数效应的有利条件和制约因素分析其实现逻辑。研究发现,数据要素乘数效应的内涵包括溢出效应和反馈效应两方面,数据要素的开发利用可以提升投资水平、消费水平、供需匹配效率和政府调控能力等,从而实现溢出效应。研究还发现,数据要素开发利用过程中,可以通过干中学不断提高原始数据积累水平、畅通数据流通渠道、提高数据分析能力,从而实现反馈效应。数据要素乘数效应的实现逻辑包括:非竞争性可以使数据要素实现报酬递增和正反馈循环,是数据要素可以发挥乘数效应的根本原因;规模经济、正外部性、干中学效应和生产力跃迁是数据要素发挥乘数效应的有利条件;低数据质量、隐私负外部性、数据共享机会成本、数据安全保护成本等可能制约数据要素发挥乘数效应。研究表明,要促进企业数字化转型,构建跨界融合的数据要素应用生态;加强数商生态体系培育,畅通数据要素流通渠道;完善数据要素安全保护制度和公共服务,培育数据安全风险管理产业生态;以效率和公平为目标,完善数据要素收益分配机制。

基于判决反馈的VDES解调系统设计与FPGA实现

甚高频数据交换系统(Very high frequency Data Exchange System,VDES)作为新一代船舶通信系统,具有广阔的应用前景。由于卫星相对船舶的高速运动,VDES中上行应用特定消息(Application-specific Message,ASM)链路会产生较大的多普勒频移,在接收端仅依靠已知训练序列估计的频偏等信道参数无法满足正确解调的性能要求。为此提出一种基于判决反馈的解调方法,通过分段解调,缩短每次解调的数据长度,提高解调时对频偏的容忍度,并利用每段解调的结果作为下一段未解调数据的导频,估计出当前数据中的信道参数。仿真结果表明,所提算法相较于无反馈相干解调算法性能大大提升。在上述研究的基础上,在可编程逻辑器件上实现了对ASM无导频上行链路的正确解调。