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991.
992.
本文重点阐述了本人在探索过程中遇到的疑难问题及解决问题的有效方法:消除电子流对高压系统的影响,负高压的产生和提高荷载能力,磁场反相,离子信号反向和自动控制的改造。 相似文献
993.
Emmanouil Kalligeros Xrysovalantis Kavousianos Dimitris Bakalis Dimitris Nikolos 《Journal of Electronic Testing》2002,18(3):315-332
In this paper we present a new reseeding technique for test-per-clock test pattern generation suitable for at-speed testing of circuits with random-pattern resistant faults. Our technique eliminates the need of a ROM for storing the seeds since the reseeding is performed on-the-fly by inverting the logic value of some of the bits of the next state of the Test Pattern Generator (TPG). The proposed reseeding technique is generic and can be applied to TPGs based on both Linear Feedback Shift Registers (LFSRs) and accumulators. An efficient algorithm for selecting reseeding points is also presented, which targets complete fault coverage and allows to well exploiting the trade-off between hardware overhead and test length. Using experimental results we show that the proposed method compares favorably to the other already known techniques with respect to test length and the hardware implementation cost. 相似文献
994.
在保证网络资源利用率高的条件下如何建立一个使所传图像主观质量最好且有效的MPEG-4传输系统,已成为一个具有挑战性的课题,就此问题提出了一个在因特网上建立MPEG-4视频流的端到端传输方案。 相似文献
995.
The goal of this article is to provide a construction of a homogeneous Lyapunov function
associated with a system of differential equations
, under the hypotheses: (1)
vanishes at x = 0 and is homogeneous; (2) the zero solution of this system is locally asymptotically stable. Moreover, the Lyapunov function
tends to infinity with x, and belongs to
, with
as large as wanted. As application to the theory of homogeneous systems, we present two well known results of robustness, in a slightly extended form, and with simpler proofs. 相似文献
996.
本文提出了一种利用双相位共轭反射镜的实时图像衬度控制方法。给出了理论分析,提出了一种实验方案,给出了模拟实验结果。 相似文献
997.
The use of atmospheric pressure MOVPE for the growth of high performance uncooled 1300 nm DFB lasers
A. J. Taylor A. S. Bridges J. Hardwick H. Lage R. H. Moss W. S. Ring 《Journal of Electronic Materials》1997,26(10):1131-1133
Manufacture of high performance uncooled 1300 nm distributed feed-back (DFB) lasers operating single mode over the −40 to
+85°C range requires control of the wavelength variation across a 2″ wafer to less than 10nm and preservation of grating definition
during processing and regrowth. We have used atmospheric pressure metalorganic vapor phase epitaxy, without substrate rotation
to achieve the necessary uniformity. Material was assessed using photoluminescence, x-ray diffraction, transmission electron
microscopy, electrochemical current/voltage profiling, and secondary ion mass spectroscopy. The devices are based on a strained
quantum well structure with an n-type grating layer to provide gain coupling. The best result gave a wavelength spread across
32×32 mm center square of a 2″ InP wafer of 3 nm. Buried heterostructure DFBs manufactured with high yield in this way operate
from −40 to +85°C, with thresholds at 85°C as low as 18 mA. 相似文献
998.
带钢热连轧卷取温度控制与改进算法 总被引:6,自引:0,他引:6
对带钢热连轧卷取温度控制的主要问题进行了分析,描述了CTC基本控制模型,并在此基础上,提出了两个新算法:全长反馈控制与头部设定自学习,经使用证明这两个新功能具有很好的控制效果。 相似文献
999.
This paper deals with the problem of global stabilization of linear discrete time systems by means of bounded feedback laws. The main result proved is an analog of one proved for the continuous time case by the authors, and shows that such stabilization is possible if and only if the system is stabilizable with arbitrary controls and the transition matrix has spectral radius less than or equal to one. The proof provides in principle an algorithm for the construction of such feedback laws, which can be implemented either as cascades or as parallel connections (“single hidden layer neural networks”) of simple saturation functions. 相似文献
1000.
In this second installment of a two part paper that overviews analog feedback circuits, computationally efficient and general feedback analysis techniques applicable to virtually all three and four terminal device technologies are formulated. As developed in Part I, these techniques coalesce signal flow and two port network theories in a way that clearly illuminates the loop gain, driving point I/O impedances, and other characteristics of any type of feedback configuration. More than simply developing the signal flow-two port methodology, this paper demonstrates its design-oriented utility by applying the new technique to the problem of assessing the performance attributes and limitations of four single loop and two dual loop feedback architectures.Three advantages are gleaned by the signal flow-two port method of feedback network analysis. The first advantage is its amenability to a straightforward application of the stability theories and compensation strategies discussed in Part I. The second is its ability to underscore the magnitude of potentially troublesome feedforward factors associated with the feedback network. Once the extent of this parasitic feedforward is highlighted, the topological nature of appropriate feedforward compensation is relatively easy to innovate. The third advantage of signal flow-two port analytical methods is its ability to simplify the analysis of dual loop feedback architectures. This last advantage is noteworthy in view of the fact that dual feedback loops offer the only practical analog mechanism for desensitizing the gain and I/O impedances with respect to uncertainties in open loop parameters. 相似文献