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991.
本文所介绍的高效辐射换热器是指在其环缝通道中安装有网状二次传热面的辐射换热器,用对比实验方法研究了它们在空气预热温度、给热系数和阻力系数上的差别.实验表明:高效辐射换热器可强化空气侧的传热,其综合传热系数达59W/(m2·℃),而阻力系数可控制在3000Pa以内. 相似文献
992.
R. Sanchis I. M. Tkachenko G. Verdú J. L. Mu oz-Cobo 《Progress in Nuclear Energy》1995,29(3-4):321-336
The aim of the work was to develop on-line methods of control and diagnostics of pressure sensors at a NPP. The analysis was carried out along two lines:
- 1. i) The detection system including the sensor itself was modeled theoretically to obtain and study its transfer function, and to establish correspondence between the spectral characteristics of the pressure signal.
- 2. ii) The numerical processing of the signal using the AR technique to reconstruct the transfer function and evaluate the system's response, to a step impulse, as well as the spectral analysis. The hydraulic model presented indicate that the spectral lines observed at 10 Hz are due to longitu-dinal oscillations of water in the system branches, while the response time of the detection system is effectively the time of signal retardation in the porous ceramic diaphragms of the δ-cell of the sensor itself.
993.
On-Line Shape recognition with incremental training using binary synaptic weights algorithm 总被引:2,自引:0,他引:2
Recognition of hand drawn shapes is beneficial in drawing packages and automated sketch entry in handheld computers. In this paper, we propose a new approach to on-line geometric shape recognition with incremental training function, which utilizes a heuristic function to reduce noise and a neural network for classification and on-line training. Instead of recognizing segments of a drawing and then performing syntactical analysis to match with a predefined shape, which is weak in terms of generalization and dealing with noise, we examine the shape as a whole. The main concept of the recognition method is derived from the fact that internal angles are very important in the perceived shape of outlines. Our application's aim is to recognize elliptic, rectangular, and triangular shapes in a way similar to human cognition of these shapes. Human beings recognize such basic shapes regardless of the variations in size, noise on the shape border, rotation and in the case of triangles, regardless of the type of the triangle. The key concept is that the neural network learns the relationships between the internal angles of a shape and its classification, therefore only a few training samples which represent the class of the shape are sufficient. Fast meremental training, which is performed on-line, is accomplished by the use of the Binary Synaptic Weights algorithm, a one pass, feedforward neural network training algorithm. Incremental training offers the advantage of adjusting the recognition capability of the system to the user's drawings. the results are very successful, such that the neural network correctly classified shapes that did not have any resemblance to the shapes in the initial training set. 相似文献
994.
本文介绍以MAX038为基础而研制的宽频带函数波形产生器,它可以产生2 ̄2×^7Hz频率范围的正弦波、三角波、锯齿波和矩形波以及与它们同步的TTL脉冲信号。 相似文献
995.
This article reports the results of a study of domain-independent function finding based on a collection of several hundred real scientific data sets. Prior studies have introduced the controversial idea of discovering functional relationships of interest to scientists directly from the data they collect. The evidence presented here supports the view that this is sometimes possible, but it also suggests how often purely data-driven discovery is not possible and how much more difficult it may be than has often been assumed. Experience with sampled examples of real scientific data suggests as well that emphasis on search in prior studies may have been misplaced. For the function-finding problems studied here, scientists typically propose only a handful of different functional relationships. The difficulty is not in searching through a large space of relationships but in evaluating a few common ones to determine if they are likely to be of scientific interest. 相似文献
996.
本文把影响地下水位变化过程作为随机过程,用频谱分析法建立随机水动力学模型模拟地下水位的变化过程,并将其用于地下水位的中长期预报。通过实例验证它具有较高的精度。 相似文献
997.
将气体动压轴压简化为转化气膜系统后,针对其动力特点,给出气膜在微幅振动下动压轴承的实用数学模型和测定动态参数的方法,并进行了测量误差的修正。 相似文献
998.
氧化铍恣导热系数是表征热电制冷红外探测器半导体制冷器部件冷板和散热板导热能力的关键参数。本文论述了氧化瓷导热系数的测量原理和方法,推导了计算公式,分析了影响测量的关键因素并提出了相应措施,对样品制作和装配工艺提出了要求。最后,给出了样品实例测并得出结论。 相似文献
999.
详细介绍了在改进红外焊缝检测仪的过程中实时信号的一种抗干扰方法--自相关方法。重点离自相关方法的数学模型,软件框图及设计思想,并给出了实验结果。 相似文献
1000.
苯乙烯与BMI树脂的反应性研究 总被引:6,自引:0,他引:6
以BMI、二烯丙基双酚A和苯乙烯共聚制得一种低粘度、贮存期长、适用于压铸成型制备复合材料的树脂体系。本文重点研究了树脂的贮存稳定性、反应性及固化树脂的力学性能和耐热性。 相似文献