基于滑动多窗口的时间序列流趋势变化检测

趋势变化检测在时间序列流中有着非常广泛的应用。针对可变长的趋势变化检测问题,提出一种基于滑动多窗口的趋势变化检测方法,通过动态生成大尺度窗口,来适应可变长的趋势变化检测。针对内存约束下长趋势变化检测问题,提出一种基于增量PLA的窗口数据近似表示方法,给出了其欧式距离下的误差分析,进而提出一种误差修正方法来降低漏检率。大量实验表明,本文提出的检测方法具有高准确率且时间效率很高。     

基于Delphi的屏幕录像实现

这里详述了屏幕录像的基本原理和屏幕录像方式：当前活动窗体录像、全屏录像和自由指定区域录像的位图获取方式;对MPEG4编码基本原理及视频流结构进行了分析,基于Delphi面向对象编程思想设计了一个MPEG4编码器,可完成I帧与P帧模式的图像编码;按一定的帧率将获取的屏幕位图数据经MPEG4编码器压缩后得到MPEG4视频流,写入到录像文件,经测试,录制效果良好,可清晰流畅播放。     

Load prediction based elastic resource scheduling strategy in Flink

In order to solve the problem that the load of big data stream computing platform fluctuates drastically while the cluster was suffering from the performance bottleneck due to the shortage of computing resources,the load prediction based elastic resource scheduling strategy in Flink (LPERS-Flink) was proposed.Firstly,the load prediction model was set up as the foundation to propose the load prediction algorithm and predict the variation tendency of the processing load.Secondly,the resource judgment model was set up to identify the performance bottleneck and resource redundancy of the cluster while the resource scheduling algorithm was proposed to draw up the resource rescheduling plan.Finally,the online load migration algorithm was proposed to execute the resource rescheduling plan and migrate processing load among nodes efficiently.The experimental results show that the strategy provides better performance promotion in the application with drastically fluctuating processing load.The scale and resource configuration of the cluster responded to the variation of processing load in time and the communication overhead of the load migration was reduced effectively.     

多级降压收集极中次级电子的研究

效率与电子回流率是考核多级降压收集极的重要指标,而多级降压收集极中次级电子的存在对效率和电子回流率有重要影响.因此,对次级电子的研究有重要意义.本文探讨了次级电子发射的物理原型,并根据其编制了相应的CAD程序, 在对多级降压收集极的试算中,取得了较好的效果.     

均匀自由流动的非牛顿流体中连续表面上的磁流体动力学流动和热传递

分析在平行自由流动的非牛顿黏弹性导电流体中,连续平展表面移动时的稳态流和热传递特性,该流动处于横向均匀磁场作用下.以二阶流体构建它的本构方程,得到了速度分布和温度断面图的数值结果.讨论了诸如黏弹性参数、磁场参数和Prandtl数等不同物理参数对诸种动量和热传递特性的影响,并给出相关图示.     

Comparison of responses of LR-115A, CR-39 and PM-355 track detectors to pulsed low-energy proton streams

The paper concerns applications of LR-115A, CR-39 and PM-355 solid-state nuclear-track detectors (SSNTDs) for investigation of pulsed fluxes of protons below 300 keV. The proton streams were generated by the RPI-IBIS device operated with hydrogen puffing [Baranowski et al. 2000. Studies of hydrogen discharges in RPI-type devices with different electrode configurations. Czech. J. Phys. 50 (Suppl. S3), 101–107]. To perform ion mass- and energy-analysis, a Thomson mass-spectrometer equipped with a special input system and exchangeable detectors was used. A quantitative analysis of proton tracks upon Thomson parabolas was performed by means of an optical microscope equipped with a CCD camera. It made possible to measure proton tracks and to determine their statistics. The paper presents proton energy spectra recorded with the selected detectors, and responses of these detectors to protons of energy from about 30 to 300 keV. The results are important for verification of detector characteristics and for measurements of protons at different experimental conditions.     

基于因特网的MPEG-4视频流技术

从力求视频流服务质量最好的角度，介绍和讨论基于因特网的MPEG-4视频流技术分压缩编码方法、QOS控制和传输结构体系。     

二参数有限随机事件流

本文讨论二参数无后效有限随机事件流的鞅性和各种二参数Ｍａｒｋｏｖ性。     

构建城域网络视频点播系统方案分析

分析了应用于宽带城域网的商用化视频点播系统的技术要点，提出了视频服务器的评价标准，并设计了适合于宽带城域网应用的分层分布式视频点播系统的结构。     

透平级S_2流面内的反问题湍流计算

本文发展了应用湍流流函数方程计算湍流流场的方法。计算了扭曲叶片Ｓ２流面的湍流流场．在非正交曲线坐标可压湍流方程组中包含了以无量纲形式表示的能量方程，熵方程和Ｋ－ε湍流模型方程。固壁边界上采用了壁函数方程。通过计算得到了透平级内部的湍流流动合理的收敛解。此方法可以通过调节子午通道的形状及环量的大小分布来防止流动中负速度的出现，为高效透平级的设计提供了一种新的途径。