基于小波的视频镜头自适应分割

随着多媒体技术的发展 ,出现了大量的视频数据 .但由于视频数据是非结构性的 ,因此为了便于视频的检索和浏览 ,必须对视频进行分段 ,而将镜头作为分段的基本单位是比较适合的 .通过仔细分析镜头串接的特点 ,根据小波的特性和小波变换检测奇变点的优点 ,提出了应用小波变换检测视频内容差异度函数奇变点的方法对镜头边界进行检测 .首先取一段视频 ,选取亮度直方图对视频的内容进行描述 ,然后提取视频内容差异度变化曲线 ,再进行多分辨小波分解 ,去噪后找出模极大值点 ,经过跟踪可较准确地找出镜头边界 .实验证明 ,该方法能自适应的对视频进行分割 ,对各种类型的镜头边界有较好的检测效果 .     

从名词的对应项缺失现象看中英文化的差异

跨语际交流中的障碍,常常是由两种语言所属的文化之间的差异造成的。语言所反映出的文化差异,表现在各个层面上。从词汇层面出发,从名词的对应项缺失现象着手,探讨了语言中反映出的中英文化的差异。     

Oscillation in nonlinear difference equations

In this paper, we shall discuss oscillatory behavior of the solutions of difference equations, including the self-adjoint second-order linear equation and the discrete version of the nonlinear wave equation. Our work is to give sufficient conditions such that every nontrivial solution of the equations oscillates.     

偏微分方程差分格式的构造

以三个典型方程为例指出了任何一个数学物理模型一定存在一个逼近它的最高阶差分格式，所有比最高阶格式的阶数低的差分格式是含有待定参数的一族方法．     

定径辊磨损机理及半包容孔型

分析出现定径辊孔型边缘和底径局部严重磨损现象的机理，指出产生这一现象的本质是由全包容定径辊孔型决定的孔型多余受力，孔型自身以及孔型与焊管之间存在不可避免的相对运动。提出了用半包容孔型辊替代全包容孔型辊能减轻Ｒ孔型的边缘和底径的磨损，从而延长定径辊使用寿命，降低了辊耗，在大，中焊管生产领域具有较好的应用前景。     

一起主变保护误动事故的分祈与处理

通过一次保护误动原因查找和分析，发现了电气回路存在的问题并对定值商榷，从而纠正了运行中的缺陷，保证电网的安全稳定运行。     

强化学习中的时间差分法在用户学习方面的应用

随着Internet上信息量的与日俱增，用户查找自己感兴趣的信息变得越来越困难。文章提出了一种使用强化学习中的时间差算法来学习用户的新学习算法，并通过实验与其它学习方法作了比较，取得了明显的成效。     

数控机床坐标反向差值及其曲线分析

提出机床坐标的反向差值Ｂｊ对精度的影响，通过对反向差值的曲线分析，可看出该坐标定位精度的大致状况。建立的曲线分析法，可对Ｂｊ值的变化规律进行分析。介绍该分析曲线在ＨＰ５５２８Ａ激光测量系统上Ｂｊ值分析软件的功能设计及应用。     

Investigation of polyelectrolyte for electrochemical detection of uric acid in presence of ascorbic acid

Uric acid (UA) was detected in the presence of ascorbic acid (AA) at GC electrode by cyclic voltametry (CV) and differential pulse voltametry (DPV) in aqueous media of cationic polyelectrolyte (poly(diallyldimethylammonium chloride) (PDDA)). Both, UA and AA are anionic nature and electro-static attraction with cationic solution. This lowered their oxidation potentials and increased anodic current. In CV studies, the UA oxidation potential was decreased by 400 mV in the presence of PDDA along with increase in peak current. Effect of PDDA and pH on E_pa and I_pa were also studied. About 360 mV difference in oxidation peak potentials was observed for AA and UA in PDDA media, which established a quick method for their simultaneous determination. The detection limit of UA in the presence of 200 folds AA was found as 1 μM with correlation coefficient of 0.994 and sensitivity of 0.05 μA μM⁻¹. The proposed method has been also applied for determining the UA in human urine without any pretreatment, and found to be satisfactory.     

Indices for the evaluation of wildfire spread simulations using contemporaneous predictions and observations of burnt area

Methods to objectively evaluate performance are critical for model development. In contrast to recent advances in wildfire simulation, there has been limited attention to evaluating fire model performance. Information to validate fire models is typically limited, commonly to a few perimeter observations at a small number of points in time. We review metrics for comparing two burnt areas at a point in time: observed and predicted. These are compared in an idealised landscape and with a case study evaluating the performance of simulations of an Australian wildfire. We assessed: Shape Deviation Index (SDI), Jaccard's coefficient, F1, Sørensen's Similarity and Area Difference Index (ADI). For decomposing fit into error components (overprediction and underprediction) we assessed the partial indices of SDI and ADI, Precision and Recall. The various metrics were evaluated for their ability to represent error and their suitability for use in model improvement frameworks.