典型视频镜头分割方法的比较

视频镜头分割作为视频处理的第一步,一直受到学者的关注和重视,数十年来已提出了大量的算法。该文对几种常用的视频分割算法作了综述,分析了基于直方图的算法、基于运动的算法、基于轮廓的算法、以及直接针对压缩视频的算法等典型算法的特征,并详细研究了各种算法中帧差异值的计算和阈值设定的方法,比较了它们的优缺点,最后对视频分割算法研究作了展望。     

基于仿真模板的Hough变换直线检测

Hough变换直线检测是遥感图像理解、分割和处理中常用的直线特征自动检测技术之一,其运算过程中所需数组的大小决定了参数空间的采样多少,直接关系到计算精度和速度.在此提出的模型仿真、模板调用方法,简便快捷地实现不同数组大小的多次试验和比较,找到满足实际精度和速度要求的数组参数;将仿真模型、仿真过程和所得参数做成易于调用的模板,供检测系统使用.应用中只需将遥感图像像素坐标映射到模型的定义区间,调用后再将结果映射回图像空间.此方法使Hough变换直线检测的调试、修改和移植变得容易,经实际应用证实本方法方便高效.     

机械电子设备中的电气干扰及抗干扰措施

从电源干扰、电磁干扰、接地错误三个方面介绍了机械电子设备中的电气干扰的来源及传输途径；从滤波、电气隔离、屏蔽、接地等四个方面介绍了具体的抗干扰措施。     

压差-电气-面积补偿型高压大流量电液比例调速阀的研制

现在工业上多采用压差补偿型比例调速阀或者流量反馈型比例调速阀 ,但传统的压差补偿型比例调速阀控制流量小 ,控制压力低 ,控制精度也不高 ;流量反馈型比例调速阀结构复杂 ,价格昂贵。为此作者根据压差 -电气 -面积补偿原理 ,采用先导式阀体结构 ,设计了能在高压工况下对大流量进行精确控制的比例调速阀 ,测试并分析了新阀的性能。     

Uniform Bi2S3 nanorods-assembled hollow spheres with excellent electrochemical hydrogen storage abilities

Hierarchical Bi₂S₃ hollow spheres have been synthesized by a facile solvothermal process in the presence of sodium tartrate. The hollow spheres are composed of numerous ultrathin nanorods with the average diameter of 15 nm. Based on the time dependent electron microscope observations, the formation mechanism of such hierarchical structures has been proposed as a sodium tartrate directed self-assembled process and oriented attachement mechanism. The morphology and size of the subunits can be controlled by adjusting the amount of sodium tartrate. The Nitrogen adsorption-desorption measurements suggest that mesopores exist in these hollow spheres. The as-derived Bi₂S₃ hollow spheres exhibit excellent electrochemical hydrogen storage properties.     

Natural tongue physique identification using hybrid deep learning methods

Multimedia Tools and Applications - Traditional Chinese Medicine (TCM) illustrates that the physique determines the susceptibility of human to certain diseases and treatment programs for illness....     

Revisiting the weighting function for lightness in the CIEDE2000 colour-difference formula

We have used 13 experimental datasets (7420 colour pairs) to study the performance of the weighting function for lightness proposed by the CIEDE2000 colour-difference formula, because it has been suggested that this function can be improved by using the weighting function for lightness S_L = 1 adopted by the CIE94 colour-difference formula. Using the standardised residual sum of squares (STRESS) index, it was found that: (i) replacing the S_L in CIEDE2000 with S_L = 1 improved the results for 7/13 datasets considered, but the improvement was statistically significant only for 1/13 datasets; (ii) a Whittle-type lightness-difference formula can be used to replace the term ∆L*/S_L in CIEDE2000, which led to a new colour-difference formula with no statistically significant difference with respect to CIEDE2000 for any of the 13 experimental datasets. A modification of the CIEDE2000 formula using a Whittle-type lightness formula is proposed.     

Conceptualization topic modeling

Multimedia Tools and Applications - Recently, topic modeling has been widely used to discover the abstract topics in the multimedia field. Most of the existing topic models are based on the...     

球形高温复合定形相变材料性能及干压成型工艺的设计与研究

以粉煤灰为基体材料、Al-Si合金粉为相变介质,采用干压成型及混合烧结法制备直径为15 mm的球形高温定形复合相变材料,设计并研究了三种施压方式(直接法、阶段法、自然法)以及成型压力对相变材料性能的影响.研究表明:成型过程中升压速率越快,材料的致密均匀性越差,甚至产生加工硬化的现象;保压时间越长致密度越高,缓慢升压而不保压则致密度偏低;成型压力越大材料越致密,力学性能越好.材料的致密度与其相变潜热呈反向关系,这与合金粉在烧结过程中的破裂情况、自身氧化以及与基体的反应程度密切相关.三种施压方式中,直接法制备效率高、材料的力学性能突出,阶段法所制备的材料在较宽的成型压力范围内(2～5 MPa)综合性能良好,自然法效率低且材料力学性能较差.当成型压力为2 MPa,采用阶段法所制备的材料密度为1.630 g/cm3、相变潜热为115.20 J/g、开裂荷载为1021 N,经100次热震其性能依然稳定.