Simultaneous Detection of Hydrodynamics,Mass Transfer and Reaction Rates in a Three-Phase Microreactor

Theoretical Foundations of Chemical Engineering - Hydrodynamics, mass transfer and reaction rates were studied experimentally in a microreactor that had a square channel with a size of 1.0 ×...     

直流GIL中线形金属微粒电动力学行为研究

直流GIL中线形金属微粒受力运动极易引发气体间隙击穿或者绝缘子沿面闪络,降低GIL的绝缘性能,严重影响直流输电系统的安全可靠运行.为研究直流GIL中线形金属导电微粒电动力学行为机理,搭建自由微粒实验装置和观测平台,并建立直流下微粒电动力学模型.通过实验与仿真相结合的方法,获得线形金属微粒荷电特性、启举与运动特性以及微粒运动导致的气隙击穿特性,并从微观角度解释了微粒启举与运动现象形成的原因.研究结果表明,线形启举电压只与半径有关,与长度和电压极性无关,随着半径增大,启举电压升高,直流电压极性不影响金属微粒启举电压幅值;线形微粒的运动及导致的气隙击穿与微粒半径、长度和电压极性有关,线形金属微粒半径小、长度增加时容易导致气隙击穿;线形金属微粒形状的不规则使得电场畸变作用加强,极性效应更明显.电晕极性效应导致正负极性下线形微粒的启举与运动及运动致气隙击穿特性呈现出明显的规律,当达到启举电压时,正极性下,线形金属微粒一端抬起后,在下极板小幅跳跃、旋转或者直立,难以贯穿气隙;负极性下,线形金属微粒贯穿气隙运动,极易出现飞萤现象,为直流GIL中线形金属微粒污染防治提供了理论指导.     

Edge enhancement of color images using a digital micromirror device

A method for orientation-selective enhancement of edges in color images is proposed. The method utilizes the capacity of digital micromirror devices to generate a positive and a negative color replica of the image used as input. When both images are slightly displaced and imagined together, one obtains an image with enhanced edges. The proposed technique does not require a coherent light source or precise alignment. The proposed method could be potentially useful for processing large image sequences in real time. Validation experiments are presented.     

Three-dimensional profiling with binary fringes using phase-shifting interferometry algorithms

Three-dimensional shape measurements by sinusoidal fringe projection using phase-shifting interferometry algorithms are distorted by the nonlinear response in intensity of commercial video projectors and digital cameras. To solve the problem, we present a method that consists in projecting and acquiring a temporal sequence of strictly binary patterns, whose (adequately weighted) average leads to a sinusoidal fringe pattern with the required number of bits. Since binary patterns consist of "ones" and "zeros"--and no half-tones are involved--the nonlinear response of the projector and the camera will not play a role, and a nearly unit contrast gray-level sinusoidal fringe pattern is obtained. Validation experiments are presented.     

An algorithm to mine general association rules from tabular data

Most methods for mining association rules from tabular data mine simple rules which only use the equality operator “=” in their items. For quantitative attributes, approaches tend to discretize domain values by partitioning them into intervals. Limiting the operator only to “=” results in many interesting frequent patterns that may not be identified. It is obvious that where there is an order between objects, operators such as greater than or less than a given value are as important as the equality operator. This motivates us to extend association rules, from the simple equality operator, to a more general set of operators. We address the problem of mining general association rules in tabular data where rules can have all operators {?, >, ≠, =} in their antecedent part. The proposed algorithm, mining general rules (MGR), is applicable to datasets with discrete-ordered attributes and on quantitative discretized attributes. The proposed algorithm stores candidate general itemsets in a tree structure in such a way that supports of complex itemsets can be recursively computed from supports of simpler itemsets. The algorithm is shown to have benefits in terms of time complexity, memory management and has good potential for parallelization.     

A blind video watermarking algorithm robust to lossy video compression attacks based on generalized Newton complex map and contourlet transform

Multimedia Tools and Applications - The rapid growth of fast communication networks for digital video transmission has created a need to copyright protection for these media. Digital video can be...