A novel keyframe extraction method based ondynamic time-domain detection windows

Real-time keyframe extraction is significant for the on-line video retrieval and recognition system. It will lead to low speed for keyframe extraction by analyzing the frames one by one on the basis of shots detection. A novel keyframes extraction method based on dynamic time-domain detection windows is presented. The video frame-sequence is divided into video units with different lengths. The frames at the edges of the window and the sampled frames inside the window are analyzed to judge the changes of the unit content. Meanwhile, a hybrid growth mode of windows and slow detection mechanism are proposed to ensure the quality and speed of the keyframe extraction. The extracted keyframes are clustered to obtain the best keyframe. The experiments show that the proposed method has a good comprehensive performance for different kinds of videos.     

Numerical analysis on the evolutionary features of deformation and failure modes of slopes

The failure of slope is a gradual accumulation process. Under the effect of many interior and exterior factors, some parts in the slope reach yield with the increase of stress, and sliding surface forms gradually till complete transfixion. With continuous increase of the plastic strain, overall failure happens on the slope. Traditional analysis method cannot display the mechanic conditions and the whole process of deformation, transfixion of sliding surfaces and failure. Meanwhile, FEM strength reduction can quantitatively show the deformation features and the process of occurrence and development of sliding surface. Based on the previous researches, the paper classifies slopes according to the features of rock and soil and the slope structure. Through analyzing the graphs of deformation and the nephograms of plastic strain under different reduction factors or safety factors, the researchers can directly find the deformation tendency of slopes and the whole process of the extension, transfixion and failure of sliding surface with the reduction of safety factor. So, the failure mechanism of slope can be found intuitively, which can provide effective basis for the prevention and governance of slopes.     

A Stress Path Damage Constitutive Model for Sang

A hypothesis that the skeleton deformation of sand is only the deformation of the interfaces of grains, and the deformation characteristics including nonlinearity, plastic deformation and shear dilation are controlled by the sliding of interfaces of grains within skeleton, is presented.The contact between grains is classified as perfect contact and sliding contact in this paper.In the elastic deformation phase, the contact between grains is regarded as perfect contact.With the increase of shear stress, there are gradual conversions from perfect contacts to sliding contacts which are viewed of damages in this paper.Based on Mohr Coulomb law, a calculation method for the damage ratio is given according to the relative distance of the stress point to the initial damage line and failure line.On this basis, a damage constitutive model is proposed.The model properties can be conveniently obtained through conventional triaxial compression test and constant stress ratio consolidation test.Test results indicate that the model is capable of predicting deformation behavior for various conditions, including varying consolidation conditions and stress paths.     

Inspection System of Material Decay Based on Image Retrieval Technology

Monitoring the material decay make use of the technique of video, computer image processing and pattern identify to detect, process and manage the external material decay image. The color character of the external material decay image are analyzed. The statistics character of the material decay image is pick-up by color histogram, color coherence vector and color correlogram. The comparability of the material decay image is presented by Euclidean distance of the color character. The match and query system of material decay based on image retrieval technology is implemented.     

Key technology of detecting hot heavy rail steel surface faults based on machine vision

Aiming at the low efficiency and precision of hot rail steel surface faults detecting at present,a suit of surface defect detection system of hot heavy rail based on the machine vision is put forward. Multi-CCD cameras are used to collect pictures. According to the geometric characteristics of the heavy rail and its defect characteristics of high-frequency region,six angle shot is used for heavy rail,and then various image processing technology are adopted in workstation. The system adopts improved Hough transform to get surface faults and Kohonen network to make a classification for the characteristics of low SVM training algorithm. The above key machine vision technology for detection of hot heavy rail surface defects greatly improves the speed and accuracy of testing and the detecting correct rate arrives over 85%.     

汽车转弯自动照明控制系统数据采集滤波方法

为了减少汽车转弯自动照明控制系统数据滤波处理中的延时,在滑动中值滤波方法基础上,提出了一种带补偿的限幅滑动中值滤波算法,通过补偿的方式跟随信号的变化趋势。该算法通过2个步骤完成滤波,先对数据进行带补偿方式的限幅处理,再进行滑动中值滤波处理。该算法综合了滑动中值滤波法的实时性以及限幅滤波法对偶然性干扰滤除的有效性,实现更准确的滤波。仿真与实测结果表明,与滑动中值滤波方法相比较,改进后的算法滤波能够实时地滤除数据中的干扰,处理时间可减少62%,滤波效果较好,且速度信号的数据滞后时间较短,实时性较高,满足系统设计要求。     

Improved Vehicle Detection Algorithm Based on Edge Information

Collecting real-time traffic flow information is a foundational function in intelligent transportation systems. Video based traffic monitoring system has advantage of installation and maintenance, so it iswidely used for traffic monitoring on main road and crossroad. Shadows result from roadside building or trees are one of the factors that arise errors in video based vehicle detection. An improved method based on edge information is proposed for vehicle detection and shadow rejection. Finally vehicle counting is achieved based on the edge detection method.     

Optimization Design of MPEG-4 Video Codec Architecture

The author analyzs computational complexity of previous MPEG-4 video codec system in terms of data processing, memory accessing and address computation, and optimizs the performance of data processing and data transfer of MPEG-4 video coding and decoding algorithm. The architecture model of the real-time MPEG-4 video codec is proposed based on the analyses. This architecture can effectively utilize computational resource in software and improve the performance of MPEG-4 video codec system.     

生物絮团系统中温度突变对日本囊对虾肠道和水体微生物多样性的影响

利用生物絮团对虾养殖系统进行日本囊对虾的养殖实验,研究温度突变对生物絮团系统中水体氮转化效率及其稳定性的影响。实验将日本囊对虾随机分为2组,对照组为消毒的洁净海水,日换水量20%（半封闭养殖系统）,实验组为初始量20 mL/L的生物絮团海水（生物絮团系统）。在实验组与对照组水质保持1周的稳定后,进行温度突变胁迫,温度骤升10℃。在温度突变过程中,温度突变对水体中氮转化通路无显著影响(P>0.05),实验组的硝酸盐氮在温度突变后有上升的趋势,温度突变实验第5天（突变前）为19.65 mg/L到实验第10天（突变后）升高到31.54 mg/L,实验组的累计速率大于对照组。高通量测序显示,实验组与对照组水体微生物中共获得了4219个OTU。实验组的丰度与多样性指数均大于对照组,温度突变前大于突变后。温度突变后的水体和肠道的微生物群落的丰度与多样性均低于突变前。结果表明生物絮团系统在应对温度突变中的表现要优于半封闭养殖系统,在微生物群落的丰度与多样性上均具有更高的稳定性。     

Nonlinearity of Electronic Throttle and Its Control

This paper introduces the development of the electronic throttle control system (ETCS) , the structure and the principle of the system are also involved. After analyzing the nonlinearity problem existing in the mechanical structure of the system, a mathematical model of the ETCS is built up. Then three controllers (PID controller, Fuzzy controller, sliding mode controller) were designed and simulated in the matlab simulink. The result indicates that the PID controller has an overshoot,but the Fuzzy controller and the sliding mode controller can settle the nonlinearity problem better.     

Video Monitor and Control System of Tunnel Based on DSP/BIOS

A video Monitor &Control system of tunnel based on DSP/BIOS is proposed,which is different from traditional video Monitor & Control system.It uses DSP to process image,and uses enhanced video input processor to qcquire image.This system satisfies all requirements of video supervision,and is a low cost system.It has a good application foreground.The system has been confirmed as a good veracity and practicability system through testing in the Zhongliang Mountain tunnel of Chongqing.     

A Direct Limiting Deformation Equilibrium Method for Wedge Sliding

A simple and direct limiting deformation equilibrium method for wedge sliding considering all the three deformation components of the discontinuity planes is presented. The traditional limiting equilibrium method is based on a statistic system assuming that sliding is resisted only by the sliding resistance parallel to the sliding direction along the line of intersection of the two discontinuity planes. Therefore, we work out the psudo-elastic system to take care of the deformation of the discontinuities and to solve the indeterminate system. Through analysis and experiment, it is illustrated that the result based on traditional method is unsafe. The calculated results are fairly consistent with the experimental ones, while those based on the traditional method are unsafe. The stiffness of the discontinuities should be emphasized.     

面向竹藤的领域语义信息检索系统研究

针对目前竹藤领域数据格式多样、集成整合不足、检索效率低下等问题,将领域术语权重和概念查询扩展相结合,提出了适用于竹籐的领域语义信息检索模型,并对竹藤领域的语义信息检索系统的检索方式、框架结构进行研究,最终建立了竹藤领域语义信息检索系统。本研究内容可有效地解决竹藤信息资源利用的技术障碍,为竹藤的宏观深层次研究,提供新的技术支持和理论依据,为其他相关领域语义信息检索提供一种新方法和思路。     

Image-based phenotyping: use of colour signature in evaluation of melon fruit colour

Fruit colour, both external and internal, is important because it relates directly to the commercial value of the product. In breeding and in pre- and postharvest studies of fruit colour, an effective method for evaluating colour is needed to replace subjective evaluations by eye. We used a series of data processing and statistical analyses used in content-based image retrieval to evaluate melon flesh colour, and assessed the efficacy of this approach. This method relies on summarizing colour information from images into colour signatures, calculating the earth mover’s distance (EMD) between colour signatures, and multi-dimensional scaling (MDS) based on an EMD matrix. Performing MDS on a set of fruit flesh images revealed important colour features, such as the yellowish-green strength in green-fleshed melons and the relative size of the green and red parts in red-fleshed melons, without the need for an explicit definition of these features. The proportion of variance due to differences among cultivars was higher by MDS than by traditional evaluation, indicating that this new method performed best at detecting colour differences among cultivars. The method provides effective, objective indicators of fruit colour, and shows considerable promise for use in research and breeding programs.     

Automatic head recognition by integrating mean shift with multiple features

To improve the head detection accuracy in video sequences captured with fixed vertical monocular camera, a novel method of head recognition based on mean shift and multiple features is proposed. Firstly, mean shift based image segmentation algorithm with color information and spatial information is suggested to derive the candidate head components in images. Furthermore, by referring to two features that the contour of human head regions are approximate round and the hair color distribution is clustered, the evaluation models based on the contour information and inside color information of candidate head components are presented for head recognition. The experimental results show that the proposed algorithm can effectively reduce the light interfere and eliminate fake target whose color information is similar to hair color distribution. The detection rate for static images can reach about 89.4%.     

Detecting Technology of Cabel Surface Defect Based on DSP and Image Recognition

The damage of bridge cable directly hazards the normal use of bridge and the safety of people. The paper discussed the signal acquisition and detection system which takes embedded DSP processor as core technology, combined with CCD, video decode chip, SDRAM, FLASH ROM, and established the fast measuring algorithm of the surface corrosion and damage, which includes deteminating the processing region, improving medium filter, sobel edge detection and dynamic threshold segment, close operation of morphology, computing defect area and saving. The experimental resuits show that this method implemented the real-time, non-contact and intelligence detecting of cable surface defect and gives the specifications of the system.     

湖北汉江流域潜在蒸散量时空变化特征分析

为了在全球气候变暖的背景下,探索湖北汉江流域蒸散发的变化趋势,为农业生产布局及水资源有效利用提供依据。以湖北汉江流域13个气象站点1960—2011年的逐日气象资料为基础,采用FAO推荐的Penman-Monteith模型计算潜在蒸散量,用Mann-Kendall非参数检验法对其进行趋势分析和突变检验,并在ArcGIS环境下利用克里金插值分析潜在蒸散量的空间变化特征。结果显示：湖北汉江流域1960—2011年的潜在蒸散量整体呈波动下降趋势,变化速率为-16.792 mm/10 a,均值为 792 mm;夏季整体下降趋势明显,变化速率为-15.149 mm/10 a,春季整体呈上升趋势,变化速率为 4.171 mm/10 a,秋季和冬季变化趋势不明显;潜在蒸散量空间分布特征表现为自东南向西北递减,较高的地区主要集中在武汉、广水、天门一带;1968年前后,潜在蒸散量出现1次突变。     

Precise measurement system of small workpiece base on video

There are some weaknesses for traditional microscope measurement, including small scope field, complex operation and subjective errors. To avoid these issues, a measurement system combining video and microscope is made. With the magnification of microscope and video, the accuracy of grating micrometer and the real-time notification of chamfer location, this system achieves high precise measurement. By displaying with two monitors, the computer can collect and display other measurement data while the chamfer is measured, which makes full use of the display resolution and enhances the efficiency of instruments. The method is valid for measuring size of special work-pieces.     

Selection of Sliding Resistant System

In selection of sliding-resistant system, the engineering geological condition must be considered. Based on the summarization of engineering examples, this paper shows that the accuracy of engineering geological survey is very important in selection of the sliding resistant system. After analyzing the structural behavior and loading conditions of sliding resistant system on cantilever pile-bolt, it shows that this system has many advantages such as reliable quality, good mechanical performance and economic benefits.     

Image edge detection algorithm in fuzzy domain

An image edge detection algorithm in fuzzy domain is proposed, which combines adaptive fuzzy enhancement and multi direction fuzzy morphology to detect the edges of fuzzy image. The adaptive fuzzy enhancement method enhances the fuzzy image within blocks with sliding windows to avoid losses of the real edges resulting from enhancing with single threshold for the whole image and lead strong adaptive ability to image region variance. The multi direction fuzzy mathematical morphology operates on the enhanced fuzzy image with structure elements of multiple different directions to extract the real edges with directionality and restrain non directional noise. Experiments show the algorithm can detect fuzzy image edge effectively with strong antinoise ability.