超声检测机器人误差补偿技术

针对多自由度检测机器人位姿调整困难问题,通过分析超声检测机器人误差的来源和特点,阐述了机体外误差补偿的原理。通过误差补偿,为计算机控制超声探头进行曲面检测提供准确的控制参数,实现曲面形工件的连续超声检测。最后通过穿透法水柱的对准及其误差分析,对机体外误差补偿方法进行了验证。

Implications from protein uptake kinetics onto dextran-grafted Sepharose FF coupled with ion exchange and affinity ligands

Our previous studies have reported the presence of "chain delivery" effects of protein adsorption onto ion exchangers with polymer-grafted ion-exchange groups, such as dextran-grafted and poly(ethylenimine)-modified Sepharose gels. However, it is unclear if the "chain delivery" occurs on affinity adsorption with specific interactions. This work is designed to address this issue. A dextran-grafted Sepharose gel was prepared, and then the matrix was modified using diethylaminoethyl, a typical ion-exchange group, or octapeptide(FYCHWQDE), an affinity ligand for human immunoglobulin G(h Ig G) to prepare ion-exchange or affinity adsorbents, respectively.Results of h Ig G adsorption showed that the uptake rate represented by the effective diffusivity of h Ig G onto the dextran-grafted ion exchangers was obviously enhanced by the dextran grafting, indicating the presence of"chain delivery" of the bound proteins on the charged groups on the dextran chains. By contrast, the effective diffusivity of h Ig G changed little as ligand density increased on the dextran-grafted FYCHWQDE adsorbents.Their adsorption capacities decreased and effective diffusivities were not accelerated by the dextran grafting.Thus, this work clarified that grafted dextran could not accelerate h Ig G uptake rate on the affinity resins, or in other words, chain delivery did not occur on the specific interaction-based affinity adsorption.

Analytical Approach to Fractional Zakharov-Kuznetsov Equations by He's Homotopy Perturbation Method

The aim of this paper is to obtain the approximate analytical solution of a fractional Zakharov-Kuznetsov equation by using homotopy perturbation method (HPM). The fractional derivatives are described in the Caputo sense. Several examples are given and the results are compared to exact solutions. The results reveal that the method is very effective and simple.

Double Integrable Couplings and Their Constructing Method

To extend the study scopes of integrable couplings, the notion of double integrable couplings is proposed in the paper. The zero curvature equation appearing in the constructing method built in the paper consists of the elements of a new loop algebra which is obtained by using perturbation method. Therefore, the approach given in the paper has extensive applicable values, that is, it applies to investigate a lot of double integrable couplings of the known integrable hierarchies of evolution equations. As for explicit applications of the method proposed in the paper, the double integrable couplings of the AKNS hierarchy and the KN hierarchy are worked out, respectively.

Framework for Freeway Auto-surveillance from Traffic Video

Video based surveillance systems have been widely used on freeway for traffic monitoring, as the cameras can provide the most intuitionistic information. In order to manage all the traffic videos automatically, in this paper, a distributed real-time auto- surveillance system is presented. The freeway traffic videos are taken as input video from Pan Tilt Zoom （PTZ） camera, and then produces an analysis of the states and activity of the vehicles in the region of interested （ROI）, if there is any abnormal instance, an alarm and corresponding traffic video are sent to awake surveillants by Ethernet. To achieve this functionality, our system relies on three main procedures. The first one initializes the system. It detects the ROI of the scene, and performs the camera calibration to remove the perspective effect of the incoming image. The second one segments moving vehicles from the images, eliminate shadow and tracks them real-time. It uses a set of methods to obtain the background of the image, extracts the moving regions and tracks these moving regions by matching them between frames of the video sequence to obtain high-level information such as color, size, velocity, and trajectories of moving vehicles. In the third procedure, activities of vehicles are analyzed based on a series of preset situations which would happen on freeway. The detail information of each vehicle and the global statistical information are checked to find out any abnormal instance, and then triggered an alarm. We present details of the system, together with experiment results which demonstrate the accuracy and time responses.