Kong Lingfu

Image Denoising Based on Non-local Means with Wiener Filtering in Wavelet Domain

Image denoising is a significant inverse problem of image processing and an important image pretreatment. The performance of image denoising is improved by using some statistic characteristics of natural image. In this paper, we combine the extensive self-similarity of images in non-local means algorithm with the minimum mean square error of Wiener filtering in wavelet domain, and then propose an image denoising algorithm based on the non-local means with wiener filtering in wavelet domain. The experimental results demonstrate that one can get denoised image with higher subjective visual quality and peak signal to noise ratio based on the proposed algorithm.

Design and performance of a six-electrode conductance probe for measuring the water fraction in oil-in-water pipe flow

The performance of ring-shape electrodes for measuring the conductance of oil-in-water mixtures in pipes was studied theoretically and experimentally. In particular the work is aimed at optimizing the probe geometry in order to decrease the axial current leakage and improve the measuring precision of water fraction under oil-well logging application. Starting from the basic four-electrode probe including two exciting and two measuring rings, a new six-electrode probe characterized by adding two guarding rings to be found, the distance and width of guarding electrodes were optimized theoretically. The experiment was performed with reference to annular, stratified and bubble phase distributions and the results were compared with available theoretical models. The analysis demonstrates the response of new six-electrode probe is accurate and reliability, the measuring precision is enhanced.

Integrating Reservation Mechanism into Grid Resource Management

In this paper, an architecture framework of grid resource management supports reservation mechanism is proposed, which provides end-to-end quality of service (QoS) for users and adjusts the level of QoS. And we describe the request definition and processing of resource reservation, and design the strategies of reservation. Reservation strategies integrate resource request control, which improves the resource performance and guarantee uses QoS

Research on a Novel Parallel Engraving Machine and its Key Technologies

In order to compensate the disadvantages of conventional engraving machine and exert the advantages of parallel mechanism, a novel parallel engraving machine is presented and some key technologies are studied in this paper. Mechanism performances are analyzed in terms of the first and the second order influence coefficient matrix firstly. So the sizes of mechanism, which are better for all the performance indices of both kinematics and dynamics, can be confirmed and the restriction due to considering only the first order influence coefficient matrix in the past is broken through. Therefore, the theory basis for designing the mechanism size of novel engraving machine with better performances is provided. In addition, method for tool path planning and control technology for engraving force is also studied in the paper. The proposed algorithm for tool path planning on curved surface can be applied to arbitrary spacial curved surface in theory, control technology for engraving force based on fuzzy neural network(FNN) has well adaptability to the changing environment. Research on teleoperation for parallel engraving machine based on B/S architecture resolves the key problems such as control mode, sharing mechanism for multiuser, real-time control for engraving job and real-time transmission for video information. Simulation results further show the feasibility and validity of the proposed methods.

ICA and Its Application in the Phase Information Extraction of Oil-Gas-Water Three-Phase Flow

The independent component analysis(ICA)is applied to studying the oil-gas-water three-phase flow noisy signals responded by conductance sensor, and extracting the flow signals which characterized the gas and liquid phase respectively so as to obtain gas/liquid phase information. The algorithm of FastICA which based on kurtosis is applied to separating the field simulation well logging oil-gas-water three-phase signals responded by multi-channel sensors. And then identify the gas/liquid phase signals between the separated signals. Compare and analysis indicate that ICA is effective in obtaining the gas/liquid phase flow characteristics of oil-gas-water three-phase flow, and the extracted independent components have explicit physical meaning corresponded to the gas phase and the liquid phase separated.

Loop-closing By Using SIFT Features for Mobile Robots

To resolve the problem of accumulative error in the real-time loop-closing of SLAM, SIFT features are used to match the visual appearance in the environment. The visually salient regions are selected from an image using Scale Saliency algorithm. Then, the SIFT features extracted from the salient regions in current image are used to match to the possible candidate features. The experiment results show the method is feasible.

Theory analysis for the virtual current distribution in an electromagnetic flowmeter with one bubble

On the theory of electromagnetic flow meter, the effect of bubbles on the virtual current distribution was studied by using two-dimensional (2D) and three-dimensional (3D) analysis. To solve this problem, it was to establish the physical equation and boundary conditions used for the virtual current distribution of the flow meter. The method of separating variables was used to solve the physical equation to obtain a semi-analytical solution, and then the method of alternating iteration was used to work out the unknown coefficients in the semi-analytical solution. The solution analyzes the virtual current distribution with one bubble at radial position, at radial position in 2D coordinates, and at random position in 3D coordinates. The bubble has some effects on the distribution of the virtual current distribution. The greater the bubble, the greater the effects; the closer the bubble from the electrodes, the greater the effects.

An Analysis on the Sharing of Educational Resources in Distance Education by Grid Technology

The essence of the modern distance education is the share of educational resources. This text aims to analyze the problems which affect the share of educational resources, such as the lack of the excellent educational network resources, the mass repeated constructions of the resources, the poor ability of intelligentized searches for resources, the difference between the network and the operative system, which have great influences on the data share among the systems, consequently they produce several information isolated islands one by one and the hardness of making mutual operation. The text also points out what limitations can be overcome by the grid education based on the grid technology, which can eliminate the information-isolated islands, and knowledge-isolated islands and realize the intelligentized searches of information and knowledge resources. As a result, this is a better way to solve the resources share problems. Also this text aims to probe a little further about the resource share modes of the distance education based on the grid technology.

Salient Closed Contour Detection Based on Multiscale Analysis and Minimum-Angle

This paper presents a novel computational approach, named MAMA, to extract perceptually salient boundaries from a set of noisy boundary fragments detected in real images. The approach first acquire a contour map using multiscale analysis. Then constructs an relation matrix between arbitrary the endpoints of each edge. At last the most salient boundary is detected by searching the smallest angle that lines got from two points and the points grad. The proposed approch guarantees the boundary is a global structure. We collect a varietry of images for testing the proposed approach with enouraging results.

A Novel Parallel Engraving Machine Based on 6-PUS Mechanism and Related Technologies

Conventional computer engraving machine has played an important role in industries such as machinery machining, printing and dyeing and entertainment, but it has the inherent disadvantages such as cutting tool can be fed only along the fixed guideway, lower degree-of-freedom(DOF) of cutting tool, lower flexibility and mobility for machining etc. Parallel mechanism has the merits such as high mechanical stiffness, high load capacity, high precision, good dynamic performance etc (Huang,1997). According to the characteristics of parallel mechanism, it has been a hot research topic to apply parallel mechanism to the domain of future machining. By applying parallel mechanism to engraving domain, its inherent advantages can be fully exerted and the disadvantages of conventional engraving machine can be overcome or compensated. But as the special structure of parallel mechanism, the related theory and technology during its engraving is very different from that of conventional engraving machine, and it is a undeveloped research topic by now. In addition, with the development of computer network technology, the new concept and method such as network machining and manufacturing has become hot research topic(Huang & Mak,2001; Taylor & Dalton,2000; Yao & Lu,1999). A novel parallel engraving machine with six-axis linkage is proposed in this paper, which uses the 6-PUS parallel mechanism with 6-DOF as the prototype, and some key technologies such as size design, tool path planning, engraving force control and teleoperation are studied on this basis.