Applied Mechanics and Materials Vols. 58-60

Abstract: Edge detection is a means of generating compact descriptions which preserve most of the structural information in an image. However, the edge image returned by the edge operators usually contains false edge points or exhibits gaps in edges which are generated by image noise. To solve the problem, a closed salient edge extraction approach was proposed, which makes use of the visual attention model given out by Itti together with the original edge image to obtain the salient edges and then the salient-edge gaps were linked so that the closed salient edge of an image can be extracted. In order to link the edges, a membership function based on the gradient and directions of endpoints of the salient edge image was carried out to control the extension of endpoints. Experimental results showed that the proposed algorithm was able to extract the closed salient edge of an image effectively especially for the image whose background was not very complex.

Abstract: Image registration is a fundamental task for combining two or more images taken from different viewpoints, different times, or different sensors. It is a process of determining the point by point correspondence between two images from the same scene. The proposed image registration method uses the area-based approach to process image registration and the objective is to find the maximum similarity through the cross-correlation measure. Most cross-correlation methods are developed based on image intensities for the direct matching purpose. However, it is extremely sensitive to the intensity changes. To counteract illumination effect, the proposed method replaces the intensity with the gradient information, and this concept comes originally from the Hough transform that points having the same parameters and should be on the same line. These two parameters are combined as the similarity between images for image registration. The experimental results obtained by means of several test images illustrate the effectiveness of the proposed image registration method.

Abstract: Digital image and video have been widely applied to many practical applications due to their simple image acquirement. Image registration is an important image processing for integrating information from images. For Image registration, it is intuitive to orientate images by matching corresponding pixels being considered idealistically identical on the overlapping region. Based on this idea, this article proposes an image registration method that applies the information theorem to the corresponding intensity data. An entropy-based objective function is developed upon the histogram of the intensity differences as to evaluate the similarity between images. Intensity differences represent the differences of the corresponding pixels between the referenced and sensed images on the overlapped region. The sensed image is aligned to the referenced image by minimizing the proposed objective function through iteratively updating the parameters of the projective transformation during the optimization process. The experimental results obtained by means of several test image sets illustrate the effectiveness and feasibility of the proposed image registration method.

Abstract: In an inductively coupled power transfer (ICPT) system, a primary capacitance is usually used to minimize the VA rating of power supply, and a secondary capacitance is adopted to maximize the power transfer. The changes of the secondary capacitance because of environmental temperature or other factors will alter the resonant frequency of the secondary side, and thus the power transfer capability is varied. In this study, the power transfer capability of ICPT systems is investigated in detail when the secondary capacitance changes. A resonant frequency control strategy is suggested to keep the system operation frequency to follow closely the secondary resonant frequency when the secondary capacitance varies. This new strategy is based on the synergic action of the system operation frequency and the primary capacitance. The performance of three frequency control methods, that is the resonant frequency control, the traditional variable frequency control, and the fixed frequency control, are compared when the secondary capacitance varies. A distinguish feature of a resonant frequency control is that the power transfer is an approximately linear function of the secondary capacitance. This linear characteristics facilitate a voltage control strategy being used to keep the load power unchanging when the secondary capacitance varies. A traditional viewpoint in an ICPT system is that maximizing of output power is achieved when the system operation frequency is equal to the secondary resonant frequency. Numerical simulations show that the power output by a resonant frequency control do not always dominate the power output from other two frequency control methods. This phenomenon suggests that above traditional viewpoint is a misconception, and should be reexamined. The power transfer capability of ICPT systems is an intricate function of the operational frequency, and thus resonant operations of the secondary side do not always guarantee maximizing the power transfer. A suitable control mechanism, such as the resonant frequency control, the variable frequency control, or the fixed frequency control, should be designed carefully according to the practical engineering requirement when the secondary capacitance varies.

Abstract: The ultimate goal of remote sensing image processing is to analyze and interpret the image. The classification is the most basic question of remote sensing image information extraction. Object-oriented classification is proposed in recent years, whose image classification is based on image segmentation. This paper introduces the spatial pyramid matching kernel method (SPM) for feature extraction, the segmentation algorithm uses mean shift, and the classifier is support vector machines（SVM）. Taking a piece of land in southern California for example, we do two experiments, including our approach and a comparing test .Comparing the results, we can see that the object-oriented classification of remote sensing image which based on SPM feature extraction can greatly improve the accuracy.

Abstract: TACAN beacon is expensive. It can not meet the needs of training and learning. The use of simulation cabinet can effectively training the personnel who operate TACAN. There are two modes of TACAN beacon switch. They are automatic and manual. There is a SCM system in the simulation cabinet. The SCM system collects the state of switches, and controls the display. It communicates with the host computer through the serial port. The computer controls the SCM through the VB program. It can simplify the writing of SCM programming and the function expanding. The method is feasible effective by the experiment, and the simulation cabinet has practical value.

Abstract: The airborne passive location has the characteristics of good mobility and scope range is wide. The location accuracy of traditional angle-measure only passive location is low and the location time is long. Passive location that use phase change rate as observation information can overcome these shortcomings noticed above. Research the process of filtering principle of MVEKF algorithm and its application in airborne single passive location. Come up with the principle of phase change rate location method, and from simulation results, using MVEKF algorithm in airborne single passive location can reach the result that positioning precisely and convergence rapidly.

Abstract: The paper focuses on eyes location under nonlinear illuminations. Considered phase congruency is insensitive to illumination, a novel algorithm of eyes location based on phase congruency images is presented. Firstly, the eyes are located roughly by integral projection. Secondly, Hough transform is used to determine the center of eyes after the images are transformed to phase congruency images. The results of experiment indicate that the algorithm is excellent in locating human eyes under nonlinear illuminations.

Abstract: TRIZ theory and electronic image stabilization technology and gray projection algorithm are introduced briefly. In the course of the study for gray projection algorithm used in forest fire monitoring system, the offset error estimation problem is encountered. Face to this problem, with provided innovation tools in TRIZ theory, we analyze this problem and resolve it through the pretreatment which re-select gray value. This method allows the algorithm to deal with obvious features of the image better. At the same time, it is showed that some help can be provided by TRIZ theory for computer algorithm design.

Abstract: Weighted Centroid Localization (WCL) is an improvement algorithm of traditional Centroid Localization (CL) in wireless sensor network. In this paper, a regular pattern of relations between the accuracy and parameters of WCL was revealed and new methods of improving the accuracy of WCL were proposed. By searching the optimum weight functions and setting proper beacons deployment, the positioning accuracy is highly improved.