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Gao Y.,Changchun Automobile Industry Institute | Sun J.,Lanzhou University of Technology
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering

Surface plasmon polariton (SPP) are waves that propagate along the metal-dielectric interface with exponentially decaying electromagnetic fields in both sides of the media. The strip surface plasmon waveguide has long been considered a useful device to achieve highly integrated optics. Analysis of SPP excitation and propagation characteristics in the waveguide by relying on a classic model, namely, Drude was presented. This research is conducted from visible light to near infrared incident wavelength. Strip SPP metal waveguide mode field distribution was studied. Results show that when the thickness of the metal remains constant and its width increases, the electromagnetic field distribution becomes increasingly concentrated in both sides of the strips. When the width of the strip is unchanged, thickness increases and the electromagnetic field distribution becomes increasingly focused on the metal inside. A long incident wavelength means that the concentration of metal strip around the electric field is small. Long incident wavelength can also lead to inter-channel interference. That is, having a large wavelength means one must select a wide strip waveguide. This study, which is about spontaneous radiation characteristics from 840 nm to 910 nm strip waveguide, reveals that a small part of radiation is evanescent to the metal area in the surface plasmon evanescent radiation patterns. Application design and analysis indicate that complete transfer of energy only occurs once in the limited transmission distance of the strip SPP waveguide. When the wavelength is long, the concentration field is reduced and coupling is reinforced. The designed coupler can realize optical WDM in 1310 and 1550 nm. © 2016, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved. Source

Li C.,Jilin University | Liu F.,Jilin University | Zhang Y.,Changchun Automobile Industry Institute
Proceedings - 2010 3rd International Congress on Image and Signal Processing, CISP 2010

Line feature is one of the most important features of palmprint image. A novel approach of principal palm-line extraction is proposed in this paper based on their characteristics of ridge edges. First, gray adjustment and median filtering are used to enhance contrast and weaken noise. Then, palm-lines are detected based on diversity and contrast. After this step, an improved Hilditch algorithm is used to do thinning, an edge tracking approach is applied to get rid of twigs and short lines, and then, the broken lines are connected. Finally, the single pixel principal palm-line image is obtained. The experiment results show that the principle palm-lines of most pictures can be detected correctly by using this algorithm referred above. Moreover, the algorithm can provide effective and accurate statistics for palmprint identification. ©2010 IEEE. Source

Feng J.,Jilin University | Wang H.,Jilin University | Li Y.,Changchun Automobile Industry Institute | Liu F.,Jilin University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Feature extraction is one of most basic problems in the research of palmprint recognition. Extracting effective palmprint feature is the crucial problem in the field of palmprint recognition. There was a research focus on how to select the feature. The lacking of main orientation for palmprint recognition system will lead to an incorrect feature extraction and matching. In order to extract more precise palmprint feature, a new method for feature extraction of palmprint was proposed in the research of palmprint recognition, which could improve the efficiency of identification. Firstly, calculating the main orientation of the whole image, and then adjusting the gradient of each pixel according to the main orientation to ensure this method has rotation invariance. Secondly, combining with the method of histogram of oriented gradient and dominant orientation. Finally, the feature value of palmprint was obtained. A reasonable threshold is set to estimate the similarity between the experimental images and the sample images. The experimental results showed that the method proposed in this paper can improve the efficiency of identification. © Springer International Publishing Switzerland 2015. Source

Yang Z.,Jilin University | Chen C.,Jilin University | Li G.,Jilin University | Wang J.,Jilin University | Zhang X.,Changchun Automobile Industry Institute
QR2MSE 2013 - Proceedings of 2013 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering

Machining tools are the main equipments for metal machining and consist of mechanical parts, electrical parts and hydraulic parts, and so on. In order to reduce the probability of failure and improve the reliability of machine tools, this paper firstly performs failure analysis by statistical method. Then the failure trends for the key parts of machining center are given using power law process. In contrast with traditional method, which optimizes maintenance under repair costs, an optimization approach for maintenance is presented under the reliability constraints of machining center that used in a northeast manufacturing plant of China. The proposed analysis process could be a useful tool to assess the reliability and optimize the maintenance policy of machine tools. © 2013 IEEE. Source

Yu Z.,Jilin University | Liu S.,Jilin University | Zhang N.,Changchun Automobile Industry Institute | Li W.,Jilin University
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery

The electromagnetism (EM)-fluid and fluid-structure interaction (FSI) modeling and solving method of shock absorber were studied. Adina software was used to establish accurate structure finite element mesh model and the finite element mesh model of EM-flow field based on EM-fluid and FSI method. Post-processing module of adina software was used for solving analysis. The velocity characteristics, indicator diagram, magnetic field distribution characteristics, core area fluid pressure field and velocity field characteristics of shock absorbers were obtained under the state of MR damper non-controlling and energized condition. The results show that under the high-speed impact of the shock absorber MR fluid and the core area fluid pressure field are changed significantly. According to the magnetic field distribution characteristics, self-designed mono tube MR damper structure can enlarge damping force adjustment range. The EM-CFD and FSI model is closed to the physical reality because of the consideration of turbulent flow of MR fluid; so the simulation results are in good agreement with the experimental results. Source

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