中国科学院机构知识库网格系统: 检索

Molecular Weight Dependency of Crystallization and Melting Behavior of beta-Nucleated Isotactic Polypropylene 期刊论文 OAI收割
journal of polymer science part b-polymer physics, 2014, 卷号: 52, 期号: 19, 页码: 1301-1308
Lu, Ying; Wang, Qiao; Men, Yongfeng

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Compounds of isotactic polypropylene (iPP) and beta-nucleating agent were used to investigate the relationship between the development of beta phase and molecular weight in iPP under quiescent crystallization conditions by using wide angle X-ray diffraction and differential scanning calorimetry techniques. In all cases the dependency of the formation of beta phase in iPP on molecular weight of iPP at a defined crystallization temperature range was found. The iPP with high molecular weight possessed a wide range of crystallization temperature in inducing rich beta phase. However poor or even no beta phase was obtained for the samples with low molecular weight in the same range. In addition an upper critical crystallization temperature of producing dominant beta phase was found at 125 degrees C. Beyond this temperature a phenomenon of prevailing alpha phase became obvious. (C) 2014 Wiley Periodicals Inc.

Gradient Structure-Induced Temperature Responsiveness in Styrene/Methyl Methacrylate Gradient Copolymers Micelles 期刊论文 OAI收割
macromolecular rapid communications, 2014, 卷号: 35, 期号: 3, 页码: 309-316
Zheng,Chao; Huang,Haiying; He,Tianbai

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In this work micelles are formed by gradient copolymer of styrene and methyl methacrylate in acetone-water mixture and their temperature responsiveness is investigated in a narrow range near room temperature. Three different kinds of structural transitions could be induced by temperature: unimers to micelle transition shrinkage/stretching of micelles and morphological transition from spherical micelles to vesicles. In addition a model analysis on the interface of gradient copolymer micelle is made to better understand these phenomena. It is found that both position and composition of the interface could alter in response to the change in temperature. According to the experiments and model analysis it is proposed that temperature responsiveness might be an intrinsic and universal property of gradient copolymer micelles which only originates from the gradient structure.

Efficient human action recognition using accumulated motion image and support vector machines (EI CONFERENCE) 会议论文 OAI收割
International Workshop on Advanced Computational Intelligence and Intelligent Informatics, IWACIII 2011, November 19, 2011 - November 23, 2011, Suzhou, China
作者: Zhang X.; Zhang J.; Zhang J.; Zhang X.; Zhang X.

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Vision-based human action recognition provides an advanced interface and research in this field of human action recognition has been actively carried out. This paper describes a scheme for recognizing human actions from a video sequences. The proposed method is an extension of the Motion History Image(MHI) method based on the ordinal measure of accumulated motion which is robust to variations of appearances. We define the accumulated motion image(AMI) using image differences firstly. Then the AMI of the video sequencesis resized to a MN regulation following the standard of training phases. Finally we employ Support Vector Machine(SVM) as a classifier to distinguish the current activity in target video sequences. In a word our proposed algorithm not only outperforms the state of art on public available KTH data set and Weizmann data set but also proves practical to some real world applications in addition this method is computationally simple and able to achieve a satisfactory accuracy.

The analysis for the reason of limit cycle generated by friction in servo system (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者: Li M.

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In this paper limit cycle which results from friction during low-velocity servo system has been discussed. First the piecewise linearization method has been applied to change nonlinear stribeck model to linear model. Second with analysis of equilibrium property it is proved the existence of limit cycle and its certain region. The analysis reveals that it is because of stability of equilibrium repeatedly changing results in the limit cycle during low-velocity state. In addition it also points that the key point to avoid this phenomenon is to keep robust stability of the close-loop system. 2010 IEEE.

Optimal multiresolution dynamic models generation based on triangle importance (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Image Analysis and Signal Processing, IASP'2010, April 12, 2010 - April 14, 2010, Xiamen, China
作者: Zhao J.; Zhang S.

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In this paper we propose an efficient method to generate optimal multiresolution dynamic models. By the method we define the triangle importance degree as a weight parameter to be embedded to the edge contraction cost so the new metric can not only measure distance error but also reflect geometric variation of local areas. A deformation degree weight is appended to the aggregated edge contraction cost for the whole animation thus sharp features on areas with large deformation can be preserved. In addition a process of mesh optimization and validity check can further alleviate the geometric distortion of the approximations. Our approach is efficient in operation easy for implementation and as a result high quality of dynamic approximations with well-preserved fine details can be generated at any given frame. 2010 IEEE.

SoC test data compression technique based on RLE-G (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Advanced Measurement and Test, AMT 2010, May 15, 2010 - May 16, 2010, Sanya, China
作者: Liu W.; Yang L.; Yang L.; Zheng X.

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Test data compression has been an effective way to reduce test data volume and test time as well as to solve automatic test equipment (ATE) memory and bandwidth limitation. We analyze the limitations of current test data compression algorithm and draw on the previous experience to deduce an optimal compression coding model suitable for SoC test data. In addition in this paper we make full use of the relevance of the test vectors and the advantages of statistical coding to present an efficient test data compression method RLE-G based on the coding model and give the RLE-G the optimal compression efficiency of the boundary conditions and realization steps. The experimental results for ISCAS 89 benchmark circuits demonstrate RLE-G have the excellent advantages of high compression ratio. (2010) Trans Tech Publications.

Qualitative determination of the components of textile products using near infrared spectroscopy (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photonics and Optoelectronics, SOPO 2010, June 19, 2010 - June 21, 2010, Chengdu, China
作者: Chen X.; Chen X.; Chen X.; Wang D.

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In the paper A total of 40 pure or two-mixed textile weaves were prepared and classification of these samples was introduced using near infrared spectroscopy (NIRS) all textile samples are selected among four classes which are Cotton-Terylene Cotton-Polyurethane Cotton and Terylene according to theirs components. Near infrared diffuse reflectance spectra of the samples were collected Mahalanobis distance was used to discriminate the samples coupled with principle components analysis (PCA) the results showed that near infrared spectroscopy could determine which class one textile weave belongs to easily comparing with traditional methods. In addition the expectation of the further research on qualitative determination of textile products by NIR technology was discussed in the end of this paper. 2010 IEEE.

Position servo control of a DC electromotor using a hybrid method based on model reference adaptive control (MRAC) (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者: Chen J.

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This paper dealed with position control problems of a DC motor servo system that had nonlinear friction and was subject to parametric uncertainties external disturbances etc. In order to overcame those unfavourable factors mentioned above a model reference adaptive control method was proposed to regulate the important and main speed loop in the positioning system which was designed with three closed control loop where a compensatory measure was given so as to counterbalance the friction torque disturbances. In addition the other two close loops were built in adjusting the position and the current of the servo system respectively that aimed to achieve the fast and precise positioning and increase dynamic stiffness against load disturbances. Experimental results illustrate satisfactory performances in steady state error load capability high rapidity and so on. 2010 IEEE.

Using bidirectional binary particle swarm optimization for feature selection in feature-level fusion recognition system (EI CONFERENCE) 会议论文 OAI收割
2009 4th IEEE Conference on Industrial Electronics and Applications, ICIEA 2009, May 25, 2009 - May 27, 2009, Xi'an, China
作者: Wang D.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

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In feature-level fusion recognition system the other is optimizing system sensor design to get outstanding cost performance. So feature selection become usually necessary to reduce dimensionality of the combination of multi-sensor features and improve system performance in system design. In general there are two main missions. One is improving the recognition correct rate as soon as possible the optimization is usually applied to feature selection because of its computational feasibility and validity. For further improving recognition accuracy and reducing selected feature dimensions this paper presents a more rational and accurate optimization Bidirectional Binary Particle Swarm Optimization (BBPSO) algorithm for feature selection in feature-level fusion target recognition system. In addition we introduce a new evaluating function as criterion function in BBPSO feature selection method. At the last we utilized Leave-One-Out method to validate the proposed method. The experiment results show that the proposed algorithm improves classification accuracy by two percentage points while the selected feature dimensions are less one dimension than original Particle Swarm Optimization approach with 16 original feature dimensions. 2009 IEEE.

Novel algorithm for computer-aided alignment of wide field of view complex optical system (EI CONFERENCE) 会议论文 OAI收割
Yang X.; Han C.

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With the advent of the new complex optical system alignment technology is necessary. In this paper is presented an alignment algorithm whose main idea is composed of damped least square method and singular value decomposition method. In addition the how and why to enter the damped factor into algorithm is explained. According to this algorithm an alignment software package was compiled and compared self-compiled software with alignment package of CODE V. Results show that this self-compiled software is much more valid than alignment package of CODE V. For a field of view of 2 R-C system average MTF over the field of view was greater than 0.3 at 50 line pairs /mm.