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Contour tracking using weighted structure tensor based variational level set
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作者 胡宏伟 马波 曹淑娟 《Journal of Beijing Institute of Technology》 EI CAS 2014年第2期218-225,共8页
A novel contour tracking method using weighted structure tensor based variational level set is proposed in this paper.The image is first converted to weighted structure tensor field by extracting apositive definite sy... A novel contour tracking method using weighted structure tensor based variational level set is proposed in this paper.The image is first converted to weighted structure tensor field by extracting apositive definite symmetric covariance matrix for each pixel.Then,a level set method is employed to represent object contour implicitly which separates the image domain into two areas each modeled by tensor field based Gaussian mixture model separately.By solving agradient flow equation of energy functional with respect to the level set,the object contour will converge to its real profile in the newly arrived frame.Experimental results on several video sequences demonstrate the better performance of our method than the other two contour tracking algorithms. 展开更多
关键词 contour tracking weighted structure tensor Gaussian mixture model level set
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Voice conversion using structured Gaussian mixture model in cepstrum eigenspace 被引量:2
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作者 LI Yangchun YU Yibiao 《Chinese Journal of Acoustics》 CSCD 2015年第3期325-336,共12页
A new methodology of voice conversion in cepstrum eigenspace based on structured Gaussian mixture model is proposed for non-parallel corpora without joint training. For each speaker, the cepstrum features of speech ar... A new methodology of voice conversion in cepstrum eigenspace based on structured Gaussian mixture model is proposed for non-parallel corpora without joint training. For each speaker, the cepstrum features of speech are extracted, and mapped to the eigenspace which is formed by eigenvectors of its scatter matrix, thereby the Structured Gaussian Mixture Model in the EigenSpace (SGMM-ES) is trained. The source and target speaker's SGMM-ES are matched based on Acoustic Universal Structure (AUS) principle to achieve spectrum transform function. Experimental results show the speaker identification rate of conversion speech achieves 95.25%, and the value of average cepstrum distortion is 1.25 which is 0.8% and 7.3% higher than the performance of SGMM method respectively. ABX and MOS evaluations indicate the conversion performance is quite close to the traditional method under the parallel corpora condition. The results show the eigenspace based structured Gaussian mixture model for voice conversion under the non-parallel corpora is effective. 展开更多
关键词 LPCC Voice conversion using structured Gaussian mixture model in cepstrum eigenspace ES GMM
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Numerical study of soil-rock mixture:Generation of random aggregate structure 被引量:6
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作者 CHEN Li YANG YongTao ZHENG Hong 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2018年第3期359-369,共11页
The soil-rock mixture(SRM) is highly heterogeneous. Before carrying out numerical analysis,a structure model should be generated. A reliable way to obtain such structure is by generating random aggregate structure bas... The soil-rock mixture(SRM) is highly heterogeneous. Before carrying out numerical analysis,a structure model should be generated. A reliable way to obtain such structure is by generating random aggregate structure based on random sequential addition(RSA). The classical RSA is neither efficient nor robust since valid positions to place new inclusions are formulated by trial, which involves repetitive overlapping tests. In this paper, the algorithm of Entrance block between block A and B(EAB)is synergized with background mesh to redesign RSA so that permissible positions to place new inclusions can be predicted,resulting in dramatic improvement in efficiency and robustness. 展开更多
关键词 soil-rock mixture(SRM) random aggregate structure(RAS) random sequential addition(RSA) EAB algorithm background mesh
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Fracture Behavior of Epoxy Asphalt Pavement on Steel Bridges based on Optical Fiber Sensing Technology and Numerical Simulation 被引量:1
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作者 胡靖 钱振东 CHEN Leilei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第4期858-862,共5页
The distributed optical fiber sensing technology was used to investigate the fracture behavior of the Epoxy Asphalt Mixture. The spatial distribution and variation of the strain development with crack propagation were... The distributed optical fiber sensing technology was used to investigate the fracture behavior of the Epoxy Asphalt Mixture. The spatial distribution and variation of the strain development with crack propagation were acquired using the brillouin optical time-domain reflectometer through the loading experiments of the composite beam structure. In addition, a finite element model of the composite beam structure was developed to analyze the mechanical responses of the epoxy asphalt mixture using the extended finite element method. The experimental results show that the development of crack propagation becomes instable with the increase of the load, and larger loads will generate deeper cracks. Moreover, the numerical results show that the mechanical response of the crack tip changes with the crack propagation, and the worst areas that subjected to crack damage are located on both sides of the composite beam structure. 展开更多
关键词 epoxy asphalt mixture composite beam structure distributed optical fi ber extended fi nite element method
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Effects of multiple but low pesticide loads on aquatic fungal communities colonizing leaf litter 被引量:1
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作者 Anne Talk Susanne Kublik +5 位作者 Marie Uksa Marion Engel Rüdiger Berghahn Gerhard Welzl Michael Schloter Silvia Mohr 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第8期116-125,共10页
In the first tier risk assessment(RA) of pesticides, risk for aquatic communities is estimated by using results from standard laboratory tests with algae, daphnids and fish for single pesticides such as herbicides, ... In the first tier risk assessment(RA) of pesticides, risk for aquatic communities is estimated by using results from standard laboratory tests with algae, daphnids and fish for single pesticides such as herbicides, fungicides, and insecticides. However, fungi as key organisms for nutrient cycling in ecosystems as well as multiple pesticide applications are not considered in the RA. In this study, the effects of multiple low pesticide pulses using regulatory acceptable concentrations(RACs) on the dynamics of non-target aquatic fungi were investigated in a study using pond mesocosm. For that, fungi colonizing black alder(Alnus glutinosa) leaves were exposed to multiple, low pulses of 11 different pesticides over a period of 60 days using a real farmer's pesticide application protocol for apple cropping.Four pond mesocosms served as treatments and 4 as controls. The composition of fungal communities colonizing the litter material was analyzed using a molecular fingerprinting approach based on the terminal Restriction Fragment Length Polymorphism(t-RFLP) of the fungal Internal Transcribed Spacer(ITS) region of the ribonucleic acid(RNA) gene(s). Our data indicated a clear fluctuation of fungal communities based on the degree of leaf litter degradation. However significant effects of the applied spraying sequence were not observed. Consequently also degradation rates of the litter material were not affected by the treatments. Our results indicate that the nutrient rich environment of the leaf litter material gave fungal communities the possibility to express genes that induce tolerance against the applied pesticides. Thus our data may not be transferred to other fresh water habitats with lower nutrient availability. 展开更多
关键词 mixture toxicity Pesticides Regulatory acceptable concentration Fungal community structure Leaf litter degradation
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Konjac glucomannan and xanthan gum as compression coat for colonic drug delivery:experimental and theoretical evaluations
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作者 Kang WANG Jiangyang FAN +1 位作者 Yanjun LIU Zhimin HE 《Frontiers of Chemical Science and Engineering》 SCIE EI CSCD 2010年第1期102-108,共7页
Compression coated tablets for oral colon specific delivery systems were developed with a mixture polysaccharide of konjac glucomannan(KGM)and xanthan gum(XG)as the compression coat.Diffusion of cimetidine from compre... Compression coated tablets for oral colon specific delivery systems were developed with a mixture polysaccharide of konjac glucomannan(KGM)and xanthan gum(XG)as the compression coat.Diffusion of cimetidine from compression coated tablets was investigated by release experiment in Vitro.0.22U/mLβ-mannanase was applied in the mimic colon solution.The structure of the mixture polysaccharide was studied by an atomic force microscope(AFM).The experimental results indicate that a KGM70 tablet with a 0.4 g coat is of good design,due to a less than 5%drug loss in the mimic upper gastrointestinal solution by the synergistic interaction between XG and KGM,and due to about 50%cumulative release in the mimic colon solution by degradation after 24 hours.The release mechanism and model are discussed based on different periods of drug release including the delay of the drug,the constant release without an enzyme and the delay of degradation.Under hydrolysis byβ-mannanase,drug release from the tablet with KGM coat shows an exponential increase,while that from the dosage with the mixture polysaccharide coat is an approximately zero-order process in which the constant release rate relates to the release velocity of a non-degraded system,the content of KGM within the coat and the average molecular weight ratio of KGM to XG.It was found that XG was the framework of the polysaccharide mixtures by AFM,which is similar to the analysis results from experiments on drug release. 展开更多
关键词 colon specific delivery compression coated tablet konjac glucomannan xanthan gum synergistic interaction release mechanism and model different period of release structure of mixture polysaccharide
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