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Search Results: 1 - 10 of 208500 matches for " L. Conghui "
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Experimental and Numerical Characterization of CaPaMan 2bis Operation
E. E. Hernandez‐Martinez,L. Conghui,G. Carbone,M. Ceccarelli
Journal of applied research and technology , 2010,
Abstract: In this paper, the operation performance of CaPaMan 2bis (Cassino Parallel Manipulator 2 bis) was investigated through labexperimental tests and computer simulations. Milli‐CaTraSys (Milli‐Cassino Tracking System) was implemented to determinedisplacements and orientation variations of CaPaMan 2bis end‐effector during experimental tests. A 3D (three dimension)virtual model was built in ADAMS environment to simulate the operation behavior for different prescribed motions. Severalprescribed motions have been simulated and tested under different conditions in order to characterize the system behavior. Inparticular, the kinematic characteristics were obtained from both, experimental tests and numerical simulations. Finally,experiment results and simulation computations were compared for purpose of performance evaluation and designcharacterization of the parallel manipulator structure and its prototype.
The Relationship between the Typhoon Storm in Fujian and Circulation Circumstances  [PDF]
Jinyu Zeng, Yi Lin, Conghui Gao
Journal of Geoscience and Environment Protection (GEP) , 2018, DOI: 10.4236/gep.2018.64017
Abstract: The cases of landing and impact of the heavy rain of typhoon in Fujian are analyzed. From the research of the mainly weather systems which caused heavy rain and the distribution characteristics of atmospheric circulation situation field, we conclude that on the basis of Fujian special geographical location and terrain, there are four types (easterly jet, warm-type sheer, inverted V-shaped trough of typhoon, westerly trough) are conductive to the circulation patterns of causing the heavy rain of typhoon. Through studying a number of typical model cases of heavy rain of typhoon, we can reveal the mechanism which causes the heavy rain of typhoon by the mostly influencing systems in different circulation backgrounds and the causes of the heavy rain of typhoon.
The Method of Flotation Froth Image Segmentation Based on Threshold Level Set  [PDF]
Ji Zhao, Huibin Wang, Lina Zhang, Conghui Wang
Advances in Molecular Imaging (AMI) , 2015, DOI: 10.4236/ami.2015.52004
Abstract: A novel flotation froth image segmentation based on threshold level set method is put forward in view of the problem of over-segmentation and under-segmentation which occurs when the existing method segmented the flotation froth images. Firstly, the proposed method adopts histogram equalization to improve the contrast of the image, and then chooses the upper threshold and lower threshold from grey value of histogram of the image equalization, and complete image segmentation using the level set method. In this paper, the model which integrates edge with region level set model is utilized, and the speed energy term is introduced to segment the target. Experimental results show that the proposed method has better segmentation results and higher segmentation efficiency on the images with under-segmentation and incorrect segmentation, and it is meaningful for ore dressing industrial.
Neuro-cognitive mechanisms underlying the emotional modulation of word reading
Danling Peng,Zhiguo Hu,Hongyan Liu,Conghui Liu,Guosheng Ding
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-0377-0
Abstract: A novel neural model for emotional modulation of word reading is proposed. This model has four principal hypotheses: the dominant activation region hypothesis, the emotional modulation hypothesis, the attentional level hypothesis, and the interaction hypothesis. Four lines of research were reviewed to provide evidence for these hypotheses: (1) neuro-cognitive studies on the mechanisms of word reading (i.e., neural networks for reading); (2) studies on the influence of words’ emotional valence on word reading; (3) studies of the effect of attention on word reading; and (4) studies on emotional modulation of word reading under different attentional levels.
Numerical Approach on Doppler Spectrum Analysis for Moving Targets Above a Time-Evolving Sea Surface
Conghui Qi;Zhiqin Zhao;Zai-Ping Nie
PIER , 2013, DOI: 10.2528/PIER13020112
Abstract: In order to analyze the Doppler spectrum of three-dimensional (3-D) moving targets above a time-evolving sea surface, a hybrid method with acceleration techniques is proposed to simulate the electromagnetic (EM) scattering from the composite moving model. This hybrid iterative method combines Kirchhoff approximation (KA) and the multilevel fast multipole algorithm (MLFMA) to solve the EM backscattering from the rough sea surface and the targets, respectively, then mutual EM coupling effects between them are taken into account through an iterative process. To overcome the vast computational cost in the iterative process, acceleration approaches which can greatly reduce the calculation time are applied. Coupling area on the sea surface is truncated according to geometrical optic principle. Then a fast far-field approximation (FAFFA) is applied to speed up the mutual interactions between the targets and the sea surface. A successive iteration method is proposed to reduce the convergence steps for the MLFMA process. The accuracy and efficiency of this hybrid method with accelerations are demonstrated. Doppler spectra of backscattering signals obtained from such numerical EM simulations are compared for different incident angles, target velocities and surface models. The broadening effects of the Doppler spectra due to the mutual EM coupling interactions are studied.
Noise Removal of Spaceborne SAR Image Based on the FIR Digital Filter
Wei Zhang,Jinzhong Yang,Conghui Fang,Dongli Fan
Computer and Information Science , 2010, DOI: 10.5539/cis.v3n1p12
Abstract: The speckle effect inevitably exists in the image of the Synthetic Aperture Radar (SAR). The removal of the speckle noise is the necessary approach before automatic partition, classification, target detection and abstraction of other quantitative special information in the SAR image, so it is very meaningful to eliminate or furthest restrain the speckle noises when the spatial resolution of the image is not be reduced. In this paper, the FIR filter is used to remove the noise in the SAR image, and optimal filtering coefficient is selected through experiment and analysis in the filtering process. The results show that the FIR filter used to remove noises in the SAR image is better than other traditional filtering methods in keeping the radiolocation feature and restraining the speckle noises, and the filtering speed is quicker. At the same time, the selection of the filtering coefficient will largely influence the de-noising effect of the FIR filter.
Augmenting Phrase Table by Employing Lexicons for Pivot-based SMT
Yiming Cui,Conghui Zhu,Xiaoning Zhu,Tiejun Zhao
Computer Science , 2015,
Abstract: Pivot language is employed as a way to solve the data sparseness problem in machine translation, especially when the data for a particular language pair does not exist. The combination of source-to-pivot and pivot-to-target translation models can induce a new translation model through the pivot language. However, the errors in two models may compound as noise, and still, the combined model may suffer from a serious phrase sparsity problem. In this paper, we directly employ the word lexical model in IBM models as an additional resource to augment pivot phrase table. In addition, we also propose a phrase table pruning method which takes into account both of the source and target phrasal coverage. Experimental result shows that our pruning method significantly outperforms the conventional one, which only considers source side phrasal coverage. Furthermore, by including the entries in the lexicon model, the phrase coverage increased, and we achieved improved results in Chinese-to-Japanese translation using English as pivot language.
Neuro-cognitive mechanisms underlying the emotional modulation of word reading
PENG Danling,HU Zhiguo,LIU Hongyan,LIU Conghui,DING Guosheng,
PENG,Danling,HU,Zhiguo,LIU,Hongyan,LIU,Conghui,DING,Guosheng
科学通报(英文版) , 2006,
Abstract: A novel neural model for emotional modulation of word reading is proposed. This model has four principal hypotheses: the dominant activation region hypothesis, the emotional modulation hypothesis, the attentional level hypothesis, and the interaction hypothesis. Four lines of research were reviewed to provide evidence for these hypotheses: (1) neuro-cognitive studies on the mechanisms of word reading (i.e., neural networks for reading); (2) studies on the influence of words’ emotional valence on word reading; (3) studies of the effect of attention on word reading; and (4) studies on emotional modulation of word reading under different attentional levels.
The two authentic methionine aminopeptidase genes are differentially expressed in Bacillus subtilis
CongHui You, HongYan Lu, Agnieszka Sekowska, Gang Fang, YiPing Wang, Anne-Marie Gilles, Antoine Danchin
BMC Microbiology , 2005, DOI: 10.1186/1471-2180-5-57
Abstract: In silico analysis of MAP evolution uncovered a coordinated pattern of MAP and deformylase that did not correlate with the pattern of 16S RNA evolution. Biochemical assays showed that both MAP (MAP_Bs) and YflG (YflG_Bs) from B. subtilis overproduced in Escherichia coli and obtained as pure proteins exhibited a methionine aminopeptidase activity in vitro. Compared with MAP_Bs, YflG_Bs was approximately two orders of magnitude more efficient when assayed on synthetic peptide substrates. Both map and yflG genes expressed in multi-copy plasmids could complement the function of a defective map gene in the chromosomes of both E. coli and B. subtilis. In contrast, lacZ gene transcriptional fusions showed that the promoter activity of map was 50 to 100-fold higher than that of yflG. Primer extension analysis detected the transcription start site of the yflG promoter. Further work identified that YvoA acted as a possible weak repressor of yflG expression in B. subtilis in vivo.Both MAP_Bs and YflG_Bs are functional methionine aminopeptidases in vitro and in vivo. The high expression level of map and low expression level of yflG may account for their essentiality and dispensality in B. subtilis, respectively, when cells are grown under laboratory conditions. Their difference in activity on synthetic substrates suggests that they have different protein targets in vivo.Ribosome-mediated protein synthesis is always initiated with either methionine (in eukaryotes) or N-formylmethionine (in prokaryotes and eukaryotic organelles) [1]. However, after removal of the N-formyl group from the polypeptide by peptide deformylase (DEF, EC 3.5.1.88), the N-terminal methionine of a large number of proteins is cleaved by methionine aminopeptidase (MAP, EC 3.4.11.18) [2,3]. The efficiency of removal of the initiator methionine is defined by a highly conserved local substrate specificity, which is determined by both methionine and its adjacent residue. MAP hydrolytically removes the N-terminal
Spx mediates oxidative stress regulation of the methionine sulfoxide reductases operon in Bacillus subtilis
CongHui You, Agnieszka Sekowska, Olivera Francetic, Isabelle Martin-Verstraete, YiPing Wang, Antoine Danchin
BMC Microbiology , 2008, DOI: 10.1186/1471-2180-8-128
Abstract: We characterized the methionine sulfoxide reductase genes msrA and msrB in Bacillus subtilis, forming an operon transcribed from a single sigma A-dependent promoter. The msrAB operon was specifically induced by oxidative stress caused by paraquat (PQ) but not by H2O2. Spx, a global oxidative stress regulator in B. subtilis, is primarily responsible for this PQ-specific induction of msrAB expression. In support of this finding, an spx deletion mutant is extremely sensitive to PQ, and increased expression of msrA was identified in a clpX mutant in which Spx accumulated. However, the Spx effect was also visible under conditions where the protein did not accumulate (PQ treatment), suggesting a specific molecular effect at the level of the Spx protein. Indeed, the CXXC motif of Spx was found essential for its function in the PQ-specific induction of msrAB expression. PQ caused a modification of Spx requiring at least one of the cysteines of the CXXC motif of Spx. The PQ modified form of Spx showed a dynamic change in vivo.The Spx mediated PQ-specific regulation pathway of the msrAB operon in B. subtilis is reported. Our results suggest that PQ induced the expression of msrAB partially through an oxidation on Spx via modification of its CXXC motif.Among the 20 protein-building amino acids, methionine has a special status. It is the first amino acid in all nascent peptides, and often retained in the mature polypeptides. Methionine residues in proteins are also involved in catalytic centers [1-5] and binding of metals, copper in particular [6,7]. However, its major role in the cell is sometimes attributed to the reactivity of its sulfur atom. Methionine is highly sensitive to reactive oxygen species (ROS) that modify it covalently, yielding methionine sulfoxide in two enantiomeric forms: R- and S-. Remarkably, this reaction is reversible and two non-homologous methionine sulfoxide reductases MsrA and MsrB can restore intact methionines from the S- and R- forms, respectively
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