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Search Results: 1 - 10 of 119924 matches for " Limei Wang "
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Meromorphic Functions Sharing Three Values  [PDF]
Changjun Li, Limei Wang
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.26095
Abstract: In this paper, we prove a result on the uniqueness of meromorphic functions sharing three values counting multiplicity and improve a result obtained by Xiaomin Li and Hongxun Yi.
Integrated Learning-Based SME Credit Rating  [PDF]
Limei Wang, Zhe Wang, Yu Hu, Tian Bai
Open Journal of Social Sciences (JSS) , 2014, DOI: 10.4236/jss.2014.24036
Abstract: SME Credit rating index system becomes a significant research topic in recent years. So many researches have focused on this topic. However, the existing researches are only focused on one aspect of the SME Credit Rating problem. In order to resolve this problem, in this paper, we use the idea of ensemble learning, which integrated several basic machine learning algorithms to improve the learning result. Through further amendments, we build a set of SME corporate credit evaluation models which have higher forecast accuracy and stronger anti-jamming capability. Finally, we prove the effectiveness of our model through carrying out a set of experiments.
Development of High Efficient and Low Toxic Oil Spill Dispersants based on Sorbitol Derivants Nonionic Surfactants and Glycolipid Biosurfactants  [PDF]
Dandan Song, Shengkang Liang, Qianqian Zhang, Jiangtao Wang, Limei Yan
Journal of Environmental Protection (JEP) , 2013, DOI: 10.4236/jep.2013.41B004
Abstract: Dispersants, usually blending with several surfactants and a solvent, are used to enhance oil spill dispersion as small droplets in water column. Although there is growing acceptance of dispersants as a counter measure to marine oil spills around the world, the two major issues with the dispersants are their toxicity to marine life and dispersion effectiveness (DE) for crude-oil, especially for heavy oil. To develop more efficient and less toxic dispersants, two kinds of sorbitol derivant nonionic surfactant (polysorbate 85 and sorbeth-40 tetraoleate), two kinds of glycolipid biosurfactants (rhamnolipid and sophorolipid) and less toxic solvent ethylene glycol butyl ether were chosen in this study, and two dispersant formulations were optimized by uniform design methods. Effects of dispersant-to-oil ratio, temperature, salinity and pH on the performance of the two optimized dispersants were investigated. The two dispersants had high dispersion effectiveness (DE) for heavy crude oil, while both dispersants keep high DE at the dispersant-to-oil ratio below 1:25 and the temperature above 5 ℃. In addition, the two dispersants also performed well in a wide range of salinity and pH values. Finally, toxicity tests revealed that the two dispersants showed low toxicity to two kinds of fish (Danio rerio and Microgobius gulosus).

 

The λ-Characteristics of the Ring Laser Based on Non-Uniform SOA  [PDF]
Zhi Wang, Limei Zhang, Yingfeng Liu, Lanlan Liu
Journal of Computer and Communications (JCC) , 2013, DOI: 10.4236/jcc.2013.17013
Abstract: Semiconductor optical amplifier-based ring cavity laser (SOA-RL), which has been widely used in optical communications, optical fiber sensing, and biophotonics fields, can be tuned at an ultra high speed up to Mega Hertz over 100 nm bandwidth range with high SNR and flatness output. A steady-state model and segmentation algorithms are employed to investigate the gain spectra of four kinds of non-uniform SOA and the lasing wavelength of the SOA-RL. It shows that the dependence of the lasing wavelength on the average width is stronger when the light propagates from narrower to wider end than conversely, and there are some particular structures to show ultra high stability lasing wavelength. It is supposed that the main reason could be the carrier density distribution along the propagation.
Description of the FDML Laser with Quasi-steady State Model of the SOA  [PDF]
Zhi Wang, Limei Zhang, Lanlan Liu, Zhenchao Sun, Yingfeng Liu, Fu Wang
Optics and Photonics Journal (OPJ) , 2013, DOI: 10.4236/opj.2013.32B015
Abstract:

Experiments and simulations demonstrate that an SOA-based ring cavity can operate as a tunable laser, wavelength- swept laser or Fourier-domain-mode-locking laser according to the relation between the roundtrip frequency and the sweeping frequency of the filter.

Microstructure and wear resistance of PTA clad Cr7C3/γ-Fe ceramal composite coating
LIU Junbo,WANG Limei,HUANG Jihua
自然科学进展 , 2006,
Abstract: A wear resistant Cr7C3/γ-Fe ceramal composite coating was fabricated on substrate of the hardening and tempering C degree steel by PTA (plasma transferred arc) cladding with (wt%) Fe-25Cr-7C elemental powder blends. Microstructure of the coating was characterized by OM, SEM, XRD and EDS. Wear resistance of the coating was tested under dry sliding wear condition at room temperature. The results indicate that the PTA clad ceramal composite coating has a rapidly solidified fine microstructure consisting of Cr7C3 primary particles uniformly distributed in the γ-Fe matrix and is metallurgically bonded to the C degree steel substrate. The PTA clad Cr7C3/γ-Fe ceramal composite coating has high hardness and excellent wear resistance under dry sliding wear test conditions. The excellent wear resistance of the Cr7C3/γ-Fe ceramal composite coating is attributed to the coating’s high hardness, strong covalent atomic bonding and refined microstructure.
The geometric structures of the Weibull distribution manifold and the generalized exponential distribution manifold
Limei Cao,Huafei Sun,Xiaojie Wang
Tamkang Journal of Mathematics , 2008, DOI: 10.5556/j.tkjm.39.2008.45-51
Abstract: Investigating the geometric structures of the distribution manifolds is a basic task in information geometry. However, by so far, most works are on the distribution manifolds of exponential family. In this paper, we investigate two non-exponential distribution manifolds —the Weibull distribution manifold and the generalized exponential distribution manifold. Then we obtain their geometric structures.
The Pitfall of Transbronchial Lung Biopsy in the Small Cell Carcinoma--Attach 64 Cases Immunohistochemistry Research
Yinping WANG,Limei QU,Yudan HAO
Chinese Journal of Lung Cancer , 2009,
Abstract: Background and objective It is very difficult to make diagnosis on the HE section to small cell lung carcinoma by bronchoscopic and easy to make misdiagnosis, we can avoid this by using immunohistochemical staining to diagnose differentially among the small cell carcinoma, poorly differentiated squamous cell carcinoma, atypical form carcinoid and lymphoma. Methods 64 cases of lung biopsy by bronchoscopic were consistency with small cell carcinoma and stained by immunochemistry for Ki67, CD56, TTF-1, CgA, Syn, P63, CK5/6, LCA, 34βE12. Results For the 64 cases, we diagnosed 61 cases to the small cell carcinoma, 1 case to the poorly differentiated squamous cell carcinoma and 2 cases to the atypical carcinoid after IHC stain. Conclusion It is the different therapy among the small cell carcinoma, poorly differentiated squamous cell carcinoma, atypical form carcinoid and lymphoma, so we can identify the diagnosis and differential diagnosis with IHC thoroughly, accordingly decrease incidence of misdiagnosis.
First Excursion Probabilities of Non-Linear Dynamical Systems by Importance Sampling
Limei REN
Progress in Applied Mathematics , 2013, DOI: 10.3968/j.pam.1925252820130501.718
Abstract: This paper suggests a procedure to estimate first excursion probabilities for non-linear dynamical systems subjected to Gaussian excitation. The approach is based on the mean up-crossing rate and importance sampling method. Firstly, by using of Poisson assumption and Rice formula, the equivalent linear system is carried out. The linearization principle is that non-linear and linear systems have the same up-crossing rate for a specified threshold. Secondly, an importance sampling technique is used in order to estimate excursion probabilities for the equivalent linear system. The variance of the failure probability estimates, the number of samples and the computational time are reduced significantly compared with direct Monte Carlo simulations.
Chance-constrained Portfolio Selection with Birandom Returns
Limei Yan
Modern Applied Science , 2009, DOI: 10.5539/mas.v3n4p161
Abstract: The aim of this paper is to solve the portfolio problem when security returns are birandom variables. Two types of portfolio selection based on chance measure are provided according to birandom theory. Since the proposed optimization problems are difficult to solve by traditional methods, a hybrid intelligent algorithm by integrating birandom simulation and genetic algorithm is designed. Finally, two numerical experiments are provided to illustrate the effectiveness of the algorithm.
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