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Search Results: 1 - 10 of 120075 matches for " XinLong Wang "
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A fast and accurate initial alignment method for strapdown inertial navigation system on stationary base

Xinlong WANG,Gongxun SHEN,

控制理论与应用 , 2005,
Abstract: In this work,a fast an d accurate stationary alignment method for strapdown inertial navigation system (SINS) is proposed.It h as been demonstrated that the stationary alignment o f SINS can be improved by employing the multipositio n technique,but the alignment time of the azimuth error is relatively longer.Over here,the two-posi tion alignment principle is presented.On the basis of this SINS error model,a fast estimation algorithm of the azimuth error for the initial a lignment of SINS on stationary base is derived f ully from the horizontal velocity outputs and the output rates,and the novel azimuth error estimatio n algorithm is used for the two-position alignment. Consequently,the speed and accuracy of the SINS' s initial alignment is enhanced greatly.The computer simulation results illustrate the efficiency of this alignment method.
A New Technique for Estimating the Lower Bound of the Trust-Region Subproblem  [PDF]
Xinlong Luo
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.24052
Abstract: Trust-region methods are popular for nonlinear optimization problems. How to determine the predicted reduction of the trust-region subproblem is a key issue for trust-region methods. Powell gave an estimation of the lower bound of the trust-region subproblem by considering the negative gradient direction. In this article, we give an alternate way to estimate the same lower bound of the trust-region subproblem.
Multiscale analysis of heart beat interval increment series and its clinical significance
XiaoLin Huang,XinBao Ning,XinLong Wang
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0596-2
Abstract: Analysis of multiscale entropy (MSE) and multiscale standard deviation (MSD) are performed for both the heart rate interval series and the interval increment series. For the interval series, it is found that, it is impractical to discriminate the diseases of atrial fibrillation (AF) and congestive heart failure (CHF) unambiguously from the healthy. A clear discrimination from the healthy, both young and old, however, can be made in the MSE analysis of the increment series where we find that both CHF and AF sufferers have significantly low MSE values in the whole range of time scales investigated, which reveals that there are common dynamic characteristics underlying these two different diseases. In addition, we propose the sample entropy (SE) corresponding to time scale factor 4 of increment series as a diagnosis index of both AF and CHF, and the reference threshold is recommended. Further indication that this index can help discriminate sensitively the mild heart failure (cardiac function classes 1 and 2) from the healthy gives a clue to early clinic diagnosis of CHF.
Risk Correlation Based on Time-Varying Copula Function and Extreme Value Theory  [PDF]
Xinlong Ji, Lu Zhou
Theoretical Economics Letters (TEL) , 2017, DOI: 10.4236/tel.2017.77151
Abstract: The dependence structure of financial assets in financial risk measurement is very important, the tail relations in particular. Authors of extant studies in this field tended to focus on the linear analysis of the financial assets, rarely considering nonlinear, asymmetric and thick-tail characteristics. Here, we apply the copulas connection function with time-varying factors to discuss the risk dependency relationship between financial assets. Moreover, we develop an SV-EVT model to fit variables’ marginal distribution combined with stochastic volatility and extreme value theory. Finally, we present an empirical comparative study of static and dynamic copula models applied to the sample comprising of the Chinese mainland A-shares and Hong Kong stock market. The results show that the CSJC copulas connection function describes the tail features of stock index better than the normal copulas connection function. Similarly, the time-varying model outperforms the static copulas model. Furthermore, we observe an asymmetry dependence change rule between Chinese mainland A-shares market and the Hong Kong stock market; the correlation of lower tail is significantly higher than that of the upper tail, and the bear market effect is remarkable. These findings indicate that time-varying Copulas-SV-EVT model can depict the correlation of financial asset tails exactly, and can thus be used to control investment risk and forecast abnormal fluctuations.
Global Transcriptome Profiling of Salicornia europaea L. Shoots under NaCl Treatment
Jinbiao Ma, Meiru Zhang, Xinlong Xiao, Jinjin You, Junru Wang, Tao Wang, Yinan Yao, Changyan Tian
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0065877
Abstract: Background Soil salinity is a major abiotic stress that limits agriculture productivity worldwide. Salicornia europaea is well adapted to extreme saline environments with more than 1,000 mM NaCl in the soil, so it could serve as an important model species for studying halophilic mechanisms in euhalophytes. To obtain insights into the molecular basis of salt tolerance, we present here the first extensive transcriptome analysis of this species using the Illumina HiSeq? 2000. Principal Findings A total of 41 and 39 million clean reads from the salt-treated (Se200S) and salt-free (SeCKS) tissues of S. europaea shoots were obtained, and de novo assembly produced 97,865 and 101,751 unigenes, respectively. Upon further assembly with EST data from both Se200S and SeCKS, 109,712 high-quality non-redundant unigenes were generated with a mean unigene size of 639 bp. Additionally, a total of 3,979 differentially expressed genes (DEGs) were detected between the Se200S and SeCKS libraries, with 348 unigenes solely expressed in Se200S and 460 unigenes solely expressed in SeCKS. Furthermore, we identified a large number of genes that are involved in ion homeostasis and osmotic adjustment, including cation transporters and proteins for the synthesis of low-molecular compounds. All unigenes were functionally annotated within the COG, GO and KEGG pathways, and 10 genes were validated by qRT-PCR. Conclusion Our data contains the extensive sequencing and gene-annotation analysis of S. europaea. This genetic knowledge will be very useful for future studies on the molecular adaptation to abiotic stress in euhalophytes and will facilitate the genetic manipulation of other economically important crops.
Solving Large Scale Unconstrained Minimization Problems by a New ODE Numerical Integration Method  [PDF]
Tianmin Han, Xinlong Luo, Yuhuan Han
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.25069
Abstract: In reference [1], for large scale nonlinear equations , a new ODE solving method was given. This paper is a continuous work. Here has gradient structure i.e. , is a scalar function. The eigenvalues of the Jacobian of ; or the Hessian of , are all real number. So the new method is very suitable for this structure. For quadratic function the convergence was proved and the spectral radius of iteration matrix was given and compared with traditional method. Examples show for large scale problems (dimension ) the new method is very efficient.
Research on the Intersection Issue in Solid Modeling Based on Curved Surfaces
曲面实体造型中曲线和曲面交点的求解

Wang Xinlong,Han Xiangli,Cui Tianyuan,
王新龙
,韩向利,崔田元

中国图象图形学报 , 1998,
Abstract: The intersecting is an important factor which influences the efficiency and the reliability of Boolean algorithms in solid modeling based on curved surfaces, and the intersecting algorithm is closely related to the geometric representation of curved surfaces. Although curved surfaces can be commonly represented with NURBS, unnecessary complexities are caused for the intersecting of quadric surfaces, which are frequently used to describe geometric features of shafts, holes and grooves etc. in mechanical part designing. Therefore, intersecting algorithms of them are required to have higher accuracy, higher efficiency and higher robustness. For this reason, we introduce a practical representation of quadric surfaces, and on the basis of that, algorithms of intersection points between quadric surfaces and several conics, fourth degree nonplanar space curves constructing their boundaries are developed.
Use of Anti-Granulocyte Scintigraphy with 99mTc-Labeled Monoclonal Antibodies for the Diagnosis of Periprosthetic Infection in Patients after Total Joint Arthroplasty: A Diagnostic Meta-Analysis
Dan Xing, XinLong Ma, JianXiong Ma, Jie Wang, Yang Chen, Yang Yang
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0069857
Abstract: The accurate diagnosis of periprosthetic joint infections (PJI) is crucial for therapy and the prevention of complications. No diagnostic test of PJI is 100% accurate. The aim of this study was to assess the use of anti-granulocyte scintigraphy using 99 mTc-labeled monoclonal antibodies to diagnose PJI after total joint arthroplasty. A systematic search of all relevant studies published through January 2013 was conducted using the MEDLINE, EMBASE, OVID, and ScienceDirect databases. Observational studies that assessed the accuracy of the anti-granulocyte scintigraphy with monoclonal antibodies or antibody fragments labeled with technetium 99 m in diagnosis for PJI and provided data on specificity and sensitivity were identified. Standard methods recommended for meta-analysis of diagnostic accuracy were used. Nineteen studies were eligible for inclusion. The results demonstrated that the area under the summary receiver operator curve was 0.88, and the diagnostic accuracy (Q*) was 0.81. Additionally, the diagnostic odds ratio (DOR) was 18.76 with a corresponding 95% confidence interval of 10.45–33.68. The pooled sensitivity and specificity of the diagnostic method for the diagnosis of PJI were 83% and 79%, respectively, while the pooled positive likelihood ratio (PLR) was 3.56, and the negative likelihood ratio (NLR) was 0.26. Anti-granulocyte scintigraphy using 99 mTc-labeled monoclonal antibodies has a reasonable role in the diagnosis of PJI after total joint arthroplasty. Due to the limitations of the present meta-analysis, additional high-quality original studies are required to confirm the predictive value.
Formation and transportation of sand-heap in an inclined and vertically vibrated container
Guoqing Miao,Kai Huang,Yi Yun,Peng Zhang,Weizhong Chen,Xinlong Wang,Rongjue Wei
Physics , 2005, DOI: 10.1103/PhysRevE.74.021304
Abstract: We report the experimental findings of formation and motion of heap in granular materials in an inclined and vertically vibrated container. We show experimentally how the transport velocity of heap up container is related to the driving acceleration as well as the driving frequency of exciter. An analogous experiment was performed with a heap-shaped Plexiglas block. We propose that cohesion force resulted from pressure gradient in ambient gas plays a crucial role in enhancing and maintaining a heap, and ratchet effect causes the movement of the heap. An equation which governs the transport velocity of the heap is presented.
Dielectric Property of MoS2 Crystal in Terahertz and Visible Region
Xianding Yan,Lipeng Zhu,Yixuan Zhou,Yiwen E,Li Wang,Xinlong Xu
Physics , 2015,
Abstract: Two-dimensional materials such as MoS2 have attracted much attention in recent years due to their fascinating optoelectronic properties. Dielectric property of MoS2 is desired for the optoelectronic application. In this paper, terahertz (THz) time-domain spectroscopy and ellipsometry technology are employed to investigate the dielectric response of MoS2 crystal in THz and visible region. The real and imaginary parts of the complex dielectric constant of MoS2 crystal are found to follow a Drude model in THz region, which is due to the intrinsic carrier absorption. In visible region, the general trend of the complex dielectric constant is found to be described with a Lorentz model, while two remarkable peaks are observed at 1.85 and 2.03 eV, which have been attributed to the splitting arising from the combined effect of interlayer coupling and spin-orbit coupling. This work affords the fundamental dielectric data for the future optoelectronic applications with MoS2.
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