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基于加权字典对学习的人脸年龄估计方法 预览
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作者 赵军 侯凯艳 杨林 《计算机工程》 CAS CSCD 北大核心 2019年第2期191-194,共4页
针对现有人脸年龄估计方法多数将人脸各部分同等对待或忽视部分特征的问题,提出一种基于加权字典对学习(DPL)的人脸年龄估计方法。将人脸进行分块,使用局部二值模式算法对人脸的主要特征区域和次要特征区域分别进行特征提取,得到人脸的... 针对现有人脸年龄估计方法多数将人脸各部分同等对待或忽视部分特征的问题,提出一种基于加权字典对学习(DPL)的人脸年龄估计方法。将人脸进行分块,使用局部二值模式算法对人脸的主要特征区域和次要特征区域分别进行特征提取,得到人脸的主要特征和次要特征,再利用这2种特征分别训练DPL模型,并赋予不同的权重,使用训练好的加权DPL模型对目标人脸图像进行年龄分类。在MORPH和FG-NET数据集上的实验结果表明,该方法具有较高的分类准确率。 展开更多
关键词 年龄估计 主要特征 次要特征 加权 字典对学习 分类
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A two-step weighted least-squares method for joint estimation of source and sensor locations: A general framework
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作者 Ding WANG Jiexin YIN +2 位作者 Tao TANG Ruirui LIU Zhidong WU 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第2期417-443,共27页
It is well known that the Two-step Weighted Least-Squares(TWLS) is a widely used method for source localization and sensor position refinement. For this reason, we propose a unified framework of the TWLS method for jo... It is well known that the Two-step Weighted Least-Squares(TWLS) is a widely used method for source localization and sensor position refinement. For this reason, we propose a unified framework of the TWLS method for joint estimation of multiple disjoint sources and sensor locations in this paper. Unlike some existing works, the presented method is based on more general measurement model, and therefore it can be applied to many different localization scenarios.Besides, it does not have the initialization and local convergence problem. The closed-form expression for the covariance matrix of the proposed TWLS estimator is also derived by exploiting the first-order perturbation analysis. Moreover, the estimation accuracy of the TWLS method is shown analytically to achieve the Cramér-Rao Bound(CRB) before the threshold effect takes place. The theoretical analysis is also performed in a common mathematical framework, rather than aiming at some specific signal metrics. Finally, two numerical experiments are performed to support the theoretical development in this paper. 展开更多
关键词 Cramér-Rao Bound(CRB) DISJOINT sources General framework Performance analysis Sensor position refinement SOURCE localization WEIGHTED LEAST-SQUARES
Radial Operators on the Weighted Bergman Spaces over the Polydisk
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作者 Ran LI Yu Feng LU 《数学学报:英文版》 SCIE CSCD 2019年第2期227-238,共12页
In this paper, we study radial operators in Toeplitz algebra on the weighted Bergman spaces over the polydisk by the(m, λ)-Berezin transform and find that a radial operator can be approximated in norm by Toeplitz ope... In this paper, we study radial operators in Toeplitz algebra on the weighted Bergman spaces over the polydisk by the(m, λ)-Berezin transform and find that a radial operator can be approximated in norm by Toeplitz operators without any conditions. We prove that the compactness of a radial operator is equivalent to the property of vanishing of its(0, λ)-Berezin transform on the boundary. In addition, we show that an operator S is radial if and only if its(m, λ)-Berezin transform is a separately radial function. 展开更多
关键词 RADIAL OPERATORS (m λ)-Berezin transform weighted BERGMAN SPACES TOEPLITZ OPERATORS
Management of Control Impacts Based on Maximizing the Spread of Influence
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作者 Alexander Tselykh Vladislav Vasilev Larisa Tselykh 《国际自动化与计算杂志:英文版》 EI CSCD 2019年第3期341-353,共13页
The choice of fulcrums for control of socio-economic systems represented by direc ted weighted signed graphs is a topic of current interest.This article proposes a new method for identifying nodes of impact and influe... The choice of fulcrums for control of socio-economic systems represented by direc ted weighted signed graphs is a topic of current interest.This article proposes a new method for identifying nodes of impact and influential nodes,which will provide a guaranteed positive system response over the growth model.The task is posed as an optimization problem to maximize the ratio of the norms of the accumulated increments of the growth vector and the exogenous impact vector.The algorithm is reduced to solving a quadratic programming problem with nonlinear restrictions.The selection of the most effective vertices is based on the cumulative gains of the component projections onto the solution vector.Numerical examples arc provided to illustrate the effectiveness of the proposed method. 展开更多
关键词 Directed WEIGHTED GRAPHS CONTROL impact SPREAD of INFLUENCE optimization algorithm growth model
The Interctitical Defocusing Nonlinear Schrodinger Equations with Radial Initial Data in Dimensions Four and Higher 预览
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作者 Chuanwei Gao Changxing Miao Jianwei Yang-Urbain 《分析理论与应用:英文刊》 CSCD 2019年第2期205-234,共30页
In this paper,we consider the defocusing nonlinear Schrodinger equation in space dimensions d≥4.We prove that if u is a radial solution which is priori bounded inthe critical Sobolev space,that is,u L∈Lt^∞Hx^Sc,the... In this paper,we consider the defocusing nonlinear Schrodinger equation in space dimensions d≥4.We prove that if u is a radial solution which is priori bounded inthe critical Sobolev space,that is,u L∈Lt^∞Hx^Sc,then u is global and scatters.In practise,we use weighted Strichartz space adapted for our setting which ultimately helps us solve the problems in cases d≥4 and 0<sc<1/2 The results in this paper extend the work of[27,Commun.PDEs,40(2015),265-308]to higher dimensions. 展开更多
关键词 Nonlinear SCHRODINGER equation SCATTERING frequency-localized Morawetz estimae WEIGHTED Strichartz space
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Impact of one satellite outage on ARAIM depleted constellation configurations
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作者 Qian MENG Jianye LIU +2 位作者 Qinghua ZENG Shaojun FENG Rui XU 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第4期967-977,共11页
Advanced Receiver Autonomous Integrity Monitoring(ARAIM) is a new technology that will provide worldwide coverage of vertical guidance in aviation navigation. The ARAIM performance and improvement under depleted const... Advanced Receiver Autonomous Integrity Monitoring(ARAIM) is a new technology that will provide worldwide coverage of vertical guidance in aviation navigation. The ARAIM performance and improvement under depleted constellations is a practical problem that needs to be faced and researched further. It is a shortcut that improves the availability in position domain whose key idea is to replace the conventional least squares process with a non-least-squares estimator to lower the integrity risk in exchange for a slight increase in nominal position error. The contributions given in this paper include two parts: First, the impacts of one satellite outage on different constellations are analyzed and compared. The conclusion is that GPS is more sensitive and vulnerable to one satellite outage. Second, a constellation weighted ARAIM(CW-ARAIM)position estimator is proposed. The position solution is replaced by a constellation weighted average solution to eliminate the constellation difference. The new solution will move close to the constellation solutions with respect to the accuracy requirement. The simulation results under baseline GPS and Galileo dual-constellation show that the one GPS satellite outage will knock the availability from 91% to only 50%. The performance remains stable with one Galileo satellite outage. With the assistance of the CW-ARAIM method, the availability can increase from 50% to more than80% under depleted GPS configurations. Even without any satellite outage, the proposed method can effectively improve the availability from 91.29% to 98.75%. The test results under optimistic constellations further verify that a balanced constellation is more important than more satellites on orbit and the superiority of CW-ARAIM method is still effective. 展开更多
关键词 Advanced receiver autonomous integrity monitoring Depleted CONSTELLATION ONE SATELLITE OUTAGE Position ESTIMATOR Weighted solution
优化加权多视角K-means聚类算法 预览
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作者 贺艳芳 梁书田 《计算机技术与发展》 2019年第3期81-84,共4页
现存的多视角聚类算法能够充分利用多个视角的信息进行聚类,因而其聚类效果较单视角聚类算法更优,但是绝大多数多视角聚类算法在聚类过程中为各个视角赋予了同等的权重值,这对于划分不明确的视角,会严重影响聚类的最终结果。目前的加权K... 现存的多视角聚类算法能够充分利用多个视角的信息进行聚类,因而其聚类效果较单视角聚类算法更优,但是绝大多数多视角聚类算法在聚类过程中为各个视角赋予了同等的权重值,这对于划分不明确的视角,会严重影响聚类的最终结果。目前的加权K-means聚类算法在面对多视角聚类任务时,能解决上述权重的取值分配问题,但其权重在迭代过程中会出现除以零错误,造成相关视角的丢失。针对这个问题,提出了一种优化加权多视角K-means聚类算法(MKSC)。该算法给每个视角分配权重,利用加权策略有效地控制各个视角的重要程度,通过引入常数对每个视角的权重进行优化,使用K-means进行聚类。通过基于人工数据集和真实数据集的实验对该算法进行验证,实验结果表明该算法较已有的多视角聚类技术具有更好的聚类性能。 展开更多
关键词 加权 优化 多视角 聚类 K-MEANS
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Vehicle Ego-Localization Based on Streetscape Image Database Under Blind Area of Global Positioning System
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作者 周经美 赵祥模 +2 位作者 程鑫 徐志刚 赵怀鑫 《上海交通大学学报:英文版》 EI 2019年第1期122-129,共8页
Vehicle positioning is critical for inter-vehicle communication, navigation, vehicle monitoring and tracking. They are regarded as the core technology ensuring safety in everyday-driving. This paper proposes an enhanc... Vehicle positioning is critical for inter-vehicle communication, navigation, vehicle monitoring and tracking. They are regarded as the core technology ensuring safety in everyday-driving. This paper proposes an enhanced vehicle ego-localization method based on streetscape image database. It is most useful in the global positioning system(GPS) blind area. Firstly, a database is built by collecting streetscape images, extracting dominant color feature and detecting speeded up robust feature(SURF) points. Secondly, an image that the vehicle shoots at one point is analyzed to find a matching image in the database by dynamic programming(DP)matching. According to the image similarity, several images with higher probabilities are selected to realize coarse positioning. Finally, different weights are set to the coordinates of the shooting location with the maximum similarity and its 8 neighborhoods according to the number of matching points, and then interpolating calculation is applied to complete accurate positioning. Experimental results show that the accuracy of this study is less than 1.5 m and its running time is about 3.6 s. These are basically in line with the practical need. The described system has an advantage of low cost, high reliability and strong resistance to signal interference, so it has a better practical value as compared with visual odometry(VO) and radio frequency identification(RFID) based approach for vehicle positioning in the case of GPS not working. 展开更多
关键词 VEHICLE ego-localization global positioning system(GPS) blind area DOMINANT color dynamic programming(DP) matching weighted INTERPOLATION
On Tubular Tilting Objects in the Stable Category of Vector Bundles
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作者 Jian Min CHEN Ya Nan LIN Shi Quan RUAN 《数学学报:英文版》 SCIE CSCD 2019年第4期494-512,共19页
The present paper focuses on the study of the stable category of vector bundles for the weighted projective lines of weight triple. We find some important triangles in this category and use them to construct tilting o... The present paper focuses on the study of the stable category of vector bundles for the weighted projective lines of weight triple. We find some important triangles in this category and use them to construct tilting objects with tubular endomorphism algebras for the case of genus one via cluster tilting theory. 展开更多
关键词 TILTING SHEAF weighted PROJECTIVE line stable CATEGORY cluster CATEGORY TUBULAR ALGEBRA
Compactness for the commutators of multilinear singular integral operators with non-smooth kernels 预览
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作者 BU Rui CHEN Jie-cheng 《高校应用数学学报:英文版(B辑)》 SCIE CSCD 2019年第1期55-75,共21页
In this paper,the behavior for commutators of a class of bilinear singular integral operators associated with non-smooth kernels on the product of weighted Lebesgue spaces is considered.By some new maximal functions t... In this paper,the behavior for commutators of a class of bilinear singular integral operators associated with non-smooth kernels on the product of weighted Lebesgue spaces is considered.By some new maximal functions to control the commutators of bilinear singular integral operators and CMO(Rn)functions,compactness for the commutators is proved. 展开更多
关键词 singular integral OPERATOR maximal function weighted norm inequality COMMUTATOR compact OPERATOR
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Combining Environmental Factors and Lab VNIR Spectral Data to Predict SOM by Geospatial Techniques 预览
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作者 GUO Long ZHANG Haitao +1 位作者 CHEN Yiyun QIAN Jing 《中国地理科学:英文版》 SCIE CSCD 2019年第2期258-269,共12页
Soil organic matter(SOM) is an important parameter related to soil nutrient and miscellaneous ecosystem services. This paper attempts to improve the performance of traditional partial least square regression(PLSR) mod... Soil organic matter(SOM) is an important parameter related to soil nutrient and miscellaneous ecosystem services. This paper attempts to improve the performance of traditional partial least square regression(PLSR) model by considering the spatial autocorrelation and soil forming factors. Surface soil samples(n = 180) were collected from Honghu City located in the middle of Jianghan Plain, China. The visible and near infrared(VNIR) spectra and six environmental factors(elevation, land use types, roughness, relief amplitude, enhanced vegetation index, and land surface water index) were used as the auxiliary variables to construct the multiple linear regression(MLR), PLSR and geographically weighted regression(GWR) models. Results showed that: 1) the VNIR spectra can increase about 39.62% prediction accuracy than the environmental factors in predicting SOM;2) the comprehensive variables of VNIR spectra and the environmental factors can improve about 5.78% and 44.90% relative to soil spectral models and soil environmental models, respectively;3) the spatial model(GWR) can improve about 3.28% accuracy than MLR and PLSR. Our results suggest that the combination of spectral reflectance and the environmental variables can be used as the suitable auxiliary variables in predicting SOM, and GWR is a promising model for predicting soil properties. 展开更多
关键词 VISIBLE near infrared spectral reflectance environmental factors spatial characteristics partial least SQUARES regression geographically weighted regression
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Total least-squares EIO model,algorithms and applications
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作者 Xingsheng Deng Ge Liu +1 位作者 Tao Zhou Sichun Peng 《大地测量与地球动力学:英文版》 2019年第1期17-25,共9页
A functional model named EIO(Errors-In-Observations) is proposed for general TLS(total least-squares)adjustment. The EIO model only considers the correction of the observation vector, but doesn’t consider to correct ... A functional model named EIO(Errors-In-Observations) is proposed for general TLS(total least-squares)adjustment. The EIO model only considers the correction of the observation vector, but doesn’t consider to correct all elements in the design matrix as the EIV(Errors-In-Variables) model does, furthermore, the dimension of cofactor matrix is much smaller. Iterative algorithms for the parameter estimation and their precise covariance matrix are derived rigorously, and the computation steps are also presented. The proposed approach considers the correction of the observations in the coefficient matrix, and ensures their agreements in every matrix elements. Parameters and corrections can be solved at the same time.An approximate solution and a precise solution of the covariance matrix can be achieved by corresponding algorithms. Applications of EIO model and the proposed algorithms are demonstrated with several examples. The results and comparative studies show that the proposed EIO model and algorithms are feasible and reliable for general adjustment problems. 展开更多
关键词 ERRORS-IN-VARIABLES Errors-In-Observations WEIGHTED total least square Parameter estimation ITERATIVE COVARIANCE solution
Weighted Least Squares Method for the Accelerated Failure Time Model with Auxiliary Covariates
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作者 Ling Hui JIN Yan Yan LIU Lang WU 《数学学报:英文版》 SCIE CSCD 2019年第7期1163-1178,共16页
This paper deals with the analysis of accelerated failure time model when the primary covariate is subject to missing. We assume that the true covariate is measured precisely on a randomly chosen validation set, where... This paper deals with the analysis of accelerated failure time model when the primary covariate is subject to missing. We assume that the true covariate is measured precisely on a randomly chosen validation set, whereas auxiliary information for primary covariate is available to all study subjects. The asymptotic properties for the proposed estimator are developed and the simulation studies show that the efficiency gain is remarkable compared to the method using only the validation sample. A real example is also provided as an illustration. 展开更多
关键词 Survival analysis ACCELERATED failure time model AUXILIARY COVARIATES validation SAMPLE WEIGHTED least SQUARES estimation
Existence and stability of invasion traveling waves for a competition system with random vs.nonlocal dispersals
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作者 Jiao Wang Zhixian Yu Yanling Meng 《生物数学学报:英文版》 2019年第1期71-91,共21页
The purpose of this paper is to investigate asymptotic behaviors of the solutions for a competition system with random vs.nonlocal dispersal.We first prove the existence of invasion traveling waves via using the theor... The purpose of this paper is to investigate asymptotic behaviors of the solutions for a competition system with random vs.nonlocal dispersal.We first prove the existence of invasion traveling waves via using the theory of asymptotic speeds of spread.Then we prove the invasion traveling waves are exponentially stable as perturbation in some exponentially weighted spaces by using the weighted energy and the squeezing technique. 展开更多
关键词 EXISTENCE STABILITY COMPETITIVE system comparison PRINCIPLE WEIGHTED energy
Joint Subcarrier and Power Allocation for Multi-UAV Systems 预览
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作者 Xin Guan Yang Huang Qingjiang Shi 《中国通信:英文版》 SCIE CSCD 2019年第1期47-56,共10页
This paper investigates subcarrier and power allocation in a multi-UAV OFDM system.The study considers a practical scenario,where certain subcarriers are unavailable for dynamic subcarrier allocation,on account of pre... This paper investigates subcarrier and power allocation in a multi-UAV OFDM system.The study considers a practical scenario,where certain subcarriers are unavailable for dynamic subcarrier allocation,on account of pre-allocation for burst transmissions.We first propose a novel iterative algorithm to jointly optimize subcarrier and power allocation,so as to maximize the sum rate of the uplink transmission in the multi-UAV OFDM system.The key idea behind our solution is converting the nontrivial allocation problem into a weighted mean square error(MSE)problem.By this means,the allocation problem can be solved by the alternating optimization method.Besides,aiming at a lower-complexity solution,we propose a heuristic allocation scheme,where subcarrier allocation and transmit power allocation are separately optimized.In the heuristic scheme,closedform solution can be obtained for power allocation.Simulation results demonstrate that in the presence of stretched subcarrier resource,the proposed iterative joint optimization algorithm can significantly outperform the heuristic scheme,offering a higher sum rate. 展开更多
关键词 MULTI-UAV OFDM SUBCARRIER ALLOCATION power ALLOCATION ALTERNATING optimization weighted MSE
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On Compressible Smooth Viscous Fluids in Slowly Expanding Balls 预览
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作者 Huicheng Yin Lin Zhang 《分析理论与应用:英文刊》 CSCD 2019年第1期28-65,共38页
In[17]and[19,20],the global existence and large time behaviors of smooth compressible fluids(including inviscid gases of Euler equations,viscous gases of Navier-Stokes equations,and rarified gases of Boltzmann equatio... In[17]and[19,20],the global existence and large time behaviors of smooth compressible fluids(including inviscid gases of Euler equations,viscous gases of Navier-Stokes equations,and rarified gases of Boltzmann equation,respectively)have been established in an infinitely expanding ball with a constant expansion speed.This paper concerns with the viscous fluids in a slowly expanding ball.By involved analy-sis on the density function and the weighted energy estimates,we show that the fluid in the slowly expanding ball smoothly tends to a vacuum state and there is no appearance of vacuum in any part of the expansive ball.Our present result is a meaningful supplement to the one in[19]. 展开更多
关键词 COMPRESSIBLE NAVIER-STOKES equations slowly EXPANDING ball weighted energy ESTIMATE global existence
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Differential Diagnostic Value of Texture Feature Analysis of Magnetic Resonance T2 Weighted Imaging between Glioblastoma and Primary Central Neural System Lymphoma 预览
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作者 Botao Wang Mingxia Liu Zhiye Chen 《中国医学科学杂志:英文版》 CAS CSCD 2019年第1期10-17,共8页
Objective To investigate the difference in tumor conventional imaging findings and texture features on T2 weighted images between glioblastoma and primary central neural system (CNS) lymphoma. Methods The pre-operativ... Objective To investigate the difference in tumor conventional imaging findings and texture features on T2 weighted images between glioblastoma and primary central neural system (CNS) lymphoma. Methods The pre-operative MRI data of 81 patients with glioblastoma and 28 patients with primary CNS lymphoma admitted to the Chinese PLA General Hospital and Hainan Hospital of Chinese PLA General Hospital were retrospectively collected. All patients underwent plain MR imaging and enhanced T1 weighted imaging to visualize imaging features of lesions. Texture analysis of T2 weighted imaging (T2WI) was performed by use of GLCM texture plugin of ImageJ software, and the texture parameters including Angular Second Moment (ASM), Contrast, Correlation, Inverse Difference Moment (IDM), and Entropy were measured. Independent sample t-test and Mann-Whitney U test were performed for the between-group comparisons, regression model was established by Binary Logistic regression analysis, and receiver operating characteristic (ROC) curve was plotted to compare the diagnostic efficacy. Results The conventional imaging features including cystic and necrosis changes (P=0.000),‘Rosette’ changes (P=0.000) and ‘incision sign’(P=0.000), except ‘flame-like edema’(P=0.635), presented significantly statistical difference between glioblastoma and primary CNS lymphoma. The texture features, ASM, Contrast, Correlation, IDM and Entropy, showed significant differences between glioblastoma and primary CNS lympoma (P=0.006,0.000, 0.002, 0.000, and 0.015 respectively). The area under the ROC curve was 0.671, 0.752, 0.695, 0.720 and 0.646 respectively, and the area under the ROC curve was 0.917 for the combined texture variables (Contrast, cystic and necrosis,‘Rosette’ changes, and ‘incision sign’) in the model of Logistic regression. Binary Logistic regression analysis demonstrated that cystic and necrosis changes,‘Rosette’ changes and ‘incision sign’ and texture Contrast could be considered as the specific texture variables f 展开更多
关键词 GLIOBLASTOMA primary central NEURAL system LYMPHOMA texture analysis T2 WEIGHTED imaging DIFFERENTIAL diagnosis
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Diffusion kurtosis imaging of microstructural changes in brain tissue affected by acute ischemic stroke in different locations 预览
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作者 Liu-Hong Zhu Zhong-Ping Zhang +2 位作者 Fu-Nan Wang Qi-Hua Cheng Gang Guo 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第2期272-279,共8页
The location of an acute ischemic stroke is associated with its prognosis. The widely used Gaussian model-based parameter, apparent diffusion coefficient (ADC), cannot reveal microstructural changes in different locat... The location of an acute ischemic stroke is associated with its prognosis. The widely used Gaussian model-based parameter, apparent diffusion coefficient (ADC), cannot reveal microstructural changes in different locations or the degree of infarction. This prospective observational study was reviewed and approved by the Institutional Review Board of Xiamen Second Hospital, China (approval No. 2014002). Diffusion kurtosis imaging (DKI) was used to detect 199 lesions in 156 patients with acute ischemic stroke (61 males and 95 females), mean age 63.15 ± 12.34 years. A total of 199 lesions were located in the periventricular white matter (n = 52), corpus callosum (n = 14), cerebellum (n = 29), basal ganglia and thalamus (n = 21), brainstem (n = 21) and gray-white matter junctions (n = 62). Percentage changes of apparent diffusion coefficient (ΔADC) and DKI-derived indices (fractional anisotropy [ΔFA], mean diffusivity [ΔMD], axial diffusivity [ΔDa], radial diffusivity ΔDr, mean kurtosis [ΔMK], axial kurtosis [ΔKa], and radial kurtosis [ΔKr]) of each lesion were computed relative to the normal contralateral region. The results showed that (1) there was no significant difference in ΔADC, ΔMD, ΔDa or ΔDr among almost all locations. (2) There was significant difference in ΔMK among almost all locations (except basal ganglia and thalamus vs. brain stem; basal ganglia and thalamus vs. gray-white matter junctions; and brainstem vs. gray-white matter junctions. (3) The degree of change in diffusional kurtosis in descending order was as follows: corpus callosum > periventricular white matter > brainstem > gray-white matter junctions > basal ganglia and thalamus > cerebellum. In conclusion, DKI could reveal the differences in microstructure changes among various locations affected by acute ischemic stroke, and performed better than diffusivity among all groups. 展开更多
关键词 nerve REGENERATION apparent DIFFUSION coefficient DIFFUSION weighted IMAGING DIFFUSION KURTOSIS IMAGING acute ISCHEMIC stroke mean KURTOSIS microstructure changes white matter 1.5 TESLA magnetic resonance system neural REGENERATION
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Integrated Trojan detecting model based on period feature statistics
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作者 Zhang Jinling LüLei 《中国邮电高校学报:英文版》 EI CSCD 2019年第1期32-39,共8页
Aiming at the problem that more popular network application and more complicated network traffic bring big challenge to current Trojan detecting technique, communication behavior of remote access Trojan(RAT) is analyz... Aiming at the problem that more popular network application and more complicated network traffic bring big challenge to current Trojan detecting technique, communication behavior of remote access Trojan(RAT) is analyzed, traffic features’ different performance in different communication sub-periods is discussed, and an integrated Trojan detecting model based on period feature statistics is presented. Feature statistics based on sub-periods and whole session(WS) respectively can increase the gap and classification ability of traffic features. The weighted integrated classifier can take full use of each base classifier’s advantage and compensate for each other’s weaknesses, therefore can strong system’s detecting and generalization capability. Experiment result shows that this system can recognize Trojan traffics from many kinds of normal traffic effectively. 展开更多
关键词 TROJAN detecting RAT WEIGHTED VOTING INTEGRATED system
Exploring evolutionary features of directed weighted hazard network in the subway construction
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作者 侯公羽 靳聪 +2 位作者 许哲东 于萍 曹怡怡 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第3期399-407,共9页
A better understanding of previous accidents is an effective way to reduce the occurrence of similar accidents in the future. In this paper, a complex network approach is adopted to construct a directed weighted hazar... A better understanding of previous accidents is an effective way to reduce the occurrence of similar accidents in the future. In this paper, a complex network approach is adopted to construct a directed weighted hazard network(DWHN) to analyze topological features and evolution of accidents in the subway construction. The nodes are hazards and accidents, the edges are multiple relationships of these nodes and the weight of edges are occurrence times of repetitive relationships. The results indicate that the DWHN possesses the property of small-world with small average path length and large clustering coefficient, indicating that hazards have better connectivity and will spread widely and quickly in the network. Moreover,the DWHN has the property of scale-free network for the cumulative degree distribution follows a power-law distribution.It makes DWHN more vulnerable to target attacks. Controlling key nodes with higher degree, strength and betweenness centrality will destroy the connectivity of DWHN and mitigate the spreading of accidents in the network. This study is helpful for discovering inner relationships and evolutionary features of hazards and accidents in the subway construction. 展开更多
关键词 accident analysis directed WEIGHTED NETWORK complex NETWORK EVOLUTIONARY FEATURES
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