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Inequalities for Scalar Curvature and Shape Operator of an R-Lightlike Submanifold in Semi-Riemannian Manifold
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作者 Menedore Karimumuryango Domitien Ndayirukiye +2 位作者 Hans-Fotsing Tetsing Gilbert Nibaruta Aboubacar Nibirantiza 《Journal of Applied Mathematics and Physics》 2023年第7期1895-1913,共19页
We establish the links between the lightlike geometry and basics invariants of the associated semi-Riemannian geometry on r-lightlike submanifold and semi-Riemannian constructed from a semi-Riemannian ambient. Then we... We establish the links between the lightlike geometry and basics invariants of the associated semi-Riemannian geometry on r-lightlike submanifold and semi-Riemannian constructed from a semi-Riemannian ambient. Then we establish some basic inequalities, involving the scalar curvature and shape operator on r-lightlike coisotropic submanifold in semi-Riemannian manifold. Equality cases are also discussed. 展开更多
关键词 semi-Riemannian Submanifold SUBMANIFOLD RIGGING Closed normalization Associated semi-Riemannian Metric
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Semi-LC/MS技术快速定量分析黄芪样品中黄芪甲苷含量 被引量:3
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作者 郑重 宋凤瑞 +3 位作者 刘舒 赵先恩 刘志强 刘淑莹 《质谱学报》 EI CAS CSCD 北大核心 2012年第4期208-211,共4页
为了测定黄芪中的黄芪甲苷含量,应用半高效液相色谱-质谱串联技术(Semi-LC/MS),以薯蓣皂苷为内标化合物,仅用一段色谱保护柱分离掉大部分干扰性成分,同时使目标化合物富集,采用Waters公司的多反应监测(MRM)扫描模式检测。结果表明:黄芪... 为了测定黄芪中的黄芪甲苷含量,应用半高效液相色谱-质谱串联技术(Semi-LC/MS),以薯蓣皂苷为内标化合物,仅用一段色谱保护柱分离掉大部分干扰性成分,同时使目标化合物富集,采用Waters公司的多反应监测(MRM)扫描模式检测。结果表明:黄芪甲苷在2.85~57.0mg/L的范围内线性关系良好,稳定性和重复性实验RSD<3%,样品回收率达98.9%。Semi-LC/MS方法可以对黄芪样品中黄芪甲苷进行快速定量分析,是一种黄芪甲苷的简单、高效、灵敏的定量检测方法。 展开更多
关键词 黄芪甲苷 半高效液相色谱-质谱串联技术(semi—LC/MS) 多反应监测(MRM) 定量分析
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基于中心损失-改进卷积自编码器的滚动轴承半监督故障诊断 被引量:3
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作者 齐咏生 巩育瑞 +2 位作者 高胜利 刘利强 李永亭 《振动与冲击》 EI CSCD 北大核心 2023年第7期301-311,共11页
当前基于深度学习的旋转机械故障诊断技术,凭借其强大的逐层加工和内置特征变换功能受到广泛关注,然而传统用于故障诊断的深度网络需要大量标签数据,且诊断结果依赖于标签的数量和准确性。为此,提出一种基于中心损失-改进卷积自编码器(c... 当前基于深度学习的旋转机械故障诊断技术,凭借其强大的逐层加工和内置特征变换功能受到广泛关注,然而传统用于故障诊断的深度网络需要大量标签数据,且诊断结果依赖于标签的数量和准确性。为此,提出一种基于中心损失-改进卷积自编码器(center loss-improved convolutional auto-encoder, CL-ICAE)的半监督故障诊断方法。该方法首先利用连续小波变换将故障信号转换为时频图,细化故障特征表征;之后构建改进的卷积自编码器网络结构,并引入批量归一化(batch normalization, BN)和Dropout,在特征提取阶段防止过拟合;之后在分类阶段,通过将中心损失(center loss)引入Softmax损失函数,构建联合损失函数,使故障特征实现类内距离更小,特征差异更大,进一步提高分类精度。最后,将所提方法通过凯斯西储大学轴承数据集和轴承故障试验平台进行验证,结果表明在少量标签样本情况下,均可实现有效的故障诊断,提升诊断准确率。 展开更多
关键词 滚动轴承 卷积自编码器 半监督 批量归一化(BN) 中心损失(CL)
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Transfer theorems for fuzzy semi-groups
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作者 吴从炘 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2000年第3期19-23,共5页
Discusses the use of the notion of fuzzy point to study some basic algebraic structures, such as group, semi group and ideal and then clarifies the links between the fuzzy point approach and the classical fuzzy approach.
关键词 FUZZY point FUZZY semi group FUZZY normal SUBGROUP FUZZY IDEAL FUZZY bi IDEAL FUZZY interior IDEAL FUZZY semi PRIMALITY and FUZZY prime IDEAL
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Strong convergence theorems for nonexpansive semi-groups in Banach spaces 被引量:2
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作者 张石生 杨莉 柳京爱 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第10期1287-1297,共11页
Some strong convergence theorems of explicit composite iteration scheme for nonexpansive semi-groups in the framework of Banach spaces are established. Results presented in the paper not only extend and improve the co... Some strong convergence theorems of explicit composite iteration scheme for nonexpansive semi-groups in the framework of Banach spaces are established. Results presented in the paper not only extend and improve the corresponding results of ShiojiTakahashi, Suzuki, Xu and Aleyner-Reich, but also give a partially affirmative answer to the open questions raised by Suzuki and Xu. 展开更多
关键词 nonexpansive semi-group demi-closed principle common fixed point uni-formly smooth Banach space weakly continuous normalized duality mapping
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Decomposition Theorems for Semi-order Fuzzy Supermartingales and Submartingales
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作者 冯玉瑚 《Journal of China Textile University(English Edition)》 EI CAS 2000年第2期96-99,共4页
Based on semi - order fuzzy supermaringales andsubmartingales, the semi- order fuzzy supermartingaleand submartingale theory is developed. The main resultis to generalize the Doob decomposition and the Riesz de-compos... Based on semi - order fuzzy supermaringales andsubmartingales, the semi- order fuzzy supermartingaleand submartingale theory is developed. The main resultis to generalize the Doob decomposition and the Riesz de-composition theorems of standard martingale theory tosemi - order fuzzy supermaringales and submartingales.The structure of semi - order fuzzy supermaringales andsubmartingales and the conditions of that they has Doobdecomposition (resp. Riesz decomposition) are discussedin detail. 展开更多
关键词 semi - order FUZZY SUPERMARTINGALE submartin-gale Doob DECOMPOSITION RIESZ DECOMPOSITION .
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COMPLETE SPACE-LIKE SUBMANIFOLDS IN LOCALLY SYMMETRIC SEMI-DEFINITE SPACES
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作者 XuSenlin ChenDongmei 《Analysis in Theory and Applications》 2004年第4期383-390,共8页
The purpose of this paper is to study complete space-like submanifolds with parallel mean curvature vector and flat normal bundle in a locally symmetric semi-defnite space satisfying some curvature conditions. We firs... The purpose of this paper is to study complete space-like submanifolds with parallel mean curvature vector and flat normal bundle in a locally symmetric semi-defnite space satisfying some curvature conditions. We first give an optimal estimate of the Laplacian of the squared norm of the second fundamental form for such submanifold. Furthermore, the totally umbilical submanifolds are characterized. 展开更多
关键词 space-like submanifolds constant mean curvature flat normal bundle second fundamental form locally symmetric semi-definite space
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Study of Changing Features of Precipitation from 1900-2010 Years in Africa-Asia Arid and Semi-Arid Area
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作者 Xiangkun Cheng Hang Cheng +1 位作者 Guowu Sun Xiaomeng Shi 《Journal of Geoscience and Environment Protection》 2017年第1期62-72,共11页
The relationship between time-space variation characteristics and the variation of the general atmospheric circulation of rainfall occurred in Asia, Africa through North Africa-Middle East-Western Middle Asia-Eastern ... The relationship between time-space variation characteristics and the variation of the general atmospheric circulation of rainfall occurred in Asia, Africa through North Africa-Middle East-Western Middle Asia-Eastern Middle Asia, Northwest China-Eastern Northwest China-North China and Northeast China is studied based on the analysis of GPCC rainfall data from 1901 to 2010 and annual precipitation in relevant cities of China from 1901 to 2010, and the data of NCEP of surface pressure as well as 500 Hpa potential high from 1950 to 2010. The result shows that the total precipitation presents a decreasing trend in north Africa to the northeast of China in recent 100 years. It has a mutation in 1950s. The precipitation presented a decreasing trend in North Africa and Middle East, in recent 100 years;it presented a further decreasing trend after 1950s. It presented a decreasing trend before 1950s and an increasing trend after 1950s in Middle Asia and Northwest china. It also presented a decreasing trend before 1950s and an increasing trend between 1950s to 1990s, and decreased later in Eastern Northwest China, North China and Northeast China which also presented in a more or less period in different areas from North Africa to Northeast China. The beginning of less precipitation years and less period occurred after it presented less period in north Africa in time and space. After it moved to the east areas as the year past, at last, the SLPA fields which presented more or less precipitations of years from North Africa to Northeast China were analyzed. It also shows that the SLPA fields which presented more were beneficial to the precipitations and presented negative effects of precipitations in the polar, high and mid- and lower latitudes. 展开更多
关键词 Asia-Africa ARID and semi-ARID Region RAINFALL above or below the normal PRECIPITATION Sea Lever Pressure ANOMALIES
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Land Characterization Analysis of Surface Temperature of Semi-Arid Mountainous City Abha, Saudi Arabia Using Remote Sensing and GIS
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作者 Javed Mallick 《Journal of Geographic Information System》 2014年第6期664-676,共13页
This knowledge of land surface temperature and its spatial variations within a city environment is of prime importance to the study of urban climate and human-environment interactions. Few studies have examined the in... This knowledge of land surface temperature and its spatial variations within a city environment is of prime importance to the study of urban climate and human-environment interactions. Few studies have examined the influence of land use and terrain on the surface temperature effects of semi-arid mountainous urban areas. This study investigates the urban environment characterization and its effects on surface temperature using remote sensing. The methodologies adapted for this study are geometric and radiometric corrections of satellite data, extraction of land use/land cover and digital elevation model, estimation of vegetation density using Normalized Difference Vegetation Index (NDVI), and estimation of surface temperature and emissivity using temperature emissivity separation (TES) algorithm. Finally geospatial model and statistical techniques are used for assessing the overall impact of urban environmental characterization on urban climate of semi-arid region of Abha, Kingdom of Saudi Arabia. Herein, results reveal that the spatial distribution of surface temperature was affected by land use/land cover (LULC) and topography. The high dense built-up and commercial/industrial areas display higher surface temperature in comparison with surrounding lands. There is gradual decrease of LULC classes’ surface temperature with the increase in altitude. The cooling effect towards the surrounding urban built-up area is found increasing at the hill located vegetated area, the downward slope and valley terrain inside the recreational park. Therefore the spatial variation in surface temperature also reflected the effects of topography on LULC classes. Suitable mountainous land use utilization would help to expand the cooling effect. In the future, the outcomes of this study could be used to build environmentally sustainable urban planning suitable to semi-arid regions and to create practices that consider the local weather environment in urban planning. 展开更多
关键词 LAND Surface Temperature LAND Use/Land COVER normalized DIFFERENCE VEGETATION Index Mountainous semi-ARID CITY GIS
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Test of Normality of Waist Measurement Data of Young Male and Female Adults based on the Quantile - Quantile Plot
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作者 F. Z. Okwonu J. N. Igabari 《Journal of Statistical Science and Application》 2017年第3期118-126,共9页
This paper investigates the normality of some real data set obtained from waist measurements of a group of 49 young adults. The quantile - quantile (Q-Q) plot and the analysis of correlation coefficients for the Q-Q... This paper investigates the normality of some real data set obtained from waist measurements of a group of 49 young adults. The quantile - quantile (Q-Q) plot and the analysis of correlation coefficients for the Q-Q plot is used to determine the normality or otherwise of the data set. In this regards, the probabilities of the quantiles were computed, modified and plotted. Thereafter the correlation coefficients for the quantile - quantile plots were obtained. Results indicate that at 0.1 level of significance, the data for young adult males of the sample were not normally distributed, and had a mean value that is within the range of low risk, healthwise, whereas the distribution of the data for young female adults showed reasonable normality, but also with a mean value that is within the range of low risk in terms of health condition. 展开更多
关键词 Correlation coefficient probability plot quantile - quantile plot test of normality waist measurement young adults.
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M.A. AND PH.D. DISSERTATIONS 1994-95 INSTITUTE FOR THE HISTORY OF ANCIENT CIVILIZATIONS NORTHEAST NORMAL UNIVERSITY, CHANGCHUN
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《Journal of Ancient Civilizations》 1995年第0期155-155,共1页
Ma Xiaoying, Assyriology, Ph.D., 1994.12 "Women’s Social Status in Old Babylonia Reflected in Marital Property" (Supervisors: Professors Lin Zhichun, Thomas Lee, Tova Meltzer, Wu Yuhong) Wang Liying, Cla... Ma Xiaoying, Assyriology, Ph.D., 1994.12 "Women’s Social Status in Old Babylonia Reflected in Marital Property" (Supervisors: Professors Lin Zhichun, Thomas Lee, Tova Meltzer, Wu Yuhong) Wang Liying, Classics, Ph.D., 1995.6 "Sallust’s Bellum Catilinae" (Supervisors: Porfessors Wang Dunshu, P.Ruth Taylor-Briggs, F. Ahlheid, Lin Zhichun) 展开更多
关键词 PH M.A CHANGCHUN DISSERTATIONS 1994-95 INSTITUTE FOR THE HISTORY OF ANCIENT CIVILIZATIONS NORTHEAST normal UNIVERSITY AND PH.D
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M.A. AND PH.D. DISSERTATIONS 1999-2000 INSTITUTE FOR THE HISTORY OF ANCIENT CIVILIZATIONS NORTHEAST NORMAL UNIVERSITY, CHANGCHUN
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《Journal of Ancient Civilizations》 2000年第1期122-122,共1页
关键词 PH AND PH.D CHANGCHUN DISSERTATIONS 1999-2000 INSTITUTE FOR THE HISTORY OF ANCIENT CIVILIZATIONS NORTHEAST normal UNIVERSITY
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First assessment of Noise-Equivalent Sigma-Zero in GF3-02 TOPSAR mode with sea surface wind speed retrieval
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作者 Junxin Yang Lihua Zhong +3 位作者 Xinzhe Yuan Xiaochen Wang Bing Han Yuxin Hu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第10期84-96,共13页
Gaofen-3-02(GF3-02)is the first C-band synthetic aperture radar(SAR)satellite with terrain observation with progressive scans of SAR(TOPSAR)imaging mode in China,which plays an essential role in marine environment mon... Gaofen-3-02(GF3-02)is the first C-band synthetic aperture radar(SAR)satellite with terrain observation with progressive scans of SAR(TOPSAR)imaging mode in China,which plays an essential role in marine environment monitoring.Given the weak scattering characteristics of the ocean,the system thermal noise superimposed on SAR images has significant interference,especially in cross-polarization channels.Noise-Equivalent Sigma-Zero(NESZ)is a measure of the sensitivity of the radar to areas of low backscatter.The NESZ is defined to be the scattering cross-section coefficient of an area which contributes a mean level in the image equal to the signal-independent additive noise level.For TOPSAR,NESZ exhibits the shape of the SAR scanning gain curve in the azimuth and the shape of the antenna pattern in the range.Therefore,the accurate measurement of NESZ plays a vital role in the application of spaceborne SAR sea surface cross-polarization data.This paper proposes a theoretical calculation method for the NESZ curve in GF3-02 TOPSAR mode based on SAR noise inner calibration data and the imaging algorithm.A method for correcting the error existing in the theoretical curve of NESZ is also proposed according to the relationship between sea surface backscattering and wind speed and the same characteristics of target scattering in the overlapping area of adjacent sub-swaths.According to assessment with wide-swath TOPSAR cross-polarization data,the GF3-02 TOPSAR mode has a very low thermal noise level,which is better than−33 dB at the edge of each beam,and controlled below−38 dB at the center of the beam.The two-dimensional reference curves of the NESZ of each beam are provided to the GF3-02 TOPSAR users.After discussing the relationship between normalized radar cross section(NRCS)and wind speed,we provide a formula for NRCS related to wind speed and radar incidence angle.Compared with the NRCS derived from this formula and the NESZ-subtracted NRCS of SAR images,the bias is−0.0048 dB,the Root Mean Square Error is 1.671 dB and the correlation coefficient is 0.939. 展开更多
关键词 GF3-02 TOPSAR Noise-Equivalent Sigma-Zero(NESZ) CROSS-POLARIZATION normalized radar cross section(NRCS) sea surface wind
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基于正则化瑞利系数的半监督k-部排序学习算法及应用 被引量:14
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作者 高炜 梁立 徐天伟 《西南师范大学学报(自然科学版)》 CAS CSCD 北大核心 2014年第4期121-125,共5页
借鉴Ralaivola给出的基于正则化瑞利系数的半监督二部排序学习算法的思想,提出基于正则化瑞利系数的半监督k-部排序学习算法.同时,将此方法运用于本体相似度计算和本体映射.通过两个实验说明新算法是有效的.
关键词 k-部排序算法 半监督学习 正则化瑞利系数 本体
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半正规、C-正规与有限群的超可解性 被引量:2
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作者 唐曾林 李世荣 曾凡辉 《广西科学》 CAS 2007年第1期1-5,共5页
利用半正规或C-正规子群刻划有限群的结构,得到若群G的每个非循环Sylow子群的极大子群在G中或半正规或C-正规,则G超可解.
关键词 半正规 C-正规 超可解 Sylow基
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半正规、C-正规对群超可解性的影响 被引量:3
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作者 曾凡辉 李世荣 《广西科学》 CAS 2003年第3期161-164,168,共5页
利用某些半正规或 C-正规子群刻划有限群的结构 ,得到有限群超可解的若干充分条件 :设有限群 G =AB,其中 A≤ G,B≤ G.若 A与 B的所有 Sylow子群在 G中半正规 ,则 G超可解 ;设 G是有限群 ,N G,G/N超可解 .若 N的所有素数阶子群含于 U(G... 利用某些半正规或 C-正规子群刻划有限群的结构 ,得到有限群超可解的若干充分条件 :设有限群 G =AB,其中 A≤ G,B≤ G.若 A与 B的所有 Sylow子群在 G中半正规 ,则 G超可解 ;设 G是有限群 ,N G,G/N超可解 .若 N的所有素数阶子群含于 U(G) ,且 N的所有 2 2 阶循环子群在 G中或半正规或 C-正规 ,则 G是超可解群 .同时推广了一些已知的结果 . 展开更多
关键词 半正规C-正规超可解 超可解 嵌入子群 Sylow基
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正态总体均值与标准差比在序约束下的广义p-值检验 被引量:2
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作者 李树有 史宁中 张宝学 《应用概率统计》 CSCD 北大核心 2009年第1期77-85,共9页
本文利用广义p-值和U-I检验法研究了多个正态总体均值与标准差比在简单半序和树序约束下的检验问题.提出了广义检验变量,得到了多个正态总体均值与标准差比在简单半序和树序约束下检验问题的广义p-值.同时运用MonteCarlo方法给出了模拟... 本文利用广义p-值和U-I检验法研究了多个正态总体均值与标准差比在简单半序和树序约束下的检验问题.提出了广义检验变量,得到了多个正态总体均值与标准差比在简单半序和树序约束下检验问题的广义p-值.同时运用MonteCarlo方法给出了模拟结果. 展开更多
关键词 广义P- 广义检验变量 U—I检验法 正态总体 半序约束.
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基于截尾分布的永久路面结构可靠度分析
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作者 王国清 张权 +2 位作者 何兆益 秦禄生 邱文利 《重庆交通大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第2期17-23,共7页
为建立基于实测参数变异范围的永久路面结构可靠度分析方法,首先基于概率等效原则和逆变换法建立参数“有界”性的双侧截尾分布随机数抽样方法;然后选取现行沥青路面设计规范中面层、基层和路基结构的验算指标建立极限状态方程并开发多... 为建立基于实测参数变异范围的永久路面结构可靠度分析方法,首先基于概率等效原则和逆变换法建立参数“有界”性的双侧截尾分布随机数抽样方法;然后选取现行沥青路面设计规范中面层、基层和路基结构的验算指标建立极限状态方程并开发多指标可靠度计算程序,将分析结果与理论分布随机变量可靠度程序对比;最后结合实测参数变异性水平,使用建立的可靠度分析方法评估京德高速永久路面结构的工后可靠度。结果表明:截尾分布更符合工程参数的真实分布,计算的可靠度更准确;中等交通荷载等级下,京德高速的路面结构可靠度为95.2%~98.7%;在累计当量轴次失效点后,永久路面结构面层、基层和路基的可靠度值均随轴次的增大而减小,且荷载越大,可靠度值下降速率越快,可靠度也越低。 展开更多
关键词 道路工程 沥青路面可靠度 半刚性基层 截断正态分布 Monte Carlo法 响应面法
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半正规、C-正规与有限群的超可解性 被引量:1
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作者 曾凡辉 李世荣 《广西科学》 CAS 2003年第2期81-85,共5页
把半正规与 C-正规结合起来 ,证明若群 G的每个 Sylow子群的极大子群在 G中或半正规或 C-正规 ,则 G超可解 .并结合半正规与 C-正规的概念得到了有限群超可解的若干充分条件 ,同时推广了一些已知结果 .
关键词 半正规 C—正规 有限群 超可解性 充分条件
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基于改进生成对抗网络的半监督语义分割
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作者 王小成 胡亚琦 王一中 《四川大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第5期99-107,共9页
为了解决对抗式半监督语义分割网络在训练过程中稳定性较差,传统语义分割网络难以对像素之间远距离依赖关系建模等问题,提出了一种结合谱归一化生成对抗网络和坐标注意力机制的半监督语义分割网络.利用谱归一化使对抗网络判别器满足利... 为了解决对抗式半监督语义分割网络在训练过程中稳定性较差,传统语义分割网络难以对像素之间远距离依赖关系建模等问题,提出了一种结合谱归一化生成对抗网络和坐标注意力机制的半监督语义分割网络.利用谱归一化使对抗网络判别器满足利普西茨连续性,从而提高了网络训练过程的稳定性且避免了梯度消失的问题;在分割网络中融入坐标注意力机制,使网络能够获取远距离像素之间的依赖关系,并扩大感受野.与基准模型相比,在PASCAL VOC 2012增强数据集中采用1/50、1/20和1/8标记数据集时,MIoU分别提升了2.2%、1.4%和1.8%;在Cityscapes城市街景数据集中采用1/8、1/4和1/2标记数据集时,MIoU分别提升了1.9%、2.1%和1.3%.实验结果证明,与其他基于对抗学习的半监督语义分割网络相比,该算法在半监督语义分割任务中具有较好的稳定性和准确性. 展开更多
关键词 语义分割 半监督学习 生成对抗网络 谱归一化 注意力机制
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