期刊文献+
共找到54,294篇文章
< 1 2 250 >
每页显示 20 50 100
Intermediate crack initiation during liquid core reduction of regular slabs:ERLS-based 3D simulation with calibrated normalized Cockcroft–Latham criterion
1
作者 Junlong Ju Zhida Zhang +1 位作者 Cheng Ji Miaoyong Zhu 《International Journal of Minerals,Metallurgy and Materials》 2026年第3期861-873,共13页
Liquid core reduction(LCR)technology,originally developed for continuous thin-slab casting,allows space for a submerged entry nozzle in a mold while improving production efficiency.Recent experimental attempts explore... Liquid core reduction(LCR)technology,originally developed for continuous thin-slab casting,allows space for a submerged entry nozzle in a mold while improving production efficiency.Recent experimental attempts explore the implementation of LCR in regular slab casting processes.However,regular slabs(2–3 times thicker than thin slabs)face critical challenges in terms of excessive deformation and stress concentration under external forces,which induce intermediate cracks and thus hinder successful LCR adoption in regular slab production.This study evaluates the feasibility of LCR for producing regular slabs and identifies optimal reduction parameters to prevent crack initiation.A three-dimensional thermal–mechanical coupled model is proposed using the finite element method(FEM),integrated with the equivalent replacement liquid steel(ERLS)method and the normalized Cockcroft–Latham damage model,to achieve quantitative prediction of intermediate crack risk during the LCR process.The ERLS model simulates the extrusion flow and expulsion behavior of the liquid core,and its accuracy is validated against actual production measurements.To identify the critical damage value leading to intermediate crack initiation,this study conducts a consistency analysis between high-temperature tensile tests and FEM-based simulations using damage models.Based on this value,crack prediction is performed for Q355 slabs with cross-sectional dimensions of 170 mm×1450 mm.Using the prediction results,an optimal reduction scheme is determined,wherein the second segment accounts for 50%of the total reduction,the third segment for 32.5%,and the fourth segment for 17.5%,with the theoretical value of maximum reduction being 34 mm.These results provide actionable guidelines for the potential implementation of LCR in regular slab-casting systems. 展开更多
关键词 continuous slab casting liquid core reduction intermediate cracking thermo-mechanical behavior finite element method normalized Cockcroft-Latham damage criterion
在线阅读 下载PDF
Normalized Solutions of Nonlinear Choquard Equations with Nonconstant Potential
2
作者 LI Nan XU Liping 《应用数学》 北大核心 2025年第1期14-29,共16页
In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with ... In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with prescribed 2-norm has some normalized solutions by introducing variational methods. 展开更多
关键词 Nonlinear Choquard equation Potential function Variational method normalized solution
在线阅读 下载PDF
Source apportionment of PM_(2.5) using dispersion normalized positive matrix factorization(DN-PMF)in Beijing and Baoding,China 被引量:1
3
作者 Ilhan Ryoo Taeyeon Kim +6 位作者 Jiwon Ryu Yeonseung Cheong Kwang-joo Moon Kwon-ho Jeon Philip K.Hopke Seung-Muk Yi Jieun Park 《Journal of Environmental Sciences》 2025年第9期395-408,共14页
Fine particulatematter(PM_(2.5))samples were collected in two neighboring cities,Beijing and Baoding,China.High-concentration events of PM_(2.5) in which the average mass concentration exceeded 75μg/m^(3) were freque... Fine particulatematter(PM_(2.5))samples were collected in two neighboring cities,Beijing and Baoding,China.High-concentration events of PM_(2.5) in which the average mass concentration exceeded 75μg/m^(3) were frequently observed during the heating season.Dispersion Normalized Positive Matrix Factorization was applied for the source apportionment of PM_(2.5) as minimize the dilution effects of meteorology and better reflect the source strengths in these two cities.Secondary nitrate had the highest contribution for Beijing(37.3%),and residential heating/biomass burning was the largest for Baoding(27.1%).Secondary nitrate,mobile,biomass burning,district heating,oil combustion,aged sea salt sources showed significant differences between the heating and non-heating seasons in Beijing for same period(2019.01.10–2019.08.22)(Mann-Whitney Rank Sum Test P<0.05).In case of Baoding,soil,residential heating/biomass burning,incinerator,coal combustion,oil combustion sources showed significant differences.The results of Pearson correlation analysis for the common sources between the two cities showed that long-range transported sources and some sources with seasonal patterns such as oil combustion and soil had high correlation coefficients.Conditional Bivariate Probability Function(CBPF)was used to identify the inflow directions for the sources,and joint-PSCF(Potential Source Contribution Function)was performed to determine the common potential source areas for sources affecting both cities.These models facilitated a more precise verification of city-specific influences on PM_(2.5) sources.The results of this study will aid in prioritizing air pollution mitigation strategies during the heating season and strengthening air quality management to reduce the impact of downwind neighboring cities. 展开更多
关键词 Source apportionment Dispersion normalized positive matrix factorization Adjacent cities Inter-city impact Source location Heating season Air quality management
原文传递
Normalized Positive Ground State Solutions for Nonhomogeneous Kirchhoff Equations
4
作者 ZHANG Xiaocang XU Liping 《应用数学》 北大核心 2025年第3期711-720,共10页
This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of norm... This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of normalized positive solutions for this equation via the Trudinger-Moser inequality and variational methods.Moreover,these solutions are also ground state solutions.Additionally,the article also characterized the asymptotic behavior of solutions.The results of this article expand the research of relevant literature. 展开更多
关键词 normalized positive ground state solution Nonhomogeneous Kirchhoff equation Variational method Exponential critical growth Trapping potential
在线阅读 下载PDF
MULTIPLE NORMALIZED SOLUTIONS FOR FRACTIONAL SCHRÖDINGER EQUATIONS WITH COMPETING POWER NONLINEARITY
5
作者 Huifang JIA Chunjiang ZHENG 《Acta Mathematica Scientia》 2025年第5期1961-1980,共20页
In this paper,we investigate the existence and multiplicity of normalized solutions for the following fractional Schrödinger equations{(-△)^(s)u+λu=|u|^(p-2)u-|u|^(q-2)u,x∈R^(N),∫_(R^(N))|u|^(2)dx=c>0,wher... In this paper,we investigate the existence and multiplicity of normalized solutions for the following fractional Schrödinger equations{(-△)^(s)u+λu=|u|^(p-2)u-|u|^(q-2)u,x∈R^(N),∫_(R^(N))|u|^(2)dx=c>0,where N≥2,s∈(0,1),2+4s/N<p<q≤2_(s)^(*)=2N/N-2s,(-△)^(s)represents the fractional Laplacian operator of order s,and the frequencyλ∈R is unknown and appears as a Lagrange multiplier.Specifically,we show that there exists a c>0 such that if c>c,then the problem(P)has at least two normalized solutions,including a normalized ground state solution and a mountain pass type solution.We mainly extend the results in[Commun Pure Appl Anal,2022,21:4113–4145],which dealt with the problem(P)for the case 2<p<q<2+4s/N. 展开更多
关键词 fractional Schrodinger equation normalized solutions variational methods com-peting power
在线阅读 下载PDF
Computing the ground state solution of Bose-Einstein condensates by an energy-minimizing normalized residual network
6
作者 Ren-Tao Wu Ji-Dong Gao +3 位作者 Yu-Han Wang Zhen-Wei Deng Ming-Jun Li Rong-Pei Zhang 《Chinese Physics B》 2025年第10期321-329,共9页
This paper introduces a novel numerical method based on an energy-minimizing normalized residual network(EMNorm Res Net)to compute the ground-state solution of Bose-Einstein condensates at zero or low temperatures.Sta... This paper introduces a novel numerical method based on an energy-minimizing normalized residual network(EMNorm Res Net)to compute the ground-state solution of Bose-Einstein condensates at zero or low temperatures.Starting from the three-dimensional Gross-Pitaevskii equation(GPE),we reduce it to the 1D and 2D GPEs because of the radial symmetry and cylindrical symmetry.The ground-state solution is formulated by minimizing the energy functional under constraints,which is directly solved using the EM-Norm Res Net approach.The paper provides detailed solutions for the ground states in 1D,2D(with radial symmetry),and 3D(with cylindrical symmetry).We use the Thomas-Fermi approximation as the target function to pre-train the neural network.Then,the formal network is trained using the energy minimization method.In contrast to traditional numerical methods,our neural network approach introduces two key innovations:(i)a novel normalization technique designed for high-dimensional systems within an energy-based loss function;(ii)improved training efficiency and model robustness by incorporating gradient stabilization techniques into residual networks.Extensive numerical experiments validate the method's accuracy across different spatial dimensions. 展开更多
关键词 Bose-Einstein condensate Gross-Pitaevskii equation energy minimization normalized residual network
原文传递
Offshore Wind Turbines Anomalies Detection Based on a New Normalized Power Index
7
作者 Bassel Weiss Segundo Esteban Matilde Santos 《Computer Modeling in Engineering & Sciences》 2025年第9期3387-3418,共32页
Anomaly detection in wind turbines involves emphasizing its ability to improve operational efficiency,reduce maintenance costs,extend their lifespan,and enhance reliability in the wind energy sector.This is particular... Anomaly detection in wind turbines involves emphasizing its ability to improve operational efficiency,reduce maintenance costs,extend their lifespan,and enhance reliability in the wind energy sector.This is particularly necessary in offshore wind,currently one of the most critical assets for achieving sustainable energy generation goals,due to the harsh marine environment and the difficulty of maintenance tasks.To address this problem,this work proposes a data-driven methodology for detecting power generation anomalies in offshore wind turbines,using normalized and linearized operational data.The proposed framework transforms heterogeneous wind speed and power measurements into a unified scale,enabling the development of a new wind power index(WPi)that quantifies deviations from expected performance.Additionally,spatial and temporal coherence analyses of turbines within a wind farm ensure the validity of these normalized measurements across different wind turbine models and operating conditions.Furthermore,a Support Vector Machine(SVM)refines the classification process,effectively distinguishing measurement errors from actual power generation failures.Validation of this strategy using real-world data from the Alpha Ventus wind farm demonstrates that the proposed approach not only improves predictive maintenance but also optimizes energy production,highlighting its potential for broad application in offshore wind installations. 展开更多
关键词 Fault identification anomaly detection normalIZATION offshore wind turbines wind energy
在线阅读 下载PDF
Normalized Solutions for p-Laplacian Schrödinger-Poisson Equations with L^(2)-Supercritical Growth
8
作者 LI Mingxue ZHANG Jiafeng 《数学理论与应用》 2025年第1期45-61,共17页
In this paper,we consider the p-Laplacian Schrödinger-Poisson equation with L^(2)-norm constraint-Δ_(p)u+|u|^(p-2)u+λu+(1/4π|x|*|u|^(2))u=|u|^(q-2)u,x∈R^(3),where 2≤p<3,5p/3<q<p*=3p/3-p,λ>0 is a... In this paper,we consider the p-Laplacian Schrödinger-Poisson equation with L^(2)-norm constraint-Δ_(p)u+|u|^(p-2)u+λu+(1/4π|x|*|u|^(2))u=|u|^(q-2)u,x∈R^(3),where 2≤p<3,5p/3<q<p*=3p/3-p,λ>0 is a Lagrange multiplier.We obtain the critical point of the corresponding functional of the problem on mass constraint by the variational method and the Mountain pass lemma,and then find a normalized solution to this equation. 展开更多
关键词 normalized solution p-Laplacian equation Schrödinger-Poisson equation Mountain pass lemma
在线阅读 下载PDF
Design of China’s ice-class fleet scale and economic viability assessment under normalized operation of the Northeast Passage
9
作者 HOU Jiaojiao HU Maixiu 《Advances in Polar Science》 2025年第3期213-228,共16页
Global warming has led to a gradual extension of the navigable window for the Arctic Route,providing a realistic possibility for the normalized commercial operation of the Northeast Passage(NEP).Based on the changes i... Global warming has led to a gradual extension of the navigable window for the Arctic Route,providing a realistic possibility for the normalized commercial operation of the Northeast Passage(NEP).Based on the changes in the navigable window of the NEP,Russia’s proposed nuclear-powered icebreaker construction scheme,and China’s potential development of a moderately sized ice-class fleet,this study establishes three scenarios for the commercial operation of the NEP.These scenarios include:(a)normalized summer operational scenario(from July to October each year),(b)normalized summer-autumn operational scenario(from June to January of the following year),and(c)normalized year-round operational scenario(12 months per year).The cargo transportation potential of the NEP under three normalized operational scenarios was predicted based on the grey prediction model.On this basis,construction scale plans for China’s ice-class fleet to meet cargo transportation demands under the three normalized operational scenarios were designed.The economic benefits of different plans were evaluated using a profit-maximization linear programming model.The research results show the following:(1)The cargo transportation potential of the NEP demonstrates a rapid growth trend in the future,with annual throughput under year-round normalized operations expected to exceed 100 million tonnes and reach 297 million tonnes.(2)Under different normalized operational scenarios,the fleet scale and vessel type composition vary.Under the normalized summer operational scenario,the optimal scale for China’s ice-class fleet is 20 vessels,consisting solely of ships classed as PC7 by the International Association of Classification Societies(IACS).Under the normalized summer-autumn operational scenario,the optimal fleet scale is 31 vessels,including 30 IACS PC7 ships and 1 IACS PC3 ship.Under the normalized year-round operational scenario,the optimal fleet scale is 45 vessels,composed of 30 IACS PC7 ships,8 IACS PC3 ships,and 7 IACS PC2 ships.(3)Among the three normalized operational scenarios,the normalized year-round operational scenario yields the best economic benefits for the fleet scale,while the normalized summer operational scenario yields the lowest economic benefits. 展开更多
关键词 ice-class fleet linear programming the Northeast Passage(NEP) normalized operation
在线阅读 下载PDF
Normalized Solutions for a Logarithmic Schrödinger Equation
10
作者 LIU Xiang LEI Chunyu 《数学理论与应用》 2025年第3期96-106,共11页
In this paper,we consider the following logarithmic Schrödinger equation:−Δu+ωu=u log|u|^(2),u∈H^(1)(R^(N)),where N≥3,and ω>0 is a constant.With an auxiliary equation,we obtain the existence of normalized... In this paper,we consider the following logarithmic Schrödinger equation:−Δu+ωu=u log|u|^(2),u∈H^(1)(R^(N)),where N≥3,and ω>0 is a constant.With an auxiliary equation,we obtain the existence of normalized solutions by using the constrained variational method. 展开更多
关键词 Logarithmic Schrödinger equation normalized solution Constrained variational method Minimization problem
在线阅读 下载PDF
High Energy Normalized Solutions for the Schrodinger Equations with Exponential Critical Growth
11
作者 ZHANG Xiao-cang XULi-ping 《Chinese Quarterly Journal of Mathematics》 2025年第1期1-19,共19页
In this paper,we study high energy normalized solutions for the following Schr?dinger equation{-Δu+V(x)u+λu=f(u),in R^(2),∫_(R^(2))|u|^(2)dx=c,where c>0,λ∈R will appear as a Lagrange multiplier,V(x)=ω|x|2 rep... In this paper,we study high energy normalized solutions for the following Schr?dinger equation{-Δu+V(x)u+λu=f(u),in R^(2),∫_(R^(2))|u|^(2)dx=c,where c>0,λ∈R will appear as a Lagrange multiplier,V(x)=ω|x|2 represents a trapping potential,and f has an exponential critical growth.Under the appropriate assumptions of f,we have obtained the existence of normalized solutions to the above Schr?dinger equation by introducing a variational method.And these solutions are also high energy solutions with positive energy. 展开更多
关键词 High energy normalized solutions Schrodinger equation Trapping potential Exponential critical growth Variational method
在线阅读 下载PDF
Biopsychosocial health status of Indonesian student nurses on the new normal Jakarta Indonesia
12
作者 Eka Rokhmiati Wahyu Purnamasari Arby James Abonalla +3 位作者 Marcos Ochoa Mary Ann Nery Mark Santos Esteve Adrian Estiva 《Frontiers of Nursing》 2026年第1期115-120,共6页
Nursing education in Indonesia experienced a number of changes during the new normal.The biopsychosocial health status reveals how students can complete their studies well at nursing school in the new normal.A quantit... Nursing education in Indonesia experienced a number of changes during the new normal.The biopsychosocial health status reveals how students can complete their studies well at nursing school in the new normal.A quantitative,descriptive correlational study sampled 368 student nurses from2 universities.This study used a biopsychosocial questionnaire,which included biological,physiological,and social dimensions.In this study,there was no significant demographic student nurse relationship with the biological,psychological,and social dimensions of health,at P-value 0.05(Age P=0.70,P=0.27,P=0.93)sex(P=1,P=0.919,P=0.5),as well as grade level(P=0.9,P=0.37,P=0.64).Student nurses were dynamic,such as process input,resulting in coping adaptation and the ability to care for themselves.There was a relationship between both universities with a psychological dimension and a P-value of 0.049.In terms of Generation Z technology,both universities played a role.Lifestyle influences can lead to intense feelings of isolation and loneliness in some teens,including self-negativity,fear of missing out on information,and shame about not meeting appropriate standards for social media.The influence of an unhealthy lifestyle impacts stress and anxiety.The student nurses assigned considered themselves to be“healthy”in terms of their biopsychosocial health status.Student nurses continued to develop in their biopsychosocial health by utilizing different coping strategies to adapt and adjust to their environment in their school of nursing. 展开更多
关键词 biopsychosocial health new normal nursing school student nurses biological psychological social
在线阅读 下载PDF
Local Characterizations of Results on the Normal Index of Subgroups in Finite Groups
13
作者 Yubo LV Yangming LI Xiaoxia DONG 《Journal of Mathematical Research with Applications》 2026年第1期33-39,共7页
Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divide... Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divides the order of a group G.In this paper,some characterizations of G being p-solvable or p-supersolvable were obtained by analyzing the normal index of certain subgroups of G.These results can be viewed as local version of recent results in the literature. 展开更多
关键词 p-solvable group p-supersolvable group normal index maximal subgroup 2-maximal subgroup
原文传递
Well-posedness and exponential stability of a dynamic frictionless contact problem with normal compliance and infinite memory
14
作者 Imane Ouakil Benyattou Benabderrahmane Yamna Boukhatem 《Applied Mathematics(A Journal of Chinese Universities)》 2026年第1期99-119,共21页
A model for dynamic frictionless contact between a viscoelastic body and foundation is considered.The viscoelastic constitutive law is assumed to be nonlinear and the contact is modelled with the normal compliance con... A model for dynamic frictionless contact between a viscoelastic body and foundation is considered.The viscoelastic constitutive law is assumed to be nonlinear and the contact is modelled with the normal compliance condition.We obtain the well-posedness using nonlinear semigroup theory arguments.Moreover,the exponential stability result of the solution is shown by using the energy method to produce a suitable Lyapunov function. 展开更多
关键词 dynamic process viscoelastic body normal compliance nonlinear semigroup theory exponential stability
在线阅读 下载PDF
Effects of joint geometric configurations on cyclic shear behavior of intermittent joints under constant normal stiffness conditions
15
作者 Bin Wang Yujing Jiang +1 位作者 Qiangyong Zhang Hongbin Chen 《Deep Underground Science and Engineering》 2026年第1期233-249,共17页
Intermittent joints are common in rock masses and are subjected to cyclic shear loads from seismic events,environmental factors,and human activities.In this study,we conducted cyclic shear tests to investigate the eff... Intermittent joints are common in rock masses and are subjected to cyclic shear loads from seismic events,environmental factors,and human activities.In this study,we conducted cyclic shear tests to investigate the effect of joint geometry(persistence,overlap,and spacing)on the cyclic shear behavior of intermittent joints under constant normal stiffness conditions.Our results revealed step‐path failure surfaces comprising tensile and shear failure surfaces.Shear failure surface controlled the degradation of shear properties,with shear strength decreasing progressively with cycles,ranging from 74.07%to 97.94%.Intermittent joints exhibited significant compressibility,with dilation predominant in early cycles and compression in later ones.Shear strength and dilation were more sensitive to joint persistence and spacing than overlap.Friction coefficients showed nonmonotonic variations with cycle number.High persistence,moderate overlap,and small spacing were identified as the most destabilizing combination.These findings offer valuable insights for stability assessment and deformation characterization in deep rock engineering. 展开更多
关键词 constant normal stiffness cyclic shear load intermittent joints joint configuration shear behavior shear strength
原文传递
Advances in Normalized cDNA Library and Its Applications 被引量:5
16
作者 张振乾 肖钢 +2 位作者 谭太龙 周可金 官春云 《Agricultural Science & Technology》 CAS 2010年第4期1-5,43,共6页
The cDNA library normalized by reassociation is a newly-developed and effective platform for EST acquisition and gene discovery.It decreases the prevalence of clones representing abundant transcripts and dramatically ... The cDNA library normalized by reassociation is a newly-developed and effective platform for EST acquisition and gene discovery.It decreases the prevalence of clones representing abundant transcripts and dramatically increases the efficiency of random sequencing and rare gene discovery.The principle,procedure and applications of normalized cDNA library were reviewed in this paper,which provides theoretical basis for the development of normalized cDNA library and discover more novel genes. 展开更多
关键词 SMART normalIZATION cDNA library
在线阅读 下载PDF
用Normalized Cut法自动提取乳腺超声图像中的肿瘤边缘 被引量:3
17
作者 苏燕妮 汪源源 《应用科学学报》 EI CAS CSCD 北大核心 2010年第6期601-608,共8页
提出一种带权重邻域灰度信息的normalized cut(Ncut)方法,该方法能够全自动提取乳腺超声图像的肿瘤边缘.通过Ncut分块乳腺超声图像中的各块灰度及空间分布特征来识别待检测肿瘤的轮廓.对于少数分割不精确的结果,可用结合局部能量项的动... 提出一种带权重邻域灰度信息的normalized cut(Ncut)方法,该方法能够全自动提取乳腺超声图像的肿瘤边缘.通过Ncut分块乳腺超声图像中的各块灰度及空间分布特征来识别待检测肿瘤的轮廓.对于少数分割不精确的结果,可用结合局部能量项的动态轮廓模型对所提取的初始边缘进行修正,使其更接近真实目标轮廓.对包含112幅乳腺肿瘤超声图像的数据库进行边缘提取,结果表明:该方法无需人工干预,能够准确有效地实现肿瘤分割,且计算量小,有望提高计算机辅助诊断的自动化程度. 展开更多
关键词 超声图像 乳腺肿瘤 边缘 自动提取 normalized CUT 局部调整
在线阅读 下载PDF
A normalized wavefield separation cross-correlation imaging condition for reverse time migration based on Poynting vector 被引量:17
18
作者 陈婷 何兵寿 《Applied Geophysics》 SCIE CSCD 2014年第2期158-166,253,共10页
Prestack reverse time migration(PSTM) is a common imaging method; however low-frequency noises reduce the structural imaging precision. Thus, the suppression of migration noises must be considered. The generation me... Prestack reverse time migration(PSTM) is a common imaging method; however low-frequency noises reduce the structural imaging precision. Thus, the suppression of migration noises must be considered. The generation mechanism of low-frequency noises is analyzed and the up-, down-, left-, and right-going waves are separated using the Poynting vector of the acoustic wave equation. The computational complexity and memory capacitance of the proposed method are far smaller than that required when using the conventional separation algorithm of 2D Fourier transform. The normalized wavefield separation crosscorrelation imaging condition is used to suppress low-frequency noises in reverse time migration and improve the imaging precision. Numerical experiments using the Marmousi model are performed and the results show that the up-, down-, left-, and right-going waves are well separated in the continuation of the wavefield using the Poynting vector. We compared the imaging results with the conventional method, Laplacian filtering, and wavefield separation with the 2D Fourier transform. The comparison shows that the migration noises are well suppressed using the normalized wavefield separation cross-correlation imaging condition and higher precision imaging results are obtained. 展开更多
关键词 acoustic wave equation Poynting vector wavefield separation normalized crosscorrelation migration noises
在线阅读 下载PDF
Normalized edge detection, and the horizontal extent and depth of geophysical anomalies 被引量:2
19
作者 李丽丽 韩立国 黄大年 《Applied Geophysics》 SCIE CSCD 2014年第2期149-157,252,253,共11页
Edge detection is an image processing technique for finding the boundaries of objects within images. It is typically used to interpret gravity and magnetic data, and find the horizontal boundaries of geological bodies... Edge detection is an image processing technique for finding the boundaries of objects within images. It is typically used to interpret gravity and magnetic data, and find the horizontal boundaries of geological bodies. Large deviations between model and true edges are common because of the interference of depth and errors in computing the derivatives; thus, edge detection methods cannot provide information about the depth of the source. To simultaneously obtain the horizontal extent and depth of geophysical anomalies, we use normalized edge detection filters, which normalize the edge detection function at different depths, and the maxima that correspond to the location of the source. The errors between model and actual edges are minimized as the depth of the source decreases and the normalized edge detection method recognizes the extent of the source based on the maxima, allowing for reliable model results. We demonstrate the applicability of the normalized edge detection filters in defining the horizontal extent and depth using synthetic and actual aeromagnetic data. 展开更多
关键词 geophysical anomalies normalized edge detection normalized total horizontal derivative regularization tilt angle theta map
在线阅读 下载PDF
Normalized Cut与分水岭变换在高光谱影像混合像元端元提取中的应用 被引量:3
20
作者 许菡 李小娟 《中国图象图形学报》 CSCD 北大核心 2012年第7期880-885,共6页
现有的遥感影像端元提取方法主要是从光谱特征角度提出,而结合空间信息的端元提取方法是近些年遥感影像混合像元分解的研究热点,为此使用图论的图像分割Normalized Cut与分水岭变换方法提出了一种改进的空间预处理模型用于高光谱遥感影... 现有的遥感影像端元提取方法主要是从光谱特征角度提出,而结合空间信息的端元提取方法是近些年遥感影像混合像元分解的研究热点,为此使用图论的图像分割Normalized Cut与分水岭变换方法提出了一种改进的空间预处理模型用于高光谱遥感影像混合像元的端元提取。该方法在混合像元端元提取过程中不仅利用遥感影像的光谱信息而且引入了像元的空间位置信息,实验结果表明本文提出的端元提取方法与现有的方法相比提高了遥感影像的混合像元分解精度。 展开更多
关键词 遥感影像分割 分水岭变换 normalized Cut 端元提取 高光谱数据
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部