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关于r边形数补数序列的混合均值性质
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作者 徐秋霞 《西华大学学报(自然科学版)》 CAS 2017年第6期101-104,共4页
利用初等方法和解析方法,研究Smarandache函数φ(n)、δ_k(n)分别与本文定义的数论函数a(n)和b(n)的混合均值,获得了4个较强的渐近进公式,从而拓展了经典的算术函数的相关研究工作。
关键词 r边形数补数 数论函数 混合均值 渐近公式
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边形数、棱锥体数及其三角形的循序逐增规律
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作者 张尔光 《科技创新导报》 2015年第6期41-46,共6页
该文遵循循序逐增原理,从对边形数、棱锥体数以及其点与点之间连线形成的三角形的量的循序逐增现象研究中,求得其循序逐增规律。应用拓扑原理,可将边形数置换为扇形图表达,将棱锥体数置换为圆形图表达,发现了棱锥体数与边形数之间的相... 该文遵循循序逐增原理,从对边形数、棱锥体数以及其点与点之间连线形成的三角形的量的循序逐增现象研究中,求得其循序逐增规律。应用拓扑原理,可将边形数置换为扇形图表达,将棱锥体数置换为圆形图表达,发现了棱锥体数与边形数之间的相近相同规律。 展开更多
关键词 边形数 棱锥体数 三角形 循序逐增规律 拓扑原理
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2个r角形数补数序列的混合均值研究 被引量:1
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作者 白甲志 黄炜 《首都师范大学学报(自然科学版)》 2017年第2期6-9,共4页
利用初等方法和解析方法,研究了两个Smarandache函数的性质,获得了混合均值性质及渐近公式,从而拓展了经典的算术函数的相关研究工作.
关键词 r边形数补数 数论函数 混合均值 渐近公式
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多边形数的毕达哥拉斯三元组
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作者 EgonScheffold 李春英 等 《数学译林》 2002年第2期191-192,共2页
关键词 边形数 毕达哥拉斯三元组 自然数 边形数 n-边形数
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两个Smarandache复合函数的均值估计 被引量:2
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作者 黄炜 赵教练 《纯粹数学与应用数学》 CSCD 2010年第6期890-894,共5页
设n是正整数,ur(n)表示不小于n的最小r边形数部分数列,vr(n)表示不超过n的最大r边形数部分数列.研究了Smarandache函数S(n)与ur(n),vr(n)的混合均值,并用解析方法得到了几个较强的渐近公式。
关键词 SMARANDACHE函数 r边形数 均值 渐近公式
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Forming defects in aluminum alloy hot stamping of side-door impact beam 被引量:12
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作者 周靖 王宝雨 +2 位作者 林建国 傅垒 马闻宇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第11期3611-3620,共10页
The forming defects, including thinning, rupture, wrinkling and springback, usually arising in producing a side-door impact beam, were investigated by trial and numerical simulation. A temperature-related constitutive... The forming defects, including thinning, rupture, wrinkling and springback, usually arising in producing a side-door impact beam, were investigated by trial and numerical simulation. A temperature-related constitutive model specific to the temperature range from 350 °C to 500 °C was established and used for the numerical simulation. The trial and numerical simulation were conducted to clarify the quantitative characteristics of forming defects and to analyze the effects of process parameters on the forming defects. Results show that the rupture situation is ameliorated and the springback is eliminated in the aluminum alloy hot stamping. The wrinkling severity decreases with increasing blank holder force (BHF), but the BHF greater than 15 kN causes the rupture at the deepest drawing position of workpiece. The forming defects are avoided with lubricant in the feasible ranges of process parameters: the BHF of 3 to 5 kN and the stamping speed of 50 to 200 mm/s. 展开更多
关键词 aluminum alloy hot stamping forming defects numerical simulation blank holder force
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Study on the Spatial Pattern Changes of Land Use Based on Fractal Dimensions in Tianjin New Coastal Area 被引量:3
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作者 白新萍 《Agricultural Science & Technology》 CAS 2011年第6期879-882,919,共5页
[Objective] The aim was to discuss the spatial pattern changes of land use in Tianjin new coastal area based on fractal dimensions.[Method] By dint of remote and geographic information system technology to obtain the ... [Objective] The aim was to discuss the spatial pattern changes of land use in Tianjin new coastal area based on fractal dimensions.[Method] By dint of remote and geographic information system technology to obtain the data of urban land use in new coastal area from 1993 to 2008,the boundary dimension,radius dimension and information dimension of each land use type were calculated based on fractal dimension.In addition,the revealed land use spatial dimension changes characteristics were analyzed.[Result] The spatial distribution of each land use type in new costal area had distinct fractal characteristics.And,the amount and changes of three types of dimension values effectively revealed the changes of complicatedness,centeredness and evenness of spatial pattern of land use in the study area.The boundary dimension of unused land and salty earth increased incessantly,which suggested its increasing complicatedness.The boundary of the port and wharf and shoal land was getting simpler.The radius dimension of the cultivated land was larger than 2,which suggested that its area spread from center to the surroundings;the one in salty land and waters distributed evenly within different radius space to the center of the city;the one in other land use types reduced gradually from center to the surroundings.The information dimension value in the woodland and orchard land,unused land and shoal land was small,and was in obvious concentrated distribution;the spatial distribution of cultivated and salty land concentrated in the outside area;the construction area in the port and wharf spread gradually on the basis of original state;the spatial distribution of waters and residents and mines were even.[Conclusion] Applying fractal dimensions to the study of spatial pattern changes of urban land use can make up for some disadvantages in classical urban spatial pattern quantitative research,which has favorable practical value. 展开更多
关键词 Land use Fractal dimension Boundary dimension Radial dimension Information dimension Tianjin New Coastal Area
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A generalized cover renewal strategy for multiple crack propagation in two-dimensional numerical manifold method 被引量:1
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作者 YU Chang-yi ZHENG Fei +1 位作者 GUO Bing-chuan LIU Qin-ya 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第8期2367-2381,共15页
Partition of unity based numerical manifold method can solve continuous and discontinuous problems in a unified framework with a two-cover system,i.e.,the mathematical cover and physical cover.However,renewal of the t... Partition of unity based numerical manifold method can solve continuous and discontinuous problems in a unified framework with a two-cover system,i.e.,the mathematical cover and physical cover.However,renewal of the topology of the two-cover system poses a challenge for multiple crack propagation problems and there are few references.In this study,a robust and efficient strategy is proposed to update the cover system of the numerical manifold method in simulation of multiple crack propagation problems.The proposed algorithm updates the cover system with a bottom-up process:1)identification of fractured manifold elements according to the previous and latest crack tip position;and 2)local topological update of the manifold elements,physical patches,block boundary loops,and non-persistent joint loops according to the scenario classification of the propagating crack.The proposed crack tracking strategy and classification of the renewal cases promote a robust and efficient cover renewal algorithm for multiple crack propagation analysis.Three crack propagation examples show that the proposed algorithm performs well in updating the cover system.This cover renewal methodology can be extended for numerical manifold method with polygonal mathematical covers. 展开更多
关键词 numerical manifold method multiple crack propagation physical cover renewal polygonal mathematical cover
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Bézier curves with shape parameter 被引量:5
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作者 王文涛 汪国昭 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第6期497-501,共5页
In this paper, Bézier basis with shape parameter is constructed by an integral approach. Based on this basis, we define the Bézier curves with shape parameter. The Bézier basis curves with shape paramet... In this paper, Bézier basis with shape parameter is constructed by an integral approach. Based on this basis, we define the Bézier curves with shape parameter. The Bézier basis curves with shape parameter have most properties of Bernstein basis and the Bézier curves. Moreover the shape parameter can adjust the curves’ shape with the same control polygon. As the increase of the shape parameter, the Bézier curves with shape parameter approximate to the control polygon. In the last, the Bézier surface with shape parameter is also constructed and it has most properties of Bézier surface. 展开更多
关键词 Bézier curve Bézier basis with shape parameter Bernstein basis
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SOME RESULTSON R_2-EDGE-CONNECTIVITY OF EVEN REGULAR GRAPHS 被引量:3
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作者 Xu Junming Dept. of Math., Univ. ofScience and Technology ofChina, Hefei230026.Em ail:XUJM@ USTC.EDU.CN 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1999年第3期366-370,共5页
Let Gbe a connected k(≥3)-regulargraph w ith girth g. A setSofthe edgesin G is called an R2-edge-cutifG- Sis disconnected and contains neither an isolated vertex nor a one- degree vertex. The R2-edge-connectivity of ... Let Gbe a connected k(≥3)-regulargraph w ith girth g. A setSofthe edgesin G is called an R2-edge-cutifG- Sis disconnected and contains neither an isolated vertex nor a one- degree vertex. The R2-edge-connectivity of G, denoted by λ″(G), is the m inim um cardinality over allR2-edge-cuts, w hich is an im portantm easure for fault-tolerance of com puter intercon- nection netw orks. In this paper, λ″(G)= g(2k- 2) for any 2k-regular connected graph G(≠ K5) that is either edge-transitive or vertex-transitive and g≥5 is given. 展开更多
关键词 CONNECTIVITY conditionalconnectivity transitive graphs.
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Integrated Method of Recognizing Huge Target
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作者 王文会 《Journal of Beijing Institute of Technology》 EI CAS 2001年第4期423-428,共6页
An integrated novel method of recognizing huge target is described that combines some relatively mature image processing techniques such as edge detection, thresholding, morphology, image segmentation and so forth. Af... An integrated novel method of recognizing huge target is described that combines some relatively mature image processing techniques such as edge detection, thresholding, morphology, image segmentation and so forth. After thresholding the edge image obtained by using Sobel operator, erosion is firstly used to reduce noise and extrusive pixels; then dilation is used to expand some separated pixels into various regions, after that the image segmentation technique is utilized to distinguish the target region with a criterion. The location of the target is also offered. Each technique adopted herein seems not complicated at all, the experimental results demonstrate the efficiency of the combination of these techniques. It is its high computational speed and remarkable robustness resulting from its simplicity that make the method promise to be applied in practical problems requiring real time processing. 展开更多
关键词 object recognition edge detection MORPHOLOGY image segmentation direction detection
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Numerical Simulation of Sloshing in Rectangular Storage Tank Using Coupled FEM-BEM 被引量:6
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作者 Hassan Saghi Mohammad Javad Ketabdari 《Journal of Marine Science and Application》 2012年第4期417-426,共10页
Sloshing of liquid can increase the dynamic pressure on the storage sidewalls and bottom in tanker ships and LNG careers. Different geometric shapes were suggested for storage tank to minimize the sloshing pressure on... Sloshing of liquid can increase the dynamic pressure on the storage sidewalls and bottom in tanker ships and LNG careers. Different geometric shapes were suggested for storage tank to minimize the sloshing pressure on tank perimeter. In this research, a numerical code was developed to model liquid sloshing in a rectangular partially filled tank. Assuming the fluid to be inviscid, Laplace equation and nonlinear free surface boundary conditions are solved using coupled FEM-BEM. The code performance for sloshing modeling is validated against available data. To minimize the sloshing pressure on tank perimeter, rectangular tanks with specific volumes and different aspect ratios were investigated and the best aspect ratios were suggested. The results showed that the rectangular tank with suggested aspect ratios, not only has a maximum surrounded tank volume to the constant available volume, but also reduces the sloshing pressure efficiently. 展开更多
关键词 rectangular storage tank sloshing phenomenon aspect ratio coupled FEM-BEM
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Topographic Characteristics for the Geomorphologic Zones in the Northwestern Edge of the Qinghai-Tibet Plateau 被引量:2
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作者 CHENG Wei-ming ZHAO Shang-min +1 位作者 ZHOU Cheng-hu CHEN Xi 《Journal of Mountain Science》 SCIE CSCD 2013年第6期1039-1049,共11页
Based on geomorphologic and digital elevation model(DEM) data, the topographic characteristics of the northwestern edge of the Qinghai-Tibet Plateau are analyzed. Five representative peaks are first determined accordi... Based on geomorphologic and digital elevation model(DEM) data, the topographic characteristics of the northwestern edge of the Qinghai-Tibet Plateau are analyzed. Five representative peaks are first determined according to the topographic profile maps for the ridge and piedmont lines, and then the topographic gradient characteristics are analyzed according to the representative topographic profile acquisition method.Based on the geomorphologic database data, the regions between the ridge and the piedmont lines are divided into four geomorphologic zones; and the topographic characteristics are finally analyzed for the different geomorphologic zones regions using the DEM data. The research results show that from the piedmont to the ridge, there exist four geomorphologic zones: arid, fluvial, periglacial and glacial. The arid has the lowest elevation, topographic gradient, relief and slope characteristics. The fluvial has lower elevation and the highest topographic gradient, but with lower relief and slope characteristics. With higher elevation, the periglcial has lower topographic gradient, but the highest relief and slope characteristics. The glacial has the highest elevation with higher topographic gradient, relief and slope characteristics. 展开更多
关键词 Topographic characteristics Geomorphologic zone Topographic gradient Topographic profile map Qinghai-Tibet Plateau
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Geometrical characteristic investigation of the Baihetan irregular columnar jointed basalt and corresponding numerical reconstruction method 被引量:2
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作者 ZHANG Jian-cong JIANG Quan +3 位作者 FENG Guang-liang LI Shao-jun PEI Shu-feng HE Ben-guo 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第2期455-469,共15页
Columnar jointed rock mass with unique geometric and geological properties is one spectacular example of geometrical order in nature.Columnar joints are generally accepted to be formed by spatially uniform volume cont... Columnar jointed rock mass with unique geometric and geological properties is one spectacular example of geometrical order in nature.Columnar joints are generally accepted to be formed by spatially uniform volume contraction during cooling.In this paper,substantial field work was performed to study the geological characteristics of irregular columnar jointed basalt on the left bank dam foundation in the Baihetan Hydropower Station,where the columnar jointed rock mass is extensively exposed due to excavation.The quantitative measurements of the sizing of polygonal crack pattern of columnar joints and assessment of their degree of irregularity were summarized.Considering the irregularity of polygonal crack pattern,a modified Voronoi polygon(MVP)method was developed to model the special polygonal crack pattern of columnar joints.The new polygonal pattern obtained by the MVP method consists of a large number of irregular polygons,of which the degree of irregularity is consistent with the field measurement results.This method can reproduce the rapid evolution from an initial ideal regular hexagonal pattern to a final actual irregular polygonal pattern as the degree of irregularity increases.The compression tests of columnar jointed rock mass with different irregularity show that the geometric irregularity has a great influence on its mechanical properties.This numerical construction method provides a reliable way to reconstruct columnar joint structure with specific polygonal crack pattern,which is consistent with onsite columnar jointed basalt. 展开更多
关键词 columnar jointed basalt geometrical characteristics degree of irregularity numerical construction modified Voronoi polygon method
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Relationship of Uncertainty Between Polygon Segment and Line Segment for Spatial Data in GIS 被引量:1
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作者 LIU Chun TONG Xiaohua 《Geo-Spatial Information Science》 2005年第3期183-188,共6页
The mathematic theory for uncertainty model of line segment are summed up to achieve a general conception, and the line error hand model of εσ is a basic uncertainty model that can depict the line accuracy and quali... The mathematic theory for uncertainty model of line segment are summed up to achieve a general conception, and the line error hand model of εσ is a basic uncertainty model that can depict the line accuracy and quality efficiently while the model of εm and error entropy can be regarded as the supplement of it. The error band model will reflect and describe the influence of line uncertainty on polygon uncertainty. Therefore, the statistical characteristic of the line error is studied deeply by analyzing the probability that the line error falls into a certain range. Moreover, the theory accordance is achieved in the selecting the error buffer for line feature and the error indicator. The relationship of the accuracy of area for a polygon with the error loop for a polygon boundary is deduced and computed. 展开更多
关键词 spatial datas error bands polygon segments uncertainty
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Bandwidth Numerical Analysis of Triangular Patch Antenna Fed by L-Shaped Probe
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作者 刘毅军 黎滨洪 +1 位作者 张亚斌 陈兴义 《Journal of Shanghai Jiaotong university(Science)》 EI 2004年第1期60-62,共3页
A single layer triangular patch antenna fed by an L-shaped probe was investigated numerically by using FDTD (Finite Difference Time Domain) method. It achieves >40% impedance bandwidth (VSWR<2) and stable radiat... A single layer triangular patch antenna fed by an L-shaped probe was investigated numerically by using FDTD (Finite Difference Time Domain) method. It achieves >40% impedance bandwidth (VSWR<2) and stable radiation pattern across the passband. The triangular patch antenna with two orientations of L-shaped probe has almost the same characteristics, such as impedance bandwidth and radiation pattern. The bandwidth vs feeding position was also investigated, the broadband characteristic can be observed when the feeding position is only in a small segment along the centerline. 展开更多
关键词 FDTD triangular patch antenna L-shaped probe
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Back analysis for soil slope based on measuring inclination data 被引量:6
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作者 孙志彬 张道兵 《Journal of Central South University》 SCIE EI CAS 2012年第11期3291-3297,共7页
Based on the analysis of several objective functions,a new method was proposed.Firstly,the feature of the inclination curve was analyzed.On this basis,the soil could be divided into several blocks with different displ... Based on the analysis of several objective functions,a new method was proposed.Firstly,the feature of the inclination curve was analyzed.On this basis,the soil could be divided into several blocks with different displacements and deformations.Then,the method of the soil division was presented,and the characteristic of single soil block was studied.The displacement of the block had two components:sliding and deformation.Moreover,a new objective function was constructed according to the deformation of the soil block.Finally,the sensitivities of the objective functions by traditional method and the new method were calculated,respectively.The result shows that the new objective function is more sensitive to mechanical parameters and the inversion result is close to that obtained by the large direct shear apparatus.So,this method can be used in slope back analysis and its effectiveness is proved. 展开更多
关键词 slope parameter back analysis soil division deformation displacement
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A New Method to Extract Text from Natural Scenes
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作者 郝峻晟 戚飞虎 +1 位作者 朱凯华 蒋人杰 《Journal of Donghua University(English Edition)》 EI CAS 2005年第4期52-57,共6页
This paper presents a new method for text detection, location and binarization from natural scenes. Several morphological steps are used to detect the general position of the text, including English, Chinese and Japan... This paper presents a new method for text detection, location and binarization from natural scenes. Several morphological steps are used to detect the general position of the text, including English, Chinese and Japanese characters. Next bonnding boxes are processed by a new “Expand, Break and Merge” (EBM) method to get the precise text areas. Finally, text is binarized by a hybrid method based on Otsu and Niblack. This new approach can extract different kinds of text from complicated natural scenes. It is insensitive to noise, distortedness, and text orientation. It also has good performance on extracting texts in various sizes. 展开更多
关键词 Text Extraction mathematical morphology bounding boxes binarization
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Analytical solutions for a uniformly loaded circular plate with clamped edges
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作者 丁皓江 李翔宇 陈伟球 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第10期1163-1168,共6页
A bi-harmonic potential function was constructed in this study. Love solution was employed to obtain analytical solutions of uniformly loaded plates with two different types of clamped edges. The treatment of clamped ... A bi-harmonic potential function was constructed in this study. Love solution was employed to obtain analytical solutions of uniformly loaded plates with two different types of clamped edges. The treatment of clamped boundary conditions was the same as that adopted by Timoshenko and Goodier (1970). The analytical solution for the first type of clamped boundary condition is identical with that obtained by Luo et al.(2004), and the solutions for both types were compared with the FEM results and the calculations of thin plate theory. 展开更多
关键词 Three-dimensional analytical solution Circular plates with clamped edges Bi-harmonic functions Axisymmetricdeformation
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Boundary States and Correlation Functions of Tricritical Ising Model from Coulomb-Gas Formalism
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作者 Smain Balaska Toufik Sahabi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第1期115-122,共8页
We consider the minimal conformaJ model describing the tricritical Ising model on the disk and on the upper half plane. Using the coulomb-gas formalism we determine its consistents boundary states as well as its one-p... We consider the minimal conformaJ model describing the tricritical Ising model on the disk and on the upper half plane. Using the coulomb-gas formalism we determine its consistents boundary states as well as its one-point and two-point correlation functions. 展开更多
关键词 boundary conformal field theory tricritical Ising model boundary states and Coulomb-gas formalism
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