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基于开放标准的电力系统图数模一体化研究 被引量:7
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作者 黄缙华 赵强 《现代电力》 2010年第6期73-78,共6页
采用开放与标准化的技术是提高电网自动化系统间集成度的基础与关键。将IEC 61970标准的公共信息模型(CIM)规范与W3C推荐的可缩放矢量图形(SVG)标准结合,设计和构建标准与开放化的系统。在技术上通过Batik包与Java组件实现对SVG图形的操... 采用开放与标准化的技术是提高电网自动化系统间集成度的基础与关键。将IEC 61970标准的公共信息模型(CIM)规范与W3C推荐的可缩放矢量图形(SVG)标准结合,设计和构建标准与开放化的系统。在技术上通过Batik包与Java组件实现对SVG图形的操作,采用Hibernate框架实现CIM模型与关系数据库的映射,实现了基于SVG/XML/CIM的图数模一体化。研究结果表明图数模一体化系统对系统间数据集成、应用集成和互操作具有实际意义。 展开更多
关键词 数模一体化 可缩放矢量 公共信息模型 IEC61970 HIBERNATE框架
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电厂管理信息系统中的SVG图形系统设计 被引量:2
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作者 叶向军 章坚民 《杭州电子科技大学学报(自然科学版)》 2008年第4期21-24,共4页
可伸缩矢量图是国际电工委员会建议使用的通用图形交换标准,基于可伸缩矢量图的图形系统可以作为不同系统间图形信息共享的平台。提出了基于公共信息模型的图数模一体化模型,利用数据库存储过程实现电厂简图的自动生成,并讨论了可伸缩... 可伸缩矢量图是国际电工委员会建议使用的通用图形交换标准,基于可伸缩矢量图的图形系统可以作为不同系统间图形信息共享的平台。提出了基于公共信息模型的图数模一体化模型,利用数据库存储过程实现电厂简图的自动生成,并讨论了可伸缩矢量图在地方电厂管理信息系统WEB上的应用。 展开更多
关键词 可伸缩矢量 数模一体化 公共信息模型 存储过程
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Principle, Modeling and Control of DC-DC Convertors for EV 被引量:3
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作者 张承宁 孙逢春 张旺 《Journal of Beijing Institute of Technology》 EI CAS 2000年第4期465-471,共7页
DC DC convertors can convert the EV's high voltage DC power supply into the low voltage DC power supply. In order to design an excellent convertor one must be guided by theory of automatic control. The principl... DC DC convertors can convert the EV's high voltage DC power supply into the low voltage DC power supply. In order to design an excellent convertor one must be guided by theory of automatic control. The principle and the method of design, modeling and control for DC DC convertors of EV are introduced. The method of the system response to a unit step function input and the frequency response method are applied to researching the convertor's mathematics model and control characteristic. Experiments show that the designed DC DC convertor's output voltage precision is high, the antijamming ability is strong and the adjustable performance is fast and smooth. 展开更多
关键词 EV DC DC convertors automatic control mathematics model Bode drawing
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二滩水电站主机安装、运行的实践
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作者 宋宏启 《水电能源科学》 2001年第3期64-68,共5页
介绍了二滩水电站主机安装中采取的有效措施 ,分析了安装中出现的主机制造质量存在的一些问题 ,同时说明了对这些问题的处理方法 .二滩水电站的主机 ,是我国已投产单机容量最大水轮发电机组 .自首台机并网发电以来 ,至今已安全运行了 2 ... 介绍了二滩水电站主机安装中采取的有效措施 ,分析了安装中出现的主机制造质量存在的一些问题 ,同时说明了对这些问题的处理方法 .二滩水电站的主机 ,是我国已投产单机容量最大水轮发电机组 .自首台机并网发电以来 ,至今已安全运行了 2 7个月 .其安装、运行的实践 ,对我国今后巨型机组的设计、制造、安装、运行均有借鉴作用 . 展开更多
关键词 巨型机组 二滩水电站 数模图 安装 运行
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Optimal path finding algorithms based on SLSD road network model 被引量:3
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作者 张小国 王庆 龚福祥 《Journal of Southeast University(English Edition)》 EI CAS 2010年第4期558-562,共5页
A solution to compute the optimal path based on a single-line-single-directional(SLSD)road network model is proposed.Unlike the traditional road network model,in the SLSD conceptual model,being single-directional an... A solution to compute the optimal path based on a single-line-single-directional(SLSD)road network model is proposed.Unlike the traditional road network model,in the SLSD conceptual model,being single-directional and single-line style,a road is no longer a linkage of road nodes but abstracted as a network node.Similarly,a road node is abstracted as the linkage of two ordered single-directional roads.This model can describe turn restrictions,circular roads,and other real scenarios usually described using a super-graph.Then a computing framework for optimal path finding(OPF)is presented.It is proved that classical Dijkstra and A algorithms can be directly used for OPF computing of any real-world road networks by transferring a super-graph to an SLSD network.Finally,using Singapore road network data,the proposed conceptual model and its corresponding optimal path finding algorithms are validated using a two-step optimal path finding algorithm with a pre-computing strategy based on the SLSD road network. 展开更多
关键词 optimal path finding road network model conceptual model digital map vehicle navigation system A algorithm Dijkstra algorithm
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RESEARCH OF THE PARAMETRIC ASSEMBLY METHOD
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作者 孙知信 陈文亮 +1 位作者 丁秋林 张娟 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1997年第2期165-169,共5页
The parametric part assembly generation method is presented. Based on the parametric part generated by means of constructive-element, through interactively inputting the relationships of the location and the assembly,... The parametric part assembly generation method is presented. Based on the parametric part generated by means of constructive-element, through interactively inputting the relationships of the location and the assembly, and by compiling operations like movement and rotation, the assembly drawing is created so as to implement the occurrence of the parameterizations of the assembly and the part drawing. The data structure of the assembly part and the key technologies of hidden line removal in the implementation of assembly process, etc. , are described in detail. 展开更多
关键词 ASSEMBLING PARAMETERS product modelling design methodology parametric drawing hidden line removal
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A Novel Algorithm to Extract Weighted Critical Area
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作者 王俊平 郝跃 +2 位作者 张会宁 张晓菊 任春丽 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第1期24-29,共6页
inductive fault analysis is a technique for enumerating likely bridges that is limited by the weighted critical area computation. Based on the rectangle model of a real defect and mathematical morphology, an efficient... inductive fault analysis is a technique for enumerating likely bridges that is limited by the weighted critical area computation. Based on the rectangle model of a real defect and mathematical morphology, an efficient algorithm is presented to compute the weighted critical area of a layout. The algorithm avoids the need to determine which rectangles belong to a net and the merging of the critical area corresponding to a net pair. Experimental resuits showing the algorithm's performance are presented. 展开更多
关键词 bridge fault defect rectangle model layout analysis mathematical morphology
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基于WebGIS的电力信息系统 被引量:4
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作者 宋文乐 张晓冬 陈勇 《电力信息化》 2012年第11期12-15,共4页
随着电力信息化技术的发展,在显示查询方面传统文字报表的表现力有限,无法直观展示电网整体运行状况,电力系统图形化展示显得尤为重要。电力WebGIS系统基于B/S模式并在ESRI ArcGIS Server平台上开发,将电网设备信息与地理信息结合起来,... 随着电力信息化技术的发展,在显示查询方面传统文字报表的表现力有限,无法直观展示电网整体运行状况,电力系统图形化展示显得尤为重要。电力WebGIS系统基于B/S模式并在ESRI ArcGIS Server平台上开发,将电网设备信息与地理信息结合起来,建立起图数模一体化的空间数据模型,直观地表达电网拓扑关系及电力系统运行状态。该系统实现了电力系统仿真平台的可视化,方便了电网工作人员协同计算工作。 展开更多
关键词 WEBGIS 电力系统 数模一体化 空间数据库
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Transect-based Three-Dimensional Road Modeling and Visualization 被引量:6
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作者 LIQingquan TANGLuliang ZUOXiaoqing LIHanwu 《Geo-Spatial Information Science》 2004年第1期14-17,共4页
On the basis of the study on road elements and th e existing three-dimensional road data models, this paper puts forward the transe ct-based road modeling, resolves the modeling of the simplest road with two roa d tra... On the basis of the study on road elements and th e existing three-dimensional road data models, this paper puts forward the transe ct-based road modeling, resolves the modeling of the simplest road with two roa d transects, and fulfils the visualization of the road. OpenGL is applied as the tool of visualization. The map texture technology, LOD algorithm and dynamic mu lti-differentiating texture technology are of benefit to the construction of 3D road GIS, and improve the speed of roaming and effective visualization. This pa per also disusses the combination of 2D digitall road map and 3D road scene, and the dynamic response between them. Finally, on the basis of the research on the transect-based road model, this paper develops the three-dimensional road geo graphic information system called virtual road ( VRoad ), which not only suppli es road designers with a set of tool which can turn the designed 2D road data in to 3D road and the high road assistant function area in computer, but also suppl ies the road management with a set of tool which can realize the road real time and interactive roaming, high-efficiency management. 展开更多
关键词 3DGIS road modeling virtual reality LOD
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An Analysis and Modeling Study of a Sea Fog Event over the Yellow and Bohai Seas 被引量:27
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作者 FU Gang GUO Jingtian +1 位作者 Angeline Pendergrass LI Pengyuan 《Journal of Ocean University of China》 SCIE CAS 2008年第1期27-34,共8页
In this study, a sea fog event which occurred on 27 March 2005 over the Yellow and Bohai Seas was investigated observationally and numerically. Almost all available observational data were used, including satellite im... In this study, a sea fog event which occurred on 27 March 2005 over the Yellow and Bohai Seas was investigated observationally and numerically. Almost all available observational data were used, including satellite imagery of Geostationary Operational Environmental Satellite (GOES)-9, three data sets from station observations at Dandong, Dalian and Qingdao, objectively reanalyzed data of final run analysis (FNL) issued by the National Center for Environmental Prediction (NCEP) and Regional Atmospheric Modeling System (RANIS) results. Synoptic conditions and fog characteristics were analyzed. The fog formed when warm, moist air was advected northwards over the cool water of the Yellow and Bohai Seas, and dissipated when a cold front brought northerly winds and cool, dry air. In order to better understand the fog formation mechanism, a high-resolution RAMS modeling with a 6km×6km grid, initialized and validated by FNL data, was designed. A 48h modeling that started from 12 UTC 26 March 2005 reproduced the main characteristics of this sea fog event. The simulated lower visibility area agreed reasonably well with the sea fog region identified from the satellite imagery. Advection cooling effect seemed to play a significant role in the fog formation. 展开更多
关键词 sea fog the Yellow and Bohai Seas satellite imagery numerical modeling low visibility area
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Measuring the Condition of Parking Lot by Image Processing
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作者 吴大勇 魏平 侯朝桢 《Journal of Beijing Institute of Technology》 EI CAS 1999年第3期232-237,共6页
Aim To study the parking management in the condition of vehicles' increasing. Methods The methods of pattern recognition and image processing were used to analyze the eigenvalues of parking lot images. Results ... Aim To study the parking management in the condition of vehicles' increasing. Methods The methods of pattern recognition and image processing were used to analyze the eigenvalues of parking lot images. Results The automatic identification of every parking place in the parking plot was realized. The automatic measuring of parked vehicle count and parking lot utilization was completed. Conclusion It can complete the real time recognition, and has some practicabilities. 展开更多
关键词 automatic measuring digital image processing pattern recognition
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Mesomechanics coal experiment and an elastic-brittle damage model based on texture features 被引量:3
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作者 Sun Chuanmeng Cao Shugang Li Yong 《International Journal of Mining Science and Technology》 EI CSCD 2018年第4期634-642,共9页
To accurately describe damage within coal, digital image processing technology was used to determine texture parameters and obtain quantitative information related to coal meso-cracks. The relationship between damage ... To accurately describe damage within coal, digital image processing technology was used to determine texture parameters and obtain quantitative information related to coal meso-cracks. The relationship between damage and mesoscopic information for coal under compression was then analysed. The shape and distribution of damage were comprehensively considered in a defined damage variable, which was based on the texture characteristic. An elastic-brittle damage model based on the mesostructure information of coal was established. As a result, the damage model can appropriately and reliably replicate the processes of initiation, expansion, cut-through and eventual destruction of microscopic damage to coal under compression. After comparison, it was proved that the predicted overall stress-strain response of the model was comparable to the experimental result. 展开更多
关键词 Mesomechanics experiment Image processing Texture feature Damage variable Damage model
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Parameter recognition for defocus blur image using cepstrum analysis 被引量:1
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作者 周曲 《High Technology Letters》 EI CAS 2008年第3期276-281,共6页
Successful restoration of blurred images depends primarily on the knowledge about the degradationparameter.Defocus blur model in the frequency domain is characterized by concentric rings and the blurradius of the poin... Successful restoration of blurred images depends primarily on the knowledge about the degradationparameter.Defocus blur model in the frequency domain is characterized by concentric rings and the blurradius of the point spread function(PSF)can be identified conveniently in the frequency field for peopleby manual means rather than for computer.This paper introduces a practical method for computer to esti-mate the defocus blur parameter in cepstrum area.Fourier transform plays an intermediate role in the pathto cepstrum domain.We suggest a weighted adjustment operation in the frequency domain and then con-vert it to the cepstrum field to increase the accuracy of recognition. 展开更多
关键词 point spread function (PSF) DEFOCUS BLUR CEPSTRUM
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A Method for Sea Surface Wind Field Retrieval from SAR Image Mode Data 被引量:4
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作者 SHAO Weizeng SUN Jian +1 位作者 GUAN Changlong SUN Zhanfeng 《Journal of Ocean University of China》 SCIE CAS 2014年第2期198-204,共7页
To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions (GMFs) have been widel... To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions (GMFs) have been widely applied for wind field retrieval from SAR images. Among them CMOD4 has a good performance under low and moderate wind conditions. Although CMOD5 is developed recently with a more fundamental basis, it has ambiguity of wind speed and a shape gradient of normalized radar cross section under low wind speed condition. This study proposes a method of wind field retrieval from SAR image by com-bining CMOD5 and CMOD4 Five VV-polarisation RADARSAT2 SAR images are implemented for validation and the retrieval re-suits by a combination method (CMOD5 and CMOD4) together with CMOD4 GMF are compared with QuikSCAT wind data. The root-mean-square error (RMSE) of wind speed is 0.75 m s-1 with correlation coefficient 0.84 using the combination method and the RMSE of wind speed is 1.01 m s-1 with correlation coefficient 0.72 using CMOD4 GMF alone for those cases. The proposed method can be applied to SAR image for avoiding the internal defect in CMOD5 under low wind speed condition. 展开更多
关键词 SAR surface wind retrieval geophysical model function CMOD4 CMOD5
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Comparison of convective parameterizations in RegCM4 experiments over China with CLM as the land surface model 被引量:36
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作者 GAO Xue-Jie SHI Ying Filippo GIORGI 《Atmospheric and Oceanic Science Letters》 CSCD 2016年第4期246-254,共9页
in the latest version of the international Centre for Theoretical Physics' regional climate model, RegCM4, CLM was introduced as a new land surface scheme. The performance over China of RegCM4-CLM with different conv... in the latest version of the international Centre for Theoretical Physics' regional climate model, RegCM4, CLM was introduced as a new land surface scheme. The performance over China of RegCM4-CLM with different convection schemes is analyzed in this study, based on a series of short- term experiments.The model is driven by ERA-Interim data at a grid spacing of 25 km.The convection schemes employed are: Emanuel; Grell; Emanuel over land and Grell over ocean; Grell over land and Emanuel over ocean; and Tiedtke. The simulated mean surface air temperature and precipitation in December-February-January and June-July-August are compared against observation. In general, better performance of Emanuel is found both for temperature and precipitation, and in both seasons. Thus, the model physics of CLM and Emanuel for the land surface processes and convection, respectively, are recommended for further application of RegCM4 over the China region. The de^ciencies that remain in the model arealso outlined and discussed. 展开更多
关键词 Regional climate model China RegCM4 temperatureprecipitation
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Variable Relation Parametric Model on Graphics Modelon for Collaboration Design 被引量:1
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作者 董玉德 赵韩 李延锋 《Journal of Donghua University(English Edition)》 EI CAS 2005年第1期45-49,共5页
A new approach to variable relation parametric model for collaboration design based on the graphic modelon has been put forward. The paper gives a parametric description model of graphic modelon, and relating method f... A new approach to variable relation parametric model for collaboration design based on the graphic modelon has been put forward. The paper gives a parametric description model of graphic modelon, and relating method for different graphic modelon based on variable constraint. At the same time, with the aim of engineering application in the collaboration design, the autonmous constraint in modelon and relative constraint between two modelons are given. Finally, with the tool of variable and relation dbase, the solving method of variable relating and variable-driven among different graphic modelon in a part, and double-acting variable relating parametric method among different parts for collaboration are given. 展开更多
关键词 graphics modelon PARAMETERIZATION VARIABLE collaboration design.
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(∈γ, ∈γ Vqδ)-intuitionistic Fuzzy(Soft) Filter of BL-algebras 被引量:6
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作者 YANG Yong-wei XIN Xiao-long HE Peng-fei 《Chinese Quarterly Journal of Mathematics》 CSCD 2014年第1期65-75,共11页
In the paper, in order to further study the properties of filters of BL-algebras, we propose the concepts of the (∈γ, ∈γ Vqδ)-intuitionistic fuzzy filters and (∈γ, ∈γ Vqδ)- intuitionistic fuzzy soft filt... In the paper, in order to further study the properties of filters of BL-algebras, we propose the concepts of the (∈γ, ∈γ Vqδ)-intuitionistic fuzzy filters and (∈γ, ∈γ Vqδ)- intuitionistic fuzzy soft filters of BL-algebras and derive some related results. Finally, we discuss the properties of images and inverse images of (∈γ, ∈γ Vqδ)-intuitionistic fuzzy soft filters of BL-algebras. 展开更多
关键词 BL-ALGEBRAS intuitionistic fuzzy sets (∈γ ∈γ Vqδ)-intuitionistic fuzzy filters soft sets
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Model-based optical metrology and visualization of 3-D complex objects 被引量:2
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作者 LIU Xiao-li LI A-meng +3 位作者 ZHAO Xiao-bo GAO Peng-dong TIAN Jin-dong PENG Xiang 《Optoelectronics Letters》 EI 2007年第2期115-118,共4页
This letter addresses several key issues in the process of model-based optical metrology, including three dimensional (3D) sensing, calibration, registration and fusion of range images, geometric representation, and v... This letter addresses several key issues in the process of model-based optical metrology, including three dimensional (3D) sensing, calibration, registration and fusion of range images, geometric representation, and visualization of reconstructed 3D model by taking into account the shape measurement of 3D complex structures,and some experimental results are presented. 展开更多
关键词 三维复杂目标 可视化 光学计量 数学模型 距离象 象融合
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Effect of processing parameters on flow behaviors and microstructure during high temperature deformation of GH4586 superalloy 被引量:3
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作者 LUO Jiao LI Xiang-yang +1 位作者 LI Cong LI Miao-quan 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期338-350,共13页
The apparent activation energy for deformation(Q)and strain rate sensitivity(m)of GH4586 superalloy are calculated and the variation trend is reasonably explained by the microstructure observations.Constitutive modell... The apparent activation energy for deformation(Q)and strain rate sensitivity(m)of GH4586 superalloy are calculated and the variation trend is reasonably explained by the microstructure observations.Constitutive modelling of this superalloy is established and the processing maps at different strains are constructed.The results show that the Q value is in the range of 751.22−878.29 kJ/mol.At a temperature of 1060°C,strain rate of 0.001 s^(−1),and strain of 0.65,the m value of GH4586 superalloy reaches a maximum of 0.42.The optimal processing parameter of GH4586 superalloy is at a deformation temperature of 1050°C and a strain rate of 0.001 s^(−1).The domains of flow instability notably expand with increasing strain during high temperature deformation of GH4586 superalloy. 展开更多
关键词 GH4586 superalloy apparent activation energy for deformation strain rate sensitivity constitutive model processing maps
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Effect of Fiber Properties on Nonwovens' Pore Structures with Fractal Geometry Analysis
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作者 杨旭红 李栋高 《Journal of Donghua University(English Edition)》 EI CAS 2005年第4期103-108,共6页
Nonwovens' pore structures are very important to their mechanical and physical properties. And the pore structures are influenced by the fiber properties and fibers arrangement in web. In this paper, the fractal geom... Nonwovens' pore structures are very important to their mechanical and physical properties. And the pore structures are influenced by the fiber properties and fibers arrangement in web. In this paper, the fractal geometry, in combination with computer image anaysis, is used to express the irregularity of pore size distribution in nonwovens, and the effect of fiber properties on fractal dimension of pore size distribution is discussed by using simulated images which are composed of nonlinear staple fibers. The results show that the fiber properties, such as crimp, diameter, angular distribution, and especially the number of fibers prominently influence the pore structure. 展开更多
关键词 NONWOVENS fiber properties fractal dimension of pore size distribution simulated images.
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