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作者： Neupane, Babita Kent State University

学位级别：硕士

Inspired by the historical construction technique and contemporary form-finding methods, as well as practices in designing and constructing masonry vaults, the thesis explores different forms that can be built without centering during construction. This thesis examines the literature associated with the geometries, construction techniques and methods used to generate masonry arches, vaults, and domes without centering or with minimum supports. The main idea about which lies on the self-supporting courses where each masonry unit has its own equilibrium condition. Based on the principles of equilibrium, this research develops algorithms for two cases: when bricks are not bonded with mortar and are bonded with mortar. The algorithms to generate an arch when subjected to additional vertical load for both cases have also been ***, using the python component in Grasshopper, a tool is developed using the proposed algorithms in this thesis. The tool is used for parametric designs to create new forms of masonry vaults which could be built without centering.

关键词： Architectural Architecture Design Unreinforced masonry vaults Equilibrium approach Design Architecture Algorithm Parametric design python script

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Experimental and XFEM modelling of high cycle fatigue crack growth in steel welded T-joints

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INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES 2019年 153卷 178-193页

作者： Nikfam, M. R. Zeinoddini, M. Aghebati, F. Arghaei, A. A. KN Toosi Univ Technol Fac Civil Engn Tehran Iran Western Univ Fac Civil & Environm Engn London ON Canada

The current paper reports the results of a series of high cycle fatigue (HCF) experiments on steel welded T-joints, tested under constant amplitude three-point bending. The eXtended Finite Element Method (XFEM) was then implemented to simulate the experiments. The crack and its growth were characterised by means of level set functions to eliminate the need for re-meshing. The study can be viewed as a first-of-its-kind in XFEM fatigue simulation of butt welded steel T-joints;where the crack geometry and growth is essentially three dimensional, making the problem particularly acute. The XFEM/fatigue crack growth (FCG) procedure employed in the study was first validated against constant amplitude HCF experiments on notched steel plates from other researchers. The same modelling procedure was then used for simulating the fatigue tests conducted on steel welded T-joints. It was found that the XFEM predictions for the crack growth, the growth rate, number of cycles to failure, crack shape and final crack size were satisfactorily comparable to those obtained in the experiments. Mean errors in the XFEM predictions for the fatigue life ranged from -20.7% to +0.9%. The morphology of the fracture surface from the numerical model, in general, had a good agreement with the corresponding experimental morphology.

关键词： Extended finite element method XFEM Fatigue crack growth python script Fatigue experiments Steel welded T-joint

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A GIS method for volumetric assessments of erosion rills from digital surface models

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EUROPEAN JOURNAL OF REMOTE SENSING 2019年第sup1期52卷 96-107页

作者： Bacova, Marketa Krasa, Josef Devaty, Jan Kavka, Petr Czech Tech Univ Dept Landscape Water Conservat Prague Czech Republic

Modern non-contact methods for data acquisition are becoming widely used for monitoring soil erosion and for assessing soil degradation after rainfall events. Photogrammetric methods are especially favored to obtain a detailed and precise digital surface model (DSM) of the surveyed area. This paper introduces the algorithm and its python implementation as a tool for ArcGIS software, which makes efficient automatic calculations of the volume of erosion rills or gullies. The input parameters are a DSM, and the rill edge polygon. The method was tested on an artificially created rill, where the result acquired using presented method was compared to the real volume. The comparison showed that the algorithm may underestimate the volume by 10-15%. In addition, the influence of the position of the rill edge polygon was tested on two DSMs of erosion rills. The resulting volumes of the rills, calculated on the basis of eight different edge polygons, varied by 5%. The algorithm also automates interpolation of the surface prior to erosion, which simplifies its usage in firstly monitored regions. The algorithm can also be used for volumetric analyses in other research areas and it is made available as a supplement of the publication.

关键词： Soil erosion rill volume DSM photogrammetry python script GIS

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Snow cover area analysis and its relation with climate variability in Chandra basin, Western Himalaya, during 2001-2017 using MODIS and ERA5 data

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ENVIRONMENTAL MONITORING AND ASSESSMENT 2020年第8期192卷 489-489页

作者： Sahu, Rakesh Gupta, R. D. Motilal Nehru Natl Inst Technol Allahabad GIS Cell Prayagraj 211004 India Motilal Nehru Natl Inst Technol Allahabad Civil Engn Dept Prayagraj 211004 India

Glaciers and snow cover area (SCA) plays an important role in river runoff in Himalayan region. There is a need to monitor SCA on spatio-temporal basis for better and efficient utilization of water resources. Moderate Resolution Imaging Spectroradiometer (MODIS) provides less cloudy data due to high temporal resolution as compared to other optical sensors for high elevation regions, and its 8-day snow cover product is globally used for snow cover estimation. The main objective of the present paper is to estimate annual and seasonal SCA in Chandra basin, Western Himalaya, and analysis of its variation with elevation, aspect, and slope during 2001 to 2017 using MODIS Terra (MOD10A2) and Aqua (MYD10A2) snow cover product as well as to correlate the same with temperature and precipitation using fifth generation European Centre for Medium-Range Weather Forecasts (ECMWF) Atmospheric Reanalysis of the global climate (ERA5) data. The total average SCA observed is 84.94% of basin area during the study period. The maximum annual average SCA was found as 91.23% in 2009 with minimum being 76.37% in 2016. Strong correlation is observed in annual and seasonal SCA with temperature which indicate that SCA variability is highly sensitive to temperature.

关键词： Chandra basin Climate change MODIS snow product python script Snow cover area

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Geometric modeling and finite element analysis of kevlar monolithic and carbon-kevlar hybrid woven fabric unit cell

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Materials Today: Proceedings 2020年 26卷 766-774页

作者： Pawan Sharma Pragati Priyanka Harlal Singh Mali Anurag Dixit Department of Mechanical Engineering Malaviya National Institute of Technology Jaipur Rajasthan 302017 India Department of Mechanical and Automation Engineering G.B. Pant Government Engineering College New Delhi 110020 India

The prediction of the mechanical strength of composites must be known before use or fabrication. The computerized modeling and analysis helps in prediction of the realistic performance of the composite products. The current research work presents the modeling routs of yarns, yarn interpolation for path, cross-section, and orientations with finite element analysis of woven fabric reinforcements. The geometrical modeling routes of textile woven reinforcements at meso-scale described by using TexGen 3.10, which is a python scripted software package, developed by the polymer composites group at the University of Nottingham, UK, works as a preprocessor for characterization of textile reinforcements. The finite element analysis of textile woven reinforcements is done by using a commercially available software package ABAQUS 6.14-5. Due to the similarity of python scripted codes in both the software’s, ABAQUS is considered as an analysis tool for textile reinforcements among the so many FE based platforms. Textile woven fabric unit cell having plain and twill weaving patterns are explained with Kevlar (monolithic) and Carbon-Kevlar (hybrid) yarns with finite element compression behaviour analysis, and discussed to understand the mechanical performance of polymer textile composites.

关键词： Reinforcement Matrix Woven Plain Twill Hybrid fabric Textile composites python script

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Spatial Data Process Using python script and Visual Programming Language in ArcGIS

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Computer Technology and Application 2013年第6期4卷 275-283页

作者： Pil Kwon The Department of Civil and Environmental Engineering Seoul National University Seoul 151-744 South Korea

Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS （Geographic Information System） software in GIS sector. However, those table data contain much unnecessary information that do not need for a certain project. Using the raw data can increase processing times and reduce performance of geoprocessing tools. This study shows steps of how the raw data are being processed using ArcGIS ModelBuilder and python script.

关键词： ArcGIS ArcMap GIS Local Moran＇s I ModelBuilder python python script visual programming language.

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Estimation of evapotranspiration and its parameters for pine, switchgrass, and intercropping with remotely-sensed images based geospatial modeling

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ENVIRONMENTAL MODELLING & SOFTWARE 2019年 121卷 104487-000页

作者： Panda, Sudhanshu Sekhar Amatya, Devendra Man Muwamba, Augustine Chescheir, George Univ North Georgia Inst Environm Spatial Anal 3820 Mundy Mill Rd Oakwood GA 30566 USA US Forest Serv Ctr Forested Wetlands Res USDA 3734 Highway 402 Cordesville SC 29434 USA Univ Georgia Coll Engn Athens GA 30602 USA North Carolina State Univ Dept Agr & Biosyst Engn Raleigh NC 27695 USA

Intercropping switchgrass (Panicum virgatum) with pine can increase bioenergy feedstock production without land opportunity costs but can potentially alter water budgets. Measuring evapotranspiration (ET) and its parameters (stomatal conductance (g(s)), leaf area index (LAI), canopy temperature (T-c), and soil moisture (SM)) across cropping systems is costly and time-consuming. However, interpretation of remotely-sensed data can facilitate the effective assessment of relative ET demands among competing forest landuses. This study develops and tests geospatial models informed by a normalized difference vegetation index (NDVI), soil adjusted vegetation index (SAVI), vegetation vigor index (VVI), and other spectral information to estimate ET and its parameters, which are measured on experimental watersheds with young pines and natural understory (YP), switchgrass only (SG), and young pine intercropped with switchgrass (IC). The treatment watersheds were replicated on three sites located across the Southeastern U.S. in Carteret, NC;Calhoun, MS;and Greene, AL. Despite the growth inconsistency for the SG only treatment, remote modeling estimation of ET parameters yielded an acceptable R-2 > 0.70, and the ET model yielded R-2 of 0.50 and a standard error of prediction of 0.94. However, ET and ET parameter model estimation for the IC performed somewhat less satisfactorily, with an R-2 of 0.47, 0.59, 0.56, 0.81, and 0.57 for ET, LAI, g(s), T-c, and SM, respectively, potentially due to inconsistencies in Landsat image pixel size and landuse homogeneity. Moreover, ET parameter models for the YP site performed rather poorly, with R-2 = 0.28, 0.63, and 0.76 for LAI, g(s), and T-c, respectively. Additionally, image analysis automation was created with python scripting and geospatial models. The findings from this study suggest that inclusion of more spatial variability, sound data mining, ultra-high resolution imagery and advanced image processing approaches to account for potent

关键词： ArcGIS ModelBuilder Canopy temperature Data mining Evapotranspiration Landsat Orthoimagery python script RBFN Software development Soil moisture SPOT Stomatal conductance Visual basics studios

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基于BIM的丽江纳西传统民居营造技术研究

基于BIM的丽江纳西传统民居营造技术研究

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作者：张劭焘北方工业大学

学位级别：硕士

本文以丽江纳西传统木构架建筑为研究对象,从木构架梳理及建立丽江纳西传统木构架体系入手,基于调研、对比分析、计算机模型配合实物验证、差异成因推演等方法,进行了引入BIM技术中REVIT平台辅助分析,并对分析结果通过实物模型加以印证... 详细信息

本文以丽江纳西传统木构架建筑为研究对象,从木构架梳理及建立丽江纳西传统木构架体系入手,基于调研、对比分析、计算机模型配合实物验证、差异成因推演等方法,进行了引入BIM技术中REVIT平台辅助分析,并对分析结果通过实物模型加以印证,保证软件分析的科学准确,完成丽江纳西传统木构架的建立,分析丽江纳西传统木构架类别之间的差异以及差异的成因,根据搜集到的资料推演丽江纳西传统木构架之间的演化关系等工作,最终得到了完善的丽江纳西传统木构架体系,以及各构件之间的演化关系等相关成果。体系建立之后,基于调研、归纳总结等方法,对最有代表性的一类传统木构架建筑即骑厦楼开展了具体的营造分析工作,从尺度模数、基础的制作、木构架的选材与加工、榫卯形制及节点的制作、屋顶瓦作等进行了一一说明与分析,最终将木构架的所有构件进行了精细化的模型制作,在文中展示了较为复杂且有特色的木构架三维模型大样以及复杂构件的组合节点。另外还根据研究成果,对骑厦楼优秀的抗震性能的成因进行了系统的分析归纳与总结,最终将骑厦楼的营造,特别是木构架的营造进行了系统详尽的阐述。根据前期针对于骑厦楼木构架营造所研究结论,引入BIM技术中的REVIT平台,对骑厦楼木构架进行数字化模型建立,进行了BIM技术在古建筑建模上的应用尝试。根据上述研究成果,运用REVIT软件完成了全部木构件的建模工作,并选取了较有代表性的构件将建模思路、方法及过程在文中做了详细的阐述,并且将最终建立的骑厦楼REVIT构件录入了REVIT模型库,方便后人调用。在建模过程中,由于建模软件的限制无法使用软件中自带的构件间智能联动这一功能,大大降低了所建成模型的智能化参数调整,因此引入Dynamo可视化编程软件,通过编写可视化程序解决了构件间无法智能联动等问题,打破了 REVIT软件在古建筑建模应用上的壁垒,同时也给Dynamo可视化编程软件的应用提供了新的思路。为保证骑厦楼智能化模型建立更为完整,进行了骑厦楼维护结构智能建立的更进一步尝试,通过python script编程语言以Dynamo编程软件中python script节点为平台实现骑厦楼维护结构的智能创建程序的编写。编写之后的程序可以实现墙体及轴网的智能化创建,并且快速准确。在编写python script程序过程中,笔者通过调用REVIT的应用程序编程接口(Application Programming Interface),踏出了REVIT软件二次开发的第一步,实现了非专业编程人员进行软件二次开发的新尝试。为今后REVIT软件的二次开发提供了一定的借鉴。

关键词：纳西建筑木构架体系 BIM Dynamo python script

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Simulating And Prototyping Software Defined Networking (SDN) Using Mininet Approach To Optimise Host Communication In Realistic Programmable Networking Environment Optimise Host Communication In Realistic Programmable Networking Environment.

Simulating And Prototyping Software Defined Networking (SDN)...

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作者： Lindinkosi Lethukuthula Zulu University of South Africa

学位级别：硕士

In this project, two tests were performed. On the first test, Mininet-WiFi was used to simulate a Software Defined Network to demonstrate Mininet-WiFia s ability to be used as the Software Defined Network emulator which can also be integrated to the existing network using a Network Virtualized Function (NVF). A typical organizationas computer network was simulated which consisted of a website hosted on the LAMP (Linux, Apache, MySQL, PHP) virtual machine, and an F5 application delivery controller (ADC) which provided load balancing of requests sent to the web applications. A website page request was sent from the virtual stations inside Mininet-WiFi. The request was received by the application delivery controller, which then used round robin technique to send the request to one of the web servers on the LAMP virtual machine. The web server then returned the requested website to the requesting virtual stations using the simulated virtual network. The significance of these results is that it presents Mininet-WiFi as an emulator, which can be integrated into a real programmable networking environment offering a portable, cost effective and easily deployable testing network, which can be run on a single computer. These results are also beneficial to modern network deployments as the live network devices can also communicate with the testing environment for the data center, cloud and mobile provides. On the second test, a Software Defined Network was created in Mininet using python script. An external interface was added to enable communication with the network outside of Mininet. The amazon web services elastic computing cloud was used to host an OpenDaylight controller. This controller is used as a control plane device for the virtual switch within Mininet. In order to test the network, a webserver hosted on the Emulated Virtual Environment a Next Generation (EVENG) software is connected to Mininet. EVE-NG is the Emulated Virtual Environment for networking. It pr

关键词： Software Defined Networking (SDN) Network Functions Virtualization (NFV) OpenDaylight Controller Mininet Linux Web Server Mininet Wi-Fi Application Delivery Controller (F5) Cloud Computing (Amazon Web Services) python script mulated Virtual Environment - Next Generation (EVE-NG)

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ParaView visualization of Abaqus output on the mechanical deformation of complex microstructures

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COMPUTERS & GEOSCIENCES 2017年 99卷 135-144页

作者： Liu, Qingbin Li, Jiang Liu, Jie Peking Univ Sch Earth & Space Sci Beijing 100871 Peoples R China Sun Yat Sen Univ Sch Earth Sci & Geol Engn Guangzhou 510275 Guangdong Peoples R China Natl Supercomp Ctr Guangzhou Guangzhou 510006 Guangdong Peoples R China Guangdong Prov Key Lab Mineral Resources & Geol P Guangzhou 510275 Guangdong Peoples R China

Abaqus (R) is a popular software suite for finite element analysis. It delivers linear and nonlinear analyses of mechanical and fluid dynamics, includes multi-body system and multi-physics coupling. However, the visualization capability of Abaqus using its CAE module is limited. Models from microtomography have extremely complicated structures, and datasets of Abaqus output are huge, requiring a visualization tool more powerful than Abaqus/CAE. We convert Abaqus output into the XML-based VTK format by developing a python script and then using ParaView to visualize the results. Such capabilities as volume rendering, tensor glyphs, superior animation and other filters allow ParaView to offer excellent visualizing manifestations. ParaView's parallel visualization makes it possible to visualize very big data. To support full parallel visualization, the python script achieves data partitioning by reorganizing all nodes, elements and the corresponding results on those nodes and elements. The data partition scheme minimizes data redundancy and works efficiently. Given its good readability and extendibility, the script can be extended to the processing of more different problems in Abaqus. We share the script with Abaqus users on GitHub.

关键词： Abaqus (R) Post-processing python script ParaView Parallel visualization

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