检索结果-内蒙古大学图书馆

25th ACM Conference on 3D Web Technology (Web3D)

作者： Piao, Xue Li, Yang Xie, Kang Zhao, Hantao Jia, Jinyuan Tongji Univ Sch Software Engn Shanghai Peoples R China Southeast Univ Sch Cyber Sci & Engn Nanjing Peoples R China Swiss Fed Inst Technol Chair Cognit Sci Zurich Switzerland

ISBN: (纸本)9781450381697

The heterogeneity of the appearance and behavior of the crowd is an important component in a realistic simulation. Using Web3D technology to recreate a large-scale crowd of virtual avatars via the internet is an increasingly important area in crowd studies, especially for emergency crowd evacuation. One major issue in the early development of real-time simulation is the challenge of introducing diversity and authenticity on avatars' appearance and behavior. Another major theoretical issue is high transmission delay on the network, which diminishes the simulation performed on the web browser when rendering a large number of visualization components. In this research, we propose a novel method to provide a lightweight solution that can simultaneously guarantee the realness and diversity of the simulated crowd. We use a parameterization technique based on shape space to distinguish the avatars' appearance. Asynchronously transmitting the rendering elements helps to reduce bandwidth pressure. The multi-level clone instancing method can generate a massive amount of heterogeneous avatars in a short time. In the end, we validated our methods with an online experiment to demonstrate its ability to solve large-scale crowd simulation problems over the internet.

关键词： web3D web browser crowd simulation evacuation behavior model parameterization avatar rendering

来源：评论

学校读者我要写书评

暂无评论

Simulation of Hurricane Harvey flood event through coupled hydrologic-hydraulic models: Challenges and next steps

引用

JOURNAL OF FLOOD RISK MANAGEMENT 2021年第3期14卷 e12716-e12716页

作者： Dullo, Tigstu T. Gangrade, Sudershan Morales-Hernandez, Mario Sharif, Md Bulbul Kao, Shih-Chieh Kalyanapu, Alfred J. Ghafoor, Sheikh Evans, Katherine J. Tennessee Technol Univ Dept Civil & Environm Engn Cookeville TN 38505 USA Univ Tennessee Bredesen Ctr Knoxville TN USA Oak Ridge Natl Lab Environm Sci Div Oak Ridge TN USA Oak Ridge Natl Lab Climate Change Sci Inst Oak Ridge TN USA Oak Ridge Natl Lab Computat Sci & Engn Div Oak Ridge TN USA Tennessee Technol Univ Dept Comp Sci Cookeville TN 38505 USA

Using the 2017 Hurricane Harvey flood event as a test case, this study set up a series of sensitivity analyses to highlight three challenges associated with large-scale flood inundation modeling, including (a) model parameterization, (b) errors in digital elevation models, and (c) effects of reservoir retention. Driven by radar-based hourly rainfall data, a series of hydrologic-hydraulic models including the VIC hydrologic model, RAPID routing model, and Flood2D-GPU hydrodynamic model are set up over Harris County, Texas, to simulate flood inundation and hazards. The results demonstrate the importance of hydrologic parameters in improving flood modeling. For a large flood event such as Hurricane Harvey, the effect of the initial water depths is insignificant. The Manning's n values may increase the peak water depth by similar to 1%, the flood extents by 65km(2), and the high danger zone by similar to 6%. On the contrary, the bathymetry correction factors may reduce the flood extent by similar to 1.4% and the high-danger zone by similar to 4%. Reducing the reservoir storage capacity to 1% may increase the flood extent by similar to 4% and the high-danger zone by similar to 17%. This study may provide supporting information to guide and prioritize the development of future high-performance computing hydrodynamic large-scale flood simulations.

关键词： digital elevation model (DEM) flood simulation graphics processing unit (GPU) Hurricane Harvey model parameterization reservoir

来源：评论

学校读者我要写书评

暂无评论

Estimating Parameters for a Doyle Fuller Newman model of a Graphite Half Cell Battery

Estimating Parameters for a Doyle Fuller Newman Model of a G...

引用

作者： Chipman, Gregory Dan Georgia Institute of Technology

学位级别：硕士

Electrochemical research involves the modeling of electrochemical systems using various types of models. models use adjustable parameters to be able to fit experimental data. Parameters of physics-based models are actual properties of the electrochemical system; and, if determined accurately, can reveal more about the inner physics of the system. Further physics-based models can be extrapolated with more confidence to other experimental conditions. Because insights obtained and ability to extrapolate from a physics-based model is based on the accuracy of the parameters obtained, the main objective of adjusting the parameters to fit the experimental data should be finding the most accurate parameter set, not the best fitting parameter set. Because of the complexity of physics-based models, adjusting parameters to fit experimental data without forethought and estimates may lead to inaccurate parameter sets. This thesis focused on laying out a procedure for estimating parameters for a physics-based model to increase the probability of obtaining an accurate parameter set for the electrochemical system. As an example, parameters were obtained for a Doyle Fuller Newman model for a graphite vs. lithium coin cell battery. These estimates were obtained from scanning electron microscopy images, the galvanostatic intermittent titration technique, and electrochemical impedance spectroscopy. These estimates were put into a Doyle Fuller Newman model in gPROMs and the simulation output was compared to experimental discharge data. These estimates can be used as a starting point for fitting the model to experimental data to find a final set of parameters for the model.

关键词： Battery modeling Physics-Based modeling model parameterization

来源：评论

学校读者我要写书评

暂无评论

Effect Level Based parameterization Method for Diffuse Scattering models at Millimeter-Wave Frequencies

引用

IEEE ACCESS 2019年 7卷 93286-93293页

作者： Tian, Haikuo Liao, Xi Wang, Yang Shad, Yu Zhou, Jihua Hu, Tao Zhang, Jie Chongqing Univ Posts & Telecommun Sch Commun & Informat Engn Chongqing 400065 Peoples R China Chongqing Jinmei Commun Co Ltd Chongqing 400030 Peoples R China Univ Sheffield Dept Elect & Elect Engn Sheffield S10 2TN S Yorkshire England

This paper proposes a multi-coefficient estimation method for the dielectric parameters of rough materials and an effect level-based parameterization method for diffuse scattering models to characterize and model the diffuse scattering propagation at millimeter-wave frequencies. Aseries of diffuse scattering propagation measurements and simulations for rough materials have been performed at 40-50 GHz in a typical indoor scenario. Theoretical reflection coefficient, transmission coefficient, and scattering coefficient of rough materials, which are requisite for the proposed estimation method, are derived based on the Fresnel theoretical model and the Gaussian rough surface model. The directive model and double-lobe model are chosen and integrated with ray tracing tool to simulate the diffuse multipath propagation for rough materials based on effect level evaluation results. The optimal model parameters are obtained and various simulation results are compared and in particular, the estimated ranges of scattering coefficients agree well with the measured values. The investigations demonstrate that the proposed parameterization method is reliable and accurate for the diffuse scattering models and can be applied for the determination of model parameters from extensive materials measurement data, especially for millimeter-wave channel analysis and modeling.

关键词： Millimeter-wave diffuse scattering model parameterization effect level propagation coefficients rough materials

来源：评论

学校读者我要写书评

暂无评论

A Review on Electrothermal modeling of Supercapacitors for Energy Storage Applications

引用

IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS 2019年第3期7卷 1677-1690页

作者： Wei, Li Wu, Ming Yan, Mengdi Liu, Shuai Cao, Qiang Wang, Huai Tongji Univ Sch Elect & Informat Engn Shanghai 201804 Peoples R China Aalborg Univ Dept Energy Technol DK-9220 Aalborg Denmark Tongji Univ Sch Mech Engn Shanghai 201804 Peoples R China

Supercapacitors (SCs) are drawing more and more attention in energy storage applications. This paper aims to discuss the state of the art of application-oriented electrothermal modeling methods for SCs and identify the limitations and future research opportunities. Electrothermal modeling is essential to model-based design, thermal management, and reliability analysis of SCs for energy storage applications. The review provides new perspectives with respect to the existing surveys, which focus mainly on materials, cell voltage balancing, electrical equivalent circuit models, and energy management systems. It covers the main aspects of electrothermal modeling of electric double-layer capacitors (EDLCs) and hybrid SCs, from heat generation mechanisms to different modeling and parameterization approaches. The outcome of the review is an archive of important research work in the topic area and an outlook on future efforts to be made.

关键词： Electrothermal modeling energy storage application heat generation heat transfer model parameterization supercapacitor (SC)

来源：评论

学校读者我要写书评

暂无评论

Systematic tests for study of tire tractive performance on soft soil: Part I - Experimental data collection

引用

JOURNAL OF TERRAMECHANICS 2019年 85卷 59-76页

作者： He, Rui Sandu, Corina Osorio, Javier E. Virginia Tech Dept Mech Engn Terramech Multibody & Vehicle Syst TMVS Lab Blacksburg VA 24061 USA US Army Engineer Res & Dev Ctr Vicksburg MS 39180 USA

Tire performance over soft soil is of interest for automotive and geotechnical engineers;the automotive engineers are mainly interested in tire tractive performance;and geotechnical engineers are concerned with the effects of the traffic brought by the tire to the soil. This two-part paper documents a series of tire and soil tests (Part I) and the application of their test data to the study of tire tractive performance over soft soil (characterized by drawbar pull) and to the model parameterization (Part II). Part I of this paper details the series of tests that are comprised of static tire deflection tests, static tire-soil tests, soil properties tests, and dynamic tire-soil tests, and describes the influence of tire inflation pressure or soil compaction level on the test data. The experimental approach presented herein produces parameterization and validation data that can be used in tire off-road traction dynamics modeling and terramechanics modeling. (C) 2019 ISTVS. Published by Elsevier Ltd. All rights reserved.

关键词： Terramechanics Tire off-road dynamics Tire test Soil test model parameterization Tractive performance Soil compaction

来源：评论

学校读者我要写书评

暂无评论

Characteristics of isoprene emission from moso bamboo leaves in a forest in central Taiwan

引用

ATMOSPHERIC ENVIRONMENT 2019年第0期211卷 288-295页

作者： Chang, Tingwei Kume, Tomonori Okumura, Motonori Kosugi, Yoshiko Kyoto Univ Grad Sch Agr Kyoto 6068502 Japan Kyushu Univ Kasuya Res Forest Fukuoka Fukuoka 8112415 Japan Natl Taiwan Univ Sch Forestry & Resource Conservat Taipei 10617 Taiwan Res Inst Environm Agr & Fisheries Habikino Osaka 5830862 Japan

The expansion of moso bamboo (Phyllostachys edulis) may potentially impact regional isoprene emissions. modeling based on field measurements is an effective approach for assessing the potential impact of the moso bamboo expansion. The G93 algorithm is one of the most widely used models, however no studies have tested the applicability of the algorithm for moso bamboo isoprene emission. This study was undertaken to establish a model for reproducing moso bamboo isoprene emission fluxes. To this aim, this study examined 1) the isoprene emission ability of moso bamboo, and 2) its responses to environmental factors such as leaf temperature and light. We also tested 3) the reproducibility of the G93 algorithm for moso bamboo isoprene emission fluxes. This study used a chamber method with a modified photosynthesis system and carbon absorbents to quantify isoprene emitted from bamboo leaves in central Taiwan under the humid subtropical climate. First, we screened isoprene emission from 12 bamboo species, and the results confirmed that moso bamboo exhibited significant isoprene emission potential. Second, we measured isoprene emission fluxes from moso bamboo leaves with light controls every month from summer to spring. The isoprene emission fluxes increased with photosynthetic photon flux density (PPFD);under sufficient PPFD conditions, the seasonal changes in the isoprene emission fluxes were regulated by leaf temperature, and low isoprene emission fluxes were found in low leaf temperature conditions. Thirdly, overestimations were observed in the G93 algorithm with the original parameters in periods with leaf temperatures < 23 degrees C. Using the G93 algorithm with site-specific parameters could improve the overestimation in the low-temperature period. This study suggests the necessity of parameterization in the G93 algorithm to reproduce the suppression of isoprene emission fluxes from moso bamboo leaves in the low-temperature period.

关键词： Isoprene emission flux Moso bamboo Photosynthetically active radiation Leaf temperature G93 algorithm model parameterization

来源：评论

学校读者我要写书评

暂无评论

The Impact of Environmental Factors on the Thermal Characteristic of a Lithium-ion Battery

引用

BATTERIES-BASEL 2020年第1期6卷 3页

作者： Liebig, Gerd Kirstein, Ulf Geissendoerfer, Stefan Zahid, Omio Schuldt, Frank Agert, Carsten DLR Inst Networked Energy Syst D-26123 Oldenburg Germany

To draw reliable conclusions about the thermal characteristic of or a preferential cooling strategy for a lithium-ion battery, the correct set of thermal input parameters and a detailed battery layout is crucial. In our previous work, an electrochemical model for a commercially-available, 40 Ah prismatic lithium-ion battery was validated under heuristic temperature dependence. In this work the validated electrochemical model is coupled to a spatially resolved, three dimensional (3D), thermal model of the same battery to evaluate the thermal characteristics, i.e., thermal barriers and preferential heat rejection patterns, within common environment layouts. We discuss to which extent the knowledge of the batteries' interior layout can be constructively used for the design of an exterior battery thermal management. It is found from the study results that: (1) Increasing the current rate without considering an increased heat removal flux at natural convection at higher temperatures will lead to increased model deviations;(2) Centralized fan air-cooling within a climate chamber in a multi cell test arrangement can lead to significantly different thermal characteristics at each battery cell;(3) Increasing the interfacial surface area, at which preferential battery interior and exterior heat rejection match, can significantly lower the temperature rise and inhomogeneity within the electrode stack and increase the batteries' lifespan.

关键词： lithium-ion battery battery modeling electrochemical-thermal model finite element method model parameterization model validation thermal performance analysis battery thermal management system cooling strategies

来源：评论

学校读者我要写书评

暂无评论

The Added Value of Different Data Types for Calibrating and Testing a Hydrologic model in a Small Catchment

引用

WATER RESOURCES RESEARCH 2020年第10期56卷 e2019WR026153-e2019WR026153页

作者： Szeles, B. Parajka, J. Hogan, P. Silasari, R. Pavlin, L. Strauss, P. Bloeschl, G. Vienna Univ Technol Inst Hydraul Engn & Water Resources Management Vienna Austria Fed Agcy Water Management Inst Land & Water Management Res Petzenkirchen Austria

This study investigated the added value of different data for calibrating a runoff model for small basins. The analysis was performed in the 66 ha Hydrological Open Air Laboratory, in Austria. An Hydrologiska Byrans Vattenbalansavdelning (HBV) type, spatially lumped hydrologic model was parameterized following two approaches. First, the model was calibrated using only runoff data. Second, a step-by-step approach was followed, where the modules of the model (snow, soil moisture, and runoff generation) were calibrated using measurements of runoff and model state variables and output fluxes. These measurements comprised laser-based measurements of precipitation, satellite and camera observations of snow, ultrasonic measurements of snow depth, eddy covariance measurements of evapotranspiration, time domain transmissometry-based soil moisture measurements, time-lapse photography of overland flow, and groundwater level measurements by piezometers. The two model parameterizations were evaluated on annual, seasonal, and daily time scales, in terms of how well they simulated snow, soil moisture, evapotranspiration, overland flow, storage change in the saturated zone, and runoff. Using the proposed step-by-step approach, the relative runoff volume errors in the calibration and validation periods were 0.00 and -0.01, the monthly Pearson correlation coefficients were 0.92 and 0.82, and the daily logarithmic Nash Sutcliffe efficiencies were 0.59 and 0.18, respectively. By using different sources of data besides runoff, the overall process consistency improved, compared to the case when only runoff was used for calibration. Soil moisture and evapotranspiration observations had the largest influence on simulated runoff, while the parameterization of the snow and runoff generation modules had a smaller influence.

关键词： hydrologic model model parameterization field observations experimental catchment

来源：评论

学校读者我要写书评

暂无评论

Developing a Parametric 3D Face model Editing Algorithm

引用

IEEE ACCESS 2020年 8卷 167209-167224页

作者： Pang, Min He, Ligang Kuang, Liqun Chang, Min He, Zhiying Han, Xie North Univ China Sch Data Sci & Technol Taiyuan 030051 Peoples R China Univ Warwick Dept Comp Sci Coventry CV4 7AL W Midlands England Jinxi Ind Grp Co Ltd Taiyuan 030001 Peoples R China North Univ China Software Sch Taiyuan 030051 Peoples R China

In the fields of computer graphics and computer vision, a great amount of research and analysis has been conducted on expression-carrying face models. How to construct more realistic and effective 3D face models has become an immense challenge to researchers. This paper proposes a parametric 3D face model editing algorithm based on existing 3D face models. The algorithm takes a number of existing 3D face models with different expressions as input, edits the models through mostly through model deformation and interpolation, and generates a new 3D face model. In particular, the face model editing process begins with selecting multiple face models with different expressions as input. Second, with one of the selected models as the source model and others as the target models, the source model and all target models are registered one by one;meanwhile, the vertex correspondence between the registered models is established. Third, the selected 3D models are parameterized to a planar disc through quasi-conformal mapping. Fourth, relying on the vertex correspondence, a set of corresponding control points between different models are established. The model is then deformed and interpolated under the guidance of the control points and by using the quasi-conformal iteration method, which produces the 2D face models with transitional expressions between the source model and the target models. Finally, the 2D models are restored to the corresponding 3D face models using the model restoration algorithm. Additionally, this paper proposes to use the Beltrami coefficient to guide the quasi-conformal iteration in performing the mapping between two planes. This coefficient then serves as a measure to evaluate the similarity between the edited model and the original one. The proposed algorithm has been evaluated through extensive experiments. The results suggest that compared with existing editing methods, the proposed method is more effective and efficient in constructing various 3D fa

关键词： Solid modeling Faces Three-dimensional displays Computational modeling Deformable models Strain Two dimensional displays Conformal mapping deformation interpolation model parameterization quasi-conformal iteration

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：