检索结果-内蒙古大学图书馆

modeling radiation belt electron dynamics during GEM challenge intervals with the dREAM3d diffusion model

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 2013年第10期118卷 6197-6211页

作者： Tu, Weichao Cunningham, G. S. Chen, Y. Henderson, M. G. Camporeale, E. Reeves, G. d. Los Alamos Natl Lab Sci & Appl Grp Los Alamos NM 87545 USA Los Alamos Natl Lab Appl Math & Plasma Phys Grp Los Alamos NM USA

As a response to the Geospace Environment modeling (GEM) Global Radiation Belt modeling Challenge, a 3d diffusion model is used to simulate the radiation belt electron dynamics during two intervals of the Combined Release and Radiation Effects Satellite (CRRES) mission, 15 August to 15 October 1990 and 1 February to 31 July 1991. The 3d diffusion model, developed as part of the dynamic Radiation Environment Assimilation model (dREAM) project, includes radial, pitch angle, and momentum diffusion and mixed pitch angle-momentum diffusion, which are driven by dynamic wave databases from the statistical CRRES wave data, including plasmaspheric hiss, lower-band, and upper-band chorus. By comparing the dREAM3d model outputs to the CRRES electron phase space density (PSd) data, we find that, with a data-driven boundary condition at L-max=5.5, the electron enhancements can generally be explained by radial diffusion, though additional local heating from chorus waves is required. Because the PSd reductions are included in the boundary condition at L-max=5.5, our model captures the fast electron dropouts over a large L range, producing better model performance compared to previous published results. Plasmaspheric hiss produces electron losses inside the plasmasphere, but the model still sometimes overestimates the PSd there. Test simulations using reduced radial diffusion coefficients or increased pitch angle diffusion coefficients inside the plasmasphere suggest that better wave models and more realistic radial diffusion coefficients, both inside and outside the plasmasphere, are needed to improve the model performance. Statistically, the results show that, with the data-driven outer boundary condition, including radial diffusion and plasmaspheric hiss is sufficient to model the electrons during geomagnetically quiet times, but to best capture the radiation belt variations during active times, pitch angle and momentum diffusion from chorus waves are required.

关键词： Radiation belt electrons 3d diffusion model dREAM3d GEM challenge

来源：评论

学校读者我要写书评

暂无评论

Archidiff: Interactive design of 3d architectural forms generated from a single image

引用

COMPUTERS IN INdUSTRY 2025年 168卷

作者： Yin, Jun Gao, Wen Li, Jizhizi Xu, Pengjian Wu, Chenglin Lin, Borong Lu, Shuai Tsinghua Univ Shenzhen Int Grad Sch Shenzhen Peoples R China Beijing Univ Technol Fac Architecture Civil & Transportat Engn Beijing Peoples R China Univ Sydney Sydney NSW Australia Zoomtech Engn co Ltd Guangzhou Peoples R China Tsinghua Univ Sch Architecture Beijing Peoples R China

3d Reconstruction Using Images has made strides in small-scale, uncomplicated scenes but struggles with complex, large-scale architectural forms. Targeting early-stage architectural design, we introduce Archidiff, a platform for 3d architectural form generation and editing from images to point clouds. First, we curated a dataset specifically tailored for architectural design, ArchiCloudNet. Second, we proposed a 3d generation method using a conditional denoising diffusion model, with an arbitrary object segmentation model to enhance recognition capabilities in complex input. Finally, we incorporate an interactive feature enabling instantaneous 2d image editing through simple drag-and-drops with simultaneous updates to 3d forms, giving designers improved control. We evaluated Archidiff's generation accuracy against cutting-edge baselines on ArchiCloudNet and two other datasets, RealCity3d and BuildingNet. We also validated it with real sketches from early-stage architectural design. The experiments indicated that our model could generate accurate architectural point clouds, providing rapid-response modification and effective processing of complex backgrounds. demostration: http://39.101.72 .109:3000/archidiff.

关键词： Architectural design Single-view reconstruction 3d interaction 3d diffusion model

来源：评论

学校读者我要写书评

暂无评论

PointInfinity: Resolution-Invariant Point diffusion models

PointInfinity: Resolution-Invariant Point Diffusion Models

引用

IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)

作者： Huang, Zixuan Johnson, Justin debnath, Shoubhik Rehg, James M. Wu, Chao-Yuan Meta FAIR Menlo Pk CA 94025 USA Univ Illinois Champaign IL 61820 USA

ISBN: (纸本)9798350353006

We present PointInfinity, an efficient family of point cloud diffusion models. Our core idea is to use a transformer-based architecture with a fixed-size, resolution-invariant latent representation. This enables efficient training with low-resolution point clouds, while allowing high-resolution point clouds to be generated during inference. More importantly, we show that scaling the test-time resolution beyond the training resolution improves the fidelity of generated point clouds and surfaces. We analyze this phenomenon and draw a link to classifier-free guidance commonly used in diffusion models, demonstrating that both allow trading off fidelity and variability during inference. Experiments on CO3d show that PointInfinity can efficiently generate high-resolution point clouds (up to 131k points, 31 more than Point-E) with state-of-the-art quality.

关键词： 3d diffusion model 3d Generation 3d reconstruction 3d Vision Computer Vision deep Learning

来源：评论

学校读者我要写书评

暂无评论

3dGS-Hd: Elimination of Unrealistic Artifacts in 3d Gaussian Splatting 6

3DGS-HD: Elimination of Unrealistic Artifacts in 3D Gaussian...

引用

6th International Conference on data-driven Optimization of Complex Systems (dOCS)

作者： Sun, Hao Qin, Junping Wang, Lei Yan, Kai Liu, Zheng Jia, Xinglong Shi, Xiaole Inner Mongolia Univ Technol Sch Data Sci & Applicat Hohhot Peoples R China

ISBN: (纸本)9798350377859;9798350377842

3d Gaussian Splatting (3dGS) can achieve higher-quality novel view synthesis (NVS) results in a relatively short period of time. Nevertheless, when sampling rates are not aligned with the camera track, unreal artifacts that are not part of the view often emerge, including floaters. This phenomenon has a significant impact on the quality of the reconstruction results. Furthermore, existing regularization methods are ineffective in terms of both inference speed and optimization. Accordingly, this study proposes the elimination of unrealistic artifacts in 3d Gaussian Splatting (3dGS-Hd), a scene optimization method based on the 3d diffusion model. This method optimizes the adaptive density mechanism by deeply understanding the local structural characteristics of the reconstructed objects, removes unrealistic artifacts, and significantly improves the reconstruction quality. Furthermore, it ensures consistency between 2d and 3d views. The results of the experiments demonstrate that this method produces notable improvements in optimization, particularly in the context of object-level reconstruction tasks.

关键词： novel view synthesis (NVS) 3d diffusion model artifacts high-quality 3d reconstruction

来源：评论

学校读者我要写书评

暂无评论

Precision process calibration and Cd predictions for low-k₁ lithography

Precision process calibration and CD predictions for low-k<s...

引用

Conference on Photomask and Next-Generation Lithography Mask Technology XII

作者： Chen, T Park, S Berger, G Coskun, TH de Vocht, J Chen, F Yu, L Hsu, S van den Broeke, d Socha, R Park, J Gronlund, K ASML Mask Tool Santa Clara CA 95054 USA

Leading resist calibration for sub-0.3 k(1) lithography demands accuracy 0.8) imaging characteristics, customized illuminations (measured vs. modeled pupil profiles), resolution enhancement technology (RET) mask with... 详细信息

ISBN: (纸本)0819458538

Leading resist calibration for sub-0.3 k(1) lithography demands accuracy < 2nm for Cd through pitch. An accurately calibrated resist process is the prerequisite for establishing production-worthy manufacturing under extreme low k(1). From an integrated imaging point of view, the following key components must be simultaneously considered during the calibration - high numerical aperture (NA > 0.8) imaging characteristics, customized illuminations (measured vs. modeled pupil profiles), resolution enhancement technology (RET) mask with OPC, reticle metrology, and resist thin film substrate. For imaging at NA approaching unity, polarized illumination can impact significantly the contrast formation in the resist film stack, and therefore it is an important factor to consider in the Cd-based resist calibration. For aggressive dRAM memory core designs at k(1)< 0.3, pattern-specific illumination optimization has proven to be critical for achieving the required imaging performance. Various optimization techniques from source profile optimization with fixed mask design to the combined source and mask optimization have been considered for customer designs and available imaging capabilities. For successful low-k(1) process development, verification of the optimization results can only be made with a sufficiently tunable resist. model that can predicate the wafer printing accurately under various optimized process settings. We have developed, for resist patterning under aggressive low-k(1) conditions, a novel 3d diffusion model equipped with double-Gaussian convolution in each dimension. Resist calibration with the new diffusion model has demonstrated a fitness and Cd predication accuracy that rival or outperform the traditional 3d physical resist models. In this work, we describe our empirical approach to achieving the nm-scale precision for advanced lithography process calibrations, using either measured Id Cd through-pitch or 2d memory core patterns. We show that for ArF imagi

关键词： process model calibration low-k(1) lithography LPM resist model polarized illumination immersion lithography 3d diffusion model vector high-NA generation of realistic aerial illuminator profile (GRAIL) Cd prediction accuracy measured illumination source profile

来源：评论

学校读者我要写书评

暂无评论

Intra-particle Analysis of Impact of H2 on Iron-oxide Reduction in CO-CO2-H2-H2O-N2 Gas Atmosphere

引用

ISIJ INTERNATIONAL 2023年第10期63卷 1595-1606页

作者： Kim, Jeong-In Kubota, Shusei Natsui, Shungo Iwanaga, Taiki Miki, Yuji Nogami, Hiroshi Tohoku Univ Grad Sch Engn Katahira 2-1-1Aoba Ku Sendai Miyagi 9808577 Japan Tohoku Univ Inst Multidisciplinary Res Adv Mat Katahira 2-1-1Aoba Ku Sendai Miyagi 9808577 Japan JFE Steel Corp Steel Res Lab 1 Kawasaki ChoChuo Ku Chiba 2600835 Japan JFE Steel Corp Steel Res Lab Chiba Japan JFE Technores Corp Sales Div 1-6-1 OtemachiChiyoda Ku Tokyo 1000004 Japan Tohoku Univ Collaborat Res Div Adv Anal Iron & Steelmaking Pr Katahira 2-1-1Aoba Ku Sendai Miyagi 9808577 Japan

Because the CO gas is usually used as the reduction gas in the blast furnace process, a huge CO2 gas has been emitted during the ironmaking process. Therefore, H-2 reduction gas has been proposed as a potential alternative to the CO gas for achieving carbon neutrality. However, the diffusion behaviors of CO and H-2 gases inside the iron-oxide particle are markedly different due to the higher gas diffusivity of H-2 gas. The reaction surface is observed in the CO reduction whereas the H-2 reduction has a broadly-reaction area. The conventional reduction analysis models were suitable for use in the CO reduction, as they assumed an exponential gas diffusion behavior through the certain reaction surface inside the particle. However, exponential diffusion is not sufficient to analyze the broad diffusion aspect of H-2 gas. In this study, the H-2-based reduction reactions is applied to the 3d diffusion model, which can accurately analyze the broad H-2 diffusion behavior. The gas components considered were the CO-CO2-H-2-H2O-N-2, considering the conditions of the blast furnace. The necessity of the 3d diffusion model was analyzed by comparing the H-2 reduction distributions with those obtained using the shrinking core model. The intra-particle distribution for reducing iron oxide particles, which have pellet and sintered ore shapes, were analyzed in CO-H-2 and CO-CO2-H-2-H2O-N-2 gas to clarify the impact of H-2 on reduction behavior. As the results, the presence of H-2 gas affected the effective gas diffusivity of the gas mixture, the reduction rate increased with the H-2 content.

关键词： 3d diffusion model hydrogen ironmaking process blast furnace hydrogen reduction gas reduction behavior

来源：评论

学校读者我要写书评

暂无评论

Novel 3d analysis of reduction behavior of single iron-oxide particle in CO-CO2 gas atmosphere

引用

CHEMICAL ENGINEERING SCIENCE 2023年 271卷

作者： Kim, Jeong-In Kubota, Shusei Natsui, Shungo Iwanaga, Taiki Miki, Yuji Nogami, Hiroshi Tohoku Univ Grad Sch Engn Katahira 2-1-1Aoba Ku Sendai Miyagi 9808577 Japan Tohoku Univ Inst Multidisciplinary Res Adv Mat Katahira 2-1-1Aoba Ku Sendai Miyagi 9808577 Japan JFE Steel Corp Steel Res Lab 1 Kawasaki ChoChuo Ku Chiba 2600835 Japan Tohoku Univ Collaborat Res Div Adv Anal Iron & Steelmaking Pro Katahira 2-1-1Aoba Ku Sendai Miyagi 9808577 Japan

The production of steel, which is achieved by the reduction of iron ores mainly through indirect reduction reactions in a blast furnace, is gradually increasing worldwide. Because the reducing gas diffuses threedimensionally, irregular particle shapes influence the reduction through differences in the diffusion length. The analysis of actual irregularly shaped iron-ore particles using existing models is difficult because they are primarily effective for 1d systems. Therefore, a novel reduction model based on the 3d diffusion equation that accommodates irregular particle shapes and 3d systems was developed in this study. The established model was validated by reproducing experimental conditions and comparing the quantified effective diffusivity and chemical reaction rate constant using the shrinking core model. In addition, the model was used to investigate the reducing behavior of an actual sintered-ore particle and the effects of particle sphericity and macro pore content. The sintered-ore particle had a higher reduction rate than that of a spherical equivalent with the same volume because sections of the surface with shorter diffusion lengths facilitated the gas diffusion. Additionally, the particle sphericity was determined to be inversely proportional to the reduction rate because the rate of gas diffusion into the particle

关键词： 3d diffusion model Blast furnace Iron oxide reduction 3d reduction behavior Reduction analysis

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：