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A visual analysis approach for data imputation via multi-party tabular data correlation strategies

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Frontiers of Information Technology & Electronic Engineering 2024年第3期25卷 398-414页

作者： Haiyang ZHU Dongming HAN Jiacheng PAN Yating WEI Yingchaojie FENG Luoxuan WENG Ketian MAO Yuankai XING Jianshu LV Qiucheng WAN Wei CHEN The state Key Lab of cad&cg Zhejiang UniversityHangzhou 310058China Wuchan Zhongda Digital Technology Co. Ltd.Hangzhou 310020China Zhejiang Metals and Materials Co. Ltd.Hangzhou 310005China

Data imputation is an essential pre-processing task for data governance,aimed at filling in incomplete ***,conventional data imputation methods can only partly alleviate data incompleteness using isolated tabular data,and they fail to achieve the best balance between accuracy and *** this paper,we present a novel visual analysis approach for data *** develop a multi-party tabular data association strategy that uses intelligent algorithms to identify similar columns and establish column correlations across multiple ***,we perform the initial imputation of incomplete data using correlated data entries from other ***,we develop a visual analysis system to refine data imputation *** interactive system combines the multi-party data imputation approach with expert knowledge,allowing for a better understanding of the relational structure of the *** significantly enhances the accuracy and eficiency of data imputation,thereby enhancing the quality of data governance and the intrinsic value of data *** validation and user surveys demonstrate that this method supports users in verifying and judging the associated columns and similar rows using theirdomain knowledge.

关键词： Data governance Data incompleteness Data imputation Data visualization Interactive visual analysis

Empowering smart city situational awareness via big mobile data

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Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 286-307页

作者： Zhiguang SHAN Lei SHI Bo LI Yanqiang ZHANG Xiatian ZHANG Wei CHEN state Information Center Beijing100045China School of Computer Science and Engineering Beihang UniversityBeijing100191China Zhongguancun Laboratory Beijing100094China Beijing Tendcloud Tianxia Technology Co. Ltd.Beijing100027China The state Key Lab of cad&cg Zhejiang UniversityHangzhou310027China

Smart city situational awareness has recently emerged as a hot topic in research societies,industries,and governments because of its potential to integrate cutting-edge information technology and solve urgent challenges that modern cities *** example,in the latest five-year plan,the Chinese government has highlighted the demand to empower smart city management with new technologies such as big data and Internet of Things,for which situational awareness is normally the crucial first *** traditional static surveillance data on cities have been available for decades,this review reports a type of relatively new yet highly important urban data source,i.e.,the big mobile data collected by devices with various levels of mobility representing the movement and distribution of public and private agents in the *** especially focus on smart city situational awareness enabled by synthesizing the localization of hundreds of thousands of mobile software Apps using the Global Positioning System(GPS).This technique enjoys advantages such as a large penetration rate(∼50%urban population covered),uniform spatiotemporal coverage,and high localization *** first discuss the pragmatic requirements for smart city situational awareness and the challenges *** we introduce two suites of empowering technologies that help fulfill the requirements of(1)cybersecurity insurance for smart cities and(2)spatiotemporal modeling and visualization for situational awareness,both via big mobile *** main contributions of this review lie in the description of a comprehensive technological framework for smart city situational awareness and the demonstration of its feasibility via real-world applications.

关键词： Smart city Mobile data Situational awareness

Computational Approaches for Traditional Chinese Painting: From the “Six Principles of Painting” Perspective

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Journal of Computer Science & Technology 2024年第2期39卷 269-285页

作者：张玮张建伟黄锦畦王懿芳封颖超杰王璐玮陈为 state Key Laboratory of cad&cg Zhejiang UniversityHangzhou 310058China Department of Computer Science and Engineering The Hong Kong University of Science and Technology Hong Kong 999077China Kellogg School of Management Northwestern UniversityEvanston 60208U.S.A Laboratory of Art and Archaeology Image Zhejiang UniversityHangzhou 310058China

Traditional Chinese painting(TCP)is an invaluable cultural heritage resource and a unique visual art *** recent years,there has been a growing emphasis on the digitalization of TCP for cultural preservation and *** resulting digital copies have enabled the advancement of computational methods for a structured and systematic understanding of *** explore this topic,we conduct an in-depth analysis of 94 pieces of *** examine the current use of computer technologies on TCP from three perspectives,based on numerous conversations with ***,in light of the“Six Principles of Painting”theory,we categorize the articles according to their research focus on artistic ***,we create a four-stage framework to illustrate the purposes of TCP ***,we summarize the popular computational techniques applied to *** work also provides insights into potential applications and prospects,with professional opinion.

关键词： traditional Chinese painting(TCP) digital humanities cultural heritage computer vision deep learning

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基于叙事结构抽象的可视分析方法综述

计算机辅助设计与图形学学报 2024年第4期36卷 503-515页

作者：叶力王磊周志光王毅刚杭州电子科技大学人文艺术与数字媒体学院杭州310018 浙江大学cad&cg国家重点实验室杭州310058

基于叙事结构抽象的可视分析方法是通过挖掘数据背后存在的叙事逻辑,提供富有洞察力和沟通力的方法.首先介绍叙事结构数据的来源,包括文本数据、图表图像数据、音视频数据、地理空间数据和多模态融合数据;然后讨论叙事结构抽象方法,包... 详细信息

基于叙事结构抽象的可视分析方法是通过挖掘数据背后存在的叙事逻辑,提供富有洞察力和沟通力的方法.首先介绍叙事结构数据的来源,包括文本数据、图表图像数据、音视频数据、地理空间数据和多模态融合数据;然后讨论叙事结构抽象方法,包括连续性、单元式和离散化3种表示;再探讨叙事结构可视化设计,包括基于视觉通道与表达形式的设计,同时介绍叙事结构交互生成方法,包括基于设计空间和注释的手动生成、AI辅助交互生成和AI自动生成;最后讨论叙事结构可视分析的创作工具以及在文化传媒、医疗健康和体育娱乐等领域的应用,并对该领域现阶段工作的不足进行总结,指出多模态融合数据可视分析、跨平台与多设备的叙事结构展示以及加强情感在叙事结构可视分析中的作用等是未来工作的研究方向.

关键词：叙事结构叙事可视化可视分析可视化创作工具

基于单目RGB数据的三维模板物体跟踪算法综述

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计算机辅助设计与图形学学报 2024年第1期36卷 1-13页

作者：宋修强金立宋婧李佳宸孟祥旭秦学英山东大学软件学院济南250101 数字媒体技术教育部工程研究中心济南250101 浙江大学cad&cg国家重点实验室杭州310030

文中介绍了三维物体跟踪技术及其最新研究进展,包括理论基础与评估指标、基于视觉特征的传统位姿求解和基于学习的位姿估计.分析了传统算法中各种特征约束、统计分割模型、能量函数以及加速策略.其中,区域及边缘约束成为跟踪的主流方向... 详细信息

文中介绍了三维物体跟踪技术及其最新研究进展,包括理论基础与评估指标、基于视觉特征的传统位姿求解和基于学习的位姿估计.分析了传统算法中各种特征约束、统计分割模型、能量函数以及加速策略.其中,区域及边缘约束成为跟踪的主流方向,多种特征可以融合产生更强的约束.统计分割模型由全局模型逐步发展为局部模型.非线性最小二乘形式的能量函数易于优化而被广泛采用.预计算、预渲染的加速策略使得跟踪的实时性极大提高.基于学习的算法现阶段在精度和速度上不及传统算法,但展现了更好的特征提取能力和处理更复杂场景的潜力.梳理了多种算法的跟踪精度及取得高精度的原因.总结了三维物体跟踪在复杂情境下跟踪精度下降和失败的问题,及其潜在的解决方案与发展方向.三维物体跟踪正朝向多特征融合、预计算、多任务的方向发展.

关键词：三维物体跟踪姿态估计增强现实

考虑多源不确定性的三维cad软件质量综合评价

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机械工程学报 2024年第13期60卷 235-246页

作者：程锦吕昊刘振宇谭建荣浙江大学流体动力基础件与机电系统国家重点实验室杭州310058 浙江大学cad&cg国家重点实验室杭州310058

三维cad软件质量综合评价需考虑功能、性能、兼容性、易用性等多种类型指标,各类指标数据获取方式不同,样本量各异,且包含不同来源的不确定性。现有软件质量评价方法未充分考虑不同类型指标数据的特点及不确定性进行针对性描述,也未根... 详细信息

三维cad软件质量综合评价需考虑功能、性能、兼容性、易用性等多种类型指标,各类指标数据获取方式不同,样本量各异,且包含不同来源的不确定性。现有软件质量评价方法未充分考虑不同类型指标数据的特点及不确定性进行针对性描述,也未根据各类指标数据不确定性和可信度的差异进行赋权,难以保证质量综合评价结果的可信度。为此,提出考虑多源不确定性的三维cad软件质量综合评价方法,根据三维cad软件的特点确定质量评价指标体系,考虑大量重复自动化测试所得性能指标充足样本数据中包含的软件性能本身不确定性和测试环境不稳定干扰,提出自减逆向云发生器以实现对两类不确定性的细分,并避免现有逆向云发生器求解云模型超熵时可能失效的问题;充分考虑易用性指标有限样本数据中的主观偏好不确定性和全局代表性,提出基于拓展区间数的易用性指标数学表征方法。在此基础上,建立三维cad软件多类型质量指标的云模型统一表征,考虑各指标的可信度进行变权求和,获得具有可信度的三维cad软件质量综合评价结果。

关键词：三维cad软件质量评价不确定性云模型拓展区间数可信度

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面向癫痫的脑电图可视分析方法

计算机辅助设计与图形学学报 2024年第5期36卷 658-667页

作者：丁国明谢潇胡玲利巫英才王爽浙江大学cad&cg国家重点实验室杭州310058 浙江大学教育学院体育学系杭州310058 浙江大学医学院附属第二医院杭州310058

为了高效地检测和分析癫痫患者脑电图中的癫痫样放电,提出一种面向癫痫的脑电图可视分析方法.首先利用浙江大学医学院附属第二医院在癫痫治疗过程中积累的脑电数据,建立基于时域和时频域视角的卷积神经网络模型,用于癫痫样放电自动分类... 详细信息

为了高效地检测和分析癫痫患者脑电图中的癫痫样放电,提出一种面向癫痫的脑电图可视分析方法.首先利用浙江大学医学院附属第二医院在癫痫治疗过程中积累的脑电数据,建立基于时域和时频域视角的卷积神经网络模型,用于癫痫样放电自动分类,使用Focal Loss作为损失函数评估放电类别分布不均衡的问题;然后在分类模型基础上,结合医生的需求设计交互式的多视图可视分析系统,其由波形分类视图、离群值检测视图和波形检查视图3个相互协作的模块组成;最后招募10位被试和2位专家,通过评估实验验证系统在癫痫诊断方面的有效性和可用性.实验结果表明,建立的分类模型在所用数据集上的平均F1分数为0.88,优于其他的脑电分类模型,且具有良好的鲁棒性;设计的系统具有良好的可用性和有效性,可以辅助医生进行癫痫诊断.

关键词：医学可视化机器学习脑电图癫痫

Force Feedback Coupling with Dynamics for Physical Simulation of Product Assembly and Operation Performance

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Chinese Journal of Mechanical Engineering 2015年第1期28卷 164-172页

作者： LIU Zhenyu TAN Jianrong DUAN Guifang FU Yun state Key Laboratory of cad&cg Zhejiang University

Most existing force feedback methods are still difficult to meet the requirements of real-time force calculation in virtual assembly and operation with complex objects. In addition, there is often an assumption that the controlled objects are completely flee and the target object is only completely fixed or flee, thus, the dynamics of the kinematic chain where the controlled objects are located are neglected during the physical simulation of the product manipulation with force feedback interaction. This paper proposes a physical simulation method of product assembly and operation manipulation based on statistically learned contact force prediction model and the coupling of force feedback and dynamics. In the proposed method, based on hidden Markov model （HMM） and local weighting learning （LWL）, contact force prediction model is constructed, which can estimate the contact force in real time during interaction. Based on computational load balance model, the computing resources are dynamically assigned and the dynamics integral step is optimized. In addition, smoothing process is performed to the force feedback on the synchronization points. Consequently, we can solve the coupling and synchronization problems of high-frequency feedback force servo. low-frequency dynamics solver servo and scene rendering servo, and realize highly stable and accurate force feedback in the physical simulation of product assembly and operation manipulation. This research proposes a physical simulation method of product assembly and operation manipulation.

关键词： contact force prediction force feedback multi-rate coupling physical simulation of manipulation virtual assembly

Real-time camera tracking using hybrid features in mobile augmented reality

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Science China(Information Sciences) 2015年第11期58卷 211-223页

作者： WANG WeiJie WAN HuaGen state Key Laboratory of cad&cg Zhejiang University

Often only simple features are employed in mobile augmented reality(AR) due to the limited computational capacity of mobile terminals, which often leads to unsteadiness of the camera tracking. In this paper, we propose a novel approach to real-time camera tracking in mobile AR using hybrid features to alleviate this problem. By integrating feature points and lines as scene features, hybrid features are generated through the process of point/line features extraction, optimization and fusion, and are used in the real-time estimation of camera parameters. A method for image feature optimization is proposed based on the scene structural analysis to meet the computational constraints of mobile terminals. In order to improve the stability of camera tracking, an iterative screening method is proposed to choose a set of stable feature lines, and hybrid features are adaptively constructed based on the composition and geometry of scene features. It is shown from the experimental results that the proposed method produces more stable and smoother camera trajectories in comparison with the method only using feature points, and a good balance is achieved between the stability and the real-time computation of the camera tracking on a mobile platform.

关键词： mobile augmented reality feature extraction camera tracking hybrid feature mobile platform