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自然科学促进经济社会发展的历史建模分析 被引量:5
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作者 程晓舫 张栋 刘景平 《科技进步与对策》 CSSCI 北大核心 2010年第7期148-152,共5页
自然科学在促进经济社会发展的过程中,充当经济社会发展的先导,不是从20世纪开始的。选择生活质量、劳动、资源、剩余和社会力5个要素建立经济社会的历史发展模型,通过模型的演绎和对数千年自然科学和经济社会发展史的考察和推导发现,... 自然科学在促进经济社会发展的过程中,充当经济社会发展的先导,不是从20世纪开始的。选择生活质量、劳动、资源、剩余和社会力5个要素建立经济社会的历史发展模型,通过模型的演绎和对数千年自然科学和经济社会发展史的考察和推导发现,在整个经济社会发展的历史进程中,自然科学的作用始终是先导性的。 展开更多
关键词 自然科学 经济社会 历史建模 资源
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UG6.0同步建模技术和基于历史建模模式的技术分析 被引量:3
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作者 毛丹丹 《轻工科技》 2015年第2期84-85,共2页
基于历史的建模技术其核心是参数化技术,依赖性的参数化关系很难对产品设计进行换代和发展,同步建模是一种设计创新的方法,强调修改一个模型的当前状态而不考虑该模型的由来、相关性和特征历史,克服传统建模的特点,提出了基于特征的快... 基于历史的建模技术其核心是参数化技术,依赖性的参数化关系很难对产品设计进行换代和发展,同步建模是一种设计创新的方法,强调修改一个模型的当前状态而不考虑该模型的由来、相关性和特征历史,克服传统建模的特点,提出了基于特征的快速模型修改,降低了浪费在重构或转换几何体的时间。 展开更多
关键词 历史 设计创新 同步
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基于空地一体的历史建筑建模 被引量:4
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作者 张启华 朱文 +1 位作者 蒋毅 何燕兰 《北京测绘》 2020年第12期1755-1758,共4页
历史建筑建模采用传统测量方法,无法准确描绘具体构件,需大量的人力、物力和时间,在作业过程容易造成历史建筑二次损坏。采用静态定点三维激光扫描和车载扫描系统技术的三维建模的方法,缺乏历史建筑的顶部纹理信息且费用高。而仅采用无... 历史建筑建模采用传统测量方法,无法准确描绘具体构件,需大量的人力、物力和时间,在作业过程容易造成历史建筑二次损坏。采用静态定点三维激光扫描和车载扫描系统技术的三维建模的方法,缺乏历史建筑的顶部纹理信息且费用高。而仅采用无人机倾斜摄影测量技术虽可快速、简便、有效地获取古建筑的相对位置、部分立面和顶部结构及建筑纹理信息,但是面对狭窄的街巷立面结构变形大、纹理质量不能满足要求。针对这些不足,项目采用空中航摄与地面摄影的方式,将空中影像与地面影像组合解算,从而形成高精度的历史建筑模型。 展开更多
关键词 历史 倾斜摄影 地面摄影
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基于建模历史一致性的协同CAD并发控制方法 被引量:2
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作者 张德军 何发智 《东南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2015年第5期828-833,共6页
为了解决CAD系统在线集成中的建模历史不一致问题,提出了一种基于建模历史一致性的协同CAD并发控制方法.首先,对协同CAD建模操作间的关系进行了详细分析.然后,构造了一种考虑建模历史的并发控制模型,该模型通过状态向量实现建模操作间... 为了解决CAD系统在线集成中的建模历史不一致问题,提出了一种基于建模历史一致性的协同CAD并发控制方法.首先,对协同CAD建模操作间的关系进行了详细分析.然后,构造了一种考虑建模历史的并发控制模型,该模型通过状态向量实现建模操作间的因果关系维护,通过重构操作历史来解决建模操作间的偏并发关系,并将存在并发关系的建模操作分为互换、屏蔽和互斥3类分别进行处理.最后,设计了一种支持建模历史一致性的协同CAD并发控制方法,本地站点产生的操作立即执行,远程站点调用并发控制模型中的处理机制以完成远程操作的并发控制.实验结果表明,在协同CAD环境中,所提方法为用户提供了自由并发交互协同工作的同时,能够维护各协同站点建模历史的一致性. 展开更多
关键词 协同CAD系统 历史 状态向量 偏并发 并发控制
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基于分层队列历史性能建模的云系统资源管理
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作者 陈斌 东一舟 毛明荣 《微型机与应用》 2016年第14期27-29,共3页
为评定企业级云系统在负载下的响应处理能力,需要对其有直接影响的资源管理能力进行评估和预测。而这种评估的有效性在对紧急资源请求、动态负载变化、消费者并行调节等协同需求因素综合考虑的情况下将显得更加有效。然而,目前尚没有对... 为评定企业级云系统在负载下的响应处理能力,需要对其有直接影响的资源管理能力进行评估和预测。而这种评估的有效性在对紧急资源请求、动态负载变化、消费者并行调节等协同需求因素综合考虑的情况下将显得更加有效。然而,目前尚没有对这些因素进行比较系统的研究报告。针对上述需求,以分层队列和历史建模技术为模型及实验基础,以大量数据实例为背景进行了分析。实验结果显示,以分层队列模型及历史性能建模为指导的新架构可以达到70%的预测准确度。以此为基础,给出了一个基于预测模型的云负载和资源管理算法。 展开更多
关键词 云计算 性能 分层队列 历史性能 资源管理
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同步建模给我们带来了什么? 被引量:2
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作者 朱旭 《工业设计》 2008年第6期38-40,42,共4页
SIEMENS PLM的同步建模技术以及业界的类似CAD建模技术将引发一场CAD设计领域的革命。而设计工程师将因此受益,大幅提高工作效率。
关键词 CAD 同步 直接 历史约束 历史建模 特征 功能性设计
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HBIM在建筑遗产保护中的应用——以山西陵川小会岭二仙庙为例 被引量:2
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作者 王崇恩 郭正可 朱向东 《中国文化遗产》 2019年第5期84-89,共6页
历史建筑信息模型(HBIM)是建筑遗产信息保存与管理的一种技术手段。相对于传统二维图纸、表格、文字、影像等数据信息收集手段而言,HBIM更能直观、准确地表达古建筑本体原貌。在分析山西古建筑的组成体系结构和构成方式的基础上,结合宋... 历史建筑信息模型(HBIM)是建筑遗产信息保存与管理的一种技术手段。相对于传统二维图纸、表格、文字、影像等数据信息收集手段而言,HBIM更能直观、准确地表达古建筑本体原貌。在分析山西古建筑的组成体系结构和构成方式的基础上,结合宋代《营造法式》和测绘数据,应用HBIM技术,归纳了古建筑构件的构造规则和建模方法,完成了山西陵川小会岭二仙庙的建筑信息模型。古建筑参数化化建模,须遵循"有依据的复原""古建筑模数制""HBIM系统性"原则。古建筑历史信息模型的建立能够为古建筑保护提供重要资料,也为传承传统建筑遗产提供帮助。 展开更多
关键词 历史筑信息 参数化 小会岭二仙庙
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基于多层特征融合的学生成绩预测模型 被引量:1
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作者 刘彤 齐慧冉 倪维健 《计算机工程与设计》 北大核心 2023年第10期2973-2978,共6页
为及时准确地对学生成绩进行预测,提出基于多层特征融合的学生成绩预测模型。针对以往研究未能对成绩信息进行有效特征表示,导致预测效果不佳的问题,利用LSTM和注意力机制的柔性结合方式实现成绩序列信息在课程和时间两个维度的同步特... 为及时准确地对学生成绩进行预测,提出基于多层特征融合的学生成绩预测模型。针对以往研究未能对成绩信息进行有效特征表示,导致预测效果不佳的问题,利用LSTM和注意力机制的柔性结合方式实现成绩序列信息在课程和时间两个维度的同步特征提取。针对学业早期训练数据不足问题,构建基于时间共现频率的相似学生计算方法,融合相似学生信息实现信息互补。实验结果表明,该模型的准确度、稳定性和及时性都高于其它基线方法。 展开更多
关键词 学生成绩预测 特征融合 长短期记忆网络 注意力机制 历史成绩 共现频率 特征提取
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CAD造型技术发展历程及其特点 被引量:2
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作者 张腾 崔志琴 +1 位作者 侯军海 徐兆华 《机械工程与自动化》 2011年第6期196-197,200,共3页
造型技术是CAD技术的核心,造型技术的发展推动着CAD技术的变革。介绍了CAD技术发展过程中其造型技术的发展历程及其技术特点。
关键词 CAD 造型技术 显式 历史建模 同步
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Prediction of tri-modal microstructure under complex thermomechanical processing history in isothermal local loading forming of titanium alloy 被引量:5
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作者 Peng-fei GAO He YANG +2 位作者 Xiao-guang FAN Zhen-ni LEI Yang CAI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第11期2423-2433,共11页
To control the tri-modal microstructure and performance,a prediction model of tri-modal microstructure in the isothermal local loading forming of titanium alloy was developed.The staged isothermal local loading experi... To control the tri-modal microstructure and performance,a prediction model of tri-modal microstructure in the isothermal local loading forming of titanium alloy was developed.The staged isothermal local loading experiment on TA15alloy indicates that there exist four important microstructure evolution phenomena in the development of tri-modal microstructure,i.e.,the generation of lamellarα,content variation of equiaxedα,spatial orientation change of lamellarαand globularization of lamellarα.Considering the laws of these microstructure phenomena,the microstructure model was established to correlate the parameters of tri-modal microstructure and processing conditions.Then,the developed microstructure model was integrated with finite element(FE)model to predict the tri-modal microstructure in the isothermal local loading forming.Its reliability and accuracy were verified by the microstructure observation at different locations of sample.Good agreements between the predicted and experimental results suggest that the developed microstructure model and its combination with FE model are effective in the prediction of tri-modal microstructure in the isothermal local loading forming of TA15alloy. 展开更多
关键词 titanium alloy isothermal local loading forming complex thermomechanical processing history tri-modal microstructure modelling
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QoS Evaluation for Web Service Recommendation 被引量:1
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作者 MA You XIN Xin +3 位作者 WANG Shangguang LI Jinglin SUN Qibo YANG Fangchun 《China Communications》 SCIE CSCD 2015年第4期151-160,共10页
Web service recommendation is one of the most important fi elds of research in the area of service computing. The two core problems of Web service recommendation are the prediction of unknown Qo S property values and ... Web service recommendation is one of the most important fi elds of research in the area of service computing. The two core problems of Web service recommendation are the prediction of unknown Qo S property values and the evaluation of overall Qo S according to user preferences. Aiming to address these two problems and their current challenges, we propose two efficient approaches to solve these problems. First, unknown Qo S property values were predicted by modeling the high-dimensional Qo S data as tensors, by utilizing an important tensor operation, i.e., tensor composition, to predict these Qo S values. Our method, which considers all Qo S dimensions integrally and uniformly, allows us to predict multi-dimensional Qo S values accurately and easily. Second, the overall Qo S was evaluated by proposing an efficient user preference learning method, which learns user preferences based on users' ratings history data, allowing us to obtain user preferences quantifiably and accurately. By solving these two core problems, it became possible to compute a realistic value for the overall Qo S. The experimental results showed our proposed methods to be more efficient than existing methods. 展开更多
关键词 Web service recommendation QoS prediction user preference overall QoSevaluation
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Data Dependent Modeling of New Contamination Cases from Urban Historic Groundwater Records
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作者 Qing Li Fengxiang Qiao Lei Yu 《Journal of Environmental Science and Engineering(A)》 2014年第5期250-256,共7页
Groundwater is the water located beneath the earth's surface in the soil pore spaces and in the fractures of rock formations. As one of the most important natural resources, groundwater is associated with the environ... Groundwater is the water located beneath the earth's surface in the soil pore spaces and in the fractures of rock formations. As one of the most important natural resources, groundwater is associated with the environment, public health, welfare, and long-term economic growth, which affects the daily activities of human beings. In modern urban areas, the primary contaminants of groundwater are artificial products, such as gasoline and diesel. To protect this important water resource, a series of efforts have been exerted, including enforcement and remedial actions. Each year, the TGPC (Texas Groundwater Protection Committee) in US publishes a "Joint Groundwater Monitoring and Contamination Report" to describe historic and new contamination cases in each county, which is an important data source for the design of prevention strategies. In this paper, a DDM (data dependent modeling) approach is proposed to predict county-level NCC (new contamination cases). A case study with contamination information from Harris County in Texas was conducted to illustrate the modeling and prediction process with promising results. The one-step prediction error is 1.5%, while the two-step error is 12.1%. The established model can be used at the county-level, state-level, and even at the country-level. Besides, the prediction results could be a reference during decision-making processes. 展开更多
关键词 Ground water environmental modeling water contamination data dependent modeling.
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Chronological Restoration of Fort Frontenac in 3D for Heritage Visualization
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作者 Mitsuyoshi Yabe Elizabeth Goins +3 位作者 Chris Jackson David Halbstein Shaun Foster Sue Bazely 《Journal of Civil Engineering and Architecture》 2015年第12期1463-1473,共11页
This paper is composed of three elements: 3D modeling, web design and heritage visualization on the basis of the chronological restoration of Fort Frontenac in 1673, 1675, 1680, 1685 and 1688, changing from narrow an... This paper is composed of three elements: 3D modeling, web design and heritage visualization on the basis of the chronological restoration of Fort Frontenac in 1673, 1675, 1680, 1685 and 1688, changing from narrow and plain to broad, grand features. The aim is to use computer graphic design to inform and create an interest in historical visualization by rebuilding Fort Frontenac using 3D modeling and interactive design. The final model can be integrated into an interactive website to learn more about the fort's historic importance. It is apparent that using computer graphics can save time and money when it comes to historical visualization. Visitors do not have to travel to the actual archaeological buildings and can simply use the web in their own homes to learn about this information virtually. In order to create a sophisticated restoration of archaeological buildings, meticulously assessing historical records will draw viewers into the visualizations, such as the historical world of Fort Frontenac. As a result, the completed restoration allows the viewers to effectively understand the fort's social system, habits and historical events. 展开更多
关键词 Heritage visualization 3D computer graphics interactive virtual design web design effective usage of learning.
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Historical Canadian Fortress in the Latest Technology
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作者 Mitsuyoshi Yabe Elizabeth Goins +3 位作者 Chris Jackson David Halbstein Shaun Foster Sue Bazely 《Journal of Earth Science and Engineering》 2015年第5期271-279,共9页
The paper examines thoroughly how utilizing the latest technology, such as a PC (personal computer), an iPad, or an iPhone, can entertain many people and allow them to learn about the archaeological findings that ha... The paper examines thoroughly how utilizing the latest technology, such as a PC (personal computer), an iPad, or an iPhone, can entertain many people and allow them to learn about the archaeological findings that have become broadly available through the application of new technology. The paper assesses web usage through the difference in availability and convenience of PC and compact devices by connection to 3D augmented reality applications. Modem technology has allowed access to this information to become radically altered, whereas historical records and remains are dwindling. However, the development of 3D technology means that the general public can experientially pursue the dignity of historical buildings. It also becomes easier through the use of the latest technology to decipher the effectiveness of people's interaction with inclusive descriptions of the documentation. This research aims at verifying the visualization of Fort Frontenac by the use of a chronological renovation process. This paper is composed of five elements: an introduction, the historical records about the necessity of 3D modeling, heritage visualization by means of 3D modeling, web design, and iPad and iPhone usage, a comparison of the architectural change that occurred in the 展开更多
关键词 Heritage visualization 3D computer graphics interactive virtual design web design iPad and iPhone use.
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