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D-S证据理论在时-空信息融合中的应用 被引量:10
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作者 李茹 李弼程 李斗 《计算机工程与应用》 CSCD 北大核心 2005年第13期174-176,共3页
多传感器的信息融合技术应用于导航、目标跟踪、目标识别等很多领域。目前用于信息融合的主要方法就是证据理论技术。论文给出了三种基于D-S证据理论的多传感器多个测量周期的信息融合(时-空信息融合)的方法。在仿真实验中对这三种方法... 多传感器的信息融合技术应用于导航、目标跟踪、目标识别等很多领域。目前用于信息融合的主要方法就是证据理论技术。论文给出了三种基于D-S证据理论的多传感器多个测量周期的信息融合(时-空信息融合)的方法。在仿真实验中对这三种方法进行了比较,分布式有反馈的方法是三种方法中最好的。 展开更多
关键词 D—S证据理论 传感器 时-空信息融合
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D-S证据理论的改进算法在时-空信息融合中的应用 被引量:6
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作者 李茹 李弼程 《数据采集与处理》 CSCD 北大核心 2005年第2期156-160,共5页
研究基于D-S证据理论的时-空信息融合,即多传感器多测量周期的信息融合,给出了三种时-空信息融合的方法:集中式、分布式无反馈和有反馈的融合算法。采用这些传统的时-空信息融合方法时,最终的融合结果会产生概率分配过分集中的现象,而... 研究基于D-S证据理论的时-空信息融合,即多传感器多测量周期的信息融合,给出了三种时-空信息融合的方法:集中式、分布式无反馈和有反馈的融合算法。采用这些传统的时-空信息融合方法时,最终的融合结果会产生概率分配过分集中的现象,而且证据冲突时还会产生有悖常理的结果。本文在传统证据理论的合成公式的基础上给出了一个有效的合成规则,并由此提出了改进的融合方法。证据冲突的概率按照各个命题的平均支持程度加权进行分配,从而提高了融合结果的可靠性与合理性。 展开更多
关键词 D—S证据理论 传感器 时-空信息融合 改进算法
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基于矩阵分析的加权证据时空融合算法研究 被引量:2
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作者 肖冰松 许蕴山 夏海宝 《弹箭与制导学报》 CSCD 北大核心 2006年第4期320-322,共3页
在多传感器目标识别系统中,为解决各传感器可信度不一致的问题,提出加权证据的方法。为便于采用计算机实现,采用基于矩阵分析的D-S证据理论。考虑融合系统的时间性和空间性,先从空间域对多传感器进行空域信息融合,然后在此基础上对时间... 在多传感器目标识别系统中,为解决各传感器可信度不一致的问题,提出加权证据的方法。为便于采用计算机实现,采用基于矩阵分析的D-S证据理论。考虑融合系统的时间性和空间性,先从空间域对多传感器进行空域信息融合,然后在此基础上对时间序列进行融合。最后进行判决,识别出目标。识别实例表明了该方法的正确性和有效性。 展开更多
关键词 多传感器 证据权 时-空信息融合 矩阵分析
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Spatial-temporal Characteristics of Land Subsidence Corresponding to Dynamic Groundwater Funnel in Beijing Municipality,China 被引量:14
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作者 CHEN Beibei GONG Huili +5 位作者 LI Xiaojuan LEI Kunchao ZHANG Youquan LI Jiwei GU Zhaoqin DANG Yanan 《Chinese Geographical Science》 SCIE CSCD 2011年第6期753-764,共12页
Due to long-term over-exploitation of groundwater in Beijing Municipality, regional groundwater funnels have formed and land subsidence has been induced. By combining a groundwater monitoring network, GPS monitor- ing... Due to long-term over-exploitation of groundwater in Beijing Municipality, regional groundwater funnels have formed and land subsidence has been induced. By combining a groundwater monitoring network, GPS monitor- ing network data, radar satellite SAR data, GIS and other new technologies, a coupled process model based on the dy- namic variation of groundwater and the deformation response of land subsidence has been established. The dynamic variation of groundwater fimnels and the land subsidence response process were analyzed systematically in Beijing. Study results indicate that current groundwater funnel areas are distributed mainly in the southwest of Shunyi District, the northeast of Chaoyang District and the northwest of Tongzhou District, with an average decline rate of groundwa- ter level of 2.66 rn/yr and a maximum of 3.82 m/yr in the center of the funnels. Seasonal and interannual differences exist in the response model of land subsidence to groundwater funnels with uneven spatial and temporal distribution, where the maximum land subsidence rate was about --41.08 mm/yr and the area with a subsidence rate greater than 30 mm/yr was about 1637.29 km2. Although a consistency was revealed to exist between a groundwater funnel and the spatial distribution characteristics of the corresponding land subsidence funnel, this consistency was not perfect. The results showed that the response model of land subsidence to the dynamic variation of groundwater was more revealing when combining conventional technologies with InSAR, GIS, GPS, providing a new strategy for environmental and hydrogeological research and a scientific basis for regional land subsidence control. 展开更多
关键词 land subsidence groundwater funnel over-exploitation of groundwater INSAR deformation response
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Spatial-temporal Characteristics of Land Use Intensity of Coastal Zone in China During 2000–2010 被引量:24
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作者 DI Xianghong HOU Xiyong +1 位作者 WANG Yuandong WU Li 《Chinese Geographical Science》 SCIE CSCD 2015年第1期51-61,共11页
Based on remote sensing and GIS techniques, land use maps in 2000, 2005 and 2010 in China′s coastal zone were produced, and structural raster data of land use were further generated to calculate land use intensity co... Based on remote sensing and GIS techniques, land use maps in 2000, 2005 and 2010 in China′s coastal zone were produced, and structural raster data of land use were further generated to calculate land use intensity comprehensive index(LUICI) for analyzing land use spatial-temporal characteristics at 1 km scale. Results show that: 1) from the perspective of spatial patterns of landforms at a macro scale, there is a significant difference in land use intensity between the north and the south of China′s coastal zone. Hotspots of changes mainly concentrated in metropolitan areas, estuaries and coastal wetlands; 2) elevation is an important factor that controlling land use spatial patterns at local scale. Land use intensity is much higher within areas below the elevation of 400 m and it decreased significantly as the elevation increasing; 3) there is a significant land-ocean gradient for land use intensity, which is low in island and near-shore areas, but high in the regions that 4–30 km far away the coastline because of much intensive human activities; however, in recent decades land use intensity had been promoted significantly in low near-shore area due to extensive sea reclamations; 4) significant differences of land use intensity were also found among provincial administrative units. A rising trend of land use intensity was found in provincial-level administrative units from 2000 to 2010. To sum up, elevation, land-ocean gradient, socio-economic status and policy are all influencing factors to the spatial patterns and temporal variations of land use intensity in China′s coastal zone. 展开更多
关键词 coastal zone land use intensity land use intensity comprehensive index(LUICI) spatial pattern ELEVATION land-ocean gradient
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Spatio-temporal GIS Data Model Based on Event Semantics 被引量:5
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作者 XUZhihong BIANFuling 《Geo-Spatial Information Science》 2003年第3期43-47,共5页
There are mainly four kinds of models to record and deal with historical information. By taking them as reference, the spatio-temporal model based on event semantics is proposed. In this model, according to the way fo... There are mainly four kinds of models to record and deal with historical information. By taking them as reference, the spatio-temporal model based on event semantics is proposed. In this model, according to the way for describing an event, all the information are divided into five domains. This paper describes the model by using the land parcel change in the cadastral information system, and expounds the model by using five tables corresponding to the five domains. With the aid of this model, seven examples are given on historical query, trace back and recurrence. This model can be implemented either in the extended relational database or in the object-oriented database. 展开更多
关键词 event semantics temporal GIS MODEL
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Spatio-temporal Fragmentation of Leisure Activities in Information Era: Empirical Evidence from Nanjing, China 被引量:10
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作者 XI Guangliang ZHEN Feng +1 位作者 Puel GILLES Fernandez VALERIE 《Chinese Geographical Science》 SCIE CSCD 2017年第1期137-150,共14页
Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragme... Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragmentation, but few studies have focused on the fragmentation of leisure activities. This study was intended to extend the extant literature by: 1) analysing the spatio-temporal fragmentation of physical and virtual leisure activities by using a dataset collected in Nanjing, China, and 2) evaluating the reasons of leisure activity fragmentation, as well as the potential spatial effect of activity fragmentation. The results indicated that virtual leisure activities are more fragmented than physical leisure activities, but the fragmentation of physical and virtual leisure activities varies on weekday and weekend, as well as in various locations and urban districts. In addition, the results suggested that sociodemographic factors and information and communication technology(ICT) variables distinctly affect the fragmentation of leisure activities. Meanwhile, the fragmentation of virtual leisure activities may enhance the transformation of traditional urban space by reallocating leisure activity times and locations. 展开更多
关键词 activity fragmentation information and communication technology(ICT) influencing mechanism China
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KNOWLEDGE DISCOVERY OF REMOTELY SENSED DATA FROM ECOLOGICAL VIEW——A Case Study of Urban Spatial-temporal Relationship in the Pearl River Delta
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作者 HUWei-ping ZHUYin-zhong 《Chinese Geographical Science》 SCIE CSCD 2003年第1期48-55,共8页
From the ecological viewpoint this paper discusses the urban spatial-temporal relationship. We take regional towns and cities as a complex man-land system of urban eco-community. This complex man-land system comprises... From the ecological viewpoint this paper discusses the urban spatial-temporal relationship. We take regional towns and cities as a complex man-land system of urban eco-community. This complex man-land system comprises two elements of ' man' and ' land' . Here, ' man' means organization with self-determined consciousness, and ' land' means the physical environment (niche) that ' man' depends on. The complex man-land system has three basic components. They are individual, population and community. Therefore there are six types of spatial relationship for the complex man-land system. They are individual, population,community,man-man, land-land and man-land spatial relationships. Taking the Pearl(Zhujiang) River Delta as a case study, the authors found some evidence of the urban spatial relationship from the remote sensing data. Firstly, the concentration and diffusion of the cities spatial relationship was found in the remote sensing imagery. Most of the cities concentrate in the core area of the Pearl River Delta, but the diffusion situation is also significant. Secondly, the growth behavior and succession behavior of the urban spatial relationship was found in the remote sensing images comparison with different temporal data. Thirdly, the inheritance, break, or meeting emergency behavior was observed from the remote sensing data. Fourthly, the authors found many cases of symbiosis and competition in the remote sensing data of the Pearl River Delta. Fifthly, the autoeciousness, stranglehold and invasion behavior of the urban spatial relationship was discovered from the remote sensing data. 展开更多
关键词 complex man-land system of urban eco-community spatial-temporalrelationship knowledge discovery remote sensing the pearl river delta
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Research on three-dimension ocean observation data integration and service technology
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作者 张新 董文 郑志刚 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第2期482-490,共9页
Currently,ocean data portals are being developed around the world based on Geographic Information Systems(GIS) as a source of ocean data and information.However,given the relatively high temporal frequency and the int... Currently,ocean data portals are being developed around the world based on Geographic Information Systems(GIS) as a source of ocean data and information.However,given the relatively high temporal frequency and the intrinsic spatial nature of ocean data and information,no current GIS software is adequate to deal effectively and efficiently with spatiotemporal data.Furthermore,while existing ocean data portals are generally designed to meet the basic needs of a broad range of users,they are sometimes very complicated for general audiences,especially for those without training in GIS.In this paper,a new technical architecture for an ocean data integration and service system is put forward that consists of four layers:the operation layer,the extract,transform,and load(ETL) layer,the data warehouse layer,and the presentation layer.The integration technology based on the XML,ontology,and spatiotemporal data organization scheme for the data warehouse layer is then discussed.In addition,the ocean observing data service technology realized in the presentation layer is also discussed in detail,including the development of the web portal and ocean data sharing platform.The application on the Taiwan Strait shows that the technology studied in this paper can facilitate sharing,access,and use of ocean observation data.The paper is based on an ongoing research project for the development of an ocean observing information system for the Taiwan Strait that will facilitate the prevention of ocean disasters. 展开更多
关键词 data integration data service spatiotemporal data warehouse STANDARD
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局部模板更新逆向联合稀疏表示目标跟踪算法 被引量:2
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作者 虞虹玲 陈颖频 +5 位作者 许艳萍 林晨 蒋旻佚 罗崇淼 陈悦 林耀进 《图学学报》 CSCD 北大核心 2022年第1期60-69,共10页
逆向联合稀疏表示算法可充分利用跟踪过程中的时间相似性和空间连续性,但由于遮挡、光照变化等的影响,易出现跟踪漂移。为解决上述问题,提出一种基于局部模板更新逆向联合稀疏表示目标跟踪算法,其通过逆向局部重构目标模板集完成逆向联... 逆向联合稀疏表示算法可充分利用跟踪过程中的时间相似性和空间连续性,但由于遮挡、光照变化等的影响,易出现跟踪漂移。为解决上述问题,提出一种基于局部模板更新逆向联合稀疏表示目标跟踪算法,其通过逆向局部重构目标模板集完成逆向联合稀疏表示。首先,在首帧初始化目标模板集,利用粒子滤波获取候选图像,并对其分块处理,构建逆向联合稀疏编码模型;然后,利用交替方向乘子法求解出稀疏编码系数,并通过2步评分机制获取最优候选图像;最后,根据相似性得分判断当前帧是否存在局部遮挡,若无遮挡,则局部更新目标模板集以减少跟踪漂移现象。实验结果表明,本文算法的跟踪精度和成功率在OTB-2013数据集上分别达到了85.4%和62.8%,在OTB100数据集上分别达到了76.8%和68.6%,速度达到每秒5.76帧,能有效提高鲁棒性,减少跟踪漂移。 展开更多
关键词 目标跟踪 逆向联合稀疏表示 时-空信息 局部模板更新 交替方向乘子法
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Environmental Factors Affecting Temporal and Spatial Dynamics of Soil Erosion in Xingguo County, South China 被引量:12
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作者 WANG Ku SHI Xue-Zheng +5 位作者 YU Dong-Sheng SHI De-Ming CHEN Jing-Ming XU Bin-Bin LIANG Yin LI De-Cheng 《Pedosphere》 SCIE CAS CSCD 2005年第5期620-627,共8页
By using soil erosion maps of four different time periods and a digital elevation model (DEM), in combination withthe remote sensing and GIS technologies, soil erosion dynamics in Xingguo County of Jiangxi Province in... By using soil erosion maps of four different time periods and a digital elevation model (DEM), in combination withthe remote sensing and GIS technologies, soil erosion dynamics in Xingguo County of Jiangxi Province in South Chinawere analyzed on both temporal and spatial scales in soils of different parent materials, altitudes and slopes. The resultsshowed that from 1958 to 2000 severe soil erosion was coming under control with a decreasing percentage of the land undersevere erosion. It was also found that the soils developed from Quaternary red clay, granite and purple shale were moresusceptible to soil erosion and that areas sitting between 200 to 500 m in altitude with a slope less than 3° or between7° to 20° where human activities were frequent remained to be zones where soil erosion was most likely to occur. Theseareas deserve special attention in monitoring and controlling. 展开更多
关键词 GIS remote sensing soil erosion South China Xingguo County
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Dynamics of Soil Erosion in Xingguo County, China, Determined Using Remote Sensing and GIS 被引量:19
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作者 PANJian-Jun ZHANGTao-Lin ZHAOQi-Guo 《Pedosphere》 SCIE CAS CSCD 2005年第3期356-362,共7页
The spatial and temporal dynamics of soil erosion in Xingguo County, Jiangxi Province, China were studied using multi-period remote sensing images and GIS. The results indicated that the soil erosion status of the reg... The spatial and temporal dynamics of soil erosion in Xingguo County, Jiangxi Province, China were studied using multi-period remote sensing images and GIS. The results indicated that the soil erosion status of the region has been improving, particularly since the 1980s, with the erosion rate showing an evident decline over the past 30 years. The improvement showed not only in the decline of eroded soil area, but also with the reduction in the extent of erosion. The extent of erosion mainly changed by one level, and the change primarily occurred with the severely or moderately eroded soil types. However, in general, soil erosion was still an overriding problem in the region with some areas becoming more serious, especially those with large quantities of granite. 展开更多
关键词 GIS remote sensing soil erosion spatial and temporal dynamics Xingguo County
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Generalized Uncertainty Principle and Thermodynamic Quantities of SAdS_5 Black Hole 被引量:1
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作者 ZHANG Li-Chun WU Yue-Qin LI Huai-Fan ZHAO Ren 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第7期97-100,共4页
Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein- Hawking black hole entropy. The different correction leading terms are obtained by the different methods. In this... Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein- Hawking black hole entropy. The different correction leading terms are obtained by the different methods. In this paper, we calculate the correction to SAdS5 black hole thermodynamic quantity due to the generalized uncertainty principle. Furthermore we derive that the black hole entropy obeys Bekenstein Hawking area theorem. The entropy has infinite correction terms. And every term is finite and calculable. The corrected Cardy-Vedinde formula is derived. In our calculation, Bekenstein Hawking area theorem still holds after considering the generalized uncertainty principle. We have not introduced any hypothesis. The calculation is simple. Physics meaning is clear. We note that our results are quite general. It is not only valid for four-dimensional spacetime but also for higher-dimensional SAdS spacetime. 展开更多
关键词 generalized uncertainty principle correction to black hole entropy area theorem high-dimensional SAdS spacetime
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Study on spatial temporal model in property management information system
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作者 李良宝 李晓东 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2004年第6期654-657,共4页
Time is an important dimension for information in the geographical information system. Data, such as the historical state of target property space and related events causing the state to be changed, should be saved as... Time is an important dimension for information in the geographical information system. Data, such as the historical state of target property space and related events causing the state to be changed, should be saved as important files. This should be applied to property management. This paper designs and constructs a spatial temporal model, which is suitable to the property data changing management and spatial temporal query by analyzing the basic types and characteristics of property management spatial changing time and date. This model uses current and historical situational layers to organize and set up the relationship between current situation data and historical dates according to spatial temporal topological relations in property entities. By using Map Basic, housing property management and spatial query is realized. 展开更多
关键词 property management spatial temporal model temporal query spatial temporal topology MIS
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Temporal and spatial characteristics of harmful algal blooms in Qingdao Waters,China 被引量:4
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作者 袁涌铨 俞志明 +1 位作者 宋秀贤 曹西华 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第2期400-414,共15页
Qingdao waters,including both the semi-enclosed Jiaozhou Bay(JB) and the adjacent water out of JB(OJB),have been the areas that are most frequently affected by harmful algal blooms(HABs) in the western Yellow Sea(west... Qingdao waters,including both the semi-enclosed Jiaozhou Bay(JB) and the adjacent water out of JB(OJB),have been the areas that are most frequently affected by harmful algal blooms(HABs) in the western Yellow Sea(west of 124°E).In this research,HAB occurrences in Qingdao waters from 1990 to 2009 were investigated using spatial tools in geographic information system(GIS) and are discussed in terms of their connection to temporal variation.Additionally,the effects of each HAB occurrence were further evaluated using a simple model.The calculated results were then visualized using a GIS software to indicate the effects of HABs in Qingdao waters during the entire period.As a result,the OJB was proven to be responsible for the frequent HAB occurrences in Qingdao waters after 2000,although JB was traditionally believed to be the principle source of HAB occurrences in Qingdao waters.In addition,increasing nitrogen and N/P structure imbalance were essential for increasing HAB occurrences in Qingdao waters throughout the entire period,especially for the recent HAB occurrences in the OJB.The results of this research would improve the current understanding on HAB occurrences in Qingdao waters,which would benefit HAB monitoring and the implementation of a control strategy in China as well. 展开更多
关键词 harmful algal blooms (HABs) geographic information system (GIS) effects evaluation ofHABs Qingdao waters
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Nature and Kinetic Architecture: The Development of a New Type of Transformable Structure for Temporary Applications
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作者 Maziar Asefi Aysan Foruzandeh 《Journal of Civil Engineering and Architecture》 2011年第6期513-526,共14页
The contemplation of contemporary architectural designs shows an increasing demand for the development of more adaptable, flexible and transformable structures. This type of structures can adapt with different environ... The contemplation of contemporary architectural designs shows an increasing demand for the development of more adaptable, flexible and transformable structures. This type of structures can adapt with different environmental conditions and meet different functions. This can help in reducing environmental waste and pollution associated with many buildings and above all can save on cost and time. Natural systems have inspired human being, since they began to build and design. Architects and designers have utilized nature as one of the main resources of information for the creation of innovative architectural spaces. One of the unique features of natural structures is the way that their components open and close in order to respond to a particular requirement or the environmental changes. This aspect has inspired many designers for the development of transformable architectural structures that can change their shape and geometry to be able to adapt with specific conditions. To make a way toward the design of transformable structure for temporary applications, the authors have developed a new type of adaptable structures according to natural forms. The proposed design applies the transformation principles that exist in potato's flower and the movement mechanisms used in a spider's leg. The design is able to fit to different topographies and have a potential to be folded to a very compact state in a very short period of time. The detailed design and the different configurations of the system applications will be presented in this paper. The result of the study shows that using modular triangular plates can create a changeable module that is not only able to respond to different functions and environmental changes but it is also able to shape different configuration to be able to respond to different user's ambitions. The compactability of this structure into 1/3 of its base dimensions; makes its transportation fast and with minimum costs. These capabilities make this structure suitable for temporary buildings such as exhibitions, temporary settlements or hospital in damaged areas. 展开更多
关键词 Flexible changeable transformable temporary structure natural lessons.
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Spatial-temporal characteristics of epidemic spread in-out flow——Using SARS epidemic in Beijing as a case study
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作者 HU BiSong GONG JianHua +4 位作者 ZHOU JiePing SUN Jun YANG LiYang XIA Yu Abdoul Nasser IBRAHIM 《Science China Earth Sciences》 SCIE EI CAS 2013年第8期1380-1397,共18页
For better detecting the spatial-temporal change mode of individual susceptible-infected-symptomatic-treated-recovered epidemic progress and the characteristics of information/material flow in the epidemic spread netw... For better detecting the spatial-temporal change mode of individual susceptible-infected-symptomatic-treated-recovered epidemic progress and the characteristics of information/material flow in the epidemic spread network between regions,the epidemic spread mechanism of virus input and output was explored based on individuals and spatial regions.Three typical spatial information parameters including working unit/address,onset location and reporting unit were selected and SARS epidemic spread in-out flow in Beijing was defined based on the SARS epidemiological investigation data in China from 2002 to 2003 while its epidemiological characteristics were discussed.Furthermore,by the methods of spatial-temporal statistical analysis and network characteristic analysis,spatial-temporal high-risk hotspots and network structure characteristics of Beijing outer in-out flow were explored,and spatial autocorrelation/heterogeneity,spatial-temporal evolutive rules and structure characteristics of the spread network of Beijing inner in-out flow were comprehensively analyzed.The results show that(1)The outer input flow of SARS epidemic in Beijing concentrated on Shanxi and Guangdong provinces,but the outer output flow was disperse and mainly includes several north provinces such as Guangdong and Shandong.And the control measurement should focus on the early and interim progress of SARS breakout.(2)The inner output cases had significant positive autocorrelative characteristics in the whole studied region,and the high-risk population was young and middle-aged people with ages from 20 to 60 and occupations of medicine and civilian labourer.(3)The downtown districts were main high-risk hotspots of SARS epidemic in Beijing,the northwest suburban districts/counties were secondary high-risk hotspots,and northeast suburban areas were relatively safe.(4)The district/county nodes in inner spread network showed small-world characteristics and information/material flow had notable heterogeneity.The suburban Tongzhou and Changping districts were the underlying high-risk regions,and several suburban districts such as Shunyi and Huairou were the relatively low-risk safe regions as they carried out minority information/material flow.The exploration and analysis based on epidemic spread in-out flow help better detect and discover the potential spatial-temporal evolutive rules and characteristics of SARS epidemic,and provide a more effective theoretical basis for emergency/control measurements and decision-making. 展开更多
关键词 in-out flow SARS BEIJING epidemic spread network spatial-temporal characteristics control measurement
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Dynamic mode decomposition of hairpin vortices generated by a hemisphere protuberance 被引量:8
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作者 TANG ZhanQi JIANG Nan 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第1期118-124,共7页
We present dynamic mode decomposition (DMD) for studying the hairpin vortices generated by hemisphere protuberance measured by two-dimensional (2D) time-resolved (TR) particle image velocimetry (PIV) in a water channe... We present dynamic mode decomposition (DMD) for studying the hairpin vortices generated by hemisphere protuberance measured by two-dimensional (2D) time-resolved (TR) particle image velocimetry (PIV) in a water channel. The hairpins dynamic information is extracted by identifying their dominant frequencies and associated spatial structures. For this quasi-periodic data system, the resulting main Dynamic modes illustrate the different spatial structures associated with the wake vortex region and the near-wall region. By comparisons with proper orthogonal decomposition (POD), it can be concluded that the dynamic mode concentrates on a certain frequency component more effectively than the mode determined by POD. During the analysis, DMD has proven itself a robust and reliable algorithm to extract spatial-temporal coherent structures. 展开更多
关键词 hairpin vortices hemisphere protuberance time-resolved particle image velocimetry dynamic mode decomposition proper orthogonal decomposition
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Gene locations may contribute to predicting gene regulatory relationships
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作者 Jun MENG Wen-yuan XU +2 位作者 Xiao CHEN Tao LIN Xiao-yu DENG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2018年第1期25-37,共13页
We propose that locations of genes on chromosomes can contribute to the prediction of gene regulatory relationships. We constructed a time-based gene regulatory network of zebrafish cardiogenesis on the basis of a spa... We propose that locations of genes on chromosomes can contribute to the prediction of gene regulatory relationships. We constructed a time-based gene regulatory network of zebrafish cardiogenesis on the basis of a spatio-temporal neighborhood method. Through the network, specific regulatory pathways and order of gene expression during zebrafish cardiogenesis were obtained. By comparing the order with locations of these genes on chromosomes, we discovered that there exists a reversal phenomenon between the order and order of gene locations. The discovery provides an inherent rule to instruct exploration of gene regulatory relationships. Specifically, the discovery can help to predict if regulatory relationships between genes exist and contribute to evaluating the correctness of discovered gene regulatory relationships. 展开更多
关键词 Prediction Gene regulatory relationships Order of gene location Spatio-temporal neighborhood method Zebrafish cardiogenesis
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