由于非常规突发事件具有罕见性、急迫性的特点,要求决策者在具体情境中极速对事件作出决策响应,通过各种非传统和非程式化的方式将事件的危害性降低至最低。为了能够快速地找到最相关的案例并及时地提示指导,本文将非常规突发事件用本...由于非常规突发事件具有罕见性、急迫性的特点,要求决策者在具体情境中极速对事件作出决策响应,通过各种非传统和非程式化的方式将事件的危害性降低至最低。为了能够快速地找到最相关的案例并及时地提示指导,本文将非常规突发事件用本体的形式来表示,分析了事件之间的不同类型的逻辑关联及相应程度,并进一步构建了非常规突发事件的本体关联网络。接着,在网络拓扑分析的基础上,我们提出了一种利用交互时间距离CTD(Commute Time Distance)的快速搜索算法,该算法利用谱分析和复杂网络性质分析,能快速找到与新加入节点(新发生突发事件)最相关的案例,从而利用相关措施对紧急危害进行及时地提示和指导。最后,结合青岛"11·22"输油管道爆炸案的实际案例,本文证明了所述方法的有效性并对网络性质进行了分析,结果表明本方法可以高效而方便地应用到各种实际情况中,为非常规突发事件的快速提示提供技术支撑。展开更多
This paper proposed a novel multi-view interactive behavior recognition method based on local self-similarity descriptors and graph shared multi-task learning. First, we proposed the composite interactive feature repr...This paper proposed a novel multi-view interactive behavior recognition method based on local self-similarity descriptors and graph shared multi-task learning. First, we proposed the composite interactive feature representation which encodes both the spatial distribution of local motion of interest points and their contexts. Furthermore, local self-similarity descriptor represented by temporal-pyramid bag of words(BOW) was applied to decreasing the influence of observation angle change on recognition and retaining the temporal information. For the purpose of exploring latent correlation between different interactive behaviors from different views and retaining specific information of each behaviors, graph shared multi-task learning was used to learn the corresponding interactive behavior recognition model. Experiment results showed the effectiveness of the proposed method in comparison with other state-of-the-art methods on the public databases CASIA, i3Dpose dataset and self-built database for interactive behavior recognition.展开更多
An analysis of the Ishii ocean heat content(OHC) in the tropical Indian Ocean from the surface to 700-m depth shows that the OHC changes dramatically on the interannual timescale in the Indian Ocean.The first mode of ...An analysis of the Ishii ocean heat content(OHC) in the tropical Indian Ocean from the surface to 700-m depth shows that the OHC changes dramatically on the interannual timescale in the Indian Ocean.The first mode of empirical orthogonal function(EOF1) of the OHC shows that there is a strong air-sea interaction pattern in the Indian Ocean with a positive(negative) loading in the east and a negative(positive) loading in the west.This seesaw oscillation pattern influences the summer precipitation in China with a North-South reversed distribution.Composite analysis shows that during a positive(negative) OHC episode,an anomalous cyclonic(anticyclonic) circulation over the western Pacific and South China weakens(enhances) the monsoonal northward flow in the lower troposphere;meanwhile,anomalous meridional circulation connects the descending(ascending) branch over the Southeast Indian Ocean and the ascending(descending) branch in South China as well as a descending(ascending) branch over North China.Analysis of the mechanism behind these features suggests that(1) the accumulation of OHC-induced vorticity is related to the wave activity over the mid-latitudes and that(2) the meridional teleconnection induced by the Indo-Pacific air-OHC interaction appears over East Asia and the western Pacific.Both of these patterns can cause summer precipitation anomalies in China.展开更多
The function of a network is affected by its structure. For example, the presence of highly interactive individuals, or hubs, influences the extent and rate of information spread across a network. In a network of inte...The function of a network is affected by its structure. For example, the presence of highly interactive individuals, or hubs, influences the extent and rate of information spread across a network. In a network of interactions, the duration over which individual variation in interactions persists may affect how the network operates. Individuals may persist in their behavior over time and across situations, often referred to as personality. Colonies of social insects are an example of a biological system in which the structure of the coordinated networks of interacting workers may greatly influence information flow within the colony, and therefore its collective behavior. Here I investigate the effects of persistence in walking patterns on interaction networks us- ing computer simulations that are parameterized using observed behavior of harvester ants. I examine how the duration of persis- tence in spatial behavior influences network structure. Furthermore, I explore how spatial features of the environment affect the relationship between persistent behavior and network structure. I show that as persistence increases, the skewness of the weighted degree distribution of the interaction network increases. However, this relationship holds only when ants are confined in a space with boundaries, but not when physical barriers are absent. These findings suggest that the influence of animal personalities on network structure and function depends on the environment in which the animals reside [Current Zoology 61 （1）： 98-106, 2015].展开更多
The problem of shock interaction with a rigid circular cylinder has been investigated using a compressible immersed boundary method coupled with high-order weighted-essentially non-oscillatory(WENO) scheme.First,the a...The problem of shock interaction with a rigid circular cylinder has been investigated using a compressible immersed boundary method coupled with high-order weighted-essentially non-oscillatory(WENO) scheme.First,the accuracy of the developed code is validated.Then,influences of the incident shock Mach number on the flow-field structure and dynamic drag coefficient,as well as time evolution of the flow field are studied.For different shock Mach number,the flow structure shows very different features.At a given dimensionless time,both the normalized shock detachment distance and the normalized vertical distance from the highest point of the primary reflected shock to the centerline of the cylinder decreases with increasing shock Mach number.However,location of the upper triple point varies non-monotonically with shock Mach number.For a case with given shock Mach number,the trajectory of the upper triple point and the time evolution of the normalized vertical distance from the highest point of the primary reflected shock to the centerline of the cylinder can both be predicted by linear correlation.Nevertheless,the time evolution of the normalized shock detachment distance is biased to be non-linear.Meanwhile,time evolution of force exerted on the cylinder is quite unsteady for a case with given shock Mach number and given cylinder diameter.For small shock Mach number,there exists a negative valley,and it disappears when the incident shock Mach number increases to a large value,e.g.,1.7.Furthermore,correlations to predict the occurrence of the peak drag and its value under different shock Mach numbers have been proposed.展开更多
文摘由于非常规突发事件具有罕见性、急迫性的特点,要求决策者在具体情境中极速对事件作出决策响应,通过各种非传统和非程式化的方式将事件的危害性降低至最低。为了能够快速地找到最相关的案例并及时地提示指导,本文将非常规突发事件用本体的形式来表示,分析了事件之间的不同类型的逻辑关联及相应程度,并进一步构建了非常规突发事件的本体关联网络。接着,在网络拓扑分析的基础上,我们提出了一种利用交互时间距离CTD(Commute Time Distance)的快速搜索算法,该算法利用谱分析和复杂网络性质分析,能快速找到与新加入节点(新发生突发事件)最相关的案例,从而利用相关措施对紧急危害进行及时地提示和指导。最后,结合青岛"11·22"输油管道爆炸案的实际案例,本文证明了所述方法的有效性并对网络性质进行了分析,结果表明本方法可以高效而方便地应用到各种实际情况中,为非常规突发事件的快速提示提供技术支撑。
基金Project(51678075)supported by the National Natural Science Foundation of ChinaProject(2017GK2271)supported by Hunan Provincial Science and Technology Department,China
文摘This paper proposed a novel multi-view interactive behavior recognition method based on local self-similarity descriptors and graph shared multi-task learning. First, we proposed the composite interactive feature representation which encodes both the spatial distribution of local motion of interest points and their contexts. Furthermore, local self-similarity descriptor represented by temporal-pyramid bag of words(BOW) was applied to decreasing the influence of observation angle change on recognition and retaining the temporal information. For the purpose of exploring latent correlation between different interactive behaviors from different views and retaining specific information of each behaviors, graph shared multi-task learning was used to learn the corresponding interactive behavior recognition model. Experiment results showed the effectiveness of the proposed method in comparison with other state-of-the-art methods on the public databases CASIA, i3Dpose dataset and self-built database for interactive behavior recognition.
基金supported by the National Basic Research Program of China(973 Program):The impact of Southern Ocean-Indian Ocean air-sea processes on East Asia and the global climate change(Grant No.2010CB950300)National Foundation of the Indian Ocean Opening Voyage Project(Grant Nos. 41149903 and 41049908)+2 种基金the Knowledge Innovation Project for Distinguished Young Scholar of the Chinese Academy of Sciences (Grant No.KZCX2-EW-QN203)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KZCX2-YWQ11-02)the National Natural Science Foundation of China (Grant No.40906010)
文摘An analysis of the Ishii ocean heat content(OHC) in the tropical Indian Ocean from the surface to 700-m depth shows that the OHC changes dramatically on the interannual timescale in the Indian Ocean.The first mode of empirical orthogonal function(EOF1) of the OHC shows that there is a strong air-sea interaction pattern in the Indian Ocean with a positive(negative) loading in the east and a negative(positive) loading in the west.This seesaw oscillation pattern influences the summer precipitation in China with a North-South reversed distribution.Composite analysis shows that during a positive(negative) OHC episode,an anomalous cyclonic(anticyclonic) circulation over the western Pacific and South China weakens(enhances) the monsoonal northward flow in the lower troposphere;meanwhile,anomalous meridional circulation connects the descending(ascending) branch over the Southeast Indian Ocean and the ascending(descending) branch in South China as well as a descending(ascending) branch over North China.Analysis of the mechanism behind these features suggests that(1) the accumulation of OHC-induced vorticity is related to the wave activity over the mid-latitudes and that(2) the meridional teleconnection induced by the Indo-Pacific air-OHC interaction appears over East Asia and the western Pacific.Both of these patterns can cause summer precipitation anomalies in China.
文摘The function of a network is affected by its structure. For example, the presence of highly interactive individuals, or hubs, influences the extent and rate of information spread across a network. In a network of interactions, the duration over which individual variation in interactions persists may affect how the network operates. Individuals may persist in their behavior over time and across situations, often referred to as personality. Colonies of social insects are an example of a biological system in which the structure of the coordinated networks of interacting workers may greatly influence information flow within the colony, and therefore its collective behavior. Here I investigate the effects of persistence in walking patterns on interaction networks us- ing computer simulations that are parameterized using observed behavior of harvester ants. I examine how the duration of persis- tence in spatial behavior influences network structure. Furthermore, I explore how spatial features of the environment affect the relationship between persistent behavior and network structure. I show that as persistence increases, the skewness of the weighted degree distribution of the interaction network increases. However, this relationship holds only when ants are confined in a space with boundaries, but not when physical barriers are absent. These findings suggest that the influence of animal personalities on network structure and function depends on the environment in which the animals reside [Current Zoology 61 （1）： 98-106, 2015].
基金supported by the National Natural Science Foundation of China(Grant Nos.51576176&91541202)the Fundamental Research Funds for the Central Universities(Grant No.2016FZA4008)the Postdoctoral Science Foundation of China(Grant No.2015M581928)
文摘The problem of shock interaction with a rigid circular cylinder has been investigated using a compressible immersed boundary method coupled with high-order weighted-essentially non-oscillatory(WENO) scheme.First,the accuracy of the developed code is validated.Then,influences of the incident shock Mach number on the flow-field structure and dynamic drag coefficient,as well as time evolution of the flow field are studied.For different shock Mach number,the flow structure shows very different features.At a given dimensionless time,both the normalized shock detachment distance and the normalized vertical distance from the highest point of the primary reflected shock to the centerline of the cylinder decreases with increasing shock Mach number.However,location of the upper triple point varies non-monotonically with shock Mach number.For a case with given shock Mach number,the trajectory of the upper triple point and the time evolution of the normalized vertical distance from the highest point of the primary reflected shock to the centerline of the cylinder can both be predicted by linear correlation.Nevertheless,the time evolution of the normalized shock detachment distance is biased to be non-linear.Meanwhile,time evolution of force exerted on the cylinder is quite unsteady for a case with given shock Mach number and given cylinder diameter.For small shock Mach number,there exists a negative valley,and it disappears when the incident shock Mach number increases to a large value,e.g.,1.7.Furthermore,correlations to predict the occurrence of the peak drag and its value under different shock Mach numbers have been proposed.
