The problem of constructing global view of heterogeneous information sources for information sharing is becoming more and more important due to the availability of multiple information sources within the virtual organ...The problem of constructing global view of heterogeneous information sources for information sharing is becoming more and more important due to the availability of multiple information sources within the virtual organization. Global view is defined to provide a unified representation of the information in the different sources by analyzing concept schemas associated with them and resolving possible semantic heterogeneity. An ontology-based method for global view construction is proposed. In the method, （ 1 ） Based on the formal ontologies, the concept of semantic affinity is introduced to assess the level of semantic relationship between information classes from different information sources; （2） Information classes are classified by semantic affinity levels using clustering procedures so that their different representations can be analyzed for unification; （3） Global view is constructed starting from selected clusters by unifying representation of their elements. The application example of using the method in the joint-aerial defense organization is illustrated and the result shows that the proposed method is feasible.展开更多
This paper presents both analytical and numerical studies on the global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback.Based on a detailed analysis of the stability switches of the t...This paper presents both analytical and numerical studies on the global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback.Based on a detailed analysis of the stability switches of the trivial equilibrium of the system,the stability charts are given in a parameter space consisting of the time delay and the feedback gains.The center manifold reduc-tion and the normal form method are used to study Hopf bifurcations with respect to the time delay.To gain an insight into the persistence of a Hopf bifurcation as the time delay varies farther away from its critical value,the method of multiple scales is used to obtain the global view of Hopf bifurcations with respect to the time delay.Both the analytical results of Hopf bifurca-tions and global view of those bifurcations are validated via a collocation scheme implemented on DDE-Biftool.The most important discovery in this paper is the well-structured global view of Hopf bifurcations for the system of concern,showing the generality of the persistence of Hopf bifurcations.展开更多
This paper presents both analytical and numerical studies on the global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback. Based on a detailed analysis of the stability switches of the ...This paper presents both analytical and numerical studies on the global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback. Based on a detailed analysis of the stability switches of the trivial equilibrium of the system, the stability charts are given in a parameter space consisting of the time delay and the feedback gains. The center manifold reduction and the normal form method are used to study Hopf bifurcations with respect to the time delay. To gain an insight into the persistence of a Hopf bifurcation as the time delay varies farther away from its critical value, the method of multiple scales is used to obtain the global view of Hopf bifurcations with respect to the time delay. Both the analytical results of Hopf bifurcations and global view of those bifurcations are validated via a collocation scheme implemented on DDE-Biftool. The most important discovery in this paper is the well-structured global view of Hopf bifurcations for the system of concern, showing the generality of the persistence of Hopf bifurcations.展开更多
On March 24, 1999, depending on its advanced technology and weapons, theS-led North Atlantic Treaty Organization(NATO) circumvented the Unit-ed Nations and brazenly used military forces against the Republic of Yugosla...On March 24, 1999, depending on its advanced technology and weapons, theS-led North Atlantic Treaty Organization(NATO) circumvented the Unit-ed Nations and brazenly used military forces against the Republic of Yugoslavia.The continuous bombing for more than two months has brought unprecedentedcatastrophe to Yugoslavia which used to be called the Garden of Eden. On May8, NATO with the US as leader again violated the UN Charter, internationallaws and the Vienna Diplomatic Convention and flagrantly bombed the展开更多
In the study of social problems, it is important to realize the organic combination of global view, local people standard,, which plays an important role in handing and understanding specific social problems undoubted...In the study of social problems, it is important to realize the organic combination of global view, local people standard,, which plays an important role in handing and understanding specific social problems undoubtedly. This article takes our country＇s public pension personal account as example ,analyzing how to realize the combination of all three in the whole research process of the individual account.展开更多
基金This project was supported by the National Natural Science Foundation of China (60172012) Hunan Provincial NaturalScience Foundation of China (03JJY3110) .
文摘The problem of constructing global view of heterogeneous information sources for information sharing is becoming more and more important due to the availability of multiple information sources within the virtual organization. Global view is defined to provide a unified representation of the information in the different sources by analyzing concept schemas associated with them and resolving possible semantic heterogeneity. An ontology-based method for global view construction is proposed. In the method, （ 1 ） Based on the formal ontologies, the concept of semantic affinity is introduced to assess the level of semantic relationship between information classes from different information sources; （2） Information classes are classified by semantic affinity levels using clustering procedures so that their different representations can be analyzed for unification; （3） Global view is constructed starting from selected clusters by unifying representation of their elements. The application example of using the method in the joint-aerial defense organization is illustrated and the result shows that the proposed method is feasible.
基金supported by the National Natural Science Foundation of China(Grant Nos.10532050,10702024)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20070287029)
文摘This paper presents both analytical and numerical studies on the global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback.Based on a detailed analysis of the stability switches of the trivial equilibrium of the system,the stability charts are given in a parameter space consisting of the time delay and the feedback gains.The center manifold reduc-tion and the normal form method are used to study Hopf bifurcations with respect to the time delay.To gain an insight into the persistence of a Hopf bifurcation as the time delay varies farther away from its critical value,the method of multiple scales is used to obtain the global view of Hopf bifurcations with respect to the time delay.Both the analytical results of Hopf bifurca-tions and global view of those bifurcations are validated via a collocation scheme implemented on DDE-Biftool.The most important discovery in this paper is the well-structured global view of Hopf bifurcations for the system of concern,showing the generality of the persistence of Hopf bifurcations.
基金Supported by the National Natural Science Foundation of China (Grant Nos.10532050)Supported by the National Natural Science Foundation of China (Grant Nos.10702024)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No.20070287029)
文摘This paper presents both analytical and numerical studies on the global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback. Based on a detailed analysis of the stability switches of the trivial equilibrium of the system, the stability charts are given in a parameter space consisting of the time delay and the feedback gains. The center manifold reduction and the normal form method are used to study Hopf bifurcations with respect to the time delay. To gain an insight into the persistence of a Hopf bifurcation as the time delay varies farther away from its critical value, the method of multiple scales is used to obtain the global view of Hopf bifurcations with respect to the time delay. Both the analytical results of Hopf bifurcations and global view of those bifurcations are validated via a collocation scheme implemented on DDE-Biftool. The most important discovery in this paper is the well-structured global view of Hopf bifurcations for the system of concern, showing the generality of the persistence of Hopf bifurcations.
文摘On March 24, 1999, depending on its advanced technology and weapons, theS-led North Atlantic Treaty Organization(NATO) circumvented the Unit-ed Nations and brazenly used military forces against the Republic of Yugoslavia.The continuous bombing for more than two months has brought unprecedentedcatastrophe to Yugoslavia which used to be called the Garden of Eden. On May8, NATO with the US as leader again violated the UN Charter, internationallaws and the Vienna Diplomatic Convention and flagrantly bombed the
文摘In the study of social problems, it is important to realize the organic combination of global view, local people standard,, which plays an important role in handing and understanding specific social problems undoubtedly. This article takes our country＇s public pension personal account as example ,analyzing how to realize the combination of all three in the whole research process of the individual account.
