Querying over XML elements using keyword search is steadily gaining popularity. The traditional similarity measure is widely employed in order to effectively retrieve various XML documents. A number of authors have al...Querying over XML elements using keyword search is steadily gaining popularity. The traditional similarity measure is widely employed in order to effectively retrieve various XML documents. A number of authors have already proposed different similarity-measure methods that take advantage of the structure and content of XML documents. However, they do not consider the similarity between latent semantic information of element texts and that of keywords in a query. Although many algorithms on XML element search are available, some of them have the high computational complexity due to searching for a huge number of elements. In this paper, we propose a new algorithm that makes use of the se-mantic similarity between elements instead of between entire XML documents, considering not only the structure and content of an XML document, but also semantic information of namespaces in elements. We compare our algorithm with the three other algorithms by testing on real datasets. The experiments have demonstrated that our proposed method is able to improve the query accuracy, as well as to reduce the running time.展开更多
We propose a three-step technique to achieve this purpose. First, we utilize a collection of XML namespaces organized into hierarchical structure as a medium for expressing data semantics. Second, we define the format...We propose a three-step technique to achieve this purpose. First, we utilize a collection of XML namespaces organized into hierarchical structure as a medium for expressing data semantics. Second, we define the format of resource descriptor for the information source discovery scheme so that we can dynamically register and/or deregister the Web data sources on the fly. Third, we employ an inverted-index mechanism to identify the subset of information sources that are relevant to a particular user query. We describe the design, architecture, and implementation of our approach—IWDS, and illustrate its use through case examples. Key words integration - heterogeneity - Web data source - XML namespace CLC number TP 311.13 Foundation item: Supported by the National Key Technologies R&D Program of China(2002BA103A04)Biography: WU Wei (1975-), male, Ph.D candidate, research direction: information integration, distribute computing展开更多
Container-based virtualization is increasingly popular in cloud computing due to its efficiency and flexibility.Isolation is a fundamental property of containers and weak isolation could cause significant performance ...Container-based virtualization is increasingly popular in cloud computing due to its efficiency and flexibility.Isolation is a fundamental property of containers and weak isolation could cause significant performance degradation and security vulnerability.However,existing works have almost not discussed the isolation problems of system log which is critical for monitoring and maintenance of containerized applications.In this paper,we present a detailed isolation analysis of system log in current container environment.First,we find several system log isolation problems which can cause significant impacts on system usability,security,and efficiency.For example,system log accidentally exposes information of host and co-resident containers to one container,causing information leakage.Second,we reveal that the root cause of these isolation problems is that containers share the global log configuration,the same log storage,and the global log view.To address these problems,we design and implement a system named private logs(POGs).POGs provides each container with its own log configuration and stores logs individually for each container,avoiding log configuration and storage sharing,respectively.In addition,POGs enables private log view to help distinguish which container the logs belong to.The experimental results show that POGs can effectively enhance system log isolation for containers with negligible performance overhead.展开更多
文摘Querying over XML elements using keyword search is steadily gaining popularity. The traditional similarity measure is widely employed in order to effectively retrieve various XML documents. A number of authors have already proposed different similarity-measure methods that take advantage of the structure and content of XML documents. However, they do not consider the similarity between latent semantic information of element texts and that of keywords in a query. Although many algorithms on XML element search are available, some of them have the high computational complexity due to searching for a huge number of elements. In this paper, we propose a new algorithm that makes use of the se-mantic similarity between elements instead of between entire XML documents, considering not only the structure and content of an XML document, but also semantic information of namespaces in elements. We compare our algorithm with the three other algorithms by testing on real datasets. The experiments have demonstrated that our proposed method is able to improve the query accuracy, as well as to reduce the running time.
文摘We propose a three-step technique to achieve this purpose. First, we utilize a collection of XML namespaces organized into hierarchical structure as a medium for expressing data semantics. Second, we define the format of resource descriptor for the information source discovery scheme so that we can dynamically register and/or deregister the Web data sources on the fly. Third, we employ an inverted-index mechanism to identify the subset of information sources that are relevant to a particular user query. We describe the design, architecture, and implementation of our approach—IWDS, and illustrate its use through case examples. Key words integration - heterogeneity - Web data source - XML namespace CLC number TP 311.13 Foundation item: Supported by the National Key Technologies R&D Program of China(2002BA103A04)Biography: WU Wei (1975-), male, Ph.D candidate, research direction: information integration, distribute computing
基金supported by the National Key R&D Program(2022YFB4500704)the National Natural Science Foundation of China(Grant No.62032008).
文摘Container-based virtualization is increasingly popular in cloud computing due to its efficiency and flexibility.Isolation is a fundamental property of containers and weak isolation could cause significant performance degradation and security vulnerability.However,existing works have almost not discussed the isolation problems of system log which is critical for monitoring and maintenance of containerized applications.In this paper,we present a detailed isolation analysis of system log in current container environment.First,we find several system log isolation problems which can cause significant impacts on system usability,security,and efficiency.For example,system log accidentally exposes information of host and co-resident containers to one container,causing information leakage.Second,we reveal that the root cause of these isolation problems is that containers share the global log configuration,the same log storage,and the global log view.To address these problems,we design and implement a system named private logs(POGs).POGs provides each container with its own log configuration and stores logs individually for each container,avoiding log configuration and storage sharing,respectively.In addition,POGs enables private log view to help distinguish which container the logs belong to.The experimental results show that POGs can effectively enhance system log isolation for containers with negligible performance overhead.
