It is one of feasible ways to use the fully-developed database management system to manage the XML data. How to generate the corresponding relational schema is a key problem to reach that target. Here described is an ...It is one of feasible ways to use the fully-developed database management system to manage the XML data. How to generate the corresponding relational schema is a key problem to reach that target. Here described is an approach to generate the relational schema according to the structure of DTD and the analysis of user query for XML data. In the view of the drawbacks of approach put forward by Jauavel Shanmugasundaram,this approach takes both the storage cost and query cost into considera-tion.展开更多
XML Schema作为XML文档模式的定义语言,其语法本身不能保证定义模式的有效性。该文首先分析影响XML文档模式有效性的因素,并构造了XML文档模式图。依据XML实例文档特点,分析了XML文档模式图性质,其中包括递归引用可能导致死锁发生的原...XML Schema作为XML文档模式的定义语言,其语法本身不能保证定义模式的有效性。该文首先分析影响XML文档模式有效性的因素,并构造了XML文档模式图。依据XML实例文档特点,分析了XML文档模式图性质,其中包括递归引用可能导致死锁发生的原因。最后,给出了XML文档模式有效性验证算法,从而弥补了常见验证工具功能的不完整。展开更多
Weather Overview is regarded as one of the crucial meteorological services supporting the Beijing 2022 Olympic and Paralympic Winter Games(hereafter as Beijing 2022).As generation of Weather Overview involves multiple...Weather Overview is regarded as one of the crucial meteorological services supporting the Beijing 2022 Olympic and Paralympic Winter Games(hereafter as Beijing 2022).As generation of Weather Overview involves multipledata,large-scale weather conditions,and vulnerability to weather changes,there still exist quite some challenges in obtaining Weather Overview.At present,knowledge graph(KG)is believed to be an effective way to describe information and knowledge.Thus,this study focuses on development of a framework to automatically generate Weather Overview using KG.We first present a three-layer KG model to generate accurate content of Weather Overview:(1)knowledge acquisition of entities and relationships to construct the specific corpora;(2)knowledge representation of the relationships between weather conditions and the events based on ontology;and(3)knowledge application of corpora,variables,and weather conditions to query and reason knowledge with Neo4j.Moreover,an XML Schema is used to achieve the standardized Weather Overview,which is formed by sentence-paragraph-text generation.This model is validated for a typical case at the Yanqing National Alpine Skiing Centre in Beijing 2022.Compared to the manual method,the accuracy and standardization of Weather Overview can be maintained above 90%,and it can be automatically generated within seconds.The method proposed in this study provides a helpful meteorological service solution to other large-scale sports events.展开更多
We investigate the limitations of existing XML search methods and propose a new semantics, related relation- ship, to effectively capture meaningful relationships of data elements from XML data in the absence of struc...We investigate the limitations of existing XML search methods and propose a new semantics, related relation- ship, to effectively capture meaningful relationships of data elements from XML data in the absence of structural constraints. Then we make an extension to XPath by introducing a new axis, related axis, to specify the related relationship between query nodes so as to enhance the flexibility of XPath. We propose to reduce the cost of computing the related relationship by a new schema summary that summarizes the related relationship from the original schema without any loss. Based on this schema summary, we introduce two indices to improve the performance of query processing. Our algorithm shows that the evaluation of most queries can be equivalently transformed into just a few selection and value join operations, thus avoids the costly structural join operations. The experimental results show that our method is effective and efficient in terms of comparing the effectiveness of the related relationship with existing keyword search semantics and comparing the efficiency of our evaluation methods with existing query engines.展开更多
文摘It is one of feasible ways to use the fully-developed database management system to manage the XML data. How to generate the corresponding relational schema is a key problem to reach that target. Here described is an approach to generate the relational schema according to the structure of DTD and the analysis of user query for XML data. In the view of the drawbacks of approach put forward by Jauavel Shanmugasundaram,this approach takes both the storage cost and query cost into considera-tion.
基金Supported by the National Key Research and Development Program of China(2018YFF0300105)Special Fund of Meteorological Emergency Service on Flood Prevention,Drought Resistance,and Typhoon Prevention(Department of Flood Control and Drought Relief-2024-01)。
文摘Weather Overview is regarded as one of the crucial meteorological services supporting the Beijing 2022 Olympic and Paralympic Winter Games(hereafter as Beijing 2022).As generation of Weather Overview involves multipledata,large-scale weather conditions,and vulnerability to weather changes,there still exist quite some challenges in obtaining Weather Overview.At present,knowledge graph(KG)is believed to be an effective way to describe information and knowledge.Thus,this study focuses on development of a framework to automatically generate Weather Overview using KG.We first present a three-layer KG model to generate accurate content of Weather Overview:(1)knowledge acquisition of entities and relationships to construct the specific corpora;(2)knowledge representation of the relationships between weather conditions and the events based on ontology;and(3)knowledge application of corpora,variables,and weather conditions to query and reason knowledge with Neo4j.Moreover,an XML Schema is used to achieve the standardized Weather Overview,which is formed by sentence-paragraph-text generation.This model is validated for a typical case at the Yanqing National Alpine Skiing Centre in Beijing 2022.Compared to the manual method,the accuracy and standardization of Weather Overview can be maintained above 90%,and it can be automatically generated within seconds.The method proposed in this study provides a helpful meteorological service solution to other large-scale sports events.
基金supported by the National Science and Technology Major Project of China under Grant No. 2010ZX01042-002-003the National Natural Science Foundation of China under Grant Nos. 61073060, 61040023, 61070055, 91024032+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe Research Funds of Renmin University of China under Grant No. 10XNI018
文摘We investigate the limitations of existing XML search methods and propose a new semantics, related relation- ship, to effectively capture meaningful relationships of data elements from XML data in the absence of structural constraints. Then we make an extension to XPath by introducing a new axis, related axis, to specify the related relationship between query nodes so as to enhance the flexibility of XPath. We propose to reduce the cost of computing the related relationship by a new schema summary that summarizes the related relationship from the original schema without any loss. Based on this schema summary, we introduce two indices to improve the performance of query processing. Our algorithm shows that the evaluation of most queries can be equivalently transformed into just a few selection and value join operations, thus avoids the costly structural join operations. The experimental results show that our method is effective and efficient in terms of comparing the effectiveness of the related relationship with existing keyword search semantics and comparing the efficiency of our evaluation methods with existing query engines.
