Showing papers on "XML published in 2001"

Generic Schema Matching with Cupid

Abstract: Schema matching is a critical step in many applications, such as XML message mapping, data warehouse loading, and schema integration. In this paper, we investigate algorithms for generic schema matching, outside of any particular data model or application. We first present a taxonomy for past solutions, showing that a rich range of techniques is available. We then propose a new algorithm, Cupid, that discovers mappings between schema elements based on their names, data types, constraints, and schema structure, using a broader set of techniques than past approaches. Some of our innovations are the integrated use of linguistic and structural matching, context-dependent matching of shared types, and a bias toward leaf structure where much of the schema content resides. After describing our algorithm, we present experimental results that compare Cupid to two other schema matching systems.

Ontologies: A Silver Bullet for Knowledge Management and Electronic Commerce

Abstract: This second editionsystematically introduces the notion of ontologies to the non-expert reader and demonstrates in detail how to apply this conceptual framework for improved intranet retrieval of corporate information and knowledge and for enhanced Internet-based electronic commerce He also describes ontology languages (XML, RDF, and OWL) and ontology tools, and the application of ontologies In addition to structural improvements, the second edition covers recent developments relating to the Semantic Web, and emerging web-based standard languages

Keys with Upward Wildcards for XML

Abstract: The paper proposes a key constraint language for XML and investigates its associated decision problems. The language is defined in terms of regular path expressions extended with downward and upward wildcards, which can not only move down XML document trees, but also upwards. In a uniform syntax it is capable of expressing both absolute keys and relative keys, which are important to hierarchically structured data. In addition, keys defined in the language can be reasoned about efficiently. The paper provides a sound and complete set of inference rules and a cubic time algorithm for determining implication of the keys.

On supporting containment queries in relational database management systems

Abstract: Virtually all proposals for querying XML include a class of query we term “containment queries”. It is also clear that in the foreseeable future, a substantial amount of XML data will be stored in relational database systems. This raises the question of how to support these containment queries. The inverted list technology that underlies much of Information Retrieval is well-suited to these queries, but should we implement this technology (a) in a separate loosely-coupled IR engine, or (b) using the native tables and query execution machinery of the RDBMS? With option (b), more than twenty years of work on RDBMS query optimization, query execution, scalability, and concurrency control and recovery immediately extend to the queries and structures that implement these new operations. But all this will be irrelevant if the performance of option (b) lags that of (a) by too much. In this paper, we explore some performance implications of both options using native implementations in two commercial relational database systems and in a special purpose inverted list engine. Our performance study shows that while RDBMSs are generally poorly suited for such queries, under conditions they can outperform an inverted list engine. Our analysis further identifies two significant causes that differentiate the performance of the IR and RDBMS implementations: the join algorithms employed and the hardware cache utilization. Our results suggest that contrary to most expectations, with some modifications, a native implementations in an RDBMS can support this class of query much more efficiently.

Reconciling schemas of disparate data sources: a machine-learning approach

Abstract: A data-integration system provides access to a multitude of data sources through a single mediated schema. A key bottleneck in building such systems has been the laborious manual construction of semantic mappings between the source schemas and the mediated schema. We describe LSD, a system that employs and extends current machine-learning techniques to semi-automatically find such mappings. LSD first asks the user to provide the semantic mappings for a small set of data sources, then uses these mappings together with the sources to train a set of learners. Each learner exploits a different type of information either in the source schemas or in their data. Once the learners have been trained, LSD finds semantic mappings for a new data source by applying the learners, then combining their predictions using a meta-learner. To further improve matching accuracy, we extend machine learning techniques so that LSD can incorporate domain constraints as an additional source of knowledge, and develop a novel learner that utilizes the structural information in XML documents. Our approach thus is distinguished in that it incorporates multiple types of knowledge. Importantly, its architecture is extensible to additional learners that may exploit new kinds of information. We describe a set of experiments on several real-world domains, and show that LSD proposes semantic mappings with a high degree of accuracy.

Indexing and Querying XML Data for Regular Path Expressions

Abstract: With the advent of XML as a standard for data representation and exchange on the Internet, storing and querying XML data becomes more and more important. Several XML query languages have been proposed, and the common feature of the languages is the use of regular path expressions to query XML data. This poses a new challenge concerning indexing and searching XML data, because conventional approaches based on tree traversals may not meet the processing requirements under heavy access requests. In this paper, we propose a new system for indexing and storing XML data based on a numbering scheme for elements. This numbering scheme quickly determines the ancestor-descendant relationship between elements in the hierarchy of XML data. We also propose several algorithms for processing regular path expressions, namely, (1) -Join for searching paths from an element to another, (2) -Join for scanning sorted elements and attributes to find element-attribute pairs, and (3) -Join for finding Kleene-Closure on repeated paths or elements. The -Join algorithm is highly effective particularly for searching paths that are very long or whose lengths are unknown. Experimental results from our prototype system implementation show that the proposed algorithms can process XML queries with regular path expressions by up to an or

Annotea: an open RDF infrastructure for shared Web annotations

Abstract: Annotea is a Web-based shared annotation system based on a general-purpose open RDF infrastructure, where annotations are modeled as a class of metadata. Annotations are viewed as statements made by an author about a Web document. Annotations are external to the documents and can be stored in one or more annotation servers. One of the goals of this project has been to re-use as much existing W3C technology as possible. We have reached it mostly by combining RDF with XPointer, XLink, and HTTP. We have also implemented an instance of our system using the Amaya editor/browser and a generic RDF database, accessible through an Apache HTTP server. In this implementation, the merging of annotations with documents takes place within the client. The paper presents the overall design of Annotea and describes some of the issues we have faced and how we have solved them.

Visual Web Information Extraction with Lixto

Abstract: We present new techniques for supervised wrapper generation and automated web information extraction, and a system called Lixto implementing these techniques. Our system can generate wrappers which translate relevant pieces of HTML pages into XML. Lixto, of which a working prototype has been implemented, assists the user to semi-automatically create wrapper programs by providing a fully visual and interactive user interface. In this convenient user-interface very expressive extraction programs can be created. Internally, this functionality is reected by the new logicbased declarative language Elog. Users never have to deal with Elog and even familiarity with HTML is not required. Lixto can be used to create an \XML-Companion" for an HTML web page with changing content, containing the continually updated XML translation of the relevant information.

Synchronized Multimedia Integration Language (SMIL) 2.0

Abstract: This document specifies the second version of the Synchronized Multimedia Integration Language (SMIL, pronounced "smile"). SMIL 2.0 has the following two design goals: * Define an XML-based language that allows authors to write interactive multimedia presentations. Using SMIL 2.0, an author can describe the temporal behavior of a multimedia presentation, associate hyperlinks with media objects and describe the layout of the presentation on a screen. * Allow reusing of SMIL syntax and semantics in other XML-based languages, in particular those who need to represent timing and synchronization. For example, SMIL 2.0 components are used for integrating timing into XHTML [XHTML10] and into SVG [SVG].

Information Modeling and Relational Databases

Abstract: Information Modeling and Relational Databases, second edition, provides an introduction to ORM (Object-Role Modeling)and much more. In fact, it is the only book to go beyond introductory coverage and provide all of the in-depth instruction you need to transform knowledge from domain experts into a sound database design. This book is intended for anyone with a stake in the accuracy and efficacy of databases: systems analysts, information modelers, database designers and administrators, and programmers. Terry Halpin, a pioneer in the development of ORM, blends conceptual information with practical instruction that will let you begin using ORM effectively as soon as possible. Supported by examples, exercises, and useful background information, his step-by-step approach teaches you to develop a natural-language-based ORM model, and then, where needed, abstract ER and UML models from it. This book will quickly make you proficient in the modeling technique that is proving vital to the development of accurate and efficient databases that best meet real business objectives.*Presents the most indepth coverage of Object-Role Modeling available anywhere, including a thorough update of the book for ORM2, as well as UML2 and E-R (Entity-Relationship) modeling. *Includes clear coverage of relational database concepts, and the latest developments in SQL and XML, including a new chapter on the impact of XML on information modeling, exchange and transformation. * New and improved case studies and exercises are provided for many topics. * The book's associated web site provides answers to exercises, appendices, advanced SQL queries, and links to downloadable ORM tools.

Detecting Changes in XML documents.

Abstract: We present a diff algorithm for XML data. This work is motivated by the support for change control in the context of the Xyleme project that is investigating dynamic warehouses capable of storing massive volumes of XML data. Because of the context, our algorithm has to be very efficient in terms of speed and memory space even at the cost of some loss of quality. Also, it considers, besides insertions, deletions and updates (standard in diffs), a move operation on subtrees that is essential in the context of XML. Intuitively, our diff algorithm uses signatures to match (large) subtrees that were left unchanged between the old and new versions. Such exact matchings are then possibly propagated to ancestors and descendants to obtain more matchings. It also uses XML specific information such as ID attributes. We provide a performance analysis of the algorithm. We show that it runs in average in linear time vs. quadratic time for previous algorithms. We present experiments on synthetic data that confirm the analysis. Since this problem is NP-hard, the linear time is obtained by trading some quality. We present experiments (again on synthetic data) that show that the output of our algorithm is reasonably close to the optimal in terms of quality. Finally we present experiments on a small sample of XML pages found on the Web.

Method and apparatus for a business applications server management system platform

Abstract: The present invention provides a system and method for integrating disparate business applications, and managing the applications processes in a hardware resource and user effort efficient manner. The automated system of the present invention uses a business systems platform comprised of several unique servers to efficiently manage multiple applications which are themselves generally distributed across a network, and to control the execution of the required tasks with minimum use of redundant data input to the several applications, thereby minimizing the use of hardware resources and user input effort. Business objects are controlled through a persistence framework which is Java, XML and EJB based.

Quilt : An XML query language for heterogeneous data sources

Abstract: The World Wide Web promises to transform human society by making virtually all types of information instantly available everywhere. Two prerequisites for this promise to be realized are a universal markup language and a universal query language. The power and flexibility of XML make it the leading candidate for a universal markup language. XML provides a way to label information from diverse data sources including structured and semi-structured documents, relational databases, and object repositories. Several XML-based query languages have been proposed, each oriented toward a specific category of information. Quilt is a new proposal that attempts to unify concepts from several of these query languages, resulting in a new language that exploits the full versatility of XML. The name Quilt suggests both the way in which features from several languages were assembled to make a new query language, and the way in which Quilt queries can combine information from diverse data sources into a query result with a new structure of its own.

Keys for XML

Abstract: We discuss the definition of keys for XML documents, payingparticular attention to the concept of a relative key, which is commonly used in hierarchically structured documents and scientific databases. � 2002 Published by Elsevier Science B.V.

Answering XML Queries on Heterogeneous Data Sources

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Updating XML

Abstract: As XML has developed over the past few years, its role has expanded beyond its original domain as a semantics-preserving markup language for online documents, and it is now also the de facto format for interchanging data between heterogeneous systems. Data sources expert XML “views” over their data, and other system can directly import or query these views. As a result, there has been great interest in languages and systems for expressing queries over XML data, whether the XML is stored in a repository or generated as a view over some other data storage format.Clearly, in order to fully evolve XML into a universal data representation and sharing format, we must allow users to specify updates to XML documents and must develop techniques to process them efficiently. Update capabilities are important not only for modifying XML documents, but also for propagating changes through XML view and for expressing and transmitting changes to documents. This paper begins by proposing a set of basic update operations for both ordered and unordered XML data. We next describe extensions to the proposed standard XML query language, XQuery, to incorporate the update operations. We then consider alternative methods for implementing update operations when the XML data is mapped into a relational database. Finally, we describe an experimental evaluation of the alternative techniques for implementing our extensions.

Efficiently Publishing Relational Data as XML Documents

Abstract: XML is rapidly emerging as a standard for exchanging business data on the World Wide Web. For the foreseeable future, however, most business data will continue to be stored in relational database systems. Consequently, if XML is to fulfill its potential, some mechanism is needed to publish relational data as XML documents. Towards that goal, one of the major challenges is finding a way to efficiently structure and tag data from one or more tables as a hierarchical XML document. Different alternatives are possible depending on when this processing takes place and how much of it is done inside the relational engine. In this paper, we characterize and study the performance of these alternatives. Among other things, we explore the use of new scalar and aggregate functions in SQL for constructing complex XML documents directly in the relational engine. We also explore different execution plans for generating the content of an XML document. The results of an experimental study show that constructing XML documents inside the relational engine can have a significant performance benefit. Our results also show the superiority of having the relational engine use what we call an “outer union plan” to generate the content of an XML document.

XIRQL: a query language for information retrieval in XML documents

Abstract: Based on the document-centric view of XML, we present the query language XIRQL. Current proposals for XML query languages lack most IR-related features, which are weighting and ranking, relevance-oriented search, datatypes with vague predicates, and semantic relativism. XIRQL integrates these features by using ideas from logic-based probabilistic IR models, in combination with concepts from the database area. For processing XIRQL queries, a path algebra is presented, that also serves as a starting point for query optimization.

Dynamic object- driven database manipulation and mapping system

Abstract: The present invention provides a system and method for dynamic object-driven database manipulation and mapping system which relates in general to correlating or translating one type of database to another type of database or to an object programming application. Correlating or translating involves relational to object translation, object to object translation, relational to relational, or a combination of the above. Thus, the present invention is directed to dynamic mapping of databases to selected objects. Also provided are systems and methods that optionally include caching components, security features, data migration facilities, and components for reading, writing, interpreting and manipulating XML and XMI data files.

Computer program connecting the structure of a xml document to its underlying meaning

Abstract: A computer program which uses a set of mappings between XML logical structures and business information model logical structures, in which the mappings describe how a document in a given XML based language conveys information in a business information model.

Learning Objects: Resources For Distance Education Worldwide

Abstract: This article discusses the topic of learning objects in three parts. First, it identifies a need for learning objects and describes their essential components based on this need. Second, drawing on concepts from recent developments in computer science, it describes learning objects from a theoretical perspective. Finally, it describes learning objects in practice, first as they are created or generated by content authors, and second, as they are displayed or used by students and other client groups.

Agent based application using data synchronization

Abstract: A network-based messaging system comprises multiple agents to communicate messages between multiple users in real time using, for example, an XML document synchronization model. Each agent has properties defined in XML and can subscribe to properties of other agents. Each agent can notify other agents which subscribe to it of changes to its properties. The agents communicate using an XML or alternative extensible data interchange protocol. The agents include device agents to represent each of multiple user devices, which may include computers on a wireline network and mobile devices on a wireless network. The agents also include persona agents to represent each user. The persona agents collect information about the properties of other agents and publish the information to other, subscribing agents. Each persona agent comprises properties to maintain state information for each device used by the corresponding user. Most of the agents reside in a centralized agent system.

Querying XML Views of Relational Data

Abstract: XML has emerged as the standard data exchange format for Internet-based business applications. This has created the need to publish existing business data, stored in relational databases, as XML. A general way to publish relational data as XML is to provide XML views over relational data, and allow business partners to query these views using an XML query language. In this paper, we address the problem of evaluating XML queries over XML views of relational data. This paper makes two main contributions. The first is a general framework for processing arbitrarily complex queries specified using the XQuery query language. The second is a technique for efficiently evaluating XML queries by pushing most of the query computation down to the relational engine.

XML presentation of general-purpose data sources

Abstract: A system and method for presenting one or more general-purpose application-accessible data sources as an XML representation is discussed. Information that describes the way data is structured or organized in the data source is accessed from the data source. A virtual file system representation comprising a plurality of hierarchical folders is provided to represent the structural information. Optionally, the virtual file system representation may be modified, either manually or according to rules sets. After any desired modification, the XML representation is generated based on the virtual file system representation.

TAX: A Tree Algebra for XML

Abstract: Querying XML has been the subject of much recent investigation. A formal bulk algebra is essential for applying database-style optimization to XML queries. We develop such an algebra, called TAX (Tree Algebra for XML), for manipulating XML data, modeled as forests of labeled ordered trees. Motivated both by aesthetic considerations of intuitiveness, and by efficient computability and amenability to optimization, we develop TAX as a natural extension of relational algebra, with a small set of operators. TAX is complete for relational algebra extended with aggregation, and can express most queries expressible in popular XML query languages. It forms the basis for the Timber XML database system currently under development by us.

Method and system for synchronizing mobile devices

Abstract: A protocol for synchronizing data is provided. Additionally, a system and method of using the protocol are also provided. The protocol allows responses to be grouped with commands in a single XML document. It provides a command for requesting a single object be sent without requiring that all unsynchronized objects be sent. It provides a command for specifying how many objects at a time should be sent and a response that indicates that more objects are available to be sent. It provides a means for arbitrarily extending the protocol in application-specific ways. It provides a means for sending updates while requesting that no updates be sent back.

Building Web Services with Java: Making Sense of XML, SOAP, WSDL, and UDDI

Abstract: From the Publisher: Building Web Services with SOAP, XML, and UDDI assumes proficiency with Java and with distributed computing tools. Throughout the book, examples will be presented using Java and the Apache SOAP platform, although a set of sidebars will address .NET development, which Microsoft developers will use to deploy Web services. The book uses progressive disclosure to present an increasingly complex project as it moves through its development cycle. The final section of the book presents linking the completed project with other systems built in J2EE and .NET.