Abstract. The Web is moving from being a collection of pages toward a collection of services that interoperate through the Internet. The first step toward this interoperation is the location of other services that can help toward the solution of a problem. In this paper we claim that location of web services should be based on the semantic match between a declarative description of the service being sought, and a description of the service being offered. Furthermore, we claim that this match is outside the representation capabilities of registries such as UDDI and languages such as WSDL. We propose a solution based on DAML-S, a DAML-based language for service description, and we show how service capabilities are presented in the Profile section of a DAML-S description and how a semantic match between advertisements and requests is performed. 1 Introduction Web services provide a new model of the Web in which sites exchange dynamic information on demand. This change is especially important for the e-business community, because it provides an opportunity to conduct business faster and more efficiently. Indeed, the opportunity to manage supply chains dynamically to achieve the greatest advantage on the market is expected to create great value added and increase productivity. On the other hand, automatic management of supply chain opens new challenges: first, web services should locate other services that provide a solution to their problems, second, services should interoperate to compose complex services. In this paper we concentrate on the first problem: the location of web services on the basis of the capabilities that they provide. The solution of this problem requires a language to express the capabilities of services, and the specification of a matching algorithm between service advertisements and service requests that recognizes when a request matches an advertisement. We adopt DAML-S as service description language because it provides a semantically based view of of web services which spans from the abstract description of the capabilities of

Queries navigate semistructured data via path expressions, and can be accelerated using an index. Our solution encodes paths as strings, and inserts those strings into a special index that is highly optimized for long and complex keys. We describe the Index Fabric, an indexing structure that provides the efficiency and flexibility we need. We discuss how "raw paths " are used to optimize ad hoc queries over semistructured data, and how "refined paths " optimize specific access paths. Although we can use knowledge about the queries and structure of the data to create refined paths, no such knowledge is needed for raw paths. A performance study shows that our techniques, when implemented on top of a commercial relational database system, outperform the more traditional approach of using the commercial system’s indexing mechanisms to query the XML. 1.

We consider the monitoring of a flow of incoming documents. More precisely, we present here the monitoring used in a very large warehouse built from XML documents found on the web. The flow of documents consists in XML pages (that are warehoused) and HTML pages (that are not). Our contributions are the following: ffl a subscription language which specifies the monitoring of pages when fetched, the periodical evaluation of continuous queries and the production of XML reports. ffl the description of the architecture of the system we implemented that makes it possible to monitor a flow of millions of pages per day with millions of subscriptions on a single PC, and scales up by using more machines. ffl a new algorithm for processing alerts that can be used in a wider context. We support

The growing infrastructure for Web Services assumes a "programmer in the loop" that hardcodes the connections between Web Services and directly programs Web Service composition. Emerging technology based on DAML-S and the Semantic Web allows Web Services to connect and transact automatically with minimal or no intervention from programmers. In this paper we discuss the problems related with autonomous Web Services, and how DAMLS provides the information to solve them. Furthermore, we describe the implementation of two demonstration systems that use such technology: the first system is a B2B application in which a business that assembles computers automatically finds partners providing parts and automatically transacts with them; the second describes is an e-commerce application that helps a user to organize a trip to a meeting automatically interacting with different Web Services and the calendar of the user stored in MS Outlook. The results of these experiments show how Web Services can be deployed on the Web to interact and provide information dynamically; second, how the transaction can be carried on automatically with no programmer intervention.

Abstract. The web is moving from being a collection of pages toward a collection of services that interoperate through the Internet. A fundamental step toward this interoperation is the ability of automatically locating services on the bases of the functionalities that they provide. Such a functionality would allow services to locate each other and automatically interoperate. Location of web services is inherently a semantic problem, because it has to abstract from the superficial differences between representations of the services provided, and the services requested to recognize semantic similarities between the two. Current Web Services technology based on UDDI and WSDL does not make any use of semantic information and therefore fails to address the problem of matching between capabilities of services and allowing service location on the bases of what functionalities are sought, failing therefore to address the problem of locating web services. Nevertheless, previous work within DAML-S, a DAML-based language for service description, shows how ontological information collected through the semantic web can be used to match service capabilities. This work expands on previous work by showing how DAML-S Service Profiles, that describe service capabilities within DAML-S, can be mapped into UDDI records providing therefore a way to record semantic information within UDDI records. Furthermore we show how this encoded information can be used within the UDDI registry to perform semantic matching. 1

Peer-to-peer distributed hash table (DHT) systems make it simple to discover specific data when their complete identifiers---or keys---are known in advance. In practice, however, users looking up resources stored in peer-to-peer systems often have only partial information for identifying these resources. In this paper, we describe techniques for indexing data stored in peerto -peer DHT networks, and discovering the resources that match a given user query. Our system creates multiple indexes, organized hierarchically, which permit users to locate data even using scarce information, although at the price of a higher lookup cost. The data itself is stored on only one (or few) of the nodes. Experimental evaluation demonstrates the effectiveness of our indexing techniques on a distributed peer-to-peer bibliographic database with realistic user query workloads.

In this paper, we study an online data mining problem from streams of semi-structured data such as XML data. Modeling semi-structured data and patterns as labeled ordered trees, we present an online algorithm StreamT that receives fragments of an unseen possibly infinite semi-structured data in the document order through a data stream, and can return the current set of frequent patterns immediately on request at any time. A crucial part of our algorithm is the incremental maintenance of the occurrences of possibly frequent patterns using a tree sweeping technique. We give modifications of the algorithm to other online mining model. We present theoretical and empirical analyses to evaluate the performance of the algorithm.

The amount of different kinds of data available electronically has increased rapidly in the last years. Beside strongly structured data obeying a rigid schema (e.g. data stored in databases), lots of data which do not present an a priori-known internal structure are spreading. Much of such data, though unstructured at a first sight, present a logical organization and can be considered semistructured [1]. The most known example of semistructured data is represented by the Web. For such data source, the need of retrieving information is becoming more and more relevant: to date, the only way to extract Web information is to use keyword-based search engines and to browse individual pages. However, the results supplied by common search engines (e.g. Altavista [9], Lycos [19], and so on) are often perceived by users as unsatisfactory: only HTML objects are indexed, the result of Web searching is often a flat list of URLs, without any structure, and, above all, several documents not related ...

Abstract. This paper presents OntoWeaver-S, an ontology-based infrastructure for building knowledge portals. In particular, OntoWeaver-S is integrated with a comprehensive web service platform, IRS-II, for the publication, discovery, and execution of web services. In this way, OntoWeaver-S supports the access and provision of remote web services for knowledge portals. Moreover, it provides a set of comprehensive site ontologies to model and represent knowledge portals, and thus is able to offer high level support for the design and development process. Finally, OntoWeaver-S provides a set of powerful tools to support knowledge portals at design time as well as at run time. 1

We consider a query subscription system that can provide users with information about web changes that interest them. We present a query subscription language and a system that combines monitoring of page changes and continuous queries, i.e., queries that are evaluated regularly. 1