15362027
ETANA-DL: managing complex information applications - an archaeology digital library
Summary form only given. Archaeological research results in the generation of large quantities of heterogeneous information managed by different projects using custom information systems. We demonstrate a prototype digital library (DL) for integrating and managing archaeological data and providing services useful to various user communities. ETANA-DL is a model-based, componentized, extensible, archaeological DL that manages complex information sources using the client-server paradigm of the open archives initiative protocol for metadata harvesting (OAI-PMH). We present a prototype of ETANA-DL that builds on the 5S meta-model for developing for archaeological systems. We demonstrate our approach, used to integrate and handle highly heterogeneous data and the various services that ETANA-DL currently supports - searching, browsing, personal collections, workflows, discussions, annotations, etc. We are working on the structural aspects of the meta-model, and have used the results to develop advanced cross-collection searching and browsing services.
10630201
Tapping the power of text mining
Sifting through vast collections of unstructured or semistructured data beyond the reach of data mining tools, text mining tracks information sources, links isolated concepts in distant documents, maps relationships between activities, and helps answer questions.
16918412
Ranking function optimization for effective Web search by genetic programming: an empirical study
Web search engines have become indispensable in our daily life to help us find the information we need. Although search engines are very fast in search response time, their effectiveness in finding useful and relevant documents at the top of the search hit list needs to be improved. In this paper, we report our experience applying genetic programming (GP) to the ranking function discovery problem leveraging the structural information of HTML documents. Our empirical experiments using the Web track data from recent TREC conferences show that we can discover better ranking functions than existing well-known ranking strategies from IR, such as Okapi, Ptfidf. The performance is even comparable to those obtained by support vector machine.
1990595
IMMC: incremental maximum margin criterion
Subspace learning approaches have attracted much attention in academia recently. However, the classical batch algorithms no longer satisfy the applications on streaming data or large-scale data. To meet this desirability, Incremental Principal Component Analysis (IPCA) algorithm has been well established, but it is an unsupervised subspace learning approach and is not optimal for general classification tasks, such as face recognition and Web document categorization. In this paper, we propose an incremental supervised subspace learning algorithm, called Incremental Maximum Margin Criterion (IMMC), to infer an adaptive subspace by optimizing the Maximum Margin Criterion. We also present the proof for convergence of the proposed algorithm. Experimental results on both synthetic dataset and real world datasets show that IMMC converges to the similar subspace as that of batch approach.
6902710
Requirements Gathering and Modeling of Domain-Specific Digital Libraries with the 5S Framework: An Archaeological Case Study with ETANA
Requirements gathering and conceptual modeling are essential for the customization of digital libraries (DLs), to help attend the needs of target communities. In this paper, we show how to apply the 5S (Streams, Structures, Spaces, Scenarios, and Societies) formal framework to support both tasks. The intuitive nature of the framework allows for easy and systematic requirements analysis, while its formal nature ensures the precision and correctness required for semi-automatic DL generation. Further, we show how 5S can help us define a domain-specific DL metamodel in the field of archaeology. Finally, an archaeological DL case study (from the ETANA project) yields informal and formal descriptions of two DL models (instances of the metamodel).
16272457
SimFusion: measuring similarity using unified relationship matrix
In this paper we use a Unified Relationship Matrix (URM) to represent a set of heterogeneous data objects (e.g., web pages, queries) and their interrelationships (e.g., hyperlinks, user click-through sequences). We claim that iterative computations over the URM can help overcome the data sparseness problem and detect latent relationships among heterogeneous data objects, thus, can improve the quality of information applications that require com- bination of information from heterogeneous sources. To support our claim, we present a unified similarity-calculating algorithm, SimFusion. By iteratively computing over the URM, SimFusion can effectively integrate relationships from heterogeneous sources when measuring the similarity of two data objects. Experiments based on a web search engine query log and a web page collection demonstrate that SimFusion can improve similarity measurement of web objects over both traditional content based algorithms and the cutting edge SimRank algorithm.
12168122
Structural properties of XPath fragments
We study structural properties of each of the main sublanguages of navigational XPath (W3c Recommendation) commonly used in practice. First, we characterize the expressive power of these language fragments in terms of both logics and tree patterns. Second, we investigate closure properties, focusing on the ability to perform basic Boolean operations while remaining within the fragment. We give a complete picture of the closure properties of these fragments, treating XPath expressions both as functions of arbitrary nodes in a document tree, and as functions that are applied only at the root of the tree. Finally, we provide sound and complete axiom systems and normal forms for several of these fragments. These results are useful for simplification of XPath expressions and optimization of XML queries.
5120213
Interaction between path and type constraints
XML [7], which is emerging as an important standard for data exchange on the World Wide Web, highlights the importance of the semistructured data. Although the XML standard itself does not require any schema or type system, a number of proposals [6, 15, 18] have been developed that roughly correspond to data definition languages. These allow one to constrain the structure of XML data by imposing a schema on it. These and other proposals also advocate the need for integrity constraints, another form of constraints that should, for example, be capable of expressing inclusion constraints and inverse relationships. The latter have recently been studied as path constraints in the context of semistructured data [4, 11]. It is likely that future XML proposals will involve both forms of constraint, and it is therefore appropriate to understand the interaction between them. This paper investigates that interaction. In particular it studies constraint implication problems, which are important both in understanding the semantics of type/constraint systems and in query optimization. A number of results on path constraint implication are established in the presences and absences of type systems. These results demonstrate that adding a type systems may in some cases simplify reasoning about path constraints and in other cases make it harder. For example, it is shown that there is a path constraint implication problem that is decidable in PTIME in the untyped context, but that becomes undecidable when a type system is added. On the other hand, there is an implication problem that is undecidable in the untyped context, but becomes not only decidable in cubic time but also finitely axiomatizable when a type system is imposed. Comments University of Pennsylvania Department of Computer and Information Science Technical Report No. MSCIS-98-16. This technical report is available at ScholarlyCommons: http://repository.upenn.edu/cis_reports/106
52151587
On XML integrity constraints in the presence of DTDs
The article investigates XML document specifications with DTDs and integrity constraints, such as keys and foreign keys. We study the consistency problem of checking whether a given specification is meaningful: that is, whether there exists an XML document that both conforms to the DTD and satisfies the constraints. We show that DTDs interact with constraints in a highly intricate way and as a result, the consistency problem in general is undecidable. When it comes to unary keys and foreign keys, the consistency problem is shown to be NP-complete. This is done by coding DTDs and integrity constraints with linear constraints on the integers. We consider the variations of the problem (by both restricting and enlarging the class of constraints), and identify a number of tractable cases, as well as a number of additional NP-complete ones. By incorporating negations of constraints, we establish complexity bounds on the implication problem, which is shown to be coNP-complete for unary keys and foreign keys.
10449065
Beyond XML Query Languages
A query language is essential, if XML is to serve effectively as an exchange medium for large data sets. The design of query languages for XML is in its infancy, and the choice of a standard may be governed more by user acceptance than by any understanding of underlying principles. One would hope that expressive power, performance, and compatibility with other languages will be considered in choosing among alternatives, but it is likely that several contenders will co-exist for some time. It is worth observing that, during the 20-year development of relational query languages, several competing languages were developed; and even today there are several relational query language standards. In spite of this, a great deal of technology was developed that was independent of the surface syntax of a query language. This included technology "below" the language such as efficient execution models and work "above" the level of language such as techniques for view definition and maintenance, triggers, etc. At Penn we are working on some of these language-independent issues. We include a summary of them here. They include execution and data models to support XML and semistructured query languages; the use of schemas and constraints in optimizing XML query languages; and tools for extracting data form existing sources and presenting it as XML. Comments Postprint version. Published in Query Language Workshop, November 1998. Publisher URL: http://www.w3.org/TandS/QL/QL98/pp/penn.html Author(s) Peter Buneman, Alin Deutsch, Wenfei Fan, Hartmut Liefke, Arnaud Sahuguet, and Wang-Chiew Tan This conference paper is available at ScholarlyCommons: http://repository.upenn.edu/db_research/14 Beyond XML Query Languages Peter Buneman Alin Deutsch Wenfei Fan Hartmut Liefke Arnaud Sahuguet Wang-Chiew Tan University of Pennsylvania fpeter,adeutsch,wfan,liefke,sahuguet,wctang@saul.cis.upenn.edu
10950599
XPath satisfiability in the presence of DTDs
We study the satisfiability problem associated with XPath in the presence of DTDs. This is the problem of determining, given a query p in an XPath fragment and a DTD D, whether or not there exists an XML document T such that T conforms to D and the answer of p on T is nonempty. We consider a variety of XPath fragments widely used in practice, and investigate the impact of different XPath operators on satisfiability analysis. We first study the problem for negation-free XPath fragments with and without upward axes, recursion and data-value joins, identifying which factors lead to tractability and which to NP-completeness. We then turn to fragments with negation but without data values, establishing lower and upper bounds in the absence and in the presence of upward modalities and recursion. We show that with negation the complexity ranges from PSPACE to EXPTIME. Moreover, when both data values and negation are in place, we find that the complexity ranges from NEXPTIME to undecidable. Finally, we give a finer analysis of the problem for particular classes of DTDs, exploring the impact of various DTD constructs, identifying tractable cases, as well as providing the complexity in the query size alone.