42359427
Subtyping Calculus of Construction (Extended Abstract)
We present in this paper a subtyping extension of Calculus of Construction. We prove that this system has good meta-theoretical properties: transitivity elimination, subject reduction, strong normalization and decidability of subtyping. This work provides a theoretical foundation for adding subtyping to proof checkers like Coq, LEGO etc.
34190440
Coercive subtyping for the calculus of constructions
6370123
Full integration of subtyping and if-expression
The combination of full subsumption and conditional expression is a challenging problem, because in such a system, a term might not have a type which is a representative of all types of the term. Therefore, the traditional type checking technique fails. Due to such a difficulty, Java typing rule for if-expression uses only a restricted form of subtyping. In this paper, we propose a type system which includes both of the above mentioned features and enjoys decidable type checking. We also show that the system has the subject reduction property. It is expected that this technique could be used to improve the type system of Java with full subsumption.
41922638
Guarded recursive datatype constructors
1048322
Soundness of Coercion in the Calculus of Constructions
A coercive subtyping system for the Calculus of Constructions is presented. The proposed system λC≤co is obtained essentially by adding coercions and η-conversion to λC≤, which is a subtyping extension to the Calculus of Constructions without coercions. We proved that a coercion c:A ≤ B is semantically sound. That is, (1) c is a term of type A → B; (2) c behaves like an identity function. This development follows the spirit of semantical interpretation of subtyping.
25276326
Web-Based Service Management of Distributed Learning
This paper tries to design structure of Web-Based Service Management of Distributed Learning (WSMDL). The structure integrating IT service and Educational Auxiliary System service flow. Help desk becomes only interface for all levels of users according to their individual demands. Though analysis of service events and user’s feedback in service flow, it also provides the decision-making to improve the quality of Web-based Service Management of Distributed Learning Service Management. The paper also depicts the functions of WSMDL.
28927892
Collaborative Filtering Using Orthogonal Nonnegative Matrix Tri-factorization
27043261
Accelerating XML Structural Matching Using Suffix Bitmaps
With the rapidly increasing popularity of XML as a data format, there is a large demand for efficient techniques in structural matching of XML data. We propose a novel filtering technique to speed up the structural matching of XML data, which is based on an auxiliary data structure called suffix bitmap. The suffix bitmap captures in a packed format the suffix tag name list of the nodes in an XML document. By comparing the respective suffix bitmaps, most of the unmatched subtrees of a document can be skipped efficiently in the course of structural matching process. Using the suffix bitmap filtering, we extend two state-of-the-art structural matching algorithms: namely the traversal matchingalgorithmand the structural join matching algorithm. The experimental results show that the extended algorithms considerably outperform the original ones.
9510053
DXEC: integrating database, XML and email for collaboration
This paper introduces DXEC, a database, XML and email enabled framework for better collaborative work. The framework use emails as the main collaboration medium, which are mainly generated automatically by OA applications and groupware systems. But instead of using them naively, each email in the system are wrapped in a XML envelop, which provides superior searching and filtering ability. Emails are stored in a XML enable database, and a XML filter engine is used to filter the incoming messages and disseminate them to relevant audiences. User profile in XPath, which can be specified by hand and refined through feedbacks, are used by the filter engine to ensure everyone received only interested messages. In this paper, we present the architecture of DXEC and introduce major components and important algorithms. We also demonstrate its use in software development process.
33357953
PISA: Federated Search in P2P Networks with Uncooperative Peers
Recently, federated search in P2P networks has received much attention. Most of the previous work assumed a cooperative environment where each peer can actively participate in information publishing and distributed document indexing. However, little work has addressed the problem of incorporating uncooperative peers, which do not publish their own corpus statistics, into a network. This paper presents a P2P-based federated search framework called PISA which incorporates uncooperative peers as well as the normal ones. In order to address the indexing needs for uncooperative peers, we propose a novel heuristic query-based sampling approach which can obtain high-quality resource descriptions from uncooperative peers at relatively low communication cost. We also propose an effective method called RISE to merge the results returned by uncooperative peers. Our experimental results indicate that PISA can provide quality search results, while utilizing the uncooperative peers at a low cost.