11775748
Schema Mapping for Interoperability in XML-based multidatabase
The main aim of a multidatabase system (MDBS) is to achieve data integration and interoperability among distributed and heterogeneous database systems. But data model heterogeneity and schema make this a challenging task. Multidatabase users can only view the global schemas whose real data come from local database systems. Thus, mappings from global schemas to local schemas should be established. At the same time, the recent emergence of XML has shown great intractability as a new standard for data representation and exchange on the Web. A data model based on XML becomes more suitable for integrating different types of systems. This paper firstly introduces a multidatabase common data model based on XML, named XML-based Integration Model (XIDM). Then, an approach of schema mappings based on XIDM in MDBSs has been presented. Finally, the illustration and implementation of schema mappings in a multidatabase prototype - Panorama are also discussed.
9157971
Service Publishing and Discovering Model in a Web Services Oriented Peer-to-Peer System
To enhance the reliability and scalability of the service oriented architecture, this paper introduces a Web Services Oriented Peer-to-peer (WSOP) architecture with a combination of centralized and decentralized characteristics, and gives a framework of service publishing and discovery model based on WSOP architecture.
13976225
WebPeer: A P2P-based system for publishing and discovering Web services
The use of Web services as an infrastructure of service sharing has made it possible to provide collaboration and interoperability in distributed computing environment. In this environment, service publishing and discovery are required as elementary functionalities for users to be able to locate the shared resources. The mechanism of service publishing and discovery with centralized architecture restricts the reliability and scalability of the distributed computing environment as the services and resources on the Web are fast emerging. The peer-to-peer (P2P) systems and applications, on the other hand, employ distributed resources to perform critical functions in a decentralized manner. This paper introduces Web Services Oriented Peer-to-peer (WSOP) architecture with a combination of centralized and decentralized characteristics, and presents a framework of service publishing and discovery model based on WSOP architecture. The prototype system - WebPeer implemented based on this model demonstrates the WSOP architecture can not only help to overcome the known obstacles in common Web Services infrastructure such as single node failure, but also extend the ability of the pure P2P systems, such as more efficiently locating the resources, increasing the interoperability between different P2P systems.
39352664
Multi-source Coastal Data Analysis
This paper presents results from the second year of a project on coastal management and decision making sponsored by the National Science Foundation Digital Government Program and carried out by a multidisciplinary research team. As one of the primary goals of the project, tide-coordinated shoreline modeling and mapping requires the integration of multi-source spatio-temporal data that include high-resolution digital elevation models (DEM) derived from IKONOS satellite images and aerial photographs, bathymetric data, water gauge data, satellite altimetric data, and water surfaces derived by a hydrodynamic hindcast model (Li et al., 2002b). Quality and accuracy assessment of these data has been made to ensure reliability of the outcomes of the data integration. The resulting shorelines derived from the integrated data are then evaluated for accuracy in comparison with traditional shorelines determined from tide-coordinated aerial surveys.
7717414
A time interval based consistency control algorithm for interactive groupware applications
Traditional concurrency control methods such as locking and serialization are not suitable for distributed interactive applications that demand fast local response. Operational transformation (OT) is the standard solution to concurrency control and consistency maintenance in group editors, an important class of interactive groupware applications. It generally trades consistency for local responsiveness, because human users can often tolerate temporary inconsistencies but do not like their interactions be lost or nondeterministically blocked. This paper presents a time interval based operational transformation algorithm (TIBOT) that overcomes the various limitations of previous related work. Our approach guarantees content convergence and is significantly more simple and efficient than existing approaches. This is achieved in a pure replicated architecture by using a linear clock and by posing some constraints on communication that are reasonable for the application domain.
41530847
A Note on Hamiltonian Cycles in K(1, r)-Free Graphs
9514355
Integration of Multi-Source Spatial Information for Coastal Management and Decision Making
This paper presents the second-year outcomes of our Digital Government project "Digitalization of Coastal Management and Decision Making Supported by Multi-Dimensional Geospatial Information and Analysis". One of the primary objectives of the second year is to develop and integrate multiple spaceborne, airborne, and in-situ remotely sensed measurements, spatio-temporal databases, coastal hydrological modeling, and geospatial information analysis for coastal management and decision making. The developed coastal management and decision-making system includes applications for coastal mapping and change detection, water surface modeling and analysis, on-site coastal management and decision-making, and web-based spatial data manipulation. Studies have also been conducted on uncertainties in the used coastal spatial data. The above system has been tested at a pilot site along Ohio's Lake Erie shore and is to be applied to a new test site in Tampa Bay, Florida.
30689406
Some hamiltonian properties of L1-graphs
Abstract A graph G is called an L 1 -graph if, for each triple of vertices u, v, and w with d ( u , v )=2 and w ∈ N ( u )∩ N ( v ), d ( u )+ d ( v )⩾| N ( u )∪ N ( v )∪ N ( w )|−1. Let G be a 2-connected L 1 -graph of order n. If δ ( G )⩾( n −2)/3 or σ 3 ( G )⩾ n , then G is hamiltonian or G∈ K , where σ 3 (G)= min {d(u)+d(v)+d(w) : {u,v,w} is an independent set in G }, K ={G : K p,p+1 ⊆G⊆K p +(p+1)K 1 for some p ⩾2}. Some results on the traceability of L 1 -graphs are also obtained.