Learn More
ÐIn current distributed systems, the notion of mobility is emerging in many forms and applications. Mobility arises naturally in wireless computing since the location of users changes as they move. Besides mobility in wireless computing, software mobile agents are another popular form of moving objects. Locating objects, i.e., identifying their current(More)
Peer-to-peer (P2P) systems are gaining increasing popularity as a scalable means to share data among a large number of autonomous nodes. In this paper, we consider the case in which the nodes in a P2P system store XML documents. We propose a fully decentralized approach to the problem of routing path queries among the nodes of a P2P system based on(More)
Preferences have been traditionally studied in philosophy, psychology, and economics and applied to decision making problems. Recently, they have attracted the attention of researchers in other fields, such as databases where they capture soft criteria for queries. Databases bring a whole fresh perspective to the study of preferences, both computational and(More)
Recently, push-based delivery has attracted considerable attention as a means of disseminating information to large client populations in both wired and wireless settings. In this paper, we address the problem of ensuring the consistency and currency of client read-only transactions in the presence of updates. To this end, additional control information is(More)
Advances in wireless network technology and the continuously increasing number of users of hand-held terminals make the latter a possible channel for o€ering personalized services to mobile users and give pace to the rapid development of mobile electronic commerce (MEC). MEC operates partially in a di€erent environment than Internet e-commerce due to the(More)
Peer-to-peer (p2p) systems are attracting increasing attention as an efficient means of sharing data among large, diverse and dynamic sets of users. The widespread use of XML as a standard for representing and exchanging data in the Internet suggests using XML for describing data shared in a p2p system. However, sharing XML data imposes new challenges in(More)
ÐThe popularity of the Web as a universal access mechanism for network information has created the need for developing web-based DBMS client/server applications. However, the current commercial applet-based approaches for accessing database systems offer limited flexibility, scalability, and robustness. In this paper, we propose a new framework for(More)
It is expected that in the near future millions of users will have access to on-line distributed databases through mobile computers. This possibility raises challenging questions regarding the consistency and availability of data. To deal with the frequent, predictable and varying in degree disconnections that occur in a mobile environment, we introduce(More)
A multidatabase system (MDBS) is a confederation of preexisting distributed, heterogeneous, and autonomous database systems. There has been a recent proliferation of research suggesting the application of object-oriented techniques to facilitate the complex task of designing and implementing MDBSs. Although this approach seems promising, the lack of a(More)