Information sharing and updates have become increasingly important in the rapidly changing world. However, owing to the distributed and decentralized nature of information collection and storage, it is not easy to use information from different sources synergistically. Ontology plays as an important role in establishing formal descriptions of a domain of discourse. In geographic information sci...

Determining the grade of semantic similarity between geospatial concepts is the basis for evaluating semantic interoperability of geographic information services and their users. Geometrical models, such as conceptual spaces, offer one way of representing geospatial concepts, which are modelled as n-dimensional regions. Previous approaches have suggested to measure semantic similarity between c...

Article history: Received: 14.11.2014. Received in revised form: 26.3.2015. Accepted: 27.3.2015. Since the cooperative communication can reduce the transmitted power and extend the transmission coverage, minimum energy routing protocols are considered to reduce the total energy consumption in a multi-hop wireless Ad Hoc network. In this paper, an Energy-balanced Multi-hop-aware Cooperative Geog...

Delay–tolerant networks (DTNs) are sparse and/or highly mobile wireless ad hoc networks which assure no continuous connectivity. One central problem in DTNs is is the routing of packets from a source towards the desired destinations. The literature provides a number of results for very restrictive scenarios in which mobile nodes have the same mobility characteristics and in which only forwardin...

1Alan M. MacEachren is Professor and Director of the GeoVISTA Center, Department of Geography, 302 Walker, Penn State University, University Park, PA 16802 USA; e-mail: [email protected] and Menno-Jan Kraak is Professor and Head of Division of Geoinformatics, Cartography and Visualization, ITC, PO Box 6, 7500 AA Enschede; e-mail: [email protected] This special issue of Cartography and Geographic Inf...

The problem of the capacity of a massively dense wireless multihop network can be broken down into separate problems at macroscopic and microscopic levels. At the microscopic level, from the local perspective, the network appears like an infinite plane with traffic that is uniform but flowing in many directions. Previous studies have assumed that it is sufficient to find the maximum sustainable...

Opportunistic routing (OR) takes advantages of the spatial diversity and broadcast nature of wireless networks to combat the time-varying links by involving multiple neighboring nodes (forwarding candidates) for each packet relay. This dissertation studies the properties, energy efficiency, capacity, throughput, protocol design and security issues about OR in multihop wireless networks. Firstly...