• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3377-3395
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• 2015

Recently, several approaches to share road conditions and/or digital contents through VANETs have been proposed, and such approaches have generally considered the radial distance from the information source as well as the TTL to provision an ephemeral, geographically-limited information sharing service. However, they implement general MANETs and have not been tailored to the constrained movement of vehicles on roads that are mostly linear. In this paper, we propose a novel application-level mechanism that can be used to share road conditions, including accidents, detours and congestion, through a VANET. We assign probabilities to roads around each of the intersections in the neighborhood road network. We then use the graph representation of the road network to build a spanning tree of roads with the information source as the root node. Nodes below the root represent junctions, and the edges represent inter-connecting road segments. Messages propagate along the branches of the tree, and as the information propagates down the branches, the probability of replication decreases. The information is replicated until a threshold probability has been reached, and our method also ensures that messages are not delivered to irrelevant vehicles, independently of their proximity to the source. We evaluated the success rate and performance of this approach using NS-3 simulations, and we used IDM car following and MOBIL lane change models to provide realistic modeling of the vehicle mobility.

• Journal of the Korean association of regional geographers
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• v.8 no.3
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• pp.295-313
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• 2002

While the growth of Taegu has occurred through the land readjustment project, the public sector development project and the construction of roads, its growth pattern has been shaped by physical constraints such as mountains, streams and rail roads. The processes of urban growth of Taegu are classified into four stages: the stage of urban embryo in the Chosun Era; the formation stage of the basic urban system after the Japanese Colonial Era up to 1960; the stage of urban growth in the industrialization period from 1960s to 1980; and lastly, the stage of urban expansion and maturation, with construction of extensive newly developed districts, after the 1980s. Since its promotion to a metropolitan city with the inclusion of Seongseo, Wolbae, Gosan, Ansim and Chilgok in 1981, those regions have grown into newly developed residential districts, with its accompanying high density and high rise apartments complexes, through the public sector development project. These newly developed districts are located about six to seven kilometers away from CBD of the city along with main radial roads. The sites are also located on the route of the fourth belt way of the city. While the Sangin, Seongseo and Jisan Beommul newly developed districts have developed contiguously with the existing built-up areas, the Siji and Chilgok districts have developed separately by the green belt and the Geumho River, respectively.