Let G be a group. Recall that the intersection graph of subgroups of G is an undirected graph whose vertex set is the set of all nontrivial subgroups of G and distinct vertices H,K are joined by an edge in this graph if and only if the intersection of H and K is nontrivial. The aim of this article is to investigate the interplay between the group-theoretic properties of a finite group G and the...

We generalize the matroid intersection theorem to distributive supermatroids, a structure that extends the matroid to the partially ordered ground set. Distributive supermatroids are special cases of both supermatroids and greedoids, and they generalize polymatroids. This is the first good characterization proved for the intersection problem of an independence system where the ground set is par...

The aim of this research is to study and develop models for driver’s lane-changing behaviour in an urban area using the logistic regression method. A pilot study was conducted using a videotape recording technique to film an approach road leading to a signalised intersection in an urban road during the morning off-peak period. Inter related coding methods were designed to described and verify t...

Following a half-century of breakneck urbanization, the capital of South Korea emerged in the late 1990s as the world’s most digitally networked city. With nearly 80 percent household broadband penetration in 2004, Seoul surpassed both global cities and ‘technopoles’ in speed and comprehensiveness in embracing broadband technology. This article describes the physical development of Seoul’s broa...

Crossing an urban traffic intersection is one of the most dangerous activities of a blind or visually impaired person's travel. Building on past work by the authors on the issue of proper alignment with the crosswalk, this paper addresses the complementary issue of knowing when it is time to cross. We describe a prototype portable system that alerts the user in real time once the Walk light is ...

Due to the limitations of urban environment, data transferred between vehicles can only change direction at intersections. Therefore, routing decision an intersection will largely affect overall decision. In this article, we propose Intersection-Based Routing with Fuzzy Multi-Factor Decision (IRFMF), which utilizes several factors decide next road segment. scheme, each introduces three includin...

Enabling Internet to Vehicular multicast communication is fraught with challenges due to the heterogeneous nature of the two networks. While the conventional multicasting in the Internet relies on ”structured” multicast routing, it is not clear how robust can be such routing structure in vehicular networks. We study the robustness of the multicast routing structure in vehicular networks for dat...

Following half a century of breakneck urbanization, the capital of South Korea emerged in the late 1990s as the most digitally networked city in the world. With nearly 80% household broadband penetration in 2004, Seoul surpassed global cities and `technopoles' in speed and comprehensiveness in embracing broadband technology. In this paper I describe the physical development of Seoul's broadband...

This paper describes a novel method for allowing an autonomous ground vehicle to predict the intent of other agents in an urban environment. This method, termed the cognitive driving framework, models both the intent and the potentially false beliefs of an obstacle vehicle. By modeling the relationships between these variables as a dynamic Bayesian network, filtering can be performed to calcula...