6,415 research outputs found
From Vehicular Networks to IoT for Smart Roads: How a Communication Engineer Can Help Solve Transportation Problems (Invited Talk)
Intelligent transportation system (ITS) is an important development that applies advanced sensing, communication, big data analysis and control technologies to ground transportation in order to improve safety, mobility and efficiency. This talk will begin with a brief introduction to our work in vehicular networks, which started more than ten years ago. As we delve deeper into vehicular networks and interact more frequently with transportation stakeholders, we realize that ITS is a truly cross-disciplinary area, in order for vehicular networks to achieve its desired impact, we need to think beyond the traditional communication domain, and start to ponder the deeper-level questions of what fundamental changes can be brought by advanced sensing and communication techniques to transportation and how the applications of advanced sensing and communication techniques can help solve crucial transportation problems. To this end, we will introduce our more recent work of developing advanced IoT technology to transform our roads into smart roads, which in the shorter term, make our roads safer and more efficient while providing the fine-grained real-time traffic information for traffic management; in the longer term, provide the much-needed road infrastructure support for the future booming CAV revolution
Research on Wireless Multi-hop Networks: Current State and Challenges
Wireless multi-hop networks, in various forms and under various names, are
being increasingly used in military and civilian applications. Studying
connectivity and capacity of these networks is an important problem. The
scaling behavior of connectivity and capacity when the network becomes
sufficiently large is of particular interest. In this position paper, we
briefly overview recent development and discuss research challenges and
opportunities in the area, with a focus on the network connectivity.Comment: invited position paper to International Conference on Computing,
Networking and Communications, Hawaii, USA, 201
On the Quality of Wireless Network Connectivity
Despite intensive research in the area of network connectivity, there is an
important category of problems that remain unsolved: how to measure the quality
of connectivity of a wireless multi-hop network which has a realistic number of
nodes, not necessarily large enough to warrant the use of asymptotic analysis,
and has unreliable connections, reflecting the inherent unreliable
characteristics of wireless communications? The quality of connectivity
measures how easily and reliably a packet sent by a node can reach another
node. It complements the use of \emph{capacity} to measure the quality of a
network in saturated traffic scenarios and provides a native measure of the
quality of (end-to-end) network connections. In this paper, we explore the use
of probabilistic connectivity matrix as a possible tool to measure the quality
of network connectivity. Some interesting properties of the probabilistic
connectivity matrix and their connections to the quality of connectivity are
demonstrated. We argue that the largest eigenvalue of the probabilistic
connectivity matrix can serve as a good measure of the quality of network
connectivity.Comment: submitted to IEEE INFOCOM 201
A Note On Obata's Rigidity Theorem I
In this note we present various extensions of Obata's rigidity theorem
concerning the Hessian of a function on a Riemannian manifold. They include
general rigidity theorems for the generalized Obata equation, and hyperbolic
and Euclidean analogs of Obata's theorem. Besides analyzing the full rigidity
case we also characterize the geometry and topology of the underlying manifold
in more general situations.Comment: Some remarks are added. A few typos are removed. The proof of one
lemma is modifie
When can we do better than autarky?
This paper provides a necessary and sufficient condition for the existence of nonautarkic contract in a risk sharing model with two-sided lack of commitment. Verifying the condition takes just one Guassian elimination of a matrix.
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