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Sipping Fuel and Saving Lives: Increasing Fuel Economy without Sacrificing Safety
Demonstrates how new fuel-efficiency technologies make it possible, and advisable, to significantly increase the fuel economy of motor vehicles without compromising their safety
Mobility: a double-edged sword for HSPA networks
This paper presents an empirical study on the performance of mobile High Speed Packet Access (HSPA, a 3.5G cellular standard) networks in Hong Kong via extensive field tests. Our study, from the viewpoint of end users, covers virtually all possible mobile scenarios in urban areas, including subways, trains, off-shore ferries and city buses. We have confirmed that mobility has largely negative impacts on the performance of HSPA networks, as fast-changing wireless environment causes serious service deterioration or even interruption. Meanwhile our field experiment results have shown unexpected new findings and thereby exposed new features of the mobile HSPA networks, which contradict commonly held views. We surprisingly find out that mobility can improve fairness of bandwidth sharing among users and traffic flows. Also the triggering and final results of handoffs in mobile HSPA networks are unpredictable and often inappropriate, thus calling for fast reacting fallover mechanisms. We have conducted in-depth research to furnish detailed analysis and explanations to what we have observed. We conclude that mobility is a double-edged sword for HSPA networks. To the best of our knowledge, this is the first public report on a large scale empirical study on the performance of commercial mobile HSPA networks
How to monitor sustainable mobility in cities? Literature review in the frame of creating a set of sustainable mobility indicators
The role of sustainable mobility and its impact on society and the environment is evident and recognized worldwide. Nevertheless, although there is a growing number of measures and projects that deal with sustainable mobility issues, it is not so easy to compare their results and, so far, there is no globally applicable set of tools and indicators that ensure holistic evaluation and facilitate replicability of the best practices. In this paper, based on the extensive literature review, we give a systematic overview of relevant and scientifically sound indicators that cover different aspects of sustainable mobility that are applicable in different social and economic contexts around the world. Overall, 22 sustainable mobility indicators have been selected and an overview of the applied measures described across the literature review has been presented
On Learning by Exchanging Advice
One of the main questions concerning learning in Multi-Agent Systems is:
(How) can agents benefit from mutual interaction during the learning process?.
This paper describes the study of an interactive advice-exchange mechanism as a
possible way to improve agents' learning performance. The advice-exchange
technique, discussed here, uses supervised learning (backpropagation), where
reinforcement is not directly coming from the environment but is based on
advice given by peers with better performance score (higher confidence), to
enhance the performance of a heterogeneous group of Learning Agents (LAs). The
LAs are facing similar problems, in an environment where only reinforcement
information is available. Each LA applies a different, well known, learning
technique: Random Walk (hill-climbing), Simulated Annealing, Evolutionary
Algorithms and Q-Learning. The problem used for evaluation is a simplified
traffic-control simulation. Initial results indicate that advice-exchange can
improve learning speed, although bad advice and/or blind reliance can disturb
the learning performance.Comment: 12 pages, 6 figures, 1 table, accepted in Second Symposium on
Adaptive Agents and Multi-Agent Systems (AAMAS-II), 200
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