Road crashes are a growing concern of governments and is rising to become one of the leading preventable causes of death, especially in developing countries. The ubiquitous presence of smartphones provides a new platform on which to implement sensor networks and driver assistance systems, as well as other ITS applications. In this paper, existing approaches of using smartphones for ITS applications are analyzed and compared. Particular focus is placed on vehicle-based monitoring systems, such as driving behavior and style recognition, accident detection and road condition monitoring systems. Further opportunities for use of smartphones in ITS systems are highlighted, and remaining challenges in this emerging field of research are identified.

No abstract

Abstract-Despite various proposed Medium Access Control (MAC) approaches, efficient medium access in VANET remains a significant challenge, especially for the broadcast of safety messages. A key contributing factor to packet loss is the hidden terminal problem, which is exacerbated by the high node mobility apparent in VANET. Since the hidden terminal problem is fundamentally a problem of lack of awareness, this work evaluates the effects of increased neighbor awareness at the MAC layer. An increased awareness of neighboring nodes' slot allocation in a TDMA-based MAC, directly impacts on the number of available slots. Therefore, the effects of TDMA frame size is also evaluated for different awareness ranges. To support the analysis, a TDMA-based MAC with configurable neighbor awareness and configurable TDMA frame size is introduced. The impact is assessed using the packet delivery ratio, receiver throughput, and end-to-end latency. The results show packet delivery ratio and receiver throughput to increase for increased awareness ranges, up to an optimal of 2 hops, after which performance worsens. An increase in TDMA frame size leads to an increase in packet delivery ratio for small awareness ranges, and an oscillating increase for large awareness ranges. The receiver throughput also initially increases for an increased TDMA frame size, but reaches an optimum,also at 2 hops.Index Terms-Vehicular Ad-hoc NETwork (VANET), Medium Access Control (MAC), Neighbor awareness.

Parallelisation of computationally expensive algorithms, such as Monte-Carlo Tree Search (MCTS), has become increasingly important in order to increase algorithm performance by making use of commonplace parallel hardware.Oakfoam, an MCTS-based Computer Go player, was extended to support parallel processing on multi-core and cluster systems. This was done using tree parallelisation for multi-core systems and root parallelisation for cluster systems.Multi-core parallelisation scaled linearly on the tested hardware on 9x9 and 19x19 boards when using the virtual loss modification. Cluster parallelisation showed poor results on 9x9 boards, but scaled well on 19x19 boards, where it achieved a four-node ideal strength increase on eight nodes.Due to this work, Oakfoam is currently one of only two open-source MCTS-based Computer Go players with cluster parallelisation, and the only one using the Message Passing Interface (MPI) standard.

a) (b) (c) Figure 1: (a) A user using the prototype system. (b) The back of the tablet portion of the device with the cameras and sensors mounted. (c) An example of the feature matching that is used for the stereo optical tracking.