Search results for " sight"

Convex rear view mirrors compromise distance and time-to-contact judgements

2007

Convex rear view mirrors increasingly replace planar mirrors in automobiles. While increasing the field of view, convex mirrors are also taken to increase distance estimates and thereby reduce safety margins. However, this study failed to replicate systematic distance estimation errors in a real world setting. Whereas distance estimates were accurate on average, convex mirrors lead to significantly more variance in distance and spacing estimations. A second experiment explored the effect of mirrors on time-to-contact estimations, which had not been previously researched. Potential effects of display size were separated from effects caused by distortion in convex mirrors. Time-to-contact est…

OLSR Mesh Networks for Broadband Access: Enhancements, Implementation and Deployment

2008

In the context of an EU FP6 project, ADHOCSYS, we have developed a reliable and cost-effective solution for broadband Internet access in rural and mountainous areas. This solution is built based on multi-hop wireless mesh networking technologies and covers many aspects such as routing, reliability, QoS, security, self-configuration, self-healing, remote network monitoring, power management etc. In this paper, we present solely the routing aspect of the developed mesh network, focusing on new routing features that have been designed, implemented, and deployed in a real-life operational network. These new features are developed based on an extended version of the OLSR protocol. The test resul…

Sightseeing in Guidebooks

2007

Sightseeing in Guidebook

2007

The keyboard as a part of visual, auditory and kinesthetic processing in sight-reading at the piano

2009

Sight-reading at the piano requires coordination of multiple modalities—visual, auditory, and kinesthetic. Visual feedback (obtained by looking at the keyboard and the fingers) is usually regarded as one means by which pianists guide musical performance, but few researchers have focused on the organisational aspects implicit in the information provided by the keyboard. This study investigated the role of the keyboard with respect to the visual, auditory, and kinesthetic modalities involved in sight-reading. Five pianists sight-read two compositions, each in a different musical style. They were then interviewed in a semi-structured interview format. A qualitative content analysis was made fr…

Distributed routing and channel allocation in multi-channel multi-hop ad hoc networks

2013

In this paper, we propose a novel routing protocol which is integrated with channel assignment for multi-channel multi-hop wireless ad hoc networks. In such a network, each node is equipped with three transceivers. One is always tuned on a control channel which is responsible for control and broadcast messages, and the other two perform as transmitter and receiver respectively for traffic flows on different data channels. The routing protocol works in an on-demand manner, and the proposed routing discovery process selects a path that potentially traverses nodes with lighter traffic load and lower number of carried flows. With a given number of non-overlapping channels, the optimal solution …

A combined relay-selection and routing protocol for cooperative wireless sensor networks

2012

International audience; In wireless sensor networks several constraints decrease communications performances. In fact, channel randomness and energy restrictions make classical routing protocols inefficient. Therefore, the design of new routing protocols that cope with these constraints become mandatory. The main objective of this paper is to present a multi-objective routing algorithm RBCR that computes routing path based on the energy consumption and channel qualities. Additionally, the channel qualities are evaluated based on the presence of relay nodes. Compared to AODV and AODV associated to a cooperative MAC protocol, RBCR provides better performances in term of delivery ratio, power …

A Network Protocol to Enhance Robustness in Tree-Based WSNs Using Data Aggregation

2007

This paper proposes a data gathering strategy for wireless sensor networks and an implementation based on the IEEE 802.15.4 standard. The algorithm combines the benefits of single-path and multi-path routing strategies in a hybrid solution which makes use of alternative paths when necessary. We adopt a caching and retransmission technique, which exploits some peculiar features of data aggregation, with the use of implicit acknowledgments of reception. The paper also discusses simulation results that show how the mentioned techniques, combined with exploitation of the features of the IEEE 802.15.4 standard have been used to obtain an efficient protocol that takes energy consumption into acco…

QoS Multi-tree Based Routing Protocol for Inter-mesh Infrastructure Communications

2016

Part 5: Network Protocols; International audience; Quality of service (QoS) in wireless mesh networks (WMN) is an active area of research, which is driven by the increasing demand for real-time and multimedia applications, such as VoIP (Voice over IP) and VoD (Video on Demand). In this paper, we propose a QoS multi-tree based routing protocol for wireless mesh environments, named Inter-Mesh Infrastructure Proactive Routing (IMPR). It is a proactive multi-tree routing protocol enabling QoS guarantee for communications from/towards the Internet network through the Mesh Gateway (MG) of the mesh infrastructure. We describe and analyze the simulation results of different scenarios conducted on t…

QoS Based Routing Protocol for Intra-Mesh Infrastructure Communications

2015

International audience; Mesh Networks (WMNs) have been considered as a promising alternative to conventional wired networks, thanks to its flexibility and easy deployment. Thus, to ensure a satisfying level of QoS guarantees for real-time and streaming applications such as Voice over IP (VoIP) and Video on Demand (VoD), we propose a novel QoS based routing protocol for wireless mesh environments, called Hybrid QoS Mesh Routing (HQMR), jointly with a clustering algorithm to enhance scalability issues within the mesh infrastructure. HQMR is composed of two routing sub-protocols: a reactive routing sub-protocol for intra-infrastructure communications and a proactive QoS based multi-tree routin…