Search results for "mobile"
showing 10 items of 1399 documents
PV-Alert: A fog-based architecture for safeguarding vulnerable road users
2017
International audience; High volumes of pedestrians, cyclists and other vulnerable road users (VRUs) have much higher casualty rates per mile; not surprising given their lack of protection from an accident. In order to alleviate the problem, sensing capabilities of smartphones can be used to detect, warn and safeguard these road users. In this research we propose an infrastructure-less fog-based architecture named PV-Alert (Pedestrian-Vehicle Alert) where fog nodes process delay sensitive data obtained from smartphones for alerting pedestrians and drivers before sending the data to the cloud for further analysis. Fog computing is considered in developing the architecture since it is an emer…
Harnessing User Values to Understand Value Co-Creation and Co-Destruction in Augmented Reality Mobile Games
2021
This paper explores the phenomena of value co- creation and co-destruction in augmented reality (AR) mobile games. More specifically, we aim to achieve an in-depth understanding of value co-creation and co- destruction occurring in Pokémon GO and the user values underlying these occurrences. Service-dominant (S-D) logic provides our study with a lens for understanding users as active co-creators, co- destroyers, and determinants of value. Further, the means-end theory establishes users’ personal values and goals as the basis for service value determination. We uncover key values highlighted in users’ positive and negative gaming experiences through a qualitative content analysis of 43 in-de…
MDP-based Resource Allocation for Uplink Grant-free Transmissions in 5G New Radio
2020
The diversity of application scenarios in 5G mobile communication networks calls for innovative initial access schemes beyond traditional grant-based approaches. As a novel concept for facilitating small packet transmission and achieving ultra-low latency, grant-free communication is attracting lots of interests in the research community and standardization bodies. However, when a network consists of both grant based and grant-free based end devices, how to allocate slot resources properly between these two categories of devices remains as an unanswered question. In this paper, we propose a Markov decision process based scheme which dynamically allocates grant-free resources based on a spec…
A non-stationary multipath fading channel model incorporating the effect of velocity variations of the mobile station
2014
A standard assumption in mobile fading channel modelling is that the mobile station (MS) moves along a straight line with constant speed. In practice, this assumption is violated in most propagation scenarios. For the development of more realistic channel models, it is therefore important to relax this restriction by allowing the MS to change its velocity. In this paper, we study the effect of velocity changes on the statistical properties of multipath fading channels. Expressions will be derived for the local autocorrelation function (ACF), the Wigner-Ville spectrum, the average Doppler shift, and the Doppler spread. Our findings show that a variation of the speed and/or the direction of t…
Resource sharing optimality in WiFi infrastructure networks
2009
In WiFi networks, mobile nodes compete for accessing a shared channel by means of a random access protocol called Distributed Coordination Function (DCF). Although this protocol is in principle fair, since all the stations have the same probability to transmit on the channel, it has been shown that unfair behaviors may emerge in actual networking scenarios. Assuming that a contending node can dynamically change its strategy, by tuning its contention parameters to non-standard values on the basis of channel observations, we prove that, for infrastructure networks with bidirectional traffic and homogeneous application requirements, selfish access strategies are able to reach equilibrium condi…
UDP flows in Cognitive Radios with Channel Aggregation and Fragmentation: A Test-bed Based Evaluation
2018
Channel aggregation (CA) and channel fragmentation (CF) have been studied extensively in cognitive radios (CRs) for many years. However, a test-bed evaluation for such techniques at flow level is still open. In this study, employing National Instruments devices, a test-bed is set up to evaluate the performance of UDP flows for CRs with CA and CF, considering the aspects of blocking, preemption, and throughput in probability. The measurements clearly show that there are performance improvements in applying CA and CF in CRs for UDP flows.
Web Services Specific Security Standards
2014
Abstract In this paper are described the aspects regarding the security within OGSA framework, introducing WS-Security standard – OASIS standard for Web Services security. There are approached the security aspects of the OGSA environment for the delivered architectures P2P – ‘Peer-to-Peer’ and there are presented the recent initiatives for creating a specific and adapted environment OGSA for the applications P2P and the specific security demands of these transactions. Furthermore, there are exposed aspects regarding the mobility of services and resources in the P2P context, with the conditions of applying WSRF framework, derived from OGSA to the P2P environments, SOA processes in P2P enviro…
On the advantages of combining differential algorithms and log-polar vision for detection of self-motion from a mobile robot
2001
Abstract This paper describes the design and implementation on programmable hardware (FPGAs) of an algorithm for the detection of self-mobile objects as seen from a mobile robot. In this context, ‘self-mobile’ refers to those objects that change in the image plane due to their own movement, and not to the movement of the camera on board of the mobile robot. The method consists on adapting the original algorithm from Chen and Nandhakumar [A simple scheme for motion boundary detection, in: Proceedings of the IEEE International Conference on Systems, Man and Cybernetics, 1994] by using foveal images obtained with a special camera whose optical axis points towards the direction of advance. It i…
UbiRoad: Semantic Middleware for Context-Aware Smart Road Environments
2010
A smart road environment is such a traffic environment that is equipped with all necessary facilities to enable seamless mobile service provisioning to the users. However, advanced sensors and network architectures deployed within the traffic environment are insufficient to make mobile service provisioning autonomous and proactive, thus minimizing drivers’ distraction during their presence in the environment. For that, an Intelligent Transportation System, which is operating on top of numerous sensor and access networks and governing the process of mobile services provisioning to the users in self-managed and proactive way, must be deployed. Specifically, such system should provide solution…
A mechanism of coalition formation in the metaphor of politics multiagent architecture
2003
Hybrid Multi-Agent Architectures allow the support of mobile robots colonies moving in dynamic, not predictable and time variable environments in order to achieve distributed solving strategies that develop collective team-oriented behaviors for solving complicate and difficult tasks. The development of a new robotic architecture for the coordination of a robot colonies in dangerous, unknown and dynamic environment is outlined. The name of this new architecture is Metaphor of Politics (MP), because it loosely takes inspiration from the political organizations of democratic governments.