Design and evaluation of a framework for cooperative and adaptive QoS control of DSRC network for road safety applications

Dedicated short-range communications (DSRC) are a promising vehicle communication technique for collaborative road safety applications (CSA). However, road safety applications require highly reliable and timely wireless communications, which present big challenges to DSRC based vehicle networks on effective and robust quality of services (QoS) provisioning due to the random channel access method applied in the DSRC technique. In this paper we examine the QoS control problem for CSA in the DSRC based vehicle networks and presented an overview of the research work towards the QoS control problem. After an analysis of the system application requirements and the DSRC vehicle network features, we propose a framework for cooperative and adaptive QoS control, which is believed to be a key for the success of DSRC on supporting effective collaborative road safety applications. A core design in the proposed QoS control framework is that network feedback and cross-layer design are employed to collaboratively achieve targeted QoS. A design example of cooperative and adaptive rate control scheme is implemented and evaluated, with objective of illustrating the key ideas in the framework. Simulation results demonstrate the effectiveness of proposed rate control schemes in providing highly available and reliable channel for emergency safety messages

Advances in Vehicular Ad-hoc Networks (VANETs): challenges and road-map for future development

Recent advances in wireless communication technologies and auto-mobile industry have triggered a significant research interest in the field of vehicular ad-hoc networks (VANETs) over the past few years. A vehicular network consists of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications supported by wireless access technologies such as IEEE 802.11p. This innovation in wireless communication has been envisaged to improve road safety and motor traffic efficiency in near future through the development of intelligent transportation system (ITS). Hence, governments, auto-mobile industries and academia are heavily partnering through several ongoing research projects to establish standards for VANETs. The typical set of VANET application areas, such as vehicle collision warning and traffic information dissemination have made VANET an interesting field of mobile wireless communication. This paper provides an overview on current research state, challenges, potentials of VANETs as well as the ways forward to achieving the long awaited ITS

Hierarchical clustering for discrimination discovery:a top-down approach

\u3cp\u3eToday, data is an essential part of many decision-making processes in businesses and social life through the use of various machine learning techniques. These methods can easily perpetuate human bias in the data and result in discrimination. Despite a growing interest in data discrimination discovery and removal, to date there is a lack of a general and robust framework to distinguish discriminatory decision-making processes from non-discriminatory ones. In this work, we present a generic framework that helps detect possible discrimination by analyzing historical data and associated decisions using a top-down unsupervised approach, which we refer to as hierarchical clustering. Our approach is highly adaptive as it gradually 'learns' users' inherent groups, and clusters their records using cohesiveness and density of points in the dataset. Moreover, we propose a progressive attribute-selection method to choose statistically relevant attributes, thus reducing the effect of noise. Finally, we adopt a recursive notion of cluster profile that is homogeneous w.r.t. decision labels. This allows for deeper insights on the data and on the decision-making underlying the final user classification. Our framework is able to identify both positive and negative bias resulting in discrimination. We also highlight patterns of discrimination revealed by the homogeneous cluster centroids, which otherwise could not be captured.\u3c/p\u3

Multicommodity games in public-cloud markets considering subadditive resource demands

In still developing, public cloud-computing markets, prices for virtual machine (VM) offerings fluctuate, and not just for spot/preemptible instances. Moreover, some (particularly derivative) providers allow for fine-grain initial resource provisioning and dynamic reprovisioning of VMs. In this preliminary study, we consider long-lived tenants of a public cloud under resource-based service-level agreements. For noncooperative aggregative multicommodity (plural IT resource) games among them, conditions are established for an interior Nash equilibrium and an exact potential (giving convergence to Nash equilibrium). Also discussed are extensions to plural IT resource demands that are subadditive in workload intensity