S. de Groot

Nonvestibular motion cueing in a fixed-base driving simulator: Effects on driver braking and cornering performance

Motion platforms can be used to provide vestibular cues in a driving simulator, and have been shown to reduce driving speed and acceleration. However, motion platforms are expensive devices, and alternatives for providing motion cues need to be investigated. In independent experiments, the following eight low-cost nonvestibular motion cueing systems were tested by comparing driver performance to control groups driving with the cueing system disengaged: (1) seat belt tensioning system, (2) vibrating steering wheel, (3) motion seat, (4) screeching tire sound, (5) beeping sound, (6) road noise, (7) vibrating seat, and (8) pressure seat. The results showed that these systems are beneficial in reducing speed and acceleration and that they improve lane-keeping and/or stopping accuracy. The seat belt tensioning system had a particularly large influence on driver braking performance. This system reduced driving speed, increased stopping distance, reduced maximum deceleration, and increased stopping accuracy. It is concluded that low-cost nonvestibular motion cueing may be a welcome alternative for improving in-simulator performance so that it better matches real-world driving performance.

A Security Architecture for Personal Networks

Personal network (PN) is a new concept utilizing pervasive computing to meet the needs of the user. As PNs edge closer towards reality, security becomes an important concern since any vulnerability in the system will limit its practical use. In this paper we introduce a security architecture designed for PNs. Our aim is to use secure but lightweight mechanisms suitable for resource constrained devices and wireless communication. We support pair-wise keys for secure cluster formation and use group keys for securing intra-cluster communication. In order to analyze the performance of our proposed mechanisms, we carry out simulations using ns-2. The results show that our mechanisms have a low overhead in terms of delay and energy consumption

Sharing Resources in Group-Oriented Networks Fednet and Related Paradigms

A personal network (PN) is a network composed of devices of a person that can communicate with each other independently from their geographical location. An extra functionality added to PNs can enable different persons to cooperate and to form a group-oriented network called a Federation of Personal Networks (Fednet). A Fednet is a secure, opportunity or purpose driven ad-hoc network for sharing personal resources. A Fednet can be composed for applications in different areas, e.g. education, entertainment, business, emergency. A number of technologies and paradigms for sharing resources and services has been reported in the literature, such as grids, virtual organizations, Secure virtual enclaves and P2P networks. In order to place Fednets amongst them, in this paper, we introduce the Fednet concept and describe its functional architecture. Then we provide a survey on related paradigms, and discuss the differences and similarities between them and Fednets emphasizing the mechanisms for controlling the access to shared resources.

Advancing simulation-based driver training: lessons learned and future perspectives

This paper aims to provide recommendations for improving the effectiveness of automatic, student-adaptive, simulation-based driver training. Using experiments and recorded data in driving simulators, three distinct issues are discussed: 1) the student, 2) the virtual driving instructor (VDI), and 3) the student-profile. We found that: first, students seek task-relevant information themselves; not providing them with feedback can be beneficial. Second, an intelligent VDI that emulates a human driving instructor is not favored. To the contrary, regressive instruction -- a relatively simple principle -- was effective in letting students drive away autonomously. Third, constructing a student-profile based on individual characteristics, such as a strength-weakness report, is viable for providing student-adaptive feedback.

Securing inter-cluster communication in Personal Networks

A Personal Network (PN) is a new type of an overlay network consisting of all personal devices belonging to a user, be they remote or local. Such continuous and seamless connectivity of all personal devices belonging to a user enables the development of new applications and improved services. A Personal Network is an intelligent and user-centric network that assists the user in an unobtrusive way. In this paper we investigate means of securing communication between geographically distributed Personal Network clusters. Clusters are ad-hoc networks of co-located personal devices. Using Virtual Private Network (VPN) technology enables the creation of secure tunnels between gateways of different clusters, making it possible to transfer all types of intra-cluster traffic securely, over the insecure public network. The ad-hoc nature of clusters when coupled with the mobile and resource constrained nature of many personal devices makes enforcing security a challenging task. We investigate the suitability of existing VPN technologies to secure inter-cluster communication. Our contribution is in identifying aspects of existing solutions that render them unsuitable in their current form for constrained personal devices. We propose a modified framework based on IPSec and KINK that better satisfies the requirements of personal devices by reducing the cost of security.

Quantitative Comparison of Resource Management Strategies in UMTS-WLAN Integration at the Radio Access Level

The WLAN integration at the UMTS radio access level is a promising interworking approach, which provides the mobile operator with additional license-free bandwidth, enhances vertical handover performance and facilitates common management of all the available radio resources. The benefits are achieved at cost of various modifications of the UMTS radio access network. The modifications may be designed in different ways and may result in different architectural options with different performance. In; this paper, we present quantitative comparison of three architectural options, putting the focus on the initial radio interface selection algorithm.

Architectural and QoS Aspects of Personal Networks

Personal networks (PNs) are future communication systems that combine wireless and infrastructure based networks to provide users a variety of services anywhere and anytime. PNs introduce new design challenges due to the heterogeneity of the involved technologies, the need for self-organization, the dynamics of the PN composition, the application-driven nature, the co-operation with infrastructure-based networks, and the security hazards. This paper discusses the challenges of security, service discovery and QoS provisioning in designing self-organized PNs and combines them all into an integrated architectural framework

The effects of control-display gain on performance of race car drivers in an isometric braking task.

Abstract To minimise lap times during car racing, it is important to build up brake forces rapidly and maintain precise control. We examined the effect of the amplification factor (gain) between brake pedal force and a visually represented output value on a drivers ability to track a target value. The test setup was a formula racing car cockpit fitted with an isometric brake pedal. Thirteen racing drivers performed tracking tasks with four control-display gains and two target functions: a step function (35 trials per gain) and a multisine function (15 trials per gain). The control-display gain had only minor effects on root mean-squared error between output value and target value, but it had large effects on build-up speed, overshoot, within-participants variability, and self-reported physical load. The results confirm the hypothesis that choosing an optimum gain involves balancing stability against physical effort.Abstract To minimise lap times during car racing, it is important to build up brake forces rapidly and maintain precise control. We examined the effect of the amplification factor (gain) between brake pedal force and a visually represented output value on a drivers ability to track a target value. The test setup was a formula racing car cockpit fitted with an isometric brake pedal. Thirteen racing drivers performed tracking tasks with four control-display gains and two target functions: a step function (35 trials per gain) and a multisine function (15 trials per gain). The control-display gain had only minor effects on root mean-squared error between output value and target value, but it had large effects on build-up speed, overshoot, within-participants variability, and self-reported physical load. The results confirm the hypothesis that choosing an optimum gain involves balancing stability against physical effort.

On the way to pole position: The effect of tire grip on learning to drive a racecar

Racecar drivers could benefit from new training methods for learning to drive fast lap times. Inspired by the learning-from-errors principle, this simulator-based study investigated the effect of the tire-road friction coefficient on the training effectiveness of a car racing task. Three groups of 15 inexperienced racecar drivers (low grip (LG), 66% of normal grip; normal grip (NG); high grip (HG), 150% of normal grip) completed four practice sessions of 10 minutes in a Formula 3 car on an oval track of 800 m. After the practice sessions, two retention sessions followed: a retention session with normal grip in a Formula 3 car and another retention session with a Formula 1 car. The results showed that LG was significantly slower than HG in the first retention session. Furthermore, LG reported a higher confidence and lower frustration than NG and HG after each of the two retention sessions. In conclusion, practicing with low grip, as compared to practicing with normal or high grip, resulted in increased confidence but slower lap times.

Architectures for Communication in Personal Networks

Personal networks (PN) is a new concept related to pervasive computing with a strong user-focus view. The key to a successful PN realization is a general network architecture that is capable of bridging different current and future technologies and offers a homogeneous and clear view to the end-user. In this paper, we focus on forming a PN by connecting remote personal devices using infrastructure-based IP networks, including 3G networks and WLAN hotspots. One way is to upgrade the current access networks with new functionality to support PNs. Since many devices in PNs are mobile and battery powered, this may help them to achieve a faster service and to save energy. However, to deploy such functionality is not easy and may hamper the adoption of PNs altogether. Therefore, in this paper we study three possible inter-cluster communication architectures that can use current IP networks. To discern the above proposal we also give a detailed picture of PN network architecture supported by infrastructure. We believe that this detailed discussion will help the success of PNs