Engine control units in the automotive industry are particular challenging real-time systems regarding their real-time analysis. Some of the tasks of such an engine control unit are triggered by the engine, i.e. the f...
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ISBN:
(纸本)9781450321532
Engine control units in the automotive industry are particular challenging real-time systems regarding their real-time analysis. Some of the tasks of such an engine control unit are triggered by the engine, i.e. the faster the angular velocity of the engine, the more frequent the tasks are executed. Furthermore, the execution time of a task may vary with the angular velocity of the engine. As a result the worst case does not necessarily occur when all tasks are activated simultaneously. Hence this behavior cannot be addressed appropriately with the currently available real-time analysis methods. In this paper we make a first step towards a real-time analysis for an engine control unit. We present a sufficient real-time analysis assuming that the angular velocity of the engine is arbitrary but fixed.
Vehicular Ad-hoc Networks (VANETs) aim to increase, among others, traffic safety and efficiency by warning and informing the driver about road events and hazards. Due to their direct impact on drivers' safety, ext...
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Vehicular Ad-hoc Networks (VANETs) aim to increase, among others, traffic safety and efficiency by warning and informing the driver about road events and hazards. Due to their direct impact on drivers' safety, external and internal attacks have to be prevented. While authentication prevents most of the external attacks, internal attackers are still able to misuse the system and inject fake - but authenticated - messages. Therefore, misbehavior detection and prevention mechanisms are required to mitigate such attacks. In this paper we provide a categorization of internal attackers to identify most relevant attack variants. Instead of using simulations, as done by most related works, we use an implementation on real vehicles to demonstrate the feasibility of location-based attacks. Especially, we demonstrate that a malware application installed on a vehicle can provoke false warnings on benign vehicles that are within the attacker's communication range. This exemplary attack is possible due to insufficiently specified VANET security standards. By using our proposed countermeasures, we show that this internal attack is detected and blocked, preventing false driver warnings.
Recent efforts in mission planning for underwater vehicles have utilised predictive models to aid in navigation, optimal path planning and drive opportunistic sampling. Although these models provide information at a u...
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ISBN:
(纸本)9781467356404
Recent efforts in mission planning for underwater vehicles have utilised predictive models to aid in navigation, optimal path planning and drive opportunistic sampling. Although these models provide information at a unprecedented resolutions and have proven to increase accuracy and effectiveness in multiple campaigns, most are deterministic in nature. Thus, predictions cannot be incorporated into probabilistic planning frameworks, nor do they provide any metric on the variance or confidence of the output variables. In this paper, we provide an initial investigation into determining the confidence of ocean model predictions based on the results of multiple field deployments of two autonomous underwater vehicles. For multiple missions of two autonomous gliders conducted over a two-month period in 2011, we compare actual vehicle executions to simulations of the same missions through the Regional Ocean Modeling System in an ocean region off the coast of southern California. This comparison provides a qualitative analysis of the current velocity predictions for areas within the selected deployment region. Ultimately, we present a spatial heat-map of the correlation between the ocean model predictions and the actual mission executions. Knowing where the model provides unreliable predictions can be incorporated into planners to increase the utility and application of the deterministic estimations.
Virtualization tools have been used in computer network classes to provide a environment for practice experiments. Although some papers describe these tools and their technical benefits, they do not provide quantitati...
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Virtualization tools have been used in computer network classes to provide a environment for practice experiments. Although some papers describe these tools and their technical benefits, they do not provide quantitative information about its effectiveness. This paper presents a proposal for systematic use of this category of tools in computer classes and a evaluation of use Netkit tool in computer network classes. It will be shown how tutorial sections has been developed to these courses, the receptivity from the students through surveys and a statistical analysis of how much students grades can be improved by applying such tutorials. Finally, it will be possible to conclude that, in fact, the use of such tools is strongly advised.
We have designed, built, tested and fielded a decision support system which provides a platform for situational awareness, planning, observation, archiving and data analysis. While still in development, our inter-disc...
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ISBN:
(纸本)9781467353038
We have designed, built, tested and fielded a decision support system which provides a platform for situational awareness, planning, observation, archiving and data analysis. While still in development, our inter-disciplinary team of computer scientists, engineers, biologists and oceanographers has made extensive use of our system in at-sea experiments since 2010. The novelty of our work lies in the targeted domain, its evolving functionalities that closely tracks how ocean scientists are seeing the evolution of their own work practice, and its actual use by engineers, scientists and marine operations personnel. We describe the architectural elements and lessons learned over the more than two years use of the system.
WiFi indoor localization has seen a renaissance with the introduction of RSSI-based approaches. However, manual finger-printing techniques that split the indoor environment into pre-defined grids are implicitly boundi...
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ISBN:
(纸本)9781467355766
WiFi indoor localization has seen a renaissance with the introduction of RSSI-based approaches. However, manual finger-printing techniques that split the indoor environment into pre-defined grids are implicitly bounding the maximum achievable localization accuracy. WoLF, our proposed Wireless localization and Laser-scanner assisted Fingerprinting system, solves this problem by automating the way indoor fingerprint maps are generated. We furthermore show that WiFi localization on the generated high resolution maps can be performed by sparse reconstruction which exploits the peculiarities imposed by the physical characteristics of indoor environments. Particularly, we propose a Bayesian Compressed Sensing (BCS) approach in order to find the position of the mobile user and dynamically determine the sufficient number of APs required for accurate positioning. BCS employs a Bayesian formalism in order to reconstruct a sparse signal using an undetermined system of equations. Experimental results with data collected in a university building validate WoLF in terms of localization accuracy under actual environmental conditions.
A number of popular engineering processes and methodologies emerged over the past years which attracted interest in research and industry. For process enactment, enterprises have to match requirements of engineering p...
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ISBN:
(纸本)9789898565105
A number of popular engineering processes and methodologies emerged over the past years which attracted interest in research and industry. For process enactment, enterprises have to match requirements of engineering processes with existing resources. Therefore, it has to be analyzed if employees have sufficient skills or if infrastructure has sufficient capabilities to match the requirements of a situational process. Both, maintaining a skill and resource database and matching requirements against this database are an enormously challenging and time-consuming task. Additionally, this matching has to be carried out regularly as employees join and leave the company and skills change over time. Based upon a formal, logical base, we present an approach that combines ontological and metamodeling technical spaces and enables an automatic analysis of engineering processes regarding the existence of necessary resources.
Optimized Link State Routing (OLSR) protocol is a leading proactive routing protocol for Mobile Ad-hoc Networks (MANETs). Since the OLSR protocol in its standard version does not support multi-path packet forwarding, ...
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The Artificial Hormone System (AHS) is a self organizing system which allocates tasks to processing elements. It works in a distributed way, is able to hold real-time conditions and can run in a mixed-signal chip envi...
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Route and service discovery in wireless multi-hop networks applies flooding or gossip routing to disseminate and gather information. Since packets may get lost, retransmissions of lost packets are required. In many pr...
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Route and service discovery in wireless multi-hop networks applies flooding or gossip routing to disseminate and gather information. Since packets may get lost, retransmissions of lost packets are required. In many protocols the retransmission timeout is fixed in the protocol specification. In this paper we demonstrate that optimization of the timeout is required in order to ensure proper functioning of flooding schemes. Based on an experimental study, we apply percolation theory and derive analytical models for computing the optimal restart timeout. To the best of our knowledge, this is the first comprehensive study of gossip routing, percolation, and restart in this context.
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