1,810 research outputs found

    High-Accuracy Tracking Using Ultrawideband Signals for Enhanced Safety of Cyclists

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    Debating Space Security: Capabilities and Vulnerabilities

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    The U.S. position in the debate on space security has been that (1) space-based systems could be developed and used to obtain decisive warghting superiority over an adversary, and (2) these space-based systems, because they might give such an inordinate advantage over any adversary, will be attacked. The Russians and Chinese, in contrast, claim to be threatened by U.S. aspirations in space but deny that they pose a serious threat to U.S. space-based systems. They view the development of advanced military space systems by the United States as evidence of a growing gap of military capabilities limited only by technological--not political--constraints. They argue that U.S. missile defense systems operating in coordination with advanced satellite sensors would weaken their nuclear retaliatory potential. This dissertation argues that the positions held by both of these parties are more extreme than warranted. An analytical evaluation quickly narrows the touted capabilities and assumed vulnerabilities of space systems to a much smaller set of concerns that can be addressed by collaboration. Chapter 2: Operationally Responsive Space (ORS): Is 24/7 Warghter Support Feasible? demonstrates the infeasibility of dramatically increasing U.S. warfighting superiority by using satellites. Chapter 3: What Can be Achieved by Attacking Satellites? makes the case that although U.S. armed forces rely extensively on its satellite infrastructure, that does not immediately make them desirable targets. The functions performed by military satellites are diffused among large constellations with redundancies. Also, some of the functions performed by these satellites can be substituted for by other terrestrial and aerial systems. Chapter 4: The Limits of Chinese Anti-Satellite Missiles demonstrates that anti-satellite (ASAT) intercepts are very complex under realistic conditions and that a potential adversary with space capabilities comparable to China's has very limited capability to use ASATs in a real-world battle scenario. Finally, in order to evaluate the chief concern raised by the Russians and Chinese, chapter 5: Satellites, Missile Defense and Space Security simulates a boost-phase missile defense system cued by the advanced Space Tracking and Surveillance (STSS) sensors. It demonstrates that even under best case assumptions, the STSS sensors are not good enough for the boost-phase missile defense system to successfully intercept and destroy an ICBM. Together, these chapters aim to narrow the contentions in the debate on space security thereby fostering the international colloboration and data sharing needed to ensure safe operations in space

    Vulnerable road users and connected autonomous vehicles interaction: a survey

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    There is a group of users within the vehicular traffic ecosystem known as Vulnerable Road Users (VRUs). VRUs include pedestrians, cyclists, motorcyclists, among others. On the other hand, connected autonomous vehicles (CAVs) are a set of technologies that combines, on the one hand, communication technologies to stay always ubiquitous connected, and on the other hand, automated technologies to assist or replace the human driver during the driving process. Autonomous vehicles are being visualized as a viable alternative to solve road accidents providing a general safe environment for all the users on the road specifically to the most vulnerable. One of the problems facing autonomous vehicles is to generate mechanisms that facilitate their integration not only within the mobility environment, but also into the road society in a safe and efficient way. In this paper, we analyze and discuss how this integration can take place, reviewing the work that has been developed in recent years in each of the stages of the vehicle-human interaction, analyzing the challenges of vulnerable users and proposing solutions that contribute to solving these challenges.This work was partially funded by the Ministry of Economy, Industry, and Competitiveness of Spain under Grant: Supervision of drone fleet and optimization of commercial operations flight plans, PID2020-116377RB-C21.Peer ReviewedPostprint (published version

    Inteligentno upravljanje prometom uz dodjelu prioriteta vozilima žurnih službi

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    Advanced traffic management systems in city traffic (traffic light management) give possibility to give priority of passage to selected type of users, such as public transport, VIP users, and emergency services. In Republic of Croatia at present time there is no existent developed adaptive algorithms that can give priority to vehicles of Emergency services through the intersection. During this research solution to give priority passage Emergency vehicles in city traffic, benefit of such advances system will be investigated and proved with a simulation model. In same project cooperative concept will be evaluated (regarding emergency services) which includes a real time vehicle to vehicle and vehicle to infrastructure communication.Napredni sustavi upravljanja gradskom prometnom mrežom (semaforiziranim raskrižjima) omogućuju prioritetni prolazak određenom tipu korisnika kao npr. javni gradski prijevoz, VIP korisnici, žurne službe. U Republici Hrvatskoj za sada nema razrađenih adaptivnih upravljačkih algoritama prema kojima vozila žurnih službi mogu prioritetno proći raskrižjem. Kroz ovo istraživanje razmotrit će se mogućnost prioritetnog prolaska žurnih službi u gradskom prometu, te će se na temelju simulacijskog modela dokazati korist takvog unaprijeđenog sustava. Također, dodatno će se razmotriti i mogućnosti kooperativnog koncepta u odnosu na vozila žurnih službi, što uključuje komunikaciju između vozila i vozila i infrastrukturu stvarnom vremenu

    Inteligentno upravljanje prometom uz dodjelu prioriteta vozilima žurnih službi

    Get PDF
    Advanced traffic management systems in city traffic (traffic light management) give possibility to give priority of passage to selected type of users, such as public transport, VIP users, and emergency services. In Republic of Croatia at present time there is no existent developed adaptive algorithms that can give priority to vehicles of Emergency services through the intersection. During this research solution to give priority passage Emergency vehicles in city traffic, benefit of such advances system will be investigated and proved with a simulation model. In same project cooperative concept will be evaluated (regarding emergency services) which includes a real time vehicle to vehicle and vehicle to infrastructure communication.Napredni sustavi upravljanja gradskom prometnom mrežom (semaforiziranim raskrižjima) omogućuju prioritetni prolazak određenom tipu korisnika kao npr. javni gradski prijevoz, VIP korisnici, žurne službe. U Republici Hrvatskoj za sada nema razrađenih adaptivnih upravljačkih algoritama prema kojima vozila žurnih službi mogu prioritetno proći raskrižjem. Kroz ovo istraživanje razmotrit će se mogućnost prioritetnog prolaska žurnih službi u gradskom prometu, te će se na temelju simulacijskog modela dokazati korist takvog unaprijeđenog sustava. Također, dodatno će se razmotriti i mogućnosti kooperativnog koncepta u odnosu na vozila žurnih službi, što uključuje komunikaciju između vozila i vozila i infrastrukturu stvarnom vremenu

    A Review on Vehicle Classification and Potential Use of Smart Vehicle-Assisted Techniques

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    Vehicle classification (VC) is an underlying approach in an intelligent transportation system and is widely used in various applications like the monitoring of traffic flow, automated parking systems, and security enforcement. The existing VC methods generally have a local nature and can classify the vehicles if the target vehicle passes through fixed sensors, passes through the short-range coverage monitoring area, or a hybrid of these methods. Using global positioning system (GPS) can provide reliable global information regarding kinematic characteristics; however, the methods lack information about the physical parameter of vehicles. Furthermore, in the available studies, smartphone or portable GPS apparatuses are used as the source of the extraction vehicle’s kinematic characteristics, which are not dependable for the tracking and classification of vehicles in real time. To deal with the limitation of the available VC methods, potential global methods to identify physical and kinematic characteristics in real time states are investigated. Vehicular Ad Hoc Networks (VANETs) are networks of intelligent interconnected vehicles that can provide traffic parameters such as type, velocity, direction, and position of each vehicle in a real time manner. In this study, VANETs are introduced for VC and their capabilities, which can be used for the above purpose, are presented from the available literature. To the best of the authors’ knowledge, this is the first study that introduces VANETs for VC purposes. Finally, a comparison is conducted that shows that VANETs outperform the conventional techniques

    A Review on Vehicle Classification and Potential Use of Smart Vehicle-Assisted Techniques

    Get PDF
    Vehicle classification (VC) is an underlying approach in an intelligent transportation system and is widely used in various applications like the monitoring of traffic flow, automated parking systems, and security enforcement. The existing VC methods generally have a local nature and can classify the vehicles if the target vehicle passes through fixed sensors, passes through the short-range coverage monitoring area, or a hybrid of these methods. Using global positioning system (GPS) can provide reliable global information regarding kinematic characteristics; however, the methods lack information about the physical parameter of vehicles. Furthermore, in the available studies, smartphone or portable GPS apparatuses are used as the source of the extraction vehicle’s kinematic characteristics, which are not dependable for the tracking and classification of vehicles in real time. To deal with the limitation of the available VC methods, potential global methods to identify physical and kinematic characteristics in real time states are investigated. Vehicular Ad Hoc Networks (VANETs) are networks of intelligent interconnected vehicles that can provide traffic parameters such as type, velocity, direction, and position of each vehicle in a real time manner. In this study, VANETs are introduced for VC and their capabilities, which can be used for the above purpose, are presented from the available literature. To the best of the authors’ knowledge, this is the first study that introduces VANETs for VC purposes. Finally, a comparison is conducted that shows that VANETs outperform the conventional techniques

    Inteligentno upravljanje prometom uz dodjelu prioriteta vozilima žurnih službi

    Get PDF
    Advanced traffic management systems in city traffic (traffic light management) give possibility to give priority of passage to selected type of users, such as public transport, VIP users, and emergency services. In Republic of Croatia at present time there is no existent developed adaptive algorithms that can give priority to vehicles of Emergency services through the intersection. During this research solution to give priority passage Emergency vehicles in city traffic, benefit of such advances system will be investigated and proved with a simulation model. In same project cooperative concept will be evaluated (regarding emergency services) which includes a real time vehicle to vehicle and vehicle to infrastructure communication.Napredni sustavi upravljanja gradskom prometnom mrežom (semaforiziranim raskrižjima) omogućuju prioritetni prolazak određenom tipu korisnika kao npr. javni gradski prijevoz, VIP korisnici, žurne službe. U Republici Hrvatskoj za sada nema razrađenih adaptivnih upravljačkih algoritama prema kojima vozila žurnih službi mogu prioritetno proći raskrižjem. Kroz ovo istraživanje razmotrit će se mogućnost prioritetnog prolaska žurnih službi u gradskom prometu, te će se na temelju simulacijskog modela dokazati korist takvog unaprijeđenog sustava. Također, dodatno će se razmotriti i mogućnosti kooperativnog koncepta u odnosu na vozila žurnih službi, što uključuje komunikaciju između vozila i vozila i infrastrukturu stvarnom vremenu

    A Vision of Quantitative Imaging Technology for Validation of Advanced Flight Technologies

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    Flight-testing is traditionally an expensive but critical element in the development and ultimate validation and certification of technologies destined for future operational capabilities. Measurements obtained in relevant flight environments also provide unique opportunities to observe flow phenomenon that are often beyond the capabilities of ground testing facilities and computational tools to simulate or duplicate. However, the challenges of minimizing vehicle weight and internal complexity as well as instrumentation bandwidth limitations often restrict the ability to make high-density, in-situ measurements with discrete sensors. Remote imaging offers a potential opportunity to noninvasively obtain such flight data in a complementary fashion. The NASA Hypersonic Thermodynamic Infrared Measurements Project has demonstrated such a capability to obtain calibrated thermal imagery on a hypersonic vehicle in flight. Through the application of existing and accessible technologies, the acreage surface temperature of the Shuttle lower surface was measured during reentry. Future hypersonic cruise vehicles, launcher configurations and reentry vehicles will, however, challenge current remote imaging capability. As NASA embarks on the design and deployment of a new Space Launch System architecture for access beyond earth orbit (and the commercial sector focused on low earth orbit), an opportunity exists to implement an imagery system and its supporting infrastructure that provides sufficient flexibility to incorporate changing technology to address the future needs of the flight test community. A long term vision is offered that supports the application of advanced multi-waveband sensing technology to aid in the development of future aerospace systems and critical technologies to enable highly responsive vehicle operations across the aerospace continuum, spanning launch, reusable space access and global reach. Motivations for development of an Agency level imagery-based measurement capability to support cross cutting applications that span the Agency mission directorates as well as meeting potential needs of the commercial sector and national interests of the Intelligence, Surveillance and Reconnaissance community are explored. A recommendation is made for an assessment study to baseline current imaging technology including the identification of future mission requirements. Development of requirements fostered by the applications suggested in this paper would be used to identify technology gaps and direct roadmapping for implementation of an affordable and sustainable next generation sensor/platform system
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