The Experts below are selected from a list of 25290 Experts worldwide ranked by ideXlab platform
Quinn Jacobson - One of the best experts on this subject based on the ideXlab platform.
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enhancing privacy and accuracy in probe vehicle based traffic Monitoring via virtual trip lines
IEEE Transactions on Mobile Computing, 2012Co-Authors: Baik Hoh, Marco Gruteser, Ryan Herring, Daniel B Work, Juancarlos Herrera, Alexandre M Bayen, Murali Annavaram, Quinn Jacobson, T Iwuchukwu, Jeff BanAbstract:Traffic Monitoring using probe vehicles with GPS receivers promises significant improvements in cost, coverage, and accuracy over dedicated infrastructure systems. Current approaches, however, raise privacy concerns because they require participants to reveal their positions to an external traffic Monitoring Server. To address this challenge, we describe a system based on virtual trip lines and an associated cloaking technique, followed by another system design in which we relax the privacy requirements to maximize the accuracy of real-time traffic estimation. We introduce virtual trip lines which are geographic markers that indicate where vehicles should provide speed updates. These markers are placed to avoid specific privacy sensitive locations. They also allow aggregating and cloaking several location updates based on trip line identifiers, without knowing the actual geographic locations of these trip lines. Thus, they facilitate the design of a distributed architecture, in which no single entity has a complete knowledge of probe identities and fine-grained location information. We have implemented the system with GPS smartphone clients and conducted a controlled experiment with 100 phone-equipped drivers circling a highway segment, which was later extended into a year-long public deployment.
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virtual trip lines for distributed privacy preserving traffic Monitoring
International Conference on Mobile Systems Applications and Services, 2008Co-Authors: Baik Hoh, Marco Gruteser, Ryan Herring, Jeff Ban, Daniel B Work, Juancarlos Herrera, Alexandre M Bayen, Murali Annavaram, Quinn JacobsonAbstract:Automotive traffic Monitoring using probe vehicles with Global Positioning System receivers promises significant improvements in cost, coverage, and accuracy. Current approaches, however, raise privacy concerns because they require participants to reveal their positions to an external traffic Monitoring Server. To address this challenge, we propose a system based on virtual trip lines and an associated cloaking technique. Virtual trip lines are geographic markers that indicate where vehicles should provide location updates. These markers can be placed to avoid particularly privacy sensitive locations. They also allow aggregating and cloaking several location updates based on trip line identifiers, without knowing the actual geographic locations of these trip lines. Thus they facilitate the design of a distributed architecture, where no single entity has a complete knowledge of probe identities and fine-grained location information. We have implemented the system with GPS smartphone clients and conducted a controlled experiment with 20 phone-equipped drivers circling a highway segment. Results show that even with this low number of probe vehicles, travel time estimates can be provided with less than 15% error, and applying the cloaking techniques reduces travel time estimation accuracy by less than 5% compared to a standard periodic sampling approach.
Jeff Ban - One of the best experts on this subject based on the ideXlab platform.
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enhancing privacy and accuracy in probe vehicle based traffic Monitoring via virtual trip lines
IEEE Transactions on Mobile Computing, 2012Co-Authors: Baik Hoh, Marco Gruteser, Ryan Herring, Daniel B Work, Juancarlos Herrera, Alexandre M Bayen, Murali Annavaram, Quinn Jacobson, T Iwuchukwu, Jeff BanAbstract:Traffic Monitoring using probe vehicles with GPS receivers promises significant improvements in cost, coverage, and accuracy over dedicated infrastructure systems. Current approaches, however, raise privacy concerns because they require participants to reveal their positions to an external traffic Monitoring Server. To address this challenge, we describe a system based on virtual trip lines and an associated cloaking technique, followed by another system design in which we relax the privacy requirements to maximize the accuracy of real-time traffic estimation. We introduce virtual trip lines which are geographic markers that indicate where vehicles should provide speed updates. These markers are placed to avoid specific privacy sensitive locations. They also allow aggregating and cloaking several location updates based on trip line identifiers, without knowing the actual geographic locations of these trip lines. Thus, they facilitate the design of a distributed architecture, in which no single entity has a complete knowledge of probe identities and fine-grained location information. We have implemented the system with GPS smartphone clients and conducted a controlled experiment with 100 phone-equipped drivers circling a highway segment, which was later extended into a year-long public deployment.
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virtual trip lines for distributed privacy preserving traffic Monitoring
International Conference on Mobile Systems Applications and Services, 2008Co-Authors: Baik Hoh, Marco Gruteser, Ryan Herring, Jeff Ban, Daniel B Work, Juancarlos Herrera, Alexandre M Bayen, Murali Annavaram, Quinn JacobsonAbstract:Automotive traffic Monitoring using probe vehicles with Global Positioning System receivers promises significant improvements in cost, coverage, and accuracy. Current approaches, however, raise privacy concerns because they require participants to reveal their positions to an external traffic Monitoring Server. To address this challenge, we propose a system based on virtual trip lines and an associated cloaking technique. Virtual trip lines are geographic markers that indicate where vehicles should provide location updates. These markers can be placed to avoid particularly privacy sensitive locations. They also allow aggregating and cloaking several location updates based on trip line identifiers, without knowing the actual geographic locations of these trip lines. Thus they facilitate the design of a distributed architecture, where no single entity has a complete knowledge of probe identities and fine-grained location information. We have implemented the system with GPS smartphone clients and conducted a controlled experiment with 20 phone-equipped drivers circling a highway segment. Results show that even with this low number of probe vehicles, travel time estimates can be provided with less than 15% error, and applying the cloaking techniques reduces travel time estimation accuracy by less than 5% compared to a standard periodic sampling approach.
Baik Hoh - One of the best experts on this subject based on the ideXlab platform.
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enhancing privacy and accuracy in probe vehicle based traffic Monitoring via virtual trip lines
IEEE Transactions on Mobile Computing, 2012Co-Authors: Baik Hoh, Marco Gruteser, Ryan Herring, Daniel B Work, Juancarlos Herrera, Alexandre M Bayen, Murali Annavaram, Quinn Jacobson, T Iwuchukwu, Jeff BanAbstract:Traffic Monitoring using probe vehicles with GPS receivers promises significant improvements in cost, coverage, and accuracy over dedicated infrastructure systems. Current approaches, however, raise privacy concerns because they require participants to reveal their positions to an external traffic Monitoring Server. To address this challenge, we describe a system based on virtual trip lines and an associated cloaking technique, followed by another system design in which we relax the privacy requirements to maximize the accuracy of real-time traffic estimation. We introduce virtual trip lines which are geographic markers that indicate where vehicles should provide speed updates. These markers are placed to avoid specific privacy sensitive locations. They also allow aggregating and cloaking several location updates based on trip line identifiers, without knowing the actual geographic locations of these trip lines. Thus, they facilitate the design of a distributed architecture, in which no single entity has a complete knowledge of probe identities and fine-grained location information. We have implemented the system with GPS smartphone clients and conducted a controlled experiment with 100 phone-equipped drivers circling a highway segment, which was later extended into a year-long public deployment.
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virtual trip lines for distributed privacy preserving traffic Monitoring
International Conference on Mobile Systems Applications and Services, 2008Co-Authors: Baik Hoh, Marco Gruteser, Ryan Herring, Jeff Ban, Daniel B Work, Juancarlos Herrera, Alexandre M Bayen, Murali Annavaram, Quinn JacobsonAbstract:Automotive traffic Monitoring using probe vehicles with Global Positioning System receivers promises significant improvements in cost, coverage, and accuracy. Current approaches, however, raise privacy concerns because they require participants to reveal their positions to an external traffic Monitoring Server. To address this challenge, we propose a system based on virtual trip lines and an associated cloaking technique. Virtual trip lines are geographic markers that indicate where vehicles should provide location updates. These markers can be placed to avoid particularly privacy sensitive locations. They also allow aggregating and cloaking several location updates based on trip line identifiers, without knowing the actual geographic locations of these trip lines. Thus they facilitate the design of a distributed architecture, where no single entity has a complete knowledge of probe identities and fine-grained location information. We have implemented the system with GPS smartphone clients and conducted a controlled experiment with 20 phone-equipped drivers circling a highway segment. Results show that even with this low number of probe vehicles, travel time estimates can be provided with less than 15% error, and applying the cloaking techniques reduces travel time estimation accuracy by less than 5% compared to a standard periodic sampling approach.
Se Woon Choi - One of the best experts on this subject based on the ideXlab platform.
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a wireless mems based inclinometer sensor node for structural health Monitoring
Sensors, 2013Co-Authors: Dae Woong Ha, Hyo Seon Park, Se Woon ChoiAbstract:This paper proposes a wireless inclinometer sensor node for structural health Monitoring (SHM) that can be applied to civil engineering and building structures subjected to various loadings. The inclinometer used in this study employs a method for calculating the tilt based on the difference between the static acceleration and the acceleration due to gravity, using a micro-electro-mechanical system (MEMS)-based accelerometer. A wireless sensor node was developed through which tilt measurement data are wirelessly transmitted to a Monitoring Server. This node consists of a slave node that uses a short-distance wireless communication system (RF 2.4 GHz) and a master node that uses a long-distance telecommunication system (code division multiple access—CDMA). The communication distance limitation, which is recognized as an important issue in wireless Monitoring systems, has been resolved via these two wireless communication components. The reliability of the proposed wireless inclinometer sensor node was verified experimentally by comparing the values measured by the inclinometer and subsequently transferred to the Monitoring Server via wired and wireless transfer methods to permit a performance evaluation of the wireless communication sensor nodes. The experimental results indicated that the two systems (wired and wireless transfer systems) yielded almost identical values at a tilt angle greater than 1°, and a uniform difference was observed at a tilt angle less than 0.42° (approximately 0.0032° corresponding to 0.76% of the tilt angle, 0.42°) regardless of the tilt size. This result was deemed to be within the allowable range of measurement error in SHM. Thus, the wireless transfer system proposed in this study was experimentally verified for practical application in a structural health Monitoring system.
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an integrative structural health Monitoring system for the local global responses of a large scale irregular building under construction
Sensors, 2013Co-Authors: Hyo Seon Park, Yunah Shin, Se Woon ChoiAbstract:In this study, a practical and integrative SHM system was developed and applied to a large-scale irregular building under construction, where many challenging issues exist. In the proposed sensor network, customized energy-efficient wireless sensing units (sensor nodes, repeater nodes, and master nodes) were employed and comprehensive communications from the sensor node to the remote Monitoring Server were conducted through wireless communications. The long-term (13-month) Monitoring results recorded from a large number of sensors (75 vibrating wire strain gauges, 10 inclinometers, and three laser displacement sensors) indicated that the construction event exhibiting the largest influence on structural behavior was the removal of bents that were temporarily installed to support the free end of the cantilevered members during their construction. The safety of each member could be confirmed based on the quantitative evaluation of each response. Furthermore, it was also confirmed that the relation between these responses (i.e., deflection, strain, and inclination) can provide information about the global behavior of structures induced from specific events. Analysis of the measurement results demonstrates the proposed sensor network system is capable of automatic and real-time Monitoring and can be applied and utilized for both the safety evaluation and precise implementation of buildings under construction.
Ryan Herring - One of the best experts on this subject based on the ideXlab platform.
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enhancing privacy and accuracy in probe vehicle based traffic Monitoring via virtual trip lines
IEEE Transactions on Mobile Computing, 2012Co-Authors: Baik Hoh, Marco Gruteser, Ryan Herring, Daniel B Work, Juancarlos Herrera, Alexandre M Bayen, Murali Annavaram, Quinn Jacobson, T Iwuchukwu, Jeff BanAbstract:Traffic Monitoring using probe vehicles with GPS receivers promises significant improvements in cost, coverage, and accuracy over dedicated infrastructure systems. Current approaches, however, raise privacy concerns because they require participants to reveal their positions to an external traffic Monitoring Server. To address this challenge, we describe a system based on virtual trip lines and an associated cloaking technique, followed by another system design in which we relax the privacy requirements to maximize the accuracy of real-time traffic estimation. We introduce virtual trip lines which are geographic markers that indicate where vehicles should provide speed updates. These markers are placed to avoid specific privacy sensitive locations. They also allow aggregating and cloaking several location updates based on trip line identifiers, without knowing the actual geographic locations of these trip lines. Thus, they facilitate the design of a distributed architecture, in which no single entity has a complete knowledge of probe identities and fine-grained location information. We have implemented the system with GPS smartphone clients and conducted a controlled experiment with 100 phone-equipped drivers circling a highway segment, which was later extended into a year-long public deployment.
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virtual trip lines for distributed privacy preserving traffic Monitoring
International Conference on Mobile Systems Applications and Services, 2008Co-Authors: Baik Hoh, Marco Gruteser, Ryan Herring, Jeff Ban, Daniel B Work, Juancarlos Herrera, Alexandre M Bayen, Murali Annavaram, Quinn JacobsonAbstract:Automotive traffic Monitoring using probe vehicles with Global Positioning System receivers promises significant improvements in cost, coverage, and accuracy. Current approaches, however, raise privacy concerns because they require participants to reveal their positions to an external traffic Monitoring Server. To address this challenge, we propose a system based on virtual trip lines and an associated cloaking technique. Virtual trip lines are geographic markers that indicate where vehicles should provide location updates. These markers can be placed to avoid particularly privacy sensitive locations. They also allow aggregating and cloaking several location updates based on trip line identifiers, without knowing the actual geographic locations of these trip lines. Thus they facilitate the design of a distributed architecture, where no single entity has a complete knowledge of probe identities and fine-grained location information. We have implemented the system with GPS smartphone clients and conducted a controlled experiment with 20 phone-equipped drivers circling a highway segment. Results show that even with this low number of probe vehicles, travel time estimates can be provided with less than 15% error, and applying the cloaking techniques reduces travel time estimation accuracy by less than 5% compared to a standard periodic sampling approach.