The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Bo Xu - One of the best experts on this subject based on the ideXlab platform.
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Context-dependent audio-visual and temporal features fusion for TV commercial detection
2013 IEEE International Symposium on Circuits and Systems (ISCAS), 2013Co-Authors: Bo Zhang, Bo XuAbstract:Automatic TV commercial block detection is a key component of an intelligent commercial management system. Rather than utilizing exclusively audio-visual characteristics like most previous works, We have proposed a SVM-DP scheme to collaboratively exploit audio-visual and global temporal characteristics associated with commercials. Firstly, likelihood values of commercial and general program are calculated by context-dependent audio-visual features and SVM-based classifiers for each video shot. And then, these values are considered as observations of a two states markov chain, providing assistance for merging shots into blocks. At last, Minimum Duration Constraint (MDC) and Maximum Segment Constraint (MSC) which grasp the global temporal characteristics are presented to search optimal combination path with Dynamic Programming approaches, respectively. Experiments performed on real video data from TV channels in China show the effectiveness of the proposed scheme.
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ISCAS - Context-dependent audio-visual and temporal features fusion for TV commercial detection
2013 IEEE International Symposium on Circuits and Systems (ISCAS2013), 2013Co-Authors: Bo Zhang, Bo XuAbstract:Automatic TV commercial block detection is a key component of an intelligent commercial management system. Rather than utilizing exclusively audio-visual characteristics like most previous works, We have proposed a SVM-DP scheme to collaboratively exploit audio-visual and global temporal characteristics associated with commercials. Firstly, likelihood values of commercial and general program are calculated by context-dependent audio-visual features and SVM-based classifiers for each video shot. And then, these values are considered as observations of a two states markov chain, providing assistance for merging shots into blocks. At last, Minimum Duration Constraint (MDC) and Maximum Segment Constraint (MSC) which grasp the global temporal characteristics are presented to search optimal combination path with Dynamic Programming approaches, respectively. Experiments performed on real video data from TV channels in China show the effectiveness of the proposed scheme.
Bo Zhang - One of the best experts on this subject based on the ideXlab platform.
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Context-dependent audio-visual and temporal features fusion for TV commercial detection
2013 IEEE International Symposium on Circuits and Systems (ISCAS), 2013Co-Authors: Bo Zhang, Bo XuAbstract:Automatic TV commercial block detection is a key component of an intelligent commercial management system. Rather than utilizing exclusively audio-visual characteristics like most previous works, We have proposed a SVM-DP scheme to collaboratively exploit audio-visual and global temporal characteristics associated with commercials. Firstly, likelihood values of commercial and general program are calculated by context-dependent audio-visual features and SVM-based classifiers for each video shot. And then, these values are considered as observations of a two states markov chain, providing assistance for merging shots into blocks. At last, Minimum Duration Constraint (MDC) and Maximum Segment Constraint (MSC) which grasp the global temporal characteristics are presented to search optimal combination path with Dynamic Programming approaches, respectively. Experiments performed on real video data from TV channels in China show the effectiveness of the proposed scheme.
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ISCAS - Context-dependent audio-visual and temporal features fusion for TV commercial detection
2013 IEEE International Symposium on Circuits and Systems (ISCAS2013), 2013Co-Authors: Bo Zhang, Bo XuAbstract:Automatic TV commercial block detection is a key component of an intelligent commercial management system. Rather than utilizing exclusively audio-visual characteristics like most previous works, We have proposed a SVM-DP scheme to collaboratively exploit audio-visual and global temporal characteristics associated with commercials. Firstly, likelihood values of commercial and general program are calculated by context-dependent audio-visual features and SVM-based classifiers for each video shot. And then, these values are considered as observations of a two states markov chain, providing assistance for merging shots into blocks. At last, Minimum Duration Constraint (MDC) and Maximum Segment Constraint (MSC) which grasp the global temporal characteristics are presented to search optimal combination path with Dynamic Programming approaches, respectively. Experiments performed on real video data from TV channels in China show the effectiveness of the proposed scheme.
Hongbin Chen - One of the best experts on this subject based on the ideXlab platform.
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Optimal Time Allocation for Wireless Information and Power Transfer in Wireless Powered Communication Systems
IEEE Transactions on Vehicular Technology, 2016Co-Authors: Feng Zhao, Hongbin ChenAbstract:In this paper, a three-node wireless powered communication system is studied, where a power receiver harvests energy from a wireless power transmitter via wireless power transfer in the downlink and then executes information transfer in the uplink. According to this simple harvest-then-transmit protocol, the power receiver cannot harvest energy and send information simultaneously. Thus, it is necessary to investigate the tradeoff between wireless power transfer and information transfer to obtain good performance. The goal of this paper is to achieve the maximum throughput by balancing the time Duration between the wireless power transfer phase and the information transfer phase while satisfying the energy causality Constraint, the time Duration Constraint, and the quality-of-service Constraint (i.e., the symbol error rate is lower than a target value). By solving the optimization problem, an optimal time allocation can be obtained. Simulation results demonstrate the effectiveness of the solution.
Dang Van Hung - One of the best experts on this subject based on the ideXlab platform.
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Verifying linear Duration Constraints of timed automata
Lecture Notes in Computer Science, 2020Co-Authors: Pham Hong Thai, Dang Van HungAbstract:This paper aims at developing a technique for checking if a timed automaton satisfies a linear Duration Constraint on the automaton states. The Constraints are represented in the form of linear Duration invariants - a simple class of chop-free Duration Calculus (DC) formulas. We prove that linear Duration invariants of timed automata are discretisable, and reduce checking if a timed automaton satisfies a linear Duration invariant to checking if the integer timed region graph of the original automaton satisfies the same linear Duration invariant. The latter can be done with exhaustive search on graphs. In comparison to the techniques in the literature, our method is more powerful: it works for the standard semantics of DC and the class of the closed timed automata while the others cannot be applied.
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ICTAC - Verifying linear Duration Constraints of timed automata
Theoretical Aspects of Computing - ICTAC 2004, 2004Co-Authors: Pham Hong Thai, Dang Van HungAbstract:This paper aims at developing a technique for checking if a timed automaton satisfies a linear Duration Constraint on the automaton states. The Constraints are represented in the form of linear Duration invariants – a simple class of chop-free Duration Calculus (DC) formulas. We prove that linear Duration invariants of timed automata are discretisable, and reduce checking if a timed automaton satisfies a linear Duration invariant to checking if the integer timed region graph of the original automaton satisfies the same linear Duration invariant. The latter can be done with exhaustive search on graphs. In comparison to the techniques in the literature, our method is more powerful: it works for the standard semantics of DC and the class of the closed timed automata while the others cannot be applied.
Rui Zhang - One of the best experts on this subject based on the ideXlab platform.
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Trajectory Design for Cellular-Connected UAV Under Outage Duration Constraint
ICC 2019 - 2019 IEEE International Conference on Communications (ICC), 2019Co-Authors: Shuowen Zhang, Rui ZhangAbstract:In this paper, we study the trajectory design for a cellular-connected unmanned aerial vehicle (UAV) with given initial and final locations, while communicating with the ground base stations (GBSs) along its flight. We consider delay-limited communications between the UAV and its associated GBSs, where a given signal-to-noise ratio (SNR) target needs to be satisfied at the receiver. However, in practice, due to various factors such as quality-of-service (QoS) requirement, GBSs' availability and UAV mobility Constraints, the SNR target may not be met at certain time periods during the flight, each termed as an outage Duration. In this paper, we aim to optimize the UAV trajectory to minimize its mission completion time, subject to a Constraint on the maximum tolerable outage Duration in its flight. To tackle this non-convex problem, we first transform it into a more tractable form and thereby reveal some useful properties of the optimal trajectory solution. Based on these properties, we then further simplify the problem and propose efficient algorithms to check the feasibility of the problem as well as to obtain its optimal and high-quality suboptimal solutions, by leveraging graph theory and convex optimization techniques. Numerical results show that our proposed trajectory designs outperform the conventional method based on dynamic programming, in terms of both performance and complexity.
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ICC - Trajectory Design for Cellular-Connected UAV Under Outage Duration Constraint
ICC 2019 - 2019 IEEE International Conference on Communications (ICC), 2019Co-Authors: Shuowen Zhang, Rui ZhangAbstract:In this paper, we study the trajectory design for a cellular-connected unmanned aerial vehicle (UAV) with given initial and final locations, while communicating with the ground base stations (GBSs) along its flight. We consider delay-limited communications between the UAV and its associated GBSs, where a given signal-to-noise ratio (SNR) target needs to be satisfied at the receiver. However, in practice, due to various factors such as quality-of-service (QoS) requirement, GBSs' availability and UAV mobility Constraints, the SNR target may not be met at certain time periods during the flight, each termed as an outage Duration. In this paper, we aim to optimize the UAV trajectory to minimize its mission completion time, subject to a Constraint on the maximum tolerable outage Duration in its flight. To tackle this non-convex problem, we first transform it into a more tractable form and thereby reveal some useful properties of the optimal trajectory solution. Based on these properties, we then further simplify the problem and propose efficient algorithms to check the feasibility of the problem as well as to obtain its optimal and high-quality suboptimal solutions, by leveraging graph theory and convex optimization techniques. Numerical results show that our proposed trajectory designs outperform the conventional method based on dynamic programming, in terms of both performance and complexity.
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Trajectory Optimization for Cellular-Connected UAV Under Outage Duration Constraint
Journal of Communications and Information Networks, 2019Co-Authors: Shuowen Zhang, Rui ZhangAbstract:Enabling cellular access for unmanned aerial vehicles (UAVs) is a practically appealing solution to realize their high-quality communications with the ground for ensuring safe and efficient operations. In this paper, we study the trajectory design for a cellular-connected UAV that needs to fly from given initial to final locations, while communicating with the ground base stations (GBSs) subject to a minimum signal-to-noise ratio (SNR) requirement along its flight. However, due to various practical considerations such as GBSs' locations and coverage range as well as UAV's trajectory and mobility Constraints, the SNR target may not be met at certain time periods during the flight, each termed as an outage Duration. In this paper, we first propose a general outage cost function in terms of outage Durations in the flight, which includes the two commonly used metrics, namely total outage Duration and maximum outage Duration as special cases. Based on it, we formulate a UAV trajectory optimization problem to minimize its mission completion time, subject to a Constraint on the maximum tolerable outage cost. To tackle this challenging (non-convex) optimization problem, we first transform it into a tractable form and thereby reveal some useful properties of the optimal trajectory solution. Based on these properties, we further simplify the problem and propose efficient algorithms to check its feasibility and obtain optimal as well as low-complexity suboptimal solutions for it by leveraging graph theory and convex optimization techniques. Numerical results show that our proposed trajectory designs outperform that by the conventional method of dynamic programming, in terms of both performance and complexity.
