Jiang Z.,Xi'an Jiaotong University |
Han J.,Xi'an Jiaotong University |
Qian C.,University of Kentucky |
Xi W.,Xi'an Jiaotong University |
And 5 more authors.
Proceedings - IEEE INFOCOM | Year: 2016
Identifying the object that attracts human visual attention is an essential function for automatic services in smart environments. However, existing solutions can compute the gaze direction without providing the distance to the target. In addition, most of them rely on special devices or infrastructure support. This paper explores the possibility of using a smartphone to detect the visual attention of a user. By applying the proposed VADS system, acquiring the location of the intended object only requires one simple action: gazing at the intended object and holding up the smartphone so that the object as well as user's face can be simultaneously captured by the front and rear cameras. We extend the current advances of computer vision to develop efficient algorithms to obtain the distance between the camera and user, the user's gaze direction, and the object's direction from camera. The object's location can then be computed by solving a trigonometric problem. VADS has been prototyped on commercial off-the-shelf (COTS) devices. Extensive evaluation results show that VADS achieves low error (about 1.5° in angle and 0.15m in distance for objects within 12m) as well as short latency. We believe that VADS enables a large variety of applications in smart environments. © 2016 IEEE.
Cheng L.,Postgraduate Team 3 ICE |
ICIME 2010 - 2010 2nd IEEE International Conference on Information Management and Engineering | Year: 2010
The Distributed Coordination Function (DCF) of IEEE 802.11 is one of most commonly used MAC protocol in channel-shared wireless network, but it can't support differentiated services among various applications. In this paper, a novel probability back-off MAC protocol is proposed to provide service differentiation as well as enhance the overall system throughput. We analyze our scheme by using a Markov Chain. The simulation results show that our scheme can properly allocate the channel capacity among stations according to different priorities and obtain a better system throughput than IEEE 802.11 DCF, furthermore, it can be adaptive to the alteration (such as proportion of priority classes, number of stations) of network, While any of the other schemes can not. © 2010 IEEE.
Song X.,Xinyang Normal University |
Li A.,Xiamen University |
Nonlinear Analysis: Real World Applications | Year: 2010
This paper establishes several criteria of stability for nonlinear differential dynamical systems relative to initial time difference by employing perturbing Lyapunov functions. The reported novel results are more easy to be tested than the existing results. As an application, these results are applied to a nonlinear dynamical system to get the stability properties relative to initial time difference. © 2009 Elsevier Ltd. All rights reserved.
Miao J.-J.,Postgraduate Team 1 ICE |
2011 International Conference on Electronics, Communications and Control, ICECC 2011 - Proceedings | Year: 2011
On the analysis of QoS control mechanism of IMS architecture in 3GPP, this paper proposed a DiffServ-based QoS control mechanism of the IMS network, using MPLS bearing technologies, from the core network and the bearer network to achieve the end to end QoS control of IMS network. © 2011 IEEE.
Han L.,Postgraduate Team 1 ICE |
Han L.,Chinese People's Liberation Army |
Proceedings of the 2012 International Conference on Industrial Control and Electronics Engineering, ICICEE 2012 | Year: 2012
In the network-centric warfare, the complete battlefield situation information and attack information for weapons can be collected and calculated by multiple sensor platforms, and the results can be distributed to the command and control systems and weapon platforms to complete target attack tasks. Track initiation is the primary problem in multi-source multi-target track processing, correct track initiation can not only reduce the calculation burden of post-processing in multi-target tracking, but also be meaningful to the discovery of interfered interesting target. Centralized algorithm first fuses the raw sensor data, and then starts the track tracing with fused points, weight the clustered sample points to fuse sample points. Clustering could be generalized from the active radar side and the passive radar side. Further more, effects caused by obstacle constraints are also discussed. © 2012 IEEE.
Chen G.,PLAUST |
Wu X.,Institution of Communication Engineering |
Zhang W.,Institution of Communication Engineering |
Zheng X.,Institution of Communication Engineering
Journal of Networks | Year: 2011
A novel cross-layer wireless resource allocation algorithm called DBMQT is proposed which distributes the resource based on dynamic buffer allocation mechanism for orthogonal frequency division multiplex access (OFDMA) system. The aim of allocation algorithm is to maximize system throughput while satisfying the QoS requirement for multi-user and multi-service. The algorithm consists of two steps. Firstly, with the assumption of a finite queue model for arrival packets, the scheme adjusts users' buffer according to dynamic buffer allocation mechanism. In the second step, a distinct scheduling priority is defined for each user integrates MAC QoS requirements, queue status and PHY Channel State Information (CSI), assuming that the power is uniformly allocated on each subcarrier. Using these scheduling priorities, a scheduling rule for mixed traffics is proposed. Simulation results indicate that the proposed algorithm can achieve better performance in terms of system throughput, packet loss rate and efficiency of the buffer than tradition algorithm under enhancing QoS guarantees for different services. © 2011 ACADEMY PUBLISHER.
Su Y.,PLAUST |
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011 - Proceedings | Year: 2011
The performance of phase-coded signals and a phase-coded signal generator based Direct Digital Synthesis(DDS) are presented in this paper. The binary phase coded waveforms are compared with polyphase coded waveforms. The comparison covers the ambiguity and autocorrection function and the simulation results are given. A realization structure of DDS is proposed. Various types of phase-coded waveforms can be easily designed using this structure by define an additional phase sequences. The realization method of other complex signals which are combined of phase-coded signal and step frequency or variable period signals are introduced. © 2011 IEEE.
Cao W.,PLAUST |
Liu A.,PLAUST |
Zhang B.,PLAUST |
Yu T.,PLAUST |
IEEE Transactions on Antennas and Propagation | Year: 2013
A novel dual-band microstrip antenna with omnidirectional circularly polarized (CP) and unidirectional CP characteristic for each band is proposed in this communication. Function of dual-band dual-mode is realized based on loading with metamaterial structure. Since the fields of the fundamental modes are most concentrated on the fringe of the radiating patch, modifying the geometry of the radiating patch has little effect on the radiation patterns of the two modes (n = 0, + 1 mode). CP property for the omnidirectional zeroth-order resonance (n = 0 mode) is achieved by employing curved branches in the radiating patch. Then a 45° inclined rectangular slot is etched in the center of the radiating patch to excite the CP property for the n = + 1 mode. A prototype is fabricated to verify the properties of the antenna. Both simulation and measurement results illustrate that this single-feed antenna is valuable in wireless communication for its low-profile, radiation pattern selectivity and CP characteristic. © 1963-2012 IEEE.
Tan X.-B.,PLAUST |
Zhang H.,PLAUST |
Yuhang Xuebao/Journal of Astronautics | Year: 2011
A system for blind modulation recognition of MPSK/MDPSK signals based on constellation recovery is proposed for non-cooperative communication applications. The system requires no prior information about the signal, and such parameters as carrier frequency, symbol rate and timing information required in the procedure of constellation recovery are estimated by use of received data samples. A phase difference method is employed to eliminate the constellation diagram diffusion caused by carrier frequency estimated offset. A subordinate function which is used to calculate subordinate value by utilizing the clustering number obtained from blind clustering of the constellation diagram is also defined in this paper, and then different MPSK/MDPSK signals can be classified by using different values of the function. Under the condition of AWGN channel, simulation proves that when SNR is above 11dB, the recognition ratio is above 90% for all kinds of signals, the ratio can achieve 100% for BPSK and 4PSK signals when SNR is above 6dB, it shows the system is effective.
Yu T.-B.,PLAUST |
ICMTCE2011 - Proceedings 2011 IEEE International Conference on Microwave Technology and Computational Electromagnetics | Year: 2011
In this paper, a S-band dual feeding capacitive disk coupled microstrip antenna has been proposed for circularly polarized operation. For the sake of understand this antenna, the characteristics according to the variation of the feeding position and size of the ground plane was investigated with the help of HFSS10 software. To verify the simulation results, the antenna has been fabricated. The measured results indicate that this antenna has an improved bandwidth and higher low angle gain, which is suitable for satellite communications. © 2011 IEEE.