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Urban road network extraction from SAR image

Urban road network extraction from SAR image

MIPPR 2007: Remote Sensing and GIS Data Processing and Applications;and Innovative Multispectral technology and Applications

作者： Cheng, Pengxue Hu, Maolin Lab. of Intelligent Computing and Signal Processing Anhui University Hefei Anhui 230039 China Key Laboratory of Wireless Sensor Network and Communication Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China

ISBN: (纸本)9780819469540

In this paper, a technique for the extraction of roads in a high resolution synthetic aperture radar (SAR) image is presented. And a three-step method is developed for the extraction of road network from space borne SAR image: the process of the feature points, road candidate detection and connection. Roads in a high resolution SAR image can be modeled as a homogeneous dark area bounded by two parallel boundaries. Dark areas, which represent the candidate positions for roads, are extracted from the image by a Gaussian probability iteration segmentation. Possible road candidates are further processed using the morphological operators. And the roads are accurately detected by Hough Transform, and the extraction of lines is achieved by searching the peak values in Hough Space. In this process, to detect roads more accurately, post-processing, including noisy dark regions removal and false roads removal is performed. At last, Road candidate connection is carried out hierarchically according to road established models. Finally, the main road network is established from the SAR image successfully. As an example, using the ERS-2SAR image data, automatic detection of main road network in Shanghai Pudong area is presented.

关键词： Feature extraction

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Multichannel analysis for uplink heterogeneous cellular networks with flexible cell association 7

Multichannel analysis for uplink heterogeneous cellular netw...

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7th IET International Conference on wireless, Mobile and Multimedia networks, ICWMMN 2017

作者： Hu, Han Wang, Hong Yang, Jie Pan, Ziyu Jiangsu Key Lab of Wireless Communications Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Jiangsu Nanjing210003 China Communication Engineering Department Nanjing Institute of Technology Jiangsu Nanjing211167 China

ISBN: (纸本)9781785615153

In this paper, an analytical framework is developed to evaluate the uplink outage and spatial blocking performance in a multichannel heterogeneous cellular network. A weighted uplink cell association criterion and random channel reuse scheme are integrated in the considered model. The spatial locations of base stations (BSs) per tier as well as the users (UEs) are modelled as independent Poisson point processes. Because of the maximum transmit power constraint, a UE is allowed to communicate with its serving BS only when it has sufficient transmit power to support full channel inversion. With the aid of stochastic geometry, uplink spatial blocking and outage probability are respectively derived, which are validated to be quite close to the true distributions by extensive simulations. Thus, the theoretical analysis developed in this paper is valid. Then, the effect of network parameters, such as weighted factor, power cut-off threshold, and channel reuse factor, can be evaluated by quickly closed-form expressions rather than error-prone system-level simulations. © Institution of Engineering and technology. All rights reserved.

关键词： Outages

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Point matching of two images under large different resolution

Point matching of two images under large different resolutio...

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MIPPR 2007: Automatic Target Recognition and Image Analysis;and Multispectral Image Acquisition

作者： Ruan, Lei Hu, Maolin Lab. of Intelligent Computing and Signal Processing AnHui University Hefei AnHui 230039 China Key Laboratory of Wireless Sensor Network and Communication Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China

ISBN: (纸本)9780819469502

Image matching is the first step in almost any 3D computer vision task, and hence has received extensive attention. In this paper, the problem is addressed from a novel perspective, which is different from the classic stereo matching paradigm. Two images with different resolutions, that is high resolution versus low resolution are matched. Since the high resolution image only corresponds to a small region of the low resolution one, the matching task therefore consists in finding a small region in the low resolution image that can be assigned to the whole high resolution image under the plane similarity transformation, which can be defined by the local area correlation coefficient to match the interest points and rectified by similarity transform. Experiment shows that our matching algorithm can be used for scale changing up to a factor of 6. And it is successful to deal with the point matching between two images under large scale.

关键词： Image matching

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Effective Prediction Mode Decision Scheme Concerning Scene Switch

Effective Prediction Mode Decision Scheme Concerning Scene S...

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International Conference on wireless communications and Signal Processing

作者： Wei Pu Dong Hu Education Ministry's Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications

ISBN: (纸本)9781509028610

In HEVC, prediction mode decision is essential for efficient coding in applications. While many fast algorithms have been designed to reduce the candidate modes, the features of scene switch frames have seldom been considered. These frames usually have no relationship with the previous frames. Thus, intra modes should be used. In this paper, we propose a simple and efficient Hash-based algorithm. It evaluates the motion intensity of videos and can detect the occurrence of scene switch efficiently. Then chooses the best prediction modes among intra ones directly for CUs in these frames. Experimental results show that it achieves 42% to 53% time saving of the switch frame prediction. Meanwhile, as the prediction time of a switch frame is about 5 to 13 times over that of a normal continuous frame, the algorithm can achieve an outstanding improvement in the prediction of the whole video, especially when dealing with multi-scene videos.

关键词： Mode decision Intra mode Motion intensity Scene switch

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Optimal power allocation and relay selection for cognitive two-way AF relaying network

Optimal power allocation and relay selection for cognitive t...

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IET International Conference on Information Science and Control Engineering 2012 (ICISCE 2012)

作者： Ronghua Luo Zhen Yang Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications China

ISBN: (纸本)9781629939254

In an underlay cognitive two-way Amplify-and-Forward (AF) relaying network, secondary users (SUS) and primary user (PU) can share the licensed spectrum simultaneously under the interference threshold constraint. In this paper, the joint power allocation and optimal relay selection scheme is proposed for allocating radio resource on cognitive nodes effectively. For power allocation problem, the objective function is to maximize the achieved minimum Signal to Interference plus Noise Ratio (SINR) at SUS, and the constraints include the total transmit power of cognitive nodes and PU interference threshold, the optimal power allocation algorithm and a simple distributed power allocation algorithm are proposed. Furthermore, based on these results, an optimal two-way relay selection scheme is proposed. Simulation results show that the proposed joint power allocation algorithms and relay selection scheme can achieve excellent system performance.

关键词： Cognitive two-way AF relaying Interference threshold Power allocation Relay selection power splitting interference threshold Allocation Algorithm Transmitter power relay Bidirectional

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A novel channel estimation method for clipped OFDM systems based on virtual pilots

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Journal of Computational Information Systems 2012年第5期8卷 1905-1912页

作者： Xie, Yongsheng Zhou, Leilei Fu, Yaoxian Key Lab. of Wireless Sensor Network and Communication Shanghai Institute of Microsystem and Information Technology CAS Shanghai 200050 China

Data as well as pilot symbols are nonlinearly distorted due to signal clipping in practical OFDM systems. The distortion inflicted on pilot symbols has great negative effect on the channel estimation. To solve this issue, a novel iterative channel estimation algorithm based on virtual pilots is introduced for clipped OFDM systems in this paper. The algorithm iteratively estimates nonlinear distortion of data symbols, and subsequently uses it for data detection. Then part or all of the detected data symbols are used as virtual pilots to perform more precise channel re-estimation. The MSE of channel estimation is derived theoretically. Simulation results show that the proposal improves the performance remarkably with moderate complexity increase at the receiver. In particular, compared to traditional algorithm, the BER performance of this method increases by 0.3 dB. © 2012 Binary Information Press.

关键词： Peak to average power ratio

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Lorentzian hard thresholding pursuit for compressed sensing in the presence of impulsive noise 4

Lorentzian hard thresholding pursuit for compressed sensing ...

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2014 4th IEEE International Conference on Information Science and technology, ICIST 2014

作者： Yun-Yun, Ji Zhen, Yang College of Communications and Information Engineering Nanjing University of Posts and Telecommunications Nanjing Jiangsu Province210003 China Key Lab of 'Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing Jiangsu Province210003 China

ISBN: (纸本)9781479948086

The Lorentzian hard thresholding pursuit algorithm is proposed in this paper to achieve efficient reconstruction for compressed sensing in the presence of impulsive noise. In the Lorentzian hard thresholding pursuit algorithm, the minimum LL2 norm problem is solved with respect to a support which is obtained through the hard thresholding operator. The convergence and reconstruction performance of the Lorentzian hard thresholding pursuit algorithm is proved in theory in this paper. Experimental results show that the reconstruction performance of the Lorentizian hard thresholding pursuit algorithm is superior to the Lorentzian iterative hard thresholding algorithm which is also an effective algorithm for sparse reconstruction of compressed sensing in the impulsive noise environment. © 2014 IEEE.

关键词： Cost functions

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Noiseless linear amplification for the single-photon entanglement of arbitrary polarization–time-bin qudit

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Chinese Physics B 2019年第1期28卷 210-217页

作者： Ling-Quan Chen Yu-Bo Sheng Lan Zhou School of Science Nanjing University of Posts and TelecommunicationsNanjing 210003China College of Electronic and Optical Engineering&College of Microelectronics Nanjing University of Posts and TelecommunicationsNanjing 210003China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology(Ministry of Education) Nanjing University of Posts and TelecommunicationsNanjing 210003China Institute of Signal Processing Transmission Nanjing University of Posts and TelecommunicationsNanjing 210003China

Single-photon entanglement(SPE) is an important source in quantum communication. In this paper, we put forward a single-photon-assisted noiseless linear amplification protocol to protect the SPE of an arbitrary polarization–time-bin qudit from the photon transmission loss caused by the practical channel noise. After the amplification, the fidelity of the SPE can be effectively increased. Meanwhile, the encoded polarization–time-bin features of the qudit can be well preserved. The protocol can be realized under the current experimental conditions. Moreover, the amplification protocol can be extended to resist complete photon loss and partial photon loss during the photon transmission. After the amplification, we can not only increase the fidelity of the target state, but also solve the decoherence problem simultaneously. Based on the above features, our amplification protocol may be useful in future quantum communication.

关键词： single-photon entanglement noiseless linear amplification polarization–time-bin qudit complete and partial photon loss

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An improved epon upstream transmission scheme with zero inter-period idle loss

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Journal of Electronics 2011年第4期28卷 664-669页

作者： Shen, Jianhua Guo, Hongmei Mi, Zhengkun Key Lab of Broadband Wireless Communication and Sensor Network Technology (NUPT) Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

Existing Ethernet Passive Optical network (EPON) Dynamic Bandwidth Allocation (DBA) algorithms suffer from the disadvantage of idle time loss, which lower the upstream bandwidth utilization. This letter proposes an improved upstream transmission scheme with idle-time eliminating mechanism. Theoretical analysis and numerical calculation prove that the improved scheme can effectively eliminate the idle time and enhance the efficiency of upstream link utilization. Simulation results have shown that the bandwidth utilization can be raised up to 15% in heavy-load scenarios while the time delay performance of Assured Forwarding (AF) and Best Effort (BE) services are improved simultaneously. © 2011 Science Press, Institute of Electronics, CAS and Springer-Verlag Berlin Heidelberg.

关键词： Channel transmission scheme Dynamic Bandwidth Allocation (DBA) algorithm Ethernet Passive Optical network (EPON) Idle time eliminating

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International Journal of Internet Manufacturing and Services 2014年第4期3卷 341-357页

作者： Win, Nwe Nwe Htay Jianmin, Bao Gang, Cui Harbin Institute of Technology Harbin150001 China Myanmar Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing210003 China

This paper presents an efficient service similarity matchmaking method that considers complex QoS structures and attributes because sole consideration of QoS constraint becomes insufficient to handle sophisticated concepts described in service documents. To overcome the shortcoming of semantic exploitation in traditional matchmaking mechanisms, we propose a novel similarity matchmaking method that compares the equivalences between service advertisements and requirements based on three essential criteria called structure, attribute and constraint similarity. The aim is to reveal the complicated QoS semantic concepts embedded in QoS-based service documents and exploit them in matchmaking. The similarity score obtained from evaluation of each similarity criteria is also calculated and a service collection set with the highest similarity scores is provided to the user as the result. The simulation and experiment results prove that our matchmaking method surpasses the other service matchmaking and discovery techniques. Copyright © 2014 Inderscience Enterprises Ltd.

关键词： Semantics

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