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Average Level Crossing Rate and Fading Duration of Multiuser Single Relay Cooperation wireless Uplinks

China communications 2013年第4期10卷 135-143页

作者：贾向东杨龙祥朱洪波 Wireless Communications Key Laboratory of Jiangsu Province Nanjing University of Posts and Telecommunications Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education College of Computer Science and Engineering Northwest Normal University

We investigate the average Level Crossing Rate （LCR） and Average Fading Duration （AFD） of multiuser single relay co- operation wireless uplinks over independent and non-identically distributed （***.d） Ray- leigh fading channels. We first present the statistical analyses of the first-hop equivalent envelope. Then, we investigate the LCR and AFD of an equivalent end-to-end envelope, and present the closed-form solutions to LCR and AFD, which are given with integral forms. Finally, we derive the Laplace approximations of LCR and AFD as well as the upper and lower bounds. The numerical results of LCR show that the upper bound is tight. For multi user systems with different number of mobile users, the analyses indicate that the LCRs are approximately the same at the low level of the envelope. envelope However, there are at the high level of the reasonable differences among the curves of LCRs. Due to that fact that AFD is the inverse function of LCR, the results for AFD are the opposite.

关键词： wireless communications multiuseruplinks level crossing rate average fadingduration

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A Node Localization Algorithm in WSNs Based on Iterative Estimation

A Node Localization Algorithm in WSNs Based on Iterative Est...

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IEEE Information technology and Mechatronics Engineering Conference (ITOEC)

作者： Rui Jiang Qian Wu Youyun Xu Broadband Wireless Communication and Sensor Network Technology Key Lab of Ministry of Education Nanjing University of Posts and Telecommunications Jiangsu China

ISBN: (纸本)9781538653746

According to the application of range-free measurement for wireless sensor networks (WSNs), a novel localization algorithm of nodes in based on iterative centroid estimation is proposed in the paper. First, we derive the centroid of the plane enclosed by the current connected beacon nodes as well as the received signal strength (RSSI) between target and beacon nodes. Then, we replace the farthest beacon node from the target node with the centroid node we derive in order to narrow the area of the plane enclosed by the connected beacon nodes and improve the location accuracy through multiple iterations. Judging from the simulation results, the proposed algorithm presents decent results of all indications and is thus eligible for localization in WSNs.

关键词： wireless sensor networks Measurement errors Signal to noise ratio Mathematical model Classification algorithms Estimation Approximation algorithms

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A Reliable Hand Tracking Method Using Kinect

A Reliable Hand Tracking Method Using Kinect

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International Conference on Image, Vision and Computing (ICIVC)

作者： Qinyu Lin Jianxin Chen Jiangyi Zhang Ling Yao Ministry of Education Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (纸本)9781728123264

Hand tracking has been focused over years in the field of human-computer interaction. But there are still some challenges such as reliability and accuracy due to the highly articulated and deformable of hand. In this paper we propose a real time hand tracking method with the depth information of the Kinect sensor. In this method, we preprocessed the depth information with a pixel filter to deal with the noise. Then we isolated the hand region from the depth image by using the KCF (Kernelized Correlation Filters) to the confined minimum depth area, which can release the limitation of hand movement range. Then the forearm region is segmented with assistance of PCA (Principle Component Analysis). And, to accurately locate the fingertip position, we integrate the maximum geodesic distance to hand centroid into EIC (Extended Inscribed Circle). And by labelling each finger to avoid mistaken fingertip determination. Experimental results verify the accuracy and reliability of our solution.

关键词： Real-time systems Human computer interaction Tracking Covariance matrices Principal component analysis Wrist Reliability

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Ternary Weighted networks with Equal Quantization Levels

Ternary Weighted Networks with Equal Quantization Levels

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Asia-Pacific Conference on communications

作者： Yuanyuan Chang Xiaofu Wu Suofei Zhang Jun Yan Key Lab of Ministry of Education in Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (数字)9781728136790

ISBN: (纸本)9781728136806

Recent progress in deep convolutional neural networks has considerably changed the landscape of speech recognition, computer vision, natural language processing and so on. However, limited by the large number of parameters, the memory space and high computational complexity, it is a challenging task to deploy the deep neural network model in embedded system. To solve this problem, we propose Equal Trained Ternary Quantization (ETTQ), a ternary quantization method by improving Trained Ternary Quantization, which uses only a full-precision scaling coefficient for each layer, and quantize the weights to three levels. These positive and negative weights have same absolute values that are trainable parameters. Experiments show that the performance of ETTQ is only slightly worse than TTQ, but can converge faster and more stable during the training over CIFAR-10 and CIFAR-100 datasets.

关键词： Quantization (signal) Neural networks Training Computational modeling Solid modeling Computer vision Backpropagation

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Heart Rate Detection with the Off-the-Shelf Camera: Static to Non-Static

Heart Rate Detection with the Off-the-Shelf Camera: Static t...

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IEEE International Conference on Signal and Image Processing (ICSIP)

作者： Rui Chen Jianxin Chen LiMing Cheng XiangJun Huang Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing China

ISBN: (数字)9781728168968

ISBN: (纸本)9781728168975

Imaging photo-plethysmography (IPPG) technique has been proven to detect heart rate (HR) with a camera. Currently it might be used in a rigid scenario, such as the static subject, the short measurement distance and good illumination. In this paper, we try to relax these constraints by extending the measurement distance and applying it to the non-static subject with IPPG technique using the off-the-shelf camera. To achieve it, the landmark detection method is used to locate the facial region of interest (ROI) for the subject during movements. On this ROI, R/G/B channel signals are extracted with the spatial average of pixels. Then we use a skin appearance model (CHROME) to remove the noise, and HR is estimated from the output of the CHROME through the power spectrum. Experimental results showed that our method works effectively in both static and non-static scenarios. In static scenario, the measurement distance can extend to 4 meters, while the accuracy can reach 86% compared with the results from a finger detection equipment. In non-static scenario, our method achieve better results than previous studies.

关键词： Heart rate Current measurement Predictive models Cameras Skin Velocity measurement Motion measurement

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Variational Quantum Domain Adaptation

arXiv

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arXiv 2023年

作者： Wu, Chunhui Pei, Junhao Wu, Yihua Zhao, Shengmei Nanjing210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing210003 China

Quantum machine learning is an important application of quantum computing in the era of noisy intermediate-scale quantum devices. Domain adaptation is an effective method for addressing the distribution discrepancy problem between the training data and the real data when the neural network model is deployed. In this paper, a variational quantum domain adaptation method is proposed by using a quantum convolutional neural network, together with a gradient reversal module, and two quantum fully connected layers, named variational quantum domain adaptation (VQDA). The simulations on the local computer and IBM Quantum Experience (IBM Q) platform by Qiskit show the effectiveness of the proposed method. The results demonstrate that, compared to its classical corresponding domain adaptation method, VQDA achieves an average improvement of 4 % on the accuracy for MNIST → USPS domain transfer under the same parameter scales. Similarly, for SYNDigits → SVHN domain transfer, VQDA achieves an average improvement of 2 % on the accuracy under the same parameter scales. Copyright © 2023, The Authors. All rights reserved.

关键词： Neural network models

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Face Recognition Based on Two-stage CNN Combined with Transfer Learning

Face Recognition Based on Two-stage CNN Combined with Transf...

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International Conference on Image, Vision and Computing (ICIVC)

作者： Anqi Zhou Jianxin Chen Jie Ding Zhaolai Pan Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing China

ISBN: (纸本)9781728123264

In recent years, pattern recognition has received wide attention, especially face recognition. Research shows that traditional methods have limits in face recognition under unrestricted environment because of illumination, facial expression, pose and so on. Deep learning is chosen to solve these problems. In this paper, we propose a complete method for face recognition under unrestricted environment by deep learning. First, we design a novel two-stage convolutional neural network for face detection and alignment. The first stage of the network aims at searching face windows and their bounding box regression vector. The second stage merges facial candidates which are covered highly. Then, the network finishes the task of face detection and alignment whose outputs are face regions and the position of the five facial landmarks. It achieves great performance on angle of faces in image and obtains accuracy of 96.1% on AFW and 98.9% on FDDB. Then faces are sent to convolutional neural network for transfer learning because of limited training samples. On the testing dataset, the accuracy of face recognition reaches to 95.3%, comparing with 89.1% of the original network. What' more, our method is better than the traditional algorithms and general CNN.

关键词： Face detection Face recognition Deep learning Transfer learning Facial Recognition Transfer (Psychology) AUXILIARY FEEDWATER

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Performance analysis of two-hop-relay cellular systems with queueing capability

Performance analysis of two-hop-relay cellular systems with ...

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2015 International Conference on Information and communications Technologies, ICT 2015

作者： Lu, Weifeng Gu, Mengmeng Yang, Luxi College of Computer Nanjing University of Posts and Telecommunications Nanjing210023 China School of Information Science and Engineering SouthEast University Nanjing210096 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing Jiangsu210023 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Jiangsu Province Nanjing Jiangsu210023 China

ISBN: (纸本)9781849199940

In this paper, we present a two-hop-relay WCDMA cellular system with queueing capability, where a call can wait in the incoming buffer at the congested Base Transceiver Station (BTS) if no channel is immediately available, so as to reduce the call blocking rate. We develop an analytic model based on Multidimensional Markov chains. Then based on this model, we can obtain the average transmission rate and the queuing delay performance of the system respectively. Finally, through numerical calculation, we analyze the impact of the various parameters on the performance of the two-hop-relay WCDMA cellular system with queueing capability.

关键词： Queueing theory

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3D Modeling of the Rotationally Symmetric Objects Using Kinect

3D Modeling of the Rotationally Symmetric Objects Using Kine...

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International Conference on Image, Vision and Computing (ICIVC)

作者： Jie Ding Jianxin Chen Anqi Zhou Zhimin Chen Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing China

ISBN: (纸本)9781728123264

With the appearance of RGB-D cameras, 3D reconstruction becomes convenient. Previous studies focused on the objects with strong structural features. But for the objects with weak structure, such as rotationally symmetric objects. There is no solution. In this paper, we propose a method to model the rotationally symmetric objects. In this method, we scan the object in one view and the point cloud is projected to the 2D space. Then, we extract the boundary of the point cloud. And the Least Square is adopted to fit the extracted boundary to improve the accuracy of the boundary. At last, we rotate the fitting boundary and get the model. To verify the effectiveness of our method, several experiments have been performed to evaluate the error of the models. In addition, we use it to reconstruct the object with the hole on one side. And the results show the efficiency and computational complexity of our method.

关键词： Three-dimensional displays Fitting Computational modeling Solid modeling Mathematical model Strain Cameras

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Secure Transmission in Multicarrier Power-Splitting wireless Powered communication networks with Full-duplex Receivers

Secure Transmission in Multicarrier Power-Splitting Wireless...

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International Conference on communication technology (ICCT)

作者： Qun Li Ding Xu Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China

We consider a three-node multicarrier network consisting of a source node, a wireless powered full-duplex destination node, and an eavesdropper. The destination node is assumed to adopt the power splitting technique to coordinate information decoding and energy harvesting. To improve security performance, the destination node can send jamming signals using the harvested energy. The problem for maximizing the secrecy rate by optimizing transmit power allocation at the source node, the transmit power allocation for jamming at the destination node and the power splitting ratio at the destination node is investigated and solved by a proposed iterative algorithm. Simulation results show that the proposed algorithm outperforms other reference algorithms.

关键词： wireless communication Energy harvesting Resource management communication system security Jamming Security Radio frequency

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