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Quantum state and process tomography via adaptive measurements

science China(Physics,Mechanics & Astronomy) 2016年第10期59卷 25-32页

作者： HengYan Wang WenQiang Zheng NengKun Yu KeRen Li DaWei Lu Tao Xin Carson Li ZhengFeng Ji David Kribs Bei Zeng XinHua Peng JiangFeng Du Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics University of Science and Technology of ChinaHefei 230026China Department of Applied Physics Zhejiang University of TechnologyHangzhou 310023China Institute for Quantum Computing University of WaterlooWaterloo N2L 3G1Canada 4Department of Mathematics&Statistics University of GuelphGuelph N1G 2W1Canada Centre for Quantum Computation&Intelligent Systems Faculty of Engineering and Information TechnologyUniversity of Technology SydneySydney NSW 2007Australia State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China Department of Physics University of GuelphGuelph N1G 2W1Canada State Key Laboratory of Computer Science Institute of SoftwareChinese Academy of SciencesBeijing 100190China Canadian Institute for Advanced Research Toronto M5G 1Z8Canada

We investigate quantum state tomography(QST) for pure states and quantum process tomography(QPT) for unitary channels via adaptive measurements. For a quantum system with a d-dimensional Hilbert space, we first propose an adaptive protocol where only 2d. 1 measurement outcomes are used to accomplish the QST for all pure states. This idea is then extended to study QPT for unitary channels, where an adaptive unitary process tomography(AUPT) protocol of d2+d.1measurement outcomes is constructed for any unitary channel. We experimentally implement the AUPT protocol in a 2-qubit nuclear magnetic resonance system. We examine the performance of the AUPT protocol when applied to Hadamard gate, T gate(/8 phase gate), and controlled-NOT gate,respectively, as these gates form the universal gate set for quantum information processing purpose. As a comparison, standard QPT is also implemented for each gate. Our experimental results show that the AUPT protocol that reconstructing unitary channels via adaptive measurements significantly reduce the number of experiments required by standard QPT without considerable loss of fidelity.

关键词： quantum tomography state reconstruction nuclear magnetic resonance

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A Gaussian approach to subspace based classification of hyperspectral images

A Gaussian approach to subspace based classification of hype...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Mahdi Khodadadzadeh Lorenzo Bruzzone Jun Li Antonio Plaza Department of Information Engineering and Computer Science University of Trento Trento Italy School of Geography and Planning Sun Yat-Sen University Guangzhou China Hyperspectral Computing Laboratory University of Extremadura Cáceres Spain

Supervised classification of hyperspectral images is a challenging task due to the relatively low ratio between the number of training samples and the number of spectral channels. Subspace-based classification methods deal with this difficulty by assuming that feature vectors lie in a low-dimensional subspace. Based on the fact that a class in a hyperspectral image may be composed of a number of different groups of materials and mixture of spectral features, we suggest to estimate several lower dimensional random subspaces for the samples within each class. For subspace learning and classification, we propose to exploit the union of random subspaces in a Gaussian Mixture Model. Experimental results, conducted on two real hyperspectral data sets, indicate that the proposed method provides competitive classification results in comparison with other state-of-the-art approaches.

关键词： Hyperspectral imaging Training Covariance matrices Computational modeling Support vector machines Gaussian mixture model

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A polynomial-based pairwise key pre-distribution and node authentication protocol for WSNs

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Telkomnika (Telecommunication computing Electronics and Control) 2015年第4期13卷 1113-1120页

作者： Banaie, Fatemeh Seno, Seyed Amin Hosseini Aldmour, Ismat Budiarto, Rahmat Network Research Laboratory Department of Engineering Ferdowsi University of Mashhad Iran Smart Networked Computing Research Group College of Computer Science and Information Technology Al Baha University Saudi Arabia

Continuous advances in the areas of sensor networks have made wireless sensor networks (WSNs) attractive for a wide variety of applications, with vastly varying requirements and characteristics. As the data sensed by nodes usually contain sensitive information, adherence to data protection requirements is vital in *** paper introduces a new and robust key pre-distribution key management scheme using random polynomial functions and a matrix. The proposed mechanism significantly increases storage efficiency and enhances network resilience against node capture. The effectiveness of the mechanism is demonstrated by security analysis and comparisontothe existing schemes. © 2015 Universitas Ahmad Dahlan.

关键词： Digital storage

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On Secrecy Performance of MISO SWIPT Systems with TAS and Imperfect CSI

On Secrecy Performance of MISO SWIPT Systems with TAS and Im...

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作者： Pan, Gaofeng Lei, Hongjiang Deng, Yansha Fan, Lisheng Yang, Jing Chen, Yunfei Ding, Zhiguo Chongqing Key Laboratory of Nonlinear Circuits and Intelligent Information Processing School of Electronic and Information Engineering Southwest University Chongqing400715 China School of Computing and Communications Lancaster University LancasterLA14YW United Kingdom Chongqing Key Laboratory of Mobile Communications Technology Chongqing University of Posts and Telecommunications Chongqing400065 China Centre for Telecommunications King's College London LondonWC2R2LS United Kingdom School of Computer Science and Educational Software Guangzhou University Guangzhou510000 China Department of Electronic Engineering Shantou University Guangdong515063 China School of Information Engineering Yangzhou University Yangzhou225009 China School of Engineering University of Warwick CoventryCV47AL United Kingdom

In this paper, a multiple-input single-output (MISO) simultaneous wireless information and power transfer (SWIPT) system, including one base station (BS) equipped with multiple antennas, one desired single-antenna information receiver (IR), and N (N > 1) single-antenna energy-harvesting receivers (ERs) is considered. Assuming that the information signal to the desired IR may be eavesdropped by ERs if ERs are malicious, we investigate the secrecy performance of the target MISO SWIPT system when imperfect channel state information (CSI) is available and adopted for transmit antenna selection at the BS. Considering that each eavesdropping link experiences independent but not necessarily identically distributed Rayleigh fading, the closed-form expressions for the exact and the asymptotic secrecy outage probability, and the average secrecy capacity are derived and verified by simulations. Furthermore, the optimal power splitting factor is derived for each ER to realize the tradeoff between the energy harvesting and the information eavesdropping. Our results reveal the impact of the imperfect CSI on the secrecy performance of MISO SWIPT systems in the presence of multiple wiretap channels. © 2016 IEEE.

关键词： Energy harvesting

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Alternative multiplicative iterative method for projection matrix design in compressive images

International Journal of Signal Processing, Image Processing...

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International Journal of Signal Processing, Image Processing and Pattern Recognition 2016年第9期9卷 357-368页

作者： Shujuan, Tian Xiaoping, Fan Jingxiong, Xie Zhetao, Li Youngjune, Choi Hiroo, Sekiya School of Information Science and Engineering Central South University Changsha410075 China The College of Information Engineering Xiangtan University Xiangtan411105 China Key Laboratory of Intelligent Computing & Information Ministry of Education Xiangtan University Xiangtan411105 China Department of Information and Computer Engineering Ajou University Suwon443749 Korea Republic of Graduate School of Advanced Integration Science Chiba University Chiba263-8522 Japan

Projection matrix plays an important role in compressive sensing (CS). Small mutual coherence between a projection matrix and a sparsijying matrix is considered to enhance reconstruction performance in CS. The equiangular tight frame (ETF) was demonstrated with minimum mutual coherence in previous works. However, ETF does not exist for any dimensions. A practical solution is to make the production of a projection matrix and a sparsijying matrix become the nearest one to ETF. Here, the optimization objective is regarded as the minimization of error between them. First, a maximum-likelihood estimation model is presented to crack the minimization problem. Then an alternative multiplicative iteration method is employed to guarantee that the error will converge to the minimum efficiently. Experimental results show that the proposed method obtains smaller mutual coherence with better reconstruction performance compared to existing methods. © 2016 SERSC.

关键词： Compressed sensing

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IMPLICIT SEMANTIC TEXT RETRIEVAL AND DISTRIBUTED IMPLEMENTATION FOR RURAL MEDICAL CARE

IMPLICIT SEMANTIC TEXT RETRIEVAL AND DISTRIBUTED IMPLEMENTAT...

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2016 4th IEEE International Conference on Cloud computing and Intelligence Systems（IEEE CCIS2016）

作者： Yutong Gao Feifan Song Xiaqing Xie Xuebin Gao Department of Computer Science and Information Engineering Taipei University of Technology Key Laboratory of Trustworthy Distributed Computing and Service (BUPT) Ministry of Education School of Economics and Management Beijing University of Posts and Telecommunications Beijing University of Posts and Telecommunications Library

ISBN: (纸本)9781509012572

The current rural medical information construction is still imperfect. Large amount of medica data related to common rural disease is used at very low utilization rate. In order to improve the utilization of these data and to provide help for rural barefoot doctors and rural residents, we developed a distributed implied semantic text retrieval model and improved the weigh calculation formula of the implied semantic text retrieva based on implied semantic text retrieval and distributed computing technology. The experiment results indicate that our retrieval framework can shorten the time of text retrieval and improve the accuracy of text retrieval.

关键词： Text retrieval Retrieval model Implied semantic analysis Weight calculation Distributed

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Erratum to “An Efficient Code-Based Threshold Ring Signature Scheme with a Leader-Participant Model”

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Security and Communication Networks 2017年第1期2017卷

作者： Guomin Zhou Peng Zeng Xiaohui Yuan Siyuan Chen Kim-Kwang Raymond Choo Department of Computer and Information Technology Zhejiang Police College Hangzhou Zhejiang Province *** Shanghai Key Laboratory of Trustworthy Computing East China Normal University Shanghai *** Department of Computer Science and Engineering University of North Texas Denton TX 76203 USAunt.edu College of Information Engineering China University of Geosciences Wuhan *** Department of Information Systems and Cyber Security University of Texas at San Antonio San Antonio TX 78249 USAutsa.edu

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Fast approximate matching of binary codes with distinctive bits

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Frontiers of computer science 2015年第5期9卷 741-750页

作者： Chenggang Clarence YAN Hongtao XIE Bing ZHANG Yanping MA Qiong DAI Yizhi LIU Institute of Information Engineering Chinese Academy of Sciences National Engineering Laboratory for Information Security Technologies Beijing 100093 China Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China Department of Automation Tsinghua University Beijing 100083 China School of Physics Beijing Institute of Technology Beijing 100081 China School of Information Science and Engineering Ocean University of China Qingdao 266100 China School of Computer Science and Engineering Hunan University of Science and Technology Xiangtan 411201 China

Although the distance between binary codes can be computed fast in Hamming space, linear search is not practical for large scale datasets. Therefore attention has been paid to the efficiency of performing approximate nearest neighbor search, in which hierarchical clustering trees （HCT） are widely used. However, HCT select cluster centers randomly and build indexes with the entire binary code, this degrades search performance. In this paper, we first propose a new clustering algorithm, which chooses cluster centers on the basis of relative distances and uses a more homogeneous partition of the dataset than HCT has to build the hierarchical clustering trees. Then, we present an algorithm to compress binary codes by extracting distinctive bits according to the standard deviation of each bit. Consequently, a new index is proposed using compressed binary codes based on hierarchical decomposition of binary spaces. Experiments conducted on reference datasets and a dataset of one billion binary codes demonstrate the effectiveness and efficiency of our method.

关键词： binary codes approximate nearest neighbor search hierarchical clustering index

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MOBILE information SYSTEMS

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China Communications 2015年第12期12卷 I0002-I0003页

作者： WANG Shangguang Ching-Hsien Hsu David Taniar Patrick Hung Beijing University of Posts and Telecommunications department of computer science and information engineering at Chung Hua University Taiwan China the Faculty of Information Technology Monash UniversityAustralia University of Ontario Institute of Technology Canada the IEEE Transactions on Services Computing International Journal of Web Services Research and International Journal of Business Process and Integration Management the Information Systems Frontiers by Springer

With the popularity of mobile infrastructures providing higher bandwidth and constant connection to the network from virtually anytime and everywhere,the way people use information resources is radically *** can use mobile devices such as mobile phones,pocket PCs,laptops,etc.,to obtain services/applications which are based on the mobile

关键词：移动信息系统管理信息系统信息资源笔记本电脑基础设施移动设备掌上电脑应用程序

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Enhancing quantum control by bootstrapping a quantum processor of 12 qubits

arXiv

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arXiv 2017年

作者： Lu, Dawei Li, Keren Li, Jun Katiyar, Hemant Park, Annie Jihyun Feng, Guanru Xin, Tao Li, Hang Long, Guilu Brodutch, Aharon Baugh, Jonathan Zeng, Bei Laflamme, Raymond Department of Physics Southern University of Science and Technology Shenzhen518055 China Institute for Quantum Computing Department of Physics and Astronomy University of Waterloo WaterlooONN2L 3G1 Canada State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University Beijing100084 China Beijing Computational Science Research Center Beijing100193 China Max-Planck-Institutfür Quantenoptik GarchingD-85748 Germany Center for Quantum Information and Quantum Control Department of Physics Department of Electrical and Computer Engineering University of Toronto TorontoONM5S 3H6 Canada Department of Mathematics and Statistics University of Guelph GuelphONN1G 2W1 Canada Perimeter Institute for Theoretical Physics Waterloo ONN2L 2Y5 Canada

Accurate and efficient control of quantum systems is one of the central challenges for quantum information processing. Current state-of-the-art experiments rarely go beyond 10 qubits and in most cases demonstrate only limited control. Here we demonstrate control of a 12-qubit system, and show that the system can be employed as a quantum processor to optimize its own control sequence by using measurement-based feedback control (MQFC). The final product is a control sequence for a complex 12-qubit task: preparation of a 12-coherent state. The control sequence is about 10% more accurate than the one generated by the standard (classical) technique, showing that MQFC can correct for unknown imperfections. Apart from demonstrating a high level of control over a relatively large system, our results show that even at the 12-qubit level, a quantum processor can be a useful lab instrument. As an extension of our work, we propose a method for combining the MQFC technique with a twirling protocol, to optimize the control sequence that produces a desired Clifford gate. Copyright © 2017, The Authors. All rights reserved.

关键词： Quantum optics

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