检索结果-南通市图书馆

Optical true time delay pool-based beamforming and limited feedback for reconfigurable intelligent surface-empowered cloud radio access networks

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science China(information sciences) 2021年第10期64卷 88-102页

作者： Huan HUANG Xiaowen WANG Chongfu ZHANG Jie PENG Muchuan YANG Songnian FU Deming LIU Kun QIU school of information and Communication Engineering Zhongshan InstituteUniversity of Electronic Science and Technology of China school of Electronic information University of Electronic Science and Technology of ChinaZhongshan Institute school of information Engineering Guangdong University of Technology school of Optical and Electronic information Huazhong University of Science and Technology

Introducing reconfigurable intelligent surfaces(RISs) greatly improves the wireless propagation environment. Limited to feedback overheads and computing power, the low-complexity precoding and the cost-effective beamforming implementation are urgently demanded in RIS-empowered millimeter-wave cloud radio access networks(mmWave C-RANs). Herein, an optical true time delay pool-based hybrid beamforming(OTTDP-based HBF) scheme, enabling centralized analog beamforming control, is proposed for RIS-empowered mmWave C-RANs. By using codebook quantization techniques, we develop a non-iterative limited feedback(NI-LF) precoding algorithm for the RIS-empowered mmWave C-RAN using the proposed OTTDP-based HBF. In the NI-LF precoding algorithm, the complex joint optimization problem of hybrid precoding and phase-shifting of RIS is equivalently formulated as a maximum ratio transmission(MRT)problem and a sparse reconstruction problem. For an active antenna unit(AAU) equipped with eight antennas, a designed example of the proposed OTTDP is presented. Furthermore, for a RIS-empowered mmWave C-RAN at 28 GHz, the received signal-to-noise ratio(SNR) curves obtained via different precoding schemes are compared and discussed. Compared with the precoding without RIS, the proposed NI-LF precoding by using different codebooks to quantize the phase-shifting of the RIS respectively achieves 20.56, 19.55, and18.93 dB performance improvement for the user located near the 49-element RIS. Moreover, performance degradations due to limited feedback are analyzed. The computational complexity and overhead of the proposed NI-LF precoding algorithm are also given and discussed.

关键词： reconfigurable intelligent surface optical true time delay millimeter-wave cloud radio access network limited feedback

M Dwarf catalog of LAMOST general survey data release one

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2015年第8期15卷 1182-1196页

作者： Yan-Xin Guo Zhen-Ping Yi A-Li Luo You-Fen Wang Yu Bai Hai-Feng Yang Yi-Han Song Jian-Jun Chen Xiao-Yan Chen Fang Zuo Bing Du Jian-Nan Zhang Yin-Bi Li Xiao Kong Meng-Xin Wang Yue Wu Ke-Fei Wu Yong-Heng Zhao Yong Zhang Yong-Hui Hou Yue-Fei Wang Ming Yang Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences University of Chinese Academy of sciences school of Mechanical Electical & Information EngineeringShandong University at Weihai school of Computer science and Technology Taiyuan University of Science and Technology Nanjing institute of astronomical Optics & Technology National Astronomical ObservatoriesChinese Academy of Sciences

We present a spectroscopic catalog of 93 619 M dwarfs from the first data release of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST）general survey. During sample selection, M giant contamination was eliminated using2 MASS photometry and Ca H/TiO molecular indices. For each spectrum, the spectral subtype and values are provided including radial velocity, Hα equivalent width, a series of prominent molecular band indices, and the metal–sensitive parameter ζ, as well as distances and the space motions for high S/N objects. In addition, Hα emission lines are measured to examine the magnetic activity properties of M dwarfs and 7179 active ones are found. In particular, a subsample with significant variation in magnetic activity is revealed through observations from different epochs. Finally, statistical analysis for this sample is performed, including the metallicity classification, the distribution of molecular band indices and their errors.

关键词： catalogs—methods: analytical—stars: statistical—stars : late-type—stars: magnetic-activity—stars

Closed-form algorithms for computing the intersection of two subspaces

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2019年第2期30卷 245-250页

作者： YAN Fenggang LIU Shuai WANG Jun JIN Ming school of information science and Engineering Harbin Institute of Technology at Weihai

Finding the intersection of two subspaces is of great interest in many fields of signal processing. Over several decades,there have been numerous formulas discovered to solve this problem, among which the alternate projection method(APM) is the most popular one. However, APM suffers from high computational complexity, especially for real-time applications. Moreover, APM only gives the projection instead of the orthogonal basis of two given subspaces. This paper presents two alternate algorithms which have a closed form and reduced complexity as compared to the APM technique. Numerical simulations are conducted to verify the correctness and the effectiveness of the proposed methods.

关键词： orthogonal projection singular value decomposition alternate projection method (APM) intersection

Multi-user security of the tweakable Even-Mansour cipher

在线全文

学校读者我要写书评

暂无评论

science China(information sciences) 2021年第5期64卷 223-225页

作者： Ping ZHANG Qian YUAN Honggang HU Peng WANG school of Computer science Nanjing University of Posts and Telecommunications school of Economics and management Southeast University school of information science and Technology University of Science and Technology of China institute of information Engineering Chinese Academy of Sciences

Dear editor,Data security, including data privacy security and data integrity security, are usually achieved by a cryptographic algorithm. Block ciphers are widely used to design the cryptographic scheme. However, in some special environments, block ciphers are no longer applicable. A tweakable blockcipher(TBC) is an improved version of a conventional block cipher, which adds an extra input, called tweak,

关键词： information Systems and Communication Service

同方期刊数据库

THREE ASPECTS ON SOLVING QUEUING SERVICE SYSTEM IN SHANGHAI WORLD EXPO

在线全文

学校读者我要写书评

暂无评论

Journal of Systems science and Systems Engineering 2013年第3期22卷 340-361页

作者： Jifa GU Shanying XU Yong FANG Kan SHI Benfu LV Geng PENG Bo WANG Li SONG Rong XIE Academy of Mathematics and Systems science Chinese Academy of Sciences school of management University of Chinese Academy of Sciences school of management Shanghai University of Science and Technology institute of Image Communication and information Processing Shanghai Jiaotong University

This paper analyzes the queuing problem that was experienced during the Shanghai World Expo of 2010. The queuing problem will be discussed at three levels. The three levels include the physical, psychological, and social aspects of the queuing problem. The collective behavior of visitors is studied through analyzing the information from the different sources, such as, the network of electronic eyes, the evaluation platform based on mobile phone system and the Internet. A hybrid information network technology is implemented. Based on the Wuli-Shili-Renli （WSR） system methodology, a new theoretical analysis framework for the queuing problem is proposed.

关键词： Shanghai world expo queuing system psychology satisfactory

Non-monotonous Sequential Subgradient Projection Algorithm for Convex Feasibility Problem

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2016年第4期32卷 1101-1110页

作者： Ya-zheng DANG Jun-ling SUN Yan GAO school of management University of Shanghai for Science and Technology school of Mathematics and information science Henan Polytechnic University

The existing methods of projection for solving convex feasibility problem may lead to slow conver- gence when the sequences enter some narrow＂corridor＂ between two or more convex sets. In this paper, we apply a technique that may interrupt the monotonity of the constructed sequence to the sequential subgradient pro- jection algorithm to construct a nommonotonous sequential subgradient projection algorithm for solving convex feasibility problem, which can leave such corridor by taking a big step at different steps during the iteration. Under some suitable conditions, the convergence is *** also compare the numerical performance of the proposed algorithm with that of the monotonous algorithm by numerical experiments.

关键词： subgradient projection algorithm non-monotonous technique convex feasibility problem

Method for triangular fuzzy multiple attribute decision making based on two-dimensional density operator method

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2024年第1期35卷 178-185页

作者： LIN Youliang LI Wu LIU Gang HUANG Dong school of Economics and management Hunan Institute of Science and TechnologyYueyang 414000China Hunan Vocational College for Nationalities Yueyang 414000China school of information science and Engineering Hunan Institute of Science and TechnologyYueyang 414000China

Aiming at the triangular fuzzy(TF)multi-attribute decision making(MADM)problem with a preference for the distribution density of attribute(DDA),a decision making method with TF number two-dimensional density(TFTD)operator is proposed based on the density operator theory for the decision maker(DM).Firstly,a simple TF vector clustering method is proposed,which considers the feature of TF number and the geometric distance of ***,the least deviation sum of squares method is used in the program model to obtain the density weight ***,two TFTD operators are defined,and the MADM method based on the TFTD operator is ***,a numerical example is given to illustrate the superiority of this method,which can not only solve the TF MADM problem with a preference for the DDA but also help the DM make an overall comparison.

关键词： fuzzy decision making clustering density operator multi-attribute decision making(MADM)

Malware Detection Algorithm Based on the Attention Mechanism and ResNet

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2020年第6期29卷 1054-1060页

作者： WANG Lele WANG Binqiang ZHAO Peipei LIU Ruyi LIU Jiangang MIAO Qiguang institute of information Technology Information Engineering University school of Computer science and Technology Xidian University Nanjing institute of information Technology

The cost of misclassifying a malware program as normal is often higher than that of misclassifying a normal program as ***,how to improve the detection accuracy of malware programs is a very important *** paper proposes a deep learning malware program detection algorithm based on attention *** 2 Vec model is used to map the Application programming interface(API) into word vectors,and all word vectors of each sample are arranged into a matrix with the same *** this basis,residual network is used to extract features of *** features are input into the attention mechanism to learn the similarity between ***,the features are weighted with the similarity to obtain the new features with better *** new features and the original features are added element by element to obtain the sample features more suitable for ***,samples are classified by *** show that the classification effect of the proposed method is better than that of the traditional machine learning method.

关键词： application program interfaces feature extraction invasive software learning (artificial intelligence) pattern classification text analysis machine learning method API deep learning malware program detection accuracy normal program malware detection algorithm sample features word vectors application programming interface word2Vec model attention mechanism Malware program Word2Vec Residual network structure Self-attention mechanism

Joint DOA and polarization estimation for unequal power sources based on reconstructed noise subspace

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2016年第3期27卷 501-513页

作者： Yong Han Qingyuan Fang Fenggang Yan Ming Jin Xiaolin Qiao school of Electronics and information Engineering Harbin Institute of Technology school of information science and Technology Shijiazhuang Tiedao University

In most literature about joint direction of arrival（DOA） and polarization estimation, the case that sources possess different power levels is seldom discussed. However, this case exists widely in practical applications, especially in passive radar systems. In this paper, we propose a joint DOA and polarization estimation method for unequal power sources based on the reconstructed noise subspace. The invariance property of noise subspace（IPNS） to power of sources has been proved an effective method to estimate DOA of unequal power sources. We develop the IPNS method for joint DOA and polarization estimation based on a dual polarized array. Moreover, we propose an improved IPNS method based on the reconstructed noise subspace, which has higher resolution probability than the IPNS method. It is theoretically proved that the IPNS to power of sources is still valid when the eigenvalues of the noise subspace are changed artificially. Simulation results show that the resolution probability of the proposed method is enhanced compared with the methods based on the IPNS and the polarimetric multiple signal classification（MUSIC） method. Meanwhile, the proposed method has approximately the same estimation accuracy as the IPNS method for the weak source.

关键词： invariance property of noise subspace(IPNS) joint DOA and polarization estimation multiple signal classification(MUSIC) reconstruction of noise subspace unequal power sources