检索结果-南通市图书馆

Group-based user pairing for virtual MIMO in LTE

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

The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 38-42页

作者： QIAN Yu fan bin ZHENG Kan Wireless Signal Processing and Network Laboratory Beijing University ofPosts and Telecommunications Beijing 100876 China

A user pairing method is proposed to improve the throughput gain of virtual multiple input multiple output （virtual MIMO） in 3G long-term evolution（LTE）. The approach taken in this study separated the user pairing into four steps： 1） the users are divided into two groups according to their signal-to-noise ratio （SNR）, and different user pairing metrics are proposed for each group; 2） the scheduler chooses a user for transmitting by a given rule; 3） the scheduler searches the pairing candidate for the selected user in each group; 4） the scheduler chooses the final pairing user from the co-group and crossover-group candidates by using a marginal utility function, to balance fairness and efficiency. The method can improve the throughput of users with high SNR, and guarantee fairness for users with low SNR, so it can be used in 3G LTE systems. The article provides both theoretical analysis and simulation results to support the idea.

关键词： virtual MIMO user pairing 3G LTE space division multiple access (SDMA)

Homography-based camera pose estimation with known gravity direction for UAV navigation

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2021年第1期64卷 133-145页

作者： Chunhui ZHAO bin fan Jinwen HU Quan PAN Zhao XU School of Automation Northwestern Polytechnical University School of Electronic Information Northwestern Polytechnical University

Relative pose estimation has become a fundamental and important problem in visual simultaneous localization and mapping. This paper statistically optimizes the solution for the homography-based relative pose estimation problem. Assuming a known gravity direction and a dominant ground plane, the homography representation in the normalized image plane enables a least squares pose estimation between two views. Furthermore, an iterative estimation method of the camera trajectory is developed for visual odometry. The accuracy and robustness of the proposed algorithm are experimentally tested on synthetic and real data in indoor and outdoor environments. Various metrics confirm the effectiveness of the proposed method in practical applications.

关键词： unmanned aerial vehicle UAV pose estimation homography least-squares estimation

Unsupervised Multi-Expert Learning Model for Underwater Image Enhancement

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 708-722页

作者： Hongmin Liu Qi Zhang Yufan Hu Hui Zeng bin fan the School of Intelligence Science and Technology and the Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China the School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China IEEE

Underwater image enhancement aims to restore a clean appearance and thus improves the quality of underwater degraded *** methods feed the whole image directly into the model for ***,they ignored that the R,G and B channels of underwater degraded images present varied degrees of degradation,due to the selective absorption for the *** address this issue,we propose an unsupervised multi-expert learning model by considering the enhancement of each color ***,an unsupervised architecture based on generative adversarial network is employed to alleviate the need for paired underwater *** on this,we design a generator,including a multi-expert encoder,a feature fusion module and a feature fusion-guided decoder,to generate the clear underwater ***,a multi-expert discriminator is proposed to verify the authenticity of the R,G and B channels,*** addition,content perceptual loss and edge loss are introduced into the loss function to further improve the content and details of the enhanced *** experiments on public datasets demonstrate that our method achieves more pleasing results in vision *** metrics(PSNR,SSIM,UIQM and UCIQE) evaluated on our enhanced images have been improved obviously.

关键词： Multi-expert learning underwater image enhancement unsupervised learning

RAMAN SPECTROSCOPIC STUDY ON THE CHAIN CONFORMATION OF ELECTROSYNTHESIZED POLY(ρ-PHENYLENE)FILMS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2005年第6期23卷 681-685页

作者： Feng-en Chen Ming-xiao Fu fan Wang bin fan Gao-quan Shi Department of Chemistry Tsinghua University Beijing 100084 Department of Chemistry Qujing Normal Institute Qujing City 655000 China

Poly（p-phenylene）（PPP） films have been electrochemically deposited on mirrorlike stainless steel （SS） electrode surfaces by direct oxidation of benzene in boron trifluoride diethyl etherate （BFEE） solutions at a constant applied potential of 1.7 V （versus Ag/AgCl）. The chain conformations of as-grown PPP films have been studied by Raman spectroscopy. The results demonstrated that high synthesis temperature favors the formation of planar PPP, and the conformation of planar PPP can be changed into torsional PPP by cooling treatment.

关键词： Poly(p-phenylene) Raman spectroscopy Conformation

Research on Services Modeling in LTE Networks

在线全文

学校读者我要写书评

暂无评论

China Communications 2016年第2期13卷 109-120页

作者： LIU Qi SHI Yameng LI Fuchang fan bin China Unicom Company Beijing 100048China School of Information Engineering Communication University of ChinaBeijing 100024China

Service modeling offers fundamental guidance to the construction and operation of mobile telecommunication networks. As the domestic LTE networks have been deployed massively, the refined LTE services model needs to be established urgently. In this paper, we firstly extract characteristic parameters of services from statistical data in 3G networks, especially in time, space and user dimension. Secondly, the development trends of LTE services are analyzed. And the refined LTE service model is established. Finally, prediction results of LTE service development in China is given, which could provide effi cient support for networks' optimization and evolution.

关键词： LTE services model refinedoperations services value

Anaerobic treatment of source-separated domestic bio-wastes with an improved upflow solid reactor at a short HRT

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2018年第4期30卷 255-264页

作者： Hongliang Wang Shikun Zhu Bo Qu Yu Zhang bin fan State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085 China University of Chinese Academy of Science Beijing 100049 China

Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demonstrated in the treatment of concentrated black water and kitchen waste. The highest methane production of 48 L/person/day was achieved at the hydraulic retention time（HRT） of 7 days, while the other measures of performance at the HRT of 8.3 days were better than at the HRT of 7 or 10 days, achieving a methane production of 43 L/person/day, removal of total chemical oxygen demand（TCOD）of 89%, removal of soluble chemical oxygen demand（SCOD） of 92%, and conversion of chemical oxygen demand（COD） to methane of 71%. It is not recommended to decrease HRT lower than 7 days due to the instability of the initial period. The concentrations of volatile fatty acids（VFAs） in the IUSR were less than 10 mg/L, indicating that the anaerobic process was stable. Sludge bed development showed that sludge bed with high microbial activity was formed in the bottom and that the precipitation zone of effluents formed should preferably occupy 30% of the height of the IUSR. The effluents of the IUSR could be used for irrigation in agriculture in combination with a settling tank accompanied by disinfection to remove solids and pathogens.

关键词： Sustainable sanitation Anaerobic treatment Source-separated domestic bio-wastes Improved upflow solid reactor

PARAMETRIC EFFECT AND NONLINEARITY PARAMETER IN BIOLOGICAL FLUIDS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Acoustics 1989年第4期8卷 341-346页

作者： Gong, Xiufen Zhu, Zheming fan, bin Nanjing Univ China

Based on the Fenlon's theory the parametric effects in fluids due to the nonlinear interaction of a low frequency pumping wave and a high frequency probing wave are analysed. The expressions of pressure amplitude of sum or difference frequency sideband and the formula of nonlinearity parameter B/A for lossy medium are derived. Theoretical calculation demonstrated, that the sideband components increase linearly with pump signal. Therefore, a method for determination of B/A is provided and the values for several biological fluids and mixtures are measured.

关键词： Biological Materials

Liquid-phase epoxidation of styrene with O_2 over alkali metal salt impregnated CoAPO-5

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2012年第1期23卷 53-56页

作者： Xiu Feng Shi Bao Ping Shi bin bin fan Rui Feng Li Institute of Special Chemicals Taiyuan University of TechnologyTaiyuan 030024China College of Chemical and Biological Engineering Taiyuan University of Science and TechnologyTaiyuan 030021China

Liquid-phase epoxidation of styrene with atmospheric O_2 was conducted over CoAPO-5 molecular *** catalytic performance of CoAPO-5 can be significantly improved by alkali metal salt impregnated on it,and styrene conversion and selectivity to styrene oxide reached 85%and 69%respectively when CsCl was impregnated on *** catalyst was recyclable and exhibited similar catalytic activity and selectivity even after three catalytic reaction cycles.

关键词： CoAPO-5 Styrene epoxidation Oxygen Alkali metal salt

Structure, Organization and Discourse：Three -dimensional Integration of Community Mobilization

在线全文

学校读者我要写书评

暂无评论

学术界 2012年第8期 268-272页

作者： fan bin Zhao Xin