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Vertical structure of predictability and information transport over the Northern Hemisphere
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作者 冯爱霞 王启光 +1 位作者 龚志强 封国林 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第2期661-668,共8页
Based on nonlinear prediction and information theory, vertical heterogeneity of predictability and information loss rate in geopotential height field are obtained over the Northern Hemisphere. On a seasonal-to-interan... Based on nonlinear prediction and information theory, vertical heterogeneity of predictability and information loss rate in geopotential height field are obtained over the Northern Hemisphere. On a seasonal-to-interannual time scale, the predictability is low in the lower troposphere and high in the mid-upper troposphere. However, within mid-upper troposphere over the subtropics ocean area, there is a relatively poor predictability. These conclusions also fit the seasonal time scale. Moving to the interannual time scale, the predictability becomes high in the lower troposphere and low in the mid-upper troposphere, contrary to the former case. On the whole the interannual trend is more predictable than the seasonal trend. The average information loss rate is low over the mid-east Pacific, west of North America, Atlantic and Eurasia, and the atmosphere over other places has a relatively high information loss rate on all-time scales. Two channels are found steadily over the Pacific Ocean and Atlantic Ocean in subtropics. There are also unstable channels. The four- season influence on predictability and information communication are studied. The predictability is low, no matter which season data are removed and each season plays an important role in the existence of the channels, except for the winter. The predictability and teleconnections are paramount issues in atmospheric science, and the teleconnections may be established by communication channels. So, this work is interesting since it reveals the vertical structure of predictability distribution, channel locations, and the contributions of different time scales to them and their variations under different seasons. 展开更多
关键词 geopotential height field information theory information loss rate PREDICTABILITY
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SYMMETRIC INFORMATION RATE OF CPM AND OPTIMAL DETECTOR DESIGN
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作者 Yang Zhimin Li Shiju Zhang Zhaoyang 《Journal of Electronics(China)》 2008年第3期294-299,共6页
This paper first calculates numerically the Symmetric Information Rate (SIR) of Cotinuous Phase Modulation (CPM) schemes over Additive White Gaussian Noise (AWGN) channel, modeling CPM and channel as a Memory-less Mod... This paper first calculates numerically the Symmetric Information Rate (SIR) of Cotinuous Phase Modulation (CPM) schemes over Additive White Gaussian Noise (AWGN) channel, modeling CPM and channel as a Memory-less Modulator (MM) plus a Markov Finite State Channel (FSMC), then proposes an optimal detector, which is of BCJR based Decision Feedback Detector (DFD) but non-iterative. It can achieve the SIR as the sequence length approaches infinity while the complexity is extremely low. Finally, both theoretic proof and numerical simulation are performed to show the op- timality. Simulation results show that it nearly achieves the theoretic bound and outperforms the Viterbi Detector (VD) with 2dB in low Eb/N0. 展开更多
关键词 Continuous Phase Modulation (CPM) Symmetric information Rate (SIR) Decision Feedback Detector (DFD) Additive White Gaussian Noise (AWGN)
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Coded Modulation Faster-than-Nyquist Transmission with Precoder and Channel Shortening Optimization 被引量:2
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作者 Hui Che Yong Bai 《China Communications》 SCIE CSCD 2021年第2期49-64,共16页
Faster-than-Nyquist(FTN)signaling can improve the spectrum efficiency(SE)of the transmission system.In this paper,we propose a coded modulation FTN(CM-FTN)transmission scheme with precoder and channel shortening(CS)op... Faster-than-Nyquist(FTN)signaling can improve the spectrum efficiency(SE)of the transmission system.In this paper,we propose a coded modulation FTN(CM-FTN)transmission scheme with precoder and channel shortening(CS)optimization to improve bit error rate(BER)performance and reduce the complexity of FTN equalizer.In our proposal,the information rate(IR)or spectral efficiency(SE)is employed and verified as a better performance metric for CM-FTN than the minimum Euclidian distance(MED).The precoder of CM-FTN is optimized for maximizing the IR criterion using the bare-bones particle swarm optimization(BB-PSO)algorithm.Further,a three-carrier CM-FTN system model is used to capture the broadening effect of precoder.Also targeting for the IR maximization,the inter-symbol interference(ISI)length for CS is optimized to reduce the receiver complexity without performance loss.Simulation results demonstrate that our method has a 0.6dB precoding gain compared with the nonprecoding scheme and a maximum of 87.5%of the complexity of FTN equalizer is reduced without BER loss. 展开更多
关键词 faster-than-Nyquist coded modulation information rate minimum Euclidian distance PRECODER channel shortening
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A novel index to evaluate discretization methods: A case study of flood susceptibility assessment based on random forest 被引量:2
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作者 Xianzhe Tang Takashi Machimura +2 位作者 Wei Liu Jiufeng Li Haoyuan Hong 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第6期313-325,共13页
The selection of a suitable discretization method(DM) to discretize spatially continuous variables(SCVs)is critical in ML-based natural hazard susceptibility assessment. However, few studies start to consider the infl... The selection of a suitable discretization method(DM) to discretize spatially continuous variables(SCVs)is critical in ML-based natural hazard susceptibility assessment. However, few studies start to consider the influence due to the selected DMs and how to efficiently select a suitable DM for each SCV. These issues were well addressed in this study. The information loss rate(ILR), an index based on the information entropy, seems can be used to select optimal DM for each SCV. However, the ILR fails to show the actual influence of discretization because such index only considers the total amount of information of the discretized variables departing from the original SCV. Facing this issue, we propose an index, information change rate(ICR), that focuses on the changed amount of information due to the discretization based on each cell, enabling the identification of the optimal DM. We develop a case study with Random Forest(training/testing ratio of 7 : 3) to assess flood susceptibility in Wanan County, China.The area under the curve-based and susceptibility maps-based approaches were presented to compare the ILR and ICR. The results show the ICR-based optimal DMs are more rational than the ILR-based ones in both cases. Moreover, we observed the ILR values are unnaturally small(<1%), whereas the ICR values are obviously more in line with general recognition(usually 10%–30%). The above results all demonstrate the superiority of the ICR. We consider this study fills up the existing research gaps, improving the MLbased natural hazard susceptibility assessments. 展开更多
关键词 Machine learning Natural hazards information change rate Discretization method
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Square Geometrical Shaping 128QAM Based Time Domain Hybrid Modulation in Visible Light Communication System 被引量:2
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作者 Peng Zou Yiheng Zhao +1 位作者 Fangchen Hu Nan Chi 《China Communications》 SCIE CSCD 2020年第1期163-173,共11页
We proposed two kinds of visible light communication(VLC)systems which respectively based on 64QAM/square geometrical shaping(SGS)128QAM time domain hybrid modulation scheme(SGSHY)and 64QAM/128QAM time domain hybrid m... We proposed two kinds of visible light communication(VLC)systems which respectively based on 64QAM/square geometrical shaping(SGS)128QAM time domain hybrid modulation scheme(SGSHY)and 64QAM/128QAM time domain hybrid modulation scheme(REGHY).These two systems can operate around specific forward error correction(FEC)threshold and maximize the achievable information rate(AIR)of the system.The principles of SGSHY and REGHY are proposed in detail,which has very low computation complexity compared with probabilistic shaping.The SGSHY outperforms REGHY at high peak to peak voltage(Vpp).Experimental results show that at high Vpp like 1.4V,which means the system is suffering from high nonlinear distortion,the AIR of SGSHY outperforms that of REGHY by 0.12Gb/s at the 2×10-2 FEC threshold.The AIR of the REGHY is at most 0.36Gb/s higher than that of 64QAM at 0.8V Vpp and 7%FEC threshold,while the(achievable information rate)AIR of SGSHY is at most 0.40Gb/s higher than that of 64QAM at 1.4V Vpp and 20%FEC threshold. 展开更多
关键词 SGS128QAM MPN TDHM nonlinear distortion achievable information rate
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Does Amplify-and-Forward Cooperative Relay Improve OFDM/OFDMA Ergodic Capacity? 被引量:1
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作者 HUANGFU Wei ZHANG Zhongshan +1 位作者 ZHANG Dandan LONG Keping 《China Communications》 SCIE CSCD 2014年第2期83-89,共7页
The ergodic information rate for Orthogonal Frequency-Division Multiplexing / Orthogonal Frequency-Division Multiple Access with amplify-and-forward (AF) relaying systems in the presence of frequency offsets is eval... The ergodic information rate for Orthogonal Frequency-Division Multiplexing / Orthogonal Frequency-Division Multiple Access with amplify-and-forward (AF) relaying systems in the presence of frequency offsets is evaluated. Unlike previous work, per-subcarrier adaptive power allocation is performed on each relay to optimize the system ergodic information rate. For a given frequency offset and total number of relays M, the AF ergodic information rate is proven to be a monotonically increasing function of α (the ratio of the power allocated to the source node and the total transmit power), implying that the maximum ergodic information rate can be obtained at α=1 (i.e., there is no cooperative relay). Furthermore, the proof of "cooperative relays cannot improve the AF ergodic information rate in a quasi-static wireless channel" is also provided in this letter. 展开更多
关键词 cooperation amplify-ano-forward (AF) ergodic information rate frequency offset Orthogonal Frequency-Division Multiplexing (OFDM) OrthogonalFrequency-Division Multiple Access(OFDMA)
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Debiased conversion measurements based target tracking with direction cosine measurements
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作者 LI Lifu CHENG Ting 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第6期1140-1150,共11页
Phased array radar’s measurements include two direction cosine and range measurements,which can be obtained in the direction cosine coordinates.State equation of the target is nonlinear with the measurements and in o... Phased array radar’s measurements include two direction cosine and range measurements,which can be obtained in the direction cosine coordinates.State equation of the target is nonlinear with the measurements and in order to solve the nonlinear problem,debiased conversion measurements based target tracking with direction cosine and range measurements in direction cosine coordinates named DCMKFPreDcos is proposed first in this paper,where the predicted information is introduced to calculate the converted measurement errors’statistical characteristics to eliminate the correlation between measurement noise and the converted measurement errors covariance.When range rate information can be obtained further,based on the above DCMKF-PreDcos’filtering result,the sequential filtering is adopted to process the additional range rate measurement and the DCMKF-PreDcos algorithm with extra range rate information is given.The predicted information is also introduced to calculate the involved statistical characteristics of converted measurements.The effectiveness of the proposed algorithms is shown in simulation results. 展开更多
关键词 nonlinear filtering range rate information target tracking direction cosine coordinates predicted information
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Empirical Research on Brand Spillover Effect of Agricultural Product under the Background of Product Injury Crisis
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作者 Yingying XU Xiaoming WANG Le ZHANG 《Asian Agricultural Research》 2017年第5期21-27,共7页
By referring to attribution theory,influence factor and internal mechanism of crisis brand generating two kinds of spillover effects are explored. In this paper,the influence mechanism on spillover effect is explored ... By referring to attribution theory,influence factor and internal mechanism of crisis brand generating two kinds of spillover effects are explored. In this paper,the influence mechanism on spillover effect is explored from the angles of network and industry information. Results show that high online review dispersion is easy to cause that consumer attributes the responsibility to the outside of the enterprise,while low online review dispersion is easy to cause that consumer attributes the responsibility to the inside of the enterprise; high industry base rate information is easy to cause that consumer attributes the responsibility to the outside of the enterprise,while low industry base rate information is easy to cause that consumer attributes the responsibility to the inside of the enterprise. When consumer attributes the responsibility to the outside of the enterprise,infectious network spillover is easy to occur. When consumer attributes the responsibility to the inside of the enterprise,contrast network spillover is easy to occur. Consumer's existing brand knowledge regulates the influence of online review dispersion on responsibility attribution and the influence of industry base rate information on responsibility attribution. Research result could provide effective theoretic reference and management suggestion for crisis enterprise and even whole industry responding to product injury crisis. 展开更多
关键词 Product injury crisis Online review dispersion Industry base rate information Spillover effect
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Verifiable Secret Sharing Scheme Based on the Plane Parametric Curve
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作者 Bin Li 《Applied Mathematics》 2021年第11期1021-1030,共10页
Verifiable secret sharing is a special kind of secret sharing. In this paper, A secure and efficient threshold secret sharing scheme is proposed by using the plane parametric curve on the basis of the principle of sec... Verifiable secret sharing is a special kind of secret sharing. In this paper, A secure and efficient threshold secret sharing scheme is proposed by using the plane parametric curve on the basis of the principle of secret sharing. And the performance of this threshold scheme is analyzed. The results reveal that the threshold scheme has its own advantage of one-parameter representation for a master key, and it is a perfect ideal secret sharing scheme. It can easily detect cheaters by single operation in the participants so that the probability of valid cheating is less than 1/<em>p</em> (where <em>p</em> is a large prime). 展开更多
关键词 Plane Parameter Curve Threshold Scheme Verifiable Secret Sharing Cheater information Rate Participating Members
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Reliability-based congestion pricing model under endogenous equilibrated market penetration and compliance rate of ATIS
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作者 钟绍鹏 邓卫 Bushell MAX 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第3期1155-1165,共11页
A reliability-based stochastic system optimum congestion pricing(SSOCP) model with endogenous market penetration and compliance rate in an advanced traveler information systems(ATIS) environment was proposed. All trav... A reliability-based stochastic system optimum congestion pricing(SSOCP) model with endogenous market penetration and compliance rate in an advanced traveler information systems(ATIS) environment was proposed. All travelers were divided into two classes. The first guided travelers were referred to as the equipped travelers who follow ATIS advice, while the second unguided travelers were referred to as the unequipped travelers and the equipped travelers who do not follow the ATIS advice(also referred to as non-complied travelers). Travelers were assumed to take travel time, congestion pricing, and travel time reliability into account when making travel route choice decisions. In order to arrive at on time, travelers needed to allow for a safety margin to their trip.The market penetration of ATIS was determined by a continuous increasing function of the information benefit, and the ATIS compliance rate of equipped travelers was given as the probability of the actually experienced travel costs of guided travelers less than or equal to those of unguided travelers. The analysis results could enhance our understanding of the effect of travel demand level and travel time reliability confidence level on the ATIS market penetration and compliance rate; and the effect of travel time perception variation of guided and unguided travelers on the mean travel cost savings(MTCS) of the equipped travelers, the ATIS market penetration, compliance rate, and the total network effective travel time(TNETT). 展开更多
关键词 reliability advanced traveler information systems market penetration compliance rate stochastic system optimum congestion pricing non-additive path cost
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Achievable information rate optimization in C‑band optical fber communication system
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作者 Zheng Liu Tianhua Xu +3 位作者 Ji Qi Joshua Uduagbomen Jian Zhao Tiegen Liu 《Frontiers of Optoelectronics》 EI CSCD 2023年第2期123-128,共6页
Optical fber communication networks play an important role in the global telecommunication network.However,nonlinear efects in the optical fber and transceiver noise greatly limit the performance of fber communication... Optical fber communication networks play an important role in the global telecommunication network.However,nonlinear efects in the optical fber and transceiver noise greatly limit the performance of fber communication systems.In this paper,the product of mutual information(MI)and communication bandwidth is used as the metric of the achievable information rate(AIR).The MI loss caused by the transceiver is also considered in this work,and the bit-wise MI,generalized mutual information(GMI),is used to calculate the AIR.This loss is more signifcant in the use of higher-order modulation formats.The AIR analysis is carried out in the QPSK,16QAM,64QAM and 256QAM modulation formats for the communication systems with diferent communication bandwidths and transmission distances based on the enhanced Gaussian noise(EGN)model.The paper provides suggestions for the selection of the optimal modulation format in diferent transmission scenarios. 展开更多
关键词 Optical fber communication Achievable information rate Mutual information Generalized mutual information
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The optimal information rate for graph access structures of nine participants 被引量:1
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作者 Yun SONG Zhihui LI +1 位作者 Yongming LI Ren XIN 《Frontiers of Computer Science》 SCIE EI CSCD 2015年第5期778-787,共10页
The information rate is an important metric of the performance of a secret-sharing scheme. In this paper we consider 272 non-isomorphic connected graph access structures with nine vertices and eight or nine edges, and... The information rate is an important metric of the performance of a secret-sharing scheme. In this paper we consider 272 non-isomorphic connected graph access structures with nine vertices and eight or nine edges, and either determine or bound the optimal information rate in each case. We obtain exact values for the optimal information rate for 231 cases and present a method that is able to derive information-theoretical upper bounds on the optimal information rate. Moreover, we apply some of the constructions to determine lower bounds on the information rate. Regarding information rate, we conclude with a full listing of the known optimal information rate (or bounds on the optimal information rate) for all 272 graphs access structures of nine participants. 展开更多
关键词 optimal information rate perfect secret-sharingscheme entropy method graph access structure splittingconstruction L-decomposition weighted decomposition
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“The Insider’s Guide to Beijing rates as one of the best,new,imaginative and informative guidebooks in a long time”—South China Morning Post 被引量:1
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《Beijing Review》 2008年第16期44-44,共1页
Immersion Guides,Beijing’s leading English-language publisher of guidebooks for Beijing and beyond,is proud to present the 2008 edition of the Insider’s Guide to Beijing (November 2007,ISBN: 978-7-5085-1172-6,90 yua... Immersion Guides,Beijing’s leading English-language publisher of guidebooks for Beijing and beyond,is proud to present the 2008 edition of the Insider’s Guide to Beijing (November 2007,ISBN: 978-7-5085-1172-6,90 yuan).This is not the run-of-the-mill guide- book written by travelers who spend a few harried days getting to know their destination.Combining the knowledge of 40 long-term residents, this is the guidebook that knows Beijing inside and out.Now in its fourth edition,this'Beijing Bible'(Beijing Today) is the most compre- hensive resource available for both travelers and residents. Fully updated annually to keep pace with the rate of change in Beijing,the Insider’s Guide provides readers with practical informa- 展开更多
关键词 The Insider’s Guide to Beijing rates as one of the best new imaginative and informative guidebooks in a long time South China Morning Post
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“The Insider’s Guide to Beijing rates as one of the best,new,imaginative and informative guidebooks in a long time”—South China Morning Post
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《Beijing Review》 2008年第20期44-44,共1页
Immersion Guides,Beijing’s leading English-language publisher of guidebooks for Beijing and beyond,is proud to present
关键词 The Insider’s Guide to Beijing rates as one of the best new imaginative and informative guidebooks in a long time South China Morning Post
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