期刊文献+
共找到6,137篇文章
< 1 2 250 >
每页显示 20 50 100
Arbitrary Decode-Forward Relaying with Re-Encoded Bits Selection Strategy for Polar Codes
1
作者 Di Guan Kai Niu Chao Dong 《China Communications》 SCIE CSCD 2023年第8期153-162,共10页
In this paper,we propose an arbitrary decode-forward single-relay scheme for finite blocklength polar codes,which can be applied to the general symmetric discrete memoryless relay channel with orthogonal receiver comp... In this paper,we propose an arbitrary decode-forward single-relay scheme for finite blocklength polar codes,which can be applied to the general symmetric discrete memoryless relay channel with orthogonal receiver components.The relay node decodes the received message.The relay node selectively re-encodes the message and transmits it to the destination node.Furthermore,in order to minimize the upper-bound of the block error probability,we propose a selection strategy to decide the proper re-encoded bit set by the relay.Simulation results are presented to illustrate the improvement in decoding performance of the proposed scheme compared to conventional relay schemes in both additive white Gaussian noise(AWGN)channel and Rayleigh fading channel(RFC). 展开更多
关键词 polar codes decode-and-forward relaying arbitrary relay channel block error rate estimation
下载PDF
Higher-order expansions of powered extremes of logarithmic general error distribution
2
作者 TAN Xiao-feng LI Li-hui 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第1期47-54,共8页
In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥1.Higher-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of nor... In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥1.Higher-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of normalizing constants.It is shown that M_(n)^(p),when v=1,converges to the Frechet extreme value distribution at the rate of 1/n,and if v>1 then M_(n)^(p)converges to the Gumbel extreme value distribution at the rate of(loglogn)^(2)=(log n)^(1-1/v). 展开更多
关键词 logarithmic general error distribution convergence rate higher-order expansion powered ex-treme
下载PDF
Bit Error Rate (BER) Performance Evaluation of Various Space-time Block Codes in MIMO Wireless Communications
3
作者 Sanjay Kumar Sharma Syed Naseem Ahmad 《通讯和计算机(中英文版)》 2010年第3期32-38,共7页
关键词 空时分组码 无线通信 MIMO BER 误码率 评价 性能
下载PDF
Symbol Error Rate Performance Analysis of Non-Orthogonal Multiple Access for Visible Light Communications 被引量:3
4
作者 Hongji Huang Jinyuan Wang +3 位作者 Jie Wang Jie Yang Jian Xiong Guan Gui 《China Communications》 SCIE CSCD 2017年第12期153-161,共9页
Non-orthogonal multiple access(NOMA) is considered as one of promising radio access techniques for visible light communications(VLC) in next-generation wireless communications systems.In order to provide theoretical s... Non-orthogonal multiple access(NOMA) is considered as one of promising radio access techniques for visible light communications(VLC) in next-generation wireless communications systems.In order to provide theoretical support for designing VLC-NOMA,we derive its analytic expressions for the symbol error rate(SER).Specifically,NOMA is first incorporated with appropriate VLC to establish a VLC-NOMA framework.Afterwards,mathematical expressions of the SER for the VLC-NOMA are developed.Moreover,numerical results are provided carefully to demonstrate that the proposed VLC-NOMA scheme outperforms than state-of-the-art orthogonal frequency division multiple access(OFDMA) one in terms of SER performance.Finally,relationships between the SER performance and the number of users,power allocation coefficient and semi-angle are well investigated,which can give us a scientific guide to devise the VLC-NOMA system for achieving better SER performance. 展开更多
关键词 VISIBLE light communication(VLC) non-orthogonal multiple access(NOMA) SYMBOL error rate (SER)
下载PDF
Low Bit Rate Underwater Video Image Compression and Coding Method Based on Wavelet Decomposition 被引量:3
5
作者 Yonggang He Xiongzhu Bu +1 位作者 Ming Jiang Maojun Fan 《China Communications》 SCIE CSCD 2020年第9期210-219,共10页
In view of the limited bandwidth of underwater video image transmission,a low bit rate underwater video compression coding method is proposed.Based on the preprocessing process of wavelet transform and coefficient dow... In view of the limited bandwidth of underwater video image transmission,a low bit rate underwater video compression coding method is proposed.Based on the preprocessing process of wavelet transform and coefficient down-sampling,the visual redundancy of underwater image is removed and the computational coefficients and coding bits are reduced.At the same time,combined with multi-level wavelet decomposition,inter frame motion compensation,entropy coding and other methods,according to the characteristics of different types of frame image data,reduce the number of calculations and improve the coding efficiency.The experimental results show that the reconstructed image quality can meet the visual requirements,and the average compression ratio of underwater video can meet the requirements of underwater acoustic channel transmission rate. 展开更多
关键词 low bit rate DOWN-SAMPLING wavelet decomposition underwater video coding
下载PDF
Prediction of proton-induced SEE error rates for the VATA160 ASIC 被引量:1
6
作者 Kai Xi Di Jiang +7 位作者 Shan-Shan Gao Jie Kong Hong-Yun Zhao Hai-Bo Yang Tian-Qi Liu Bin Wang Bing Ye Jie Liu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第1期88-93,共6页
We predict proton single event effect(SEE)error rates for the VATA160 ASIC chip on the Dark Matter Particle Explorer(DAMPE) to evaluate its radiation tolerance.Lacking proton test facilities,we built a Monte Carlo sim... We predict proton single event effect(SEE)error rates for the VATA160 ASIC chip on the Dark Matter Particle Explorer(DAMPE) to evaluate its radiation tolerance.Lacking proton test facilities,we built a Monte Carlo simulation tool named PRESTAGE to calculate the proton SEE cross-sections.PRESTAGE is based on the particle transport toolkit Geant4.It adopts a location-dependent strategy to derive the SEE sensitivity of the device from heavy-ion test data,which have been measured at the HI-13 tandem accelerator of the China Institute of Atomic Energy and the heavy-ion research facility in Lanzhou.The AP-8,SOLPRO,and August 1972 worst-case models are used to predict the average and peak proton fluxes on the DAMPE orbit.Calculation results show that the averaged proton SEE error rate for the VATA160 chip is approximately 2.17×10^(-5)/device/day.Worst-case error rates for the Van Allen belts and solar energetic particle events are 1-3 orders of magnitude higher than the averaged error rate. 展开更多
关键词 PROTON ASIC SINGLE EVENT effects error rates
下载PDF
Achieving high bit rate logical stochastic resonance in a bistable system by adjusting parameters 被引量:1
7
作者 杨定新 谷丰收 +2 位作者 冯国金 杨拥民 Andrew Ball 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第11期146-150,共5页
The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not ... The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not suitable for practical applications. First, we examine the responses of the bistable system with fixed parameters to different bit rate logic input signals, showing that an arbitrary high bit rate LSR in a bistable system cannot be achieved. Then, a normalized transform of the LSR bistable system is introduced through a kind of variable substitution. Based on the transform, it is found that LSR for arbitrary high bit rate logic signals in a bistable system can be achieved by adjusting the parameters of the system, setting bias value and amplifying the amplitudes of logic input signals and noise properly. Finally, the desired OR and AND logic outputs to high bit rate logic inputs in a bistable system are obtained by numerical simulations. The study might provide higher feasibility of LSR in practical engineering applications. 展开更多
关键词 logical stochastic resonance high bit rate logic gate
下载PDF
Modeling and forecasting exchange rate volatility in Bangladesh using GARCH models:a comparison based on normal and Student's t-error distribution 被引量:2
8
作者 S.M.Abdullah Salina Siddiqua +1 位作者 Muhammad Shahadat Hossain Siddiquee Nazmul Hossain 《Financial Innovation》 2017年第1期238-256,共19页
Background:Modeling exchange rate volatility has remained crucially important because of its diverse implications.This study aimed to address the issue of error distribution assumption in modeling and forecasting exch... Background:Modeling exchange rate volatility has remained crucially important because of its diverse implications.This study aimed to address the issue of error distribution assumption in modeling and forecasting exchange rate volatility between the Bangladeshi taka(BDT)and the US dollar($).Methods:Using daily exchange rates for 7 years(January 1,2008,to April 30,2015),this study attempted to model dynamics following generalized autoregressive conditional heteroscedastic(GARCH),asymmetric power ARCH(APARCH),exponential generalized autoregressive conditional heteroscedstic(EGARCH),threshold generalized autoregressive conditional heteroscedstic(TGARCH),and integrated generalized autoregressive conditional heteroscedstic(IGARCH)processes under both normal and Student’s t-distribution assumptions for errors.Results and Conclusions:It was found that,in contrast with the normal distribution,the application of Student’s t-distribution for errors helped the models satisfy the diagnostic tests and show improved forecasting accuracy.With such error distribution for out-of-sample volatility forecasting,AR(2)–GARCH(1,1)is considered the best. 展开更多
关键词 Exchange rate VOLATILITY ARCH GARCH Student’s t error distribution
下载PDF
100-112 Gbit/s complete ETDM systems based on monolithically integrated transmitter and receiver modules
9
作者 王轲 李杰 +14 位作者 Anders Djupsjbacka Marek Chaciński Urban Westergren Sergei Popov Gunnar Jacobsen Volker Hurm Robert Elvis Makon Rachid Driad Herbert Walcher Josef Rosenzweig Andreas G.Steffan G.Giorgis Mekonnen Heinz-Gunter Bach 李卓 Ari T.Friberg 《Journal of Beijing Institute of Technology》 EI CAS 2011年第3期410-414,共5页
Traditional intensity modulated two-level electrical time-division multiplexing (ETDM) transmission systems working at 100 -112 Gbit/s were investigated. The complete ETDM systems based on monolithically integrated ... Traditional intensity modulated two-level electrical time-division multiplexing (ETDM) transmission systems working at 100 -112 Gbit/s were investigated. The complete ETDM systems based on monolithically integrated transmitter and receiver modules were demonstrated with biterror-rate (BER) performance of 10-s at 107 Gbit/s, and near error-free standard forward error correction (FEC) threshold (2 × 10 -3) at 112 Gbit/s. The experiment results showed that directly modulated high-speed ETDM transmission systems with the symbol rates at 100 Gbaud and beyond were promising candidate for cost-effective 100 GbE applications and might be a preform of the next generation of Terabit/s Ethernet. 展开更多
关键词 100 Gigabit Ethernet (GbE) bit-error-rate Eye-diagram electrical time-division multiplexing (ETDM) system MODULES
下载PDF
Performance Analysis of Outage Probability and Error Rate of Square M-QAM in Mobile Wireless Communication Systems over Generalized α-μ Fading Channels with Non-Gaussian Noise
10
作者 Fares S. Aimehmadi Osamah S. Badarneh 《China Communications》 SCIE CSCD 2018年第1期62-71,共10页
This paper derives new and exact closed-form expressions for the average symbol error rate(SER) of square M-ary quadrature amplitude modulation(M-QAM) in wireless communication systems over theα-μfading channels sub... This paper derives new and exact closed-form expressions for the average symbol error rate(SER) of square M-ary quadrature amplitude modulation(M-QAM) in wireless communication systems over theα-μfading channels subject to an additive non-Gaussian noise. The obtained expressions take into account static and mobile wireless receivers. In addition, a closed-form expression for the outage probability in mobile networks is obtained. Please note that all derived expressions in this paper a valid for integer and non-integer values of the fading parameters. Analytical results are presented to study the impact of noise shaping parameter, severity of fading, and mobility on the average SER. Monte-Carlo simulations results are also provided to validate the accuracy of the analytical results. 展开更多
关键词 α-μ FADING SYMBOL error rate NON-GAUSSIAN noise random WAYPOINT mobili-ty model
下载PDF
Very Low Bit-Rate Video Coding Based on Wavelet Transform
11
作者 Hou Weidong Mo Yulong Wei Chunlong (School of Communication & Information Engineering) 《Advances in Manufacturing》 SCIE CAS 1998年第4期12-16,共5页
Two video coding schemes based on wavelet transform achieving very low bit rate are presented in this paper. The first is a hybrid motion compensated wavelet transform(MC WT)system which behaves better at very low ... Two video coding schemes based on wavelet transform achieving very low bit rate are presented in this paper. The first is a hybrid motion compensated wavelet transform(MC WT)system which behaves better at very low bit rates than the block DCT residual coder. The second is a new efficient coding system based on a simple frame differencing wavelet transform(FD WT)which performs well in both PSNR and visual quality with substantially reduced complexity. 展开更多
关键词 very low bit rate video coding wavelet transform video compression
下载PDF
Reducing the Error Rate of Drug Delivery in Hospital Pharmacies: From the Angle of Pharmacy Quality Control Circle 被引量:1
12
作者 Wang Shuling Chen Hui +1 位作者 De Xianhui Liu Linchuan 《Asian Journal of Social Pharmacy》 2019年第2期66-76,共11页
Objective To explore the effect of applying pharmacy quality control circle to reduce the error rate of drug delivery in inpatient pharmacy,and to improve the service quality of inpatient pharmacy staff.Methods Accord... Objective To explore the effect of applying pharmacy quality control circle to reduce the error rate of drug delivery in inpatient pharmacy,and to improve the service quality of inpatient pharmacy staff.Methods According to the ten standardized steps of pharmaceutical product management and Gantt chart,fishbone diagram and Plato were used to analyze the causes of drug delivery errors in hospital pharmacies,to find countermeasures and confirm the implementation effect.Results and Conclusion The error rate was reduced from 52% before implementation to 27.8%,and the target achievement rate was 100%.The staff’s understanding and application ability of pharmaceutical product circle was further enhanced.The “Training Standard for Newcomers” has reference value for hospital inpatient pharmacies and it can be promoted continuously.Pharmaceutical quality control circle can improve the quality of pharmacy services in hospitals. 展开更多
关键词 quality control circle INPATIENT PHARMACY DRUG error rate
下载PDF
Variable Bit Rate Fuzzy Control for Low Delay Video Coding
13
作者 ZHONG Min ZHOU Yimin +1 位作者 LUO Minke ZUO Wen 《ZTE Communications》 2017年第2期55-65,共11页
Rate control plays a critical role in achieving perceivable video quality under a variable bit rate,limited buffer sizes and low delay applications.Since a rate control system exhibits non-linear and unpredictable cha... Rate control plays a critical role in achieving perceivable video quality under a variable bit rate,limited buffer sizes and low delay applications.Since a rate control system exhibits non-linear and unpredictable characteristics,it is difficult to establish a very accurate rate-distortion(R-D)model and acquire effective rate control performance.Considering the excellent control ability and low computing complexity of the fuzzy logic in non-linear systems,this paper proposes a bitrate control algorithm based on a fuzzy controller,named the Fuzzy Rate Control Algorithm(FRCA),for All-Intra(AI)and low-delay(LD)video source coding.Contributions of the proposed FRCA mainly consist of four aspects.First,fuzzy logic is adopted to minimize the deviation between the actual and the target buffer size in the hypothetical reference decoder(HRD).Second,a fast lookup table is employed in fuzzy rate control,which reduces computing cost of the control process.Third,an input domain determination scheme is proposed to improve the precision of the fuzzy controller.Fourth,a novel scene change detection is introduced and integrated in the FRCA to adaptively adjust the Group-of-Pictures(GOP)length when the source content fluctuates.The FRCA can be transplanted and implemented in various industry coders.Extensive experiments show that the FRCA has accurate variable bit-rate control ability and maintains a steady buffer size during the encoding processes.Compared with the default configuration encoding under AI and LD,the proposed FRCA can achieve the target bit rates more accurately in various classical encoders. 展开更多
关键词 rate CONTROL video coding fuzzy CONTROL bit PER PIXEL rate-DISTORTION model
下载PDF
Very Low Bit Rate Video Coding Using Motion Compensated 3 D Wavelet Transform
14
作者 HOU Wei dong MO Yu long (School of Communication and Information Engineering, Shanghai University) HU Hai ping (School of Sciences, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第4期342-344,共3页
A new motion compensated 3 D wavelet transform (MC 3DWT) video coding scheme is presented in this paper. The new coding scheme has a good performance in average PSNR, compression ratio and visual quality of reconst... A new motion compensated 3 D wavelet transform (MC 3DWT) video coding scheme is presented in this paper. The new coding scheme has a good performance in average PSNR, compression ratio and visual quality of reconstructions compared with the existing 3 D wavelet transform (3DWT) coding methods and motion compensated 2 D wavelet transform (MC WT) coding method. The new MC 3DWT coding scheme is suitable for very low bit rate video coding. 展开更多
关键词 video coding very low bit rate 3 D wavelet transform motion compensation
下载PDF
3-D Wavelet Transform for Very Low Bit-Rate Video Coding
15
作者 Hou Weidong Mo Yulong Zhu Qiuyu Wei Chunlong (Shool of Communication and Information Engineering, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第2期48-51,共4页
A new improved Goh's 3 D wavelet transform(WT) coding scheme is presented in this paper. The new scheme has great advantages including a simple code structure, low computation cost and good performance in PSNR, c... A new improved Goh's 3 D wavelet transform(WT) coding scheme is presented in this paper. The new scheme has great advantages including a simple code structure, low computation cost and good performance in PSNR, compression ratios and visual quality of reconstructions, when compared to the other existing 3 D WT coding methods and the 2 D WT based coding methods. The new 3 D WT coding scheme is suitable for very low bit rate video coding. 展开更多
关键词 video coding video compression very low bit rate 3 D wavelet transform
下载PDF
Rate Control for MPEG-4 Bit Stream
16
作者 王振洲 李桂苓 《Transactions of Tianjin University》 EI CAS 2003年第4期279-282,共4页
For a very long time video processing dealt exclusively with fixed-rate sequences of rectangular shaped images. However, interest has been recently moving toward a more flexible concept in which the subject of the pro... For a very long time video processing dealt exclusively with fixed-rate sequences of rectangular shaped images. However, interest has been recently moving toward a more flexible concept in which the subject of the processing and encoding operations is a set of visual elements organized in both time and space in a flexible and arbitrarily complex way. The moving picture experts group (MPEG- 4) standard supports this concept and its verification model (VM) encoder has adopted scalable rate control (SRC) as the rate control scheme, which is based on the spatial domain and compatible with constant bit rate (CBR) and variable bit rate (VBR). In this paper,a new rate control algorithm based on the DCT domain instead of the pixel domain is presented. More-(over), macroblock level rate control scheme to compute the quantization step for each macroblock has been adopted. The experimental results show that the new algorithm can achieve a much better result than the original one in both peak signal-to-noise ratio (PSNR) and the coding bits, and that the new algorithm is more flexible than test model 5 (TM5) rate control algorithm. 展开更多
关键词 moving picture experts group verification model scalable rate control constant bit rate variable bit rate
下载PDF
Quantum Bit Error Avoidance
17
作者 A. Y. Shiekh 《Journal of Applied Mathematics and Physics》 2018年第11期2382-2386,共5页
Qubit errors might be avoided by using the quantum Zeno effect to inhibit evolution.
关键词 QUANTUM bit QUANTUM error AVOIDANCE
下载PDF
Reducing the Internal Difference Error Rate in Hospital Pharmacies:From the Angle of Quality Control Circle 被引量:1
18
作者 Wang Shuling Lei Yingzi +2 位作者 Liu Linchuan Wang Ruili He Yalan 《Asian Journal of Social Pharmacy》 2020年第2期73-82,共10页
Objective To improve the management level of pharmacy dispensing center,reduce dispensing errors and promote the safety of drug use.Methods Hospital pharmacies could be managed according to the theory of quality contr... Objective To improve the management level of pharmacy dispensing center,reduce dispensing errors and promote the safety of drug use.Methods Hospital pharmacies could be managed according to the theory of quality control circle(QCC).Based on the ten steps of QCC,the internal difference error rate in pharmacies could be reduced.Results and Conclusion The error rate of pharmacies was reduced from 2.74‰to 0.57‰,and the goal achievement rate was 108.466.Besides,the progress rate reached 84.82%.The abilities of circle members were improved,and the operation of pharmacy was more standardized.The activity of QCC is helpful to reduce the internal difference error rate,improve the operation level of pharmacy and ensure the safety of drug use. 展开更多
关键词 quality control circle(QCC) medical institution internal difference error rate
下载PDF
DESIGN ISSUES FOR BIT RATE-ADAPTIVE 3R O/E/O TRANSPONDER IN INTELLIGENT OPTICAL NETWORKS
19
作者 ZHU Xu ZENG Qing-ji +2 位作者 YANG Xu-dong LIU Feng-qing XIAO Shi-lin 《Journal of Shanghai Jiaotong university(Science)》 EI 2002年第2期215-219,共5页
This paper reported the design and implementation of a bit rate adaptive Optical Electronic Optical(O/E/O)transponder accomplishing almost full data rate transparency up to 2.5 Gb/s with 3R(Reamplifying,Reshaping and ... This paper reported the design and implementation of a bit rate adaptive Optical Electronic Optical(O/E/O)transponder accomplishing almost full data rate transparency up to 2.5 Gb/s with 3R(Reamplifying,Reshaping and Retiming)processing in electronic domain.Based on the chipsets performing clock recovery in several continuous bit rate ranges,a clock and data regenerating circuit self adaptive to the bit rate of input signal was developed.Key design issues were presented,laying stress on the functional building blocks and scheme for the bit rate adaptive retiming circuit.The experimental results show a good scalability performance. 展开更多
关键词 intelligent optical network transponder bit rate adaptive clock and data regenerating
下载PDF
Enhancement of Voice Quality and Bit-rate Reduction by Prosodic Control in G.723.1 Vocoder
20
作者 Jong-kuk KIM 《Journal of Measurement Science and Instrumentation》 CAS 2011年第2期179-183,共5页
Speech coding techniques have been studied not truly to reduce the complexity and bit rate but also to improve the sound quality. CELP type vocoder, used as standard, supports the great stead quality even low bit rate... Speech coding techniques have been studied not truly to reduce the complexity and bit rate but also to improve the sound quality. CELP type vocoder, used as standard, supports the great stead quality even low bit rate. In this paper, the preprocessing of input speech to reduce the bit rate is different from the conventional vocoder. Different kinds of parameter are used for the preprocessing compared with the other parameters to t'md the more appropriate parameter for the vocoder. The Parameters are used to synthesize the speech not to encode or decode for coding technique so we proposed the simple algorithm not to have the influence on the processing time or the computation time. The parameters in the preprocessing step are speaking rate, duration, and PSOLA technique. 展开更多
关键词 CELPocoder bit rate PSOLA technique prosodic
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部