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A Reduced Search Soft-Output Detection Algorithm and Its Application to Turbo-Equalization
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作者 樊祥宁 窦怀宇 毕光国 《Journal of Southeast University(English Edition)》 EI CAS 2001年第1期8-12,共5页
To decrease the complexity of MAP algorithm, reduced state or reduced search techniques can be applied. In this paper we propose a reduced search soft output detection algorithm fully based on the principle of M a... To decrease the complexity of MAP algorithm, reduced state or reduced search techniques can be applied. In this paper we propose a reduced search soft output detection algorithm fully based on the principle of M algorithm for turbo equalization, which is a suboptimum version of the Lee algorithm. This algorithm is called soft output M algorithm (denoted as SO M algorithm), which applies the M strategy to both the forward recursion and the extended forward recursion of the Lee algorithm. Computer simulation results show that, by properly selecting and adjusting the breadth parameter and depth parameter during the iteration of turbo equalization, this algorithm can obtain good performance and complexity trade off. 展开更多
关键词 MAP algorithm Lee algorithm soft output M algorithm turbo equalization
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Nonlinear effect of the structured light profilometry in the phase-shifting method and error correction 被引量:3
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作者 张万祯 陈浙泊 +2 位作者 夏彬峰 林斌 曹向群 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第4期324-329,共6页
Digital structured light (SL) profilometry is increasingly used in three-dimensional (3D) measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measure... Digital structured light (SL) profilometry is increasingly used in three-dimensional (3D) measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measurement accuracy. In this paper, first, we review the nonlinear effects of the projector-camera system in the phase-shifting structured light depth measurement method. We show that high order harmonic wave components lead to phase error in the phase-shifting method. Then a practical method based on frequency domain filtering is proposed for nonlinear error reduction. By using this method, the nonlinear calibration of the SL system is not required. Moreover, both the nonlinear effects of the projector and the camera can be effectively reduced. The simulations and experiments have verified our nonlinear correction method. 展开更多
关键词 structured light profilometry depth measurement phase-shifting algorithm nonlinear effect
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Phase-shifting digital holography in image reconstruction 被引量:3
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作者 于瀛洁 周文静 +1 位作者 Yannis Orphanos Vivi Tornari 《Journal of Shanghai University(English Edition)》 CAS 2006年第1期59-64,共6页
A phase-shifting digital holography scheme developed to investigate internal defects in artworks is described. Phase-shifting is utilized to obtain a clear reconstructed object wave from a rough surface texture. A rev... A phase-shifting digital holography scheme developed to investigate internal defects in artworks is described. Phase-shifting is utilized to obtain a clear reconstructed object wave from a rough surface texture. A reverse-transform algorithm is employed to reconstruct the object wave on its original position of unknown distance or the imaging position from the object wave information on the holographic plane. To get the clearest reconstruction the exact registration of the unknown distance is determined by applying the intensity sum as the auto-focusing function, The spatial resolution of the reconstruction image is also investigated for a variety of affecting factors. Laboratory results of reconstruction images under deformation are presented. 展开更多
关键词 holographic interferometry digital holography phase-shifting technique reverse-transform algorithm auto-focusing function spatial resolution.
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Optimization of the seismic processing phase-shift plus finite-difference migration operator based on a hybrid genetic and simulated annealing algorithm 被引量:2
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作者 Luo Renze Huang Yuanyi +2 位作者 Liang Xianghao Luo Jun Cao Ying 《Petroleum Science》 SCIE CAS CSCD 2013年第2期190-194,共5页
Although the phase-shift seismic processing method has characteristics of high accuracy, good stability, high efficiency, and high-dip imaging, it is not able to adapt to strong lateral velocity variation. To overcome... Although the phase-shift seismic processing method has characteristics of high accuracy, good stability, high efficiency, and high-dip imaging, it is not able to adapt to strong lateral velocity variation. To overcome this defect, a finite-difference method in the frequency-space domain is introduced in the migration process, because it can adapt to strong lateral velocity variation and the coefficient is optimized by a hybrid genetic and simulated annealing algorithm. The two measures improve the precision of the approximation dispersion equation. Thus, the imaging effect is improved for areas of high-dip structure and strong lateral velocity variation. The migration imaging of a 2-D SEG/EAGE salt dome model proves that a better imaging effect in these areas is achieved by optimized phase-shift migration operator plus a finite-difference method based on a hybrid genetic and simulated annealing algorithm. The method proposed in this paper is better than conventional methods in imaging of areas of high-dip angle and strong lateral velocity variation. 展开更多
关键词 Migration operator phase-shift plus finite-difference hybrid algorithm genetic andsimulated annealing algorithm optimization coefficient
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Blind Equalization Algorithm Based on MCMA and DSE-CMA 被引量:2
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作者 GENG Nian XUE Ni RU Guobao 《Wuhan University Journal of Natural Sciences》 CAS 2008年第1期67-70,共4页
A new blind equalization algorithm based on the modified constant modulus algorithm (MCMA) and dithered signederror constant modulus algorithm (DSE-CMA) is proposed. This dithered signed-error MCMA (DSE-MCMA) ca... A new blind equalization algorithm based on the modified constant modulus algorithm (MCMA) and dithered signederror constant modulus algorithm (DSE-CMA) is proposed. This dithered signed-error MCMA (DSE-MCMA) can not only reduce the computational complexity, but also recover the phase rotation in the complex channel. Simulation results have verified the analysis and indicated the good property of DSE-MCMA. 展开更多
关键词 blind equalization modified constant modulus algorithm (MCMA) intersymbol interference
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Improved Algorithm of Histogram Equalization and Its Actualization 被引量:2
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作者 仲伟波 赵福军 +1 位作者 李鹏 宁书年 《Journal of China University of Mining and Technology》 2003年第1期52-54,共3页
A new improved algorithm of histogram equalization was discussed and actualized by analyzing the traditional algorithm. This improved algorithm has better effect than the traditional one, especially it is used to proc... A new improved algorithm of histogram equalization was discussed and actualized by analyzing the traditional algorithm. This improved algorithm has better effect than the traditional one, especially it is used to process poor quality images. 展开更多
关键词 IMPROVE histogram equalization algorithm GRAY
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BLIND EQUALIZATION OF MIMO SYSTEMS BASED ON ORTHOGONAL CONSTANT MODULUS ALGORITHM 被引量:1
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作者 Shi Kun Zhang Xudong 《Journal of Electronics(China)》 2006年第2期181-183,共3页
This paper investigates adaptive blind source separation and equalization for Multiple Input Multiple Output (MIMO) systems. To effectively recover input signals, remove Inter-Symbol Interference (ISI) and suppress In... This paper investigates adaptive blind source separation and equalization for Multiple Input Multiple Output (MIMO) systems. To effectively recover input signals, remove Inter-Symbol Interference (ISI) and suppress Inter-User Interference (IUI), the array input is first transformed into the signal subspace, then with the derived orthogonality between weight vectors of different input signals, a new orthogonal Constant Modulus Algorithm (CMA) is proposed. Computer simulation results illustrate the promising performance of the proposed method. Without channel identification, the proposed method can recover all the system inputs simultaneously and can be adaptive to channel changes without prior knowledge about signals. 展开更多
关键词 Multiple Input Multiple Output (MIMO) system Blind equalization Constant Modulus algorithm (CMA) ORTHOGONALITY
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An Orthogonal Wavelet Transform Fractionally Spaced Blind Equalization Algorithm Based on the Optimization of Genetic Algorithm
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作者 廖娟 郭业才 季童莹 《Defence Technology(防务技术)》 SCIE EI CAS 2011年第2期65-71,共7页
An orthogonal wavelet transform fractionally spaced blind equalization algorithm based on the optimization of genetic algorithm(WTFSE-GA) is proposed in viewof the lowconvergence rate,large steady-state mean square er... An orthogonal wavelet transform fractionally spaced blind equalization algorithm based on the optimization of genetic algorithm(WTFSE-GA) is proposed in viewof the lowconvergence rate,large steady-state mean square error and local convergence of traditional constant modulus blind equalization algorithm(CMA).The proposed algorithm can reduce the signal autocorrelation through the orthogonal wavelet transform of input signal of fractionally spaced blind equalizer,and decrease the possibility of CMA local convergence by using the global random search characteristics of genetic algorithm to optimize the equalizer weight vector.The proposed algorithm has the faster convergence rate and smaller mean square error compared with FSE and WT-FSE.The efficiency of the proposed algorithm is proved by computer simulation of underwater acoustic channels. 展开更多
关键词 information processing technique genetic algorithm orthogonal wavelet transform fractionally spaced equalizer blind equalization underwater acoustic channel
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A Variable Metric Algorithm with Broyden Rank One Modifications for Nonlinear Equality Constraints Optimization
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作者 Chunyan Hu Zhibin Zhu 《Open Journal of Optimization》 2013年第1期33-37,共5页
In this paper, a variable metric algorithm is proposed with Broyden rank one modifications for the equality constrained optimization. This method is viewed expansion in constrained optimization as the quasi-Newton met... In this paper, a variable metric algorithm is proposed with Broyden rank one modifications for the equality constrained optimization. This method is viewed expansion in constrained optimization as the quasi-Newton method to unconstrained optimization. The theoretical analysis shows that local convergence can be induced under some suitable conditions. In the end, it is established an equivalent condition of superlinear convergence. 展开更多
关键词 equalITY Constrained OPTIMIZATION Variable Metric algorithm BROYDEN RANK ONE Modification SUPERLINEAR Convergence
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Blind Equalization Using a Hybrid Algorithm of Multilayer Neural Network
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作者 梁启联 《High Technology Letters》 EI CAS 1996年第1期47-50,共4页
A novel blind equalization scheme based on multilayer neural network and Higher OrderCumulants(HOC)is proposed in the paper.The training of the neural network uses a newhybrid algorithm which has strict convex charact... A novel blind equalization scheme based on multilayer neural network and Higher OrderCumulants(HOC)is proposed in the paper.The training of the neural network uses a newhybrid algorithm which has strict convex character(after a threshold)and converges muchfaster than the CMA algorithm.The inverse channel is built on the basis of the estimatedchannel and the training of neural network.The scheme can be used in nonlinear and timevarying channel and to deal with PAM or QAM signals.Simulation results Show that it per-forms well for blind equalization. 展开更多
关键词 BLIND equalIZATION Multilayer neural network HIGHER order CUMULANTS Hybrid algorithm CONVEX CHARACTER
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The Fast Blind Equalization Algorithm with Global Convergence
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作者 LuJun LiTong 《通信学报》 EI CSCD 北大核心 1997年第3期79-82,共4页
TheFastBlindEqualizationAlgorithmwithGlobalConvergenceLuJunLiTong(InstituteofInformationandEngineeringofPLA,... TheFastBlindEqualizationAlgorithmwithGlobalConvergenceLuJunLiTong(InstituteofInformationandEngineeringofPLA,Zhengzhou450002)A... 展开更多
关键词 盲道均衡 整体收敛 均衡算法 全局最小值 信号
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Fast Fading Channel Neural Equalization Using Levenberg-Marquardt Training Algorithm and Pulse Shaping Filters
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作者 Tiago Mota Jorgean Leal Antonio Lima 《International Journal of Communications, Network and System Sciences》 2014年第2期71-74,共4页
Artificial Neural Network (ANN) equalizers have been successfully applied to mitigate Inter symbolic Interference (ISI) due to distortions introduced by linear or nonlinear communication channels. The ANN architecture... Artificial Neural Network (ANN) equalizers have been successfully applied to mitigate Inter symbolic Interference (ISI) due to distortions introduced by linear or nonlinear communication channels. The ANN architecture is chosen according to the type of ISI produced by fixed, fast or slow fading channels. In this work, we propose a combination of two techniques in order to minimize ISI yield by fast fading channels, i.e., pulse shape filtering and ANN equalizer. Levenberg-Marquardt algorithm is used to update the synaptic weights of an ANN comprise only by two recurrent perceptrons. The proposed system outperformed more complex structures such as those based on Kalman filtering approach. 展开更多
关键词 Decision Feedback equalizers Levenberg-Marquardt algorithm Pulse Shaping Recurrent Neural Networks
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Receiver-channel based adaptive blind equalization approach for GPS dynamic multipath mitigation 被引量:6
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作者 Zhao Yun Xue Xiaonan Zhang Tingfei 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第2期378-384,共7页
Aiming at mitigating multipath effect in dynamic global positioning system (GPS) satellite navigation applications, an approach based on channel blind equalization and real-time recursive least square (RLS) algori... Aiming at mitigating multipath effect in dynamic global positioning system (GPS) satellite navigation applications, an approach based on channel blind equalization and real-time recursive least square (RLS) algorithm is proposed, which is an application of the wireless communication channel equalization theory to GPS receiver tracking loops. The blind equalization mechanism builds upon the detection of the correlation distortion due to multipath channels; therefore an increase in the number of correlator channels is required compared with conventional GPS receivers. An adaptive estimator based on the real-time RLS algorithm is designed for dynamic estimation of multipath channel response. Then, the code and carrier phase receiver tracking errors are compensated by removing the estimated multipath components from the correlators' outputs. To demonstrate the capabilities of the proposed approach, this technique is integrated into a GPS software receiver connected to a navigation satellite signal simulator, thus simulations under controlled dynamic multipath scenarios can be carried out. Simulation results show that in a dynamic and fairly severe multipath environment, the proposed approach achieves simultaneously instantaneous accurate multipath channel estimation and significant multipath tracking errors reduction in both code delay and carrier phase. 展开更多
关键词 Blind equalization Correlation distortion Dynamic multipath mitigation Real-time recursive least square algorithm Satellite navigation
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Self-adjusting decision feedback equalizer for variational underwater acoustic channel environments 被引量:4
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作者 Yasong Luo Zhong Liu +1 位作者 Shengliang Hu Jingbo He 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第1期26-33,共8页
Aimed at the abominable influences to blind equaliza-tion algorithms caused by complex time-space variability existing in underwater acoustic channels, a new self-adjusting decision feedback equalization (DFE) algor... Aimed at the abominable influences to blind equaliza-tion algorithms caused by complex time-space variability existing in underwater acoustic channels, a new self-adjusting decision feedback equalization (DFE) algorithm adapting to different under-water acoustic channel environments is proposed by changing its central tap position. Besides, this new algorithm behaves faster convergence speed based on the analysis of equalizers’ working rules, which is more suitable to implement communications in dif-ferent unknown channels. Corresponding results and conclusions are validated by simulations and spot experiments. 展开更多
关键词 underwater acoustic communication equalization algorithm variable underwater acoustic channel self-adjusting.
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A Novel Sequential Soft Output Viterbi Algorithm
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作者 钱学诚 赵春明 程时昕 《Journal of Southeast University(English Edition)》 EI CAS 1999年第2期20-23,共4页
In order to fully utilize the soft decision ability of the outer decoder in a concatenated system, reliability information (called soft output) from the inner decoder or equalizer is required. In this paper, based on... In order to fully utilize the soft decision ability of the outer decoder in a concatenated system, reliability information (called soft output) from the inner decoder or equalizer is required. In this paper, based on the analysis of typical implementations of soft output VA, a novel algorithm is proposed by utilizing the property of Viterbi algorithm. Compared with the typical implementations, less processing expense is required by the new algorithm for weighting the hard decisions of VA. Meanwhile, simulation results show that, deterioration in performance of this algorithm is usually small for decoding of convolutional code and negligible for equalization. 展开更多
关键词 equalIZATION DECODING soft output Viterbi algorithm
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AN EFFICIENT FAST ENCODING ALGORITHM FOR VECTOR QUANTIZATION 被引量:1
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作者 徐润生 陆哲明 +1 位作者 许晓鸣 张卫东 《Journal of Shanghai Jiaotong university(Science)》 EI 2000年第2期23-27,32,共6页
A fast encoding algorithm was presented which made full use of two characteristics of a vector, its sum and variance. In this paper, a vector was separated into two subvectors, one is the first half of the coordinates... A fast encoding algorithm was presented which made full use of two characteristics of a vector, its sum and variance. In this paper, a vector was separated into two subvectors, one is the first half of the coordinates and the other contains the remaining coordinates. Three inequalities based on the characteristics of the sums and variances of a vector and its two subvectors were introduced to reject those codewords which are impossible to be the nearest codeword. The simulation results show that the proposed algorithm is faster than the improved equal average eaual variance nearest neighbor search (EENNS) algorithm. 展开更多
关键词 VECTOR QUANTIZATION nearest NEIGHBOR SEARCH equal AVERAGE nearest NEIGHBOR SEARCH algorithm equal AVERAGE equal variance nearest NEIGHBOR SEARCH algorithm Document code:A
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GLOBAL CONVERGENCE OF NONMONOTONIC TRUST REGION ALGORITHM FOR NONLINEAR OPTIMIZATION 被引量:1
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作者 Tong Xiaojiao 1,2 \ Zhou Shuzi 1 1 Dept. of Appl.Math.,Hunan Univ.,Changsha 41 0 0 82 .2 Dept.of Math.,Changsha Univ.of Electric Power,Changsha41 0 0 77 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2000年第2期201-210,共10页
A trust region algorithm for equality constrained optimization is given in this paper.The algorithm does not enforce strict monotonicity of the merit function for every iteration.Global convergence of the algorithm i... A trust region algorithm for equality constrained optimization is given in this paper.The algorithm does not enforce strict monotonicity of the merit function for every iteration.Global convergence of the algorithm is proved under the same conditions of usual trust region method. 展开更多
关键词 Nonmonotone algorithm equality constrains trust region method global convergence.
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VISCOSITY APPROXIMATION METHODS FOR THE SPLIT EQUALITY COMMON FIXED POINT PROBLEM OF QUASI-NONEXPANSIVE OPERATORS 被引量:1
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作者 赵静 王盛楠 《Acta Mathematica Scientia》 SCIE CSCD 2016年第5期1474-1486,共13页
Let H;, H;, H;be real Hilbert spaces, let A : H;→ H;, B : H;→ H;be two bounded linear operators. The split equality common fixed point problem(SECFP) in the infinite-dimensional Hilbert spaces introduced by Moudaf... Let H;, H;, H;be real Hilbert spaces, let A : H;→ H;, B : H;→ H;be two bounded linear operators. The split equality common fixed point problem(SECFP) in the infinite-dimensional Hilbert spaces introduced by Moudafi(Alternating CQ-algorithm for convex feasibility and split fixed-point problems. Journal of Nonlinear and Convex Analysis)is to find x ∈ F(U), y ∈ F(T) such that Ax = By,(1)where U : H;→ H;and T : H;→ H;are two nonlinear operators with nonempty fixed point sets F(U) = {x ∈ H;: Ux = x} and F(T) = {x ∈ H;: Tx = x}. Note that,by taking B = I and H;= H;in(1), we recover the split fixed point problem originally introduced in Censor and Segal. Recently, Moudafi introduced alternating CQ-algorithms and simultaneous iterative algorithms with weak convergence for the SECFP(1) of firmly quasi-nonexpansive operators. In this paper, we introduce two viscosity iterative algorithms for the SECFP(1) governed by the general class of quasi-nonexpansive operators. We prove the strong convergence of algorithms. Our results improve and extend previously discussed related problems and algorithms. 展开更多
关键词 split equality common fixed point problems quasi-nonexpansive operator strong convergence viscosity iterative algorithms Hilbert space
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TRANSFORM DOMAIN CONJUGATE GRADIENT ALGORITHM FOR ADAPTIVE FILTERING
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作者 S.C.Chan T.S.Ng 《Journal of Electronics(China)》 2000年第1期69-76,共8页
This paper proposed a new normalized transform domain conjugate gradient algorithm (NT-CGA), which applies the data independent normalized orthogonal transform technique to approximately whiten the input signal and ut... This paper proposed a new normalized transform domain conjugate gradient algorithm (NT-CGA), which applies the data independent normalized orthogonal transform technique to approximately whiten the input signal and utilises the modified conjugate gradient method to perform sample-by-sample updating of the filter weights more efficiently. Simulation results illustrated that the proposed algorithm has the ability to provide a fast convergence speed and lower steady-error compared to that of traditional least mean square algorithm (LMSA), normalized transform domain least mean square algorithm (NT- LMSA), Quasi-Newton least mean square algorithm (Q-LMSA) and time domain conjugate gradient algorithm (TD-CGA) when the input signal is heavily coloured. 展开更多
关键词 Adaptive filtering CONJUGATE GRADIENT algorithm ORTHOGONAL transform Channel equalIZATION ECHO CANCELLATION
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ALGORITHMS FOR A SYSTEM OF GENERALIZED MIXED EQUILIBRIUM PROBLEMS AND A COUNTABLE FAMILY OF SOME NONLINEAR MULTI-VALUED NONEXPANSIVE-TYPE MAPS
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作者 Ogonnaya Michael ROMANUS Ukamaka Victoria NNYABA Monday Ogudu NNAKWE 《Acta Mathematica Scientia》 SCIE CSCD 2018年第6期1805-1820,共16页
In this paper, relaxed iterative algorithms of Krasnoselskii-type and Halpern-type that approximate a solution of a system of a generalized mixed equilibrium problem anda common fixed point of a countable family of to... In this paper, relaxed iterative algorithms of Krasnoselskii-type and Halpern-type that approximate a solution of a system of a generalized mixed equilibrium problem anda common fixed point of a countable family of totally quasi-C-asymptotically nonexpansivemulti-valued maps are constructed. Strong convergence of the sequence generated by thesealgorithms is proved in uniformly smooth and strictly convex real Banach spaces with Kadec-Klee property. Furthermore, several applications of our theorems are also presented. Finally,our theorems are significant improvements on several important recent results for this classof nonlinear problems. 展开更多
关键词 Halpern-type algorithm Krasnoselskii-type algorithm system of generalizedmixed equilibrium problems totally quasi-C-asymptotically nonexpansive multi-valued maps equally continuous maps
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