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Soft Decoding Scheme of Convolution Code Combined with Huffman Coding
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作者 郭东亮 陈小蔷 吴乐南 《Journal of Southeast University(English Edition)》 EI CAS 2002年第3期208-211,共4页
This paper proposes a modification of the soft output Viterbi decoding algorithm (SOVA) which combines convolution code with Huffman coding. The idea is to extract the bit probability information from the Huffman codi... This paper proposes a modification of the soft output Viterbi decoding algorithm (SOVA) which combines convolution code with Huffman coding. The idea is to extract the bit probability information from the Huffman coding and use it to compute the a priori source information which can be used when the channel environment is bad. The suggested scheme does not require changes on the transmitter side. Compared with separate decoding systems, the gain in signal to noise ratio is about 0 5-1.0 dB with a limi... 展开更多
关键词 soft output Viterbi decoding a priori information Huffman coding convolution code
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Improved Design and SOVA Algorithm for Serial Concatenated Convolutional Code 被引量:2
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作者 万蕾 匡镜明 《Journal of Beijing Institute of Technology》 EI CAS 2001年第2期180-185,共6页
To improve the performance of the short interleaved serial concatenated convolutional code(SCCC) with low decoding iterative times, the structure of Log MAP algorithm is introduced into the conventional SOVA decoder... To improve the performance of the short interleaved serial concatenated convolutional code(SCCC) with low decoding iterative times, the structure of Log MAP algorithm is introduced into the conventional SOVA decoder to improve its performance at short interleaving delay. The combination of Log MAP and SOVA avoids updating the matrices of the maximum path, and also makes a contribution to the requirement of short delay. The simulation results of several SCCCs show that the improved decoder can obtain satisfied performance with short frame interleaver and it is suitable to the high bit rate low delay communication systems. 展开更多
关键词 serial concatenated convolutional code Turbo code iterative decoder WCDMA
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Blind recognition of k/n rate convolutional encoders from noisy observation 被引量:14
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作者 Li Huang Wengu Chen +1 位作者 Enhong Chen Hong Chen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第2期235-243,共9页
Blind recognition of convolutional codes is not only essential for cognitive radio, but also for non-cooperative context. This paper is dedicated to the blind identification of rate k/n convolutional encoders in a noi... Blind recognition of convolutional codes is not only essential for cognitive radio, but also for non-cooperative context. This paper is dedicated to the blind identification of rate k/n convolutional encoders in a noisy context based on Walsh-Hadamard transformation and block matrix (WHT-BM). The proposed algorithm constructs a system of noisy linear equations and utilizes all its coefficients to recover parity check matrix. It is able to make use of fault-tolerant feature of WHT, thus providing more accurate results and achieving better error performance in high raw bit error rate (BER) regions. Moreover, it is more computationally efficient with the use of the block matrix (BM) method. © 2017 Beijing Institute of Aerospace Information. 展开更多
关键词 Cognitive radio convolution convolutional codes Error correction Hadamard matrices Hadamard transforms Linear transformations Mathematical transformations Matrix algebra Signal encoding
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Blind reconstruction of convolutional code based on segmented Walsh-Hadamard transform 被引量:12
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作者 Fenghua Wang Hui Xie Zhitao Huang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第5期748-754,共7页
Walsh-Hadamard transform (WriT) can solve linear error equations on Field F2, and the method can be used to recover the parameters of convolutional code. However, solving the equations with many unknowns needs enorm... Walsh-Hadamard transform (WriT) can solve linear error equations on Field F2, and the method can be used to recover the parameters of convolutional code. However, solving the equations with many unknowns needs enormous computer memory which limits the application of WriT. In order to solve this problem, a method based on segmented WriT is proposed in this paper. The coefficient vector of high dimension is reshaped and two vectors of lower dimension are obtained. Then the WriT is operated and the requirement for computer memory is much reduced. The code rate and the constraint length of convolutional code are detected from the Walsh spectrum. And the check vector is recovered from the peak position. The validity of the method is verified by the simulation result, and the performance is proved to be optimal. 展开更多
关键词 convolutional code blind reconstruction Walsh-Hadamard transform (WriT) tinear error equation.
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Improved Adaptive Random Convolutional Network Coding Algorithm 被引量:2
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作者 Guo Wangmei Cai Ning Wang Xiao 《China Communications》 SCIE CSCD 2012年第11期63-69,共7页
To address the issue of field size in random network coding, we propose an Improved Adaptive Random Convolutional Network Coding (IARCNC) algorithm to considerably reduce the amount of occupied memory. The operation o... To address the issue of field size in random network coding, we propose an Improved Adaptive Random Convolutional Network Coding (IARCNC) algorithm to considerably reduce the amount of occupied memory. The operation of IARCNC is similar to that of Adaptive Random Convolutional Network Coding (ARCNC), with the coefficients of local encoding kernels chosen uniformly at random over a small finite field. The difference is that the length of the local encoding kernels at the nodes used by IARCNC is constrained by the depth; meanwhile, increases until all the related sink nodes can be decoded. This restriction can make the code length distribution more reasonable. Therefore, IARCNC retains the advantages of ARCNC, such as a small decoding delay and partial adaptation to an unknown topology without an early estimation of the field size. In addition, it has its own advantage, that is, a higher reduction in memory use. The simulation and the example show the effectiveness of the proposed algorithm. 展开更多
关键词 convolutional network coding adaptive network coding algorithm random coding
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Construction of Regular Rate-Compatible LDPC Convolutional Codes 被引量:2
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作者 Liwei Mu Chulong Liang +1 位作者 Zhiyong Liu Daru Pan 《China Communications》 SCIE CSCD 2016年第8期97-102,共6页
In this paper, we propose a new method to derive a family of regular rate-compatible low-density parity-check(RC-LDPC) convolutional codes from RC-LDPC block codes. In the RC-LDPC convolutional family, each extended... In this paper, we propose a new method to derive a family of regular rate-compatible low-density parity-check(RC-LDPC) convolutional codes from RC-LDPC block codes. In the RC-LDPC convolutional family, each extended sub-matrix of each extended code is obtained by choosing specified elements from two fixed matrices HE1K and HE1K, which are derived by modifying the extended matrices HE1 and HE2 of a systematic RC-LDPC block code. The proposed method which is based on graph extension simplifies the design, and prevent the defects caused by the puncturing method. It can be used to generate both regular and irregular RC-LDPC convolutional codes. All resulted codes in the family are systematic which simplify the encoder structure and have maximum encoding memories which ensure the property. Simulation results show the family collectively offer a steady improvement in performance with code compatibility over binary-input additive white Gaussian noise channel(BI-AWGNC). 展开更多
关键词 binary-input additive white Gaussian noise channel(BI-AWGNC) extended matrices rate-compatible low-density parity-check(RC-LDPC) convolutional codes
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Construction of Rate-Compatible(RC) Low-Density Parity-Check(LDPC) Convolutional Codes Based on RC-LDPC Block Codes 被引量:1
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作者 穆丽伟 韩国军 刘志勇 《Journal of Shanghai Jiaotong university(Science)》 EI 2016年第6期679-683,共5页
In this paper,a family of rate-compatible(RC) low-density parity-check(LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method.The resulted RC-LDPC convolutional codes,which are de... In this paper,a family of rate-compatible(RC) low-density parity-check(LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method.The resulted RC-LDPC convolutional codes,which are derived by permuting the matrices of the corresponding RC-LDPC block codes,are systematic and have maximum encoding memory.Simulation results show that the proposed RC-LDPC convolutional codes with belief propagation(BP) decoding collectively offer a steady improvement on performance compared with the block counterparts over the binary-input additive white Gaussian noise channels(BI-AWGNCs). 展开更多
关键词 rate-compatible(RC) low-density parity-check(LDPC) convolutional codes systematic maximum encoding memory belief propagation(BP) decoding
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Structured sparsity assisted online convolution sparse coding and its application on weak signature detection 被引量:1
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作者 Huijie MA Shunming LI +2 位作者 Jiantao LU Zongzhen ZHANG Siqi GONG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2022年第1期266-276,共11页
Due to the strong background noise and the acquisition system noise,the useful characteristics are often difficult to be detected.To solve this problem,sparse coding captures a concise representation of the high-level... Due to the strong background noise and the acquisition system noise,the useful characteristics are often difficult to be detected.To solve this problem,sparse coding captures a concise representation of the high-level features in the signal using the underlying structure of the signal.Recently,an Online Convolutional Sparse Coding(OCSC)denoising algorithm has been proposed.However,it does not consider the structural characteristics of the signal,the sparsity of each iteration is not enough.Therefore,a threshold shrinkage algorithm considering neighborhood sparsity is proposed,and a training strategy from loose to tight is developed to further improve the denoising performance of the algorithm,called Variable Threshold Neighborhood Online Convolution Sparse Coding(VTNOCSC).By embedding the structural sparse threshold shrinkage operator into the process of solving the sparse coefficient and gradually approaching the optimal noise separation point in the training,the signal denoising performance of the algorithm is greatly improved.VTNOCSC is used to process the actual bearing fault signal,the noise interference is successfully reduced and the interest features are more evident.Compared with other existing methods,VTNOCSC has better denoising performance. 展开更多
关键词 Dictionary learning Online convolutional sparse coding(OCSC) Signal denoising Signal processing Weak signature detection
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Determination of quantum toric error correction code threshold using convolutional neural network decoders 被引量:1
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作者 Hao-Wen Wang Yun-Jia Xue +2 位作者 Yu-Lin Ma Nan Hua Hong-Yang Ma 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第1期136-142,共7页
Quantum error correction technology is an important solution to solve the noise interference generated during the operation of quantum computers.In order to find the best syndrome of the stabilizer code in quantum err... Quantum error correction technology is an important solution to solve the noise interference generated during the operation of quantum computers.In order to find the best syndrome of the stabilizer code in quantum error correction,we need to find a fast and close to the optimal threshold decoder.In this work,we build a convolutional neural network(CNN)decoder to correct errors in the toric code based on the system research of machine learning.We analyze and optimize various conditions that affect CNN,and use the RestNet network architecture to reduce the running time.It is shortened by 30%-40%,and we finally design an optimized algorithm for CNN decoder.In this way,the threshold accuracy of the neural network decoder is made to reach 10.8%,which is closer to the optimal threshold of about 11%.The previous threshold of 8.9%-10.3%has been slightly improved,and there is no need to verify the basic noise. 展开更多
关键词 quantum error correction toric code convolutional neural network(CNN)decoder
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Ensemble of High Performance Structured Binary Convolutional LDPC Codes with Moderate Rates 被引量:1
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作者 Liwei Mu 《China Communications》 SCIE CSCD 2020年第10期195-205,共11页
An algebraic construction methodology is proposed to design binary time-invariant convolutional low-density parity-check(LDPC)codes.Assisted by a proposed partial search algorithm,the polynomialform parity-check matri... An algebraic construction methodology is proposed to design binary time-invariant convolutional low-density parity-check(LDPC)codes.Assisted by a proposed partial search algorithm,the polynomialform parity-check matrix of the time-invariant convolutional LDPC code is derived by combining some special codewords of an(n,2,n−1)code.The achieved convolutional LDPC codes possess the characteristics of comparatively large girth and given syndrome former memory.The objective of our design is to enable the time-invariant convolutional LDPC codes the advantages of excellent error performance and fast encoding.In particular,the error performance of the proposed convolutional LDPC code with small constraint length is superior to most existing convolutional LDPC codes. 展开更多
关键词 algebraic construction (n 2 n−1)codes convolutional low-density parity-check(LDPC)codes fast encoding maximum achievable syndrome former memory large girth
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Algebraic Approach to Random Convolutional Network Coding over Wireless Packet Networks
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作者 郭网媚 刘斌越 蒋馥蔚 《Transactions of Tianjin University》 EI CAS 2013年第4期307-312,共6页
To characterize the algebraic structure of wireless network coding, a hypergragh is utilized to model wireless packet networks from network layer. The algebraic description of random convolutional network coding is de... To characterize the algebraic structure of wireless network coding, a hypergragh is utilized to model wireless packet networks from network layer. The algebraic description of random convolutional network coding is deduced, and the coding condition is also presented. Analyses and simulations show that random convolutional coding is capacity-achieving with probability approaching 1. 展开更多
关键词 wireless network coding random convolutional network coding HYPERGRAPH capacity-achieving
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Self-Encoded Multiple Access Multiuser Convolutional Codes in Uplink and Downlink Cellular Systems
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作者 Jong Hak JUNG Won Mee JANG Lim NGUYEN 《International Journal of Communications, Network and System Sciences》 2009年第4期249-257,共9页
Self-encoded spread spectrum eliminates the need for traditional pseudo noise (PN) code generators. In a self-encoded multiple access (SEMA) system, the number of users is not limited by the number of available sequen... Self-encoded spread spectrum eliminates the need for traditional pseudo noise (PN) code generators. In a self-encoded multiple access (SEMA) system, the number of users is not limited by the number of available sequences, unlike code division multiple access (CDMA) systems that employ PN codes such as m-, Gold or Kassami sequences. SEMA provides a convenient way of supporting multi-rate, multi-level grades of service in multimedia communications and prioritized heterogeneous networking systems. In this paper, we propose multiuser convolutional channel coding in SEMA that provides fewer cross-correlations among users and thereby reducing multiple access interference (MAI). We analyze SEMA multiuser convolutional coding in additive white Gaussian noise (AWGN) channels as well as fading channels. Our analysis includes downlink synchronous system as well as asynchronous system such as uplink mobile-to-base station communication. 展开更多
关键词 SPREAD SPECTRUM Self-Encoded Multiple Access MULTIUSER convolutional coding MULTIUSER Detection
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Convolutional Sparse Coding in Gradient Domain for MRI Reconstruction 被引量:1
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作者 Jiaojiao Xiong Hongyang Lu +1 位作者 Minghui Zhang Qiegen Liu 《自动化学报》 EI CSCD 北大核心 2017年第10期1841-1849,共9页
关键词 梯度图像 稀疏编码 MRI 卷积 应用 分割图像 空间采样 磁共振成像
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Performance of Convolutionally Coded Multicarrier DS-CDMA System
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作者 SONG Li-xin HUANG Tian-shu DU Guang-yu 《Semiconductor Photonics and Technology》 CAS 2005年第4期281-286,共6页
A new convolutionally coded direct sequence (DS) CDMA system is proposed. The outputs of a convolutional encoder modulate multiple band-limited DS-CDMA waveforms. The receiver detects and combines signals for the desi... A new convolutionally coded direct sequence (DS) CDMA system is proposed. The outputs of a convolutional encoder modulate multiple band-limited DS-CDMA waveforms. The receiver detects and combines signals for the desired user and feeds a soft-decision Viterbi decoder. The performance of this system is compared to that of a convolutionally coded single carrier DS CDMA system with a Rake receiver. At roughly equivalent receiver complexity, results will demonstrate superior performance of the coded multicarrier system. 展开更多
关键词 convolutional code Rayleigh fading Multicarrier CDMA Frequency diversity Narrow-band interference
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NEW METHOD TO RECOVER INTERNET PACKET LOSSES USING(2,1,m)SYSTEMATIC CONVOLUTIONAL CODES
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作者 Peng Bo Wei Gang(Institute of Electron. Eng. and Control, South China University of Technology,Guangzhou 510640) 《Journal of Electronics(China)》 2002年第2期199-203,共5页
A new method to recover packet losses using (2,1,m) convolutional codes is proposed. The erasure correcting decoding algorithm and the decoding determinant theorem is presented. It is also proved that the codes with o... A new method to recover packet losses using (2,1,m) convolutional codes is proposed. The erasure correcting decoding algorithm and the decoding determinant theorem is presented. It is also proved that the codes with optimal distance profile have also optimal delay characteristic. Simulation results show that the proposed method can recover the packet losses more elliciently than RS codes over different decoding delay conditions and thus suits for different packet network delav conditions. 展开更多
关键词 convolutional code: Packet loss Erasure correcting codes
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The Mirror Equivalence Concept of Convolutional Codes and Turbo-Codes
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作者 Horia Balta Alexandru Isar Dorina Isar Maria Kovaci Cornel Balint 《通讯和计算机(中英文版)》 2012年第7期852-861,共10页
关键词 TURBO码 卷积码 等价 镜子 穷举搜索 设计程序 技术委员会 TCS
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Theoretical Analysis of Bit-Error Probability for Convolutional Codes with Weight Enumerators
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作者 Zhang Tianyi 《无线互联科技》 2012年第12期123-125,共3页
The paper introduces the state reduction algorithm and accelerated state reduction algorithm are used to compute the distance weight enumerator(transfer function)T[x,y] of convolutional codes.Next use computer simulat... The paper introduces the state reduction algorithm and accelerated state reduction algorithm are used to compute the distance weight enumerator(transfer function)T[x,y] of convolutional codes.Next use computer simulation to compare upper bound on the bit error probability on an additive white Gaussian noise(AWGN) for maximum free distance(MFD) codes of previously found and optimum distance spectrum(ODS) codes with rate 1/4,overall constraint length are 5 and 7,respectively.Finally,a method of how to search for good convolutional codes is given. 展开更多
关键词 英文摘要 编辑工作 学术论文 期刊
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Error Probability for Convolutional Codes with Weight Enumerating Function
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作者 Tianyi Zhang Yongtao Liu 《无线互联科技》 2013年第1期121-122,共2页
The paper introduces the state reduction algorithm and accelerated state reduction algorithm are used to compute the distance weight enumerator(transfer function) T[x,y] of convolutional codes.Next use computer simula... The paper introduces the state reduction algorithm and accelerated state reduction algorithm are used to compute the distance weight enumerator(transfer function) T[x,y] of convolutional codes.Next use computer simulation to compare upper bound on the bit error probability on an additive white Gaussian noise (AWGN) for maximum free distance (MFD) codes of previously found and optimum distance spectrum (ODS) codes with rate 1/4,overall constraint length are 5 and 7,respectively. Finally,a method of how to search for good convolutional codes is given. 展开更多
关键词 无线技术 互联网 无线网络 网络科技
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Joint Source-Channel Decoding of EVRC Speech Encoder Using Residual Redundancy
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作者 阿哈麦德 尤肖虎 高西奇 《Journal of Southeast University(English Edition)》 EI CAS 2002年第2期103-107,共5页
The enhanced variable rate codec (EVRC) is a standard for the 'Speech ServiceOption 3 for Wideband Spread Spectrum Digital System,' which has been employed in both IS-95cellular systems and ANSI J-STC-008 PCS ... The enhanced variable rate codec (EVRC) is a standard for the 'Speech ServiceOption 3 for Wideband Spread Spectrum Digital System,' which has been employed in both IS-95cellular systems and ANSI J-STC-008 PCS (personal communications systems). This paper concentrateson channel decoders that exploit the residual redundancy inherent in the enhanced variable ratecodec bitstream. This residual redundancy is quantified by modeling the parameters as first orderMarkov chains and computing the entropy rate based on the relative frequencies of transitions.Moreover, this residual redundancy can be exploited by an appropriately 'tuned' channel decoder toprovide substantial coding gain when compared with the decoders that do not exploit it. Channelcoding schemes include convolutional codes, and iteratively decoded parallel concatenatedconvolutional 'turbo' codes. 展开更多
关键词 residual redundancy convolutional codes turbo codes
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Integrated Joint Source-Channel Symbol-by-Symbol Decoding of Variable-Length Codes Using 3-D MAP Sequence Estimation 被引量:1
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作者 WU Jing CHEN Shuzhen 《Wuhan University Journal of Natural Sciences》 CAS 2007年第3期471-475,共5页
Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this pape... Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this paper is to salvage as many data from the damaged packets as possible for higher audiovisual quality. This paper proposes an integrated joint source-channel decoder (I-JSCD) at a symbol-level using three-dimensional (3-D) trellis representation for first-order Markov sources encoded with VLC source code and convolutional channel code. This method combines source code and channel code state-spaces and bit-lengths to construct a two-dimensional (2-D) state-space, and then develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol. Experiment results demonstrate that our method results in significant improvement in decoding performance, it can salvage at least half of (50%) data in any channel error rate, and can provide additional error resilience to VLC stream like image, audio, video stream over high error rate links. 展开更多
关键词 integrated joint source-channel decoding (I-JSCD) variable-length code (VLC) exp-Golomb code convolutional code: maximum a-oosteriori (MAP)
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