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Note on maximal distance separable codes
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作者 杨建生 王德秀 靳庆芳 《Journal of Shanghai University(English Edition)》 2009年第5期409-411,共3页
In this paper, the maximal length of maximal distance separable (MDS) codes is studied, and a new upper bound formula of the maximal length of MDS codes is obtained. Especially, the exact values of the maximal length ... In this paper, the maximal length of maximal distance separable (MDS) codes is studied, and a new upper bound formula of the maximal length of MDS codes is obtained. Especially, the exact values of the maximal length of MDS codes in some parameters are given. 展开更多
关键词 maximal distance separable (MDS) code orthogonal Latin matrix Mq(k)
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On Deep Holes of Projective Reed-Solomon Codes over Finite Fields with Even Characteristic
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作者 XU Xiaofan 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2023年第1期15-19,共5页
Projective Reed-Solomon code is an important class of maximal distance separable codes in reliable communication and deep holes play important roles in its decoding.In this paper,we obtain two classes of deep holes of... Projective Reed-Solomon code is an important class of maximal distance separable codes in reliable communication and deep holes play important roles in its decoding.In this paper,we obtain two classes of deep holes of projective Reed-Solomon codes over finite fields with even characteristic.That is,let F_(q) be finite field with even characteristic,k∈{2,q-2},and let u(x)be the Lagrange interpolation polynomial of the first q components of the received vector u∈F_(q)+1 q Suppose that the(q+1)-th component of u is 0,and u(x)=λx^(k)+f_(≤k-2)(x),λx^(q-2)+f_(≤k-2)(x),where λ∈F^(*)_(q) and f_(≤k-2)(x)is a polynomial over F_(q) with degree no more than k-2.Then the received vector u is a deep hole of projective Reed-Solomon codes PRS(F_(q),k).In fact,our result partially solved an open problem on deep holes of projective Reed-Solomon codes proposed by Wan in 2020. 展开更多
关键词 finite field even characteristic projective Reed-Solomon code deep hole
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Maximal codes
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作者 Mohammed. Sabiri 《Journal of Mathematics and System Science》 2017年第9期261-268,共8页
In this work we try to introduce the concept of Maximal codes that are built over rings, more precisely we will give Maximal codes for special rings, Namely that the notion of maximal codes has been used by Chritophe ... In this work we try to introduce the concept of Maximal codes that are built over rings, more precisely we will give Maximal codes for special rings, Namely that the notion of maximal codes has been used by Chritophe Chapote, these maximal codes are constructed over finite fields, and these codes are used for coding and decoding. 展开更多
关键词 cyclic codes dual code noetherian local ring maximal codes.
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OCDMA SystemSignature Code Design Theory Via Finite Projective Geometry 被引量:1
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作者 Li Chuanqi Sun Xiaohan +1 位作者 Zhang Mingde Je-Myung Jeong 《工程科学(英文版)》 2005年第4期37-44,共8页
Optical orthogonal code is the main signature code employed by optical CDMA system. Starting from modern mathematics theory, finite projective geometry and Galois theory, the essential connection between optical ortho... Optical orthogonal code is the main signature code employed by optical CDMA system. Starting from modern mathematics theory, finite projective geometry and Galois theory, the essential connection between optical orthogonal code designing and finite geometry theory were discussed; find out the corresponding relationship between the parameter of OOC and that of finite geometry space. In this article, the systematic theory of OOC designing based on projective geometry is established in detail. The designing process and results of OOC on projective plane PG(2,q) and on m-dimension projective space are given respectively. Furthermore, the analytical theory for the corresponding relation between OOC with high cross-correlation and k-D manifold of projective space is set up. The OOC designing results given in this article have excellent performance, whose maximum cross-correlation is 1, and the cardinality reaches the Johnson upper bound, i.e. it realizes the optimization in both MUI and system capacity. 展开更多
关键词 OCDMA系统 有限射影几何学 有限域 向量空间 光学正交码
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融合引调水工程的抽水蓄能电站与光伏联合运行短期优化调度模型
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作者 龙鑫 罗彬 +3 位作者 陈永灿 陈刚 聂状 史华勃 《电网技术》 北大核心 2026年第1期112-121,I0068-I0070,I0072,I0073,共15页
为解决“双碳”背景下我国西部部分地区同时面临水资源空间分布不均及新能源消纳的双重难题,提出将引调水工程、抽水蓄能电站及光伏电站三者统筹开发运行。基于此背景,提出了一种三者联合运行的短期优化调度模型。首先,采用改进蚁群聚... 为解决“双碳”背景下我国西部部分地区同时面临水资源空间分布不均及新能源消纳的双重难题,提出将引调水工程、抽水蓄能电站及光伏电站三者统筹开发运行。基于此背景,提出了一种三者联合运行的短期优化调度模型。首先,采用改进蚁群聚类算法处理光伏不确定性,构建光伏出力场景;其次,以联合体期望收益最大为目标,以机组为最小调度单元,对抽蓄电站、抽蓄机组、引调水工程以及电网约束进行精细化建模;然后,将原模型经线性化处理转化为混合整数线性规划模型并通过商业求解器CPLEX进行求解;最后,通过算例分析表明,所提模型不仅实现了水资源的跨地域空间调配,还通过抽蓄快速调节能力实现光伏的全额消纳以及平稳送出并提高了联合体收益,又在峰谷平电价的引导下,有效降低了电网峰谷差。 展开更多
关键词 抽水蓄能电站 引调水工程 光伏不确定性 整体期望收益最大 混合整数线性规划
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某地铁上盖项目超限高层结构的转换层分析
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作者 张雨 吴磊 +2 位作者 姚亮亮 张红友 彭程 《建筑结构》 北大核心 2026年第3期40-46,共7页
在已投入运营的地铁运用库上建设的某高层剪力墙住宅项目,建筑方案的变动使上部住宅剪力墙与下部转换梁的位置出现偏心,导致受力复杂、传力多级化等问题。对比分析了早期方案与现行新方案的差异,阐述了新方案整体布置对现有运用库的影响... 在已投入运营的地铁运用库上建设的某高层剪力墙住宅项目,建筑方案的变动使上部住宅剪力墙与下部转换梁的位置出现偏心,导致受力复杂、传力多级化等问题。对比分析了早期方案与现行新方案的差异,阐述了新方案整体布置对现有运用库的影响,并梳理了转换梁与转换柱的搭接关系等内容。针对本工程转换结构的特点,重点对比研究了梁板转换与箱形转换两种方案,分析了两种方案下转换梁的弯矩、剪力及位移变化规律。分析结果表明,箱形转换方案中,上、下层楼板可协同工作,共同分担转换梁的内力,且下层楼板的分担作用尤为显著。基于转换梁与巨筒柱的搭接关系、转换梁的应力状态,以及箱形转换下层楼板的有利贡献,最终确定采用箱形转换方案,可为类似转换方案的分析提供借鉴。 展开更多
关键词 地铁上盖项目 超限高层建筑 转换层设计 梁板转换 箱形转换 抗震性能
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基于国产BIMBase软件的输变电示范工程设计与交付——以绍兴市110 kV变电站项目为例
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作者 陈默君 《工程建设与设计》 2026年第1期72-75,共4页
针对BIM在国内输变电工程应用中存在的问题,论文以绍兴市110 kV变电站项目为例,详细分析国产BIMBase软件在设计与交付过程中的实际应用。研究结果表明,利用BIMBase软件能够准确地实时共享和管理项目信息,解决了设计阶段信息误差大、返... 针对BIM在国内输变电工程应用中存在的问题,论文以绍兴市110 kV变电站项目为例,详细分析国产BIMBase软件在设计与交付过程中的实际应用。研究结果表明,利用BIMBase软件能够准确地实时共享和管理项目信息,解决了设计阶段信息误差大、返工和修改需求频繁等问题,可以显著提高工程设计与交付的效率和质量。 展开更多
关键词 建筑信息模型 输变电工程 模型编码 项目管理 设计优化
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基于嵌入式系统的Tcode识别 被引量:3
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作者 薛江 王知衍 曹晓叶 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2013年第5期61-67,共7页
针对传统二维条码在移动终端应用中存在的问题,开发了一个嵌入式的简化二维条码手机Tcode编解码识别系统.该系统包括编解码模块和识别模块.基于Reed-Solomon算法,针对不同数量字符定义了编码及映射方案;提出了基于采样阈值的分块滑动二... 针对传统二维条码在移动终端应用中存在的问题,开发了一个嵌入式的简化二维条码手机Tcode编解码识别系统.该系统包括编解码模块和识别模块.基于Reed-Solomon算法,针对不同数量字符定义了编码及映射方案;提出了基于采样阈值的分块滑动二值化算法来保留定位点,通过圆点滤波结合连通区域形状判定来寻找定位点;采用改进的投影法来进行字符切分.对各种手机的识别测试实验表明,该系统的正确识别率可达95%以上,配合Reed-Solomon算法纠错机制,最终能实现100%正确识别.实验同时证明,在嵌入式设备中,该系统的效率和稳定性能很好地满足应用要求. 展开更多
关键词 Tcode 编码 解码 识别 嵌入式系统 二值化 投影
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ON THE MAXIMAL DISJOINT SYSTEM IN Riesz ALGEBRAS AND REPRESENTATION
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作者 徐景峰 熊洪允 《Transactions of Tianjin University》 EI CAS 1999年第1期85-87,共3页
Let E be an Archimedean Riesz algebra possessing a weak unit element e and a maximal disjoint system {e,: i∈I} in which e, is a projection element for each i. The principal band generated by eiis denoted by B(ei). T... Let E be an Archimedean Riesz algebra possessing a weak unit element e and a maximal disjoint system {e,: i∈I} in which e, is a projection element for each i. The principal band generated by eiis denoted by B(ei). The main result in this paper says that if there exists a completely regular Hausdorff space X such that E is Riesz algebra isomorphic to C(X) then for every i ∈ I there exists a completely regular Hausdorff space X, such that B(ei) is Riesz algebra isomorphic to C(Xi). Under an additional condition the inverse holds. 展开更多
关键词 Riesz algebra maximal disjoint system REPRESENTATION projection element weak unit element
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The Self-dual Codes over Formal Power Series Rings 被引量:1
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作者 LIU Xiu-sheng LIU Hua-lu 《Chinese Quarterly Journal of Mathematics》 CSCD 2014年第1期30-38,共9页
The codes of formal power series rings R_∞=F[[r]]={sum from i=0 to ∞(a_lr^l|a_l∈F)}and finite chain rings R_i={a_0+a_1r+…+a_(i-1)r^(i-1)|a_i∈F}have close relationship in lifts and projection.In this paper,we stud... The codes of formal power series rings R_∞=F[[r]]={sum from i=0 to ∞(a_lr^l|a_l∈F)}and finite chain rings R_i={a_0+a_1r+…+a_(i-1)r^(i-1)|a_i∈F}have close relationship in lifts and projection.In this paper,we study self-dual codes over R_∞by means of self-dual codes over Ri,and give some characterizations of self-dual codes over R_∞. 展开更多
关键词 self-dual codes γ-adic codes projective codes
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A free monoid containing all prefix codes
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作者 CAO Chun-hua LIU Qin YANG Di 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第4期596-603,共8页
In this paper,we exhibit a free monoid containing all prefix codes in connection with the sets of i-th powers of primitive words for all i≥2.This extends two results given by Shyr and Tsai in 1998 at the same time.
关键词 prefix code free monoid primitive word maximal prefix code
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成本编码(COST CODE)体系在海外工程项目的应用与思考 被引量:1
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作者 孟祥民 《建筑经济》 北大核心 2020年第S02期97-99,共3页
介绍中外工程项目成本管理的不同理念,研究和讨论海外工程项目使用的成本编码(COST CODE)体系在具体实践过程中更好实现目标工程成本费用管控,与工程项目总进度计划、施工组织设计实行结合,真正实现工程成本费用的溯源性和可追溯性。
关键词 项目成本管理 成本编码 管理体系 溯源性 信息化管理
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Quantized Decoders that Maximize Mutual Information for Polar Codes
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作者 Zhu Hongfei Cao Zhiwei +1 位作者 Zhao Yuping Li Dou 《China Communications》 SCIE CSCD 2024年第7期125-134,共10页
In this paper,we innovatively associate the mutual information with the frame error rate(FER)performance and propose novel quantized decoders for polar codes.Based on the optimal quantizer of binary-input discrete mem... In this paper,we innovatively associate the mutual information with the frame error rate(FER)performance and propose novel quantized decoders for polar codes.Based on the optimal quantizer of binary-input discrete memoryless channels(BDMCs),the proposed decoders quantize the virtual subchannels of polar codes to maximize mutual information(MMI)between source bits and quantized symbols.The nested structure of polar codes ensures that the MMI quantization can be implemented stage by stage.Simulation results show that the proposed MMI decoders with 4 quantization bits outperform the existing nonuniform quantized decoders that minimize mean-squared error(MMSE)with 4 quantization bits,and yield even better performance than uniform MMI quantized decoders with 5 quantization bits.Furthermore,the proposed 5-bit quantized MMI decoders approach the floating-point decoders with negligible performance loss. 展开更多
关键词 maximize mutual information polar codes QUANTIZATION successive cancellation decoding
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Quasi-cyclic Random Projection Code and Hardware Implementation
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作者 Saifeng Shi Min Wang +1 位作者 Xinlu Lu Jun Wu 《Communications and Network》 2013年第3期86-92,共7页
Random Projection Code (RPC) is a mechanism that combines channel coding and modulation together and realizes rate adaptation in the receiving end. Random projection code’s mapping matrix has significant influences o... Random Projection Code (RPC) is a mechanism that combines channel coding and modulation together and realizes rate adaptation in the receiving end. Random projection code’s mapping matrix has significant influences on decoding performance as well as hardware implementation complexity. To reduce hardware implementation complexity, we design a quasi-cyclic mapping matrix for RPC codes. Compared with other construction approaches, our design gets rid of data filter component, thus reducing chip area 7284.95 um2, and power consumption 331.46 uW in 0.13 um fabrication. Our simulation results show that our method does not cause any performance loss and even gets 0.2 dB to 0.5 dB gain at BER 10-4. 展开更多
关键词 Quasi-cyclic MAPPING MATRIX RANDOM PROJECTION code HARDWARE Implementation
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On the Maximal Disjoint Division in Riesz Spaces
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作者 熊洪允 苗新河 《Transactions of Tianjin University》 EI CAS 2003年第2期161-164,共4页
The authors p oint out a problem in the article of Ref.(Xiong Hongyun,Rong Ximin.Maximal disjoint systems in Riesz space and representation.Acta Math Sinica ,1998,41(4):763-766.)and revise it.Let E be an Archimed ean ... The authors p oint out a problem in the article of Ref.(Xiong Hongyun,Rong Ximin.Maximal disjoint systems in Riesz space and representation.Acta Math Sinica ,1998,41(4):763-766.)and revise it.Let E be an Archimed ean Riesz space possessing a weak unit e and a maximal disjoint division{e i:i∈I} in which each e i is a proj ection element. Concerning the following statements:(1) There exists a completel y regular Hausdorff space X such that E is Riesz isomorphic to C(X);(2) For every i∈I there exi sts a completely regular Hausdorff space X i such that the band generated by e i is Riesz isomorphic to C(X i).It is shown that (1) implies (2),and find some conditions for the inverse bein g true are found.Furthermore,if each X i in (2) is a compact Ha usdorff space, a necessary and sufficient condition is established under which E can be represented as a C(X) for some compact Hausdorff space X.As corollaries, corresponding results for late rally complete Riesz spaces are obtained. 展开更多
关键词 weak unit maximal disjoint division projection element Riesz homomorphism laterally complete
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Evaluations of Novel Waveform Coding Signals Based on Finite Projective Plane
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作者 Chien-Hsing Liao Tai-Kuo Woo +1 位作者 Chi-Chung Chen Ing-Jiunn Su 《Journal of Electronic Science and Technology》 CAS CSCD 2016年第1期54-59,共6页
The most popular and representative classic waveform codes are referred to as orthogonal,bi-orthogonal,simplex,and etc,but the choice of waveform codes is essentially identical in error performance and cross correlati... The most popular and representative classic waveform codes are referred to as orthogonal,bi-orthogonal,simplex,and etc,but the choice of waveform codes is essentially identical in error performance and cross correlation characteristic.Though bi-orthogonal coding requires half the bandwidth of the others,such coding scheme is attractive only when large bandwidth is available.In this paper,a novel finite projective plane(FPP) based waveform coding scheme is proposed,which is with similar error performance and cross correlation.Nevertheless,the bandwidth requirement will grow in a quadratic way,but not in an exponential way with the values of message bit numbers(k).The proposed scheme takes obvious advantages over the bi-orthogonal scheme when k ≥ 6. 展开更多
关键词 Finite projective plane orthogonal coding simplex coding waveform coding
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Performances of Chaos Coded Modulation Schemes Based on Mod-MAP Mapping and High Dimensional LDPC Based Mod-MAP Mapping with Belief Propagation
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作者 Naim Khodor Jean-pierre Cances +1 位作者 Vahid Meghdadi Raymond Quere 《International Journal of Communications, Network and System Sciences》 2010年第6期495-506,共12页
In this paper, we propose to generalize the coding schemes first proposed by Kozic &amp;amp;amp;al to high spectral efficient modulation schemes. We study at first Chaos Coded Modulation based on the use of small ... In this paper, we propose to generalize the coding schemes first proposed by Kozic &amp;amp;amp;al to high spectral efficient modulation schemes. We study at first Chaos Coded Modulation based on the use of small dimensional modulo-MAP encoding process and we give a solution to study the distance spectrum of such coding schemes to accurately predict their performances. However, the obtained performances are quite poor. To improve them, we use then a high dimensional modulo-MAP mapping process similar to the low-density generator-matrix codes (LDGM) introduced by Kozic &amp;amp;amp;al. The main difference with their work is that we use an encoding and decoding process on GF (2m) which enables to obtain better performances while preserving a quite simple decoding algorithm when we use the Extended Min-Sum (EMS) algorithm of Declercq &amp;amp;amp;Fossorier. 展开更多
关键词 CHAOS coded Modulation Expectation Maximization Gaussian or Rayleigh Mixtures LOW-DENSITY Parity-Check (LDPC) LOW-DENSITY Generator-Matrix (LDGM) Factor Graph Extended Min-Sum (EMS)
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Developing Projects with Low-code Combined with ChatGPT
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作者 Wei Xiong Bing Li +1 位作者 Zhao Wu Bo Hang 《计算机教育》 2023年第12期204-213,共10页
This paper aims to explore a simpler and more user-friendly way of generating software based on model-driven development.Previous studies have attempted to generate code from domain models,hoping to reduce coding time... This paper aims to explore a simpler and more user-friendly way of generating software based on model-driven development.Previous studies have attempted to generate code from domain models,hoping to reduce coding time by increasing modeling time.However,as code tools become more advanced,it is challenging to improve efficiency because models are abstract while implementations are concrete.This paper proposes a novel approach that integrates ChatGPT as a plug-in into the whole R&D process and combines it with our code generation tool to enhance R&D efficiency.We have developed some demos to demonstrate the effectiveness of our approach.According to our evaluation,our approach can save more than 90%of the work in implementing the code generation tool,leaving only about 10%of the work for code review,code improvement,and unit testing. 展开更多
关键词 ChatGPT Low-code code generation Software engineering Project development
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CONSTRUCTION OF NONSYSTEMATIC LOW-DENSITY PARITY-CHECK CODES BASED ON SYMMETRIC BALANCED INCOMPLETE BLOCK DESIGN
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作者 Lin Dengsheng Li Qiang Li Shaoqian 《Journal of Electronics(China)》 2008年第4期445-449,共5页
This paper studies the nonsystematic Low-Density Parity-Check(LDPC)codes based onSymmetric Balanced Incomplete Block Design(SBIBD).First,it is concluded that the performancedegradation of nonsystematic linear block co... This paper studies the nonsystematic Low-Density Parity-Check(LDPC)codes based onSymmetric Balanced Incomplete Block Design(SBIBD).First,it is concluded that the performancedegradation of nonsystematic linear block codes is bounded by the average row weight of generalizedinverses of their generator matrices and code rate.Then a class of nonsystematic LDPC codes con-structed based on SBIBD is presented.Their characteristics include:both generator matrices andparity-check matrices are sparse and cyclic,which are simple to encode and decode;and almost arbi-trary rate codes can be easily constructed,so they are rate-compatible codes.Because there aresparse generalized inverses of generator matrices,the performance of the proposed codes is only0.15dB away from that of the traditional systematic LDPC codes. 展开更多
关键词 Low-Density Parity-Check (LDPC) codes Nonsystematic codes Symmetric Balanced Incomplete Block Design (SBIBD) Finite projective geometries
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Multi-Wavelength vs. Binary Code Pattern Unwrapping in Fringe Projection Method 被引量:1
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作者 R. Talebi J. Johnson +1 位作者 A. Abdel-Dayem M. Saadatseresht 《通讯和计算机(中英文版)》 2014年第3期291-304,共14页
关键词 二进制代码 多波长 条纹 投射法 相位展开 码型 固相萃取 不连续性
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