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IEEE International Conference on Image Processing

作者： Tsung-Yu Lin Tyng-Luh Liu Inst. of Inf. Sci. Taipei Taiwan

ISBN: (纸本)9781479957521

Recent advances in tackling large-scale computer vision problems have supported the use of an extremely high-dimensional descriptor to encode the image data. Under such a setting, we focus on how to efficiently carry out similarity search via employing binary codes. Observe that most of the popular high-dimensional descriptors induce feature vectors that have an implicit 2-D structure. We exploit this property to reduce the computation cost and high complexity. Specifically, our method generalizes the Iterative Quantization (ITQ) framework to handle extremely high-dimensional data in two steps. First, we restrict the dimensionality-reduction projection to a block-diagonal form and decide it by independently solving several moderate-size PCA sub-problems. Second, we replace the full rotation in ITQ with a bilinear rotation to improve the efficiency both in training and testing. Our experimental results on a large-scale dataset and comparisons with a state-of-the-art technique are promising.

关键词： binary codes cryptography image coding iterative methods 2D structure bilinear rotation block-diagonal form dimensionality-reduction projection extremely high-dimensional data feature vectors high-dimensional descriptors iterative quantization framework binary codes Computer vision Pattern recognition Principal component analysis Quantization (signal) Training Vectors binary code hashing similarity search binary code hashing image coding images computer vision iterative methods cryptography Pattern recognition principal components analysis Functional training Eigenvector Improved Transmission Quality

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Classification of open and closed convex codes on five neurons

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ADVANCES IN APPLIED MATHEMATICS 2020年 112卷

作者： Goldrup, Sarah Ayman Phillipson, Kaitlyn St Edwards Univ Math Dept Austin TX 78704 USA

Neural codes, represented as collections of binary strings, encode neural activity and show relationships among stimuli. Certain neurons, called place cells, have been shown experimentally to fire in convex regions in space. A natural question to ask is: Which neural codes can arise as intersection patterns of convex sets? While past research has established several criteria, complete conditions for convexity are not yet known for codes with more than four neurons. We classify all neural codes with five neurons as convex/non-convex codes. Furthermore, we investigate which of these codes can be represented by open versus closed convex sets. Interestingly, we find a code which is an open but not closed convex code and demonstrate a minimal example for this phenomenon. (C) 2019 Elsevier Inc. All rights reserved.

关键词： binary code Convex Neural code Sparse

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Improved linear programming bound on sizes of doubly constant-weight codes

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FINITE FIELDS AND THEIR APPLICATIONS 2018年 54卷 230-252页

作者： Phan Thanh Toan Kim, Hyun Kwang Kim, Jaeseon Ton Duc Thang Univ Fac Math & Stat Fract Calculus Optimizat & Algebra Res Grp Ho Chi Minh City Vietnam Pohang Univ Sci & Technol Dept Math Pohang 37673 South Korea

In this paper we give new constraints on the distance distribution of doubly constant-weight (binary) codes. These constraints improve the linear programming bound on sizes of doubly constant-weight codes. Computations are done for all codes of length n <= 28 and all improved upper bounds are shown. We moreover show that the improved upper bounds give rise to further new upper bounds. (C) 2018 Elsevier Inc. All rights reserved.

关键词： binary code Doubly constant-weight code Linear programming Upper bound

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A new class of distance-optimal binary cyclic codes and their duals

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APPLICABLE ALGEBRA IN ENGINEERING COMMUNICATION AND COMPUTING 2023年第1期34卷 99-109页

作者： Liu, Kaiqiang Ren, Wenli Wang, Feng Wang, Jianpeng Southwest Jiaotong Univ Sch Math Chengdu 610031 Peoples R China Dezhou Univ Sch Math & Big Data Dezhou 253023 Peoples R China

Let m = 8k and alpha be a primitive element of the finite field GF (2(m)), where k >= 2 is an integer. In this paper, a class of binary cyclic codes C-(u,C-v) of length 2(m) - 1 with two nonzeros alpha(-u) and alpha(-v) is studied, where (u, v) = (1, (2(m) - 1)/17). It turns out that C-(u,C-v) has parameters [2(m) - 1, 2(m) - m - 9, 4] and is distance-optimal with respect to the Sphere Packing bound. The weight distribution of the dual of C-(u,C-v) is also completely determined based on some results on Gaussian periods.

关键词： Cyclic code binary code Distance-optimal Sphere packing bound Weight distribution

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Ultrafast all-optical 4-bit digital encoders using differential phase modulation in semiconductor optical amplifier-Mach-Zehnder interferometer configuration

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OPTICAL ENGINEERING 2013年第3期52卷

作者： Mehra, Rekha Jaiswal, Shikha Dixit, Hemant Kumar Govt Engn Coll Dept Elect & Commun FOSI MIEEELMISTE Ajmer India CCS Univ Dept Phys SDPG Coll Meerut Uttar Pradesh India Univ Allahabad Dept Elect & Commun Allahabad 211002 Uttar Pradesh India

A novel approach for all-optical digital encoder for both binary-to-gray code and gray-to-binary code have been proposed. Design is based on the basic concept of digital encoder using the exclusive OR (XOR) addition. The XOR gate used in these encoders has been implemented using differential phase modulation between two arms of the Mach-Zehnder interferometer (MZI), in which a semiconductor optical amplifier is placed symmetrically in both arms of MZI. For the most severely degraded output bit, i.e., least significant bit for gray-to-binary encoder, the extinction ratio obtained is 2.35 while the minimum bit error rate is zero at 10 GB/s. For the second most significant bit of gray-to-binary encoder and for all the three bits except the most significant bit of binary-to-gray encoder, the extinction ratio obtained is around 27 dB. For the most significant bit, as input and output bits are same, the extinction ratio is very high, approaching infinity. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE) [DOI: 10.1117/***.52.3.035202]

关键词： semiconductor optical amplifier Mach-Zendher Interferometer gray code binary code digital encoder

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New quasi-symmetric designs constructed using mutually orthogonal Latin squares and Hadamard matrices

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DESIGNS codeS AND CRYPTOGRAPHY 2006年第2期41卷 195-198页

作者： Bracken, Carl McGuire, Gary Ward, Harold Univ Virginia Dept Math Charlottesville VA 22904 USA Natl Univ Ireland Dept Math Maynooth Kildare Ireland

Using Hadamard matrices and mutually orthogonal Latin squares, we construct two new quasi-symmetric designs, with parameters 2 - (66,30,29) and 2 - (78,36,30). These are the first examples of quasi-symmetric designs with these parameters. The parameters belong to the families 2 - (2u(2) - u,u (2) -u,u(2) - u - 1) and 2 - (2u(2) + u,u(2), u(2) - u), which are related to Hadamard parameters. The designs correspond to new codes meeting the Grey-Rankin bound.

关键词： binary code Grey-Rankin bound Hadamard matrix mutually orthogonal Latin squares quasi-symmetric

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Improved word-aligned binary compression for text indexing

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IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING 2006年第6期18卷 857-861页

作者： Anh, VN Moffat, A Univ Melbourne Dept Comp Sci & Software Engn Melbourne Vic 3010 Australia

We present an improved compression mechanism for handling the compressed inverted indexes used in text retrieval systems, extending the word-aligned binary coding carry method. Experiments using two typical document collections show that the new method obtains superior compression to previous static codes, without penalty in terms of execution speed.

关键词： data compaction and compression textual databases indexing methods file organization compression inverted index binary code text retrieval system text searching Web searching

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On the Minimal Distance of binary Self-Dual Cyclic codes

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IEEE TRANSACTIONS ON INFORMATION THEORY 2009年第11期55卷 4860-4863页

作者： Heijne, Bas Top, Jaap Univ Groningen Dept Math & Comp Sci IWI NL-9700 AK Groningen Netherlands

In this paper, an explicit construction of binary self-dual cyclic codes of length going to infinity with a minimal distance at least half the square root of is presented. The same idea is also used to construct more general binary cyclic codes with a large minimal distance. Finally, in the special case of self-dual cyclic codes, a simplified version of a proof by Conway and Sloane is given, showing an upper bound for the distance of binary self-dual codes.

关键词： BCH bound binary code cyclic code minimal distance self-dual code

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On a hypercube coloring problem

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JOURNAL OF COMBINATORIAL THEORY SERIES A 2004年第2期108卷 199-204页

作者： Östergard, PRJ Aalto Univ Dept Elect & Commun Engn Helsinki 02015 Finland

Let chi(k)(n) denote the minimum number of colors necessary to color the n-dimensional hypercube so that no two vertices that are at a distance at most k from each other get the same color. In other words, this is the smallest number of binary codes with minimum distance k + 1 that form a partition of the n-dimensional binary Hamming space. It is shown that chi(2)(n) similar to n and chi(3)(n) similar to 2n as n tends to infinity. (C) 2004 Elsevier Inc. All rights reserved.

关键词： binary code chromatic number hypercube vertex coloring

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ERROR CONTROL-SYSTEM FOR A IONOSPHERIC LINK

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ANNALES DES TELECOMMUNICATIONS-ANNALS OF TELECOMMUNICATIONS 1982年第5-6期37卷 272-284页

作者： CHAVAND, F GOUTELARD, C HARARI, S UER MATH F-80039 AMIENSFRANCE

Cet article présente l’étude d’un codage correcteur d’erreur adapté à un modem 1200 bit/s, autoadaptatif opérant sur la liaison ionosphérique. Une analyse de la répartition des erreurs a été faite en simulant en laboratoire une liaison spécifique dont les caractéristiques ont été mesurées avec un sondeur ionosphérique par rétrodiffusion. Le codage retenu consiste à mettre en cascade deux codes. L’un corrige les erreurs isolées et les petits paquets d’erreurs (code de Reed Solomon); l’autre corrige les erreurs de coupure (code de Kasami). Ces deux codes sont entrelacés. Le rendement du système de correction est de 50 %. Une simulation de correction a permis de montrer que, pour un taux moyen d’erreur de l’ordre de 10−4, il permet dans la plupart des cas étudiés, de gagner un facteur 100 sur ce taux d’erreur. This paper presents an error correcting system designed for a 1 200 bit/s self adaptative modem operating on the HF channel. An analysis of error statistics has been made simulating a specific link whose characteristics had been measured beforehand by a HF backscattering probe. The coding system which has been chosen consists of a cascade of two cyclic codes. One corrects long bursts of errors (Kasami code), the other corrects single errors and small bursts (Reed Solomon code). Both codes are interleaved. The overall rate is 50 %. An error correction simulation has shown that in most of the cases studied, with a ber of 10−4 a coding gain of at least 10−2 has been achieved.

关键词： binary code code binaire code correcteur erreur code produit code Reed-Solomon Decametric wave Digital transmission Erreur transmission Error burst Error correcting code Error rate Evanouissement Fading Ionospheric propagation Onde décamétrique Paquet erreur Product code Propagation ionosphérique Reed-Solomon code Taux erreur Transmission error Transmission numérique

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