20,363 Hits in 4.0 sec

Codebooks from almost difference sets

Cunsheng Ding, Tao Feng
2007 Designs, Codes and Cryptography  
In this paper, a generic construction of codebooks using almost difference sets is considered and several classes of codebooks nearly meeting the Welch bound are obtained.  ...  Recently, constructions of codebooks with difference sets meeting Welch's bound on the maximum cross-correlation amplitude were developed.  ...  Constructions of codebooks from difference sets 2.1 Difference sets and almost difference sets We first introduce difference sets and almost difference sets that are the building blocks of the complex  ... 
doi:10.1007/s10623-007-9140-z fatcat:jaqxdk372bbzfideuagew3l3ey

New Constructions of Asymptotically Optimal Codebooks via Cyclotomic Classes of Order 8

Wanfeng Qi, Yueying Song, Rui Ma, Lingli Tang, Qian Wang
2019 Mathematical Problems in Engineering  
In this paper, we construct a new class of asymptotically optimal codebooks by using the product of some special finite fields and almost difference sets, which are composed of cyclotomic classes of order  ...  Asymptotically optimal codebooks are a family of codebooks that can approach an optimal codebook meeting the Welch bound when the lengths of codewords are large enough.  ...  Cyclotomic class is now widely used to construct almost difference sets. An almost difference set of a finite field F is a subset with elements satisfying special properties.  ... 
doi:10.1155/2019/8708161 fatcat:id6q7k2fnngl5crb2oeyvqviti

On testing trained vector quantizer codebooks

Dong Sik Kim, Taejeong Kim, Sang Uk Lee
1997 IEEE Transactions on Image Processing  
In order to test the resultant codebook, validating-set-distortion (VSD) is calculated on a separate validating set (VS).  ...  Codebooks that yield small difference between the TSD and the VSD are regarded as good ones.  ...  Remark 1: From Lemma 1 and [18] , converges to the -optimal distortion almost surely as with fixed for TS-optimal codebook .  ... 
doi:10.1109/83.557343 pmid:18282935 fatcat:uqoafhcsuzhwbbz2y5nkgu2dsm

Cepstral Statistics Compensation and Normalization Using Online Pseudo Stereo Codebooks for Robust Speech Recognition in Additive Noise Environments

J.-w. HUNG
2008 IEICE transactions on information and systems  
, in relative word error rate reduction for experiments conducted on Test Set A of the Aurora-2 digit database.  ...  The algorithms are simple yet efficient noise reduction techniques that use online-constructed pseudostereo codebooks to evaluate the statistics in both clean and noisy environments.  ...  It is expected that the features' statistics obtained from the two codebooks can be more accurate, and the developed approaches based on the two codebooks can be implemented almost on-line.  ... 
doi:10.1093/ietisy/e91-d.2.296 fatcat:ia3iqtodjnfxfo7j4ujzd5y7tm

Achieving the Welch Bound With Difference Sets

P. Xia, S. Zhou, G.B. Giannakis
2005 IEEE Transactions on Information Theory  
Codebooks constructed from difference sets readily satisfy such a property, because for every (N; K; ) difference set u u u, the complement u u u is also a difference set with parameters (N; N 0K; N 02K  ...  This can be easily verified from definition of the WBE codebook (2) and the necessary and sufficient conditions of the MWBE codebook (5). • WBE codebooks are "almost trivially easy" to find [23] , while  ... 
doi:10.1109/tit.2005.846411 fatcat:wfjl6tlgkzekfgjhhg3wf47jje

Pyramid texture compression and decompression using interpolative vector quantization

Young-Su Kwon, In-Cheol Park, Chong-Min Kyung
2000 Proceedings 2000 International Conference on Image Processing (Cat. No.00CH37101)  
The proposed compression scheme uses interpolative texel difference vector quantization that compresses the difference between the interpolated surfaces generated by the representative value and the correct  ...  Vector quantization is used to compress all levels of the pyramid texture to one representative value databook, one residual codebook and one index map.  ...  After the size of the codebook is determined, the initial training vectors that are the complete set of the difference vectors are gained from the partitioned texture block.  ... 
doi:10.1109/icip.2000.899261 dblp:conf/icip/KwonPK00 fatcat:qc3ap2ybwzcsxnqrbi6bdzg2sm

The Effect of Finite Rate Feedback on CDMA Signature Optimization and MIMO Beamforming Vector Selection

Wei Dai, Youjian Liu, B. Rider
2009 IEEE Transactions on Information Theory  
In CDMA signature optimization, for a particular user, the receiver selects a signature vector from a codebook to best avoid interference from other users, and then feeds the corresponding index back to  ...  Further, we show that random codebooks generated from the isotropic distribution are asymptotically optimal not only on average, but also in probability.  ...  For any finite , set and Proposition 1: Let with . 1) and almost surely. 2) All moments of and converge. 3) For all measurable sets such that , we have .  ... 
doi:10.1109/tit.2009.2023717 fatcat:ug47ltsgf5cahp6giqwu3klgie

Research on Vocabulary Sizes and Codebook Universality

Wei-Xue Liu, Jian Hou, Hamid Reza Karimi
2014 Abstract and Applied Analysis  
Experimental results indicate that, under the condition that the vocabulary size is large enough, the vocabularies built from different datasets are exchangeable and universal.  ...  In almost all existing works on codebooks, the building of the visual vocabulary follows a basic routine, that is, extracting local image descriptors and clustering with a user-designated number of clusters  ...  From Figures 2 and 3 , we can see that the codebook generated from different image database has almost the same recognition rates with the different vocabulary sizes.  ... 
doi:10.1155/2014/697245 fatcat:lgzqaqyxzbe3lckhsqz246z6ai

Experimental Evaluation of the Bag-of-Features Model for Unsupervised Learning of Images

Mariana Afonso, Luis F. Teixeira
2015 Procedings of the British Machine Vision Conference 2015  
The results show that regardless of the codebook size used, the performance almost always increases with the average number of keypoints per image.  ...  Each image is represented by a frequency histogram of visual words from a codebook.  ...  The results show that regardless of the codebook size used, the performance almost always increases with the average number of keypoints per image.  ... 
doi:10.5244/c.29.146 dblp:conf/bmvc/AfonsoT15 fatcat:nz7dgcr6dzhz5kc7jziqyzmmnm

Gauss periods and codebooks from generalized cyclotomic sets of order four

Liqin Hu, Qin Yue
2012 Designs, Codes and Cryptography  
As an application, we get the maximum cross-correlation amplitudes of three codebooks from generalized cyclotomic sets of order four and supply conditions on p and q such that they nearly meet the Welch  ...  Ding and Feng [5] used almost difference sets to construct codebooks nearly meeting the maximum-Welch-bound. In this paper, we always assume that p, q are distinct primes with gcd( p−1, q−1) = 4.  ...  Sarwate [8] gave a well-rounded treatment of MWBE and WBE codebook. Several authors gave a generic construction of complex codebooks with difference sets (see [2] [3] [4] 11] ).  ... 
doi:10.1007/s10623-012-9648-8 fatcat:ksm2zvdi5bdkfhh7zw7mnuedmi

A Fast Search Algorithm for Vector Quantization Using Hyperplane Decision Rule

Ahmed Swilem, Kousuke Imamura, Hideo Hashimoto
2002 The Journal of The Institute of Image Information and Television Engineers  
Vector quantization is the process of encoding vector data as an index to a dictionary or codebook of representative vectors.  ...  In this paper, we describe a new method allowing significant acceleration of codebook design and encoding processes for vector quantization.  ...  The proposed method has almost the same performance of the Lee & Chen method for codebook sizes from 64 to more than this size.  ... 
doi:10.3169/itej.56.1513 fatcat:xrwo45l5hrhifj4glzhknobk3i

Scene Categorization with Classified Codebook Model

Xu YANG, De XU, Songhe FENG, Yingjun TANG, Shuoyan LIU
2011 IEICE transactions on information and systems  
This paper presents an efficient yet powerful codebook model, named classified codebook model, to categorize natural scene category.  ...  The current codebook model typically resorts to large codebook to obtain higher performance for scene categorization, which severely limits the practical applicability of the model.  ...  As final experiment, to investigate the robustness of CCM at small codebook size, we conduct scene categorization with different amount of images in train set.  ... 
doi:10.1587/transinf.e94.d.1349 fatcat:inbvlwni35bwbcsxy7p346ajmu

Improvement of Rotation Matrix Based Differential Limited Feedback with DFT Codebook and Its Application in CoMP Environment

Yin Zhu, Yusheng Ji, Ping Wang, Fuqiang Liu
2014 Journal of Communications  
In addition, the modified algorithm is also applied to a per-cell codebook based coordinated multi-point (CoMP) transmission system to verify its applicability to different MIMO scenarios.  ...  Although the rotation matrix codebook and the precoding codebook in their scheme are optimally constructed, they are not fit for a practical system due to the structure constraints.  ...  The receiver quantizes the CSI into a codeword of a finite set called codebook that is both known to the transmitter and the receiver, then the index of the codeword is fed back from the receiver via a  ... 
doi:10.12720/jcm.9.6.498-505 fatcat:qtshznpbc5fb7dcy2g2o4fzse4

Reverse Engineering Vector Quantizers By Training Set Synthesis

Srivatsan Kandadai, Charles D. Creusere
2004 Zenodo  
The following enumerates the different steps used in the synthesis of a training set from a given VQ codebook.  ...  produce almost the same results as the VQs designed from the original training set.  ... 
doi:10.5281/zenodo.38628 fatcat:6qgewlbn7jexpba5mukg7yy3ye

A scalable architecture for multilingual speech recognition on embedded devices

Martin Raab, Rainer Gruhn, Elmar Nöth
2011 Speech Communication  
We introduce Multilingual Weighted Codebooks that give good results with low decoding complexity. These codebooks depend on the actual language combination and increase the training complexity.  ...  The monolingual codebook on which such a system relies is not appropriate for multilingual recognition.  ...  This means, each language got a different HMM set, and this HMM set was trained with speech from the corresponding language.  ... 
doi:10.1016/j.specom.2010.07.007 fatcat:e6cczqxbhndhlflemexquetn24
« Previous Showing results 1 — 15 out of 20,363 results