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Reconnaissance de codes correcteurs / Blind reconstruction of error-correcting codesTixier, Audrey 14 October 2015 (has links)
Dans cette thèse, nous nous intéressons au problème de la reconnaissance de code. Ce problème se produit principalement lorsqu'une communication est observée dans un milieu non-coopératif. Une liste de mots bruités issus d'un code inconnu est obtenue, l'objectif est alors de retrouver l'information contenue dans ces mots bruités. Pour cela, le code utilisé est reconstruit afin de décoder les mots observés. Nous considérons ici trois instances de ce problème et proposons pour chacune d'elle une nouvelle méthode. Dans la première, nous supposons que le code utilisé est un turbo-code et nous proposons une méthode pour reconstruire la permutation interne (les autres éléments du turbo-codeur pouvant être facilement reconstruits grâce aux méthodes existantes). Cette permutation est reconstruite pas à pas en recherchant l'indice le plus probable à chaque instant. Plus précisément, la probabilité de chaque indice est déterminée avec l'aide de l'algorithme de décodage BCJR. Dans la seconde, nous traitons le problème de la reconnaissance des codes LDPC en suggérant une nouvelle méthode pour retrouver une liste d'équations de parité de petits poids. Celle-ci généralise et améliore les méthodes existantes. Finalement, avec la dernière méthode, nous reconstruisons un code convolutif entrelacé. Cette méthode fait appel à la précédente pour retrouver une liste d'équations de parité satisfaites par le code entrelacé. Puis, en introduisant une représentation sous forme de graphe de l'intersection de ces équations de parité, nous retrouvons simultanément l'entrelaceur et le code convolutif. / In this PhD, we focus on the code reconstruction problem. This problem mainly arises in a non-cooperative context when a communication consisting of noisy codewords stemming from an unknown code is observed and its content has to be retrieved by recovering the code that is used for communicating and decoding with it the noisy codewords. We consider here three possible scenarios and suggest an original method for each case. In the first one, we assume that the code that is used is a turbo-code and we propose a method for reconstructing the associated interleaver (the other components of the turbo-code can be easily recovered by the existing methods). The interleaver is reconstructed step by step by searching for the most probable index at each time and by computing the relevant probabilities with the help of the BCJR decoding algorithm. In the second one, we tackle the problem of reconstructing LDPC codes by suggesting a new method for finding a list of parity-check equations of small weight that generalizes and improves upon all existing methods. Finally, in the last scenario we reconstruct an unknown interleaved convolutional code. In this method we used the previous one to find a list of parity-check equations for this code. Then, by introducing a graph representing how these parity-check equations intersect we recover at the same time the interleaver and the convolutional code.
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A METHOD FOR FINDING BETTER SPACE-TIME CODES FOR MIMO CHANNELSPanagos, Adam G., Kosbar, Kurt 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Multiple-input multiple output (MIMO) communication systems can have dramatically higher
throughput than single-input, single-output systems. Unfortunately, it can be difficult to find the
space-time codes these systems need to achieve their potential. Previously published results
located good codes by minimizing the maximum correlation between transmitted signals. This
paper shows how this min-max method may produce sub-optimal codes. A new method which
sorts codes based on the union bound of pairwise error probabilities is presented. This new
technique can identify superior MIMO codes, providing higher system throughput without
increasing the transmitted power or bandwidth requirements.
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Analysis On the Optimum Group Synchronization Code of TIROS SatelliteQiu-Cheng, Xie, Jie, Cao 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, Nevada / In this paper, the group synchronization code (length n = 60 bit) of the TIROS Satellite was analysed. It seems to us the code isn't optimization. A series of optimum group sync codes (n = 60) have been searched out with error tolerance E = 1, 2, 3, 4, 5, 6 and 10, 12. Their error sync probabilities are less than the error sync probability of the TIROS code (from two times to two order of magnitudes about). These optimum or qansi-optimum codes will be presented for application in the second generation of the Meteorological Satellites of China.
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THE SEARCHING METHOD OF QUASI-OPTIMUM GROUP SYNC CODES ON THE SUBSET OF PN SEQUENCESJie, Cao, Qiu-cheng, Xie 11 1900 (has links)
International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / As the code length is increasing, the search of optimum group sync codes will be more and more difficult, even impossible. This paper gives the searching method of quasi-optimum group sync codes on the small subset of PN sequences -- CVT-TAIL SEARCHING METHOD and PREFIX-SUFFIX SEARCHING METHOD. We have searched out quasi-optimum group sync codes for their lengths N=32-63 by this method and compared them with corresponding optimum group sync codes for their lengths N=32-54. They are very approximative. The total searching time is only several seconds. This method may solves the problems among error sync probability, code length and searching time. So, it is a good and practicable searching method for long code.
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NEAR-FAR RESISTANT PSEUDOLITE RANGING USING THE EXTENDED KALMAN FILTERIltis, Ronald A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Pseudolites have been proposed for augmentation/replacement of the GPS system in radiolocation
applications. However, a terrestrial pseudolite system suffers from the near-far effect due to received
power disparities. Conventional code tracking loops as employed in GPS receivers are unable to
suppress near-far interference. Here, a multiuser code tracking algorithm is presented based on the
extended Kalman filter (EKF.) The EKF jointly tracks the delays and amplitudes of multiple received
pseudolite waveforms. A modified EKF based on an approximate Bayesian estimator (BEKF) is also
developed, which can in principle both acquire and track code delays, as well as detect loss-of-lock.
Representative simulation results for the BEKF are presented for code tracking with 2 and 5 users.
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Research and Recommendation of Optimum Group Synchronization Codes for N = 7 -- 32Zhongkui, Lei, Qiucheng, Xie, Jie, Cao 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, Nevada / In this paper, based on a series of research achievements [2,3,4,5,6], are examined the "The Optimum Frame Synchronization Codes" provided by J. L. Maury Jr. and F. J. Styles for IRIG Telemetry Standards USA, and furthermore, recommended a set of Optimum Group Synchronization Codes for China Telemetry Standards.
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A New Error Control Scheme for Remote Control SystemZhou, Tingxian, Yin, Xiaohua, Zhao, Xianming 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / How to rise the reliability of the data transmission is one of the main problem faced by modern digital communication designers. This paper studies the error-correcting codes being suitable for the channel existing both the random and burst error. A new error control scheme is given. The scheme is a concatenated coding system using an interleaved Reed-Solomon code with symbols over GF (24) as the outer code and a Viterbi-decoded convolutional code as the inner code. As a result of the computer simulation, it is proved that the concatenated coding system has a output at a very low bit error rate (BER)and can correct a lot of compound error patterns. It is suitable for the serious disturb channel existing both the random and burst error. This scheme will be adopted for a remote control system.
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La loi et son interprétation à travers le Code civil (1804-1870) / The law and interpretation forward the french civil Code (1804-1870)Bloquet, Sylvain 20 January 2011 (has links)
Souscrivant à une conception large de la loi, les rédacteurs du Code civil n'enfermeraient pas le juge dans une exégèse étroite de la législation.La doctrine civiliste du XIXème siècle, partagée entre une mémoire de tradition et une mémoire de fondation, entendait interpréter le Code civil en respectant l'esprit de ses auteurs. / Endorsing a broad conception of law, the authors of the french Civil Code does not confine the judge in a close exegesis of the legislation.Civil doctrine of the XIXth century, shared between a memory of tradition and memory of foundation, intended to interpret the Civil Code respecting the spirit of its authors.
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Effect of 3-methylthymine on solution structures and thermodynamic stabilities of double-helical deoxyribonucleic acids.January 2011 (has links)
Zhong, Yangliu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 50-57). / Abstracts in English and Chinese. / Title Page --- p.i / Thesis Committee --- p.ii / Abstract (English Version) --- p.iv / Abstract (Chinese Version) --- p.V / Acknowledgement --- p.vi / Table of Contents --- p.viii / List of Tables --- p.X / List of Figures --- p.xii / List of Abbreviations and Symbols --- p.xiii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- DNA methylation --- p.1 / Chapter 1.2 --- Repair of m3T --- p.2 / Chapter 1.3 --- Objectives of this work --- p.3 / Chapter 1.4 --- DNA structure --- p.3 / Chapter 1.4.1 --- Nomenclature scheme for DNA --- p.3 / Chapter 1.4.2 --- Base pair scheme --- p.4 / Chapter 1.4.3 --- Sugar conformation --- p.5 / Chapter 1.4.4 --- Backbone conformation --- p.7 / Chapter 2 --- Materials and Methods --- p.9 / Chapter 2.1 --- Sample design --- p.9 / Chapter 2.2 --- Sample preparation --- p.10 / Chapter 2.3 --- NMR analysis --- p.10 / Chapter 2.3.1 --- Resonance assignment --- p.12 / Chapter 2.3.2 --- Determination of sugar conformation --- p.13 / Chapter 2.3.3 --- Determination of backbone conformation --- p.14 / Chapter 2.4 --- UV melting study --- p.15 / Chapter 3 --- Effect of m3T on Double-Helical Structures and Stabilities --- p.17 / Chapter 3.1 --- Resonance assignments --- p.17 / Chapter 3.2 --- Effect of m3T on double-helical DNA structures --- p.19 / Chapter 3.2.1 --- Base pairing mode --- p.19 / Chapter 3.2.2 --- Sugar conformation --- p.21 / Chapter 3.2.3 --- Backbone conformation --- p.22 / Chapter 3.3 --- Effect of m3T on double-helical DNA stabilities --- p.25 / Chapter 3.4 --- Discussion --- p.26 / Chapter 3.4.1 --- Single-strand requirement in FTO repair --- p.26 / Chapter 3.4.2 --- Relationship between m3T pairing structure and stability --- p.27 / Chapter 4 --- Effect of m3T Mispair on Double-Helical DNA Structures and Stabilities --- p.28 / Chapter 4.1 --- Resonance assignments --- p.28 / Chapter 4.2 --- Effect of m3T mispair on double-helical DNA structures --- p.32 / Chapter 4.2.1 --- Pairing mode of T m3T --- p.34 / Chapter 4.2.2 --- Pairing mode of G m3T --- p.35 / Chapter 4.2.3 --- Pairing mode of C.m3T --- p.35 / Chapter 4.3 --- Effect of m3T mispair on double-helical DNA stabilities --- p.36 / Chapter 4.4 --- Discussion --- p.36 / Chapter 4.4.1 --- Predominant mutation --- p.37 / Chapter 4.4.2 --- Relationship between m3T pairing structure and stabilities --- p.37 / Chapter 5 --- Conclusion and Future Work --- p.39 / Chapter Appendix I --- Proton chemical shift values (ppm) of AmT --- p.40 / Chapter Appendix II --- Proton chemical shift values (ppm) of RefAT --- p.41 / Chapter Appendix III --- Proton chemical shift values of NmT samples --- p.42 / Chapter Appendix IV --- "Σ1' and %S of TmT, GmT and CmT" --- p.45 / Chapter Appendix V --- "1H-31P HSQC spectra of (a) TmT, (b) GmT and (c) CmT" --- p.46 / Chapter Appendix VI --- "1H-31P COSY spectra of (a) TmT, (b) GmT and (c) CmT" --- p.47 / Chapter Appendix VII --- "31P chemical shifts, 3JH3'P and %Bi of TmT, GmT and CmT" --- p.48 / Chapter Appendix VIII --- "UV melting curves of RefAT, AmT, TmT, GmT and CmT" --- p.49 / References --- p.50
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Implementation of BIM in the Municipal Plan Review ProcessRicardo Belliard, Liz Shantalle 01 May 2016 (has links)
Obtaining a building permit is an important step for any construction project. Whether it is for a new construction or a remodel job, the process involves a plan review performed by building officials. The purpose of this research was to explore ways in which Building Information Modeling (BIM) could be used to aid code officials during the plan review process. The objectives of the study were to determine if the level of detail in BIM was complete enough to allow a plan review to be perform accurately, to identify the extent to which architects are comfortable with using their models for the plan review, and to identify barriers to implementation. A case study was conducted where BIM was used to supplement the traditional 2D plans plan review process. Additionally, a survey was given to local architects to obtain their thoughts on using BIM in the plan review process. The research found that BIM has the potential of helping code officials visualize the project, extract information from objects, and allow them to have a better understanding of unique building features relationship to other building elements. Challenges of using BIM in the plan review process identified by architects included: the accuracy of the model, the level of detail modeled, legal implications, and ability of reviewers to use BIM.
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