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Brus : en studie om finansinspektionens interna kommunikationPettersson, Lina, Gustavsson, Isabelle January 2011 (has links)
Uppsatsens syfte var att analysera Finansinspektionens kommunikationssystem samt att utvärdera hur deras interna kommunikation fungerar i praktiken. Författarna valde att utföra en fallstudie för att på så sätt kunna gå djupare inom en specifik organisation. Insamling av empiri har skett genom en kombination av kvalitativ och kvantitativ metod med tre personliga intervjuer samt en större enkätundersökning med medarbetare på Finansinspektionen. Respondenterna och informanterna valdes delvis medvetet men även genom ett slumpmässigt urval. Den teoretiska referensramen som studien bygger på innefattar ett flertal kommunikationsmodeller, såsom Shannon och Weavers basmodell, olika slag av intern kommunikation och Osgood och Schramms kommunikationsmodeller. Empiri och analys sammanfördes, slutsatsen författarna kom fram till var att Finansinspektionens interna kommunikation som helhet fungerar bra. Detta har framkommit både genom de personliga intervjuerna och den enkätundersökning som genomförts, liksom att de huvudsakliga informationsvägarna som idag används inom Finansinspektionen är de som medarbetarna föredrar. De främsta sätten att kommunicera internt inom Finansinspektionen är genom intranätet och de fredagsmöten som hålls varje vecka och av dessa synes medarbetarna prioritera båda kanalerna. Emellertid dök en del förslag på förbättringar upp samt synpunkter på vissa specifika delar, inom den interna kommunikationen, där det fanns behov av förändring. Bland annat ansåg en del av respondenterna att sökfunktionen på intranätet kunde förbättras och att fredagsmötena var av mer social karaktär.
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A NOVEL AND GENERIC METHOD FOR EXAMINING THE RELATIONSHIP BETWEEN ENERGY SECURITY AND DIVERSITY OF AN ENERGY SYSTEMRanjan, Ashish 06 December 2013 (has links)
In an energy system, diversity of supply—that is, reliance on a variety of mutually disparate energy suppliers and their energy supplies—is seen by many researchers and policymakers as an important component of energy security.
This thesis describes a novel and generic method for examining the relationship between energy security (as represented by an energy-security index derived from a set of energy security indicators) and diversity (as defined by the Shannon-Wiener diversity index) of an energy system, its entities, and flows. While diversity is often presented by policy makers as being essential to maintaining or improving the energy security of an energy system, the thesis employs the equations associated with the two indices to show that a diverse supply need not be secure and a secure supply need not be diverse. Several examples of the relationship and the events that can affect it are also provided. / N/A
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Interference Mitigation for Cellular Networks: Fundamental Limits and ApplicationsZhou, Lei 20 March 2013 (has links)
Interference is a key limiting factor in modern communication systems. In a wireless cellular network, the performance of cell-edge users is severely limited by the intercell interference. This thesis studies the use of interference-channel and relay-channel techniques to mitigate intercell interference and to improve the throughput and coverage of cellular networks. The aim of this thesis is to demonstrate the benefit of the proposed interference mitigation schemes through both information theoretical studies and applications in the cellular network.
There are three mains results in this thesis: First, it is shown that for the $K$-user cyclic Gaussian interference channel, where the $k$th user interferes with only the ($k -1$)th user (mod $K$) in the network, the Etkin-Tse Wang power splitting strategy achieves the capacity region to within 2 bits in the weak interference regime. For the special 3-user case, this gap can be sharpened to $1\frac{1}{2}$ bits by the time-sharing technique. Second, it is shown that for a two-user Gaussian interference channel with an in-band-reception and out-of-band transmission relay, generalized hash-and-forward together with Han-Kobayashi information splitting can achieve the capacity region of this channel to within a constant number of bits in a certain weak-relay regime. A generalized-degrees-of-freedom analysis in the high signal-to-noise ratio regime reveals that in the symmetric channel setting, each common relay bit improves the sum rate up to two bits. The third part of this thesis studies an uplink multicell joint processing model in which the base stations are connected to a centralized processing server via rate-limited digital backhaul links. This thesis proposes a suboptimal achievability scheme employing the Wyner-Ziv compress-and-forward relaying technique and successive-interference-cancellation decoding. The main advantage of the proposed approach is that it results in achievable rate regions that are easily computable, in contrast to previous schemes in which the rate regions can only be characterized by exponential number of rate constraints.
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'England's Giorgione' Charles H. Shannon and Venetianism in late Victorian art /McKeown, William Carlisle. Weingarden, Lauren S., January 2005 (has links)
Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Lauren S. Weingarden, Florida State University, School of Visual Arts and Dance, Dept. of Art History. Title and description from dissertation home page (viewed June 7, 2005). Document formatted into pages; contains xviii, 294 pages. Includes bibliographical references.
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The Shannon-McMillan theorem and related results for ergodic quantum spin lattice systems and applications in quantum information theorySzkoła, Arleta. Unknown Date (has links) (PDF)
Techn. University, Diss., 2004--Berlin.
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Informação de Fisher e entropia de Shannon de osciladores com massa dependente da posição / Fisher information and Shannon entropy of oscillators with position dependent massMacedo, Diego Ximenes January 2017 (has links)
MACEDO, D. X. Informação de Fisher e entropia de Shannon de osciladores com massa dependente da posição. 2017. 65 f. Tese (Doutorado em Física) – Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Giordana Silva (giordana.nascimento@gmail.com) on 2017-04-12T20:33:31Z
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Previous issue date: 2017 / In this work we study from both classical and quantum point of view the position dependent mass harmonic oscillator (PDMHO). Classically, we use the Legendre transformation to find the Hamiltonian of the system. Next, we define two functions, and , to simplify the hamiltonian of the PDMHO. By using the Poisson algebra we find the expressions for the position and moment. At last, by using a canonical transformation we relate the equations of the PDMHO to those of the simple harmonic oscillator (SHO). Quantically, we write the Hamiltonian of the PDMHO in terms of the operators and . Next, we consider that these operators satisfy the same algebra that those of the SHO. By assuming that both the classical and quantum PDMHO have the same form, we are able to find a simple form for the PDMHO Hamiltonian. Finally, by transforming the Schrödinger equation (SE) of the PDMHO into that of the SHO, we can write the wave function of the PDMHO in terms of that of the SHO. We will study two time-dependent systems, namely and , we observe that as , they tend to a simple harmonic oscillator. For each system we find the position and momentum (classical study), as well as the wave-function (quantum study). For both systems we analyze the the position e momentum uncertainty, the product uncertainty, the fisher information and Shannon entropy, for the ground state, as a function of the parameter. / Neste trabalho estudamos clássica e quanticamente o oscilador harmônico com massa dependente da posição (OHMDP). Na parte clássica, utilizamos a transformação de Legendre para encontrar a hamiltoniana do sistema. A seguir definimos duas funções e para escrevermos a hamiltoniana do OHMDP de uma forma mais simples. Utilizando a álgebra de Poisson encontramos as expressões para a posição e o momento. Por fim, através de uma transformação canônica veremos como relacionar as equações do OHMDP com aquelas do oscilador harmônico simples (OHS). Na parte quântica, escrevemos a hamiltoniana do OHMDP em termos de operadores e . Em seguida, vamos supor que estes operadores satisfaçam a mesma relação de comutação que os operadores abaixamento e levantamento do OHS. Analisando que condição deve ser satisfeita para que os osciladores OHMDP clássico e quântico tenham o mesmo potencial, encontramos uma forma simplificada da hamiltoniana do OHMDP. Em seguida, transformamos a equação de Schrödinger (ES) para o OHMDP na ES para o OHS. Assim, obtemos a função de onda do OHMDP em termos da função de onda do OHS. Estudaremos dois sistemas com massa dependente da posição, a saber: e , vemos que quando , recaímos no OHS. Para cada sistema encontraremos a posição e o momento (estudo clássico), bem como a função de onda (estudo quântico). Para os dois sistemas analisaremos também o comportamento da incerteza na posição, incerteza no momento, produto de incerteza, informação de Fisher e entropia de Shannon, para o estado fundamental, em função do parâmetro de deformação.
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Oscilador harmônico Caldirola-Kanai e aplicação da Teoria da Informação de Fisher e Entropia de ShannonSilva, Gilvan Ferreira January 2017 (has links)
SILVA, G. F. Oscilador harmônico de Caldirola-Kanai e aplicação da Teoria da Informação de Fisher e Entropia de Shannon. 2017. 61 f. Dissertação (Mestrado em Física) – Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Pós-Graduação em Física (posgrad@fisica.ufc.br) on 2017-06-13T15:46:22Z
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Previous issue date: 2017 / CAPES / In this dissertation, we give a brief historical overview of the elements that form it, namely Quantum Harmonic Oscillators with explicit temporal dependence; Lewis & Riesenfelds Method of the Invariants associated with Hartley & Rays technique; Shannon’s entropy and Fisher’s information theory. In this introductory description, we seek to present a procedural view of scientific knowledge. Also, in the introduction, we present the motivations for the execution of the academic work and its organization. In a later chapter, we describe Lewis and Riesenfeld’s formalism applied to oscillators that have an explicit temporal dependency. To better describe it, we divide the chapter into sections in which we define the Invariant, find its self-states, relate the self-states with the Schrödinger’s solution, and apply the formalism to the time-dependent oscillator which, in our work, was the well-known Caldirola-Kanai with M(t) = m eγt. We find the solutions in the coordinate of the position and, after that, we work with the wave function of the ground state. In the following chapter, we determine the uncertainty. To do so, we use the creation and destruction algebra of operators, So known by physicists. We find the Shannon’s entropy and Fisher’s information. We do an analysis of the analytical and graphical results, establishing a comparison between these techniques. / Nesta dissertação, fazemos um breve histórico dos elementos que a compõem, a saber, Osciladores Harmônicos Quânticos com dependência temporal explícita; Método dos Invariantes de Lewis e Riesenfeld associado com a técnica de Hartley e Ray; Entropia de Shannon e Teoria da informação de Fisher. Na descrição introdutória, buscamos apresentar uma visão processual dos conhecimentos científicos. Ainda, na introdução, apresentamos as motivações para a execução do trabalho acadêmico e sua organização. Em capítulo posterior, descrevemos o formalismo de Lewis e Riesenfeld aplicados a osciladores que têm uma dependência temporal explícita. Para melhor descrever, dividimos o capítulo em seções nas quais definimos o Invariante, encontramos seus autoestados, relacionamos os autoestados com a solução de Schrödinger e aplicamos o formalismo ao oscilador com dependência temporal que, para o nosso trabalho, foi o conhecido Oscilador de Caldirola-Kanai com M(t) = m eᵞt. Encontramos as soluções na coordenada da posição e, após, trabalhamos com a função de onda do estado fundamental. No capítulo seguinte, determinamos a incerteza. Para tanto, utilizamos a álgebra de operadores criação e destruição, tão conhecida pelos físicos. Encontramos a entropia de Shannon e a Informação de Fisher. Por fim, uma análise dos resultados analíticos e gráficos, estabelecendo uma comparação entre as técnicas.
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Entropické modely datového provozu / Entropic models of data trafficBlažek, Petr January 2015 (has links)
This thesis solves possibility of using entropy for anomaly detection in data communication and especially for security attacks. The main advantage of using entropy is ability to identify unknown attacks because entropy detects changes in network traffic but not the content as existing methods. In this work was tested the suitability of different models entropy (Shannon, Renyi, Tsallis). Also been tested the effect of Renyi and Tsallis parameter on resulting entropy. From the resulting values, I found that all tested entropy achieve good result in the identification of anomalies in network traffic.
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On the assessment of manufacturing systems complexity / Εκτίμηση πολυπλοκότητας συστημάτων παραγωγήςΕυθυμίου, Κωνσταντίνος 12 October 2013 (has links)
Objective of the present study is the development of methods for the assessment of
manufacturing systems complexity and the investigation of flexibility and complexity
relationship. Towards this target, a complete approach based on information theory
permitting the analytical, quantitative and systematic modeling and quantification of both
static and dynamic manufacturing complexity is proposed. Static complexity concerns the
structure of the manufacturing systems, namely the products, the processes, the resources that
constitute the systems as well as their interconnections. Static complexity is treated as the
information that is required for the description of a manufacturing system. Multi domain
matrices modeling the relationships between products, processes and resources are formalized
as networks following the notions of graph theory. The information content of each matrix is
assessed employing Shannon entropy measure and their aggregation yields the static
complexity. Dynamic complexity is related to the uncertainty in the behaviour of a
manufacturing system and in the present study is associated with the unpredictability of the
performance indicators timeseries. The unpredictability of the performance indicators
timeseries, which are provided by computer simulation, is captured employing the Lempel
Ziv algorithm that calculates the Kolmogorov complexity. The dynamic complexity is either
the unpredictability of a specific timeseries or the weighted mean of a series of performance
indicators timeseries produced under different product demand scenarios. The relationship
between flexibility and complexity is investigated for a group of 19 different configurations of
a manufacturing system. In particular, operation flexibility that refers to the system’s ability
to produce a set of products through different machines, materials, operations and sequences
of operations and total complexity, and both static and dynamic are examined employing a
utility function. As a case study, two assembly lines producing three car floor model types at
three different product mixes are investigated. The dynamic complexity of each assembly
line is assessed and the relationship between product mix and dynamic complexity is studied.
The evaluation of the case study revealed the efficiency of the suggested approach validated
its applicability to industrial environments. / Αντικείμενο της παρούσας διατριβής είναι η ανάπτυξη μεθόδων για την εκτίμηση
πολυπλοκότητας συστημάτων παραγωγής και η διερεύνηση της σχέσης ευελιξίας και
πολυπλοκότητας. Προς αυτή την κατεύθυνση προτείνεται μια ολοκληρωμένη προσέγγιση
βασισμένη στην θεωρία της πληροφορίας που επιτρέπει μια αναλυτική, ποσοτικοποιημένη
και συστηματική προτυποποίηση και εκτίμηση τόσο της στατικής όσο και της δυναμικής
πολυπλοκότητας των συστημάτων παραγωγής. Η στατική πολυπλοκότητα αφορά την δομή
των συστημάτων παραγωγής, και σχετίζεται με τα προϊόντα, τις διεργασίες, τους
παραγωγικούς πόρους που αποτελούν το σύστημα καθώς και τις μεταξύ τους σχέσεις. Η
στατική πολυπλοκότητα αντιμετωπίζεται ως η πληροφορία που απαιτείται για να περιγραφεί
ένα σύστημα παραγωγής. Πολυ-πεδιακοί πίνακες αναπαριστούν τις σχέσεις μεταξύ
προϊόντων, διεργασιών και πόρων και προτυποποιούνται ως δίκτυα ακολουθώντας την
θεωρία γράφων. Το πληροφοριακό περιεχόμενο κάθε πίνακα εκτιμάται με την χρήση της
εντροπίας Shannon και το άθροισμα για όλους τους πίνακες δίνει την στατική
πολυπλοκότητα. Η δυναμική πολυπλοκότητα σχετίζεται με την αβεβαιότητα της
συμπεριφοράς των συστημάτων παραγωγής και στην παρούσα διατριβή συνδέεται με την
απροβλεψιμότητα των χρονοσειρών δεικτών απόδοσης ενός συστήματος. Οι χρονοσειρές
των δεικτών απόδοσης προκύπτουν από υπολογιστική προσομοίωση και η απροβλεψιμότητα
τους εκτιμάται με των αλγόριθμο Lempel Ziv ο οποίος υπολογίζει την πολυπλοκότητα
Kolmogorov. Η δυναμική πολυπλοκότητα είναι η απροβλεψιμότητα είτε μιας συγκεκριμένης
χρονοσειράς είτε ο σταθμισμένος μέσος όρος ενός συνόλου χρονοσειρών δεικτών απόδοσης.
Η σχέση ευελιξίας – πολυπλοκότητας διερευνάται για 19 διαμορφώσεις ενός συστήματος
παραγωγής. Συγκεκριμένα, η ευελιξία λειτουργίας που αναφέρεται στην ικανότητα ενός
συστήματος να παράγει ένα σύνολο προϊόντων χρησιμοποιώντας διαφορετικές μηχανές και
διεργασίες και πολυπλοκότητα τόσο η στατική όσο και η δυναμική μελετώνται με μια
συνάρτηση χρησιμότητας. Ως περίπτωση μελέτης εξετάζονται δύο γραμμές συναρμολόγησης
που παράγουν τρία δάπεδα αμαξιού σε τρία μείγματα παραγωγής. Η δυναμική
πολυπλοκότητα κάθε γραμμής και η σχέση μείγματος παραγωγής και δυναμικής
πολυπλοκότητα μελετώνται. Η αξιολόγηση της περίπτωσης μελέτης αποδεικνύει την
αποτελεσματικότητα των προτεινόμενων μεθόδων σε βιομηχανικό περιβάλλον.
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Analyse et construction de codes LDPC non-binaires pour des canaux à evanouissement / Analysis and Design of Non-Binary LDPC Codes over Fading ChannelsGorgoglione, Matteo 25 October 2012 (has links)
Au cours des 15 dernières années, des progrès spectaculaires dans l'analyse et la conception des codes définis par des graphes bipartites et dé-codables par des algorithmes itératifs ont permis le développement de systèmes de correction d'erreurs, avec des performances de plus en plus proches la limite théorique de Shannon. Dans ce contexte, un rôle déterminant a été joué par la famille des codes à matrice de parité creuse, appelés codes LDPC (pour « Low-Density Parity-Check », en anglais), introduit par Gallager au début des années 60 et décrits plus tard en termes de graphes bipartites. Négligés pendant de longues années, ces codes ont été redécouverts à la fin des années 90, après que la puissance du décodage itératif a été mise en évidence grâce à l'invention des Turbo-codes. Ce n'est qu'au début des années 2000 que les techniques nécessaires à l'analyse et l'optimisation des codes LDPC ont été développées, techniques qui ont permis ensuite la construction des codes avec des performances asymptotiques proches de la limite de Shannon. Cette remarquable avancée a motivé l'intérêt croissant de la communauté scientifique et soutenu le transfert rapide de cette technologie vers le secteur industriel. Plus récemment, un intérêt tout particulier a été porté aux codes LDPC définis sur des alphabets non-binaires, grâce notamment à leur meilleure capacité de correction en « longueur finie ». Bien que Gallager ait déjà proposé l'utilisation des alphabets non-binaires, en utilisant l'arithmétique modulaire, les codes LDPC non-binaires définis sur les corps finis n'ont étés étudiés qu'à partir de la fin des années 90. Il a été montré que ces codes offrent de meilleures performances que leurs équivalents binaires lorsque le bloc codé est de longueur faible à modérée, ou lorsque les symboles transmis sur le canal sont eux-mêmes des symboles non-binaires, comme par exemple dans le cas des modulations d'ordre supérieur ou des canaux à antennes multiples.Cependant, ce gain en performance implique un coût non négligeable en termes de complexité de décodage, quipeut entraver l'utilisation des codes LDPC non binaires dans des systèmes réels, surtout lorsque le prix à payer encomplexité est plus important que le gain en performance.Cette thèse traite de l'analyse et de la conception des codes LDPC non binaires pour des canaux à évanouissements. L'objectif principal de la thèse est de démontrer que, outre le gain en performance en termes de capacité de correction, l'emploi des codes LDPC non binaires peut apporter des bénéfices supplémentaires,qui peuvent compenser l'augmentation de la complexité du décodeur. La « flexibilité » et la « diversité »représentent les deux bénéfices qui seront démontrées dans cette thèse. La « flexibilité » est la capacité d'unsystème de codage de pouvoir s'adapter à des débits (rendements) variables tout en utilisant le même encodeuret le même décodeur. La « diversité » se rapporte à sa capacité d'exploiter pleinement l'hétérogénéité du canal de communication.La première contribution de cette thèse consiste à développer une méthode d'approximation de l'évolution de densité des codes LDPC non-binaires, basée sur la simulation Monte-Carlo d'un code « infini ». Nous montrons que la méthode proposée fournit des estimations très fines des performances asymptotiques des codes LDPCnon-binaires et rend possible l'optimisation de ces codes pour une large gamme d'applications et de modèles de canaux.La deuxième contribution de la thèse porte sur l'analyse et la conception de système de codage flexible,utilisant des techniques de poinçonnage. Nous montrons que les codes LDPC non binaires sont plus robustes au poinçonnage que les codes binaires, grâce au fait que les symboles non-binaires peuvent être partialement poinçonnés. Pour les codes réguliers, nous montrons que le poinçonnage des codes non-binaires obéit à des règles différentes, selon que l'on poinçonne des symboles de / Over the last 15 years, spectacular advances in the analysis and design of graph-basedcodes and iterative decoding techniques paved the way for the development of error correctionsystems operating very close to the theoretical Shannon limit. A prominent rolehas been played by the class of Low Density Parity Check (LDPC) codes, introduced inthe early 60's by Gallager's and described latter in terms of sparse bipartite graphs. In theearly 2000's, LDPC codes were shown to be capacity approaching codes for a wide rangeof channel models, which motivated the increased interest of the scientific community andsupported the rapid transfer of this technology to the industrial sector. Over the past fewyears there has been an increased interest in non-binary LDPC codes due to their enhancedcorrection capacity. Although Gallager already proposed in his seminal work the use ofnon-binary alphabets (by using modular arithmetic), non-binary LDPC codes defined overfinite fields have only been investigated starting with the late 90's. They have been provento provide better performance than their binary counterparts when the block-length issmall to moderate, or when the symbols sent through channel are not binary, which is thecase for high-order modulations or for multiple-antennas channels. However, the performancegain comes at a non-negligible cost in the decoding complexity, which may prohibitthe use of non-binary LDPC codes in practical systems, especially when the price to payin decoding complexity is too high for the performance gain that one can get.This thesis addresses the analysis and design of non-binary LDPC codes for fadingchannels. The main goal is to demonstrate that besides the gain in the decoding performance,the use of non-binary LDPC codes can bring additional benefits that may offsetthe extra cost in decoding complexity. Flexibility and diversity are the two benefitsthat we demonstrate in this thesis. The exibility is the capacity of a coding system toaccommodate multiple coding rates through the use of a unique encoder/decoder pair. Thediversity of a coding system relates to its capacity to fully exploit the communicationchannel's heterogeneity.The first contribution of the thesis is the development of a Density Evolution approximationmethod, based on the Monte-Carlo simulation of an infinite code. We showthat the proposed method provides accurate and precise estimates of non-binary ensemblethresholds, and makes possible the optimization of non-binary codes for a wide range ofapplications and channel models.The second contribution of the thesis consists of the analysis and design of flexiblecoding schemes through the use of puncturing. We show that the non-binary LDPCcodes are more robust to puncturing than their binary counterparts, thanks to the factthat non-binary symbol-nodes can be only partially punctured. For regular codes, we showthat the design of puncturing patterns must respect different rules depending on whetherthe symbol-nodes are of degree 2 or higher. For irregular codes we propose an optimizationprocedure and we present optimized puncturing distributions for non-binary LDPC codes,iiiwhich exhibit a gap to capacity between 0.2 and 0.5dB , for punctured rates varying from0.5 to 0.9.The third contribution investigates the non-binary LDPC codes transmitted over aRayleigh (fast) fading channel, in which different modulated symbols are affected by differentfading factors. In case of one-to-one correspondence between modulated and codedsymbols, deep fading can make some coded symbols totally unrecoverable, leading to apoor system performance. In order to avoid this phenomenon, binary diversity can beexploited by using a bit-interleaver module placed between the encoder and the modulator.We propose an optimized interleaving algorithm, inspired from the Progressive Edge-Growth (PEG) method, which ensures maximum girth of th
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