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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Verifying Permutation Rewritable Hazard Free Loops

Dobrogost, Michal 10 1900 (has links)
<p>We present an extension to the language of Atomic Verifiable Operation (AVOp) streams to allow the expression of loops which are rewritable via an arbitrary permutation. Inspired by (and significantly extending) hardware register rotation to data buffers in multi-core programs, we hope to achieve similar performance benefits in expressing software pipelined programs across many cores. By adding loops to AVOp streams, we achieve significant stream compression, which eliminates an impediment to scalability of this abstraction. Furthermore, we present a fast extension to the previous AVOp verification process which ensures that no data hazards are present in the program’s patterns of communication. Our extension to the verification process is to verify loops without completely unrolling them. A proof of correctness for the verification process is presented.</p> / Master of Science (MSc)
162

A RESAMPLING BASED APPROACH IN EVALUATION OF DOSE-RESPONSE MODELS

Fu, Min January 2014 (has links)
In this dissertation, we propose a computational approach using a resampling based permutation test as an alternative to MCP-Mod (a hybrid framework integrating the multiple comparison procedure and the modeling technique) and gMCP-Mod (generalized MCP-Mod) [11], [29] in the step of identifying significant dose-response signals via model selection. We name our proposed approach RMCP-Mod or gRMCP-Mod correspondingly. The RMCP-Mod/gRMCP-Mod transforms the drug dose comparisons into a dose-response model selection issue via multiple hypotheses testing, an area where not much extended researches have been done, and solve it using resampling based multiple testing procedures [38]. The proposed approach avoids the inclusion of the prior dose-response knowledge known as "guesstimates" used in the model selection step of the MCP-Mod/gMCP-Mod framework, and therefore reduces the uncertainty in the significant model identification. When a new drug is being developed to treat patients with a specified disease, one of the key steps is to discover an optimal drug dose or doses that would produce the desired clinical effect with an acceptable level of toxicity. In order to nd such a dose or doses (different doses may be able to produce the same or better clinical effect with similar acceptable toxicity), the underlying dose-response signals need to be identified and thoroughly examined through statistical analyses. A dose-response signal refers to the fact that a drug has different clinical effects at many quantitative dose levels. Statistically speaking, the dose-response signal is a numeric relationship curve (shape) between drug doses and the clinical effects in quantitative measures. It's often been a challenge to nd correct and accurate efficacy and/or safety dose-response signals that would best describe the dose-effect relationship in the drug development process via conventional statistical methods because the conventional methods tend to either focus on a fixed, small number of quantitative dosages or evaluate multiple pre-denied dose-response models without Type I error control. In searching for more efficient methods, a framework of combining both multiple comparisons procedure (MCP) and model-based (Mod) techniques acronymed MCP-Mod was developed by F. Bretz, J. C. Pinheiro, and M. Branson [11] to handle normally distributed, homoscedastic dose response observations. Subsequently, a generalized version of the MCP- Mod named gMCP-Mod which can additionally deal with binary, counts, or time-to-event dose-response data as well as repeated measurements over time was developed by J. C. Pinheiro, B. Bornkamp, E. Glimm and F. Bretz [29]. The MCP-Mod/gMCP-Mod uses the guesstimates" in the MCP step to pre-specify parameters of the candidate models; however, in situations where the prior knowledge of the dose-response information is difficult to obtain, the uncertainties could be introduced into the model selection process, impacting on the correctness of the model identification. Throughout the evaluation of its application to the hypothetical and real study examples as well as simulation comparisons to the MCP-Mod/gMCP-Mod, our proposed approach, RMCP-Mod/gRMCP-Mod seems a viable method that can be used in the practice with some further improvements and researches that are still needed in applications to broader dose-response data types. / Statistics
163

Application of Permutation Genetic Algorithm for Sequential Model Building–Model Validation Design of Experiments

Kianifar, Mohammed R., Campean, Felician, Wood, Alastair S. 08 1900 (has links)
Yes / The work presented in this paper is motivated by a complex multivariate engineering problem associated with engine mapping experiments, which require efficient Design of Experiment (DoE) strategies to minimise expensive testing. The paper describes the development and evaluation of a Permutation Genetic Algorithm (PermGA) to support an exploration-based sequential DoE strategy for complex real-life engineering problems. A known PermGA was implemented to generate uniform OLH DoEs, and substantially extended to support generation of Model Building–Model Validation (MB-MV) sequences, by generating optimal infill sets of test points as OLH DoEs, that preserve good space filling and projection properties for the merged MB + MV test plan. The algorithm was further extended to address issues with non-orthogonal design spaces, which is a common problem in engineering applications. The effectiveness of the PermGA algorithm for the MB-MV OLH DoE sequence was evaluated through a theoretical benchmark problem based on the Six-Hump-Camel-Back (SHCB) function, as well as the Gasoline Direct Injection (GDI) engine steady state engine mapping problem that motivated this research. The case studies show that the algorithm is effective at delivering quasi-orthogonal space-filling DoEs with good properties even after several MB-MV iterations, while the improvement in model adequacy and accuracy can be monitored by the engineering analyst. The practical importance of this work, demonstrated through the engine case study, also is that significant reduction in the effort and cost of testing can be achieved. / The research work presented in this paper was funded by the UK Technology Strategy Board (TSB) through the Carbon Reduction through Engine Optimization (CREO) project.
164

Origamis et groupes de permutation / Origamis and permutation groups

Zmiaikou, David 08 September 2011 (has links)
Un origami est un revêtement du tore T2, éventuellement ramifié au-dessus de l'origine.Cet objet a été introduit par William P. Thurston et William A. Veech dans les années 1970.Un origami peut être vu comme un ensemble fini de copies du carreau unitaire qui sont collées par translations. Ainsi, un origami est un cas particulier d'une surface de translation,un élément de l'espace des modules de surfaces de Riemann munies d'une 1-forme holomorphe.Un origami O avec n carreaux correspond à une paire de permutations (σ, τ ) Є 2 Sn X Sn définie à conjugaison près. Le groupe Mon(O) engendré par une telle paire s'appelle le groupe de monodromie de O. On dit qu'un origami est primitif si son groupe de monodromie est un groupe de permutation primitif. Il y a une action naturelle du groupeGL2(Z) sur les origamis, le stabilisateur de O pour cette action est le groupe de Veechdésigné par GL(O). Le groupe de monodromie est un invariant des GL2(Z)-orbites.Dans le chapitre 3 de la thèse, nous montrons que le groupe de monodromie de tout origami primitif à n carreaux dans la strate H(2k) est An ou Sn si n ≥ 3k + 2, et noustrouvons la borne exacte quand 2k + 1 est premier. La même proposition est vraie pourla strate H(1; 1) si n =/= 6. Dans le chapitre 4, nous considérons les origamis réguliers,i.e. ceux pour lesquels le nombre de carreaux est égal à l'ordre du groupe de monodromie.Nous construisons de nouvelles familles d'origamis intéressantes et cherchons leurs strates et groupes de Veech. Nous estimons également le nombre de GL2(Z)-orbites et strates distinctes des origamis réguliers ayant un groupe de monodromie donné. Afin de trouver une borne inférieure pour les origamis alternés, nous prouvons que chaque permutation dans An quifixe peu de points est le commutateur d'une paire engendrant An. Dans le chapitre 6, nous étudions une propriété de sous-groupes de PSL2(Z) qui est liée à la propriété d'être le groupe de Veech d'un origami. / An origami is a covering of the torus T2, possibly ramified above the origin. This objectwas introduced by William P. Thurston and William A. Veech in 1970s. Un origami can beviewed as a finite collection of copies of the unitary square that are glued by translations.Thus, un origami is a particular case of a translation surface, that is, an element of the moduli space of Riemann surfaces equipped with a holomorphic 1-form.An n-square origami O corresponds to a pair of permutations (σ, τ ) Є 2 Sn X Sn defined up to conjugation. The group Mon(O) generated by such a pair is called the monodromy group of O. We say that an origami is primitive if its monodromy group is a primitive permutation group. There is a natural action of group GL2(Z) on the origamis, the stabilizer of O for this action is the Veech group denoted by GL(O). The monodromy group is aninvariant of the GL2(Z)-orbits.In the chapter 3 of the thesis, we show that the monodromy group of any primitive n-square origami in the stratum H(2k) is either An or Sn if n ≥ 3k + 2, and we find the exact bound when 2k + 1 is prime. The same proposition is true for the stratum H(1; 1) if n =/= 6.In the chapter 4, we consider the regular origamis, i.e. the origamis for which the number of squares equals the order of the monodromy group. We construct new families of origamis and investigate their strata and Veech groups. Also, we estimate the number of distinct GL2(Z)-orbits and strata of regular origamis with a given monodromy group. In order to find a lower bound for alternating origamis, we prove that each permutation in An which fixes few points is the commutator of a pair generating An. In the chapter 6, we study a subgroup property of PSL2(Z) that is related to the property to be the Veech group of an origami.
165

Vitesse de convergence de l'échantillonneur de Gibbs appliqué à des modèles de la physique statistique / The convergence rate of the Gibbs sampler for some statistical mechanics models

Helali, Amine 11 January 2019 (has links)
Les méthodes de Monte Carlo par chaines de Markov MCMC sont des outils mathématiques utilisés pour simuler des mesures de probabilités π définies sur des espaces de grandes dimensions. Une des questions les plus importantes dans ce contexte est de savoir à quelle vitesse converge la chaine de Markov P vers la mesure invariante π. Pour mesurer la vitesse de convergence de la chaine de Markov P vers sa mesure invariante π nous utilisons la distance de la variation totale. Il est bien connu que la vitesse de convergence d’une chaine de Markov réversible P dépend de la deuxième plus grande valeur propre en valeur absolue de la matrice P notée β!. Une partie importante dans l’estimation de β! consiste à estimer la deuxième plus grande valeur propre de la matrice P, qui est notée β1. Diaconis et Stroock (1991) ont introduit une méthode basée sur l’inégalité de Poincaré pour estimer β1 pour le cas général des chaines de Markov réversibles avec un nombre fini d'état. Dans cette thèse, nous utilisons la méthode de Shiu et Chen (2015) pour étudier le cas de l'algorithme de l'échantillonneur de Gibbs pour le modèle d'Ising unidimensionnel avec trois états ou plus appelé aussi modèle de Potts. Puis, nous généralisons le résultat de Shiu et Chen au cas du modèle d’Ising deux- dimensionnel avec deux états. Les résultats obtenus minorent ceux introduits par Ingrassia (1994). Puis nous avons pensé à perturber l'échantillonneur de Gibbs afin d’améliorer sa vitesse de convergence vers l'équilibre. / Monte Carlo Markov chain methods MCMC are mathematical tools used to simulate probability measures π defined on state spaces of high dimensions. The speed of convergence of this Markov chain X to its invariant state π is a natural question to study in this context.To measure the convergence rate of a Markov chain we use the total variation distance. It is well known that the convergence rate of a reversible Markov chain depends on its second largest eigenvalue in absolute value denoted by β!. An important part in the estimation of β! is the estimation of the second largest eigenvalue which is denoted by β1.Diaconis and Stroock (1991) introduced a method based on Poincaré inequality to obtain a bound for β1 for general finite state reversible Markov chains.In this thesis we use the Chen and Shiu approach to study the case of the Gibbs sampler for the 1−D Ising model with three and more states which is also called Potts model. Then, we generalize the result of Shiu and Chen (2015) to the case of the 2−D Ising model with two states.The results we obtain improve the ones obtained by Ingrassia (1994). Then, we introduce some method to disrupt the Gibbs sampler in order to improve its convergence rate to equilibrium.
166

Applications du calcul des probabilités à la recherche de régions génomiques conservées

Grusea, Simona 03 December 2008 (has links) (PDF)
Cette thèse se concentre sur quelques sujets de probabilités et statistique liés à la génomique comparative. Dans la première partie nous présentons une approximation de Poisson composée pour calculer des probabilités impliquées dans des tests statistiques pour la significativité des régions génomiques conservées trouvées par une approche de type région de référence.<br>Un aspect important de notre démarche est le fait de prendre en compte l'existence des familles multigéniques. Dans la deuxième partie nous proposons trois mesures, basées sur la distance de transposition dans le groupe symétrique, pour quantifier l'exceptionalité de l'ordre des gènes dans des régions génomiques conservées. Nous avons obtenu des expressions analytiques pour leur distribution dans le cas d'une permutation aléatoire. Dans la troisième partie nous avons étudié la distribution du nombre de cycles dans le graphe des points de rupture d'une permutation signée aléatoire. Nous avons utilisé la technique ``Markov chain imbedding'' pour obtenir cette distribution en terme d'un produit de matrices de transition d'une certaine chaîne de Markov finie. La connaissance de cette<br>distribution fournit par la suite une très bonne approximation pour la distribution de la distance d'inversion.
167

Codes et tableaux de permutations, construction, énumération et automorphismes / Permutation codes and permutations arrays: construction, enumeration and automorphisms

Bogaerts, Mathieu 22 June 2009 (has links)
<p>Un code de permutations G(n,d) un sous-ensemble C de Sym(n) tel que la distance de Hamming D entre deux éléments de C est supérieure ou égale à d. Dans cette thèse, le groupe des isométries de (Sym(n),D) est déterminé et il est prouvé que ces isométries sont des automorphismes du schéma d'association induit sur Sym(n) par ses classes de conjugaison. Ceci mène, par programmation linéaire, à de nouveaux majorants de la taille maximale des G(n,d) pour n et d fixés et n compris entre 11 et 13. Des algorithmes de génération avec rejet d'objets isomorphes sont développés. Pour classer les G(n,d) non isométriques, des invariants ont été construits et leur efficacité étudiée. Tous les G(4,3) et les G(5,4) ont été engendrés à une isométrie près, il y en a respectivement 61 et 9445 (dont 139 sont maximaux et décrits explicitement). D’autres classes de G(n,d) sont étudiées.<p><p><p><p> <p><p><p><p>A permutation code G(n,d) is a subset C of Sym(n) such that the Hamming distance D between two elements of C is larger than or equal to d. In this thesis, we characterize the isometry group of the metric space (Sym(n),D) and we prove that these isometries are automorphisms of the association scheme induced on Sym(n) by the conjugacy classes. This leads, by linear programming, to new upper bounds for the maximal size of G(n,d) codes for n and d fixed and n between 11 and 13. We develop generating algorithms with rejection of isomorphic objects. In order to classify the G(n,d) codes up to isometry, we construct invariants and study their efficiency. We generate all G(4,3) and G(4,5)codes up to isometry; there are respectively 61 and 9445 of them. Precisely 139 out of the latter codes are maximal and explicitly described. We also study other classes of G(n,d)codes.<p><p><p><p> / Doctorat en sciences, Spécialisation mathématiques / info:eu-repo/semantics/nonPublished
168

Implementation of 3GPP LTE QPP Interleaver for SiLago

Dey, Spandan January 2019 (has links)
Modern wireless communication systems have seen an increased usage of various channel coding techniques to facilitate improved throughput and latency. Interleavers form an integral part of these coding techniques and play a critical role by making the communication more robust and resilient to noise and other interference. The ever increasing need for higher throughputs and lower latencies has made designers to pursue a more parallel design approach giving rise to parallel adaptations of these encoding/decoding techniques. A bulk of the modern telecommunication occurs over Wireless Wide Area Network (WWAN), commonly referred to as cellular networks. The 3rd Generation Partnership Project (3GPP), Long Term Evolution (LTE) develops and specifies the standards that are used in cellular communication. Their current most widely used "4G" standard employs Turbo coding techniques and a Quadratic Permutation Polynomial (QPP) interleaver. Silicon Large Grain Object or SiLago is a Coarse Grain Reconfigurable Fabric facilitating a modular approach towards electronics hardware development. The concept is similar to LEGO bricks, that is to have a library of hardened blocks (similar to Lego bricks) out of which systems of various types and functionalities can be built. This thesis investigates the state-of-the-art parallel interleavers and parallel interleaving techniques available for the 3GPP LTE QPP interleavers, and implements two interleaver designs, one for Radix 2 and another for Radix 4 decoding techniques. A physical synthesis is carried out in 28nm technology and the results in terms of power and area are reported. / Moderna trådlösa kommunikationssystem har sett ökad användning av olika kanaler kodningstekniker för att underlätta förbättrad genomströmning och latens. Interleavers utgör en integrerad del av dessa kodningstekniker och spelar en viktig roll genom att göra kommunikation mer robust och fjädrande för brus och andra störningar. Det ökande behovet av högre genomströmningar och lägre latenser har gjort konstruktörer att driva en mer parallell design tillvägagångssätt som ger upphov till parallella anpassningar av dessa kodningstekniker. En stor del av modern telekommunikation är via Wireless Wide Area Network (WWAN), vanligen kallad mobilnät. Det Third Generation Partnership Project (3GPP), Long Term Evolution (LTE) utvecklar och specificerar de standarder som används i mobil kommunikation. Deras nuvarande mest använda "4G" standard använder Turbo-kodning tekniker och en Quadratic Permutation Polynomial (QPP) interleaver. Silicon Large Grain Object eller SiLago är ett grovt kornkonfigurerbart tygstöd ett modulärt tillvägagångssätt för elektronikutveckling. Konceptet är liknande LEGO-tegelstenar, det är med ett library av härdade block (liknande Lego-tegelstenar), varav system av olika typer och funktioner kan byggas. Denna avhandling undersöker de toppmoderna parallella interleaversna och parallellinterfolieringen tekniker som är tillgängliga för 3GPP LTE QPP interleavers, och implementerar tvåinterleavers mönster, en för Radix 2 och en annan för Radix 4avkodningstekniker. En fysisk syntes utförs i 28nm-teknik och resultaten i kraft och area rapporteras.
169

SOME PERMUTATION BINOMIALS AND WEAK CARLITZ'S CONJECTURE

黃培琨, HUANG, PEI-KUN Unknown Date (has links)
壹、引言 近年來,訊號傳送的途徑,已擺脫了傳統上著重管線傳送的優勢;有愈來愈多的訊號 彌漫在廣闊的空間裡,而這種無線式的傳送所需面臨的問題是:不具有排它性,任何 有接收器材的非原始接收者都可以截聽到訊息,由於因應而生的保密技術格外受矚目 ,密碼學(CRYPTOGRAPHY)便是滿足此需要的學問。本論文所探討的排列多項式(PE RMUTATION POLYNOMIAL)是密碼學中重要的工具之一。 貳、論文主體 所謂排列多項式,即是佈於代數體上的多項式,把此多項式當成函數而作用於代數體 (FIELD )上,如果此函數具有一對一的性質,則是排列多項式。即 f(x)=a。+ a1 x1 + ....anxn ≡ Fq〔X〕且 f(a)╪f(b),a,b≡Fq,a╪b. 在論文中,介紹先進學者對排列多項式的認識。如:LAGRANGE'S INTERPOLATION是利 用函數值來描繪多項式,著名的學者CARLITZ ,利用特殊多項式來合成出排列多項式 ,論文中有更進一步的合成法提出,而HERMITE 跟DICKSON 學者則提出Ft函數其冪次 的變化情形,來判別排列多項式之是否,是最通俗的判別理論。 此外,由吾人所蒐集的資料中發現,在祗有兩項的多項式中,被發現到其它更簡捷快 速的判別方法,故二項式的多項式的探討是本論文的第一主題,對於 k j X+bx ≡Fq〔X〕, 給予固定類型的q,k,j情形下,祗須檢定b是否具特 殊性質就可決定是否為排列多項式,這是一種方法。另有學者並不固定q,k,j, 反而從q,k,j數字下手,找尋出某種關連性,其結果使得係數b,只有當b=0 ,時才有機會是排列多項式,乘下單項式的判別過程,就很容易了。另外還有一種方 法也是找尋q,k,j間的關係,不過其結果在找出:多項式為非排列多項式,是比 較特別的地方。上述三方法,本論文網羅大部份有關論文,綜合各家之長,並適當給 予一同於原作者的新觀點證明方法。 至於本論文第二主題是著名的CARLITZ'S CONJECTURE此預測敘述:對於任何具有最高 冪次是偶數的多項式,必定存在一個自然數k,使得給定的代數體,其元素個數只要 超過k,則此多項式必定不是排列多項式。此預測當degree n=10,12,14, and 2m 時 已被證實為真。本論文僅就n=2m,做系統地探討及重新證明。 參、結語 本論文所論的兩主題,對於佈於代數體上的多項式是否為排列多項式,在判別的過程 上應有相當的助益才是。
170

Postupy pro detekci změny v některých speciálních regresních modelech / Postupy pro detekci změny v některých speciálních regresních modelech

Exnarová, Petra January 2013 (has links)
Title: Detection of change in some special regression models Author: Bc. Petra Exnarová Department: Department of Probability and Mathematical Statistics Supervisor: Prof. RNDr. Marie Hušková, DrSc. Abstract: Presented thesis deals with testing of change in three special cases of change-point analysis. First of them is case of continuous change in linear regression (so-called broken-line model), the other two are related to change in parameters of discrete value distributions - simple case of Bernoulli distributed variables is studied first and then the approach is generalized for case of Multi- nomial distribution. Both situations of known and unknown change point are described for all three cases. Beside approximation by using limit theorems, the bootstrap method and permutation test are described for all studied cases as well. The comparison of critical values gained by different approaches for the particular tests and small power analysis is done using simulations. Keywords: change-point analysis, broken-line model, discrete distribution, boot- strap, permutation test 1

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