Готові списки джерел за темами / Substitution matrices

Добірка наукової літератури з теми "Substitution matrices"

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Опубліковано: 14 березня 2023

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Статті в журналах з теми "Substitution matrices"

1

Koshi, J. M., and R. A. Goldstein. "Context-dependent optimal substitution matrices." Protein Engineering Design and Selection 8, no. 7 (July 1, 1995): 641–45. http://dx.doi.org/10.1093/protein/8.7.641.

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2

Hautus, M. L. J. "Substitution of matrices over rings." Linear Algebra and its Applications 226-228 (September 1995): 353–70. http://dx.doi.org/10.1016/0024-3795(95)00155-k.

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3

BARBÉ, ANDRÉ M. "FRACTALS BY NUMBERS." Fractals 03, no. 04 (December 1995): 651–61. http://dx.doi.org/10.1142/s0218348x95000588.

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We introduce an extension of an earlier defined simple, number-based matrix substitution system for obtaining fractal matrices, by considering cyclic substitutions. The elements of the resulting matrices are related to representations of their addresses in a mixed number base. The Hutchinson operator for the limit form of a geometrical representation of the fractal matrix is derived. It is shown that the class of fractal limit sets obtainable from cyclic substitutions does not extend the class obtainable from the simple substitutions.
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4

Barlowe, Scott, Heather B. Coan, and Robert T. Youker. "SubVis: an interactive R package for exploring the effects of multiple substitution matrices on pairwise sequence alignment." PeerJ 5 (June 27, 2017): e3492. http://dx.doi.org/10.7717/peerj.3492.

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Understanding how proteins mutate is critical to solving a host of biological problems. Mutations occur when an amino acid is substituted for another in a protein sequence. The set of likelihoods for amino acid substitutions is stored in a matrix and input to alignment algorithms. The quality of the resulting alignment is used to assess the similarity of two or more sequences and can vary according to assumptions modeled by the substitution matrix. Substitution strategies with minor parameter variations are often grouped together in families. For example, the BLOSUM and PAM matrix families are commonly used because they provide a standard, predefined way of modeling substitutions. However, researchers often do not know if a given matrix family or any individual matrix within a family is the most suitable. Furthermore, predefined matrix families may inaccurately reflect a particular hypothesis that a researcher wishes to model or otherwise result in unsatisfactory alignments. In these cases, the ability to compare the effects of one or more custom matrices may be needed. This laborious process is often performed manually because the ability to simultaneously load multiple matrices and then compare their effects on alignments is not readily available in current software tools. This paper presents SubVis, an interactive R package for loading and applying multiple substitution matrices to pairwise alignments. Users can simultaneously explore alignments resulting from multiple predefined and custom substitution matrices. SubVis utilizes several of the alignment functions found in R, a common language among protein scientists. Functions are tied together with the Shiny platform which allows the modification of input parameters. Information regarding alignment quality and individual amino acid substitutions is displayed with the JavaScript language which provides interactive visualizations for revealing both high-level and low-level alignment information.
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5

BALDI, PIERRE. "Substitution Matrices and Hidden Markov Models." Journal of Computational Biology 2, no. 3 (January 1995): 487–91. http://dx.doi.org/10.1089/cmb.1995.2.487.

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6

Dosztányi, Zs, and A. E. Torda. "SUBSTITUTION MATRICES BASED ON FORCE FIELDS." Biochemical Society Transactions 28, no. 5 (October 1, 2000): A146. http://dx.doi.org/10.1042/bst028a146.

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7

G., Renganayaki, and Achuthsankar S. Nair. "Hubsm: A Novel Amino Acid Substitution Matrix for Comparing Hub Proteins." International Journal of Advanced Research in Computer Science and Software Engineering 7, no. 8 (August 30, 2017): 212. http://dx.doi.org/10.23956/ijarcsse.v7i8.53.

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Анотація:
Sequence alignment algorithms and database search methods use BLOSUM and PAM substitution matrices constructed from general proteins. These de facto matrices are not optimal to align sequences accurately, for the proteins with markedly different compositional bias in the amino acid. In this work, a new amino acid substitution matrix is calculated for the disorder and low complexity rich region of Hub proteins, based on residue characteristics. Insights into the amino acid background frequencies and the substitution scores obtained from the Hubsm unveils the residue substitution patterns which differs from commonly used scoring matrices .When comparing the Hub protein sequences for detecting homologs, the use of this Hubsm matrix yields better results than PAM and BLOSUM matrices. Usage of Hubsm matrix can be optimal in database search and for the construction of more accurate sequence alignments of Hub proteins.
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8

Aledo, Pablo, and Juan Carlos Aledo. "Proteome-Wide Structural Computations Provide Insights into Empirical Amino Acid Substitution Matrices." International Journal of Molecular Sciences 24, no. 1 (January 2, 2023): 796. http://dx.doi.org/10.3390/ijms24010796.

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The relative contribution of mutation and selection to the amino acid substitution rates observed in empirical matrices is unclear. Herein, we present a neutral continuous fitness-stability model, inspired by the Arrhenius law (qij=aije−ΔΔGij). The model postulates that the rate of amino acid substitution (i→j) is determined by the product of a pre-exponential factor, which is influenced by the genetic code structure, and an exponential term reflecting the relative fitness of the amino acid substitutions. To assess the validity of our model, we computed changes in stability of 14,094 proteins, for which 137,073,638 in silico mutants were analyzed. These site-specific data were summarized into a 20 square matrix, whose entries, ΔΔGij, were obtained after averaging through all the sites in all the proteins. We found a significant positive correlation between these energy values and the disease-causing potential of each substitution, suggesting that the exponential term accurately summarizes the fitness effect. A remarkable observation was that amino acids that were highly destabilizing when acting as the source, tended to have little effect when acting as the destination, and vice versa (source → destination). The Arrhenius model accurately reproduced the pattern of substitution rates collected in the empirical matrices, suggesting a relevant role for the genetic code structure and a tuning role for purifying selection exerted via protein stability.
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9

LIU, XIN, and WEI-MOU ZHENG. "AN AMINO ACID SUBSTITUTION MATRIX FOR PROTEIN CONFORMATION IDENTIFICATION." Journal of Bioinformatics and Computational Biology 04, no. 03 (June 2006): 769–82. http://dx.doi.org/10.1142/s0219720006002156.

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Amino acid substitution matrices play an essential role in protein sequence alignment, a fundamental task in bioinformatics. Most widely used matrices, such as PAM matrices derived from homologous sequences and BLOSUM matrices derived from aligned segments of PROSITE, did not integrate conformation information in their construction. There are a few structure-based matrices, which are derived from limited data of structure alignment. Using databases PDB_SELECT and DSSP, we create a database of sequence-conformation blocks which explicitly represent sequence-structure relationship. Members in a block are identical in conformation and are highly similar in sequence. From this block database, we derive a conformation-specific amino acid substitution matrix CBSM60. The matrix shows an improved performance in conformational segment search and homolog detection.
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10

Vilim, R. B., R. M. Cunningham, B. Lu, P. Kheradpour, and F. J. Stevens. "Fold-specific substitution matrices for protein classification." Bioinformatics 20, no. 6 (February 5, 2004): 847–53. http://dx.doi.org/10.1093/bioinformatics/btg492.

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Більше джерел

Дисертації з теми "Substitution matrices"

1

Anfinsen, Jarle. "Making substitution matrices metric." Thesis, Norwegian University of Science and Technology, Department of Computer and Information Science, 2005. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9237.

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With the emergence and growth of large databases of information, efficient methods for storage and processing are becoming increasingly important. The existence of a metric distance measure between data entities enables efficient index structures to be applied when storing the data. Unfortunately, this is often not the case. Amino acid substitution matrices, which are used to estimate similarities between proteins, do not yield metric distance measures. Finding efficient methods for converting a non-metric matrix into a metric one is therefore highly desirable. In this work, the problem of finding such conversions is approached by embedding the data contained in the non-metric matrix into a metric space. The embedding is optimized according to a quality measure which takes the original data into account, and a distance matrix is then derived using the metric distance function of the space. More specifically, an evolutionary scheme is proposed for constructing such an embedding. The work shows how a coevolutionary algorithm can be used to find a spatial embedding and a metric distance function which try to preserve as much of the proximity structure of the non-metrix matrix as possible. The evolutionary scheme is compared to three existing embedding algorithms. Some modifications to the existing algorithms are proposed, with the purpose of handling the data in the non-metric matrix more efficiently. At a higher level, the strategy of deriving a metric distance function from a spatial embedding is compared to an existing algorithm which enforces metricity by manipulating the data in the non-metric matrix directly (the triangle fixing algorithm). The methods presented and compared are general in the sense that they can be applied in any case where a non-metric matrix must be converted into a metric one, regardless of how the data in the non-metric matrix was originally derived. The proposed methods are tested empirically on amino acid substitution matrices, and the derived metric matrices are used to search for similarity in a database of proteins. The results show that the embedding approach outperforms the triangle fixing approach when applied to matrices from the PAM family. Moreover, the evolutionary embedding algorithms perform best among the embedding algorithms. In the case of the PAM250 scoring matrix, a metric distance matrix is found which is more sensitive than the mPAM250 matrix presented in a recent paper. Possible advantages of choosing one method over another are shown to be unclear in the case of matrices from the BLOSUM family.

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2

Rizzato, Francesca. "Towards a deeper understanding of protein sequence evolution." Doctoral thesis, SISSA, 2016. http://hdl.handle.net/20.500.11767/4904.

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Most bioinformatic analyses start by building sequence alignments by means of scoring matrices. An implicit approximation on which many scoring matrices are built is that protein sequence evolution is considered a sequence of Point Accepted Mutations (PAM) (Dayhoff et al., 1978), in which each substitution happens independently of the history of the sequence, namely with a probability that depends only on the initial and final amino acids. But different protein sites evolve at a different rate (Echave et al., 2016) and this feature, though included in many phylogenetic reconstruction algorithms, is generally neglected when building or using substitution matrices. Moreover, substitutions at different protein sites are known to be entangled by coevolution (de Juan et al., 2013). This thesis is devoted to the analysis of the consequences of neglecting these effects and to the development of models of protein sequence evolution capable of incorporating them. We introduce a simple procedure that allows including the among-site rate variability in PAM-like scoring matrices through a mean-field-like framework, and we show that rate variability leads to non trivial evolutions when considering whole protein sequences. We also propose a procedure for deriving a substitution rate matrix from Single Nucleotide Polymorphisms (SNPs): we first test the statistical compatibility of frequent genetic variants within a species and substitutions accumulated between species; moreover we show that the matrix built from SNPs faithfully describes substitution rates for short evolutionary times, if rate variability is taken into account. Finally, we present a simple model, inspired by coevolution, capable of predicting at the same time the along-chain correlation of substitutions and the time variability of substitution rates. This model is based on the idea that a mutation at a site enhances the probability of fixing mutations in the other protein sites in its spatial proximity, but only for a certain amount of time.
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3

Lefebvre, Dominique. "Hexagallates de lanthanide pour matrices laser et substrats d'épitaxie : élaboration, étude cristallographique et spectroscopique." Paris 6, 1986. http://www.theses.fr/1986PA066415.

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Différentes méthodes de cristallogenèse de la MgGa 11O 19 sont testées, notamment l'élaboration par tirage Czochralski. Affinement structural confirmant la structure de type magnétoplombite du composé. Substitution ionique permettant d'accroitre les paramètres cristallins du composé étudié en vue de son utilisation comme support pour la croissance d'hexaferrites alcalinoterreux. Détermination du domaine schématique de composition des aluminogallates La1-xNdxMgGa11O19. Étude des propriétés optiques du néodyme par réflexion diffuse, RPE et fluorescence.
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4

Gelly, Jean-Christophe. "Système d'information et outils de prédiction structurale spécifiques de classes de protéines : Base de données KNOTTIN et matrices de substitution EvDTree dépendantes de la structure." Montpellier 2, 2004. http://www.theses.fr/2004MON20026.

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5

Theroine, Camille. "Etude de la réaction de capture neutronique radiative pour le noyau instable du ¹⁷³Lu par méthode directe et par réaction de substitution." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00797443.

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L'objectif de ce document est de présenter une étude sur la réaction de capture neutronique radiative du noyau instable du ¹⁷³Lu afin de déterminer sa section efficace (n,γ). Si globalement, pour les noyaux stables de nombreuses informations sont à disposition, il reste un véritable manque de données pour les noyaux radioactifs. La première partie de cette thèse se consacre à la présentation des différents formalismes impliqués dans le calcul d'une section efficace ainsi qu'à l'utilisation du code TALYS basé sur ces différents modèles. TALYS nous a permis d'évaluer la section efficace (n,γ) sur le ¹⁷³Lu en s'appuyant sur la connaissance de la réaction de capture sur le ¹⁷⁵Lu. Dans un deuxième temps, la section efficace (n,γ) sur le ¹⁷³Lu a été mesurée sur l'installation LANSCE avec le détecteur 4π DANCE. Cette expérience s'est révélée être un véritable défi tant pour la fabrication de la cible de ¹⁷³Lu que pour l'obtention de données dû à la grande radioactivité de cet isotope. Nous avons pu extraire des informations intéressantes comme le taux de capture total, identifier et caractériser de nouvelles résonances, déterminer des paramètres comme l'espacement moyen, les largeurs neutroniques et les largeurs γ ainsi que la valeur de la fonction densité. Tous ces nouveaux renseignements nous ont permis de reconstruire la section efficace (n,γ) sur le ¹⁷³Lu jusqu'à 200 eV. Grâce à ces différentes informations, nous avons estimé une correction à appliquer sur la section efficace évaluée par TALYS permettant in fine d'obtenir une nouvelle évaluation de cette quantité. La troisième partie de cette thèse est consacrée à apporter des informations supplémentaires sur la réaction ¹⁷³Lu(n,γ)¹⁷⁴Lu en utilisant la méthode de substitution. En premier lieu, nous avons testé la validité de cette méthode sur une réaction connue : ¹⁷⁵Lu(n,γ)¹⁷⁶Lu avec la réaction ¹⁷⁴Yb(³He,p)¹⁷⁶Lu puis dans un second temps nous avons regardé la réaction ¹⁷³Lu(n,γ)¹⁷⁴Lu avec la réaction ¹⁷⁴Yb(³He,t)¹⁷⁴Lu. Pour cela, la probabilité d'émission γ dans ces deux voies a été mesurée et comparée à un calcul TALYS. Cette comparaison a révélé de grandes disparités entre les réactions de transfert utilisées et les réactions induites par des neutrons. Notre investigation s'est alors orientée à regarder de plus près la distribution de spins du noyau composé formé. Celle-ci a pu être extraite grâce à un ajustement de la probabilité d'émission γ mesurée. Cette distribution montre que les réaction (³He,X) peuplent en réalité des spins beaucoup plus grands que ceux issus de la réaction (n,γ). La mesure des rapports des intensités de transitions γ corroborent aussi ce résultat même si les spins peuplés semblent être plus faibles. Cette expérience a mis clairement en évidence qu'une réaction induite par un faisceau d'³He ne pouvait pas se substituer à une réaction (n,γ). Tout au long de ce document, nous avons montré par différents aspects, à quel point il peut être difficile d'obtenir des informations sur les noyaux radioactifs tels que le ¹⁷³Lu et que pour le futur de nombreux défis tant expérimentaux que théoriques sont encore à relever.
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6

Peroglio-Martynovitch, Marianna. "Composites organiques-inorganiques poreux pour la substitution osseuse." Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0083/these.pdf.

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Le premier matériau est conçu afin d’augmenter la ténacité des blocs céramiques poreux existants, trop fragiles lors de la mise en place dans la cavité osseuse à combler. Le composite est obtenu par infiltration d’une céramique poreuse avec une solution ou une nanodispersion à base de poly(E-caprolactone). Après séchage, les pores sont recouverts par une fine couche de polymère, comme mis en évidence par la microscopie électronique à balayage. La porosimétrie mercure et la tomographie X ont montré qu’après infiltration le diamètre des pores diminue mais l’interconnectivité des pores est préservée. Du point de vue mécanique, des essais de flexion 4 points, compression et traction ont permis d’apprécier le rôle bénéfique du poly(E-caprolactone) sur les propriétés à rupture. On constate un changement du type de rupture, de catastrophique pour la céramique poreuse seule à contrôlée pour le composite, accompagné d’une forte augmentation de l’énergie à rupture dans le cas du composite. Un suivi de la rupture (par loupe binoculaire et camera à haute résolution lors des essais mécaniques conventionnels et par microscopie électronique à balayage environnemental lors de traction in-situ) a montré que le mécanisme de renforcement principal dans ce type de composites est le pontage par des fibrilles. Ces fibrilles peuvent être de plusieurs tailles suivant la distribution de taille des pores de la céramique poreuse de départ. Trois types de céramique poreuse sont utilisés pour la fabrication des composites : alumine, hydroxyapatite-(β-tricalcium phosphate) et bioverre. Le deuxième matériau est obtenu par infiltration d’une mousse polyuréthane avec un ciment phosphocalcique à base d’alpha-TCP. Ce matériau est souple pendant la prise, ce qui devrait être favorable à la mise en place du substitut dans la cavité osseuse à combler. Après prise on obtient une fine couche de ciment sur la surface de la mousse. Ce composite présente une porosité interconnectée et possède une macro- et microporosité comme mis en évidence par microscopie électronique à balayage et tomographie X. La taille des macropores dans le composite est déterminée par la taille des pores de la mousse polymère et par la quantité de ciment utilisée ; la taille des micropores quant à elle est déterminée par le ratio liquide/poudre utilisé pour gâcher le ciment. Les essais de compression ont montré une nette augmentation du module d’Young et de la contrainte à rupture ; la rupture du composite est de type contrôlée avec un endommagement progressif de la structure. Des essais préliminaires de culture in-vitro avec des cellules stromales humaines de la moelle osseuse ont montré une bonne adhésion et prolifération des cellules. Outre l’α-TCP, le plâtre est le deuxième matériau inorganique qui a été utilisé comme revêtement de la mousse polymère
Bone substitute more easy to handle are obtained by infiltrating a porous ceramic (alumina, hydroxyapatite-beta tricalcium phosphate or bioglass) with a solution or a nanodispersion based on polycaprolactone. Pores are covered with a layer of polymer and rupture, which is catastrophic for the ceramic, becomes a controlled one in the case of the composite, with a strong increase in energy to break thanks to crack bridging by polymer fibrils. Another kind of composite material, pliable during insertion, is obtained by infiltrating a polyurethane sponge with plaster or a cement based on alpha tricalcium phosphate. After setting, a layer of cement is obtained on the surface of the pores, the Young modulus and the strength at break are increased in compression and rupture of the composite is of controlled type, with a progressive damage of the structure. In-vitro tests showed the cytocompatability of the composite
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7

Sellami, Tarek. "Dynamique commune des fractals de rauzy de même matrice d' incidence." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4030/document.

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On sait que la matrice d'incidence associée à une substitution ne suffit pas pour déterminer complètement le système dynamique associé, même dans des cas très simples, il existe plusieurs substitutions associées à une même matrice car il existe de nombreux mots ayant le même abélianisé. Dans cette thèse, on étudie les points communs de deux lignes brisées associées à deux substitutions $sigma_1$ et $sigma_2$ irréductibles unimodulaires de type Pisot qui ont la même matrice d'incidence. On identifie les points communs de ces deux lignes brisées à partir d'un algorithme. On montre ainsi que l'intersection de ces deux lignes brisées est aussi une ligne brisée associée au point fixe d'une nouvelle substitution. On montre plus précisément que si $sigma_1$ vérifie la conjecture Pisot et $0$ est un point intérieur à son fractal de Rauzy alors ces points communs peuvent être engendrés par une substitution définie sur un alphabet appelé alphabet des paires équilibrées. Cette substitution est obtenue à partir d'un algorithme, l'algorithme des paires équilibrées. On obtient ainsi l'intersection des intérieurs des deux fractals de Rauzy. En prenant la clôture de cet ensemble on obtient un ensemble substitutif. La condition que $0$ est un point intérieur au fractal de Rauzy associé à la substitution $sigma_1$ nous permet de montrer que l'intersection des deux fractals de Rauzy est de mesure positive. Dans une deuxième partie du travail on s'intéresse à l'étude de la frontière du fractal de Rauzy. Le fractal de Rauzy est dit fractal mais c'est en fait sa frontière qui est fractale
The matrix of a substitution is not sufficient to completely determine the dynamics associated with it, even in the simplest cases since there are many words with the same abelianization. In this paper we study the common points of the canonical broken lines associated with two different irreducible Pisot unimodular substitutions σ1 and σ2 having the same incidence matrix. We prove that if σ1 verifies the Pisot conjecture and 0 is an inner point to the Rauzy fractal associated with the substitution σ1 then these common points can be generated with a substitution on an alphabet of so-called balanced pairs, and we obtain in this way the intersection of the interior of two Rauzy fractals
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8

Billard, Romain. "Mise au point d’un composite à fibre oxyde et matrice d’aluminosilicate de baryum modifiée." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0291/document.

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L’intérêt de ces travaux est de proposer un nouveau composite BaAl2Si2O8 (BAS) renforcé par des fibres d’alumine ayant des propriétés physiques similaires tout en étant plus réfractaire que les composites SiO2 / SiO2. La forme cristalline hexagonale du BAS est la forme stable à haute température. Cependant, elle est métastable en dessous de 1590 °C et il est donc nécessaire de la stabiliser pour éviter les transformations cristallines. La stabilisation de la forme hexagonale par substitution atomique, notamment par du rubidium à hauteur de 5 % atomique a été la solution retenue. Concernant le composite à matrice BAS, le choix de fibres d’alumine est motivée par la compatibilité physico-chimique BAS / alumine. Diverses voies d’élaboration de la matrice BAS et du composite BAS / alumine ont été explorées. La voie d’élaboration par « reactive spark plasma sintering » (R-SPS) apporte un gain important en termes de réduction du temps d’élaboration et de rendement. Ce gain de temps évite donc l’exposition du BAS aux hautes températures et le risque de transformation de la phase hexagonale en monoclinique. Cependant la mise en forme par SPS de matériaux oxydes, dont le BAS, est confrontée à l’existence de gradients thermiques importants au sein de l’échantillon. C’est pourquoi, la mise en oeuvre d’un moule chauffant est développée comme une alternative au SPS. Ce système, en cours d’évaluation, devrait permettre l’utilisation de cycles thermiques équivalents à ceux du SPS, tout en limitant fortement les gradients thermiques
The main purpose of the present work is to propose a new BaAl2Si2O8 (BAS) composite reinforced with alumina fibers exhibiting similar physical properties but a higher refractoriness than SiO2 / SiO2 composites. The hexagonal crystal form of BAS is the stable one at high temperatures. However, it is metastable below 1590 °C and it is therefore necessary to stabilize it in order to prevent crystalline transformations. The stabilization of the hexagonal form by atomic substitution, including rubidium at 5 atomic % has been chosen. Regarding the matrix BAS composite, the alumina fibers selection has been justified by their low physical and chemical reactivity with this material. Several elaboration methods of the BAS matrix and of the BAS / alumina composite have been investigated. The development by "reactive spark plasma sintering" (R-SPS) brings an important benefit in terms of reduced elaboration time and yield. This saving time thus limits the BAS exposure to high temperatures and the risk of transformation into monoclinic. Nevertheless, the SPS shaping of oxide materials, including the BAS, is confronted with the presence of important thermal gradient within the sample. This is why shaping in a heating mold is currently in progress, as an alternative to the SPS. This system should allow the use the same thermal cycles as for SPS, but with lower thermal gradient
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9

Gomes, Susana Raquel Rodrigues. "Desenvolvimento de matrizes biomiméticas como substitutos de pele destinados ao tratamento de queimaduras." Doctoral thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10931.

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Анотація:
Dissertação para obtenção do Grau de Doutor em Engenharia Biomédica
A Engenharia de Tecidos apresenta actualmente soluções comerciais, para o tratamento de lesões provocadas por queimadura com perda total de pele, que não preenchem todos os requisitos para serem denominados de substitutos definitivos de pele. O objectivo deste trabalho consistiu no desenvolvimento e caracterização físico-química e biológica da componente dérmica de um substituto de pele baseada numa matriz de nanofibras, obtida através da técnica de electrofiação. Os polímeros escolhidos foram a gelatina (GEL), o quitosano (CS) e a policaprolactona (PCL), usando como solvente comum o ácido acético. Estes foram depositados individualmente e em mistura, resultando em três tipos de matrizes: unitárias, binárias e ternária. No sistema de matrizes unitárias apenas a de PCL é hidrofóbica. Em termos de propriedades mecânicas a de PCL é a mais elástica e dúctil e a de GEL a mais rígida e frágil. Os testes in vitro revelaram adesão e proliferação celular em todas as matrizes. Porém, apenas nas matrizes de PCL e CS foi observada migração de células em profundidade. Nos testes in vivo constatou-se uma boa integração das matrizes de CS e de GEL nas feridas, resultando numa cicatriz re-epitelizada ao final de 4 semanas. No sistema de matrizes binárias e ternária, a de PCL/GEL é a menos hidrofílica. Relativamente às propriedades mecânicas observou-se um domínio da componente CS nas misturas preparadas com este polímero. Já a matriz de PCL/GEL reflecte a mistura de ambos os componentes. Os testes in vitro apresentaram adesão e proliferação celular em todas as matrizes. Foram encontradas evidências de processos de invasão celular em todas as matrizes, excepto na matriz de PCL/GEL. Finalmente, em termos de testes in vivo destacou-se uma boa integração das matrizes de CS/GEL e de CS/PCL/GEL na lesão, resultando numa cicatriz re-epitelizada ao final de 4 semanas.
Fundação da Ciência e Tecnologia - bolsa de Doutoramento SFRH / BD / 37854 / 2007
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Seif, El Dine Bassels. "Etude du comportement mécanique de sols grossiers à matrice." Phd thesis, Ecole des Ponts ParisTech, 2007. http://pastel.archives-ouvertes.fr/pastel-00002992.

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Анотація:
Les objectifs de notre travail de recherche sont de contribuer à l'amélioration de la connaissance du comportement mécanique des sols grossiers à matrice, et de proposer une procédure rationnelle de caractérisation de leur comportement mécanique. En vue d'atteindre ces objectifs, il est important de comprendre l'effet des gros éléments dans ces sols. Pour cela, nous travaillerons sur des sols grossiers de référence à matrice sableuse, en vue de mieux comprendre l'effet des inclusions sur le comportement mécanique des mélanges. Ces travaux s'inscrivent dans le prolongement des recherches développées dans le cadre de la thèse de Pedro [2004]. Ces travaux rentrent également dans le cadre du projet de coopération bilatéral franco-libanais CEDRE entre l'ENPC-CERMES et l'Université Libanaise, Faculté de Génie, Beyrouth. (Intro. Auteur)
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Книги з теми "Substitution matrices"

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Substitution: Dynamical Systems : Spectral Analysis (Lecture Notes in Mathematics). Springer, 1988.

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Частини книг з теми "Substitution matrices"

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Queffélec, Martine. "Matrices of Measures." In Substitution Dynamical Systems - Spectral Analysis, 193–207. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-11212-6_7.

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Queffélec, Martine. "Matrices of measures." In Substitution Dynamical Systems-Spectral Analysis, 144–59. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/bfb0081897.

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3

Schneider, Adrian, Gaston H. Gonnet, and Gina M. Cannarozzi. "Synonymous Codon Substitution Matrices." In Computational Science – ICCS 2006, E1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/11758525_148.

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Schneider, Adrian, Gaston H. Gonnet, and Gina M. Cannarozzi. "Synonymous Codon Substitution Matrices." In Computational Science – ICCS 2006, 630–37. Berlin, Heidelberg: Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/11758525_86.

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de Launey, Warwick, and Dane Flannery. "Substitution schemes for cocyclic Hadamard matrices." In Algebraic Design Theory, 223–37. Providence, Rhode Island: American Mathematical Society, 2011. http://dx.doi.org/10.1090/surv/175/19.

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Cao, Minh Duc, Trevor I. Dix, and Lloyd Allison. "Computing Substitution Matrices for Genomic Comparative Analysis." In Advances in Knowledge Discovery and Data Mining, 647–55. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01307-2_64.

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Kitchovitch, Stephan, Yuedong Song, Richard van der Wath, and Pietro Liò. "Substitution Matrices and Mutual Information Approaches to Modeling Evolution." In Lecture Notes in Computer Science, 259–72. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-11169-3_19.

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Mancheron, Alban, and Irena Rusu. "Pattern Discovery Allowing Wild-Cards, Substitution Matrices, and Multiple Score Functions." In Lecture Notes in Computer Science, 124–38. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-39763-2_10.

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Porto, Alexandre H. L., and Valmir C. Barbosa. "A Methodology for Determining Amino-Acid Substitution Matrices from Set Covers." In Lecture Notes in Computer Science, 138–48. Berlin, Heidelberg: Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/11732242_13.

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Méndez, Juan, Antonio Falcón, Mario Hernández, and Javier Lorenzo. "Discovering the Intrinsic Dimensionality of BLOSUM Substitution Matrices Using Evolutionary MDS." In Advances in Soft Computing, 369–76. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-74972-1_48.

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Тези доповідей конференцій з теми "Substitution matrices"

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Błażej, Paweł, Paweł Mackiewicz, Stanisław Cebrat, and Małgorzata Wańczyk. "Using evolutionary algorithms in finding of optimized nucleotide substitution matrices." In Proceeding of the fifteenth annual conference companion. New York, New York, USA: ACM Press, 2013. http://dx.doi.org/10.1145/2464576.2464598.

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Chin, Kuo-fan, Minxian Wu, and Shaomin Zhou. "Using symbolic substitution method on optical matrix multiplication." In Optical Computing. Washington, D.C.: Optica Publishing Group, 1989. http://dx.doi.org/10.1364/optcomp.1989.tui6.

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Анотація:
The optical matrix computing often plays a very important role in optical digital processing, many transformation and information processings in optics can be converted into a group of basic matrix multiplications1. Now, many approaches to implement such calculations have been provided2-4. But to all the existed schemes and systems, the difficulty is the long time sequence and the lower accuracy obtained, as well as a rather complicated system is required. In this paper, we have tried to use optical symbolic substitution method5 combined with the calculation of outer product of matrices to solve the multiplication of matrices. Preliminary experimental result has been obtained successively.
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Korves, Brian A., Brian J. Slaboch, and Philip A. Voglewede. "Mechanism State Matrices for Spatial Reconfigurable Mechanisms." In ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/detc2012-71361.

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Анотація:
This paper improves augmented mechanism state matrices by replacing joint code with screw system notation. The proposed substitution allows for a more specific description of the joints in the mechanism and the capability to describe both spatial and planar mechanisms. Examples are provided which elucidate the proposed approach.
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4

Sacan, Ahmet, and I. Hakki Toroslu. "Amino Acid Substitution Matrices Based on 4-Body Delaunay Contact Profiles." In 2007 IEEE 7th International Symposium on BioInformatics and BioEngineering. IEEE, 2007. http://dx.doi.org/10.1109/bibe.2007.4375651.

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Boraik, Aziz Nasser, Rosni Abdullah, and Ibrahim Venkat. "IP-MSA: Independent order of progressive multiple sequence alignments using different substitution matrices." In INTERNATIONAL CONFERENCE ON QUANTITATIVE SCIENCES AND ITS APPLICATIONS (ICOQSIA 2014): Proceedings of the 3rd International Conference on Quantitative Sciences and Its Applications. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4903614.

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Agrawal, Ankit, and Xiaoqiu Huang. "Pairwise Statistical Significance of Local Sequence Alignment Using Substitution Matrices with Sequence-Pair-Specific Distance." In 2008 International Conference on Information Technology (ICIT). IEEE, 2008. http://dx.doi.org/10.1109/icit.2008.63.

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Naidu, Vijay, and Ajit Narayanan. "Using different substitution matrices in a string-matching technique for identifying viral polymorphic malware variants." In 2016 IEEE Congress on Evolutionary Computation (CEC). IEEE, 2016. http://dx.doi.org/10.1109/cec.2016.7744156.

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Jimenez-Morales, David, Larisa Adamian, and Jie Liang. "Detecting remote homologues using scoring matrices calculated from the estimation of amino acid substitution rates of beta-barrel membrane proteins." In 2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 2008. http://dx.doi.org/10.1109/iembs.2008.4649414.

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Zhang, Jin, X. J. Chen, and W. L. Wang. "Dynamic Analysis Technique of Rotating Centrifugal Impeller." In ASME 1991 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/91-gt-050.

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Анотація:
A dynamic analysis technique which can be employed in rotating centrifugal impeller is presented in this paper. It shows that multi–component partition can be made in repetitive sector region of the centrifugal impeller. The basic repectivie sector region of the centrifugal impeller is divided into three substructures: the full blade, the short blade and the sectorial part of the disc. By using Benfield mode substitution combined with group transformation successfully, the Hermite generalized mass and stiffness matrices under the reduced coordinates are derived. From this, the natural frequencies and the corresponding modal shapes of the bladed disc coupled system can be solved. The comparison of the analytical results obtained by using this method, other methods and the experimental data of models verifies the reliability, practicability and considerable economic benefits of the method presented in this paper.
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Tampieri, A., M. Sandri, T. D’Alessandro, M. Banobre-Lopez, and J. Rivas. "Innovative Biomimetic Hybrid Composites to Repair Multifunctional Anatomical Region." In ASME 2010 5th Frontiers in Biomedical Devices Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/biomed2010-32059.

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The development of biomimetic materials for osteochondral tissue substitution and repair can be the start for a revolution in the classical procedures of orthopaedic surgery. The persisting problems, linked to the absence of a complete functional recovery of the articulation and to the stabilization and protraction of the half-life of an articular prosthesis can be overcome by the new class of osteochondral substitutes. The characteristics of the artificial bone tissue are drastically different from those of the natural one and this is mainly due to the absence of the peculiar self-organizing interaction between apatite crystals and proteic matrix. At this purpose a biomimetic approach was used in which apatitic phases are directly nucleated on different macromolecular matrices, which act as template and induce peculiar physico-chemical features in the mineral phase to create a substitute for osteochondral lesions. In particular a biologically inspired approach was applied to nucleate bone-like hydroxyapatite (HA) nanocrystals on self-assembling collagen fibers. Biohybrid composite materials were obtained mimicking composition, structure and morphology of human osteochondral interfaces. [1–4]
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