Academic literature on the topic 'Matrice formage'

Thermogravimetry does not give specific information on residual organic solvents in polymeric matrices unless it is hyphenated with the so-called evolved gas analysis. The purpose of this study was to apply, for the first time, derivative thermogravimetry (DTG) to characterize a residual solvent and a drug in poly-d,l-lactide-co-glycolide (PLGA) microspheres. Ethyl formate, an ICH class 3 solvent, was used to encapsulate progesterone into microspheres. DTG provided a distinct peak, displaying the onset and end temperatures at which ethyl formate started to evolve from to where it completely escaped out of the microspheres. DTG also gave the area and height of the solvent peak, as well as the temperature of the highest mass change rate of the microspheres. These derivative parameters allowed for the measurement of the amount of residual ethyl formate in the microspheres. Interestingly, progesterone affected not only the residual solvent amount but also these derivative parameters. Another intriguing finding was that there was a linear relationship between progesterone content and the peak height of ethyl formate. The residual solvent data calculated by DTG were quite comparable to those measured by gas chromatography. In summary, DTG could be an efficient and practical quality control tool to evaluate residual solvents and drugs in various polymeric matrices.

Background: Fumigants are approved in many countries and used to treat food, feed, and seed. The amount of residue that remains in fumigated materials is measured and reported. Objective: The optimization and validation of a high-sensitivity headspace solid-phase microextraction gas chromatograph mass spectrometer (HS-SPME-GCMS) method for determination of eight fumigant residues—phosphine, methyl bromide, cyanogen, sulfuryl fluoride, ethylene oxide, propylene oxide, ethyl bromide and ethyl formate—in a range of food matrices were developed. The food matrices included grain, oilseed, dried fruit, and nut. Methods: The new method was used to determine residue levels from a fumigant complex in food matrices by monitoring the change of the absorption of spiked standards and desorption of fumigant from fumigated samples. Results: Based on the observation, the process of physical sorption and chemisorption was defined. The equilibrium time of the sample analysis was chosen at 5 hours. The LODs of the fumigants were in the range of 0.03 to 1.99 ng/g. Response to a range of diluted authentic standards gave significant linear regressions (r2 > 0.9983), and the RSDs were ≤8.7% at the 3 ng/g level of aged spiking standard, except for sulfuryl fluoride, for which the LOD was 1.99 ng/g and the RSD value was 39.7% (6.64 ng/g). Conclusions: The performance of the HS-SPME-GCMS method was more sensitive than the use of a gas syringe, except for sulfuryl fluoride. Highlights: An innovative multifumigant residue detection method based on HS-SPME sampling technology with gas chromatograph-mass selective detection (GC-MSD) analysis was established, including phosphine, methyl bromide, cyanogen, sulfuryl fluoride, ethylene oxide, propylene oxide, ethyl bromide, and ethyl formate; The first report of a sorption study of the process of physical sorption and chemisorption of residual fumigant in fruit and food matrices by an HS-SPME-GCMS method; Consider the effect of time on fumigant behavior in dried fruit, grain, and nut; The LODs of the fumigants were in the range of 0.03 to 1.99 ng/g.

Abstract Background: Fumigants are approved in many countries and used to treat food, feed, and seed. The amount of residue that remains in fumigated materials is measured and reported. Objective: The optimization and validation of a high-sensitivity headspace solid-phase microextraction gas chromatograph mass spectrometer (HS-SPME-GCMS) method for determination of eight fumigant residues—phosphine, methyl bromide, cyanogen, sulfuryl fluoride, ethylene oxide, propylene oxide, ethyl bromide and ethyl formate—in a range of food matrices were developed. The food matrices included grain, oilseed, dried fruit, and nut. Methods: The new method was used to determine residue levels from a fumigant complex in food matrices by monitoring the change of the absorption of spiked standards and desorption of fumigant from fumigated samples. Results: Based on the observation, the process of physical sorption and chemisorption was defined. The equilibrium time of the sample analysis was chosen at 5 hours. The LODs of the fumigants were in the range of 0.03 to 1.99 ng/g. Response to a range of diluted authentic standards gave significant linear regressions (r2 > 0.9983), and the RSDs were ≤8.7% at the 3 ng/g level of aged spiking standard, except for sulfuryl fluoride, for which the LOD was 1.99 ng/g and the RSD value was 39.7% (6.64 ng/g). Conclusions: The performance of the HS-SPME-GCMS method was more sensitive than the use of a gas syringe, except for sulfuryl fluoride. Highlights: An innovative multifumigant residue detection method based on HS-SPME sampling technology with gas chromatograph-mass selective detection (GC-MSD) analysis was established, including phosphine, methyl bromide, cyanogen, sulfuryl fluoride, ethylene oxide, propylene oxide, ethyl bromide, and ethyl formate; The first report of a sorption study of the process of physical sorption and chemisorption of residual fumigant in fruit and food matrices by an HS-SPME-GCMS method; Consider the effect of time on fumigant behavior in dried fruit, grain, and nut; The LODs of the fumigants were in the range of 0.03 to 1.99 ng/g.

El protocolo notarial de Pedro de Castañeda (1537-1538) es el segundo más antiguo de la ciudad de Lima. Según el Diccionario de la Real Academia, los protocolos notariales consisten en una “serie ordenada de escrituras matrices y otros documentos que un notario o escribano autoriza y custodia con ciertas formalidades”. Se trata, pues, de un volumen encuadernado que se formaba por la reunión de los registros de escrituras públicas del año, o bienio, y en las que se empleaba papel sellado.

Objetivo: O lanamento do game Pokemon GO gerou um frenesi nunca antes visto no Brasil em relao a um jogo de videogame e revelou ao pas a existncia de um pblico aficionado por cultura pop e tecnologia, os chamados nerds. A tomada das cidades pelos caadores de monstrinhos virtuais teve uma enorme repercusso na grande mdia e levou diferentes pblicos a se posicionarem a respeito. Assumindo o consumo como prtica identitria, o presente trabalho teve o objetivo de analisar a constituio identitria dos usurios brasileiros do Pokemon GO por meio dos discursos que se estabeleceram a partir do anncio do lanamento do jogo no pas. Mtodo: Adotamos a Anlise de Discurso Foucaultiana (ADF), que evidencia como certos discursos revelam regularidades. O corpus de pesquisa foi formado por matrias veiculadas durante vinte meses, a partir do anncio do produto. Relevncia: O pblico nerd tem ganho importncia social e econmica, tanto pela relevncia da cultura pop no mundo contemporneo, quanto pelo crescimento da indstria do entretenimento. Resultados: Identificamos duas formaes discursivas relacionadas ao consumo do Pokemon GO no Brasil: uma referente busca de legitimidade da identidade nerd e outra ao estigma a essa imputado. Contribuio metodolgica: A pesquisa apresenta uma operacionalizao sistematizada do mtodo foucaultiano. Contribuio terica: Os achados levam ao entendimento do consumo nerd como uma arena de poltica da identidade. Contribuio social: O estudo pe em evidncia uma identidade social que, a despeito de seu relevo econmico, ainda se caracteriza como minoritria.

AbstractThe present paper uses spectral theory of linear operators to construct approximatelyminimal realizations of weighted languages. Our new contributions are: (i) a new algorithm for the singular value decomposition (SVD) decomposition of finite-rank infinite Hankel matrices based on their representation in terms of weighted automata, (ii) a new canonical form for weighted automata arising from the SVD of its corresponding Hankelmatrix, and (iii) an algorithmto construct approximateminimizations of given weighted automata by truncating the canonical form.We give bounds on the quality of our approximation.

Summary In this paper the author constructs several properties for double series and its convergence. The notions of convergence of double sequence have already been introduced in our previous paper [18]. In section 1 we introduce double series and their convergence. Then we show the relationship between Pringsheim-type convergence and iterated convergence. In section 2 we study double series having non-negative terms. As a result, we have equality of three type sums of non-negative double sequence. In section 3 we show that if a non-negative sequence is summable, then the sequence of rearrangement of terms is summable and it has the same sums. In the last section two basic relations between double sequences and matrices are introduced.

Background and Objectives: The use of synthetic cannabinoids has increased around the world. As a result, the implementation of accurate analysis in human biological matrices is relevant and fundamental. Two different analytical technologies, ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) and high-sensitivity gas chromatography-mass spectrometry (GC-MS) were used for the determination of three synthetic cannabinoids JWH-122, JWH 210, UR-144 and their metabolites in urine of consumers. Materials and Methods: Sample preparation included an initial hydrolysis with β-glucuronidase and liquid-liquid extraction. The UHPLC-HRMS method included a Kinetex 2.6 u Biphenyl 100A (100 × 2.1 mm, 2.6 μm) (Phenomenex, Italy) column with a gradient mobile phase consisting of mobile phase A (ammonium formate 2mM in water, 0.1% formic acid) and mobile phase B (ammonium formate 2mM in methanol/acetonitrile 50:50 (v/v), 0.1% formic acid) and a full-scan data-dependent MS2 (ddMS2) mode was used (mass range 100–1000 m/z). The GC-MS method employed an ultra-Inert Intuvo GC column (HP-5MS UI, 30 m × 250 µm i.d, film thickness 0.25 µm; Agilent Technologies, Santa Clara, CA, USA) and electron-impact (EI) mass spectra were recorded in total ion monitoring mode (scan range 40–550 m/z). Results: Both methods have been successfully used for screening of parent synthetic cannabinoids and their metabolites in urine samples of consumers. Conclusions: The screening method applied JWH-122, JWH-210, UR-144 and their metabolites in urine of consumers can be applied to other compounds of the JWH family.

La problématique industrielle du thermoformage de composites à fibres longues et matrice thermoplastique s'inscrit dans la volonté de maîtriser la mise en oeuvre de matériaux à hautes performances mécaniques tout en assurant un coût raisonnable de fabrication. Le procédé constitue un challenge car il tente de mettre en forme un matériau au cours de sa transformation: chauffage, transfert sous la presse, pressage et refroidissement combinés. La mise en forme de pièces complexes révèle ainsi l'apparition de défauts tels que des "froissements" de nappes de fibres à l'intérieur des rayons, des porosités et de la mifration de la résine. La simulation de ce procédé de formage n'est pas encore aussi mature, même si des logiciels de drapage ou de thermofromage commencent à apparaître. Les codes de calcul actuels sont très délicats à utliliser sur des zones réparties, alors que malheureusement le point clé de la simulation du thermoformage des composites. Par ailleurs, comme nous pouvons nous y attendre, les résultats de calcul dépendent très fortement d'un "coefficient de frottement", paramètre scalaire ajustable au contenue physique très discutable. L'objectif de ce travail est d'obtenir une meilleure compréhension du procédé de thermoformage assisté par pionçon via l'etude des processus physiques impliqués dans la déformation des plis. En effet, une bonne connaissance du comportement ainsi que la maîtrise de la détermination expérimentale des grandeurs associées à la modélisation favoriseront une meilleure mise en données d'un code de calcul et donc une meilleure simulation du procédé
The industrial problem of thermoforming of composites materials with long fibers and thermoplastic matrix is in the desire to control the forming process at high mechanical performance while ensuring a reasonable cost of manufacture. The process is a challenge cause it attemps fo form a material during its processing: heating, transfer to the press, pressing and cooling. Complex part forming reveals the occurence of detects such as "fiber buckling", porosity and migration of the resin. The simulation of the process is not yet as mature, even if software of draping or thermoforming begin to appear. The current codes are not suitable to use in distributed areas, while unfortunately this is the key point of the simulation. Moreover, as we expect, the calculation results depend very strongly on the friction "friction coeffecient", scalar parameter which is strongly varaible. The objective of this work is to obtain a better understanding of the thermoforming through the study of physical processes involved in the ply deformation. In fact, a good knowledge of the behavior and good determination of experimental parameters associated in the modeling lead to a better data for coding and therefoer a better simulation of the process

On a etudie les interactions entre verre et metal a haute temperature, afin de resoudre des problemes de collage entre emaux pour les vitrages automobiles et revetements metalliques recouvrant la matrice de formage (tissu metallique). La realisation d'un test reproduisant les conditions de mise en forme a permis de quantifier la force de collage. Les resultats experimentaux ont montre que la viscosite de la phase vitreuse est l'un des parametres les plus importants. Nous avons modelise la force de collage en fonction de celle-ci. Nous avons ainsi pu mettre en evidence l'influence du facteur mecanique (accrochage par inter-penetration du verre et des fibres metalliques en contact) et de la composition chimique. On a montre aussi que l'on peut s'opposer a l'effet de la viscosite en jouant sur des parametres directement lies a l'email. L'examen des proprietes electriques des verres ne nous a pas permis d'etablir une correlation evidente entre ces proprietes et la force de collage. Cependant, on a constate qu'en appliquant une tension continue au systeme email/revetement de matrice, il etait possible de diminuer la force de collage entre email et tissu metallique. La mesure de l'intensite en fonction de la tension appliquee nous a permis, en faisant un parallele avec ce que l'on connait sur la corrosion des metaux dans des electrolytes aqueux, de donner une interpretation des phenomenes conduisant a la diminution de la force de collage.

Dans le cas de tôles aéronautiques en TA6V, le procédé de formage superplastique (SPF) est mis en œuvre à des températures voisines de 900°C. Les outillages de formage réalisés en aciers réfractaires moulés, sont soumis à des contraintes thermomécaniques très sévères susceptibles de provoquer leur endommagement. L'objectif de l'étude est de sélectionner des procédés de rechargement et de soudage utilisés pour réparer ces outillages et de caractériser les rechargements d'un point de vue microstructural et mécanique. Les paramètres de soudage et de remplissage sont optimisés afin de garantir la meilleure qualité des rechargements réalisés. L'influence des paramètres liés au procédé de rechargement et aux matériaux utilisés, sur la propension des aciers moulés à fissurer en cours de soudage, est étudiée. Ces analyses sont conduites d'une manière qualitative sur des macrographies en coupe et quantitative en utilisant la technique de traitement d'images. Pour des rechargements de fortes profondeurs, les techniques de refusion de surface et de beurrage ont été développées. Les performances mécaniques des structures réparées sont évaluées par des essais de fatigue oligocyclique. Le comportement mécanique des éprouvettes rechargées est également analysé à l'aide de la simulation numérique
Superplastic forming (SPF) of TA6V aeronautical sheets is performed at temperatures close to 900°C. Forming tools, manufactured with heat resistant cast steels, are exposed to highly severe thermomechanical stress likely to cause their damage. The purpose of this study is to develop weld repair techniques for SPF dies and to characterize the weld joints using microstructural investigations and mechanical testing. The parameters of welding and filling are optimized in order to guarantee the best quality of the welded zone. The influence that parameters related to the weld repair process and the materials used, have on the propensity of the cast steels to crack during welding, is investigated. These analyses are performed on the macrographs of the welded zone and also using image analysis technique. For the very deep groove, two weld repair techniques are developed, the surface remelting of the material and the buttering. The mechanical performances of the repaired structures are evaluated using low cycle fatigue tests. The mechanical behaviour of the weld repair joints is also investigated using numerical simulation

The experience of void, essential to the production of forms and to make use them, can be considered as the base of the activities that attend to the formative processes. If void and matter constitutes the basic substances of architecture. Their role in the definition of form, the symbolic value and the constructive methods of it defines the quality of the space. This job inquires the character of space in the architecture of Moneo interpreting the meaning of the void in the Basque culture through the reading of the form matrices in the work of Jorge Oteiza and Eduardo Chillida. In the tie with the Basque culture a reading key is characterized by concurring to put in relation some of the theoretical principles expressed by Moneo on the relationship between place and time, in an unique and specific vision of the space. In the analysis of the process that determines the genesis of the architecture of Moneo emerges a trajectory whose direction is constructed on two pivos: on the one hand architecture like instrument of appropriation of the place, gushed from an acquaintance process who leans itself to the reading of the relations that define the place and of the resonances through which measuring it, on the other hand the architecture whose character is able to represent and to extend the time in which he is conceived, through the autonomy that is conferred to them from values. Following the trace characterized from this hypothesis, that is supported on the theories elaborated from Moneo, surveying deepens the reading of the principles that construct the sculptural work of Oteiza and Chillida, features from a search around the topic of the void and to its expression through the form. It is instrumental to the definition of a specific area that concurs to interpret the character of the space subtended to a vision of the place and the time, affine to the sensibility of Moneo and in some way not stranger to its cultural formation. The years of the academic formation, during which Moneo enters in contact with the Basque artistic culture, seem to be an important period in the birth of that knowledge that will leads him to the formulation of theories tied to the relationship between time, place and architecture. The values expressed through the experimental work of Oteiza and Chillida during years '50 are valid bases to the understanding of such relationships. In tracing a profile of the figures of Oteiza and Chillida, without the pretension that it is exhaustive for the reading of the complex historical period in which they are placed, but with the needs to put the work in a context, I want to be evidenced the important role carried out from the two artists from the Basque cultural area within which Moneo moves its first steps. The tie that approaches Moneo to the Basque culture following the personal trajectory of the formative experience interlaces to that one of important figures of the art and the Spanish architecture. One of the more meaningful relationships is born just during the years of his academic formation, from 1958 to the 1961, when he works like student in the professional office of the architect Francisco Sáenz de Oiza, who was teaching architectural design at the ETSAM. In these years many figures of Basque artists alternated at the professional office of Oiza that enjoys the important support of the manufacturer and maecenas Juan Huarte Beaumont, introduced to he from Oteiza. The tie between Huarte and Oteiza is solid and continuous in the years and it realizes in a contribution to many of the initiatives that makes of Oteiza a forwarder of the Basque culture. In the four years of collaboration with Oiza, Moneo has the opportunity to keep in contact with an atmosphere permeated by a constant search in the field of the plastic art and with figures directly connected to such atmosphere. It’s of a period of great intensity as in the production like in the promotion of the Basque art. The collective “Blanco y Negro”, than is held in 1959 at the Galería Darro to Madrid, is only one of the many times of an exhibition of the work of Oteiza and Chillida. The end of the Fifties is a period of international acknowledgment for Chillida that for Oteiza. The decade of the Fifties consecrates the hypotheses of a mythical past of the Basque people through the spread of the studies carried out in the antecedent years. The archaeological discoveries that join to a context already rich of signs of the prehistoric era, consolidate the knowledge of a strong cultural identity. Oteiza, like Chillida and other contemporary artists, believe in a cosmogonist conception belonging to the Basques, connected to their matriarchal mythological past. The void in its meaning of absence, in the Basque culture, thus as in various archaic and oriental religions, is equivalent to the spiritual fullness as essential condition to the revealing of essence. Retracing the archaic origins of the Basque culture emerges the deep meaning that the void assumes as key element in the religious interpretation of the passage from the life to the death. The symbology becomes rich of meaningful characters who derive from the fact that it is a chthonic cult. A representation of earth like place in which divine manifest itself but also like connection between divine and human, and this manipulation of the matter of which the earth it is composed is the tangible projection of the continuous search of the man towards God. The search of equilibrium between empty and full, that characterizes also the development of the form in architecture, in the Basque culture assumes therefore a peculiar value that returns like constant in great part of the plastic expressions, than in this context seem to be privileged regarding the other expressive forms. Oteiza and Chillida develop two original points of view in the representation of the void through the form. Both use of rigorous systems of rules sensitive to the physics principles and the characters of the matter. The last aim of the Oteiza’s construction is the void like limit of the knowledge, like border between known and unknown. It doesn’t means to reduce the sculptural object to an only allusive dimension because the void as physical and spiritual power is an active void, that possesses that value able to reveal the being through the trace of un-being. The void in its transcendental manifestation acts at the same time from universal and from particular, like in the atomic structure of the matter, in which on one side it constitutes the inner structure of every atom and on the other one it is necessary condition to the interaction between all the atoms. The void can be seen therefore as the action field that concurs the relations between the forms but is also the necessary condition to the same existence of the form. In the construction of Chillida the void represents that counterpart structuring the matter, inborn in it, the element in absence of which wouldn’t be variations neither distinctive characters to define the phenomenal variety of the world. The physics laws become the subject of the sculptural representation, the void are the instrument that concurs to catch up the equilibrium. Chillida dedicate himself to experience the space through the senses, to perceive of the qualities, to tell the physics laws which forge the matter in the form and the form arranges the places. From the artistic experience of the two sculptors they can be transposed, to the architectonic work of Moneo, those matrices on which they have constructed their original lyric expressions, where the void is absolute protagonist. An ambit is defined thus within which the matrices form them drafts from the work of Oteiza and Chillida can be traced in the definition of the process of birth and construction of the architecture of Moneo, but also in the relation that the architecture establishes with the place and in the time. The void becomes instrument to read the space constructed in its relationships that determine the proportions, rhythms, and relations. In this way the void concurs to interpret the architectonic space and to read the value of it, the quality of the spaces constructing it. This because it’s like an instrument of the composition, whose role is to maintain to the separation between the elements putting in evidence the field of relations. The void is that instrument that serves to characterize the elements that are with in the composition, related between each other, but distinguished. The meaning of the void therefore pushes the interpretation of the architectonic composition on the game of the relations between the elements that, independent and distinguished, strengthen themselves in their identity. On the one hand if void, as measurable reality, concurs all the dimensional changes quantifying the relationships between the parts, on the other hand its dialectic connotation concurs to search the equilibrium that regulated such variations. Equilibrium that therefore does not represent an obtained state applying criteria setting up from arbitrary rules but that depends from the intimate nature of the matter and its embodiment in the form. The production of a form, or a formal system that can be finalized to the construction of a building, is indissolubly tied to the technique that is based on the acquaintance of the formal vocation of the matter, and what it also can representing, meaning, expresses itself in characterizing the site. For Moneo, in fact, the space defined from the architecture is above all a site, because the essence of the site is based on the construction. When Moneo speaks about “birth of the idea of plan” like essential moment in the construction process of the architecture, it refers to a process whose complexity cannot be born other than from a deepened acquaintance of the site that leads to the comprehension of its specificity. Specificity arise from the infinite sum of relations, than for Moneo is the story of the oneness of a site, of its history, of the cultural identity and of the dimensional characters that that they are tied to it beyond that to the physical characteristics of the site. This vision is leaned to a solid made physical structure of perceptions, of distances, guideline and references that then make that the process is first of all acquaintance, appropriation. Appropriation that however does not happen for directed consequence because does not exist a relationship of cause and effect between place and architecture, thus as an univocal and exclusive way does not exist to arrive to a representation of an idea. An approach that, through the construction of the place where the architecture acquires its being, searches an expression of its sense of the truth. The proposal of a distinction for areas like space, matter, spirit and time, answering to the issues that scan the topics of the planning search of Moneo, concurs a more immediate reading of the systems subtended to the composition principles, through which is related the recurrent architectonic elements in its planning dictionary. From the dialectic between the opposites that is expressed in the duality of the form, through the definition of a complex element that can mediate between inside and outside as a real system of exchange, Moneo experiences the form development of the building deepening the relations that the volume establishes in the site. From time to time the invention of a system used to answer to the needs of the program and to resolve the dual character of the construction in an only gesture, involves a deep acquaintance of the professional practice. The technical aspect is the essential support to which the construction of the system is indissolubly tied. What therefore arouses interest is the search of the criteria and the way to construct that can reveal essential aspects of the being of the things. The constructive process demands, in fact, the acquaintance of the formative properties of the matter. Property from which the reflections gush on the relations that can be born around the architecture through the resonance produced from the forms. The void, in fact, through the form is in a position to constructing the site establishing a reciprocity relation. A reciprocity that is determined in the game between empty and full and of the forms between each other, regarding around, but also with regard to the subjective experience. The construction of a background used to amplify what is arranged on it and to clearly show the relations between the parts and at the same time able to tie itself with around opening the space of the vision, is a system that in the architecture of Moneo has one of its more effective applications in the use of the platform used like architectonic element. The spiritual force of this architectonic gesture is in the ability to define a place whose projecting intention is perceived and shared with who experience and has lived like some instrument to contact the cosmic forces, in a delicate process that lead to the equilibrium with them, but in completely physical way. The principles subtended to the construction of the form taken from the study of the void and the relations that it concurs, lead to express human values in the construction of the site. The validity of these principles however is tested from the time. The time is what Moneo considers as filter that every architecture is subordinate to and the survival of architecture, or any of its formal characters, reveals them the validity of the principles that have determined it. It manifests thus, in the tie between the spatial and spiritual dimension, between the material and the worldly dimension, the state of necessity that leads, in the construction of the architecture, to establish a contact with the forces of the universe and the intimate world, through a process that translate that necessity in elaboration of a formal system.

Cette thèse propose trois contributions aux preuves mathématiques assistées par ordinateur. On s'intéresse non seulement aux preuves reposant sur le calcul, mais aussi aux preuves formelles, qui sont àla fois produites et vérifiées à l'aide d'un logiciel appelé assistant à la preuve.Dans la première partie, nous illustrons le thème de l'expérimentation au service de la preuve en nous intéressant au problème de la complexité des algorithmes de multiplication matricielle. Cette question a historiquement été posée de manière de plus en plus abstraite: les approches modernes ne construisent pas d'algorithmes explicites mais utilisent des résultats théoriques pour améliorer la borne inférieure sur la célèbre constante oméga. Nous sommes revenus à une approche plus pratique en essayant de programmer certains des algorithmes impliqués par ces résultats théoriques. Cette approche expérimentale a révélé un motif inattendu dans des algorithmes existants. Alors que ces algorithmes contiennent une nouvelle variable epsilon dont la présence est réputée les rendre impraticables pour des tailles de matrices raisonnables, nous avons découvert que nous pouvions construire des algorithmes de multiplication matricielle en parallèle sans epsilon avec une complexité asymptotique qui peut théoriquement battre l'algorithme de Strassen pour les multiplications. Un sous-produit de cette exploration est un outil symbolique en Ocaml qui peut analyser, composer et exporter des algorithmes de multiplication matricielle. Nous pensons aussi qu'il pourrait être utilisé pour construire de nouveaux algorithmes pratiques de multiplication matricielle.Dans la deuxième partie, nous décrivons une preuve formelle de l'irrationalité de la constante zeta(3), en suivant la démonstration historique due à Apéry. L'étape cruciale de cette preuve est d'établir que deux suites de nombres rationnels satisfont une surprenante récurrence commune. Il est en fait possible de "découvrir"cette récurrence en utilisant des algorithmes symboliques, et leurs implémentations existantes dans un système de calcul formel. De fait,ce travail constitue un exemple d'une approche dite sceptique de la démonstration formelle de théorèmes, dans lequel des calculs sont principalement réalisés par un logiciel efficace de calcul formel puis vérifiés formellement dans un assistant à la preuve. Incidemment, ce travail questionne la valeur des certificats de télescopage créatif comme preuves complètes d'identités. Cette preuve formelle est également basée sur de nouvelles bibliothèques de mathématiques,formalisées pour ses besoins. En particulier, nous avons formalisé et simplifié une étude du comportement asymptotique de la suite ppcm(1,.., n). Ce travail est conduit dans l'assistant à la preuve Coq et prolonge les bibliothèques Mathematical Components.Dans la dernière partie, nous présentons une procédure qui calcule les approximations d'une classe d'intégrales propres et impropres tout en produisant simultanément un preuve formelle Coq de la correction du résultat de ce calcul. Cette procédure utilise une combinaison d'arithmétique d'intervalles et d'approximations polynomiales rigoureuses de fonctions. Ce travail utilise crucialement les possibilités de calculer efficacement à l'intérieur de la logique sous-jacente au système Coq. Il s'agit d'une extension de la bibliothèque CoqInterval d'approximation numérique d'une classe d'expressions réelles. Sa mise en œuvre a également donné lieu à des extensions de la bibliothèque Coquelicot d'analyse réelle, notamment pour améliorer le traitement des intégrales impropres. Nous illustrons l'intérêt de cet outil et ses performances en traitant des exemples standards mais non triviaux de la littérature, sur lesquels d'autres outils se sont en certains cas révélés incorrects
This thesis proposes three contributions to computer-aidedmathematical proofs. It deals, not only with proofs relying oncomputations, but also with formal proofs, which are both produced andverified using a piece of software called a proof assistant.In the first part, we illustrate the theme of experimentation at theservice of proofs by considering the problem of the complexity ofmatrix multiplication algorithms. This problem has historically beenapproached in an increasingly abstract way: modern approaches do notconstruct algorithms but use theoretical results to improve the lowerbound on the famous omega constant. We went back to a more practicalapproach by attempting to program some of the algorithms implied bythese theoretical results. This experimental approach reveals anunexpected pattern in some existing algorithms. While these algorithmscontain a new variable epsilon whose presence is reputed to renderthem inefficient for the purposes of reasonable matrix sizes, we havediscovered that we could build matrix multiplication algorithms inparallel without epsilon's with an asymptotic complexity which cantheoretically beat Strassen's algorithm in terms of the number ofmultiplications. A by-product of this exploration is a symbolic toolin Ocaml which can analyze, compose and export matrix multiplicationalgorithms. We also believe that it could be used to build newpractical algorithms for matrix multiplication.In the second part, we describe a formal proof of the irrationality ofthe constant zeta (3), following the historical demonstration due toApéry. The crucial step of this proof is to establish that twosequences of rational numbers satisfy a suprising commonrecurrence. It is in fact possible to "discover" this recurrence usingsymbolic algorithms, and their existing implementations in a computeralgebra system. In fact, this work is an example of a skepticalapproach to the formal proof of theorems, in which computations aremainly accomplished by an efficient computer algebra program, and thenformally verified in a proof assistant. Incidentally, this workquestions the value of creative telescoping certificates as completeproofs of identities. This formal proof is also based on newmathematical libraries, which were formalised for its needs. Inparticular, we have formalized and simplified a study of theasymptotic behaviour of the sequence lcm(1,..., n). This work isdeveloped in the Coq proof assistant and extends the MathematicalComponents libraries.In the last part, we present a procedure which computes approximationsof a class of proper and improper integrals while simultaneouslyproducing a Coq formal proof of the correction of the result of thiscomputation. This procedure uses a combination of interval arithmeticand rigorous polynomial approximations of functions. This work makescrucial use of the possibility to efficiently compute inside Coq'slogic. It is an extension of the CoqInterval library providingnumerical approximation of a class of real expressions. Itsimplementation has also resulted in extensions to the Coquelicotlibrary for real analysis, including a better treatment of improperintegrals. We illustrate the value of this tool and its performanceby dealing with standard but nontrivial examples from the literature,on which other tools have in some cases been incorrect

Le but de ce travail est d'analyser les effets de deux facteurs de croissance, l'egf et fgf acide sur la proliferation et la differenciation de cellules osseuses isolees de calottes craniennes de ftus de rat. Les effets mitogenes de ces facteurs sont mesures par incorporation de thymidine tritiee et numeration cellulaire, sur des cellules pre-confluentes ou confluentes poussant en presence de serum a 2%. L'effet mitogene est proportionnel a la dose et est maximal au bout de 18 h. La densite cellulaire provoque un deplacement des doses de demi-stimulation vers des concentrations plus importantes, ce qui pourrait etre lie a une diminution du nombre de recepteurs a ces facteurs. Le fgfa est plus puissant que l'egf et reduit le temps de doublement apparent de la population cellulaire. Dans une deuxieme partie, nous nous sommes interessees aux effets de l'egf et du fgfa sur la differenciation des cellules osseuses, en suivant l'expression de la phosphatase alcaline (pa) et la formation des nodules osseux. L'activite pa augmente au cours du processus de mineralisation pour atteindre une valeur maximale de 400 nmole/min/mg proteine, au 15eme jour de culture. Le pm apparent de cette proteine est de 120000. L'addition des facteurs induit une transformation transitoire de la morphologie cellulaire. L'egf et le fgfa inhibent l'activite pa surtout des cellules non confluentes et cette inhibition est fonction du temps de traitement et de la concentration. Cet effet differentiel est confirme par l'analyse histochimique et biochimique de l'activite enzymatique. Ces facteurs de croissance additionnes aux premiers jours de culture retardent l'apparition et diminuent la taille des nodules osseux au 15eme jour alors que l'activite pa est restauree. Dans le but d'identifier les cellules sensibles a l'egf et au fgfa, un double marquage par le brdu (un analogue de la thymidine) et la pa montre que les cellules differenciees ne proliferent pas. Puis, une etude de la liaison du fgfa aux cellules osseuses en culture met en evidence 3 types de recepteurs au fgfa et de pm apparent 120000, 105000 et 85000. Enfin, nous avons cherche a localiser le fgfa au niveau cellulaire et tissulaire. Des techniques d'immunofluorescence demontrent la presence de fgfa dans certaines cellules et semblent mettre en evidence du fgfa au niveau de la matrice osteoide in vivo

Ce travail est consacré aux approximants de Padé. On commence par une amélioration du calcul des coefficients des polynômes orthogonaux par rapport à une fonctionnelle linéaire quelconque en utilisant la méthode Cestac de J. Vignes. On étend les notions d'approximants de Padé en deux points des séries formelles aux séries de fonctions. On étend également la méthode de C. Brezinski, pour l'estimation de l'erreur des approximants de Padé en un point dans le cas normal, au cas non normal et au cas des approximants de Padé en deux points. On étudie la stabilité et la convergence des formules de quadrature de Gauss pour une fonction poids polynomiale de degré inferieur ou égal à 2. Enfin, les approximants de Padé matriciels rectangulaires ayant des polynômes générateurs à coefficients matriciels carrés sont définis ; des relations de récurrence que vérifient ces polynômes sont établies. On obtient un algorithme QD matriciel ; on généralise le théorème de Shohat-Favard et on étend la procédure de Kronrod pour l'estimation de l'erreur de ces approximants.

Dans cette thèse, nous établissons un modèle à deux échelles à la fois pour des matrices de cantilevers unidimensionnels et bidimensionnels en régime de fonctionnement élastodynamique avec des applications possibles aux réseaux de microscopes à force atomique (AFM). Son élaboration est basée sur une analyse asymptotique pour les structures minces élastiques, une approximation à deux échelles et une mise à l'échelle utilisée pour l'homogénéisation des milieux fortement hétérogènes. Nous complétons la théorie de l'approximation à deux échelles pour les problèmes aux limites du quatrième ordre posés dans des domaines minces périodiques connexes seulement dans certaines directions. Notre modèle reproduit la dynamique globale du support ainsi que les mouvements locaux des cantilevers. Pour simplifier la suite du travail, nous concentrons nos travaux à l'étude de matrices de leviers constituées de lignes découplées en régime dynamique. Comme le support des leviers est élastique, l'effet du couplage entre levier est pris en compte. La vérification du modèle est soigneusement réalisée. Nous montrons que chaque mode propre peut être décomposé en produits d'un mode de base avec un mode de levier. Nous présentons une méthode de discrétisation du modèle et effectuons sa vérification numérique en la comparant avec des résultats de simulation par éléments finis du problème d'élasticité tridimensionnel. Par ailleurs, nous avons élaboré de nouveaux outils d'aide à la conception de réseaux d'AFM. Une boîte à outils d'optimisation robuste est interfacée avec le modèle permettant d'optimiser un design avant micro-fabrication. Un algorithme d'estimation de l'état statique combinant la mesure de déplacements mécaniques par interférométrie et le modèle a été introduit. Nous avons également synthétisé un régulateur quadratique linéaire (LQR) pour un réseau de cantilevers en mode dynamique comprenant actionneurs et capteurs régulièrement espacées. Dans le but de mettre en oeuvre le contrôle en temps réel, nous proposons une approximation semi-décentralisée qui peut être réalisé par un circuit électronique distribué analogique. Plus précisément, notre processeur analogique peut être réalisé par un réseau périodique de résistances (PNR). La méthode d'approximation de commande est basée sur deux concepts généraux, à savoir sur un calcul fonctionnel (c'est-à-dire des fonctions d'opérateurs) et sur la formule de représentation d'une fonction d'opérateur de Dunford-Schwartz. Cette méthode d'approximation est étendue pour la résolution d'un problème de filtrage optimal robuste de type H∞ de la dynamique d'un réseau de leviers couplés avec sources aléatoires de bruit.

Depuis sa première définition par Hudson et Parthasarathy en 1984, l'intégration stochastique quantique offre un outil puissant pour la description de certaines évolutions en physique quantique. De nombreuses questions restent ouvertes cependant, en particulier dans le domaine de la représentabilité intégrale des opérateurs. La définition récente par Attal d'une méthode complètement explicite de l'approximation de l'espace de Fock usuel par un analogue discret a justifié l'intérêt d'une bonne connaissance du calcul stochastique quantique à temps discret. Nous définissons rigoureusement un tel calcul stochastique et obtenons une caractérisation des opérateurs admettant des représentations intégrales ou des représentations sous la forme de noyau de Maassen-Meyer, avec des expressions explicites dans les deux cas. Ces résultats nous permettent de préciser complètement le lien entre le calcul à temps discret et le calcul à temps continu et en particulier de montrer que la formule d'Itô quantique de composition des intégrales se déduit rigoureusement de relations de commutation, par exemple des relations de commutation entre matrices de Pauli. Nous appliquons ensuite nos résultats pour obtenir une caractérisation, dans l'espace de Fock usuel, des opérateurs qui sont représentables en intégrales stochastiques quantiques parmi les classes fondamentales que sont les opérateurs de seconde quantification et de seconde quantification différentielle. Enfin, nous utilisons ces techniques pour obtenir des résultats de convergence de solutions d'équations aux différences vers des équations différentielles stochastiques quantiques. Ces résultats nous permettent de montrer qu'une évolution en mécanique quantique obtenue par des interactions répétées est déterminée, à la limite, par une équation de Langevin quantique. Cette équation de Langevin décrit un couplage entre un ``petit système'' et un ``réservoir'', ce réservoir et les coefficients de l'équation se déduisant explicitement de l'interaction que l'on répète. Ces résultats permettent en particulier d'obtenir une description rigoureuse des mesures en continu et des approximations de ``coarse graining'' en optique quantique.

Il volume raccoglie i contributi della giornata di studio tenuta il 16 giugno 2010 all’Università di Firenze su Abbazie e paesaggi medievali in Toscana, cioè sulle forme del territorio che hanno strutturato per secoli i modi di vita nelle campagne della nostra regione. Si afferma oggi una infatuazione per quel paesaggio, cui fa riscontro una mancanza di interesse per la sua conservazione o per trasformazioni rispettose delle regole che lo hanno prodotto. È quindi opportuno presentare, al vaglio del metodo storico, uno sguardo sintetico sul paesaggio medievale, dalle premesse di antica matrice alle ragioni economiche della formazione monastica e feudale fino alla comparsa di un nuovo assetto apprezzato per la sua utile bellezza, in un persistente sostrato di misteriosa affabulazione. La Toscana permette molteplici riscontri di ciò che effettivamente sopravvive del pervasivo ordine stabilito nel Medioevo anche per le sue esemplari rappresentazioni letterarie e iconografiche, coeve e moderne.

Abstract This paper considers the least solutions of linear matrix inequalities (LMIs) in criteria of admissibility for continuous singular fractional order systems (FOS). The new criteria are given which are strict LMIs and do not involve equality constraint and with the less LMI decision variables. With brief and simple results of this paper, the numbers of solved matrices are reduced from a pair of matrices to just a matrix in which we can analyze singular fractional order systems with completely consistent format as normal systems.

This paper presents a formalized approach to specify and implement design matrix support for systems engineering applications that structure large and complex product models. Design matrixes can clearly visualize the relationships between large amounts of hierarchically structured engineering objects and higher level systems engineering design objects like requirements and functions in the product model. Examples of structures that can be lied out along the X and Y axis of a design matrix are stakeholder trees, requirement trees, function-means trees, product concept trees, and implementation trees. The cells of the design matrix visualize how corresponding objects at the axes relate to each other. One benefit with configurable design matrixes is that the information content and layout of a design matrix can be specified by a user, and all software implementation effort is handled automatically by a generic software framework that is included in the engineering application. The paper provides an overview of the theory behind a formal specification language for configurable design matrixes. It gives examples of design matrix specifications and screen shoots of instances of these design matrixes generated by a prototype engineering application called FMDesign. The examples of different types of design matrixes are taken from a aircraft product model of a small business jet. A formal software specification of the design matrix specification language and the example engineering application is provided in UML class diagrams.

The goal of Boolean Matrix Factorization (BMF) is to approximate a given binary matrix as the product of two low-rank binary factor matrices, where the product of the factor matrices is computed under the Boolean algebra. While the problem is computationally hard, it is also attractive because the binary nature of the factor matrices makes them highly interpretable. In the last decade, BMF has received a considerable amount of attention in the data mining and formal concept analysis communities and, more recently, the machine learning and the theory communities also started studying BMF. In this survey, we give a concise summary of the efforts of all of these communities and raise some open questions which in our opinion require further investigation.

This brief note considers the solutions of LMIs in the criteria for admissibility for continuous singular systems and discrete singular systems. The new criteria are given which are strict LMI and do not involve equality constraint. The main trait of the criteria is that they simplify and improve the existing results. To judge the admissibility of singular systems, only the lest solved variable P is introduced without involving the additional matrix Q in the corresponding LMIs. With the brief and simple results of this paper, the numbers of solved matrices are reduced from a pair of matrices to just a matrix in which we can analyze singular systems with the completely consistent format as normal systems.

Abstract The need for higher productivity has lead to the design of machines operating at higher speeds. At high speed the rigid body assumption is no longer valid and the links should be considered flexible. In this work a method which is based on Modified Lagrange Equation for modeling flexible mechanism is presented. The method posses a more computational efficiency for not requiring the transformation from the local coordinate system to the global coordinate system. Also an approach using the homogeneous coordinate for element matrices generation is presented. The approach leads to a formalism where the displacement vector is expressed as a product of two matrices and a vector. The first matrix is a function of rigid body motion. The second matrix is a function of rigid body configuration. The vector is a function of elastic displacement. This formal separation helps to facilitate the generation of element matrices using symbolic manipulations.

Abstract This paper describes an existing interface which allows extraction of linear models from an MSC/NASTRAN output file and conversion into MATRIXX readable format for control design and simulation. The interface is demonstrated using an MSC/NASTRAN model of a satellite microwave antenna. In addition to the existing interface, a proposed expanded interface allowing additional information to be transfered between MSC/NASTRAN and MATRIXX is presented. Candidate information includes component mass and stiffness matrices, and outputs from MSC/NASTRAN’s Design Sensitivity Analysis (DSA) package. This sensitivity data would allow open or closed loop robustness analysis, and simultaneous structural and controller design. Additionally, the ability to transfer linear controllers designed in MATRIXX to MSC/NASTRAN would allow evaluation of such controllers on the full order model.

Los modelos de equilibrio general computable (EGC) son sistemas de ecuaciones matemáticas que permiten describir una economía completa. Intensivos en datos, estos requieren que la información utilizada para resolver dichas ecuaciones esté organizada de manera particular que toma la forma de una Matriz de Contabilidad Social (MCS), la cual describe el flujo circular de transacciones entre agentes económicos para un periodo de referencia. En este documento se describe el procedimiento seguido para la construcción de una MCS para Costa Rica para el año 2016, la cual utiliza, tanto los Cuadros de Oferta y Utilización, como las Cuentas Económicas Integradas más recientes del Sistema de Cuentas Nacionales del Banco Central de Costa Rica (BCCR) como fuente principal de datos. La MCS resultante identifica 139 actividades y 183 productos. Además de detallar los pasos tradicionales para la construcción de este tipo de matrices, este documento constituye una contribución importante al estado de la ciencia en Latinoamérica al proveer una descripción detallada de todos los ajustes necesarios para desagregar actividades económicas, productos y factores productivos. A pesar de que la MCS aquí descrita ha sido desarrollada para ser utilizada con la Plataforma de Modelado Económico Ambiental Integrada (IEEM), puede ser utilizada para calibrar cualquier modelo de EGC.