In the past few decades, significant progress has been made in addressing control problems for a variety of engineering systems having smooth dynamics. In practice, one often encounters also non-smooth systems in various branches of science and engineering, such as for example mechanical systems subject to impact. Motivated by the read/write head flying height regulation problem in hard disk drives, where the close proximity of the read/write head to the disk surface results in intermittent contact between the two and a bimodal system behavior, this thesis studies the output regulation problem in switched bimodal linear systems against known and unknown exogenous input signals. The regulation problems in bimodal systems presented in this thesis are solved within sets of Q-parameterized controllers, in which the Q parameters are designed to yield internal stability and exact output regulation in the closed loop switched system. The proposed parameterized controllers are constructed mainly in two steps. The first step is based on constructing a switched observer-based state feedback central controller for the switched linear system. The second step involves augmenting the switched central controller with additional dynamics (i.e. Q parameter) to construct a parameterized set of switched controllers. Based on the proposed sets of Q-parameterized controllers, four main regulation problems are addressed and corresponding regulator synthesis algorithms are proposed. The first problem concerns regulation against known deterministic exogenous inputs, where no stability or structural constraints are imposed on the Q parameter. The second problem is similar to the first, except that the Q parameter is constrained to be a linear combination of basis functions. This structure of the Q parameter is considered in the rest of the thesis. The third problem involves regulation against exogenous inputs involving known deterministic components and unknown random components, and where the regulator is designed subject to an H2 performance constraint. The last problem involves the development of adaptive regulators against unknown sinusoidal exogenous inputs. The different regulator synthesis algorithms are developed based on solving sets of linear matrix inequalities or bilinear matrix inequalities. The last two proposed regulation methods are successfully evaluated on an experimental setup motivated by the flying height regulation problem in hard disk drives, and involving a mechanical system with switched dynamics.

In the past few decades, significant progress has been made in addressing control problems for a variety of engineering systems having smooth dynamics. In practice, one often encounters also non-smooth systems in various branches of science and engineering, such as for example mechanical systems subject to impact. Motivated by the read/write head flying height regulation problem in hard disk drives, where the close proximity of the read/write head to the disk surface results in intermittent contact between the two and a bimodal system behavior, this thesis studies the output regulation problem in switched bimodal linear systems against known and unknown exogenous input signals. The regulation problems in bimodal systems presented in this thesis are solved within sets of Q-parameterized controllers, in which the Q parameters are designed to yield internal stability and exact output regulation in the closed loop switched system. The proposed parameterized controllers are constructed mainly in two steps. The first step is based on constructing a switched observer-based state feedback central controller for the switched linear system. The second step involves augmenting the switched central controller with additional dynamics (i.e. Q parameter) to construct a parameterized set of switched controllers. Based on the proposed sets of Q-parameterized controllers, four main regulation problems are addressed and corresponding regulator synthesis algorithms are proposed. The first problem concerns regulation against known deterministic exogenous inputs, where no stability or structural constraints are imposed on the Q parameter. The second problem is similar to the first, except that the Q parameter is constrained to be a linear combination of basis functions. This structure of the Q parameter is considered in the rest of the thesis. The third problem involves regulation against exogenous inputs involving known deterministic components and unknown random components, and where the regulator is designed subject to an H2 performance constraint. The last problem involves the development of adaptive regulators against unknown sinusoidal exogenous inputs. The different regulator synthesis algorithms are developed based on solving sets of linear matrix inequalities or bilinear matrix inequalities. The last two proposed regulation methods are successfully evaluated on an experimental setup motivated by the flying height regulation problem in hard disk drives, and involving a mechanical system with switched dynamics.

No description available.

The purpose of this work was to study learn about grain refinement mechanisms and texture development in cast n-type Bi90Sb10 alloy caused by severe plastic deformation. The practical objective is to produce a fine grained and textured microstructure in Bi90Sb10 alloy with enhanced thermoelectric performance and mechanical strength. In the study, twelve millimeter diameter cast bars of Bi90Sb10 alloy were encapsulated in square cross section aluminum 6061 alloy containers. The composite bars were equal channel angular (ECAE) extruded through a 90 degree angle die at high homologous temperature. Various extrusion conditions were studied including punch speed (0.1, 0.3 and 0.6 in/min), extrusion temperature (220, 235 and 250oC), number of extrusion passes (1, 2 and 4), route (A, BC and C), and exit channel area reduction ratio (half and quarter area of inlet channel). The affect of an intermediate long term heat treatment (for 100 hours at 250oC under 10-3 torr vacuum) was explored. Processed materials were characterized by optical microscopy, x-ray diffraction, energy dispersive spectroscopy, wavelength dispersive spectroscopy and scanning electron microscopy. Texture was analyzed using the {006} reflection plane to identify the orientation of the basal poles in processed materials. The cast grains were irregularly shaped, had a grain size of hundreds-of-microns to millimeters, and showed inhomogeneous chemical composition. Severe plastic deformation refines the cast grains through dynamic recrystallization and causes the development of a bimodal microstructure consisting of fine grains (5-30 micron) and coarse grains (50-300 micron). ECAE processing of homogenizied Bi-Sb alloy causes grain refinement and produces a more uniform microstructure. Texture results show that ECAE route C processing gives a similar or slightly stronger texture than ECAE route A processing. In both cases, the basal-plane poles become aligned with the shear direction. Reduction area exit channel extrusion is more effective for both grain refinement and texture enhancement than simple ECAE processing.

The objective of the study was to investigate the air pollution of working place and the fence of aluminum plants. Four sites were selected for conducting the sampling of particulate matter¡]PM¡^to establish the fingerprints of PM in aluminum plants. Moreover, the receptor model was used to apportion the major contributing sources of particulate matter. The results of the study showed that PM concentrations in the working places were high, which might be emitted from manufacturing or mechanical operating process in the melting furnace, the continuous casting, and etc. The total suspended solid concentrations from non-combustion pollution source ¡]such as hot rolling , cold rolling, and plate industry¡^ were usually below 200 µg /m3. Moreover, the size distributions of PM in working places were usually bi-modal type. The particle sizes with the highest concentration in five and coarse fractions were 0.18~0.56 µm respectively. As for the combustion sources, the particle sizes with the highest concentration were 0.56~1.0 µm and 11.5~24.7 µm, respectively. The particle emitted from zinc casting source were mostly in the fine particle fraction¡]1.0~3.2 µm¡^. The fingerprint profiles of PM from the working places showed that the major metal content of the hot rolling were Al, Zn, K, Cr. Among then, Cr might be source of from the using of chromate acid. The most abundant water-soluble ions were sulfate ion and chlorine and chloride. The carbon content accounted for about 22% of the PM mass. The ratio of organic carbon to elemental carbon were 2.54 and 2.80. The major metal content of melting process was Al, the minor metals were Zn, k, Ca, Fe. The ratio of anion to cation¡]A/C¡^ was about 0.80. The most abundant ion sulfate, while the chloride, the fluoride, potassium, and the ammonium ions were minor ones. The carbon content accounted about 19.2% and 27.3% of PM mass respectively. The ratio of organic carbon to elemental carbon were 1.21 and 1.07. Moreover, the major metals were k, Ca, Fe. The major ion was chloride, while the nitrate calcium and potassium ions were minor ones. The A/C was 0.7. The carbon content accounted for 54.8% and 51.0% of PM2.5 and PM10, respectively. The ratio of organic carbon to elemental carbon was about 2.9. The results obtained from receptor modeling showed that the contribution percentage of fugitive PM from the aluminum plant (including hot rolling, melting furnace, and low-wave furnace) was between 5.9 and 13.2%, Another major source was traffic refracted pollution with a contribution percentage between 17.0% and 23.0%, Fur then more, in the surrounding PM, was between 11.2% and 20.7%, while the contribution from the steel plant and Moreover, the municipal incineration was 2.5~6.5% and 2.3~5.0%,respectively. The sea salt contributed 4.3~7.1% of PM mass. The unsolved percentage was 7.0~11.8%.

Formål og problemstilling: Formålet med studien er å få innblikk i den erfaring lærere, som underviser en klasse med hørselshemmede og hørende elever, har med tanke på tilrettelegging av et fag når tegnspråk og norsk skal ivaretas. Opplæringslovens § 2-6 sier noe om tegnspråkopplæring i grunnskolen, den gir rett til opplæring i og på tegnspråk for elever som har behov for det. Problemstillingen ble som følger: Hvilken erfaring har lærere med realisering av § 2-6 i klasser med hørende og hørselshemmede elever slik at faglig deltakelse er en mulighet for de elevene? Teoretisk ramme: Studiens teoretiske ramme har vært knyttet til Cummins teori om utvikling av tospråklighet og Säljös beskrivelse av sosiokulturelt læringssyn. Styringsdokumenter og tidligere forskning blir også vektlagt. Metode: I studien ble en kvalitativ tilnærming benyttet. Datainnsamlingen besto av observasjon og semistrukturert intervju. Det ble analysert etter en temabasert tilnærming (Dalen, 2011). Empirien ble så lagt frem og drøftet etter fire kategorier; læringsmiljø, organisering av ressurser, tegnspråkkompetanse og pedagogisk tilrettelegging. Resultater: Mønsteret i studien viste godt tilrettelagte læringsmiljøer bortsett fra det krav § 2-6 har til tegnspråk og utvikling av bimodal tospråklighet. Avviket var en skole der informanten hadde god hørselsfaglig bakgrunn i tillegg til tegnspråkkompetanse. Studien viste elever som hadde nytte av tekniske hjelpemidler i forhold til hørselsutnyttelse og behersket norsk tale og skrift. Informantene opplevde at elevenes norskkunnskaper, tilgjengelige ressurser og visualisering av undervisning, bidro til faglig måloppnåelse og deltakelse i klassens faglige diskusjoner. Hovedpoeng i konklusjonen: Undervisning på tegnspråk kan bety undervisning uten reel samhandling med medelever, noe som ikke er formålstjenlig. § 2-6 elever som har nytte av tekniske hjelpemidler til lytte- og taleproduksjon kan profitere på å veksle mellom modalitetene norsk og tegnspråk. Tegnspråkkompetente lærere vil kunne gi medelever opplæring i tegn/tegnspråk, gi felles undervisning på NMT og støtte med tegnspråk ved behov. En slik kommunikasjonsform vil bidra til en inkluderende undervisning og bedre læringsforutsetninger for elevene. Men en slik undervisning vil kreve endring av § 2-6, skal realisering av § 2-6 være oppnåelig. Nøkkelord: Opplæringslovens § 2-6, bimodal tospråklighet, hørselsnedsettelse

Bimodal and nanocrystalline aluminum alloys are being investigated as stronger replacements for conventional polycrystalline aluminum alloys. Higher strengths are achieved by reducing the grain size of a metal; however, as the grain size is reduced the ductility diminishes. One solution that limits this decrease in ductility is the addition of a few microcrystalline grains into a nanocrystalline alloy, creating a bimodal microstructure that offers a better balance of strength and ductility. Two- and three-dimensional microstructural finite element (FE) simulations of monotonic and fatigue failures in Al-5083 having bimodal grain structures are conducted. To reduce the computational time and facilitate the modeling of microstructural features, a global-local model is developed. Macroscopic linear elastic and nonlinear plastic properties for each of the bimodal compositions are first used to simulate the tensile and fatigue tests in a global FE model. Subsequently, a local model that represents a single element at the center of the global model is built with distinct coarse grains (CGs) distributed throughout an ultra-fine grain (UFG) matrix. Ten percent of the elements in this model are defined as CGs, after which nanocrystalline and polycrystalline properties are assigned to the UFG and CG regions, respectively. Available fatigue test data is utilized to generate a low cycle fatigue damage model for bimodal grains size Al-5083 and obtain the damage model constants for varied levels of coarse grains. This fatigue damage model is then used in conjunction with a finite element continuum damage modeling approach, namely, successive initiation, to predict the damage and crack initiation sites and propagation paths in bimodal grains size alloys. The successive initiation method is used to continually accumulate damage in elements and initiate and propagate the crack through grains that reach the failure criteria defined for monotonic and cyclic loading. It is observed from the monotonic FE model that cracks initiate on the boundaries between CGs and UFGs then propagate through the UFG matrix around the CG until they become large enough to extend into the CGs themselves. In the cyclic FE models, the crack is observed to initiate in a CG and propagate along the CG and the surrounding UFG matrix.

The Orbifold Landau-Ginzburg Mirror Symmetry Conjecture states that for a quasihomogeneous singularity W and a group G of symmetries of W, there is a dual singularity WT and dual group GT such that the orbifold A-model of W/G is isomorphic to the orbifold B-model of WT/GT. The Landau-Ginzburg A-model is the Frobenius algebra HW,G constructed by Fan, Jarvis, and Ruan, and the B-model is the Orbifold Milnor ring of WT . The unorbifolded conjecture has been verified for Arnol'd's list of simple, unimodal and bimodal quasi-homogeneous singularities with G the maximal diagonal symmetry group by Priddis, Krawitz, Bergin, Acosta, et al. [9], and by Fan-Shen [4] and Acosta [1] for all two dimensional invertible singularities and by Krawitz for all invertible singularities of 3 dimensions and greater in [8]. Based on this Krawitz posed the Orbifold Landau-Ginzburg Mirror Symmetry Conjecture, where the A-model is still the Frobenius algebra HW,G constructed by Fan, Jarvis, and Ruan but constructed with respect to a proper subgroup G of the maximal group of symmetries GW and the B-model is the orbifold Milnor ring of WT orbifolded with respect to a non-trivial group K in SLn of order [GW :J]. I verify this Orbifold Landau-Ginzburg Mirror Symmetry Conjecture for all unimodal and bimodal quasi-homogeneous singularities in Arnol'd's list with G = J < GW, being the minimal admissible diagonal symmetry group. I also discuss some axioms and properties of these singularities.

No description available.

L'objectif de cette thèse est d'étudier le développement communicationnel multimodal des jeunes enfants français âgés de 18 mois à 3 ans et demi. Nous nous concentrons donc autant sur l'apparition et le développement des gestes et des combinaisons bimodales alliant un geste et un (ou plusieurs) mot(s) que sur celui de la langue et tâchons d'étudier le rôle du geste dans les étapes précoces de l'acquisition du langage. L'intérêt de cette recherche est qu'elle fait un pont entre (1) les recherches sur la gestualité du jeune enfant durant la période pré-verbale ainsi que sur son entrée dans la période verbale (l'arrivée des énoncés à un mot et deux mots dans ses productions) et (2) les recherches sur l'enfant d'âge scolaire (6 ans et plus) et l'adulte, qui communiquent tous deux en utilisant leur langue maternelle et des gestes co-verbaux. Notre corpus est constitué de 154 vidéos de jeunes enfants en train de jouer avec un ensemble ludique comportant une maison et des personnages en situation de jeu triadique (en présence d'un adulte). Notre premier objectif consistait à vérifier l'hypothèse que la production des gestes communicationnels et l'émergence des combinaisons bimodales annonce l'arrivée des énoncés à deux mots (comme cela a été déjà montré pour les enfants italiens et américains). En fait, il apparaît que ce processus s'étend au-delà des énoncés à deux mots, car ces combinaisons geste+Xmots apparaissent toujours avant les énoncés X+1mot. Il semble donc que le geste joue un rôle dans le développement des verbalisations enfantines avant d'être utilisé comme co-verbal chez l'enfant plus âgé et chez l'adulte. Notre second objectif consistait à observer, qualitativement, l'évolution des conduites communicatives lors de situations de jeux triadique, et plus précisément à voir sur quelles ressources communicationnelles s'appuie l'enfant pour exprimer des suites d'événements (scripts liés à son activité ludique) qui nécessitent non pas une seule, mais deux ou plusieurs prédications. Là encore, il apparaît que les gestes et les combinaisons bimodales sont intégrées aux premières tentatives de verbalisation. Ce travail confirme que le geste joue bien un rôle dans le développement linguistique enfantin. Une meilleure connaissance de ces gestes nous permettra donc une meilleure connaissance du développement de l'enfant et nous aidera à repérer plus efficacement et plus précocement les troubles développementaux de l'enfant. De plus, s'il existe déjà des indices pour mesurer le développement des performances linguistiques, cette recherche soulève la question de la création d'un indice pouvant mesurer les performances communicationnelles multimodales enfantines, c'est-à-dire la création d'un indice prenant en compte l'intégralité des ressources sémiotiques mobilisées par l'enfant et pas seulement la langue. / The aim of this thesis is to study the development of multimodal communication in young French children aged from 18 months to 3 years and a half while acquiring the French language. We will focus on the emergence and development of gestures, gesture-word combinations and language and will try to understand the role of gesture in the early stages of language acquisition. The interest of this research is that it fills the gap between (1) research on the young child first gestures during the pre-verbal period and the period during which he begins to acquire his mother tongue (the appearance of one-word and two-words sets in his productions) AND (2) research about older children (age 6 and older) and adults who both communicate using their mother tongue and co-speech gestures. Our corpus is composed of 154 videos of young children playing with an adult and a house game set (triadic situation). Using these data, we first wanted to test the hypothesis that the production of communicative gestures and the emergence of gesture-word combinations both predict the production of two-words speech in young children (as it has already been shown for Italian and American children). In fact, our results point to a more general developmental scheme with gesture+Xwords combination always preceding the upcoming of X+1words verbal utterances. Gesture use does play a role in the development of language at early stages as well as at later stages, when the child begins to produce long sentences (composed of more than two words) and combines them with co-speech gestures. Our second objective was to observe qualitative changes in the child's communicative behavior in a triadic situation, and more precisely to study the communicative resources the child uses to express sequences of events (scripts related to playful activities) which require not one, but two or more predicates. Again, it appears that gestures and bimodal combinations are integrated within the first attempts to produce verbalizations. This work confirms that gesture use does play a role in language development. A better understanding of these gestures will allow us a better understanding of child development and help us to identify earlier and more effectively developmental disorders in children. In addition, if there already is an index to measure the development of language performance, this research questions the creation of an index that can assess the multimodal communicative performance, that is to say the creation of an index taking into account all the semiotic resources mobilized by the child and not just verbal language.