Nanostructures often possess unique properties, which may lead to the development of new microelectronic and optoelectronic devices. They also provide an opportunity to test fundamental quantum mechanical concepts such as the role of quantum confinement. Considerable effort has been made to understand the electronic and structural properties of nanostructures, but many fundamental issues remain. In this work, the electronic and structural properties of nanostructures are examined using several new computational methods. The effect of dimensional confinement on quantum levels is investigated for hydrogenated Ge <110> using the plane-wave density-functional-theory pseudopotential method. We present a real-space pseudopotential method for calculating the electronic structure of one-dimensional periodic systems such as nanowires. As an application of this method, we examine H-passivated Si nanowires. The band structure and heat of formation of the Si nanowires are presented and compared to plane wave methods. Our method is able to offer the same accuracy as the traditional plane wave methods, but offers a number of computational advantages such as the ability to handle large systems and a better ease of implementation for highly parallel platforms. Doping is important to many potential applications of nano-regime semiconductors. A series of first-principles studies are conducted on the P-doped Si <110> nanowires by the real-space pseudopotential methods. Nanowires of varied sizes and different doping positions are investigated. We calculate the binding energies of P atoms, band gaps of the wires, energetics of P atoms in different doping positions and core-level shift of P atoms. Defect wave functions of P atoms are also analyzed. In addition, we study the electronic properties of phosphorus-doped silicon <111> nanofilms using the real-space pseudopotential method. Nanofilms with varied sizes and different doping positions are investigated. We calculate the binding energies of P atoms, band gaps of the films, and energetics of P atoms in different doping positions. Quantum confinement effects are compared with P-doped Si nanocrystals and as well as nanowires. We simulate the nanofilm STM images with P defects in varied film depths, and make a comparison with the experimental measurement. / text

No description available.

Denna studie undersöker hur programledare i ett tv-program för teckenspråkiga ungdomar använder sig av token blend i svenskt teckenspråk. Det teoretiska ramverket för studien är mental space theory som hämtats från kognitiv lingvistik och har vidareutvecklas för teckenspråk av den amerikanske lingvisten Scott Liddell. Inom denna teori är man bland annat intresserad av att studera hur det tomma området framför kroppen kan ge mening i teckenspråket. Studien visar att bruket av token blend är vanligt i redaktionella texter som presenteras i ett tv-program. Stödanteckningar på skriven svenska tycks inte påverka bruket av token blend. Frekvensen av token blend är jämförbar med en sakprosatext som framförs utan skrivet manuskript. Däremot är blicken riktad mot kamerorna och knappast alls mot token, vilket annars är vanligt i spontant språkbruk.

Matter on a length scale comparable to that of a chemical bond is governed by the theory of quantum mechanics, but quantum mechanics is a many body theory, hence for the sake of chemistry or solid state physics, finding solutions to the governing equation, Schrodinger's equation, is hopeless for all but the smallest of systems. As the number of electrons increases, the complexity of solving the equations grows rapidly without bound. One way to make progress is to treat the electrons in a system as independent particles and to attempt to capture the many-body effects in a functional of the electrons' density distribution. When this approximation is made, the resulting equation is called the Kohn-Sham equation, and instead of requiring solving for one function of many variables, it requires solving for many functions of the three spatial variables. This problem turns out to be easier than the many body problem, but it still scales cubically in the number of electrons. In this work we will explore ways of obtaining the solutions to the Kohn-Sham equation in the framework of real-space pseudopotential density functional theory. The Kohn-Sham equation itself is an eigenvalue problem, just as Schrodinger's equation. For each electron in the system, there is a corresponding eigenvector. So the task of solving the equation is to compute many eigenpairs of a large Hermitian matrix. In order to mitigate the problem of cubic scaling, we develop an algorithm to slice the spectrum into disjoint segments. This allows a smaller eigenproblem to be solved in each segment where a post-processing step combines the results from each segment and prevents double counting of the eigenpairs. The efficacy of this method depends on the use of high order polynomial filters that enhance only a segment of the spectrum. The order of the filter is the number of matrix-vector multiplication operations that must be done with the Hamiltonian. Therefore the performance of these operations is critical. We develop a scalable algorithm for computing these multiplications and introduce a new density functional theory code implementing the algorithm. / text

Pour leur survie, les hommes se sont créés, au fil de leur évolution, leur propre « milieu de vie » fait d’éléments pouvant les mettre à l’abri des dangers et leur faciliter l’existence. Les villes sont nées de ces besoins et au sein d’elles des espaces ludiques et de confort sont apparus. Sont venus ensuite des désirs d’expression et de partage qui distinguent les villes les unes des autres. A la Renaissance, les villes européennes nées des inspirations de la Grèce antique se sont érigées en modèle avec leurs places publiques aménagées. La volonté de leurs concepteurs et des mouvements artistiques ont donné à ces aires urbaines leurs formes diverses. Avec l’apparition des nouvelles technologies, c’est encore une autre étape qui se présente et enrichit la ville d’une dimension complémentaire : l’espace virtuel accompagne désormais l’espace réel. Le virtuel a aujourd’hui une importance capitale au sein des villes et véhicule l’art urbain. C’est l’étude de cette évolution, ce parcours depuis la ville en tant que besoin jusqu’à la ville moderne modelée par ses espaces virtuels que notre travail se propose d’analyser. Le croisement entre le réel et le virtuel nous offre une dimension nouvelle avec des contraintes mais également un champ nouveau d’expression. De l’Europe jusqu’en Chine, les espaces publics sont aujourd’hui des œuvres d’art à part entière et accordent à la ville son identité, son image, reflet de sa culture et de son patrimoine architectural et artistique. / To survive, human beings have created their own “living environment” throughout their evolution to protect themselves from dangers and facilitate their existence. Cities were formed to fulfill these needs, to perform different spacial functions and to present the comfort for living. The continuing demand and expression have distinguished cities from each other, so that we can experience the beauty of difference. During the Renaissance, Europeans were inspired by ancient Greece with their public places' structures. The will of the designers and artistic movements then have given these urban areas various forms. With the development of new tehcnologies, we have various ways to enrich cities: the virtual space is now interconnected with the real space. Nowadays, virtual spaces has become an important channel to deliver urban art.This study aims to analyze this evolution path of city spaces, from basic human needs to how virtual space have figured modern world. The cross between real space and virtual space offers and also restrains a new dimension for expression. From Europe to China, public spaces are definitely artwork itself and also give each city its identity and its image. It also reflects its culture, architectural and artistic heritage.

L’art moderne et contemporain a quitté le régime de la Représentation pour expérimenter d’autres fonctions et proposer à un nouveau « regardeur » d’autres rapports avec la réalité vécue. Pour cela, il faut que quelque chose de fondamental ait changé dans la relation de l’artiste au monde : l’espace n’est plus quelque chose qu’il élabore au moyen de l’oeuvre, ou en elle. L’espace est, pour l’artiste moderne, une « donnée » dans laquelle il est placé d’emblée, à l’instar de tout être. Cela veut dire qu’il n’y a pas d’espace propre à l’oeuvre d’art qui ne soit l’espace du monde lui-même. L’art, c’est le monde, à travers l’engagement de tout ce qui l’occupe.C’est ce que Jean Paulhan (1884-1968), en parlant des cubistes, avait appelé « l’espace brut » ou « l’espace spontané », et qui est désigné ici comme « l’espace réel », pour le différencier de toute fiction spatiale. C’est aussi ce que Marcel Duchamp a élaboré à travers ses expérimentations sur les choses et le langage, l’ayant conduit à concevoir cette complexematrice de l’art qu’est le Ready-made en remplacement de la Perspective. Ainsi, ce qu’on nomme art contemporain est un art qui s’élabore dans le monde, impliquant les êtres et les choses, les formes et les signes, mais aussi la « lumière » des idées, toujours déjà là. Comprendre l’art, c’est, pour chacun, appréhender, sans pouvoir se dérober, comment se joue une rencontre entre ces entités contradictoires, visant une unité nouvelle et exprimant l’intuition du monde comme Tout.Cette thèse est un tel effort de compréhension qui, dans ma pratique de commissaire d’exposition et de critique d’art, a été partagé avec des artistes, au plus près des oeuvres et dans de multiples contextes, dans le cadre de ces institutions « d’aménagement du territoire » que sont les Fonds régionaux d’art contemporain / Modern and contemporary art have abandoned the system of Representation to experiment with other functions and to offer a new “beholder” different relations with a lived reality. To do this, something fundamental had to alter the artist’s relation to the world: space is no longer developed by means of the work, or within it. For modern artist, space is a “given” in which he is immediately placed, like any being. This means that there is no space peculiar to the work of art which is not the space of the world itself. Art is the world, through the involvement of everything occupying its space.This is what, in talking about the Cubists, Jean Paulhan (1884-1968) called “raw space” and “spontaneous space”, which is here described as “real space”, to differentiate it from any spatial fiction. It is also what Marcel Duchamp developed in his experiments involving things and language, leading him to devise that new matrix of art known as the Readymade,replacing Perspective. So what we call contemporary art is an art that is developed within the world, involving beings and things, forms and signs, invariably already there. For everyone, understanding art is grasping how, without being able to sidestep, the encounter between these contradictory entities is enacted, aimed at a new unity and expressing the intuition of the world as a Whole.This thesis is such an effort at comprehension, which, in my activities as an exhibition curator and art critic, has been shared with artists, at very close quarters with works and in many different contexts, within the framework of those institutions of “regional development”, the regional contemporary art collections (FRAC).

abstract: 4H-SiC has been widely used in many applications. All of these benefit from its extremely high critical electric field and good electron mobility. For example, 4H-SiC possesses a critical field ten times higher than that of Si, which allows high-voltage blocking layers composed of 4H-SiC to be approximately a tenth the thickness of a comparable Si device. This, in turn, reduces the device on-resistance and power losses while maintaining the same high blocking capability. Unfortunately, commercial TCAD tools like Sentaurus and Silvaco Atlas are based on the effective mass approximation, while most 4H-SiC devices are not operated under low electric field, so the parabolic-like band approximation does not hold anymore. Hence, to get more accurate and reliable simulation results, full-band analysis is needed. The first step in the development of a full-band device simulator is the calculation of the band structure. In this work, the empirical pseudopotential method (EPM) is adopted. The next task in the sequence is the calculation of the scattering rates. Acoustic, non-polar optical phonon, polar optical phonon and Coulomb scattering are considered. Coulomb scattering is treated in real space using the particle-particle-particle-mesh (P3M) approach. The third task is coupling the bulk full-band solver with a 3D Poisson equation solver to generate a full-band device simulator. For proof-of-concept of the methodology adopted here, a 3D resistor is simulated first. From the resistor simulations, the low-field electron mobility dependence upon Coulomb scattering in 4H-SiC devices is extracted. The simulated mobility results agree very well with available experimental data. Next, a 3D VDMOS is simulated. The nature of the physical processes occurring in both steady-state and transient conditions are revealed for the two generations of 3D VDMOS devices being considered in the study. Due to its comprehensive nature, the developed tool serves as a basis for future investigation of 4H-SiC power devices. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2020

The goal of computational research in the fields of engineering, physics, chemistry or as a matter of fact in any field, is to study the properties of systems from the various principles available. In computational engineering, particularly in nano-scale simulations involving low-energy physics or chemistry, the goal is to model such structures and understand their properties from first principles or better known as \textit{Ab Initio} calculations. Geometry optimization is the basic component used in modeling molecules. The calculations involved are used to find the coordinates or the positions of the atoms of the molecule where it has the minimum energy and is hence stable. Efficient calculation of the forces acting on the atoms is the most important factor to be able to study the stable geometry of a molecule. In this thesis, the approach used begins with efficient electronic structure calculations using all electron calculations which paves the way for efficient force calculations. Kohn-Sham equations Density functional theory (DFT) are used to find the electron wave functions as accurately as possible using a finite element basis that introduces minimum errors in calculations. FEAST, a highly efficient density matrix based eigenvalue solver, is used to obtain accurate eigenvalues. Derivation of forces is done using the Hellmann-Feynman theorem. To find the minimum energy configuration of the system, Newton's iterative method is used that converges to the desired coordinates where the energy at the global minimum is found. The theory behind energy minimization and the calculations involved will be elaborated in this thesis and a method to move the atom in the existing framework will be discussed.

I denna studie tittar jag på vilka filmiska särdrag som förekommer i konstnärlig teckenspråkstext, Visual Vernacular, ur en kognitiv beskrivningsmodell för teckenspråk (Liddell 2003) som utgångspunkt för att öka förståelsen om Visual Vernaculars unika uppbyggnad. Tre Visual Vernacular-texter, från Amerika, Italien och Polen tas med till denna studies analysarbete vilket skett via annotering och ett urval av Visual Vernacular-segment för att finna kopplingar till filmiska uttrycksmedel. Sedan delades arbetet upp i händelsebaserade Visual Vernacular-segment som grundar sig på att tecknarens händer antingen representeras av substitutor och/eller avbildas av manipulator, och beskrivningsbaserade Visual Vernacular-segment som representeras av deskriptor. Därefter presenteras resultatet av vilka real space blend de olika Visual Vernacular-segmenten innehåller samt hur kopplingarna med de filmiska uttrycksmedlen ser ut. Det framgår att Visual Vernacular utmärker sig genom användningen av förstapersonsperspektiv (Point of View) det vill säga, att tecknaren skapar en surrogatblend med eller utan avbildande tecken. Tecknaren kan skapa avbildande blend tillsammans med surrogatblend och använda uppdelade zoner samt onomatopoetiska eller adverbiella munrörelser för att uppge flera real space blend simultant i estetiskt syfte. De filmiska uttrycksmedel som förekommer i Visual Vernacular består av bildutsnitt såsom helbild, halvbild och närbild, fast de kan spelas upp som flera bildlager samtidigt för att skapa en händelse. Det innebär att tecknaren i en Visual Vernacular-text kan personifiera vilken karaktär som helst och framföra innehållet i olika skala med eller utan zoom men i samma händelse. Genom att försöka finna kopplingar till filmiska uttrycksmedel är resultatet från denna studie att det förekommer uttryckssätt som hör ihop med teckenspråk, exempelvis visuell komprimering som inte går att jämföra med film. Resultatet visar även att antalet real space blend i en Visual Vernacular-text kan uppgå till 40 blend per minut vilket är dubbelt så många jämfört med en narrativ teckenspråkstext. Avslutningsvis visar det att Visual Vernacular är en unik berättelsekonst på teckenspråk som har möjlighet att förstås av teckenspråkiga från hela världen. / In this study, I look at the cinematic features that appear in artistic sign language texts, Visual Vernacular from a cognitive description model for sign language (Liddell 2003) as a starting point to increase understanding of the unique structure of Visual Vernacular. Three Visual Vernacular texts, from America, Italy and Poland, are included in the analysis of this study, which is done through annotation and a selection of Visual Vernacular-segments to find a connection to cinematic features. The work is then divided into action-based Visual Vernacular which is based on the signer’s hand either being represented by substitutor and/or depicted by a manipulator, and description-based Visual Verrnacular represented by a descriptor. After that, the results are presented of which real space blend these Visual Vernacular segments contain and what connections with cinematic features look like. It appears that Visual Vernacular is distinguished by the use of a first-person perspective (Point of View), that is, that the signer creates a surrogat blend with or without depicting signs. The signer can create a depicting blend together with a surrogat blend and use partitioning zones as well as onomatopoeic or adverbial mouth movements to indicate several real space blends simultaneously for aesthetic purposes. The cinematic features that occur in Visual Vernacular consist of cinematography such as long shot, medium shot and close-up but they are played as several cinematography layers simultaneously to create an event. This means that the signer in a Visual Vernacular-text can personify himself in any character and present the content on different scales with or without zoom but in the same event. By trying to find connections to cinematic features, the results from this study lead to the assumption that there are features that are related to sign language, for example, visual compression that cannot be compared with film. The results show that the number of real space blends in a Visual Vernacular text can amount to 40 blends per minute, which is twice as much in relation to a narrative sign language text. In conclusion, it shows that Visual Vernacular is a unique storytelling art in sign language that has the opportunity to be understood by sign language users from all over the world.

Previous studies on children’s acquisition of depicting verbs in signed languages have chiefly studied the use of classifiers in verbs of motion and location, particularly the order in which the different classes of handshape are acquired. The age of the children in these studies have ranged from age three to thirteen, and an important finding has been that classifier constructions are not fully acquired until early adolescence. Most of these studies have used an elicitation tool to investigate the production and comprehension of classifiers, but have not provided any adult target norms of the test items when scoring children’s achievement. The present dissertation provides a detailed description of both adults’ and children’s verb constructions in descriptions of cutting and breaking events in Swedish Sign Language (SSL), specifically focusing on the number of hands used in signing, handshape category and hand activity, which has not been previously described for any sign language. As part of this study, 14 deaf adults (ages 20–72) and 11 deaf children (2;1–6;6) of deaf parents, all native-users of SSL, performed a task that involved describing 53 video clips of cutting and breaking events. The clips show an event in which an actor separates material, either with the aid of a tool or without. Additionally, some clips show an entity separating by itself without an actor being involved. The adults described the events with depicting verb constructions that are produced with two hands. The analysis of the handshapes produced three categories: substitutor, manipulator and descriptor. The most frequent construction in the description of events without a tool was two acting manipulators (depicting a hand handling an object), whereas in descriptions of events with a tool the combinations were acting substitutor or manipulator with a non-acting manipulator. The acting hand referred to the tool and the non-acting manipulator to the affected entity. In descriptions of events without an actor, either two substitutors or two manipulators were used. In addition to depicting verb constructions, the descriptions also contained resultative complements, i.e. signs carrying information about the result of the activity being carried out. The complements were either lexical signs or some form of depicting verb construction. Similar observations have not been noted for any other signed language. In the manner of the adults, the children used depicting verb constructions in descriptions of cutting and breaking events (681 tokens), but they also used pointing and lexical signs (64 tokens). Nearly half of the verb constructions that were used by the children corresponded to the adult target forms. The majority of the constructions describing events without a tool corresponded to the adult target forms using two acting manipulators, even among the youngest informants. In events with a tool, only a third of the constructions corresponded to the adult target forms (emerging at 4;8 – 5;0); the remaining two-thirds were deviating constructions in terms of number of hands, handshape category and hand activity. Resultative complement are sparsely used by children (57 tokens), the most chosen type of complement being lexical signs. Pervasive features of children’s constructions were the addition of contact between the hands and a preference for substitutors, something not found in adults’ constructions. These features were elucidated within the framework of Real Space blending theory, with the study showing that children first use visible blended entities and that invisible blended entities do not emerge until 4;8–5;0. / <p>Disputationen teckenspråkstolkas</p>