Quantum algorithm for Bose-Einstein condensate quantum fluid dynamics

The dynamics of vortex solitons in a BEC superfluid is studied. A quantum lattice-gas algorithm (localization-based quantum computation) is employed to examine the dynamical behavior of vortex soliton solutions of the Gross-Pitaevskii equation (phi^4 interaction nonlinear Schroedinger equation). Quantum turbulence is studied in large grid numerical simulations: Kolmogorov spectrum associated with a Richardson energy cascade occurs on large flow scales. At intermediate scales a k^{-6} power law emerges, in a classical-quantum transition from vortex filament reconnections to Kelvin wave-acoustic wave coupling. The spontaneous exchange of intermediate vortex rings is observed. Finally, at very small spatial scales a k^{-3} power law emerges, characterizing fluid dynamics occurring within the scale size of the vortex cores themselves, a characteristic Kelvin wave cascade region. Poincare recurrence is studied: in the free non-interacting system, a fast Poincare recurrence occurs for regular arrays of line vortices. The recurrence period is used to demarcate dynamics driving the nonlinear quantum fluid towards turbulence, since fast recurrence is an approximate symmetry of the nonlinear quantum fluid at early times. This class of quantum algorithms is useful for studying BEC superfluid dynamics over a broad range of wave numbers, from quantum flow to a pseudo-classical inviscid flow regime to a Kolmogorov inertial subrange.Comment: 10 pages, 6 figure

Quantum Algorithm for Bose-Einstein Condensate Quantum Fluid Dynamics: Twisting of Filamentary Vortex Solitons Demarcated by Fast Poincare Recursion

The dynamics of vortex solitons is studied in a BEC superfluid. A quantum lattice-gas algorithm (measurementbased quantum computation) is employed to examine the dynamical behavior vortex soliton solutions of the Gross-Pitaevskii equation (ø4 interaction nonlinear Schroedinger equation). Quantum turbulence is studied in large grid numerical simulations: Kolmogorov spectrum associated with a Richardson energy cascade occurs on large flow scales. At intermediate scales, a new k-6 power law emerges, due to vortex filamentary reconnections associated with Kelvin wave instabilities (vortex twisting) coupling to sound modes and the exchange of intermediate vortex rings. Finally, at very small spatial scales a k-3power law emerges, characterizing fluid dynamics occurring within the scale size of the vortex cores themselves. Poincaré recurrence is studied: in the free non-interacting system, a fast Poincaré recurrence occurs for regular arrays of line vortices. The recurrence period is used to demarcate dynamics driving a nonlinear quantum fluid towards turbulence, since fast recurrence is an approximate symmetry of the nonlinear quantum fluid at early times. This class of quantum algorithms is useful for studying BEC superfluid dynamics and, without modification, should allow for higher resolution simulations (with many components) on future quantum computers

First-class Compositions - Defining and composing object and aspect compositions with first-class operators

A considerable amount of research, especially within the OO and AOSD communities, has focused on understanding the potential and limitations of various composition techniques. This has led to a large number of proposals for alternative composition techniques, including many variations of message dispatch, inheritance, and aspect mechanisms. This paper makes the case that there is no single perfect composition technique that suits every situation, since different techniques incur different trade-offs. The proper composition technique to use depends on the particular design problem and its requirements (e.g., with respect to adaptability, reusability, understandability, robustness, etc. of the various elements of the design). However, most programming languages limit the available composition techniques to a very few. To address this, we propose a novel composition model, called Co-op. The model provides dedicated abstractions that can be used to express a wide variety of object composition techniques ("composition operators''). Examples include various forms of inheritance, delegation, and aspects. The proposed model unifies objects (with encapsulated state and a message interface) and composition operators; composition operators are specified as first-class citizens. Multiple composition operators can be combined within the same application, and composition operators can even be used to compose new composition operators from existing ones. This opens new possibilities for developing domain-specific composition operators, taxonomies of composition operators, and for reuse and refinement of composition operators. To validate and experiment with the proposed model, we have designed and implemented a simple language, Co-op/I, that we also use in this paper to show concrete examples

Un análisis de parecido familiar de la construcción media: un enfoque funcional-cognitivo

This doctoral dissertation aims at delimiting the lexical-semantic and discourse-pragmatic features that regulate well-formedness in middle expressions and which could legitimate the adscription of a particular nominal, verb, or adjunct to the middle construction in English. The middle construction is here analysed in terms of its prototype effects (cf. Taylor, 1995; Langacker, 2008; Sakamoto, 2001; Goldberg, 1995; and Marín Arrese, 2001 and 2013), hence accommodating not only prototypical instances but also marginal structures largely ignored in the literature. This dissertation examines the prototype effects of the middle construction by exploring the Agent-like features of the Subject entity, the aspectuality of the verb, the role of the implicit Agent, and the nature of the middle adjunct. The structures analysed here conform a family of intransitive constructions that are understood as segments on the Unergative – Middle – Ergative continuum. The idea that the middle construction can actually be considered as a prototype category accommodating central and marginal structures contrasts with the postulates of the projectionist model (cf. Pinker, 1989; Ackema and Schoorlemmer, 1994; Hale and Keyser, 2002; and Fagan, 1992). The projectionist approach cannot account for the process of lexical-constructional interaction of the middle construction in an entirely satisfactory way. This is so because it does not attend to the prototype effects and discourse-pragmatic factors surrounding the middle construction, since it merely focuses on the structural information (cf. Hundt, 2007: 60; and Lemmens, 1998: 4). Therefore, it seems to be pertinent to apply the notions of ‘family-resemblance’ (cf. Wittgenstein, 1958) and ‘prototype effects’ (cf. Taylor, 1995) to the study of the middle construction, following cognitive-linguistic perspectives such as those of Lakoff (1987), Langacker (1987, 1991, 2008), Taylor (1995), and Goldberg (1995, 2006). The theory of prototypes allows for the application of the idea of a family-resemblance relation among different but related structures in order to justify the accommodation of non-prototypical cases into the prototype category. This doctoral dissertation applies a usage-based methodology to carry out a corpus study of contextualised examples. The compilation process has been conducted through the ‘Concordance’ within the Sketch Engine tool. The total sample retrieved and analysed here is 14099 instances, based on colloconstructional schemas which combine ±Animate subject entities with 254 different verbal predicates (cf. Levin, 1993), collocated with middable adjuncts (cf. Davidse and Heyvaert, 2007). The family-resemblance analysis challenges the traditionally accepted restricting features associated with the middle construction, thus demonstrating that both central and marginal structures can be accommodated within the middle prototype category. This is due to the fact that the segments of the continuum share certain commonalities with respect to their syntactic, semantic, pragmatic and cognitive underlying schemas, as well as a functional symmetry in the underlying structure of the subject and the verb (cf. Rijkhoff, 1991, 2002, 2008a and 2008b). In addition, the family-resemblance analysis of the middle prototype category is also based on the similarities and differences found across the family members examined in terms of their processes of Compositional Cospecification (cf. Yoshimura, 1998; Yoshimura and Taylor, 2004). Such process involves the specification of the semantics of the predicate in accordance with the meaning of the nominal and the semantic value of the adjunct in the middle construction. The family of constructions analysed includes: (i) prototypical action-oriented middles; (ii) prototypical ergative-like middles; (iii) the metonymically-motivated extensions of the action-oriented prototype (namely, Locative, Means, and Circumstanceof- Instrument middles); and (iv) metonymically-motivated extensions from the ergativelike prototype (namely, Agent-Instrument and Experiencer-Subject middles). Corpus data reveal that prototypical ergative-like middles are the most productive group (with 6801 instances, 68.24%), followed by prototypical action-oriented-middles (with 3633 examples, 25.77%). Among the metonymically-motivated extensions, the most productive structures are Experiencer-Subject middles (with 1789 instances, 12.69%), followed by Agent-Instrument middles (with 286 examples, 2.03%), whereas the least frequent types are Locative middles (with 48 instances, 0.34%), Means middles (with 60 examples, 0.43%), and Circumstance-of-Instrument middles (with 7 instances, 0.05%). The rest of corpus examples belong to the semantic types of Destiny- and Resultoriented middles (with 1475 instances, 10.46%).El propósito de esta tesis es delimitar las características léxico-semánticas y discursivo-pragmáticas que regulan la formación de expresiones medias y que podrían legitimar la adscripción de un determinado nominal, verbo o adjunto a la construcción media inglesa. La construcción media se analiza en términos de sus efectos prototípicos (cf. Taylor, 1995; Langacker, 2008; Sakamoto, 2001; Goldberg, 1995; y Marín Arrese, 2001 y 2013), acomodando no sólo ejemplos centrales sino también estructuras marginales generalmente ignoradas en la literatura. Esta tesis doctoral examina los efectos prototípicos de la construcción media mediante la exploración de las características pseudo-agentivas de la entidad sujeto, la aspectualidad del verbo, el rol del argumento agente implícito y la naturaleza del adjunto. Las estructuras analizadas forman una familia de construcciones intransitivas que se entienden como segmentos del continuo Inergativo – Medio – Ergativo. La idea de que la construcción media, de hecho, pueda considerarse como una categoría prototípica que acomoda estructuras centrales y periféricas contrasta con los postulados del modelo proyeccionista (cf. Pinker, 1989; Ackema y Schoorlemmer, 1994; Hale y Keyser, 2002; y Fagan, 1992). Dicho modelo no puede dar cuenta del proceso de interacción léxico-construccional de la construcción media de forma satisfactoria. Esto se debe a que el modelo proyeccionista no atiende a los efectos prototípicos y los factores discursivo-pragmáticos de la construcción media, ya que se centra únicamente en la información estructural (cf. Hundt, 2007: 60; y Lemmens, 1998: 4). Por ello, parece pertinente aplicar las nociones de ‘parecido familiar’ (cf. Wittgenstein, 1958) y ‘efectos prototípicos’ (cf. Taylor, 1995) al estudio de la construcción media, siguiendo perspectivas cognitivistas tales como las de Lakoff (1987), Langacker (1987, 1991, 2008), Taylor (1995) y Goldberg (1995, 2006). La teoría de los prototipos permite la aplicación de la idea de una relación de parecido familiar entre estructuras distintas pero relacionadas, justificando así la acomodación de casos marginales dentro de la categoría prototípica. Esta tesis doctoral aplica una metodología basada en el uso para llevar a cabo un estudio de corpus de ejemplos contextualizados. El proceso de compilación se ha llevado a cabo a través de la sección ‘Concordancia’ de la herramienta Sketch Engine. La muestra total analizada aquí es de 14099 ejemplos, basados en esquemas colo-construccionales en los que se combinan entidades de sujeto ±Animadas y 254 predicados verbales distintos (cf. Levin, 1993), colocados con adverbios compatibles con la construcción media (cf. Davidse y Heyvaert, 2007). El análisis de parecido familiar cuestiona las características restrictivas tradicionalmente asociadas con la construcción media, demostrando así que tanto las estructuras centrales como las marginales pueden acomodarse dentro de la categoría prototípica media. Esto se debe a que todos los segmentos del continuo comparten ciertas semejanzas con respecto a sus esquemas subyacentes de naturaleza sintáctica, semántica, pragmática y cognitiva, así como una simetría funcional en la estructura subyacente del sujeto y el predicado (cf. Rijkhoff, 1991, 2002, 2008a y 2008b). Además, el análisis de parecido familiar de la categoría prototípica media también se basa en las similitudes y diferencias encontradas entre los miembros de la familia de estructuras examinadas en función de sus procesos de Coespecificación Composicional (cf. Yoshimura, 1998; Yoshimura y Taylor, 2004). Dicho proceso se refiere a que la semántica del verbo se especifica de acuerdo con el significado del nominal y el valor semántico del adjunto en la construcción media. La familia de construcciones analizadas incluye: (i) medias prototípicas orientadas a la acción; (ii) medias prototípicas de naturaleza ergativa; (iii) extensiones metonímicamente motivadas de las medias prototípicas orientadas a la acción (concretamente, locativas, de medio e instrumentales de circunstancia); y (iv) extensiones metonímicamente motivadas de las medias prototípicas de naturaleza ergativa (concretamente, agentivo-instrumentales y de sujeto experimentador). Los datos del corpus examinado revelan que las medias prototípicas de naturaleza ergativa son las más productivas (con 6801 ejemplos, 68.24%), seguidas de las medias prototípicas orientadas a la acción (con 3633 ejemplos, 25.77%). Entre las extensiones motivadas metonímicamente, las estructuras más productivas son las medias de sujeto experimentador (con 1789 ejemplos 12.69%), seguidas de las medias agentivo-instrumentales (con 286 ejemplos, 2.03%), mientras que las menos frecuentes pertenecen a la clase de locativas (con 48 ejemplos, 0.34%), de medio (con 60 ejemplos, 0.43%), e instrumentales de circunstancia (con 7 ejemplos, 0.05%). El resto de ejemplos del corpus pertenecen a los tipos semánticos de medias orientadas al Destino y Resultado (con 1475 ejemplos, 10.46%)

Three Solitudes and a DJ: A Mashed-up Study of Counterpoint in a Digital Realm

This dissertation is primarily concerned with developing an understanding of how the use of pre-recorded digital audio shapes and augments conventional notions of counterpoint. It outlines a theoretical framework for analyzing the contrapuntal elements in electronically and digitally composed musics, specifically music mashups, and Glenn Gould’s Solitude Trilogy ‘contrapuntal radio’ works. Conventional studies of counterpoint encompass sixteenth- through early twentieth-century modernist and neo- classical materials but stop there. Composition by magnetic tape and computer software using pre-existing recorded audio offers the potential for a new study of music that displays clear contrapuntal elements but lacks the analytical models to outline the underlying musical systems. Central to these investigations is the assertion that counterpoint operates not only within the sphere of art music but also in the compositional logic of non-musical sound works (radio documentary) and in the harmonic and melodic underpinnings of popular music. The first chapter examines technological and cultural developments that contribute to the formation of digital contrapuntal music. The second and third chapters outline the traditional musical elements—harmony, form, and texture—of contrapuntal radio and mashups, respectively. Chapter Four explores how counterpoint exists in the sonic space of the stereo or mono sound field. Chapter Five presents the notion of program as a useful concept for analyzing interaction between lyric samples to form original narratives. These two final chapters present the original contributions from contrapuntal radio and mashups to a study of counterpoint. In each of these chapters, counterpoint forms the basis for how we perceive the underlying systems of musical works composed by traditional counterpoint or by assembling pre-existing recorded audio. The connection between the old and new is important, as one does not supplant but augment the other. As such, counterpoint is a fluid musical concept, rather than a fixed system of rules governing composition in a narrow musical palette