335 research outputs found

    Using regular expressions to express bowing patterns for string players

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    The study of bowing is critically important for string players. Traditional bowing annotations are a valuable part of orchestral and individual documentation, but they do not help the performer to search a piece for other passages that should be bowed the same way, or to identify alternative bowing styles. We introduce a notation based on regular expressions that describes patterns of notes in the music, as well as the bowing to be applied to the pattern. These expressions support complex bowings, and not just single annotations without musical context. The notation is simpler than general tools for regular expressions used in some software, and is suitable for use by students and musicians. We have developed a music editor that implements the notation and edits documents in Lilypond. The approach has been evaluated by experimenting with the editor on six violin sonatas by Mozart. The experiments demonstrate that the regular expression notation is successful at finding passages and inserting the bowings; that the patterns occur a number of times; and the bowings can be inserted automatically and consistently

    Bowing models for string players

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    A bowing is a sequence of bow motions that enable a piece of music to be played on a string instrument with an appropriate interpretation and sound. Traditional notation shows only the bow direction for a few notes. We propose a bowing model, which contains information about the bowings of all the notes, and we show how the bowing model can be represented in software and describe how algorithms can use it to perform several tasks that help the performer. The model, and the algorithms, are suitable both for offline editing of music and for presentation on an electronic display during performance. In particular, software can show or hide bowings on various notes, according to the performer's needs; it can calculate a full bowing; it can modify a bowing based on preferences indicated by the performer; and it can allow bowings to be archived and searched. This approach is not prescriptive: the performer is in full control of all artistic decisions, while the software carries out repetitive tasks

    Using compound earcons to represent hierarchies

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    Previous research on non-speech audio messages called <i>earcons</i> showed that they could provide powerful navigation cues in menu hierarchies. This work used <i>hierarchical</i> earcons. In this paper we suggest <i>compound</i> earcons provide a more flexible method for presenting this information. A set of sounds was created to represent the numbers 0-4 and dot. Sounds could then be created for any node in a hierarchy by concatenating these simple sounds. A hierarchy of four levels and 27 nodes was constructed. An experiment was conducted in which participants had to identify their location in the hierarchy by listening to an earcon. Results showed that participants could identify their location with over 97% accuracy, significantly better than with hierarchical earcons. Participants were also able to recognise previously unheard earcons with over 97% accuracy. These results showed that compound earcons are an effective way of representing hierarchies in sound

    Motion space reduction in a haptic model of violin and viola bowing

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    A haptic model of bowing the violin and viola is presented that focuses on just the geometry of the contact point between the bow hair and the string, giving a simplified description that focuses on aspects which the performer thinks about consciously. The model allows artificial constraints on the bow motion to be provided, giving the player physical feedback if one dimension of the contact point becomes incorrect, while allowing full movement in other dimensions

    Exploring Indonesian aquaculture futures

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    Aquaculture is the fastest-growing food production sector globally, with production projected to double within the next 15–20 years. Future growth of aquaculture is essential to providing sustainable supplies of fish in national, regional and global fish food systems; creating jobs; and maintaining fish at affordable levels for resource-poor consumers. To ensure that the anticipated growth of aquaculture remains both economically and ecologically sustainable, we need to better understand the likely patterns of growth, as well as the opportunities and challenges, that these trends present. This knowledge will enable us to better prioritize investments that will help ensure the sustainable development of the sector. In Indonesia, WorldFish and partners have applied a unique methodology to evaluate growth trajectories for aquaculture under various scenarios, as well as the opportunities and challenges these represent. Indonesia is currently the fourth largest aquaculture producer globally, and the sector needs to grow to meet future fish demand. The study overlapped economic and environmental models with quantitative and participatory approaches to understand the future of aquaculture in Indonesia. Such analyses, while not definitive, have provided new understanding of the future supply and demand for seafood in Indonesia stretching to 2030. The learning from this research provides a foundation for future interventions in Indonesian fish food systems, as well as a suite of methodologies that can be applied more widely for insightful analyses of aquaculture growth trajectories in other countries or regions

    Dynamics of spin-2 Bose condensate driven by external magnetic fields

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    Dynamic response of the F=2 spinor Bose-Einstein condensate (BEC) under the influence of external magnetic fields is studied. A general formula is given for the oscillation period to describe population transfer from the initial polar state to other spin states. We show that when the frequency and the reduced amplitude of the longitudinal magnetic field are related in a specific manner, the population of the initial spin-0 state will be dynamically localized during time evolution. The effects of external noise and nonlinear spin exchange interaction on the dynamics of the spinor BEC are studied. We show that while the external noise may eventually destroy the Rabi oscillations and dynamic spin localization, these coherent phenomena are robust against the nonlinear atomic interaction.Comment: 16 pages, 7 figures. accepted by Phys. Rev.

    Many body physics from a quantum information perspective

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    The quantum information approach to many body physics has been very successful in giving new insight and novel numerical methods. In these lecture notes we take a vertical view of the subject, starting from general concepts and at each step delving into applications or consequences of a particular topic. We first review some general quantum information concepts like entanglement and entanglement measures, which leads us to entanglement area laws. We then continue with one of the most famous examples of area-law abiding states: matrix product states, and tensor product states in general. Of these, we choose one example (classical superposition states) to introduce recent developments on a novel quantum many body approach: quantum kinetic Ising models. We conclude with a brief outlook of the field.Comment: Lectures from the Les Houches School on "Modern theories of correlated electron systems". Improved version new references adde

    Toward a Multifaceted Heuristic of Digital Reading to Inform Assessment, Research, Practice, and Policy

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    In this commentary, the author explores the tension between almost 30 years of work that has embraced increasingly complex conceptions of digital reading and recent studies that risk oversimplifying digital reading as a singular entity analogous with reading text on a screen. The author begins by tracing a line of theoretical and empirical work that both informs and complicates our understanding of digital literacy and, more specifically, digital reading. Then, a heuristic is proposed to systematically organize, label, and define a multifaceted set of increasingly complex terms, concepts, and practices that characterize the spectrum of digital reading experiences. Research that informs this heuristic is used to illustrate how more precision in defining digital reading can promote greater clarity across research methods and advance a more systematic study of promising digital reading practices. Finally, the author discusses implications for assessment, research, practice, and policy

    Efficient and Correct Stencil Computation via Pattern Matching and Static Typing

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    Stencil computations, involving operations over the elements of an array, are a common programming pattern in scientific computing, games, and image processing. As a programming pattern, stencil computations are highly regular and amenable to optimisation and parallelisation. However, general-purpose languages obscure this regular pattern from the compiler, and even the programmer, preventing optimisation and obfuscating (in)correctness. This paper furthers our work on the Ypnos domain-specific language for stencil computations embedded in Haskell. Ypnos allows declarative, abstract specification of stencil computations, exposing the structure of a problem to the compiler and to the programmer via specialised syntax. In this paper we show the decidable safety guarantee that well-formed, well-typed Ypnos programs cannot index outside of array boundaries. Thus indexing in Ypnos is safe and run-time bounds checking can be eliminated. Program information is encoded as types, using the advanced type-system features of the Glasgow Haskell Compiler, with the safe-indexing invariant enforced at compile time via type checking
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