152 research outputs found

    The haptic iPod: passive learning of multi-limb rhythm skills

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    Recent experiments showed that the use of haptic vibrotactile devices can support the learning of multi-limb rhythms [Holland et al., 2010]. These experiments centred on a tool called the Haptic Drum Kit, which uses vibrotactiles attached to wrists and ankles, together with a computer system that controls them, and a midi drum kit. The system uses haptic signals in real time, relying on human entrainment mechanisms [Clayton, Sager and Will, 2004] rather than stimulus response, to support the user in playing multi-limbed rhythms. In the present paper, we give a preliminary report on a new experiment, that aims to examine whether passive learning of multi-limb rhythms can occur through the silent playback of rhythmic stimuli via haptics when the subject is focusing on other tasks. The prototype system used for this new experiment is referred to as the Haptic iPod.Paper presented at the Workshop: When Words Fail: What can Music Interaction tell us about HCI? at BCS HCI Conference 2011, Newcastle, U

    Rate-determining process in MISIM photocells for optoelectronic conversion using photo-induced pure polarization current without carrier transfer across interfaces

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    Recently, we proposed a [metal|insulator|semiconductor|insulator|metal] (MISIM) photocell, as a novel architecture for high-speed organic photodetectors. The electric polarization in the S layer, induced by modulated light illumination, propagates into the outside circuit as a polarization current through the I layers, without any carrier transfer across the interfaces. In the present work, we examined the MISIM photocells consisting of zinc-phthalocyanine(ZnPc)-C60 bilayers for the S layer and Parylene C for the two I layers, to understand the fundamental aspects of the MISIM photocells, such as current polarity and modulation-frequency dependence. It was found that, in such devices, the current polarity was primarily determined by the polarization in the S layer, which was induced by the donor–acceptor charge-transfer upon illumination. Furthermore, the ON and OFF current, which appeared in the periods of illumination-on and -off, respectively, exhibited significantly different dependence on the modulation frequency. This was well-explained by an imbalance between a quick polarization in the S layer during illumination and its slow relaxation in the dark

    Song walker harmony space: embodied interaction design for complex musical skills

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    Tonal harmony is widely considered to be the most technical and complex part of music theory. Consequently harmonic skills can be hard to acquire. Furthermore, experience of the flexible manipulation of harmony in real time generally requires the ability to play an instrument. Even for those with instrumental skills, it can be difficult to gain clear insight into harmonic abstractions. The above state of affairs gives rise to substantial barriers not only for beginners but also for many experienced musicians. To address these problems, Harmony Space (Holland et al. 2009) is an interactive digital music system designed to give insight into a wide range of musical tasks in tonal harmony, ranging from performance and composition to analysis. Harmony Space employs a principled set of spatial mappings to offer fluid, precise, intuitive control of harmony. These mappings give rise to sensory-motor and music-theoretic affordances that are hard to obtain in any other way. As a result, harmonic abstractions are rendered amenable to concrete, visible control by simple spatial manipulation. In the language of conceptual metaphor theory, many relationships in tonal harmony become accessible to rapid, universal, low-level, robust human inference mechanisms using image schemata such as containment, contact, centre-periphery, and source-path-goal. This process is more rapid, and imposes far less cognitive load, than slow, abstract symbolic reasoning. Using the above principles, several versions of Harmony Space have been de-signed to exploit specific interaction styles for different purposes. We note some key variants, such as the desktop version (Holland 1994), the camera tracked version (Holland et al. 2009), while focusing principally on the most recent version, Song Walker (Holland et al. 2011), which employs whole body interaction. Preliminary results from a study of the Song Walker system are outlined, in which both beginners and expert musicians undertook a range of musical tasks involving the performance, composition and analysis of music. Finally, we offer a discussion of the limitations of the current system, and outline directions for future wor

    Novel deposition methods for metal dithiolenes

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    Square planar metal bis-dithiolenes are interesting targets for incorporation into electronic and optoelectronic devices as they characteristically display multiple stable redox states, coupled with strong absorption at particularly low energies. This work focuses on novel methods for the formation of thin films of metal bis-dithiolenes for incorporation into devices. The synthesis, structure and spectroscopic properties of a novel class of polymerisable heteroleptic nickel dithiolene complex, containing pendent thiophene units, [Ni(R2pipdt)(b-3ted)] are described [R = Bz (3a), iPr (3b); pipdt = piperazine- 3,2-dithione; b-3ted = bis-(3-thienyl)-1,2-ethylenedithiolene]. Electrooxidation of (3a) showed it to incorporate into a polymeric film over an electrode surface, which consisted of intact dithiolene units, by covalent linking of the pendent thienyl groups. This polymer film showed some redox activity, with the intense, low energy, absorption red-shifted by 4360 cm-1. Co-polymerisation of (3a) with thiophene yielded a highly conductive film, with the intense, low energy, absorption red-shifted to a lesser extent (3500 cm-1). The films displayed interesting optical properties, however, their use was restricted by their poor redox activity, thought to be due to poor ion transport through the films. The synthesis of two novel dithiolene ligand systems, containing pendent polymerisable indolyl groups (mi-5edt and mi-5hdt), are described, and their incorporation into complexes investigated for nickel [Ni(mi-5edt)2 (6) and Ni(mi-5hdt)2 (8)], and copper f[Cu(mi-5edt)2][TMA] ([7][TMA]) and [Cu(mi-5hdt)2][TMA] ([9][TMA])g investigated [(mi-5edt) = 1-(N-methylindol-5-yl)-ethane-1,2-dithiolate and (mi-5hdt) = 1- (N-methylindol-5-yl)-hex-1-ene-1,2-dithiolate, TMA = tetramethylammonium]. Each complex was characterised in terms of its structure, redox and optical properties, and the effect of the ligand design, and the metal centre, compared. The complexes of nickel were shown to yield polymer films under electrooxidative conditions, through covalent linking of the indolyl groups, with superior redox activity to 3a, and with an equally intense low energy absorption. The monoanionic complexes of copper were shown to deposit, under electrooxidative conditions, as neutral molecular films that were otherwise unobtainable by conventional solution techniques. The incorporation of the more soluble novel indolyl functionalised nickel dithiolene 8 into electronic devices was investigated. Electrochromic devices were formed using poly- 8 as the active layer. The devices were able to switch their optical absorption profile at 860 nm through three absorbing states by application of a suitable potential difference across the film. Field-effect transistors were fabricated using a molecular film of 8 as the active layer. The devices showed ambipolar charge transport properties, though with a bias for n-channel operation, with mobilities μ ≈ 1 x 10-4 cm2V-1s-1. Photovoltaic devices were formed from a blended film of 8 with P-3HT and with MDMO-PPV [P-3HT = regioregular poly-3-hexylthiophene, MDMO-PPV = poly(2-methoxy-5- (3',7'-dimethyloctyloxy)-1,4-phenylene-vynylene)]. 8 was shown to contribute to the photocurrent at wavelengths beyond the polymer component, thus harvesting more visible light, however efficiencies below 0.1 % suggested inefficient charge transport by 8 in the film. Structurally continuous films of Ni(b-3ted)2 (10) could be formed by a process of electrodeposition. The formed films displayed conductivities 40 times greater than for conventional solution cast films. By a detailed study of the level of residual ion doping, the molecular packing, and the morphology of the films, this improved performance was attributed to the formation of a more dense polycrystalline array, with larger crystallites, which formed good electronic contact with the electrodes, and with each other. This electrodeposition technique was used to fabricate field-effect transistors from 10. The devices showed poor mobilities (μ ≈ 1 x 10^-8 cm2V-1s-1), owing to the poor intermolecular overlap of the dithiolene units in the solid-state, but suggested this technique to be suitable for a wide range of semiconductors, with more favourable electronic properties, as an alternative to conventional vapour or solution deposition

    Electropolymerisable dithiolene complexes

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    Whole body interaction in abstract domains

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    Whole Body Interaction appears to be a good fit of interaction style for some categories of application domain, such as the motion capture of gestures for computer games and virtual physical sports. However, the suitability of whole body interaction for more abstract application domains is less apparent, and the creation of appropriate whole body interaction designs for complex abstract areas such as mathematics, programming and musical harmony remains challenging. We argue, illustrated by a detailed case study, that conceptual metaphor theory and sensory motor contingency theory offer analytic and synthetic tools whereby whole body interaction can in principle be applied usefully to arbitrary abstract application domains. We present the case study of a whole body interaction system for a highly abstract application area, tonal harmony in music. We demonstrate ways in which whole body interaction offers strong affordances for action and insight in this domain when appropriate conceptual metaphors are harnessed in the design. We outline how this approach can be applied to abstract domains in general, and discuss its limitations.Published versio

    Feeling the beat where it counts: fostering multi-limb rhythm skills with the haptic drum kit

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    This paper introduces and explores a tool known as the Haptic Drum Kit. The Haptic Drum Kit employs four computer-controlled vibrotactile devices, one attached to each limb via the wrists and ankles. In the mode of use discussed in this paper, haptic pulses are used to guide the playing, on a drum kit, of rhythmic patterns that require multi-limb co-ordination. The immediate aim is to foster rhythm skills and multi-limb coordination. A broader aim is to systematically develop skills in recognizing, identifying, memorizing, retaining, analyzing, reproducing and composing monophonic and polyphonic rhythms. We consider the implications of three different theories for this approach: the work of the music educator Dalcroze (1865-1950 [1]; the entrainment theory of human rhythm perception and production [2,3]; and sensory motor contingency theory [4]. In this paper we introduce the Haptic Drum Kit; consider the implications of the above theories for this approach; report on a design study; and identify and discuss a variety of emerging design issues. As part of the design study, audio and haptic guidance was compared for five people learning to play polyphonic drum patterns of varying complexity. The results indicate that beginning drummers are able to learn intricate drum patterns from the haptic stimuli alone, although haptic plus audio is the mode of presentation preferred by subjects

    Controlling the crystallinity and crystalline orientation of “shuttlecock” naphthalocyanine films for near-infrared optoelectronic applications

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    The thin film properties of tin(II) 2,3-naphthalocyanine (SnNPc) were interrogated and various strategies for controlling the crystallinity and crystalline orientation within the films were assessed. SnNPc is shown to crystallize in the space group P21/c (Z = 4), where the molecular arrangement consists of alternating layers of concave and convex overlap, induced by the out-of-plane Sn atoms, resulting in a 3D slipped-π-stack network structure analogous to that reported for Phase I of titanyl phthalocyanine. The thin films were studied by X-ray diffraction, atomic force microscopy and absorption spectroscopy and are highly sensitive not just to the conditions during growth, but also to substrate pre- and post-deposition treatment. While the films grown at room temperature were largely amorphous, the crystallinity was enhanced with substrate temperature, with the molecules orienting in a standing molecular geometry. A thin layer of 3,4:9,10-perlenetetracarboxylic dianhydride induces a lying molecular geometry of the same polymorph as that of the single crystal, while different polymorphs are accessible through solvent vapor annealing of amorphous films. Transient photocurrent measurements showed a dramatic improvement in photodetector device bandwidth for the lying molecular geometry, which was attributed to enhanced photoconductivity along the π-stacking axis, while solvent vapor annealing could be used to tune the photosensitivity across the near-infrared region
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