619 research outputs found

    ColorPhylo: A Color Code to Accurately Display Taxonomic Classifications

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    Color may be very useful to visualise complex data. As far as taxonomy is concerned, color may help observing various species’ characteristics in correlation with classification. However, choosing the number of subclasses to display is often a complex task: on the one hand, assigning a limited number of colors to taxa of interest hides the structure imbedded in the subtrees of the taxonomy; on the other hand, differentiating a high number of taxa by giving them specific colors, without considering the underlying taxonomy, may lead to unreadable results since relationships between displayed taxa would not be supported by the color code. In the present paper, an automatic color coding scheme is proposed to visualise the levels of taxonomic relationships displayed as overlay on any kind of data plot. To achieve this goal, a dimensionality reduction method allows displaying taxonomic “distances” onto a Euclidean two-dimensional space. The resulting map is projected onto a 2D color space (the Hue, Saturation, Brightness colorimetric space with brightness set to 1). Proximity in the taxonomic classification corresponds to proximity on the map and is therefore materialised by color proximity. As a result, each species is related to a color code showing its position in the taxonomic tree. The so called ColorPhylo displays taxonomic relationships intuitively and can be combined with any biological result. A Matlab version of ColorPhylo is available at http://sy.lespi.free.fr/ColorPhylo-homepage.html. Meanwhile, an ad-hoc distance in case of taxonomy with unknown edge lengths is proposed

    Vibrational spectroscopic image analysis of biological material using multivariate curve resolution - alternating least squares

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    Multivariate data analysis techniques are ideal to decrypt chemical differences between anatomical features or tissue areas in hyperspectral images of biological samples. This protocol provides a user-friendly pipeline and graphical user interface (GUI) for data pre-processing and un-mixing of pixel spectra into their contributing pure components by multivariate curve resolution-alternating least squares (MCR-ALS) analysis. The analysis considers the full spectral profile to identify the chemical compounds and to visualize their distribution across the sample to categorize chemically distinct areas. Results are rapidly achieved (usually less than 30 - 60 min/image) and are easy to interpret and evaluate both in terms of chemistry and biology, making the method generally more powerful than principal component analysis (PCA) or single band intensity heap maps. In addition, chemical and biological evaluation of the results by means of reference matching and segmentation maps (based on k-means clustering) are possible

    Sculpting Unrealities: Using Machine Learning to Control Audiovisual Compositions in Virtual Reality

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    This thesis explores the use of interactive machine learning (IML) techniques to control audiovisual compositions within the emerging medium of virtual reality (VR). Accompanying the text is a portfolio of original compositions and open-source software. These research outputs represent the practical elements of the project that help to shed light on the core research question: how can IML techniques be used to control audiovisual compositions in VR? In order to find some answers to this question, it was broken down into its constituent elements. To situate the research, an exploration of the contemporary field of audiovisual art locates the practice between the areas of visual music and generative AV. This exploration of the field results in a new method of categorising the constituent practices. The practice of audiovisual composition is then explored, focusing on the concept of equality. It is found that, throughout the literature, audiovisual artists aim to treat audio and visual material equally. This is interpreted as a desire for balance between the audio and visual material. This concept is then examined in the context of VR. A feeling of presence is found to be central to this new medium and is identified as an important consideration for the audiovisual composer in addition to the senses of sight and sound. Several new terms are formulated which provide the means by which the compositions within the portfolio are analysed. A control system, based on IML techniques, is developed called the Neural AV Mapper. This is used to develop a compositional methodology through the creation of several studies. The outcomes from these studies are incorporated into two live performance pieces, Ventriloquy I and Ventriloquy II. These pieces showcase the use of IML techniques to control audiovisual compositions in a live performance context. The lessons learned from these pieces are incorporated into the development of the ImmersAV toolkit. This open-source software toolkit was built specifically to allow for the exploration of the IML control paradigm within VR. The toolkit provides the means by which the immersive audiovisual compositions, Obj_#3 and Ag Fás Ar Ais Arís are created. Obj_#3 takes the form of an immersive audiovisual sculpture that can be manipulated in real-time by the user. The title of the thesis references the physical act of sculpting audiovisual material. It also refers to the ability of VR to create alternate realities that are not bound to the physics of real-life. This exploration of unrealities emerges as an important aspect of the medium. The final piece in the portfolio, Ag Fás Ar Ais Arís takes the knowledge gained from the earlier work and pushes the boundaries to maximise the potential of the medium and the material

    Physical pixels

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    Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2000.Includes bibliographical references (leaves 48-51).The picture element, or pixel, is a conceptual unit of representation for digital information. Like all data structures of the computer, pixels are invisible and therefore require an output device to be seen. The physical unit of display, or physical pixel, can be any form that makes the pixel visible. Pixels are often represented as the electronically addressable phosphors of a video monitor, but the potential for different visualizations inspires the development of novel phenotypes. Four new systems of physical pixels are presented: Nami, Peano, the Digital Palette and 20/20 Refurbished. In each case, the combination of material, hardware and software design results in a unique visualization of computation. The chief contribution of this research is the articulation of a mode of artistic practice in which custom units of representation integrate physical and digital media to engender a new art.by Kelly Bowman Heaton.S.M

    Visual routines and attention

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (leaves 90-93).by Satyajit Rao.Ph.D

    INJURY-INDUCED HAND DOMINANCE TRANSFER

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    Hand dominance is the preferential use of one hand over the other for motor tasks. 90% of people are right-hand dominant, and the majority of injuries (acute and cumulative trauma) occur to the dominant limb, creating a double-impact injury whereby a person is left in a functional state of single-handedness and must rely on the less-dexterous, non-dominant hand. When loss of dominant hand function is permanent, a forced shift of dominance is termed injury-induced hand dominance transfer (I-IHDT). Military service members injured in combat operation may face I-IHDT following mutilating injuries (crush, avulsion, burn and blast wounds) that result in dominant limb amputation or limb salvage. Military occupational therapy practitioners utilize an intervention called Handwriting For Heroes to facilitate hand dominance transfer. This intervention trains the injured military member how to write again using the previously non-dominant hand. Efficacy and clinical effectiveness studies were needed to validate the use of this intervention. This dissertation contains three studies related to I-IHDT. One study measured handwriting performance in adults who previously (greater than 2 years ago) lost function of their dominant hands. Results verified that handwriting performance, when measured on two separate occasions (six-weeks apart) was similar (stable). A second study examined the efficacy of Handwriting For Heroes in non-impaired participants. Results demonstrated a positive effect on the variables that measured the written product: legibility, writing speed (letters-per-minute); as well as a positive effect on the variables that measured the writing process: kinematic and kinetic parameters. The final study examined the clinical effectiveness of Handwriting For Heroes in an injured military population. Results did not show as positive results as the efficacy study, despite similar compliance with the intervention. Specifically, non-impaired participants started with faster writing speeds in their non-dominant hands (higher letters-per-minute) and made more gains (wider ranges). The non-impaired participants also started with faster dexterity (betters scores on the Grooved Pegboard) but they made fewer gains than the injured service members (smaller ranges). Nevertheless, injured participants clearly made gains in all dependent variables thereby demonstrating clinical effectiveness of the interventio
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