1,146 research outputs found

    Universality and the five-dimensional Ising model

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    We solve the long-standing discrepancy between Monte Carlo results and the renormalization prediction for the Binder cumulant of the five-dimensional Ising model. Our conclusions are based on accurate Monte Carlo data for systems with linear sizes up to L=22. A detailed analysis of the corrections to scaling allows the extrapolation of these results to L=\infinity. Our determination of the critical point, K_c=0.1139150 (4), is more than an order of magnitude more accurate than previous estimates.Comment: 6 pages LaTeX, 1 PostScript figure. Uses cite.sty (included) and epsf.sty. Also available as PostScript and PDF file at http://www.tn.tudelft.nl/tn/erikpubs.htm

    Rwanda’s Troubled Gacaca Courts

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    Massively-parallel bit-serial neural networks for fast epilepsy diagnosis: a feasibility study

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    There are about 1% of the world population suffering from the hidden disability known as epilepsy and major developing countries are not fully equipped to counter this problem. In order to reduce the inconvenience and danger of epilepsy, different methods have been researched by using a artificial neural network (ANN) classification to distinguish epileptic waveforms from normal brain waveforms. This paper outlines the aim of achieving massive ANN parallelization through a dedicated hardware using bit-serial processing. The design of this bit-serial Neural Processing Element (NPE) is presented which implements the functionality of a complete neuron using variable accuracy. The proposed design has been tested taking into consideration non-idealities of a hardware ANN. The NPE consists of a bit-serial multiplier which uses only 16 logic elements on an Altera Cyclone IV FPGA and a bit-serial ALU as well as a look-up table. Arrays of NPEs can be driven by a single controller which executes the neural processing algorithm. In conclusion, the proposed compact NPE design allows the construction of complex hardware ANNs that can be implemented in a portable equipment that suits the needs of a single epileptic patient in his or her daily activities to predict the occurrences of impending tonic conic seizures

    Constrained action selection in children with developmental coordination disorder

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    The effect of advance (‘precue’) information on short aiming movements was explored in adults, high school children, and primary school children with and without developmental coordination disorder (n = 10, 14, 16, 10, respectively). Reaction times in the DCD group were longer than in the other groups and were more influenced by the extent to which the precue constrained the possible action space. In contrast, reaction time did not alter as a function of precue condition in adults. Children with DCD showed greater inaccuracy of response (despite the increased RT). We suggest that the different precue effects reflect differences in the relative benefits of priming an action prior to definitive information about the movement goal. The benefits are an interacting function of the task and the skill level of the individual. Our experiment shows that children with DCD gain a benefit from advance preparation in simple aiming movements, highlighting their low skill levels. This result suggests that goal-directed RTs may have diagnostic potential within the clinic

    From Sensor to Observation Web with Environmental Enablers in the Future Internet

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    This paper outlines the grand challenges in global sustainability research and the objectives of the FP7 Future Internet PPP program within the Digital Agenda for Europe. Large user communities are generating significant amounts of valuable environmental observations at local and regional scales using the devices and services of the Future Internet. These communities’ environmental observations represent a wealth of information which is currently hardly used or used only in isolation and therefore in need of integration with other information sources. Indeed, this very integration will lead to a paradigm shift from a mere Sensor Web to an Observation Web with semantically enriched content emanating from sensors, environmental simulations and citizens. The paper also describes the research challenges to realize the Observation Web and the associated environmental enablers for the Future Internet. Such an environmental enabler could for instance be an electronic sensing device, a web-service application, or even a social networking group affording or facilitating the capability of the Future Internet applications to consume, produce, and use environmental observations in cross-domain applications. The term ?envirofied? Future Internet is coined to describe this overall target that forms a cornerstone of work in the Environmental Usage Area within the Future Internet PPP program. Relevant trends described in the paper are the usage of ubiquitous sensors (anywhere), the provision and generation of information by citizens, and the convergence of real and virtual realities to convey understanding of environmental observations. The paper addresses the technical challenges in the Environmental Usage Area and the need for designing multi-style service oriented architecture. Key topics are the mapping of requirements to capabilities, providing scalability and robustness with implementing context aware information retrieval. Another essential research topic is handling data fusion and model based computation, and the related propagation of information uncertainty. Approaches to security, standardization and harmonization, all essential for sustainable solutions, are summarized from the perspective of the Environmental Usage Area. The paper concludes with an overview of emerging, high impact applications in the environmental areas concerning land ecosystems (biodiversity), air quality (atmospheric conditions) and water ecosystems (marine asset management)

    Fibulin-4 is essential for maintaining arterial wall integrity in conduit but not muscular arteries

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    Homozygous or compound heterozygous mutations in fibulin-4 (FBLN4) lead to autosomal recessive cutis laxa type 1B (ARCL1B), a multisystem disorder characterized by significant cardiovascular abnormalities, including abnormal elastin assembly, arterial tortuosity, and aortic aneurysms. We sought to determine the consequences of a human disease-causing mutation in FBLN4 (E57K) on the cardiovascular system and vascular elastic fibers in a mouse model of ARCL1B. Fbln4E57K/E57K mice were hypertensive and developed arterial elongation, tortuosity, and ascending aortic aneurysms. Smooth muscle cell organization within the arterial wall of large conducting vessels was abnormal, and elastic fibers were fragmented and had a moth-eaten appearance. In contrast, vessel wall structure and elastic fiber integrity were normal in resistance/muscular arteries (renal, mesenteric, and saphenous). Elastin cross-linking and total elastin content were unchanged in large or small arteries, whereas elastic fiber architecture was abnormal in large vessels. While the E57K mutation did not affect Fbln4 mRNA levels, FBLN4 protein was lower in the ascending aorta of mutant animals compared to wild-type arteries but equivalent in mesenteric arteries. We found a differential role of FBLN4 in elastic fiber assembly, where it functions mainly in large conduit arteries. These results suggest that elastin assembly has different requirements depending on vessel type. Normal levels of elastin cross-links in mutant tissue call into question FBLN4\u27s suggested role in mediating lysyl oxidase-elastin interactions. Future studies investigating tissuespecific elastic fiber assembly may lead to novel therapeutic interventions for ARCL1B and other disorders of elastic fiber assembly. 2017 © The Authors, some rights reserved

    Genome Halving and Aliquoting Under the Copy Number Distance

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    Large-scale genome rearrangements occur frequently in species evolution and cancer evolution. While the computation of evolutionary distances is tractable for balanced rearrangements, such as inversions and translocations, computing distances involving duplications and deletions is much more difficult. In the recently proposed Copy Number Distance (CND) model, a genome is represented as a Copy Number Profile (CNP), a sequence of integers, and the CND between two CNPs is the length of a shortest sequence of deletions and amplifications of contiguous segments that transforms one CNP into the other. In addition to these segmental events, genomes also undergo global events such as Whole Genome Duplication (WGD) or polyploidization that multiply the entire genome content. These global events are common and important in both species and cancer evolution. In this paper, we formulate the genome halving problem of finding a closest preduplication CNP that has undergone a WGD and evolved into a given CNP under the CND model. We also formulate the analogous genome aliquoting problem of finding the closest prepolyploidzation CNP under the CND distance. We give a linear time algorithm for the halving distance and a quadratic time dynamic programming algorithm for the aliquoting distance. We implement these algorithms and show that they produce reasonable solutions on simulated CNPs

    Equilibrium crystal shapes in the Potts model

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    The three-dimensional qq-state Potts model, forced into coexistence by fixing the density of one state, is studied for q=2q=2, 3, 4, and 6. As a function of temperature and number of states, we studied the resulting equilibrium droplet shapes. A theoretical discussion is given of the interface properties at large values of qq. We found a roughening transition for each of the numbers of states we studied, at temperatures that decrease with increasing qq, but increase when measured as a fraction of the melting temperature. We also found equilibrium shapes closely approaching a sphere near the melting point, even though the three-dimensional Potts model with three or more states does not have a phase transition with a diverging length scale at the melting point.Comment: 6 pages, 3 figures, submitted to PR

    Prevalidation of body sway shooting test without the use of weapons

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    El principal objetivo de este estudio es realizar un estudio previo a la validación de un test de medición del equilibrio en tiro olímpico sin el uso de la pistola. Para ello, se han comparado los resultados del anålisis del movimiento del centro de presiones (CP) de dos pruebas de equilibrio eståtico: en la primera prueba se usó una mancuerna para simular la acción de disparo, mientras que en la segunda se usó la pistola. Se encontró una fuerte correlación entre los dos test en todas las variables del CP y una correlación lineal inversa entre el peso corporal y los movimientos del CP. No se encontró relación alguna entre los movimientos del CP y el rendimiento deportivo. El estudio concluye que el test con mancuerna puede ser vålido para la medición del equilibrio específico en tiro olímpico y se recomienda profundizar en el estudio con una muestra de mayor tamañoThe main objective of the present work is the pre-validation of a test able to provide reliable body sway measurements in Olympic shooting, without the use of a pistol. For this reason the results of the analysis of the body sway data of two static bipodal balance tests have been compared: during the first a dumbbell was used to simulate shooting, while for the second test a pistol was used. A strong correlation between the two tests regarding all variables was found. A statistically significant inverse linear correlation was also found between body weight and the movements of the COP (centre of pressure). No statistically significant relations were found between the movements of the COP and performance. The study concludes that dumbbell tests could be perfectly reliable for measuring specific body sway on Olympic shooting. Future studies on the validation of the same test with larger sample size are recommende
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