208 research outputs found

    A Cross National Comparison on the Awareness of Adopting FOSS4G to NSDI in Developing Countries

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    In this study, we constructed an assessment framework that was consisted of 9 indicators about functional, economic and public value for FOSS4G adoption to NSDI and alternatives such as data sharing, data management, utilization and construction and derived relative weights using AHP method. For the AHP, we conducted a survey to developing countries’ 10 respondents from 9 Asian and Latin American countries. Firstly, result of the survey showed that economic value indicator came in the highest weight with 0.425, followed by functional value indicator with 0.345 and public value indicator with 0.230. Secondly, result of the alternatives analysis showed that data sharing alternative came in the highest adoption rate with 0.824, followed by data management with 0.780, data utilization with 0.778. This means that developing countries want to introduce FOSS4G to their NSDI from economic motivation. This study focused on the comprehensive aspect for adopting FOSS4G to NSDI that is different from the previous researches that were focused on the software engineering aspect to the adoption

    Early warning for critical transitions using machine-based predictability

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    Detecting critical transitions before they occur is challenging, especially for complex dynamical systems. While some early-warning indicators have been suggested to capture the phenomenon of slowing down in the system's response near critical transitions, their applicability to real systems is yet limited. In this paper, we propose the concept of predictability based on machine learning methods, which leads to an alternative early-warning indicator. The predictability metric takes a black-box approach and assesses the impact of uncertainties itself in identifying abrupt transitions in time series. We have applied the proposed metric to the time series generated from different systems, including an ecological model and an electric power system. We show that the predictability changes noticeably before critical transitions occur, while other general indicators such as variance and autocorrelation fail to make any notable signals

    Reservoir Computing based on Quenched Chaos

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    Reservoir computing (RC) is a brain-inspired computing framework that employs a transient dynamical system whose reaction to an input signal is transformed to a target output. One of the central problems in RC is to find a reliable reservoir with a large criticality, since computing performance of a reservoir is maximized near the phase transition. In this work, we propose a continuous reservoir that utilizes transient dynamics of coupled chaotic oscillators in a critical regime where sudden amplitude death occurs. This "explosive death" not only brings the system a large criticality which provides a variety of orbits for computing, but also stabilizes them which otherwise diverge soon in chaotic units. The proposed framework shows better results in tasks for signal reconstructions than RC based on explosive synchronization of regular phase oscillators. We also show that the information capacity of the reservoirs can be used as a predictive measure for computational capability of a reservoir at a critical point. (c) 2020 Elsevier Ltd. All rights reserved

    Simultaneous determination of position and mass in the cantilever sensor using transfer function method

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    We present the simultaneous measurement of mass and position of micro-beads attached to the cantilever-based mass sensors using the transfer function method. 10 ??m diameter micro-beads were placed on micro-cantilevers and the cantilevers were excited by lead-zirconate-titanate through low-pass filtered random voltages. The cantilever vibration was measured via a laser Doppler vibrometer before and after applying the beads. From the measured transfer function, the bead position was identified using its influence on the cantilever kinetic energy. The bead mass was then obtained by analyzing the wave propagation near the beads. The predicted position and mass agreed well with actual values.open0
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