10,134 research outputs found

    The effect of a market factor on information flow between stocks using minimal spanning tree

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    We empirically investigated the effects of market factors on the information flow created from N(N-1)/2 linkage relationships among stocks. We also examined the possibility of employing the minimal spanning tree (MST) method, which is capable of reducing the number of links to N-1. We determined that market factors carry important information value regarding information flow among stocks. Moreover, the information flow among stocks evidenced time-varying properties according to the changes in market status. In particular, we noted that the information flow increased dramatically during periods of market crises. Finally, we confirmed, via the MST method, that the information flow among stocks could be assessed effectively with the reduced linkage relationships among all links between stocks from the perspective of the overall market

    Two-dimensional heterogeneous photonic bandedge laser

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    We proposed and realized a two-dimensional (2D) photonic bandedge laser surrounded by the photonic bandgap. The heterogeneous photonic crystal structure consists of two triangular lattices of the same lattice constant with different air hole radii. The photonic crystal laser was realized by room-temperature optical pumping of air-bridge slabs of InGaAsP quantum wells emitting at 1.55 micrometer. The lasing mode was identified from its spectral positions and polarization directions. A low threshold incident pump power of 0.24mW was achieved. The measured characteristics of the photonic crystal lasers closely agree with the results of real space and Fourier space calculations based on the finite-difference time-domain method.Comment: 14 pages, 4 figure

    Customizing an English-Korean Machine Translation System for Patent Translation

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    PACLIC 21 / Seoul National University, Seoul, Korea / November 1-3, 200

    Humanitarian Supply Chain/Logistics: Roadmap to Effective Relief Effort

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    Between the years of 2000 and 2012, natural disasters caused 1.7 trillion dollars in damage and affected 2.9 billion people (dosomething.org). In Americas (ranked second globally in terms of natural disasters) between 2007 and 2016, disasters caused 255,033 deaths, 898,816 injuries and damages worth 470billion(Disasters,2017).In2016alone,naturaldisasterscaused470 billion (Disasters, 2017). In 2016 alone, natural disasters caused 175 billion in damage with 8,700 lives (Munich RE, 2017). The above numbers reflect the amount of physical destruction only but do not include indirect losses such as unemployment, environmental consequences, and business disruptions. Therefore, the full impact of these catastrophic events is much greater than these numbers suggest. Response to and management of disaster relief supply chain is different from that of commercial supply chain/logistics in many aspects. Since humanitarian relief efforts depend to a large extent on international donors and the donors usually respond well to emergency, a well thought out long term strategic plan to relive human suffering is not well established. But studies indicate that investment in the planning stage of humanitarian supply chain is much more effective and saves many lives than spending on the operation side of relief efforts. This paper explores alternative ways to respond and manage humanitarian relief efforts utilizing the principles of commercial supply chain. More specifically, this paper addresses/outlines the process to improve relief outcomes by investing in the prepared stage of humanitarian supply chain

    Blow-up dynamics for smooth finite energy radial data solutions to the self-dual Chern-Simons-Schr\"odinger equation

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    We consider the finite-time blow-up dynamics of solutions to the self-dual Chern-Simons-Schr\"odinger (CSS) equation (also referred to as the Jackiw-Pi model) near the radial soliton QQ with the least L2L^{2}-norm (ground state). While a formal application of pseudoconformal symmetry to QQ gives rise to an L2L^{2}-continuous curve of initial data sets whose solutions blow up in finite time, they all have infinite energy due to the slow spatial decay of QQ. In this paper, we exhibit initial data sets that are smooth finite energy radial perturbations of QQ, whose solutions blow up in finite time. Interestingly, their blow-up rate differs from the pseudoconformal rate by a power of logarithm. Applying pseudoconformal symmetry in reverse, this also yields a first example of an infinite-time blow-up solution, whose blow-up profile contracts at a logarithmic rate. Our analysis builds upon the ideas of previous works of the first two authors on (CSS) [21,22], as well as the celebrated works on energy-critical geometric equations by Merle, Rapha\"el, and Rodnianski [33,38]. A notable feature of this paper is a systematic use of nonlinear covariant conjugations by the covariant Cauchy-Riemann operators in all parts of the argument. This not only overcomes the nonlocality of the problem, which is the principal challenge for (CSS), but also simplifies the structure of nonlinearity arising in the proof.Comment: 80 page

    Real-time 3-D Mapping with Estimating Acoustic Materials

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    This paper proposes a real-time system integrating an acoustic material estimation from visual appearance and an on-the-fly mapping in the 3-dimension. The proposed method estimates the acoustic materials of surroundings in indoor scenes and incorporates them to a 3-D occupancy map, as a robot moves around the environment. To estimate the acoustic material from the visual cue, we apply the state-of-the-art semantic segmentation CNN network based on the assumption that the visual appearance and the acoustic materials have a strong association. Furthermore, we introduce an update policy to handle the material estimations during the online mapping process. As a result, our environment map with acoustic material can be used for sound-related robotics applications, such as sound source localization taking into account various acoustic propagation (e.g., reflection)
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