2,846 research outputs found

    Shielding method for polycrystalline and epitaxy growths

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    Technique prevents silicon wafers from adhering to susceptor following silicon epitaxial deposition. Annular ring of refractory material goes around wafer during epitaxial deposit. Silicon is deposited on ring, susceptor, and portions of wafer. Ring breaks away from susceptor and wafer and no silicon undergrowth occurs

    The China A shares follow random walk but the B shares do not

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    The China A-Share stocks and the China B-Share stocks are common stocks issued by companies incorporated in China. These two classes of common stocks differ in the nationality of the investors each is restricted to by law. For the most part, the A shares, quoted in the Chinese yuan, or renminbi, are for Chinese nationals while the B shares, quoted in foreign currencies, are for non-Chinese nationals and residents of Macau, Hong Kong and Taiwan. This paper identified eighty-six companies issuing both the A and B shares and tested if these shares weekly returns follow a random walk. Employing the Lo and MacKinlay variance ratio test statistics, it is discovered that five times more B shares rejected the random walk as did the A shares. Moreover, both the Shenzhen and Shanghai B-Share indexes reject the random walk while neither the Shenzhen nor Shanghai A-Share index reject the random walk.

    The Taiwan stock market does follow a random walk

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    Applying the Lo and MacKinlay variance ratio test on the weekly returns from the Taiwan stock market from 1990 to mid 2006, I obtained results strongly indicative of the fact that not only does the Taiwan composite stock index move in a random walk fashion, returns for the individual stocks do so as we. Previous authors employing the same methodology obtained opposite results, namely, that the movements of the Taiwan stock composite index do not follow a random walk.random walk

    Joint models for noise annoyance and WTP for road noise reduction

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    Previous CV studies of the WTP for road noise reduction have used stated annoyance as an independent variable. We argue that this may be inappropriate due to potential endogeneity bias. Instead, an alternative model is proposed that treats both WTP and annoyance as endogenous variables in a simultaneous equation model as a combination of a linear regression with an ordered probit with correlated error terms and possibly common parameters. Thus, information on stated annoyance is utilised to estimate WTP without bias. Application of the model to a dataset from Copenhagen indicates a potential for improving the precision of the estimate of WTP for noise reduction with CV data.Road noise, annoyance, WTP, hurdle model, qualitative responses

    The Recent Performance of the Traditional Measure of Core Inflation in G7 Countries

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    In this paper we undertake an empirical investigation concerning the performance of the traditional measure of core inflation in recent years. We consider the group of G7 countries and explore both the high-frequency and the low-frequency relations between overall inflation and core inflation. We find that the traditional core measure, obtained by subtracting from the overall index those components which exhibit high volatility and which are responsible for the short-run variability of inflation, is a reliable indicator of trend inflation for a group of countries including the USA, Canada and Japan. The innovation accounting shows that for the three countries the transitory shock, i.e. the total inflation shock, has limited persistence and hence there is a relatively quick convergence of overall inflation to its trend component.Core Inflation Indicator; Structural Cointegrated VARs; Permanent-transitory Decompositions

    Manifold Constrained Low-Rank Decomposition

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    Low-rank decomposition (LRD) is a state-of-the-art method for visual data reconstruction and modelling. However, it is a very challenging problem when the image data contains significant occlusion, noise, illumination variation, and misalignment from rotation or viewpoint changes. We leverage the specific structure of data in order to improve the performance of LRD when the data are not ideal. To this end, we propose a new framework that embeds manifold priors into LRD. To implement the framework, we design an alternating direction method of multipliers (ADMM) method which efficiently integrates the manifold constraints during the optimization process. The proposed approach is successfully used to calculate low-rank models from face images, hand-written digits and planar surface images. The results show a consistent increase of performance when compared to the state-of-the-art over a wide range of realistic image misalignments and corruptions

    The Visual Social Distancing Problem

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    One of the main and most effective measures to contain the recent viral outbreak is the maintenance of the so-called Social Distancing (SD). To comply with this constraint, workplaces, public institutions, transports and schools will likely adopt restrictions over the minimum inter-personal distance between people. Given this actual scenario, it is crucial to massively measure the compliance to such physical constraint in our life, in order to figure out the reasons of the possible breaks of such distance limitations, and understand if this implies a possible threat given the scene context. All of this, complying with privacy policies and making the measurement acceptable. To this end, we introduce the Visual Social Distancing (VSD) problem, defined as the automatic estimation of the inter-personal distance from an image, and the characterization of the related people aggregations. VSD is pivotal for a non-invasive analysis to whether people comply with the SD restriction, and to provide statistics about the level of safety of specific areas whenever this constraint is violated. We then discuss how VSD relates with previous literature in Social Signal Processing and indicate which existing Computer Vision methods can be used to manage such problem. We conclude with future challenges related to the effectiveness of VSD systems, ethical implications and future application scenarios.Comment: 9 pages, 5 figures. All the authors equally contributed to this manuscript and they are listed by alphabetical order. Under submissio

    Human-centric light sensing and estimation from RGBD images: the invisible light switch

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    Lighting design in indoor environments is of primary importance for at least two reasons: 1) people should perceive an adequate light; 2) an effective lighting design means consistent energy saving. We present the Invisible Light Switch (ILS) to address both aspects. ILS dynamically adjusts the room illumination level to save energy while maintaining constant the light level perception of the users. So the energy saving is invisible to them. Our proposed ILS leverages a radiosity model to estimate the light level which is perceived by a person within an indoor environment, taking into account the person position and her/his viewing frustum (head pose). ILS may therefore dim those luminaires, which are not seen by the user, resulting in an effective energy saving, especially in large open offices (where light may otherwise be ON everywhere for a single person). To quantify the system performance, we have collected a new dataset where people wear luxmeter devices while working in office rooms. The luxmeters measure the amount of light (in Lux) reaching the people gaze, which we consider a proxy to their illumination level perception. Our initial results are promising: in a room with 8 LED luminaires, the energy consumption in a day may be reduced from 18585 to 6206 watts with ILS (currently needing 1560 watts for operations). While doing so, the drop in perceived lighting decreases by just 200 lux, a value considered negligible when the original illumination level is above 1200 lux, as is normally the case in offices
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