22,848 research outputs found

    Automatic landmark extraction from a class of hands using growing neural gas

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    A new method for automatically building statistical shape models from a set of training examples and in particular from a class of hands. In this method, landmark extraction is achieved using a self-organising neural network, the Growing Neural Gas (GNG), which is used to preserve the topology of any input space. Using GNG, the topological relations of a given set of deformable shapes can be learned. We describe how shape models can be built automatically by posing the correspondence problem on the behaviour of self-organising networks that are capable of adapting their topology to an input manifold, and due to their dynamic character to readapt it to the shape of the objects. Results are given for the training set of hand outlines, showing that the proposed method preserves accurate models

    Maximizing stakeholders' interests: An empirical analysis of the stakeholder approach to corporate governance

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    The purpose of this paper is to build on the emerging stakeholder model of corporate governance by analyzing the CSR function at board level, board diversity, and stakeholder engagement, and how it relates to financial performance. Based on an empirical study of an international sample of large companies, we find board responsibility for CSR to be a key factor in promoting engagement with primary and secondary stakeholders of the firm. Depending on the legal tradition of the country in which the company is based, we find evidence that board diversity and stakeholder engagement are positively correlated with firm financial performance.Corporate governance; corporate social responsibility; board diversity; stakeholder engagement; firm performance;

    Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300

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    We report on the unveiling of the nature of the unidentified X-ray source 3XMM J005450.3-373849 as a Seyfert-2 galaxy located behind the spiral galaxy NGC 300 using Hubble Space Telescope data, new spectroscopic Gemini observations and available XMM-Newton and Chandra data. We show that the X-ray source is positionally coincident with an extended optical source, composed by a marginally resolved nucleus/bulge, surrounded by an elliptical disc-like feature and two symmetrical outer rings. The optical spectrum is typical of a Seyfert-2 galaxy redshifted to z=0.222 +/- 0.001, which confirms that the source is not physically related to NGC 300. At this redshift the source would be located at 909+/-4 Mpc (comoving distance in the standard model). The X-ray spectra of the source are well-fitted by an absorbed power-law model. By tying NHN_\mathrm{H} between the six available spectra, we found a variable index Γ\Gamma running from ~2 in 2000-2001 years, to 1.4-1.6 in the 2005-2014 period. Alternatively, by tying Γ\Gamma, we found variable absorption columns of N_H ~ 0.34 x 10−2210^{-22} cm−2^{-2} in 2000-2001 years, and 0.54-0.75 x 10−2210^{-22} cm−2^{-2} in the 2005-2014 period. Although we cannot distinguish between an spectral or absorption origin, from the derived unabsorbed X-ray fluxes, we are able to assure the presence of long-term X-ray variability. Furthermore, the unabsorbed X-ray luminosities of 0.8-2 x 1043^{43} erg s−1^{-1} derived in the X-ray band are in agreement with a weakly obscured Seyfert-2 AGN at z≈0.22z \approx 0.22.Comment: MNRAS, accepte

    Challenges among Latine DACA Recipients and Anxiety: A Systematic Meta-Analytic Review

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    Immigrant-origin Latine young adults (ILYAs) face a challenge that is specific to their developmental period. As ILYAs transition from high school to beyond (e.g., workforce, college, etc.), they begin to grapple with participating in normative experiences for all young adults in the U.S. (e.g., obtaining a driver’s license, getting their first job at 16). The lives of ILYA, particularly those who are DACAmented or DACA eligible, are characterized by the legal and social contradiction that arises from growing up in the U.S. yet facing barriers to full participation in U.S. society. The nonexistent synthesis of the exponentially growing literature in this area, therefore, leads to an inaccurate depiction of the anxiety-based outcomes in ILYAs residing in the U.S. The goal of the present study is to summarize, by means of meta-analysis, previous research on anxiety in immigrant-origin Latine young adults within the context of challenges surrounding DACA in order to understand the associations among these variables and sociodemographic moderators to identify the impact of this policy has on well-being. A final sample of six studies that contained a total participant sample of 2,583 (Mage = 22.8) was collected. All studies were published within the last three years and passed an assessment of bias and quality checklist. Findings indicated a small-sized effect of the anxiety-challenges relationship that was not significant. Moderator models were conducted for age, sex, and geographic location, in which geographic location was the only significant moderator for the observed correlation. Findings reinforce that DACAmented ILYAs are resilient in the face of an already precarious, uncertain position in society. Finally, clinical, research, and policy implications are discussed

    Exploiting the increasing correlation of space constrained massive MIMO for CSI relaxation

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    In this paper, we explore low-complexity transmission in physically-constrained massive multiple-input multiple-output (MIMO) systems by means of channel state information (CSI) relaxation. In particular, we propose a strategy to take advantage of the correlation experienced by the channels of neighbour antennas when deployed in tightly packed antenna arrays. The proposed scheme is based on collecting CSI for only a subset of antennas during the pilot training stage and, subsequently, using averages of the acquired CSI for the remaining closely-spaced antennas. By doing this, the total number of radio frequency (RF) chains, for both CSI acquisition and data transmission, and the baseband signal processing are reduced, hence simplifying the overall system operation. At the same time, this impacts the quality of the channel estimation produced after the CSI acquisition process. To characterize this tradeoff, we explore the impact that the number of antennas with instantaneous CSI has on the performance, signal processing complexity, and energy efficiency of time-division duplex (TDD) systems. The analytical and simulation results presented in this paper show that the application of the proposed strategy in size-constrained antenna arrays is able to significantly enhance the energy efficiency against systems with full CSI availability, while approximately preserving their average performance
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