6,905 research outputs found

    A fair payment system with online anonymous transfer

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2007.Includes bibliographical references (p. 26-27).Physical cash can be anonymously transfered. Transferability is a desirable property because it allows for flexible, private commerce where neither the seller nor the buyer must identify themselves to the bank. In some cases, however, anonymity can be abused and lead to problems such as blackmail and money laundering. In 1996, Camenisch, Piveteau, and Stadler introduced the concept of fairness for (non-transferable) ECash, where a trusted authority can revoke the anonymity of certain transactions as needed. To our knowledge, no current ECash system supports both anonymous transfer and fairness. We have designed and implemented such a system. Also, we formally describe a set of desirable properties for ECash systems and prove that our system meets all of these properties under the Strong RSA assumption and the Decisional Diffie-Hellman assumption in the random oracle model. Furthermore, we provide extensions for our system that could allow it to deal with offline payments and micropayments. Our system has been implemented in java. Tests have shown that it performs and scales well, as expected.by Bin D. Vo.M.Eng

    Bayesian integration of audio and visual information for multi-target tracking using a CB-member filter

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    A new method is presented for integration of audio and visual information in multiple target tracking applications. The proposed approach uses a Bayesian filtering formulation and exploits multi-Bernoulli random finite set approximations. The work presented in this paper is the first principled Bayesian estimation approach to solve the sensor fusion problems that involve intermittent sensory data (e.g. audio data for a person who occasionally speaks.) We have examined our method with case studies from the SPEVI database. The results show nearly perfect tracking of people not only when they are silent but also when they are not visible to the camera (but speaking).Reza Hoseinnezhad, Ba-Ngu Vo, Ba-Tuong Vo, David Suterhttp://www.icassp2011.com/en/welcom

    Combination of a magnetic Feshbach resonance and an optical bound-to-bound transition

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    We use laser light near resonant with an optical bound-to-bound transition to shift the magnetic field at which a Feshbach resonance occurs. We operate in a regime of large detuning and large laser intensity. This reduces the light-induced atom-loss rate by one order of magnitude compared to our previous experiments [D.M. Bauer et al. Nature Phys. 5, 339 (2009)]. The experiments are performed in an optical lattice and include high-resolution spectroscopy of excited molecular states, reported here. In addition, we give a detailed account of a theoretical model that describes our experimental data

    Gaps in Safety within LGBTQ+ Leisure Spaces for Diverse LGBTQ+ People: White Homonormativity and Considerations for Inclusion in Safe Spaces

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    Given the white homonormativity of LGBTQ+ leisure spaces, diverse LGBTQ+ people (such as cisgender lesbian, bisexual, and queer (LBQ) women, transgender and gender nonconforming (TGNC) individuals, and racialized LGBTQ+ people) have been found to have social and health inequities within LGBTQ+ leisure spaces due to their intersectionality as racial, sexual, and gender minorities, among other social identities. LGBTQ+ leisure spaces, such as LGBTQ+ community centres and recreation groups, provide opportunities for identity development and contribute to the overall well-being of LGBTQ+ people. These so-called ‘safe spaces,’ however, can be sites of discrimination for diverse LGBTQ+ people, arguably due to dominant groups reinforcing whiteness and white privilege in those spaces. This article presents literature that critiques LGBTQ+-specific safe spaces and provides recommendations for the practice of inclusion within these spaces for diverse LGBTQ+ people. Given the potential positive outcomes associated with LGBTQ+ leisure spaces, a better understanding of problematic LGBTQ+ leisure spaces is vital for professionals in social work and allied fields to develop interventions and policies for use within those spaces that support LGBTQ+ people’s overall well-being, as well as consider frameworks of diversity and inclusion. To construct inclusive LGBTQ+ leisure spaces for diverse LGBTQ+ people, an interrogation and deconstruction of both heteronormativity and homonormativity are necessary within and outside those settings. This can be done through the creation of safer spaces, such as “counterspaces.

    A Consistent Metric for Performance Evaluation of Multi-Object Filters

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    The concept of a miss-distance, or error, between a reference quantity and its estimated/controlled value, plays a fundamental role in any filtering/control problem. Yet there is no satisfactory notion of a miss-distance in the well-established field of multi-object filtering. In this paper, we outline the inconsistencies of existing metrics in the context of multi-object miss-distances for performance evaluation. We then propose a new mathematically and intuitively consistent metric that addresses the drawbacks of current multi-object performance evaluation metrics

    Adsorption properties and third sound propagation in superfluid 4^4He films on carbon nanotubes

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    We consider the adsorption properties of superfluid 4^4He films on carbon nanotubes. One major factor in the adsorption is the surface tension force arising from the very small diameter of the nanotubes. Calculations show that surface tension keeps the film thickness on the tubes very thin even when the helium vapor is increased to the saturated pressure. The weakened Van der Waals force due to the cylindrical geometry also contributes to this. Both of these effects act to lower the predicted velocity of third sound propagation along the tubes. It does not appear that superfluidity will be possible on single-walled nanotubes of diameter about one nm, since the film thickness is less than 3 atomic layers even at saturation. Superfluidity is possible on larger-diameter nanotube bundles and multi-walled nanotubes, however. We have observed third sound signals on nanotube bundles of average diameter 5 nm which are sprayed onto a Plexiglass surface, forming a network of tubes.Comment: 4 pages, accepted for Journal of Physics: Conference Series (Proceedings of LT25

    Foreword

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    This work reports on the performances of ohmic contacts fabricated on highly p-type doped 4H-SiC epitaxial layer selectively grown by vapor-liquid-solid transport. Due to the very high doping level obtained, the contacts have an ohmic behavior even without any annealing process. Upon variation of annealing temperatures, it was shown that both 500 and 800 °C annealing temperature lead to a minimum value of the Specific Contact Resistance (SCR) down to 1.3×10−6 Ω⋅cm2. However, a large variation of the minimum SCR values has been observed (up to 4×10−4 Ω⋅cm2). Possible sources of this fluctuation have been also discussed in this paper

    Model-based learning for point pattern data

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    This article proposes a framework for model-based point pattern learning using point process theory. Likelihood functions for point pattern data derived from point process theory enable principled yet conceptually transparent extensions of learning tasks, such as classification, novelty detection and clustering, to point pattern data. Furthermore, tractable point pattern models as well as solutions for learning and decision making from point pattern data are developed

    The Current Adoption of Dry-Direct Seeding Rice (DDSR) in Thailand and Lessons Learned for Mekong River Delta of Vietnam

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    The paper documents the joint study trip, organized by CCAFS Southeast Asia for Vietnamese rice researchers, extension workers, as well as local decision makers, to visit Thailand in April 2018. The goal of the study trip was to observe and learn the experience of Thai farmers on the large-scale adoption process of dry-direct seeding rice (DDSR), a viable alternative to address regional scarcity of fresh water in irrigation caused by the drought and salinity intrusion in the Mekong River Delta
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