227 research outputs found

    Computing the Rate-Distortion Function of Gray-Wyner System

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    In this paper, the rate-distortion theory of Gray-Wyner lossy source coding system is investigated. An iterative algorithm is proposed to compute rate-distortion function for general successive source. For the case of jointly Gaussian distributed sources, the Lagrangian analysis of scalable source coding in [1] is generalized to the Gray-Wyner instance. Upon the existing single-letter characterization of the rate-distortion region, we compute and determine an analytical expression of the rate-distortion function under quadratic distortion constraints. According to the rate-distortion function, another approach, different from Viswanatha et al. used, is provided to compute Wyner's Common Information. The convergence of proposed iterative algorithm, RD function with different parameters and the projection plane of RD region are also shown via numerical simulations at last.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

    Environmental economic impact assessment in China: Problems and prospects

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    The use of economic valuation methods to assess environmental impacts of projects and policies has grown considerably in recent years. However, environmental valuation appears to have developed independently of regulations and practice of environmental impact assessment (EIA), despite its potential benefits to the EIA process. Environmental valuation may be useful in judging significance of impacts, determining mitigation level, comparing alternatives and generally enabling a more objective analysis of tradeoffs. In China, laws and regulations require the use of environmental valuation in EIA, but current practice lags far behind. This paper assesses the problems and prospects of introducing environmental valuation into the EIA process in China. We conduct four case studies of environmental economic impact assessment (EEIA), three of which are based on environmental impact statements of construction projects (a power plant, a wastewater treatment plant and a road construction project) and one for a regional pollution problem (wastewater irrigation). The paper demonstrates the potential usefulness of environmental valuation but also discusses several challenges to the introduction and wider use of EEIA, many of which are likely to be of relevance far beyond the Chinese context. The paper closes with suggesting some initial core elements of an EEIA guidelineEnvironmental impact assessment; Environmental valuation; China; Economic analysis

    DNet: distributional network for distributional individualized treatment effects

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    There is a growing interest in developing methods to estimate individualized treatment effects (ITEs) for various real-world applications, such as e-commerce and public health. This paper presents a novel architecture, called DNet, to infer distributional ITEs. DNet can learn the entire outcome distribution for each treatment, whereas most existing methods primarily focus on the conditional average treatment effect and ignore the conditional variance around its expectation. Additionally, our method excels in settings with heavy-tailed outcomes and outperforms state-of-the-art methods in extensive experiments on benchmark and real-world datasets. DNet has also been successfully deployed in a widely used mobile app with millions of daily active users

    Deep Learning for Feynman's Path Integral in Strong-Field Time-Dependent Dynamics

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    Feynman's path integral approach is to sum over all possible spatio-temporal paths to reproduce the quantum wave function and the corresponding time evolution, which has enormous potential to reveal quantum processes in classical view. However, the complete characterization of quantum wave function with infinite paths is a formidable challenge, which greatly limits the application potential, especially in the strong-field physics and attosecond science. Instead of brute-force tracking every path one by one, here we propose deep-learning-performed strong-field Feynman's formulation with pre-classification scheme which can predict directly the final results only with data of initial conditions, so as to attack unsurmountable tasks by existing strong-field methods and explore new physics. Our results build up a bridge between deep learning and strong-field physics through the Feynman's path integral, which would boost applications of deep learning to study the ultrafast time-dependent dynamics in strong-field physics and attosecond science, and shed a new light on the quantum-classical correspondence

    Genetic variants of p27 and p21 as predictors for risk of second primary malignancy in patients with index squamous cell carcinoma of head and neck

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    <p>Abstract</p> <p>Background</p> <p>Cell cycle deregulation is common in human cancer, and alterations of <it>p27 </it>and <it>p21</it>, two critical cell cycle regulators, have been implicated in the development of many human malignancies. Therefore, we hypothesize that <it>p27 </it>T109G polymorphism individually or in combination with <it>p21 </it>(C98A and C70T) polymorphisms modifies risk of second primary malignancy (SPM) in patients with index squamous cell carcinoma of head and neck (SCCHN).</p> <p>Methods</p> <p>A cohort of 1,292 patients with index SCCHN was recruited between May 1995 and January 2007 at the M.D. Anderson Cancer Center and followed for SPM occurrence. Patients were genotyped for the three polymorphisms. A log-rank test and Cox proportional hazards models were used to compare SPM-free survival and SPM risk.</p> <p>Results</p> <p>We found that patients with <it>p27 </it>109 TG/GG, <it>p21 </it>98 CA/AA and <it>p21 </it>70 CT/TT variant genotypes had a worse SPM-free survival and an increased SPM risk than those with the corresponding <it>p27</it>109 TT, <it>p21 </it>98 CC, and <it>p21 </it>70 CC common genotypes, respectively. After combining the three polymorphisms, there was a trend for significantly increased SPM risk with increasing number of the variant genotypes (<it>P</it><sub>trend </sub>= 0.0002). Moreover, patients with the variant genotypes had an approximately 2.4-fold significantly increased risk for SPM compared with those with no variant genotypes (HR, 2.4, 95% CI, 1.6-3.6).</p> <p>Conclusions</p> <p>These results suggest that <it>p27 </it>T109G polymorphism individually or in combination with <it>p21 </it>(C98A and C70T) polymorphisms increases risk of SPM in patients with index SCCHN.</p

    Hazard identification of dehydroacetic acid and its sodium salt used as food additives based on systematic literature searches

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    The current study, using a systematic-literature-search approach, was intended to conduct hazard identification for dehydroacetic acid (DHA) and sodium dehydroacetate (DHA-S) which are currently used as food additives in China. DHA and DHA-S belong to the category of low toxic chemicals in terms of acute toxicity, mainly causing adverse effects in the central nervous system. Its subacute, subchronic and chronic toxicity mainly include significant reduction of body weight and food intake as well as anticoagulant effect. Reproductive development toxicity result show they can decrease body weight and inhibit bone development in offspring. According to the hazard identification result, oral intake of dehydroacetic acid and its sodium salt can produce a variety of toxic effects above certain doses. Further study is needed to determine the acceptable daily intake of DHA and its sodium salt and provide scientific evidence for safely use of these compounds as food additives

    Environmental economic impact assessment in China: Problems and prospects

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    The use of economic valuation methods to assess environmental impacts of projects and policies has grown considerably in recent years. However, environmental valuation appears to have developed independently of regulations and practice of environmental impact assessment (EIA), despite its potential benefits to the EIA process. Environmental valuation may be useful in judging significance of impacts, determining mitigation level, comparing alternatives and generally enabling a more objective analysis of tradeoffs. In China, laws and regulations require the use of environmental valuation in EIA, but current practice lags far behind. This paper assesses the problems and prospects of introducing environmental valuation into the EIA process in China. We conduct four case studies of environmental economic impact assessment (EEIA), three of which are based on environmental impact statements of construction projects (a power plant, a wastewater treatment plant and a road construction project) and one for a regional pollution problem (wastewater irrigation). The paper demonstrates the potential usefulness of environmental valuation but also discusses several challenges to the introduction and wider use of EEIA, many of which are likely to be of relevance far beyond the Chinese context. The paper closes with suggesting some initial core elements of an EEIA guidelin
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