389 research outputs found

    A generic framework for context-sensitive analysis of modular programs

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    Context-sensitive analysis provides information which is potentially more accurate than that provided by context-free analysis. Such information can then be applied in order to validate/debug the program and/or to specialize the program obtaining important improvements. Unfortunately, context-sensitive analysis of modular programs poses important theoretical and practical problems. One solution, used in several proposals, is to resort to context-free analysis. Other proposals do address context-sensitive analysis, but are only applicable when the description domain used satisfies rather restrictive properties. In this paper, we argĂŒe that a general framework for context-sensitive analysis of modular programs, Le., one that allows using all the domains which have proved useful in practice in the non-modular setting, is indeed feasible and very useful. Driven by our experience in the design and implementation of analysis and specialization techniques in the context of CiaoPP, the Ciao system preprocessor, in this paper we discuss a number of design goals for context-sensitive analysis of modular programs as well as the problems which arise in trying to meet these goals. We also provide a high-level description of a framework for analysis of modular programs which does substantially meet these objectives. This framework is generic in that it can be instantiated in different ways in order to adapt to different contexts. Finally, the behavior of the different instantiations w.r.t. the design goals that motivate our work is also discussed

    The Paleoproterozoic Zhaigou banded iron formation in the Fuping Complex, North China Craton: Geochemistry, geochronology and implications for genesis and tectonic setting

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    Precambrian Banded iron formations (BIFs) provide important insights on the chemical composition of ancient seawater, as well as the tectonic setting of their formation. The Precambrian BIFs deposits in the North China Craton are widely distributed in the Archean greenstone belts and are composed predominantly of Neoarchean Algoma-type including those in the Anshan-Benxi and eastern Hebei areas of the Eastern Block, together with minor Paleoproterozoic Superior-type BIFs in the southern segment of the trans-North China Orogen. The Zhaigou BIF deposit is associated with Paleoproterozoic Wanzi supracrustal sequence and amphibolite in the Fuping Complex in central North China Craton. Here, we present petrological, geochronological and geochemical data of the meta-sedimentary rocks, BIF ores and amphibolites from the Zhaigou BIF deposit in the Fuping Complex for the first time to constrain the formation age, source characteristics and depositional setting, and evaluate the redox states of the Paleoproterozoic seawater. Whole-rock geochemical data show that the BIF ores are enriched in HREE with low (La/Yb)PAAS values (0.037–0.073), and exhibit positive Eu (3.34–6.21) and Pr (1.05–1.10) anomalies. The PAAS-normalized REY patterns resemble 1:100 mixture of high-temperature hydrothermal fluid and seawater, indicating the involvement of the two end members. In combination with wholerock geochemical data of BIF ores, trace elements of magnetite and U-Pb ages of detrital zircons from the metasedimentary rocks, we propose that crustal components from the Fuping TTG gneiss also contributed to the BIFs. The geochemical features suggest that the protolith of amphibolite is basalt formed in island arc setting. The negative Ce anomaly (Ce/Ce* = 0.81 ~ 0.90) indicates the deposition of the Zhaigou BIF ore in an oxidizing environment. Zircon U-Pb data on the BIF ore yield weighted mean 207Pb/206Pb ages of 2028 ± 33 Ma and 1874 ± 52 Ma, representing the formation age of the Zhaigou BIF deposit and the subsequent metamorphic event, respectively. The Zhaigou BIF deposit belongs to the Algoma-type which shows close association with the Paleoproterozoic sedimentary sequence and basaltic magmatism in oceanic island arc setting. The Paleoproterozoic seawater forming the Zhaigou deposit was oxidized after the Great Oxygenation Event (GOE) during the terrane assembly in the trans-North China Orogen.Tao Zeng, Li Tang, Han-Hui Wang, M. Santosh, Yuan-Ming Shen

    Health and social care service utilisation and associated expenditure among community-dwelling older adults with depressive symptoms

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    AIMS: Late-life depression has substantial impacts on individuals, families and society. Knowledge gaps remain in estimating the economic impacts associated with late-life depression by symptom severity, which has implications for resource prioritisation and research design (such as in modelling). This study examined the incremental health and social care expenditure of depressive symptoms by severity. METHODS: We analysed data collected from 2707 older adults aged 60 years and over in Hong Kong. The Patient Health Questionnaire-9 (PHQ-9) and the Client Service Receipt Inventory were used, respectively, to measure depressive symptoms and service utilisation as a basis for calculating care expenditure. Two-part models were used to estimate the incremental expenditure associated with symptom severity over 1 year. RESULTS: The average PHQ-9 score was 6.3 (standard deviation, s.d. = 4.0). The percentages of respondents with mild, moderate and moderately severe symptoms and non-depressed were 51.8%, 13.5%, 3.7% and 31.0%, respectively. Overall, the moderately severe group generated the largest average incremental expenditure (US5886;955886; 95% CI 1126-10 647 or a 272% increase), followed by the mild group (US3849; 95% CI 2520-5177 or a 176% increase) and the moderate group (US1843;951843; 95% CI 854-2831, or 85% increase). Non-psychiatric healthcare was the main cost component in a mild symptom group, after controlling for other chronic conditions and covariates. The average incremental association between PHQ-9 score and overall care expenditure peaked at PHQ-9 score of 4 (US691; 95% CI 444-939), then gradually fell to negative between scores of 12 (US−35;95 - 35; 95% CI - 530 to 460) and 19 (US -171; 95% CI - 417 to 76) and soared to positive and rebounded at the score of 23 (US$601; 95% CI -1652 to 2854). CONCLUSIONS: The association between depressive symptoms and care expenditure is stronger among older adults with mild and moderately severe symptoms. Older adults with the same symptom severity have different care utilisation and expenditure patterns. Non-psychiatric healthcare is the major cost element. These findings inform ways to optimise policy efforts to improve the financial sustainability of health and long-term care systems, including the involvement of primary care physicians and other geriatric healthcare providers in preventing and treating depression among older adults and related budgeting and accounting issues across services

    Full counting statistics of information content

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    We review connections between the cumulant generating function of full counting statistics of particle number and the R\'enyi entanglement entropy. We calculate these quantities based on the fermionic and bosonic path-integral defined on multiple Keldysh contours. We relate the R\'enyi entropy with the information generating function, from which the probability distribution function of self-information is obtained in the nonequilibrium steady state. By exploiting the distribution, we analyze the information content carried by a single bosonic particle through a narrow-band quantum communication channel. The ratio of the self-information content to the number of bosons fluctuates. For a small boson occupation number, the average and the fluctuation of the ratio are enhanced.Comment: 16 pages, 5 figure

    Mass measurements of neutron-deficient Y, Zr, and Nb isotopes and their impact on rp and Îœp nucleosynthesis processes

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    © 2018 The Authors. Published by Elsevier B.V. This manuscript is made available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International licence (CC BY-NC-ND 4.0). For further details please see: https://creativecommons.org/licenses/by-nc-nd/4.0/Using isochronous mass spectrometry at the experimental storage ring CSRe in Lanzhou, the masses of 82Zr and 84Nb were measured for the first time with an uncertainty of ∌10 keV, and the masses of 79Y, 81Zr, and 83Nb were re-determined with a higher precision. The latter are significantly less bound than their literature values. Our new and accurate masses remove the irregularities of the mass surface in this region of the nuclear chart. Our results do not support the predicted island of pronounced low α separation energies for neutron-deficient Mo and Tc isotopes, making the formation of Zr–Nb cycle in the rp-process unlikely. The new proton separation energy of 83Nb was determined to be 490(400) keV smaller than that in the Atomic Mass Evaluation 2012. This partly removes the overproduction of the p-nucleus 84Sr relative to the neutron-deficient molybdenum isotopes in the previous Îœp-process simulations.Peer reviewe

    Measurements of the Mass and Full-Width of the ηc\eta_c Meson

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    In a sample of 58 million J/ψJ/\psi events collected with the BES II detector, the process J/Ïˆâ†’ÎłÎ·c\psi\to\gamma\eta_c is observed in five different decay channels: ÎłK+K−π+π−\gamma K^+K^-\pi^+\pi^-, ÎłÏ€+π−π+π−\gamma\pi^+\pi^-\pi^+\pi^-, ÎłK±KS0π∓\gamma K^\pm K^0_S \pi^\mp (with KS0→π+π−K^0_S\to\pi^+\pi^-), ÎłÏ•Ï•\gamma \phi\phi (with ϕ→K+K−\phi\to K^+K^-) and Îłppˉ\gamma p\bar{p}. From a combined fit of all five channels, we determine the mass and full-width of ηc\eta_c to be mηc=2977.5±1.0(stat.)±1.2(syst.)m_{\eta_c}=2977.5\pm1.0 ({stat.})\pm1.2 ({syst.}) MeV/c2c^2 and Γηc=17.0±3.7(stat.)±7.4(syst.)\Gamma_{\eta_c} = 17.0\pm3.7 ({stat.})\pm7.4 ({syst.}) MeV/c2c^2.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.

    Direct Measurements of the Branching Fractions for D0→K−e+ÎœeD^0 \to K^-e^+\nu_e and D0→π−e+ÎœeD^0 \to \pi^-e^+\nu_e and Determinations of the Form Factors f+K(0)f_{+}^{K}(0) and f+π(0)f^{\pi}_{+}(0)

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    The absolute branching fractions for the decays D0→K−e+ÎœeD^0 \to K^-e ^+\nu_e and D0→π−e+ÎœeD^0 \to \pi^-e^+\nu_e are determined using 7584±198±3417584\pm 198 \pm 341 singly tagged Dˉ0\bar D^0 sample from the data collected around 3.773 GeV with the BES-II detector at the BEPC. In the system recoiling against the singly tagged Dˉ0\bar D^0 meson, 104.0±10.9104.0\pm 10.9 events for D0→K−e+ÎœeD^0 \to K^-e ^+\nu_e and 9.0±3.69.0 \pm 3.6 events for D0→π−e+ÎœeD^0 \to \pi^-e^+\nu_e decays are observed. Those yield the absolute branching fractions to be BF(D0→K−e+Îœe)=(3.82±0.40±0.27)BF(D^0 \to K^-e^+\nu_e)=(3.82 \pm 0.40\pm 0.27)% and BF(D0→π−e+Îœe)=(0.33±0.13±0.03)BF(D^0 \to \pi^-e^+\nu_e)=(0.33 \pm 0.13\pm 0.03)%. The vector form factors are determined to be ∣f+K(0)∣=0.78±0.04±0.03|f^K_+(0)| = 0.78 \pm 0.04 \pm 0.03 and ∣f+π(0)∣=0.73±0.14±0.06|f^{\pi}_+(0)| = 0.73 \pm 0.14 \pm 0.06. The ratio of the two form factors is measured to be ∣f+π(0)/f+K(0)∣=0.93±0.19±0.07|f^{\pi}_+(0)/f^K_+(0)|= 0.93 \pm 0.19 \pm 0.07.Comment: 6 pages, 5 figure

    Measurements of J/psi Decays into 2(pi+pi-)eta and 3(pi+pi-)eta

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    Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector, the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and (7.24+-0.96+-1.11)X10^{-4}, respectively.Comment: 11 pages, 6 figure
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