1,133 research outputs found

    Is Machine Learning Unsafe and Irresponsible in Social Sciences? Paradoxes and Reconsidering from Recidivism Prediction Tasks

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    The paper addresses some fundamental and hotly debated issues for high-stakes event predictions underpinning the computational approach to social sciences. We question several prevalent views against machine learning and outline a new paradigm that highlights the promises and promotes the infusion of computational methods and conventional social science approaches

    CLIMATE CHANGE INFLUENCES ON THE RISK OF AVIAN INFLUENZA OUTBREAKS AND ASSOCIATED ECONOMIC LOSS

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    This paper examines the effect that climate has on Avian Influenza outbreak probability. The statistical analysis shows across a broad region the probability of an outbreak declines by 0.22% when the temperature rises 1 Celsius degree and increases by 0.34% when precipitation increases by 1millimeter. These results indicate that the realized climate change of the last 20 years not only has been a factor behind recent HPAI outbreaks, but that climate change is likely to play an even greater role in the future. The statistical results indicate that overall, the risk of an AI outbreak has been increased by 51% under past climate change and 3-4% under future climate change. An economic evaluation shows the increased probability of outbreaks has caused damages of about 107millioninChinaand107 million in China and 29 million in the United States due to past climate change. In the year of 2011-2030, for countries with a high proportion of chicken production, economic loss could reach 105105-146 million in China and 1212-18 million in the United Sates.Climate change, Avian Influenza outbreaks, GDP loss, Environmental Economics and Policy, Research Methods/ Statistical Methods,

    Chinese High-speed Railway: Efficiency Comparison and the Future

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    High-speed railway (HSR) network building was initiated in China in the early 2000s, and full-scale construction began several years later as a larger use phase started in 2008. Thereafter, the expansion speed has been impressive. Network investment could be considered as a success, if evaluating the amount of high-speed railway usage already during the expansion phase. The diffusion models built in this research show that expansion in the network and growth of the passengers will continue at least until the following decade. The performance is evaluated in terms of DEA efficiency model. It is shown that efficiency started from very low levels, but it has been increasing together with the expansion of HSR network. Currently, the efficiency is near the level of the leading European High-speed (HS) countries (Germany and France). However, it is projected with linear model and by Bass diffusion models that the efficiency will reach Japanese and South Korean standards in the next decade. A somewhat larger network length with smaller relative growth of passengers, but with a higher growth of passenger-km seems to be able to reach even the frontier efficiency.</p

    Global stability of vaccine-age/staged-structured epidemic models with nonlinear incidence

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    We consider two classes of infinitely dimensional epidemic models with nonlinear incidence, where one assumes that the rate of a vaccinated individual losing immunity depends on the vaccine-age and another assumes that, before the vaccine begins to wane, there is a period during which the vaccinated individuals have complete immunity against the infection. The first model is given by a coupled ordinary-hyperbolic differential system and the second class is described by a delay differential system. We calculate their respective basic reproduction numbers, and show they characterize the global dynamics by constructing the appropriate Lyapunov functionals

    Analysis on Factors Affecting the Self-Repair Capability of SMA Wire Concrete Beam

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    Crack expansion of concrete is the initial damage stage of structures, which may cause greater damage to structures subject to long-term loads or under extreme conditions. In recent years, the application of intelligent materials to crack self-repair has become a hotspot among researchers. In order to study the influence of factors on the self-repair capability of shape memory alloy (SMA) wire concrete beam, both theoretical and experimental methods were employed for analysis. For the convenience of experiment, composite materials (epoxy cement mortar and silicone polymer clay) instead of concrete were used. The SMA wires were externally installed on and internally embedded in epoxy resin cement mortar beams and silicone polymer clay beams. Comparison of crack repair situation between two installation methods turns out that both methods possess their own advantages and disadvantages and should be employed according to the actual situation. The influence of unbonded length on the self-repair capability of embedded type SMA wire beams and the necessary minimum unbonded length to achieve self-repair function were studied. The results state clearly that the longer the unbonded length is, the better the crack repair situation is

    A sex-role-preference model for HIV transmission among men who have sex with men in China

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    Background: Men who have sex with men (MSM) are much more likely to be infected with HIV than the general population. China has a sizable population of MSM, including gay, bisexual men, money boys and some rural workers. So reducing HIV infection in this population is an important component of the national HIV/AIDS prevention and control program. Methods: We develop a mathematical model using a sex-role-preference framework to predict HIV infection in the MSM population and to evaluate different intervention strategies. Results: An analytic formula for the basic reproduction ratio R0 was obtained; this yields R0 = 3.9296 in the current situation, so HIV will spread very fast in the MSM population if no intervention measure is implemented in a timely fashion. The persistence of HIV infection and the existence of disease equilibrium (or equilibria) are also shown. We utilized our model to simulate possible outcomes of antiretroviral therapy and vaccination for the MSM population. We compared the effects of these intervention measures under different assumptions about MSM behaviour. We also found that R0 is a decreasing function of the death rate of HIV-infected individuals, following a power law at least asymptotically. Conclusion: HIV will spread very fast in the MSM population unless intervention measures are implemented urgently. Antiretroviral therapy can have substantial impact on the reduction of HIV among the MSM population, even if disinhibition is considered. The effect of protected sexual behaviour on controlling the epidemic in the MSM population largely depends on the sex-ratio preference of different sub-populations

    5′-Methyl­sulfanyl-4′-oxo-7′-phenyl-3′,4′-dihydro-1′H-spiro­[cyclo­hexane-1,2′-quinazoline]-8′-carbonitrile dimethyl­formamide monosolvate

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    In the title compound, C21H21N3OS·C3H7NO, the carbonitrile mol­ecule is built up of two fused six-membered rings and one six-membered ring linked through a spiro C atom. The 1,3-diaza ring adopts an envelope conformation and the cyclo­hexane ring adopts a chair conformation. The dihedral angle between the aromatic rings is 46.7 (3)°. In the crystal, the components are linked by N—H⋯O hydrogen bonds
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