988 research outputs found

    Controlling PM2.5 in Chengdu: Analysis and Recommendations from the China, U.S. and California Experience

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    Chengdu, China, is experiencing rapid economic growth and urbanization at a cost of serious air pollution problems. China has developed a series of policies to reduce PM2.5 emissions and to reform energy structure. However, problems exist which may prevent effectively implementation of the PM2.5 policies, include poor PM2.5 monitoring, isolated environmental management, lack of health improvement target, unclear consequence of non-compliance, and unequally distributed PM2.5 management. This research reviews U.S. PM2.5 emission control technologies related to coal-fired boilers and iron and steel manufacturing industries, which represent major emission sources of Chengdu. Chengdu’s choice of PM2.5 control technology should always consider its local characteristics. By learning the U.S. and California PM2.5 control experiences, their effective policy features are identified, include clear consequence of failure to compliance, strong states and local authorities, comprehensive monitoring and reporting system, health-based standards, and regional air quality management district. U.S. practice also shows innovative policy tools, such as technology standards, use of economic incentives, and cap and trade programs. These U.S. and California policy mechanisms can help to address problems and challenges existing in Chengdu and China’s PM2.5 management. Based on the analysis of the China, U.S. and California policies related to PM2.5, I make the following recommendation: develop integrated policy framework and giving stronger authority to environmental protection agencies; consider health effects as a qualification of the PM2.5 standards; establish comprehensive and accurate PM2.5 monitoring and reporting system; specify clear consequences for non-compliance and strengthening enforcement; divide provinces and big areas into regional air quality management districts by considering local characteristics; use technology-based emission standards to reflect emission limitation and performance; use economic incentives to drive emission reduction; and enhance public disclosure of information

    Multi-labeled Relation Extraction with Attentive Capsule Network

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    To disclose overlapped multiple relations from a sentence still keeps challenging. Most current works in terms of neural models inconveniently assuming that each sentence is explicitly mapped to a relation label, cannot handle multiple relations properly as the overlapped features of the relations are either ignored or very difficult to identify. To tackle with the new issue, we propose a novel approach for multi-labeled relation extraction with capsule network which acts considerably better than current convolutional or recurrent net in identifying the highly overlapped relations within an individual sentence. To better cluster the features and precisely extract the relations, we further devise attention-based routing algorithm and sliding-margin loss function, and embed them into our capsule network. The experimental results show that the proposed approach can indeed extract the highly overlapped features and achieve significant performance improvement for relation extraction comparing to the state-of-the-art works.Comment: To be published in AAAI 201

    Power vs. Spectrum 2-D Sensing in Energy Harvesting Cognitive Radio Networks

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    Energy harvester based cognitive radio is a promising solution to address the shortage of both spectrum and energy. Since the spectrum access and power consumption patterns are interdependent, and the power value harvested from certain environmental sources are spatially correlated, the new power dimension could provide additional information to enhance the spectrum sensing accuracy. In this paper, the Markovian behavior of the primary users is considered, based on which we adopt a hidden input Markov model to specify the primary vs. secondary dynamics in the system. Accordingly, we propose a 2-D spectrum and power (harvested) sensing scheme to improve the primary user detection performance, which is also capable of estimating the primary transmit power level. Theoretical and simulated results demonstrate the effectiveness of the proposed scheme, in term of the performance gain achieved by considering the new power dimension. To the best of our knowledge, this is the first work to jointly consider the spectrum and power dimensions for the cognitive primary user detection problem

    Expected-loss-based accounting for the impairment of financial instruments:: the FASB and IASB IFRS 9 Approaches

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    This paper outlines the work of the FASB and the IASB on the development of expected-loss methods for measuring the impairment of financial instruments arising from credit losses, and describes and compares key features of the different approaches developed by the two standard setters. It also provides information indicative of the possible effect of differences between the two approaches and summarises arguments for and against the main elements of the approaches proposed by the two standard setters

    Continuous particle manipulation and separation in a hurdle-combined curved microchannel using DC dielectrophoresis

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    This paper presents a novel dielectrophoresis (DEP)-based microfluidic device which combines round hurdle with an S-shaped curved microchannel for continuous manipulation and separation of microparticles. Local nonuniform electric fields are generated by means of both constricted gaps and curved sections having equal width. Under the effect of negative DEP, particles transporting throughout the microchannel electrokinetically will be directed away from either inner wall or hurdle edge. Both experiment and numerical simulation were conducted, the results of which showed that the trajectories of fix-sized (i.e. 10 or 15 μm) polystyrene (PS) particles could be controlled by adjusting applied voltage, and continuous size-based separation of 10 and 15 μm particles was achieved. Compared to other microchannel designs that make use of either obstacle or curvature individually for electric field gradient, the developed microchannel offers advantages such as improved controllability over particle motion, lower requirement of applied voltage, reduced fouling and particle adhesion, etc. © 2013 AIP Publishing LLC
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