Li Jin

The changing of arguments and their attack relation is an intrinsic property of a variety of argumentation systems. So, it is very important to efficiently figure out how the status of arguments in a system evolves when the system is updated. However, unlike other areas of argumentation that have been deeply explored, such as argumentation semantics, proof theories, and algorithms, etc., dynamics of argumentation systems has been comparatively neglected. In this paper, we formulate a general theory (called a division-based method) to cope with this problem based on a new concept: the division of an argumentation framework. When an argumentation framework is updated, it is divided into three parts: an unaffected, an affected, and a conditioning part. The status of arguments in the unaffected sub-framework remains unchanged, while the status of the affected arguments is computed in a special argumentation framework (called a conditioned argumentation framework, or briefly CAF) that is composed of an affected part and a conditioning part. We have proved that under a certain semantics that satisfies the directionality criterion (complete, preferred, ideal, or grounded semantics), the extensions of the updated framework are equal to the result of a combination of the extensions of an unaffected sub- framework and sets of the extensions of a set of assigned CAFs. Due to the efficiency of the division-based method, it is expected to be very useful in various kinds of argumentation systems where arguments and attacks are dynamics.

© 2017 American Chemical Society.Food waste makes up approximately 15% of municipal solid waste generated in the United States, and 95% of food waste is ultimately landfilled. Its bioavailable carbon and nutrient content makes it a major contributor to landfill methane emissions, but also presents an important opportunity for energy recovery. This paper presents the first detailed analysis of monthly food waste generation in California at a county level, and its potential contribution to the state's energy production. Scenarios that rely on excess capacity at existing anaerobic digester and solid biomass combustion facilities, and alternatives that allow for new facility construction, are developed and modeled. Potential monthly electricity generation from the conversion of gross food waste using a combination of AD and combustion varies from 420 to 700 MW, averaging 530 MW. At least 66% of gross high moisture solids and 23% of gross low moisture solids can be treated using existing county infrastructure, and this fraction increases to 99% of high moisture solids and 55% of low moisture solids if waste can be shipped anywhere within the state. Biogas flaring practices at AD facilities can reduce potential energy production by 10 to 40%..

Prior studies report that the business group structure and the associated intra-group capital flows are prone to conflicts of interest between controlling shareholders and minority investors. Yet business group is a prevalent and stable structure around the globe, particularly where capital markets are underdeveloped. Using data from China, this paper empirically studies the trade-off between the negative and positive roles played by intra-group capital flows and tests the efficiency implications of such trade-off. We find that from the perspective of the whole group, intra-group capital flows are most efficient when the groups are least subject to conflicts of interest between controlling shareholders and minority shareholders and when they face strong external financing constraints.

The unprecedented economic changes taking place in China over the past three decades have led to significant new fiscal pressures for the central and provincial governments. The relative decline of public ownership and rise of the private sector has forced governments to substitute revenues from new taxes for the funds formerly provided by public enterprises. The shift from profit distribution to tax revenues has led to a realignment of power between local governments and the central government while the growing disparity in wealth between have and have-not provinces has increased the pressure on the central government to further consolidate control over tax revenues and to apply the enhanced revenues to fund fiscal redistribution transfers. At the same time, modernization of the economy and the influx of foreign investment have created pressure to revamp tax laws and tax administration so both resemble more closely western market economy norms. These processes may lead to an irreversible shift of fiscal power from provincial governments to the central government and a consequent consolidation of political power, changing forever the political economy of modern China.