Synthesis of robot control for assembly processes

The paper addresses the control of an automatic assembly process represented by the typical operation of peg-in-hole insertion. The control problem is to track a prespecified trajectory defined by the peg position and orientation relative to the hole location (nominal control). The problem is compounded by the assumption that misalignment and variation in system parameters may occur such that the nominal control must be complemented with a synthesis which regulates the perturbed stage of the system. The regulation is achieved using a robust servomechanism approach and a force feedback approach. The two approaches are illustrated using simulation results.     

The causal effective field approximation— Application to elastic waves in fibrous composites

A new version of the effective field approach is presented with application to random fibrous composites. The approach incorporates the causality of the response and the static results, which comply with the best bounds available. Extensive comparison with other methods is given.     

Solar desalination in conjunction with controlled environmental agriculture in Arid zones

There are many factors which favor the juxtaposition of a solar still to a controlled environment agriculture (CEA) greenhouse. A modular, easy on-site construction, low-cost solar still was designed and tested. Its annual average daily productivity and efficiency values were 2.35 l/m² and 30%, respectively. The feasibility of using the CEA greenhouse's hot brackish water reservoir as the still feedstock for enhanced nocturnal production was tested and found to enhance productivity significantly. A total lifecycle cost analysis of the solar still has shown it to be less economical by a factor of 1.25, relative to a small reverse osmosis unit for the CEA farm size considered, in the case of brackish water, whereas, in the case of sea water desalination, the solar still may be more economical.     

Promises and pitfalls in environmentally extended input–output analysis for China: A survey of the literature

As the world's largest developing economy, China plays a key role in global climate change and other environmental impacts of international concern. Environmentally extended input–output analysis (EE-IOA) is an important and insightful tool seeing widespread use in studying large-scale environmental impacts in China: calculating and analyzing greenhouse gas emissions, carbon and water footprints, pollution, and embodied energy. This paper surveys the published articles regarding EE-IOA for China in peer-reviewed journals and provides a comprehensive and quantitative overview of the body of literature, examining the research impact, environmental issues addressed, and data utilized. The paper further includes a discussion of the shortcomings in official Chinese data and of the potential means to move beyond its inherent limitations.     

The impact of China's carbon allowance allocation rules on the product prices and emission reduction behaviors of ETS-covered enterprises

It is an important task for China to allocate carbon emission allowance to realize its carbon reduction target and establish carbon trading market. China has designed several allocation rules within seven pilot regions. What influence those rules may cause is closely related with the enthusiasm of emission trading scheme (ETS) covered enterprises' participation in carbon market, and more importantly, with the mechanism design and sustainable development of carbon market. For this purpose, the multi-stage profit model is developed to analyze the ETS-covered enterprises' product prices and emission reduction behaviors under different allocation rules. The results show that, first, under the rules of grandfathering, self-declaration and auctioning, when deciding the optimal product price and optimal carbon emission reduction, those enterprises may focus on maximizing current stage profit; however, under the rule of benchmarking, those enterprises may care more about the impact of current decisions on the profit in next stage. Second, the optimal product price policy is positively correlated with the price of the same kind products, consumers' low-carbon awareness and government subsidy. Finally, along with the increase of carbon price, consumers' low-carbon awareness and government subsidy and the decrease of carbon emission cap, those enterprises tend to reduce carbon emissions.