A time-domain inverse aeroacoustic method based on the convective Ffowcs Williams–Hawkings equation is presented. The method allows to determine, in real-time, the unsteady forces exerted on rotating blades in the presence of a moving medium. The inversion procedure is based on a space-time regularization with a mixed l1,2-norm, which guarantees accuracy and smoothness of the solution. The method is initially verified through synthetic acoustic signals emitted by rotating sources in a constant flow, up to a convective Mach number of about 0.88. Then the method is validated through signals generated by a propeller immersed in a wind-tunnel jet flow, up to a Mach number of 0.06. Due to the reduced convective Mach number, the leading aeroacoustic effect is derived from a variation of the blade loading. It is argued that the onset of flow separation at high values of the rotor advance ratio is responsible for the onset of force fluctuations that the inverse method is able to retrieve both qualitatively and quantitatively.@en

In response to excessive energy consumption and severe pollution, green building has gained increasing attention around the world. Governments’ top-down incentive schemes and consumers’ bottom-up choice preferences are two major channels of residential green building promotion. Regarding the bottom-up route, high liveability performance is critical to ensuring that occupants are willing to make secondary purchases or provide recommendations. Therefore, this paper, using post-occupancy evaluation, aims to evaluate and compare the liveability performance of green and conventional buildings from the perspectives of occupants. The results verified that the eco-label effect (i.e., subjective differences for building types) influenced the occupants’ evaluations of building performance. When controlling for eco-label bias, we found that green buildings were not superior to conventional buildings in terms of liveability. This is highly relevant to evaluations of the orientation of green building certifications that concentrate on the consumption of energy and material resources but neglect the living experience of occupants. In addition, indicators related to thermal comfort (e.g., indoor temperature or frequency of air conditioner use) played an important role in the occupants’ liveability evaluations. These findings provide concrete guidance regarding how the evaluation systems of green building certifications in various countries should be upgraded in the near future.

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Based on extensive review of the literature, this paper tries to generalize the application of BCA in environmental regulations. Specifically, this study talks about the practice of Benefit-cost analysis (BCA) in governments of such developed countries as USA, UK and EU, steps to conduct BCA in policy-making, strengths and limitations of its application in policy area. Evaluation of non-market impacts and social discount rate, are thoroughly discussed. Some suggestions are summarized for better application of BCA in regulatory choice.@en