Together with economic development and accelerated urbanization, the urban population in China has been increasing rapidly, and anthropogenic heat released by large-scale energy consumption in cities is expected to be a vital factor affecting the climate. In this paper, the Weather Research and Forecasting (WRF) model coupled with the Urban Canopy Model (UCM) is employed to simulate the regional impacts on climate under the two scenarios: the underlying surface changes due to urbanization (USCU) and anthropogenic heat release (AHR). Three experiments were performed from December 2006 to December 2008. With respect to the USCU, the surface albedo and the available surface soil water decrease markedly. With the inclusion of AHR, the two scenarios give rise to increased surface temperatures over most areas of China. Especially in the urban agglomeration area of the Yangtze River delta, the combination of USCU and AHR could result in an increase of 2°C in the surface air temperature. The influence of AHR on surface air temperature in winter is greater than the influence of USCU without considering any extra sources of heat, but the opposite is found in summer. The combination of USCU and AHR leads to changes in the surface energy budget. They both increase sensible heat flux, but USCU decreases latent heat flux significantly, and AHR increases latent heat flux slightly. Nevertheless, under the influence of these two scenarios, the precipitation increases in some areas, especially in the Beijing–Tianjin–Hebei region, while it decreases in other areas, most notably the Yangtze River delta.

No abstract

No abstract

No abstract

No abstract

No abstract

Wireless sensor networks are often based on omni-sensing and communication models. In contrast, in this paper, we investigate sensor networks with directional sensing and communication capability. Due to the distinct characteristics and potential effects on coverage and connectivity of the network, novel analysis and solutions are demanded. Toward this end, this paper analyzes deployment strategies for satisfying given coverage probability requirements with directional sensing models. Moreover, for sensors with directional communication model, we propose methods for checking and repairing the connectivity of the network. We design efficient protocols to implement our idea. A set of experiments are also performed to prove the effectiveness of our solution.

No abstract