There is a large uncertainty in the relative roles of human land use, climate change and carbon dioxide fertilization in changing desert dust source strength over the past 100 years, and the overall sign of human impacts on dust is not known. We used visibility data from meteorological stations in dusty regions to assess the anthropogenic impact on long term trends in desert dust emissions. We ...

atmospheric visibility has been defined as the greatest distance at which an observer can see a black object viewed against the horizon sky, which in quantitative terminology is known as visual range. visibility, in the absence of special meteorological events (e.g. rain and fog), is an excellent indicator of air quality. visibility impairment results from light scattering and absorption by atm...

Hong Kong's surface visibility has decreased in recent years due to air pollution from rapid social and economic development in the region. In addition to deteriorating health standards, reduced visibility disrupts routine civil and public operations, most notably transportation and aviation. Regional estimates of visibility solved operationally using available ground and satellite-based estima...

data is a difficult problem for enterprises. This is due to huge amounts of e.g. complex business processes within and across enterprise boundaries, heterogeneous technology stacks, and fragmented data. To remain competitive, visibility into the enterprise and partner networks on different, interrelated abstraction levels is desirable. We show the query and data processing capabilities of a nov...

Fast rendering of dynamic scenes with natural illumination, all-frequency shadows and spatially-varying reflections is important but challenging. One main difficulty brought by moving objects is that the runtime visibility update of dynamic occlusion is usually time-consuming and slow. In this paper, we present a new visibility sampling technique and show that efficient all-frequency rendering ...

The role of scenic landscapes in restoring human mental fatigue has begun to receive attention from landscape researchers. However, little is known about the positive role of visually-preferred landscapes on restorative environments and in improving the mental fatigue of people. This study attempted to determine the relationship between the predictors of preference and restorative components of...

the islamic calendar is based on lunar months, which begin when the thin crescent moon is actually sighted in the western sky after sunset within a day or so after the new moon. the islamic dates begin at sunset on the previous day. the visibility of the lunar crescent as a function of the moon's age - the time counted from the new moon - is obviously of great importance to muslims. the da...