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A growing body of literature suggests that restrictive public health measures implemented to control COVID-19 have had negative impacts on physical activity. We examined how Stay Home orders in Houston, New York City, and Seattle impacted outdoor physical activity patterns, measured by daily bicycle and pedestrian count data. We assessed changes in activity levels between the period before and during Stay Home orders. Across all three cities, we found significant changes in bicycle and pedestrian counts from the period before to the period during Stay Home orders. The direction of change varied by location, likely due to differing local contexts and outbreak progression. These results can inform policy around the use of outdoor public infrastructure as the COVID-19 pandemic continues.

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To harvest more energy from wind, wind turbine size has rapidly increased, entailing the serious concern on the reliability of the wind turbine. Accordingly, the international standard requires turbine designers to estimate the extreme load that could be imposed on a turbine during normal operations. At the design stage, physics-based load simulations can be used for this purpose. However, simulating the extreme load associated with a small load exceedance probability is computationally prohibitive. In this study, we propose using importance sampling combined with order statistics to reduce the computational burden significantly while achieving much better estimation accuracy than existing methods.

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In order to meet renewable energy goals in the near future, the deployment of photovoltaic (PV) panels on buildings will dramatically increase. The objective of this paper is to introduce an improved design for PV cladding systems that will greatly contribute to meeting these renewable energy goals. Typically, building-integrated photovoltaic (BIPV) panels are vertically oriented as cladding and they are not coupled with individual storage batteries. The proposed cladding couples a tilted BIPV panel with one or more storage batteries at each building placement. Thus, the tilted BIPV plus battery system is independent of other power generation in the building and it is referred to as a “building perma-power link” (BPPL) cladding element. Each cladding panel is designed as a stand-alone system, which will be useful for installation, operation, and maintenance. The hyper-redundancy of multiple BPPL cladding panels for a typical building significantly enhances its overall energy resiliency. In order to foster manufacturing ease, each individual cladding unit has been designed at tilts of 45° and 60°. An example of a mid-rise building in Seattle, Washington is provided. The degree of building energy resiliency provided through multiple BPPLs is examined.