Minimal-waste design of timber layouts from non-standard reclaimed elements: A combinatorial approach based on structural reciprocity

The use of timber allows reducing the environmental impact in the construction sector. However, as the demand for construction timber rises, the pressure on the world’s forest is increasing too. To maintain an adequate supply of timber from sustainable forests in the coming decades, the building industry must adopt practices that reduce the impact on forestry. Reuse is one of the principles of Circular Economy (CE). Among the technical challenges of reuse are the variability and the short size of the stock of elements coming either from demolition or from new construction, such as cut-offs and temporary scaffolding. This work presents a study for the design of structural configurations with short and non-regular sized elements that would normally be considered waste. The configurations are based on the principle of structural reciprocity and are generated by an optimization algorithm that allows minimizing the material waste and maximizing the stock elements use. A computational strategy based on the SPEA-II multi-objective method is employed for the investigation of optimal trade-offs between competing objective functions, such as structural lightness and optimal use of stock inventory. The goal of this work is demonstrating the feasibility of an industrial process, borrowing key elements from the Industry 4.0 paradigm, for a streamlined and economical production of standardized building components using non-standard reclaimed elements.

UAV-Exclusive Violence

This chapter outlines the extent to which UAV-exclusive violence both aligns with and diverges from the more resolvable asymmetry-challenges of the past. The chapter first acknowledges the considerable overlap between historical and current asymmetry in terms of their tension with the warrior ethos. As it then details, this analogy to the past breaks down in regard to the moral justifications for killing in war. This chapter argues that the unprecedented capacity of UAV-exclusive military force to erode the structural reciprocity of war has undermined the ability of the United States to interpret and apply morally acceptable limits on its violence. The chapter concludes by exploring the implications of UAV-exclusive violence for the regulation of lethal force.