Decelerating I/O Power Management

System suspend/resume is crucial to energy proportionality of modern computers, from wearable to cloud servers. Ironically, this OS mechanism itself is slow and energy hungry. Through characterizing the Linux kernel on a variety of modern system-on-chips (SoCs), we show the major reason as slow power state transitions of IO, which keeps CPU waiting. Furthermore, we argue that the IO wait can hardly be reduced to a satisfactory level, because most of slow transitions of IO are bounded by peripherals, low-speed buses, or physical factors. Therefore, the kernel execution for suspend/resume should be offloaded to a miniature core that waits more efficiently. To fix this problem, we propose a power management core running novel hypervisor that dynamically translates and executes Power Management functions. This method not only supports offloading a complex kernel subsystem but also provides forward compatibility with a commodity kernel. Based on QEMU, an open source hypervisor, we implement the backend for ARMv7M ISA. We optimize QEMU’s translation by directly mapping flag emulation to hardware. In the end, we are able to achieve 100% increase performance compared with QEMU’s original version

1,4-Ditosyl-1,4-diazepane

In the title compound, C19H24N2O4S2, the dihedral angle formed by the benzene rings is 82.88 (7)°, and the mol­ecular conformation is enforced by weak intra­molecular C—H⋯O contacts. Two C atoms of the 1,4-diazepane ring are disordered over two sets of sites with a refined occupancy ratio of 0.534 (13):0.466 (13). In the crystal, mol­ecules are linked by weak inter­molecular C—H⋯O inter­actions into chains parallel to the a axis

Recent Advances in Flame Retardant and Mechanical Properties of Polylactic Acid: A Review.

The large-scale application of ecofriendly polymeric materials has become a key focus of scientific research with the trend toward sustainable development. Mechanical properties and fire safety are two critical considerations of biopolymers for large-scale applications. Polylactic acid (PLA) is a flammable, melt-drop carrying, and strong but brittle polymer. Hence, it is essential to achieve both flame retardancy and mechanical enhancement to improve safety and broaden its application. This study reviews the recent research on the flame retardant functionalization and mechanical reinforcement of PLA. It classifies PLA according to the type of the flame retardant strategy employed, such as surface-modified fibers, modified nano/micro fillers, small-molecule and macromolecular flame retardants, flame retardants with fibers or polymers, and chain extension or crosslinking with other flame retardants. The functionalization strategies and main parameters of the modified PLA systems are summarized and analyzed. This study summarizes the latest advances in the fields of flame retardancy and mechanical reinforcement of PLA.pre-print3656 K

“What should be computed” for supporting post-pandemic recovery policymaking?:A life-oriented perspective

The COVID-19 pandemic has caused various impacts on people’s lives, while changes in people’s lives have shown mixed effects on mitigating the spread of the SARS-CoV-2 virus. Understanding how to capture such two-way interactions is crucial, not only to control the pandemic but also to support post-pandemic urban recovery policies. As suggested by the life-oriented approach, the above interactions exist with respect to a variety of life domains, which form a complex behavior system. Through a review of the literature, this paper first points out inconsistent evidence about behavioral factors affecting the spread of COVID-19, and then argues that existing studies on the impacts of COVID-19 on people’s lives have ignored behavioral co-changes in multiple life domains. Furthermore, selected uncertain trends of people’s lives for the post-pandemic recovery are described. Finally, this paper concludes with a summary about “what should be computed?” in Computational Urban Science with respect to how to catch up with delays in the SDGs caused by the COVID-19 pandemic, how to address digital divides and dilemmas of e-society, how to capture behavioral co-changes during the post-pandemic recovery process, and how to better manage post-pandemic recovery policymaking processes.</p

“What should be computed” for supporting post-pandemic recovery policymaking?:A life-oriented perspective

The COVID-19 pandemic has caused various impacts on people’s lives, while changes in people’s lives have shown mixed effects on mitigating the spread of the SARS-CoV-2 virus. Understanding how to capture such two-way interactions is crucial, not only to control the pandemic but also to support post-pandemic urban recovery policies. As suggested by the life-oriented approach, the above interactions exist with respect to a variety of life domains, which form a complex behavior system. Through a review of the literature, this paper first points out inconsistent evidence about behavioral factors affecting the spread of COVID-19, and then argues that existing studies on the impacts of COVID-19 on people’s lives have ignored behavioral co-changes in multiple life domains. Furthermore, selected uncertain trends of people’s lives for the post-pandemic recovery are described. Finally, this paper concludes with a summary about “what should be computed?” in Computational Urban Science with respect to how to catch up with delays in the SDGs caused by the COVID-19 pandemic, how to address digital divides and dilemmas of e-society, how to capture behavioral co-changes during the post-pandemic recovery process, and how to better manage post-pandemic recovery policymaking processes.</p