Process-induced skew reduction in nominal zero-skew clock trees

Abstract — This work develops an analytic framework for clock tree analysis considering process variations that is shown to correspond well with Monte Carlo results. The analysis frame-work is used in a new algorithm that constructs deterministic nominal zero-skew clock trees that have reduced sensitivity to process variation. The new algorithm uses a sampling approach to perform route embedding during a bottom-up merging phase, but does not select the best embedding until the top-down phase. This results in clock trees that exhibit a mean skew reduction of 32.4 % on average and a standard deviation reduction of 40.7 % as verified by Monte Carlo. The average increase in total clock tree capacitance is less than 0.02%. I

Analysis and mitigation of variability in subthreshold design

Subthreshold circuit design is a compelling method for ultra-low power applications. However, subthreshold designs show dramati-cally increased sensitivity to process variations due to the exponen-tial relationship of subthreshold drive current with Vth variation. In this paper, we present an analysis of subthreshold energy efficiency considering process variation, and propose methods to mitigate its impact. We show that, unlike superthreshold circuits, random dopant fluctuation is the dominant component of variation in subthreshold operation. We investigate how this variability can be ameliorated with proper circuit sizing and choice of circuit logic depth. We then present a statistical analysis of the energy efficiency of subthreshold circuits considering process variations. We show that the energy optimal supply voltage increases due to process variations and study its dependence on circuit parameters. We verify our analytical mod-els against Monte Carlo SPICE simulations and show that they accu-rately predict the minimum energy and energy optimal supply voltage. Finally, we use the developed statistical energy model to determine the optimal pipelining depth in subthreshold designs

Identifying target areas for risk-based surveillance and control of Transboundary Animal Diseases: A seasonal analysis of slaughter and live-trade cattle movements in Uganda

Abstract Animal movements are a major driver for the spread of Transboundary Animal Diseases (TADs). These movements link populations that would otherwise be isolated and hence create opportunities for susceptible and infected individuals to meet. We used social network analysis to describe the seasonal network structure of cattle movements in Uganda and unravel critical network features that identify districts or sub-regions for targeted risk-based surveillance and intervention. We constructed weighted, directed networks based on 2019 between-district cattle movements using official livestock mobility data; the purpose of the movement (‘slaughter’ vs. ‘live trade’) was used to subset the network and capture the risks more reliably. Our results show that cattle trade can result in local and long-distance disease spread in Uganda. Seasonal variability appears to impact the structure of the network, with high heterogeneity of node and edge activity identified throughout the seasons. These observations mean that the structure of the live trade network can be exploited to target influential district hubs within the cattle corridor and peripheral areas in the south and west, which would result in rapid network fragmentation, reducing the contact structure-related trade risks. Similar exploitable features were observed for the slaughter network, where cattle traffic serves mainly slaughter hubs close to urban centres along the cattle corridor. Critically, analyses that target the complex livestock supply value chain offer a unique framework for understanding and quantifying risks for TADs such as Foot-and-Mouth disease in a land-locked country like Uganda. These findings can be used to inform the development of risk-based surveillance strategies and decision making on resource allocation. For instance, vaccine deployment, biosecurity enforcement and capacity building for stakeholders at the local community and across animal health services with the potential to limit the socio-economic impact of outbreaks, or indeed reduce their frequency

The Grizzly, April 23, 1990

Earth Day: Success! • Ready for Graduation • Letters: New Curriculum Comments; Studio Cottage Vandal Victims; In Support of Sanger • Condom Commission Report • New Meal Plans Next Year • Tracksters Finish Season at MACs • Lady Bears Run Ahead • Netters Roll • Bears Bounce • Hackers No More • Why Earth Day? • Earth Day: Serious? • RAs for 90-91 • Support Your Local RA • Art at UC • Tunnel Steams BWC • Lisa\u27s Heart\u27s in Art • Soda Can\u27s Debut • Video Reviews • Promotions for Faculty • Desktop Aids New Editor • Exam Schedulehttps://digitalcommons.ursinus.edu/grizzlynews/1256/thumbnail.jp

Fully Autonomous Mixed Signal SoC Design & Layout Generation Platform

We present FASoC, the world’s first autonomous mixed-signal SoC framework driven entirely by user constraints, along with a suite of automated generators for analog blocks. The process agnostic framework takes high-level user intent as inputs to generate optimized and fully verified analog blocks using a cell-based design methodology. Our approach is highly scalable and silicon-proven by an SoC prototype which includes 2 PLLs, 3 LDOs, 1 SRAM, and 2 temperature sensors fully integrated with a processor in a 65nm CMOS process. The physical design of all blocks, including analog, is achieved using optimized synthesis and APR flows in commercially available tools. The framework is portable across different processes and requires no human in the loop, dramatically accelerating design time.This material is based on research sponsored by Air Force Research Laboratory (AFRL) and Defense Advanced Research Projects Agency (DARPA) under agreement number FA8650 18 2 7844. The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright notation thereon.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/165331/1/Fully Autonomous Mixed Signal SoC Design & Layout Generation Platform.pdfDescription of Fully Autonomous Mixed Signal SoC Design & Layout Generation Platform.pdf : Main articleSEL

The Grizzly, February 19, 1991

Wismer Renovations • Movies Moved • Clark Wins NEH Grant: Travels to China • Teaching Catalan, An Alternative Language • Book Fair Comes to Ursinus • Italian Market: A Way of Life • Unchangeable South Street • Screaming Trees • Death of a Salesperson • Murder at Toranno\u27s • Swimmers Prepare for MAC Championship • Men\u27s Basketball Finishes Season with 11-14 Record • Black History Month • He\u27s Back! David Lee Roth, Stud or Stroker? • Modern Shakespeare • Wrestlers Romp • Schafer Tells of Track Troubles • Women Race at MAC Championships • Gymnasts Having Fun • Letter: Olin, for Students or Posterity? • Domestic Policy: A Matter of Perspective • Ah, Um, Uh... • An Elegantly Simple Plan • Radioactivity at Ursinus Collegehttps://digitalcommons.ursinus.edu/grizzlynews/1271/thumbnail.jp

Modification and preservation of environmental signals in speleothems

Speleothems are primarily studied in order to generate archives of climatic change and results have led to significant advances in identifying and dating major shifts in the climate system. However, the climatological meaning of many speleothem records cannot be interpreted unequivocally; this is particularly so for more subtle shifts and shorter time periods, but the use of multiple proxies and improving understanding of formation mechanisms offers a clear way forward. An explicit description of speleothem records as time series draws attention to the nature and importance of the signal filtering processes by which the weather, the seasons and longer-term climatic and other environmental fluctuations become encoded in speleothems. We distinguish five sources of variation that influence speleothem geochemistry: atmospheric, vegetation/soil, karstic aquifer, primary speleothem crystal growth and secondary alteration and give specific examples of their influence. The direct role of climate diminishes progressively through these five factors. \ud \ud We identify and review a number of processes identified in recent and current work that bear significantly on the conventional interpretation of speleothem records, for example: \ud \ud 1) speleothem geochemistry can vary seasonally and hence a research need is to establish the proportion of growth attributable to different seasons and whether this varies over time. \ud \ud 2) whereas there has traditionally been a focus on monthly mean Ã�´18O data of atmospheric moisture, current work emphasizes the importance of understanding the synoptic processes that lead to characteristic isotope signals, since changing relative abundance of different weather types might 1Corresponding author, fax +44(0)1214145528, E-mail: [email protected] control their variation on the longer-term. \ud \ud 3) the ecosystem and soil zone overlying the cave fundamentally imprint the carbon and trace element signals and can show characteristic variations with time. \ud \ud 4) new modelling on aquifer plumbing allows quantification of the effects of aquifer mixing. \ud \ud 5) recent work has emphasized the importance and seasonal variability of CO2-degassing leading to calcite precipitation upflow of a depositional site on carbon isotope and trace element composition of speleothems. \ud \ud 6) Although much is known about the chemical partitioning between water and stalagmites, variability in relation to crystal growth mechanisms and kinetics is a research frontier. \ud \ud 7) Aragonite is susceptible to conversion to calcite with major loss of chemical information, but the controls on the rate of this process are obscure. \ud \ud Analytical factors are critical to generate high-resolution speleothem records. A variety of methods of trace element analysis are available, but standardization is a common problem with the most rapid methods. New stable isotope data on Irish stalagmite CC3 compares rapid laser-ablation techniques with the conventional analysis of micromilled powders and ion microprobe methods. A high degree of comparability between techniques for Ã�´18O is found on the mm-cm scale, but a previously described high-amplitude oxygen isotope excursion around 8.3 ka is identified as an analytical artefact related to fractionation of the laser-analysis associated with sample cracking. High-frequency variability of not less than 0.5o/oo may be an inherent feature of speleothem Ã�´18O records