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Power consumption has increasingly become a first-class design constraint to satisfy requirements for scientific workloads and other widely used workloads, such as machine learning. To meet performance and power requirements, system designers often use architectural simulators, such as gem5, to model component and system-level behavior. However, performance and power modeling tools are often isolated and do not make it accessible to integrate with one another for rapid performance and power system co-design. Although studies have previously explored power modeling with gem5 and validation on real hardware, there are several flaws with this approach. First, power models are sometimes not open source, making it difficult to apply them to different simulated systems. The current interface for implementing power models in gem5 also relies on hard-coded strings provided by the user to model dynamic and static power. This makes defining power models for components cumbersome and restrictive, as gem5’s MathExpr string formula parser has support for limited mathematical operations. Third, previous works only implement one form of power model for one component. This unnecessarily limits users from combining other power models, which may model certain system components with higher accuracy. Instead, we posit that decoupling how power models are integrated with simulators from the design of power models themselves will enable better power modeling in simulators. Accordingly, we extend our prior work on designing and implementing an extensible, generalizable power modeling interface by integrating support for McPAT into it and validating it emits correct power values. 

Abstract The Rashba effect enables control over the spin degree of freedom, particularly in polar materials where the polar symmetry couples to Rashba‐type spin splitting. The exploration of this effect, however, has been hindered by the scarcity of polar materials exhibiting the bulk‐Rashba effect and rapid spin‐relaxation effects dictated by the D'yakonov–Perel mechanism. Here, a polar LiNbO₃‐typeR3cphase of Bi_1‐xIn_1+xO₃withx≈0.15–0.24 is stabilized via epitaxial growth, which exhibits a bulk‐Rashba effect with suppressed spin relaxation as a result of its unidirectional spin texture. As compared to the previously observed non‐polarPnmaphase, this polar phase exhibits higher conductivity, reduced bandgap, and enhanced dielectric and piezoelectric responses. Combining first‐principles calculations and multimodal magnetotransport measurements, which reveal weak (anti)localization, anisotropic magnetoresistance, planar‐Hall effect, and nonreciprocal charge transport, a bulk‐Rashba effect without rapid spin relaxation is demonstrated. These findings offer insights into spin‐orbit coupling physics within polar oxides and suggest potential spintronic applications. 

Abstract Over the next 5 yr, the Dark Energy Spectroscopic Instrument (DESI) will use 10 spectrographs with 5000 fibers on the 4 m Mayall Telescope at Kitt Peak National Observatory to conduct the first Stage IV dark energy galaxy survey. Atz< 0.6, the DESI Bright Galaxy Survey (BGS) will produce the most detailed map of the universe during the dark-energy-dominated epoch with redshifts of >10 million galaxies spanning 14,000 deg². In this work, we present and validate the final BGS target selection and survey design. From the Legacy Surveys, BGS will target anr< 19.5 mag limited sample (BGS Bright), a fainter 19.5 <r< 20.175 color-selected sample (BGS Faint), and a smaller low-zquasar sample. BGS will observe these targets using exposure times scaled to achieve homogeneous completeness and cover the footprint three times. We use observations from the Survey Validation programs conducted prior to the main survey along with simulations to show that BGS can complete its strategy and make optimal use of “bright” time. BGS targets have stellar contamination <1%, and their densities do not depend strongly on imaging properties. BGS Bright will achieve >80% fiber assignment efficiency. Finally, BGS Bright and BGS Faint will achieve >95% redshift success over any observing condition. BGS meets the requirements for an extensive range of scientific applications. BGS will yield the most precise baryon acoustic oscillation and redshift-space distortion measurements atz< 0.4. It presents opportunities for new methods that require highly complete and dense samples (e.g.,N-point statistics, multitracers). BGS further provides a powerful tool to study galaxy populations and the relations between galaxies and dark matter.