Critical Velocity is Associated with Combat Specific Performance Measures in a Special Forces Unit

Over recent years, military research has focused on ways of being able to predict operational success and readiness through the development of simulated operational tasks measuring the physical limits of the soldier. Therefore, to properly prepare the tactical athlete for the demands and rigor of combat, accurate assessment of baseline physical abilities and limitations are necessary. Currently, western armies use a basic physical fitness test, which has been heavily argued to have no bearing on operational readiness, thus they are in the process of transitioning to a more specific combat readiness test. However, specific assessments to predict operational success/readiness are inefficient or lacking. A single test that requires minimal time, but provides simultaneous assessment of the necessary physical characteristics (i.e. aerobic and anaerobic capacities) may provide a unique opportunity to enhance soldier performance assessment. The 3-min all-out run, is a relatively new test that has been recently validated. It provides two performance estimates, critical velocity (CV) and anaerobic distance capacity (ADC). CV provides a measure of the individual\u27s aerobic capacity, while the ADC is an indicator of anaerobic capacity. The purpose of this study, therefore, is to examine the relationship between CV and ADC from the 3-min all-out run and combat specific tasks (2.5-km run, 50-m casualty carry, and repeated sprints with rush shooting) in an elite special force unit. Eighteen male soldiers (age: 19.9 ± 0.8 years; height: 177.6 ± 6.6 cm; body mass: 74.1 ± 5.8 kg; BMI: 23.52 ± 1.63) from an elite combat special force unit of the Israel Defense Forces (IDF) volunteered to complete a 3-min all-out run, while wearing a global positioning system (GPS) unit, and a battery of operational CST (2.5-km run, 50-m casualty carry and 30-m repeated sprints with rush shooting (RPTDS)). Estimates of CV and ADC from the 3-min all-out run were determined from the downloaded GPS data with CV calculated as the average velocity of the final 30 s of the run and ADC as the velocity-time integral above CV. CV exhibited significant negative correlations with the 2.5-km run time (r = - 0.62, p \u3c 0.01), and RPTDS time (r = - 0.71p \u3c 0.01). However, CV (r = - 0.31) or ADC (r = 0.16) did not show any correlation with the 50-m casualty carry run. In addition, CV was positively correlated with the average velocity during the 2.5- km run (r = 0.64, p \u3c 0.01). Stepwise regression identified CV as the most significant performance measure associated with the 2.5-km run time, and BMI and CV measures as significant predictors of RPTDS time (R2= 0.67, p \u3c 0.05). Our main findings indicate that CV was highly related to performance during CST, including the 2.5-km run and RPTDS, but not the 50-m casualty carry. Using the 3-min all-out run as a testing measurement offers a more efficient and simpler way in assessing both aerobic and anaerobic capabilities (CV and ADC) with-in a relatively large sample. In this regard, this method of testing may be conducive to a military type environment whether for selection purposes, to predict combat readiness, to prescribe a training program or just a need analysis for the company commander

DeLTA: GPU Performance Model for Deep Learning Applications with In-depth Memory System Traffic Analysis

Training convolutional neural networks (CNNs) requires intense compute throughput and high memory bandwidth. Especially, convolution layers account for the majority of the execution time of CNN training, and GPUs are commonly used to accelerate these layer workloads. GPU design optimization for efficient CNN training acceleration requires the accurate modeling of how their performance improves when computing and memory resources are increased. We present DeLTA, the first analytical model that accurately estimates the traffic at each GPU memory hierarchy level, while accounting for the complex reuse patterns of a parallel convolution algorithm. We demonstrate that our model is both accurate and robust for different CNNs and GPU architectures. We then show how this model can be used to carefully balance the scaling of different GPU resources for efficient CNN performance improvement

Balancing reliability, cost, and performance tradeoffs with FreeFault

Abstract—Memory errors have been a major source of system failures and fault rates may rise even further as memory continues to scale. This increasing fault rate, especially when combined with advent of integrated on-package memories, may exceed the capabilities of traditional fault tolerance mecha-nisms or significantly increase their overhead. In this paper, we present FreeFault as a hardware-only, transparent, and nearly-free resilience mechanism that is implemented entirely within a processor and can tolerate the majority of DRAM faults. FreeFault repurposes portions of the last-level cache for storing retired memory regions and augments a hardware memory scrubber to monitor memory health and aid retirement decisions. Because it relies on existing structures (cache associativity) for retirement/remapping type repair, FreeFault has essentially no hardware overhead. Because it requires a very modest portion of the cache (as small as 8KB) to cover a large fraction of DRAM faults, FreeFault has almost no impact on performance. We explain how FreeFault adds an attractive layer in an overall resilience scheme of highly-reliable and highly-available systems by delaying, and even entirely avoiding, calling upon software to make tradeoff decisions between memory capacity, performance, and reliability. I

Continuation-Based Pull-In and Lift-Off Simulation Algorithms for Microelectromechanical Devices

The voltages at which microelectromechanical actuators and sensors become unstable, known as pull-in and lift-off voltages, are critical parameters in microelectromechanical systems (MEMS) design. The state-of-the-art MEMS simulators compute these parameters by simply sweeping the voltage, leading to either excessively large computational cost or to convergence failure near the pull-in or lift-off points. This paper proposes to simulate the behavior at pull-in and lift-off employing two continuation-based algorithms. The first algorithm appropriately adapts standard continuation methods, providing a complete set of static solutions. The second algorithm uses continuation to trace two kinds of curves and generates the sweep-up or sweep-down curves, which can provide more intuition for MEMS designers. The algorithms presented in this paper are robust and suitable for general-purpose industrial MEMS designs. Our algorithms have been implemented in a commercial MEMS/integrated circuits codesign tool, and their effectiveness is validated by comparisons against measurement data and the commercial finite-element/boundary-element (FEM/BEM) solver CoventorWare

A novel system for quenching during flash sintering

The study of the ruling mass transfer mechanisms in Flash Sintering (FS) has gotten a lot of attention in recent years. Some mechanisms have been suggested, e.g. nucleation due to movement of charged defects, Joule heating runaway and chemical reaction propagation[1]. In order to further study the phenomena which occur during the different FS stages and shed light on the ruling mass transfer mechanisms, a novel simple system was developed. In this system (Figure 1), FS is done on a ceramic green body in a vertical tubular furnace using vacuum to hold the sample inside the furnace. This configuration enables dropping the sample into a glass of distilled water (or other suitable coolant) at any time, thus quenching the sample and freezing the microstructure of the material under FS conditions. The quenched sample can be taken to further investigation of the microstructure, such as SEM analysis. The system design and initial results of FS and quenching of gadolinium-cerium oxide samples will be presented. Please click Additional Files below to see the full abstract

A short review of FS mechanisms

The current views on flash sintering (FS) will be reviewed with focus on mechanism research [1]. The mechanism of FS has been under debate since its discovery and three main mechanisms were suggested: defect nucleation, Joule heating runaway and electrochemical reactions. We believe that thermal runaway is essential for FS initiation; by calculating the thermal runaway of the green body, the onset temperature can be predicted. Since sintering under AC stimulus was achieved, electrochemical reactions can account for FS only if breaking the symmetry is dealt with. Symmetry breaking is indeed possible due to imperfect contacts and uneven kinetics of, e.g., redox reactions at different facets in oxides. The effect of electrode material on threshold conditions and of electrochemical reactions on the final microstructure were also discovered. The work done in our group showing that the FS onset conditions of highly Fe doped strontium titanate change under different pO2, unties the link between flash onset and ionic defect concentrations [2]. However, the influence of charged defects and of electrode materials on the flash process and threshold conditions cannot be ignored. Clear evidence for the nucleation of a new phase using in-situ XRD analysis was also shown. Further research to unveil all the effects affecting all stages of FS and their relations is needed. The evidence for a formation of a new phase during the flash found by Raj group might be connected to formation of a softened / liquid phase. Moreover, since phase transition limits temperature rise, it might account for the low temperatures measured using in-situ XRD. Lastly, since both liquid formation and electrochemical reactions are a trigger for thermal runaway, we believe that all the suggested mechanisms are linked. Further research for discovering proof of liquid formation and electrode effects will shed light on the triggers of thermal runaway thus solving the problem of FS mechanism. Stages II and III of the flash are yet to be understood, with currently clear hints toward the importance of point defects and of huge temperature gradients. [1] M.Z. Becker, N. Shomrat, and Y. Tsur, Recent Advances in Mechanism Research and Methods for Electric-Field-Assisted Sintering of Ceramics, Advanced Materials, 1706369 (2018) [2] N. Shomrat, E. Dor, S. Baltianski, and Y. Tsur, The influence of doping on flash sintering conditions in SrTi1-xFexO3-δ, Journal of the European Ceramic Society, 37, 179-188, (2017)

Automated solid phase synthesis of oligoarabinofuranosides

Automated solid phase synthesis enables rapid access to the linear and branched arabinofuranoside oligosaccharides. A simple purification step is sufficient to provide the conjugation ready oligosaccharides in good yield