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The effect of negative bias temperature instability (NBTI) varies significantly according to given workloads. Finding a feasible worst case workload is difficult due to logical correlation within the logic circuit under consideration. In this article, we propose an NBTI-aware subset simulation (SS) framework that efficiently and accurately finds the failure probability covering various input duty cycles determined by different workloads. In addition, the proposed method is incorporated with the NBTI mitigation technique to facilitate workload-aware mitigation. Through numerical experiments using benchmark circuits, the proposed method achieves up to 36 times speedup compared to a naive Monte Carlo method. The NBTI mitigation based on SS demonstrates $1.78\times $ better mitigation for multiple input duty cycles compared to the conventional method. [ABSTRACT FROM AUTHOR]

Abstract: An experimental investigation was conducted on the effect of thermal shock during cooling on residual mechanical properties of fiber concrete exposed to elevated temperatures from 200 to 800°C. Various cooling regimes were used including natural cooling, spraying water for a series of durations from 5 to 60min, and quenching in water. The temperature determination results prove that the rapid cooling regimes such as quenching in water, or water spraying for 30min or more, caused an action of “thermal shock” to concrete under elevated temperature, characterized by a high temperature decreasing rate ranged from 25 to 44min/°C. The experimental results indicate that, compared with natural cooling, thermal shock induced by water quenching and spraying water caused more severe damage to concrete, in terms of greater losses in compressive strength, tensile splitting strength, and fracture energy. The fact that the impact of spraying water for 30min or more on mechanical properties was almost the same as that of water quenching, indicates that spraying water for 30min or more could cause thermal shock to a similar degree to water quenching, which is in good agreement with the results of the temperature determination. Hybrid fiber (steel fiber and polypropylene fiber) can enhance residual strength and fracture energy of concrete subjected to thermal shock induced by rapid cooling from high temperatures up to 800°C to room temperature. [Copyright &y& Elsevier]

The study of adversarial attacks is crucial in the design of robust neural network models. In this work, we propose a hyperparameter optimization framework for black-box adversarial attacks. We observe that hyperparameters are extremely important to enhance the query efficiency of many black-box adversarial attack methods. Hence, we propose an adaptive hyperparameter tuning framework such that, in each query iteration, the attacker can adaptively selects the hyperparameter configuration based on the feedback from the victim to improve the attack success rate and query efficiency of the attack algorithm. The experiment results show, by adaptively tuning the attack hyperparameters, our technique outperforms the original algorithm, where the query efficiency is improved by 33.63% on the NES algorithm for untargeted attacks, 44.47% on the Bandits algorithm for untargeted attacks, and 32.24% improvement on the Bandits algorithm for targeted attacks. [ABSTRACT FROM AUTHOR]

Acceleration of deep neural network (DNN) inference has gained increasing attention recently with the wide adoption of DNNs for practical applications. For computer vision tasks where inputs are images, existing works mostly focus on improving the throughput of inference for multiple images. However, in many real-time applications, it is critical to reduce the latency of a single image inference, which is more complicated than improving the throughput because of the inherent data dependencies. On the other hand, from human brain's perspective, the complexity in our visual surroundings is first encoded as a pattern of light on a two dimensional array of photoreceptors, with little direct resemblance to the original input or the ultimate percept. Within just a few hundred microns of retinal thickness, this initial signal encoded by our photoreceptors must be transformed into an adequate representation of the entire visual scene. Inspired by how the retina helps human brain incept new information efficiently, we present an end-to-end structured framework built using any existing convolutional neural network (CNN) as the backbone. The proposed framework, called VisualNet, can create task parallelism for the backbone during the inference of a single image. Experiments using a number of neural networks for the ImageNet classification task and the CIFAR-10 classification task on GPUs and CPUs show that the proposed VisualNet reduces the latency of the regular network it builds on by up to 80.6% when both are fully parallelized with state-of-the-art acceleration libraries. At the same time, VisualNet can achieve similar or slightly higher accuracy. [ABSTRACT FROM AUTHOR]

A new BODIPY derivative bearing hydrazone and hydrazide moieties was developed as an efficient dual-channel ratiometric fluorescence chemodosimeter 1 for Cu 2+ in neutral aqueous medium via Cu 2+ -mediated hydrolysis of C N bond in hydrazone unit. Confocal microscopy experiments have demonstrated that chemodosimeter 1 could also be used in live cells for the fast detection of Cu 2+ . [ABSTRACT FROM AUTHOR]

Abstract: In this paper, an experimental investigation was conducted to explore the relationship between explosive spalling occurrence and residual mechanical properties of fiber-toughened high-performance concrete exposed to high temperatures. The residual mechanical properties measured include compressive strength, tensile splitting strength, and fracture energy. A series of concretes were prepared using OPC (ordinary Portland cement) and crushed limestone. Steel fiber, polypropylene fiber, and hybrid fiber (polypropylene fiber and steel fiber) were added to enhance fracture energy of the concretes. After exposure to high temperatures ranged from 200 to 800 °C, the residual mechanical properties of fiber-toughened high-performance concrete were investigated. For fiber concrete, although residual strength was decreased by exposure to high temperatures over 400 °C, residual fracture energy was significantly higher than that before heating. Incorporating hybrid fiber seems to be a promising way to enhance resistance of concrete to explosive spalling. [Copyright &y& Elsevier]