1,087 research outputs found

    Mezoporozni katalizator PtSnO2/C s povećanom katalitičkom aktivnoŔću za elektrooksidaciju etanola

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    In this paper, we report the synthesis, characterization, and electrochemical evaluation of a mesoporous PtSnO2/C catalyst, called PtSnO2(M)/C, with a nominal Pt : Sn ratio of 3 : 1. Brunauerā€“Emmettā€“Teller and transmission electron microscopy characterizations showed the obvious mesoporous structure of SnO2 in PtSnO2(M)/C catalyst. X-ray photoelectron spectroscopy analysis exhibited the interaction between Pt and mesoporous SnO2. Compared with Pt/C and commercial PtSnO2/C catalysts, PtSnO2(M)/C catalyst has a lower active site, but higher catalytic activity for ethanol electro-oxidation reaction (EOR). The enhanced activity could be attributed to Pt nanoparticles deposited on mesoporous SnO2 that could decrease the amount of poisonous intermediates produced during EOR by the interaction between Pt and mesoporous SnO2. This work is licensed under a Creative Commons Attribution 4.0 International License.U ovom radu prikazana je sinteza, karakterizacija i elektrokemijska ocjena mezoporoznog katalizatora PtSnO2/C (PtSnO2(M)/C), s nominalnim omjerom Pt : Sn od 3 : 1. Karakterizacije Brunauer-Emmett-Tellerovom metodom i transmisijskom elektronskom mikroskopijom pokazale su očitu mezoporoznu strukturu SnO2 u katalizatoru PtSnO2(M)/C. Analiza rendgenskom fotoelektronskom spektroskopijom pokazala je interakciju između Pt i mezoporoznog SnO2. U usporedbi s Pt/C i komercijalnim katalizatorima PtSnO2/C, katalizator PtSnO2(M)/C ima slabije aktivno mjesto, ali veću katalitičku aktivnost za reakciju elektrooksidacije etanola (EOR). PoboljÅ”ana aktivnost mogla bi se pripisati nanočesticama Pt pohranjenim na mezoporoznom SnO2, Å”to bi moglo smanjiti količinu otrovnih međuprodukata proizvedenih tijekom elektrooksidacije etanola interakcijom između Pt i mezoporoznog SnO2. Ovo djelo je dano na koriÅ”tenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

    A Computationally Efficient Neural Video Compression Accelerator Based on a Sparse CNN-Transformer Hybrid Network

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    Video compression is widely used in digital television, surveillance systems, and virtual reality. Real-time video decoding is crucial in practical scenarios. Recently, neural video compression (NVC) combines traditional coding with deep learning, achieving impressive compression efficiency. Nevertheless, the NVC models involve high computational costs and complex memory access patterns, challenging real-time hardware implementations. To relieve this burden, we propose an algorithm and hardware co-design framework named NVCA for video decoding on resource-limited devices. Firstly, a CNN-Transformer hybrid network is developed to improve compression performance by capturing multi-scale non-local features. In addition, we propose a fast algorithm-based sparse strategy that leverages the dual advantages of pruning and fast algorithms, sufficiently reducing computational complexity while maintaining video compression efficiency. Secondly, a reconfigurable sparse computing core is designed to flexibly support sparse convolutions and deconvolutions based on the fast algorithm-based sparse strategy. Furthermore, a novel heterogeneous layer chaining dataflow is incorporated to reduce off-chip memory traffic stemming from extensive inter-frame motion and residual information. Thirdly, the overall architecture of NVCA is designed and synthesized in TSMC 28nm CMOS technology. Extensive experiments demonstrate that our design provides superior coding quality and up to 22.7x decoding speed improvements over other video compression designs. Meanwhile, our design achieves up to 2.2x improvements in energy efficiency compared to prior accelerators.Comment: Accepted by DATE 202

    TOAST: Transfer Learning via Attention Steering

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    Transfer learning involves adapting a pre-trained model to novel downstream tasks. However, we observe that current transfer learning methods often fail to focus on task-relevant features. In this work, we explore refocusing model attention for transfer learning. We introduce Top-Down Attention Steering (TOAST), a novel transfer learning algorithm that keeps the pre-trained backbone frozen, selects task-relevant features in the output, and feeds those features back to the model to steer the attention to the task-specific features. By refocusing the attention only, TOAST achieves state-of-the-art results on a number of transfer learning benchmarks, while having a small number of tunable parameters. Compared to fully fine-tuning, LoRA, and prompt tuning, TOAST substantially improves performance across a range of fine-grained visual classification datasets (e.g., 81.1% -> 86.2% on FGVC). TOAST also outperforms the fully fine-tuned Alpaca and Vicuna models on instruction-following language generation. Code is available at https://github.com/bfshi/TOAST.Comment: Code is available at https://github.com/bfshi/TOAS

    Draining the Water Hole: Mitigating Social Engineering Attacks with CyberTWEAK

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    Cyber adversaries have increasingly leveraged social engineering attacks to breach large organizations and threaten the well-being of today's online users. One clever technique, the "watering hole" attack, compromises a legitimate website to execute drive-by download attacks by redirecting users to another malicious domain. We introduce a game-theoretic model that captures the salient aspects for an organization protecting itself from a watering hole attack by altering the environment information in web traffic so as to deceive the attackers. Our main contributions are (1) a novel Social Engineering Deception (SED) game model that features a continuous action set for the attacker, (2) an in-depth analysis of the SED model to identify computationally feasible real-world cases, and (3) the CyberTWEAK algorithm which solves for the optimal protection policy. To illustrate the potential use of our framework, we built a browser extension based on our algorithms which is now publicly available online. The CyberTWEAK extension will be vital to the continued development and deployment of countermeasures for social engineering.Comment: IAAI-20, AICS-2020 Worksho

    Point Normal Orientation and Surface Reconstruction by Incorporating Isovalue Constraints to Poisson Equation

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    Oriented normals are common pre-requisites for many geometric algorithms based on point clouds, such as Poisson surface reconstruction. However, it is not trivial to obtain a consistent orientation. In this work, we bridge orientation and reconstruction in implicit space and propose a novel approach to orient point clouds by incorporating isovalue constraints to the Poisson equation. Feeding a well-oriented point cloud into a reconstruction approach, the indicator function values of the sample points should be close to the isovalue. Based on this observation and the Poisson equation, we propose an optimization formulation that combines isovalue constraints with local consistency requirements for normals. We optimize normals and implicit functions simultaneously and solve for a globally consistent orientation. Owing to the sparsity of the linear system, an average laptop can be used to run our method within reasonable time. Experiments show that our method can achieve high performance in non-uniform and noisy data and manage varying sampling densities, artifacts, multiple connected components, and nested surfaces

    A critical review of improved deep learning methods for the remaining useful life prediction of lithium-ion batteries.

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    As widely used for secondary energy storage, lithium-ion batteries have become the core component of the power supply system and accurate remaining useful life prediction is the key to ensure its reliability. Because of the complex working characteristics of lithium-ion batteries as well as the model parameter changing along with the aging process, the accuracy of the online remaining useful life prediction is difficult but urgent to be improved for the reliable power supply application. The deep learning algorithm improves the accuracy of the remaining useful life prediction, which also reduces the characteristic testing time requirement, providing the possibility to improve the power profitability of predictive energy management. This article analyzes, reviews, classifies, and compares different adaptive mathematical models on deep learning algorithms for the remaining useful life prediction. The features are identified for the modeling ability, according to which the adaptive prediction methods are classified. The specific criteria are defined to evaluate different modeling accuracy in the deep learning calculation procedure. The key features of effective life prediction are used to draw relevant conclusions and suggestions are provided, in which the high-accuracy deep convolutional neural network ā€” extreme learning machine algorithm is chosen to be utilized for the stable remaining useful life prediction of lithium-ion batteries

    Bi-Mapper: Holistic BEV Semantic Mapping for Autonomous Driving

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    A semantic map of the road scene, covering fundamental road elements, is an essential ingredient in autonomous driving systems. It provides important perception foundations for positioning and planning when rendered in the Bird's-Eye-View (BEV). Currently, the prior knowledge of hypothetical depth can guide the learning of translating front perspective views into BEV directly with the help of calibration parameters. However, it suffers from geometric distortions in the representation of distant objects. In addition, another stream of methods without prior knowledge can learn the transformation between front perspective views and BEV implicitly with a global view. Considering that the fusion of different learning methods may bring surprising beneficial effects, we propose a Bi-Mapper framework for top-down road-scene semantic understanding, which incorporates a global view and local prior knowledge. To enhance reliable interaction between them, an asynchronous mutual learning strategy is proposed. At the same time, an Across-Space Loss (ASL) is designed to mitigate the negative impact of geometric distortions. Extensive results on nuScenes and Cam2BEV datasets verify the consistent effectiveness of each module in the proposed Bi-Mapper framework. Compared with exiting road mapping networks, the proposed Bi-Mapper achieves 2.1% higher IoU on the nuScenes dataset. Moreover, we verify the generalization performance of Bi-Mapper in a real-world driving scenario. The source code is publicly available at https://github.com/lynn-yu/Bi-Mapper.Comment: Accepted to IEEE Robotics and Automation Letters (RA-L). The source code is publicly available at https://github.com/lynn-yu/Bi-Mappe

    Human-System Integration

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