29 research outputs found

    Global Adversarial Attacks for Assessing Deep Learning Robustness

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    It has been shown that deep neural networks (DNNs) may be vulnerable to adversarial attacks, raising the concern on their robustness particularly for safety-critical applications. Recognizing the local nature and limitations of existing adversarial attacks, we present a new type of global adversarial attacks for assessing global DNN robustness. More specifically, we propose a novel concept of global adversarial example pairs in which each pair of two examples are close to each other but have different class labels predicted by the DNN. We further propose two families of global attack methods and show that our methods are able to generate diverse and intriguing adversarial example pairs at locations far from the training or testing data. Moreover, we demonstrate that DNNs hardened using the strong projected gradient descent (PGD) based (local) adversarial training are vulnerable to the proposed global adversarial example pairs, suggesting that global robustness must be considered while training robust deep learning networks.Comment: Submitted to NeurIPS 201

    3d polyaniline nanofibers anchored on carbon paper for high-performance and light-weight supercapacitors

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    In the field of advanced energy storage, nanostructured Polyaniline (PANI) based materials hold a special place. Extensive studies have been done on the application of PANI in supercapacitors, however, the structure–property relationship of these materials is still not understood. This paper presents a detailed characterization of the novel sodium phytate doped 3D PANI nanofibers anchored on different types of carbon paper for application in supercapacitors. An excellent relationship between the structures and properties of the synthesized samples was found. Remarkable energy storage characteristics with low values of solution, charge transfer and polarization resistance and a specific capacitance of 1106.9 ± 1.5 F g−1^{−1} and 779 ± 2.6 F g−1^{−1} at current density 0.5 and 10 Ag−1^{−1}, respectively, was achieved at optimized conditions. The symmetric supercapacitor assembly showed significant enhancement in both energy density and power density. It delivered an energy density of 95 Wh kg−1^{−1} at a power of 846 W kg−1^{−1}. At a high-power density of 16.9 kW kg−1^{−1}, the energy density can still be kept at 13 Wh kg−1^{−1}. Cyclic stability was also checked for 1000 cycles at a current density of 10 Ag−1^{−1} having excellent retention, i.e., 96%

    Predictive role of fragmented QRS in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

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    Objective: Fragmented QRS (fQRS), as defined by additional spikes in the QRS complex of a 12-lead electrocardiogram (ECG), is a marker of scarred myocardium. In patients with coronary artery disease (CAD), fQRS is a predictor of heart failure (HF) and other major adverse cardiac events (MACE). The study was aimed to evaluate the role of fQRS in prediction of HF in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Methods: In a prospective, non-randomized, small observational study, we enrolled 188 consecutive patients with STEMI undergoing primary PCI. Patients were grouped according to the presence or absence of fQRS and their in-hospital, 1 and 6-month MACE outcomes were assessed. Results: Of the 188 patients, fQRS were noted in 92 (48.94%) patients. Patients with fQRS were more likely to have Killip class II/III/IV. Patients with fQRS had a significantly higher corrected QT interval, lower left ventricular ejection fraction (LVEF), and higher N-terminal pro brain natriuretic peptide (NT-pro BNP) at 24 hours and 48 hours compared to patients without fQRS. The in-hospital (P=0.001), 30-day (P=0.03) and 6-month (p=0.01) MACE were higher in patients with fQRS. On logistic multiple analysis, fQRS in anterior leads (OR=3.70, CI=1.68-10.02, p=0.001), fQRS in more than 2 leads (OR=5.20, CI=1.51-12.83, p=0.01), NT-proBNP (OR=1.05, CI=1.03-1.08, p=0.02) and Killip class II/III/IV were found to be significant predictors for HF hospitalization. Conclusion: Our findings suggest that fQRS can be a predictor for HF in patients with STEMI and provide a simple and readily available technique for predicting prognosis. Larger studies are required to validate these findings

    Comparative analysis of genome-wide association studies signals for lipids, diabetes, and coronary heart disease: Cardiovascular Biomarker Genetics Collaboration

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    To evaluate the associations of emergent genome-wide-association study-derived coronary heart disease (CHD)-associated single nucleotide polymorphisms (SNPs) with established and emerging risk factors, and the association of genome-wide-association study-derived lipid-associated SNPs with other risk factors and CHD events

    Critical analysis of Big Data Challenges and analytical methods

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    Big Data (BD), with their potential to ascertain valued insights for enhanced decision-making process, have recently attracted substantial interest from both academics and practitioners. Big Data Analytics (BDA) is increasingly becoming a trending practice that many organizations are adopting with the purpose of constructing valuable information from BD. The analytics process, including the deployment and use of BDA tools, is seen by organizations as a tool to improve operational efficiency though it has strategic potential, drive new revenue streams and gain competitive advantages over business rivals. However, there are different types of analytic applications to consider. Therefore, prior to hasty use and buying costly BD tools, there is a need for organizations to first understand the BDA landscape. Given the significant nature of the BD and BDA, this paper presents a state-of-the-art review that presents a holistic view of the BD challenges and BDA methods theorized/proposed/employed by organizations to help others understand this landscape with the objective of making robust investment decisions. In doing so, systematically analysing and synthesizing the extant research published on BD and BDA area. More specifically, the authors seek to answer the following two principal questions: Q1 – What are the different types of BD challenges theorized/proposed/confronted by organizations? and Q2 – What are the different types of BDA methods theorized/proposed/employed to overcome BD challenges?. This systematic literature review (SLR) is carried out through observing and understanding the past trends and extant patterns/themes in the BDA research area, evaluating contributions, summarizing knowledge, thereby identifying limitations, implications and potential further research avenues to support the academic community in exploring research themes/patterns. Thus, to trace the implementation of BD strategies, a profiling method is employed to analyze articles (published in English-speaking peer-reviewed journals between 1996 and 2015) extracted from the Scopus database. The analysis presented in this paper has identified relevant BD research studies that have contributed both conceptually and empirically to the expansion and accrual of intellectual wealth to the BDA in technology and organizational resource management discipline

    Finite Element Simulation of Deep Drawing Process to Minimize Earing

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    Earing defect in drawing process is highly undesirable not only because it adds on an additional trimming operation but also because the uneven material flow demands extra care. The objective of this work is to study the earing problem in the Deep Drawing of circular cup and to optimize the blank shape to reduce the earing. A finite element model is developed for 3-D numerical simulation of cup forming process in ABAQUS. Extra-deep-drawing (EDD) steel sheet has been used for simulation. Properties and tool design parameters were used as input for simulation. Earing was observed in the simulated cup and it was measured at various angles with respect to rolling direction. To reduce the earing defect initial blank shape was modified with the help of anisotropy coefficient. Modified blanks showed notable reduction in earing
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