180 research outputs found
Block Switching: A Stochastic Approach for Deep Learning Security
Recent study of adversarial attacks has revealed the vulnerability of modern
deep learning models. That is, subtly crafted perturbations of the input can
make a trained network with high accuracy produce arbitrary incorrect
predictions, while maintain imperceptible to human vision system. In this
paper, we introduce Block Switching (BS), a defense strategy against
adversarial attacks based on stochasticity. BS replaces a block of model layers
with multiple parallel channels, and the active channel is randomly assigned in
the run time hence unpredictable to the adversary. We show empirically that BS
leads to a more dispersed input gradient distribution and superior defense
effectiveness compared with other stochastic defenses such as stochastic
activation pruning (SAP). Compared to other defenses, BS is also characterized
by the following features: (i) BS causes less test accuracy drop; (ii) BS is
attack-independent and (iii) BS is compatible with other defenses and can be
used jointly with others.Comment: Accepted by AdvML19: Workshop on Adversarial Learning Methods for
Machine Learning and Data Mining at KDD, Anchorage, Alaska, USA, August 5th,
2019, 5 page
Towards Query-Efficient Black-Box Adversary with Zeroth-Order Natural Gradient Descent
Despite the great achievements of the modern deep neural networks (DNNs), the
vulnerability/robustness of state-of-the-art DNNs raises security concerns in
many application domains requiring high reliability. Various adversarial
attacks are proposed to sabotage the learning performance of DNN models. Among
those, the black-box adversarial attack methods have received special
attentions owing to their practicality and simplicity. Black-box attacks
usually prefer less queries in order to maintain stealthy and low costs.
However, most of the current black-box attack methods adopt the first-order
gradient descent method, which may come with certain deficiencies such as
relatively slow convergence and high sensitivity to hyper-parameter settings.
In this paper, we propose a zeroth-order natural gradient descent (ZO-NGD)
method to design the adversarial attacks, which incorporates the zeroth-order
gradient estimation technique catering to the black-box attack scenario and the
second-order natural gradient descent to achieve higher query efficiency. The
empirical evaluations on image classification datasets demonstrate that ZO-NGD
can obtain significantly lower model query complexities compared with
state-of-the-art attack methods.Comment: accepted by AAAI 202
(Methanol-κO){1-[2-(piperazin-4-ium-1-yl-κN 1)ethylÂiminoÂmethyl-κN]naphthalen-2-olato-κO}bisÂ(thioÂcyanato-κN)nickel(II) methanol monosolvate
In the title solvated complex, [Ni(C17H21N3O)(NCS)2(CH3OH)]·CH3OH, the Ni2+ ion is coordinated by one phenolate O, one imine N, and one amine N atom of the tridentate Schiff base ligand, two thioÂcyanate N atoms and one methanol O atom, resulting in a distorted cis-NiO2N4 octaÂhedral geometry. The chelate ring formed by the phenolate O and imine N atoms approximates to an envelope with the Ni atom as the flap, whereas the chelate ring formed by the two N atoms is twisted about the C—C bond. In the crystal, the components are linked by O—H⋯O, N—H⋯O, N—H⋯S, and O—H⋯S hydrogen bonds
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Computational methods reveal novel functionalities of PIWI-interacting RNAs in human papillomavirus-induced head and neck squamous cell carcinoma.
Human papillomavirus (HPV) infection is the fastest growing cause of head and neck squamous cell carcinoma (HNSCC) today, but its role in malignant transformation remains unclear. This study aimed to conduct a comprehensive investigation of PIWI-interacting RNA (piRNA) alterations and functionalities in HPV-induced HNSCC. Using 77 RNA-sequencing datasets from TCGA, we examined differential expression of piRNAs between HPV16(+) HNSCC and HPV(-) Normal samples, identifying a panel of 30 HPV-dysregulated piRNAs. We then computationally investigated the potential mechanistic significances of these transcripts in HPV-induced HNSCC, identifying our panel of piRNAs to associate with the protein PIWIL4 as well as the RTL family of retrotransposon-like genes, possibly through direct binding interactions. We also recognized several HPV-dysregulated transcripts for their correlations with well-documented mutations and copy number variations in HNSCC as well as HNSCC clinical variables, demonstrating the potential ability of our piRNAs to play important roles in large-scale modulation of HNSCC in addition to their direct, smaller-scale interactions in this malignancy. The differential expression of key piRNAs, including NONHSAT077364, NONHSAT102574, and NONHSAT128479, was verified in vitro by evaluating endogenous expression in HPV(+) cancer vs. HPV(-) normal cell lines. Overall, our novel study provides a rigorous investigation of piRNA dysregulation in HPV-related HNSCC, and lends critical insight into the idea that these small regulatory transcripts may play crucial and previously unidentified roles in tumor pathogenesis and progression
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Identification and characterization of dysregulated P-element induced wimpy testis-interacting RNAs in head and neck squamous cell carcinoma.
It is clear that alcohol consumption is a major risk factor in the pathogenesis of head and neck squamous cell carcinoma (HNSCC); however, the molecular mechanism underlying the pathogenesis of alcohol-associated HNSCC remains poorly understood. The aim of the present study was to identify and characterize P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) and PIWI proteins dysregulated in alcohol-associated HNSCC to elucidate their function in the development of this cancer. Using next generation RNA-sequencing (RNA-seq) data obtained from 40 HNSCC patients, the piRNA and PIWI protein expression of HNSCC samples was compared between alcohol drinkers and non-drinkers. A separate piRNA expression RNA-seq analysis of 18 non-smoker HNSCC patients was also conducted. To verify piRNA expression, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed on the most differentially expressed alcohol-associated piRNAs in ethanol and acetaldehyde-treated normal oral keratinocytes. The correlation between piRNA expression and patient survival was analyzed using Kaplan-Meier estimators and multivariate Cox proportional hazard models. A comparison between alcohol drinking and non-drinking HNSCC patients demonstrated that a panel of 3,223 piRNA transcripts were consistently detected and differentially expressed. RNA-seq analysis and in vitro RT-qPCR verification revealed that 4 of these piRNAs, piR-35373, piR-266308, piR-58510 and piR-38034, were significantly dysregulated between drinking and non-drinking cohorts. Of these four piRNAs, low expression of piR-58510 and piR-35373 significantly correlated with improved patient survival. Furthermore, human PIWI-like protein 4 was consistently upregulated in ethanol and acetaldehyde-treated normal oral keratinocytes. These results demonstrate that alcohol consumption may cause dysregulation of piRNA expression in HNSCC and in vitro verifications identified 4 piRNAs that may be involved in the pathogenesis of alcohol-associated HNSCC
Block Switching: A Stochastic Approach for Deep Learning Security
Recent study of adversarial attacks has revealed the vulnerability of modern deep learning models. That is, subtly crafted perturbations of the input can make a trained network with high accuracy and produce arbitrary incorrect predictions, while maintaining imperceptible to human vision system. In this paper, we introduce Block Switching (BS), a defense strategy against adversarial attacks based on stochasticity. BS replaces a block of model layers with multiple parallel channels, and the active channel is randomly assigned in the run time, hence unpredictable to the adversary. We show empirically that BS leads to a more dispersed input gradient distribution and superior defense effectiveness compared with other stochastic defenses such as stochastic activation pruning. Compared to other defenses, BS is also characterized by the following features: (i) BS causes less test accuracy drop; (ii) BS is attack-independent; and (iii) BS is compatible with other defenses and can be used jointly with others
AdvMS: a multi-source multi-cost defense against adversarial attacks
Designing effective defense against adversarial attacks is a crucial topic as deep neural networks have been proliferated rapidly in many security-critical domains such as malware detection and self-driving cars. Conventional defense methods, although shown to be promising, are largely limited by their single-source single-cost nature: The robustness promotion tends to plateau when the defenses are made increasingly stronger while the cost tends to amplify. In this paper, we study principles of designing multi-source and multi-cost schemes where defense performance is boosted from multiple defending components. Based on this motivation, we propose a multi-source and multi-cost defense scheme, Adversarially Trained Model Switching (AdvMS), that inherits advantages from two leading schemes: adversarial training and random model switching. We show that the multi-source nature of AdvMS mitigates the performance plateauing issue and the multi-cost nature enables improving robustness at a flexible and adjustable combination of costs over different factors which can better suit specific restrictions and needs in practice.Accepted manuscrip
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