Evaluating Similitude and Robustness of Deep Image Denoising Models via Adversarial Attack

Deep neural networks (DNNs) have a wide range of applications in the field of image denoising, and they are superior to traditional image denoising. However, DNNs inevitably show vulnerability, which is the weak robustness in the face of adversarial attacks. In this paper, we find some similitudes between existing deep image denoising methods, as they are consistently fooled by adversarial attacks. First, denoising-PGD is proposed which is a denoising model full adversarial method. The current mainstream non-blind denoising models (DnCNN, FFDNet, ECNDNet, BRDNet), blind denoising models (DnCNN-B, Noise2Noise, RDDCNN-B, FAN), and plug-and-play (DPIR, CurvPnP) and unfolding denoising models (DeamNet) applied to grayscale and color images can be attacked by the same set of methods. Second, since the transferability of denoising-PGD is prominent in the image denoising task, we design experiments to explore the characteristic of the latent under the transferability. We correlate transferability with similitude and conclude that the deep image denoising models have high similitude. Third, we investigate the characteristic of the adversarial space and use adversarial training to complement the vulnerability of deep image denoising to adversarial attacks on image denoising. Finally, we constrain this adversarial attack method and propose the L2-denoising-PGD image denoising adversarial attack method that maintains the Gaussian distribution. Moreover, the model-driven image denoising BM3D shows some resistance in the face of adversarial attacks.Comment: 12 pages, 15 figure

An enhanced predictive hierarchical power management framework for islanded microgrids

This paper proposes an enhanced three-layer predictive hierarchical power management framework for secure and economic operation of islanded microgrids. The tertiary control, guaranteeing the microgrid economic operation, is built upon the semi-definite programming-based AC optimal power flow model, which periodically sends power references to secondary control. To mitigate uncertainties arising from renewable generations and loads, a centralized linear model predictive control (MPC) controller is proposed and implemented for secondary control. The MPC controller can effectively regulate the microgrid system frequency by closely tracking reference signals from the tertiary controller with low computational complexity. Droop-based primary controllers are implemented to coordinate with the secondary MPC controller to balance the system in real time. Both synchronous generators (SGs) and solar photovoltaics (PVs) are simulated in the microgrid power management framework. A unified linear input-state estimator (ULISE) is proposed for SG state variable estimation and control anomaly detection due to compromised cyber-physical system components, etc. Simulation results demonstrated that SG states can be accurately estimated, while inconsistency in control signals can be effectively detected for an enhanced MPC. Furthermore, comparing with conventional proportional-integral (PI) control, the proposed hierarchical power management scheme exhibits superior frequency regulation capability whilst maintaining lower system operating costs

Numeričko istraživanje utjecaja radijalne zračnosti na performanse kompresora s kombiniranim tokom

In mixed-flow compressor, the leakage flow through the tip clearance generates the tip leakage vortex by the interaction with the main flow, and consequently makes the flow in the impeller passage more complex. Different tip clearances generate different intensity of disturbance to main flow. In this paper, numerical analysis is performed using a commercial code to investigate tip clearance effects on main flow. The performance of mixed-flow impeller with four different clearances between impeller and stationary shroud are evaluated and compared with experimental results. The impeller performance curves are obtained for different mass flow parameters with different tip clearances at design speed. The results show that the tip leakage flow strongly interacts with main flow and contributes to total pressure loss and performance reduction. The pressure and performance decrement are approximately linearly proportional to the gap between impeller and stationary shroud. Though the velocity vectors distribution, the computed results reveal that the intensity of the disturbance generated by the leakage flow interacts with the main flow has rather a large influence over efficiency. And the quantity of backflow is minimum when the tip clearance is 0.5 mm, while the 0.75mm tip clearance, by contrast, has a considerable effect on main flow by the interaction with leakage flow.Kod kompresora s kombiniranim tokom, protok rasipanja kroz radijalnu zračnost stvara vršni vrtlog rasipanja zbog interakcije s glavnim tokom te uzročno tok u prolazu rotora čini kompleksnijim. Različite veličine radijalne zračnosti uzrokuju različiti intenzitet smetnje glavnom toku. U ovom članku, numerička analiza provodi se korištenjem komercijalnog koda kako bi se istražio utjecaj radijalne zračnosti na glavni tok. Ocjenjene su performanse rotora kombiniranog toka sa četiri različite radijalne zračnosti između rotora i stacionarnog kućišta te su uspoređene s eksperimentalnim rezultatima. Krivulje performansa rotora dobivene su za različite parametre masenog protoka sa različitim radijalnim zračnostima pri konstrukcijskoj brzini. Rezultati pokazuju kako protok vršnog rasipanja ima snažno međudjelovanje s glavnim tokom i da pridonosi potpunom gubitku tlaka i smanjenju performansa. Smanjenje tlaka i performansi približno je linearno proporcionalno razmaku između rotora i stacionarnog kućišta. Kroz raspored vektora brzine, računalni izračuni otkrivaju kako intenzitet smetnja koje se stvaraju kod međudjelovanja protoka rasipanja i glavnog toka, ima priličan utjecaj na efikasnost. Kvantiteta protutoka je minimalna kad radijalna zračnost iznosi 0.5mm, a usporedno tome, kad je radijalna zračnost 0.75mm, ima značajan utjecaj na glavni tok kroz međudjelovanje s protokom rasipanja

Synthesis of Esters of Ginsenoside Metabolite M1 and Their Cytotoxicity on MGC80-3 Cells

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SIRT3 Protects Rotenone-induced Injury in SH-SY5Y Cells by Promoting Autophagy through the LKB1-AMPK-mTOR Pathway.

SIRT3 is a class III histone deacetylase that modulates energy metabolism, genomic stability and stress resistance. It has been implicated as a potential therapeutic target in a variety of neurodegenerative diseases, including Parkinson's disease (PD). Our previous study demonstrates that SIRT3 had a neuroprotective effect on a rotenone-induced PD cell model, however, the exact mechanism is unknown. In this study, we investigated the underlying mechanism. We established a SIRT3 stable overexpression cell line using lentivirus infection in SH-SY5Y cells. Then, a PD cell model was established using rotenone. Our data demonstrate that overexpression of SIRT3 increased the level of the autophagy markers LC3 II and Beclin 1. After addition of the autophagy inhibitor 3-MA, the protective effect of SIRT3 diminished: the cell viability decreased, while the apoptosis rate increased; α-synuclein accumulation enhanced; ROS production increased; antioxidants levels, including SOD and GSH, decreased; and MMP collapsed. These results reveal that SIRT3 has neuroprotective effects on a PD cell model by up-regulating autophagy. Furthermore, SIRT3 overexpression also promoted LKB1 phosphorylation, followed by activation of AMPK and decreased phosphorylation of mTOR. These results suggest that the LKB1-AMPK-mTOR pathway has a role in induction of autophagy. Together, our findings indicate a novel mechanism by which SIRT3 protects a rotenone-induced PD cell model through the regulation of autophagy, which, in part, is mediated by activation of the LKB1-AMPK-mTOR pathway