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531 results on '"Khodayar, Mohammad"'

15. Graph-based Faulted Line Identification Using Micro-PMU Data in Distribution Systems

Author

Zhang, Ying, Wang, Jianhui, and Khodayar, Mohammad

Subjects
Electrical Engineering and Systems Science - Systems and Control
Abstract

Motivated by increasing penetration of distributed generators (DGs) and fast development of micro-phasor measurement units ({\mu}PMUs), this paper proposes a novel graph-based faulted line identification algorithm using a limited number of {\mu}PMUs in distribution networks. The core of the proposed method is to apply advanced distribution system state estimation (DSSE) techniques integrating {\mu}PMU data to the fault location. We propose a distributed DSSE algorithm to efficiently restrict the searching region for the fault source in the feeder between two adjacent {\mu}PMUs. Based on the graph model of the feeder in the reduced searching region, we further perform the DSSE in a hierarchical structure and identify the location of the fault source. Also, the proposed approach captures the impact of DGs on distribution system operation and remains robust against high-level noises in measurements. Numerical simulations verify the accuracy and efficiency of the proposed method under various fault scenarios covering multiple fault types and fault impedances.

Published
2020

26. Convolutional Graph Auto-encoder: A Deep Generative Neural Architecture for Probabilistic Spatio-temporal Solar Irradiance Forecasting

Author

Khodayar, Mahdi, Mohammadi, Saeed, Khodayar, Mohammad, Wang, Jianhui, and Liu, Guangyi

Subjects
Computer Science - Machine Learning, Statistics - Machine Learning
Abstract

Machine Learning on graph-structured data is an important and omnipresent task for a vast variety of applications including anomaly detection and dynamic network analysis. In this paper, a deep generative model is introduced to capture continuous probability densities corresponding to the nodes of an arbitrary graph. In contrast to all learning formulations in the area of discriminative pattern recognition, we propose a scalable generative optimization/algorithm theoretically proved to capture distributions at the nodes of a graph. Our model is able to generate samples from the probability densities learned at each node. This probabilistic data generation model, i.e. convolutional graph auto-encoder (CGAE), is devised based on the localized first-order approximation of spectral graph convolutions, deep learning, and the variational Bayesian inference. We apply our CGAE to a new problem, the spatio-temporal probabilistic solar irradiance prediction. Multiple solar radiation measurement sites in a wide area in northern states of the US are modeled as an undirected graph. Using our proposed model, the distribution of future irradiance given historical radiation observations is estimated for every site/node. Numerical results on the National Solar Radiation Database show state-of-the-art performance for probabilistic radiation prediction on geographically distributed irradiance data in terms of reliability, sharpness, and continuous ranked probability score., Comment: 8 pages, 11 figures

Published
2018

30. Antioxidant and anti-inflammatory potential of vanillic acid improves nephrotoxicity induced by sodium arsenite in mice.

Author

Khodayar, Mohammad Javad, Shirani, Maryam, Shariati, Saeedeh, Khorsandi, Layasadat, and Mohtadi, Shokooh

Subjects
*BLOOD urea nitrogen, *SUPEROXIDE dismutase, *SODIUM arsenite, *OXIDATIVE stress, *DRINKING water, *GLUTATHIONE peroxidase
Abstract

This study examined the potential of vanillic acid (VA) to protect against renal oxidative stress and inflammation caused by sodium arsenite (SA) in mice. Mice were assigned to five groups: control, VA (100 mg/kg), SA (50 ppm in drinking water for 8 weeks), and SA + VA (50 and 100 mg/kg orally in the 7th and 8th weeks). After the experiment was ended, the Mice were sacrificed and serum and renal tissue samples were collected for additional assessments. Treatment with VA suppressed SA-induced increase in blood urea nitrogen and creatinine in the serum. Furthermore, renal histological damage induced by SA administration was ameliorated with VA treatment. Also, the increase in the level of lipid peroxidation marker (thiobarbituric acid reactive substances) along with the reduction in total thiol levels and the diminished activities of antioxidant enzymes (catalase, superoxide dismutase, and glutathione peroxidase) in the renal tissue of SA-treated mice were effectively reversed following treatment with VA. The results exhibited that the VA-treated groups (50 and 100 mg/kg) mitigated the elevation of inflammatory markers in kidney tissue (tumor necrosis factor-α and nitric oxide) in SA-exposed mice. Our research findings indicate that VA could be a potential therapeutic agent for the management of SA-associated nephrotoxicity. [ABSTRACT FROM AUTHOR]

Published
2024
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34. Distributionally Robust Multistage Dispatch With Discrete Recourse of Energy Storage Systems

Author

Zheng, Xiaodong, Khodayar, Mohammad E., Wang, Jianhui, Yue, Meng, and Zhou, Anping

Abstract

Energy storage systems (ESS) are indispensable building blocks of power systems with a high share of variable renewable energy. As energy-limited resources, ESS should be carefully modeled in uncertainty-aware multistage dispatch. On the modeling side, we develop a two-stage model for ESS that respects the nonanticipativity of multistage dispatch, and implement it into a distributionally robust model predictive control scheme. The ESS model features multiple selective operational modes, which enable its power interval to be scheduled in chronological dispatch. On the algorithm side, we propose to evaluate the future worst-case cost expectation over a convex relaxation of the non-convex and discrete value function of the recourse. This gives rise to a novel algorithm that efficiently solves a typical class of two-stage distributionally robust optimization problems, which are equipped with discrete recourse and infinite support. The advantage of the algorithm over the state-of-the-art nested column-and-constraint generation method is theoretically interpreted. Simulation is performed on the modified IEEE 118-bus system and 300-bus system. Results show that ESS function well on the basis of the proposed model and control scheme, and also demonstrate the superiority of the novel algorithm.

Published
2024
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39. Thymoquinone Effects on the Expression of p62 Gene in CisplatinInduced Testicular Damage in Mice.

Author

Shojaedini, Mina, Hemadi, Masoud, Saki, Ghasem, Fakhredini, Fereshtesadat, Khodayar, Mohammad Javad, and Khorsandi, Layasadat

Subjects
GENE expression, TESTIS injuries, CISPLATIN, AUTOPHAGY, HISTOMORPHOMETRY
Abstract

Background: Cisplatin (CPN) is widely used for the management of various malignant tumors. Objectives: This study investigated the effects of Thymoquinone (TQN) on the expression of the p62 gene in CPN-induced testicular damage in mice. Methods: Histomorphometry, testis injury scores, expression of p62, and protein levels of LC3-II were assessed. Results: Cisplatin induced histological changes, increased p62 expression (P < 0.01), and reduced LC3-II levels (P < 0.001). Thymoquinone pretreatment decreased p62 expression while increasing LC3-II protein levels. Thymoquinone significantly reversed the testicular injury scores and improved histomorphometric parameters. Conclusions: The results indicate that TQN enhances autophagy and improves testicular tissue in CPN-intoxicated mice. [ABSTRACT FROM AUTHOR]

Published
2024
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46. Behind-the-Meter Load and PV Disaggregation via Deep Spatiotemporal Graph Generative Sparse Coding With Capsule Network

Author

Saffari, Mohsen, Khodayar, Mahdi, Khodayar, Mohammad E., and Shahidehpour, Mohammad

Abstract

Nowadays, rooftop photovoltaic (PV) panels are getting enormous attention as clean and sustainable sources of energy due to the increasing energy demand, depreciating physical assets, and global environmental challenges. In residential areas, the large-scale integration of these generation resources influences the customer load profile and introduces uncertainty to the distribution system’s net load. Since such resources are typically located behind the meter (BtM), an accurate estimation of BtM load and PV power will be crucial for distribution network operation. This article proposes the spatiotemporal graph sparse coding (SC) capsule network that incorporates SC into deep generative graph modeling and capsule networks for accurate BtM load and PV generation estimation. A set of neighboring residential units are modeled as a dynamic graph in which the edges represent the correlation among their net demands. A generative encoder–decoder model, i.e., spectral graph convolution (SGC) attention peephole long short-term memory (PLSTM), is devised to extract the highly nonlinear spatiotemporal patterns from the formed dynamic graph. Later, to enrich the latent space sparsity, a dictionary is learned in the hidden layer of the proposed encoder–decoder, and the corresponding sparse codes are procured. Such sparse representation is used by a capsule network to estimate the BtM PV generation and the load of the entire residential units. Experimental results on two real-world energy disaggregation (ED) datasets, Pecan Street and Ausgrid, demonstrate more than 9.8% and 6.3% root mean square error (RMSE) improvements in BtM PV and load estimation over the state-of-the-art, respectively.

Published
2024
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49. Antiepileptic Activity of Zingerone on Maximal Electroshock and Pentylenetetrazole-Induced Seizure in Mice.

Author

Afzali-Boroujeni, Zakiye Sadat, Kalantar, Hadi, Zeidooni, Leila, Molavinia, Shahrzad, and Khodayar, Mohammad Javad

Subjects
EPILEPSY, OXIDATIVE stress, SUPEROXIDE dismutase, SEIZURES (Medicine), DEATH rate
Abstract

Background and objectives: Epilepsy is a chronic disorder affecting a broad spectrum of individuals. Recently, there has been increased interest in the role of oxidative stress in epilepsy; adjuvant antiepileptic medicines aimed at reducing oxidative stress may serve as a novel therapeutic approach. In the present study, we investigated the effects of zingerone, a phenolic compound, on maximal electroshock (MES) and pentylenetetrazole (PTZ)-induced seizures and oxidant/antioxidant biomarkers in mice. Methods: In the MES model, the first and second groups received saline and phenytoin (25 mg/kg i.p.), respectively. Groups three to five received zingerone (5, 10, and 30 mg/kg). Thirty minutes later, the digital electroconvulsiometer developed seizures. In the PTZ model, the first and second groups received saline, whereas the others received diazepam (3 mg/kg, i.p.) or zingerone (5, 10, and 30 mg/kg). On day five, PTZ (80 mg/kg, i.p.) was administered to all groups. After behavioral experiments, the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and the level of thiobarbituric acid reactive substances (TBARS) in the brain tissue of PTZ model mice were measured. Results: Our findings suggest that zingerone may have anticonvulsant effects by increasing latency and decreasing the duration of clonic convulsion, tonic hindlimb extension, and mortality rate. Additionally, zingerone administration increased SOD and CAT activities and decreased TBARS levels in the brain tissue of PTZ model mice. Conclusion: This study suggests that zingerone protects against epileptic seizures and alleviates the oxidative stress associated with epilepsy pathogenesis. [ABSTRACT FROM AUTHOR]

Published
2024
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50. Sodium Cromolyn Modulates Carrageenan-Induced Acute Inflammation Through the Interleukin-6 Levels.

Author

Hemmati, Ali Asghar, Ghafourian, Mehri, Khodayar, Mohammad Javad, Zarin, Hadi, Rounkian, Masoumeh Saberi, and Jalali, Amir

Subjects
ANTIALLERGIC agents, EDEMA, ANIMAL models in research, NONSTEROIDAL anti-inflammatory agents, CLINICAL trials
Abstract

The article focuses on the anti-inflammatory properties of sodium cromolyn in rats induced by carrageenan and its impact on IL-6 levels. It discusses the method of inducing carrageenan paw edema, administration of sodium cromolyn, and IL-6 levels evaluation.It highlights sodium cromolyn as an alternative to nonsteroidal anti-inflammatory drugs (NSAIDs) due to its anti-inflammatory properties.

Published
2024
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