Resiliency-oriented operation of distribution networks under unexpected wildfires using multi-horizon information-gap decision theory

Extreme events may trigger cascading outages of different components in power systems and cause a substantial loss of load. Forest wildfires, as a common type of extreme events, may damage transmission/distribution lines across the forest and disconnect a large number of consumers from the electric network. Hence, this paper presents a robust scheduling model based on the notion of information-gap decision theory (IGDT) to enhance the resilience of a distribution network exposed to wildfires. Since the thermal rating of a transmission/distribution line is a function of its temperature and current, it is assumed that the tie-line connecting the distribution network to the main grid is equipped with a dynamic thermal rating (DTR) system aiming at accurately evaluating the impact of a wildfire on the ampacity of the tie-line. The proposed approach as a multi-horizon IGDT-based optimization problem finds a robust operation plan protected against the uncertainty of wind power, solar power, load, and ampacity of tie-lines under a specific uncertainty budget (UB). Since all uncertain parameters compete to maximize their robust regions under a specific uncertainty budget, the proposed multi-horizon IGDT-based model is solved by the augmented normalized normal constraint (ANNC) method as an effective multi-objective optimization approach. Moreover, a posteriori out-of-sample analysis is used to find (i) the best solution among the set of Pareto optimal solutions obtained from the ANNC method given a specific uncertainty budget, and (ii) the best resiliency level by varying the uncertainty budget and finding the optimal uncertainty budget. The proposed approach is tested on a 33-bus distribution network under different circumstances. The case study under different conditions verifies the effectiveness of the proposed operation planning model to enhance the resilience of a distribution network under a close wildfire. © 2022 The Author(s

Investigating the relationship between carotid intima-media thickness, flow-mediated dilatation in brachial artery and nuclear heart scan in patients with rheumatoid arthritis for evaluation of asymptomatic cardiac ischemia and atherosclerotic changes

Background: Cardiovascular disease is the most common cause of death worldwide. In order to prevent and treat heart diseases, we need to estimate the trend of non-cardiac diseases with the cardiovascular system. Arthritis Rheumatoid is a chronic immune/inflammatory process which leads to subclinical atherosclerosis and increases cardiovascular disease. We examined the patients who referred to our nuclear medicine center for MPI and correlated their findings with flow-mediated dilatation (FMD) of the brachial artery and carotid intima-media thickness (CIMT) in arthritis rheumatoid patients. Material and methods: A total 30 known cases with arthritis rheumatoid were referred to our department for MPI and the single-photon emission computed tomography (SPECT) imaging were visually and quantitatively evaluated by two nuclear medicine physicians and the correlation of the measured FMD and CIMT were evaluated and compared with ultrasonography data. Demographic information such as gender, age and sex and medical history (risk factors, cardiovascular sign and symptoms, lab findings, medication etc…) were recorded in questionnaire sheets and were analyzed by SPSS.20. Chi-square and student t-test were used for further analysis. Results: The mean CIMT (R = 0.452 ± 0.07, L = 0.447 ± 0.08) and %FMD (R = 7.22 ± 8.66, L = 6.42 ± 11.88) were measured for all subjects. Age was the only parameter correlated with both right and left CIMT (P = 0.033 and P = 0.024, respectively). Among the patients, 26.7% had mild ischemia (SSS < 8) and 3 of them suffered from active arthritis rheumatoid. All patients with RA showed normal ventricular ejection fraction and normal volumes and among them, 93.3% had normal functional performance (normal wall motion…). Moreover, the mean CIMT and %FMD were not significantly different in ischemic and non-ischemic patients. Among ischemic patients, just the course of the disease was associated with CIMT and none of the parameters was correlated with FMD. Conclusions: There is no significant statistical difference between ischemic and non-ischemic patients and also the functional performance with values of CIMT and FMD. Among all populations, the parameter of age, and in ischemic group, the course of disease were found as the only variable correlated with CIMT

Cluster-Based Toxicity Estimation of Osteoradionecrosis Via Unsupervised Machine Learning: Moving Beyond Single Dose-Parameter Normal Tissue Complication Probability by Using Whole Dose-Volume Histograms for Cohort Risk Stratification

PURPOSE: Given the limitations of extant models for normal tissue complication probability estimation for osteoradionecrosis (ORN) of the mandible, the purpose of this study was to enrich statistical inference by exploiting structural properties of data and provide a clinically reliable model for ORN risk evaluation through an unsupervised-learning analysis that incorporates the whole radiation dose distribution on the mandible. METHODS AND MATERIALS: The analysis was conducted on retrospective data of 1259 patients with head and neck cancer treated at The University of Texas MD Anderson Cancer Center between 2005 and 2015. During a minimum 12-month posttherapy follow-up period, 173 patients in this cohort (13.7%) developed ORN (grades I to IV). The (structural) clusters of mandibular dose-volume histograms (DVHs) for these patients were identified using the K-means clustering method. A soft-margin support vector machine was used to determine the cluster borders and partition the dose-volume space. The risk of ORN for each dose-volume region was calculated based on incidence rates and other clinical risk factors. RESULTS: The K-means clustering method identified 6 clusters among the DVHs. Based on the first 5 clusters, the dose-volume space was partitioned by the soft-margin support vector machine into distinct regions with different risk indices. The sixth cluster entirely overlapped with the others; the region of this cluster was determined by its envelopes. For each region, the ORN incidence rate per preradiation dental extraction status (a statistically significant, nondose related risk factor for ORN) was reported as the corresponding risk index. CONCLUSIONS: This study presents an unsupervised-learning analysis of a large-scale data set to evaluate the risk of mandibular ORN among patients with head and neck cancer. The results provide a visual risk-assessment tool for ORN (based on the whole DVH and preradiation dental extraction status) as well as a range of constraints for dose optimization under different risk levels

Numerical comparison of two methods for integration of active rear steering, torque vectoring and hydraulically interconnected suspension

This paper proposes the integration of three chassis control systems. In the first part, three chassis control systems including hydraulically interconnected suspension, torque vectoring system and active rear steering are introduced then these subsystems are evaluated by ramp steer and step steer manoeuvres; effectiveness and limits of subsystems are also reviewed. Then, two methods (optimal control and rule-based method) are proposed for integrated vehicle dynamics system. Both methods are evaluated with various manoeuvres to understand the advantages and disadvantages of each method

Effects of dichloromethane and N-butanol fractions of Nigella sativa on ACHN and GP-293 cell line morphology, viability, and apoptosis

Background: Renal cell carcinoma (RCC) is among the top death-causing cancers. Medicinal herbs can also have beneficial effects on RCC treatment. In this project, we aimed to study the antitumor effect of dichloromethane and N-butanol fractions of hydroalcoholic extract of Nigella sativa (N. sativa) on the morphology, viability, and apoptosis of ACHN (human renal adenocarcinoma) and GP-293 (normal renal epithelial) cell lines. Materials and Methods: In this experimental study, N-butanol and dichloromethane fractions of N. sativa were obtained, and ACHN and GP293 cell lines were treated with various concentrations of dichloromethane (0–100 μg/mL) and N-butanol (0–12.5 μg/mL) fractions for 24, 48, and 72 hours. Then, morphological changes, viability, and apoptosis were investigated. Results: Our results indicated that dichloromethane and N-butanol fractions cause morphological changes and significant decreases in the percentage of live cells in the ACHN cell line, in a dose- and time-dependent manner. In the GP-293 cell line, however, a lower toxicity was observed in comparison with that found for ACHN. The results of flow cytometry showed an apoptotic effect of dichloromethane and N-butanol fractions on the ACHN cell line but a higher rate of apoptosis induction for the total extract compared to the two fractions in the renal cancer cell line compared to the normal cell line. Conclusion: Our findings demonstrated that these two fractions of N. sativa induce inhibitory effects on the ACHN cell line morphology and viability. These effects were lower than those induced by the total extract. In addition, the two fractions caused more marked effects in the renal cancer cell line compared with the GP-293 cell line