Radar sensor based machine learning approach for precise vehicle position estimation

Estimating vehicles' position precisely is essential in Vehicular Adhoc Networks (VANETs) for their safe, autonomous, and reliable operation. The conventional approaches used for vehicles' position estimation, like Global Positioning System (GPS) and Global Navigation Satellite System (GNSS), pose significant data delays and data transmission errors, which render them ineffective in achieving precision in vehicles' position estimation, especially under dynamic environments. Moreover, the existing radar-based approaches proposed for position estimation utilize the static values of range and azimuth, which make them inefficient in highly dynamic environments. In this paper, we propose a radar-based relative vehicle positioning estimation method. In the proposed method, the dynamic range and azimuth of a Frequency Modulated Continuous Wave radar is utilized to precisely estimate a vehicle's position. In the position estimation process, the speed of the vehicle equipped with the radar sensor, called the reference vehicle, is considered such that a change in the vehicle's speed changes the range and azimuth of the radar sensor. For relative position estimation, the distance and relative speed between the reference vehicle and a nearby vehicle are used. To this end, only those vehicles are considered that have a higher possibility of coming in contact with the reference vehicle. The data recorded by the radar sensor is subsequently utilized to calculate the precision and intersection Over Union (IOU) values. You Only Look Once (YOLO) version 4 is utilized to calculate precision and IOU values from the data captured using the radar sensor. The performance is evaluated under various real-time traffic scenarios in a MATLAB-based simulator. Results show that our proposed method achieves 80.0% precision in position estimation and obtains an IOU value up to 87.14%, thereby outperforming the state-of-the-art.

Identifying the Prevalence of Dysphagia among Patients Diagnosed with Unilateral Vocal Fold Immobility

OBJECTIVE

To identify dysphagia prevalence and characteristics among patients with unilateral vocal fold immobility (UVFI) through a systematic review of current literature.

DATA SOURCES

Embase, PubMed, ScienceDirect, Wiley Online Library.

REVIEW METHODS

Four electronic databases were reviewed according to the PRISMA criteria. Original English-language studies examining dysphagia among adult patients with UVFI met eligibility. Two researchers independently analyzed qualified articles.

RESULTS

Of 227 studies discovered through the literature search, 17 satisfied eligibility criteria. The prevalence of symptomatic dysphagia ranged from 55.6% to 69.0%, and the aspiration rate was 20.0% to 50.0%. Self-reporting and clinical evaluation were used to identify symptomatic dysphagia, while videofluoroscopic swallowing study and functional endoscopic evaluation of swallowing evaluated aspiration. Left-sided UVFI predominated. The most common causes of UVFI were iatrogenic and idiopathic. Central lesions and acute-onset UVFI were each associated with more severe dysphagia. Patients were more likely to aspirate on liquids versus purées and pastes. Benefits of medialization thyroplasty and vocal cord injection were equivocal.

CONCLUSION

A significant portion of patients with UVFI present with dysphagia due to anatomic and physiologic disruptions during the swallow. Study population heterogeneity and small sample sizes in the reviewed studies may have compromised reliability, calling for large-scale studies with rigorous methodology. Future studies should not only strive to identify the mechanics of the disordered swallow but also explore patients' quality of life and the effectiveness of current treatments for dysphagia with underlying UVFI.

Thyroid inhibitory, antiperoxidative and hypoglycemic effects of stigmasterol isolated from Butea monosperma

Stigmasterol, isolated from the bark of Butea monosperma was evaluated for its thyroid hormone and glucose regulatory efficacy in mice. Its administration at 2.6 mg/kg/d for 20 days reduced serum triiodothyronine (T(3)), thyroxin (T(4)) and glucose concentrations as well as the activity of hepatic glucose-6-phophatase (G-6-Pase) with a concomitant increase in insulin indicating its thyroid inhibiting and hypoglycemic properties. A decrease in the hepatic lipid peroxidation (LPO) and an increase in the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) suggested its antioxidative potential. The highest concentration tested (5.2 mg/kg) evoked pro-oxidative activity.