A hybrid approach for identifying factors affecting driver reaction time using naturalistic driving data

The National Transportation Safety Board (NTSB) estimates that 80% of the deaths and injuries resulting from rear-end collisions could be prevented by the use of advanced collision avoidance systems. While autonomous or higher-level vehicles will be equipped with this technology by default, most of the vehicles on our roadways will lack these advances, so rear-end crashes will dominate accident statistics for many years to come. However, a simple and cost-effective in-vehicle device that uses predictive tools and real-time driver-behavior and roadway data can significantly reduce the likelihood of these crashes. In this paper, we propose a hybrid physics/data-driven approach that can be used in a kinematic-based forward-collision warning system. In particular, we use a hierarchical regularized regression model to estimate driver reaction time based on individual driver characteristics, driving behavior, and surrounding driving conditions. This personalized reaction time is input into the Brill's one-dimensional car-following model to calculate the critical distance for collision warning. We use the Second Strategic Highway Research Program (SHRP-2)'s Naturalistic Driving Study (NDS) data, the largest and most comprehensive study of its kind, to model driver brake-to-stop response time. The results show that the inclusion of driver characteristics increases model precision in predicting driver reaction times.This publication was partially supported by a grant from the U.S. Department of Transportation , Office of the Secretary of Transportation (OST), Office of the Assistant Secretary for Research and Technology under Grant no. DTRT12-G-UTC16 and a grant from Qatar National Research Fund (QNRF) under Grant no. NPRP8-910-2-387 . The findings and conclusions of this study are those of the author and do not necessarily represent the views of the VTTI, SHRP 2, the Transportation Research Board, or the National Academies. Furthermore, the contents of this chapter reflect the views of the author, who is responsible for the facts and the accuracy of the information presented herein. The U.S. Government assumes no liability for the contents or use thereof.Scopu

Distribution of White Spots after Debanding in Orthodontic Patients

Statement of problem: Fixed orthodontic appliances can interfere with removing bacterial plaques from dental surfaces which can ultimately lead to white spot formation.Purpose: The aim of this study was to evaluate the quantity of white spots and areas of decalcification following fixed orthodontic treatment.Materials and Methods: A total of 100 patients undergoing or scheduled for fixed orthodontic treatment were divided into two groups. Group A consisted of fifty volunteers before the initiation of therapy and group B included fifty patients at the end of their treatment. In group A, the buccal surfaces of the first molars in each quadrant were examined for the presence of enamel decalcifications. After removing the orthodontic bands in group B, the buccal surfaces of the first molars in each quadrant were examined for white spots. Gender, oral hygiene level, plaque index, type of cement and duration of treatment were recorded for all patients. Binomial logistic regression, chi-square and Mann-Whitney U-tests were used for statistical analysis.Results: The number of white spots in group A was 28 (14%) which was significantly lower than group B with 83 (41.5%) decalcified lesions (P<0.01). Oral hygiene and duration of treatment had a significant effect on the occurrence of white spots (P<0.05).Conclusion: The results showed that patients with orthodontic bands are at higher risk for white spot formation and good oral hygiene demonstrates a protective effect on their reduction. Both professional and daily oral hygiene measures can decrease thecariogenicity of bacterial plaques in these patients

Gap measurement and bond strength of five selected adhesive systems bonded to tooth structure

The ability of a restorative material to bond and seal the interface with tooth structure is perhaps the most significant factor in determining resistance to marginal caries. Thus, the quality and durability of marginal seal and bond strength are major considerations in the selection of restorative materials. The purpose of this study was to compare the bond strength and marginal discrepancies of five adhesive systems: All-Bond 2, Clearfil Liner Bond, KB 200, ProBond and AELITE Bond. Twenty-five buccal and 25 lingual cavities were prepared in 25 caries-free extracted molar teeth, giving 10 cavities for each of the 5 adhesive systems. All teeth were restored with the resin composite Pertac Hybrid, or PRISMA Total Performance Hybrid with their appropriate adhesive systems. After restoration, the teeth were thermo-cycled, were stained with a 1.5% aqueous solution of a procion dye (reactive orange 14) and sectioned coronally with a saw microtome. Three sections of 200 μm thickness were prepared from each restoration which were then examined microscopically to measure marginal gap widths using a confocal tandem microscope. Shear bond strength measurements were carried out on the dentine bond using a universal testing machine. The All-Bond 2 adhesive system was found to have higher shear bond strength and to have the least gap width at the cementodentinal margin

Electrochemical layered double hydroxide (LDH)-based biosensors for pesticides detection in food and environment samples: A review of status and prospects

The need for food and agricultural resources is constantly rising, resulting in pesticide poisoning and environmental hazards. Diverse technologies collaborate to develop effective biosensors for detecting different pesticides, as it is difficult to achieve an efficient mechanism to detect pesticides. Novel solutions to reduce the cost and time for preparing samples in pesticide detection are being developed using new technologies. Moreover, methods like electrochemical techniques and fluorescence spectroscopy are now being improved to increase the sensitivity and make the operation more convenient. This article reviews the remarkable evolution in the structure of various Layered Double Hydroxides (LDHs), their various synthesis techniques, and their uses in various fields, especially in biological applications to detect pesticides in diverse contaminated samples. LDHs are layered materials with special characteristics favorable for pesticide detection. LDHs, have recently aroused increasing interest in research. We also discuss the latest advances made in the emergent strategies for improving the antimicrobial activity of LDHs. © 2022 Elsevier Lt