Driving Simulator Study for Evaluating the Effectiveness of Virtual Warnings to Improve the Safety of Interaction Between Cyclists and Vehicles

Globally, cyclists account for 3% of all road traffic deaths, with the highest percentage occurring in Europe (8%) where the bicycle is considered a true alternative mode of transport. Among the causes of crashes are vehicles overtaking cyclists, especially on rural roads. In this study, a new application of augmented reality (AR) warnings for connected vehicles is tested by means of a driving simulator. The overall objective of the study consists in assessing the effectiveness of three proposed AR systems in improving the safety of interactions between vehicles and cyclists, especially during overtaking maneuvers. The AR systems were tested on a sample of 46 drivers and provided them with additional virtual visual information aimed at improving the driver’s risk perception and assessment of safe distance from a cyclist. The virtual warning configurations were: (i) a yellow safety zone around the cyclist; (ii) a color-changing safety zone that changes from red to green when the driver has safe lateral space to overtake the cyclist; (iii) the same color-changing security zone but with an additional acoustic warning. The AR warnings were found to be quite effective as they helped drivers overtake cyclists more safely. With AR warnings (especially with the additional audio), it was found that drivers adopted longer distances from cyclists and entered the oncoming lane less frequently, thus lowering the risk of collision with cyclists as well as the risk of head-on collision with oncoming vehicles.

Internal hernia of the stomach through the lateral space of the colostomy: a case report

An 81-year-old woman had undergone laparoscopic abdominoperineal resection for rectal cancer. A permanent colostomy was created through an intraperitoneal route. Three months after the surgery, the patient presented with lower abdominal pain and vomiting. Computed tomography showed gastric incarceration through the lateral space of the lifted sigmoid colostomy. Although the herniated stomach was reduced by nasogastric tube decompression, the patient experienced a recurrence of gastric hernia shortly thereafter. A laparoscopic operation was performed, and a new colostomy was constructed through an extraperitoneal route. The patient had no hernia recurrence during the 20 months of follow-up after the operation. Gastric internal hernia associated with colostomy can occur as a rare complication. Although reduction of the incarcerated stomach is possible by nasogastric tube decompression, surgical repair of the hernia may be the optimal management to prevent recurrence.

Evaluation of condyle-fossa relationships in adolescents with various skeletal patterns using cone-beam computed tomography

ABSTRACT Objectives: To evaluate the condyle-fossa relationship in adolescents with various skeletal patterns using cone-beam computed tomography (CBCT). Materials and Methods: CBCT images obtained in 120 adolescent patients were used for this study. The patients were divided into 3 groups according to 3 criteria: (1) age (early, middle, and late adolescence); (2) facial height ratio or Jarabak quotient (hyperdivergent, normodivergent, and hypodivergent); and (3) ANB classification (Class I, Class II, and Class III). Temporomandibular joint space (TMJS: AS, anterior space; SS, superior space; PS, posterior space; MS, medial space; LS, lateral space), width and depth of the condyle (MLT, mediolateral thickness; APT, anteroposterior thickness), articular slope (ArS) and vertical height of the fossa (VHF) were measured and compared using CBCT. Results: Differences in condyle-fossa relationships were not significantly different between male and female adolescents, but were significantly different (P < .05) between left and right sides. The mean values showed no statistical differences according to age and skeletal pattern. Most measurements in the sagittal view showed that SS was the greatest, and the mean ratio of AS to SS to PS was 1.00 to 1.27 to 1.19, respectively. The mean values of coronal MS and LS were not significantly different. Conclusions: There were almost no statistical differences in the TMJS in adolescents across various factors except between left and right sides.

The Optimality of the Handbrake Cornering Technique

The paper investigates the optimality of the handbrake cornering, a strategy widespread among rally drivers. Nonlinear optimal control techniques are used to mimic real driver behavior. A proper yet simple cost function is devised to induce the virtual optimal driver to control the car at its physical limits while using the handbrake technique. The optimal solution is validated against experimental data by a professional rally driver performing the handbrake technique on a loose off-road surface. The effects of road surface, inertial properties, center of mass position, and friction coefficient are analyzed to highlight that the optimality of the maneuver does not depend on the particular vehicle data set used. It turns out that the handbrake maneuvering corresponds to the minimum time and minimum (lateral) space strategy on a tight hairpin corner. The results contribute to the understanding of one of the so-called aggressive driving techniques.

Experimental Study on Seakeeping Performance of a Catamaran with Asymmetric Demi-Hulls

To capture the seakeeping performance of a catamaran with asymmetric demi-hulls, tank tests were carried out in regular head waves using a scaled model with 2.036 m in length. The lateral space between the demi-hulls was changed in the tests as W/B=2.55, 2.90 and 3.25, where W denotes breadth overall and B the breadth of the demi-hull. Also, two models with different water lines of inside flat and outside round (IF-type) and of outside flat and inside round (OF-type) were used. OF-type is superior to IF-type in both ship motion and added resistance performances in waves at the design speed. In IF-type series, the smallest clearance, W/B=2.55 is the best in the added resistance performance.