Abstract

Hand grip strength is often considered may predict cognitive functioning and has been established as associates of cognitive performance with individual differences in some particular cross-sectional studies. However, little is known about hand grip strength and cognitive performance in the elderly individuals, and it is not known whether changes in hand grip strength may be associated with preservation/decline in cognitive functioning. We have studied the impact of hand grip strength on cognition function in healthy kitchen workers. Participants (n = 90, age range: 25–40 years) randomly assigned in to two groups according to their nature of work: Group I-Control group (n = 47) - workers recruited for simple work such as dusting, cleaning dining tables and floor. Group II-Study group (n = 43) - workers recruited for firm work such as cooking large quantity of food, kneading dough, rolling chapattis, cut and sauté the vegetables and dish washing. For the analyses, we used at dominant and non- dominant hand, hand grip strength (HGS), reaction time task, sensory disability test (SDT) and cognitive function test (CFT) among both the groups. We observed that visual reaction time (VRT) and auditory reaction time (ART) were significantly improved in dominant hand of study group, when compare to control group, however it was comparable in non-dominant hand among both the groups. In addition to, among all control and study group female workers there was significant positive correlation between VRT & ART and significant negative correlation between at dominant hand HGS & VRT as well as between at dominant hand HGS & ART. We also observed that dominant hand HGS was a significant predictor of VRT and ART and however there was no any significant variation in body mass index (BMI), sensory disability test (SDT) and cognitive function test (CFT) among both groups. We found that muscle strength (as measured by hand grip strength) was associated with improved reaction time. Hence by using a simple muscle strength test, is one way of obtaining useful information for the development of nerve-muscle coordination. Increased handgrip strength would be associated with preservation of cognitive function.

Abstract

Traffic flow will harmonize to forward conditions. The time and distance required for harmonization can have a significant effect on the traffic density behavior. The flow can evolve into clusters of vehicles or become uniform depending on parameters such as safe time headway and safe distance headway. In this paper, a new model is presented to provide a realistic characterization of traffic behavior during the harmonization period. Results are presented for a discontinuous density distribution on a circular road which shows that this model produces more realistic traffic behavior than other models in the literature. Document type: Article

Abstract

Purpose Advanced Driver Assistance Systems (ADAS) have been among the key innovations in the automotive market for over a decade, since they promote traffic safety. This tendency is strengthened even more lately, with the introduction of the autonomous vehicles. A plethora of ADAS exist in the market today, using common warning thresholds for all drivers. However, since we are not all driving the same way, by offering common systems for all the drivers, neither the acceptance nor the effectiveness levels of ADAS are optimal. This manuscript attempts to optimize the Collision Avoidance System (CAS) warning, through intelligent personalized algorithms. Methods Starting with the identification of the dynamic parameters for driving behaviour modeling on the longitudinal road axis, the personalization parameters for ADAS are derived that form the basis for the algorithms developed. Also, based on literature studies, the safety boundaries for warning provision by the CAS are set and implemented in the algorithms. Results Specific personalized algorithms for the longitudinal road axis behaviour are developed, based on Time to Collision and Time Headway. The proposed algorithms based on Time Headway were assessed on-road with 10 drivers and were positively evaluated by the majority of the participants, with a varying degree of reliability and usability. Conclusions Based on the results obtained, it can be concluded that with the proposed algorithms, the initial hypothesis of the paper is verified, i.e. personalised warnings would get a greater acceptance by the drivers, of course without braking the safety limits. Further improvements of the algorithm could be achieved, possibly through a better determination of the car following event, since its definition includes a few assumptions. Document type: Article

Abstract

In this study, we investigated if the driver's ability to take over vehicle control when being engaged in a secondary task (Surrogate Reference Task) can be predicted by a subject's multitasking ability and reaction time. 23 participants performed a multitasking test and a simple response task and then drove for about 38 min highly automated on a highway and encountered five take-over situations. Data analysis revealed significant correlations between the multitasking performance and take-over time as well as gaze distributions for Situations 1 and 2, even when reaction time was controlled. This correlation diminished beginning with Situation 3, but a stable difference between the worst multitaskers and the best multitaskers persisted. Reaction time was not a significant predictor in any situation. The results can be seen as evidence for stable individual differences in dual task situations regarding automated driving, but they also highlight effects associated with the experience of a take-over situation. En este estudio se investigó la capacidad del conductor para tomar el control del vehículo, en una tarea secundaria puede predecirse por la habilidad multitarea del sujeto y la reacción inmediata. Participaron 23 personas ejecutando una prueba de tareas múltiples y una de simple respuesta , conduciendo durante 38 min de forma altamente automatizada, encontrándose cinco situaciones de toma de posesión. Los datos revelaron una correlación significativa entre el rendimiento multitarea y la toma del tiempo, así como la distribución de la situación 1 y 2, aunque el tiempo de reacción se controló. Esta relación disminuye comenzando con la situación 3, persistiendo una diferencia estable en la toma en el tiempo entre los peores y los mejores. El tiempo de reacción no fue un predictor significativo. Los resultados pueden ser vistos como evidencia de las diferencias individuales estables en situaciones de doble tarea respecto a la conducción automática. Document type: Article