Legibility of Light-Emitting Diode Destination Indicators Mounted on the Front of Public Buses

Light-emitting diode (LED) destination indicators mounted on the front of buses enable pedestrians to quickly identify bus numbers. In this study, the factors affecting their legibility were investigated. We aimed to deduce the process of enhancing the legibility of LED destination indicators. Combinations of different text colors, text fonts and information display locations were investigated in this study. Significant differences were observed at the longest visual range when these combinations were used. The optimal information display was obtained using the New Johnston Medium typeface with yellow font color on a black background. For the glare distance, significant differences were observed when different information display locations were used. Superior results were obtained when information was centered. This study is of practical importance to people who depend on public transport, especially those in an emergency. In the future, these results can be used as a guide for designing LED destination indicators that are mounted on the front of public buses

CITIES: Energetic Efficiency, Sustainability; Infrastructures, Energy and the Environment; Mobility and IoT; Governance and Citizenship

This book collects important contributions on smart cities. This book was created in collaboration with the ICSC-CITIES2020, held in San José (Costa Rica) in 2020. This book collects articles on: energetic efficiency and sustainability; infrastructures, energy and the environment; mobility and IoT; governance and citizenship

Evaluating Drivers’ Understanding of Automotive Symbols Related to Powertrain and Advanced Driver Assistant Systems

The purpose of this research was to evaluate drivers’ understanding of automotive symbols meaning and what action to take in response to a symbol. With the dramatic increase in vehicle technology, the availability of a wide range of powertrain options, and the development of advanced driver assistant systems (ADAS), instrument cluster interfaces have become more complex, increasing the demand on drivers. Understanding the needs and preferences of a diverse group of drivers is essential for the development of digital instrument cluster interfaces that improve driver’s understanding of critical information about the vehicle. This research was divided in three studies. Study I evaluated teen drivers’, between 15 to 17 years of age, understanding of symbols from vehicles featuring advanced driving assistant systems and multiple powertrain configurations. The teenage driver population was selected for this study because in the U.S., the teenage driving population is at the highest risk of being involved in a crash. Teens often demonstrate poor vehicle control skills and poor ability to identify hazards, thus proper understanding of automotive indicators and warnings may be even more critical for this population. In addition, teen drivers are usually not represented in automotive symbol comprehension studies. In this research, teen drivers’ (N=72) understanding of automotive symbols was compared to three other groups with specialized driving experience and technical knowledge: automotive engineering graduate students (N=48), driver rehabilitation specialists (N=16), and performance driving instructors (N=15). Participants matched 42 symbols to their descriptions and then selected the five symbols they considered most important. Teen drivers demonstrated lower performance (Mean=29%) identifying symbols than the other three groups (Mean=60%). For all groups, responses on symbols related to basic vehicle functions and common to all powertrain types had significantly higher scores than symbols related to advanced driving assistant system (ADAS) functions or those that are powertrain specific. Overall, the five symbols selected by the participants as most important were related to powertrain and safety warnings. Study II investigated drivers’ understanding, and preferences related to powertrain and ADAS symbols presented on instrument clusters. Participants answered questions that evaluated nine symbol’s comprehension, familiarity, and helpfulness. Then, participants were presented with information from the owner’s manual for each symbol and responded if the information changed their understanding of the symbol. Lastly, participants rated their need for more information to understand the symbols and shared their preferences about how the automotive interface could help them better understand the symbols. Teen drivers (N=30), normal drivers (N=20), driving rehabilitation specialists (N=20), and automotive engineering students (N=48) participated in this study. When comparing the groups’ performance on the comprehension testing, driving rehabilitation specialists had the best performance. Teen drivers had the poorest performance. Symbols with an implied or arbitrary icon-function relationship demonstrated poorer comprehension for all participant groups. Symbols with a direct icon-function relationship received higher comprehension scores and helpfulness ratings independent of previous exposure. Symbols considered less helpful received higher ratings on the need for additional information, suggesting that drivers need additional information to understand the symbol when the symbol meaning is not clear. Automotive engineering students and normal drivers reported being considerably less satisfied with the information presented on the dashboard of their vehicles. Study III investigated drivers’ understanding of six automotive symbols presented on the instrument cluster or infotainment screen on a driving simulator study. Teens drivers between 15 to 17 years of age (N=24), adult drivers between 30 to 54 years (N=24), and senior drivers between 65 to 80 years of age participated in this study. The results of this driving simulator study suggest that presenting automotive symbols on in-vehicle displays with text description improved driver’s understanding of symbols meaning and what action to take in response to a symbol. Symbol type and previous experience with the symbol were contributing factors on symbol comprehension. Participants reported having higher previous experience with the powertrain symbols than the ADAS symbols and in general demonstrated significantly better understanding of symbols meaning and what action to take in response to powertrain symbols than ADAS symbols. Driving experience was not observed to be a contributing factor to correctly identifying a symbols’ meaning nor what action to take in response to the symbol in this study. Mixed evidence was observed on the negative impact of text descriptions on driving performance. Performance on the driving simulator and cognitive workload measures of mean and maximum index of cognitive activity (ICA) suggest that text descriptions did not negatively impact driving performance. On the other hand, eye glance off the road time, symbol reaction times, and the self-reported cognitive workload measures suggest that text descriptions negatively impact driving performance. Further research is needed to evaluate the impact of text descriptions on driving performance. In the end, participants demonstrated to prefer having more information about the symbols presented at the in-vehicle displays both when driving and while stopped. The inclusion of the teenage driver population under 18 years in future symbol comprehension testing studies and the exploration of alternative methods to communicate vehicle information to the driver should be considered by vehicle manufacturers. The results of this study may help automotive professionals when developing new vehicle interfaces to aid inexperienced and experienced drivers. The results of this study may help when developing new vehicle interfaces, ensuring that indicators and warnings are presented in a way that aid both inexperienced and experienced drivers. Overall, this study demonstrates that the evaluation of symbol’s comprehension and the comparison of alternative methods to communicate information on the in-vehicle displays greatly benefit from testing on a dynamic setting using a driving simulator versus a paper and pen survey. The dynamic setting allowed a comprehensive analysis of the effects of powertrain and ADAS warning symbols on driver’s understanding of the symbol, driving performance, and preference

Vehicle and Traffic Safety

The book is devoted to contemporary issues regarding the safety of motor vehicles and road traffic. It presents the achievements of scientists, specialists, and industry representatives in the following selected areas of road transport safety and automotive engineering: active and passive vehicle safety, vehicle dynamics and stability, testing of vehicles (and their assemblies), including electric cars as well as autonomous vehicles. Selected issues from the area of accident analysis and reconstruction are discussed. The impact on road safety of aspects such as traffic control systems, road infrastructure, and human factors is also considered

Medical devices with embedded electronics: design and development methodology for start-ups

358 p.El sector de la biotecnología demanda innovación constante para hacer frente a los retos del sector sanitario. Hechos como la reciente pandemia COVID-19, el envejecimiento de la población, el aumento de las tasas de dependencia o la necesidad de promover la asistencia sanitaria personalizada tanto en entorno hospitalario como domiciliario, ponen de manifiesto la necesidad de desarrollar dispositivos médicos de monitorización y diagnostico cada vez más sofisticados, fiables y conectados de forma rápida y eficaz. En este escenario, los sistemas embebidos se han convertido en tecnología clave para el diseño de soluciones innovadoras de bajo coste y de forma rápida. Conscientes de la oportunidad que existe en el sector, cada vez son más las denominadas "biotech start-ups" las que se embarcan en el negocio de los dispositivos médicos. Pese a tener grandes ideas y soluciones técnicas, muchas terminan fracasando por desconocimiento del sector sanitario y de los requisitos regulatorios que se deben cumplir. La gran cantidad de requisitos técnicos y regulatorios hace que sea necesario disponer de una metodología procedimental para ejecutar dichos desarrollos. Por ello, esta tesis define y valida una metodología para el diseño y desarrollo de dispositivos médicos embebidos

Shortest Route at Dynamic Location with Node Combination-Dijkstra Algorithm

Abstract— Online transportation has become a basic requirement of the general public in support of all activities to go to work, school or vacation to the sights. Public transportation services compete to provide the best service so that consumers feel comfortable using the services offered, so that all activities are noticed, one of them is the search for the shortest route in picking the buyer or delivering to the destination. Node Combination method can minimize memory usage and this methode is more optimal when compared to A* and Ant Colony in the shortest route search like Dijkstra algorithm, but can’t store the history node that has been passed. Therefore, using node combination algorithm is very good in searching the shortest distance is not the shortest route. This paper is structured to modify the node combination algorithm to solve the problem of finding the shortest route at the dynamic location obtained from the transport fleet by displaying the nodes that have the shortest distance and will be implemented in the geographic information system in the form of map to facilitate the use of the system. Keywords— Shortest Path, Algorithm Dijkstra, Node Combination, Dynamic Location (key words