IEEE Transactions on Intelligent Transportation Systems, 2019
This paper proposes a new framework for predicting arrival sequences of aircraft based on a prefe... more This paper proposes a new framework for predicting arrival sequences of aircraft based on a preference learning approach that emulates the sequencing strategies of human air traffic controllers by learning from historical data. The proposed algorithm works in two stages: it first learns the probabilistic preferences between each pair of arriving aircraft, and the overall sequence for a new set of aircraft is then determined by combining the pairwise probabilities. The proposed model is validated using historical traffic data at Incheon International Airport, and its performance is evaluated using Spearman's rank correlation and dynamic simulation analysis. A possible application for the proposed method in decision support for arrival sequencing is also suggested.
The aim of this paper is to model the traffic generated in a FTTX network for voice and data tran... more The aim of this paper is to model the traffic generated in a FTTX network for voice and data transmission. Thus, we commence with a traffic model that represents the use that network subscribers make of the system, allowing the generation of requests sent by the subscribers connected to the return channels. The model uses the number of subscribers assigned to each return channel. The traffic in each return channel is obtained from the aggregation of the separated traffic streams originated by the user’s applications executed. Later, a model of the branches from the cable network is developed, considering both the upstream channels and the downstream channel of the controller. The results obtained in these processes can be validated using the real data provided by a FTTX cable operator. For the accomplishment of the model, the OPNET simulation language has been used. In addition, the results have been exported to MATLAB, which permits the execution of all types of statistical analyse...
... al aumento en la oferta de canales como estrategia de la expansión del negocio, lo que implic... more ... al aumento en la oferta de canales como estrategia de la expansión del negocio, lo que implica una demanda de ancho de banda. ... En (Loguinov y Radha, 2001) se realiza el análisis de flujo multimedia para clientes de línea conmutada para vídeos codificados mediante MPEG ...
Efficient driving has been positioned as the most popular alternative to reduce air pollution and... more Efficient driving has been positioned as the most popular alternative to reduce air pollution and obtain fuel savings. However, efficient driving requires a continuous learning process in order to prevent users reverting to their original habits. To facilitate the learning process, on-board tutoring systems have appeared. In this study, the authors analyse in detail the impact of two types of such eco-feedback devices on driver's behaviour. The evaluated tutoring systems include information related to the optimal engaged gear, but also related to other safety and comfort parameters. Their analysis is based on one of the largest and heterogeneous population groups of non-professional drivers who have participated in experiments with feedback devices specifically designed to achieve more efficient driving. A total number of 158 volunteers participated in the experiments covering periods of time between 3 and 11 months and using the feedback devices during their daily routine. Results show that, in general, users evolve positively following the eco-driving recommendations throughout the duration of the experiments. In addition, there are significant differences in the use of the tutoring system depending on the type of route, the time of day and other factors such as age or gender.
En el corto plazo, la industria del robot autonomo y de los drones sera un factor de desarrollo i... more En el corto plazo, la industria del robot autonomo y de los drones sera un factor de desarrollo importante. Tanto la fabricacion de los propios dispositivos, como del desarrollo del software que los hace funcionar seran actividades empresariales de importancia en el sector TIC. No obstante, el futuro de los robots de trabajo autonomo es colaborar unos con otros y con el entorno que los rodea (adaptacion al contexto). Para ello, deben de ser capaces de interactuar con otros equipos mediante protocolos de comunicacion y sistemas de razonamiento. Por ello, en este trabajo se presenta una experiencia encaminada a la obtencion de un sistema de trabajo colaborativo para que un grupo/enjambre de robots autonomos de limpieza puedan trabajar de forma conjunta. La experiencia se basa en un laboratorio abierto que permite a los alumnos proponer y realizar sus propios desarrollos. En el trabajo se presentan tanto los aspectos metodologicos de la experiencia, como los avances que se han consegui...
Video delivery over a mobile ad-hoc network that can be deployed by members of an emergency servi... more Video delivery over a mobile ad-hoc network that can be deployed by members of an emergency service in an incident zone is an appealing tool for emergency and rescue services, but has not be studied yet. In order to design and test a suitable solution, we have generated realistic evaluation scenarios by modeling fireman action plans and GPS traces from real situations. The Emergency Overlay Routing (EOR) protocol is a reactive protocol integrated into a store-carry-forward architecture. It selects ferry nodes to transport video data from a camera in the Incident Area to the Incident Chief’s node, looking for the minimum delay, but reliable, candidate. The evaluation of EOR shows its superiority to the well-known DTN routing protocol, PROPHET, under this conditions.
Proceedings of the XVII International Conference on Human Computer Interaction
In the last years the number of devices that provide information about the car the driving proces... more In the last years the number of devices that provide information about the car the driving process has increased considerably. This also implies an increased level of distraction and, thus, a decrease in safety. In this context, Head-Up Display devices (HUDs) may be considered adequate representation interfaces because they are transparent and they are located in the vision line of the driver. HUDs allow drivers to view what is behind the screen without looking away from the road. However, we must analyse the impact of these devices in order to fully consider them safe in a driving context. In this paper we present an evaluation of HUDs in a real driving context, analysing different kinds of information. Firstly, we assess the display of efficient driving data gathered from a mobile app. Next, we compare HUDs with conventional devices. Finally, we perform several tests using a GPS assistant, due to the current relevance of these services. A total of 20 non-professional drivers have participated in the experiments. They had to drive vehicles equipped with a HUD display. We evaluate the subjective opinion of the users using questionnaires in order to know whether HUDs are acceptable in a vehicle or not. Results show a positive feedback from users and a high sensation of safety.
Diesel engines of the vehicles in the transport sector are responsible for most of the CO 2 emiss... more Diesel engines of the vehicles in the transport sector are responsible for most of the CO 2 emissions into the environment. An alternative to reduce fuel consumption is to promote efficient driving techniques. The aim of this paper is to assess the impact of efficient driving on fuel consumption in professional fleets. Data captured from the engine control unit (ECU) of the vehicles are complemented with external information from weather stations and context data from the transport companies. The paper proposes linear and quadratic models in order to quantify the impact of all the terms influencing energy consumption. The analysis was made from the traces captured from a passenger transport company in Spain with more than 50 bus routes. 20 vehicles of five different models were monitored and 58 drivers participated in the study. The results indicate that efficient driving has significant influence on fuel consumption, which confirms efficient driving as a valid and economical option for reducing consumption and therefore emissions of harmful particles into the atmosphere. According to the proposed model, in average external conditions, a driver that increases efficiency from 25% to 75% can reach savings in fuel consumption of up to 16 L/100 km in the analysed bus fleet, which is a significant improvement considering the long distances covered by professionals of the transport sector.
Ad-hoc networks have long been studied as an ideal technology to provide communications in emerge... more Ad-hoc networks have long been studied as an ideal technology to provide communications in emergency operations when network infrastructures are not available. Nevertheless, this area has not yet delivered enough mature technologies or working prototypes. We suspect that, among other issues, this is due to a lack of understanding of this application domain that forces researchers to make too many assumptions. One of those concerns is the mobility of network nodes. This paper describes, analyzes, and simulates the mobility traces of a fire department during 30 wildfires. The analysis shows interesting insights into the communication range and the type of network in these scenarios. For instance, multi-hop routes are unlikely, so the network behaves like a delay-tolerant network. In addition, the simulation results present a clear image of the network performance under different circumstances that can be used to design applications. We found that the network capacity is low due to the sparse network connectivity. Moreover, the buffer size has a much bigger impact on data delivery than the delay-tolerant routing protocol selected. We think that these are valuable insights and that the traces constitute an important asset for the research community. INDEX TERMS Ad hoc networks, disruption tolerant networking, vehicular ad hoc networks, emergency services, geographic information systems. THOMAS PLAGEMANN received the D.Sc. degree in computer science from the Swiss Federal Institute of Technology (ETH), Zurich, Switzerland, in 1994. He has been a Professor with the University of Oslo, Oslo, Norway, since 1996, where he currently leads the research group in distributed multimedia systems with the Department of Informatics. He has authored over 150 papers in peer reviewed journals, conferences, and workshops in his field. His research interests include protocol architectures and middleware solutions for multimedia communication and mobile systems, future Internet, and multimodal sensor systems and event processing. He is a member of the Association for Computing Machinery (ACM). He received the Medal of ETH Zurich in 1995. He currently serves as Associate Editor for the ACM Transactions on Multimedia Computing, Communication, and Applications, an Area Editor for the Computer Communications (Elsevier), and the Editor-in-Chief for the Multimedia Systems (Springer).
Abstract In recent years, the number of on-board devices that provide information about the vehic... more Abstract In recent years, the number of on-board devices that provide information about the vehicle, the driving process and the environment has increased. Nevertheless, these devices can be very distracting. Head-up display devices (HUDs) and speech recognition may be good technologies to enrich the experience of drivers while keeping safety under control. Thus, the purpose of this study is to carry out an evaluation of these technologies under real conditions. A total of 50 drivers participated in a study divided into two parts. In the first part, we performed an evaluation of the usage of driving assistants with HUD devices under real conditions. We also compared HUDs with conventional head-down display (HDD) screens. Finally, we asked users about their opinion on methods of interaction with HUDs. Considering the results, the second part of the study aimed at evaluating interaction with HUD devices using speech recognition. 65% of the drivers prefer to use HUDs instead of HDDs for safety reasons. Furthermore, the participants prefer to interact with HUDs using voice commands. 86.66% of the users stated that this method of interaction improved their feeling of safety. The main conclusion is that users agree that driving assistants combined with HUDs are useful and safe at the same time. Moreover, the interaction with HUDs through voice commands is accepted by the majority of the users; it improves their sensation of safety because they do not need to look away from the road to use driving assistants.
Evaluating driving from the point of view of efficiency is a complex task. The environment is con... more Evaluating driving from the point of view of efficiency is a complex task. The environment is continuously changing and there is no direct relationship between all the factors that affect fuel consumption. In this paper, we propose a method to evaluate driving that can fit any scenario. It is based on Data Envelopment Analysis (DEA). This technique allows us to measure the efficiency of the drivers and to ascertain which behaviors they should improve. There are many solutions to evaluate driving in the literature. However, these solutions have difficulties adapting to changes in the driving environment and the result of the evaluation could be inaccurate. A driver could be classified as less efficient when in fact the driving could be affected by factors beyond his or her control. In addition, they do not provide the sources of inefficiency. With our method, we can analyze and quantify the cause of inefficiency. This proposal has been used to evaluate drivers of a bus fleet in Spain. The results show that drivers who were rated as efficient achieve lower fuel consumption. They can save up to 9.21% in comparison with the least efficient drivers. It is also observed that anticipation is a skill that saves a large amount of fuel and that it is an aspect that most bus drivers have a lot of room for improvement.
International Journal of Human-Computer Interaction, 2016
ABSTRACT The popularity of Interactive Digital Television (IDTV) applications has grown in recent... more ABSTRACT The popularity of Interactive Digital Television (IDTV) applications has grown in recent years, playing a significant role in today’s society. This new type of television allows users to access interactive applications in order to look for information, for communication or educational purposes, or just for fun. Most of these applications require text entry and many users expect a user experience similar to that of computers. Although the most common device to interact with television is the conventional remote control, other devices available on the market may be used in this context. Thus, in this article we aim to evaluate and compare different text input methods for IDTV applications using devices alternative to conventional remote controls. We have carried out an empirical study with 52 participants. We analyze entry speeds, error rates, and subjective impressions for six different entry methods, taking into account the particular characteristics of the users. As devices we have used a full-sized keyboard, a palm-sized keyboard, a gyroscopic remote point-select, and a modified touchpad. The fastest method is the standard keyboard, but in an IDTV context many users report discomfort and problems under low lighting conditions. Also, error rates are considerably higher with both keyboards when modifier keys need to be used. The results obtained with the gyroscopic remote and the touchpad are similar. Nevertheless, while users complain about fatigue problems with the former, their feedback about the latter is very positive. We have also observed that age is a major factor affecting the performance of the users. We expect our results to contribute to the design of new text entry methods for IDTV.
2015 International Conference on Computer, Information and Telecommunication Systems (CITS), 2015
Concerns about global warming and energy costs have induced transport companies to take measures ... more Concerns about global warming and energy costs have induced transport companies to take measures to reduce fuel consumption. Among the different options available, efficient driving is widely used, allowing a reduction in fuel consumption of around 10%. However, changing the driver's behavior is not exempt of problems. The success of efficient driving techniques in the long term is related to the motivation of the driver and, for that reason, an adaptive training system according to the driver's needs can prove much more successful than giving general instructions that do not solve their inefficiencies. Therefore, a properly description of the driver's behavior and the adaptation of the evaluation analysis to the context is a key factor for the learning process in efficient driving. In this paper we propose an adaptive learning system for efficient driving, which allows the evaluation of professional drivers of urban public transport in their work environment. With the proposed system, we can identify failure points relating to the context, making a focused evaluation. The first evaluation results show that the set of patterns designed to evaluate the application of efficient driving techniques can identify the incorrect actions of the drivers. Based on the results, it is possible to make personalized recommendations to improve driver performance.
Video popularity characterization, in a News-on-demand service, is the core issue of this paper. ... more Video popularity characterization, in a News-on-demand service, is the core issue of this paper. It will concentrate on the digital edition of six Spanish regional newspapers, where the different news articles are classified into a wide variety of issues. Request video data has been analyzed, including how accesses were distributed along the different topics, during a period of nine months, where the number of requests fluctuated between 85,758 and 586,398 over a minimum of 519 videos and a maximum of 4,221. On the one hand, the statistical function from which video popularity would come from is likely to be unknown. The problem has been tackled with some statistical functions, such as Zipf-like, Mandelbrot and Stretched, which are well-known in the literature. Another method called Box-Cox transformation has been looked into for this specific field. On the other hand, a brief overview has been carried out about the popularity growth tendency, that is how many days a video takes to ...
Previous work has demonstrated the feasibility of Bluetooth Low Energy (BLE) as an alternative te... more Previous work has demonstrated the feasibility of Bluetooth Low Energy (BLE) as an alternative technology for data transfers in inter-vehicular communication (IVC) scenarios. Bluetooth 5.x core specifications enhance the trade-off between energy requirements, communication range and flexibility. In this paper, we aim to analyse the potential of Bluetooth 5 features for VANET applications, proposing a connectionless communication system. By means of field experiments, we evaluate long range and 2 × speed features, defining a set of communication scenarios. This allows us to test both Bluetooth 5.x range and application throughput. The evaluation includes experiments of V2I communications carried out under real highway traffic conditions. The experiments conducted demonstrate that communication ranges up to 300 m may be achieved depending on the communications scenario. The results also show how throughput degrades as the distance between devices increases. The results obtained are us...
Public transport companies face great expenses. In order to be profitable companies, they need to... more Public transport companies face great expenses. In order to be profitable companies, they need to reduce costs in all aspects. In addition, many countries have increased taxes to force transport companies to reduce their fuel consumption and, thus, greenhouse effect emissions. Efficient driving is the cheapest way to achieve this goal. In this paper, we analyze the economic impact of one of the most influential efficient driving techniques in an urban bus company. We calculate the difference of consumption between a well-performed deceleration using the inertia of the vehicle and a loss of speed obtained by using the brakes. For this purpose, we compare a real track performed by any driver in a precise vehicle with a simulated ideal track. To obtain the deceleration of the simulation, we develop a linear regression model on over 170,000 samples captured from the same vehicle over a period of one month. The results show that the costs of the vehicle under test in one month may be reduced by more than 2500 € by using this technique. With these results, we can see that it is worth trying to anticipate different situations while driving only by applying inertia adequately.
IEEE Transactions on Intelligent Transportation Systems, 2019
This paper proposes a new framework for predicting arrival sequences of aircraft based on a prefe... more This paper proposes a new framework for predicting arrival sequences of aircraft based on a preference learning approach that emulates the sequencing strategies of human air traffic controllers by learning from historical data. The proposed algorithm works in two stages: it first learns the probabilistic preferences between each pair of arriving aircraft, and the overall sequence for a new set of aircraft is then determined by combining the pairwise probabilities. The proposed model is validated using historical traffic data at Incheon International Airport, and its performance is evaluated using Spearman's rank correlation and dynamic simulation analysis. A possible application for the proposed method in decision support for arrival sequencing is also suggested.
The aim of this paper is to model the traffic generated in a FTTX network for voice and data tran... more The aim of this paper is to model the traffic generated in a FTTX network for voice and data transmission. Thus, we commence with a traffic model that represents the use that network subscribers make of the system, allowing the generation of requests sent by the subscribers connected to the return channels. The model uses the number of subscribers assigned to each return channel. The traffic in each return channel is obtained from the aggregation of the separated traffic streams originated by the user’s applications executed. Later, a model of the branches from the cable network is developed, considering both the upstream channels and the downstream channel of the controller. The results obtained in these processes can be validated using the real data provided by a FTTX cable operator. For the accomplishment of the model, the OPNET simulation language has been used. In addition, the results have been exported to MATLAB, which permits the execution of all types of statistical analyse...
... al aumento en la oferta de canales como estrategia de la expansión del negocio, lo que implic... more ... al aumento en la oferta de canales como estrategia de la expansión del negocio, lo que implica una demanda de ancho de banda. ... En (Loguinov y Radha, 2001) se realiza el análisis de flujo multimedia para clientes de línea conmutada para vídeos codificados mediante MPEG ...
Efficient driving has been positioned as the most popular alternative to reduce air pollution and... more Efficient driving has been positioned as the most popular alternative to reduce air pollution and obtain fuel savings. However, efficient driving requires a continuous learning process in order to prevent users reverting to their original habits. To facilitate the learning process, on-board tutoring systems have appeared. In this study, the authors analyse in detail the impact of two types of such eco-feedback devices on driver's behaviour. The evaluated tutoring systems include information related to the optimal engaged gear, but also related to other safety and comfort parameters. Their analysis is based on one of the largest and heterogeneous population groups of non-professional drivers who have participated in experiments with feedback devices specifically designed to achieve more efficient driving. A total number of 158 volunteers participated in the experiments covering periods of time between 3 and 11 months and using the feedback devices during their daily routine. Results show that, in general, users evolve positively following the eco-driving recommendations throughout the duration of the experiments. In addition, there are significant differences in the use of the tutoring system depending on the type of route, the time of day and other factors such as age or gender.
En el corto plazo, la industria del robot autonomo y de los drones sera un factor de desarrollo i... more En el corto plazo, la industria del robot autonomo y de los drones sera un factor de desarrollo importante. Tanto la fabricacion de los propios dispositivos, como del desarrollo del software que los hace funcionar seran actividades empresariales de importancia en el sector TIC. No obstante, el futuro de los robots de trabajo autonomo es colaborar unos con otros y con el entorno que los rodea (adaptacion al contexto). Para ello, deben de ser capaces de interactuar con otros equipos mediante protocolos de comunicacion y sistemas de razonamiento. Por ello, en este trabajo se presenta una experiencia encaminada a la obtencion de un sistema de trabajo colaborativo para que un grupo/enjambre de robots autonomos de limpieza puedan trabajar de forma conjunta. La experiencia se basa en un laboratorio abierto que permite a los alumnos proponer y realizar sus propios desarrollos. En el trabajo se presentan tanto los aspectos metodologicos de la experiencia, como los avances que se han consegui...
Video delivery over a mobile ad-hoc network that can be deployed by members of an emergency servi... more Video delivery over a mobile ad-hoc network that can be deployed by members of an emergency service in an incident zone is an appealing tool for emergency and rescue services, but has not be studied yet. In order to design and test a suitable solution, we have generated realistic evaluation scenarios by modeling fireman action plans and GPS traces from real situations. The Emergency Overlay Routing (EOR) protocol is a reactive protocol integrated into a store-carry-forward architecture. It selects ferry nodes to transport video data from a camera in the Incident Area to the Incident Chief’s node, looking for the minimum delay, but reliable, candidate. The evaluation of EOR shows its superiority to the well-known DTN routing protocol, PROPHET, under this conditions.
Proceedings of the XVII International Conference on Human Computer Interaction
In the last years the number of devices that provide information about the car the driving proces... more In the last years the number of devices that provide information about the car the driving process has increased considerably. This also implies an increased level of distraction and, thus, a decrease in safety. In this context, Head-Up Display devices (HUDs) may be considered adequate representation interfaces because they are transparent and they are located in the vision line of the driver. HUDs allow drivers to view what is behind the screen without looking away from the road. However, we must analyse the impact of these devices in order to fully consider them safe in a driving context. In this paper we present an evaluation of HUDs in a real driving context, analysing different kinds of information. Firstly, we assess the display of efficient driving data gathered from a mobile app. Next, we compare HUDs with conventional devices. Finally, we perform several tests using a GPS assistant, due to the current relevance of these services. A total of 20 non-professional drivers have participated in the experiments. They had to drive vehicles equipped with a HUD display. We evaluate the subjective opinion of the users using questionnaires in order to know whether HUDs are acceptable in a vehicle or not. Results show a positive feedback from users and a high sensation of safety.
Diesel engines of the vehicles in the transport sector are responsible for most of the CO 2 emiss... more Diesel engines of the vehicles in the transport sector are responsible for most of the CO 2 emissions into the environment. An alternative to reduce fuel consumption is to promote efficient driving techniques. The aim of this paper is to assess the impact of efficient driving on fuel consumption in professional fleets. Data captured from the engine control unit (ECU) of the vehicles are complemented with external information from weather stations and context data from the transport companies. The paper proposes linear and quadratic models in order to quantify the impact of all the terms influencing energy consumption. The analysis was made from the traces captured from a passenger transport company in Spain with more than 50 bus routes. 20 vehicles of five different models were monitored and 58 drivers participated in the study. The results indicate that efficient driving has significant influence on fuel consumption, which confirms efficient driving as a valid and economical option for reducing consumption and therefore emissions of harmful particles into the atmosphere. According to the proposed model, in average external conditions, a driver that increases efficiency from 25% to 75% can reach savings in fuel consumption of up to 16 L/100 km in the analysed bus fleet, which is a significant improvement considering the long distances covered by professionals of the transport sector.
Ad-hoc networks have long been studied as an ideal technology to provide communications in emerge... more Ad-hoc networks have long been studied as an ideal technology to provide communications in emergency operations when network infrastructures are not available. Nevertheless, this area has not yet delivered enough mature technologies or working prototypes. We suspect that, among other issues, this is due to a lack of understanding of this application domain that forces researchers to make too many assumptions. One of those concerns is the mobility of network nodes. This paper describes, analyzes, and simulates the mobility traces of a fire department during 30 wildfires. The analysis shows interesting insights into the communication range and the type of network in these scenarios. For instance, multi-hop routes are unlikely, so the network behaves like a delay-tolerant network. In addition, the simulation results present a clear image of the network performance under different circumstances that can be used to design applications. We found that the network capacity is low due to the sparse network connectivity. Moreover, the buffer size has a much bigger impact on data delivery than the delay-tolerant routing protocol selected. We think that these are valuable insights and that the traces constitute an important asset for the research community. INDEX TERMS Ad hoc networks, disruption tolerant networking, vehicular ad hoc networks, emergency services, geographic information systems. THOMAS PLAGEMANN received the D.Sc. degree in computer science from the Swiss Federal Institute of Technology (ETH), Zurich, Switzerland, in 1994. He has been a Professor with the University of Oslo, Oslo, Norway, since 1996, where he currently leads the research group in distributed multimedia systems with the Department of Informatics. He has authored over 150 papers in peer reviewed journals, conferences, and workshops in his field. His research interests include protocol architectures and middleware solutions for multimedia communication and mobile systems, future Internet, and multimodal sensor systems and event processing. He is a member of the Association for Computing Machinery (ACM). He received the Medal of ETH Zurich in 1995. He currently serves as Associate Editor for the ACM Transactions on Multimedia Computing, Communication, and Applications, an Area Editor for the Computer Communications (Elsevier), and the Editor-in-Chief for the Multimedia Systems (Springer).
Abstract In recent years, the number of on-board devices that provide information about the vehic... more Abstract In recent years, the number of on-board devices that provide information about the vehicle, the driving process and the environment has increased. Nevertheless, these devices can be very distracting. Head-up display devices (HUDs) and speech recognition may be good technologies to enrich the experience of drivers while keeping safety under control. Thus, the purpose of this study is to carry out an evaluation of these technologies under real conditions. A total of 50 drivers participated in a study divided into two parts. In the first part, we performed an evaluation of the usage of driving assistants with HUD devices under real conditions. We also compared HUDs with conventional head-down display (HDD) screens. Finally, we asked users about their opinion on methods of interaction with HUDs. Considering the results, the second part of the study aimed at evaluating interaction with HUD devices using speech recognition. 65% of the drivers prefer to use HUDs instead of HDDs for safety reasons. Furthermore, the participants prefer to interact with HUDs using voice commands. 86.66% of the users stated that this method of interaction improved their feeling of safety. The main conclusion is that users agree that driving assistants combined with HUDs are useful and safe at the same time. Moreover, the interaction with HUDs through voice commands is accepted by the majority of the users; it improves their sensation of safety because they do not need to look away from the road to use driving assistants.
Evaluating driving from the point of view of efficiency is a complex task. The environment is con... more Evaluating driving from the point of view of efficiency is a complex task. The environment is continuously changing and there is no direct relationship between all the factors that affect fuel consumption. In this paper, we propose a method to evaluate driving that can fit any scenario. It is based on Data Envelopment Analysis (DEA). This technique allows us to measure the efficiency of the drivers and to ascertain which behaviors they should improve. There are many solutions to evaluate driving in the literature. However, these solutions have difficulties adapting to changes in the driving environment and the result of the evaluation could be inaccurate. A driver could be classified as less efficient when in fact the driving could be affected by factors beyond his or her control. In addition, they do not provide the sources of inefficiency. With our method, we can analyze and quantify the cause of inefficiency. This proposal has been used to evaluate drivers of a bus fleet in Spain. The results show that drivers who were rated as efficient achieve lower fuel consumption. They can save up to 9.21% in comparison with the least efficient drivers. It is also observed that anticipation is a skill that saves a large amount of fuel and that it is an aspect that most bus drivers have a lot of room for improvement.
International Journal of Human-Computer Interaction, 2016
ABSTRACT The popularity of Interactive Digital Television (IDTV) applications has grown in recent... more ABSTRACT The popularity of Interactive Digital Television (IDTV) applications has grown in recent years, playing a significant role in today’s society. This new type of television allows users to access interactive applications in order to look for information, for communication or educational purposes, or just for fun. Most of these applications require text entry and many users expect a user experience similar to that of computers. Although the most common device to interact with television is the conventional remote control, other devices available on the market may be used in this context. Thus, in this article we aim to evaluate and compare different text input methods for IDTV applications using devices alternative to conventional remote controls. We have carried out an empirical study with 52 participants. We analyze entry speeds, error rates, and subjective impressions for six different entry methods, taking into account the particular characteristics of the users. As devices we have used a full-sized keyboard, a palm-sized keyboard, a gyroscopic remote point-select, and a modified touchpad. The fastest method is the standard keyboard, but in an IDTV context many users report discomfort and problems under low lighting conditions. Also, error rates are considerably higher with both keyboards when modifier keys need to be used. The results obtained with the gyroscopic remote and the touchpad are similar. Nevertheless, while users complain about fatigue problems with the former, their feedback about the latter is very positive. We have also observed that age is a major factor affecting the performance of the users. We expect our results to contribute to the design of new text entry methods for IDTV.
2015 International Conference on Computer, Information and Telecommunication Systems (CITS), 2015
Concerns about global warming and energy costs have induced transport companies to take measures ... more Concerns about global warming and energy costs have induced transport companies to take measures to reduce fuel consumption. Among the different options available, efficient driving is widely used, allowing a reduction in fuel consumption of around 10%. However, changing the driver's behavior is not exempt of problems. The success of efficient driving techniques in the long term is related to the motivation of the driver and, for that reason, an adaptive training system according to the driver's needs can prove much more successful than giving general instructions that do not solve their inefficiencies. Therefore, a properly description of the driver's behavior and the adaptation of the evaluation analysis to the context is a key factor for the learning process in efficient driving. In this paper we propose an adaptive learning system for efficient driving, which allows the evaluation of professional drivers of urban public transport in their work environment. With the proposed system, we can identify failure points relating to the context, making a focused evaluation. The first evaluation results show that the set of patterns designed to evaluate the application of efficient driving techniques can identify the incorrect actions of the drivers. Based on the results, it is possible to make personalized recommendations to improve driver performance.
Video popularity characterization, in a News-on-demand service, is the core issue of this paper. ... more Video popularity characterization, in a News-on-demand service, is the core issue of this paper. It will concentrate on the digital edition of six Spanish regional newspapers, where the different news articles are classified into a wide variety of issues. Request video data has been analyzed, including how accesses were distributed along the different topics, during a period of nine months, where the number of requests fluctuated between 85,758 and 586,398 over a minimum of 519 videos and a maximum of 4,221. On the one hand, the statistical function from which video popularity would come from is likely to be unknown. The problem has been tackled with some statistical functions, such as Zipf-like, Mandelbrot and Stretched, which are well-known in the literature. Another method called Box-Cox transformation has been looked into for this specific field. On the other hand, a brief overview has been carried out about the popularity growth tendency, that is how many days a video takes to ...
Previous work has demonstrated the feasibility of Bluetooth Low Energy (BLE) as an alternative te... more Previous work has demonstrated the feasibility of Bluetooth Low Energy (BLE) as an alternative technology for data transfers in inter-vehicular communication (IVC) scenarios. Bluetooth 5.x core specifications enhance the trade-off between energy requirements, communication range and flexibility. In this paper, we aim to analyse the potential of Bluetooth 5 features for VANET applications, proposing a connectionless communication system. By means of field experiments, we evaluate long range and 2 × speed features, defining a set of communication scenarios. This allows us to test both Bluetooth 5.x range and application throughput. The evaluation includes experiments of V2I communications carried out under real highway traffic conditions. The experiments conducted demonstrate that communication ranges up to 300 m may be achieved depending on the communications scenario. The results also show how throughput degrades as the distance between devices increases. The results obtained are us...
Public transport companies face great expenses. In order to be profitable companies, they need to... more Public transport companies face great expenses. In order to be profitable companies, they need to reduce costs in all aspects. In addition, many countries have increased taxes to force transport companies to reduce their fuel consumption and, thus, greenhouse effect emissions. Efficient driving is the cheapest way to achieve this goal. In this paper, we analyze the economic impact of one of the most influential efficient driving techniques in an urban bus company. We calculate the difference of consumption between a well-performed deceleration using the inertia of the vehicle and a loss of speed obtained by using the brakes. For this purpose, we compare a real track performed by any driver in a precise vehicle with a simulated ideal track. To obtain the deceleration of the simulation, we develop a linear regression model on over 170,000 samples captured from the same vehicle over a period of one month. The results show that the costs of the vehicle under test in one month may be reduced by more than 2500 € by using this technique. With these results, we can see that it is worth trying to anticipate different situations while driving only by applying inertia adequately.
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Papers by David Melendi