E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Select papers from UCAmI 2011 - the 5th International Symposium on Ubiquitous Computing and Ambient Intelligence (UCAmI'11)"

Quicklinks

A special issue of Sensors (ISSN 1424-8220).

Deadline for manuscript submissions: closed (30 March 2012)

Special Issue Editors

Guest Editor
Dr. Francisco Moya

School of Computer Science, University of Castilla-La Mancha, Paseo de la Universidad 4, 13071 Ciudad Real, Spain
E-Mail
Phone: +34 646396848
Interests: large scale heterogeneous distributed systems; sensor networks; common sense reasoning; networks-on-chip; electronic design automation
Guest Editor
Dr. José Bravo

MAml Research Lab, Castilla La-Mancha University, 13071 Ciudad Real, Spain
Website | E-Mail
Phone: +34926295300 Ext 3713
Interests: ubiquitous computing; context aware; RFID; natural interaction; visualization; information mosaics

Special Issue Information

Dear Colleagues,

The 5th International Symposium on Ubiquitous Computing and Ambient Intelligence (UCAmI'11) will be held on 6-9 December 2011, in Riviera Maya (Mexico).

Both academia and industry are invited to submit papers about any of the following topics of interest:

  • Integrating lightweight and/or mobile devices in AmI  environments (telephones, RFID, consumer electronics, sensors, smart devices, etc.)
  • Mobile Ad Hoc Networks support for AmI environments for wireless sensor networks (WSNs), MANETs, VANETs, etc., (architectures, protocols, etc.)
  • Sensing location and context awareness (context modelling, adaptation, sentient computing, etc.)
  • Human-Centric Interfaces for AmI environments
  • Middleware support for AmI and ubiquitous computing environments (WSNs, MANET, VANETs, RFID, etc.)
  • Artificial intelligence approaches (agents, affective computing, ontologies, semantic reasoning, etc.)
  • Applications for AmI environments (e-learning, e-health, Home Automation,   e-payment, ticketing, etc.)
  • Specific services for AmI  (service discovery, security, data delivery,   coordination, etc.)
  • Communication and radio technologies (NFC, Bluetooth, etc.)
  • Quality attributes in AmI applications (real-time, quality of service, fault-tolerance, etc.).
  • Software technologies for AmI (frameworks, components, aspect-orientation, service-orientation, software product line, etc.)

Dr. José Bravo
Dr. Francisco Moya
Guest Editors

Published Papers (44 papers)

View options order results:
result details:
Displaying articles 1-44
Export citation of selected articles as:

Research

Open AccessArticle A Bandwidth-Efficient Service for Local Information Dissemination in Sparse to Dense Roadways
Sensors 2013, 13(7), 8612-8639; doi:10.3390/s130708612
Received: 29 April 2013 / Revised: 19 June 2013 / Accepted: 27 June 2013 / Published: 5 July 2013
Cited by 6 | PDF Full-text (554 KB) | HTML Full-text | XML Full-text
Abstract
Thanks to the research on Vehicular Ad Hoc Networks (VANETs), we will be able to deploy applications on roadways that will contribute to energy efficiency through a better planning of long trips. With this goal in mind, we have designed a gas/charging station
[...] Read more.
Thanks to the research on Vehicular Ad Hoc Networks (VANETs), we will be able to deploy applications on roadways that will contribute to energy efficiency through a better planning of long trips. With this goal in mind, we have designed a gas/charging station advertising system, which takes advantage of the broadcast nature of the network. We have found that reducing the number of total sent packets is important, as it allows for a better use of the available bandwidth. We have designed improvements for a distance-based flooding scheme, so that it can support the advertising application with good results in sparse to dense roadway scenarios. Full article
Open AccessArticle Context-Aware Mobile Collaborative Systems: Conceptual Modeling and Case Study
Sensors 2012, 12(10), 13491-13507; doi:10.3390/s121013491
Received: 1 September 2012 / Revised: 25 September 2012 / Accepted: 30 September 2012 / Published: 9 October 2012
Cited by 5 | PDF Full-text (1235 KB) | HTML Full-text | XML Full-text
Abstract
A Mobile Collaborative System (MCOS) enable the cooperation of the members of a team to achieve a common goal by using a combination of mobile and fixed technologies. MCOS can be enhanced if the context of the group of users is considered in
[...] Read more.
A Mobile Collaborative System (MCOS) enable the cooperation of the members of a team to achieve a common goal by using a combination of mobile and fixed technologies. MCOS can be enhanced if the context of the group of users is considered in the execution of activities. This paper proposes a novel model for Context-Aware Mobile COllaborative Systems (CAMCOS) and a functional architecture based on that model. In order to validate both the model and the architecture, a prototype system in the tourism domain was implemented and evaluated. Full article
Open AccessArticle Towards a Ubiquitous User Model for Profile Sharing and Reuse
Sensors 2012, 12(10), 13249-13283; doi:10.3390/s121013249
Received: 19 August 2012 / Revised: 23 September 2012 / Accepted: 24 September 2012 / Published: 28 September 2012
Cited by 5 | PDF Full-text (890 KB) | HTML Full-text | XML Full-text
Abstract
People interact with systems and applications through several devices and are willing to share information about preferences, interests and characteristics. Social networking profiles, data from advanced sensors attached to personal gadgets, and semantic web technologies such as FOAF and microformats are valuable sources
[...] Read more.
People interact with systems and applications through several devices and are willing to share information about preferences, interests and characteristics. Social networking profiles, data from advanced sensors attached to personal gadgets, and semantic web technologies such as FOAF and microformats are valuable sources of personal information that could provide a fair understanding of the user, but profile information is scattered over different user models. Some researchers in the ubiquitous user modeling community envision the need to share user model’s information from heterogeneous sources. In this paper, we address the syntactic and semantic heterogeneity of user models in order to enable user modeling interoperability. We present a dynamic user profile structure based in Simple Knowledge Organization for the Web (SKOS) to provide knowledge representation for ubiquitous user model. We propose a two-tier matching strategy for concept schemas alignment to enable user modeling interoperability. Our proposal is proved in the application scenario of sharing and reusing data in order to deal with overweight and obesity. Full article
Open AccessArticle Enhancing Health Care Delivery through Ambient Intelligence Applications
Sensors 2012, 12(9), 11435-11450; doi:10.3390/s120911435
Received: 29 May 2012 / Revised: 12 July 2012 / Accepted: 15 August 2012 / Published: 24 August 2012
Cited by 9 | PDF Full-text (712 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents the implementation of a smart environment that employs Ambient Intelligence technologies in order to augment a typical hospital room with smart features that assist both patients and medical staff. In this environment various wireless and wired sensor technologies have been
[...] Read more.
This paper presents the implementation of a smart environment that employs Ambient Intelligence technologies in order to augment a typical hospital room with smart features that assist both patients and medical staff. In this environment various wireless and wired sensor technologies have been integrated, allowing the patient to control the environment and interact with the hospital facilities, while a clinically oriented interface allows for vital sign monitoring. The developed applications are presented both from a patient’s and a doctor’s perspective, offering different services depending on the user’s role. The results of the evaluation process illustrate the need for such a service, leading to important conclusions about the usefulness and crucial role of AmI in health care. Full article
Open AccessArticle Provision of Ubiquitous Tourist Information in Public Transport Networks
Sensors 2012, 12(9), 11451-11476; doi:10.3390/s120911451
Received: 29 May 2012 / Revised: 29 June 2012 / Accepted: 15 August 2012 / Published: 24 August 2012
Cited by 3 | PDF Full-text (606 KB) | HTML Full-text | XML Full-text
Abstract
This paper outlines an information system for tourists using collective public transport based on mobile devices with limited computation and wireless connection capacities. In this system, the mobile device collaborates with the vehicle infrastructure in order to provide the user with multimedia (visual
[...] Read more.
This paper outlines an information system for tourists using collective public transport based on mobile devices with limited computation and wireless connection capacities. In this system, the mobile device collaborates with the vehicle infrastructure in order to provide the user with multimedia (visual and audio) information about his/her trip. The information delivered, adapted to the user preferences, is synchronized with the passage of vehicles through points of interest along the route, for example: bus stops, tourist sights, public service centres, etc. Full article
Figures

Open AccessArticle CANoE: A Context-Aware Notification Model to Support the Care of Older Adults in a Nursing Home
Sensors 2012, 12(9), 11477-11504; doi:10.3390/s120911477
Received: 31 May 2012 / Revised: 17 June 2012 / Accepted: 16 August 2012 / Published: 24 August 2012
Cited by 5 | PDF Full-text (947 KB) | HTML Full-text | XML Full-text
Abstract
Taking care of elders in a nursing home is not an easy task. Caregivers face two major problems: a lack of awareness of the situations surrounding the elderly care and the lack of information regarding the availability and the activities of other caregivers
[...] Read more.
Taking care of elders in a nursing home is not an easy task. Caregivers face two major problems: a lack of awareness of the situations surrounding the elderly care and the lack of information regarding the availability and the activities of other caregivers to support their coordination process. Various efforts have proposed solutions to cope with these problems, but they do it without considering all the requirements imposed by the criticality of this type of environment. In this paper we propose CANoE, a model for the design of context-aware notifications in critical environments, such as a nursing home. The main feature of this model is that it considers three sources of context (the environment, and the issuer and the receiver of the notification) for adapting the content, the terms of delivery and the presentation of the notification message. Based on the CANoE model we developed the CANoE-Aw and CU-IDA systems, which were evaluated through two case studies in a nursing home. The results of these evaluations provide evidence that caregivers achieved an increased awareness of the situations of care of the elderly and perceived the systems as adequate tools to support their coordination while attending a situation of care. Full article
Open AccessArticle Detecting Unknown Attacks in Wireless Sensor Networks That Contain Mobile Nodes
Sensors 2012, 12(8), 10834-10850; doi:10.3390/s120810834
Received: 10 June 2012 / Revised: 28 July 2012 / Accepted: 31 July 2012 / Published: 7 August 2012
Cited by 1 | PDF Full-text (886 KB) | HTML Full-text | XML Full-text
Abstract
As wireless sensor networks are usually deployed in unattended areas, security policies cannot be updated in a timely fashion upon identification of new attacks. This gives enough time for attackers to cause significant damage. Thus, it is of great importance to provide protection
[...] Read more.
As wireless sensor networks are usually deployed in unattended areas, security policies cannot be updated in a timely fashion upon identification of new attacks. This gives enough time for attackers to cause significant damage. Thus, it is of great importance to provide protection from unknown attacks. However, existing solutions are mostly concentrated on known attacks. On the other hand, mobility can make the sensor network more resilient to failures, reactive to events, and able to support disparate missions with a common set of sensors, yet the problem of security becomes more complicated. In order to address the issue of security in networks with mobile nodes, we propose a machine learning solution for anomaly detection along with the feature extraction process that tries to detect temporal and spatial inconsistencies in the sequences of sensed values and the routing paths used to forward these values to the base station. We also propose a special way to treat mobile nodes, which is the main novelty of this work. The data produced in the presence of an attacker are treated as outliers, and detected using clustering techniques. These techniques are further coupled with a reputation system, in this way isolating compromised nodes in timely fashion. The proposal exhibits good performances at detecting and confining previously unseen attacks, including the cases when mobile nodes are compromised. Full article
Open AccessArticle Ubiquitous Green Computing Techniques for High Demand Applications in Smart Environments
Sensors 2012, 12(8), 10659-10677; doi:10.3390/s120810659
Received: 19 March 2012 / Revised: 23 July 2012 / Accepted: 27 July 2012 / Published: 3 August 2012
Cited by 3 | PDF Full-text (587 KB) | HTML Full-text | XML Full-text
Abstract
Ubiquitous sensor network deployments, such as the ones found in Smart cities and Ambient intelligence applications, require constantly increasing high computational demands in order to process data and offer services to users. The nature of these applications imply the usage of data centers.
[...] Read more.
Ubiquitous sensor network deployments, such as the ones found in Smart cities and Ambient intelligence applications, require constantly increasing high computational demands in order to process data and offer services to users. The nature of these applications imply the usage of data centers. Research has paid much attention to the energy consumption of the sensor nodes in WSNs infrastructures. However, supercomputing facilities are the ones presenting a higher economic and environmental impact due to their very high power consumption. The latter problem, however, has been disregarded in the field of smart environment services. This paper proposes an energy-minimization workload assignment technique, based on heterogeneity and application-awareness, that redistributes low-demand computational tasks from high-performance facilities to idle nodes with low and medium resources in the WSN infrastructure. These non-optimal allocation policies reduce the energy consumed by the whole infrastructure and the total execution time. Full article
Open AccessArticle FunBlocks. A Modular Framework for AmI System Development
Sensors 2012, 12(8), 10259-10291; doi:10.3390/s120810259
Received: 6 June 2012 / Revised: 12 July 2012 / Accepted: 27 July 2012 / Published: 30 July 2012
Cited by 2 | PDF Full-text (377 KB) | HTML Full-text | XML Full-text
Abstract
The last decade has seen explosive growth in the technologies required to implement Ambient Intelligence (AmI) systems. Technologies such as facial and speech recognition, home networks, household cleaning robots, to name a few, have become commonplace. However, due to the multidisciplinary nature of
[...] Read more.
The last decade has seen explosive growth in the technologies required to implement Ambient Intelligence (AmI) systems. Technologies such as facial and speech recognition, home networks, household cleaning robots, to name a few, have become commonplace. However, due to the multidisciplinary nature of AmI systems and the distinct requirements of different user groups, integrating these developments into full-scale systems is not an easy task. In this paper we propose FunBlocks, a minimalist modular framework for the development of AmI systems based on the function module abstraction used in the IEC 61499 standard for distributed control systems. FunBlocks provides a framework for the development of AmI systems through the integration of modules loosely joined by means of an event-driven middleware and a module and sensor/actuator catalog. The modular design of the FunBlocks framework allows the development of AmI systems which can be customized to a wide variety of usage scenarios. Full article
Figures

Open AccessArticle Harnessing the Interaction Continuum for Subtle Assisted Living
Sensors 2012, 12(7), 9829-9846; doi:10.3390/s120709829
Received: 19 March 2012 / Revised: 3 July 2012 / Accepted: 11 July 2012 / Published: 23 July 2012
Cited by 6 | PDF Full-text (5124 KB) | HTML Full-text | XML Full-text
Abstract
People interact with each other in many levels of attention, intention and meaning. This Interaction Continuum is used daily to deal with different contexts, adapting the interaction to communication needs and available resources. Nevertheless, computer-supported interaction has mainly focused on the most direct,
[...] Read more.
People interact with each other in many levels of attention, intention and meaning. This Interaction Continuum is used daily to deal with different contexts, adapting the interaction to communication needs and available resources. Nevertheless, computer-supported interaction has mainly focused on the most direct, explicit and intrusive types of human to human Interaction such as phone calls, emails, or video conferences. This paper presents the results of exploring and exploiting the potentials of undemanding interaction mechanisms, paying special attention to subtle communication and background interaction. As we argue the benefits of this type of interaction for people with special needs, we present a theoretical framework to define it and propose a proof of concept based on Augmented Objects and a color codification mechanism. Finally, we evaluate and analyze the strengths and limitations of such approach with people with cognitive disabilities. Full article
Open AccessArticle Using a Communication Model to Collect Measurement Data through Mobile Devices
Sensors 2012, 12(7), 9253-9272; doi:10.3390/s120709253
Received: 19 May 2012 / Revised: 21 June 2012 / Accepted: 25 June 2012 / Published: 5 July 2012
Cited by 11 | PDF Full-text (1025 KB) | HTML Full-text | XML Full-text
Abstract
Wireless systems and services have undergone remarkable development since the first mobile phone system was introduced in the early 1980s. The use of sensors in an Ambient Intelligence approach is a great solution in a medical environment. We define a communication architecture to
[...] Read more.
Wireless systems and services have undergone remarkable development since the first mobile phone system was introduced in the early 1980s. The use of sensors in an Ambient Intelligence approach is a great solution in a medical environment. We define a communication architecture to facilitate the information transfer between all connected devices. This model is based in layers to allow the collection of measurement data to be used in our framework monitoring architecture. An overlay-based solution is built between network elements in order to provide an efficient and highly functional communication platform that allows the connection of a wide variety of devices and technologies, and serves also to perform additional functions such as the possibility to perform some processing in the network that may help to improve overall performance. Full article
Open AccessArticle A Reasoning Hardware Platform for Real-Time Common-Sense Inference
Sensors 2012, 12(7), 9210-9233; doi:10.3390/s120709210
Received: 15 May 2012 / Revised: 13 June 2012 / Accepted: 27 June 2012 / Published: 4 July 2012
Cited by 1 | PDF Full-text (484 KB) | HTML Full-text | XML Full-text
Abstract
Enabling Ambient Intelligence systems to understand the activities that are taking place in a supervised context is a rather complicated task. Moreover, this task cannot be successfully addressed while overlooking the mechanisms (common-sense knowledge and reasoning) that entitle us, as humans beings, to
[...] Read more.
Enabling Ambient Intelligence systems to understand the activities that are taking place in a supervised context is a rather complicated task. Moreover, this task cannot be successfully addressed while overlooking the mechanisms (common-sense knowledge and reasoning) that entitle us, as humans beings, to successfully undertake it. This work is based on the premise that Ambient Intelligence systems will be able to understand and react to context events if common-sense capabilities are embodied in them. However, there are some difficulties that need to be resolved before common-sense capabilities can be fully deployed to Ambient Intelligence. This work presents a hardware accelerated implementation of a common-sense knowledge-base system intended to improve response time and efficiency. Full article
Open AccessArticle Enabling Flexible and Continuous Capability Invocation in Mobile Prosumer Environments
Sensors 2012, 12(7), 8930-8954; doi:10.3390/s120708930
Received: 22 March 2012 / Revised: 17 June 2012 / Accepted: 19 June 2012 / Published: 28 June 2012
Cited by 10 | PDF Full-text (559 KB) | HTML Full-text | XML Full-text
Abstract
Mobile prosumer environments require the communication with heterogeneous devices during the execution of mobile services. These environments integrate sensors, actuators and smart devices, whose availability continuously changes. The aim of this paper is to design a reference architecture for implementing a model for
[...] Read more.
Mobile prosumer environments require the communication with heterogeneous devices during the execution of mobile services. These environments integrate sensors, actuators and smart devices, whose availability continuously changes. The aim of this paper is to design a reference architecture for implementing a model for continuous service execution and access to capabilities, i.e., the functionalities provided by these devices. The defined architecture follows a set of software engineering patterns and includes some communication paradigms to cope with the heterogeneity of sensors, actuators, controllers and other devices in the environment. In addition, we stress the importance of the flexibility in capability invocation by allowing the communication middleware to select the access technology and change the communication paradigm when dealing with smart devices, and by describing and evaluating two algorithms for resource access management. Full article
Open AccessArticle WebTag: Web Browsing into Sensor Tags over NFC
Sensors 2012, 12(7), 8675-8690; doi:10.3390/s120708675
Received: 20 March 2012 / Revised: 8 June 2012 / Accepted: 19 June 2012 / Published: 26 June 2012
Cited by 6 | PDF Full-text (422 KB) | HTML Full-text | XML Full-text
Abstract
Information and Communication Technologies (ICTs) continue to overcome many of the challenges related to wireless sensor monitoring, such as for example the design of smarter embedded processors, the improvement of the network architectures, the development of efficient communication protocols or the maximization of
[...] Read more.
Information and Communication Technologies (ICTs) continue to overcome many of the challenges related to wireless sensor monitoring, such as for example the design of smarter embedded processors, the improvement of the network architectures, the development of efficient communication protocols or the maximization of the life cycle autonomy. This work tries to improve the communication link of the data transmission in wireless sensor monitoring. The upstream communication link is usually based on standard IP technologies, but the downstream side is always masked with the proprietary protocols used for the wireless link (like ZigBee, Bluetooth, RFID, etc.). This work presents a novel solution (WebTag) for a direct IP based access to a sensor tag over the Near Field Communication (NFC) technology for secure applications. WebTag allows a direct web access to the sensor tag by means of a standard web browser, it reads the sensor data, configures the sampling rate and implements IP based security policies. It is, definitely, a new step towards the evolution of the Internet of Things paradigm. Full article
Figures

Open AccessArticle Subtitle Synchronization across Multiple Screens and Devices
Sensors 2012, 12(7), 8710-8731; doi:10.3390/s120708710
Received: 4 June 2012 / Revised: 15 June 2012 / Accepted: 15 June 2012 / Published: 26 June 2012
PDF Full-text (954 KB) | HTML Full-text | XML Full-text
Abstract
Ambient Intelligence is a new paradigm in which environments are sensitive and responsive to the presence of people. This is having an increasing importance in multimedia applications, which frequently rely on sensors to provide useful information to the user. In this context, multimedia
[...] Read more.
Ambient Intelligence is a new paradigm in which environments are sensitive and responsive to the presence of people. This is having an increasing importance in multimedia applications, which frequently rely on sensors to provide useful information to the user. In this context, multimedia applications must adapt and personalize both content and interfaces in order to reach acceptable levels of context-specific quality of service for the user, and enable the content to be available anywhere and at any time. The next step is to make content available to everybody in order to overcome the existing access barriers to content for users with specific needs, or else to adapt to different platforms, hence making content fully usable and accessible. Appropriate access to video content, for instance, is not always possible due to the technical limitations of traditional video packaging, transmission and presentation. This restricts the flexibility of subtitles and audio-descriptions to be adapted to different devices, contexts and users. New Web standards built around HTML5 enable more featured applications with better adaptation and personalization facilities, and thus would seem more suitable for accessible AmI environments. This work presents a video subtitling system that enables the customization, adaptation and synchronization of subtitles across different devices and multiple screens. The benefits of HTML5 applications for building the solution are analyzed along with their current platform support. Moreover, examples of the use of the application in three different cases are presented. Finally, the user experience of the solution is evaluated. Full article
Open AccessArticle Configuring a Context-Aware Middleware for Wireless Sensor Networks
Sensors 2012, 12(7), 8544-8570; doi:10.3390/s120708544
Received: 8 May 2012 / Revised: 11 June 2012 / Accepted: 12 June 2012 / Published: 25 June 2012
Cited by 8 | PDF Full-text (716 KB) | HTML Full-text | XML Full-text
Abstract
In the Future Internet, applications based on Wireless Sensor Networks will have to support reconfiguration with minimum human intervention, depending on dynamic context changes in their environment. These situations create a need for building these applications as adaptive software and including techniques that
[...] Read more.
In the Future Internet, applications based on Wireless Sensor Networks will have to support reconfiguration with minimum human intervention, depending on dynamic context changes in their environment. These situations create a need for building these applications as adaptive software and including techniques that allow the context acquisition and decisions about adaptation. However, contexts use to be made up of complex information acquired from heterogeneous devices and user characteristics, making them difficult to manage. So, instead of building context-aware applications from scratch, we propose to use FamiWare, a family of middleware for Ambient Intelligence specifically designed to be aware of contexts in sensor and smartphone devices. It provides both, several monitoring services to acquire contexts from devices and users, and a context-awareness service to analyze and detect context changes. However, the current version of FamiWare does not allow the automatic incorporation related to the management of new contexts into the FamiWare family. To overcome this shortcoming, in this work, we first present how to model the context using a metamodel to define the contexts that must to be taken into account in an instantiation of FamiWare for a certain Ambient Intelligence system. Then, to configure a new context-aware version of FamiWare and to generate code ready-to-install within heterogeneous devices, we define a mapping that automatically transforms metamodel elements defining contexts into elements of the FamiWare family, and we also use the FamiWare configuration process to customize the new context-aware variant. Finally, we evaluate the benefits of our process, and we analyze both that the new version of the middleware works as expected and that it manages the contexts in an efficient way. Full article
Figures

Open AccessArticle Open-WiSe: A Solar Powered Wireless Sensor Network Platform
Sensors 2012, 12(6), 8204-8217; doi:10.3390/s120608204
Received: 1 May 2012 / Revised: 4 June 2012 / Accepted: 8 June 2012 / Published: 13 June 2012
Cited by 11 | PDF Full-text (738 KB) | HTML Full-text | XML Full-text
Abstract
Because battery-powered nodes are required in wireless sensor networks and energy consumption represents an important design consideration, alternate energy sources are needed to provide more effective and optimal function. The main goal of this work is to present an energy harvesting wireless sensor
[...] Read more.
Because battery-powered nodes are required in wireless sensor networks and energy consumption represents an important design consideration, alternate energy sources are needed to provide more effective and optimal function. The main goal of this work is to present an energy harvesting wireless sensor network platform, the Open Wireless Sensor node (WiSe). The design and implementation of the solar powered wireless platform is described including the hardware architecture, firmware, and a POSIX Real-Time Kernel. A sleep and wake up strategy was implemented to prolong the lifetime of the wireless sensor network. This platform was developed as a tool for researchers investigating Wireless sensor network or system integrators. Full article
Open AccessArticle An Indoor Navigation System for the Visually Impaired
Sensors 2012, 12(6), 8236-8258; doi:10.3390/s120608236
Received: 27 April 2012 / Revised: 29 May 2012 / Accepted: 31 May 2012 / Published: 13 June 2012
Cited by 39 | PDF Full-text (873 KB) | HTML Full-text | XML Full-text
Abstract
Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they
[...] Read more.
Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they involve an important deployment effort or use artifacts that are not natural for blind users. This paper presents an indoor navigation system that was designed taking into consideration usability as the quality requirement to be maximized. This solution enables one to identify the position of a person and calculates the velocity and direction of his movements. Using this information, the system determines the user’s trajectory, locates possible obstacles in that route, and offers navigation information to the user. The solution has been evaluated using two experimental scenarios. Although the results are still not enough to provide strong conclusions, they indicate that the system is suitable to guide visually impaired people through an unknown built environment. Full article
Open AccessArticle Process-in-Network: A Comprehensive Network Processing Approach
Sensors 2012, 12(6), 8112-8134; doi:10.3390/s120608112
Received: 23 April 2012 / Revised: 30 May 2012 / Accepted: 4 June 2012 / Published: 12 June 2012
PDF Full-text (741 KB) | HTML Full-text | XML Full-text
Abstract
A solid and versatile communications platform is very important in modern Ambient Intelligence (AmI) applications, which usually require the transmission of large amounts of multimedia information over a highly heterogeneous network. This article focuses on the concept of Process-in-Network (PIN), which is defined
[...] Read more.
A solid and versatile communications platform is very important in modern Ambient Intelligence (AmI) applications, which usually require the transmission of large amounts of multimedia information over a highly heterogeneous network. This article focuses on the concept of Process-in-Network (PIN), which is defined as the possibility that the network processes information as it is being transmitted, and introduces a more comprehensive approach than current network processing technologies. PIN can take advantage of waiting times in queues of routers, idle processing capacity in intermediate nodes, and the information that passes through the network. Full article
Open AccessArticle On the Use of Sensor Fusion to Reduce the Impact of Rotational and Additive Noise in Human Activity Recognition
Sensors 2012, 12(6), 8039-8054; doi:10.3390/s120608039
Received: 19 March 2012 / Revised: 5 June 2012 / Accepted: 6 June 2012 / Published: 11 June 2012
Cited by 18 | PDF Full-text (561 KB) | HTML Full-text | XML Full-text
Abstract
The main objective of fusion mechanisms is to increase the individual reliability of the systems through the use of the collectivity knowledge. Moreover, fusion models are also intended to guarantee a certain level of robustness. This is particularly required for problems such as
[...] Read more.
The main objective of fusion mechanisms is to increase the individual reliability of the systems through the use of the collectivity knowledge. Moreover, fusion models are also intended to guarantee a certain level of robustness. This is particularly required for problems such as human activity recognition where runtime changes in the sensor setup seriously disturb the reliability of the initial deployed systems. For commonly used recognition systems based on inertial sensors, these changes are primarily characterized as sensor rotations, displacements or faults related to the batteries or calibration. In this work we show the robustness capabilities of a sensor-weighted fusion model when dealing with such disturbances under different circumstances. Using the proposed method, up to 60% outperformance is obtained when a minority of the sensors are artificially rotated or degraded, independent of the level of disturbance (noise) imposed. These robustness capabilities also apply for any number of sensors affected by a low to moderate noise level. The presented fusion mechanism compensates the poor performance that otherwise would be obtained when just a single sensor is considered. Full article
Figures

Open AccessArticle Personalized Alert Notifications and Evacuation Routes in Indoor Environments
Sensors 2012, 12(6), 7804-7827; doi:10.3390/s120607804
Received: 7 May 2012 / Revised: 4 June 2012 / Accepted: 5 June 2012 / Published: 8 June 2012
Cited by 12 | PDF Full-text (5449 KB) | HTML Full-text | XML Full-text
Abstract
The preparedness phase is crucial in the emergency management process for reaching an adequate level of readiness to react to potential threats and hazards. During this phase, emergency plans are developed to establish, among other procedures, evacuation and emergency escape routes. Information and
[...] Read more.
The preparedness phase is crucial in the emergency management process for reaching an adequate level of readiness to react to potential threats and hazards. During this phase, emergency plans are developed to establish, among other procedures, evacuation and emergency escape routes. Information and Communication Technologies (ICT) can support and improve these procedures providing appropriate, updated and accessible information to all people in the affected zone. Current emergency management and evacuation systems do not adapt information to the context and the profile of each person, so messages received in the emergency might be useless. In this paper, we propose a set of criteria that ICT-based systems could achieve in order to avoid this problem adapting emergency alerts and evacuation routes to different situations and people. Moreover, in order to prove the applicability of such criteria, we define a mechanism that can be used as a complement of traditional evacuation systems to provide personalized alerts and evacuation routes to all kinds of people during emergency situations in working places. This mechanism is composed by three main components: CAP-ONES for notifying emergency alerts, NERES for defining emergency plans and generating personalized evacuation routes, and iNeres as the interface to receive and visualize these routes on smartphones. The usability and understandability of proposed interface has been assessed through a user study performed in a fire simulation in an indoor environment. This evaluation demonstrated that users considered iNeres easy to understand, to learn and to use, and they also found very innovative the idea to use smartphones as a support for escaping instead of static signals on walls and doors. Full article
Figures

Open AccessArticle A Novel Human Autonomy Assessment System
Sensors 2012, 12(6), 7828-7854; doi:10.3390/s120607828
Received: 11 May 2012 / Revised: 31 May 2012 / Accepted: 4 June 2012 / Published: 8 June 2012
Cited by 3 | PDF Full-text (2916 KB) | HTML Full-text | XML Full-text
Abstract
This article presents a novel human autonomy assessment system for generating context and discovering the behaviors of older people who use ambulant services. Our goal is to assist caregivers in assessing possibly abnormal health conditions in their clients concerning their level of autonomy,
[...] Read more.
This article presents a novel human autonomy assessment system for generating context and discovering the behaviors of older people who use ambulant services. Our goal is to assist caregivers in assessing possibly abnormal health conditions in their clients concerning their level of autonomy, thus enabling caregivers to take countermeasures as soon as possible. Full article
Figures

Open AccessArticle Compiler Optimizations as a Countermeasure against Side-Channel Analysis in MSP430-Based Devices
Sensors 2012, 12(6), 7994-8012; doi:10.3390/s120607994
Received: 16 May 2012 / Revised: 4 June 2012 / Accepted: 4 June 2012 / Published: 8 June 2012
PDF Full-text (2125 KB) | HTML Full-text | XML Full-text
Abstract
Ambient Intelligence (AmI) requires devices everywhere, dynamic and massively distributed networks of low-cost nodes that, among other data, manage private information or control restricted operations. MSP430, a 16-bit microcontroller, is used in WSN platforms, as the TelosB. Physical access to devices cannot be
[...] Read more.
Ambient Intelligence (AmI) requires devices everywhere, dynamic and massively distributed networks of low-cost nodes that, among other data, manage private information or control restricted operations. MSP430, a 16-bit microcontroller, is used in WSN platforms, as the TelosB. Physical access to devices cannot be restricted, so attackers consider them a target of their malicious attacks in order to obtain access to the network. Side-channel analysis (SCA) easily exploits leakages from the execution of encryption algorithms that are dependent on critical data to guess the key value. In this paper we present an evaluation framework that facilitates the analysis of the effects of compiler and backend optimizations on the resistance against statistical SCA. We propose an optimization-based software countermeasure that can be used in current low-cost devices to radically increase resistance against statistical SCA, analyzed with the new framework. Full article
Open AccessArticle A Communication Model to Integrate the Request-Response and the Publish-Subscribe Paradigms into Ubiquitous Systems
Sensors 2012, 12(6), 7648-7668; doi:10.3390/s120607648
Received: 9 May 2012 / Revised: 31 May 2012 / Accepted: 4 June 2012 / Published: 7 June 2012
Cited by 11 | PDF Full-text (1502 KB) | HTML Full-text | XML Full-text
Abstract
The Request-Response (RR) paradigm is widely used in ubiquitous systems to exchange information in a secure, reliable and timely manner. Nonetheless, there is also an emerging need for adopting the Publish-Subscribe (PubSub) paradigm in this kind of systems, due to the advantages that
[...] Read more.
The Request-Response (RR) paradigm is widely used in ubiquitous systems to exchange information in a secure, reliable and timely manner. Nonetheless, there is also an emerging need for adopting the Publish-Subscribe (PubSub) paradigm in this kind of systems, due to the advantages that this paradigm offers in supporting mobility by means of asynchronous, non-blocking and one-to-many message distribution semantics for event notification. This paper analyzes the strengths and weaknesses of both the RR and PubSub paradigms to support communications in ubiquitous systems and proposes an abstract communication model in order to enable their seamless integration. Thus, developers will be focused on communication semantics and the required quality properties, rather than be concerned about specific communication mechanisms. The aim is to provide developers with abstractions intended to decrease the complexity of integrating different communication paradigms commonly needed in ubiquitous systems. The proposal has been applied to implement a middleware and a real home automation system to show its applicability and benefits. Full article
Figures

Open AccessArticle Managing RFID Sensors Networks with a General Purpose RFID Middleware
Sensors 2012, 12(6), 7719-7737; doi:10.3390/s120607719
Received: 27 February 2012 / Revised: 29 May 2012 / Accepted: 4 June 2012 / Published: 7 June 2012
Cited by 8 | PDF Full-text (526 KB) | HTML Full-text | XML Full-text
Abstract
RFID middleware is anticipated to one of the main research areas in the field of RFID applications in the near future. The Data EPC Acquisition System (DEPCAS) is an original proposal designed by our group to transfer and apply fundamental ideas from System
[...] Read more.
RFID middleware is anticipated to one of the main research areas in the field of RFID applications in the near future. The Data EPC Acquisition System (DEPCAS) is an original proposal designed by our group to transfer and apply fundamental ideas from System and Data Acquisition (SCADA) systems into the areas of RFID acquisition, processing and distribution systems. In this paper we focus on how to organize and manage generic RFID sensors (edge readers, readers, PLCs, etc…) inside the DEPCAS middleware. We denote by RFID Sensors Networks Management (RSNM) this part of DEPCAS, which is built on top of two new concepts introduced and developed in this work: MARC (Minimum Access Reader Command) and RRTL (RFID Reader Topology Language). MARC is an abstraction layer used to hide heterogeneous devices inside a homogeneous acquisition network. RRTL is a language to define RFID Reader networks and to describe the relationship between them (concentrator, peer to peer, master/submaster). Full article
Open AccessArticle Study of LZ-Based Location Prediction and Its Application to Transportation Recommender Systems
Sensors 2012, 12(6), 7496-7517; doi:10.3390/s120607496
Received: 20 April 2012 / Revised: 21 May 2012 / Accepted: 30 May 2012 / Published: 4 June 2012
Cited by 7 | PDF Full-text (765 KB) | HTML Full-text | XML Full-text
Abstract
Predicting users’ next location allows to anticipate their future context, thus providing additional time to be ready for that context and react consequently. This work is focused on a set of LZ-based algorithms (LZ, LeZi Update and Active LeZi) capable of learning mobility
[...] Read more.
Predicting users’ next location allows to anticipate their future context, thus providing additional time to be ready for that context and react consequently. This work is focused on a set of LZ-based algorithms (LZ, LeZi Update and Active LeZi) capable of learning mobility patterns and estimating the next location with low resource needs, which makes it possible to execute them on mobile devices. The original algorithms have been divided into two phases, thus being possible to mix them and check which combination is the best one to obtain better prediction accuracy or lower resource consumption. To make such comparisons, a set of GSM-based mobility traces of 95 different users is considered. Finally, a prototype for mobile devices that integrates the predictors in a public transportation recommender system is described in order to show an example of how to take advantage of location prediction in an ubiquitous computing environment. Full article
Figures

Open AccessArticle Personal Pervasive Environments: Practice and Experience
Sensors 2012, 12(6), 7109-7125; doi:10.3390/s120607109
Received: 1 April 2012 / Revised: 8 May 2012 / Accepted: 23 May 2012 / Published: 29 May 2012
Cited by 2 | PDF Full-text (1208 KB) | HTML Full-text | XML Full-text
Abstract
In this paper we present our experience designing and developing two different systems to enable personal pervasive computing environments, Plan B and the Octopus. These systems were fully implemented and have been used on a daily basis for years. Both are based on
[...] Read more.
In this paper we present our experience designing and developing two different systems to enable personal pervasive computing environments, Plan B and the Octopus. These systems were fully implemented and have been used on a daily basis for years. Both are based on synthetic (virtual) file system interfaces and provide mechanisms to adapt to changes in the context and reconfigure the system to support pervasive applications. We also present the main differences between them, focusing on architectural and reconfiguration aspects. Finally, we analyze the pitfalls and successes of both systems and review the lessons we learned while designing, developing, and using them. Full article
Open AccessArticle Meeting People’s Needs in a Fully Interoperable Domotic Environment
Sensors 2012, 12(6), 6802-6824; doi:10.3390/s120606802
Received: 8 April 2012 / Revised: 11 May 2012 / Accepted: 22 May 2012 / Published: 25 May 2012
Cited by 3 | PDF Full-text (437 KB) | HTML Full-text | XML Full-text
Abstract
The key idea underlying many Ambient Intelligence (AmI) projects and applications is context awareness, which is based mainly on their capacity to identify users and their locations. The actual computing capacity should remain in the background, in the periphery of our awareness, and
[...] Read more.
The key idea underlying many Ambient Intelligence (AmI) projects and applications is context awareness, which is based mainly on their capacity to identify users and their locations. The actual computing capacity should remain in the background, in the periphery of our awareness, and should only move to the center if and when necessary. Computing thus becomes ‘invisible’, as it is embedded in the environment and everyday objects. The research project described herein aims to realize an Ambient Intelligence-based environment able to improve users’ quality of life by learning their habits and anticipating their needs. This environment is part of an adaptive, context-aware framework designed to make today’s incompatible heterogeneous domotic systems fully interoperable, not only for connecting sensors and actuators, but for providing comprehensive connections of devices to users. The solution is a middleware architecture based on open and widely recognized standards capable of abstracting the peculiarities of underlying heterogeneous technologies and enabling them to co-exist and interwork, without however eliminating their differences. At the highest level of this infrastructure, the Ambient Intelligence framework, integrated with the domotic sensors, can enable the system to recognize any unusual or dangerous situations and anticipate health problems or special user needs in a technological living environment, such as a house or a public space. Full article
Figures

Open AccessArticle Geometric and Colour Data Fusion for Outdoor 3D Models
Sensors 2012, 12(6), 6893-6919; doi:10.3390/s120606893
Received: 29 February 2012 / Revised: 15 May 2012 / Accepted: 17 May 2012 / Published: 25 May 2012
Cited by 2 | PDF Full-text (2574 KB) | HTML Full-text | XML Full-text
Abstract
This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may
[...] Read more.
This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may be inefficient if the scene is digitalized under unsuitable technical (specific scanner on-board camera) and environmental (rain, dampness, changing illumination) conditions. We address our research towards the integration of images and range data to produce photorealistic models. Our proposal is based on decoupling the colour integration and geometry reconstruction stages, making them independent and controlled processes. This issue is approached from two different viewpoints. On the one hand, given a complete model (geometry plus texture), we propose a method to modify the original texture provided by the scanner on-board camera with the colour information extracted from external images taken at given moments and under specific environmental conditions. On the other hand, we propose an algorithm to directly assign external images onto the complete geometric model, thus avoiding tedious on-line calibration processes. We present the work conducted on two large Roman archaeological sites dating from the first century A.D., namely, the Theatre of Segobriga and the Fori Porticus of Emerita Augusta, both in Spain. The results obtained demonstrate that our approach could be useful in the digitalization and 3D modelling fields. Full article
Open AccessArticle Ubiquitous Mobile Knowledge Construction in Collaborative Learning Environments
Sensors 2012, 12(6), 6995-7014; doi:10.3390/s120606995
Received: 19 March 2012 / Revised: 18 May 2012 / Accepted: 18 May 2012 / Published: 25 May 2012
Cited by 9 | PDF Full-text (615 KB) | HTML Full-text | XML Full-text
Abstract
Knowledge management is a critical activity for any organization. It has been said to be a differentiating factor and an important source of competitiveness if this knowledge is constructed and shared among its members, thus creating a learning organization. Knowledge construction is critical
[...] Read more.
Knowledge management is a critical activity for any organization. It has been said to be a differentiating factor and an important source of competitiveness if this knowledge is constructed and shared among its members, thus creating a learning organization. Knowledge construction is critical for any collaborative organizational learning environment. Nowadays workers must perform knowledge creation tasks while in motion, not just in static physical locations; therefore it is also required that knowledge construction activities be performed in ubiquitous scenarios, and supported by mobile and pervasive computational systems. These knowledge creation systems should help people in or outside organizations convert their tacit knowledge into explicit knowledge, thus supporting the knowledge construction process. Therefore in our understanding, we consider highly relevant that undergraduate university students learn about the knowledge construction process supported by mobile and ubiquitous computing. This has been a little explored issue in this field. This paper presents the design, implementation, and an evaluation of a system called MCKC for Mobile Collaborative Knowledge Construction, supporting collaborative face-to-face tacit knowledge construction and sharing in ubiquitous scenarios. The MCKC system can be used by undergraduate students to learn how to construct knowledge, allowing them anytime and anywhere to create, make explicit and share their knowledge with their co-learners, using visual metaphors, gestures and sketches to implement the human-computer interface of mobile devices (PDAs). Full article
Open AccessArticle Architecture for Improving Terrestrial Logistics Based on the Web of Things
Sensors 2012, 12(5), 6538-6575; doi:10.3390/s120506538
Received: 20 March 2012 / Revised: 10 May 2012 / Accepted: 15 May 2012 / Published: 18 May 2012
Cited by 8 | PDF Full-text (2331 KB) | HTML Full-text | XML Full-text
Abstract
Technological advances for improving supply chain efficiency present three key challenges for managing goods: tracking, tracing and monitoring (TTM), in order to satisfy the requirements for products such as perishable goods where the European Legislations requires them to ship within a prescribed temperature
[...] Read more.
Technological advances for improving supply chain efficiency present three key challenges for managing goods: tracking, tracing and monitoring (TTM), in order to satisfy the requirements for products such as perishable goods where the European Legislations requires them to ship within a prescribed temperature range to ensure freshness and suitability for consumption. The proposed system integrates RFID for tracking and tracing through a distributed architecture developed for heavy goods vehicles, and the sensors embedded in the SunSPOT platform for monitoring the goods transported based on the concept of the Internet of Things. This paper presents how the Internet of Things is integrated for improving terrestrial logistics offering a comprehensive and flexible architecture, with high scalability, according to the specific needs for reaching an item-level continuous monitoring solution. The major contribution from this work is the optimization of the Embedded Web Services based on RESTful (Web of Things) for the access to TTM services at any time during the transportation of goods. Specifically, it has been extended the monitoring patterns such as observe and blockwise transfer for the requirements from the continuous conditional monitoring, and for the transfer of full inventories and partial ones based on conditional queries. In definitive, this work presents an evolution of the previous TTM solutions, which were limited to trailer identification and environment monitoring, to a solution which is able to provide an exhaustive item-level monitoring, required for several use cases. This exhaustive monitoring has required new communication capabilities through the Web of Things, which has been optimized with the use and improvement of a set of communications patterns. Full article
Open AccessArticle IVAN: Intelligent Van for the Distribution of Pharmaceutical Drugs
Sensors 2012, 12(5), 6587-6609; doi:10.3390/s120506587
Received: 19 March 2012 / Revised: 12 May 2012 / Accepted: 14 May 2012 / Published: 18 May 2012
Cited by 15 | PDF Full-text (1340 KB) | HTML Full-text | XML Full-text
Abstract
This paper describes a telematic system based on an intelligent van which is capable of tracing pharmaceutical drugs over delivery routes from a warehouse to pharmacies, without altering carriers’ daily conventional tasks. The intelligent van understands its environment, taking into account its location,
[...] Read more.
This paper describes a telematic system based on an intelligent van which is capable of tracing pharmaceutical drugs over delivery routes from a warehouse to pharmacies, without altering carriers’ daily conventional tasks. The intelligent van understands its environment, taking into account its location, the assets and the predefined delivery route; with the capability of reporting incidences to carriers in case of failure according to the established distribution plan. It is a non-intrusive solution which represents a successful experience of using smart environments and an optimized Radio Frequency Identification (RFID) embedded system in a viable way to resolve a real industrial need in the pharmaceutical industry. The combination of deterministic modeling of the indoor vehicle, the implementation of an ad-hoc radiating element and an agile software platform within an overall system architecture leads to a competitive, flexible and scalable solution. Full article
Open AccessArticle Enabling Communication in Emergency Response Environments
Sensors 2012, 12(5), 6380-6394; doi:10.3390/s120506380
Received: 1 April 2012 / Revised: 25 April 2012 / Accepted: 27 April 2012 / Published: 14 May 2012
Cited by 1 | PDF Full-text (721 KB) | HTML Full-text | XML Full-text
Abstract
Effective communication among first responders during response to natural and human-made large-scale catastrophes has increased tremendously during the last decade. However, most efforts to achieve a higher degree of effectiveness in communication lack synergy between the environment and the technology involved to support
[...] Read more.
Effective communication among first responders during response to natural and human-made large-scale catastrophes has increased tremendously during the last decade. However, most efforts to achieve a higher degree of effectiveness in communication lack synergy between the environment and the technology involved to support first responders operations. This article presents a natural and intuitive interface to support Stigmergy; or communication through the environment, based on intuitively marking and retrieving information from the environment with a pointer. A prototype of the system was built and tested in the field, however the pointing activity revealed challenges regarding accuracy due to limitations of the sensors used. The results obtained from these field tests were the basis for this research effort and will have the potential to enable communication through the environment for first responders operating in highly dynamical and inhospitable disaster relief environments. Full article
Open AccessArticle An Approach for Representing Sensor Data to Validate Alerts in Ambient Assisted Living
Sensors 2012, 12(5), 6282-6306; doi:10.3390/s120506282
Received: 20 March 2012 / Revised: 30 April 2012 / Accepted: 4 May 2012 / Published: 11 May 2012
Cited by 13 | PDF Full-text (1442 KB) | HTML Full-text | XML Full-text
Abstract
The mainstream of research in Ambient Assisted Living (AAL) is devoted to developing intelligent systems for processing the data collected through artificial sensing. Besides, there are other elements that must be considered to foster the adoption of AAL solutions in real environments. In
[...] Read more.
The mainstream of research in Ambient Assisted Living (AAL) is devoted to developing intelligent systems for processing the data collected through artificial sensing. Besides, there are other elements that must be considered to foster the adoption of AAL solutions in real environments. In this paper we focus on the problem of designing interfaces among caregivers and AAL systems. We present an alert management tool that supports carers in their task of validating alarms raised by the system. It generates text-based explanations—obtained through an argumentation process—of the causes leading to alarm activation along with graphical sensor information and 3D models, thus offering complementary types of information. Moreover, a guideline to use the tool when validating alerts is also provided. Finally, the functionality of the proposed tool is demonstrated through two real cases of alert. Full article
Figures

Open AccessArticle Sharing Human-Generated Observations by Integrating HMI and the Semantic Sensor Web
Sensors 2012, 12(5), 6307-6330; doi:10.3390/s120506307
Received: 16 March 2012 / Revised: 3 May 2012 / Accepted: 3 May 2012 / Published: 11 May 2012
Cited by 1 | PDF Full-text (1555 KB) | HTML Full-text | XML Full-text
Abstract
Current “Internet of Things” concepts point to a future where connected objects gather meaningful information about their environment and share it with other objects and people. In particular, objects embedding Human Machine Interaction (HMI), such as mobile devices and, increasingly, connected vehicles, home
[...] Read more.
Current “Internet of Things” concepts point to a future where connected objects gather meaningful information about their environment and share it with other objects and people. In particular, objects embedding Human Machine Interaction (HMI), such as mobile devices and, increasingly, connected vehicles, home appliances, urban interactive infrastructures, etc., may not only be conceived as sources of sensor information, but, through interaction with their users, they can also produce highly valuable context-aware human-generated observations. We believe that the great promise offered by combining and sharing all of the different sources of information available can be realized through the integration of HMI and Semantic Sensor Web technologies. This paper presents a technological framework that harmonizes two of the most influential HMI and Sensor Web initiatives: the W3C’s Multimodal Architecture and Interfaces (MMI) and the Open Geospatial Consortium (OGC) Sensor Web Enablement (SWE) with its semantic extension, respectively. Although the proposed framework is general enough to be applied in a variety of connected objects integrating HMI, a particular development is presented for a connected car scenario where drivers’ observations about the traffic or their environment are shared across the Semantic Sensor Web. For implementation and evaluation purposes an on-board OSGi (Open Services Gateway Initiative) architecture was built, integrating several available HMI, Sensor Web and Semantic Web technologies. A technical performance test and a conceptual validation of the scenario with potential users are reported, with results suggesting the approach is sound. Full article
Open AccessArticle An Event Driven Hybrid Identity Management Approach to Privacy Enhanced e-Health
Sensors 2012, 12(5), 6129-6154; doi:10.3390/s120506129
Received: 20 March 2012 / Revised: 27 April 2012 / Accepted: 29 April 2012 / Published: 10 May 2012
Cited by 1 | PDF Full-text (3235 KB) | HTML Full-text | XML Full-text
Abstract
Credential-based authorization offers interesting advantages for ubiquitous scenarios involving limited devices such as sensors and personal mobile equipment: the verification can be done locally; it offers a more reduced computational cost than its competitors for issuing, storing, and verification; and it naturally supports rights
[...] Read more.
Credential-based authorization offers interesting advantages for ubiquitous scenarios involving limited devices such as sensors and personal mobile equipment: the verification can be done locally; it offers a more reduced computational cost than its competitors for issuing, storing, and verification; and it naturally supports rights delegation. The main drawback is the revocation of rights. Revocation requires handling potentially large revocation lists, or using protocols to check the revocation status, bringing extra communication costs not acceptable for sensors and other limited devices. Moreover, the effective revocation consent—considered as a privacy rule in sensitive scenarios—has not been fully addressed.This paper proposes an event-based mechanism empowering a new concept, the sleepyhead credentials, which allows to substitute time constraints and explicit revocation by activating and deactivating authorization rights according to events. Our approach is to integrate this concept in IdM systems in a hybrid model supporting delegation, which can be an interesting alternative for scenarios where revocation of consent and user privacy are critical. The delegation includes a SAML compliant protocol, which we have validated through a proof-of-concept implementation. This article also explains the mathematical model describing the event-based model and offers estimations of the overhead introduced by the system. The paper focus on health care scenarios, where we show the flexibility of the proposed event-based user consent revocation mechanism. Full article
Figures

Open AccessArticle Mobile, Collaborative Situated Knowledge Creation for Urban Planning
Sensors 2012, 12(5), 6218-6243; doi:10.3390/s120506218
Received: 19 March 2012 / Revised: 19 April 2012 / Accepted: 28 April 2012 / Published: 10 May 2012
Cited by 6 | PDF Full-text (789 KB) | HTML Full-text | XML Full-text
Abstract
Geo-collaboration is an emerging research area in computer sciences studying the way spatial, geographically referenced information and communication technologies can support collaborative activities. Scenarios in which information associated to its physical location are of paramount importance are often referred as Situated Knowledge Creation
[...] Read more.
Geo-collaboration is an emerging research area in computer sciences studying the way spatial, geographically referenced information and communication technologies can support collaborative activities. Scenarios in which information associated to its physical location are of paramount importance are often referred as Situated Knowledge Creation scenarios. To date there are few computer systems supporting knowledge creation that explicitly incorporate physical context as part of the knowledge being managed in mobile face-to-face scenarios. This work presents a collaborative software application supporting visually-geo-referenced knowledge creation in mobile working scenarios while the users are interacting face-to-face. The system allows to manage data information associated to specific physical locations for knowledge creation processes in the field, such as urban planning, identifying specific physical locations, territorial management, etc.; using Tablet-PCs and GPS in order to geo-reference data and information. It presents a model for developing mobile applications supporting situated knowledge creation in the field, introducing the requirements for such an application and the functionalities it should have in order to fulfill them. The paper also presents the results of utility and usability evaluations. Full article
Open AccessArticle Detection of (In)activity Periods in Human Body Motion Using Inertial Sensors: A Comparative Study
Sensors 2012, 12(5), 5791-5814; doi:10.3390/s120505791
Received: 8 March 2012 / Revised: 7 April 2012 / Accepted: 27 April 2012 / Published: 4 May 2012
Cited by 15 | PDF Full-text (919 KB) | HTML Full-text | XML Full-text
Abstract
Determination of (in)activity periods when monitoring human body motion is a mandatory preprocessing step in all human inertial navigation and position analysis applications. Distinction of (in)activity needs to be established in order to allow the system to recompute the calibration parameters of the
[...] Read more.
Determination of (in)activity periods when monitoring human body motion is a mandatory preprocessing step in all human inertial navigation and position analysis applications. Distinction of (in)activity needs to be established in order to allow the system to recompute the calibration parameters of the inertial sensors as well as the Zero Velocity Updates (ZUPT) of inertial navigation. The periodical recomputation of these parameters allows the application to maintain a constant degree of precision. This work presents a comparative study among different well known inertial magnitude-based detectors and proposes a new approach by applying spectrum-based detectors and memory-based detectors. A robust statistical comparison is carried out by the use of an accelerometer and angular rate signal synthesizer that mimics the output of accelerometers and gyroscopes when subjects are performing basic activities of daily life. Theoretical results are verified by testing the algorithms over signals gathered using an Inertial Measurement Unit (IMU). Detection accuracy rates of up to 97% are achieved. Full article
Figures

Open AccessArticle An Early Fire Detection Algorithm Using IP Cameras
Sensors 2012, 12(5), 5670-5686; doi:10.3390/s120505670
Received: 29 February 2012 / Revised: 19 April 2012 / Accepted: 28 April 2012 / Published: 3 May 2012
Cited by 9 | PDF Full-text (958 KB) | HTML Full-text | XML Full-text
Abstract
The presence of smoke is the first symptom of fire; therefore to achieve early fire detection, accurate and quick estimation of the presence of smoke is very important. In this paper we propose an algorithm to detect the presence of smoke using video
[...] Read more.
The presence of smoke is the first symptom of fire; therefore to achieve early fire detection, accurate and quick estimation of the presence of smoke is very important. In this paper we propose an algorithm to detect the presence of smoke using video sequences captured by Internet Protocol (IP) cameras, in which important features of smoke, such as color, motion and growth properties are employed. For an efficient smoke detection in the IP camera platform, a detection algorithm must operate directly in the Discrete Cosine Transform (DCT) domain to reduce computational cost, avoiding a complete decoding process required for algorithms that operate in spatial domain. In the proposed algorithm the DCT Inter-transformation technique is used to increase the detection accuracy without inverse DCT operation. In the proposed scheme, firstly the candidate smoke regions are estimated using motion and color smoke properties; next using morphological operations the noise is reduced. Finally the growth properties of the candidate smoke regions are furthermore analyzed through time using the connected component labeling technique. Evaluation results show that a feasible smoke detection method with false negative and false positive error rates approximately equal to 4% and 2%, respectively, is obtained. Full article
Open AccessArticle Automatic Construction of 3D Basic-Semantic Models of Inhabited Interiors Using Laser Scanners and RFID Sensors
Sensors 2012, 12(5), 5705-5724; doi:10.3390/s120505705
Received: 22 March 2012 / Revised: 16 April 2012 / Accepted: 2 May 2012 / Published: 3 May 2012
Cited by 22 | PDF Full-text (1203 KB) | HTML Full-text | XML Full-text
Abstract
This paper is focused on the automatic construction of 3D basic-semantic models of inhabited interiors using laser scanners with the help of RFID technologies. This is an innovative approach, in whose field scarce publications exist. The general strategy consists of carrying out a
[...] Read more.
This paper is focused on the automatic construction of 3D basic-semantic models of inhabited interiors using laser scanners with the help of RFID technologies. This is an innovative approach, in whose field scarce publications exist. The general strategy consists of carrying out a selective and sequential segmentation from the cloud of points by means of different algorithms which depend on the information that the RFID tags provide. The identification of basic elements of the scene, such as walls, floor, ceiling, windows, doors, tables, chairs and cabinets, and the positioning of their corresponding models can then be calculated. The fusion of both technologies thus allows a simplified 3D semantic indoor model to be obtained. This method has been tested in real scenes under difficult clutter and occlusion conditions, and has yielded promising results. Full article
Open AccessArticle Personalized Health Care System with Virtual Reality Rehabilitation and Appropriate Information for Seniors
Sensors 2012, 12(5), 5502-5516; doi:10.3390/s120505502
Received: 5 March 2012 / Revised: 11 April 2012 / Accepted: 25 April 2012 / Published: 30 April 2012
Cited by 7 | PDF Full-text (676 KB) | HTML Full-text | XML Full-text
Abstract
The concept of the information society is now a common one, as opposed to the industrial society that dominated the economy during the last years. It is assumed that all sectors should have access to information and reap its benefits. Elderly people are,
[...] Read more.
The concept of the information society is now a common one, as opposed to the industrial society that dominated the economy during the last years. It is assumed that all sectors should have access to information and reap its benefits. Elderly people are, in this respect, a major challenge, due to their lack of interest in technological progress and their lack of knowledge regarding the potential benefits that information society technologies might have on their lives. The Naviga Project (An Open and Adaptable Platform for the Elderly and Persons with Disability to Access the Information Society) is a European effort, whose main goal is to design and develop a technological platform allowing elder people and persons with disability to access the internet and the information society. Naviga also allows the creation of services targeted to social networks, mind training and personalized health care. In this paper we focus on the health care and information services designed on the project, the technological platform developed and details of two representative elements, the virtual reality hand rehabilitation and the health information intelligent system. Full article
Figures

Open AccessArticle Architecture of a Framework for Providing Information Services for Public Transport
Sensors 2012, 12(5), 5290-5309; doi:10.3390/s120505290
Received: 2 March 2012 / Revised: 29 March 2012 / Accepted: 10 April 2012 / Published: 26 April 2012
Cited by 2 | PDF Full-text (498 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents OnRoute, a framework for developing and running ubiquitous software that provides information services to passengers of public transportation, including payment systems and on-route guidance services. To achieve a high level of interoperability, accessibility and context awareness, OnRoute uses the ubiquitous
[...] Read more.
This paper presents OnRoute, a framework for developing and running ubiquitous software that provides information services to passengers of public transportation, including payment systems and on-route guidance services. To achieve a high level of interoperability, accessibility and context awareness, OnRoute uses the ubiquitous computing paradigm. To guarantee the quality of the software produced, the reliable software principles used in critical contexts, such as automotive systems, are also considered by the framework. The main components of its architecture (run-time, system services, software components and development discipline) and how they are deployed in the transportation network (stations and vehicles) are described in this paper. Finally, to illustrate the use of OnRoute, the development of a guidance service for travellers is explained. Full article
Figures

Open AccessArticle Assessing Ambiguity of Context Data in Intelligent Environments: Towards a More Reliable Context Managing System
Sensors 2012, 12(4), 4934-4951; doi:10.3390/s120404934
Received: 22 February 2012 / Revised: 3 April 2012 / Accepted: 6 April 2012 / Published: 17 April 2012
Cited by 14 | PDF Full-text (518 KB) | HTML Full-text | XML Full-text
Abstract
Modeling and managing correctly the user context in Smart Environments is important to achieve robust and reliable systems. When modeling reality we must take into account its ambiguous nature. Considering the uncertainty and vagueness in context data information it is possible to attain
[...] Read more.
Modeling and managing correctly the user context in Smart Environments is important to achieve robust and reliable systems. When modeling reality we must take into account its ambiguous nature. Considering the uncertainty and vagueness in context data information it is possible to attain a more precise picture of the environment, thus leading to a more accurate inference process. To achieve these goals we present an ontology that models the ambiguity in intelligent environments and a data fusion and inference process that takes advantage of that extra information to provide better results. Our system can assess the certainty of the captured measurements, discarding the unreliable ones and combining the rest into a unified vision of the current user context. It also models the vagueness of the system, combining it with the uncertainty to obtain a richer inference process. Full article
Open AccessArticle Uranus: A Middleware Architecture for Dependable AAL and Vital Signs Monitoring Applications
Sensors 2012, 12(3), 3145-3161; doi:10.3390/s120303145
Received: 21 February 2012 / Revised: 28 February 2012 / Accepted: 29 February 2012 / Published: 7 March 2012
Cited by 11 | PDF Full-text (1837 KB) | HTML Full-text | XML Full-text
Abstract
The design and realization of health monitoring applications has attracted the interest of large communities both from industry and academia. Several research challenges have been faced and issues tackled in order to realize effective applications for the management and monitoring of people with
[...] Read more.
The design and realization of health monitoring applications has attracted the interest of large communities both from industry and academia. Several research challenges have been faced and issues tackled in order to realize effective applications for the management and monitoring of people with chronic diseases, people with disabilities, elderly people. However, there is a lack of efficient tools that enable rapid and possibly cheap realization of reliable health monitoring applications. The paper presents Uranus, a service oriented middleware architecture, which provides basic functions for the integration of different kinds of biomedical sensors. Uranus has also distinguishing characteristics like services for the run-time verification of the correctness of running applications and mechanisms for the recovery from failures. The paper concludes with two case studies as proof of concept. Full article

Journal Contact

MDPI AG
Sensors Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
sensors@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Sensors
Back to Top