Γκουμόπουλος Χρήστος

Περίληψη:
The GAME2AWE platform aims to provide a versatile tool for elderly fall prevention through exergames that integrate exercises, and simulate real-world environments and situations to train balance and reaction time using augmented and virtual reality technologies. In order to lay out the research area of interest, a review of the literature on systems that provide exergames for the elderly utilizing such technologies was conducted. The proposed use of augmented reality exergames on mobile devices as a complement to the traditional Kinect-based approach is a method that has been examined in the past with younger individuals in the context of physical activity interventions, but has not been studied adequately as an exergame tool for the elderly. An evaluation study was conducted with seniors, using multiple measuring scales to assess aspects such as usability, tolerability, applicability, and technology acceptance. In particular, the Unified Theory of Acceptance and Use of Technology (UTAUT) model was used to assess acceptance and identify factors that influence the seniors’ intentions to use the game platform in the long term, while the correlation between UTAUT factors was also investigated. The results indicate a positive assessment of the above user experience aspects leveraging on both qualitative and quantitative collected data.

Περίληψη:
The Internet of Things (IoT) paradigm advocates the massive use of sensing and communication technologies embedded in the physical world, which provides the potential to collect huge volumes of data and connect them to intelligent systems. As the number of IoT devices is increasing with geometric progress, ensuring interoperability and handling of the big heterogeneous data they generate is of major importance for the development of smart applications and services. In this context, a systematic review of contemporary IoT frameworks based on a multi-level interoperability consideration is performed and findings are critically discussed. Challenges and open issues that emerge in this research area are pointed out, and research opportunities and insights are suggested. Motivated by the shortcomings of the current solutions to support open, interoperable, intelligent and collaborative IoT environments, the concept of Semantic Social Network of Things (SSNT) is introduced. SSNT specifies the integration of device-to-device collaborative services which semantically enable heterogeneous objects to (socially) interact and participate in communities of smart objects. By establishing social relationships and taking collaborative actions, such communities can support users to achieve their goals. A middleware-based framework architecture is presented to enact the SSNT abstraction, and a proof-of-concept application in the smart agriculture domain is outlined to demonstrate important features of this approach.

Περίληψη:
Pervasive Computing (PerComp) research remains to this date technology-centric, requiring more focus on utilizing human and societal intelligence. To bridge this gap we motivate the need for a conceptual framework that provides a vision for enabling end-users to participate actively in the design of PerComp applications. The framework in particular provides guidance for the development of tools that allow end-users to configure their own smart environments. It emphasizes the benefits of using Smart Objects (SOs) as components of PerComp applications under a system engineering perspective and the benefits of using affordances as dynamic connectable capabilities under a user experience perspective. A generic application model is developed within the framework that manifests the concepts governing the structure and operation of applications composed by connecting SOs together and adhering to a rule-based behavior. A multi-layered software mediator is defined to provide a platform for the runtime support of such PerComp applications. Theoretical foundations for the key concepts adopted regarding the interaction design and system engineering perspectives are discussed and the results of a user evaluation study focusing on the perceived usability of the high-level conceptual models and the developed tools are reported.

Περίληψη:
Ubiquitous Computing, Mobile Computing and the Internet of Things (collectively referred to as UMI herein) involve recent advances in technology areas such as low-cost and miniaturized processing and sensing technologies, high-bandwidth wireless networking and so on. UMI technologies can also support the recent attempts to reform computing education. Yet, to accomplish this potential, relevant UMI learning scenarios are needed. Creating such scenarios can be challenging, since this particular field of computing education is still in its infancy. This paper discusses learning design knowledge which can orientate the future design of UMI learning scenarios. Content analysis was applied on ten quality UMI-oriented learning scenarios. The scenarios were freely accessible in online platforms, and they were designed for middle school education and for the UMI domain. Two different methodological approaches were employed: the first one involved mapping the scenarios to existing predefined learning design elements (i.e. design concepts, design principles, and design patterns). The learning design elements were previously defined in an online database and they involved ubiquitous tools. The second method involved mapping the scenarios to the parameters of a UMI learning ecology. The performed analysis revealed design concepts, principles, patterns and key characteristics underpinning the selected UMI scenarios: they cater for students’ active learning and engage them in interdisciplinary projects in which students are learning across contexts in groups and solve meaningful problems that exploit the functionalities of the UMI technologies. Several recommendations concerning the creation of quality UMI learning scenarios are suggested, such as: striking a balance between conceptual understanding and 21st century lifelong learning skills, highlighting how students’ collaboration is expected to happen in a UMI scenario, providing many opportunities for instructional scaffolding and explicitly mentioning spatiotemporal aspects of the UMI scenarios. These findings could be of interest to computing education researchers, tutors, and curriculum designers who wish to design UMI oriented educational scenarios.

Περίληψη:
Stress management is related to improved senior well-being and health. The purpose of this work is to identify individual characteristics that suggest the existence of stress and associate these characteristics with features extracted from biometric signals. For identifying these characteristics, on the one hand emotional/psychological measurements are collected using specific questionnaires and on the other hand features are extracted from biosignals collected using wireless sensors. The results of a pilot study with the participation of 12 seniors (mean age 59.7 ±5.8) are reported. Our results indicate that electrodermal activity and heart rate variability features are valid stress indicators for seniors.

Περίληψη:
This paper describes the design and calibration of a highly accurate temperature measurement system for pervasive computing applications. A negative temperature coefficient (NTC) thermistor with high resistance tolerance is interfaced through a conditioning circuit to a 12-bit digital converter of a wireless microcontroller. The system is calibrated to minimize the effect of component uncertainties and achieves an accuracy of ±0.03 °C on average (±0.05 °C in worst cases) in a 5 °C to 45 °C range. The calibration process is based on a continuous temperature sweep, while calibration data are simultaneously logged to reduce the delays and cost of conventional calibration approaches. An uncertainty analysis is performed to support the validity of the reported performance results. The described approach for interfacing the thermistor to the hardware platform can be straightforwardly adjusted for different thermistors, temperature ranges/accuracy levels/resolutions, and voltage ranges. The low power communication combined with the energy consumption optimization adopted enable an operation to be autonomic for several months to years depending on the application’s measurement frequency requirements. The system cost is approximately $45 USD in components, while its design and compact size allow its integration with extended monitoring systems in various pervasive computing environments. The system has been thoroughly tested and validated in a field trial concerning a precision agriculture application and is currently used in a health monitoring application.

Περίληψη:
Smart mobile devices, due to their ubiquitous nature and high level penetration in everyday life, can be a key component of an Ambient Assisted Living system to improve the quality of life of older people. This paper presents the development and evaluation of Senior App Suite, a system created for assisting seniors’ personal independence and social inclusion. The system integrates mobile computing combined with web and service-oriented technologies to offer a mobile application suite that seniors can easily use to access services, spanning various application areas such as social networking, emergency detection and overall well-being. The research hypothesis is that using such services can be beneficial for decreasing social isolation. There is quantitative indication that this assumption is realistic backed up also by the qualitative analysis from the user’s feedback derived during a pilot study (n = 22) suggesting that Senior App Suite can motivate people in new activities, maintain connection with social ties, give joy and self-confidence, and increase the frequency and quality of social interactions. Our contribution is a detailed methodology spanning the research, design, development, and evaluation of a solution that aims to improve the quality of life of seniors while addressing open issues identified in related initiatives.

Περίληψη:
Engineering of pervasive computing (PerComp) systems is a new scientific field and from an educational perspective needs to draw from a large number of knowledge domains. The appearance of related courses in computer science curricula has a decade history, but the growth of interest has led in recent years to the design of more advanced PerComp educational programs. In this paper we present our experiences in organizing, managing and teaching a PerComp curriculum at a postgraduate level since 2010 using distance learning methodologies in the Hellenic Open University (HOU). We discuss the distinct characteristics and related challenges of distance education and how these characteristics affected program organization, educational material structuring, laboratory courses delivering, and student assessment. We report our main findings and conclusions extracted by an online survey filled by students enrolled in the program, discuss the lessons learned and also provide a number of suggestions for further development.

Περίληψη:
Precision irrigation based on the “speaking plant” approach can save water and maximize crop yield, but implementing irrigation control can be challenging in system integration and decision making. In this paper we describe the design of an adaptable decision support system and its integration with a wireless sensor/actuator network (WSAN) to implement autonomous closed-loop zone-specific irrigation. Using an ontology for defining the application logic emphasizes system flexibility and adaptability and supports the application of automatic inferential and validation mechanisms. Furthermore, a machine learning process has been applied for inducing new rules by analyzing logged datasets for extracting new knowledge and extending the system ontology in order to cope, for example, with a sensor type failure or to improve the accuracy of a plant state diagnosis. A deployment of the system is presented for zone specific irrigation control in a greenhouse setting. Evaluation of the developed system was performed in terms of derivation of new rules by the machine learning process, WSN performance and mote lifetime. The effectiveness of the developed system was validated by comparing its agronomic performance to traditional agricultural practices.

Περίληψη:
Many have attempted to bring the exciting pervasive computing research area into the classroom. Here, we present our experience in organizing and teaching a postgraduate pervasive computing program via distance learning at the Hellenic Open University.

Περίληψη:
This paper describes a novel approach to realize symbiotic ecologies within Next Generation Ambient Intelligent Environments (NGAIEs). The proposed approach comprises novel ontology and agent technologies allowing for adaptation on a variety of levels. The metaphor of symbiotic ecologies reflects a meaningful integration of relevant entities (i.e., services, devices, agents) and information within NGAIEs to accomplish a specific user’s task by relying on the symbiotic relationship of the user and his/her intelligent environment. We adopt a service-oriented architecture, combined with (a) intelligent agents that support adaptive task realization and enhanced human-machine interaction and (b) ontologies that provide knowledge representation, management of heterogeneity at user and device level, semantically rich resource discovery and adaptation using ontology alignment mechanisms. In this article, we analyse heterogeneity concerning user behaviour and adaptive user interaction modelling. Furthermore, we focus on heterogeneity regarding the representation of the states of entities and their availability over different networks. The paper will also report on the deployment of a system prototype in a real world setting which is the intelligent flat (iSpace) at the University of Essex.

Περίληψη:
In order for Ambient Ecologies (AEs) to provide a viable and functional service to people in their day-to-day lives, it is paramount for the AEs to autonomously learn and adapt to the requirements of the human users living in their everyday environments which are populated with a large number of potentially heterogeneous artefacts/devices (different manufacturers, different descriptions of properties, etc.). In this paper, we will propose the concept of emerging and adaptive fuzzy logic based behaviours which are based on dynamically created activity spheres. We will provide details both on the conceptual notions behind this approach as well as the detailed results from a real world deployment of our proposed system.

Περίληψη:
Pervasive Awareness Systems (PASs) collect awareness information from sensors and devices in smart environments and can present it to remote users by using various awareness objects. In this paper, we present a pervasive awareness management framework for supporting the conception, design and realisation of applications that foster social connectedness between communities. The framework consists of • an awareness model that considers user disturbance and privacy • a service-oriented platform that provides core awareness services • assorted tools that support communities to create, adapt and appropriate such applications. A PAS prototype is presented along with a usability evaluation of the tools.

Περίληψη:
As the computer disappears in the environments surrounding our activities, the objects therein become augmented with sensors, actuators, processors, memories, wireless communication modules and they can receive, store, process and transmit information. In addition to objects, spaces also undergo a change towards becoming smart and eventually Ambient Intelligence (AmI) spaces. In order to model the way everyday activities are carried out within an AmI environment, we introduce the notion of ‘‘activity sphere’’. In this paper, we are interested in the ontology-based representation of activity spheres from two different perspectives (as creators and as observers), as well as the modeling and control of the dynamic nature of activity spheres.

Περίληψη:
Our research has been performed in the context of the EU-funded R&D project PLANTS. In this paper, we describe an ontology-driven architecture for developing systems that can be used in precision agriculture applications. Central to our approach is the use of an ontology, which views plants and associated computation as an integral part and allows the interaction of plants and artefacts in the form of synergistic mixed societies. PLANTS ontology sets up a conceptual framework that combines the knowledge about sensors, actuators and other domain concepts available, on the one hand, and the biological studies about plant stressing and sensing mechanisms and consequent plant behaviour, on the other hand, to make plants a proactive component of agricultural systems.

Περίληψη:
An important characteristic of ubiquitous computing (UbiComp) environments is the integration of information, communication and sensing technologies into our everyday objects, giving rise to a new proactive computing model in homes. A smart home uses networked sensors, devices and appliances to build an intelligent environment in which many activities in the home are automated and where devices and services seamlessly cooperate to support domestic tasks. Programming and maintaining such an infrastructure is challenging because suitable abstractions are currently missing. In this work we have attempted to define ambient ecologies as a metaphor for modeling UbiComp applications, specify design patterns and programming principles and develop infrastructure to provide a paradigm of application engineering and tools to support ambient ecology designers, developers and end-users. We describe our model and the middleware architecture and present the engineering of applications in a smart home environment.

Περίληψη:
Given the resulting complexity of the ambient applications that one can form in the Ubiquitous or Pervasive Computing domain it is required to abstract the intricacies of a heterogeneous supporting environment (e.g., intrinsic characteristics of specific communication models) away from the application logic. These applications will be characterized by the increasing ubiquity of interactions between many possibly heterogeneous artifacts and services. This paper presents the Plug/Synapse abstraction, which provides a conceptual model for building ubiquitous computing applications in a high-level programming manner. GAS-OS is the software layer that implements the Plug/Synapse model and the concepts encapsulated in GAS, a generic architectural style, which can be used to describe everyday environments populated with computational artifacts. The paper examines also the design and architecture of GAS-OS, which is the minimum set of modules and functionalities that every device must afford, in order to be a ubiquitous computing artifact and participate in artifact collections.

Περίληψη:
Trip generation is the most time consuming phase in the solution process of crew scheduling problems faced by large transportation companies such as airlines and railways. A large number of trips must be constructed while satisfying a complex set of regulations. In this paper, we present an efficient trip generation method that utilizes originally a rule modeling system in order to reduce the corresponding search space. Special pruning rules are defined using a high-level rule language, which also supports the modeling of the business regulations required in the scheduling process. In addition, the legality checking mechanism involved has been tuned to perform efficiently in order to cope with the vast amount of the legality checks required by the trip generator. The algorithms are tested as a module for a crew scheduling application satisfying the tight response time requirements of a production system. We present experimental results based on problems provided by a major European airline that validate the usefulness and applicability of our work.

Περίληψη:
The day-to-day resource management problem is caused by a set of unexpected events which disturb the planned daily activities and thus change the long-term optimal schedule. The solution to this problem presupposes that all the regulations for the handling of resources in the particular application domain have been satisfied. In this paper, a new approach to handling the rules in the resource management problem is presented. An object-oriented application specific language that allows the flexible expression of the rules, as well as the corresponding rule handling subsystem are presented. The design of the whole system is based on a generic meta-model derived from the object-oriented paradigm. This makes the system applicable to a wide range of problem domains such as repairs management, airline and other transportation scheduling, school scheduling, etc. The system has been developed and tested as a subsystem of the DAYSY system, a day-to-day resource management system for the airline domain.