Abstract: This work addresses networked embedded systems enabling the seam-
less interconnection of smart building automations to the Internet and
their abstractions as webservices. In our approach, such abstractions are
used to primarily create a exible, holistic and scalable system and allow
external end-users to compose and run their own smart/green building
automation application services on top of this system.
Towards this direction, in this paper we present a smart building test-
bed consisting of several sensor motes and spanning across seven rooms.
Our test-bed's design and implementation simultaneously addresses sev-
eral corresponding system layers; from hardware interfaces, embedded
IPv6 networking and energy balancing routing algorithms to a RESTful
architecture and over the web development of sophisticated, smart, green
scenarios. In fact, we showcase how IPv6 embedded networking combined
with RESTful architectures make the creation of building automation ap-
plications as easy as creating any other Internet Web Service.
Abstract: In this work we present the architecture and implementation of WebDust, a software platform for managing multiple, heterogeneous (both in terms of software and hardware), geographically disparate sensor networks. We describe in detail the main concepts behind its design, and basic aspects of its implementation, including the services provided to end-users and developers. WebDust uses a peer-to-peer substrate, based on JXTA, in order to unify multiple sensor networks installed in various geographic areas. We aim at providing a software framework that will permit developers to deal with the new and critical aspects that networks of sensors and tiny devices bring into global computing, and to provide a coherent set of high level services, design rules and technical recommendations, in order to be able to develop the envisioned applications of global sensor networks. Furthermore, we give an overview of a deployed distributed testbed, consisting of a total 56 nodes and describing in more detail two specific testbed sites and the integration of the related software and hardware technologies used for its operation with our platform. Finally, we describe the design and implementation of an interface option provided to end-users, based on the popular Google Earth application.
Abstract: In this work, we present a concrete framework, based on webservices-oriented architecture, for integrating small programmable objects in the web of things.
Functionality and data gathered by the Small Programmable Objects (SPO) are exposed using WebServices. Based on this, by exploiting XML encoding, SPO can be comprehensible by any web application. The architecture proposed is focused in providing secure and efficient interoperability between SPO and the web.
Additionally, the proposed architecture provides management capabilities for deploying, maintaining and operating SPO applications across multiple networks.
We present the multilayer architecture of our system and its implementation, which uses a combination of Java Standard and Micro Editions. Finally, we present a case study presenting our implementation. In this application we use SunSPOTs, which are wireless network motes developed by Sun Microsystems.
Abstract: Raising awareness among young people and changing their behaviour and habits concerning energy usage is key to achieving sustained energy saving. Additionally, young people are very sensitive to environmental protection so raising awareness among children is much easier than with any other group of citizens. This work examines ways to create an innovative Information & Communication Technologies (ICT) ecosystem (including web-based, mobile, social and sensing elements) tailored specifically for school environments, taking into account both the users (faculty, staff, students, parents) and school buildings, thus motivating and supporting young citizens¢ behavioural change to achieve greater energy efficiency. A mixture of open-source IoT hardware and proprietary platforms on the infrastructure level, are currently being utilized for monitoring a fleet of 18 educational buildings across 3 countries, comprising over 700 IoT monitoring points. Hereon presented is the system¢s high-level architecture, as well as several aspects of its implementation, related to the application domain of educational building monitoring and energy efficiency. The system is developed based on open-source technologies and services in order to make it capable of providing open IT-infrastructure and support from different commercial hardware/sensor vendors as well as open-source solutions. The system presented can be used to develop and offer new app-based solutions that can be used either for educational purposes or for managing the energy efficiency of the building. The system is replicable and adaptable to settings that may be different than the scenarios envisioned here (e.g., targeting different climate zones), different IT infrastructures and can be easily extended to accommodate integration with other systems. The overall performance of the system is evaluated in real-world environment in terms of scalability, responsiveness and simplicity.
Abstract: The Greek School Network (GSN) is the nationwide network that connects all units of primary and secondary education in Greece. GSN offers a significant set of diverse services to more than 15.000 schools and administrative units, and more than 60.000 teachers, placing GSN second in infrastructure size nationwide. GSN has relied on the emerging power of open source software to build cutting-edge services capable of covering internal administrative and monitoring needs, end user demands, and, foremost, modern pedagogical requirements for tools and services. GSN provides a wide set of advanced services, varying from web mail to virtual classrooms and synchronous/asynchronous tele-education. This paper presents an evaluation of GSN open source services based on the opinions of users who use GSN for educational purposes, and on usage and traffic measurement statistics. The paper reaches the conclusion that open source software provides a sound technological platform that meets the needs for cutting edge educational services deployment, and innovative, competitive software production for educational networks.
Abstract: Service Oriented Computing and its most famous implementation technology WebServices (WS) are becoming an important enabler of networked business models. Discovery mechanisms are a critical factor to the overall utility of WebServices. So far, discovery mechanisms based on the UDDI standard rely on many centralized and area-specific directories, which poses information stress problems such as performance bottlenecks and fault tolerance. In this context, decentralized approaches based on Peer to Peer overlay networks have been proposed by many researchers as a solution. In this paper, we propose a new structured P2P overlay network infrastructure designed for WebServices Discovery. We present theoretical analysis backed up by experimental results, showing that the proposed solution outperforms popular decentralized infrastructures for web discovery, Chord (and some of its successors), BATON (and it¢s successor) and Skip-Graphs.
Abstract: Wireless sensor networks can be very useful in applications that require the detection of crucial events, in physical environments subjected to critical conditions, and the propagation of data reporting their realization to a control center. In this paper we propose jWebDust, a generic and modular application environment for developing and managing applications that are based on wireless sensor networks. Our software architecture provides a range of services that allow to create customized applications with minimum implementation effort that are easy to administrate. We move beyond the ?networking-centric? view of sensor network research and focus on how the end user (administrator, control center supervisor, etc.) will visualize and interact with the system.
We here present its open architecture, the most important design decisions, and discuss its distinct features and functionalities. jWebDust allows heterogeneous components to interoperate (real world sensor networks will rarely be homogeneous) and allows the integrated management and control of multiple such networks by also defining web-based mechanisms to visualize the network state, the results of queries, and a means to inject queries in the network. The architecture also illustrates how existing protocols for various services can interoperate in a bigger framework - such as the tree construction, query routing, etc.
Abstract: Recommender Systems (RSs) have been extensively utilized as a means of reducing the information overload and offering travel recommendations to tourists. The emerging mobile RSs are tailored to mobile device users and promise to substantially enrich tourist experiences, recommending rich multimedia content, context-aware services, views/ratings of peer users, etc. New developments in mobile computing, wireless networking, web technologies and social networking leverage massive opportunities to provide highly accurate and effective tourist recommendations that respect personal preferences and capture usage, personal, social and environmental contextual parameters. This article follows a systematic approach in reviewing the state-of-the-art in the field, proposing a classification of mobile tourism RSs and providing insights on their offered services. It also highlights challenges and promising research directions with respect to mobile RSs employed in tourism.
Abstract: Webservices are becoming an important enabler of the Semantic Web. Besides the need for a rich description mechanism, Web Service information should be made available in an accessible way for machine processing. In this paper, we propose a new P2P basedapproach for WebServices discovery. Peers that store WebServices information, such as data item descriptions, are efficiently located using a scalable and robust data indexing structure for Peer-to-Peer data networks, NIPPERS. We present a theoretical analysis which shows that the communication cost of the query and update operations scale double-logarithmically with the number of NIPPERS nodes. Furthermore, we show that the network is robust with respect to failures fulfilling quality of webservices requirements.
Abstract: In many cryptographic applications it is necessary to generate
elliptic curves (ECs) with certain security properties. These curves
are commonly constructed using the Complex Multiplication method
which typically uses the roots of Hilbert or Weber polynomials. The former
generate the EC directly, but have high computational demands,
while the latter are faster to construct but they do not lead, directly, to
the desired EC. In this paper we present in a simple and unifying manner
a complete set of transformations of the roots of a Weber polynomial to
the roots of its corresponding Hilbert polynomial for all discriminant values
on which they are defined. Moreover, we prove a theoretical estimate
of the precision required for the computation of Weber polynomials. Finally,
we experimentally assess the computational efficiency of theWeber
polynomials along with their precision requirements for various discriminant
values and compare the results with the theoretical estimates. Our
experimental results may be used as a guide for the selection of the most
efficient curves in applications residing in resource limited devices such as
smart cards that support secure and efficient Public Key Infrastructure
Abstract: In this paper we present the design of jWebDust, a generic and modular application environment for developing and managing applications based on wireless sensor networks that are accessible via the internet. Our software architecture provides a range of services that allow to create customized web-based applications with minimum implementation effort that are easy to administrate. We here present its open architecture, the most important design decisions, and discuss its distinct features and functionalities. jWebDust allows heterogeneous components to interoperate and the integrated management and control of multiple such networks by defining web-based mechanisms to visualize the network state, the results of queries, and a means to inject queries in the network.
Abstract: In this work we present the design of jWebDust, a
software environment for monitoring and controlling sensor networks via a web interface. Our software architecture provides a range of services that allow to create customized applications with minimum implementation effort that are easy to administrate. We present its open architecture, the most important design decisions, and discuss its distinct features and functionalities. jWebDust will allow heterogeneous components to operate in the same sensor network, and the integrated management and control of multiple such networks by defining web-based mechanisms to visualize the network state, the results of queries, and a means to inject queries in the network.
Abstract: For the Internet of Things to ﬁnally become a reality, obstacles on different levels need to be overcome. This is especially true for the upcoming challenge of leaving the domain of technical experts and scientists. Devices need to connect to the Internet and be able to offer services. They have to announce and describe these services in machine understandable ways so that user-facing systems are able to ﬁnd and utilize them. They have to learn about their physical surroundings, so that they can serve sensing or acting purposes without explicit conﬁguration or programming. Finally, it must be possible to include IoT devices in complex systems that combine local and remote data, from different sources, in novel and surprising ways.
We show how all of that is possible today. Our solution uses open standards and state-of-the art protocols to achieve this. It is based on 6LowPAN and CoAP for the communications part, semantic web technologies for meaningful data exchange, autonomous sensor correlation to learn about the environment, and software built around the Linked Data principles to be open for novel and unforeseen applications.
Abstract: We present the basic concepts behind the design and implementation of WebDust, a peer-to-peer platform for organizing,
monitoring and controlling wireless sensor networks, along with a discussion of its application regarding an actual testbed.
Our software architecture provides a range of services that allow to create customized applications with relatively low
implementation overhead. WebDust aims to allow heterogeneous components to operate in the same sensor network, and
give the ability to manage and control large numbers of such networks, possibly on a global scale. We also give insight to
several applications that can be implemented using our platform, and a description of our current testbed.