Properties of Multilayered Interphases in SiC/SiC Chemical-Vapor-Infiltrated Composites with "Weak" and "Strong" Interfaces

The interfacial properties of SiC/SiC composites with interphases that consist of (C-SiC) sequences deposited on the fibers have been determined by single-fiber push-out tests. The matrix has been reinforced with either as-received or treated Nicalon fibers. The measured interfacial properties are correlated with the fiber-coatingbond strength and the number of interlayers. For the composites reinforced with as-received (weakly bonded) fibers, interfacial characteristics are extracted from the nonlinear portion of the stress-displacement curve by fitting Hsueh's push-out model. The interfacial characteristics are controlled by the carbon layer adjacent to the fiber. The resistance to interface crack growth and fiber sliding increases as the number of (C-SiC) sequences increases. For the composites reinforced with treated (strongly bonded) fibers, the push-out curves exhibit an uncommon upward curvature, which reflects different modes of interphase cracking and a contribution of fiber roughness.     

A Novel Trust-Aware Geographical Routing Scheme for Wireless Sensor Networks

Wireless sensor networks are vulnerable to a wide set of security attacks, including those targeting the routing protocol functionality. The applicability of legacy security solutions is disputable (if not infeasible), due to severe restrictions in node and network resources. Although confidentiality, integrity and authentication measures assist in preventing specific types of attacks, they come at high cost and, in most cases, cannot shield against routing attacks. To face this problem, we propose a secure routing protocol which adopts the geographical routing principle to cope with the network dimensions, and relies on a distributed trust model for the detection and avoidance of malicious neighbours. A novel function which adaptively weights location, trust and energy information drives the routing decisions, allowing for shifting emphasis from security to path optimality. The proposed trust model relies on both direct and indirect observations to derive the trustworthiness of each neighboring node, while it is capable of defending against an increased set of routing attacks including attacks targeting the indirect trust management scheme. Extensive simulation results reveal the advantages of the proposed model.     

An architectural approach towards Future Media Internet

Internet is the most important information exchange means nowadays and has become the core communication environment, not only for business relations, but also for social and human interaction. Yet, the immense success of Internet has created even higher hopes and expectations for new immersive and real-time applications and services. However, there are no guarantees that the current Internet will be able to support them. To face the new requirements coming from these new applications and services, several architectural approaches have been proposed. Evolutionary and clean-slate approaches, based on content-centric architectures, have been proposed for meeting new requirements regarding media. This paper highlights the main architectural functions and presents a revolutionary protocol stack and a holistic architectural approach that targets Future Media Internet (FMI). Among the architectural functions and the holistic approach, the paper presents solutions to overcome the current content delivery limitations, moving intelligence in the network and converting it into a content oriented/centric network, that goes well beyond current CDNs; supporting the functionalities for producing, publishing, caching, finding and consuming content; and a novel Future Media Internet protocol stack and network architecture.     

Domestic Water Charges in Ireland - Issues and Challenges Conveyed through Social Media

This paper analyses a Twitter dataset to explore water governance and stakeholder engagement during the introduction of domestic water charges in Ireland. The results highlight active Twitter use during the analysis period, reflective of widespread protest centred on a new utility, Irish Water. The analysis shows protest activities were dispersed and not cohesive, with tweets largely focused on economic and political issues and not on the provision of a sustainable water supply. The findings extend our understanding of these events and provide some insights into the role of social media in water governance and stakeholder engagement issues in an Irish and wider context.     

Human motion recognition using a wireless sensor-based wearable system

The future of human computer interaction systems lies in how intelligently these systems can take into account the user’s context. Research on recognizing the daily activities of people has progressed steadily, but little focus has been devoted to recognizing jointly activities as well as movements in a specific activity. For many applications such as rehabilitation, sports medicine, geriatric care, and health/fitness monitoring the importance of combined recognition of activity and movements can drive health care outcomes. A novel algorithm is proposed that can be tuned to recognize on-the-fly range of activities and fine movements within a specific activity. Performance of the algorithm and a case study on obtaining optimal features from sensor and parameter values for the algorithm to detect fine motor movements are presented.     

Seamless Content Delivery over Mobile 3G+/4G Networks

Widespread and affordable mobile broadband access opens up opportunities for delivery of new streaming services everywhere and anytime. However, what is expected to fundamentally change the way how people use the network is the ability to produce, and seamlessly deliver and share their own multimedia content. In this paper we describe the content distribution and adaptation architecture that we have implemented and tested, the results utilising new coding formats of video coding (e.g. SVC, MVC) and new methods for increasing the robustness of video delivery.