On the performance of key pre-distribution for RPL-based IoT Networks

A core ingredient of the the Internet of Things (IoT) is the use of deeply embedded resource constrained devices, often connected to the Internet over Low Power and Lossy Networks. These constraints compounded by the need for unsupervised operation within an untrusted environment create considerable challenges for the secure operation of these systems. In this paper, we propose a novel method to secure an edge IoT network using the concept of key pre-distribution proposed by Eschenauer and Gligor in the context of distributed sensor networks. First, we investigate the performance of the unmodified algorithm in the Internet of Things setting and then analyse the results with a view to determine its performance and thus its suitability in this context. Specifically, we investigate how ring size influences performance in order to determine the required ring size that guarantees full connectivity of the network. We then proceed to propose a novel RPL objective function and associated metrics that ensure that any node that joins the network can establish secure communication with Internet destinations. , N., , H., , Th., , Th., , A., , P

Secure routing in IoT networks with SISLOF

In this paper, we propose a modification of the RPL routing protocol by introducing the SISLOF Objective Function ensuring that only motes that share a suitable key can join the RPL routing table. This will ensure that all IoT network motes connect in a secure method. SISLOF uses the concept of key pre-distribution proposed by Eschenauer and Gligor in the context of the Internet of Things. First, we discuss related work that provide evidence that the key pre-distribution scheme in the context of the IoT with default RPL metrics fails to achieve the full network connectivity using the same ring size, however full time connectivity can be achieved but with a great cost in term of the large rings sizes. We introduce the SISLOF Objective Function and explain the modification it does to the RPL messages (DIO and DAO). We finally show the performance of the key pre-distribution in the context of the Internet of Things when SISLOF is used as the Objective Function of the RPL routing protocol

The effect of representation location on interaction in a tangible learning environment

Drawing on the 'representation' TUI framework [21], this paper reports a study that investigated the concept of 'representation location' and its effect on interaction and learning. A reacTIVision-based tangible interface was designed and developed to support children learning about the behaviour of light. Children aged eleven years worked with the environment in groups of three. Findings suggest that different representation locations lend themselves to different levels of abstraction and engender different forms and levels of activity, particularly with respect to speed of dynamics and differences in group awareness. Furthermore, the studies illustrated interaction effects according to different physical correspondence metaphors used, particularly with respect to combining familiar physical objects with digital--based table-top representation. The implications of these findings for learning are discussed

Self-tracking in Parkinson’s: The lived efforts of self-management

People living with Parkinson's disease engage in self-tracking as part of their health self-management. Whilst health technologies designed for this group have primarily focused on improving the clinical assessments of the disease, less attention has been given to how people with Parkinson's use technology to track and manage their disease in their everyday experience. We report on a qualitative study in which we systematically analysed posts from an online health community (OHC) comprising people with Parkinson's (PwP). Our findings show that PwP track a diversity of information and use a wide range of digital and non-digital tools, informed by temporal and structured practices. Using an existing framework of sensemaking for chronic disease self-management, we also identify new ways in which PwP engage in sensemaking, alongside a set of new challenges that are particular to the character of this chronic disease. We relate our findings to technologies for self-tracking offering design implications

Public goods: using pervasive computing to inspire grassroots activism

Pervasive computing technology enables social mapping and sharing of local knowledge to create relationships beyond established social and cultural boundaries; it also enables the development of new practices around place, identity, and community. For more than a decade, the authors have explored the potential costs and benefits of using pervasive computing to facilitate codiscovery with communities across London, with the aim of supporting grassroots activities that help urban communities take action toward environmental sustainability. A core ingredient of these explorations is the making of artifacts to provide both the focus for communal experiences and a way to create public goods--that is, tangible representations of the intangible things we value most about our communities. Specific projects explore alternative material representations of stories, skills, games, songs, techniques, memories, hyper-local lore, and experiential knowledge of the environment. In this article, the authors present work that investigates how public goods can provide the focus for the development of grassroots community groups focused on hyper-local concerns. They also show how creating objects constructed to communicate the activist message of these communities in a tangible manner provides more affective and illustrative ways to facilitate the codiscovery of uncommon insights. This article is part of a special issue on pervasive analytics and citizen science

Efficient leaching of cellulases produced by Trichoderma harzianum in solid state fermentation

Recovery of cellulases from solid state culture of #Trichoderma harzianum$ was efficiently achieved by hydraulic pressing. Pressing of fermented solids yielded carboxymethyl-cellulase (CMCase) extraction efficiency of 71% and a ratio of leachate to fermented solids of 0.58 (v/w). Addition of water to pressed solids and second pressing improved the efficiency (95%) with simultaneous increase in the ratio to 1.16 (v/w). The overall extraction of filter paper activity was lower (85%) than that of CMCase. This technique is simple and its extraction efficiency is similar to that obtained in multiple-contact counter-current systems. The hydraulic press in its individuality was not used earlier to leach the product from fermented solids. (Résumé d'auteur

Magnetospheric considerations for solar system ice state

The current lattice configuration of the water ice on the surfaces of the inner satellites of Jupiter and Saturn is likely shaped by many factors. But laboratory experiments have found that energetic proton irradiation can cause a transition in the structure of pure water ice from crystalline to amorphous. It is not known to what extent this process is competitive with other processes in solar system contexts. For example, surface regions that are rich in water ice may be too warm for this effect to be important, even if the energetic proton bombardment rate is very high. In this paper, we make predictions, based on particle flux levels and other considerations, about where in the magnetospheres of Jupiter and Saturn the ∼MeV proton irradiation mechanism should be most relevant. Our results support the conclusions of Hansen and McCord (2004), who related relative level of radiation on the three outer Galilean satellites to the amorphous ice content within the top 1 mm of surface. We argue here that if magnetospheric effects are considered more carefully, the correlation is even more compelling. Crystalline ice is by far the dominant ice state detected on the inner Saturnian satellites and, as we show here, the flux of bombarding energetic protons onto these bodies is much smaller than at the inner Jovian satellites. Therefore, the ice on the Saturnian satellites also corroborates the correlation

The 3D Menpo Facial Landmark Tracking Challenge

This is the final version of the article. It is the open access version, provided by the Computer Vision Foundation. Except for the watermark, it is identical to the IEEE published version. Available from IEEE via the DOI in this record.Test descriptionRecently, deformable face alignment is synonymous to the task of locating a set of 2D sparse landmarks in intensity images. Currently, discriminatively trained Deep Convolutional Neural Networks (DCNNs) are the state-of-the-art in the task of face alignment. DCNNs exploit large amount of high quality annotations that emerged the last few years. Nevertheless, the provided 2D annotations rarely capture the 3D structure of the face (this is especially evident in the facial boundary). That is, the annotations neither provide an estimate of the depth nor correspond to the 2D projections of the 3D facial structure. This paper summarises our efforts to develop (a) a very large database suitable to be used to train 3D face alignment algorithms in images captured "in-the-wild" and (b) to train and evaluate new methods for 3D face landmark tracking. Finally, we report the results of the first challenge in 3D face tracking "in-the-wild".The work of S. Zafeiriou and A. Roussos has been partially funded by the EPSRC Project EP/N007743/

Pectinase-hyperproducing mutants of Aspergillus niger C28B25 for solid-state fermentation of coffee pulp

The aim of this study was to improve mold strains for the production of pectinases by solid-state fermentation (SSF) of coffee pulp. A screening of 248 strains, isolated in Mexico's coffee-growing areas, permitted us to select a wild strain of #Aspergillus niger$ which in 72 h attains a peak production of 27.7 U ml-1(138 U g-1 dry pulp) of pectinase measured by viscosimetry. Though the use of a selective culture medium with low water activity (aw = 0.954) with 2-deoxy-glucose (2DG) it was possible to isolate pectinase-hyperproductive mutant strains for SSF(44.5 U ml-1, 228 U g-1 dry pulp). Derepressed mutant strains that hyperproduced pectinase by submerged fermentation (SmF) were also obtained using a classic selective medium with high water activity (pectin + 2DG) with aw = 0.999. A comparison between both classes of mutants, called AW96 and AW99, respectively, points out the need to design special selective media in order to obtain strains adapted either to SSF or Smf in which the aw level would be a key selecting factor. (Résumé d'auteur

Examining the Effect of Visitor Motivation on Observed Visit Strategies Using Mobile Computer Technologies

This article examines the interaction between visitor motivation and in-museum visitor behavior. The authors postulate that, in order to understand this aspect of the dynamics of museum visiting, we need to view the motivations to visit the museum as lists compiled by individual visitors but also as part of wider lists of reasons for visiting that exist in society-which they refer to as cultural itineraries. Self-report methods have been used to capture patterns of motivation that emerge across the data, which in this case were used to examine their relation to visit strategies as manifested by visitor pathways through the London Zoo. Visitor pathways were captured through the novel use of mobile location-sensing technology which offers distinct opportunities in this context that have been unexplored in audience research. The combination of standard research methodology and automated location tracking used in this study allowed us to indentify two distinct visit strategies that directly relate to social groupings with different motivations: (a) groups with an education/participation motivation, who visit exhibits only, and (b) groups with a social event motivation, who spend a considerable amount of time on nonexhibit related activities and socializing with other family members and friends. © 2013 Copyright Taylor and Francis Group, LLC