Gas chromatographic instrumentation for gas analysis of the martian atmosphere. volume i- third monthly letter technical report final report

Gas chromatographic instrumentation for gas analysis of mars atmospher

BANZKP: a Secure Authentication Scheme Using Zero Knowledge Proof for WBANs

-Wireless body area network(WBAN) has shown great potential in improving healthcare quality not only for patients but also for medical staff. However, security and privacy are still an important issue in WBANs especially in multi-hop architectures. In this paper, we propose and present the design and the evaluation of a secure lightweight and energy efficient authentication scheme BANZKP based on an efficient cryptographic protocol, Zero Knowledge Proof (ZKP) and a commitment scheme. ZKP is used to confirm the identify of the sensor nodes, with small computational requirement, which is favorable for body sensors given their limited resources, while the commitment scheme is used to deal with replay attacks and hence the injection attacks by committing a message and revealing the key later. Our scheme reduces the memory requirement by 56.13 % compared to TinyZKP [13], the comparable alternative so far for Body Area Networks, and uses 10 % less energy

Qualité de service et réseaux ad-hoc - un état de l'art

Les réseaux locaux sans fil suscitent un engouement important depuis l'apparit- ion de produits commerciaux basés sur la norme IEEE 802.11. Les débits atteints aujourd'hui par ces réseaux permettent d'exécuter des applications complexes nécessitant des garanties sur le débit, le délai ou encore la gigue des communications.Les travaux autour de Mobile IP ou d'UMTS devraient donner naissance à un certain nombre de protocoles de qualité de service pour les réseaux sans fil avec point d'accès, dans lesquels le réseauest divisé en zones géographiquesadministrées par des stations fixes.Ces travaux ne peuvent être transposés directement aux réseaux ad-hoc, dans lesquels aucune infrastructure fixe n'est présente.Ces réseaux ne disposent pas encore de protocoles de qualité deservice standards adaptés à leurs spécifici- tés. Cet article présente un état de l'art des recherches dans ce domaine

Micro-optics for Opto-genetic Neuro-stimulation with Micro-LED Arrays

The breakthrough discovery of a nanoscale optically gated ion channel protein, Channelrhodopsin 2 (ChR2), in combination with a genetically expressed optically activated ion pump, Halorhodopsin, allowed the direct stimulation and inhibition of individual action potentials with light alone. This thesis describes the development of optics and micro-optics which when used with micro-led array sources, collects and projects light efficiently and uniformly onto such opto-genetically modified specimens. When used with enhanced light gated ion channels and pumps these systems allow us to further our understanding of both brain and visual systems. Micro-LED arrays permit spatio-temporal control of neuron stimulation on sub-millisecond timescales. However, micro-led arrays are disadvantaged by the broad-angular spread of their light emission and their low spatial fill factor. We present the design of macro and micro-optics systems for use with a micro-LED arrays consisting of a matrix of 25μm diameter micro-LEDs with 150 or 80μm centre-to-centre spacing. On one system, the micro-LED array is imaged onto off-the-shelf micro-optics using macro-optics and in the other system; micro-LED array and custom micro-optics are optimised and integrated together. The two systems are designed to improve the fill-factor from 2% to more than 78% by capturing a larger fraction of the LED emission and directing it correctly to the sample plane. This approach allows low fill factor arrays to be used effectively, which in turn has benefits in terms of thermal management and electrical drive from CMOS backplane electronics. These systems were implemented as an independent set that could be connected to a variety of different microscopes available for Patch-clamp and Multi-electrode measurements. As well, the feasibility of an eye prosthesis was tested using virtual reality optics and a fake eye to stimulate ganglion cells and by doing in-vivo stimulation of the genetically modified retina of a mouse.Open Acces

A Survey of Green Networking Research

Reduction of unnecessary energy consumption is becoming a major concern in wired networking, because of the potential economical benefits and of its expected environmental impact. These issues, usually referred to as "green networking", relate to embedding energy-awareness in the design, in the devices and in the protocols of networks. In this work, we first formulate a more precise definition of the "green" attribute. We furthermore identify a few paradigms that are the key enablers of energy-aware networking research. We then overview the current state of the art and provide a taxonomy of the relevant work, with a special focus on wired networking. At a high level, we identify four branches of green networking research that stem from different observations on the root causes of energy waste, namely (i) Adaptive Link Rate, (ii) Interface proxying, (iii) Energy-aware infrastructures and (iv) Energy-aware applications. In this work, we do not only explore specific proposals pertaining to each of the above branches, but also offer a perspective for research.Comment: Index Terms: Green Networking; Wired Networks; Adaptive Link Rate; Interface Proxying; Energy-aware Infrastructures; Energy-aware Applications. 18 pages, 6 figures, 2 table

BRuIT : Bandwidth Reservation under Interferences Influence

This paper deals with the bandwidth reservation problem in ad hoc networks and with the influence that interferences between signals have on this problem. We show that interferences could decrease the applications rates. This can be a real problem for applications that need guarantees. We propose a distributed protocol (called BRuIT) for bandwidth reservation in ad hoc networks that takes into account the existence of interferences from far transmissions. The protocol is analyzed through simulations carried out under NS: we evaluate the signaling overhead required for maintaining the knowledge of existing interferences ; we show that this knowledge reduces delays in case of congestion ; we measure the time for rebuilding broken routes ; and finally we show that this protocol maintains the rate of accepted applications.Cet article traite du problème de réservation de bande passante dans les réseaux ad-hoc et de l’influence des interférences hertziennes sur ce problème. Nous montrons que le phénomène d’interférences peut être à l’origine de pertes de bande passante qui peuvent être problématique pour les applications nécessitant des garanties. nous proposons un protocole distribué de réservation de bande passante pour réseaux ad-hoc appelé BRuIT. Ce protocole prend en compte l’existence d’interférences entre transmissions lointaines. Les performances de BRuIT sont analysées au moyen de simulations sous NS

Gas chromatographic instrumentation for gas analysis of the martian atmosphere. volume ii- overall program summary final report

Laboratory model of gas chromatographic instrument for analysis of Mars atmospher

Jumps: Enhancing hop-count positioning in sensor networks using multiple coordinates

Positioning systems in self-organizing networks generally rely on measurements such as delay and received signal strength, which may be difficult to obtain and often require dedicated equipment. An alternative to such approaches is to use simple connectivity information, that is, the presence or absence of a link between any pair of nodes, and to extend it to hop-counts, in order to obtain an approximate coordinate system. Such an approximation is sufficient for a large number of applications, such as routing. In this paper, we propose Jumps, a positioning system for those self-organizing networks in which other types of (exact) positioning systems cannot be used or are deemed to be too costly. Jumps builds a multiple coordinate system based solely on nodes neighborhood knowledge. Jumps is interesting in the context of wireless sensor networks, as it neither requires additional embedded equipment nor relies on any nodes capabilities. While other approaches use only three hop-count measurements to infer the position of a node, Jumps uses an arbitrary number. We observe that an increase in the number of measurements leads to an improvement in the localization process, without requiring a high dense environment. We show through simulations that Jumps, when compared with existing approaches, reduces the number of nodes sharing the same coordinates, which paves the way for functions such as position-based routing

Jihadism in Central Asia: A Credible Threat After the Western Withdrawal From Afghanistan?

Jihadist groups operating in Central Asia pose a real threat, but they are not the only or even the primary danger facing the region’s regimes

Cross-points in the Dirichlet-Neumann method II: a geometrically convergent variant

When considered as a standalone iterative solver for elliptic boundary value problems, the Dirichlet-Neumann (DN) method is known to converge geometrically for domain decompositions into strips, even for a large number of subdomains. However, whenever the domain decomposition includes cross-points, i.e.$\!$ points where more than two subdomains meet, the convergence proof does not hold anymore as the method generates subproblems that might not be well-posed. Focusing on a simple two-dimensional example involving one cross-point, we proposed in a previous work a decomposition of the solution into two parts: an even symmetric part and an odd symmetric part. Based on this decomposition, we proved that the DN method was geometrically convergent for the even symmetric part and that it was not well-posed for the odd symmetric part. Here, we introduce a new variant of the DN method which generates subproblems that remain well-posed for the odd symmetric part as well. Taking advantage of the symmetry properties of the domain decomposition considered, we manage to prove that our new method converges geometrically in the presence of cross-points. We also extend our results to the three-dimensional case, and present numerical experiments that illustrate our theoretical findings