Abstract
Raven is a Multi-Object Adaptive Optics (MOAO) scientific demonstrator which will be used on-sky at the Subaru observatory from 2014. Raven is currently being built and tested at the University of Victoria AO Lab. This paper presents an overview of the optomechanical design and the software architecture of Raven, and gives the current status of this project. Raven includes three open loop wavefront sensors (WFSs), a laser guide star WFS and two figure/truth WFSs. Two science channels containing deformable mirrors (DMs) feed light to the Subaru IRCS spectrograph. Central to the Raven is a Calibration Unit which contains multiple sources, a telescope simulator including two phase screens and a ground layer DM that can be used to calibrate and test Raven in the lab. Preliminary results on calibration and open-loop AO correction using a tomographic reconstructor are presented.

Abstract
As the size and cost of embedded devices continue to decrease, it becomes economically feasible to densely deploy networks with very large quantities of such nodes, and thus enabling the implementation of networks with increasingly larger number of nodes becomes a relevant problem. In this paper we describe a novel algorithm to obtain the number of live nodes with a very low time-complexity. In particular, we develop a mechanism to estimate the number of nodes or the number of proposed values (COUNT), with a time complexity that increases sublinearly with the number of nodes. The approach we propose is based on the wise exploitation of dominance-based protocols and offers excellent scalability properties for emerging applications in dense Cyber Physical Systems.

Abstract
Data centers are large energy consumers and a substantial portion of this power consumption is due to the control of physical parameters, which bring the need of high effciency environmental control systems. In this paper, we describe a hardware sensing platform specifi cally tailored to collect physical parameters (temperature, pressure, humidity and power consumption) in large data centers. This platform is an important enabler to find opportunities to optimize energy consumption. We also introduce an analysis of the delay to obtain the sensing data from the sensor network. This analysis provides an insight into the time scales supported by our platform, and also allows to study the delay for different datacenter topologies.

Abstract
While Cluster-Tree network topologies look promising for WSN applications with timeliness and energy-efficiency requirements, we are yet to witness its adoption in commercial and academic solutions. One of the arguments that hinder the use of these topologies concerns the lack of flexibility in adapting to changes in the network, such as in traffic flows. This paper presents a solution to provide these networks with the ability to self-adapt to different bandwidth and latency requirements, imposed by traffic flows, by changing the cluster's duty-cycle and scheduling. Importantly, our approach enables a network to change its cluster scheduling without requiring long inaccessibility times or the re-association of the nodes. We show how to apply our methodology to the case of IEEE 802.15.4/ZigBee cluster-tree WSNs without significant changes to the protocol. Finally, we analyze and demonstrate the validity of our methodology through a comprehensive simulation and experimental validation using commercially available technology on a Structural Health Monitoring application scenario.

Abstract
The electromagnetic theory presents a unifying explanation of electric and magnetic phenomena underlying our technological society. It is a fundamental physical theory taught in engineering schools at university level. In this theory the electromagnetic field is a vector field permeating space. An important aspect relating to students difficulties and misconceptions is the difficulty in visualizing vector fields. With the goal of enhancing student understanding and studying student engagement we have developed high quality 3D visualizations of electromagnetic situations. These make use of accurate computation of the field lines, together with realistic rendering using the open source software Blender. We present examples of electrostatic situations with both an assessment of the student understanding and an evaluation of the students' perceptions of the importance of the visualizations. Complex interplay between visualization specific issues and the abstract notion of the field is identified in the students' conceptions. It is found that the visualizations are not used as substitutes of other learning resources. They are perceived as allowing a quick access to content and prompting motivation. The adequacy of the visualization to the subject content as well as the capacity to use it as self-assessment is valued by the students.

Abstract
Active pre-main-sequence binaries with separations of around 10 stellar radii present a wealth of phenomena unobserved in common systems. The study of these objects is extended from classical T Tauri stars to the Herbig Ae star HD 104237. The primary has a mass 2.2 +/- 0.2 M-circle dot and secondary 1.4 +/- 0.3 M-circle dot. Spectrointerferometry with the VLTI/AMBER in the K-band continuum and the Br gamma line is presented. It is found that the K-band continuum squared visibilities are compatible with a circumbinary disc with a radius of similar to 0.5 AU. However, a significant fraction (similar to 50 per cent) of the flux is unresolved and not fully accounted by the stellar photospheres. The stars probably do not hold circumstellar discs, in addition to the circumbinary disc, due to the combined effects of inner magnetospheric truncation and outer tidal truncation. This unresolved flux likely arises in compact structures inside the tidally disrupted circumbinary disc. Most (greater than or similar to 90 per cent) of the Br gamma line emission is unresolved. The line-to-continuum spectroastrometry shifts in time, along the direction of the Ly alpha jet known to be driven by the system. The shift is anticorrelated with the Br gamma equivalent width. It is shown that the unresolved Br gamma emission cannot originate in the jet but instead is compatible with stellar emission from the orbiting binary components. The increase in the absolute value of the equivalent width of the line takes place at periastron passage; it could arise in an accretion burst, a flare or in the increase in effective size of the emission region by the interaction of the magnetospheres. The binary longitude of the ascending node is found to be Omega = (235 +/- 3)degrees and the orbit retrograde. The origin of the jet is revisited. The tidal disruption of the circumstellar discs creates difficulties to ejection models that rely on stellar magnetosphere and disc coupling. A scenario of a stellar wind collimated by a circumbinary disc wind is suggested.