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Randolph, VT, United States

Vermont Technical College is a public technical college with two main campuses located in Randolph Center and Williston, Vermont. The College also has nursing campuses in other locations throughout the state. The college is a part of the Vermont State Colleges, a consortium of Vermont's five public colleges, governed by a common board of trustees, chancellor and Council of Presidents, each college with its own president and deans. Total enrollment is approximately 1,650; the average class size is 14; and the student-to-faculty ratio is 10:1. Wikipedia.

Ouellette J.E.,Vermont Technical College | Ouellette J.E.,Dartmouth College | Lyon J.G.,Dartmouth College | Brambles O.J.,Dartmouth College | And 3 more authors.
Journal of Geophysical Research A: Space Physics

We summarize the results of a study on the impact of plasmaspheric plumes on dayside reconnection using a three-dimensional magnetospheric simulation code. We find that the mass loading of magnetospheric flux tubes slows local reconnection rates, though not as much as predicted by Borovsky et al. (2013) due to differences in how well the Cassak-Shay theory matches magnetospheric configurations with and without plasmaspheric plumes. Additionally, we find that in some circumstances reconnection activity is enhanced on either side of the plumes, which moderates its impact on the total dayside reconnection rate. These results provide evidence that plasmaspheric plumes have both local- and global-scale effects on dayside reconnection. ©2016. American Geophysical Union. All Rights Reserved. Source

Zhang B.,High Altitude Observatory | Brambles O.J.,Dartmouth College | Wiltberger M.,High Altitude Observatory | Lotko W.,Dartmouth College | And 2 more authors.
Geophysical Research Letters

This paper investigates the effects of magnetospheric mass loading on the control of dayside magnetic reconnection using global magnetospheric simulations. The study iys motivated by a recent debate on whether the integrated dayside magnetic reconnection rate is solely controlled by local processes (local-control theory) or global merging processes (global-control theory). The local-control theory suggests that the integrated dayside reconnection rate is controlled by the local plasma parameters. The global-control theory argues that the integrated rate is determined by the net force acting on the flow in the magnetosheath rather than the local microphysics. Controlled numerical simulations using idealized ionospheric outflow specifications suggest a possible mixed-control theory, that is, (1) a small amount of mass loading at the dayside magnetopause only redistributes local reconnection rate without a significant change in the integrated reconnection rate and (2) a large amount of mass loading reduces both local reconnection rates and the integrated reconnection rate on the dayside. The transition between global-control- and local-control-dominated regimes depends on (but not limited to) the source region, the amount, the location, and the spatial extension of the mass loading at the dayside magnetopause. ©2016. American Geophysical Union. All Rights Reserved. Source

Ouellette J.E.,Vermont Technical College | Ouellette J.E.,Dartmouth College | Lyon J.G.,Dartmouth College | Rogers B.N.,Dartmouth College
Journal of Geophysical Research: Space Physics

Using a three-dimensional magnetospheric simulation code we have studied the properties of magnetic reconnection at the subsolar point on solar wind parameters for southward interplanetary magnetic field conditions and compared the results with the predictions of the Cassak-Shay theory. We find that this theory predicts reconnection rates on the order of our observations and produces reasonable predictions of the reconnection outflow speed. We have quantified the contributions that differences between the assumed and measured mass, energy, and outflow density scalings make to predictions of the reconnection rate and outflow speed. In general, the theory makes reasonable assumptions about the mass and energy flux into the reconnection layer, but their outflowing counterparts are overestimated due to the narrowness of the reconnection outflow jet. Lastly, we find that newly reconnected flux tubes exit the merging region before their mass density can equilibrate, requiring a correction to the predicted outflow density. Key Points Reconnection rates are generally consistent with Cassak-Shay theory Outflow speeds are also consistent with Cassak-Shay estimates Outflow density may need to be corrected for mixing time ©2014. American Geophysical Union. All Rights Reserved. Source

Brandon C.S.,Vermont Technical College
SpaceOps 2012 Conference

A CubeSat is a payload package having dimensions 10cm x 10cm x 10cm and a mass that cannot exceed 1.33 kg. They can also be made in double and triple length (10cm x 10cm x 30cm and 4 kg). Although a number of CubeSats have previously been developed and launched into Earth orbit, none have accomplished missions involving interplanetary navigation. A version of NASA's GPS Enhanced Onboard Navigation System (GEONS) rewritten in Ada/SPARK for enhanced reliability, will use a sophisticated space tested GPS system and a star / near body tracking camera for navigation components. The non-standard low energy transfer strategy through a Lissajous orbit at the Earth-Moon L1 Lagrange point to achieve Lunar orbit insertion and a safe decent to the Lunar surface require sophisticated navigation systems. The triple CubeSat would get a ride with a communications satellite launch to the geosynchronous transfer orbit (GTO). The CubeSat would then travel under its own power to the Moon. Two variations are being studied, and the Vermont Lunar CubeSat project will use high-energy mono-propellant and/or a long duration ion thruster for propulsion to the Moon. The chemically propelled mission would have a double CubeSat as a booster carrying the single CubeSat as payload from the GTO to Lunar orbit insertion. The chemically propelled single CubeSat would then descend to a soft landing on the Moon. The xenon ion drive triple CubeSat would travel to the Moon and enter orbit for observations with its instrument payload. It would use the low energy transfer ala the ESA SMART-1 spacecraft. We have been selected by NASA for the ELaNa IV launch on an Orbital Sciences Minotaur 1 to a 500 km orbit in July, 2013. This single CubeSat would test the navigation software and hardware, sending celestial, GPS and GEONS information to our ground station. © 2012 by Dr. Carl S. Brandon. Source

Chapin P.,Vermont Technical College | Skalka C.,University of Vermont
ACM Transactions on Information and System Security

We describe SpartanRPC, a secure middleware technology that supports cooperation between distinct security domains in wireless sensor networks. SpartanRPC extends nesC to provide a link-layer remote procedure call (RPC) mechanism, along with an enhancement of configuration wirings that allow specification of remote, dynamic endpoints. RPC invocation is secured via an authorization logic that enables servers to specify access policies and requires clients to prove authorization. This mechanism is implemented using a combination of symmetric and public key cryptography. We report on benchmark testing of a prototype implementation and on an application of the framework that supports secure collaborative use and administration of an existing WSN data-gathering system. © 2014 ACM. Source

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