Automatic application object migration in sensor networks

Object migration in wireless sensor networks has the potential to reduce energy consumption for a wireless sensor network mesh. Automated migration reduces the need for the programmer to perform manual static analysis to find an efficient layout solution. Instead, the system can self-optimise and adjust to changing conditions. This paper describes an automated, transparent object migration system for wireless sensor networks, implemented on a micro Java virtual machine. The migration system moves objects at runtime around the sensor mesh to reduce communication overheads. The movement of objects is transparent to the application developer. Automated transparent object migration is a core component of Hydra, a distributed operating system for wireless sensor networks that is currently under development. Performance of the system under a complex performance test scenario using a real-world dataset of seismic events is described. The results show that under both simple and complex conditions the migration technique can result in lower data traffic and consequently lower overall energy cost

Capturing Trojans and Irregular Satellites - the key required to unlock planetary migration

It is now accepted that the Solar system's youth was a dynamic and chaotic time. The giant planets migrated significant distances to reach their current locations, and evidence of that migration's influence on the Solar system abounds. That migration's pace, and the distance over which it occurred, is still heavily debated. Some models feature systems in which the giant planets were initially in an extremely compact configuration, in which Uranus and Neptune are chaotically scattered into the outer Solar system. Others feature architectures that were initially more relaxed, and smoother, more sedate migration. To determine which of these scenarios best represents the formation of our Solar system, we must turn to the structure of the system's small body populations, in which the scars of that migration are still clearly visible. We present the first results of a program investigating the effect of giant planet migration on the reservoirs of small bodies that existed at that time. As the planets migrate, they stir these reservoirs, scattering vast numbers of small bodies onto dynamically unstable orbits in the outer Solar system. The great majority of those bodies are rapidly removed from the system, through collisions and ejections, but a small number become captured as planetary Trojans or irregular satellites. Others are driven by the migration, leading to a significant sculpting of the asteroid belt and trans-Neptunian region. The capture and retention efficiencies to these stable reservoirs depend on the particular migration scenario used. Advocates of chaotic migration from an initially compact scenario argue that smoother, more sedate migration cannot explain the observed populations of Trojans and irregular satellites. Our results draw a strikingly different picture, revealing that such smooth migration is perfectly capable of reproducing the observed populations.Comment: 13 pages, accepted for publication in the peer-reviewed proceedings of the 12th annual Australian Space Science Conferenc

On the evolution of the resonant planetary system HD128311

A significant number of the known multiple exoplanetary systems are containing a pair of giant planets engaged in a low order mean motion resonance. Such a resonant condition protects the dynamics of these planets resulting in very stable orbits. According to recent studies the capture into a resonance is the result of a planetary migration process induced by the interaction of the planets with a protoplanetary disk. If the migration is slow enough (adiabatic) next to a mean motion resonance, the two planets will also be in apsidal corotation. The recently refined orbital parameters of the system HD 128311 suggest that the two giant planets are in a 2:1 mean motion resonance, however without exhibiting apsidal corotation. Thus the evolution of this system can not be described by an adiabatic migration process alone. We present possible evolution scenarios of this system combining migration processes and sudden perturbations. We model migration scenarios through numerical integration of the gravitational N-body problem with additional non-conservative forces. Planet-planet scattering has been investigated by N-body simulations. We show that the present dynamical state of the system HD128311 may be explained by such evolutionary processes.Comment: 4 Pages, 7 Figures, accepted for AA Letter

Google Apps for Education: Valparaiso University\u27s Migration Experience

Many campuses are investigating cloud-based or hosted email solutions. This paper will cover Valparaiso University’s decision to move to the Google Apps for Education platform and our campus migration strategy. Google Apps offers significant savings in both cost of service and cost of support / maintenance while simultaneously offering functionality improvements to the campus experience over our previous system. Valparaiso University was using the GroupWise email and calendaring system and began the process of migrating all of campus to the Google Apps for Education platform in early 2011. Our process began with a student led evaluation team to select the new platform and started rolling out to new students beginning summer of 2011 with migration of existing students conducted from July 2011 through October 2011. Faculty / Staff migration began in December 2011 and were rolled out on a department by department basis throughout the spring 2012 Semester. Heavy promotion and utilization of multiple “Meet Google Apps” presentations greatly enhanced communication about the process and reduced migration anxiety. Apps were limited during migration process to those that reproduced existing system functionality to avoid over-taxing IT support resources. Valparaiso University’s migration process has been refined several times and overall feedback from students, faculty, and staff has been very positive throughout the process

Heterogeneous migration flows from the Central Plateau of Burkina Faso: the role of natural and social capital

This paper uses a system of labour supply equations and data from Burkina Faso collected in 2003 to test the conditions underlying two different migratory movements: continental and intercontinental migration. We provide theoretical reasoning and empirical evidence that heterogeneity in migration is related to heterogeneity in rural households. We find that comparatively asset-poor households embark on continental migration, whereas intercontinental migration takes place in comparatively wealthy households in response to opportunities for accumulation of wealth in Europe. We also find that access to religion-specific migrant networks plays a positive and negative role in explaining, respectively, intercontinental and continental migratio

Alarm system for insect migration using weather radars

The pilot system for forecasting insect migrations to next two days will be operated during May and June 2008. Forecasts are concentrating on two major pests; namely diamond-back moth and bird cherry aphid. Five to ten pilot users will get automatic SMS warning messages and are able to study the situation more thoroughly via specific web pages. The pilot users report to the study team about their findings and the usefulness of the service. The validity of the service will be tested using field traps

Biomimetic and Biophysical Approach to Profile Metastatic Cancer Cell Migration

Honors Research ScholarshipCancer metastasis is a complex process by which cells in a primary tumor acquire an aggressive phenotype, and travel to distant, secondary sites in the body. One aspect of cancer metastasis is cell migration toward the vascular system, called invasion. Multiple modalities of single cell invasion exist, including amoeboid migration and mesenchymal migration. Amoeboid migration is less well understood, and in particular, the forces involved in amoeboid migration have yet to be fully elucidated at a subcellular scale. Cellular traction force microscopy, or CTFM, is one method used to probe migration forces. However, this approach is largely limited to two dimensions, and is limited by the size of the pillars on the substrate. To address these limitations, we developed a system using microfluidics and DNA origami capable of real-time force measurement of cell migration on a subcellular scale with a 10 pN resolution. Microfluidic devices were made using soft lithography and replica molding in our laboratory. DNA origami were made using protocols developed by Michael Hudoba and Dr. Carlos Castro in the Nanoengineering and Biodesign Laboratory. The devices were imaged using TIRF microscopy to study dwell times of the sensors in the open and closed states, and the devices were analyzed with an AFM to determine that they are best suited for measuring shear forces. Further, the presence of streptavidin protein was found to have a significant effect on DOFS binding with a p-value less than 0.05. DOFS concentrations around 1 nM were found to provide the most coverage while minimizing structure aggregation. Thus, our microfluidic devices are able to be functionalized with DNA origami force sensors with a high degree of attachment. This platform is thus capable of measuring cell migration and adhesion forces, and future work should harness this system to create 3D maps of cell migration to gain insight into invasion.Institute for Materials ResearchSecond-Year Transformational Experience Program (STEP)A one-year embargo was granted for this item.Academic Major: Biomedical Engineerin