The Internet introduces a new global marketplace for a large number of relatively unknown and often small companies often offering substitutive or complimentary products and services. The merchants profit from reduced costs, reduced time, and unsold stocks. Customers are attracted by increasing convenience and fast fulfillment. Merchants offering these products and services on this new marketpl...

Graceful degradation entails a proportional loss of functionality or the reduction in the quality of services a system provides in response to faults. Compared to traditional techniques, graceful degradation is a promising approach to achieving fault tolerance at reduced cost. Current research using this approach in distributed embedded systems assumes a central management unit responsible for ...

GPU Shape Grammars provide a solution for interactive procedural generation, tuning and visualization of massive environment elements for both video games and production rendering. Our technique generates detailed models without explicit geometry storage. To this end we reformulate the grammar expansion for generation of detailed models at the tesselation control and geometry shader stages. Usi...

The satellite formation flying system is a collaborative system where multiple satellites cooperate in a formation to perform consensus mission in space LEO (Low-Earth-Orbit) through librations points. In recent years, this kind of formation flying systems are getting attention because of reduced cost of mission, failures and recovery and flexibility. If one big spacecraft is at a mission and i...

The feasibility of a buoyancy-based control approach for regulating the horizontal position of atmospheric balloons in stratified and turbulent environmental flows is investigated. Two different control rules are considered, and numerical investigations are performed for a challenging case related to tropical cyclones. The low energy requirement of the buoyancy-based control approach allows con...

Teams of artificially intelligent planetary rovers have tremendous potential for space exploration, allowing for reduced cost, increased flexibility and increased reliability. However, having these multiple autonomous devices acting simultaneously leads to a problem of coordination: to achieve the best results, the they should work together. This is not a simple task. Due to the large distances...

Most of deterministic solvers for rarefied gas dynamics use discrete velocity (or discrete ordinate) approximations of the distribution function on a Cartesian grid. This grid must be sufficiently large and fine to describe the distribution functions at every space position in the computational domain. For 3-dimensional hypersonic flows, like in re-entry problems, this induces much too dense ve...

This study aims to provide statistical evidence of the complementarity between classical test theory and item response models for certain educational assessment purposes. Such complementarity might support, at a reduced cost, future development of innovative procedures for item calibration in adaptive testing. Classical test theory and the generalized partial credit model are applied to tests c...

The changes in the political climate in recent years have significantly changed the way in which military sonar systems are designed and procured. Prior to 1990, military requirements were a major technology pull for technology developments, with large military research budgets funding semiconductor, system and software research. However, the end of the cold war brought major changes in the per...