Umbra is a new Sandia-developed modeling and simulation framework. The Umbra framework allows users to quickly build models and simulations for intelligent system development, analysis, experimentation, and control and supports tradeoff analyses of complex robotic systems, device, and component concepts. Umbra links together heterogeneous collections of modeling tools. The models in Umbra inclu...

Measurements of the statistical characteristics of umbra and sunflecks at different depths inside a willow coppice — Salix viminalis and Salix dasyclados — were carried out at Tartu Observatory, Tõravere, Estonia, in 1997. A new instrument, the sunfleck indicator, constructed by M. Sulev, was used. This instrument, moving perpendicularly to rows in the horizontal direction, counts the number an...

Sandia’s Umbra modular simulation framework was designed to enable the modeling of robots for manufacturing, military, and security system concept evaluation. Umbra generalizes data-flow-based simulation to enable modeling of heterogeneous interaction phenomena via a multiple worlds abstraction. This and other features make Umbra particularly suitable for developing simulation federates. Umbra’...

We provide an algebraic setting for cumulants and factorial moments through the classical umbral calculus. Main tools are the compositional inverse of the unity umbra, connected with the logarithmic power series, and a new umbra here introduced, the singleton umbra. Various formulae are given expressing cumulants, factorial moments and central moments by umbral functions.

Umbra is an efficient and scalable memory shadowing tool built on top of DynamoRIO, which is a state-ofthe-art runtime code manipulation system. Using the APIs provided by DynamoRIO, Umbra inserts code into the applications runtime instruction stream to perform memory address translation from application memory to shadow memory. Umbra also provides a simple interface that enables developers to ...

This paper describes a modeling, simulation, and integration framework developed at Sandia National Laboratories with support from ORION International Technologies, Inc. This framework, called Umbra, increases the efficiency for developing new applications and for integrating new and/or existing applications. A process for rapidly and effectively developing new modeling and simulation applicati...

this work deals with effects of asymmetric stiffness on the dynamic behaviour of the rotor system. the analysis is presented through an extended lagrangian hamiltonian mechanics on the asymmetric rotor system, where symmetries are broken in terms of the rotor stiffness. the complete dynamics of asymmetries of rotor system is investigated with a case study. in this work, a mathematical model is ...

The puparium of Salpingogaster nigra and Eosalpingogaster umbra are described, and diagnosis and illustrations are provided. The morphology of immature stages of the genera Salpingogaster and Eosalpingogaster are studied and compared for the first time. The results are in agreement with previous molecular analyses that recognise both genera as valid. We found two different puparium morphotypes ...

In one concept proposed under the NASA Small Aircraft Transportation System program, pilots would self-separate by observing other aircraft near an airport using ADS-B and a moving-map display. An Airport Management Module (AMM) would sequence this traffic. The question was, however, whether the concept was practical and whether an automated Cockpit Associate (CA) could relieve pilot workload a...