1,922 research outputs found
Animated Otto-Langen Atmospheric Engine
Based on an existing relationship between Dr. Owen and the Deutsches Museum, Otto-Mated was given the opportunity to collaborate with the two in a year-long senior design project. Otto-Mated was tasked with modeling and simulating the Otto-Langen Atmospheric Engine as a form of preservation and education. The model was created in SolidWorks and animated in Blender, effectively providing the museum with accurate and educational videos demonstrating the engine’s function. Within this document are the plans, decisions, and processes used to create our final product for Deutsches Museum
Validation and Experimental Testing of Observers for Robust GNSS-Aided Inertial Navigation
This chapter is the study of state estimators for robust navigation. Navigation of vehicles is a vast field with multiple decades of research. The main aim is to estimate position, linear velocity, and attitude (PVA) under all dynamics, motions, and conditions via data fusion. The state estimation problem will be considered from two different perspectives using the same kinematic model. First, the extended Kalman filter (EKF) will be reviewed, as an example of a stochastic approach; second, a recent nonlinear observer will be considered as a deterministic case. A comparative study of strapdown inertial navigation methods for estimating PVA of aerial vehicles fusing inertial sensors with global navigation satellite system (GNSS)-based positioning will be presented. The focus will be on the loosely coupled integration methods and performance analysis to compare these methods in terms of their stability, robustness to vibrations, and disturbances in measurements
Properties of four numerical schemes applied to a scalar nonlinear scalar wave equation with a GR-type nonlinearity
We study stability, dispersion and dissipation properties of four numerical
schemes (Iterative Crank-Nicolson, 3'rd and 4'th order Runge-Kutta and
Courant-Fredrichs-Levy Non-linear). By use of a Von Neumann analysis we study
the schemes applied to a scalar linear wave equation as well as a scalar
non-linear wave equation with a type of non-linearity present in GR-equations.
Numerical testing is done to verify analytic results. We find that the method
of lines (MOL) schemes are the most dispersive and dissipative schemes. The
Courant-Fredrichs-Levy Non-linear (CFLN) scheme is most accurate and least
dispersive and dissipative, but the absence of dissipation at Nyquist
frequency, if fact, puts it at a disadvantage in numerical simulation. Overall,
the 4'th order Runge-Kutta scheme, which has the least amount of dissipation
among the MOL schemes, seems to be the most suitable compromise between the
overall accuracy and damping at short wavelengths.Comment: 9 pages, 8 Postscript figure
Canine Cardiac Troponin I Significantly Complements Established Prognostic Composite Score In Dogs With Systemic Inflammation.
Physics of the interior of a black hole with an exotic scalar matter
We use a numerical code to consider the nonlinear processes arising when a
Reissner-Nordstrom black hole is irradiated by an exotic scalar field (modelled
as a free massless scalar field with an opposite sign for its energy-momentum
tensor). These processes are quite different from the processes arising in the
case of the same black hole being irradiated by a pulse of a normal scalar
field. In our case, we did not observe the creation of a spacelike strong
singularity in the T-region of the space-time. We investigate the antifocusing
effects in the gravity field of the exotic scalar field with the negative
energy density and the evolution of the mass function. We demonstrate the
process of vanishing of the black hole when it is irradiated by a strong pulse
of an exotic scalar field.Comment: 16 pages, 16 figures. Text has been rewritten and restructured,
Penrose diagrams have been added, appendix with convergence tests has been
added. Co-author has been added. Conclusions are unchange
Nonlinear Observer for Tightly Integrated Inertial Navigation Aided by Pseudo-Range Measurements
A modular nonlinear observer for inertial navigation aided by pseudo-range measurements is designed and analyzed. The attitude observer is based on a recent nonlinear complementary filter that uses magnetometer and accelerometer vector measurements to correct the quaternion attitude estimate driven by gyro measurements, including gyro bias estimation. A tightly integrated translational motion observer is driven by accelerometer measurements, employs the attitude estimates, and makes corrections using the pseudo-range and range-rate measurements. It estimates position, range bias errors, velocity and specific force in an earth-fixed Cartesian coordinate frame, where the specific force estimate is used as a reference vector for the accelerometer measurements in the attitude observer. The exponential stability of the feedback interconnection of the two observers is analyzed and found to have a semiglobal region of attraction with respect to the attitude observer initialization and local region of attraction with respect to translational motion observer initialization. The latter is due to linearization of the range measurement equations that is underlying the selection of injection gains by solving a Riccati equation. In typical applications, the pseudo-range equations admit an explicit algebraic solution that can be easily computed and used to accurately initialize the position and velocity estimates. Hence, the limited region of attraction is not seen as a practical limitation of the approach for many applications. Advantages of the proposed nonlinear observer are low computational complexity and a solid theoretical foundation
Dynamic study of carbon nanotube growth and catalyst morphology evolution during acetylene decomposition on Co/SBA-15 in an environmental TEM
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