Development and validation of a general purpose linearization program for rigid aircraft models

A FORTRAN program that provides the user with a powerful and flexible tool for the linearization of aircraft models is discussed. The program LINEAR numerically determines a linear systems model using nonlinear equations of motion and a user-supplied, nonlinear aerodynamic model. The system model determined by LINEAR consists of matrices for both the state and observation equations. The program has been designed to allow easy selection and definition of the state, control, and observation variables to be used in a particular model. Also, included in the report is a comparison of linear and nonlinear models for a high performance aircraft

On a family of elliptic curves

Abstract. The main aim of this paper is to put a lower bound on the rank of elliptic curves from the infinite family Cm: y 2 = x3−m2x+1, m ∈ Z+. We shall prove that rankCm ≥ 2 for m ≥ 2 and that rankC4k ≥ 3 for the infinite subfamily C4k, k ≥ 1. The idea has been taken from paper [1]; in fact we are attempting to solve two problems stated there. 1. Introduction. A

User's manual for interactive LINEAR: A FORTRAN program to derive linear aircraft models

An interactive FORTRAN program that provides the user with a powerful and flexible tool for the linearization of aircraft aerodynamic models is documented in this report. The program LINEAR numerically determines a linear system model using nonlinear equations of motion and a user-supplied linear or nonlinear aerodynamic model. The nonlinear equations of motion used are six-degree-of-freedom equations with stationary atmosphere and flat, nonrotating earth assumptions. The system model determined by LINEAR consists of matrices for both the state and observation equations. The program has been designed to allow easy selection and definition of the state, control, and observation variables to be used in a particular model

Coaching and Training Paraprofessionals to Implement Communication Strategies in the Classroom with Students with Disabilities

The purpose of this project was to evaluate the effects of a training and coaching intervention on increasing paraprofessionals use of communication strategies to increase the participation between students with disabilities and paraprofessionals. Students with CCN struggle to interact with peers and communicate appropriately, and therefore need guided instruction by adults. To encourage interactions across contexts, paraprofessionals must first learn how to use communication strategies. This skill also was chosen to extend our knowledge on coaching paraprofessionals to use different communication strategies to promote communication with students with ESN and CCN

Derivation and definition of a linear aircraft model

A linear aircraft model for a rigid aircraft of constant mass flying over a flat, nonrotating earth is derived and defined. The derivation makes no assumptions of reference trajectory or vehicle symmetry. The linear system equations are derived and evaluated along a general trajectory and include both aircraft dynamics and observation variables

Absolute flux measurements for swift atoms

While a torsion balance in vacuum can easily measure the momentum transfer from a gas beam impinging on a surface attached to the balance, this measurement depends on the accommodation coefficients of the atoms with the surface and the distribution of the recoil. A torsion balance is described for making absolute flux measurements independent of recoil effects. The torsion balance is a conventional taut suspension wire design and the Young modulus of the wire determines the relationship between the displacement and the applied torque. A compensating magnetic field is applied to maintain zero displacement and provide critical damping. The unique feature is to couple the impinging gas beam to the torsion balance via a Wood's horn, i.e., a thin wall tube with a gradual 90 deg bend. Just as light is trapped in a Wood's horn by specular reflection from the curved surfaces, the gas beam diffuses through the tube. Instead of trapping the beam, the end of the tube is open so that the atoms exit the tube at 90 deg to their original direction. Therefore, all of the forward momentum of the gas beam is transferred to the torsion balance independent of the angle of reflection from the surfaces inside the tube

Application and flight test of linearizing transformations using measurement feedback to the nonlinear control problem

The design of nonlinear controllers has relied on the use of detailed aerodynamic and engine models that must be associated with the control law in the flight system implementation. Many of these controllers were applied to vehicle flight path control problems and have attempted to combine both inner- and outer-loop control functions in a single controller. An approach to the nonlinear trajectory control problem is presented. This approach uses linearizing transformations with measurement feedback to eliminate the need for detailed aircraft models in outer-loop control applications. By applying this approach and separating the inner-loop and outer-loop functions two things were achieved: (1) the need for incorporating detailed aerodynamic models in the controller is obviated; and (2) the controller is more easily incorporated into existing aircraft flight control systems. An implementation of the controller is discussed, and this controller is tested on a six degree-of-freedom F-15 simulation and in flight on an F-15 aircraft. Simulation data are presented which validates this approach over a large portion of the F-15 flight envelope. Proof of this concept is provided by flight-test data that closely matches simulation results. Flight-test data are also presented

I nie miłować ciężko, i miłować / Nędzna pociecha

Fragment pochodzi z Sonetu V. O nietrwałej miłości rzeczy świata tego Mikołaja Sępa Szarzyńskiego. Cytat jest antytezą, w której poeta przeciwstawia dwa sposoby życia: pierwszy to życie bez miłości, a drugi – życie wypełnione miłością (Fragment tekstu)