Control and Optimization Laboratorieshttp://hdl.handle.net/10945/296192019-05-24T05:00:17Z2019-05-24T05:00:17Z10581Naval Postgraduate School - Cyber SummitIrvine, CynthiaGarfinkel, SimsonEagle, ChrisAnderson, DavidMcEachen, FrankKragh, FrankStanica, PantelimonCanright, DavidBuettner, RauBordetsky, AlexLuscombe, JamesFord, DavidDenning, DorothyArquilla, Johnhttp://hdl.handle.net/10945/378072016-07-14T22:03:31Z2009-10-29T00:00:00ZNaval Postgraduate School - Cyber Summit
Irvine, Cynthia; Garfinkel, Simson; Eagle, Chris; Anderson, David; McEachen, Frank; Kragh, Frank; Stanica, Pantelimon; Canright, David; Buettner, Rau; Bordetsky, Alex; Luscombe, James; Ford, David; Denning, Dorothy; Arquilla, John
2009 CyberSecurity Summit, Naval Postgraduate School
2009-10-29T00:00:00ZFormal Analysis of Elastically Supported Beam ColumnsBrock, John E.http://hdl.handle.net/10945/303622016-07-14T18:49:09Z1966-01-01T00:00:00ZFormal Analysis of Elastically Supported Beam Columns
Brock, John E.
A method is presented for the systematic analysis of elastically supported beam-columns or
tie-bars in which formal notational devices simplify the handling of complicated discontinuous lateral loads.
Various relationships between axial load and support modulus are treated and three particular cases (fixedfixed,
pinned-pinned, and free-free ends) are exhibited.
The article of record as published may be located at DOI 10.1007/BF00532055
1966-01-01T00:00:00ZTip-loaded Cantilever BeamsBrock, John E.http://hdl.handle.net/10945/303632016-07-14T18:48:56Z1966-12-01T00:00:00ZTip-loaded Cantilever Beams
Brock, John E.
The author is Professor of Mechanical Engineering at the U. S. Naval Postgraduate School, Monterey, California, and formerly Director of Engineering Sciences of the Service Bureau Corporation, a subsidiary of IBM. His Ph.D. degree is from the University of Minnesota and he has written many papers on the analysis of piping structures, one of which appeared in the May 1961 issue of this Journal. He serves on the Mechanical Design Committee of the American Standards Association Committee on Code for Pressure Piping and on the ASTM Committee A-1 on steel. He is a member of ASME, ASTM, ASEE, and Sigma Xi.
The article of record as published may be located at DOI:10.1111/j.1559-3584.1965.tb05605.x
1966-12-01T00:00:00ZBehavior of Separation Constants for Finite Gyromagnetic PlasmasBevc, Vladislavhttp://hdl.handle.net/10945/303612016-07-14T18:48:55Z1965-11-01T00:00:00ZBehavior of Separation Constants for Finite Gyromagnetic Plasmas
Bevc, Vladislav
The type of the functions appearing in the expressions for electromagnetic fields in finite magnetoplasmas depends only on the properties of the medium manifested in separation constants. Theomega-betaplane of the Brillouin diagram is partitioned into a definite number of zones characterized by the type of possible field solutions. The general behavior of the separation constants in theomega-betaplane including the complex region based on calculations covering a wide variation of the determining parameter is described. Effects of ion motions are discussed, and the generality of the presented approach is pointed out.
The article of record as published may be located at DOI.org/10.1109/TAP.1965.1138550
1965-11-01T00:00:00ZFormulation of Stability Conditions for Systems Containing Driven RotorsRoss, I. Michaelhttp://hdl.handle.net/10945/303262017-06-06T20:50:12Z1996-03-01T00:00:00ZFormulation of Stability Conditions for Systems Containing Driven Rotors
Ross, I. Michael
The much maligned energy-sink analysis is revisited to derive stability conditions for a dual-spin spacecraft that is subjected to possible energy additions by the motor torque. Landon's old idea of subtracting the work done by the motor torque from the energy function is applied to the case when both the platform and the rotor are
quasirigid. This is made possible by way of a separation axiom that allows one to obtain an expression for the motor torque. It is shown that this process leads naturally to a symmetric stability condition expressible in terms of Hubert's core energy.
Journal of Guidance, Control and Dynamics; The article of record as published may be located at http://arc.aiaa.org/loi/jgcd
1996-03-01T00:00:00ZLow-Earth-Orbit Maintenance: Reboost vs Thrust-Drag CancellationRoss, I. MichaelAlfriend, Kyle T.http://hdl.handle.net/10945/303252017-06-06T20:50:12Z1995-07-01T00:00:00ZLow-Earth-Orbit Maintenance: Reboost vs Thrust-Drag Cancellation
Ross, I. Michael; Alfriend, Kyle T.
We define the problem of orbit maintenance within an atmosphere as keeping the spacecraft within a specified altitude
band about a mean circular orbit.
Journal of Guidance, Control and Dynamics; The article of record as published may be located at http://arc.aiaa.org/loi/jgcd
1995-07-01T00:00:00ZNutational Stability and Core Energy of a Quasirigid GyrostatRoss, I. Michaelhttp://hdl.handle.net/10945/303242017-06-06T20:50:17Z1993-07-01T00:00:00ZNutational Stability and Core Energy of a Quasirigid Gyrostat
Ross, I. Michael
The asymptotic nutational stability of a quasirigid gyrostat is analyzed. The primary purpose of this analysis is to resolve a debate concerning the use of the energy-sink method of analysis for systems containing driven rotors. It is shown that when the work done by the motor torque is not taken into account, the analysis leads to a contradiction even when the total energy is dissipative. A proper application of Landon's original idea yields a relationship between the time rate of change of Hubert's "core energy" and the energy dissipation rate of the damping mechanisms in the spacecraft. The analysis shows that the core energy might increase during a rotor
despin condition; hence, the minimality of core energyﾃ__a previous criterionﾃ__is not always guaranteed. A criterion for the design of the damper to insure dissipation of the core energy is presented; this condition is always satisfied for the case of a constant relative rotor spin speed that facilitates a "closed-form" solution to the
nutation angle time history of an axisymmetric gyrostat. The stability condition resulting from this analysis is
consistent with the Landon-Iorillo stability criterion.
Journal of Guidance, Control and Dynamics; The article of record as published may be located at http://arc.aiaa.org/loi/jgcd
1993-07-01T00:00:00ZSecond Look at Approximating Differential InclusionsFahroo, FaribaRoss, I., Michaelhttp://hdl.handle.net/10945/303222017-06-06T20:50:15Z2001-02-01T00:00:00ZSecond Look at Approximating Differential Inclusions
Fahroo, Fariba; Ross, I., Michael
In many direct methods for numerically solving optimal control problems, a collocation technique is used. What distinguishes numerous direct collocation schemes is the discretization of the time history and the way the state equations are satisfied at various discrete points. In one of the earliest schemes, cubic splines
were used as the interpolating polynomials over the time segments. The state differential equations were imposed at the midpoints by way of a Hermiteﾃ__Simpson implicit integration method. Generalizations
of these collocation schemes were employed by Herman and Conway and Conway and Larson in the form of higher-order Gaussﾃ__Lobatto and by Enright and Conway in the form of Rungeﾃ__Kutta-type quadrature rules. The use of higher-order integration rules facilitates a larger step size that results in a smaller number of discretization nodes or optimization variables. Because the efficiency and even convergence of nonlinear programming (NLP)problems improves for a problem of smaller size, finding ways to
accurately and ef ficiently discretize optimal control problems is of great interest in this area of research.
Journal of Guidance, Control and Dynamics
The article of record as published may be located at http://arc.aiaa.org/loi/jgcd
2001-02-01T00:00:00ZGravitational Effects of Earth in Optimizing Delta V for Deflecting Earth-Crossing AsteroidsRoss, I. MichaelPark, Sang-YoungPorter, Scott D. V.http://hdl.handle.net/10945/303212017-06-06T20:50:18Z2001-10-01T00:00:00ZGravitational Effects of Earth in Optimizing Delta V for Deflecting Earth-Crossing Asteroids
Ross, I. Michael; Park, Sang-Young; Porter, Scott D. V.
Analyses incorporating the gravitational effects of Earth to calculate optimal impulses for de ecting Earthcrossing
asteroids are presented. The patched conic method is used to formulate the constrained optimization problem. Geocentric constraints are mapped to heliocentric variables by the use of the impact parameter. The result is a uni ed nonlinear programming problem in the sense that no distinctions are made for short or long warning times. Numerical solutions indicate that the delta V requirements are considerably more than those of the previously published two-body analysis that excluded third-body effects. Generally speaking, the increments in the
minimum delta V due to the gravitational effects of the Earth are large (by asmuch as 60%) for near-Earth asteroids, and the errors diminish for orbits with large eccentricities (e>0.7). Some interesting results for short warning times are also discussed.
Journal of Spacecraft and Rockets
The article of record as published may be located at http://arc.aiaa.org/loi/jsr
2001-10-01T00:00:00ZUnscented Kalman Filtering: NPSAT1 Ground Test ResultsGong, QiRoss, Michael I.http://hdl.handle.net/10945/296852016-07-14T22:01:21Z2006-08-21T00:00:00ZUnscented Kalman Filtering: NPSAT1 Ground Test Results
Gong, Qi; Ross, Michael I.
NPSAT1 is a small satellite that employs magnetic sensing and actuation for attitude control. The spacecraft orientation and angular velocity should, therefore, be estimated from the magnetometer readings. The inherent nonlinear dynamics of the system poses a challenging problem on the observer design. This paper demonstrates the ground test results of NPSAT1 state estimation using the Unscented Kalman Filter (UKF) - a fairly recent method with inherent appeals of extended Kalman 'Filter but with no need for linearization; thus more suitable for highly nonlinear 'filtering and control applications. The quaternion-based modeling constraint that the quaternion has a unit norm is enforced by treating the norm of the quaternion as a dummy measurement. The experimental results show the superior performance of the UKF in practice.
The article of record as published may be located at http://dx.doi.org/10.2514/6.2006-6352; Approved for public display, distribution unlimited; Proceedings of AIAA-Guidance, Navigation, and Control Conference and Exhibit ; Paper no. AIAA-2006-6352, Keystone, Colorado, Aug. 21-24, 2006
2006-08-21T00:00:00Z