Results 251 to 260 of about 842,020 (274)
Some of the next articles are maybe not open access.
On the Influence of Time‐Varying Flow Velocity on Unsteady Aerodynamics
Journal of the American Helicopter Society, 1994The effects of a periodic free-stream velocity on the unsteady aerodynamics of an airfoil in incompressible flow are examined. Existing theories are reviewed, and their simplifications and limitations are properly identified. A new general aerodynamic theory for an airfoil undergoing a combination of harmonic pitching, plunging and fore-aft motion is ...
B. G. van der Wall, J. G. Leishman
openaire +3 more sources
Analysis on Optimality of Proportional Navigation With Time-Varying Velocity
Journal of the Korean Society for Aeronautical & Space Sciences, 20095IJT QBQFS TIPXT UIBU UIF DPOWFOUJPOBM QSPQPSUJPOBM OBWJHBUJPO HVJEBODF 1/( MBXXJUIBDPOTUBOUOBWJHBUJPOHBJOJTBOPQUJNBMTPMVUJPOTUSJDUMZBMTPXIFOUIFWFMPDJUZJTWBSZJOH EVSJOH FOHBHFNFOU &TQFDJBMMZ 1/( XJUI OBWJHBUJPO DPOT UBOU JT BO PQUJNBMTPMVUJPO NJOJNJ[JOH B DMPTJOH WFMPDJUZ XFJHIUFE JOEVDFEESBH 8 IJMF NPTU PG QSFWJPVTTUVEJFT PO PQUJNBMJUZ PG 1/( XFSF ...
In-Soo Jeon, Jin-Ik Lee
openaire +1 more source
Estimation of time-varying velocities of moving objects by time-frequency representations
IEEE Transactions on Image Processing, 2003An approach to the estimation of motion parameters of moving objects in a video-sequence, by using the SLIDE (subspace-based line detection algorithm) algorithm, is considered. The proposed procedure projects video-frames to the coordinate axes, in order to obtain synthetic images containing information about the motion parameters.
Igor, Djurovic, Srdjan, Stanković
openaire +2 more sources
Modeling highway vehicles with time-varying velocity
Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148), 2001A model of the lateral and longitudinal dynamics of a highway vehicle with a time varying velocity is presented. The model describes the motion of the center of mass, the interaction between the tires and the road, and the relationship between the suspension and the pitch and roll motion.
openaire +1 more source
Intercept of Nonmoving Targets at Arbitrary Time-Varying Velocity
Journal of Guidance, Control, and Dynamics, 1998From the text (Conclusions): A proportional navigation guidance law is applied to an interceptor that has arbitrary time-varying velocity and is to reach a nonmoving target point. When the proportional constant is greater than unity, intercept will occur for all initial conditions, except for the case when the interceptor is moving away from the target
openaire +2 more sources
Rapid Motion Estimation of a Target Moving with Time-Varying Velocity
AIAA Guidance, Navigation and Control Conference and Exhibit, 2007This paper describes the development of a vision-based motion estimation and target tracking system for a small unmanned air vehicle (SUAV) equipped with an inertially stabilized gimballed camera. The work concentrates on the design of a new rapid motion estimation algorithm for a ground target moving with time-varying velocity.
Vladimir Dobrokhodov +7 more
openaire +1 more source
Verification of numerical analysis for unwinding cable with time-varying unwinding velocity
Textile Research Journal, 2021In this study, the nonlinear unwinding behavior of cables in a transient state wound in a cylindrical spool package was analyzed using unwinding dynamics. In previous studies, investigations were conducted using constant unwinding velocity. However, this method is limited due to complexities regarding the analysis of the actual behavior where the ...
Hyun-Gyu Park +6 more
openaire +1 more source
Closed-form optimal guidance law for missiles of time-varying velocity
Journal of Guidance, Control, and Dynamics, 1996An optimal guidance law for missiles with time-varying velocity is investigated. The closed-form solution is derived and properties of the key variables of the solution, such as a time-to-go-like function and the time-varying guidance gain, are studied.
Cho, HJ +2 more
openaire +2 more sources
Determination of the group velocity using the time-varying autoregressive TVAR
2007 9th International Symposium on Signal Processing and Its Applications, 2007A time-varying autoregressive ldquoTVARrdquo approach is used for modeling nonstationary signals, and frequency information is then extracted from the TVAR parameters. In this study, we present the application of the TVAR spectrum on the acoustic signal backscattered by an elastic tube.
R. Latif +3 more
openaire +1 more source
Velocity measurement of a diffuse object by using time-varying speckles
Optical and Quantum Electronics, 1976The relation between the velocity of a moving diffuse object and the mean number of integrated speckles in the certain time interval at the far-field plane of the object is obtained. By using this relation based on the first order statistics of integrated speckles, a new method of measuring the velocity of the diffuse object is proposed and ...
Junji Ohtsubo, Toshimitsu Asakura
openaire +1 more source