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651.
A numerical and analytical method for constructing a shape of the axisymmetric body streamlined with jet blowout by the specified velocity distribution along its meridian section is proposed. The foundation of the method is the iteration process based on the solutions of an inverse problem in the plane case and a primal problem for the axisymmetric body. A program realizing the iteration process is set up and examples of numerical calculations are given.  相似文献   
652.
A recursive method for calculating decoupling zeroes in the linear multiconnected dynamic system based on the application of matrix canonization techniques is proposed. Its essence is that the problem dimension is successively decreased and reduced to finding eigenvalues of some matrix. The results obtained can be used to check controllability and observability as well as to calculate uncontrollable and unobservable modes of the dynamic system.  相似文献   
653.
654.
A decentralized detection problem is considered in which a number of identical sensors transmit a finite-valued function of their observations to a fusion center which makes a final decision on one of M alternative hypotheses. The authors consider the case in which the number of sensors is large, and they derive (asymptotically) optimal rules for determining the messages of the sensors when the observations are generated from a simple and symmetrical set of discrete distributions. They also consider the tradeoff between the number of sensors and the communication rate of each sensor when there is a constraint on the total communication rate from the sensors to the fusion center. The results suggest that it is preferable to have several independent sensors transmitting low-rate (coarse) information instead of a few sensors transmitting high-rate (very detailed) information. They also suggest that an M-ary hypothesis testing problem can be viewed as a collection of M(M-1)/2 binary hypothesis testing problems. From this point of view the most useful messages (decision rules) are those that provide information to the fusion center that is relevant to the largest possible numbers of these binary hypothesis testing problems  相似文献   
655.
The trajectory control of aircraft in rapid, nonlinear maneuvers is discussed. Based on nonlinear invertibility theory, a control law is derived to independently control roll, pitch, and sideslip angles using rudder, elevator, and aileron. Integral feedback is introduced in order to obtain robustness in the control system to parameter uncertainty. The stability of the zero dynamics is examined. Simulation results are presented to show that in a closed-loop system, precise simultaneous lateral and longitudinal maneuvers can be performed despite the presence of uncertainty in the stability derivatives  相似文献   
656.
The problem of lateral motion stabilization is analytically solved for the fourth-order model of aircraft motion using the method of output signal control synthesis that is based on the control object decomposition. Numerical simulation data are presented.  相似文献   
657.
The Juno Radiation Monitoring (RM) Investigation   总被引:1,自引:0,他引:1  
The Radiation Monitoring Investigation of the Juno Mission will actively retrieve and analyze the noise signatures from penetrating radiation in the images of Juno’s star cameras and science instruments at Jupiter. The investigation’s objective is to profile Jupiter’s \(>10\mbox{-MeV}\) electron environment in regions of the Jovian magnetosphere which today are still largely unexplored. This paper discusses the primary instruments on Juno which contribute to the investigation’s data suite, the measurements of camera noise from penetrating particles, spectral sensitivities and measurement ranges of the instruments, calibrations performed prior to Juno’s first science orbit, and how the measurements may be used to infer the external relativistic electron environment.  相似文献   
658.
The SEIS (Seismic Experiment for Interior Structures) instrument on board the InSight mission to Mars is the critical instrument for determining the interior structure of Mars, the current level of tectonic activity and the meteorite flux. Meeting the performance requirements of the SEIS instrument is vital to successfully achieve these mission objectives. The InSight noise model is a key tool for the InSight mission and SEIS instrument requirement setup. It will also be used for future operation planning. This paper presents the analyses made to build a model of the Martian seismic noise as measured by the SEIS seismometer, around the seismic bandwidth of the instrument (from 0.01 Hz to 1 Hz). It includes the instrument self-noise, but also the environment parameters that impact the measurements. We present the general approach for the model determination, the environment assumptions, and we analyze the major and minor contributors to the noise model.  相似文献   
659.
A major challenge posed by aircraft tracking problems is the nondeterministic nature of an aircraft flight, due to the difficulty of predicting the pilot's actions. Accurate aircraft maneuver models are however highly desirable, particularly in air defense applications, to achieve accurate tracking and prediction. Through analysis of actual fighter aircraft trajectories and comparison with the Singer maneuver model, particularly in terms of prediction performance, coordinated turn (CT) aircraft maneuver models are presented, compared, and validated. A more general CT model is shown to better model actual trajectories than the classical CT model used in the literature  相似文献   
660.
Radiobiological effects of single cosmic heavy ions on individual, actively metabolizing test organisms, plants of Wolffia arrhiza, have been explored in an experiment flown aboard the Russian Biosatellite 10. Mortality induced during space flight, population dynamics during subsequent cultivation, and morphological anomalies occurring in the plants of these cultures were investigated. Correlation of these effects with the passage of a heavy ion was achieved by inserting monolayers of plants in a stack of surrounding plastic nuclear track detectors (BIO-STACK). Enhanced initial mortality and delayed decline of induced anomalies have been significantly associated with the passage of single heavy ions, in particular if ions penetrated the budding region of the plants. The prolonged persistence of anomalies in filial generations as an indication of delayed genetic damage has been detected for the first time as the consequence of the hit by a single heavy ion. Regarding radiation protection of space crew during prolonged missions, especially outside the magnetosphere, this appears to be a significant finding.  相似文献   
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