Parallel resonant converter with LLC-type commutation

It is shown that by using a proper transformation of state variables, the third-order system of the parallel resonant converter (PRC) with LLC-type commutation can be analyzed by means of a two-dimensional state-plane diagram. A set of characteristic curves which can be used for the converter design is derived from the analysis. It is shown from these curves that the converter possesses more desirable features than the conventional PRC     

Geometric aspects of long-term noncoherent integration

Long-term integration is defined as integration, perhaps interrupted, over time periods long enough for targets to move through volumes in space resolvable by the radar. Because the motion of the target is unknown prior to detection, long-term integration must be performed along multiple paths representing plausible target paths. The geometry of such a set of integration paths affects detection performance in several ways. The simplest implementation of long-term integration, using constant radial velocity paths, is investigated. The effects of path geometry on detection is quantified and optimized for a target whose motion is nearly radial but otherwise unknown     

Test Results with an Experimental Direction-Finding System

A direction-finding system was built that can simultaneously estimate the arrival angles of two incident signals. It is conceptually straightforward to extend the system to cases with greater numbers of signals. The system is designed to work with uncorrelated signals whose form is unknown, e.g., two communications signals residing in the same bandwidth. Pulsed as well as continuous signals can be handled. The technique involves the determination of the received signal's correlation matrix as an intermediate step. Pattern range tests were performed to determine angle estimate bias and accuracy.     

Large angle pitch attitude maneuver of a satellite using solarradiation pressure

The force exerted by the solar radiation, though very small in magnitude, produces significant effects, especially in the case of high altitude satellites. The solar radiation pressure represents one freely available environmental force that may be put to use for various purposes. This may lead to enhancement of the life of the satellite since it consumes a very nominal amount of on-board energy. The advantages offered by the solar radiation pressure have drawn the attention of several researchers. Various controllers were proposed for many space missions, particularly for attitude control and stabilization of satellites. A controller for achieving large angle pitch attitude maneuver is described. The proposed control law is very simple in its form and requires a minimum number of on-board computations. Varieties of cases are tried and the effect of various parameters is studied     

Air transport security and crisis management

Network management is one of the key technologies needed to fulfill the requirements. In other words, a new paradigm for network management is also needed, in order to address the requirements arising both from the ATN side and the telecommunication side of the new telecommunication infrastructure. In particular, the new network management paradigm will incorporate the ATN management framework consisting of related standards, along with the telecommunication management framework, notably Telecommunication Management Network (TMN) standards from ITU-T.     

Data Quantization for Narrowband Signal Detection

In automatic radar detection, digital integration of the envelope detector outputs is often used as a good approximation to the optimum. This requires quantizing the envelope detector outputs. In this paper, quantizer structures for narrowband signal detection are considered. Quantizer characteristics are derived to optimize performance as measured by the detector efficacy?an asymptotic performance measure. Asymptotic and finite sample performance results are presented. The results obtained are not limited in their application to Gaussian noise only, although this important case is given specific consideration.     

Stochastic Dynamic System Suboptimal Control with Uncertain Parameters

The control of a linear system with random coefficients is studied here. The cost function is of a quadratic form and the random coefficients are assumed to be partially observable by the controller. By means of the stochastic Bellman equation, the optimal control of stochastic dynamic models with partially observable coefficients is derived. The optimal control is shown to be a linear function of the observable states and a nonlinear function of random parameters. The theory is applied to an optimal control design of an aircraft landing in wind gust.