Showing papers by "Applied Science Private University published in 1982"

A Model and Tracking Algorithm for a Class of Video Targets

Abstract: Algorithms are developed for a real-time, automatic system capable of tracking two-dimensional (2-D) targets in complex scenes. A mathematical model of 2-D image spatial and temporal evolution applicable to certain classes of targets and target perturbations is developed. It is shown that for small target perturbations the 2-D tracking problem may be approximated as a 1-D time-varying parameter estimation problem. A CCD-implementable solution is developed which is particularly useful when considering target rotation and dilation and target/background separation. Results of system simulation and suggestions for future research are presented.

Observation of 1- to 5-second microtremors and their application to earthquake engineering. Part II. Evaluation of site effect upon seismic wave amplification due to extremely deep soil deposits

Abstract: The usefulness of long-period microtremor observation for earthquake engineering problems at extremely deep soil deposit site was examined in this study. Microtremor observations were made in the Niigata Plain, Japan, and in Los Angeles, California, where depths to the basement rock are several kilometers. These two locations were selected because strong-motion records obtained during the Niigata earthquake of 1964 and the San Fernando earthquake of 1971 contain large long-period amplitudes. Understanding why these predominate long-period motions were recorded is important for the evaluation of seismic input motions for large-scale structures. Long-period microtremor observations were carried out in both areas in order to evaluate the characteristics of deep soil. Observations were performed simultaneously at a number of stations to distinguish the nature of deep soil deposit. The result of Fourier analysis showed that amplitude of microtremors in long-period range increases systematically from the point of basement rock outcrop to deep deposit site, with the increase corresponding to the depth-to-basement rock. This relationship coincides with that observed in the strong-motion earthquake records. These analyses indicated that simultaneous observation of long-period microtremors at a number of stations can provide insight to the characteristic of deep soil amplification and, therefore, permit estimation of seismic input motions for large-scale structures.

Optimal Query Processing for Distributed Database Systems

Abstract: A model is developed for determining the optimal policy for processing a given relational model query. The model is based on operating cost (processing cost and communication cost), which is a function of selection of sites for processing query operations, sequence of operations, file size, and data reduction functions. The optimal policy specifies the site selection and sequence of operations that yield minimum operating cost.

Hyperthermia: Electromagnetic Heating of Deep-Seated Tumors

Abstract: Alternate methods for producing electromagnetic heating of deep-seated tumors are compared, with the focus on techniques which involve the use of a nonradiating electromagnetic field. A preference for sources which produce an electric field parallel to skin/fat/ muscle interfaces is expressed and an apparatus which accomplishes this is described. Experimental evidence in support of the theoretical rankdng of source types is presented. The evidence includes tests on animals and humans.

Investigation of a Rotor Bearing Assembly Incorporating a Squeeze-Film Damper Bearing

Abstract: Squeeze-film damper bearings, when properly designed, are a simple means of curbing instabilities and reducing vibration in rotor-bearing assemblies. This paper describes vibration tests carried ou...

An Aid to Hidden Surface Removal in Real Time CGI Systems

Abstract: One of the limiting factors in the development of real-time Computer Generated Image systems for displaying perspective colour scenes is finding a suitable solution to the hidden surface problem. This paper presents a solution to this problem, whereby spatial properties of a three-dimensional 'model' held in the Computer Generated Image system database are utilized in order to minimize hidden surface computations for producing moving perspective scenes. This solution is particularly acceptable to situations involving a fixed model and moving eye point. Often Computer Generated Image systems resort to processing individual surfaces from objects in the model to obtain display priority levels; the solution presented is based upon the use of preprocessed relative priority levels which only require complete objects to be given priority levels thus reducing real-time computation. Once an absolute display priority level for an object is found it will be shown that all surfaces forming that object have known display priority levels. Techniques used to obtain object display priority levels are discussed, together with background information concerning the hidden surface problem.

Renormalized Field Theory of Weakly Anisotropic Antiferromagnets under Gaussian Random Fields

Abstract: Antiferromagnets with weak spin anisotropy under Gaussian random fields are shown to exhibit just the same bicritical and tetracritical behaviors as those without random fields. Second order transitions occur only for unphysical space dimensionality 4< d< 6 and multi· critical points are also subject to d .... d-2 rule. It is predicted that weakly anisotropic antiferromagnets such as La-doped GdAIO. will have 2nd·order bicriticalline surrounding 1storder spin flop plane.