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Following Mandelbrot's fractal theory, it was found that the fractal dimension could be obtained in medical images by the concept of fractional Brownian motion. An estimation concept for determination of the fractal dimension based upon the concept of fractional Brownian motion was discussed. Two applications were found: 1) classification; 2) edge enhancement and detection. For the purpose of classification, a normalized fractional Brownian motion feature vector was defined from this estimation concept. It represented the normalized average absolute intensity difference of pixel pairs on a surface at different scales. The feature vector used relatively few data items to represent the statistical characteristics of the medical image surface and was invariant to linear intensity transformation. Finally, by calculating normalized fractional Brownian motion feature vectors in five different ultrasonic image surfaces, it was found that the classification of normal and abnormal ultrasonic liver images could be obtained from the differences between their feature vectors. For edge enhancement and detection application, a transformed image was obtained by calculating the fractal dimension of each pixel over the whole medical image. The fractal dimension value of each pixel was obtained by calculating the fractal dimension of a 7 x 7 pixel block centered on this pixel. Preliminary results using projection radiographs suggest that the fractal based image transformation appears to hold promise as an edge enhancement and preprocessing algorithm that does not increase noise in the way that gradient operators do. © 1989 IEEE

Qualitative analysis is important because it is not subjective and does not have the potential for variation from one observer to another. A description is given of how statistical hypothesis testing can be used to select the quantitative descriptors best capable of distinguishing between normal and abnormal liver texture. Information is also presented on how both parametric and nonparametric discriminant analysis can be applied to determine how well the quantitative analysis compares with the qualitative diagnosis supplied for each case studied.

While cooccurrence matrices have been shown to be helpful in quantitating image texture, the amount of data associated with them can rapidly become unmanageable because a separate cooccurrence matrix can be calculated for each displacement vector chosen. Here, a method for choosing the direction of the displacement vector that is based on the most dominant edge obtained from gradient analysis is discussed. Also, the anatomy of the liver is used to suggest the most important intersample spacing in constructing cooccurrence matrices for the evaluation of diffuse liver disease.

Spectral analysis of Doppler ultrasound has been known to yield valuable information to assess the state of circulation in the peripheral blood vessels. In the past, the raw Doppler data have been directly input into a dedicated spectrum analyzer or, more recently, transformed on a microcomputer with the fast Fourier technique. The fast Hartley technique is used to transform these data. The Hartley transform has the advantages of being a purely real-numbered transform, and therefore for real Doppler data, is not only more conceptually straightforward, but also requires less computer memory, is simpler to calculate, and is better suited to large-scale integration implementation. © 1988 IEEE

Recent developments in image digitization have made possible a more quantitative analysis of ultrasonic imagery of the liver, which could lead to a more sensitive method for changes in liver texture as an aid in the diagnosis of liver disease. The approach described is the statistical analysis of one-dimensional intensity (gray-level) histograms obtained from B-mode ultrasonic images. First-order statistical parameters are used to characterize the location, variability, skewness and kurtosis of the histograms. One typical normal study and one typical abnormal study are presented to shown the type of results that have been obtained.

A new type of RC op oscillator has been designed. For amplitude stabilization, diodes are added in the feedback of the linear circuit. A model has been developed for a nonlinear element, which affects the frequency of oscillation. The model can be used to design the oscillator for different frequencies and to calculate frequency and amplitude sensitivity with respect to the parameter of the system.

A personal computer applications course has been developed. This course is a follow up to an introductory programming course for non-computer science majors. The primary objective of the course is to introduce the major personal computer applications areas: operating system use, word processing, spreadsheet programming, data base management, and communications. For each area, there will be a discussion of its use and related problems. Students will use a representative and a comparison will be made with other systems. The course will be taught using Apple IIe's or Commodore 64 computers. A course outline has been created and approved. The course will be offered for the first time in the Spring of 1984. Budget considerations, the practical difficulties involved with students using copyrighted software, and a desire to have students leave with software they can take with them, make it attractive to use public domain software when possible. Current research is directed towards finding and documenting public domain software for use in this course. Principal sources being investigated are the program libraries of personal computer users groups and educational cooperatives.

Pattern recognition techniques for cloud type and cloud amount classification were applied to digital infrared SMS-1 data. The cloud classification results were used in a numerical radiation model to determine solar radiation during Phase III of the GARP Atlantic Tropical Experiment. In order to assess the effects on radiation computations of cloud information derived from both satellite and ship data, cloud analyses based on both data sources were prepared for input into the numerical radiation model. -from Authors

The paper presents methods of space allocation applicable to architectural design. These techniques have been developed in the past twenty years and are presented in this paper in such a way that they mav also be applied to other disciplines. Four categories are presented that identify the variations in the dimensioning of the elements, either unit dimension or variable dimension, and the variation in the shape of the boundary, either a simple rectangle or a multi-faceted boundary.

The use of gradient operators for image enhancement has been widely reported in the literature, but they have not been used routinely in the medical arena, particularly in the most common radiographic plain film procedure, chest radiographs. Gradient operators such as Sobel and Roberts operators, not only enhance image edges but also tend to enhance noise. Overall, the Sobel operator was found to be superior to the Roberts operator in edge enhancement. A theoretical explanation for the superior performance of the Sobel operator was developed based on the concept of analyzing the x and y Sobel masks as linear Alters. By applying pill box, Gaussian, or median filtering prior to applying a gradient operator, noise was reduced, but the pill box and Gaussian filters were much more computationally efficient than the median filter with approximately equal effectiveness in noise reduction. © 1988 IEEE