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The spatial Bessel filters are analyzed for their ability to reduce ultrasonic speckle and increase the boundaries of regions of interest (ROI) in medical B-mode images and a new parameter is defined for measuring the edge visibility. The results have shown the use of Bessel spatial filters in providing speckle reduction along with the ability to increase the boundaries of regions of interest in B-mode images and the quantitative measures have supported the visual perception of contrast and enhanced edge visibility.

A multiparameter approach involving classification of breast masses in ultrasonic B-scan images is described and discussed.

The envelope of the backscattered echo from tissue is described by means of a compound probability density function (pdf).

Breast cancer diagnosis through ultrasound tissue characterization was studied using receiver operating characteristic (ROC) analysis of combinations of acoustic features, patient age, and radiological findings. A feature fusion method was devised that operates even if only partial diagnostic data are available. The ROC methodology uses ordinal dominance theory and bootstrap resampling to evaluate [A.sub.z] and confidence intervals in simple as well as paired data analyses. The combined diagnostic feature had an [A.sub.z] of 0.96 with a confidence interval of [0.93, 0.99] at a significance level of 0.05. The combined features show statistically significant improvement over prebiopsy radiological findings. These results indicate that ultrasound tissue characterization, in combination with patient record and clinical findings, may greatly reduce the need to perform biopsies of benign breast lesions. Index Terms--Bootstrap, breast ultrasonic imaging, ROC analysis, tissue characterization.

An approach to demonstrate flat fading in communication systems is presented here, wherein the basic concepts are reinforced by means of a series of MATLAB (Mathworks, Inc., Natick, MA 01760-2098 USA) simulations. Following a brief introduction to fading in general, models for flat fading are developed and simulated using MATLAB. The concept of outage is also demonstrated using MATLAB. The authors suggest that the use of MATLAB exercises will assist the students in gaining a better understanding of the various nuances of flat fading. Index Terms--Fading, MATLAB-based instruction, mobile communications, simulation of fading, wireless systems.

Data analytics‐based tools are used extensively in industry, business, science, engineering, and medicine. Efforts are being made to transform the undergraduate course in engineering probability by incorporating the data analytics while retaining the concept‐driven topics. The author has been engaged in these efforts since 2017–2018. This manuscript reports on a number of data analytics‐based assignments alongside the traditional ones consisting of exercises requiring proofs, derivations, and calculations created during the fall quarter of 2018–2019. These assignments rely on computational tools and are connected to the theoretical concepts allowing the students to understand and appreciate the use of conceptual topics to practical application in machine vision, robotics, medical diagnostics, and so forth. The details on these assignments along with their implementation, results, and lessons learnt and conclusions drawn are presented. [ABSTRACT FROM AUTHOR]

A course in probability is a requirement in Baccalaureate Programs in Electrical and Computer Engineering. Students view this course as conceptual with little connection to real world problems. Efforts have been undertaken to mitigate this issue and connect the conceptual topics to data analytics to make the course relevant. Data analytics based exercises are now integral to the course. Several demos were created to link statistical concepts with practice through analysis of data. In this study, a demo created to illustrate the concept of diversity to improve the performance of a machine vision system is described. It incorporates concepts of Bayes' rule, single and multiple random variables, goodness fit tests, random number simulation and data analytics to illustrate the pedagogy of diversity and associated data processing. Student survey results suggest that these demos enhance that the learning experience in the engineering probability course. [ABSTRACT FROM AUTHOR]

Chi‐square goodness of fit testing to examine whether or not it is reasonable to assume that a random sample of the data comes from a specific probability density was one of the topics covered in an undergraduate engineering probability course. In the absence of details on this topic in engineering probability books, a Matlab® demo was created to facilitate the link between theory and practice. The step‐by‐step procedure to determine the closest fit among a number of continuous densities has been demonstrated involving binning (fixed width and fixed population), parameter estimation, and computation of the test statistic, degrees of freedom and the P values. The cautionary aspects of the test regarding the variability in test results have been illustrated by choosing a smaller size data through permutation. The pedagogical aspects of procedure demonstrated suggest that it may be used to fill the gaps in textbooks devoted to probability and statistics. [ABSTRACT FROM AUTHOR]

A module has been developed to expand the scope of the undergraduate course in engineering probability to include data analytics. Starting with demos using data from hypothetical experiments in machine vision, students were exposed to the topics of confusion matrix, transition matrix, receiver operating characteristic curves, Bayes' rule, and concepts of random variables bridging the gap between theory and applications. Student were given unique data sets requiring estimation of a priori and conditional probabilities, positive predictive values, and error rates in the machine vision classifier. Student surveys conducted at the start and conclusion of the course seem to suggest that they gained an enhanced understanding of the applications of probability concepts to data analytics. The methodology can easily be extended to cover other topics such as hypothesis testing and diversity analysis to shift the emphasis of the engineering probability course from pure theory to applications. [ABSTRACT FROM AUTHOR]

ABSTRACT A Matlab workbook capable of generating complete solutions to a set of linear equations is presented. While standard routines in Matlab and Maple provide solutions to a set of equations, additional work is needed to interpret and relate them to the concepts covered in an undergraduate course in Linear Algebra. One also runs into difficulties when the system of equations is inconsistent. The workbook, started as a simple demo for students, evolved into its present form where the solutions to a set of linear equations are displayed on a single page with explanations, annotations, and equations that match the work by the instructor in class. Regardless of whether the system is consistent or inconsistent with general or unique solutions, the solution set is presented with information such as the rank of a matrix, pivots, null space, free and basic variables, etc., providing the pedagogy. The solutions are compared to those obtained using standard packages from Matlab and Maple demonstrating their shortcomings and limits. In contrast, the results of the workbook provide complete instructive aspects of solutions to a set of linear equations enhancing the educational experience of students. © 2017 Wiley Periodicals, Inc. Comput Appl Eng Educ 25:345-351, 2017; View this article online at ; DOI [ABSTRACT FROM AUTHOR]

Research describing the use of the Nakagami model for modeling the echo from breast tissue is presented. In particular the Nakagami distribution is investigated as a means of separating benign and malignant breast masses.

A general statistical model based on Nakagami distribution is explored as a means of describing the backscattered ultrasonic echo from tissues.

Presents a study which examined the statistics of the backscattered ultrasonic echo from tissue using Rayleigh, K and Nakagami distributions. Theoretical model; Computational approach; Results and conclusions.

Explores the possibility of enhancing the ability of Nakagami statistics for ultrasonic tissue characterization through the techniques of diversity and compounding. Definition of Nakagami distribution; Diagram of a diversity processor; Results from simulation of random numbers showing the validity of the analytical model for the parameters of the Nakagami model.

On-fiber devices are fabricated by removing the cladding over a short length of the multimode fiber and replacing it with an active medium like electrooptic or magnetooptic material When a field is applied, the index of this modified cladding goes up, leading to a redistribution of modal amplitudes, which may or may not he accompanied by optical power loss due to radiation modes. Significant optical power loss occurs when the induced index change is large while modal redistribution of amplitudes takes place with negligible power loss when the index change is very small. This modal redistribution has been investigated and expressions for the amplitude coupling coefficient related the modal amplitudes before and after the application of the field are derived. These coupling coefficients have been evaluated as a function of the induced index change in the cladding. The results indicate that this modal redistribution may be used as a sensing mechanism. [ABSTRACT FROM AUTHOR]

A simple fabrication method is described which is capable of producing physically repeatable biconical tapers in optical fibers. A resistively heated platinum wire furnace provides the heat with standard fiber-optic positioning equipment to secure the fiber. The method does not require computer control and has the advantages of low cost, fast sample turn-around time, and the ability to concatenate multiple tapers on a single fiber. Experimental results demonstrating repeatable taper formation and the wavelength filtering property of the tapers is shown. Issues of varying the taper shape are addressed and measurement methods of the physical and optical characteristics are presented. Limited control of the taper symmetry is discussed, and recommendations for enhancement at the cost of simplicity are included. [ABSTRACT FROM AUTHOR]

A double frequency method of measuring bubble size which has better spatial resolution than previous techniques, is described. Bubbles are insonified simultaneously by a swept, relatively low, ''pumping'' frequency near their resonance and a high ''imaging'' frequency. Theoretical expressions are derived for the sound scattered by a bubble under the influence of these two frequencies. Existence of sharp resonance behavior in the scattered sound at the sum frequency is shown both theoretically and experimentally. [ABSTRACT FROM AUTHOR]

The departure of speckle magnitude from Rayleigh statistics was applied to examine insonated phantoms with both low and high concentrations of scatterers. A mathematical model, the K distribution of Jakeman, was used to characterize non-Rayleigh statistics. This model contains a parameter, α, which characterizes the clustering of the scattering sites in a medium. It is shown from phantom experiments that alpha is linearly proportional to the log-scaled scatterer concentration in a range from about 1 to 30 scatterers per sample volume. © 1991 Acoustical Society of America. [ABSTRACT FROM AUTHOR]