Wisconsin Alumni Research Foundation

About: Wisconsin Alumni Research Foundation is a nonprofit organization based out in Madison, Wisconsin, United States. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 4209 authors who have published 3523 publications receiving 61017 citations.

Dual bridge matrix converter

Abstract: A dual bridge matrix converter has a line-side converter with controllable switches that receives AC power and provides unidirectional power to high and low DC link lines, and a load-side converter which receives the power from the DC link lines and provides AC power to output lines. A clamp circuit is connected across the DC link lines and includes a series connected diode and a capacitor. Negative DC link current will be conducted through the clamp diode to charge the clamp capacitor to avoid voltage spikes on the DC link lines. A controllable switch may be connected in parallel with the clamp diode and is turned on when the voltage across the clamp capacitor is above a threshold that is greater than the normal peak-to-peak AC input voltage. The switch is turned off when the voltage across the clamp capacitor is lower than the threshold voltage.

Image compression system and method having optimized quantization tables

Abstract: A digital image compression preprocessor for use in a discrete cosine transform-based digital image compression device is provided. The preprocessor includes a gathering mechanism for determining discrete cosine transform statistics from input digital image data. A computing mechanism is operatively coupled to the gathering mechanism to calculate a image distortion array and a rate of image compression array based upon the discrete cosine transform statistics for each possible quantization value. A dynamic programming mechanism is operatively coupled to the computing mechanism to optimize the rate of image compression array against the image distortion array such that a rate-distortion-optimal quantization table is derived. In addition, a discrete cosine transform-based digital image compression device and a discrete cosine transform-based digital image compression and decompression system are provided. Also, a method for generating a rate-distortion-optimal quantization table, using discrete cosine transform-based digital image compression, and operating a discrete cosine transform-based digital image compression and decompression system are provided.

Method and apparatus for flux and torque sensing in electrical machines

Abstract: To determine the flux in the air gap of an electrical machine having distributed stator windings, the voltages across two coils of a phase belt in certain phases of the stator are measured and the voltage across one coil in each phase belt is subtracted from the voltage in the other coil. The voltage differences are integrated to provide a measure of the air gap flux. Measurement of the entire air gap flux about the machine can be obtained utilizing two coils in a phase belt per phase of the machine. The instantaneous electromagnetic torque in the machine can be calculated directly as a function of the calculated air gap flux and of the currents in the stator windings. Such flux and torque measurements are obtained utilizing electrical connections to the existing coils of the machine, without the need to modify the machine by adding further windings or sensors. The flux and torque signals so obtained may be utilized in motor controllers, and are particularly useful for control of AC induction motors.

Network-based viewing of images of three-dimensional objects

Abstract: A three-dimensional object may be imaged from several viewpoints distributed about the object, and the image obtained at each viewpoint may be stored in conjunction with the viewpoint's coordinates about the object. The object's image can then be transmitted for display over a client-server computer network, and the user may issue commands to manipulate the object, so as to very accurately simulate manipulation of the actual three-dimensional object. The client computer may display the object's image from one of the viewpoints. If the user then wishes to manipulate the object, the user will issue a command to the server to index from the coordinates of the first viewpoint to the coordinates of some adjacent viewpoint(s). The images of the adjacent viewpoints will then be displayed in a sequence corresponding to the order in which the coordinates of the viewpoints are indexed. Zooming (enlargement and reduction of views) and other features are also discussed, as well as various procedures for enhancing transmission time (and thus display speed).

Inequalities in lesbian, gay, bisexual, and transgender (LGBT) health and health care access and utilization in Wisconsin.

Abstract: There are known health disparities between lesbian, gay, bisexual and transgender (LGBT) people and non-LGBT people, but only in the past couple of decades have population-based health surveys in the United States included questions on sexual and gender identity. We aimed to better understand LGBT disparities in health, health care access and utilization, and quality of care. Data are from the Survey of the Health of Wisconsin (SHOW) from 2014 to 2016 (n = 1957). The analyses focused on comparing health care access and utilization, and quality of care between LGB and non-LGB people and transgender and cisgender people. 3.8% (n = 73) identified as lesbian, gay or bisexual, and 1.3% (n = 25) were transgender. LGB adults were 2.17 (95th CI: 1.07–4.4) times more likely to delay obtaining health care. Transgender adults were 2.76 (95th CI: 1.64–4.65) times more likely to report poor quality of care and 2.78 (95th CI: 1.10–7.10) unfair treatment when receiving medical care. The results show differences in health care access and utilization and quality of care, and they add to the growing body of literature that suggest that improved health care services for LGBT patients are needed to promote health equity for LGBT populations.