A fast-initializing digital equalizer with on-line tracking for data communications

A theory is developed for a digital equalizer for use in reducing intersymbol interference (ISI) on high speed data communications channels. The equalizer is initialized with a single isolated transmitter pulse, provided the signal-to-noise ratio (SNR) is not unusually low, then switches to a decision directed, on-line mode of operation that allows tracking of channel variations. Conditions for optimal tap-gain settings are obtained first for a transversal equalizer structure by using a mean squared error (MSE) criterion, a first order gradient algorithm to determine the adjustable equalizer tap-gains, and a sequence of isolated initializing pulses. Since the rate of tap-gain convergence depends on the eigenvalues of a channel output correlation matrix, convergence can be improved by making a linear transformation on to obtain a new correlation matrix

Design of FIR digital filters for pulse shaping and channel equalization using time-domain optimization

Three algorithms are developed for designing finite impulse response digital filters to be used for pulse shaping and channel equalization. The first is the Minimax algorithm which uses linear programming to design a frequency-sampling filter with a pulse shape that approximates the specification in a minimax sense. Design examples are included which accurately approximate a specified impulse response with a maximum error of 0.03 using only six resonators. The second algorithm is an extension of the Minimax algorithm to design preset equalizers for channels with known impulse responses. Both transversal and frequency-sampling equalizer structures are designed to produce a minimax approximation of a specified channel output waveform. Examples of these designs are compared as to the accuracy of the approximation, the resultant intersymbol interference (ISI), and the required transmitted energy. While the transversal designs are slightly more accurate, the frequency-sampling designs using six resonators have smaller ISI and energy values

The Brownie Baker Case: Ingredients Of Success

This case study examines The Brownie Baker, which makes gourmet and specialty baked goods, from an operations management perspective.  Its product line includes brownies, muffins, Danishes, cookies, cakes, and Hispanic pastries.  Located in Fresno, California, the bakery distributes its products across much of the United States.  The Brownie Baker was acquired by president and CEO, Dennis Perkins, in 1990.   What started with four or five employees and $180,000 in annual sales has grown to 80 employees and more than 10 million dollars in sales in 2007.  Perkins’ down-to-earth, receptive management style coupled with product innovations and productivity improvements have been key ingredients in the company’s successful growth.  Perkins himself was named the Small Business Administration’s  Central California Business Person of the Year in 1999, and The Brownie Baker was awarded the Small Business Administration’s Western Region Choice Award in 2004.  This case details the operations strategies and management techniques that have led to these accomplishments

Facts from Fiction: Packaging Misinformation

Previous research established that readers learn both accurate and inaccurate information from fictional stories. The current study explored factors that might moderate the impact of misinformation. Participants read fictional stories that contain three assertions; the first two were labeled as set-up assertions, and the last were labeled as the critical assertion. First, there was a manipulation of plausibility of information within the stories by presenting either assertions with truthful information, assertions with small lies (plausible misinformation), or assertions with big lies (implausible misinformation). Second, there was manipulation of reliability of the fictional stories by presenting big lies or truthful information in the set-up assertions before the critical assertion. Each story had two set-up assertions (either both are big lies, or both are truthful) that were presented prior to the critical assertion. We expected to replicate many existing findings found within the misinformation literature. Of most interest in this study, we observed being presented with misinformation led to lower accuracy and being presented with subtle misinformation led to higher production of that misinformation on the general-knowledge test. The setup assertion manipulation interacted with the type of critical assertion in one way: When the critical assertion was presented accurately in a story, the setup assertions mattered a lot in that reliable narrators presenting true critical assertions and led to greater accuracy on the general knowledge test than when unreliable narrators presented this information

Sunrise Medical And The Quickie Wheelchair

This case profiles the Quickie Wheelchair, first developed by a group of entrepreneurs in Fresno, California and now manufactured by Sunrise Medical, the world’s leading manufacturer of customized lightweight wheelchairs. Topics such as strategy, product design, location planning, quality control, and just-in-time systems make this case suitable for use in a production and operations management course

A digital technique to compensate for time- base error in magnetic tape recording

Digital technique for compensation of time base error in magnetic tape recorder dat

An Educational, Economic and Community Survey of Blount County, Tennessee

General statements: In 1922 the Board of Trustees of the University of Tennessee acting on the suggestion of President Morgan, authorized the establishment of a Department of Rural Education in the University, whose functions should be: first, to study intensively rural school conditions in Tennessee; second, to train teachers for the rural schools; and, third, to cooperate with the State school authorities in every way possible to make the work of the rural schools more nearly meet the needs of the rural communities. Following the approval and promise of co-operation of the State Department of Education, it was decided to make a series of surveys or rural communities for the purpose of determining conditions in the different counties and of offering suggestions for their improvement. The first of the series was that of Union County, made in the fall of 1922. Following this were surveys of Lewis, Crockett, Pickett, Monroe, Bledsoe, and Jackson counties. At the request of the County Board of Education and the Superintendent of Schools for a study of the economic, social, and educational conditions in Blount county, this survey was conducted. The purpose of the survey was to ascertain existing conditions in the county and with the aid of the University, to devise some plans for improving these conditions. The information to be presented in this survey has been taken from reports of fifty-one of the sixty-one rural school communities. Although not mathematically correct in every detail, it is believed that the data included in this survey are fairly representative of conditions in the county