New Approaches and Techniques for Drawing Lines on Raster Devices.

Two basic approaches to drawing lines on raster devices are discussed and improved upon. The first is the recursive bisection algorithm, a method recently proposed by John Rankin, which uses a fractal approach to draw lines. The second is the double-step algorithm, a method proposed by Xiaolin Wu and Jon Rokne, which is based on the traditional Bresenham approach to drawing lines. Although a number of line drawing algorithms exist, the algorithms presented are of interest because the double-step algorithm is one of the fastest line drawing algorithms. Furthermore, since lines are self-similar and fractals have been found to be useful in drawing other self-similar objects such as coastlines, plants, and terrain, the investigation of such an approach appears to be a worthwhile endeavor. In addition, some of the ideas presented can be applied to other line drawing algorithms and related problems such as incremental linear interpolation. Regarding the recursive bisection algorithm, modifications making it faster than the traditional Bresenham method while reducing the logarithmic space requirements to a constant are discussed. A more detailed examination of the error analysis is presented as well. A parallel version of the algorithm is also developed in which only two operations reducible to multiplication/division are required, equaling the lower bound and half the amount needed by the parallel Bresenham algorithm. In addition, the amount of logic needed is small. In the second part, modifications to the double-step line drawing algorithm are presented that allow additional pixels to be determined during some of the loop iterations. It is then shown that the resulting algorithm reduces the number of iterations by up to 33% while keeping the same worst case performance, code complexity, and initialization costs as the double-step algorithm. Lastly, this approach is generalized and applied to one of the fastest incremental linear interpolation algorithms, giving similar results

A modeling and simulation framework for electrokinetic nanoparticle treatment

The focus of this research is to model and provide a simulation framework for the packing of differently sized spheres within a hard boundary. The novel contributions of this dissertation are the cylinders of influence (COI) method and sectoring method implementations. The impetus for this research stems from modeling electrokinetic nanoparticle (EN) treatment, which packs concrete pores with differently sized nanoparticles. We show an improved speed of the simulation compared to previously published results of EN treatment simulation while obtaining similar porosity reduction results. We mainly focused on readily, commercially available particle sizes of 2 nm and 20 nm particles, but have the capability to model other sizes. Our simulation has graphical capabilities and can provide additional data unobtainable from physical experimentation. The data collected has a median of 0.5750 and a mean of 0.5504. The standard error is 0.0054 at α = 0.05 for a 95% confidence interval of 0.5504 ± 0.0054. The simulation has produced maximum packing densities of 65% and minimum packing densities of 34%. Simulation data are analyzed using linear regression via the R statistical language to obtain two equations: one that describes porosity reduction based on all cylinder and particle characteristics, and another that focuses on describing porosity reduction based on cylinder diameter for 2 and 20 nm particles into pores of 100 nm height. Simulation results are similar to most physical results obtained from MIP and WLR. Some MIP results do not fall within the simulation limits; however, this is expected as MIP has been documented to be an inaccurate measure of pore distribution and porosity of concrete. Despite the disagreement between WLR and MIP, there is a trend that porosity reduction is higher two inches from the rebar as compared to the rebar-concrete interface. The simulation also detects a higher porosity reduction further from the rebar. This may be due to particles aggregating before reaching the rebar that can easily be seen in the graphical representation of the simulation cylinders. The dissertation author has created a web based framework to allow an interdisciplinary team to work in concert with access to the simulation and the results generated. The results are stored into a MySQL database. The database currently holds 271 simulation runs. Simulation requests can be entered into a web interface and will automatically be processed in the order entered and the results stored into the database. Results can also be retrieved from the database and filtered based on any simulation parameter. Statistical analysis can be completed on the data points stored in the database by using version of Rweb modified by the dissertation author. The result is a collaborative framework that can be extended to address future investigations into pore packing and chloride blocking

The synthesis of sound with application in a MIDI environment

The wide range of options for experimentation with the synthesis of sound are usually expensive, difficult to obtain, or limit the experimenter. The work described in this thesis shows how the IBM PC and software can be combined to provide a suitable platform for experimentation with different synthesis techniques. This platform is based on the PC, the Musical Instrument Digital Interface (MIDI) and a musical instrument called a digital sampler. The fundamental concepts of sound are described, with reference to digital sound reproduction. A number of synthesis techniques are described. These are evaluated according to the criteria of generality, efficiency and control. The techniques discussed are additive synthesis, frequency modulation synthesis, subtractive synthesis, granular synthesis, resynthesis, wavetable synthesis, and sampling. Spiral synthesis, physical modelling, waveshaping and spectral interpolation are discussed briefly. The Musical Instrument Digital Interface is a standard method of connecting digital musical instruments together. It is the MIDI standard and equipment conforming to that standard that makes this implementation of synthesis techniques possible. As a demonstration of the PC platform, additive synthesis, frequency modulation synthesis, granular synthesis and spiral synthesis have been implemented in software. A PC equipped with a MIDI interface card is used to perform the synthesis. The MIDI protocol is used to transmit the resultant sound to a digital sampler. The INMOS transputer is used as an accelerator, as the calculation of a waveform using software is a computational intensive process. It is concluded that sound synthesis can be performed successfully using a PC and the appropriate software, and utilizing the facilities provided by a MIDI environment including a digital sampler

1991 OURE report, including the 1st Annual UMR Undergraduate Research Symposium -- Entire Proceedings

The Opportunities for Undergraduate Research Experiences program began in 1990. The aims were to enrich the learning process and make it more active, encourage interaction between students and faculty members, raise the level of research on the campus, help recruit superior students to the graduate program, and support the notion that teaching and research are compatible and mutually reinforcing. Chancellor Jischke made available an annual budget of $50,000 to support the program. As the papers herein attest, the OURE program is achieving its goals — UMR graduates have performed research on an enormous variety of topics, have worked closely with faculty members, and have experienced deeply both the pleasures and frustrations of research. Several of the undergraduates whose papers are included are now graduate students at UMR or elsewhere. Others, who have not yet graduated, are eager to submit proposals to the next OURE round. I am sure all involved join me in expressing gratitude to Chancellor Jischke for inaugurating the program. The first section of this volume is made up of papers presented at the first annual UMR Undergraduate Research Symposium, held in April 1991. Joining the UMR undergraduates in the Symposium were students from other colleges and universities who had participated in an NSF- sponsored summer program of research on parallel processing conducted by the UMR Computer Science Department