Other Engineering Commons^™

Winter/Spring 2003, 90.9 Wmpg Fm

WMPG Program Guides

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Sizes And Shapes Of 10-Ma Distal Fall Pyroclasts In The Ogallala Ggroup, Nebraska, William I. Rose, C. M. Riley, S. Dartevelle

Department of Geological and Mining Engineering and Sciences Publications

Size distributions of distal ashfall particles from correlated 10-Ma layers in Nebraska, measured using laser diffraction methods, are lognormal with mode diameters of ∼90 mm. This ashfall is ∼100% bubble-wall shards of rhyolite glass and apparently represents a distal ashfall from an eruption 1400 km away. Measured terminal velocities of these ash particles are 0.2–18 cm/s, consistent with Stokes Law settling of spherical particles with diameters of 9–50 mm. Surface area of the ash particles, measured with gas adsorption, is 20–30 times the surface area of equivalent Stokes spheres. These results highlight the effects of shape and atmospheric drag in …

Quantitative Shape Measurements Of Distal Volcanic Ash, William I. Rose, Colleen M. Riley, Gregg J. Bluth

Department of Geological and Mining Engineering and Sciences Publications

Large-scale volcanic eruptions produce fine ash (< 200 μm) which has a long atmospheric residence time (1 hour or more) and can be transported great distances from the volcanic source, thus, becoming a hazard to aircraft and public health. Ash particles have irregular shapes, so data on particle shape, size, and terminal velocities are needed to understand how the irregular-shaped particles affect transport processes and radiative transfer measurements. In this study, a methodology was developed to characterize particle shapes, sizes , and terminal velocities for three ash samples of different compositions. The shape and size of 2,500 particles from 1) distal fallout (~100 km) of the October 14, 1974 Fuego eruption (basaltic), 2) the secondary maxima (~250 km) of the August 18, 1992 Spurr eruption (andesitic), and 3) the Miocene Ash Hollow member, Nebraska (rhyolitic) were measured using image analysis techniques. Samples were sorted into 10 to 19 terminal velocity groups (0.6-59.0 cm/s) using an air elutriation device. Grain size distributions for the samples were measured using laser diffraction. Aspect ratio, feret diameter, and perimeter measurements were found to be the most useful descriptors of how particle shape affects terminal velocity. These measurement values show particle shape differs greatly from a sphere (commonly used in models and algorithms). The diameters of ash particles were 10-120% larger than ideal spheres at the same terminal velocity, indicating that irregular particle shape greatly increases drag. Gas-adsorption derived surface areas are 1 to 2 orders of magnitude higher than calculated surface areas based on measured dimensions and simple geometry, indicating that particle shapes are highly irregular. Correction factors for surface area were derived from the ash sample measurements so that surface areas calculated by assuming spherical particle shapes can be corrected to reflect more realistic values.

Retrieval Of Mass And Sizes Of Particles In Sandstorms Using Two Modis Ir Bands: A Case Study Of April 7 2001 Sandstorm In China, Yingxin Gu, William I. Rose, Gregg J. Bluth

Department of Geological and Mining Engineering and Sciences Publications

A thermal infrared remote sensing retrieval method developed by Wen and Rose [1994], which retrieves particle sizes, optical depth, and total masses of silicate particles in the volcanic cloud, was applied to an April 07, 2001 sandstorm over northern China, using MODIS. Results indicate that the area of the dust cloud observed was 1.34 million km2, the mean particle radius of the dust was 1.44 μm, and the mean optical depth at 11 μm was 0.79. The mean burden of dust was approximately 4.8 tons/km2 and the main portion of the dust storm on April 07, 2001 contained 6.5 million …

High Auality Time-Scale Modification Of Speech Using A Peak Alignment Overlap-Add Alogroithm (Paola), David Dorran, Robert Lawlor, Eugene Coyle

Conference papers

The duration of a speech passage can be altered using audio time-scale modification techniques. Time-scale modification can be achieved in the time domain by segmenting the input signal into overlapping frames and recombining the frames with an overlap differing from the analysis overlap. We present a time-scale modification algorithm that uses a simple peak alignment technique to synchronise overlapping synthesis frames. The peak alignment overlap-add (Paola) algorithm also takes advantage of waveform properties to ensure a high quality output for the minimum number of iterations. The new algorithm produces a time-scaled output of approximately equal quality to that of an …

Independent Subspace Analysis Using Locally Linear Embedding, Derry Fitzgerald, Eugene Coyle

Conference papers

While Independent Subspace Analysis provides a means of blindly separating sound souces from a single channel signal, it does have a number of problems. In particular the amount of information required for separation of sources varies with the signal. This is a result of the variance-based nature of Principal Component Analysis, which is used for dimensional reduction in the Independent Subspace Analysis algorithm. In an attempt to overcome this problem the use of a non-variance based dimensional reduction method, Locally Linear Embedding, is proposed. Locally Linear Embedding is a geometry based dimensional reduction technique. The use of this approach is …

Drum Transcription In The Presence Of Pitched Instruments Using Prior Subspace Analysis, Derry Fitzgerald, Robert Lawlor, Eugene Coyle

Conference papers

This paper demonstrates the use of Prior Subspace Analysis (PSA) as a method for transcribing drums in the presence of pitched instruments. PSA uses prior subspaces that represent the sources to be transcribed to overcome some of the problems associated with other subspace methods such as Independent Subspace Analysis (ISA) or sub-band ISA. The use of prior knowledge results in improved robustness for transcription purposes and enables the method to work more readily in the presence of pitched instruments than other subspace methods. The system presented in this paper attempts to extend the use of PSA to transcribe drum sounds …

An Efficient Audio Time-Scale Modification Algorithm For Use In A Subband Implementation, David Dorran, Robert Lawlor

Conference papers

The Paola algorithm, is an efficient algorithm for the time scale modification of speech. It uses a simple peak alignment technique to synchronise synthesis frames and takes waveform properties and the desired time-scale factor into account to determine optimum alogrithm parameters. However, PAOLA has difficulties with certain waveform types and can result in poor synchronisation for subband implementations. SOLA is a less efficient algorithm but resolves the issues associated with PAOLA's implementation. The authors present an algorithm that is a combination of the two approaches that proves to be an efficient and effective algorithm for a subband implementation.

Time-Scale Modification Of Speech Using A Synchronised And Adaptive Overlap-Add (Saola) Algorithm, David Dorran, Robert Lawlor, Eugene Coyle

Conference papers

The synchonised overlap-add (SOLA) algorithm is a commercially popular and considerably researched audio time-scale modification technique. It operates in the time domain and uses a correlation technique to ensure that synthesis frames overlap in a synchronous manner. We present a modification to SOLA that allows the analysis step size adapt to the desired time-scale factor. The synchronised and adaptive overlap-add (SAOLA) alogorithm improves upon the output quality of SOLA for high time-scale factors and reduces the computational requirements for low time-scale factors. However, the computational requirements for high time-scale factors are increased.

Drum Transcription Using Automatic Grouping Of Events And Prior Subspace Analysis, Derry Fitzgerald, Robert Lawlor, Eugene Dermot Coyle Professor

Conference papers

While Prior Subspace Analysis (PSA) has proved an effective tool for transcribung mixtures of snare, kick drum and hi-hat, attempts to extend it to increased numbers of drum types have met with mixed results. To overcome this an automatic grouping method has been developed to group drum events on their similarity in frequency content. Combined with PSA this creates a system able to handle robustly greater numbers of drum types. The effectiveness of this method is demonstrated in a drum transcription algorithm.

Time Scale Modification Of Music Using A Subband Approach Based On The Bark Scale, David Dorran, Robert Lawlor

Conference papers

Time-domain time-scaling algorithms are efficient in comparison to their frequency-domain counterparts, but they rely upon the existence of a quasi-periodic signal to produce a high quality output. This requirement makes them unsuitable for use on multi-pitched signals such as polyphonic music. However, time-domain techniques applied on a subband basis can resolve the multi-pitch problem. The authors propose an improved subband implementation based upon the bark scale for the time scale modification of music. The new subband approach is supported by psychoacoustic and music theory and subjectively through informal listening tests.

Prior Subspace Analysis For Drum Transcription, Derry Fitzgerald, Robert Lawlor, Eugene Coyle

Conference papers

This paper introduces the technique of Prior Subspace Analysis (PSA) as an alternative to Independent Subspace Analysis (ISA) in cases where prior knowledge about the sources to be separated is available. The use of prior knowledge overcomes some of the problems associated with ISA, in particular the problem of estimating the amount of information required for separation. This results in improved robustness for drum transcription purposes. Prior knowledge is incorporated by use of a set of prior frequency subspaces that characterise features of the sources to be extracted. The effectiveness and robustness of PSA is demonstrated by its use in …

A Multiobjective Approach Applied To The Protein Structure Prediction Problem, Richard O. Day

Theses and Dissertations

Interest in discovering a methodology for solving the Protein Structure Prediction problem extends into many fields of study including biochemistry, medicine, biology, and numerous engineering and science disciplines. Experimental approaches, such as, x-ray crystallographic studies or solution Nuclear Magnetic Resonance Spectroscopy, to mathematical modeling, such as minimum energy models are used to solve this problem. Recently, Evolutionary Algorithm studies at the Air Force Institute of Technology include the following: Simple Genetic Algorithm (GA), messy GA, fast messy GA, and Linkage Learning GA, as approaches for potential protein energy minimization. Prepackaged software like GENOCOP, GENESIS, and mGA are in use to …

Ir-Based Estimation Of Velocities Above Flames Spreading Over Different Fuels, Lulu Sun, Xiangyang Zhou, David R. Weise, Shankar Mahalingam

Publications

Wildfire spread in living vegetation such as chaparral in California and eucalyptus forests in Australia often causes significant damage to infrastructure and ecosystems. A physically based empirical model to predict fire spread rate is used in the United States to assist in a variety of fire management operations. The spread model does not adequately describe the chemical processes of combustion in live fuels.

Prior to describing and modeling the chemical processes of combustion in wildland fuels using computational fluid dynamics, we are investigating a technique to non-intrusively measure flame gas velocities using thermal imagery. By tracing "hot" pixels through successive …

Fall/Winter 2002, 90.9 Wmpg Fm

WMPG Program Guides

Newspaper format

Spring 2002, 90.9 Wmpg Fm

WMPG Program Guides

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Summer 2002, 90.9 Wmpg Fm

WMPG Program Guides

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Ancient Astronomical Alignments: Fact Or Fiction?, Frank Prendergast

Articles

No abstract provided.

Observations Of Volcanic Clouds In Their First Few Days Of Atmospheric Residence: The 1992 Eruptions Of Crater Peak, Mount Spurr Volcano, Alaska, William I. Rose, Gregg J. Bluth, David J. Schneider, Gerald G. J. Ernst, Colleen M. Riley, Lydia J. Henderson, Robert G. Mcgimsey

Department of Geological and Mining Engineering and Sciences Publications

Satellite SO2 and ash measurements of Mount Spurr’s three 1992 volcanic clouds are compared with ground‐based observations to develop an understanding of the physical and chemical evolution of volcanic clouds. Each of the three eruptions with ratings of volcanic explosivity index three reached the lower stratosphere (14 km asl), but the clouds were mainly dispersed at the tropopause by moderate to strong (20–40 m/s) tropospheric winds. Three stages of cloud evolution were identified. First, heavy fallout of large (>500 μm) pyroclasts occurred close to the volcano (vent) during and immediately after the eruptions, and the cloud resembled an advected …

Motorized Insulated Damper Assembly For Furnace Systems, William Max Kirk, Timothy Wentz

Durham School of Architectural Engineering and Construction: Faculty Publications

A damper unit is provided that is adapted to be positioned in a furnace duct line. The damper unit has a housing which is in communication with a fresh air source and a furnace system. The housing has a damper blade which is moveable between an open position which allows air flow through the housing and a closed position which prevents air flow through the housing. The blade is coupled with a Solenoid so that when the Solenoid is activated the blade is moved to an open position allowing air flow through the housing. Further, a fan is located in …

A Verification And Validation Assessment Of Rapid Availability Prototyping For Testing Operational Readiness, Gurhan Tarman

Theses and Dissertations

Throughout the world, new techniques are developed to test and evaluate systems. The Department of Defense and the US Air Force conduct numerous studies into the reliability and maintainability of current and future weapons systems in an effort to understand the reliability, maintainability, and availability (RM&A) costs of these systems. Furthermore, they must verify RM&A characteristics of systems, which are still in the development phase. The Air Force Operational Test and Evaluation Center (AFOTEC) is responsible for testing new equipment to ensure their RM&A characteristics meet specifications. Rapid Availability Prototyping for Testing Operational Readiness (RAPTOR) is the software tool developed …

Summer 2001, 90.9 Wmpg Fm

WMPG Program Guides

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Use Of Goes Thermal Infrared Imagery For Eruption Scale Measurements, Soufrière Hills, Montserrat, William I. Rose, Gari C. Mayberry

Department of Geological and Mining Engineering and Sciences Publications

GOES two-band IR data are used to estimate the magnitude of small eruption clouds (ash; <∼10⁵ tonnes of fine [1–25 µm in diameter] ash, and 5–15 km asl). The method is demonstrated on clouds from Soufrière Hills Volcano, Montserrat in 1997–99. The clouds in early 1999 were much smaller, were generally emplaced lower in the atmosphere and contained an order of magnitude less fine ash than 1997 clouds generated during the most intense phase of the eruption to date. Although GOES has an excellent capability for large eruption clouds, its use for smaller eruptions like Montserrat highlights several shortcomings, including …

The Offenses Of Missile Defense System Failure, Ibpp Editor

International Bulletin of Political Psychology

This article describes the political psychology of analyses of a recent United States testing failure of components of a limited ballistic missile defense system.

Winter/Spring 2001, 90.9 Wmpg Fm

WMPG Program Guides

Newspaper format.

Summer 2000, 90.9 Wmpg Fm

WMPG Program Guides

No abstract provided.

Winter/Spring 2000, 90.9 Wmpg Fm

WMPG Program Guides

Newspaper format

Fall/Winter 2000, Wmpg 90.9 Fm

WMPG Program Guides

WMPG program guide for Fall/Winter 2000

Includes notes from Program Director, information on shows and events, and schedule.

History, Religion And Meaning: American Reflections On The Holocuast And Israel, Jules Simon

Departmental Papers (Philosophy)

No abstract provided.

Application Of Wavelets And Principal Component Analysis In Image Query And Mammography, Sol Neeman Ph.D.

Engineering Studies Faculty Publications and Creative Works

Breast cancer is currently one of the major causes of death for women in the U.S. Mammography is currently the most effective method for detection of breast cancer and early detection has proven to be an efficient tool to reduce the number of deaths. Mammography is the most demanding of all clinical imaging applications as it requires high contrast, high signal to noise ratio and resolution with minimal x-radiation. According to studies [36], 10% to 30% of women having breast cancer and undergoing mammography, have negative mammograms, i.e. are misdiagnosed. Furthermore, only 20%-40% of the women who undergo biopsy, have …