Digital Commons Network^™

Tuning Parameter Tolerance Design: Foundations, Methods, And Measures, Daniel A. Mcadams, Kristin L. Wood

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, a novel technique is presented to solve tolerance design problems. To achieve the desired performance tolerance, the technique uses a subtle, but significant, change in the design: the addition of a tuning parameter in place of an increase in component precision. Statistical models are used to develop a framework for the tuning parameter design method. Also developed is a new, dimensionless design metric which ranks candidate tuning parameters. A step-by-step method is developed for the application of tuning parameters using this metric. The step-by-step tuning parameter design method is applied to a heavy-duty manual stapler as a …

Search For R-Parity Violating Decays Of Supersymmetric Particles In E+E- Collisions At Centre-Of-Mass Energies Near 183 Gev, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

Searches for pair-production of supersymmetric particles under the assumption that R-parity is violated via a single dominant LLE¯LLE¯, LQD¯LQD¯ or U¯D¯D¯U¯D¯D¯ coupling are performed using the data collected by the ALEPH collaboration at centre-of-mass energies of 181–184 GeV. The observed candidate events in the data are in agreement with the Standard Model expectations. Upper limits on the production cross-sections and lower limits on the masses of charginos, sleptons, squarks and sneutrinos are derived.

Preservice Teachers’ Beliefs About Teaching And Learning, Helga M. Gudenschwager

Dissertations and Theses @ UNI

Research shows that knowing what preservice teachers believe about teaching and learning helps their instructors to reinforce those beliefs that are compatible with current approaches in education and challenge those that promote the perpetuation of antiquated and ineffective teaching practices. Four main research questions guided this study: 1. To what extent the beliefs expressed by participants aligned with traditional or constructivist perspectives? 2. Do elementary and secondary majors differ in terms of their preference for practices aligned with these perspectives? 3. Do elementary and secondary majors differ in terms of their beliefs about the goals of education and effective strategies …

Hone Sludge Metal As An Alternative Partial Substitute Of Sand In Concrete, Cynthia Garcia-Guillen

Dissertations and Theses @ UNI

Many metal industries in Iowa and throughout the United States produce a hone sludge, a product of the cutting and polishing metal work process. This sludge is listed by the EPA as a hazardous waste. The disposal of this sludge has become an enormous burden to the manufacturer in terms of time, storage, transportation, and disposal costs.

The purpose of this study is to determine the performance characteristics of using hone sludge (byproduct of the metal industry) as a partial substitute of fine aggregate (sand) in concrete. This would reduce the disposal cost of the sludge and reduce hazardous releases …

Pre-Inoculation Effect Of Sic In Production Of Thin Wall Ductile Iron Castings, Nikolay Y. Laukhin

Dissertations and Theses @ UNI

Pre-inoculation effect of SiC additions and its effect on castability, microstructure, and magnesium recovery in thin wall ductile iron plates have been studied. Experimental results were compared with alternative FeSi75 furnace pre-inoculation additions.

The first series of experiments aimed to set the baseline of iron quality, when using FeSi75 pre-inoculant

In the second series of experiment, different methods of introduction of Sic into liquid iron were studied. It was established that Sic added into the stream during the tapping into the flow-through chamber or added directly into the flow-through chamber produced lower Si recovery. The most effective method of introduction …

Impairment In Dichotic Listening Following Anterior Communicating Artery Aneurysm, Paul Michael Evitts

Dissertations and Theses @ UNI

Dichotic listening involves the simultaneous presentation of stimuli binaurally and was initially a method for determining cerebral dominance or laterality of hemispheric function. Since its inception, dichotic listening has evolved into a method for assessing neurologic pathology. An interruption in the central auditory pathways will result in a detectable asymmetry of dichotic scores. Impaired dichotic listening has been well documented in numerous neurological etiologies, but dichotic listening in patients who present anterior communicating artery (ACoA) aneurysm has yet to be documented. Due to the location of the ACoA and the substrates of innervation, central auditory pathways responsible for the transmission …

An Evaluation Of Two Different Data Modeling Techniques For Data Warehousing, Litao Fu

Dissertations and Theses @ UNI

The database community is devoting increasing attention to the research themes concerning data warehouses. After having invested a lot of time and resources to build huge and complex information systems, managers ask for support in obtaining quickly summary information to help in planning and decision making. Data warehousing systems address this issue by enabling managers to acquire and integrate information from different sources and to query efficiently very large databases. Building a data warehouse requires adopting design and implementation techniques completely different from those underlying information. Multidimensional data structures used for decision support applications in data warehouses have rather different …

A Systolic Image Difference Algorithm For Rle-Compressed Images, Fikret Erçal, Mark Allen, Hao Feng

Computer Science Faculty Research & Creative Works

A new systolic algorithm which computes image differences in run-length encoded (RLE) format is described. The binary image difference operation is commonly used in many image processing applications including automated inspection systems, character recognition, fingerprint analysis, and motion detection. The efficiency of these operations can be improved significantly with the availability of a fast systolic system that computes the image difference as described in this paper. It is shown that for images with a high similarity measure, the time complexity of the systolic algorithm is small and, in some cases, constant with respect to the image size. A formal proof …

A Hysteresis Current-Regulated Control For Multi-Level Drives, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

Most multi-level converters are controlled through the use of voltage-source based control techniques such as space-vector modulation or multi-level sine-triangle modulation. However, in many applications such as field oriented drives, a high bandwidth current-source inverter based control is more desirable. In this paper, the concept of a multi-level hysteresis current-source control is set forth. The new control is experimentally verified using a four-level converter/induction motor drive system and the results are compared to a space vector modulation controller. A dynamic study involving a step change in current command demonstrates the controls high bandwidth.

Drawbacks Of The Dissolution Method For Measurement Of The Liquid-Solid Mass-Transfer Coefficients In Two-Phase Flow Packed-Bed Reactors Operated At Low And High Pressures, Muthanna H. Al-Dahhan, Wes Highfill, Boon Tee Ong

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Dissolution Method Was Used Predominantly at Atmospheric Conditions to Measure the Liquid-Solid Mass-Transfer Coefficient in Two-Phase Flow Packed-Bed Reactors. in an Attempt to Investigate the Effect of Reactor Pressure and Gas Flow Rate on the Liquid-Solid Mass-Transfer Coefficient in a Trickle-Bed Reactor using the Dissolution Method, Difficulties Were Encountered in Implementing This Method at Low- to High-Pressure Operation. Noticeable Losses in the Dissolved Material Were Observed as a Result of Flashing/stripping from the Liquid Phase to the Atmosphere and the Effluent Gas Stream. This Leads to Misinterpretation of the Effect of Reactor Pressure and to Improper Conclusions. in This …

Double-Slit Model For Partially Wetted Trickle Flow Hydrodynamics, I. Iliuta, F. Larachi, M. (Muthanna) H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Double-Slit Model Developed Can Predict the Frictional Two-Phase Pressure Drop, External Liquid Holdup, Pellet-Scale External Wetting Efficiency, and Gas - Liquid Interfacial Area in Cocurrent Downflow Trickle-Bed Reactors Operated under Partially Wetted Conditions in the Trickle Flow Regime. the Model, an Extension of the Holub Et Al. (1992, 1993) Mechanistic Pore-Scale Phenomenological Approach, Was Designed to Mimic the Actual Bed Void by Two Inclined and Interconnected Slits: Wet and Dry Slit. the External Wetting Efficiency is Linked to Both the Pressure Drop and External Liquid Holdup. the Model Also Predicts Gas - Liquid Interfacial Areas in Partially Wetted Conditions. …

Computational Finance Models, Michael Gene Hilgers

Business and Information Technology Faculty Research & Creative Works

The author discusses his involvement in developing computational finance software. These computational finance models attempt to model the randomness of a stock's price. At a fixed future time, a stock's price is modeled as a random variable with a normal distribution centered about the current price adjusted with a simple growth multiplier. The standard deviation of this normal distribution depends on the length of time into the future one peers and the volatility of the market. As the market becomes more volatile and we look further ahead, the less likely the stock will have a price near the adjusted current …

Transitivity And The Choice Of A Preposition In Any Language, Valerie Hascoet

Other Resources

This thesis examines the question of determination of transitivity for a verb through a comparison of processes involved in English and in French. It takes in several theories belonging to the area of the syntax-semantics interface in order to understand how a predicate is construed as either intransitive or direct transitive or indirect transitive in either language.The study focuses on a corpus of verbs that present different argument structures in French and in English. It analyses the various factors that determine the choice of a transitivity status for a given predicate. It discusses whether that process of determination lies in …

Bs News

Building Services Engineering

No abstract provided.

Working Memory And Human Reasoning : An Individual Differences Approach, Alison Jayne Capon

School of Psychology Theses

Experiments 1-3 investigated the relationship between working memory and syllogistic and five-ten-n series spatial inference. A secondary aim was to replicate the findings of Shah and Miyake (1996) who suggested the use of separate central resources of working memory for spatial and verbal ability. The correlational analysis showed that the complex verbal and spatial working memory span tasks were associated together and consistently predicted reasoning performance in both verbal and visual modalities. The confirmatory factor analysis showed that three factors best accounted for the data -a verbal, a spatial, and a general resource. All the span tasks and most of …

Adaptive Information Filtering: Evolutionary Computation And N-Gram Representation, Daniel R. Tauritz, Ida G. Sprinkhuizen-Kuyper

Computer Science Faculty Research & Creative Works

Adaptive Information Filtering (AIF) is concerned with filtering information streams in changing environments. The changes may occur both on the transmission side (the nature of the streams can change) and on the reception side (the interests of a user can change). The research described in this paper details the progress made in a prototype AIF system based on weighted n-gram analysis and evolutionary computation. A major advance is the design and implementation of an n-gram class library allowing experimentation with different values of n instead of solely with 3-grams as in the past. The new prototype system was tested on …

Accumulation Of Heavy Metals By Vegetables Grown In Mine Wastes, George P. Cobb, Kristin Sands, Melissa Waters, Bobby G. Wixson, Elaine Dorward-King

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Lead, cadmium, arsenic, and zinc were quantified in mine wastes and in soils mixed with mine wastes. Metal concentrations were found to be heterogeneous in the wastes. Iceberg lettuce, Cherry Belle radishes, Roma bush beans, and Better Boy tomatoes were cultivated in mine wastes and in waste-amended soils. Lettuce and radishes had 100% survival in the 100% mine waste treatments compared to 0% and 25% survival for tomatoes and beans, respectively. Metal concentrations were determined in plant tissues to determine uptake and distribution of metals in the edible plant parts. Individual soil samples were collected beneath each plant to assess …

Ethics Exercises For Civil, Environmental, And Geological Engineers, Paul Michael Santi

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The practices of civil, environmental, and geological engineering share many common ethical dilemmas. These fields typically require extensive interaction with clients and regulatory agencies, while dealing with unpredictable earth materials for design and uncertain design parameters. Consequently, a capstone design course must address not only technical issues, but also a wide range of ethical and behavioral issues. This study presents a series of exercises used in the classroom to teach these issues through dealing with "gray" ethical areas, concepts of advocacy and the use of compromise, relating specific stories to global concepts, proper behavior in the corporate environment, and the …

Plastic Manufacturing Process Selection Methodology Using Self-Organizing Map (Som)/Fuzzy Analysis, R. Raviwongse, Venkat Allada, T. Sandidge

Engineering Management and Systems Engineering Faculty Research & Creative Works

For plastic products, one of the crucial decisions made during the preliminary design stage is the selection of an appropriate manufacturing process. In many industries, the selection of the manufacturing process is primarily based on the empirical knowledge and past experience of the manufacturing personnel. This selection procedure may result in inconsistent or poor choices if the manufacturing personnel fail to map correctly the product characteristics with the manufacturing efficacy of various manufacturing processes. This paper presents an intelligent self-organizing map (SOM)/fuzzy-based model to aid designers in the selection of an appropriate plastic manufacturing process. The plastic part attributes are …

Dolomitization And Dolomite Neomorphism: Trenton And Black River Limestones (Middle Ordovician) Northern Indiana, U.S.A., M. I N Chan, Jay M. Gregg, Kevin L. Shelton

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Trenton and Black River Limestones are dolomitized extensively along the axis of the Kankakee Arch in Indiana, with the proportion of dolomite decreasing to the south and southeast of the arch. Planar and nonplanar dolomite replacement textures and rhombic (type 1) and saddle (type 2) void-filling dolomite cements are present. Three stages of dolomitization, involving different fluids, are inferred on the basis of petrographic and geochemical characteristics of the dolomites. Nonferroan planar dolomite has relatively high δ18O values (-1.8 to -6.1‰ PDB) and has ⁸⁷Sr/⁸⁶Sr ratios (0.70833 to 0.70856) that overlap those of Middle Ordovician seawater. …

Border Detection On Digitized Skin Tumor Images, Z. Zhang, William V. Stoecker, Randy Hays Moss

Chemistry Faculty Research & Creative Works

A radial search technique is presented for detecting skin tumor borders in clinical dermatology images. First, it includes two rounds of radial search based on the same tumor center. The first-round search is independent, and the second-round search is knowledge-based tracking. Then a rescan with a new center is used to solve the blind-spot problem. The algorithm is tested on model images with excellent performance, and on 300 real clinical images with a satisfactory result

The Influence Of Poly(Acrylic Acid) Molar Mass On The Properties Of Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Sinead Kenny, Robert G. Hill, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The influence of poly (acrylic acid) molar mass was investigated on cements formed from zinc oxide-apatite mixtures at three aging times: one, seven and 28 days. Cements based on both hydroxyapatite and fluorapatite were investigated. The compressive strength, un-notched fracture strength and fracture toughness increased markedly with poly (acrylic acid) molar mass. The fracture toughness and un-notched fracture strength increased with aging time for the two highest molar mass cements but decreased with time for the two lowest molar mass cements. The greater chain entanglement density present in the higher molar mass cements is thought to contribute significantly to the …

Pyrolysis-Mass Spectrometry For Rapid Classification Of Oysters According To Rearing Area, J. Krupcík, P. Oswald, I. Spánik, P. Májek, M. Bajdichová, P. Sandra, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Current concern for the safety and traceability of food, as well as the desire of oyster farmers, for marketing reason, to emphasize the geographical origin of their production, requires new methods to make possible a real product identification. In this study, 181 oyster samples were analyzed to determine their origin area. These samples were collected in nine French rearing areas at four different times of the year (spring, summer, and the beginning and end of autumn) and from four to eight sites in each area to provide a variability parameter. Analysis of fingerprints after Curie point pyrolysis-mass spectrometry, by an …

Analysis Of A Novel Four-Level Dc/Dc Boost Converter, Keith Corzine, Sonal K. Majeethia

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, novel two-quadrant buck/boost and one-quadrant boost four-level DC/DC power converters are introduced. The primary application for these converters is that of interfacing a low-voltage DC source, such as a fuel cell or battery, to a high-voltage four-level inverter. One important feature of the four-level DC/DC power converters proposed is the ability to perform the power conversion and balance the inverter capacitor voltages simultaneously. With the capacitor voltage balancing, it is possible to obtain the full voltage from the inverter. For the boost converter, the steady-state and nonlinear average-value (NLAM) models are developed. The NLAM is verified against …

Electron Correlations Observed Through Intensity Interferometry, Michael Schulz, Robert Moshammer, Wayne M. Schmitt, Holger Kollmus, Bernold Feuerstein, Rido Mann, Siegbert Hagmann, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

Intensity interferometry was applied to study electron correlations in doubly ionizing ion-atom collisions. In this method, the probability to find two electrons emitted in the same double ionization event with a certain momentum difference is compared to the corresponding probability for two uncorrelated electrons from two independent events. The ratio of both probabilities, the so-called correlation function, is found to sensitively reveal electron correlation effects, but it is rather insensitive to the collision dynamics.

The Effects Of A Rational Emotive Behavior Therapy Intervention On Irrational Beliefs And Burnout Among Middle School Teachers In The State Of Iowa, Shirley Anderson

Dissertations and Theses @ UNI

The purpose of this study was to investigate the effects of a Rational Emotive Behavior Therapy (REBT) bibliotherapy intervention on the level of burnout and irrational beliefs. This study specifically examined the impact of a REBT bibliotherapy intervention on middle school teachers' irrational beliefs and level of emotional exhaustion, depersonalization, and personal accomplishment, using the Maslach Burnout Inventory-Educators Survey (Maslach, Jackson, & Schwab, 1986) and the Irrational Beliefs Test (Jones, 1968).

The subjects in this study consisted of 167 middle school teachers in the State of Iowa. These teachers taught sixth, seventh, or eighth grade or a combination of these …

Assessing The Classification Accuracy Of Digitized National Aerial Photography Program Imagery: Comparison With Botanical Data, Mark Arthur Alexander

Dissertations and Theses @ UNI

The ability to acquire and use remotely sensed data has revolutionized large-scale ecological studies by reducing dependence on difficult and expensive field survey techniques for acquisition of land use and land cover data. Multispectral satellite imagery, typically from the Landsat Multispectral Scanner (MSS), Thematic Mapper (TM) and the SPOT High Resolution Visible (HRV) instruments, has proven particularly valuable in surveying and classifying vegetation cover (Frank & Thorn, 1985). Further studies have concluded that alpine vegetation communities and habitats can be mapped successfully by including the geomorphic parameters of elevation, slope, and incidence when classifying remotely sensed data.

This research analyzes …

Photodecomposition Of Crystal Violet Dye In Water Solution And Suspensions Of Metal Oxides, Tatiana Yurievna Zakharian

Dissertations and Theses @ UNI

Photodecomposition and photodecolorization of crystal violet dye were studied in water solution, hydrogen peroxide solution and suspensions of metal oxides. Spectroscopic evidence for the formation of methylated pararosanilines and demethylated derivatives of Michler's ketone as the reaction intermediates was obtained for the photodecomposition of crystal violet in water solution. The mechanism of formation of the intermediates was discussed in terms of charges of individual atoms calculated using Spartan software.

Photooxidation of crystal violet was shown to occur faster in hydrogen peroxide solution due to the higher oxidation potential of hydrogen peroxide and hydroxyl radicals. A mechanism similar to photooxidation in …

A Leadership Model And Supervisory Skills Perceived By Production Employees, Supervisors, And Managers As Important To The Improvement Of Employee Performance In Manufacturing, Douglas R. Hotek

Dissertations and Theses @ UNI

The purpose of this research was to provide to industry and education a better understanding of what makes a supervisor a good supervisor of today's educated and technically skilled work force. Manufacturing firms that depend on advanced technologies and employee-technology relationships have made an impact on the role of supervision. The modern supervisor has a new role in managing production operations. The role has changed from that of directing and controlling employees to that of effectively leading the improvement of employee performance. This study builds upon previous research in an effort to further identify and authenticate a leadership model with …

Examining The Impact Of Internet Electronic Commerce On Commercial Organizations In Saudi Arabia, Fahad Abdullah Alyabis

Dissertations and Theses @ UNI

Saudi Arabia is undergoing tremendous change in both infrastructure and economics, which is helping the Internet to flourish in the region. Although growth of electronic commerce (EC) is slow, it is becoming increasingly global. Businesses worldwide are engaging in this commercial evolution.

The purpose of this study was to provide consumers and commercial organizations in Saudi Arabia with practical information regarding electronic commerce. It attempted to explore the perspectives of Internet users, information technology (IT) professionals, business owners, and managers of online businesses in Saudi Arabia.

Two survey instruments were used to gather data for this study. The first survey …