Engineering Commons^™

Passive Fathometer Processing, Peter Gerstoft, William S. Hodgkiss, Martin Siderius, Chen-Fen Huang, Chris H. Harrison

Electrical and Computer Engineering Faculty Publications and Presentations

Ocean acoustic noise can be processed efficiently to extract Green's function information between two receivers. By using noise array-processing techniques, it has been demonstrated that a passive array can be used as a fathometer [Siderius, et al., J. Acoust. Soc. Am. 120, 1315-1323 (2006)]. Here, this approach is derived in both frequency and time domains and the output corresponds to the reflection sequence. From this reflection sequence, it is possible to extract seabed layering. In the ocean waveguide, most of the energy is horizontally propagating, whereas the bottom information is contained in the vertically propagating noise. Extracting the seabed information …

Stormwater Quality Characterization, Modeling, And Management For The Greater Milwaukee Area, Wisconsin, Puripus Soonthornnonda

Theses and Dissertations

Storm sewer pipes in the Greater Milwaukee area collect poluted stormwater runoff

Bs News

Building Services Engineering

No abstract provided.

Department Of Biological Systems Engineering Newsletter, Issue 3, Vol. 2, December 2007

BSE Department Magazine

Contents:
New Tractor Test Track Dedication
From the Department Head
Awards
Meet the Faculty
Alumni News
Student News
Summer Graduations
Quarter-scale Tractor Competition
ASABE Student Branch
ASABE International Preprofessional Council
Distinguished Fellowship Awards
John and Louise Skala Fellowships
Researching Plant Sterols
Milton E. Mohr Fellowship in Agriculture
Scholarships and Ice Cream
100 YEARS As a University of Nebraska Department
Alumnus Profile
Career opportunities in food engineering
Congratulations
Comings and Goings

Phase Iii Development Of A Short-Radius Guardrail For Intersecting Roadways, Cody S. Stolle, Karla A. Polivka, Robert W. Bielenberg, Ronald K. Faller, Dean L. Sicking, John R. Rohde, John D. Reid

Nebraska Department of Transportation Research Reports

No abstract provided.

Experimental Verification Of Source Temperature Modulation Via A Thermal Switch In Thermal Energy Harvesting, Robin Mccarty, D. Monaghan, Kevin P. Hallinan, Brian Sanders

Mechanical and Aerospace Engineering Faculty Publications

This paper provides a description of research seeking to experimentally verify the effectiveness of a thermal switch used in series with TE devices for waste heat recovery for constant and variable source heat input and for variable source thermal capacitance (mass). Using an experimental set-up comprised serially of a fixed heat source, a variable thermal resistance air gap serving as a thermal switch, a thermoelectric device and a heat sink, the time-averaged power output to power input ratios improved up to 15% and 30% respectively for constant and variable heat input in certain design space conditions. The experimental results, as …

Evaluation Of The Role Of Driver’S Knowledge Of Who Has The Right-Of-Way Contributes To Interstate On-Ramp Crashes, Deogratias Eustace, Vamsi Krishna Indupuru

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

The knowledge of drivers on who has the right-of-way between the one on mainline lanes of a freeway and the one entering the freeway through on-ramp junction lane was evaluated. In addition, drivers’ opinions on how to make the on-ramp junctions safer were collected. A survey instrument with 21 items requesting drivers’ information in regard with demographics, freeway driving experience, knowledge of right-of-way and merging practices was used for data collection. The results show that crashes are relatively rare events and for some reasons, most of them never happen but result into near misses, which can not be reported and …

Optimal Receiver For Space Time Spreading Across A Time Hopping Ppm Over Ultra Wideband Saleh-Valenzuela Mimo Channel, Peter Vial, Beata J. Wysocki, Tadeusz A. Wysocki

Faculty Publications in Computer & Electronics Engineering (to 2015)

This paper outlines a technique which can use multiple transmit antennas to send more than one binary bit using the same number of transmit antennas over a single transmission. It uses Ultra Wideband orthogonal pulse position modulation to achieve this, with the receiver employing a Rake receiver and a Maximum Ratio Combiner optimal detector. This is done over a Space Time Spreading Time Hopping Ultra Wideband Pulse Position Modulation system assuming a rich multipath Saleh-Valenzuela MIMO channel model. Simulation results indicate that a significant gain can be achieved compared with other proposed schemes utilising multiple transmit antennas for Ultra Wide …

Computational Complexity Of Determining Which Statements About Causality Hold In Different Space-Time Models, Vladik Kreinovich, Olga Kosheleva

Departmental Technical Reports (CS)

Causality is one of the most fundamental notions of physics. It is therefore important to be able to decide which statements about causality are correct in different models of space-time. In this paper, we analyze the computational complexity of the corresponding deciding problems. In particular, we show that: for Minkowski space-time, the deciding problem is as difficult as the Tarski's decision problem for elementary geometry, while for a natural model of primordial space-time, the corresponding decision problem is of the lowest possible complexity among all possible spacetime models.

Interval Computations And Interval-Related Statistical Techniques: Tools For Estimating Uncertainty Of The Results Of Data Processing And Indirect Measurements, Vladik Kreinovich

Departmental Technical Reports (CS)

In many practical situations, we only know the upper bound D on the (absolute value of the) measurement error d, i.e., we only know that the measurement error is located on the interval [-D,D]. The traditional engineering approach to such situations is to assume that d is uniformly distributed on [-D,D], and to use the corresponding statistical techniques. In some situations, however, this approach underestimates the error of indirect measurements. It is therefore desirable to directly process this interval uncertainty. Such "interval computations" methods have been developed since the 1950s. In this chapter, we provide a brief overview of related …

Reasons Why Mobile Telephone Conversations May Be Annoying: Considerations And Pilot Studies, Nigel Ward, Anais G. Rivera, Alejandro Vega

Departmental Technical Reports (CS)

Mobile telephone conversations in public places are often annoying to bystanders. Previous work has focused on the psychological and social causes for this, but has not examined the possible role of properties of the communication channel. In our paper "Do Bystanders and Dialog Participants Differ in Preferences for Telecommunications Channels?" (21st International Symposium on Human Factors in Telecommunication, 2008) we consider the possibility that a reason for the annoyance could be that bystander preferences differ from talker preferences, but conclude that this is in fact unlikely to be a major factor. This technical report provides supplemental information, specifically a broader …

Different Learned Coordinate Frames For Planning Trajectories And Final Positions In Reaching, Claude Ghez, Robert A. Scheidt, Hank Heijink

Biomedical Engineering Faculty Research and Publications

We previously reported that the kinematics of reaching movements reflect the superimposition of two separate control mechanisms specifying the hand's spatial trajectory and its final equilibrium position. We now asked whether the brain maintains separate representations of the spatial goals for planning hand trajectory and final position. One group of subjects learned a 30° visuomotor rotation about the hand's starting point while performing a movement reversal task (“slicing”) in which they reversed direction at one target and terminated movement at another. This task required accuracy in acquiring a target mid-movement. A second group adapted while moving to—and stabilizing at—a single …

Analysis And Characterization Of A Sige Bicmos Low Power Operational Amplifier, Archana Yarlagadda

Masters Theses

Integrated circuit design for space applications can require radiation immunity, cryogenic operation and low power consumption. This thesis provides analysis and characterization of a SiGe BiCMOS low power operational amplifier (op amp) designed for lunar surface applications. The op amp has been fabricated on a commercially available 0.35-micron Silicon-Germanium (SiGe) BiCMOS process. The Heterojunction bipolar transistors (HBT) available in the SiGe process have been used in this op amp to take advantage of the total ionizing dose (TID) irradiation immunity and superb cryogenic operation, along with PMOS devices that show better TID immunity than their NMOS counterparts. The key features …

Scalability Of Manet Routing Protocols For Heterogeneous And Homogenous Networks, Huda Al Amri, Mehran Abolhasan, Tadeusz Wysocki

Faculty Publications in Computer & Electronics Engineering (to 2015)

In Mobile Ad hoc Network (MANET), mobility, traffic and node density are main network conditions that significantly affect the performance of routing protocols. Much of the previous researches in MANET routing have focused on developing strategies, which suit one specific networking scenario. Therefore, there is no existing protocol that can work well in all different networking scenarios. This paper reviews characteristics of each different classes of routing protocols. Moreover, most of current routing protocols assume homogeneous networking conditions where all nodes have the same capabilities and resources. Although homogenous networks are easy to model and analysis, they exhibits poor scalability …

41st Conference On Senior Engineering Design Projects, College Of Engineering And Applied Sciences

Senior Engineering Design Conference

The 41st Conference on Senior Engineering Design Projects was held on December 4, 2007 at the College of Engineering and applied Sciences on the Parkview Campus of Western Michigan University. The college sponsors the conference to showcase the work of its graduating seniors, who are required to complete a capstone project that puts into practice what they have learned. Many of the projects are sponsored by business and industry.

An Investigation On The Corrosion Resistance And Stress Corrosion Cracking Of Ductile Ni-Resist Cast Irons In Desalination Plants., Yahya Abdulla Alzafin

Theses

Two cases of stress corrosion cracking failures of brine pumps casings have been reported. These pumps are installed in two desalination plants located on the coast of Arabian Gulf in UAE. The materials of construction of failed parts are Ni-Resist Ductile Irons (NDI) and the environment is brine, which is concentrated seawater. Two brands of pumps had different lives to total failure; one lived 18 years while the other lasted only 5 years. The failed parts of former pumps were made out of NDI material as per American standard ASTM A439 D2 (designated D material) whereas those of latter pumps …

A Computer Model Of Gluconeogenesis And Lipid Metabolism In The Perfused Liver, Elie Chalhoub, Richard W. Hanson, Joanne M. Belovich

Chemical & Biomedical Engineering Faculty Publications

A mathematical model of the perfused rat liver was developed to predict intermediate metabolite concentrations and fluxes in response to changes in various substrate concentrations in the perfusion medium. The model simulates gluconeogenesis in the liver perfused separately with lactate and pyruvate and the combination of these substrates with fatty acids (oleate). The model consists of key reactions representing gluconeogenesis, glycolysis, fatty acid metabolism, tricarboxylic acid cycle, oxidative phosphorylation, and ketogenesis. Michaelis-Menten-type kinetic expressions, with control by ATP/ADP, are used for many of the reactions. For key regulated reactions (fructose-1,6-bisphosphatase, phosphofructokinase, pyruvate carboxylase, pyruvate dehydrogenase complex, and pyruvate kinase), rate …

The Impacts Of Congestion On Commercial Vehicle Tours Characteristics And Costs, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Congestion is a common phenomenon in all major cities of the world. Increased travel time and uncertainty brought about by congestion impacts the efficiency of logistics operations. Recent studies indicate that a significant proportion of commercial vehicle kilometers traveled (VKT) and vehicle hours traveled (VHT) are generated by trip-chains or multi-stop tours. This paper presents research demonstrating the impact of congestion on multi-stop tours in urban areas. An analytical model, numerical experiments, and real-world tour data are used to understand the impact of congestion on tour characteristics, carriers? costs, VKT, and VHT. This research shows that travel time/distance between customer …

Modelagem Da Vida De Fadiga E Do Acúmulo De Deformações Permanentes Em Pavimentos Asfálticos Por Meio De Um Modelo De Dano Contínuo, Victor Ferreira Teixeira, Flavio V. Souza, Jorge Barbosa Soares

Mechanical & Materials Engineering Faculty Publications

: It is known that the conditions of the Brazilian roadways have an enormous impact over the national economy. In face of this problem, there is a need for new methodologies for pavement analyses and design that can more accurately predict pavement distresses. Among the main methods currently used, one can find purely empirical methods and mechanistic-empirical methods which make use of the pavement structure response. The evolution of numerical methods such as the Finite Element Method (FEM) or the Boundary Element Method (BEM) has made the mechanistic-empirical methods more popular for pavement analysis applications. This work shows a mechanistic …

Separate Adaptive Mechanisms For Controlling Trajectory And Final Position In Reaching, Robert A. Scheidt, Claude Ghez

Biomedical Engineering Faculty Research and Publications

We examined control of the hand's trajectory (direction and shape) and final equilibrium position in horizontal planar arm movements by quantifying transfer of learned visuomotor rotations between two tasks that required aiming the hand to the same spatial targets. In a trajectory-reversal task (“slicing”), the hand reversed direction within the target and returned to the origin. In a positioning task (“reaching”), subjects moved the hand to the target and held it there; cursor feedback was provided only after movement ended to isolate learning of final position from trajectory direction. We asked whether learning acquired in one task would transfer to …

Prolonged Quadriceps Activity Following Imposed Hip Extension: A Neurophysiological Mechanism For Stiff-Knee Gait?, Michael D. Lewek, T. George Hornby, Yasin Y. Dhaher, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

The biomechanical characteristics of stiff knee gait following neurological injury include decreased knee flexion velocity at toe-off, which may be due to exaggerated quadriceps activity. The neuromuscular mechanism underlying this abnormal activity is unclear, although hyperexcitable heteronymous reflexes may be a source of impaired coordination. The present study examines the contribution of reflex activity from hip flexors on knee extensors following stroke and its association with reduced swing-phase knee flexion during walking. Twelve individuals poststroke and six control subjects were positioned in supine on a Biodex dynamometer with the ankle and knee held in a static position. Isolated hip extension …

Moral Development In Pilot Populations, Erica Anne Diels

Doctoral Dissertations and Master's Theses

Ethical issues are becoming more commonplace in society today and while most industries are taking steps to improve poor ethical decisions through ethics education, aviation is lagging behind in both understanding of ethical issues inherent to the industry and ethics education. In this study three groups of pilots (students, instructors, and faculty) at Embry-Riddle Aeronautical University are examined in an effort to determine moral development level in terms of P score on the Defining Issues Test 2 (DIT2) and two domain specific additional questions. It was hypothesized that differences would be found between the groups and that the moral development …

Sold Downstream: Free Speech, Fair Use, And Anti-Circumvention Law, R. Terry Parker

The University of New Hampshire Law Review

[Excerpt] “Here’s a hypo. Living in Asia, I purchased a shameful amount of music and movies, all legit purchases through reputable stores, HMV and Tower Records, but little of which will get reissued. I wanted to preserve my collection but software in the discs prevented me from ripping backup copies to my computer. Lacking the technological savvy to get around this software myself, I purchased and used a product to help me circumvent these controls. Discuss.

Courts agree that copying the music and movies here is infringement but that fair use may provide a defense. However, courts do not agree …

What Is Rcu, Fundamentally?, Paul E. Mckenney, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Read-copy update (RCU) is a synchronization mechanism that was added to the Linux kernel in October of 2002. RCU achieves scalability improvements by allowing reads to occur concurrently with updates. In contrast with conventional locking primitives that ensure mutual exclusion among concurrent threads regardless of whether they be readers or updaters, or with reader-writer locks that allow concurrent reads but not in the presence of updates, RCU supports concurrency between a single updater and multiple readers. RCU ensures that reads are coherent by maintaining multiple versions of objects and ensuring that they are not freed up until all pre-existing read-side …

Creating Micro- And Nanostructures On Tubular And Spherical Surfaces, O. Lima, L. Tan, A. Goel, Lmehrdad Negahban, Z. Li

Faculty Publications from Nebraska Center for Materials and Nanoscience

The authors developed a new technique to create micro- and nanometer scale structures on curved free-standing objects by combining embossing/imprinting lithography approaches with mechanical loadings on elastic films. Embossing/imprinting generates small structures and mechanical loading determines shape or geometry of the final object. As a result, a portion of the tubes with a radius between 0.5 and 3.5 mm and a portion of the spheres with a radius between 2.4 and 7.0 mm were fabricated with grating line features (period of 700 nm) and microlens array features (lens radius of 2.5 µm) atop, respectively. It was found that both static …

Technical Evaluation Of Hardwood Biorefinery Using The "Near-Neutral" Hemicellulose Extraction Process, Haibo Mao

Electronic Theses and Dissertations

A technical analysis was performed for a new process that produces ethanol and acetic acid from hardwood in addition to bleached hardwood Kraft pulp. The new process, termed the "near neutral" hemicellulose extraction process, involves the extraction of wood hemicellulose using green liquor prior to conventional Kraft pulping. This thesis assumes that the new process is located at an existing kraft pulp mill. Ancillary unit operations in the process include hydrolysis of the extracted carbohydrates using sulfuric acid, filtration of the extract to remove lignin that was extracted with the carbohydrates, liquid-liquid extraction of acetic acid and by-product furfural, liming …

Using Gis To Optimize The Design And Implementation Of The Rtk Reference Network In Abu Dhabi, Mustafa Abdulla Mohammed Almusawa

Theses

Several challenging applications and construction works demand real-time measurements for positioning at the centimeter-level accuracy. This positioning accuracy can be obtained by using a Global Positioning System (GPS) roving unit and employing a single reference station (base-station) or through utilizing the service of multiple reference stations forming a Real-Time Kinematics (RTK) Reference Network.

The limitation of the single reference approach is that measurement errors are distance dependent and good accuracy can be only obtained when distances are less than 10 kms. In addition, this method requires a nearby Geodetic Control Point (GCP). Recently, RTK reference networks are widely established in …

Flow Structures In An Enclosed Simplified Full Scale Under-Hood Engine Compartment During Steady State Operation, Chin Hoong Leong

Masters Theses

An experimental study of flow structures in an enclosed simplified full scale under-hood engine compartment will be conducted during steady state operation using whole field velocity measuring technique. 2D Particle Image Velocimetry (PIV) is planned for multiple cross sections in the test volume. Emphasis is given on understanding the flow structures of the 3D under-hood flow using multiple 2D PIV measurements. A recent study conducted on the engine compartment only consists of three 2D PIV measurement cross sections that sufficiently display 2D flow behavior at specific regions. Therefore, a detailed 3D flow mapping in the enclosure on various cross sections …

Analysis Of Freight Tours In A Congested Urban Area Using Disaggregated Data: Characteristics And Data Collection Challenges, Miguel Andres Figliozzi, Lynsey Kingdon, Andrea Wilkitzki

Civil and Environmental Engineering Faculty Publications and Presentations

Confidentiality issues are usually an insurmountable barrier that precludes the collection of detailed and complete freight data. However, when detailed disaggregated truck activity data is available, the analysis of commercial vehicle routes and trip chain structures can provide insightful information about urban commercial vehicle tours, travel patterns, and congestion levels. Where truck data is usually aggregated and cross-sectional, this research analyzes several months of detailed truck activity records in a congested urban area and thus contributes a level of investigation unavailable with aggregated data. To the best of the author's knowledge, there is no published research regarding the analysis of …

Deconvolution And Segmentation Of Ground Penetrating Radar Images, Vincent Krause

Masters Theses

Ground Penetrating Radar is a valuable tool for infrastructure condition evaluation as well as in archaeology and geology. The image produced by a GPR scan can be difficult to interpret due to the weak reflection amplitude, the overlap of reflections, and due to outside interference. This thesis proposes an algorithm to automate GPR scan interpretation. This will enable maintenance engineers to read GPR scans quickly and accurately.

The proposed algorithm framework uses an optimization-based deconvolution technique followed by a segmentation process. Each column of the image is deconvoluted and thus reducing them to a list of ordered pairs of reflection …