Engineering Commons^™

Ultrasonic Technique For Investigation Of The Effect Of Grid-Generated Turbulence On Sound Wave Propagation, Tatiana A. Andreeva, William W. Durgin

Office of the Provost Scholarship

This paper concerns an experimental study of the effects of the grid-generated turbulence on the propagation of acoustical waves in a wind tunnel. Turbulence effects are investigated using ultrasound time-of-flight method, employing counter-propagating ultrasonic pulses. Turbulence effects are an important source of error in the active probing of the atmosphere using sound sources. The emphasis is on the propagation time fluctuations and their interpretation using theoretical analysis of Kolmogorov.

An Algorithm Using Length-R Paths To Approximate Subgraph Isomorphism, Fred Depiero, David Krout

Electrical Engineering

The ‘LeRP’ algorithm approximates subgraph isomorphism for attributed graphs based on counts of length-r paths. The algorithm provides a good approximation to the maximal isomorphic subgraph. The basic approach of the LeRP algorithm differs fundamentally from other methods. When comparing structural similarity LeRP uses a neighborhood of nodes that varies in size dynamically. This approach provides sufficient evidence of similarity to permit LeRP to form a node-to-node mapping and can be computed with polynomial effort in the worst-case. Results from over 32,000 simulated cases are reported. We demonstrate that LeRP does not need a high dynamic range of node and …

Improving Dsp Performance With A Small Amount Of Field Programmable Logic, John Y. Oliver, Venkatesh Akella

Electrical Engineering

We show a systematic methodology to create DSP + field-programmable logic hybrid architectures by viewing it as a hardware/software codesign problem. This enables an embedded processor architect to evaluate the trade-offs in the increase in die area due to the field programmable logic and the resultant improvement in performance or code size. We demonstrate our methodology with the implementation of a Viterbi decoder. A key result of the paper is that the addition of a field-programmable data alignment unit (FPDAU) between the register-file and the computational blocks provides 15%-22% improvement in the performance of a Viterbi decoder on the state-of-the-art …

Vibration-Based Crack Diagnosis In Rotating Shafts During Acceleration Through Resonance, Jerzy T. Sawicki, Xi Wu, George Y. Baaklini, Andrew L. Gyekenyesi

Mechanical Engineering

The dynamic response of a cracked Jeffcott rotor passing through the critical speed with constant acceleration is investigated analytically and numerically. The nonlinear equations of motion are derived and include a simple hinge model for small cracks and Mayes' modified funciton for deep cracks. The equations of motion are integrated in the rotating coordinate system. The angle between the crack centerline and the shaft vibaiton (whirl) vector is used to determine the clsoing and opening of the crack, allowing one to study the dynamic response with and without the rotor weight dominance. Vibration phase response is used as one of …

The Biomechanical Aspects Of Pedestrian Protection, Krishnakanth Aekbote, Peter Schuster, Sunny Kankanala, Srini Sundararajan, Stephen W. Rouhana

Mechanical Engineering

In this paper a biomechanical basis for pedestrian protection is presented based on reviews of epidemiological and biomechanical studies conducted over the last three decades. Epidemiological studies reveal the nature and cause of pedestrian crashes and injuries sustained in the field. The various factors that influence pedestrian crashes and fatalities such as pedestrian demographics, time and location of crash, type of vehicles involved and their design characteristics, impact speeds, and nature and severity of injuries sustained are covered in the epidemiology section. The biomechanical studies identify the injury mechanisms and the biomechanical tolerances. Several biomechanical studies that attempt to identify …

Analysis Of Temperatures At A Municipal Solid Waste Landfill, Nazli Yesiller, James L. Hanson

Civil and Environmental Engineering

A study is conducted to determine the thermal regime within and around a municipal solid waste landfill located in midwestern U.S.A. Spatial distributions of temperatures have been determined over time since 1999 within the waste mass, liner and cover systems, and surrounding subgrade. Seasonal variations, placement of waste, age of waste, depth and location of waste, and available moisture have significant effects on temperatures. Temperatures of wastes at shallow depths, bottom liner systems prior to waste placement, and final cover systems conform to seasonal temperature variations. Steady elevated temperatures are reached with respect to air and ground temperatures at central …

Telog Pr-31 Water Level Tracker, Stuart W. Styles

BioResource and Agricultural Engineering

The Irrigation Training and Research Center, working under a technical service agreement with the United States Bureau of Reclamation (USBR) Mid-Pacific Region, has undertaken a performance review of advanced electronic water level measurement technologies in irrigation applications. An example is the Telog PR-31 Level Tracker.

Government Highline Canal – A Win-Win Solution, Charles M. Burt, Stuart W. Styles

BioResource and Agricultural Engineering

The Irrigation Training and Research Center, working under a technical service agreement with the United States Bureau of Reclamation (USBR) Upper Colorado Region, Western Colorado Area Office, performed canal modernization on the Government Highline Canal in the form of automated canal structures, in-system storage, and new operational procedures that could significantly reduce operational spill.

Itrc Weir Stick, Stuart W. Styles

BioResource and Agricultural Engineering

The Irrigation Training and Research Center, working under a technical service agreement with the United States Bureau of Reclamation (USBR) Mid-Pacific Region, has developed a new weir rule for open-channel flow rate measurement.

California Crop And Soil Evapotranspiration, Charles Burt

BioResource and Agricultural Engineering

The goal of this publication is to provide water users, consultants, water agency personnel, and others throughout California with information that will: (a) help individual water users with irrigation scheduling and system design and (b) help agricultural water agency personnel with water balances and future planning.

The tables in this publication represent the consolidation of results from thousands of annual ET simulations that accounted for crop, rainfall (wet, dry, or “typical”), soil, and irrigation method in each of 13 major ETo zones in California. The annual simulations used daily water balances at the soil surface, crop canopy, and soil root …