Engineering Commons^™

Renewable Energy And Disaster-Resistant Buildings, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Hurricanes, floods, tornados and earthquakes create natural disasters that can destroy homes, businesses and the natural environment. Such disasters can happen with little or no warning, leaving hundreds or even thousands of people without medical services, potable water, sanitation, communications and electrical services for up to several weeks. The 2004 hurricane season ravaged the State of Florida, U.S.A., with four major hurricanes within a 6-week timeframe. Over nine million people evacuated their homes and damage to property was extensive.

One proactive strategy to minimize this type of destruction and disruption to lives is the implementation of disaster-resistant buildings that are …

High-Impact, Energy-Absorbing Vehicle Barrier System: U.S. Patent No. Us 6,926,461 B1, Ronald K. Faller, Dean L. Sicking, John R. Rohde, A. Keller, Robert W. Bielenberg, James C. Holloway, Kenneth H. Addink, Karla A. Polivka

Department of Civil and Environmental Engineering: Faculty Publications

A high-impact, energy-absorbing vehicle barrier system generally includes a substantially rigid outer containment wall coupled via cable restraint assemblies with an energy-absorbing inner impact wall, and energy-absorbing cartridges strategically positioned between the impact wall and containment-wall: The impact wall is constructed of a number of rectangular tubes coupled with one another to presents a substantially smooth, uniform surface to passing vehicles. The energy-absorbing cartridges generally consist of a number of foam sheets which compress and crush between the containment wall and impact wall to absorb energy from an errant vehicle striking the face of the impact wall, while the deflection …

Efficient And Effective Schemes For Streaming Media Delivery, Cheng Huang

All Computer Science and Engineering Research

The rapid expansion of the Internet and the increasingly wide deployment of wireless networks provide opportunities to deliver streaming media content to users at anywhere, anytime. To ensure good user experience, it is important to battle adversary effects, such as delay, loss and jitter. In this thesis, we first study efficient loss recovery schemes, which require pure XOR operations. In particular, we propose a novel scheme capable of recovering up to 3 packet losses, and it has the lowest complexity among all known schemes. We also propose an efficient algorithm for array codes decoding, which achieves significant throughput gain and …

Novel Distributed Cable Sensors For Detection Of Cracks In Rc Structures, Genda Chen, David Pommerenke

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, the development of a fundamentally new, topology-based cable sensor design concept is summarized for crack detection in reinforced concrete (RC) structures. The sensitivity, spatial resolution, and signal loss of sensors are investigated both numerically and experimentally. Two sensors were fabricated and validated with small- and large-scale laboratory tests under different loads. Both were proven sensitive to crack of various sizes from visually undetectable to excessive, giving the location and severity of damage simultaneously. One sensor has been installed on a three-span bridge for its long-term monitoring. It is capable of recording damage that has occurred during a …

Electrohydrodynamic Instability Of Thin Conductive Liquid Films, Xiangfa Wu, Yuris A. Dzenis

Department of Engineering Mechanics: Faculty Publications

This paper considers the effect of surface charges on the surface instability of thin conductive liquid films. A characteristic relation is obtained for determining the wave number of the fastest growing mode as a function of surface tension, dispersive van der Waals force, and electrostatic tractions exerted by the film surface charges. Two natural length scales of the microsystem are further introduced to account for the coupling effects on the dewetting pattern development. The present results can be used for controlled surface pattern modulation in a spinodal-dewetting scenario via amplification of surface waves of selected modes.

A Chain-Type Wireless Sensor Network For Monitoring Long Range Infrastructures, Chang Wen Chen, Yu Wang, Ivica Kostanic

Electrical Engineering and Computer Science Faculty Publications

We present in this paper an investigation on a special class of wireless sensor networks for monitoring critical infrastructures that may extend for hundreds of miles in distances. Such networks are fundamentally different from traditional sensor networks in that the sensor nodes in this class of networks are deployed along narrowly elongated geographical areas and form a chain-type topology. Based on careful analysis of existing sensor network architectures, we first demonstrate the needs to develop new architecture and networking protocols to match the unique topology of chain-type sensor networks. We then propose hierarchical network architecture that consists of clusters of …

Determination Of Dynamic Powder Modeling Parameters Via Optical Methods, Todd E. Sparks, Heng Pan, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Dynamic parameters, such as restitution and friction coefficients are important for powder flow simulations of laser based deposition processes. These parameters are difficult to find, especially for industrial metal powders. This paper introduces an optical method for measuring restitution and friction coefficients. The free falling powder flow was illuminated by a laser sheet. In order to obtain particle velocity, streaks proportional to particle velocities was generated by laser pulse obtained by a chopper. Recorded imaged were analyzed to determine particle velocities both before and after various impact conditions as well as impact parameters.

Dynamic Modeling Of Slurry Bubble Column Reactors, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Multicomponent, One-Dimensional, and Compartment-Based Dynamic Model Developed by Rados Et Al. (Catal. Today 2003, 79-80, 211-218) Has Been Used to Study the Performance of Slurry Bubble Columns Operated with Two Chemical Reaction Systems. One Reaction Causes Contraction in the Gas-Phase Volume, and the Other Causes Expansion. the Change in the Gas Flow Rate (Expansion or Contraction) Along the Reactor as a Result of the Chemical Reaction Kinetics is Accounted for by the overall Mass Balance of the Gas Phase Represented by Large and Small Bubbles. the Importance of Properly Accounting for the Change in the Gas Flow Rate Has …

Multicomponent Flow-Transport-Reaction Modeling Of Trickle Bed Reactors: Application To Unsteady State Liquid Flow Modulation, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

A One-Dimensional Reactor and Catalyst Pellet Scale Flow-Transport-Reaction Model Utilizing the Multicomponent Stefan-Maxwell Formulation for Inter- and Intraphase Transport is Developed to Simulate Unsteady State Operation in Trickle Bed Reactors. the Governing Equations and Method of Solution Are Discussed. Results Are Presented for a Model Reaction System (Hydrogenation of A-Methylstyrene) under Gas Reactant Limiting Conditions, for Liquid Flow Modulation as a Test Case of Unsteady State Operation. Model Simulations Predict that Periodic Liquid Flow Modulation Can Alter the Supply of Liquid and Gaseous Reactants to the Catalyst and Result in Reactor Performance Enhancement above that Achieved in Steady State Operation. …

Workpiece Alignment For Hybrid Laser Aided Part Repair Process, Ajay Panackal Padathu, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Work piece alignment is a key issue for hybrid laser aided part repair,a process utilizing both machining and laser deposition.Proper alignment can greatly improve the accuracy of the repair process.This paper introduces a method for aligning a physical work piece and a CAD model using a Renis aw touch probe and software tools. Also discussed is a model for computing 5-axis CNC positions based on a desired work piece orientation.

Freeze-Form Extrusion Fabrication Of Ceramics, Tieshu Huang, Michael S. Mason, Greg Hilmas, Ming-Chuan Leu

Materials Science and Engineering Faculty Research & Creative Works

A novel, environmentally friendly solid freeform fabrication method called Freeze-form Extrusion Fabrication (FEF) has been developed for the fabrication of ceramic-based components. The method is based on deposition of ceramic pastes using water as the media. The ceramic solids loading can be 50 vol. % or higher and initial studies have focused on the use of aluminum oxide (Al₂O₃). The FEF system components and their interaction are examined, and the main process parameters affecting part geometry defined. 3-D shaped components have been fabricated by extrusion deposition of the ceramic paste in a layer-by-layer fashion. The feasibility …

Sensitivity Analysis Of Process Parameters In Laser Deposition, Zhiqiang Fan, Kaushik Phatak, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In laser cladding with powder injection process, process output parameters, including melt pool temperature and melt pool dimensions, are critical for part quality. This paper uses simulation and experiments to investigate the effect of the process input parameters: laser power, powder mass flow rate, and scanning speed on the output parameters. Numerical simulations and experiments are conducted using a factorial design. The results are statistically analyzed to determine the significant factors and their interactions. The simulation results are compared to experimental results. The quantitative agreement/disagreement is discussed and further research is outlined.

Part Repair Using A Hybrid Manufacturing System, Kunnayut Eiamsa-Ard, Hari Janardanan Nair, Lan Ren, Jianzhong Ruan, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Nowadays, part repair technology is gaining more interest from military and industries due to the benefit of cost reducing as well as time and energy saving. Traditionally, part repair is done in the repair department using welding process. The limitations of the traditional welding process are becoming more and more noticeable when the accuracy and reliability are required. Part repair process has been developed utilizing a hybrid manufacturing system, in which the laser aided deposition and CNC cutting processes are integrated. Part repair software is developed in order to facilitate the users. The system and the software elevate the repair …

Integral Channels In Metal Components And Fabrication Thereof, Rajiv S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

An internal channel in a metal body for use in applications where internal fluid flow within a metal body is desired, as in a heat exchanger. The internal channel is formed in the metal body by frictionally stirring with a pin plunged into the metal body, and traversing the metal body with the pin.

Spawn: Service Provision In Ad-Hoc Wireless Networks, Radu Handorean, Gruia-Catalin Roman, Rohan Sen, Gregory Hackmann, Christopher Gill

All Computer Science and Engineering Research

The increasing ubiquity of wireless mobile computing platforms has opened up the potential for unprecedented levels of communication, coordination and collaboration among mobile computing devices, most of which will occur in an ad hoc, on-demand manner. This paper describes SPAWN, a middleware supporting service provision in ad-hoc wireless networks. The aim of SPAWN is to provide the software resources on mobile devices that facilitate electronic collaboration. This is achieved by applying the principles of service oriented computing (SOC), an emerging paradigm that has seen success in wired settings. SPAWN is an adaptation and extension of the Jini model of SOC …

Ccfss Technical Bulletin Fall 2005, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Experimental Investigation Of The Travel-Time Variance Of An Acoustic Wave Propagating Through The Grid-Generated Turbulence, Tatiana A. Andreeva, William W. Durgin

Office of the Provost Scholarship

An experimental technique for the investigation of the behaviour of acoustic wave propagation through a turbulent medium is discussed. The present study utilizes the ultrasonic travel-time technique to diagnose a grid-generated turbulence. Travel-time variance is studied versus mean flow velocity, travel distance and outer turbulence scale. The effect of thermal fluctuations, which result in fluctuations of sound speed, is studied using a heated-grid experiment. Experimental data obtained using ultrasonic technique confirm numerical and theoretical predictions of nonlinear increase of the travel-time variance with propagation distance, which could be connected to the occurrence of caustics. The effect of turbulent intensity on …

Acuta Enews August 2005, Vol. 34, No. 8

ACUTA Newsletters

ln This Issue

Report from the 34th Annual ACUTA Conference

Board report.................. Riny Ledgerwood, San Diego State Univ., Secretary/Treasurer

From the President...................... Patricia Todus, Northwester Univ., ACUTA President 2005-06

Tech Talk: Passwords: Who Can Keep Them All Straight?..................... Kevin Tanzillo, Dux PR

Domain Names Are Valuable Assets.................... Jeri A. Semer, CAE, ACUTA Executive Director

DC Update........................ Whitney Johnson, Retired, No. Michigan Univ.

FYI: Useful Information from the Campus....................... Student Monitor

Mobile Phones Get Their Own Suffix

Web Tip: Online Facilities & Services Database................ Aaron Fuehrer, ACUTA Computer Service Mgr.

Ashland University Expanding its Universe...................... Teresa Sutter, Ashland University

Welcome New …

On Quantum Versions Of Record-Breaking Algorithms For Sat, Evgeny Dantsin, Vladik Kreinovich, Alexander Wolpert

Departmental Technical Reports (CS)

It is well known that a straightforward application of Grover's quantum search algorithm enables to solve SAT in O(2^(n/2)) steps. Ambainis (SIGACT News, 2004) observed that it is possible to use Grover's technique to similarly speed up a sophisticated algorithm for solving 3-SAT. In this note, we show that a similar speed up can be obtained for all major record-breaking algorithms for satisfiability. We also show that if we use Grover's technique only, then we cannot do better than quadratic speed up.

Discrete Conservation Of Nonnegativity For Elliptic Problems Solved By The Hp-Fem, Pavel Solin, Thomas Vejchodsky, Roberto Araiza

Departmental Technical Reports (CS)

Most results related to discrete nonnegativity conservation principles (DNCP) for elliptic problems are limited to finite differences (FDM) and lowest-order finite element methods (FEM). In this paper we confirm that a straightforward extension to higher-order finite element methods (hp-FEM) in the classical sense is not possible. We formulate a weaker DNCP for the Poisson equation in one spatial dimension and prove it using an interval computing technique. Numerical experiments related to the extension of this result to 2D are presented.

Interval-Type And Affine Arithmetic-Type Techniques For Handling Uncertainty In Expert Systems, With Applications To Geoinformatics And Computer Security, Martine Ceberio, Vladik Kreinovich, Sanjeev Chopra, Luc Longpre, Hung T. Nguyen, Bertram Ludaescher, Chitta Baral

Departmental Technical Reports (CS)

Expert knowledge consists of statements Sj (facts and rules). The expert's degree of confidence in each statement Sj can be described as a (subjective) probability (some probabilities are known to be independent). Examples: if we are interested in oil, we should look at seismic data (confidence 90%); a bank A trusts a client B, so if we trust A, we should trust B too (confidence 99%). If a query Q is deducible from facts and rules, what is our confidence p(Q) in Q? We can describe Q as a propositional formula F in terms of Sj; computing p(Q) exactly is …

Optimizing Transmission Time Of Scalable Coded Images In Peer-To-Peer Networks, Xiao Su, Rod Fatoohi, Tao Wang

Faculty Publications

In this paper, we study how to optimize image transmission time in peer-to-peer networks by considering the property of bitstreams generated by image coding algorithms. Images can be either scalable coded or nonscalable coded. Since transmission of nonscalable coded images is well understood, we focus on the transmission of scalable coded images in this paper.Because scalable coding embeds lower bit-rate bitstreams into higher bit-rate bitstreams, there exists a many-to-one relationship between supplying and requesting peers. When a requesting peer asks for an image coded in a particular bit rate, multiple peers with the same image but coded in different bit …

Evaluation Of Modal And Fema Pushover Procedures Using Strong-Motion Records Of Buildings, Rakesh K. Goel

Civil and Environmental Engineering

The objective of this investigation is to evaluate the FEMA-356 Nonlinear Static Procedure (NSP) and a recently developed Modal Pushover Analysis (MPA) procedure using recorded motions of four buildings that were damaged during the 1994 Northridge earthquake. For this purpose, displacements and drifts from the FEMA-356 NSP and the MPA procedures are compared with the values “derived” from the recorded motions. It is found that the FEMA-356 NSP typically underestimates the drifts in upper stories and overestimates them in lower stories when compared to the recorded motions. Among the four FEMA-356 distributions considered, the “Uniform” distribution led to the most …

Robust Initial Matching Of Free-Form Objects Represented By Point Cloud Data, Nimun A. Jahangir

Digitized Theses

No abstract provided.

Evolutionary Algorithm For The Placement Of Fluid Power Valves On A Valve Stand, Trichy M. Kethara Pasupathy, Ravi Teja Seethamraju, Robert G. Wilhelm

Department of Mechanical and Materials Engineering: Faculty Publications

The choice of placement of fluid power valves on a valve stand and routing by pipes has an impact on operational costs. Choosing the right placement that provides optimum routing configuration or determining the optimum routing for a chosen placement are both computationally hard problems. An evolutionary algorithm (EA), to minimize operational costs while optimizing placement and routing of valves, is developed here. The best practices in the industry are abstracted and implemented in the EA. In this paper, the algorithm and its performance for examples with varying complexities are presented. Our results meet or exceed experienced designers’ solutions.

Knowledge Representation, Organization, And Formalization For Simulation Modeling Of Discrete Manufacturing System, Jung Hung Ma

All-Inclusive List of Electronic Theses and Dissertations

Simulation is an useful tool that helps managers making decision by designing models for real systems. It helps companies to study behaviors of real systems hy analyzing computer models and improve the systems based on the experiments' results. However, cross-domain knowledge requirement and lack of tools facilitate modeling are the main reasons that make industries hesitate to use simulation to assist making decision. This research is an attempt to develop robust knowledge representations for discrete manufacturing system and conceptual simulation model. A modeling methodology was proposed to utilize these knowledge representations (KRs) for developing conceptual simulation models from application domain …

Experimental Determination Of Probabilistic Edge-Delamination Strength Of A Graphite–Fiber/Epoxy Composite, Xiangfa Wu, Yuris A. Dzenis

Department of Engineering Mechanics: Faculty Publications

Probabilistic edge-delamination strength of a thermosetting polymer composite was studied experimentally in this work. During the procedure, by means of edge-delamination tensile test, the graphite–fiber/epoxy laminate made of unidirectional Toray P7051S- 20Q-1000 prepregs with an optimized lay-up of [12₂/–12₂/0₂]_S was used for examining its probabilistic distributions of the edgedelamination onset stress and the ultimate tensile strength. Acoustic emission (AE) equipment and optical microscope were utilized to capture the edge-delamination initiation and characterize the failure modes during delaminating. Fractographical analysis based on scanning electron microscope (SEM) was conducted for the characterization of the microscopic …

From Intervals To Domains: Towards A General Description Of Validated Uncertainty, With Potential Applications To Geospatial And Meteorological Data, Vladik Kreinovich, Olga Kosheleva, Scott A. Starks, Kavitha Tupelly, Gracaliz P. Dimuro, Antonio C. Da Costa Rocha, Karen Villaverde

Departmental Technical Reports (CS)

When physical quantities xi are numbers, then the corresponding measurement accuracy can be usually represented in interval terms, and interval computations can be used to estimate the resulting uncertainty in y=f(x1,...,xn).

In some practical problems, we are interested in more complex structures such as functions, operators, etc. Examples: we may be interested in how the material strain depends on the applied stress, or in how a physical quantity such as temperature or velocity of sound depends on a 3-D point.

For many such structures, there are ways to represent uncertainty, but usually, for each new structure, we have to perform …

An Experimental Investigation Of Ionization Of Supersonic Air By A Corona Discharge, Udyavar S. Satyanand

Mechanical and Aerospace Engineering Dissertations - Archive

A technique is developed to ionize supersonic air flow in a shock tube by a weak corona discharge. The driven section of the tube is open to the atmosphere. The shock propagates in the driven section at about 1 km/s by means of an area contraction near the downstream end of the driven section. Air is ionized by a unipolar corona discharge device comprising of a sharp-edged wedge as a high-field electrode inserted in a 41.25 mm (2 in.) ID tube that forms a low-field electrode. The device requires less than 0.5 W. A ring probe, downstream of the corona …

Numerical Simulation Of Pulse Detonation Phenomena In A Parallel Environment, Prashaanth Ravindran

Mechanical and Aerospace Engineering Theses - Archive

The objective of this work was to develop a parallel algorithm that would be used in the simulation of the detonation process in the chamber of a pulse detonation engine. The emphasis is laid on reducing computation time while maintaining the accuracy of the solution and subsequently developing a numerical solution to be in agreement with real-world physical characteristics of a detonation wave initiation, build-up and progression. The flow is assumed to be unsteady, inviscid and non heat conducting. To adhere to real time effects, the flow equations are coupled with finite rate chemistry and the vibrational energy equation are …