Engineering Commons^™

Robustness Of Multiple Objective Decision Analysis Preference Functions, William K. Klimack

Theses and Dissertations

This research investigated value and utility functions in multiobjective decision analysis to examine the relationship between them in a military decision making context. The impact of these differences was examined to improve implementation efficiency. The robustness of the decision model was examined with respect to the preference functions to reduce the time burden imposed on the decision maker. Data for decision making in a military context supports the distinction between value and utility functions. Relationships between value and utility functions and risk attitudes were found to be complex. Elicitation error was significantly smaller than the difference between value and utility …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 18, Number 9, June 2002, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A twelve page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Closed Loop Identification Of A First Order Plus Dead Time Process Model Under Pi Control, Tony Kealy, Aidan O'Dwyer

Conference papers

Abstract -- This paper discusses the estimation of the parameters of a first order plus dead-time process model using the closed-loop step response data of the process under proportional plus integral (PI) control. The proportional gain and the integral time, in the PI controller, are chosen such that the closed-loop step response exhibits an under-damped response. From this response data, five characteristic points are used to determine a second order plus dead-time model and subsequently, the frequency response of the closed-loop system. Knowing the dynamics of the closed-loop system and the dynamics of the controller, the open-loop dynamics of the …

Movements And Settlements Of Highway Bridge Approaches, Bernadette Dupont, David L. Allen

Kentucky Transportation Center Research Report

This report is a discussion of the bridge approach settlement or movement problem that is so prevalent in the United States. An explanation and/or description is given of the causes of these movements as described in the literature. A discussion concerning the cost to highway agencies is also given. A review and discussion of current practices in the country is given . This includes construction practices on approach embankment foundations, the approach embankment itself, various types of approach slabs, types of abutments and end bents, and drainage around approach embankments and bridge ends. A survey of all 50 states was …

Long-Term Benefits Of Stabilizing Soil Subgrades, Tommy C. Hopkins, Tony L. Beckham, Liecheng Sun, Bixian Ni, Barry Butcher

Kentucky Transportation Center Research Report

Chemical admixtures have been used extensively since the mid-eighties in Kentucky to improve bearing strengths of soil subgrades. Most pavements in Kentucky are constructed on clayey soils. Although short-term observations at a small number of sites showed that chemical stabilization worked very well, a need existed to perform a more comprehensive review and to assess the long-term benefits of this subgrade stabilization method. The main intent of this study was an attempt to address questions concerning bearing strengths, longevity, durability, structural credit, economics, and performance of pavements resting on soil subgrades mixed with chemical admixtures. In-depth field and laboratory studies …

Modular Machine Learning Methods For Computer-Aided Diagnosis Of Breast Cancer, Mia Kathleen Markey '94

Doctoral Dissertations

The purpose of this study was to improve breast cancer diagnosis by reducing the number of benign biopsies performed. To this end, we investigated modular and ensemble systems of machine learning methods for computer-aided diagnosis (CAD) of breast cancer. A modular system partitions the input space into smaller domains, each of which is handled by a local model. An ensemble system uses multiple models for the same cases and combines the models' predictions.

Five supervised machine learning techniques (LDA, SVM, BP-ANN, CBR, CART) were trained to predict the biopsy outcome from mammographic findings (BIRADS™) and patient age based on a …

Nonresonant Detection Of Terahertz Radiation In Field Effect Transistors, W. Knap, V. Kachorovskii, Y. Deng, S. Rumyantsev, J.-Q. Lü, R. Gaska, M. S. Shur, Grigory Simin, X. Hu, M. Asif Khan, C. A. Saylor, L. C. Brunel

Faculty Publications

We present an experimental and theoretical study of nonresonant detection of subterahertz radiation in GaAs/AlGaAs and GaN/AlGaN heterostructurefield effect transistors. The experiments were performed in a wide range of temperatures (8–300 K) and for frequencies ranging from 100 to 600 GHz. The photoresponse measured as a function of the gate voltage exhibited a maximum near the threshold voltage. The results were interpreted using a theoretical model that shows that the maximum in photoresponse can be explained by the combined effect of exponential decrease of the electron density and the gate leakage current.

Further Examination Of Moore's Law With Data Envelopment Analysis, Timothy R. Anderson, Rolf Färe, Shawna Grosskopf, Lane Inman, Xiaoyu Song

Engineering and Technology Management Faculty Publications and Presentations

Although it has stood the test of time for over 30 years, Moore's Law addresses but a single aspect of microprocessor design. As a proxy for technology, the number of transistors in an integrated circuit represents a limited perspective on the technology as a whole. Anderson et al. proposed a set of metrics by which to measure a technology, and a means to measure its progress over time utilizing data envelopment analysis. In this revised model, the assumption of state of the art (SOA) on product release is dropped, technical progress is measured iteratively over time, the effective time elapsed …

On Localized Control In Qos Routing, Srihari Nelakuditi, Srivatsan Varadarajan, Zhi-Li Zhang

Faculty Publications

In this note, we study several issues in the design of localized quality-of-service (QoS) routing schemes that make routing decisions based on locally collected QoS state information (i.e., there is no network-wide information exchange among routers). In particular, we investigate the granularity of local QoS state information and its impact on the design of localized QoS routing schemes from a theoretical perspective. We develop two theoretical models for studying localized proportional routing: one using the link-level information and the other using path-level information. We compare the performance of these localized proportional routing models with that of a global optimal proportional …

A Localized Adaptive Proportioning Approach To Qos Routing, Srihari Nelakuditi, Zhi-Li Zhang

Faculty Publications

In QoS routing, paths for flows are selected based on knowledge of resource availability at network nodes and the QoS requirements of flows. Several QoS routing schemes have been proposed that differ in the way they gather information about the network state and select paths based on this information. We broadly categorize these schemes into best path routing and proportional routing. The best path routing schemes gather global network state information and always select the best path for an incoming I-low,based on this global view. It has been shown that best path routing schemes require frequent exchange of network state, …

Crystallization Kinetics, Structural Parameters And Optical Properties Of Some Semiconducting Oxide Glasses Doped With Rare Earth And Transition Metal Ions, Khawlah Mohammad Ahmad Al-Yahyaei

Theses

No abstract provided.

Synthesis, Characterization And Applications Of Some Conducting Polymers, Fatma Yousif Mohamed Balhey

Theses

Conducting polymers emerged as a new class of materials by the end of the sixties. Since then many efforts have been made to put these materials to

industrial use. Among the achievements are their applications in the semiconductor industry, medical field, chemical and biological sensors, etc. A

different track that alleviated the prospects of the application of conducting

polymers is the modification of the polymer film, namely through the inclusion of metallic moieties for specific target usage. In this thesis the candidate aimed

to synthesis well established and extensively studied class of electrically conductive polymer, 3-methylthiophene. The polymer was then …

Incorporating Web-Based Homework Problems In Engineering Dynamics, Ralph E. Flori, David B. Oglesby, Timothy A. Philpot, Nancy E. Hubing, Richard H. Hall, Vikas Yellamraju

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We are involved in a project funded by the Department of Education (FIPSE) which focuses on developing interactive software to improve the teaching and learning of engineering statics, dynamics, and mechanics of materials. This paper presents an overview of this project, discusses its objectives, and focuses on one particular aspect of the project.the use of web-based homework problems as assessment tools to evaluate student learning. The overall project includes creating, for all three engineering mechanics courses, the following web-based learning tools: (a) Animated theory modules, using Macromedia.s Flash development software, which display basic theory and example problems in an engaging, …

Engineering Management At Umr -- Alumni Voices, Stephen A. Raper

Engineering Management and Systems Engineering Faculty Research & Creative Works

The Department of Engineering Management at the University of Missouri-Rolla is among the oldest of its kind in the United States, and has over 2000 Bachelors level alumni graduates. The Department will undergo ABET accreditation under the new assessment based criteria in the fall of 2002. The new criteria specify that engineering programs should seek to continuously improve their degree offerings through an ongoing assessment process that includes constituent input. Our own department has specified undergraduate alumni as one of the prime or key constituents that will be queried for input into our own processes. For the first time in …

Adaptive Predictive Congestion Control Of High-Speed Atm Networks, Sarangapani Jagannathan, Jayasree Talluri

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes an auto regressive moving average (ARMAX)-based adaptive control methodology to prevent congestion in high-speed asynchronous transfer mode (ATM) networks. Adaptive controller is developed to control traffic where sources adjust their transmission rates in response to the feedback information from the network switches. Specifically, the buffer dynamics at a given switch is modeled as a nonlinear discrete-time system and an ARMAX controller is designed so as to predict the explicit values of the transmission rates of the sources so as to prevent congestion. Tuning methods are provided for the unknown coefficients of the ARMAX model to estimate the …

Three Dimensional Deformable Modeling Of The Spine, Rania Atef

Archived Theses and Dissertations

The purpose of this work is the development of a 3D deformable model of the spinal lumbar region. The data for the spine comes from the National Library of Medicine website (NLM). The 3D model uses several NURBS patches as modeling primitives. This work is part of a larger system aimed at building a 3D surgical simulator coupled with a force - feedback.PHANToM robot in a virtual reality CA VE system.

The input to this system is a set of two-dimensional CT images. They are processed and edge detected to produce a set of contoured images containing the vertebral data. …

Enhancing Image Classification And Content Query Using Perception-Based Models, Ahmed Badr El-Din

Archived Theses and Dissertations

Searching a digital image library, having large number of digital images or video sequences turned to be more and more important in this multimedia age. As time passes, a growing number of people are using the Internet for searching and browsing through different multimedia databases. To make such searching practical, effective image coding and searching based on image semantics is becoming increasingly important. In current real-world image databases, the prevalent retrieval techniques involve human-supplied text annotations to describe image semantics. These text annotations are then used as the basis for searching, using mature text search algorithms that are available as …

Marketing Characteristics Of The Service Of Project Management In Egypt, Mohamed Ali Alhadidi

Archived Theses and Dissertations

The Project Management profession has been facing, since its introduction, a serious impediment establishing a significant and well-defined role among the Egyptian construction community. In an attempt to uncover the reasons behind this impediment, a problem identification research was conducted with service-provider firms of different sizes, origins, and backgrounds. The research confirmed the observation. It also arrived at the main obstacle hampering the development of Project Management in Egypt. This obstacle was the poor communication of the service and its benefits to the market. A barrier, built of mismarketing, has therefore parted between Project Management professionals and their clients. This …

Construction Delays Of High Investment Projects In Egypt, Nora Mohamed El-Gohary

Archived Theses and Dissertations

In evaluating the overall performance and success of construction projects, time is usually used as a major factor in such evaluation. Unsatisfactory time performance shows up as delays. Construction delays are very critical to the owner and contractor, because they suffer due to lost profit, additional overhead costs, increased costs of financing, and payment of liquidated or actual damages. Despite that, delays in completion of projects are repetitive in the Egyptian construction industry. Current Egyptian statistics and studies did not provide sufficient information and analysis of the delay phenomenon. Studying and analyzing the problem is a step towards its solution …

Classification Of Risks For International Construction Joint Ventures Projects, Yasser Abd El Ghany Azmy Elshabassy

Archived Theses and Dissertations

No abstract provided.

Three-Dimensional Modeling Of The Lumbar Spine For Simulation Purposes, Ayman Hamdy Mohamed Kassem

Archived Theses and Dissertations

Human spine modeling started gaining its popularity in world war II for military purposes as a result of studying the phenomenon of pilot spine cracking during ejection. It started with simple beam modeling and continued to get more complicated and realistic. Modeling the spine is a challenging problem because of its detailed anatomical structure, the motion of soft and bone tissues and the deformations that occur during different loads. Realistic spine modeling is expected to have a significant impact in a world where spinal injuries and deformities account for a large percentage of all injuries. In this research, a spinal …

A Water And Wastewater Sector Performance Assessment: A Comparative Study, Reham Khalifa

Archived Theses and Dissertations

The water and wastewater sector has been one of the infrastructure sectors gaining increasing importance recently. Governments have been focusing major efforts and significant volumes of their budgets towards the improvement of this sector and the increase of water and wastewater coverage. The key problem in most of the water_and wastewater utilities is the absence of performance assessment tools.

This research utilizes the calculation of a group of financial and operational indicators for a sample size of 234 utilities from countries across the world as a mean of comparison of their performance. Egypt is represented in the sample size by …

Building General Indicator Cost Indexes For The Construction Industry Price Movement In The Egyptian Market, Bahaee Nabil Labib Khalil

Archived Theses and Dissertations

This thesis (The "Thesis") is submitted to the Department of Engineering at the American University in Cairo in partial :fulfillment of the requirements for the degree of Master of Science. The aim of the Thesis is Building General Indicator Cost Indexes for the Construction Industry Price Movement in the Egyptian Market. It is prepared by Bahaee N. L. Khalil under the supervision of Dr. Amr A. G. Hassanein (Associate Professor, Construction Engineering Department, the American University in Cairo). Construction cost indexes is mainly utilized in planning estimates required at an early stage of a project conception to assist with the …

Interaction Of Silica Fume And Polypropylene Fibers In High Performance Concrete, May Tarek Massoud

Archived Theses and Dissertations

The use of mineral admixtures and fibers is becoming essential in the new generation of high performance concrete since they introduce enhancement in mechanical properties as well as several durability aspects. Some of the advantages gained when properly employing high performance concrete are significant improvements in strength, drastically reduced permeability, better resistance to a wide spectrum of chemicals, superior performance in freezing and thawing conditions and enhanced thermal resistance. Although silica fume and polypropylene fibers are increasingly used in high performance concrete, yet, relatively little work has focused on the interaction of both ingredients in such concretes. The main aim …

An Optimal Production Plan In A Make-To-Stock Manufacturing Environment Using Mixed Integer Programming, Amr Mohamed Nofal

Archived Theses and Dissertations

The main aim of this thesis is to develop an optimization model that provides an optimal production plan for a make-to-stock (MTS) manufacturing environment that includes the production of multi products on multiple machines over a definite number of planning periods. While optimizing the production plan and inventory levels for this general problem under study, a set of constraints will be kept throughout the planning horizon. These constraints include maximum production capacity, maxrmum storage capacity, minimum and maximum coverage, minimum production quantities and others. Mixed integer programming (MIP) will be used as a tool to optimize the total cost involved …

Impact Of Lignin From Non-Wood Pulping Processes On Kraft Wastewater Treatment And Receiving Water Quality, Mohamed Hamdy Nour

Archived Theses and Dissertations

The Kraft process is typically used for pulping non-wood raw materials, I ike rice straw, in order to dissolve the non cellulose organic fraction, essentially lignin, and leave behind the fibrous residual as pulp for paper production. Rice straw, however, also contains a high percentage of silica that dissolves in the process. The wastewater derived from vacuum filtration of the pulp solution is referred to as black liquor, owing to its dark color and complex makeup with high BOD, caustic, silica, and TDS. The high silica concentration in the black liquor prohibits conventional chemical recovery due to scaling of the …

The Use Of Information Technology In Providing Government Services In Egypt, Sherif Ahmed Sherif

Archived Theses and Dissertations

Futurist Alvin Toffler (1980) wrote about three "waves" of civilization. Ln the First Wave, agiiculture enabled nomadic peoples to settle into villages and cities. In the Se;:ond 'Nave, the industrial revolution made possible the modem industrial state. The Third Wave has begun in which computer and communications technologies will transform the national and global economies into information driven economies. The Third wave triggers the Information Revolution which will have political and societal impacts every bit as profound as those of the First and Second Waves.

Throughout human history, mankind has witnessed incremental changes as well as sudden sweeping transformations. In …

3d Finite Element Modeling Of The Welding Process, Ihab Fanous Zakaria

Archived Theses and Dissertations

The modeling and simulation of the welding process has been of main concern for different fields of applications. It is used mainly to check for the residual stresses generated due to welding. These stresses may reach a value near the yielding level and may cause several failure types in the welded strnctures. Several attempts have been clone in analyzing the welding process using different approaches. Analytical methods have been developed with many approximations and assumptions to handle the highly non-linear behavior of the problem. On the other hand, experimental methods in monitoring the residual stresses in a welded structure may …

Framework For Developming A Standard Construction Information Classification System For The Egyptian Construction Industry, Rehab M Anwar Wahch

Archived Theses and Dissertations

The construction industry is known to be rich with information. Yet to-date there is no available system that standardizes this inormation so that it can be used as a common system throughout the design, construction, and management of a project and supports view conversion especially when different participants in building and construction represent different disciplines, each having his own view on information. This form of information standardization is termed as "construction information classification system (CICS) ". Currently the Egyptian industry does not have an adequate standardized construction information classification system (CICS). The only available systems in use are company-specific internal …

Bs News

Building Services Engineering

No abstract provided.