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2011

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Articles 31 - 42 of 42

Full-Text Articles in Systems Engineering

Achieving Ultrafine Grains In Mg Az31b-O Alloy By Cryogenic Friction Stir Processing And Machining, Anwaruddin Mohammed Jan 2011

Achieving Ultrafine Grains In Mg Az31b-O Alloy By Cryogenic Friction Stir Processing And Machining, Anwaruddin Mohammed

Theses and Dissertations--Manufacturing Systems Engineering

This thesis presents results from the application of cryogenic cooling on multiple-pass friction stir processing and the subsequent orthogonal machining on friction stir processed and as-received Mg AZ31B-O disks, and shows their combined effects on microstructure and microhardness values. A simple friction stir tool, a specially designed fixture and liquid nitrogen are used to perform multiple-pass friction stir processing experiments on Mg AZ31B-O alloy. The friction stir processed and as-received sheets are then made into disks for the orthogonal machining experiments. This study analyzes the microhardness, microstructure changes by cryogenic friction stir processing and the effect of machining conditions such …


Development Of Risk Uncertainty Factors From Historical Nasa Projects, Tahani R. Amer Jan 2011

Development Of Risk Uncertainty Factors From Historical Nasa Projects, Tahani R. Amer

EMSE Doctoral Projects

NASA is a good investment of federal funds and strives to provide the best value to the nation. NASA has consistently budgeted to unrealistic cost estimates, which are evident in the cost growth in many of its programs. In this investigation, NASA has been using available uncertainty factors from the Aerospace Corporation, Air Force, and Booz Allen Hamilton to develop projects' risk posture. NASA has no insight into the developmental of these factors and, as demonstrated here, this can lead to unrealistic risks in many NASA Programs and projects (P/p). The primary contribution of this project is the development of …


Architecture Value Mapping: Using Fuzzy Cognitive Maps As A Reasoning Mechanism For Multi-Criteria Conceptual Design Evaluation, Atmika Singh Jan 2011

Architecture Value Mapping: Using Fuzzy Cognitive Maps As A Reasoning Mechanism For Multi-Criteria Conceptual Design Evaluation, Atmika Singh

Doctoral Dissertations

"The conceptual design phase is the most critical phase in the systems engineering life cycle. The design concept chosen during this phase determines the structure and behavior of the system, and consequently, its ability to fulfill its intended function. A good conceptual design is the first step in the development of a successful artifact. However, decision-making during conceptual design is inherently challenging and often unreliable. The conceptual design phase is marked by an ambiguous and imprecise set of requirements, and ill-defined system boundaries. A lack of usable data for design evaluation makes the problem worse. In order to assess a …


The Effects Of Anti-Price Gouging Legislation On Supply Chain Dynamics, Jason Edward Maynard Jan 2011

The Effects Of Anti-Price Gouging Legislation On Supply Chain Dynamics, Jason Edward Maynard

Master's Theses

The purpose of this thesis is to model the effects of anti-price gouging (APG) legislation on the costs to businesses during the recovery period of a disaster. A system dynamics model of a business’s replenishment procedures is used to simulate the effects of APG legislation on business performance. Economists have published expansive research on the effects of price ceilings on supply and demand, but there is little research evidence on the operational consequences of price ceiling legislation on business costs. APG legislation increases consumer’s forward buying and shortage gaming after a disaster by removing price incentives to be frugal. Forward …


Proving Sustainability: The International Development Monitoring Initiative, Evan A. Thomas, Zdenek Zumr Jan 2011

Proving Sustainability: The International Development Monitoring Initiative, Evan A. Thomas, Zdenek Zumr

Mechanical and Materials Engineering Faculty Publications and Presentations

Nearly a billion people in the world lack access to safe drinking water, two billion have inadequate sanitation facilities, three billion use biomass for their daily energy needs and nearly half the world's population live in rural isolation, lacking access to the most basic human services. Combined, these limitations are a leading cause of the perpetuating cycle of poverty and political insecurity. Meanwhile, the majority of international development agencies are responsible for self-reporting project outcomes. At best, expert spot-checks are conducted in the field occasionally. These results tend to show individual project success, while meta- surveys indicate on-going challenges in …


Delayed-Bang Approach Towards More Sustainable Critical Infrastructure Risk Management, C. Ariel Pinto, Michael K. Mcshane, Abhishek S. Pathak Jan 2011

Delayed-Bang Approach Towards More Sustainable Critical Infrastructure Risk Management, C. Ariel Pinto, Michael K. Mcshane, Abhishek S. Pathak

Finance Faculty Publications

This article describes the Delayed Bang Approach for determining the value of risk management alternatives in critical infrastructure security. The discussion includes (1) the need for sustainable risk management (2) the importance of time valuation in evaluating competing loss prevention and loss reduction alternatives, (3) the convergence of deterministic engineering economics, survivability analysis, and probabilistic analysis, and (4) hypothetical examples of the Delayed-Bang Approach and significance towards more sustainable risk management.


Design And Analysis Of A Speed-Aware Routing Protocol For Mobile Ad Hoc Networks, Kirthana Akunuri Jan 2011

Design And Analysis Of A Speed-Aware Routing Protocol For Mobile Ad Hoc Networks, Kirthana Akunuri

Masters Theses

"The flexibility of movement for the wireless ad hoc devices, referred to as node mobility, introduces challenges such as dynamic topological changes, increased frequency of route disconnections and high packet loss rate in Mobile Ad hoc Wireless Network (MANET) routing. This research proposes a novel on-demand routing protocol, Speed-Aware Routing Protocol (SARP) to mitigate the effects of high node mobility by reducing the frequency of route disconnections in a MANET. SARP identifies a highly mobile node which forms an unstable link by predicting the link expiration time (LET) for a transmitter and receiver pair. When the nodes have high relative …


Quantifying The Carbon Footprint Of Lean Waste, Kristen Donovan Balinski Jan 2011

Quantifying The Carbon Footprint Of Lean Waste, Kristen Donovan Balinski

Masters Theses

"The objective of this paper is to provide a method of quantifying lean wastes in terms of carbon dioxide emissions by using value stream mapping. Lean manufacturing, a process based on waste identification and reduction, is a growing trend in industry and a proven method of lowering costs. The environmental impact of these wastes can be quantified by identifying the metrics associated with them, and using existing reports to convert those metrics into measurements of carbon dioxide. Growing environmental concerns are prompting federal government regulation of greenhouse gas or carbon dioxide emissions, as seen in the American Clean Energy and …


Integration Of Model-Based Systems Engineering And Virtual Engineering Tools For Detailed Design, Akshay Kande Jan 2011

Integration Of Model-Based Systems Engineering And Virtual Engineering Tools For Detailed Design, Akshay Kande

Masters Theses

"Design and development of a system can be viewed as a process of transferring and transforming data using a set of tools that form the system's development environment. Conversion of the systems engineering data into useful information is one of the prime objectives of the tools used in the process. With complex systems, the objective is further augmented with a need to represent the information in an accessible and comprehensible manner. The importance of representation is easily understood in light of the fact that the stakeholder's ability to make prompt and appropriate decisions is directly related to his understanding of …


Presentation: Proving Sustainability: The International Development Monitoring Initiative, Evan A. Thomas Jan 2011

Presentation: Proving Sustainability: The International Development Monitoring Initiative, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

Presentation detailing the activities and products of the Sustainable Water, Energy and Environmental Technologies Laboratory at Portland State University (SWEETLab). The lab also works to develop standards to help evaluate and compare projects and outcomes around the world. Water treatment and sanitation practices, as well as newly designed cookstoves, are highlighted.


Developing A Time And Motion Study For A Lean Healthcare Environment, Michael Winston Patton Jr. Jan 2011

Developing A Time And Motion Study For A Lean Healthcare Environment, Michael Winston Patton Jr.

University of Kentucky Master's Theses

This thesis outlines the development of a standard methodology for performing a time and motion study in a lean healthcare environment. Time and motion studies have been used in healthcare environments in the past, however they have nearly all been exclusive to a particular healthcare enterprise. To develop the time and motion study methodology, a study was designed to examine how resident doctors spend their time. This study was performed in response to coming changes in the work hours for all residents. Once the methodology was developed, trial observations were conducted. The data from these observations was analyzed to determine …


Assessing System Architectures: The Canonical Decomposition Fuzzy Comparative Methodology, Jason Paul Dauby Jan 2011

Assessing System Architectures: The Canonical Decomposition Fuzzy Comparative Methodology, Jason Paul Dauby

Doctoral Dissertations

"The impacts of decisions made during the selection of the system architecture propagate throughout the entire system lifecycle. The challenge for system architects is to perform a realistic assessment of an inherently ambiguous system concept. Subject matter expert interpretations, intuition, and heuristics are performed quickly and guide system development in the right overall direction, but these methods are subjective and unrepeatable. Traditional analytical assessments dismiss complexity in a system by assuming severability between system components and are intolerant of ambiguity. To be defensible, a suitable methodology must be repeatable, analytically rigorous, and yet tolerant of ambiguity. The hypothesis for this …