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Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

A Comparison Between Single And Dual Monitor Productivity And The Effects Of Window Management Styles On Performance, Alex Stegman, Chen Ling, Randa Shehab Apr 2015

A Comparison Between Single And Dual Monitor Productivity And The Effects Of Window Management Styles On Performance, Alex Stegman, Chen Ling, Randa Shehab

Dr. Chen Ling

Several research studies have been published on user opinion and productivity of using dual monitor systems. These studies found that users typically enjoy using multiple monitors, but none found a strong increase in performance and productivity. Other researchers have focused on improving multiple monitor usability, but often without any statistical framework. This study compared single and dual monitor productivity measures: task time, cursor movement, and number of window switches. Additionally, window management styles (WMS) were studied in order to help designers understand user behavior better. WMS were broken into two categories, toggler and resizer, and then compared to the WMS ...


The Effect Of Streamwise Vortices On The Frost Growth Rate In Developing Laminar Channel Flows, Brian Storey, Anthony Jacobi Jul 2012

The Effect Of Streamwise Vortices On The Frost Growth Rate In Developing Laminar Channel Flows, Brian Storey, Anthony Jacobi

Brian Storey

An experimental study is presented to assess the influence of streamwise vortices on frost growth in a steady, developing, laminar channel flow. Using a simple model and scale analysis, frost growth rate (ablimation) data are normalized with respect to temperature, humidity and time. Measurements from baseline experiments in a rectangular channel are found to be accurately correlated using the proposed scaling relation. Upon introducing streamwise vortices in the channel flow, frost growth still follows the scaling relation, but local growth rates were observed to increase by more than 7% in regions where the streamwise vortices induce a surface-normal flow toward ...


Rules And Limitations Of Building Delay-Tolerant Topologies For Coupled Systems, Rifat Sipahi, Wei Qiao Apr 2012

Rules And Limitations Of Building Delay-Tolerant Topologies For Coupled Systems, Rifat Sipahi, Wei Qiao

Rifat Sipahi

This paper investigates the equilibrium behavior of broadly studied synchronization dynamics of coupled systems, among which shared information is delayed. The underlying relationship is established between graph structures and the largest amount of delay the dynamics can withstand without losing stability. In particular, based on Cartesian product of graphs, we present the rules and limitations for synthesizing the graphs of large-scale systems that can remain stable for as large delays as possible. Examples are provided to demonstrate the results.


Magnetic And Structural Investigation Of Heat Treated Ion Beam Sputtered Amorphous Co₇₄Fe₆B₁₅Si₅ Films, V. Harris, S. Oliver, W. Nowak, C. Vittoria, R. Culbertson, W. Elam, K. Kim Apr 2011

Magnetic And Structural Investigation Of Heat Treated Ion Beam Sputtered Amorphous Co₇₄Fe₆B₁₅Si₅ Films, V. Harris, S. Oliver, W. Nowak, C. Vittoria, R. Culbertson, W. Elam, K. Kim

Vincent G. Harris

As-deposited and annealed specimens of ion beam sputtered amorphous Co₇₄Fe₆B₁₅Si₅ thin films were examined to explore the correlation between changes in magnetic properties and atomic structure. Specimens were characterized magnetically, by traditional ac and dc techniques and structurally, via conversion-electron extended x-ray absorption fine structure analysis. Results show significant ordering of the higher order atomic shells around the transition metal ions well below the crystallization temperature. This ordering evolves into a body- centered-cubic configuration around both the Co and Fe ions. Increases in nearest neighbor peak positions in the EXAFS Fourier transforms were observed to correlate with increasing annealing temperatures ...


Effects Of Boron Implantation In Films Of Iron-Nickel, J. Ryu, K. Castell, W. Nowak, C. Vittoria Dec 2010

Effects Of Boron Implantation In Films Of Iron-Nickel, J. Ryu, K. Castell, W. Nowak, C. Vittoria

Welville B. Nowak

We have implanted boron ions into films of Fe-Ni alloy composition. A homogeneous distribution of boron was determined from the sputter Auger analysis with a concentration of 18% and 34% for low- and high-dose implantation, respectively. The resistivity of film was increased by a factor of 2 and 4 as a result of low- and high-dose implantation, respectively. The magnetic properties of these films are studied as a function of annealing temperature by using FMR measurements. Both the uniaxial anisotropy field and FMR linewidth are dramatically decreased as a result of annealing at elevated temperatures. The changes of effective magnetization ...


A Business-Mapping Approach To Multi-Criteria Group Selection Of Collection Centers And Recovery Facilities, Kishore Pochampally, Surendra Gupta Oct 2010

A Business-Mapping Approach To Multi-Criteria Group Selection Of Collection Centers And Recovery Facilities, Kishore Pochampally, Surendra Gupta

Surendra M. Gupta

For a prospective reverse supply chain to operate efficiently, the designing of that chain must involve selection of collection centers and recovery facilities that have sufficient success potentials. These success potentials depend heavily on the participation (in the reverse supply chain) of three important groups that have multiple, conflicting, and incommensurate goals. Therefore, the potentials must be evaluated based on the maximized consensus among the three groups, viz., (i) Consumers whose primary concern is convenience, (ii) Local government officials whose primary concern is environmental consciousness, and (iii) Supply chain company executives whose primary concern is profit. In this paper, we ...


Design Of An Integrated Component Recovery System, Pitipong Veerakamolmal, Surendra Gupta Oct 2010

Design Of An Integrated Component Recovery System, Pitipong Veerakamolmal, Surendra Gupta

Surendra M. Gupta

This paper presents a two-stage disassembly and retrieval system that provides a unique solution for planning selective component recovery from products. The solution approach uses a process sequencing technique to schedule the operations in both stages to optimize the operational makespan.


A Combinatorial Cost-Benefit Analysis Methodology For Designing Modular Electronic Products For The Environment, Pitipong Veerakamolmal, Surendra Gupta Oct 2010

A Combinatorial Cost-Benefit Analysis Methodology For Designing Modular Electronic Products For The Environment, Pitipong Veerakamolmal, Surendra Gupta

Surendra M. Gupta

This paper presents a technique to analyze the efficiency of designing electronic products for the environment. The efficiency of each design is indicated using a Design for Disassembly Index (DfDI). DfDI uses a disassembly tree (DT) which relies on the product's bill of materials as its structural blueprint. DfDI can be used to compare the efficiency among alternative designs, identifying the best alternative for a product retirement plan. In addition, the index offers designers with an important measure to help improve future products.


A Multi-Phase Mathematical Programming Approach To Strategic Planning Of An Efficient Reverse Supply Chain Network, Kishore Pochampally, Surendra Gupta Oct 2010

A Multi-Phase Mathematical Programming Approach To Strategic Planning Of An Efficient Reverse Supply Chain Network, Kishore Pochampally, Surendra Gupta

Surendra M. Gupta

Strategic planning of a supply chain network is one of the most challenging aspects of reverse logistics. To effectively satisfy drivers such as profitability, environmental regulations and asset recovery, only the most economical used products must be reprocessed in only the recovery facilities that have the potential to efficiently reprocess them. Due to uncertainties in supply, quality and reprocessing times of used-products, the cost-benefit function in the literature that selects the most economical product to reprocess from a set of used-products is not appropriate for direct adoption. Moreover, due to the same uncertainties, any traditional forward supply chain approach to ...


System Dynamics Approach In Inventory Management Of End-Of-Life Products In A Disassembly Line, Badr Johar, Surendra Gupta Sep 2010

System Dynamics Approach In Inventory Management Of End-Of-Life Products In A Disassembly Line, Badr Johar, Surendra Gupta

Surendra M. Gupta

A major challenge original equipment manufacturers (OEMs) currently face is how to implement an effective reverse supply chain network that is both cost effective and efficient. The rapid increase in the end-of-life (EOL) products returns from end customers back to origin for recovery or proper disposal can be said one of the main reasons behind this interest. Thus, the purpose of this paper is to examine the relationship between all elements of inventory management in the disassembly context using the system dynamic modeling approach to analyze the inventory of disassembled parts. Analysis of different market scenarios is conducted. The system ...


Dynamic Programming For Solving Disassembly-To-Order System Under Stochastic Yields, Limited Supply, And Quantity Discount, Amre Massoud, Surendra Gupta Sep 2010

Dynamic Programming For Solving Disassembly-To-Order System Under Stochastic Yields, Limited Supply, And Quantity Discount, Amre Massoud, Surendra Gupta

Surendra M. Gupta

In this paper, we consider the disassembly-to-order (DTO) problem where a variety of returned end-of-life (EOL) products are disassembled in order to satisfy the demand for specified numbers of components. However, a lot of uncertainties exist in the disassembly process that further complicates the process. A DTO model has been developed that takes into consideration the different system uncertainties and variability. The DTO model was solved in multiple periods using dynamic programming (DP). The main objective was to determine optimal number of takeback EOL products in every period from each supplier to fulfill the demand of components while maximizing total ...


An Evaluation Of The Effect Of Sensor Embedded Products In Product Disassembly With Precedence Relationships, Mehmet Ilgin, Surendra Gupta Sep 2010

An Evaluation Of The Effect Of Sensor Embedded Products In Product Disassembly With Precedence Relationships, Mehmet Ilgin, Surendra Gupta

Surendra M. Gupta

A promising solution approach to deal with the uncertainty associated with disassembly yield is sensor embedded products (SEPs) which involve sensors implanted during the production process. This study presents a quantitative assessment of the impact of SEPs on the various performance measures of a kanban-controlled air conditioner disassembly line. First, separate design of experiments studies based on orthogonal arrays are carried out for the cases with and without SEPs. Then, the results of paired-t tests comparing two cases based on different performance measures are presented.


Linear Physical Programming For Solving The Multi-Criteria Disassembly-To-Order Problem Under Stochastic Yields, Limited Supply, And Quantity Discount, Amre Massoud, Surendra Gupta Sep 2010

Linear Physical Programming For Solving The Multi-Criteria Disassembly-To-Order Problem Under Stochastic Yields, Limited Supply, And Quantity Discount, Amre Massoud, Surendra Gupta

Surendra M. Gupta

This paper focuses on the disassembly-to-order (DTO) problem. End-of-life (EOL) products are purchased from a number of suppliers in order to be disassembled into individual components to satisfy the demand for specified numbers of components. However, there are a lot of uncertainties that complicates the process. Previous work in the literature solved the DTO problem under multiple uncertainties and a single objective. Other models solved the multicriteria DTO problem with a single uncertainty. This paper develops a multi-criteria DTO model that takes into consideration multiple system uncertainties and solves it using Linear Physical Programming (LPP). The main objective was to ...


An Optimization Framework For Advanced Disassembly/Repair-To-Order Systems With Remaining-Life Adjustment, Onder Ondemir, Surendra Gupta Sep 2010

An Optimization Framework For Advanced Disassembly/Repair-To-Order Systems With Remaining-Life Adjustment, Onder Ondemir, Surendra Gupta

Surendra M. Gupta

Due to environmental awareness and realization of cost savings, disassembly-to-order (DTO) concept has become popular. One of the main obstacles to making optimal DTO decisions is the uncertainty involved in end-of-life products (EOLPs). This uncertainty is due to the lack of information about the condition and the quantity of EOLPs returned. This uncertainty is removed by advanced disassembly/repair-to-order systems utilizing sensors to monitor the products in their life-cycle. Sensor technology enables remaining life estimation, thus allows advanced DTO models to deal with sophisticated component and product demands with remaining life adjustment. This paper presents an optimization framework for advanced ...


Cost-Benefit Analysis Of Sensor-Embedded Products Based Disassembly-To-Order System, Onder Ondemir, Surendra Gupta Sep 2010

Cost-Benefit Analysis Of Sensor-Embedded Products Based Disassembly-To-Order System, Onder Ondemir, Surendra Gupta

Surendra M. Gupta

Due to environmental awareness and realization of cost savings, disassembly-to-order (DTO) concept has become popular. One of the main obstacles to making optimal DTO decisions is the uncertainty involved in end-of-life products (EOLPs). This uncertainty is due to the lack of information about the condition and the quantity of EOLPs returned. This uncertainty can be removed by sensors monitoring the products in their life-cycle. However, DTO systems utilizing these sensors will be more costly to establish and maintain. This paper presents economic justification of establishing advanced disassembly-to-order (DTO) systems in which sensor-embedded end-of-life products are disassembled in order to fulfill ...


Enhancing Design Learning Using Groupware, Andrew Wodehouse, Ozgur Eris, Hillary Grierson, Ade Mabogunje Dec 2006

Enhancing Design Learning Using Groupware, Andrew Wodehouse, Ozgur Eris, Hillary Grierson, Ade Mabogunje

Ozgur Eris

Project work is increasingly used to help engineering students integrate, apply and expand on knowledge gained from theoretical classes in their curriculum and expose students to `real world' tasks. To help facilitate this process, the department of Design, Manufacture and Engineering Management at the University of Strathclyde has developed a web-based groupware product called LauLima to help students store, share, structure and apply information when they are working in design teams. This paper describes a distributed design project class in which LauLima has been deployed in accordance with a Design Knowledge Framework that describes how design knowledge is generated and ...


Maintenance Outsourcing Of A Multi-Process Manufacturing System With Multiple Contractors, Hakan Tarakci, Kwei Tang, Herb Moskowitz, Robert Plante Dec 2005

Maintenance Outsourcing Of A Multi-Process Manufacturing System With Multiple Contractors, Hakan Tarakci, Kwei Tang, Herb Moskowitz, Robert Plante

Hakan Tarakci

Consider a manufacturer with a manufacturing system that consists of multiple processes. The manufacturer’s revenue is determined by the minimum of the uptimes among the processes. The maintenance functions of the processes are outsourced to independent contractors so that each contractor is responsible only for one process. A performance-based incentive contract is offered to each contractor, consisting of an uptime target level and a bonus rate for exceeding the uptime target. Under the incentive contract, a contractor receives a bonus only when the achieved uptime exceeds the target level specified in the contract. We develop a model for jointly ...


Insisting On Truth At The Expense Of Conceptualization: Can Engineering Portfolios Help?, Ozgur Eris Dec 2005

Insisting On Truth At The Expense Of Conceptualization: Can Engineering Portfolios Help?, Ozgur Eris

Ozgur Eris

Teaching and promoting conceptual thinking in engineering education is challenging. Two recently introduced design thinking models are compared in order to explore the reasons behind this challenge. The comparison results in key distinctions between divergent and convergent thinking, and between concept and knowledge domains. The differentiating principle is shown to be a common principle of the two models, truth-value, or logical status, of the propositions that engineers make. Building on this insight, divergent thinking by inquiry is identified as a mechanism for promoting conceptual thinking, and a specific implementation of engineering portfolios is proposed as a pedagogical tool.


Incentive Maintenance Outsourcing Contracts For Channel Coordination And Improvement, Hakan Tarakci, Kwei Tang, Herb Moskowitz, Robert Plante Dec 2005

Incentive Maintenance Outsourcing Contracts For Channel Coordination And Improvement, Hakan Tarakci, Kwei Tang, Herb Moskowitz, Robert Plante

Hakan Tarakci

Consider a manufacturer who has a process with an increasing failure rate over time. In order to improve the process performance, the following two types of maintenance activity are outsourced to an external contractor: (i) preventive maintenance is performed periodically to improve the reliability of the process when the process is functional; and (ii) corrective maintenance is used to restore the process to a specified condition when it fails. We consider the use of incentive contracts to induce the contractor to select the maintenance policy that optimizes the total profit of the manufacturer and contractor. It is demonstrated that an ...


Cluster Treatment Of Characteristic Roots, Ctcr, A Unique Methodology For The Complete Robustness Analysis Of Linear Time Invariant Multiple Time Delay Systems Against Delay Uncertainties, Rifat Sipahi Dec 2004

Cluster Treatment Of Characteristic Roots, Ctcr, A Unique Methodology For The Complete Robustness Analysis Of Linear Time Invariant Multiple Time Delay Systems Against Delay Uncertainties, Rifat Sipahi

Rifat Sipahi

Today, many high-tech applications such as simultaneous metal machining, neural networks, internet data congestion, population dynamics, chemical processes, formation flight problems, etc., appear in the form of multiple time delay systems (MTDS ). Due to the presence of delays, the stability of the dynamics is under question and needs to be addressed. In the last four decades, the stability analysis of the general class, Linear Time Invariant MTDS (LTI-MTDS), has been one of the challenging problems of the systems and control community, which originates from the complex stability analysis due to their infinite dimensionality. For tackling this, a unique procedure is ...