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

A Hybrid Simulation Model Of Inbound Logistics Operations In Regional Food Supply Systems, Anuj Mittal, Caroline C. Krejci Dec 2015

A Hybrid Simulation Model Of Inbound Logistics Operations In Regional Food Supply Systems, Anuj Mittal, Caroline C. Krejci

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Regional food hubs aggregate, distribute, and market local food, with a goal of promoting environmental and social sustainability. They provide an alternative distribution channel through which small-scale producers can access wholesale markets. However, food hubs face many barriers to growth and success. In particular, they are often unable to achieve the logistical and operational efficiencies that characterize conventional large-scale food distribution. One possible method of improving food hub efficiency targets inbound logistics operations - specifically, the scheduling of producer deliveries to the food hub. In this paper, we describe a hybrid simulation model of the inbound logistics operations of a food ...


Stakeholders' Requirements Assessment For Biofuel Production, Mostafa F. Fawzy, Paul J. Componation, Guiping Hu Nov 2015

Stakeholders' Requirements Assessment For Biofuel Production, Mostafa F. Fawzy, Paul J. Componation, Guiping Hu

Industrial and Manufacturing Systems Engineering Publications

Biofuel is one of the alternatives transportation fuel to substitute petroleum in the United States. Fast pyrolysis, as one of the most promising thermochemical based advanced biofuel production techniques, has been brought to the forefront of biofuel industry. With limited information about the manufacturing of fast pyrolysis units, a thorough understanding of stakeholders' requirements is timely and necessary. This study develops a comprehensive analysis of stakeholders' requirements. Subject matter experts were interviewed to rank, review, and evaluate a set of requirements for a variety of fast pyrolysis unit sizes. The requirements with the evaluations were then used to determine the ...


Is Now A Good Time For Iowa To Invest In Cellulosic Biofuels? A Real Options Approach Considering Construction Lead Times, Yihua Li, Chung-Li Tseng, Guiping Hu Sep 2015

Is Now A Good Time For Iowa To Invest In Cellulosic Biofuels? A Real Options Approach Considering Construction Lead Times, Yihua Li, Chung-Li Tseng, Guiping Hu

Industrial and Manufacturing Systems Engineering Publications

The revised Renewable Fuel Standard of the U.S. mandates a production of 16 billion gallons per year by 2022 from cellulosic biofuels. Iowa, rich in agricultural residues like corn stover, is a major player in contributing to the fulfillment of the cellulosic biofuels mandate. Is it a good time for Iowa to start investing in cellulosic biofuels? Using a fast pyrolysis facility as an example, we present a real options approach for valuing the investment of a new technology for producing cellulosic biofuels subject to construction lead times and uncertain fuel price. We conduct a case study on Iowa ...


Techno-Economic Analysis Of Advanced Biofuel Production Based On Bio-Oil Gasification, Qi Li, Yanan Zhang, Guiping Hu Sep 2015

Techno-Economic Analysis Of Advanced Biofuel Production Based On Bio-Oil Gasification, Qi Li, Yanan Zhang, Guiping Hu

Industrial and Manufacturing Systems Engineering Publications

This paper evaluates the economic feasibility of a hybrid production pathway combining fast pyrolysis and bio-oil gasification. The conversion process is simulated with Aspen Plus® for a 2000 t d-1 facility. Techno-economic analysis of this fast pyrolysis and bio-oil gasification pathway has been conducted to assess the economic feasibility. A total capital investment of $438 million has been estimated and the minimum fuel selling price (MSP) is $5.6 per gallon of gasoline equivalent. The sensitivity analysis shows that the MSP is most sensitive to internal rate of return, fuel yield, biomass feedstock cost, and fixed capital investment. Monte-Carlo simulation ...


Characteristics Of A Multi-User Tutoring Architecture, Stephen B. Gilbert, Eliot H. Winer, Joseph Holub, Trevor Richardson, Michael C. Dorneich, Michael Hoffman Jun 2015

Characteristics Of A Multi-User Tutoring Architecture, Stephen B. Gilbert, Eliot H. Winer, Joseph Holub, Trevor Richardson, Michael C. Dorneich, Michael Hoffman

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Intelligent tutor systems have been quite successful in instruction of individuals (Koedinger, Anderson, Hadley, & Mark, 1997; Ritter, Kulikowich, Lei, McGuire, & Morgan, 2007; Vanlehn, et al., 2005), but multiple challenges exist when attempting to tutor a team. Sottilare, Holden, Brawner, and Goldberg (2011) describe some of the architectural challenges of team tutoring at a high level in terms of functional requirements. In this paper we describe specific challenges in terms of implementing a team architecture within the Generalized Intelligent Framework for Tutoring (GIFT), including simultaneous startup and synchronization with distributed team members, maintaining state of multiple users, and timing feedback for teams and individuals appropriately.


Integration Of Progressive Hedging And Dual Decomposition In Stochastic Integer Programs, Ge Guo, Gabriel Hackebeil, Sarah M. Ryan, Jean-Paul Watson, David L. Woodruff May 2015

Integration Of Progressive Hedging And Dual Decomposition In Stochastic Integer Programs, Ge Guo, Gabriel Hackebeil, Sarah M. Ryan, Jean-Paul Watson, David L. Woodruff

Industrial and Manufacturing Systems Engineering Publications

We present a method for integrating the Progressive Hedging (PH) algorithm and the Dual Decomposition (DD) algorithm of Carøe and Schultz for stochastic mixed-integer programs. Based on the correspondence between lower bounds obtained with PH and DD, a method to transform weights from PH to Lagrange multipliers in DD is found. Fast progress in early iterations of PH speeds up convergence of DD to an exact solution. We report computational results on server location and unit commitment instances.


Toward Scalable Stochastic Unit Commitment. Part 2: Solver Configuration And Performance Assessment, Kwok Cheung, Dinakar Gade, Cesar Silva-Monroy, Sarah M. Ryan, Jean-Paul Watson, Roger Wets, David L. Woodruff Apr 2015

Toward Scalable Stochastic Unit Commitment. Part 2: Solver Configuration And Performance Assessment, Kwok Cheung, Dinakar Gade, Cesar Silva-Monroy, Sarah M. Ryan, Jean-Paul Watson, Roger Wets, David L. Woodruff

Industrial and Manufacturing Systems Engineering Publications

In this second portion of a two-part analysis of a scalable computa- tional approach to stochastic unit commitment, we focus on solving stochastic mixed-integer programs in tractable run-times. Our solution technique is based on Rockafellar and Wets' progressive hedging algorithm, a scenario-based decomposi- tion strategy for solving stochastic programs. To achieve high-quality solutions in tractable run-times, we describe critical, novel customizations of the progressive hedging algorithm for stochastic unit commitment. Using a variant of the WECC- 240 test case with 85 thermal generation units, we demonstrate the ability of our approach to solve realistic, moderate-scale stochastic unit commitment problems with ...


Toward Scalable Stochastic Unit Commitment. Part 1: Load Scenario Generation, Yonghan Feng, Ignacio Rios, Sarah M. Ryan, Kai Spurkel, Jean-Paul Watson, Roger Wets, David L. Woodruff Apr 2015

Toward Scalable Stochastic Unit Commitment. Part 1: Load Scenario Generation, Yonghan Feng, Ignacio Rios, Sarah M. Ryan, Kai Spurkel, Jean-Paul Watson, Roger Wets, David L. Woodruff

Industrial and Manufacturing Systems Engineering Publications

Unit commitment decisions made in the day-ahead market and during subsequent reliability assessments are critically based on forecasts of load. Tra- ditional, deterministic unit commitment is based on point or expectation-based load forecasts. In contrast, stochastic unit commitment relies on multiple load sce- narios, with associated probabilities, that in aggregate capture the range of likely load time-series. The shift from point-based to scenario-based forecasting necessi- tates a shift in forecasting technologies, to provide accurate inputs to stochastic unit commitment. In this paper, we discuss a novel scenario generation method- ology for load forecasting in stochastic unit commitment, with application to ...


The Team Multiple Errands Test: A Platform To Evaluate Distributed Teams, Jamiahus Walton, Desmond Carletus Bonner, Kelsey Walker, Samantha Mater, Michael C. Dorneich, Stephen B. Gilbert, Robert West Mar 2015

The Team Multiple Errands Test: A Platform To Evaluate Distributed Teams, Jamiahus Walton, Desmond Carletus Bonner, Kelsey Walker, Samantha Mater, Michael C. Dorneich, Stephen B. Gilbert, Robert West

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Teams have the ability to achieve goals that are unobtainable by individuals alone. However, there is little agreement on a standard model for researching the performance of distributed teams. Initial pilot results suggest that the Multiple Errands Test (MET), when adapted to a team in a virtual environment, is a platform for evaluating the impact of feedback characteristics. To demonstrate the potential of the Team MET as a platform for future team research in the broader CSCW community, an example study is described in which team members are given feedback in one of four conditions: individual private, team private, individual ...


Evaluating Distributed Teams With The Team Multiple Errands Test, Jamiahus Walton, Stephen B. Gilbert, Eliot Winer, Michael C. Dorneich, Desmond Bonner Jan 2015

Evaluating Distributed Teams With The Team Multiple Errands Test, Jamiahus Walton, Stephen B. Gilbert, Eliot Winer, Michael C. Dorneich, Desmond Bonner

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Modern day teams, whether in the military or civilian workplace, have the ability to achieve goals that are otherwise unobtainable by individuals. The timing and characteristics of feedback that teams receive during training are critical. Though there is a solid foundation of research on optimal feedback, there is limited exploration of what constitutes ideal team feedback including addressing the individual team member versus the whole team and whether that feedback is public (visible to the entire team) or private (visible only to one member of the team). Previous research that studied the effect of feedback on team performance has yielded ...


Comparing Systems Engineering And Project Success In Commercial-Focused Versus Government-Focused Projects, Paul J. Componation, Michael C. Dorneich, Jordan L. Hansen Jan 2015

Comparing Systems Engineering And Project Success In Commercial-Focused Versus Government-Focused Projects, Paul J. Componation, Michael C. Dorneich, Jordan L. Hansen

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

This work looks at the relationship between systems engineering and project success industry lead in aerospace, agriculture, defense & security, energy and related areas. The projects included both commercial-focused and government-focused efforts. Differences were found in both the overall risk levels and the measures of success for the two groups. In addition, government-focused projects showed a notably larger number of significant relationships between system engineering processes and project success than the commercial-focused projects. The research notes that further investigation is warranted, in particular looking at individual industry sectors, exploring the impact of team dispersion, and developing a better understanding of interrelationships ...


Authoring Effective Embedded Tutors: An Overview Of The Extensible Problem Specific Tutor (Xpst) System, Stephen B. Gilbert, Stephen B. Blessing, Enruo Guo Jan 2015

Authoring Effective Embedded Tutors: An Overview Of The Extensible Problem Specific Tutor (Xpst) System, Stephen B. Gilbert, Stephen B. Blessing, Enruo Guo

Industrial and Manufacturing Systems Engineering Publications

The Extensible Problem Specific Tutor (xPST) allows authors who are not cognitive scientists and not programmers to quickly create an intelligent tutoring system that provides instruction akin to a model-tracing tutor. Furthermore, this instruction is overlaid on existing software, so that the learner’s interface does not have to be made from scratch. The xPST architecture allows for extending its capabilities by the addition of plug-ins that communicate with additional third-party software. After reviewing this general architecture, we describe three major implementations that we have created using the xPST system, each using different third-party software as the learner’s interface ...


Joint Downlink Base Station Association And Power Control For Max-Min Fairness: Computation And Complexity, Ruoyu Sun, Mingyi Hong, Zhi-Quan Luo Jan 2015

Joint Downlink Base Station Association And Power Control For Max-Min Fairness: Computation And Complexity, Ruoyu Sun, Mingyi Hong, Zhi-Quan Luo

Industrial and Manufacturing Systems Engineering Publications

In a heterogeneous network (HetNet) with a large number of low power base stations (BSs), proper user-BS association and power control is crucial to achieving desirable system performance. In this paper, we systematically study the joint BS association and power allocation problem for a downlink cellular network under the max-min fairness criterion. First, we show that this problem is NP-hard. Second, we show that the upper bound of the optimal value can be easily computed, and propose a two-stage algorithm to find a high-quality suboptimal solution. Simulation results show that the proposed algorithm is near-optimal in the high-SNR regime. Third ...


The Use Of Virtual Welding Simulators To Evaluate Experienced Welders, A.P. Byrd, R.G. Anderson, Richard Stone Jan 2015

The Use Of Virtual Welding Simulators To Evaluate Experienced Welders, A.P. Byrd, R.G. Anderson, Richard Stone

Industrial and Manufacturing Systems Engineering Publications

Virtual reality welding simulations have been, and continue to be, a trend in welding training programs. The goal of this study was to examine the use of virtual reality simulations as an assessment tool for existing welders. This study used a virtual reality welding simulator, VRTEX® 360, to assess the existing skills of experienced and trained novice welders. This study also used the shielded metal arc welding (SMAW) process to perform simple and complex welds. Performance was evaluated through a quality score, which was based on the following five welding parameters: arc length, position, work angle, travel angle, and travel ...


Using Conceptgrid As An Easy Authoring Technique To Check Natural Language Responses, Stephen B. Blessing, Shrenik Devasani, Stephen B. Gilbert, Jivko Sinapov Jan 2015

Using Conceptgrid As An Easy Authoring Technique To Check Natural Language Responses, Stephen B. Blessing, Shrenik Devasani, Stephen B. Gilbert, Jivko Sinapov

Industrial and Manufacturing Systems Engineering Publications

ConceptGrid provides a template-style approach to check natural language responses by students using a model-tracing style intelligent tutoring system. The tutor-author creates, using a web-based authoring system, a latticestyle structure that contains the set of required concepts that need to be in a student response. The author can also create just-in-time feedback based on the concepts present or absent in the student's response. ConceptGrid is integrated within the xPST authoring tool and was tested in two experiments, both of which show the efficacy of the technique to check student answers. The first study tested the tutor's effectiveness overall ...


Multi-Agent Distributed Optimization Via Inexact Consensus Admm, Tsung-Hui Chang, Mingyi Hong, Xiangfeng Wang Jan 2015

Multi-Agent Distributed Optimization Via Inexact Consensus Admm, Tsung-Hui Chang, Mingyi Hong, Xiangfeng Wang

Industrial and Manufacturing Systems Engineering Publications

Multi-agent distributed consensus optimization problems arise in many signal processing applications. Recently, the alternating direction method of multipliers (ADMM) has been used for solving this family of problems. ADMM based distributed optimization method is shown to have faster convergence rate compared with classic methods based on consensus subgradient, but can be computationally expensive, especially for problems with complicated structures or large dimensions. In this paper, we propose lowcomplexity algorithms that can reduce the overall computational cost of consensus ADMM by an order of magnitude for certain large-scale problems. Central to the proposed algorithms is the use of an inexact step ...


Evaluation Of The Impacts Of Governmental Policies On The Biofuels Supply Chain Design Under Uncertainty, Narges Kazemzadeh, Guiping Hu Jan 2015

Evaluation Of The Impacts Of Governmental Policies On The Biofuels Supply Chain Design Under Uncertainty, Narges Kazemzadeh, Guiping Hu

Industrial and Manufacturing Systems Engineering Publications

There is a growing interest in the use of biomass as a source of energy around the world. In the United States, the Renewable Fuel Standard (RFS) sets policies and mandates to support the production and consumption of biofuels. However, the uncertainties associated with the governmental and local policies and regulations on both production and consumption have imposed significant impacts on the biofuel supply chain network. This study aims to determine the optimal design of the biofuel supply chain to maximize annual profit under the impacts of governmental policies. In this study, two-stage stochastic programming models are developed in which ...


Allocating Resources To Enhance Resilience, With Application To Superstorm Sandy And An Electric Utility, Cameron A. Mackenzie, Christopher W. Zobel Jan 2015

Allocating Resources To Enhance Resilience, With Application To Superstorm Sandy And An Electric Utility, Cameron A. Mackenzie, Christopher W. Zobel

Industrial and Manufacturing Systems Engineering Publications

This article constructs a framework to help a decisionmaker allocate resources to increase his or her organization's resilience to a system disruption, where resilience is measured as a function of the average loss per unit time and the time needed to recover full functionality. Enhancing resilience prior to a disruption involves allocating resources from a fixed budget to reduce the value of one or both of these characteristics. We first look at characterizing the optimal resource allocations associated with several standard allocation functions. Because the resources are being allocated before the disruption, however, the initial loss and recovery time ...