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

Similarity Evaluation Of Topography Measurement Results By Different Optical Metrology Technologies For Additive Manufactured Parts, Yi Zheng, Xiao Zhang, Shaodong Wang, Qing Li, Hantang Qin, Beiwen Li Mar 2020

Similarity Evaluation Of Topography Measurement Results By Different Optical Metrology Technologies For Additive Manufactured Parts, Yi Zheng, Xiao Zhang, Shaodong Wang, Qing Li, Hantang Qin, Beiwen Li

Industrial and Manufacturing Systems Engineering Publications

The surface topographic measurements can be used by the additive manufacturing (AM) industry for in-situ quality inspection. However, disagreements may arise when we use different technologies to measure the topography of the same sample surface due to noise, sampling or optical properties of the sample surface, which may cause miscommunications or confusions between manufacturers. Thus, proposing methods for rating the similarities to match surface topographic data measured by various optical techniques is of crucial importance. This research investigates similarity evaluation methods for three-dimensional point-cloud topography data acquired by different technologies. Two different optical techniques (focus variation microscopy and structured light ...


Evaluation Of An Intelligent Team Tutoring System For A Collaborative Two-Person Problem: Surveillance, Alec Ostrander, Desmond Bonner, Jamiahus Walton, Anna Slavina, Kaitlyn M. Ouverson, Adam Kohl, Stephen Gilbert, Michael Dorneich, Anne Sinatra, Eliot H. Winer Jan 2019

Evaluation Of An Intelligent Team Tutoring System For A Collaborative Two-Person Problem: Surveillance, Alec Ostrander, Desmond Bonner, Jamiahus Walton, Anna Slavina, Kaitlyn M. Ouverson, Adam Kohl, Stephen Gilbert, Michael Dorneich, Anne Sinatra, Eliot H. Winer

Industrial and Manufacturing Systems Engineering Publications

This paper describes the development and evaluation of an Intelligent Team Tutoring System (ITTS) for pairs of learners working collaboratively to monitor an area. In the Surveillance Team Tutor (STT), learners performed a surveillance task in a virtual environment, communicating to track hostile moving soldiers. This collaborative problem solving task required significant communication to achieve the common goal of perfect surveillance. In a pilot evaluation, 16 two-person teams performed the task within one of three feedback conditions (Individual, Team, or None) across four trials each. The STT used a unique approach to filtering feedback so that teams in both individual ...


A Multi-Stage Optimization Model For Flexibility In Engineering Design, Ramin Giahi, Cameron A. Mackenzie, Chao Hu Jan 2019

A Multi-Stage Optimization Model For Flexibility In Engineering Design, Ramin Giahi, Cameron A. Mackenzie, Chao Hu

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Engineered systems often operate in uncertain environments. Understanding different environments under which a system will operate is important in engineering design. Thus, there is a need to design systems with the capability to respond to future changes. This research explores designing a hybrid renewable energy system while taking into account long-range uncertainties of 20 years. The objective is to minimize the expected cost of the hybrid renewable energy system over the next 20 years. A design solution may be flexible, which means that the design can be adapted or modified to meet different scenarios in the future. The value of ...


Statistical Reliability Of Wind Power Scenarios And Stochastic Unit Commitment Cost, Didem Sari, Sarah M. Ryan Nov 2018

Statistical Reliability Of Wind Power Scenarios And Stochastic Unit Commitment Cost, Didem Sari, Sarah M. Ryan

Industrial and Manufacturing Systems Engineering Publications

Probabilistic wind power scenarios constitute a crucial input for stochastic day-ahead unit commitment in power systems with deep penetration of wind generation. To minimize the cost of implemented solutions, the scenario time series of wind power amounts available should accurately represent the stochastic process for available wind power as it is estimated on the day ahead. The high computational demands of stochastic programming motivate a search for ways to evaluate scenarios without extensively simulating the stochastic unit commitment procedure. The statistical reliability of wind power scenario sets can be assessed by approaches extended from ensemble forecast verification. We examine the ...


Evidence Of Problem Exploration In Creative Designs, Jaryn A. Studer, Shanna R. Daly, Seda Mckilligan, Colleen M. Seifert Nov 2018

Evidence Of Problem Exploration In Creative Designs, Jaryn A. Studer, Shanna R. Daly, Seda Mckilligan, Colleen M. Seifert

Industrial Design Publications

Design problems are often presented as structured briefs with detailed constraints and requirements, suggesting a fixed definition. However, past studies have identified the importance of exploring design problems for creative design outcomes. Previous protocol studies of designers has shown that problems can “co-evolve” with the development of solutions during the design process. But to date, little evidence has been provided about howdesigners systematically explore presented problems to create better solutions. In this study, we conducted a qualitative analysis of 252 design problems collected from publically available sources, including award-winning product designs and open-source design competitions. This database offers an independent ...


Optimizing Design For Resilience For Risk-Averse Firms Using Expected Utility And Value-At-Risk, Ramin Giahi, Cameron A. Mackenzie, Chao Hu May 2018

Optimizing Design For Resilience For Risk-Averse Firms Using Expected Utility And Value-At-Risk, Ramin Giahi, Cameron A. Mackenzie, Chao Hu

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Research Problem •Determine how resilience should be integrated into a firm’s design decisions •Optimize design for a risk-averse firm that incorporates resilience


Online Testing To Assess Performance Of Students In A Large Engineering Class, Vrishtee Rane, Cameron A. Mackenzie May 2018

Online Testing To Assess Performance Of Students In A Large Engineering Class, Vrishtee Rane, Cameron A. Mackenzie

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Fall 2017: Engineering Economic Analysis course •242 students: in-class and distance learning •New assessment procedure: Online testing modules •7 required online testing modules •2 bonus testing modules to earn an A •Semester grades determined completely by number of modules passed •Unlimited number of attempts for each testing module •Randomly chosen questions


Modeling Uncertainty In Rooftop Pv Investment, Anuj Mittal, Cameron A. Mackenzie, Caroline C. Krejci, Taylor B. Elkins May 2018

Modeling Uncertainty In Rooftop Pv Investment, Anuj Mittal, Cameron A. Mackenzie, Caroline C. Krejci, Taylor B. Elkins

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

No abstract provided.


Supply Chain Risk Analysis Using Dynamic Fault Tree, Xue Lei, Cameron A. Mackenzie May 2018

Supply Chain Risk Analysis Using Dynamic Fault Tree, Xue Lei, Cameron A. Mackenzie

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Outline: 1. Motivations 2. Main-backup supply chain 3. Mutual-assistance supply chain 4. Conclusions


Decision Making For Different Types Of Variation In A Manufacturing System, Xue Lei, Cameron A. Mackenzie, Caroline Krejci May 2018

Decision Making For Different Types Of Variation In A Manufacturing System, Xue Lei, Cameron A. Mackenzie, Caroline Krejci

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Common cause variation: Natural part of the process; Acting on process.

Special cause variation: From external sources; searching and mitigating causes.


Design Optimization Under Long-Range Uncertainty, Ramin Giahi, Cameron A. Mackenzie, Chao Hu May 2018

Design Optimization Under Long-Range Uncertainty, Ramin Giahi, Cameron A. Mackenzie, Chao Hu

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Flexibility in engineering system design: •Flexibility in system design and implications for aerospace systems (Saleh et.al 2003) •A flexible and robust approach for preliminary engineering design based on designer's preference (Nahmet.al, 2007) •A real options approach to hybrid electric vehicle architecture design for flexibility (Kang et.al 2016) •Our research: •Simulation optimization •Long range uncertainty •Add flexibility and robustness to design


A Multi-Stage Stochastic Programming For Lot-Sizing And Scheduling Under Demand Uncertainty, Zhengyang Hu, Guiping Hu May 2018

A Multi-Stage Stochastic Programming For Lot-Sizing And Scheduling Under Demand Uncertainty, Zhengyang Hu, Guiping Hu

Industrial and Manufacturing Systems Engineering Publications

A stochastic lot-sizing and scheduling problem with demand uncertainty is studied in this paper. Lot-sizing determines the batch size for each product and scheduling decides the sequence of production. A multi-stage stochastic programming model is developed to minimize overall system costs including production cost, setup cost, inventory cost and backlog cost. We aim to find the optimal production sequence and resource allocation decisions. Demand uncertainty is represented by scenario trees using moment matching technique. Scenario reduction is used to select scenarios with the best representation of original set. A case study based on a manufacturing company has been conducted to ...


Application Of Bayesian Belief Network For Agile Kanban Backlog Estimation, Eric D. Weflen, Kevin Korniejczuk, Sharon Lau, Steven S. Kryk, Cameron A. Mackenzie, Iris V. Rivero Jan 2018

Application Of Bayesian Belief Network For Agile Kanban Backlog Estimation, Eric D. Weflen, Kevin Korniejczuk, Sharon Lau, Steven S. Kryk, Cameron A. Mackenzie, Iris V. Rivero

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

What is Agile Kanban?

  • Different from Kanban for JIT manufacturing!
  • Visualization of workflow
  • Limit work in process (WIP)


A Design Framework For Additive Manufacturing Through The Synergistic Use Of Axiomatic Design Theory And Triz, Sarath C. Renjith, Gül E. Okudan Kremer, Kijung Park Jan 2018

A Design Framework For Additive Manufacturing Through The Synergistic Use Of Axiomatic Design Theory And Triz, Sarath C. Renjith, Gül E. Okudan Kremer, Kijung Park

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Additive manufacturing has emerged as an integral part of modern manufacturing because of its unique capabilities for rapid prototyping and the design flexibility. In order to take full advantage of additive manufacturing, Design for Additive Manufacturing (DfAM) has risen to provide design frameworks, methodologies, and a set of guidelines for effective product designs under additive manufacturing. However, the existing DfAM methods have limitations in that most methods rely on either too general or too specific design requirements and parameters for additive manufacturing; an effective design framework that can consider the capabilities and constraints of additive manufacturing at an early design ...


3d Perception-Based Collision-Free Robotic Leaf Probing For Automated Indoor Plant Phenotyping, Yin Bao, Dylan Shah, Lie Tang Jan 2018

3d Perception-Based Collision-Free Robotic Leaf Probing For Automated Indoor Plant Phenotyping, Yin Bao, Dylan Shah, Lie Tang

Agricultural and Biosystems Engineering Publications

Various instrumentation devices for plant physiology study such as spectrometer, chlorophyll fluorimeter, and Raman spectroscopy sensor require accurate placement of their sensor probes toward the leaf surface to meet specific requirements of probe-to-target distance and orientation. In this work, a Kinect V2 sensor, a high-precision 2D laser profilometer, and a six-axis robotic manipulator were used to automate the leaf probing task. The relatively wide field of view and high resolution of Kinect V2 allowed rapid capture of the full 3D environment in front of the robot. The location and size of each plant were estimated by k-means clustering where “k ...


An Investigation On Selected Factors That Cause Variability In Additive Manufacturing, Anusha Velineni, Elif Elçin Günay, Kijung Park, Gül E. Okudan Kremer, Thomas M. Schnieders, Richard T. Stone Jan 2018

An Investigation On Selected Factors That Cause Variability In Additive Manufacturing, Anusha Velineni, Elif Elçin Günay, Kijung Park, Gül E. Okudan Kremer, Thomas M. Schnieders, Richard T. Stone

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Additive manufacturing (AM) brings significant freedom in design, yet it can get hard to produce the same part at identical dimensional tolerances; this is also known as the reproducibility problem. Reproducibility, the ability to produce the same part under similar conditions, is one of the major challenges in AM as reproducibility plays an important role in the replacement of worn-out or damaged parts in an assembly. The objective of this paper is to identify the impacts of two most common factors (i.e., layer thickness and printing speed) on the dimensional accuracy of additively manufactured parts through a designed experiment ...


A Design For Affordances Framework For Product Packaging: Food Packaging Case Study, Ahmad Abdelhafiz Mumani, Richard T. Stone, Esraa Abdelall Jan 2018

A Design For Affordances Framework For Product Packaging: Food Packaging Case Study, Ahmad Abdelhafiz Mumani, Richard T. Stone, Esraa Abdelall

Industrial and Manufacturing Systems Engineering Publications

Since affordances provided by packaging features play a major role in facilitating user packaging interaction, it is important to integrate the concept of affordances into the packaging design process and to understand the interrelationships between packaging features and affordances. A framework is proposed for linking user requirements to packaging design features utilizing the concept of affordances. The framework is accomplished in two main steps; first, determine the affordances required to facilitate performing packaging-related tasks, and second, link these affordances to packaging features. Previous packaging usability studies were reviewed to elicit requirements in terms of affordance properties such as intuitiveness, responsiveness ...


Sequential Exploration-Exploitation With Dynamic Trade-Off For Efficient Reliability Analysis Of Complex Engineered Systems, Mohammadkazem Sadoughi, Chao Hu, Cameron A. Mackenzie, Amin Toghi Eshghi, Soobum Lee Jul 2017

Sequential Exploration-Exploitation With Dynamic Trade-Off For Efficient Reliability Analysis Of Complex Engineered Systems, Mohammadkazem Sadoughi, Chao Hu, Cameron A. Mackenzie, Amin Toghi Eshghi, Soobum Lee

Industrial and Manufacturing Systems Engineering Publications

A new sequential sampling method, named sequential exploration-exploitation with dynamic trade-off (SEEDT), is proposed for reliability analysis of complex engineered systems involving high dimensionality and a wide range of reliability levels. The proposed SEEDT method is built based on the ideas of two previously developed sequential Kriging reliability methods, namely efficient global reliability analysis (EGRA) and maximum confidence enhancement (MCE) methods. It employs Kriging-based sequential sampling to build a surrogate model (i.e., Kriging model) that approximates the performance function of an engineered system, and performs Monte Carlo simulation on the surrogate model for reliability analysis. A new acquisition function ...


Comparing Visual Assembly Aids For Augmented Reality Work Instructions, Anastacia Macallister, Melynda Hoover, Stephen Gilbert, James Oliver, Rafael Radkowski, Timothy Garrett, Joseph Holub, Eliot Winer, Scott Terry, Paul Davies Jan 2017

Comparing Visual Assembly Aids For Augmented Reality Work Instructions, Anastacia Macallister, Melynda Hoover, Stephen Gilbert, James Oliver, Rafael Radkowski, Timothy Garrett, Joseph Holub, Eliot Winer, Scott Terry, Paul Davies

Mechanical Engineering Conference Presentations, Papers, and Proceedings

Increased product complexity and the focus on zero defects, especially when manufacturing complex engineered products, means new tools are required for helping workers conduct challenging assembly tasks. Augmented reality (AR) has shown considerable promise in delivering work instructions over traditional methods. Many proof-of-concept systems have demonstrated the feasibility of AR but little work has been devoted to understanding how users perceive different AR work instruction interface elements. This paper presents a between-subjects study looking at how interface elements for object depth placement in a scene impact a user’s ability to quickly and accurately assemble a mock aircraft wing in ...


The Challenges Of Building Intelligent Tutoring Systems For Teams, Desmond Bonner, Stephen B. Gilbert, Michael C. Dorneich, Eliot Winer, Anne M. Sinatra, Anna Slavina, Anastacia Macallister, Joseph Holub Sep 2016

The Challenges Of Building Intelligent Tutoring Systems For Teams, Desmond Bonner, Stephen B. Gilbert, Michael C. Dorneich, Eliot Winer, Anne M. Sinatra, Anna Slavina, Anastacia Macallister, Joseph Holub

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Intelligent Tutoring Systems have been useful for individual instruction and training, but have not been widely created for teams, despite the widespread use of team training and learning in groups. This paper reviews two projects that developed team tutors: the Team Multiple Errands Task (TMET) and the Recon Task developed using the Generalized Intelligent Framework for Tutoring (GIFT). Specifically, this paper 1) analyzes why team tasks have significantly more complexity than an individual task, 2) describes the two team-based platforms for team research, and 3) explores the complexities of team tutor authoring. Results include a recommended process for authoring a ...


Homcam: A Wireless 360-Degree Wearable Streaming Camera For Remote Situational Awareness, Brian Peck, Stephen Gilbert, Eliot Winer, Robert Ray Sep 2016

Homcam: A Wireless 360-Degree Wearable Streaming Camera For Remote Situational Awareness, Brian Peck, Stephen Gilbert, Eliot Winer, Robert Ray

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

The growth of mobile and wearable technologies has enabled a host of new applications, including remote situational awareness, in which a device worn by a remote partner can simulate being present in the remote location for an observer. We illustrate this idea by constructing the HomCam, a helmet-based omnidirectional video system that gives an observer the 360-degree perspective of a remote wearer. To our knowledge, the HomCam was the first wearable system that enabled real-time streaming of 360-degree video to a remote location built from commercial-of-the-shelf hardware. This paper describes related efforts, the HomCam prototype, its visual display, and an ...


An Agricultural Harvest Knowledge Survey To Distinguish Types Of Expertise, Chase Meusel, Chase Grimm, Stephen B. Gilbert, Greg R. Luecke Sep 2016

An Agricultural Harvest Knowledge Survey To Distinguish Types Of Expertise, Chase Meusel, Chase Grimm, Stephen B. Gilbert, Greg R. Luecke

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Gaining insight into the unique characteristics of participants during user research is a valuable tool for both recruitment and understanding differences within the target population. This work describes an agricultural harvest knowledge survey that was created for user research studies that observed experienced combine operators driving a combine simulator in virtual crop fields. Two variations of the survey were designed, utilized, and evaluated in two separate studies. Both studies found a difference between low and high knowledge operators' performance on the knowledge survey in addition to performance differences. Based on the success of this survey as a population segmentation tool ...


Implementing Native Support For Oculus And Leap Motion In A Commercial Engineering Visualization And Analysis Platform, Anastacia Macallister, Siemens Plm Software, Eliot H. Winer Feb 2016

Implementing Native Support For Oculus And Leap Motion In A Commercial Engineering Visualization And Analysis Platform, Anastacia Macallister, Siemens Plm Software, Eliot H. Winer

Mechanical Engineering Publications

While previous research in academia points to the ability of Natural User Interfaces (NUIs) and low-cost display devices to help users better understand a design, there does not exist much research on how these devices can be integrated into existing legacy code used by engineering and design firms. The lack of commercial engineering software that integrates NUIs and low-cost display devices, like the Oculus Rift, can be attributed to the fast changing device market and the lack of awareness many engineering software makers show in emerging interaction paradigms. The lack of work in the area of integrating low-cost immersion devices ...


The Wear Scale: Developing A Measure Of The Social Acceptability Of A Wearable Device, Norene Kelly, Stephen B. Gilbert Jan 2016

The Wear Scale: Developing A Measure Of The Social Acceptability Of A Wearable Device, Norene Kelly, Stephen B. Gilbert

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

The factors affecting the social acceptability of wearable devices are not well understood, yet they have a strong influence on whether a new wearable succeeds or fails. Factors uniquely affecting wearable acceptability as compared to other technology include manners, moral codes, the symbolic communication of dress, habits of dress, fashion, context of use, form, and aesthetics. This paper describes the development of the WEarable Acceptability Range (WEAR Scale), designed to predict acceptance of a particular wearable. First, the construct "social acceptability of a wearable" was defined using literature and an interview study. Second, the WEAR Scale's item pool was ...


Ultrahard Polycrystalline Cubic Boron Nitride Composite Through Hybrid Laser/Waterjet Heat (Lwh) Treatment, Jingnan Zhao, Pranav Shrotriya Jan 2016

Ultrahard Polycrystalline Cubic Boron Nitride Composite Through Hybrid Laser/Waterjet Heat (Lwh) Treatment, Jingnan Zhao, Pranav Shrotriya

Mechanical Engineering Publications

Ultra-hard materials that are chemically inert and thermally stable at high temperatures are desirable for enhancing machining and wear performance in demanding chemical and thermal environments. Single and polycrystalline diamonds are the hardest tool materials; however, at high temperatures, diamond reacts with ferrous alloys, losing its chemical inertness and thermal stability. In contrast, cubic boron nitride (cBN) has exceptional chemical and thermal stability but has much lower hardness (35-45 GPa). Increasing the hardness of BN is expected to fill the property gap in state-of-the-art tool materials as shown and to generate huge industrial interest for meeting the stringent design requirements ...


The Hidden Challenges Of Team Tutor Development, Desmond Bonner, Anna Slavina, Anastacia Macallister, Joseph Holub, Stephen B. Gilbert, Anne M. Sinatra, Michael C. Dorneich, Eliot H. Winer Jan 2016

The Hidden Challenges Of Team Tutor Development, Desmond Bonner, Anna Slavina, Anastacia Macallister, Joseph Holub, Stephen B. Gilbert, Anne M. Sinatra, Michael C. Dorneich, Eliot H. Winer

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

This paper describes the unexpected challenges of team tutor development such as the task and logistics. Previously, a research team from Iowa State University (ISU) working with the U.S. Army Research Laboratory (ARL) developed the reconnaissance (Recon) task for simple team tutoring with the Generalized Intelligent Framework for Tutoring (GIFT) (Bonner et al., 2015; Gilbert et al., 2015). Considerations were included for the testing environment such as audio-based team interactions, initialization of the scenario simultaneously, and the inclusion of eyetracking and screen capture technology. Throughout the process of tutor development, several computational challenges have been encountered such as the ...


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 ...


Operator-Centered Task Analysis: A Hybrid Methodology For Human-Machine Interaction Observation In The Field, Chase Meusel, Norene Kelly, Stephen Gilbert, Michael Dorneich, Brian Gilmore, Bruce Newendorp Sep 2015

Operator-Centered Task Analysis: A Hybrid Methodology For Human-Machine Interaction Observation In The Field, Chase Meusel, Norene Kelly, Stephen Gilbert, Michael Dorneich, Brian Gilmore, Bruce Newendorp

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

The practice of human factors in agriculture presents numerous challenges for the researcher. Difficulties include measuring operator behaviors in the agricultural field as well as identifying individual tasks, order of tasks, length of tasks, and operator motivation for each task. To confidently build a baseline for how operators use and appropriate their resources during the planting agricultural season, a variety of qualitative and quantitative research methods were combined to create OCTA (operator-centered task analysis), a hybrid methodology to observe, document, explain, and potentially predict operator behaviors in the field. The OCTA model draws from four main methodologies: observation, interview, behavioral ...


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 ...


A Novel Framework For Visual Detection And Exploration Of Performance Bottlenecks In Organic Photovoltaic Solar Cell Materials, A. Aboulhassan, D. Baum, O. Wodo, Baskar Ganapathysubramanian, A. Amassian, M. Hadwiger Jan 2015

A Novel Framework For Visual Detection And Exploration Of Performance Bottlenecks In Organic Photovoltaic Solar Cell Materials, A. Aboulhassan, D. Baum, O. Wodo, Baskar Ganapathysubramanian, A. Amassian, M. Hadwiger

Mechanical Engineering Publications

Current characterization methods of the so-called Bulk Heterojunction (BHJ), which is the main material of Organic Photovoltaic (OPV) solar cells, are limited to the analysis of global fabrication parameters. This reduces the efficiency of the BHJ design process, since it misses critical information about the local performance bottlenecks in the morphology of the material. In this paper, we propose a novel framework that fills this gap through visual characterization and exploration of local structure-performance correlations. We also propose a formula that correlates the structural features with the performance bottlenecks. Since research into BHJ materials is highly multidisciplinary, our framework enables ...