Decision-making is becoming increasingly complex as data expands and
resources decrease. My research centers on using prescriptive
(integer optimization) and predictive (machine learning) analytics,
together with algorithms, to effectively allocate scarce resources.
My research team and I employ mathematical modeling and the
development of methods and tools to benefit vulnerable and
marginalized individuals, groups, and populations.
The convergence of novel analytical technologies and open-source software can create solutions that improve quality of life, increase fairness, restore dignity, and make significant societal impact. Active research areas include analytics to benefit refugees and asylum seekers, survivors of human trafficking, and foster care. My research is supported by the National Science Foundation (Operations Engineering) grants CMMI-1825348, CMMI-1841893, CMMI-1935602, the Ragnar Söderberg Foundation, and others.
My research deeply influences students. Students who work with me learn the tools and techniques to develop innovative models and algorithms to tackle challenging real-world problems with significant societal impact. Through research involvement and related projects, students make contributions that expand the current boundaries of knowledge. Many earn MS and PhD degrees and go on to have productive and influential careers. If you are interested in learning more, see my CV, or email me.
I am Associate Professor of Operations and Industrial Engineering at WPI, and hold a Ph.D. in Industrial Engineering from the University of Pittsburgh. I publish in journals such as Operations Research, INFORMS Journal on Computing, European Journal of Operational Research, IISE Transactions, Decision Support Systems, Discrete Optimization, IJCAI, Socio-Economic Planning Sciences, Journal of Cleaner Production, Journal of Combinatorial Optimization, Health Systems, and Bioinformatics.
Excellent PhD student Pitchaya Wiratchotisatian and I recently submitted a manuscript "A Reformulation Technique to Solve Polynomial Optimization Problems with Separable Objective Functions of Bounded Integer Variables." We explore novel reformulations of a class of polynomial integer optimization problems having separable objective functions of bounded integer variables. I particularly like this work due to an algebraic identity we leverage to reformulate polynomial functions of bounded integer variables into integer linear expressions that are amenable to integer optimization solvers. And it works! We demonstrate strong performance on fairly large test instances. Hope you enjoy reading!Read More
A recent manuscript has been accepted at Production and Operations Management (FT Top 50 Outlet!) on how to efficiently allocate aid to refugee camp systems under uncertainty, coauthored with senior WPI Operations PhD candidate Shima Azizi, as well as Ozyegin PhD student Cem Deniz Caglar Bozkir, Ozyegin Professor O. Erhun Kundakcioglu, and Northwestern PhD student Ali Kaan Kurbanzade. We are grateful to the thoughtful comments of the editorial team that improved the paper, as well as National Science Foundation Operations Engineering program for their support of this research (award number 1825348).Read Preprint
It's so rewarding to see the great work of students be recognized! Newly graduated WPI IE senior Johanna (Joey) Whitwell was given a shout out by Worcester Polytechnic Institute President Laurie Leshin at the 2021 commencement ceremony. Joey was featured for her work with me in developing methods to match refugees to safe, stable employment options in Mexico City with amazing nonprofit INTRARE.Watch Clip
Our conference paper Dynamic Placement in Refugee Resettlement with Narges Ahani, Paul Gölz, Ariel Procaccia, and Alex Teytelboym was recently accepted for the 2021 ACM conference on Economics and Computation. We introduce a dynamic allocation system based on two-stage stochastic programming to account for weekly allocations of annual capacity. The approach further improves employment outcomes over our paper Placement Optimization in Refugee Resettlement. We are grateful to the National Science Foundation Operations Engineering program for their support of this research (award number 1825348).Download Preprint
Aleksandr Kazachkov and Elias Khalil are doing an amazing job of organizing the Discrete Optimization Talks (DOTs) series. There are a number of really great talks in the DOTs series, and I'm honored to be among them! My recent talk on new stability representations for many-to-one matching via integer optimization, which is joint work with great colleagues Pitchaya Wiratchotisatian and Hoda Atef-Yekta, is now up at here, where you can also see all of the previous talks in the series.Link to DOT Talk
I have the honor of serving as President-Elect for the INFORMS Section on Public Sector Operations Research (PSOR). We are the INFORMS subdivision dedicated to, in the words of the INFORMS slogan, "doing good with good OR." Here are all of this year's officers, with a hat tip to Phebe Vayanos who assembled the figure and is serving as the PSOR Communications Officer.PSOR Officers
Our manuscript Placement Optimization in Refugee Resettlement with outstanding colleagues and WPI Data Science PhD student Narges Ahani, Tommy Andersson, Alessandro Martinello, and Alex Teytelboym is now available online at Operations Research. We use analytics, specifically integer optimization and machine learning, to improve refugee resettlement. Our paper includes a case study with the US resettlement agency HIAS where we deploy Annie™ MOORE, the software tool we develop and describe that can sort through vast refugee-host matching possibilities to optimize integration outcomes. We are grateful to the National Science Foundation Operations Engineering program for their support of this research (award number 1825348).Download Preprint
Super proud of the hard work and dedication of my PhD student Pitchaya Wiratchotisatian on her most recent manuscript "A Comparative Study of Stability Representations for Solving Many-to-One Matching Problems with Ties and Incomplete Lists via Integer Optimization", together with Hoda Atef Yekta. Here we explore novel representations for stability in solving stable many-to-one matching problems, including the construction of cohorts. Enjoy the read!Read More
I recently learned that I am among this year's list of Academic Data Leaders at Chief Data Officer Magazine. Certainly an honor! Thank you, CDO Magazine.Read More
Here is a recent technical report posted to Optimization Online on community medicine: how to select, route, and schedule medical workers to visit patients in the community. This research was led by WPI Operations PhD student Shima Azizi, in collaboration with Brenton Faber, Sharon Johnson, Renata Konrad, and myself. This study is the first optimization-based framework for programmatically operating community paramedicine and derives insights into the model's behavior by conducting comprehensive analytical experiments on test instances based on real data. We are grateful to WPI's Healthcare Delivery Institute for their support.Read More
Recently published paper at Transportation Research Part D with excellent colleagues Irina Harris and Vasco Sanchez Rodrigues at Cardiff Business School, as well as Joe Sarkis at WPI. We study the effects of coopetition in maritime logistics, specifically container shipping. Using realistic data from two major retailers, we develop a novel integer optimization model that allocates goods to containers, and containers to vessels, in a manner that minimizes both traditional economic costs as well as environmental costs, and provide analyses and insights. We believe our research sets the stage for future investigations.Read More
A nice opinion piece about how to conduct responsible anti-human trafficking research in operation and analytics, with excellent colleagues R. A. Konrad and K. Maass. Very grateful for the support of the National Science Foundation Operations Engineering program (award numbers 1841893 and 1935602).Download from arXiv
A recent UN report describes in its "Anti-Slavery Agenda of Tomorrow" section some recent work with K. Maass and R. A. Konrad. It reads Computational analysis may be useful to this end, for example in optimizing resource allocation to ensure maximum social impact. We are grateful for the support of the National Science Foundation Operations Engineering program (award number 1841893).Download Report
A recently accepted manuscript is now available online at Omega: W. Liu, A. C. Trapp, S. Djamasbi, "Outlier-Aware, Density-Based Gaze Fixation Identification," available online, Omega, 2020.Read Preprint
A recent manuscript was published and is now available online at JORS:
A. C. Trapp, R. A. Konrad, J. Sarkis, Amy Z. Zeng, Closing the Loop: Forging High Quality Agile Virtual Enterprises in a Reverse Supply Chain via Solution Portfolios, Journal of the Operational Research Society, 2020.Read Preprint
Here is a recent preprint joint with excellent coauthors Pat Flaherty (UMass Amherst), WPI Data Science PhD student Pitchaya Wiratchotisatian, UMass Amherst PhD student Ji Ah Lee, and UMass Amherst PhD student Zhou Tang on solving the maximum a-posteriori (MAP) clustering problem under the Gaussian mixture model. We develop exact approaches to solve this problem using mixed-integer nonlinear optimization techniques.Read More
Here is a recent policy article by esteemed colleague Tommy Andersson urging the European Union to adopt AI-based matching of refugees to host communities. Tommy is a key collaborator on Annie™ MOORE, our software tool that can sort through vast refugee-host matching possibilities to optimize integration outcomes.Read More
Forbes Magazine recently featured an article with a vignette on joint work with terrific colleagues Alex Teytelboym, Alessandro Martinello, Tommy Andersson, and WPI Data Science PhD student Narges Ahani on using analytics to improve refugee resettlement. We appreciate the attention to detail, as they note that our matching software Annie™ MOORE recommends match outcomes, that can then be fine-tuned by resettlement decision-makers. The associated technical report can be found at this link. We are grateful to the National Science Foundation (NSF), especially the Operations Engineering program, for their support of this research.Read More
Good news: PhD student Shima Azizi passed her qualifier this week! We are all very proud of her hard work on the topic of improving efficiency in community paramedicine. I'm grateful for both committee members, Prof. Michael Ginzberg and Prof. Sharon Johnson (pictured), as well as Prof. Brent Faber and Prof. Renata Konrad, for their support.Read More
I had the privilege of visiting the University of Toronto and speaking in their Operations Research Seminar on refugee resettlement research, joint with colleagues Narges Ahani, Tommy Andersson, Paul Gölz, Alessandro Martinello, Ariel Procaccia, and Alex Teytelboym. Thanks to Tim Chan for the invitation!Read More
Had the opportunity to present on placement optimization in refugee resettlement at the INFORMS Speaker Series of the Isenberg School of Management, University of Massachusetts Amherst. This is joint work with Alex Teytelboym, Alessandro Martinello, Tommy Andersson, and Narges Ahani.Read More
Here is a short video clip of my lightning talk presentation for the "Global Impact: The Latin American Experience" series at WPI's 2019 Arts & Sciences Week. My talk was entitled: Developing Data-Informed Holding and Judicial Capacity Levels for Asylum Seekers at the Southern Border.Watch here!
Had the privilege of speaking with Laurie Leshin, President of WPI, about the work of my research team and I in improving refugee resettlement matching, as well as matching WPI students to project centers.Read More
R. A. Konrad (PI), A. C. Trapp (co-PI), M. Dank (co-PI), K. Maass (co-PI), NSF (Operations Engineering) award "ISN2: Disrupting Human Trafficking via Needs Matching and Capacity Expansion," Research award CMMI-1935602Read More
K. Maass, A. C. Trapp, R. A. Konrad, "Optimizing Placement of Residential Shelters for Human Trafficking Survivors" accepted for publication, Socio-Economic Planning Sciences, 2019.Read More
A. C. Trapp, NSF (Operations Engineering) supplement award to "Matching Problems in Refugee Resettlement," Research award CMMI-1825348: "Extension of Immigration Study to Operational Challenges at the United States Southern Border,"Read More
F. Zhang, C. Wang, A. C. Trapp, P. Flaherty, A Global Optimization Algorithm for Sparse Mixed Membership Matrix Factorization, New Advances in Statistics and Data Science, ICSA Book Series in Statistics, Springer, pp. 129-156, 2019.Read More
I had the privilege of visiting Middle Eastern Technical University (METU) and giving a seminar to their IE group on refugee resettlement research, joint with colleagues
R. A. Konrad (PI), A. C. Trapp (co-PI), M. Dank (co-PI), K. Maass (co-PI), NSF (Operations Engineering) award "EAGER: ISN: A Data Analytic Approach to Understanding Human Trafficking Networks," Research award CMMI-1841893Read More
T. Petit, A. C. Trapp, "Enriching Solutions to Combinatorial Problems via Solution Engineering" published online, INFORMS Journal on Computing, 2019Read More
A. C. Trapp, W. Liu, S. Djamasbi, "Identifying Fixations in Gaze Data via Inner-Density and Optimization" published online, INFORMS Journal on Computing, 2019.Read More
M. Shojaiezadeh, S. Djamasbi, R. Paffenroth, A. C.Trapp, "Detecting Task Demand via an Eye Tracking Machine Learning System" Decision Support Systems, Vol. 116, pp. 91-101, 2019.Read More
A. C. Trapp, A. Teytelboym, N. Ahani, T. Andersson, "Refugee Resettlement via Machine Learning and Integer Optimization," Keynote Presentation and Paper for OR60 Annual Conference, Lancaster, UK, 2018.Read More
R. A. Konrad, A. C. Trapp, T. Palmbach, J. S. Blom, "Overcoming Human Trafficking via Operations Research and Analytics: Opportunities for Methods, Models, and Applications," European Journal of Operational Research, Vol. 259 (2), pp. 733-745, 2017.