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 transform the world around us. Active research areas include analytics to benefit refugees and asylum seekers, survivors of human trafficking, the homeless, and children in the foster care system. My research is supported by the National Science Foundation awards FW-HTF-2222713, CMMI-1825348, CMMI-1841893, CMMI-1935602, the T. Rowe Price Foundation, the France-Merrick Foundation, the Ragnar Söderberg Foundation, and others.
As a researcher, I have the honor of helping students develop the skills and knowledge they need to address some of the most pressing challenges facing our world. My students learn to create innovative models and algorithms that push the boundaries of current knowledge and make meaningful contributions. Many of them go on to earn advanced degrees and have successful, influential careers. If you want to learn more about how you can be a part of this exciting research, drop me a line via email.
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 outlets such as Operations Research, Production and Operations Management, INFORMS Journal on Computing, PLOS ONE, 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.
On June 2, 2023 WPI hosted the Innovations in Immigration Analytics Conference, co-chaired by Geri L. Dimas and Daniel Reichman. Over 80 persons attended to learn of how advanced analytics, intentionally designed, can positively affect areas of immigration including migration, refugee causes, and asylum.Read More
Our paper DiversiTree: A New Method to Efficiently Compute Diverse Sets of Near-Optimal Solutions to Mixed-Integer Optimization Problems with Izuwa Ahanor and Hugh Medal has been accepted at INFORMS Journal on Computing. We develop a new method for mixed-integer programs that emphasizes diversity in near-optimal solutions. Compared to existing methods, our approach significantly increases solution set diversity without sacrificing runtime. Our methods can be easily integrated into integer programming solvers to enhance solution diversity.Download Preprint
I had the pleasure of joining Dr. Yongjia Song of Clemson University and Dr. Karmel Shehadeh of Lehigh University for a recent IISE OR for Social Good podcast to discuss my work in using operations research and analytics to benefit vulnerable populations. It's a great honor to work with many dedicated and talented collaborators, including amazing students here at Worcester Polytechnic Institute, to advance these causes together, and I am grateful to have the opportunity to amplify their efforts. I hope you get a chance to listen in, and that together we can continue to build a brighter future.Listen!
Was proud to see the shout out on our refugee resettlement work on CNN! Annie™ MOORE is our refugee resettlement software named after the Irish woman Annie Moore from the late 1800s, who was the first immigrant to arrive on Ellis Island. Annie™ is developed for and used by HIAS, a leading American refugee resettlement agency, to resettle refugees in the United States. Grateful to the National Science Foundation Operations Engineering program for their support (award number 1825348).Read online
Our paper Dynamic Placement in Refugee Resettlement with Narges Ahani, Paul Gölz, Ariel Procaccia, and Alex Teytelboym has been accepted at Operations Research. We introduce a dynamic allocation mechanism based on stochastic programming that accounts for the value of future slots of capacity to inform resettlement decisions. The approach recovers over 99% of the hindsight optimal allocation as in Placement Optimization in Refugee Resettlement, and is used by HIAS, a leading American refugee resettlement agency. We are grateful to the National Science Foundation Operations Engineering program for their support (award number 1825348).Download Preprint
INFORMS interviewed me as the outgoing president of the INFORMS PSOR section. As I am passionate about improving outcomes for vulnerable populations and I shared about the wide range of public sector applications at PSOR. From combatting human trafficking to tackling governmental challenges and public health issues, PSOR has many impactful activities in using operations research and analytics for societal benefit.Watch Clip
Congratulations to my outstanding colleague and former student Pitchaya Wiratchotisatian for her great work on our joint manuscript "A Reformulation Technique to Linearize A Class of Polynomial Functions of Bounded Integer Variables". We present a mathematical reformulation technique that linearizes polynomial functions of integer variables of any degree, and shows through computational experiments that it is effective in solving large integer optimization problems, indicating its potential for real-world applications.
A link to a preprint is here. Enjoy reading!Read More
Congratulations to my outstanding colleagues, including WPI Data Science PhD candidate Geri L. Dimas, former WPI Industrial Engineering student Malak El Khalkhali, former Northeastern Industrial Engineering student Alex Bender, Northeastern Assistant Professor Kayse Lee Maass, WPI Associate Professor Renata A. Konrad, domain expert Jeff Blom, and WPI Professor Joe Zhu on our manuscript "Estimating Effectiveness of Identifying Human Trafficking via Data Envelopment Analysis". The article discusses the first application of data envelopment analysis (DEA) to evaluate the performance of transit monitoring stations at intercepting potential human-trafficking victims along the Nepal-India border, and recommends specific operational improvements based on our evaluation of station performance.
A link to a preprint is here. Enjoy reading!Read at IJAA
Congratulations to my outstanding colleagues, including WPI Associate Professor Renata A. Konrad, joint with Northeastern Assistant Professor Kayse Lee Maass, and WPI Data Science PhD candidate Geri L. Dimas, on our next manuscript "Perspectives on How to Conduct Responsible Anti-Human Trafficking Research in Operations and Analytics". Here we showcase Operations Research and Analytics can aid in combating human trafficking, with insights divided into three categories: representation of trafficking, survivor and community considerations, and analytics.
A link to a preprint is here. Enjoy reading!Read More
Together with amazing collaborators Alex Teytelboym and WPI Data Science students Ryan Killea and Fatemeh Farajzadeh, and in partnership with HIAS, we introduce RUTH: Refugees Uniting Through HIAS. RUTH is a new software platform that elicits preferences of Ukrainians displaced by the war, and then uses intentionally designed algorithms to recommend welcoming communities throughout the United States that honor the expressed preferences of refugees.Read More
We develop a new algorithmic framework for public sector decision making, joint with outstanding WPI undergraduate Frederick "Forrest" Miller, Northeastern IE PhD candidate Yaren Kaya, WPI Data Science PhD candidate Geri L. Dimas, Dr. Kayse Lee Maass, and Dr. Renata A. Konrad. Our framework optimizes the benefit to cost ratio of decision problems, exemplified through the challenge of expanding capacity for NYC's runaway and homeless youth shelter system, resulting in optimal marginal deployments of capacity that are both low-cost and efficient, and has potential for use in other public sector challenges.Read More
Way to go, Fatemeh Farajzadeh on our first joint manuscript "Optimization for Secure and Humane Border Operations". Here we explore that large migrant movements worldwide create complex humanitarian crises at national borders, and outline how advanced analytics and optimization techniques can be used to address common operational challenges and improve both security and humanitarian aspects of border operations.
A link to a preprint is here. Enjoy reading!Read More
Super proud of the hard work and dedication of Dr. Pitchaya Wiratchotisatian on her most recent manuscript "Stability Representations of Many-to-One Matching Problems An Integer Optimization Approach", together with sharp colleague Dr. Hoda Atef Yekta. Here we explore novel representations for stability in solving stable many-to-one matching problems, including the construction of cohorts.Read More
A recent manuscript has been accepted at IISE Transactions on how to project the collective capacity required by service providers to adequately meet the needs of RHY in NYC. This project was led from beginning to end by outstanding Northeastern Industrial Engineering PhD candidate Yaren Bilge Kaya, and joint with Northeastern Assistant Professor Kayse Lee Maass, WPI Data Science PhD candidate Geri L. Dimas, WPI Associate Professor Renata A. Konrad, and NYU Research Professor Meredith Dank.Read Preprint
I am PI on a new NSF RAPID award, with excellent colleague Sarah Stanlick (co-PI). This award will support pre-arrival and post-arrival data collection for refugees that have been relocated to the United States through the pathway of humanitarian parole. There is great potential for this data to inform context-appropriate matching systems to better serve needs. This is NSF RAPID award "RAPID: Data Collection for Designing Refugee Matching Systems," research award CMMI-2233377.Read More
A recent manuscript has been accepted at PLOS One that classifies the body of Operations Research and Analytics research related to the anti-human trafficking domain. It was led from start to finish by amazing WPI Data Science PhD candidate Geri L. Dimas, and joint with WPI Associate Professor Renata A. Konrad, and Northeastern Assistant Professor Kayse Lee Maass. 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 1841893 and1935602).Read full version
I am PI on a new NSF Future of Work award! We will use combinatorial optimization to exchange resources among participating nonprofit organizations to maximize total surplus value. This is with excellent colleagues: Jen Pazour (PI, RPI), Yunus Telliel (co-PI), and Sarah Stanlick (co-PI). This award is my largest thus far and lasts four years. While the anticipated theoretical and methodological contributions are exciting, just as exciting is the expected shaping of the nonprofit ecosystems to move from competing to sharing and empowering. This is NSF (FW-HTF) award "Collaborative Research: FW-HTF-R: Mobilizing Nonprofit Resources and Talents with a Community Tool for Purpose-Driven Work," award FW-HTF-2222713.Read More
Dr. Shima Azizi successfully defended her PhD dissertation entitled Mixed Integer Linear and Nonlinear Optimization for Disadvantaged Populations with Accents of Fairness and Balance focusing on the application of advanced integer linear and nonlinear optimization to improve outcomes for disadvantaged populations such as high needs emergency room utilizers, refugees, and foster care children. Many thanks to Shima's committee members Dr. Renata Konrad, Dr. Sharon Johnson, and Dr. Erhun Kundakcıoğlu for their consideration and contributions. Congrats, Shima! We are very glad that you have had a successful conclusion of this chapter of your career. We from the WPI community wish you the very best in your next steps! You have a bright future ahead of you.Read More
Dr. Narges Ahani successfully defended her PhD dissertation entitled Analytics for Refugee Resettlement and focusing on the application of advanced analytics, including machine learning and integer optimization, to improve refugee outcomes. We are grateful for committee members Dr. Randy Paffenroth, Dr. Osman Özaltın, and Dr. Alexander Teytelboym for their time and energy. We also thank the National Science Foundation (NSF) (Operations Engineering) grant CMMI-1825348, and others for supporting Narges on her journey. Congrats, Narges! We wish you well on the next chapter of your career! You have a bright and impactful career ahead.Read More
I was interviewed by INFORMS on the Ukrainian refugee crisis. As of late April 2022 there are over 5 millions refugees and 13 million displaced peoples in Ukraine. I shared thoughts on how intentional use of operations research and data science technologies like Annie™ MOORE can help with such crises.Listen!
This is a new manuscript with excellent coauthors Sophia Mantell, Yaren Bilge Kaya, Kayse Lee Maass, Renata Konrad, Geri L. Dimas, and Meredith Dank on the use of discrete event simulation to investigate runaway and homeless youth shelters and associated capacity shortages. We consider a realistic shelter setting in New York City and study various capacity interventions to alleviate resource scarcity.Read More
This is a new manuscript with excellent coauthors Izuwa Ahanor and Hugh Medal from the University of Tennessee, Knoxville. We introduce diversity metrics into the node selection rules of branch-and-bound algorithms to improve the diversity of encountered high-quality solutions. The collected sets of high-quality solutions exhibit higher levels of diversity than comparable approaches.Read More
I had the honor of giving an invited talk at the Industrial and Manufacturing Engineering departmental colloquium this spring at Penn State University. The topic of the talk was on risk-averse refugee resettlement. It was a great visit! Many thanks to Dr. Jose Ventura and Dr. Saurabh Bansal for the invitation, and James Wyland for his kind assistance with accommodations.Read More
WPI Data Science PhD student Fatemeh Farajzadeh and I coauthored this technical report. Tens of millions of individuals experiencing forced migration call for operations research and analytics researchers to attend to optimization challenges along the borderlands of nations. Guided by dual humanitarian and security purposes, in this short review we outline key borderland operations challenges and propose avenues for future research to proactively mitigate such challenges. We are grateful for the support of the National Science Foundation (Operations Engineering) grant CMMI-1825348.Read More
WPI Data Science PhD student Narges Ahani and I coauthored this technical report on designing human-centric decision support systems, the thinking that underscores the design of Annie™ MOORE, the world's first refugee resettlement software. Our premise: while outstanding technology and knowledge exists to solve real-world decision optimization and analytics challenges, only by having a deep understanding of the problem at hand via mutual trust from the stakeholders, is it possible to develop sustained technological solutions to address real stakeholder needs. Several vignettes are presented with unique insights that highlight how this looks in associated contexts. Special thanks to the National Science Foundation (Operations Engineering) grant CMMI-1825348 for their support.Read More
I am serving as a panelist on Friday November 19 at the (virtual) 2021 NetHope Global Summit for a panel session on nonprofits and partnerships in AI and technology. I will speak about our successful partnership with HIAS and soon-to-graduate WPI Data Science PhD student Narges Ahani on the development of Annie™ MOORE, the world's first refugee resettlement software that uses machine learning and optimization to recommend placements of refugees to communities. I will be joined on the panel by Bo Percival from Humanitarian OpenStreetMap and Sajjad Anwar from Development Seed. Many thanks to Leila Toplic at NetHope for organizing this session and to the National Science Foundation (award number 1825348) for supporting the associated research.NetHope Global Summit 2021
I am now serving as President for the INFORMS Section on Public Sector Operations Research (PSOR), which was announced at the recent PSOR Business Meeting associated with INFORMS Annual Conference. PSOR is the INFORMS subdivision dedicated to, in the words of the INFORMS slogan, "doing good with good OR." It is an honor to serve with these outstanding individuals who each are doing terrific work to elevate operations research and analytics in the public sector.INFORMS PSOR Home
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
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
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.