Joshua Letchford, Ph.D.
R&D S&E, Computer Science

R&D S&E, Computer Science
Biography
Dr. Joshua Letchford is a Principal Member of Technical Staff at Sandia National Laboratories in Livermore, California. He has worked on a range of interdisciplinary projects across the domains of cybersecurity, residential solar adoption, non-proliferation, power grid resilience, supply chain security, and nuclear and cyber deterrence. His research interests span game theory, Stackelberg games, graphs, machine learning, experimental wargaming, deterrence and linear optimization. Joshua holds a Ph.D in Computer Science from Duke University and a Bachelor’s degree in Computer Engineering and Computer Science from the University of Southern California.
Education
Joshua earned his B.S. in Computer Engineering & Computer Science from University of Southern California, and holds a Ph.D in Computer Science from Duke University.
Publications
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Letchford, J., Epifanovskaya, L., Lakkaraju, K., Armenta, M., Reddie, A., Whetzel, J., Reinhardt, J., Chen, A., Fabian, N., Hingorani, S., Iyer, R., Krishman, R., Laderman, S., Lee, M., Mohan, J., Nacht, M., Prakkamakul, S., Sumner, M., Tibbets, J., … Zhang, C. (2022). Experimental Wargaming with SIGNAL. Military Operations Research. https://www.osti.gov/biblio/1882885 Publication ID: 80381
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Lakkaraju, K., Reddie, A., Letchford, J., & Letchford, J. (2021). Tracing Hosue Advisory Committee Meeting Slides [Presentation]. https://www.osti.gov/biblio/1884108 Publication ID: 75384
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Booth, R., Letchford, J., & Letchford, J. (2021). Wargaming when War is not the Answer: Multipurpose collective conflict resolution games [Conference Presenation]. https://doi.org/10.2172/1873277 Publication ID: 78886
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Letchford, J., Booth, R., & Booth, R. (2021). Gaming Research for Alliance Network Dynamics Assent Draft Ruleset (Report 2). https://doi.org/10.2172/1765623 Publication ID: 75355
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Letchford, J. (2020). Designing SIGNAL as an Experimental Wargame [Conference Poster]. https://www.osti.gov/biblio/1812853 Publication ID: 74439
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Lakkaraju, K., Epifanovskaya, L., Letchford, J., Whetzel, J., Armenta, M., Goldblum, B., Tibbetts, J., & Tibbetts, J. (2020). SIGNAL Game Manual. https://doi.org/10.2172/1643226 Publication ID: 74087
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Lakkaraju, K., Reinhardt, J., Letchford, J., Whetzel, J., Goldblum, B.L., Reddie, A.W., & Reddie, A.W. (2020). Experimental wargames to address the complexity-scarcity GAP [Conference Poster]. Simulation Series. https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85090851709&origin=inward Publication ID: 73193
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Thorve, S., Hu, Z., Lakkaraju, K., Letchford, J., Vullikanti, A., Marathe, A., Swarup, S., & Swarup, S. (2020). An active learning method for the comparison of agent-based models [Conference Poster]. Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS. https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85096660603&origin=inward Publication ID: 72554
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Epifanovskaya, L., Lakkaraju, K., Letchford, J., Reinhardt, J., Whetzel, J., Reddie, A., & Reddie, A. (2019). Experimental Gaming: Introducing the Project on Nuclear Gaming?s SIGNAL Framework [Conference Poster]. https://www.osti.gov/biblio/1643669 Publication ID: 68989
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Lakkaraju, K., Epifanovskaya, L., Stites, M., Letchford, J., Reinhardt, J., Whetzel, J., & Whetzel, J. (2019). Online games for studying human behavior. Social-Behavioral Modeling for Complex Systems. https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85102539764&origin=inward Publication ID: 62589
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Epifanovskaya, L., Lakkaraju, K., Letchford, J., Stites, M., Reinhardt, J., Whetzel, J., & Whetzel, J. (2018). Modeling Economic Interdependence in Deterrence Using a Serious Game. Journal on Policy and Complex Systems, 4(2). https://doi.org/10.18278/jpcs.4.2.8 Publication ID: 63060
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Reinhardt, J., Lakkaraju, K., Letchford, J., Epifanovskaya, L., Whetzel, J., & Whetzel, J. (2018). Expanding the Wargaming Toolbox [Conference Poster]. https://www.osti.gov/biblio/1526136 Publication ID: 62521
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Epifanovskaya, L., Lakkaraju, K., Letchford, J., Stites, M., Reinhardt, J., Mohan, J., & Mohan, J. (2018). Toward a Quantitative Approach to Data Gathering and Analysis for Nuclear Deterrence Policy [Conference Poster]. https://doi.org/10.1007/978-3-319-96661-8_26 Publication ID: 61386
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Epifanovskaya, L., Lakkaraju, K., Letchford, J., Stites, M., Reinhardt, J., & Reinhardt, J. (2018). Toward a Quantitative Approach to Data Gathering and Analysis for Nuclear Deterrence Policy [Conference Poster]. Springer Proceedings in Complexity. https://doi.org/10.1007/978-3-319-96661-8_26 Publication ID: 58655
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Letchford, J. (2016). Game Theory for Proactive Dynamic Defense and Attack Mitigation in Cyber-Physical Systems. https://doi.org/10.2172/1330190 Publication ID: 52653
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Chen, R.L.-Y., Letchford, J., Kao, G., & Kao, G. (2016). Network Security Games with Probabilistic Evasion [Conference Poster]. https://www.osti.gov/biblio/1394879 Publication ID: 52326
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Chen, R.L.-Y., Letchford, J., Kao, G., & Kao, G. (2016). Network Security Games with Probabilistic Evasion [Conference Poster]. https://www.osti.gov/biblio/1364700 Publication ID: 50101
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Letchford, J., Letchford, J., Mayo, J., Mayo, J., Armstrong, R., Armstrong, R., & Armstrong, R. (2015). Cybersecurity Design Techniques Targeting and Leveraging HPC [Conference Poster]. https://www.osti.gov/biblio/1252927 Publication ID: 43364
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Lakkaraju, K., Letchford, J., Vorobeychik, Y., Zhang, H., & Zhang, H. (2015). Promoting Solar Technology Diffusion Through Data-Driven Behavior Modeling [Presentation]. https://www.osti.gov/biblio/1514003 Publication ID: 42460
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Zhang, H., Vorobeychik, Y., Letchford, J., Lakkaraju, K., & Lakkaraju, K. (2015). Data-driven agent-based modeling, with application to rooftop solar adoption [Conference Poster]. Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS. https://doi.org/10.1007/s10458-016-9326-8 Publication ID: 43075
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Lakkaraju, K., Vorobeychik, Y., Letchford, J., & Letchford, J. (2015). Promoting Solar Technology Diffusion Through Data-Driven Behavior Modeling [Presentation]. https://www.osti.gov/biblio/1244911 Publication ID: 41293
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Letchford, J., Lakkaraju, K., Vorobeychik, Y., & Vorobeychik, Y. (2014). Individual household modeling of photovoltaic adoption [Conference Poster]. AAAI Fall Symposium – Technical Report. https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84940385096&origin=inward Publication ID: 37506
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Letchford, J., Vorobeychik, Y., & Vorobeychik, Y. (2012). Computing Optimal Security Strategies in Networked Domains: A Cost-Benefit Approach [Conference]. https://www.osti.gov/biblio/1062826 Publication ID: 25928
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Vorobeychik, Y., Letchford, J., & Letchford, J. (2011). Computing Optimal Security Strategies in Networked Domains: A Cost-Benefit Approach [Conference]. https://www.osti.gov/biblio/1106317 Publication ID: 24866
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Letchford, J. (2011). Computing Randomized Security Strategies in Networked Domains [Conference]. https://www.osti.gov/biblio/1120411 Publication ID: 22510