About Me

Gonzalo Martinez is currently a 5th year PhD candidate (ABD) at the University of Notre Dame, working under supervision of Prof. Aaron Striegel.

Publications

2021 JMIR mHealth & uHealth Martinez, G. J., Mattingly, S. M., Robles-Granda, P., Saha, K., Sirigiri, A., Young, J., Chawla, N. V., De Choudhury, M., D’Mello, S., Mark, G., Striegel, A. D. Predicting Participant Compliance with Fitness Tracker Wearing and EMA Protocols in Information Workers: An Observational study. In Journal of Medical Internet Research mHealth & uHealth [In Press].
2021

IEEE Pervasive

 Mirjafari, S., Bagherinezhad, H., Nepal, S., Martinez, G.J., Saha, K., Obuchi, M., Pino, A., Chawla, N., Dey, A., Striegel, A. & Campbell, A. Predicting Job Performance using Mobile Sensing. In IEEE Pervasive Computing Magazine special issue on Future of Work. [In Press]
2021

IEEE Pervasive

 Nepal, S., Martinez, G.J., Mirjafari, S., Mattingly, S. M., Das Swain, V., Striegel, A., Pino, A. & Campbell, A. Assessing The Impact of Commuting on Workplace Performance Using Mobile Sensing. In IEEE Pervasive Computing Magazine special issue on Future of Work. [In Press]
2021

PACM IMWUT

 Saha, K., Grover, T., Mattingly, S. M., Das Swain, V., Gupta, P., Martinez, G. J., Robles-Granda, P., Mark, G., Striegel, A., & De Choudhury, M. Person-Centered Predictions of Psychological Constructs with Social Media Contextualized by Multimodal Sensing. In Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (PACM IMWUT).
2021

IEEE CCCN

 Martinez, G. J., Dubrovskiy, G., Zhu, S., Mohammed, A., Lin, H., Laneman, J.N., Striegel, A., Pragada, R. & Castor, D. An Open Real-World Dataset of Cellular UAV Communication Properties. In the 30th International Conference on Computer Communications and Networks. [Invited Paper]
2021

CHI

 Talkad Sukumar, P., Breideband, T., Martinez, G.J., Caruso, M., Rose, S., Steputis, C., D’Mello, S., Mark, G. & Striegel, A. Designing an Interactive Visualization System for Monitoring Participant Compliance in a Large-Scale, Longitudinal Study. In Extended Abstracts of the CHI Conference on Human Factors in Computer Systems.
2021

CHI

 Saha, K., Seybolt, J., Mattingly, S. M., Aledavood, T., Konjeti, C., Martinez, G. J., Grover, T., Mark, G., & De Choudhury, M. (2021). What Life Events are Disclosed on Social Media, How, When, and By Whom? In Proceedings of the CHI Conference on Human Factors in Computer Systems.
2021

NPJ Digital Medicine

 Mattingly, S. M., Grover, T., Martinez, G.J., Aledavood, T., Robles-Granda, P., Nies, K., Striegel, A. & Mark, G. The Effects of Seasons and Weather on Sleep Patterns Measured through Longitudinal Multimodal Sensing. Nature Partner Journals Digital Medicine
2021

IEEE Comp
Intelligence
Magazine

 Robles-Granda, P., Lin, S., Wu, X., Martinez, G.J., Mattingly, S.M., Moskal, E., Striegel, A., Chawla, N.V., D’Mello, S., Gregg, J., Nies, K., Mark, G., Grover, T., Campbell, A., Mirjafari, S., Saha, K., De Choudhury, M. & Dey, A.K. Jointly predicting job performance, personality, cognitive ability, affect, and well-being. In IEEE Computational Intelligence Magazine.
2020
Eurovis		 Talkad Sukumar, P., Martinez, G.J., Grover, T., Mark, G., D’Mello, S., Chawla, N.V., Mattingly, S.M. & Striegel, A. Characterizing Exploratory Behaviors on a Personal Visualization Interface Using Interaction Logs. In EuroVis.
2020
SDM		 Lin., S, Wu, S., Martinez, G.J. & Chawla, N.V. Filling Missing Values on Wearable-Sensory Time Series Data. In SIAM International Conference on Data Mining (SDM20)
2020

PerCom Wristsense

 Martinez, G.J., Mattingly, S.M., Young, J., Faust, L., Dey, A., Campbell, A., De Choudhury, M., Mirjafari, S., Nepal, S., Robles-Granda, P., Saha, K. & Striegel, A. Improved Sleep Detection Through the Fusion of Phone Agent and Wearable Data Streams. In Pervasive Computing WristSense 2020: 6th Workshop on Sensing Systems and Applications using Wrist Worn Smart Devices. [Best Paper Honorable Mention]
2020 PerCom

Wristsense

 Martinez, G.J., Mattingly, S.M., Mirjafari, S., Nepal, S., Campbell, A., Dey, A., Striegel, A. On the Quality of Real-world Wearable Data in a Longitudinal Study of Information Workers. In Pervasive Computing WristSense 2020: 6th Workshop on Sensing Systems and Applications using Wrist Worn Smart Devices.
2020

PACM IMWUT

 Nepal, S.K., Mirjafari, S., Martinez, G.J., Audia, P., Striegel, A. & Campbell, A. Detecting Job Promotion in the Workplace using Mobile Sensing. In Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (PACM IMWUT).
2020

IEEE BigData

 Lin, S., Faust, L., D’Mello, S., Martinez G.J. & Chawla, N. V. MBead: Semi-supervised Multilabel Behaviour Anomaly Detection on Multivariate Temporal Sensory Data. In IEEE International Conference on Big Data.
2019
PACM IMWUT		 Das Swain, V., Saha, K., Rajvanshy, H., Sirigiri, A., Gregg, J. M., Lin, S., Martinez, G.J., Mattingly, S.M., Mirjafari, S., Mulukutla, R., Nepal, S., Nies, K., Reddy, M. D., Robles-Granda, P., Campbell, A., Chawla, N. V., D’Mello, S., Dey, A. K., Kaifeng, J., Liu, Q., Mark, G., Moskal, E., Striegel, A., Tay, L., Abowd, G. D. & De Choudhury, M. A Multisensor Person-Centered Approach to Understand the Role of Daily Activities in Job Performance with Organizational Personas. In Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (PACM IMWUT).
2019
PACM IMWUT		 Mirjafari, S., Masaba, K., Grover, T., Wang, W., Audia, P., Campbell, A., Chawla, N. V., Das Swain, V., De Choudhury, M., Dey, A. K., D’Mello, S., Gao, G., Gregg, J. M., Jagannath, K., Jiang, K., Lin, S., Liu, Q., Mark, G., Martinez, G.J., Mattingly, S. M., Moskal, E., Mulukutla, R., Nepal, S., Nies, K., Reddy, M.D., Robles-Granda, P., Saha, K., Sirigiri, A. & Striegel, A. Differentiating Higher and Lower Job Performers in the Workplace Using Mobile Sensing. In Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (PACM IMWUT).
2019

CHI

 Saha, K., Bayraktaroglu, A. E., Campbell, A., Chawla, N. V., De Choudhury, M., D’Mello, S., Dey, A. K., Gao, G., Gregg, J. M., Jagannath, K., Mark, G., Martinez, G.J., Mattingly, S. M., Moskal, E., Sirigiri, A., Striegel, A. & Whi Yoo, D. Social Media as A Passive Sensor in Longitudinal Studies of Human Behavior and Wellbeing. In Extended Abstracts of the CHI Conference on Human Factors in Computer Systems.
2019

CHI

 Mattingly, S. M., Gregg, J.M., Audia, P., Bayraktaroglu, A. E., Campbell, A., Chawla, N. V., Das Swain, V., De Choudhury, M., D’Mello, S., Dey, A. K., Gao, G., Jagannath, K., Jiang, K., Lin, S., Liu, Q., Mark, G., Martinez G. J., Masaba, K., Mirjafari, S., Moskal, E., Mulukutla, R., Nies, K., Reddy, M.D., Robles-Granda, P., Saha, K., Sirigiri, A. & Striegel, A. The Tesserae Project: Large-Scale, Longitudinal, In Situ, Multimodal Sensing of Information Workers. In Extended Abstracts of the CHI Conference on Human Factors in Computer Systems.
2019
ACII		 Saha, K., Reddy, M.D., Das Swain, V., Gregg, J. M., Grover, T., Lin, S., Martinez, G.J., Mattingly, S.M., Mirjafari, S., Mulukutla, R., Nies, K., Robles-Granda, P., Sirigiri, A., Whi Yoo, D., Audia, P., Campbell, A., Chawla, N.V., D’Mello, S., Dey, A. K., Jiang, K., Liu, Q., Mark, G., Moskal, E., Striegel, A. & De Choudhury, M. Imputing Missing Social Media Data Stream in Multisensor Studies of Human Behavior. In the International Conference on Affective Computing and Intelligent Interaction (ACII).
2017

IEEE DySpan

 Kleber, N., Termos, A., Martinez, G. J., Merritt, J., Hochwald, B., Chisum, J., Striegel, A. & Laneman J. N. RadioHound: A pervasive sensing platform for sub-6 GHz dynamic spectrum monitoring. In IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN), 1–2. [Demo Publication]
2015

CLEI Journal

 Martinez, G. J., Val, L. Capataz: a framework for distributing algorithms via the World Wide Web. CLEI Electronic Journal, 18(08).
2014

CLEI Conference

 Martinez, G.J., Val, L. Implementing cross-platform distributed algorithms using standard web technologies. In 2014 XL Latin American Computing Conference (CLEI IEEE).

Research and Teaching Experience

University of Notre Dame

Research Assistant, Computer Science and Engineering

  • Produced backend and mobile systems to support everyday operation of the Tesserae study, such as data collection, compliance computations, and participant communications.
  • Designed the database schema with 100+ tables and 4TB in size. Parsed all data that is being used across 5 Universities in the Tesserae study for analysis.
  • The Tesserae study is a year-long study of 750 participants where we use a combination of sensors and social media data to understand the behaviors that support good workplace performance.
  • Analyzed compliance data, patterns of use of wearable technology, sleep data directly captured by a wearable, and the fusion of multiple sensors for more accurate sleep readings.
  • Built a mobile application and gathered mobile network data using a Low Altitude Unmanned Aircraft Vehicle for the Drone Sounder project. Analyzed the results, produced a research paper (currently in editing), and an open-source dataset to be made public at the time of publishing.
  • Created a prototype server backend and frontend for the Radiohound project, a custom spectrum sensing network capable of tuning from 25 MHz to 6 GHz, which covers nearly all widely-deployed wireless activity. The backend and frontend enabled us to see the data as it was coming in from the hardware sensors developed at ND in a close to real-time manner.

Universidad Catolica del Uruguay (2013 – 2016)

  • Worked on the implementation of a framework for distributing algorithms using standard web technologies that resulted in two research papers in a top CS conference in Latin America.
  • Lectured in the Object-Oriented Programming course. Was also a teaching assistant helping implement Team Based Learning methodology in Data Structures and Algorithms, Artificial Intelligence, and Functional Programming.

Professional Experience

Risk Manager (Data Scientist Intern), Decision Science and Data Strategy, Credit & Fraud Risk, American Express (Jun 2021 – Aug 2021)

  • Created a defaulter case review tool to allow for online analysis of trends and signals to identify defaulters and patterns that may have been missed by the machine learning models. Results were delivered in half of the time that was expected.
  • Created a model for the prediction of defaulters using gradient boosting techniques and a machine learning pipeline built with LightAutoML. This model outperformed the existing model in the key metrics defined by the company.
  • Presented my work to upper-level management and peers in my team.

Full Stack Software Developer, Web department, Decemberlabs (Jan 2016 – Aug 2016)

  • Developed the backend and frontend of multiple web-based applications, as well as maintained and upgraded the backend of mobile applications for startups in the United States, resulting in ambitious projects being completed on time and on budget.
  • The technology stack included MySQL, Yii, Laravel, Angular JS, HTML+CSS.

Senior Java Developer, Lithium Software (Oct 2013 – Feb 2016)

  • Developed in-house applications for our client El Correo Uruguayo (post office of Uruguay).
  • Upgraded and consolidated tracking applications in the agency by replacing several satellite applications with a web-based centralized server running on J2EE technology.

Web Developer, Freelance, (Apr 2008 – Aug 2016)

  • Development of http://cotizadorlogistico.com (04/2015 – 08/2016)
  • Development and maintenance of 15 different websites and an elementary school management system for my client RedTotal (04/2008 – 06/2010) .
  • Academic Management System for Instituto Crandon – (06/2012 – 08/2016). As part of a three people team, developed and maintained a Java Web Application to substitute paper-based processes, i.e. creation, editing and validation of grades reports, creation of Ministry of Education required documentation, etc. Tasks developed included requirements analysis, development, documentation development and training employees in the use of the system developed. Technologies used during the project: Java, Git, Tomcat, Hibernate, Vaadin Framework, Eclipse IDE, MySQL running on top of an Ubuntu Server 2012 virtual machine.