As Project Leader                                                                                                                               

• BaybayinDigitized: OCR Mobile Application and Dataset Hub

UP ISC Research Grant, Intelligent Systems Center, University of the Philippines.

Duration: 01 August 2025 – 31 July 2027

• Covariance-driven topological analysis of stock market movements

IM Faculty Research Grant, Institute of Mathematics, University of the Philippines – Diliman

Duration: 01 January 2025 – 31 December 2025

• Utilizing Topological Data Analysis and Kernel Methods to Solve Classification Tasks

Research Grants Under the Computational Research Laboratory, Institute of Mathematics, University of the Philippines – Diliman

Duration: 01 April 2024 – 31 Mar 2025.

• Analyzing Genetic Admixture on Marmoset Genomic Data Using Persistent Homology

Research Grants Under the Computational Research Laboratory Program of the Institute of Mathematics, University of the Philippines – Diliman

Duration: 01 Aug 2022 – 31 July 2023.

• Temperature and Precipitation Impacts on Multi-Strain Dengue Transmission Dynamics in the Philippines (Project No. 22225 PhDIA YEAR 1)

Office of the Vice Chancellor for Research and Development, University of the Philippines – Diliman

Duration: 01 Jun 2022 – 31 May 2023 (Extended to 31 Dec 2023)

• Estimating the Resultant Efficacy of the Administration of Two or More Vaccines in a Single Community

Bayanihan to Recover as One Act: Grant for Research on COVID-19 in the Philippines

Funded by: Philippine Government

Duration: 01 Jun 2021 – 31 May 2022 (Extended to 31 July 2022).

• Modeling Structural Breakpoints in Volatility of Philippine Peso-US Dollar Currency Exchange Rate

(MAT-19-1-01 Accepted for Publication)

Natural Sciences Research Institute, University of the Philippines – Diliman

Duration: 01 Jan 2019 – 31 Dec 2019.

As Co-Project Leader

• Comparative Study of Persistent Homology and Mapper Applied to Biological Data

Natural Sciences Research Institute, University of the Philippines – Diliman

Duration: 01 Jan 2024 – 31 Dec 2024.

• Computational Laboratory for Covid-19 Modeling and Forecasting

Republic Act 11494 Bayanihan to Recover as One Act

Funded by: Philippine Government

Duration: 01 Jan 2021 – 30 Jun 2021

• Allocation of Different COVID-19 Vaccines to a Heterogeneous Population: Exploring Various Scenarios

Bayanihan to Recover as One Act: Grant for Research on COVID-19 in the Philippines

Funded by: Philippine Government

Duration: 14 Dec 2020 – 30 Jun 2021

Teaching

• Math 271.1 : Numerical Analysis I
• Math 197 : Special Topics (Machine Learning for Intelligent Systems)
• Math 180.1 : Operations Research I
• Math 171 : Introduction to Numerical Analysis
• Math 21, 22, 23 : Elementary Analysis I, II, III
• Math 20 : Precalculus: Functions and their Graphs

Advising

Current Student Advisees:

1. Kyla Louise M. Ramos: BS Mathematics. Undergraduate Research topic: numerical analysis, machine learning.
2. Maryan Rhycel B. Sison: BS Mathematics. Undergraduate Research topic: numerical analysis, machine learning.
3. Paola Angelee A. Dela Rosa: BS Mathematics. Undergraduate Research topic: numerical analysis, machine learning.
4. Josh David: BS Mathematics. Undergraduate Research topic: machine learning.
5. Isaiah John Mariano: BS Mathematics. Undergraduate Research topic: machine learning methods.
6. Oliver Salem: BS Mathematics. Undergraduate Research topic: kernel methods.
7. Aidan Raphael R. Prieto: B.S. Mathematics. Undergraduate thesis topic: Mathematical finance, optimization.
8. A C Bernadette M. Ducusin: M.S. Applied Mathematics (Mathematical Finance). Graduate thesis topic: Optimal Investment with Transaction Cost. Co-advising with Dr. Rhudaina Mohammad.
9. Maikel Roi M. Aguilar: M.S. Applied Mathematics (Optimization and Approximation). Graduate thesis topic: Genetic Algorithm Solution to an Evacuation Planning Model.
10. Russell Fitzgerald Santos: M.S. Applied Mathematics (Mathematics in Life and Physical Science). Co-advising with Dr. Rhudaina Mohammad.
11. Keith Bocian: Ph.D. Data Science.
12. Raul Clavido: Ph.D. Data Science.
13. James Arnold E. Nogra: Ph.D. Data Science.
14. Michael E. Subido: Ph.D. Mathematics. Dissertation topic: Temperature and Precipitation Impacts on Multi-Strain Dengue Transmission Dynamics in the Philippines. Co-advising with Dr. Aurelio de los Reyes V.
15. Dhee Jee Ann Pusing: Professional Masters in Data Science and Analytics. Capstone project: developing custom kernel functions for applications like image classification, mainly focused on cancer or tumor identification. Co-advising with Dr. Joseph Ryan Lansangan (School of Statistics).

Refereed Journal Papers

(* denotes graduate student coauthor)

1. Pino, R., Mendoza, R.G., Sambayan, R. (2025). MaBaybay-OCR: A Matlab-based Baybayin optical character recognition package. SoftwareX, 29, 102003.
2. Riñon EM*, Sambayan R. 2024. Topological Approach for Detection of Structural Breakpoints in Philippine Stock Price Data Surrounding the COVID-19 Pandemic . Philippine Journal of Science 153(3): 1177–1188, June 2024.
3. Pino R*, Mendoza R, Sambayan R. 2022. Block-level Optical Character Recognition System for Automatic Transliterations of Baybayin Texts Using Support Vector Machine. Philippine Journal of Science 151(1), pp. 303—315, ISSN 0031 – 7683, Feb 2022.
4. Pino R*, Mendoza R, Sambayan R. 2021. A Baybayin word recognition system. PeerJ Computer Science 7:e596 https://doi.org/10.7717/peerj-cs.596, Jun 2021.
5. Pino R*, Mendoza R, Sambayan R. 2021. Optical character recognition system for Baybayin scripts using support vector machine. PeerJ Computer Science 7:e360 https://doi.org/10.7717/peerj-cs.360, Feb 2021.
6. Rivero*, Y. Onuma*, and T. Kato. (2019) Threshold Auto-Tuning Metric Learning. IEICE Transactions on Information and Systems, vol. E102-D, no.6, pp.1163—1170, June 2019.
7. Rivero* and T. Kato. (2018) Parametric Models for Mutual Kernel Matrix Completion. IEICE Transactions on Information and Systems, vol. E101-D, no.12, pp.2976—2983, Dec. 2018.
8. Rivero*, R. Lemence, and T. Kato. (2017). Mutual Kernel Matrix Completion. IEICE Transactions on Information and Systems, vol. E100-D, no.8, pp.1844—1851, Aug. 2017.

Refereed Conference Proceedings

1. C. R. Bargo, R. R. Sambayan, H. R. L. D. Improso, J. E. C. Lope; Modeling the effects of disparities in vaccine efficacies and rollout rates. AIP Conf. Proc.30 September 2024; 3163 (1): 030001. https://doi.org/10.1063/5.0212659
2. R.L. Improso*, R. Sambayan, M.C. Bargo, J.E. Lope. “Estimating the Resultant Efficacy of the Rollout of Multiple Vaccines in a Population.” AIP Conf. Proc.12 January 2024; 2982 (1): 020010. https://doi.org/10.1063/5.0183373
3. Rivero and F. G. David. (2019) “Modeling Structural Breakpoints in Volatility of Philippine Peso-US Dollar Currency Exchange Rate”. Empowering Science and Mathematics for Global Competitiveness: Proceedings of the Science and Mathematics International Conference (SMIC 2018, Jakarta, Indonesia), eds Rahmawati, Y. and Taylor, P.C, CRC Press.