Education

2016 - 2019: University of Florida
PhD Mechanical Engineering: 3.68/4.00 GPA Identification of material model parameters from experimental data December 2019 graduation

2014 - 2016: Stellenbosch University
MEng Mechanical Engineering: cum laude
Thesis: Obtaining non-linear orthotropic material models for pvc-coated polyester via inverse bubble inflation. https://hdl.handle.net/10019.1/98627 pdf.

2009 - 2013: University of Colorado - Colorado Springs
BSc Mechanical Engineering: 3.72/4.00 GPA with honor


Peer-reviewed journal articles

Jekel, C. F., Venter, G., Venter, M. P., Stander, N., & Haftka, R. T. (2018). Similarity measures for identifying material parameters from hysteresis loops using inverse analysis, International Journal of Material Forming. doi:10.1007/s12289-018-1421-8 pdf.

Charles F. Jekel, Gerhard Venter, Martin P. Venter. Modeling PVC-coated polyester as a hypoelastic non-linear orthotropic material, Composite Structures, Volume 161, 1 February 2017, Pages 51-64, ISSN 0263-8223, doi:10.1016/j.compstruct.2016.11.019 pdf.

Charles F. Jekel, Gerhard Venter, and Martin P. Venter. Obtaining a hyperelastic non-linear orthotropic material model via inverse bubble inflation analysis, Structural and Multidisciplinary Optimization, pages 1-9, 2016, ISSN 1615-1488, doi:10.1007/s00158-016-1456-8 pdf.


Conference papers

Charles F. Jekel, Raphael T. Haftka, Gerhard Venter, and Martin P. Venter. Lack-of-fit Tests to Indicate Material Model Improvement or Experimental Data Noise Reduction, 2018 AIAA Non-Deterministic Approaches Conference, AIAA SciTech Forum, (AIAA 2018-1664) doi:10.2514/6.2018-1664 pdf.


Technical reports and other non-refereed papers

C. F. Jekel and G. Venter, pwlf: A Python Library for Fitting 1D Continuous Piecewise Linear Functions, 2019. [Online]. Available: https://github.com/cjekel/piecewise_linear_fit_py pdf.

Jekel, C.F. and Haftka, R.T., 2018. Classifying Online Dating Profiles on Tinder using FaceNet Facial Embeddings. arXiv preprint arXiv:1803.04347 pdf.


Python libraries

pwlf: A Python library for fitting 1D continuous piecewise linear functions.

tindetheus: A Python application that allows users to build their own personalized machine learning models using computer vision. The models can automatically like users on Tinder, based on the user’s own historical preference.

similaritymeasures: Quantify the difference between two curves using the Partial Curve Mapping method, Area between two curves, Discrete Fréchet distance, or Curve Length based similarity measure. These methods are particularly useful for identifying parameters from material load/unload curves.


Professional experience

Sandia National Laboratories

2018: Research & Development Graduate Intern

Works in the Verification Validation (VV), Uncertainty Quantification (UQ), Credibility Process group. R&D of statistical methods to estimate extreme tail probabilities with a limited number of samples.

University of Florida

2016 - present: Research Assistant / Instructor

Applied optimization to find model parameters that match experimental data, and research on quantifying the difference between experimental data and numerical models. Created and taught a Python Programming course.

UTC Aerospace Systems

2013 - 2014: Manufacturing Engineer
2012: Manufacturing Engineer Intern

Worked directly with all OEM final assembly lines to interface with Product Engineering on issues related to manufacturing. Participated on Integrated Product Development Teams to improve manufacturing processes associated with specialty aircraft seats (pilot, flight attendant, and observer) for commercial platforms.

University of Colorado - Colorado Springs

2010 - 2013: Student Assistant IV

All-purpose IT wizard. Graphic design guru.


Courses taught

2017: Python Programming - 1 credit hour graduate course - Syllabus - Course material

Created and taught the first Python Programming course in the MAE department at the University of Florida. The course covers topics from the basics of Python to the most popular scientific Python libraries in an effort to prepare graduate students to perform research in Python.


Honors and awards

2016: University of Florida GSFA - four year graduate school fellowship
2016: Stellenbosch departmental bursary - three year PhD funding
2016: MEng, obtained cum laude
2014: Wilhelm Frank Trust - research funding (~$50k secured with team)
2013: BSc, obtained with honor - graduated third in class
2010: Reisher Family Scholarship - three year award
2009: Braxton Technologies Scholarship - four year award