Chicago does not address what to do with conference papers found in library databases. The examples below are based on their guidance for journal articles.
3. Simon Y. Liu, "Data-Intensive Research and Scientific Discovery" (Paper presentation, 40th Annual Computer Software and Applications Conference, Atlanta, GA, June 2016), http://doi.ieeecomputersociety.org.ezproxy.umgc.edu/10.1109/COMPSAC.2016.260.
Liu, Simon Y. "Data-Intensive Research and Scientific Discovery." Paper presented at the 40th Annual Computer Software and Applications Conference, Atlanta, GA, June 2016. http://doi.ieeecomputersociety.org.ezproxy.umgc.edu/10.1109/COMPSAC.2016.260.
Use the database name.
3. Ethan S. Kallman, "Ghost Mapping: Psychogeography Meets the Academy" (Paper presentation, 10th Regional Geographers' Annual Meeting, Chatham, England, October 2003), Project MUSE.
Kallman, Ethan S. "Ghost Mapping: Psychogeography Meets the Academy." Paper presented at the 10th Regional Geographers' Annual Meeting, Chatham, England, October 2003. Project MUSE.
3. Sergey Levine and Vladlen Koltun, "Continuous Inverse Optimal Control with Locally Optimal Examples" (Paper presentation, 29th International Conference on Machine Learning, Edinburgh, Scotland, June 2012), arxiv.org/pdf/1206.4617v1.pdf.
Levine, Sergey, and Vladlen Koltun. "Continuous Inverse Optimal Control with Locally Optimal Examples." Paper presented at the 29th International Conference on Machine Learning, Edinburgh, Scotland, June 2012. arxiv.org/pdf/1206.4617v1.pdf.