Juan Martin Caicedo

Compressive strength models for ordinary portland cement composites are typically deterministic and rely on parameters such as water-to-cement ratio, porosity, and chemical composition. Whi...

Objective: This research aims to extract human gait parameters from floor vibrations. The proposed approach provides an innovative methodology on occupant activity, contributing to a broader understanding of how human movements interact within their built environment. Methods and Procedures: A multilevel probabilistic model was developed to estimate cadence and walking speed through the analysis of floor vibrations induced by walking. The model addresses challenges related to missing or incomplete information in the floor acceleration signals. Following the Bayesian Analysis Reporting Guidelines (BARG) for reproducibility, the model was evaluated through twenty-seven walking experiments, capturing floor vibration and data from Ambulatory Parkinson’s Disease Monitoring (APDM) wearable sensors. The model was tested in a real-time implementation where ten individuals were recorded walking at their own selected pace. Results: Using a rigorous combined decision criteria of 95% high posterior density (HPD) and the Range of Practical Equivalence (ROPE) following BARG, the results demonstrate satisfactory alignment between estimations and target values for practical purposes. Notably, with over 90% of the 95% HPD falling within the region of practical equivalence, there is a solid basis for accepting the estimations as probabilistically aligned with the estimations using the APDM sensors and video recordings. Conclusion: This research validates the probabilistic multilevel model in estimating cadence and walking speed by analyzing floor vibrations, demonstrating its satisfactory comparability with established technologies such as APDM sensors and video recordings. The close alignment between the estimations and target values emphasizes the approach’s efficacy. The proposed model effectively tackles prevalent challenges associated with missing or incomplete data in real-world scenarios, enhancing the accuracy of gait parameter estimations derived from floor vibrations. Clinical impact: Extracting gait parameters from floor vibrations could provide a non-intrusive and continuous means of monitoring an individual’s gait, offering valuable insights into mobility and potential indicators of neurological conditions. The implications of this research extend to the development of advanced gait analysis tools, offering new perspectives on assessing and understanding walking patterns for improved diagnostics and personalized healthcare. Clinical and Translational Impact Statement: This manuscript introduces an innovative approach for unattended gait assessments with potentially significant implications for clinical decision-making. By utilizing floor vibrations to estimate cadence and walking speed, the technology can provide clinicians with valuable insights into their patients’ mobility and functional abilities in real-life settings. The strategic installation of accelerometers beneath the flooring of homes or care facilities allows for uninterrupted daily activities during these assessments, reducing the reliance on specialized clinical environments. This technology enables continuous monitoring of gait patterns over time and has the potential for integration into healthcare platforms. Such integration can enhance remote monitoring, leading to timely interventions and personalized care plans, ultimately improving clinical outcomes. The probabilistic nature of our model enables uncertainty quantification in the estimated parameters, providing clinicians with a nuanced understanding of data reliability.

Session 1426 Earthquake Engineering Education: A Modern Approach S.J. Dyke, B. Nepote, J.M. Caicedo, S.M. Johnson and E.A. Oware Washington University in St. Louis Abstract Currently civil engineering undergraduates have limited opportunities to gain an understanding of the principles of structural dynamics or exposure to the innovative new structural control meth- ods. “Hands-on” experiments seem to be particularly effective for teaching basic concepts in dynamics and control. The objective of the educational program described in this paper is to sys- tematically integrate these topics into the undergraduate civil engineering curriculum. Three bench-scale seismic simulator tables are being used to integrate a series of “hands-on” experi- ments in structural dynamics and control throughout the civil engineering curriculum at Washing- ton University. This paper discusses how structural dynamics and earthquake engineering are being integrated into the undergraduate program at Washington University. Additionally, outreach activities and undergraduate research experiences influenced by the equipment are discussed. Fur- thermore, an outgrowth of this program, the multi-institutional University Consortium on Instruc- tional Shake Tables, is introduced. 1. Introduction The importance of understanding the effect of earthquakes on structures to the civil engineering community is apparent. Recent catastrophic earthquakes in Northridge, Kobe, Turkey and Taiwan have reminded us of the powerful and potentially deadly consequences of such natural events. At the undergraduate level, few students have opportunities to gain experience with the behavior of structures subjected to earthquake loading. Even fewer students are exposed to the exciting possi- bilities that recently developed structural control techniques offer the civil engineer. In the last two decades, the concept of using structural control systems to mitigate the potentially catastrophic effects of severe seismic events has attracted much attention in the civil engineering research community. These types of control systems, often termed protective systems, offer the advantage of being able to dynamically modify the responses of a structure to increase its safety, reliability, and serviceability. This technology has the potential to revolutionize earthquake engi- neering, especially in vulnerable existing buildings which are characteristically difficult and expensive to retrofit. The undergraduate students at Washington University are aware of these issues and have demonstrated a great deal of interest in earthquake resistant design. The goal of the educational program described herein is to provide the undergraduate students at Washington University with an understanding of basic concepts in structural dynamics and expo- sure to the exciting new structural control techniques. This objective is being achieved by inte- grating a series of “hands-on” experiments into the civil engineering curriculum. The experiments have been designed to provide the students with a background in the basic principles of structural