Realistic Modeling of Human Timings for Wearable Cognitive Assistance

TL;DR

This paper introduces a comprehensive human behavior model for Wearable Cognitive Assistance systems, enabling human-independent benchmarking and optimization of system performance and resource efficiency.

Contribution

It presents the first end-to-end human emulation model for WCA, derived from statistical analysis, and a novel framework for optimizing resource-responsiveness tradeoffs.

Findings

Model shows a 36% larger gap in task durations under high impairment.

Combining the model with optimization reduces frame processing by 50%.

Energy consumption decreases by 20% with the proposed approach.

Abstract

Wearable Cognitive Assistance (WCA) applications present a challenge to benchmark and characterize due to their human-in-the-loop nature. Employing user testing to optimize system parameters is generally not feasible, given the scope of the problem and the number of observations needed to detect small but important effects in controlled experiments. Considering the intended mass-scale deployment of WCA applications in the future, there exists a need for tools enabling human-independent benchmarking. We present in this paper the first model for the complete end-to-end emulation of humans in WCA. We build this model through statistical analysis of data collected from previous work in this field, and demonstrate its utility by studying application task durations. Compared to first-order approximations, our model shows a ~36% larger gap between step execution times at high system impairment versus low. We further introduce a novel framework for stochastic optimization of resource consumption-responsiveness tradeoffs in WCA, and show that by combining this framework with our realistic model of human behavior, significant reductions of up to 50% in number processed frame samples and 20% in energy consumption can be achieved with respect to the state-of-the-art.