OCOct 22, 2025
Endogenous Aggregation of Multiple Data Envelopment Analysis Scores for Large Data SetsHashem Omrani, Raha Imanirad, Adam Diamant et al.
We propose an approach for dynamic efficiency evaluation across multiple organizational dimensions using data envelopment analysis (DEA). The method generates both dimension-specific and aggregate efficiency scores, incorporates desirable and undesirable outputs, and is suitable for large-scale problem settings. Two regularized DEA models are introduced: a slack-based measure (SBM) and a linearized version of a nonlinear goal programming model (GP-SBM). While SBM estimates an aggregate efficiency score and then distributes it across dimensions, GP-SBM first estimates dimension-level efficiencies and then derives an aggregate score. Both models utilize a regularization parameter to enhance discriminatory power while also directly integrating both desirable and undesirable outputs. We demonstrate the computational efficiency and validity of our approach on multiple datasets and apply it to a case study of twelve hospitals in Ontario, Canada, evaluating three theoretically grounded dimensions of organizational effectiveness over a 24-month period from January 2018 to December 2019: technical efficiency, clinical efficiency, and patient experience. Our numerical results show that SBM and GP-SBM better capture correlations among input/output variables and outperform conventional benchmarking methods that separately evaluate dimensions before aggregation.
APOct 22, 2025
AI Pose Analysis and Kinematic Profiling of Range-of-Motion Variations in Resistance TrainingAdam Diamant
This study develops an AI-based pose estimation pipeline to enable precise quantification of movement kinematics in resistance training. Using video data from Wolf et al. (2025), which compared lengthened partial (pROM) and full range-of-motion (fROM) training across eight upper-body exercises in 26 participants, 280 recordings were processed to extract frame-level joint-angle trajectories. After filtering and smoothing, per-set metrics were derived, including range of motion (ROM), tempo, and concentric/eccentric phase durations. A random-effects meta-analytic model was applied to account for within-participant and between-exercise variability. Results show that pROM repetitions were performed with a smaller ROM and shorter overall durations, particularly during the eccentric phase of movement. Variance analyses revealed that participant-level differences, rather than exercise-specific factors, were the primary driver of variation, although there is substantial evidence of heterogeneous treatment effects. We then introduce a novel metric, \%ROM, which is the proportion of full ROM achieved during pROM, and demonstrate that this definition of lengthened partials remains relatively consistent across exercises. Overall, these findings suggest that lengthened partials differ from full ROM training not only in ROM, but also in execution dynamics and consistency, highlighting the potential of AI-based methods for advancing research and improving resistance training prescription.
MED-PHOct 31, 2019
The importance of evaluating the complete automated knowledge-based planning pipelineAaron Babier, Rafid Mahmood, Andrea L. McNiven et al.
We determine how prediction methods combine with optimization methods in two-stage knowledge-based planning (KBP) pipelines to produce radiation therapy treatment plans. We trained two dose prediction methods, a generative adversarial network (GAN) and a random forest (RF) with the same 130 treatment plans. The models were applied to 87 out-of-sample patients to create two sets of predicted dose distributions that were used as input to two optimization models. The first optimization model, inverse planning (IP), estimates weights for dose-objectives from a predicted dose distribution and generates new plans using conventional inverse planning. The second optimization model, dose mimicking (DM), minimizes the sum of one-sided quadratic penalties between the predictions and the generated plans using several dose-objectives. Altogether, four KBP pipelines (GAN-IP, GAN-DM, RF-IP, and RF-DM) were constructed and benchmarked against the corresponding clinical plans using clinical criteria; the error of both prediction methods was also evaluated. The best performing plans were GAN-IP plans, which satisfied the same criteria as their corresponding clinical plans (78%) more often than any other KBP pipeline. However, GAN did not necessarily provide the best prediction for the second-stage optimization models. Specifically, both the RF-IP and RF-DM plans satisfied all clinical criteria 25% and 15% more often than GAN-DM plans (the worst performing planning), respectively. GAN predictions also had a higher mean absolute error (3.9 Gy) than those from RF (3.6 Gy). We find that state-of-the-art prediction methods when paired with different optimization algorithms, produce treatment plans with considerable variation in quality.
LGJul 17, 2018
Automated Treatment Planning in Radiation Therapy using Generative Adversarial NetworksRafid Mahmood, Aaron Babier, Andrea McNiven et al.
Knowledge-based planning (KBP) is an automated approach to radiation therapy treatment planning that involves predicting desirable treatment plans before they are then corrected to deliverable ones. We propose a generative adversarial network (GAN) approach for predicting desirable 3D dose distributions that eschews the previous paradigms of site-specific feature engineering and predicting low-dimensional representations of the plan. Experiments on a dataset of oropharyngeal cancer patients show that our approach significantly outperforms previous methods on several clinical satisfaction criteria and similarity metrics.
LGMay 23, 2018
Learning to Optimize Contextually Constrained Problems for Real-Time Decision-GenerationAaron Babier, Timothy C. Y. Chan, Adam Diamant et al.
The topic of learning to solve optimization problems has received interest from both the operations research and machine learning communities. In this work, we combine techniques from both fields to address the problem of learning to generate decisions to instances of continuous optimization problems where the feasible set varies with contextual features. We propose a novel framework for training a generative model to estimate optimal decisions by combining interior point methods and adversarial learning, which we further embed within an data generation algorithm. Decisions generated by our model satisfy in-sample and out-of-sample optimality guarantees. Finally, we investigate case studies in portfolio optimization and personalized treatment design, demonstrating that our approach yields advantages over predict-then-optimize and supervised deep learning techniques, respectively.