no code implementations • 7 Nov 2023 • Young Woong Park, Jinhak Kim, Dan Zhu
In this study, we propose analyses on missing value patterns using six real-world data sets in various applications, as well as the conditions for applicability of imputation algorithms.
no code implementations • 12 Dec 2017 • Seokhyun Chung, Young Woong Park, Taesu Cheong
The proposed model minimizes mean squared errors while ensuring that the majority of the important regression assumptions are met.
no code implementations • 15 Mar 2017 • Young Woong Park
We propose a data aggregation-based algorithm with monotonic convergence to a global optimum for a generalized version of the L1-norm error fitting model with an assumption of the fitting function.
no code implementations • 27 Jan 2017 • Young Woong Park, Diego Klabjan
For high dimensional cases, an iterative heuristic algorithm is proposed based on the mathematical programming models and a core set concept, and a randomized version of the algorithm is derived to guarantee convergence to the global optimum.
no code implementations • 20 Jan 2017 • Young Woong Park, Diego Klabjan
We propose a mixed integer programming (MIP) model and iterative algorithms based on topological orders to solve optimization problems with acyclic constraints on a directed graph.
no code implementations • 10 Sep 2016 • Young Woong Park, Diego Klabjan
Principal component analysis (PCA) is often used to reduce the dimension of data by selecting a few orthonormal vectors that explain most of the variance structure of the data.
no code implementations • 5 Jul 2016 • Young Woong Park, Diego Klabjan
We propose a clustering-based iterative algorithm to solve certain optimization problems in machine learning, where we start the algorithm by aggregating the original data, solving the problem on aggregated data, and then in subsequent steps gradually disaggregate the aggregated data.
no code implementations • 5 Jul 2016 • Young Woong Park, Yan Jiang, Diego Klabjan, Loren Williams
We examine the performance of our algorithms on a stock keeping unit (SKU) clustering problem employed in forecasting halo and cannibalization effects in promotions using real-world retail data from a large supermarket chain.