Soondo Hong

Learn More
This paper discusses an order batching formulation and heuristic solution procedure suitable for a large-scale order picking situation in parallel-aisle picking systems. Order batching can decrease the total travel distance of pickers not only through reducing the number of trips, but also by shortening the length of each trip. In practice, some order(More)
MOTIVATION Histone modifications regulate chromatin structure and gene expression. Although nucleosome formation is known to be affected by primary DNA sequence composition, no sequence signature has been identified for histone modifications. It is known that dense H3K4me3 nucleosome sites are accompanied by a low density of other nucleosomes and are(More)
This research presents several heuristics to optimize the location of crossovers in a conveyor-based Automated Material Handling System (AMHS) for a semiconductor wafer fabrication facility. The objective is to determine the location of crossovers that minimizes the total cost of the expected work-in-process on the conveyor and the cost of installing and(More)
This study analyzes impacts by batch picking on picker blocking in narrow-aisle order picking, and determines appropriate batch formations for a better order picking throughput. We present multiple-pick analytical models to offer insights about picker blocking in batch picking. Several simulation studies over a variety of batching situations scrutinize(More)
A bucket brigade strategy allows workloads in warehouses to be distributed with a minimal level of managerial planning and oversight. However, the variability and uncertainty of the pick locations within a particular order or batch often results in picker blocking and subsequent losses in productivity. This study formulates an order batching model for(More)
This note develops analytical picker blocking models to simply and accurately assess picker blocking in parallel-aisle order picking systems when multiple picks occur at a pick point. The Markov chain-based models characterize the two bounding walking speeds for modeling picker movement: unit walk-time and instantaneous walk-time. The unit-walk time model(More)
Understanding gene regulatory information in DNA remains a significant challenge in biomedical research. This study presents a computational approach to infer gene regulatory programs from primary DNA sequences. Using DNA around transcription start sites as attributes, our model predicts gene regulation in the gene. We find that H3K27ac around TSS is an(More)
  • 1