This article investigates the effect of assigning the most-active items to the best locations in unit-load warehouses with non-traditional aisles. Specifically, the performance of flying-V and fishbone designs are investigated when products exhibit different velocity profiles. Both single-and dual-command operations are considered for a warehouse where receiving and shipping are located at the midpoint of one side of the warehouse. For dual-command operations, a fishbone design shows similar reductions in travel distances for both random and turnover-based storage policies. The fishbone designs that provide the best performance have a diagonal cross aisle that extends to the upper corners of the picking space and are approximately half as tall as they are wide. In general, warehouse design parameters that perform best under random storage also perform well under turnover-based storage.Keywords: Warehouses, turnover-based storage, dual-command operations, fishbone aisles, flying-V cross aisle optimal facility layout. AIIE Transactions, 4(2), 144-147. Malmborg, C.J. and Krishnakumar, B. (1987) On the optimality of the cube per order index for conventional warehouses with dual command cycles. Material Flow, 4, 169-175. Malmborg, C.J. and Krishnakumar, B. (1990) A revised proof of optimality for the cube-per-order index rule for stored item location.

Unit-load warehouses store and retrieve unit-loads, typically pallets. When storage and retrieval operations are not coordinated, travel is from a pickup and deposit (P&D) point to a pallet location and back again. In some facilities, workers interleave storage and retrieval operations to form a dual-command cycle. Two new aisle designs proposed by Gue and Meller ("Improving the unit-load warehouse." In Progress in Material Handling Research: 2006. Material Handling Industry of America, Charlotte, NC, 2006) use diagonal aisles to reduce the travel distance to a single pallet location by approximately 10 and 20% for the two designs, respectively. We develop analytical expressions for travel between pallet locations for one of these-the fishbone design. We then compare fishbone warehouses that have been optimized for dual-command to traditional warehouses that have been optimized in the same manner, and show that an optimal fishbone design reduces dual-command travel by 10-15%.

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The use of video lectures is a common method of delivering course content in online learning environments. Over time, our understanding of what makes an effective online video has evolved with advances in educational research and technology. In the past decade, free online video services such as YouTube have allowed widespread dissemination of instructional videos. Prevalence of high-quality instruction produced by organizations such as Kahn Academy has advanced our knowledge of effective video techniques and raised our students' expectations. Recent research has explored the elements of lecture videos and presentation styles that either contribute to, or detract from, student engagement. This paper explores one instructor's experience with teaching an online course in engineering economics multiple times, the original development of lecture videos and the subsequent editing and rework of those videos. Until recently, the effectiveness of the course videos was judged primarily from student feedback in course evaluations. However, the most recent version of our institution's learning management system allows collection of detailed student viewing data on the videos, including number of views, average view time and drop-off rates. Correlation between video viewing habits and student performance is explored and recommendations and lessons learned are provided.