Maximizing space utilization in unit-load warehouses.

Layouts of Unit-Load Warehouses with Multiple Slot Heights

Transportation Science ◽

10.1287/trsc.2020.0993 ◽

2020 ◽

Vol 54 (5) ◽

pp. 1332-1350

Author(s):

Luis F. Cardona ◽

Kevin R. Gue

Keyword(s):

Simulation Model ◽

Travel Time ◽

Operating Costs ◽

Unit Load ◽

Space Utilization ◽

Duration Of Stay

We describe a method to generate layouts for unit-load warehouses that use multiple slot heights as a way to maximize warehouse space utilization. The problem has two parts: slots must be arranged into rack-bays, and rack-bays must be arranged into a layout. We describe two methods for the first subproblem, depending on whether the warehouse has directed picking and put-away. For the second, we describe a simulation model and a greedy procedure based on the duration-of-stay storage policy. We observe significant benefits of using multiple slot heights in unit-load warehouses with respect to footprint, expected travel time, and cost of racking. For a typical warehouse, we expect space savings between 25% and 35%, depending on the number of slot types, and savings of between 15% and 25% in annual operating costs.

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Possibility of detecting a high-beta-gamma LLW repository prior to underground space utilization

Journal of Nuclear Fuel Cycle and Environment ◽

10.3327/jnuce.5.29 ◽

1999 ◽

Vol 5 (2) ◽

pp. 29-35

Author(s):

Hiroyuki Ikuse ◽

Shuji Hashimoto ◽

Masafumi Yamamoto ◽

Katsuhide Matsumura

Keyword(s):

Underground Space ◽

Space Utilization ◽

High Beta

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EVALUATION OF MOUNTAIN AREA AS NON-POINT SOURCE OF NITROGEN FOR SETO INLAND SEA: THE NORTHERN SHIKOKU REGION, JAPAN

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.31519/conferencearticle_5b1b9389d98135.84095825 ◽

2017 ◽

Author(s):

Shohei Morisawa ◽

Yukio Komai ◽

Takao Kunimatsu ◽

...

Keyword(s):

Average Concentration ◽

Point Sources ◽

Seto Inland Sea ◽

Mountain Streams ◽

Unit Load ◽

Mountain Areas ◽

Mountain Area ◽

The Seto Inland Sea ◽

Unit Load Method ◽

Important Position

The northern Shikoku region is located in the Western part of Japan and faces towards the Seto Inland Sea. The forest area, which is one of the non-point sources in the Seto Inland Sea watershed, occupies 75% of the land use in the watershed of the northern Shikoku region. The amount of loadings of nutrients and COD in the Seto Inland Sea has been estimated by the unit load method but actually the data has not been investigated. It is however, necessary to know the real concentration of nitrogen in mountain streams to evaluate the role which is the mountain area plays as non-point sources. Therefore, more water samples of mountain streams in the watershed need to be taken and the concentrations of nitrogen analyzed. The mountain streams in the northern Shikoku area were investigated from April, 2015 to November, 2015. The number of sampling sites was 283, in addition to the past data by Kunimatsu et al. The average concentration of nitrate nitrogen in Ehime, Kagawa, and Tokushima was 0.61mg/L, 0.78mg/L and 0.34mg/L, respectively. The environmental standard range for nitrogen in the Seto Inland Sea is from between less than 0.2mg/L and less than 1mg/L. Therefore, the average concentration of nitrogen in these regions was over category II, and those of mountain streams in Kagawa Prefecture exceeded category III. About 20% of mountain streams were more than 1mg/L. It has become clear that mountain areas occupy an important position as non-point sources for the Seto Inland Sea.

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