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The warehouse traveling salesman problem and its application
No full text2019-10-18The traveling salesman problem (TSP) is a famous problem providing fundamental tool to many practical fields, including the transportation, the delivery service, the supply chain, the manufacturing, etc. To adapt to different real world problems, some variants of the TSP have been proposed and attracted much attention among researchers. One particular problem is called the generalized traveling salesman problem (GTSP) whose goal is to select one point each from multiple sets of points and come up with a tour with the minimum length. In this dissertation, we will propose a new variant of the TSP, called the warehouse traveling salesman problem (WTSP), which is an extension of the GTSP and arises because of the occurrence of Amazon's random stow. Random stow is a type of Amazon's warehouse applying randomized strategy, in which the storage of products can be considered to be placed randomly. When an order arrives, the worker will pick up the required number of items in the order by moving back and forth in the random stow. The WTSP is to help the worker find the shortest tour whiling completing the order fulfillment. To solve the WTSP, we propose two methods. The first one is to transform the WTSP to the GTSP so that one can deploy the state-of-the-art GTSP solvers to solve the transformed GTSP problem. We also develop a meta-heuristic algorithm based on the conditional Markov chain search (CMCS) algorithm to solve the WTSP directly. The numerical experiments compare these two methods, and show that CMCS based method can solve the WTSP more efficiently. To demonstrate the practical usage of the WTSP, we apply the WTSP model to the warehouse order fulfillment strategy in which a warehouse runner picks up multiple items from multiple shelves in a single run. The result indicates that a warehouse applying the WTSP model can significantly reduce the order-picking traveling costs compared to Amazon's semi-automatic warehouse using Kiva robots to fulfill the orders
Daily Trojan, vol. 198, no. 33, Oct 11, 2019
No full textDaily Trojan, vol. 198, no. 33, Oct 11, 2019
Daily Trojan, vol. 198, no. 40, Oct 25, 2019
No full textDaily Trojan, vol. 198, no. 40, Oct 25, 2019
Isaac Pacht, letter and enclosed brochure, 1955-05-18, to "friend"
No full textIsaac Pacht, letter and enclosed brochure, 1955 May 18, to "friend". "May I urge you most earnestly to read the enclosed brochure which reveals a situation in our Los Angeles public school system…" -- first line. Brochure published by Hardy-Petty Headquarters, 1256 West Seventh Street, Los Angeles, California, USA
Joseph Morton, "Do school books tell the truth?", newspaper clipping, [People's World Magazine], 1953-10-23
No full textJoseph Morton, "Do school books tell the truth?", newspaper clipping from People's World Magazine, 1953 October 23
"School bill faces snag", newspaper clipping, [People's World Magazine], vol. 19, no. 17, 1956-01-25
No full text"School bill faces snag", newspaper clipping from People's World Magazine, volume 19, number 17, 1956 January 25
"LA school standards periled by 'economy' plan", newspaper clipping, [People's World Magazine], 1955-11-04
No full text"LA school standards periled by 'economy' plan", newspaper clipping from People's World Magazine, 1955 November 04
Southern California Peace Crusade, Peace Newsgram, newsletter, 1955-07-05
No full textPeace Newsgram, newsletter, Southern California Peace Crusade, 326 West Third Street, Los Angeles, California, USA, 1955 July 05
Southern California Peace Crusade, Peace Newsgram, newsletter, 1955-06-01
No full textPeace Newsgram, newsletter, Southern California Peace Crusade, 326 West Third Street, Los Angeles, California, USA, 1955 June 01
Everybody's Committee to Outlaw War, Appeal to the living, leaflet
No full textEverybody's Committee to Outlaw War, 1805 Wilshire Boulevard, Los Angeles, California, USA, An appeal to the living, leaflet