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Please scroll down for article-it is on subsequent pages With 12,500 members from nearly 90 countries, INFORMS is the largest international association of operations research (O.R.) and analytics professionals and students. INFORMS provides unique networking and learning opportunities for individual professionals, and organizations of all types and sizes, to better understand and use O.R. and analytics tools and methods to transform strategic visions and achieve better outcomes. For more information on INFORMS, its publications, membership, or meetings visit http://www.informs.org

This pa per re ports on a new par al lel im ple men ta tion of the pri mal sim plex method for mini mum cost net work flow prob lems, that de com poses both the piv ot ing and pric ing op era tions. The selfscheduling ap proach is both flexi ble and ef fi cient; its im ple men ta tion is close in speed t o the best serial code when us ing one proc es sor, and is ca pa ble of sub stan tial speed ups as par al lel co m put ing units are added. An in-depth com pu ta tional study of ran domly gen er ated trans por ta tion and transship ment prob lems veri fied the ef fec tive ness of this ap proach, with re sults on a 20-proces sor 80386based sys tem that are com peti tive with-and oc ca sion ally su pe rior to-mas sively par al lel im plemen ta tions us ing tens of thou sands of proc es sors. A micro-analysis of the code's be hav ior iden ti fied un ex pected sources of (the oc ca sion ally su per lin ear) speedup, in clud ing the evo lu tion a ry to pol ogy of the net work ba sis.

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