Column generation is an indispensable tool in computational optimization to solve a mathematical program by iteratively adding the variables of the model. Even though the method is simple in theory there are many algorithmic choices and we discuss the most common ones. Particular emphasis in put on the dual interpretation, relating column generation to Langrangian relaxation and cutting plane a...

let a and b be n × m matrices. the matrix b is said to be g-row majorized (respectively g-column majorized) by a, if every row (respectively column) of b, is g-majorized by the corresponding row (respectively column) of a. in this paper all kinds of g-majorization are studied on mn,m, and the possible structure of their linear preservers will be found. also all linear operators t : mn,m ---> mn...

influence of soil organic matter (som) on the adsorption, desorption and transport of polycyclic aromatic hydrocarbons (pahs) has already been given full investigation in soils. in this paper, confocal laser scanning microscope (clsm) was used to elucidate aqueous leaching of pahs in different types of soil with soil columns, which enhanced understanding on transport of pahs appreciably. four t...

Progressive collapse is a situation where local failure of a primary structural component leads to the collapse of adjoining members which, in turn, leads to additional collapse. Hence, the total damage is disproportionate to the original cause. The most common local failure in framed structure is assumed to be column failure. In this paper, a new approach for dynamic column removal in framed s...

in order to investigate the gas separation ability of a column packed with nanozeolitic material, nano nay zeolite was synthesized and granulated. these uniform granules packed in a chromatographic column were utilized for separation of xe and kr under various operating conditions. with regards to the response peaks obtained from trace injections of xe and kr into the column, the first and seco...