A general iterative solver for unbalanced inconsistent transportation problems
Journal Title: Archives of Transport - Year 2016, Vol 37, Issue 1
Abstract
The transportation problem, as a particular case of a linear programme, has probably the highest relative frequency with which appears in applications. At least in its classical formulation, it involves demands and supplies. When, for practical reasons, the total demand cannot satisfy the total supply, the problem becomes unbalanced and inconsistent, and must be reformulated as e.g. finding a least squares solution of an inconsistent system of linear inequalities. A general iterative solver for this class of problems has been proposed by S. P. Han in his 1980 original paper. The drawback of Han’s algorithm consists in the fact that it uses in each iteration the computation of the Moore-Penrose pseudoinverse numerical solution of a subsystem of the initial one, which for bigger dimensions can cause serious computational troubles. In order to overcome these difficulties we propose in this paper a general projection-based minimal norm solution approximant to be used within Han-type algorithms for approximating least squares solutions of inconsistent systems of linear inequalities. Numerical experiments and comparisons on some inconsistent transport model problems are presented.<br/><br/>
Authors and Affiliations
Doina Carp, Constantin Popa, Cristina Serban
Evaluation of influence of mobility management instruments implemented in separated areas of the city on the changes in modal split
The article presents results of research aimed at construction of the model for evaluation of potential impact of mobility management instruments implemented in areas of high volume of work related trips. The model helps...
Design of brake force distribution model for front-and-rear-motor-drive electric vehicle based on radial basis function
To achieve high-efficiency and stable brake of a front-and-rear-motor-drive electric vehicle (FRMDEV) with parallel cooperative braking system, a multi-objective optimal model for brake force distribution is created base...
THE INF-SUP CONDITION TESTS FOR SHELL/PLATE FINITE ELEMENTS
Development of high-performance finite elements for thick, moderately thick, as well as thin shells and plates, was one of the active areas of the finite element technology for 40 years, followed by hundreds of publicati...
Business situation in the freight road transport in Poland
The article covers characteristics of the methodology of studying business activity in the freight road transport in Poland. Such studies have been conducted at the Motor Transport Institute in Warsaw, every quarter of a...
A method to achieve comparable thermal states of car brakes during braking on the road and on a high-speed roll-stand
The temperature of a brake friction surface influences significantly the braking effectiveness. The paper describes a heat transfer process in car brakes. Using a developed program of finite element method, the temperatu...