Practical design of tall frame-tube and diagrids are formulated as two discrete optimization problems searching for minimal weight undercodified constraints under gravitational and wind loading due to Iranian codes of practice for steel structures (Part 6 & Part 10). Particular encoding of design vector is proposed to efficiently handle both problems leading to minimal search space. Two types o...

Abstract—This paper evaluates oil displacement by water in Hauterivian sandstone reservoir of Kashkari oil field in North of Afghanistan. The core samples of this oil field were taken out from well No-21st, and the relative permeability and fractional flow are analyzed. Steady state flow laboratory experiments are performed to empirically obtain the fractional flow curves and relative permeabil...

This paper deals with the application of fourth kind Chebyshev wavelets (FKCW) in solving numerically a model of HIV infection of CD4+T cells involving Caputo fractional derivative. The present problem is a system of nonlinear fractional differential equations. The goal is to approximate the solution in the form of FKCW truncated series. To do this, an operational matrix of fractional integrati...

Given an instance of the minimum cost flow problem, the corresponding inverse problem is to modify the arc costs as little as possible so that a given feasible flow becomes optimal to the modified minimum cost flow problem. In this article, we study this inverse problem in that the modifications are measured by the weighted bottleneck-type Hamming distance. We present a new efficient algorithm ...

We consider the quickest flow problem in dynamic networks with a single source s and a single sink t: given an amount of flow F , find the minimum time needed to send it from s to t, and the corresponding optimal flow over time. We introduce new mathematical formulations and derive optimality conditions for the quickest flow problem. Based on the optimality conditions, we develop a new costscal...

In this paper, theory and algorithms for solving the multiple objective minimum cost flow problem are reviewed. For both the continuous and integer case exact and approximation algorithms are presented. In addition, a section on compromise solutions summarizes corresponding results. The reference list consists of all papers known to the authors which deal with the multiple objective minimum cos...

Given a generalized network and a generalized feasible flow f, we consider a problem finding a modified edge cost d such that f is minimum cost with respect to d and the maximum deviation between the original edge cost and d is minimum. This paper shows the relationship between this problem and minimum mean circuit problems and analyze a binary search algorithm for this problem.

We present fast and simple fully polynomial-time approximation schemes (FPTAS) for generalized versions of maximum flow, multicommodity flow, minimum cost maximum flow, and minimum cost multicommodity flow. We extend and refine fractional packing frameworks introduced in FPTAS’s for traditional multicommodity flow and packing linear programs. Our FPTAS’s dominate the previous best known complex...

We consider the quickest flow problem in dynamic networks with a single source s and a single sink t: given a flow F , find the minimum time needed to send F from s to t, and the corresponding optimal flow over time. We introduce new mathematical formulations and derive optimality conditions for the quickest flow problem. Based on the optimality conditions, we develop a new cost-scaling algorit...

Let N be a single-source single-sink ow network with n nodes, m arcs, and positive arc costs. We present a pseudo-polynomial algorithm that computes a maximum ow of minimum cost for N in time O(3=4 m p log n), where is the cost of the ow. This improves upon previously known methods for networks where the minimum cost of the ow is small. We also show an application of our ow algorithm to a well-...