a new network simplex algorithm to reduce consecutive‎ ‎degenerate pivots and prevent ‎stalling‎

Authors

z. ‎aghababazadeh‎‎

department of mathematics‎, ‎science and‎ ‎research branches‎, ‎islamic azad university‎, ‎tehran‎, ‎iran‎. m. ‎rostamy-‎malkhalifeh‎‎

department of mathematics‎, ‎science and‎ ‎research branches‎, ‎islamic azad university‎, ‎tehran‎, ‎iran‎.

abstract

it is well known that in operations research‎, ‎degeneracy can cause a cycle in a network‎ ‎simplex algorithm which can be prevented by maintaining strong‎ ‎feasible bases in each pivot‎. ‎also‎, ‎in a network consists of n arcs‎ ‎and m nodes‎, ‎not considering any new conditions on the entering‎ ‎variable‎, ‎the upper bound of consecutive degenerate pivots is equal‎ $left( ‎begin{array}{c}‎ ‎n-m+k ‎ ‎k ‎ ‎end{array}‎ ‎right)$‎ ‎where $k$ is the number of degenerate arcs in the basis‎. ‎as‎ ‎well as‎, ‎the network simplex algorithm may stall if it goes through‎ ‎some long consecutive degenerate pivot‎. ‎through conditions such as‎ ‎(lrc) and (lrs) upon entering variable rules‎, ‎this upper bound can‎ ‎be reduced to $mn$ and $m^2$ respectively‎. ‎in this current paper we‎ first suggest a new algorithm for anti--stalling in which a new‎ ‎condition is provided to the entering variable and then show that‎ ‎through this algorithm there are at most $k$ consecutive degenerate ‎pivots.‎

similar resources

A new network simplex algorithm to reduce consecutive‎ ‎degenerate pivots and prevent ‎stalling‎

It is well known that in operations research‎, ‎degeneracy can cause a cycle in a network‎ ‎simplex algorithm which can be prevented by maintaining strong‎ ‎feasible bases in each pivot‎. ‎Also‎, ‎in a network consists of n arcs‎ ‎and m nodes‎, ‎not considering any new conditions on the entering‎ ‎variable‎, ‎the upper bound of consecutive degenerate pivots is equal‎ $left( ‎begin{array}{c}‎ ‎n...

full text

A network simplex algorithm with O(n) consecutive degenerate pivots

In this paper, we suggest a new pivot rule for the primal simplex algorithm for the minimum cost flow problem, known as the network simplex algorithm. Due to degeneracy, cycling may occur in the network simplex algorithm. By maintaining strongly feasible bases due to Cunningham [1976, 1979], cycling can be prevented but without restrictions on the entering variable, the algorithm can still perf...

full text

A New Method to Reduce Energy Consumption in Manet Network Routing based on OLSR Protocol and Genetic Algorithm

Mobile Ad Hoc Networks (MANET) can be considered as a class of unstructured networks created by a number of autonomous wireless and sensor nodes. The inherent characteristics of such networks have made specific applications, such as multimedia transfer and challenging. Basically, the functionality of a node and very few resources directly affect the delivery of packets which depends on the ...

full text

A New Method to Reduce Energy Consumption in Manet Network Routing based on OLSR Protocol and Genetic Algorithm

Mobile Ad Hoc Networks (MANET) can be considered as a class of unstructured networks created by a number of autonomous wireless and sensor nodes. The inherent characteristics of such networks have made specific applications, such as multimedia transfer and challenging. Basically, the functionality of a node and very few resources directly affect the delivery of packets which depends on the ...

full text

An Efficient Extension of Network Simplex Algorithm

In this paper, an efficient extension of network simplex algorithm is presented. In static scheduling problem, where there is no change in situation, the challenge is that the large problems can be solved in a short time. In this paper, the Static Scheduling problem of Automated Guided Vehicles in container terminal is solved by Network Simplex Algorithm (NSA) and NSA+, which extended the stand...

full text

My Resources

Save resource for easier access later


Journal title:
international journal of industrial mathematics

جلد ۸، شماره ۳، صفحات ۲۰۹-۲۱۴

Hosted on Doprax cloud platform doprax.com

copyright © 2015-2023