This paper deals with a bi-objective hybrid no-wait flowshop scheduling problem minimizing the makespan and total weighted tardiness, in which we consider transportation times between stages. Obtaining an optimal solution for this type of complex, large-sized problem in reasonable computational time by using traditional approaches and optimization tools is extremely difficult. This paper presen...

 This paper present unequal-sized facilities layout solutions generated by a genetic search program named LADEGA (Layout Design using a Genetic Algorithm). The generalized quadratic assignment problem requiring pre-determined distance and material flow matrices as the input data and the continuous plane model employing a dynamic distance measure and a material flow matrix are discussed. Computa...

In this paper we study the complexity of Cutting Planes (CP) refutations, and tree-like CP refutations. Tree-like CP proofs are natural and still quite powerful. In particular, the propositional pigeonhole principle (PHP) has been shown to have polynomial-sized tree-like CP proofs. Our main result shows that a family of tautologies, introduced in this paper requires exponential-sized tree-like ...

We present a new mathematical model for a permutation flowshop scheduling problem with sequence-dependent setup times considering minimization of two objectives, namely makespan and weighted mean total earliness/tardiness. Only small-sized problems with up to 20 jobs can be solved by the proposed integer programming approach. Thus, an effective multi-objective immune system (MOIS) is specially ...

This paper aims to study the locomotive assignment problem which is very important for railway companies, in view of high cost of operating locomotives. This problem is to determine the minimum cost assignment of homogeneous locomotives located in some central depots to a set of pre-scheduled trains in order to provide sufficient power to pull the trains from their origins to their destinations...

Small and medium-sized logistics companies are playing an increasingly important part in social life. We selected the data of small and medium-sized logistical companies in Beijing, Shanghai and Guangzhou, reformulated ordinal regression support vector machine method so that different input points could make different contributions to decide hyper plane, to analyze multi-classification of credi...

We consider the classical line simplification problem subject to a given error bound but with additional topology constraints as they arise for example in the map rendering domain. While theoretically inapproximability has been proven for these problem variants, we show that in practice one can solve medium sized instances optimally using an integer linear programming approach and larger instan...

In today’s lecture, we will construct exponential sized PCPs for NP. More formally, we will show that the NP-Complete problem, Circuit-Satisfiability (Circuit-SAT) is in PCP1,1−δ[O(n), O(1)] for some 0 < δ < 1. Recall that the PCP Theorem states that Circuit-SAT ∈ PCP1,1−δ[O(log n), O(1)]. However, as we will see in later lectures, the exponential sized PCPs for Circuit-SAT will be used in prov...

The objective of this paper is to determine the efficiency of manufacturing companies in Kenya over the period of 2009 to 2011 as well as suggesting appropriate policies to be employed by the manufacturing companies in Kenya based on the findings of the study. Three critical inputs variables (raw materials, staff expenses and plant and machinery) and two output variables (net sale and earnings ...

The problem of minimizing a quadratic form over the standard simplex is known as the standard quadratic optimization problem (SQO). It is NPhard, and contains the maximum stable set problem in graphs as a special case. In this note we show that the SQO problem may be reformulated as an (exponentially sized) linear program.