Iranian Journal of Operations Research

An Integer Programming Model and a Tabu Search Algorithm to Generate α-labeling of Special Classes of Quadratic Graphs

Kourosh Eshghi

First, an integer programming model is proposed to find an α-labeling for quadratic graphs. Then, a Tabu search algorithm is developed to solve large scale problems. The proposed approach can generate α-labeling for special classes of quadratic graphs, not previously reported in the literature. Then, the main theorem of the paper is presented. We show how a problem in graph theory can be modeled and solved by an integer programming model and a metaheuristic approach.

The Impact of CSR and Semi-TDPD on Price-Based Revenue Sharing Contract

Mahdi Shafiei

We develop a new coordination contract of manufacturer-retailer in a distribution system. A revenue sharing contract based on retail price is modelled, which is more practical to handle channel conflict. We also integrate two concepts of CSR (Corporate Sociality Responsible) and Semi-TDPD (Semi Third Degree Price Discrimination) into our model. Semi-TDPD strategy makes it possible to exploit the opportunity of customer behavior, by adopting a price discrimination strategy. According to this strategy, some customers who cannot or are not willing to pay the posted price, are allowed to purchase at lower prices through bargaining. To illustrate the proposed approach, we present some numerical examples. Through these examples, we investigate the impact of CSR and Semi-TDPD on decisions and also the good performance of this coordination.

Exploring Energy Efficiency and Service Quality of Airlines with Cruise Speed Control

Saiedeh Gholami

In the past decade, fuel consumption and CO₂ emission have increased in the airline industry. Large CO₂ footprint has a damaging effect on the environment. Global concerns over this issue has made the airline industry to be greener. Most efforts of the green airline industry are improving the fuel consumption to reduce the CO₂ emission and its environmental damage. Here, we use cruise speed control to control the fuel consumption and CO₂ emission. Each aircraft has a different speed level needing a different fuel consumption. Service quality is studied besides the energy consumption. We investigate two objectives including total energy consumption (TEC) and passenger service level (PSL). TEC and PSL are conflicting in nature. We develop a mixed-integer nonlinear programming model to integrate schedule design, aircraft assignment and maintenance routing problems. We make use of the augmented ε-constraint method to solve the problem. To evaluate the model, a real data based on the Emirates airline flights is used. The results are compared using four different scenarios

Considering Stochastic and Combinatorial Optimization

Abdollah Arasteh

Here, issues connected with characteristic stochastic practices are considered. In the first part, the plausibility of covering the arrangements of an improvement issue on subjective subgraphs is studied. The impulse for this strategy is a state where an advancement issue must be settled as often as possible for discretionary illustrations. Then, a preprocessing stage is considered that would quicken ensuing inquiries by discovering a settled scattered subgraph covering the answer for an arbitrary subgraph with a high likelihood. This outcome is grown to the basic instance of matroids, in addition to advancement issues taking into account the briefest way and resource covering sets. Next, a stochastic improvement model is considered where an answer is sequentially finished by picking an accumulation of “points”. Our crucial idea is the profit of adaptivity, which is investigated for an extraordinary sort of an issue. For the stochastic knapsack issue, the industrious upper and lower cutoff points of the “adaptivity hole” between ideal adaptive and non-adaptive methodologies are checked. Also, an algorithm is described that accomplishes a close ideal estimate. Finally, complicational results are shown to verify the optimal adaptive approaches.