Multi-choice KNAPSACK PROBLEM is a branch of regular KNAPSACK PROBLEM where the objects are classified in different classes and each class has one and only one representative in final solution. Although it is assumed that each object belongs to just one class, sometimes this assumption is not valid in real PROBLEMs. In this case an object may belong to the several classes. In fuzzy multi-choice KNAPSACK PROBLEM (FMCKP), fuzzy sets are applied to show that each object is a member of each class with a membership grade. In this paper we proposed two new models for fuzzy multi-choice KNAPSACK PROBLEM. These models have a fuzzy constraint and so we applied the fuzzy linear programming (FLP) approach to solve them. Typical examples show the capability and efficiency of the proposed models.

Multi-choice KNAPSACK PROBLEM is a branch of regular KNAPSACK PROBLEM where the objects are classified in different classes and each class has one and only one representative in final solution. Although it is assumed that each object belongs to just one class, sometimes this assumption is not be respected in real PROBLEMs. In this case an object may be belongs to the several classes. We have used the fuzzy sets concept to show that each object may be a member of each class with a membership grade. We called it a fuzzy multi-choice KNAPSACK PROBLEM (FMCKP). We consider two objectives for the PROBLEM: The first one is to maximize the profit of selected combination and the second one is to minimize the total differences of the deviation of ideal relation for each class. Developing such a bi-objective model, we applied the fuzzy linear programming (FLP) approach to solve it. Experiments on a lot of typical examples show the capability and efficiency of the proposed model.

In this paper, the concept of ¶*-quasiconvexity is introduced by using convexifactors. Mond-Weir-type and Schaible-type duals are associated with a multiobjective fractional programming PROBLEM, and various duality results are established under the assumptions of ¶*-pseudoconvexity and ¶*-quasiconvexity.

Selecting an optimum combination of items from a set of items, known as KNAPSACK PROBLEMs, is an important issue in the decision making domain. In this paper, a new approach is developed to solve a Multiple Attribute KNAPSACK PROBLEM (MAKP) in which each combination of items is evaluated using some quantitative and qualitative attributes. The assumed qualitative attributes cannot be measured by a mathematical formulation but by a DM/expert. In this paper, a Genetic Algorithm (GA) model has been developed to generate different combinations as the sequential population of the GA model. To rate the qualitative attributes for each chromosome (or combination) in the population, a Neural Network (NN) model has been developed. The ratings (or scores) resulted from quantitative attributes (by NN) and qualitative attributes (by mathematical formulation) for each chromosome form a row of a decision matrix. Having the decision matrix and known weights of attributes, the combinations in each population are ranked by applying a MADM model. The ranks obtained for each chromosome shows the fitness of that chromosome. Using the GA model, the best combination is achieved. The results of conducted experiments show the capability of the proposed approach to deal with MAKP PROBLEMs.

The vehicle routing PROBLEM is one of the most well-known optimization PROBLEMs, which aims to design an optimum set of routes with the lowest cost for servicing the customers in a way that is consistent with the existing constraints. The wide practical application and scope of this PROBLEM has attracted much attention from researchers. But in return, the severity of solving has created difficulties and increased the need for heuristic and meta-heuristic solutions. This research represents a greedy heuristic method based on first categorizing then routing methods, to solve the capacitated vehicle routing PROBLEM (CVRP) using the capabilities of PROBLEM reduction to the KNAPSACK PROBLEM. The advantages of this method include the consideration of effective criteria such as distance between customers, distance between customers to depot and demand of points in decision making, decent speed and quality of solution and the ability to utilize the benefits of reduction. Standard samples from CVRPLIB were used to evaluate the results and comparing them.

In this paper, a new approximate method is presented to solve multi-dimensional KNAPSACK PROBLEM by using multiple criteria decision making (MCDM). In order to, initially efficiency values for every item is calculated then items are ranked by using MCDM. Finally, items are selected in according to their rank.