A hybrid model based on fuzzy VIKOR and the classical optimal search to detect illegal chemical warehouses

Abstract

The use of chemical weapons has turned into an increasing risk for the world. In this study, a hybrid approach on the basis of fuzzy VIKOR and the optimal search model to cope with an important case study called the detection of illegal chemical warehouses is introduced. It is obvious that such illegal activities are accomplished under high secret considerations. Therefore, we have several types of ambiguity and uncertainty in this problem. First, fuzzy VIKOR is used to prioritize the suspicious warehouses based on time and cost of a search under fuzzy environment. Also the probability of existence of chemical agents in each warehouse $(P_i)$ and the probability of detection $({\alpha }_i)$ in case materials exist in warehouse, are estimated. Next, the output of VIKOR i.e., $Q$ is assumed as an input of optimal search model and optimal strategy for searching is achieved by solving a stochastic dynamic programming. According to this hybrid approach, we start from the location that has the maximum value of $\frac{{\alpha }_i{P}_i}{Q_i}.$ Although we get benefits of fuzzy logic, VIKOR, and classical optimal search, the suggested method is easy to understand and straightforward to utilize in real-world problems. Also this model can enhance the robust nature of hybrid approach and reduces its sensitivity to the change of weights.

Keywords:

• Illegal chemical warehouses
• optimal search
• VIKOR
• fuzzy sets
• stochastic dynamic programming

Acknowledgement

The authors would like to thank the Editor-in-Chief Prof. Shahamat U. Khan and the anonymous reviewers for their insightful comments and suggestions.

Data availability statement

Data will be available on request.

Disclosure statement

The authors declare that they have no conflict of interests.

Notes

1 https://www.opcw.org/chemical-weapons-convention