s. esmaeeli

There is significant interest in studying security games for defense op-timization and reducing the effects of attacks on various security systems involving vital infrastructures, financial systems, security, and urban safe-guarding centers. Game theory can be used as a mathematical tool to maximize the efficiency of limited security resources. In a game, players are smart, and it is natural for each player (defender or attacker) to try to deceive the opponent using various strategies in order to increase his payoff. Defenders can use deception as an effective means of enhancing security protection by giving incorrect information, hiding specific security resources, or using fake resources. However, despite the importance of de-ception in security issues, there is no considerable research on this field, and most of the works focus on deception in cyber environments. In this paper, a mixed-integer linear programming problem is proposed to allocate forces efficiently in a security game with multiple attackers using game the-ory analysis. The important subjects of information are their credibility and reliability. Especially when the defender uses deceptive defense forces, there are more ambiguity and uncertainty. Security game with Z-number payoffs is considered to apply both ambiguities in the payoffs and the reli-ability of earning these payoffs. Finally, the proposed method is illustrated by some numerical examples.

In this research, the SiC-matrix composite with different amounts of TiC (0, 2.5, 5, 7.5, and 10 wt%) supplemented with additives including 4.3 wt% Al2O3 and 5.7 wt% Y2O3 were utilized to initiate the required liquid phase. The sintering process was performed using pressureless sintering at      1900 °C for 1.5 hours under argon atmosphere. The composition and microstructure of the obtained composites were analyzed using X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), and Energy-Dispersive X-ray Spectroscopy (EDX). The results showed that TiC additives improved the densification of samples and impeded the growth of SiC grains. According to the phase analysis, the SiC was the main phase, while the TiC and YAG were characterized as partial phases. Additionally, due to the reaction of TiC and Al2O3, the composition of the liquid phase contained YAG and YAM. Assessments revealed that the microstructure and the final properties of composites were affected by density, produced phases and their distribution in the matrix, and grain size. According to the results, upon increasing the TiC up to 5 wt%, all the measured properties including density, hardness, elastic modulus, and fracture toughness improved and reached 97.40%, 26.73 GPa, 392 GPa, and 5.80 MPa.m1/2, respectively. However, with increasing the additives to more than 5 wt%, these properties deteriorated. Microscopic evaluations revealed that crack deflection and crack bridging mechanisms contributed to the fracture toughness of SiC ceramics.