## 7 Conclusions and Recommendations  
This extensive examination of supplementary dampers aimed at enhancing the seismic performance of structures has yielded significant insights into the contemporary advancements within this vital domain of structural engineering. The evaluation of various damping technologies, alongside their applications and performance metrics, has highlighted notable progress in bolstering the seismic resilience of both newly constructed and retrofitted structures. The review underscores the pivotal role that supplementary dampers play in alleviating the detrimental impacts of seismic activities on structures. The deployment of these damping systems has consistently resulted in enhanced structural performance, minimized damage, and improved safety for occupants during seismic events. The array of damper types available, such as viscous dampers, viscoelastic dampers, friction dampers, and metallic yield dampers, equips engineers with a flexible set of tools to meet specific structural needs and address seismic challenges effectively. A significant conclusion drawn from this review is the critical nature of the design and integration of supplementary dampers within the overall structural framework. The efficacy of these dampers is largely contingent upon their optimal placement, sizing, and compatibility with the structural design. Therefore, engineers are encouraged to perform comprehensive analyses and simulations to refine the damper configurations, ensuring maximum protection against seismic threats. The review has underscored the increasing inclination toward performance-based design methodologies within the realm of seismic engineering. The utilization of supplementary dampers has emerged as an effective strategy for meeting specific performance goals, facilitating enhanced control over structural responses during seismic occurrences. This transition to performance-based design demands a more comprehensive understanding of damper functionality and its interplay with the primary structural system. In practical terms, the review has presented a variety of case studies illustrating the successful application of supplementary dampers across diverse structures, such as skyscrapers, bridges, and essential infrastructure. These empirical examples offer critical insights and best practices for future applications, highlighting the adaptability and efficacy of damping technologies across different structural forms. Notwithstanding the considerable advancements in this domain, several aspects require additional investigation and development. One critical area pertains to the long-term performance and resilience of supplementary dampers when subjected to fluctuating environmental conditions and repeated seismic activities. Further research is essential to evaluate the aging properties of various damper types and formulate effective maintenance protocols that will ensure their sustained performance throughout the lifespan of the structure. A critical area that warrants further exploration is the advancement of sophisticated control algorithms for adaptive damping systems. With the ongoing progress in smart materials and sensing technologies, there exists significant potential for the development of more responsive and efficient damping solutions capable of real-time adaptation to fluctuating seismic conditions. The combination of supplementary dampers with other seismic mitigation strategies, such as base isolation and structural health monitoring systems, represents a promising direction for future research. Hybrid systems that integrate various protective measures may provide improved seismic performance and resilience. From a practical perspective, there is an urgent need for the standardization and formalization of design protocols for supplementary dampers. Although numerous countries have established guidelines for damper design within their seismic codes, a lack of consistency in methodology persists.