## 4 Conclusions  
This study applied personal characteristics, operation mode (including exposure time, movement speed, and angular rotation speed), and characteristics of hardware interfaces to construct the FCACIS. The experimental results revealed a significant difference in SSQ scores between subjects who navigated in a 3D virtual store with and without the FCACIS. The result showed that the FCACIS can reduce the severity of cybersickness. Additionally, personal characteristics such as age resulted in significant differences in the induction of cybersickness. The cybersickness symptoms induced in those under 40 years of age were relatively mild, whereas those over 40 years of age had an increasing trend in symptoms. Those between 40 and 59 years old were most affected. The symptoms of those over 60 years of age were less severe. The FCACIS could effectively alleviate cybersickness for subjects over 40 years old. In contrast, the difference due to sex was not significant, but the FCACIS could effectively reduce the symptoms of cybersickness in men and women. In terms of hardware interfaces, the anti-cybersickness effect of the FCACIS for flat-panel displays was greater than that for HMDs. Additionally, the FCACIS significantly reduced the symptoms of cybersickness for the 3 DOF controller.  
Because this study focused on the development and piloting of the fuzzy-control anti-cybersickness intelligent system, there was a small sample size. In the future, based on the results of this research, the weights of personal characteristics and hardware modes will be able to be more accurately adjusted, and the crisp values of the fuzzy set of the operation mode (exposure time, movement speeds, and angular rotation velocities) will also be adjusted to improve the performance of the FCACIS. Additionally, a large sample size of different ages--under 40 years old, 41-59 years old, and over 60 years old--will be considered to obtain complete assessment information.  
Conceptualization, C.-L.L.; methodology, C.-L.L.; software, C.-L.L.; validation, C.-L.L. and S.-T.U.; formal analysis, C.-L.L.; investigation, C.-L.L.; resources, C.-L.L.; data curation, C.-L.L. and S.-T.U.; writing--original draft preparation, C.-L.L.; writing--review and editing, C.-L.L. and S.-T.U.; visualization, C.-L.L.; supervision, C.-L.L. and S.-T.U.; project administration, C.-L.L.; funding acquisition, C.-L.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Science and Technology Council, Taiwan (grant no. NSTC 112-2221-E-238-002).  
This research was conducted according to the guidelines of the Declaration of Helsinki and approved by the Jen-Ai Hospital Institutional Review Board, Taiwan (IRB No: 202300060B0, 14 September 2023).  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy reasons.  
All the participants are gratefully acknowledged.  
The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.