• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.405-410
• /
• 2002

In this paper, numerical method of evaluating the influence of Dual Mass Flywheel(DMFW) to the torsional vibration of the automotive power train system is developed. And we applied the procedure to the currently being developed HMC's DMFW attached to an FF car to find out the best performance characteristics during the Tip-in/Tip-out operating condition. In doing this we compared the numerical results with the experimental results and Performed Parametric studies. We find out that the torsional vibrational characteristics of power train system can be significantly improved when we optimally choose DMFW, and the developed numerical procedure could be used as valuable tools in developing new DMFW.

• Restorative Dentistry and Endodontics
• /
• v.44 no.4
• /
• pp.44.1-44.11
• /
• 2019

Objectives: To compare the flexural cyclic fatigue resistance and the length of the fractured segments (FLs) of recently introduced M-Pro rotary files with that of RaCe rotary files in curved canals and to evaluate the fracture surface by scanning electron microscopy (SEM). Materials and Methods: Thirty-six endodontic files with the same tip size and taper (size 25, 0.06 taper) were used. The samples were classified into 2 groups (n = 18): the M-Pro group (M-Pro IMD) and the RaCe group (FKG). A custom-made simulated canal model was fabricated to evaluate the total number of cycles to failure and the FL. SEM was used to examine the fracture surfaces of the fragmented segments. The data were statistically analyzed and comparisons between the 2 groups for normally distributed numerical variables were carried out using the independent Student's t-test. A p value less than 0.05 was considered to indicate statistical significance. Results: The M-Pro group showed significantly higher resistance to flexural cyclic fatigue than the RaCe group (p < 0.05), but there was no significant difference in the FLs between the 2 groups (p ≥ 0.05). Conclusions: Thermal treatment of nickel-titanium instruments can improve the flexural cyclic fatigue resistance of rotary endodontic files, and the M-Pro rotary system seems to be a promising rotary endodontic file.