ABSTRACT
This paper presents a method to build a dynamic target curve producer corresponding to the rising time setting and the ultimate target temperature as a reference for a fuzzy logic controller that is used in the metal heating process application. To achieve this goal, there are some quantization factors in a fuzzy controller that must be set according to the system situation, as well as the experience of experts that will cause the controller to have a lack of adaptivity. To solve this problem, in this paper, all the quantization factors are analyzed thoroughly, and a self-tuning module is designed to make it possible for the controller to perform real-time adjustments based on the system situation and, eventually, make it more adaptive. During the design process, a simulation comparing the control capabilities of the conventional fuzzy logic controller and the self-tuning fuzzy logic controller (STFLC) is made using a finite element analysis. Finally, experiments are carried out on the induction heating system to verify the effect of the proposed STFLC. The results show that, with the proposed self-tuning module, the control capability and adaptivity of the controller were drastically improved.
ABSTRACT
OBJECTIVE: The aim of this study was to evaluate the correlation between scintigraphy and videofluoroscopy (VFS) in swallowing evaluation and the ability of scintigraphy to predict penetration/aspiration in VFS. DESIGN: This is a case-control study enrolling 50 patients with dysphagia who received scintigraphy and VFS and 18 age-matched control subjects who received scintigraphy alone. Three parameters were compared between scintigraphy and VFS: premature pharyngeal entry, pharyngeal transit time, and postswallow pharyngeal stasis, with cutoff values defining dysfunction of 3% or greater, 1.2 secs or longer, and 9% or greater, respectively. RESULTS: The correlation coefficients were fair to good between scintigraphy and VFS (r = 0.678, 0.837, and 0.721 for premature pharyngeal entry, pharyngeal transit time, and postswallow pharyngeal stasis, respectively, P < 0.05). The scintigraphy parameters also had good predictive value for the VFS findings, with sensitivity, specificity, positive predictive values, and negative predictive values between 70% and 95%. Scintigraphy had good sensitivity in detecting 91% of aspirations and 81% of penetrations and/or aspirations in VFS if one of the three parameters was abnormal; however, the specificities were low (46% and 52% for scintigraphy and VFS, respectively). CONCLUSIONS: The measurements of premature pharyngeal entry, pharyngeal transit time, and postswallow pharyngeal stasis by scintigraphy were correlated with those of VFS. Scintigraphy also had good sensitivity in detecting penetration and/or aspiration in VFS.
