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Recently, traffic accidents due to drowsy driving, operation mistake in the power plant by drowsiness and decrease arousal in employment during work have been attracted as problems. To avoid such an accident, arousal level could be quantitatively evaluated in real time. We suggested that the one of the parameters of Duffing oscillator parameters is related to the conventional arousal level using the EEG frequency component. However, in this examination, effects on the EEG from visual and active behavior were considered, but those from hearing also need to be investigated. In this paper, we performed the experiment in the musical environment using rock and classic music to investigate the model parameters for effect of the auditory stimulation, and acquired EEG data in Visual cortex and Frontal lobe. The acquired EEG data was used to identify the model parameters, which were identified solving the inverse problem by Least Square method. Results of investigating correlation between conventional arousal revel and model parameter shows a significant correlation in case of the auditory environmental situation. Moreover, Visual cortex is better than Frontal lobe as a measurement point in this evaluation method.

Cooling treatment is known as one of the effective treatment for injury. It has an optimum cooling temperature level depending on a symptom or an injury. Hence a highly precise temperature control function is required for a cooling device for this kind of treatment. A mathematical model of cooling device using a Peltier element is necessary to realize its functions. In this paper, we examined the characteristics of model parameters by identification experimentally and comparison of its values. Three cooling devices (A, B and C) were used. A Peltier element of device A and device B were the same size with different cooling performance respectively. Whereas a Peltier element of device C was bigger than the two devices. Effects of devices size and cooling performance on the model parameters were investigated. It is shown that most of the parameter values were increased in the device C. The Seebeck coefficient and the internal resistance had little dependent relation with the device size while the other heat conductances were strongly dependence upon the size. From these results, the characteristics of each parameters became mostly evident by comparison of three devices of different sizes and cooling performances. However, it is required to analyze more and utilize different devices to carry out the development of cooling device by using this model.Copyright © 2016 by ASME

The decrease of arousal level has led to serious accidents in driving and operation of machine. A system to accurately evaluate arousal level in real time is required to prevent such accidents. In this paper, we examined whether parameters of the mathematical model, which are determined in each time shifting window using EEG data could be used as a method to evaluate the arousal level. The modified Duffing oscillator was proposed as a mathematical model to perform simplified parameters calculation and identification. It was applied to EEG data, which is obtained by EEG acquisition experimentation in alternative repeat of relaxed and concentrated state. As a result of the parameters identification in theta band, alpha band, beta band, and 4–30 Hz band, it is shown that each parameter is repeating increase and decrease with time progress of each experiment. Especially, the relationship between the conventional arousal level and parameter B, which is the coefficient of the proportional term in the modified Duffing oscillator shows a significant correlation. It is suggested that parameter B of the modified Duffing oscillator would evaluate the arousal level. Since this evaluation method of arousal level does not require analyzing for each band, it can be used to calculate the arousal level in real time.Copyright © 2016 by ASME