With the advancement of wearable technology, many physiological monitoring instruments are gradually being converted into wearable devices. However, as a consumer product, the blood pressure monitor is still a cuff-type device, which does perform a beat-by-beat continuous blood pressure measurement. Consequently, the cuffless blood pressure measurement device was developed and it is based on the pulse transit time (PTT), although its accuracy remains inadequate. According to the cardiac hemodynamic theorem, blood pressure relates to the arterial characteristics and the contours of the pulse wave include some characteristics of the artery. Therefore, the purpose of this study was to use the contour characteristics of the pulses measured by photoplethysmography (PPG) to estimate the blood pressure using a linear multi-dimension regression model. Ten subjects participated in the experiment, and the blood pressure levels of the subjects were elevated by exercise. The results showed that the mean and standard deviation (mean ± SD) of the root mean square error of the estimated systolic and diastolic pressures within the best five parameters were 6.9 ± 2.81 mmHg and 4.0 ± 0.65 mmHg, respectively. Compared to the results that used one parameter, the PTT, for estimating the systolic and diastolic pressures, 8.2 ± 2.1 mmHg and 4.5 ± 0.79 mmHg, respectively, our results were better.

This research examines price determinants of used car using the example on Taiwan used car auctions. The used cars which were produced in Taiwan and whose final price does not exceed one million New Taiwan Dollars. Research data from used cars auction website which included 504 successful transactions in Taiwan used car auction marketing. The log-linear multiple regression model is applied to evaluate this data. According to the results, polynomial log-linear multiple regression models is more suitable for this research and produces better results. As the result shows that the chosen variables can explain changes in price determinants of used cars in Taiwan auctions marketing and Toyota has very strong brand reputation in Taiwan. All chosen variables are statistically significant at 1% confidence interval (p-value<0.01) and all coefficient signs are as expected. Only one variable MILEAGE is not statistically significant. ENGINE is a second variable in decreased marginal effect of engine size on price determinants. This research conclusion is useful for local traffic authority and used car traders to control driver's price determinants choice on used car displacement. Contribution/ Originality: This study explores price determinants of used car in Taiwan auctions marketing. It contributes first logical analysis on log-linear multiple regression model. This research conclusion is useful for local traffic authority and used car traders to control driver's price determinants choice on used car displacement.