This study aimed to investigate which areas AI is sensitive when inputting panoramic radiographs with dental area masked and when inputting unmasked ones. Therefore, the null hypothesis of this study was that masking dental area would not make a difference in the sensitive areas of osteoporosis determination of AI. For this study 1165 female(average age 48.4 ± 23.9 years) from whom panoramic radiographs were taken were selected. Either osteoporosis or normal should be clearly defined by oral and maxillofacial radiologists. The panoramic radiographs from the female were classified as either osteoporosis or normal according to the mandibular inferior cortex shape. VGG-16 model was used to get training, validating, and testing to determine between osteoporosis or normal. Two experiments were performed; one using unmasked images of panoramic radiographs, and the other using panoramic radiographs with dental region masked. In two experiments, accuracy of VGG-16 was 97.9% with unmasked images and 98.6% with dental-region-masked images. In the osteoporosis group, the sensitive areas identified with unmasked images included cervical vertebrae, maxillary and mandibular cancellous bone, dental area, zygomatic bone, mandibular inferior cortex, and cranial base. The osteoporosis group shows sensitivity on mandibular cancellous bone, cervical vertebrae, and mandibular inferior cortex with masked images. In the normal group, when unmasked images were input, only dental region was sensitive, while with masked images, only mandibular cancellous bone was sensitive. It is suggestive that when dental influence of panoramic radiographs was excluded, AI determined osteoporosis on the mandibular cancellous bone more sensitively.

In this study, the masking effect of olfactory stimulus on the awakening state due to sound stimuli while driving using Graphic Driving Simulator was observed through the response of autonomic nervous system. The test was conducted for 11 males in their twenties. The siren of ambulance car was presented to them as auditory stimulus for 30 secs while driving in a situation of high way in the condition of both peppermint and control, respectively, and LF/HF ratio of HRV (Heart Rate Variability), the activity index of sympathetic nerve, and GSR (Galvanic Skin Response) response were examined. The test was proceeded in the order of three stages, that is, sound stimuli (test 1), driving performance, and sound stimuli (test 2), and fragrance stimulus, driving performance, and sound stimuli (test 3), and the physiological signal of GSR, HRV was measured in the whole stages. As a result of test, comparing the results of before and after auditory stimulus test (1) (p < 0.01), test (2) (p < 0.05), and test (3) (p <0.01), driving performance test (2) (p < 0.01), test (3) (p < 0.01), and olfactory stimulus test (3) (p < 0.05), respectively, GSR response increased, showing significant difference in all the tests. It indicates that when auditory stimulus was presented to the subjects, they were in the awakening state as sympathetic nervous system got activated. As a result of comparing auditory stimulus while driving before and after presenting olfactory stimulus, there was no significant difference in GSR response. The LF/HF ratio of HRV increased, showing a significant difference only in test (2) (p < 0.05), and in driving performance test (2) (p < 0.05) in auditory stimulus, however, it showed no significant difference in olfactory stimulus. As a result of comparing auditory stimulus while driving before and after presenting olfactory stimulus, there was a decrease, showing significant difference (p < 0.05) in LF/HF ratio of HRV. That is, it means that the activation of sympathetic nervous system decreased, and that parasympathetic nervous system got activated. From these results, it was observed that while driving, the awakening level due to auditory stimulus was settled with olfactory stimulus. In conclusion, it was drawn that while driving, olfactory stimulus could have the masking effect on auditory stimulus.

본 연구는 자동차 시뮬레이터에서 운전 중 제시된 후각 자극이 외부에서 제시된 청각자극의 각성 상태에 대한 마스킹 효과를 자율신경계 반응을 통해 알아보고자 하였다. 실험은 20대 남성 11명을 대상으로 하였고, 향 자극은 peppermint를 제시하였다. 청각자극은 구급차 싸이렌 소리를 70~75db의 크기로 30초 동안 제시하였다. 자동차 운전 상황은 편도 3차선의 한적한 도로를 주행하였고 자율신경계의 반응은 피부반응(GSR: Galvanic skin Response)의 변화를 살펴보았다. 실험결과 control, 운전수행, 후각 자극 중 운전 수행, 각각에서 청각 자극 제시 전,후 비교는 모두 유의차(p＜0.05)를 보이며 제시 후가 증가하였고, 각각의 청각 자극 후의 비교는 유의차를 보이지 않았다. control, 후각 자극, 각각의 운전수행 전,후 비교는 모두 유의차(p＜0.05)를 보이며 후가 증가하였고, 각각의 운전수행 후의 비교는 유의차를 보이지 않았다. control과 후각자극의 비교는 유의차(p＜0.05)를 보이며 후각 자극 시 증가하였다. 위와 같은 결과는 후각 자극이 운전수행중 청각자극으로 인한 각성 수준에 영향을 주지 못함을 의미한다. 즉 후각 자극이 청각자극에 대한 마스킹 효과가 일어나지 않음을 시사한다.