The purpose of this study is to develop a pH measurement system capable of measuring the acidity of saliva to check the change in pH level in saliva during driving and to detect whether fatigue is affected. When the pH level is checked at rest and operation, and oxygen concentration is supplied additionally, it will be verified whether the fatigue is reduced. It is reported that the pH level in saliva is divided into stages from 0 to 14, and the lower the value based on step 7, the higher the fatigue, and the lower the fatigue. In particular, in enclosed vehicles, drowsiness and fatigue due to increased carbon dioxide have increased, leading to a major cause of traffic accidents. Therefore, fatigue may be detected in advance by analyzing fatigue through a change in pH level by supplying oxygen during operation. The electromotive force generated by the existing itself is a level of several mV to develop a pH measurement system, so it is developed by expanding it to a range that can be measured using a readout circuit. In the experiment, 13 male experimenters in their 20s measured pH levels in resting and driving conditions. After 20 minutes of rest, the process of inhaling oxygen for 20 minutes was repeated three times. The oxygen concentration used in the experiment was 21% oxygen and 30% oxygen concentration in the atmospheric state, and in the oxygen supply method, a triangular flask was directly connected to the subject’s nose and then oxygen was supplied. As a result of collecting and analyzing saliva after rest and operation, it was confirmed that the pH level tended to decrease in the operating state. In addition, as a result of increasing the pH level when the oxygen concentration is 30% more than 21%, it is confirmed that fatigue tends to decrease as the oxygen concentration increases. Therefore, it was possible to confirm a significant change in fatigue by analyzing the pH level of saliva through this pH measurement system. This study can be used as a fatigue test in various environments through simple pH measurement.

The The purpose of this study is to establish evaluation criteria for the purchase of electric vehicles and to present an evaluation model using quantitative scales for evaluation factors. This study was limited to the study of purchasing factors related to electric vehicles, and the spatial scope was limited to potential buyers in their 20s to 50s living in the Daejeon area. Based on the survey, the factors affecting the purchase factors (energy economics, image, performance, maintenance, price) were examined using the AHP method, and the priorities were analyzed to determine how much influence these factors have on the purchase of electric vehicles. In addition, in order to verify the logical consistency of the survey items, a consistency ratio test (c) was conducted. Through this study, priority considerations for the purchase of electric vehicles were presented, and information on future consumer interest in electric vehicles was conducted. It is judged to be able to provide an opportunity to provide various services for each layer.

자동차 고급화 추세에 따라 소비자의 차량 실내 환경에 대한 관심이 증가함에 따라 자동차의 기본적 성능뿐만 아니라 실내 쾌적성 향상에 관심이 증대되고 있다. 또한 자동차 실내 쾌적성에 대한 연구는 운전자에게 만족을 제공하 는데 그치지 않고, 운전자의 불쾌지수 및 스트레스를 낮추어서 교통사고의 위험을 줄이는데 기여할 수 있기 때문에 매우 중요한 연구 주제이다. 따라서 본 연구에서는 운전자의 뇌파측정을 통해 통풍시트의 온도변화에 따른 쾌적감 변화와 쾌적온도를 알아보고, 온도변화에 따른 남녀간 쾌적감에 대한 차이를 탐색하고자 하였다. 연구결과 첫째 통풍시 트의 온도가 22℃, 25℃, 28℃에서 각각의 실험군을 비교한 결과 28℃보다 25℃에서 통계적으로 유의하게 쾌적감이 더 높게 나타났다. 둘째 통풍시트 온도 변화에 따른 남녀간 쾌적감에 대한 실험결과 남성과 여성이 온도에 따라 느끼는 쾌적감은 통계적으로 유의한 차가 없는 것으로 나타났다. 향후 자동차의 실내온도와 통풍시트의 온도 변화에 따른 운전자의 쾌적감 변화를 파악하여 상관관계를 분석한다면, 운전자의 쾌적성을 확보하여 휴먼에러로 인한 교통사고를 낮출수 있을 뿐만 아니라 자동차의 전기에너지의 사용량을 줄일 수 있을 것이다.

본 연구의 목적은 승강기 갇힘 사고 시 승객의 불안감을 해소할 수 있는 가장 안정적인 색 온도를 제안하는 것이다. 승강기 내부 조명의 색온도를 4단계(3000 K, 6000 K, 9000 K, 12000 K)로 조절하였다. 실험은 20대 성인 남성 20명을 대상으로 진행이 되었다. 각 상황별 이용자의 자율신경계 반응을 관찰하기 위해 심전도를 측정하여 분석하였다. 분석결과, 12000 K와 비교 시 3000 K, 6000 K, 9000 K에서 교감신경계 활성도가 감소하였으며 통계적으로 유의한 차이가 인정되었다(p < 0.01). 그 중 3000 K의 조건에서 교감신경계 활성도가 가장 낮았다. 본 연구를 통해 승강기 갇힘 사고 시 3000 K의 색 온도가 승객으로부터 안정감을 유발하는 사실을 알 수 있었다. 본 연구결과를 활용한다면 승강기 갇힘 사고 시 승객의 안정성을 확보할 수 있을 것으로 보인다.

본 연구에서는 기존의 신호체계에서 발생하는 황색 신호 딜레마 상황에서 운전자의 상태를 파악하고 새로운 신호체계를 제안하고자 한다. 특히, 생체신호 분석을 통해 운전자 중심의 대처모형을 제안한다. 이를 위해 자동차 그래픽 시뮬레이터를 통해 교차로 도로 주행상황을 구현하여 기존의 신호체계와 본 연구에서 제안하는 신호체계에서 운전자의 생리적 반응을 관찰하여 규명하고자 한다. 따라서 대조군(기존 신호체계)과 새로운 황색 신호체계를 실험군(새로운 신호체계)으로 나누어 20대 초보 운전자를 중심으로 실험을 진행하였다. 그 결과, 대조군보다 실험군에서 교감신경의 출현이 우세하였으며 통계적으로 유의차가 인정되었다(p<0.05). 이를 통해 새로운 신호체계가 운전자가 긴장감을 유발하는 것처럼 보이지만 교감신경과 부교감신경의 비율이 6:4로 이상적인 균형으로 해석할 수 있다. 결론적으로, 본 연구에서 제안하는 대처 신호체계를 교통체계에 적용한다면 운전자가 더욱 안정적인 주행이 가능할 것으로 보인다.

본 연구에서는 뇌파와 맥파를 이용한 생체신호 분석을 통해 자율주행차량 사용자에게 안정감을 유발하는 최적의 색온도를 제안하고자 하였다. 이를 위해 3000 K, 4000 K, 5000 K, 6000 K의 색온도를 갖는 조명을 자율주행 환경에 적용하여 제시하였다. 실험은 자동차 그래픽 시뮬레이터가 구비된 실험실에서 진행되었으며, 실험절차는 다음과 같다. 1) 안정기(5분), 2) U-K테스트(3분), 3) 자율주행+조명(3분). 이 과정은 색온도를 변경해가며 총 4회 반복되었다. 수집된 시계열데이터에 대해 주파수 분석을 실시하였고 파워 스펙트럼 분석을 통해 주파수 대역별 power값을 산출하였다. 뇌파는 안정의 지표인 α파와 각성의 지표인 β에 대해 분석을 실시하였으며, 맥파의 경우 교감신경계 활성도에 대해 분석을 실시하였다. 산출된 데이터는 연구대상자 개인 간 편차를 줄이기 위해 정규화하여 통계분석을 실시하였다. 1차 분석 결과, 뇌파의 경우 5000 K의 조명을 제시하였을 때 α파가 가장 높았고, 대부분의 조명 제시 상황에서 β파가 증가하였다. 맥파의 경우 주행 상황에서 SNSA가 증가하였다. β파와 SNSA에 대한 2차 분석 결과, 유의수준 5%에서 색온도 간 유의한 차이가 인정되지 않았다. 결론적으로, α파가 가장 높은 5000 K의 색온도가 안정감을 유발한다고 볼 수 있다. 이러한 결과를 자율주행차량에 적용한다면, 탑승자의 높은 만족도를 유발할 수 있을 것으로 보인다. 나아가, 이와 같은 긍정적인 효과가 자율주행차량의 수용으로 이어질 수 있다.

휴전국인 우리나라는 의무복무제도를 시행하고 있다. 이에 취업 및 진학을 한 20대 초반의 사회 초년생은 군 입대 문제로 많은 고민과 큰 걱정을 하고 있다. 이에 군에 대한 부정적인 인식과 군 생활 적응은 사회가 같이 풀어야 할 문제이다. 따라서 방송사 등 문제 해결을 위해 다각적으로 노력하고 있으나 역부족이다. 실제 군 입대 후 스트레스 및 불안정 심리상태의 장병 비중이 높다. 따라서 본 연구는 군 생활에서 일상적인 방법을 통해 스트레스, 불안감을 감소시키고, 집중력을 향상 시키고자 실행하였다. 주의 집중력 증가 및 스트레스, 불안감의 변화를 측정하기 위해 SMR파 대역의 주파수를 직접 노출시킨 실험군과 그렇지 않은 대조군으로 실험을 진행하였다. 실험군과 대조군대한 대응표본 t-검정 결과는 신뢰수준 95%에서 t=2.487, p=0.042로 유의차가 인정되었다. 즉, 가상사격영상에서 특정 주파수를 제시한 실험군의 피실험자들이 스트레스 및 불안정 심리의 완화효과가 발생하였다. 본 실험의 결과를 활용하면 젊은 장병들의 군 생활 적응에 효과가 높은 것으로 사료된다. 추후 연구에서는 심전도와 뇌파의 상관관계의 확인이 필요하다.

본 연구는 운전 중 외부 소음으로 유발된 스트레스를 줄이기 위한 방법으로 심박변화율의 상관관계 분석의 선행연구와 음원의 주파수에서 운전자로 하여금 안정상태를 유발하는 음악과 소음 발생 시 심전도의 변화가 있는 지의 여부를 규명하기 위한 목적이다. 매년 자동차의 증가로 인하여 운전자 및 동승자가 외부 소음으로부터 스트레스가 증가하는 추세이다. 자동차 운전 시 외부 소음에 의한 스트레스는 불안, 면역약화, 우울, 심장 질환 등 여러 가지 질병을 일으키고 있다. 따라서 외부 소음으로부터 스트레스를 줄이기 위한 자동차 시뮬레이터를 실시하여 여러 가지 청각 자극을 주어 운전자가 반응하는 연구를 진행하였다. RM-ANOVA (Repeated Measures-ANOVA) 통계분석 결과, 집단별 유의차가 인정되었다(ρ<0.05). 사후 검정을 통해 어떤 요인 간의 차이가 발생하는지를 알아보았다. 사후검정 결과는 요인1(안정) 과 요인2(시뮬레이션운전), 요인1(안정)과 요인3(운전+경찰사이렌), 요인1(안정)과 요인4(운전+경찰사이렌+음악)에서 유의한 차이를 발견할 수 있었다. 또한, 교감신경계 활성도가 가장 높은 집단은 운전+경찰사이렌+음악을 실시한 요인 4이며, 다음으로 운전+경찰사이렌인 요인 3이며, 다음으로 운전을 실시한 요인 2, 마지막으로 안정기 순으로 나타났다. 결론적으로 운전 중 경찰 사이렌 소리를 들려주어도 심전도의 변화는 유의차가 인정되지 않았다. 또한, 사이렌 소리에 안정된 주파수의 음악을 들려주어도 심전도의 변화에 차이가 발생하지 않았다(ρ<0.01). 향후 연구에서는 운전 중 심전 도의 안정을 찾을 수 있는 여러 가지 음악을 들려주어서 심전도가 안정화되는 음악을 찾는 연구방법이 선행되어야 할 것이다.

When taking X-ray, Some of them are not only absorbed as they pass through the body, but some are scattered and blurred. To prevent this problem, 'X-Ray Grid' was placed between the body and the film. Conventionally, in order to manufacture an X-ray grid, a lead sheet and an aluminum sheet were adhered with epoxy or the like, cut to a predetermined thickness, and formed in a line at a predetermined angle. New grids are actively being developed to solve this problem. In this study, Laser beam was irradiated on a photosensitive glass having high X-ray transmittance to form an oblique lattice type channel. When the photosensitive glass is exposed to Laser beam, Previous studies have shown that laser exposure to photosensitive glass reacts with UV-Laserto form high-precision microstructures. The photosensitive glass exposed by the laser is heat-treated at a high temperature to crystallize the exposed part. When the crystallized patterns are etched with a hydrofluoric acid liquid solution, a structure having a depth is completed. The completed structure is filled with metals with X-ray shielding properties. The angle of incidence can be processed up to 18, which is the angle of incidence of ordinary X-ray, The upper surface line width of theetched pattern is 20um or less and The depth of processing after etching was found to be more than 100um, which means 'the filler can be deposited sufficiently'.

This study is aimed to find out whether there is difference in the physiological change of a human body according to the illumination and color of interior space or not and to specify the effect of the condition of illumination and color, respectively on the attention. In order to do so, White and Green were selected for colors and 4,000k, 5,000k, and 6000k were done for color temperature, and then attention was identified. Examining the results, the more color temperature increased, the more attention improved (P < 0.05), and in the case of EEG, α wave decreased while performing the task of attention (P < 0.01), and β wave decreased more in Green than White in color condition, and it increased more in 4,000k than 5,000k and 6,000k (p < 0.05) in color temperature condition. To sum up, color condition didn't contribute to the attention much, in the case of color temperature, when it is 6,000k, it is judged that it helped to improve attention. It is considered that relaxation contributed to improving attention, as β wave and sympathetic nerve decreased in 6,000k (p < 0.05). It is judged that the relaxation of tensions which happened due to a beta wave and the reduction of sympathetic nervous system activity in 6,000k, a condition of high color temperature, contributed to the improvement of concentration. In further researches, it is intended that a test will be conducted for the subjects of different ages, and the correlation between color temperature and color stimulation and the influence of them on human body would be observed in subdivided, various test conditions through various color temperature and color stimulation.

The purpose of this study was to explore olfactory sensitivity of odors from injection molding processing. To do this, the experiment was carried out in an injection molding factory, and participants were exposed to the environment where odor-substances (Formaldehyde, Benzene, Toluene, Ethylbenzene, Xylene, Styrene) exist. In addition, we used the subjective scale using semantic adjectives as an olfactory sensitivity. As a result, the assessment structure of olfactory sensitivity was composed of eight factors (irritant, thermal, tense, unique, like-dislike, active, stable, masculine), and the main factor which was irritant characteristics explained 20% of the total olfactory sensibility. These results suggested that odors from injection molding processing would cause more negative emotional responses than the flavor which is mainly used in olfactory sensitivity. This study, as a basic study of the improvement in a factory environment for the efficiency of work, has limits in that it was conducted to the extent of identifying the olfactory sensitivity structure of those who were at a laboratory and who were exposed to the environment of odor substance induced in the injection molding processing. Therefore, for the method of removing malodorous substance, the effect of materials which can neutralize it, and the comparison of a direct performance in the environment where negative sensitivity structure exists, a series of studies which aim to improve the environment of injection molding factories, such as performance assessment in the environment of a factory and an office need to be conducted. It is expected that when these studies are put together, the improvement guidelines will be provided as a type that can maximize the effectiveness of work in the factory environment where injection molding processing is done.

As contemporary society has become more complicated, specialized, and segmented, people are experiencing more diverse types of stress. In particular, while several factors associated with job stress have been examined among nurses, who belong to a professional group, the existing research has made no quantitative assessments of stress that reflect temporal differences in individuals. Therefore, the aim of this study is to understand the effects of job stress on alpha-amylase with regard to the working hours of nurses, to assess the variations in jobs stress over time, and provide basic data to improve the quality of nursing services. Ninety nurses working in three shifts in general, emergency, and intensive care wards of a university hospital in D City participated in this study. Salivary alpha-amylase (SAA) was extracted and analyzed at two-hour intervals from 07:00 to 15:00 from nurses on the day shift and from 23:00 to 07:00 from those working the night shift. The SAA level was highest between 23:00 and 01:00 for nurses in general wards (mean±S.D. 39.00±14.88) and between 11:00 and 13:00 for those in both intensive care units and emergency wards (mean ± S.D. 67.50 ± 62.93 and mean ± S.D. 39.67±35.96, respectively). The characteristic variation in SAA was significant between 23:00 and 01:00 (p < 0.01) and for those in their fifties or older (p < 0.01). The activation ratio of alpha-amylase, a stress reactant, showed an increase when the sympathetic nervous system was activated by mental stress; in addition, job stress was manifested with the effect of awakening at different time segments and at different ages among the nurses. With the aim of raising the level of service based on the nurses maintaining their mental health, it is necessary to focus sharply on the time segment for critical control and to conduct repetitive studies to determine the divisions of eustress critical values as well as to expand the population.

It is important to understand psychological and physiological responses of occupants who seated in a chair in order to shape a comfortable indoor official environment. So it is needed to find out optimal seated conditions. The purpose of this study was to explore optimal condition of seat air conditioning control based on psychological or subjective responses (perceived temperature and comfort sensation) and physiological responses (heartrate variability; HRV). To do this, experimental conditions were designed by the difference of indoor temperature and seat air conditioning temperature. In the experiment 1, seven experimental conditions were designed with one control condition which was not used seat air conditioning system, and six experimental conditions which the difference of indoor temperature and seat air conditioning temperature (-1℃～-6℃). In the experiment 2, four experimental conditions were designed with one control condition and three experimental conditions (-3℃～-5℃). In addition, participants’ psychological or subjective response was measured by CSV (comfort sensation vote) and PTS (perceived temperature sensitivity) as a psychological or subjective response, and heartrate variability was measured as a physiological response. As a result, in the experiment 1, it was reported that the optimal conditions of seat air conditioning control based on participants’ psychological or subjective comfort were from -3℃ to -5℃ experimental conditions. In addition, in the experiment 2, it was reported that the optimal condition of seat air conditioning control based on participants’ physiological comfort was -4℃ experimental condition. These results suggested that seat air conditioning could affected to comfort sensation of occupants in an appropriate range, rather than unconditionally.

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.

In this study, it was observed through the ability of performing secondary tasks and baseline fetal heart rate how the supply of lavender, peppermint and highly concentrated oxygen (40%) affected distraction due to the performance of secondary tasks in the driving environment. Twelve male university students conducted secondary tasks while driving in the environments (6 in total) mixed and designed with oxygen concentration (21%, 40%) and the condition of odors (Normal, Lavender, Peppermint). The test was proceeded in order of stable state (5mins), driving (5mins), and secondary tasks (1min), and by extracting ECG data from every section by 30secs, the mean value of baseline fetal heart rate was calculated. As a result of analysis, in the ability of performing secondary tasks, a percentage of correct answers showed no difference in oxygen concentration and the condition of odors (p > 0.05). In performance completion time, a percentage of correct answers decreased showing a statistically significant difference in the condition of odors compared with the condition where odors were not provided (p < 0.05). As for baseline fetal heart rate, in the comparison between sections, while performing secondary tasks, it increased showing a significant difference compared with stable state and driving state (p < 0.05). The effect of interaction was observed in oxygen concentration and the condition of odors. When odors were not provided, baseline fetal heart rate decreased in 40% oxygen concentration compared with 21% oxygen concentration (p < 0.05), however, when peppermint was provided, it increased in 40% oxygen concentration compared with 21% oxygen concentration (p < 0.05). In conclusion, the fact that the condition of odors increased the ability of calculation, and when only the highly concentrated oxygen was provided, parasympathetic nerve system was activated, however, when highly concentrated oxygen was provided with peppermint at the same time, sympathetic nervous system (sns) was activated, which had a negative effect on the autonomic nervous system was drawn.

본 연구는 냉 난방공조 조건에서 예상 온열감 반응(predicted mean vote; PMV)의 변화에 따른 심리 생리적 감성반응의 변화를 살펴보고자 하였다. 이를 위해 기존 공조 시스템의 냉 난방 가동에 따라 PMV의 변화를 유도하고, 쾌/불쾌 및 각성/이완 정도를 심리적 감성반응으로, 심박률(heart rate; HR)을 생리적 감성반응으로 활용하여 PMV 변화에 따른 심리 생리적 감성반응을 측정하였다. 그 결과, 동일한 PMV 변화 범위 내에서 재실자의 심리적 쾌/불쾌 및 긴장/이완 반응과 생리적 반응이 공조 조건이 달라짐에 따라 변화하는 것으로 나타났다. 이러한 결과는 난방과 냉방의 공조조건에 따라 재실자의 실내 온열환경에 대한 감성반응이 서로 다를 뿐 아니라 각 공조 조건에 민감한 감성반응이 존재하는 것으로 해석할 수 있다. 이는 실내 온열조건을 재실자에게 가장 적합하도록 조절하고자 할 때, 인간의 심리 및 생리적 감성반응을 모두 고려해야 할 필요가 있음을 시사한다.

본 연구에서는 50대 택시 운전자를 대상으로 동작 신호인 Jerk-Cost function(JC)와 차간거리의 분산계수(Anterior-Posterior Coefficient of Variation, APCV), 차선이격거리의 분산계수(Medial-Lateral Coefficient of Variation, MLCV)와 같은 차량 통제 데이터를 이용하여 운전 중 문자 메시지 전송 또는 네비게이션 검색과 같은 동시 과제 수행이 운전 수행 능력에 어떠한 영향을 미치는지를 알아보고자 하였다. 남성 14명과 여성 14명을 대상으로 실험을 진행하였다. 피험자는 일정 속도(80km/hr or 100km/hr)로 주행하는 선행 차량과 일정 거리 30m를 유지하며 주행하도록 하였다. 처음 1분간은 운전만을 수행하게 하였으며, 다음 1분 동안은 운전만을 수행하거나 운전과 함께 동시 과제를 수행하도록 하였다. MLCV와 APCV는 80km/hr와 100km/hr 주행 시 Driving only에 비해 Driving + Sending Text Message(STM)와 Driving + Searching Navigation(SN)에서 유의하게 증가하였다. JC 또한 주행 시 Driving only에 비해 Driving + STM과 Driving + SN에서 증가하였다. 본 연구를 통해 운전 경력이 길고 운전 전문가라고 할 수 있는 50대 택시 운전자도 운전만을 수행하는 경우에 비해 운전과 함께 문자 메시지 전송 또는 네비게이션 검색 과제를 수행하게 될 경우 동작 패턴이 거칠어지고 차량 통제가 어려워진다는 사실을 도출할 수 있었다.