• Journal of Ecology and Environment
• /
• 제32권3호
• /
• pp.149-158
• /
• 2009

American sycamore seedlings were grown in chambers with two different ozone concentrations ($O_3$-free air and air with additional $O_3$) for 45 days. Both the control and the $O_3$ chambers included non-fertilized and fertilized plants. After 18 days of $O_3$ fumigation, seedlings were placed in a clean chamber for 27 days. Seedlings under ozone fumigation showed a significant decrease in pigment contents and photosynthetic activity, and a significant increase in lipid peroxidation. Fertilization enhanced physiological damage such as the inhibition of photosynthetic activity and the increase of lipid peroxidation under ozone fumigation. During the recovery phase, the physiological damage level of seedlings increased with ozone fumigation. In addition, physiological damage was observed in the fertilized seedlings. Superoxide dismutase (SOD) and glutathione reductase (GR) activities of $O_3$-treated seedlings increased up to 33.8% and 16.3% in the fertilized plants. The increase of SOD activity was higher in the fertilized plants than in the non-fertilized plants. Negative effects of ozone treatment were observed in the biomass of the leaves and the total dry weight of the fertilized sycamore seedlings. The $O_3$-treated seedlings decreased in stem, root and total dry weight, and the loss of biomass was statistically significant in the fertilized plants. In conclusion, physiological disturbance under normal nutrient conditions has an effect on growth response. In contrast, in conditions of energy shortage, although stress represents a physiological inhibition, it does not seem to affect the growth response.

• 한국HCI학회:학술대회논문집
• /
• 한국HCI학회 2009년도 학술대회
• /
• pp.173-177
• /
• 2009

일상생활에서 활용 가능한 다양한 종류의 생체 신호 획득 및 분석 방법이 연구되고 있다. 기존의 생체 신호 분석 방법은 표준화된 임계치를 사용하여 해석한 결과를 제공하며 신호 측정 당시의 상황이 고려되지 않아 잡음 혹은 외부 환경의 영향을 받기 쉬운 단점이 있다. 본 논문에서는 생체 신호뿐만 아니라 기타 정황정보를 기반으로 하여 개인화된 신호를 분석하기 위한 모델(Personalized Decision Making method, PDM)을 제안한다. 개인화된 신호 해석 모델은 사용자의 맥락 정보, 사용자의 맥락 정보, 사용자의 나이, 성별, 현재의 몸 및 정신 상태, 음식 및 카페인의 섭취 여부, 측정 시간 및 측정 요일 등을 기반으로 각 맥락 간의 연관 관계를 나타내고, 이상적인 사용자의 생체 신호 예측치를 베이즈 정리를 기반으로 획득한다. 개인화된 해석 모델(ACM)을 통해 표준 임계치를 적용한 해석에 비해 인식의 정확도를 높일 수 있으며, 다양한 측정시의 조건을 알면 현재 사용자의 건강상태를 개인화된 분석과 유사한 정확도로 예측이 가능하다. 제안한 방법은 현재 관측된 관측치의 분포를 모르더라도, 현재 사용자의 상태를 맥락정보를 기반으로 하여 예측할 수 있으므로, 일반적인 데이터 모델을 기반으로 개개인에 맞는 얼굴 표정을 인식하는 연구 등에 활용이 가능하다.

• 한국자동차공학회논문집
• /
• 제18권3호
• /
• pp.1-7
• /
• 2010

Recently, the vehicle driving device has been designed for driver's convenience. Especially, the automobile industry develops the vehicle using the joystick instead of steering wheel from the concept car. The biggest strength of using the joystick is that the driver feels less workload and fatigue than when the driver uses steering wheel. However, this kind of study still needs more research and experiments for more accurate result. Therefore, this research evaluated workload according to the driving device by the survey and the measurement of physiological signal. The reason not only using the survey also using the measurement of physiological signal is to support the result of the survey which is not enough to bring the accurate result. There were tow different kinds of methods to carry out this research; SWAT (Subjective Workload Assessment Technique) for the survey and the biopac equipment for the measurement of physiological signal. Furthermore, previously established driving simulator, GPS (Global Positioning System), and Seoul-Cheonan virtual expressway DB were used for the experiment. As the result of the experiment with 13 subjects, it was certain that using joystick device brings less workload and fatigue to the drivers than using steering wheel following both methods-the survey and the measurement of physiological signal. Also, it confirmed the significant result from the SPSS (Statistical Package for the Social Sciences) statistics analysis program.

• Journal of Ginseng Research
• /
• 제42권2호
• /
• pp.175-182
• /
• 2018

Background: The impact of fungicide azoxystrobin, applied as foliar spray, on the physiological and biochemical indices and ginsenoside contents of ginseng was studied in ginseng (Panax ginseng Mey. cv. "Ermaya") under natural environmental conditions. Different concentrations of 25% azoxystrobin SC (150 g a.i./ha and 225 g a.i./ha) on ginseng plants were sprayed three times, and the changes in physiological and biochemical indices and ginsenoside contents of ginseng leaves were tested. Methods: Physiological and biochemical indices were measured using a spectrophotometer (Shimadzu UV-2450). Every index was determined three times per replication. Extracts of ginsenosides were analyzed by HPLC (Shimadzu LC20-AB) utilizing a GL-Wondasil $C_{18}$ column. Results: Chlorophyll and soluble protein contents were significantly (p = 0.05) increased compared with the control by the application of azoxystrobin. Additionally, activities of superoxide dismutase, catalase, ascorbate peroxidase, peroxidase, and ginsenoside contents in azoxystrobin-treated plants were improved, and malondialdehyde content and $O_2^-$ contents were reduced effectively. Azoxystrobin treatments to ginseng plants at all growth stages suggested that the azoxystrobin-induced delay of senescence was due to an enhanced antioxidant enzyme activity protecting the plants from harmful active oxygen species. When the dose of azoxystrobin was 225 g a.i./ha, the effect was more significant. Conclusion: This work suggested that azoxystrobin played a role in delaying senescence by changing physiological and biochemical indices and improving ginsenoside contents in ginseng leaves.

• KSBB Journal
• /
• 제30권5호
• /
• pp.245-252
• /
• 2015

The aim of this study was to investigate the efficacy of enhanced physiological activities in cultures isolated from Korean fermented watery Kimchi, Dongchimi, of single lactic acid bacteria (LAB), and when these three are mixed LAB as probiotics. Using the BIOLOG system and 16S rRNA sequencing, the isolates were characterized, and identified and assigned to Leuconostoc mesenteroides DK-3, Leuconostoc dextranicum DK-6, and Lactobacillus curvatus DK-13, respectively. Growth rate and pH changes, production of organic acids as metabolites, and physiological activities of the single and mixed LAB cultures, were monitored and compared. In mixed LAB cultures after 72 h of incubation, the maximum concentrations of lactic acid and acetic acid were approximately 340.5 mM and 191.9 mM, respectively, and pH changed from 7.00 to 3.62. Mixed LAB cultures were able to eliminate 96.3% of nitrite. Activities of antioxidant and ${\beta}$-galactosidase were 60.3% and 16.8 units/mg, respectively. Significant antibacterial activity of the concentrated supernatants was demonstrated against several food-poisoning bacteria. Physiological activities obtained from the mixed LAB cultures have been shown to be considerably higher than those of single LAB cultures. In conclusion, these studies demonstrate that compared to the single cultures, all physiological activities in mixed LAB cultures are significantly enhanced.

• 대한의용생체공학회:의공학회지
• /
• 제23권1호
• /
• pp.73-79
• /
• 2002

최근 들어 컴퓨터와 디스플레이 기술의 발달로 실제 공포 상황에서의 자극과 거의 유사한 자극을 유발할 수 있는 가상환경의 창조가 가능하게 되었으며 이러한 실제 상황에서의 노출치료 대안으로 가상현실을 이용한 공포증의 치료방법이 사용되어져 왔다. 하지만 가상환경이 공포증 환자 에게 심리적이나 생리적으로 어떠한 영향을 미치는지에 대한 연구는 거의 전무한 실정이다. 따라서 본 논문에서는 가상환경 하에서 공포증환자와 정상인의 생리적 반응에 대한 평가를 함으로써 가상환경이 미치는 영향에 대하여 분석하고. 또한 가상현실 치료 시에 공포증환자의 생리적 반응의 변화를 측정함으로써 치료의 성공유무를 판단할 수 있는 지표를 제시하고자 한다. 본 실험은 스물 두 명의 정상인 (평균 32.74세)과 서른여섯 명의 비행공포증 환자를 대상으로 두 그룹으로 나누어 진행되었다. 생리적 반응으로는 심박동수, 피부저항. 그리고 피부 온도를 측정하였다. 실험결과. 두 그룹에서의 피부저항은 유의한 차이(T(56)=2.978, p〈0.01)를 보였으며, 공포증 환자 그룹 중 가상현실로 공포증이 치료가 된 서른세 명의 피부저항은 치료가 진행됨에 따라 점차 정상인의 특성 쪽으로 가까워짐을 보였다. 본 연구를 통해 생리적 반응. 특히 피부저항은 가상환경에서 피험자의 상태를 이해하거나, 가상환경을 이용한 치료의 결과를 검증하는데 유용하게 사용될 수 있을 것이라 사려된다.

• 한국지능시스템학회논문지
• /
• 제17권3호
• /
• pp.322-327
• /
• 2007

심리학 분야의 연구자들은 Electroencephalographic(EEG)을 오래전부터 인간 두뇌의 활동을 측정 기록하는데 사용하였다. 과학이 발달함에 따라 점차적으로 인간의 두뇌에서 감정을 조절하는 기본적인 영역들이 밝혀지고 있다. 그래서 인간의 감정을 조절하는 인간의 두뇌 활동 영역들을 EEG를 이용하여 측정하였다. 손짓이나 고개의 움직임은 사람들 사이에 대화를 위한 인간의 몸 언어로 사용된다. 그리고 그것들의 인식은 컴퓨터와 인간 사이에 유용한 회화수단으로 매우 중요하다. 몸짓에 관한 연구들은 주로 영상을 통한 인식 방법이 주를 이루고 있다. 많은 연구자들의 기존 연구에서는 생체신호나 몸짓중 한 가지만을 이용하여 감정인식 방법 연구를 하였다. 본 논문에서는 EEG 신호와 몸짓을 같이 사용해서 사람의 감정을 인식하였다. 그리고 인식의 대상자를 운전자라는 특정 대상자를 설정하고 실험을 하였다. 실험 결과 생체신호와 몸짓을 같이 사용한 실점의 인식률이 둘 중 한 가지만을 사용한 것보다 높은 인식률을 보였다. 생체신호와 몸짓들의 특징 신호들은 강화학습의 개념을 이용한 IFS(Interactive Feature Selection)를 이용하여 특징 선택을 하였다.

• 대한인간공학회지
• /
• 제30권6호
• /
• pp.705-713
• /
• 2011

Objective: The aim of this study is to compare results of emotion recognition by several algorithms which classify three different emotional states(happiness, neutral, and surprise) using physiological features. Background: Recent emotion recognition studies have tried to detect human emotion by using physiological signals. It is important for emotion recognition to apply on human-computer interaction system for emotion detection. Method: 217 students participated in this experiment. While three kinds of emotional stimuli were presented to participants, ANS responses(EDA, SKT, ECG, RESP, and PPG) as physiological signals were measured in twice first one for 60 seconds as the baseline and 60 to 90 seconds during emotional states. The obtained signals from the session of the baseline and of the emotional states were equally analyzed for 30 seconds. Participants rated their own feelings to emotional stimuli on emotional assessment scale after presentation of emotional stimuli. The emotion classification was analyzed by Linear Discriminant Analysis(LDA, SPSS 15.0), Support Vector Machine (SVM), and Multilayer perceptron(MLP) using difference value which subtracts baseline from emotional state. Results: The emotional stimuli had 96% validity and 5.8 point efficiency on average. There were significant differences of ANS responses among three emotions by statistical analysis. The result of LDA showed that an accuracy of classification in three different emotions was 83.4%. And an accuracy of three emotions classification by SVM was 75.5% and 55.6% by MLP. Conclusion: This study confirmed that the three emotions can be better classified by LDA using various physiological features than SVM and MLP. Further study may need to get this result to get more stability and reliability, as comparing with the accuracy of emotions classification by using other algorithms. Application: This could help get better chances to recognize various human emotions by using physiological signals as well as be applied on human-computer interaction system for recognizing human emotions.

• 산업경영시스템학회지
• /
• 제38권3호
• /
• pp.14-20
• /
• 2015

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 ($-1^{\circ}C{\sim}-6^{\circ}C$). In the experiment 2, four experimental conditions were designed with one control condition and three experimental conditions ($-3^{\circ}C{\sim}-5^{\circ}C$). 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 $-3^{\circ}C$ to $-5^{\circ}C$ 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 $-4^{\circ}C$ experimental condition. These results suggested that seat air conditioning could affected to comfort sensation of occupants in an appropriate range, rather than unconditionally.

• 지능정보연구
• /
• 제11권2호
• /
• pp.81-103
• /
• 2005

신경계의 뉴런 구조는 흥분 뉴런과 억제 뉴런으로 구성되며 각각의 흥분 뉴런과 억제 뉴런은 주동근 뉴런(agonistic neuron)에 의해 활성화되며 길항근 뉴런(antagonist neuron)에 의해 비활성화 된다. 본 논문에서는 인간 신경계의 생리학적 뉴런 구조를 분석하여 퍼지 논리를 이용한 생리학적 퍼지 신경망을 제안한다. 제안된 구조는 주동근 뉴런에 의해 흥분 뉴런이 될 수 있는 뉴런들을 선택하여 흥분시켜 출력층으로 전달하고 나머지 뉴런들을 억제시켜 출력층에 전달시키지 않는다. 신경계를 기반으로 한 제안된 생리학적 퍼지 신경망의 학습구조는 입력층, 학습 데이터의 특징을 분류하는 중간층, 그리고 출력 층으로 구성된다. 제안된 퍼지 신경망의 학습 및 인식 성능을 평가하기 위해 정확성이 요구되는 의학의 한 분야인 기관지 편평암 영상 인식과 영상 인식의 주요 응용 분야인 차량번호판 인식에 적용하여 기존의 신경망과 성능을 비교 분석하였다. 실험 결과에서는 제안된 생리학적 퍼지 신경망이 기존의 신경망보다 학습 시간과 수렴성이 개선되었을 뿐만 아니라, 인식에 있어서도 우수한 성능이 있음을 확인하였다.