The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) and driving performance of relatively aged and high-experienced drivers. The s

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.

인간 활동이 생태계의 훼손과 생물다양성의 변화에 미치는 영향을 경관생태학적 측면에서 분석하고 해석하는 연구가 활발히 진행되고 있다. 본 연구는 우리나라의 35개 농촌마을을 대상으로 자연생태계의 교란정도를 알 수 있는 귀화식물분포현황을 조사하였다. 대상지에 대한 토지이용 현황도를 제작하고 이를 바탕으로 경관지수를 이용하여 경관생태학적특성을 정량화하였다. 이를 바탕으로 대상지의 경관지수와 귀화식물 분포특성의 상관관계를 분석하였다. 경관지수는 공간분석 프로그램인 FRAGSTATS를 이용하여 산출하였으며 귀화식물의 분포특성은 Urbanization Index와 Naturalization Index를 이용하였다. 연구 결과 귀화율과 패치밀도, 귀화율과 가장자리밀도, 귀화율과 면적가중평균형태지수 등이 양의 상관관계를 나타냈으며 귀화율과 핵심면적백분율, 귀화율과 평균핵심지역 등이 음의 상관관계가 있는 것으로 분석되었다.

The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) during driving. The participants included 29 taxi drivers; 14 males aged 56.7 ± 4.3 with 29.7 ± 7.0 years of driving experiences and 15 females aged 55.5 ± 3.5 with 20.1 ± 5.7 years of driving experiences. All subjects were instructed to keep a certain distance (30m) from the car ahead and a constant speed (80km/h or 100km/h). SCL was measured during driving only and driving with secondary tasks. SCL was more increased during the driving with secondary tasks than driving only. By increasing the driving speed, SCL was increased during the driving with secondary taks. Secondary tasks increased an activation of sympathetic nerve system. However, there were no significant differences in the SCL according to gender.

The purpose of this study was to quantitatively evaluate the effects of the secondary task with unexpected situation during simulated driving using the variable indicating control of vehicle. The subjects were participated 50s people including 15 males with 29.5±6.7 years of driving experiences and 15 females with 20.1±5.6 years of driving experiences. All subjects were instructed to keep a certain distance (30m) from the car ahead and a constant speed (80km/hr or 100km/hr). Sending text message(STM) and Searching navigation(SN) were selected as the secondary task. Experiment consisted of driving alone for 1 minute and driving with secondary task for 1 minute. It was defined driving phase and unexpected situation phase respectively. Medial-lateral coefficient of variation(MLCV) of car movement was analyzed for evaluating lane keeping in this study. In the results, MLCV was increased by 118.3% at 100km/hr. In the case of secondary task, MLCV in STN and in SN were increased by 235.1% and 290.3%, respectively. There was no significant difference between male and female. In case of driving at high-speed and with secondary task, it may be disturbed constant control of the vehicle when unexpected situation appeared suddenly.

The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) and deviation of vehicle speed during driving. The participants included 30 he

본 연구의 목적은 차량 통제 변인과 동작의 부드러움 변인을 이용하여 동시 과제 수행이 운전 수행 능력에 미치는 영향을 정량적으로 제시하는 것이다. 1~2년의 운전 경력을 가진 피험자 20명이 실험에 참여하였다. 피험자는 동작분석을 위해 상지(shoulder, elbow, wrist) 및 하지(knee, ankle, toe)에 9개의 마커를 부착한 후, 운전 시뮬레이터를 이용하여 80km/hr로 주행하는 선행 차량과 30m의 간격을 유지하며 직선 주행하도록 하였다. 동시과제는 문자 메시지 보내기와 네비게이션 검색으로 선정하였다. 실험 시간은 2분으로 운전 시작 후 1분은 운전만을, 다음 1분은 운전과 동시과제를 함께 실시하도록 하였고, 각각 운전구간과 동시과제구간으로 정의하였다. 차간거리(Anterior-Posterior Coefficient of Variation, APCV) 및 차선이격거리의 분산계수(Medial-Lateral Coefficient of variation, MLCV)와 저크비용함수(Jerk-cost function, JC)를 이용하여 운전 수행 능력을 평가하였다. APCV는 운전구간에 비해 운전 중 네비게이션 검색 시 222.1% 증가하였다. MLCV는 문자 메시지 전송 과제를 수행할 경우, 318.2%, 네비게이션 검색 과제를 수행할 경우 309.4%가 증가하였다. JC는 운전구간에 비해 동시과제 수행 시, 팔꿈치, 무릎, 발목, 발가락에서 유의하게 증가하였고, 하지마커 전체의 평균값은 문자과제 수행 시 218.2%, 네비게이션 과제 수행 시 294.7%가 증가하였다. 운전 중 동시과제의 수행은 JC를 증가시켜 운전자의 동작의 부드러움을 감소시키고, APCV와 MLCV를 증가시켜 차량의 횡적 종적 통제를 어렵게 한다고 결론 내릴 수 있다.

Tomato were stored at different temperatures(10℃, 20℃, room temperature and 30℃) for 5 days. During the storage period, Brix, pH, color, texture, vitamin C, lycopene were analyzed. Brix and pH had a little change. Texture force of tomato decreased with storage time and we could see a softening for tomato stored at 30℃ for 1 day. Addtional, the L*(lightness) and b*(yellowness) decreased and a*(redness) increased with storage time. Addtionally, content of vitamin C increased up to 9.08㎎/100g~17.82㎎/100g after 5 days storage according storage temperature, whereas content of lycopene increased up to 3.81㎎/㎏~34.56㎎/㎏ after 5 days storage according storage temperature. Optimal mature temperature for tomato was room temperature.

The focus of the current study was to investigate the physicochemical properties of a corn starch-sponge matrix prepared at a low concentration below gel forming by freeze-drying. The effect of variables(starch concentration, heating temperature, and heating hold time) on the physicochemical properties of the samples was analyzed by response-surface methodology. Regression models on the properties of samples such as hardness, springiness, and water solubility index(WSI) showed high correlation coefficients(r>0.95) and significant F values, but regression models for the other properties(swelling power, apparent viscosity, reducing sugar content, and digestibility) showed them to have relatively low significance. Sample hardness of sample showed the highest value at condition of 90℃ and 5%, whereas springiness was at a maximum at 130℃ and 5%. Also, at 1% of starch concentration, mechanical properties were greatly decreased as the relative humidity increased, compared with the 3% and 5%, especially in the hardness of samples. The WSI showed an increasing trend with heating temperature regardless of starch concentration. Overall, the physicochemical properties of freeze-dried corn starch-sponge matrix were influenced much more by starch concentration and heating temperature than by heating hold time. The results of this study show that the basic properties of freeze-dried corn starch-sponge matrix can be used for the specific food applications or as a functional material for its stability.

This study was conducted to investigate the dietary behavior of day-care center teachers and their meal attitudes during meal time in Jeonju area. Self administered questionnaires were collected from 266 day-care center teachers who worked in a national(public) or private day-care center. The Statistical data analysis was conducted using SPSS v. 12.0. All subjects were women, and 64.7% were married(p<0.001), over more than 60% were junior college graduates(p<0.05), and 73.7% had salaries greater than 1, 000, 000 won(p<0.001). The breakfast skipping ratio of the subjects was very high, and about 66.5% of the respondents had irregular meals. The snack intake ratios of the subjects in private day-care centers were higher than the subjects in national(public) day-care centers(p<0.001). Approximately 56% of the subjects responded that education about eating is very important for providing balanced nutrition to young children. About 84% of subjects had no experience with the continuing-education program for teachers(p<0.01), and they wanted to know more about balanced nutrition. The meal attitude education score during meal time was 4.53±0.36. The relationship between meal attitude education and the dietary behavior of day-care teachers was significantly different based on the "frequency of overeating"(p<0.05) and "self-recognition of eating habit"(p<0.05). These findings suggest that a nutrition education program for day-care center teachers should be developed so that they can effectively manage meal attitude education for young children and provide good nutrition for themselves.

The chemical composition characteristics of jujube wine using different preparation methods including extraction in -soju (25%) and fermentation were investigated. The jujube wine was prepared by soaking in soju using- whole fruit(WJ-S1) or seed-removed fruit(WJ-S2). Fermentations of the jujube wine were started by using whole fruit(WJ-F1), seed-removed fruit(WJ-F2) or extracts of whole fruit(WJ-F3) after adding 24% sucrose. The pH of all samples decreased from a range of 4.92~5.42 at the start time to 3.66~4.97 after 100 days. The treatment WJ-F3 showed the lowest pH among all treatments. Total acid content was 0.67~1.01% at the initial stage and then changed to 0.51~0.88% after 100 days. Total sugar and reducing sugar contents were 1.20~13.8% and 0.50~4.45% at initial stage and then changed to 1.53~4.52% and 1.75~3.82% after 100 days respectively. These sugars decreased during the preparation and fermentation of the jujube wine. The amounts of free sugars including fructose, glucose, and sucrose ranged from 1.53~4.52% and treatment WJ-F3 showed the highest amount(1.95~13.64%) compared the other treatment. glucose level were high in treatment WJ-S1 and WJ-S2, and fructose was increased in treatments WJ-F1, WJ-F2, and WJ-F3 after 60 days. Amino nitrogen content was 0.02~0.11% after 20 days and 0.07~0.14% after 40 days respectively. Solid content was 2.68~7.76% at the initial fermentation stage and changed to 4.81~9.73% after 100 days. Hunter color(L values) were 88.45~96.74 at the initial stage and then changed to 92.62~100.45 after 100 days. Preference tests a significant difference between the two types (extraction and fermentation) of jujube wine. And treatment WJ-S2 received the highest preference scores among the all treatments.