• Title/Summary/Keyword: 짝의 t-검정

Search Result 12, Processing Time 0.019 seconds

Storage stability of reduced sulfur gases in Tedlar bag sampler: Test of two different storing approaches (Tedlar-bag 시료채집법을 이용한 황화합물의 경시적 농도 변화특성: 시료의 생성방식의 차이에 따른 비교연구)

  • Jo, Hyo-Jae;Kim, Ki-Hyun
    • Analytical Science and Technology
    • /
    • v.24 no.3
    • /
    • pp.212-218
    • /
    • 2011
  • In this study, temporal stability of 5 reduced sulfur compounds (RSCs) including ($H_2S$, $CH_3SH$, DMS, $CS_2$, and DMDS) was investigated up to 30 days. To learn the temporal changes in RSC concentration levels, two types of long-term storage experiment were carried out by employing two different approaches for sample storing in Tedlar bag samplers. The first one named as a forward (F) storage method consists of preparing all samples in the beginning of experiment. All these samples were analyzed sequentially through time. The second approach named as a reversed (R) storage method was carried out by preparing each sample through time and by analyzing all of them in the last day. For these experiments, RSC standards were prepared at 10 ppb in 10 L Tedlar bag. The results of both methods were consistent enough to show a tendency of the concentration reduction through time. Moreover, the lightest RSC, $H_2S$ showed the most significant reduction of 84.8% at the end of experiment. To validate difference between these results, t-test was applied to the data obtained between the two methods at 90% significance level. According to t-test, the results of the two approaches were greatly distinguished from 3 RSCs ($H_2S$, $CH_3SH$, and DMDS). The results also indicated that the temporal reduction of RSC differs greatly between light ($H_2S$ and $CH_3SH$) and heavy RSCs (DMS, DMDS, and $CS_2$). The former generally exhibited much significant reduction through time due probably to their lower stability.

The Educational Effect of Human Body Exploration Camp on Health Promotion of Elementary Students (초등학생을 위한 인체탐험캠프가 건강증진에 미치는 교육적 효과)

  • Im, Hee Kyoung;Park, Jeonghyun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.16 no.8
    • /
    • pp.5111-5120
    • /
    • 2015
  • In this paper, learn how to establish a proper lifestyle and health management through professional and systematic health education for children and young people, and laid the foundations for lifelong health, and to present the saeroeun paradigm complements the problems of school health education This study aimed to examine the effectiveness of the human body exploration camp program on elementary students in health promotion aspect. Survey was done pre-, post- and followup- tests for 61 participants in the camp. The evaluation consisted of 53 questionnaires multiple-choice written test on the changes of knowledge and attitude. Factor analysis and reliability analysis were used to SPSS WIN18.0 verify questionnaire's reliability and validity, and paired t-test were carried out in order to analyze knowledge and shift in attitude. In addition, regression analysis was carried out in order to the relation between the satisfaction, knowledge and attitude. By this study, we showed as follows. First, knowledge were increased post- than pre-test, follow up- than pre-test(p<0.01). Second, shift in attitude changed positively post- than pre-test(p<0.01), follow up- than pre-test(p<0.05). Third, satisfaction was closely related to shift in attitude(p<0.01). Therefore, it suggested that the implement of human body exploration camp for elementary students could be an alternative strategy in health education.