• Title/Summary/Keyword: Test of Homogeneity

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Evaluation Techniques for Residual Structural Performance of a Reinforced Concrete slab under Fire Damage (화재 피해를 입은 철근콘크리트 슬래브의 잔존 구조성능 평가기법)

  • Choi, Kwang-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.588-594
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    • 2020
  • This study proposes non-destructive rebound-hardness and ultrasonic testing methods to more accurately evaluate the residual structural performance of reinforced concrete structures in a fire. Techniques are also proposed to assess the stiffness used in the deflection calculation with natural frequencies obtained by vibration tests. In the compressive strength evaluation using rebound hardness, the residual compressive strength of thick specimens and a larger water/cement (W/C) ratio were shown to be large. The homogeneity of concrete at high temperature compared to ambient temperature conditions was assessed by the velocity of ultrasonic waves that penetrate the concrete, and it followed W/C or thickness of slab makes little different results. To assess the stiffness of fire-damaged slabs and increase in deflection, the natural frequency was measured by vibration tests and incorporated into the equation of the stiffness. The application of this technique to the slab experiment showed that it can be a very reasonable evaluation technique. In addition, to evaluate the residual strength of a member after fire, a test of the strength of a component was carried out during and after heating.

Effects of the Doin Gigong Exercise on the Shoulder-Arm Pain in Women (도인기공체조가 여성의 견비통(肩臂痛)에 미치는 효과(效果))

  • Youn, Hyoun-min;Kim, Mi-young;Kim, Yi-soon;Lim, Jin-seob
    • Journal of Acupuncture Research
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    • v.22 no.1
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    • pp.177-190
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    • 2005
  • Objective : This study intends to identify the effects of the Doin Gigong Exercise on the shoulder-arm pain in Women. Methods : The study was performed with nonequivalent control group pretest-posttest design. A total of 45 subjects were divided into 25 persons in experimental groups and 20 persons in contrastive group by convenience sampling. The data were collected by using questionnaires and measured values from June, 2004, to August, 2004. Results : The results of the study are as follows: 1. The homogeneity testing revealed that most study variables were equally distributed between experimental and control groups. 2. The first hypothesis: The experimental group who performed the Doin Gigong Exercise and who decreased on the subjective symptom scale was supported(t=10.245, p=.000). 3. The scond hypothesis : The experimental group who received Doin Gigong Exercise and who decreased on the subjective pain(VAS) was supported(t=6.816, p=.000). 4. The third hypothesis: The experimental group who received Doin Gigong Exercise and who decreased on the muscular stiffness measured techniques(UNIQUE) was supported (t=7.114, p.000). Conclusions : Based on the results described above, it is considered that the Doin Gigon Exercise is clearly effective in all an values of the 5 measured. Therefore, the Doin Gigong Exercise can be thought of as effective nursing intervention for the reduction of shoulder-arm pain in women.

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Evaluation for the Manufacturing Characteristics and Thermal Conductivity of Engineering Scale Bentonite-Sand Buffer Blocks (공학규모 벤토나이트-모래 완충재 블록의 성형특성 및 열전도도 평가)

  • Lee, Deuk-Hwan;Yoon, Seok;Kim, Jin-Seop;Lee, Gi-Jun;Kim, Ji-Won;Kim, Min-Jun
    • Journal of the Korean Geotechnical Society
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    • v.38 no.12
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    • pp.113-123
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    • 2022
  • The required density relationship according to the press pressure of the floating die method and the homogeneity of the density distribution in the buffer block was evaluated to analyze the manufacturing characteristics of engineering scale bentonite-sand buffer blocks. In addition, the thermal conductivity was measured and compared with that of the pure bentonite buffer block to evaluate the level of thermal conductivity performance improvement of the bentonite-sand buffer material. As a result, it was confirmed that the standard deviation of dry density decreased to 0.011 and showed a homogeneous density distribution under the condition of press pressure greater than 400 kg/cm2. Furthermore, as a result of the thermal conductivity test, the thermal conductivity of the buffer with optimum moisture content conditions was 1.345 and 1.261 W/(m·K) under the press pressure of 400 and 600 kg/cm2, respectively. It increased by 16.1% and 11.0% compared to the pure bentonite buffer material. Based on the results of this study, it is judged that it can be used as fundamental data for manufacturing a homogeneous bentonite-sand buffer block on an engineering scale.

The Effect of Small Group Plastic Artistic Activities on the Emotional Intelligence of Early Young Children (소집단 소조활동이 유아의 정서지능에 미치는 효과)

  • Kim, Young Ju;Choi, Im Soo
    • Korean Journal of Childcare and Education
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    • v.3 no.1
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    • pp.17-37
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    • 2007
  • An abundant emotional experience in childhood can be a basis of success of their life. In this research, I set up a hypothesis as follows to see if a group plastic activities are effective for the improvement of children's emotional intelligence and self-emotion awareness ability, self-emotion management ability, self-motivation ability, other's emotion awareness ability and personal relationship skill ability. The research subjects were 40 children of 5 years old(experimental Group: 20, controlled group: 20) in Y kindergarten located in Ulsan. In pretest, we confirmed homogeneity between experiment and control group using child emotional checklist and then applied small group plastic artistic activities to the experiment group. Data analysis was performed with population, percentage, t-test and Cronbach a. The findings of this study were: First, the group plastic artistic activities was effective for the emotional intelligence of children. Second, the small group plastic activities was effective for the self-emotion awareness, self-emotion control and self motivation ability of children. Third, the small group plastic activities was effective for the awareness ability about other's emotion and personal relationship skill ability. The result of this study implies that the small group plastic artistic activities are effective children's emotion and we need to develop the various activity program and practice for children's emotion development.

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Microbiological Hazard Analysis for HACCP System Application to fermented milk (발효유류의 HACCP 시스템 적용을 위한 미생물학적 위해 분석)

  • Park, Seong-Bin;Kwon, Sang-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.438-444
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    • 2015
  • The aim of this research was to apply a HACCP system (Hazard Analysis Critical Control Point) to fermented milk. The main ingredients of fermented milk, work facilities and workers were obtained from a company named YD, which is located in Seobuk-gu, Cheonan-si between November 5 2013 to April 13, 2014. A manufacturing process chart was prepared by referring to the manufacturing process of fermented milk manufacturers in common. The manufacturing process chart was made with raw materials; Raw milk, High Fructose Corn Syrup, Oligosaccharides, Lactic Acid bacteria and Subsidiary ingredients, Warehousing of packaging materials, Storage, Input, Preheating, Mixing, Homogeneity, Sterilization, Precooling, Culture, Filtration, In packaging, Out packaging, Storage, and Consignment, as listed Table 1. The results of the microbiological hazard analysis on the raw materials was safe after sterilization($90^{\circ}C{\pm}5^{\circ}C$, $35{\pm}3min.$) On the other hand,a microorganism test of an environment and workers suggested that the microbiological hazard should be reduced through systematic cleaning and disinfection accompanied by improved personal hygiene based on hygienic education on workers and the management of microorganisms in air.

The Impact of Grouping Methods on Free Inquiry Implementation: The Case of Two Middle Schools Adopting Different Grouping Methods (소집단 구성 방식이 자유 탐구 수행에 미치는 영향: 소집단 구성 방식을 달리한 두 중학교의 사례)

  • Park, Jae-Yong;Lee, Ki-Young
    • Journal of The Korean Association For Science Education
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    • v.32 no.4
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    • pp.686-702
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    • 2012
  • This study investigated the impact of grouping methods on free inquiry implementation through the use of mixed research methods. Some 113 7th graders and 2 science teachers in two middle schools participated in this study. The 113 students who participated in this study were grouped by homogeneity and heterogeneity according to scientific inquiry skills and personality types respectively, and performed free inquiry activities on the same subject for three weeks. Data were collected by means of a test on science inquiry skills and from focus group interviews with 36 students and in-depth interviews with 2 teachers. The quantitative results of this study showed that homogeneous grouping was more effective than heterogeneous grouping in improvement of scientific inquiry skills. Meanwhile, the qualitative results revealed both the students and teachers perceived that it was effective to compose a small group according to their affective quality than their cognitive quality. Particularly, most of the students preferred the method of small group from the personality types. Some students and both teachers proposed that it is necessary to collect enough information on students and to use them in mixture with the method of small group according to the affective quality.

Effect of Residual Shear Strain on the Relationship between Volumetric Strain and Effective Stress after Liquefaction (액상화 후 잔류전단변형률이 체적변형률과 유효응력 관계에 미치는 영향)

  • Kwon, Youngcheul
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.11
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    • pp.55-62
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    • 2010
  • The settlements by liquefaction seldom occur uniformly because of soil homogeneity, however differential settlements are major cause of the damages to structures. From the past researches, author paid attention to the fact that stress history during undrained cyclic shear process affects greatly on the volumetric strains of the post-liquefaction. Therefore, the effect of the residual shear strain in cyclic shear process was examined in this study. The experiment apparatus based on strain control with volumetric strain control device was used for the study to investigate the effect of the residual strain on the relationship between volumetric strain and effective stress of clean and granite sandy soil. It could be seen an insignificant difference in the volumetric strain after liquefaction under various residual shear strain conditions in the case of clean sand. On the other hand, in granite sandy soil, the volumetric strain after liquefaction was small when the lower level of the residual shear strain was applied. And, the residual shear strain during cyclic shear affected the shape of the relation curve between effective stress and volumetric strain as well.

The Effects of Improvement of Interaction on Teaching and Learning in Nursing Education Using Change Laboratory Method (간호교육에서 변화실험실을 활용한 강의 상호작용 개선이 교수-학습에 미치는 효과)

  • Kim, Jong Kyung;Yang, Young Hee;Lee, Jeong Eun;Song, Hee-Seung
    • The Journal of the Korea Contents Association
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    • v.17 no.10
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    • pp.385-393
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    • 2017
  • The purpose of this study was to develop and apply the participation-centered lecture model and practice principle developed by the Change Laboratory Method to improve the lecture interaction of nursing education and verify the effect. The experimental group was 91, and control group was 83 students who studied in the 3rd and 4th grade at one College of Nursing, This study developed the detail participatory lecture method on January and February and applied it to the students in March, and April, 2017, In the pre-survey, general characteristics, class attitude, and learning strategies were examined and homogeneity test was conducted. Post-survey was conducted with participation, satisfaction, and performance, The results showed that the experimental group and the control group were homogeneous. The average participation levels of the experimental and control groups were 3.98 and 3.77 respectively(t=2.38, p<.05). However, there was no statistically significant difference in the satisfaction and achievement. Therefore, it was expected to improve the participation and performance of students through the application of the participation-centered lecture. In the future, it will be necessary to prepare and implement effective methods for improvement of teaching methods in each subject.

Analysis of Elevation Variation within a Rice Paddy Field (수도작 포장 균평도의 연중 변화 분석)

  • Sung, Je-Hoon;Jang, Soon-Woo
    • Korean Journal of Soil Science and Fertilizer
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    • v.39 no.5
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    • pp.307-314
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    • 2006
  • Elevation differences within a paddy field relate strongly to plant health, crop homogeneity, and pest control. For precision agriculture (PA), the elevation within a field should be precisely controlled. We analyzed variation in elevation within two rice paddies over one crop cycle. The study took place in two rectangular plots (Field A and Field B, each $50m{\times}30m$). Elevations within the two plots were measured by a laser-equipped surveying instrument, that could determine elevations to precisions of 1 mm. The test fields were divided into grids with 30 squares; elevation was measured at the center of each $5{\times}10-m$ grid square. This study measured elevation during nine observation periods from pre-plowing to post-harvest. Descriptive statistics showed the highest elevations after plowing due to soil disturbance. One-way analysis of variance (ANOVA) revealed significant elevation differences before and after plowing and transplanting, although elevations were similar over the period of crop growth. Comparison of pre-plowing and post-harvest data showed differences in elevations, indicating that elevation changes occurred during plowing, rice transplanting, plant growth, and harvesting. In summary, the above statistical analyses indicated that elevation changes occurred due to plowing but not during the plant growth season or due to harvesting.

Effect of 12 Hours Fasting Resistance Exercise on Metabolic Efficiency and Fatigue in Convergence Ages (융복합 시대의 12시간 공복저항운동이 대사효율성 및 피로물질에 미치는 영향)

  • Baek, Soon-Gi
    • Journal of Digital Convergence
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    • v.14 no.9
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    • pp.471-478
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    • 2016
  • The purpose of this study to examine the effect of 12 hours fasting resistance exercise on metabolic efficiency and fatigue of middle-aged female for 8 weeks. 50 middle-aged female target group pre-test exercise group(EX) and the control over the homogeneity in the control group(CON) were selected for this purpose divided into two groups. Exercise group(EX) is maintained after 8 weeks four times weeks 12 hours fasting resistance was performed for 60 minutes, the control group(CON) were compared to a normal life with the group of the exercise group(EX). Resistance applied to the exercise group(EX) were using free weights and a fixed mechanism applied around the upper and lower body exercise program for heart muscle, exercise intensity based on the 70% 1RM until 4 weeks, 5-8, which was performed by the aid program set to 80%. Through this procedure were as follows. First, 12 hours fasting resistance exercise showed the significance of the interaction effect in metabolic efficiency, blood pressure(SBP, DBP), fat, fasting glucose, fasting insulin(p<.01). Second, 12 hours fasting resistance exercise showed the significance of the interaction effect in the treatment program in which lactic acid, uric acid(p<.01).