• 대한기계학회논문집
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• 제19권11호
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• pp.3003-3013
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• 1995

The characteristics of the flow field in the tangentially fired furnace are presented. Experiments are conducted in the simplified cold type isothermal flow model. In the measurement of flow field, a hot wire anemometer is used. The hot wire was calibrated by lookup table method. The mean velocity field and turbulence characteristics are showed with changing the nozzle angle. In the center of the model, the low speed, unstable flow region is formed. The size and position of these regions are varied with changing the nozzle angle. It can be used as fundamental data in the design of the large furnace. From the experimental results, various turbulent characteristics of swirling flow field is obtained. And the entrainment mechanism of the jet flow field is described from the distribution of the skewness and the flatness. It can be used the raw data of approximate calculation and turbulent modelling.

• 한국초등과학교육학회지:초등과학교육
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• 제22권2호
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• pp.149-155
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• 2003

The objective of this research was to study the impact of metacognitive lesson models on the formation of magnetic field concepts. The subjects of this research was eighty students from two sixth grade classes. One class of forty of these students was the experimental group, which the metacognitive strategic lesson model was applied, and the other class of forty students was the control group which the traditional lessons were conducted. As the result of the experiment, the experimental group and the control group, which previously did not show difference in terms of achievement of conceptualizing magnetic field, displayed a significant difference. According to the comparison between the pre-experiment test on the students' previous concepts and the achievement of the students after the experiment, the middle group showed difference between the experimental group and the control group in a small degree. The lower group showed a notable difference between the two groups and the higher group showed no difference. In terms of achievements shown in different questions asked, there was little difference in the questions that were stated in the textbook while there was a significant difference in the questions that applied the contents of the textbook. The higher academic group, according to the test on the previous concepts, did not show much difference between the experimental group and the control group when they were asked about the concepts of the textbook. In terms of the comparison in the metacognitive levels, both the higher and lower metacognitive experimental groups' average grade was higher than the control groups' and showed an important statistical difference.

• 한국농공학회지
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• 제39권2호
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• pp.134-142
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• 1997

This study was performed to evaluate the drain runoff characteristics from one paddy field, and to provide the basic data required for the determination of flood discharge and unit drainage water for drainage improvement and farmland consolidation. For this purpose, under the assumption that drain discharge from paddy field was similar to outflow of reservoir, runoff model based on storage equation was applied to the experimental field, and simulated results were compared to the measured discharge at weir point. To estimate effective storage volume of paddy field with water depth, 4 regression formula were examined such as linear, exponential, power, and combined. From the observed runoff characteristics, it was shown to be 3.3~16.3${\ell}$/sec in weir discharge, 57.2~98% in runoff ratio, and relative error of simulated result was 3.0~39.4%, 8.5 ~56.0 % for peak flow and runoff ratio, respectively. Curve number by SCS method was calculated as mean value of 96.4 using measured rainfall and runoff data, it was considered relatively high because paddy field has generally flooding depth contrary to the upland watershed area.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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• pp.57-64
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• 2001

There are some previous reports that some animals such as rats and birds move in a large group and act abnormally to avoid the large earthquake. This study is to experimentally testify what relations exist between the anomalous animal behavior and electric field effect, which is reported due to the piezoelectric effects in a basement rock before earthquake occurrences. When electric field is applied to the whole bottom of the cage, they show nervous behaviors such as grooming, washing their faces, standing on legs or running around in panic to avoid the electric field. When more strong electric field is applied, they jump with shrieking and mount on the electric line. The rat shows more sensitive anomalous behavior than the bird. Even though the current to the experimental birds and rats is just a few $\mu$A, they react in various ways. The anomalous animal behaviors under the small ground electric field may have some relations to the actual phenomena before great earthquake. This kind of study is quite worthy for the understanding of earthquake precursors.

• 한국환경보건학회지
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• 제21권1호
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• pp.78-85
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• 1995

Ornithine decarboxylase(ODC) is an indicate enzyme in carcinogenesis. We divided Sprague Dawley rats into six groups: control, electric field exposure, X-ray only irradiation, X-ray irradiation with electric field exposure group, Sr-90 injected group and Sr-90 and electric field complex exposure group. The ODC activity was measured in rat's bone marrow cell every week. The results were summarized as follows: The ODC activitied was increased in X-ray irradiated, Sr-90 injected and Sr-90 and electric field complex exposed group as compared with that of control(p<0.05). The ODC activity was increased comparing that of control neither in X-ray and electric field complex exposed group nor electric field only exposed group. This result suggests that the electric field doesn't have myeloid carcinogenicity and myeloid cancer incidence caused by ionized radiation is suppressed by electric field exposure.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권4호
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• pp.48-57
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• 2020

The objective of this study was to investigate the feasibility of organic compost for reducing soil loss in 25% sloped farm land. For the study, laboratory and field experiment were performed. After nine weeks monitoring in pot test, hardness of the amended soil with organic compost (1%~3%, w/w) showed two times higher than the control soil. Furthermore, soil loss of that was decreased by 95% under rainfall simulation test. From the result of laboratory experiment, organic compost with 2% (w/w) was applied for field experimental plot. After six month from April to September, the amount of soil loss became 67% of the initial, and the growth of natural vegetation was not hampered. Therefore, organic compost can be used as amendment materials to reduce soil loss in sloped farmland.

• Structural Engineering and Mechanics
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• 제89권2호
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• pp.199-211
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• 2024

The loading capacity of engineering structures/components reduces after the initiation and propagation of crack eventually leads to the final failure. Hence, it becomes essential to deal with the crack and its effects at the design and simulation stages itself, by detecting the prone area of the fracture. The phase-field (PF) method has been accepted widely in simulating fracture problems in complex geometries. However, most of the PF methods are formulated with second order continuity theoryinvolving C⁰ continuity. In the present study, PF method based on fourth-order (i.e., higher order) theory, maintaining C¹ continuity has been proposed for ductile fracture simulation. The formulation includes fourth-order derivative terms of phase field variable, varying between 0 and 1. Applications of fourth-order PF theory to ductile fracture simulation resulted in novelty in this area. The proposed formulation is numerically solved using a two-dimensional finite element (FE) framework in 3-layered manner system. The solutions thus obtained from the proposed fourth order theory for different benchmark problems portray the improvement in the accuracy of the numerical results and are well matched with experimental results available in the literature. These results are also compared with second-order PF theory and a comparison study demonstrated the robustness of the proposed model in capturing ductile behaviour close to experimental observations.

• 동의생리병리학회지
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• 제26권2호
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• pp.212-220
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• 2012

In this study, we tried a study on a direction of the field of oriental medicine on accepting complementary alternative medicine by analyzing the related thesis, journals and papers on the complementary alternative medicine published in the field of oriental medicine. As the result of analyzing the present study of the field of oriental medicine on the complementary alternative medicine, there have been 22 studies on the complementary alternative medicine. Thesis, papers were mainly experimental papers about the bee venom therapy, energy therapy, fasting therapy, and colon therapy, and the journals were actively studied in order of clinical paper, experimental paper, and reference paper about the bee venom therapy, energy therapy, and reflexolgy. The acceptance of complementary alternative medicine by the field of oriental medicine through a scientific relation should be conducted more systemically by setting the main academy taking charge of the study on common characteristics of the complementary alternative medicines on the classification of NCCAM as well as the related academies taking charge of the study on the unique characteristic of each complementary alternative medicine. First, additional studies are needed to make the most of characteristics of each complementary alternative medicine through the main academy and the related academies, and for the next, additional studies are necessary to complement the research trend on each complementary alternative medicine through the main academy and related academies.

• Child Health Nursing Research
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• 제28권3호
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• pp.167-175
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• 2022

Purpose: The present study aimed to develop and examine the effectiveness of a pediatric nursing competency-building program for nursing students. Methods: This was a quasi-experimental study with a nonequivalent control group pretest-posttest design conducted between October and December 2021. The participants included 40 nursing students (20 each in the experimental and control groups) at a university in a South Korean city. The pediatric nursing competency-building program integrated problem-based learning and simulation into clinical field practice. The experimental group participated in the program, while the control group did not. Data were analyzed using the 𝑥² test, the independent t-test, and repeated-measures analysis of variance. Results: Pediatric nursing competency and clinical performance showed a greater increase in the experimental group than in the control group. However, the change in problem-solving ability in the experimental group was not significantly different from that in the control group. Conclusion: The pediatric nursing competency-building program effectively improved students' pediatric nursing competency and clinical performance.

• 한국보육지원학회지
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• 제15권4호
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• pp.59-81
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• 2019

Objective: The purpose of this study was to analyze the influence of early childhood science education instruction through the implementation of science teaching methods and science teaching attitudes of preschool teachers. Methods: This study was conducted on 52 female students in the early childhood education department of Early Childhood Science Education at G university in Gyeongbuk province. The data collected in this study were analyzed through reliability analysis, carbon scanners verification, and homogeneity verification; ANCOVA was used to verify the effectiveness of the program. Results: First, the results showed that the post-test belief of science teaching methods of the experimental group were significantly different than that of the control group. Second, the results showed that the post-test scores of science teaching attitudes of the experimental group were significantly higher than that of the control group. Conclusion/Implications: This study suggests that there were positive influences of early childhood science education instruction through the field practice on the belief of science teaching methods and science teaching attitudes of preschool teachers.