• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.10-16
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• 2011

Purpose: The partial volume effect occurs because of limit of the spatial resolution. It makes partial loss of intensity and causes SUV to be lower than it should actually be. So the purpose of this study is to calculate recovery coefficient for correcting PVE from phantom study and to compare before and after SUV correction applying to PET/CT examination. Materials and Methods: The flangeless Esser PET phantom consisting of four hot cylinders was used for this study. All of the hot cylinders were filled with FDG solution of 20.72 MBq per 1000 ml, and the phantom background was filled with FDG solution of different concentrations (33.30, 22.20, 16.65 MBq per 6440 ml) to yield H/B ratios of around 4:1, 6:1 and 8:1. Using the Biograph Truepoint 40(SIEMENS, Germany), we applied recovery coefficient method to 30 patients who were diagnosed with lung cancer after PET/CT exam. And then we analyzed and compared SUV before and after correcting partial volume effect. Results: The smaller the diameter of hot cylinder becomes, the more recovery coefficient decreased. When we applied recovery coefficient to clinical patients and compared SUV before and after correcting PVE, before the correction all lesions gave an average max SUV of 7.83. And after the correction, the average max SUV increases to 10.31. The differences in the max SUV between before and after correction were analyzed by paired t test. As a result, there were statistically significant differences (t=7.21, p=0.000). Conclusion: The SUV for quantification should be measured precisely to give consistent information of tumor uptake. But PVE is one of factors that causes SUV to be lower and to be underestimated. We can correct this PVE and calculate corrected SUV using the recovery coefficient from phantom study. And if we apply this correction method to clinical patients, we can finally assess and provide quantitative analysis more accurately.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5937-5942
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• 2012

This study used silicon that is similar to the density of the tissue of the human body to compensate for the uneven areas that are in contact with air in order to reduce susceptible artifacts. The subjects of the study were 16 normal people and the areas of the human body in which there are a lot of uneven areas with complicated structure and a lot of susceptible artifacts were formed since the surface area that comes into contact with the air is large were the areas that were chosen to be examined. A 3.0T superconducting magnetic resonance device was used as the test equipment and SPIR images that are sensitive to magnetic differences were obtained as sagittal planes on a line that extended the metatarsal and the phalanges, including the middle of the longitudinal arc and the 5 distal phalanxes. The method of analysis was to reduce the susceptibility between the tissue and the air to discover the reduction of susceptible artifacts by comparing the SNR and CNR before and after applying silicon. A statistical analysis was utilized for the sample matching T examination. The results of the study revealed that the susceptible artifacts were reduced in the images of the uneven areas that were compensated and applied with silicon. The SNR increased in significant amount in correlation from $3.91{\pm}1.33$ before application to $21.69{\pm}4.52$ after application and the CNR decreased in significant amount in correlation from $28.97{\pm}8.20$ before application to $4.88{\pm}2.14$. In conclusion, this study did not affect the voxel but it was an innovative method of improvement that compensated for the fundamental issue of the difference in susceptibility between the air and the body. The application is simple and the study has great significance in that it proposed a method to reduce susceptible artifacts in a low cost and highly efficient manner.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.919-926
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• 2021

In this study, we wanted to find out the optimal angle as a modified tangential projection of the patella. In the experiment, we used Kyoto Kagaku's PBU-50 phantom. In the supine position, the F-T angle was set to 95°, 105°, 115°, 125°, 135°, 145°, and Patella tangential projection images were obtained by varying the X-ray tube angle by 5° so that the angle between the X-ray centerline and tibia at each angle was 5~20°. Image J was used for image analysis and the congruence angle, lateral patellofemoral angle, patellofemoral index and contrast to noise ratio(CNR) were also measured. SPSS 22 was used for statistical analysis, and the mean values of congruence angle, patellofemoral angle, patellofemoral index, and CNR were compared with Merchant method through one-way batch analysis and corresponding sample t-test. As a result of the study, in the case of congruence angle, the angle of incidence of the knee-angle X-ray centerline was 105°-72.5° (20° tangential irradiation), 115°-72.5°, 77.5° (15, 20° tangential irradiation), 125°-82.5° (20° tangential irradiation), lateral patellofemoral angle is 115°-72.5°, 77.5° (15, 20° tangential irradiation), 125°-72.5° (10° tangential irradiation), patellofemoral index is 115°-72.5° (15° tangential irradiation) and 125°-72.5° (10° tangential irradiation) were not significantly different from Merchant method (p> .05). In case of CNR, it is not different from Merchant method at 105°-67.5°, 72.5° (15, 20° tangential irradiation), 115°-67.5°, 72.5°, 77.5° (10, 15, 20° tangential irradiation). (P> .05). Based on the results of this study, high diagnostic value images can be obtained by setting the knee angle and the angle of incidence of the X-ray tube to 115°-72.5° (15° tangential irradiation) during the modified tangential examination of the knee bone. It was confirmed.

• Korean Journal of Psychosomatic Medicine
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• v.29 no.2
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• pp.153-161
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• 2021

Objectives : The purpose of this study is to compare bleeding tendency of selective serotonin reuptake inhibitor (SSRI) and serotonin norepinephrine reuptake inhibitors (SNRI) using platelet function analyzer (PFA-100) in patients with major depressive disorder. Methods : This study is a prospective open-label study conducted by a single institution. A total of 41 subjects diagnosed with major depressive disorder under the DSM-5 diagnostic criteria participated in this study. The subjects were classified into SSRI (escitalopram) groups and SNRI (duloxetine) groups, respectively, according to random assignments. The closure time (CT) was measured using a platelet function analyzer (PFA-100) before each antidepressant was administered and after 6 weeks. Paired-sample t-test was conducted within each group to determine whether a specific antidepressant had an effect on closure time. In order to confirm the relative change in platelet function between the two groups, an independent sample t-test was conducted to compare and analyze the change in closure time between the two groups. Results : There was no significant changes in closure time (CEPI-CT, CADP-CT) before and 6 weeks after drug administration in the SSRI and SNRI groups, and there was no difference in the amount of changes in closure time between the two groups. Conclusions : Our results showed no difference in bleeding tendency between SSRI and SNRI. This study suggests that further large-scale studies on bleeding tendency for various antidepressants are needed in the future.

• Journal of Elementary Mathematics Education in Korea
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• v.16 no.3
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• pp.359-388
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• 2012

The study aims to extract the framework of sub-factors of spatial sense, to develop test instruments based on the framework to investigate the actual spatial sense ability of fourth to sixth graders in elementary school and to analyze the results. According to the framework of sub-factors of spatial sense of the study, spatial sense has two factors of spatial visualization and spatial orientation. Spatial visualization is divided into mental rotation, mental transformation and figure-ground perception while spatial orientation is categorized into direction sense, distance sense, and location sense. Based on the framework, the test instrument for spatial sense ability was developed and the test was conducted to 430 fourth to sixth students in five elementary schools in capital areas. The following conclusions were drawn from the results obtained in the study. Firstly, the higher school year gets, the more spatial sense grows. However, spatial visualization is developed much more than spatial orientation and their order is reversed with higher graders. Secondly, the most insufficient abilities among fourth to sixth elementary school students' spatial sense were mental transformation of spatial visualization and location sense of spatial orientation. Thirdly, the reasons of differences in sub-factors of spatial sense and graders seem to be from effects of students' learning experiences of spatial sense of mathematics curriculum and the complexities of test items.

• Journal of the Korean Society of Earth Science Education
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• v.9 no.3
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• pp.341-351
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• 2016

The purpose of this study is to investigate the effects of pre-service teachers of elementary school who take courses in 'Science and Textbook Research' on science teaching efficacy and science knowledge after experimental treatment. For this purpose, this study was aimed at intensive course four classes (118 students) enrolled in the 'Science and Textbook Research' course and experimented from the beginning of September to the end of November. The experiment was about teaching textbooks and teaching methods for one semester, and the pre- service teachers of elementary school made the demonstration of science cooperation classes by group. The results and analysis of the study were analyzed by the corresponding sample test in before and after the group test. The conclusion of the study is as follows. First, after taking this class the pre - service teachers of elementary school were effective in science teaching efficacy. Second, after taking this course, pre-service teachers of elementary school were effective in acquiring science knowledge. Third, it was seemed to positive effect on Perception of pre-service teachers of elementary school in Demonstration classes. Pre-service teachers of elementary school have created science course plan by analyzing the tasks according to the principles of instructional design, and they found that they had the right mind and confidence in the lesson.

• 대한공업교육학회지
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• v.44 no.2
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• pp.1-27
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• 2019

In recent years, space planning ability using 3D sketch software is required in the working field of interior design. However, vocational high school do not respond appropriately to changes in the industry, because the class of vocational high school consists of hands-on practical classes and 2D CAD based classes. There is a shortage of 3D sketch software-based instruction programs that can improve students' spatial planning skills. Therefore, this study is to develop instruction program using 3D sketch software for 'Planning for Residential Space' unit of NCS-based on interior design subject and to find out the effect on students' academic achievement by applying to vocational high school class. The 3d sketch software based instructional program developed in this study was developed through four stages of preparation, development, implementation and evaluation according to the PDIE model process. The experimental design model used nonequivalent group posttest-only design in this study. Experiments were conducted on vocational high school students in construction and 9 hours of interior design subjects were applied. After the experiments, students were tested for academic achievement in the cognitive, affective, and psychomotor areas. As a result, the instruction program using the 3d sketch program developed in this study was found to be more effective in improving students' academic achievement than existing manual instruction program in both cognitive, affective, and psychomotor areas.

• Journal of Life Science
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• v.21 no.11
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• pp.1612-1618
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• 2011

The present study was undertaken to analyze the effects of different types of treatment on excess post exercise oxygen consumption (EPOC), flexibility, free radical and antioxidants in women using a horseback riding therapeutic device. Subjects were trained in regular horseback riding exercises for 12 weeks (3 times/wk). The effects of this exercise were examined by means of a single session of horseback riding that lasted for 30 min. 21 women were recruited from a public health center and divided into 3 groups (passive recovery group, passive+massage recovery group, and dynamic recovery group). 3 types of recovery patterns were determined after a single trial of horseback riding exercise. Their flexibility were determined pre-and post-training by Paired T test, and ANOVA were used to analyze the data. The results were as follows: Among the 3 groups, the dynamic recovery group showed the highest levels of EPOC compared to the other groups, and also showed higher levels of anti-oxidants, as did the passive+massage recovery group compared to the passive recovery group. Moreover, horseback riding exercise greatly increased flexibility in the women. In conclusion, regular horseback riding training is recommended to enhance the flexibility of women and dynamic recovery is recommended to enhance EPOC and anti-oxidants after a single bout of exercise. Further study is needed in this area.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.2
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• pp.162-174
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• 2020

This study aimed to develop a creative education class program using metaphor, one of the creative thinking techniques, and to examine the effectiveness of the program targeting for randomly sampled 338 students in six middle schools. The creative education class program with the metaphor was developed based on content elements concerning 'astronomy' in 2015 science curriculum revision in South Korea. The program was tested for validity after being modified and supplemented three times by forming a group of experts, and the final version of the program was applied to school education fields during four periods, including block time. To find out the effectiveness of the program and the implementation, creative education class satisfaction test and creative thinking process test were conducted. That is to say, the creative education class satisfaction test was conducted before treatment and the creative thinking process test was implemented both before and after treatment. The results of the study are as follows. First, in this study, the program was developed with the emphasis on students voluntarily and actively participating in creative education programs while utilizing creative thinking methods. Second, the statistical results of the pre- and post-class about the creative education program using the metaphor of creative thinking techniques represented significant results(p<.05). In other words, the two-dependent samples by students' pre-and post-score about the creative education class showed significant statistical test results (p<.05). It turned out that the creative education program using metaphor has had a positive impact on research participants. Third, in regards to the results of the creative education class satisfaction test, 101 out of 338 students(30%) answered 'Strongly Agree' and 137(41%) answered 'Agree', indicating the subjects' satisfaction with the class was high in general. On the other hand, concerning difficulties of the creative class, 137(41%) answered "Lack of time" as the main factor, followed by 98(30%) "Difficulties of problems they were required to solve", 73(22%) answered "Conflicts with friends", and 24(7%) said "Difficulties of contents." These responses were taken into account as considerations for further development of creative education programs.

• Journal of Science Education
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• v.41 no.3
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• pp.334-350
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• 2017

The purposes of this study are to develop scientific-inquiry based on STEAM education program and to investigate the effects of the program on middle-school students' interests, self-efficacy, and career choice about science, technology/engineering, and mathematics. In order to develop this program, the literature investigation and previous studies were conducted, so that finally the developmental direction was based on scientific inquiry and the developmental theme and model were selected. A total 92 first-graders in G middle-school of Daegu city were participated in this study. A single group pre-post test paired t-test was conducted to figure out changes of students' interest, self-efficacy, and career choices before or after applying this program. In addition, in-depth interviews were conducted with 14 students to find their specific responses. The results of this study were as follows. First, STEAM education program on the theme of 'RC Airplane' was developed on the basis of the 'ADBA' model. Second, the developed STEAM educational program not only results a decisive difference statistically but also has significant effects on middle-school students' interests, self-efficacy, and career choice in science, technology/engineering, and mathematics, who are involved in the free-semester program, across the overall affective domain. In conclusion, the STEAM educational program in this study could affect significant meanings to middle-school students during the free-semester. It could contribute to facilitate middle-school students' education for happiness and to grow the creative STEAM talents.