• Journal of Korean Neurosurgical Society
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• v.62 no.5
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• pp.536-544
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• 2019

Objective : The objective of this study was to evaluatelong-term radiologic prognosis and characteristics of in-stent stenosis (ISS) after stent assisted coiling (SAC) for cerebral aneurysm and analyze its risk factors. Methods : Radiological records of 362 cases of SAC during 10 years were retrospectively reviewed. Patients were included in this study if they had follow-up angiogram using catheter selected angiography at least twice. All subjected were followed up from 12 months to over 30 months. Of 120 patients, 123 aneurysms were enrolled. Patient data including age, sex, aneurysm size, neck size, procedural complication, kinds of stent, ISS associated symptom, ruptured state, location of ISS, degree of ISS, radiologic prognosis of ISS, follow-up period of time, and medical comorbidities such as hypertension, diabetes mellitus (DM), dyslipidemia, and smoking were collected.Statistical comparisons of group clinical characteristics were conducted for the total population. Results : Among 123 casesof aneurysm, 22 cases (17.9%) of ISS were revealed on follow-up angiography. Multiple stenting was performed in three cases and intra-procedural rupture occurred in two cases. Most cases were asymptomatic and symptomatic stenosis was identified in only one case. Sixteen cases were ruptured aneurysm. Mild stenosis was observed in 11 cases. Moderate stenosis was found in eight cases and severe stenosis was identified in three cases. Mean timing of identification of ISS was 8.90 months. The most common type was proximal type. Most cases were improved or not changed on follow-up angiography. Only one case was aggravated from mild stenosis to occlusion of parent artery. Mean follow-up period was 44.3 months. We compared risk factors and characteristic between ISS group and non-ISS group using univariate analysis. Multiple stenting was performed for three cases (13.6%) of the ISS group and four cases (4.0%) of the non-ISS group, showing no statistical difference between the two groups (p=0.108). Additionally, the proportion of patients who had more than two risk factors among four medical risk factors (hypertension, DM, dyslipidemia, and smoking) was higher in the ISS group than that in the non-ISS group, the difference between the two was not statistically significant either (31.8% vs. 12.9%, p=0.05). Conclusion : Clinical course and long-term prognosis of ISS might be benign. Most cases of ISS could be improved or not aggravated. Control of medical co-morbidity might be important. To the best of our knowledge, our study had more cases with longer follow-up period of time than other reports.

• Korean Journal of Child Education & Care
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• v.18 no.4
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• pp.65-89
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• 2018

Objective: The purpose of this study is to analyze the science concepts and teaching and learning methods presented in the science education-related activities of the Nuri Curriculum teacher guidebooks for ages 3-5. Methods: The research data included 772 activities related to science education in the teachers' guidebook. The analysis of science concepts was based on physical science (force and motion, physical structure, electricity and magnetism, light and shadow, sound properties), chemistry (material properties, material reaction), life science (organizational structure, growth and change, heredity and evolution, animal plant and human relationships), earth science (earth system interaction, earth system structure, and universe), engineering (designed world, engineering design, engineering, technology and society) and ecology (environment preservation). Teaching and learning methods were analyzed according to the types of small and large group activities and of free play activities. Results: Science concepts were mainly presented in the fields of engineering, chemistry, and life science commonly among children aged 3-5, whereas the concepts of physical science were lowly presented in all ages. Science concepts appeared mainly in the daily subjects of 'animal plant and nature', 'life tools', 'environment and life', and 'spring, summer, autumn and winter'. As the teaching and learning method, free paly activities (science area, free outdoor selection activity, math and manipulative activity) were mostly used for the ages of 3 and 4, and small and large group activities (cooking, story sharing, music activity) were for the age of 5. Conclusion/Implications: It is necessary to select the level of science area and concept that can be taught according to the age of children and the timing of the teaching.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.610-619
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• 2018

This study was carried out in August and September 2016 to investigate the species composition and biomass of benthic diatoms in Yubu Island, Gomso Bay, Imja Island, and Yeoja Bay tidal flat of Southwestern coast. There were 181 species of 48 genera in Yubu Island tidal flats, 194 species of 51 genera in Gomso Bay tidal flats, 224 species of 64 genera in Imja Island tidal flats and 188 species of 56 genera in Yeoja Bay tidal flats. A total of 274 species of 70 genera appeared. Pennales appeared more widely than Centrales and were dominated by Paralia sulcata and Navicula spp. Biomass of Yubu Island tidal flat ranged from $18.8-136.1mg\;m^{-2}$, $31.9-215.7mg\;m^{-2}$ in Gomso Bay, $2.9-120.2mg\;m^{-2}$ in Imja Island and $10.1-147.7mg\;m^{-2}$ in Yeoja Bay. The range of total biomass from 4 areas was $2.9-215.7mg\;m^{-2}$. The concentration of phaeopigment and degradation product of chlorophyll-a was $1.7-470.8mg\;m^{-2}$ in Yubu Island tidal flat, $52.3-277.2mg\;m^{-2}$ in Gomso Bay, $0.6-78.9mg\;m^{-2}$ in Imja Island and $39.1-346.3mg\;m^{-2}$ in Yeoja Bay. Compared with the results reported in this study area and the domestic tidal flats, it cannot be directly compared and evaluated due to various factors such as the timing of the survey, the frequency of the survey, the analysis method and geography. The southwestern coast of Korea has a variety of benthic diatoms and the high concentration of chlorophyll-a is the main determinant of primary productivity.

• Korean Journal of Heritage: History & Science
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• v.47 no.4
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• pp.178-191
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• 2014

Jin-Sang is a local specialty donation to the palace. A local specialty donation to the palace is classified Jehyang, Bangmul, Mulseon, Medicine according to characteristic, when, use. Among these, Mulseon Jin-Sang is Most foods. And King was reduced Mulseon Jin-Sang in order to obtain a good image of the king. King Suk-Jong was frequently reduced Mulseon. But frequently changes of goods did not reflect to document. So type of goods, quantity is not clear in early 18th century. In 1728, King Yeong-Jo was published a Jingsangbyeldandngrok to clear type of goods, quantity. This book is written area, timing, quantity of Mulseon. Among these, type of goods, quantity are important. This book was written 176 kinds of goods. These goods was most of the fishery. And raw materials are largely accounted. In addition to processing the various creatures become like dried, pickled. By analyzing the regional allocation features, there are many types order by Gyeongsang-do, Hamgyeong-do. Gangwon-do. This area is faced east sea, so many fisheries have become records. In Gyeongsang-do, Cholla-do, these area were occupied a large portion of the fruit. And Jeju Island was assigned oranges. Finally, it has been assigned dried, pickled foods than living thing in distant area.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.208-215
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• 2019

The goal of this study was to analyze the reactivity of a volumetric water content sensor (soil moisture sensor) and tensiometer and to review their use in the early detection of a shallow landslide. We attempted to demonstrate shallow and rapid slope collapses using three different soil ratios under artificial rainfall at 120 mm/h. Our results showed that the measured value of the volumetric water-content sensor converged to 30~37%, and that of the tensiometer reached -3~-5 kPa immediately before the collapse of the soil under all three conditions. Based on these results, we discussed a temporal range for early warnings of landslides using measurements of the volumetric water content sensors installed at the bottom of the soil slope, but could not generalize and clarify the exact timing for these early warnings. Further experiments under various conditions are needed to determine how to use both sensors for the early detection of shallow landslides.

• Journal of Navigation and Port Research
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• v.43 no.1
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• pp.42-48
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• 2019

The significance of PNT information in the fourth industrial revolution is viewed differently in relation to the past. Autonomous vehicles, autonomous vessels, smart grids, and national infrastructure require sustainable and reliable services in addition to their high precision service. Satellite navigation system, which is the most representative system for providing PNT information, receive signals from satellites outside the earth so signal reception power is low and signal structures for civilian use are open to the public. Therefore, it is vulnerable to intentional and unintentional interference or hacking. Satellite navigation systems, which can easily acquire high performance of PNT information at low cost, require alternatives due to its vulnerability to the hacking. This paper proposed R-Mode (Ranging Mode) technology that utilizes currently operated navigation and communication infrastructure in terms of Signals of OPportunity (SoOP). For this, the Nationwide Differential Global Navigation Satellite System (NDGNSS), which currently gives a service of Medium Frequency (MF) navigation signal broadcasting, was used to validate the feasibility of a backup infrastructure in domestic maritime areas through simulation analysis.

• Journal of the Korean School Mathematics Society
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• v.23 no.4
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• pp.449-468
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• 2020

TIMSS is a representative international comparative study that analyzes changes in mathematics and science achievement, and it collects information on the educational system, curriculum, teaching and learning situation of participating countries as well as research and check, and provides implications for each country's mathematics and science education. Although domestic TIMSS studies focused on the results of achievement related to the evaluation of mathematics, not many have taken a closer look at the content and characteristics of the assessment framework. Therefore, the purpose of this study was to analyze the characteristics of the TIMSS 2019 mathematics assessment framework, and to derive implications for the mathematics curriculum and mathematics learning by examining the students' study time in light of the Korean mathematics curriculum. The implications derived from the results of this study are summarized as follows: First, it is necessary to check the connection between content elements in the mathematics and education process. Second, it is necessary to check the appropriateness and connectivity of the learning timing of the content elements in the mathematics and education courses. Finally, it is necessary to verify that the hierarchy of content areas and the structure of content systems in mathematics and education courses are consistent with the direction of mathematics education at the international level. This study can be used as a basis for mathematics and curriculum revisions, and can be used to set directions for the development of large-scale evaluation frameworks.

• Korean Journal of Remote Sensing
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• v.38 no.6_3
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• pp.1837-1846
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• 2022

The annual increase in chemical accidents is causing damage to life and the environment due to the spread and residual of substances. Environmental damage investigation is more difficult to determine the geographical scope and timing than human damage investigation. Considering the reality that there is a lack of professional investigation personnel, it is urgent to develop an efficient quantitative evaluation method. In order to improve this situation, this paper conducted a chemical accidents investigation using unmanned aerial vehicles(UAV) equipped with various sensors. The damaged area was calculated by Ortho-image and strength of agreement was calculated using the normalized difference vegetation index image. As a result, the Cohen's Kappa coefficient was 0.649 (threshold 0.7). However, there is a limitation in that analysis has been performed based on the pixel of the normalized difference vegetation index. Therefore, there is a need for a chemical accident investigation plan that overcomes the limitations.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.414-424
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• 2021

The purpose of this retrospective study was to evaluate the skeletal and dental maturity according to the vertical facial type and sex in Korean children in the developmental stage. In total, 184 participants aged 8 - 14 years were selected and divided into three groups based on the mandibular plane angle. For the comparison between the sexes, the three groups were each divided into male and female subgroups. The skeletal and dental maturity were assessed using lateral cephalograms, hand-wrist radiographs and panoramic radiographs. The vertical growth group showed significantly greater cervical vertebral and hand-wrist maturity than that in the horizontal growth group. Dental maturity was the highest in the vertical growth group. Girls showed greater skeletal maturity than boys, and no distinct difference was observed between the dental maturity of the sexes. Analysis of the vertical facial type in children can provide ancillary indicators that may help determine the optimal timing for orthodontic treatment initiation. Earlier initiation of orthodontic treatment may be considered for patients with vertical facial growth patterns.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.53-62
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• 2023

The purpose of this study is to find an optimized imaging technique and evaluate its usefulness by comparing and analyzing the difference in contrast enhancement of lower extremity artery according to the patient's heart rate during lower extremity Computed Tomography Angiography examination. From January 2022 to August 22nd, 139 outpatients who visited Ajou University Hospital and underwent lower extremity angio CT examination were targeted. According to the heart rate, the groups were divided into four groups: A(HR ≤65), B(65 < HR < 80), C(80≤ HR). In addition, among patients with a heart rate of 65 or less, the heart rate was considered, and the scan was divided into D, E, F group with a delay time. The time of arrival of contrast medium and the average value of contrast enhancement were compared and analyzed. As a result of quantitative evaluation, B and C groups with a heart rate of more than 65 times had better HU values in the popliteal artery than A group (HR ≤ 65), and D group showed better HU improvement effects compared to A group (p<0.001). The comparative analysis with other groups was insignificant. The difference in heart rate affected the angiographic intensity of the lower extremities artery. Therefore, it is effective to apply the appropriate test timing for each patient by using the heart rate during the lower extremity angio CT Scan.