• Journal of the Korean Geotechnical Society
• /
• v.37 no.11
• /
• pp.93-105
• /
• 2021

In this study, we evaluated the effect of soil fine contents on the formation of underground cavities and ground cave-ins induced by damaged sewer pipes. Simulating the domestic rainfall conditions and ground conditions, model tests were performed under three different fine particle contents conditions (7.5%, 15%, and 25%). By repeating the groundwater supply and drainage twice, ground settlement and the amount of discharged soil were obtained. Also, digital images were taken at regular time intervals during the model tests, and internal displacement and deformation were measured using PIV technique. As the cycles were repeated, the soil with high fine content showed greater resistance to the formation of underground cavities. The ground cave-ins, identified by the collapse of the surface, occurred only when the fine particle content was 15%. It is presumed to be due to the suffusion phenomenon; further study was needed to investigate the effect of fine particle contents on the suffusion phenomenon and associated changes of soil strength.

• Geophysics and Geophysical Exploration
• /
• v.25 no.3
• /
• pp.120-128
• /
• 2022

There are 17,000 reservoir dams in Korea, of which more than 85% were built over 50 years ago. Old embankment dams are weakened by internal erosion and suffusion phenomena due to preferential leakage paths and this ongoing weakening can cause their failure. Therefore, early warning associated with leakage in an embankment dam is crucial to prevent its failure. An electrical resistivity survey is a non-destructive, real-time and in-situ technique for detecting the development of leakage zones and general conditions of embankment dams. Because of its advantages, the electrical resistivity survey is widely used for reservoir safety inspections. However, the electrical resistivity survey is still not officially included in the precise safety inspection of reservoir dams because it cannot present a quantitative index of dam safety. In this study, we propose a method for calculating the leak index according to the water content evaluated from the electrical resistivity survey and/or induced polarization survey. Particularly, by proposing a quantitative leak index calculation method from monitoring surveys and independent surveys, we provide a theoretical basis for including electrical resistivity and induced polarization surveys as components of the precise safety inspection of reservoirs dams.

• Journal of the Korean Society of Radiology
• /
• v.16 no.4
• /
• pp.381-386
• /
• 2022

Non-Destruction Test (NDT) is a method to check internal defects without destroying the product. Among them, radiographic testing (RT) uses high-energy radiation, so it is very important to prevent radiation exposure of workers. Therefore, in this study, in this study, a radiation sensor structure that improves radiation detection performance compared to the existing PbI₂ and can immediately detect accidents in RT was presented. For evaluation, the conversion efficiency was analyzed in the gamma ray source through FLUKA simulation. PbI₂ with overlapping Gd₂O₂S:Tb presented in this study showed a higher radiation sensitivity from 1.22 to 3.22 times than that of non-overlapping PbI₂. This indicates that the presented sensor is suitable for use as a radiation sensor for source detection in RT.

• Journal of Oriental Neuropsychiatry
• /
• v.34 no.3
• /
• pp.125-139
• /
• 2023

Objectives: This was a preliminary study to re-verify the reliability and validity of the Core Seven Emotions Inventory-Short Form (CSEI-s) and to establish standards for an objective scoring system such as T-scores and percentile for the normative group. Methods: Subjects were sampled through population-proportional regional allocation based on adults aged 20 or older and 65 or younger who voluntarily consented. Reliability was analyzed by performing an internal consistency (Cronbach's α) test and calculating means and standard deviations for each scale. The validity was analyzed between the CSEI-s and STAXI-K, SADS, COMOSWB, HADS, K-PANAS, Core emotions VAS. Results: The CSEI-s revealed notable gender discrepancies in aspects such as thought (思), fear (恐), and fright (驚), with women generally scoring higher than men. CSEI-s scores showed statistically significant differences in joy (喜) and thought (思) between those in their 20s and those in their 50s and 60s. As a result of the validity analysis, the seven-factor configuration was found to be statistically valid, and as a result of the correlation analysis with the coexistence scale, the correlation between each emotion and the seven emotions was found to be statistically significant. Cronbach's α for the CSEI-s was .891, showing statistically significant reliability. Conclusions: A preliminary study was conducted to standardize the shortened form of the Core Emotion Scale, and the reliability and validity were confirmed. A main survey of more people should be conducted in the future. Future results can contribute to revitalizing the development of oriental medicine evaluation tools and establishing an evidence base by standardizing the CSEI-s.

• KIPS Transactions on Computer and Communication Systems
• /
• v.12 no.3
• /
• pp.119-126
• /
• 2023

Sarcopenia is not well known enough to be classified as a disease in 2021 in Korea, but it is recognized as a social problem in developed countries that have entered an aging society. The diagnosis of sarcopenia follows the international standard guidelines presented by the European Working Group for Sarcopenia in Older People (EWGSOP) and the d Asian Working Group for Sarcopenia (AWGS). Recently, it is recommended to evaluate muscle function by using physical performance evaluation, walking speed measurement, and standing test in addition to absolute muscle mass as a diagnostic method. As a representative method for measuring muscle mass, the body composition analysis method using DEXA has been formally implemented in clinical practice. In addition, various studies for measuring muscle mass using abdominal images of MRI or CT are being actively conducted. In this paper, we develop an AI image segmentation model based on abdominal images of CT with a relatively short imaging time for the diagnosis of sarcopenia and describe the multicenter validation. We developed an artificial intelligence model using U-Net that can automatically segment muscle, subcutaneous fat, and visceral fat by selecting the L3 region from the CT image. Also, to evaluate the performance of the model, internal verification was performed by calculating the intersection over union (IOU) of the partitioned area, and the results of external verification using data from other hospitals are shown. Based on the verification results, we tried to review and supplement the problems and solutions.

• Journal of Korean Elementary Science Education
• /
• v.42 no.1
• /
• pp.194-209
• /
• 2023

This study aims to present implications for the appropriate establishment and development of a science-authorized textbook system through an understanding of the process of selecting science-authorized textbooks and analyzing the perception of teachers. Toward this end, this study conducted interviews with five elementary school teachers who participated in the science textbook selection process, surveys on 32 teachers, and analysis on the authors of the textbooks. The result demonstrated, first, that the "opinion gathering" stage was the most important one, and a council was formed in consideration of career and major. Moreover, the evaluation standard was reorganized and used according to the situation of the school. Second, in the process of opinion gathering, the teachers used a method for reviewing the entire textbook for each teacher. Inquiry activities and textbook composition (readability) were crucially considered as internal factors, and teaching and learning materials, such as videos, were deemed extremely important as external factors. The variable of the author, which is an indicator of the reliability and expertise of textbooks, was also recognized as vital. Third, the deliberation by the School Committee and the report by the principal were recognized as the administrative final step after selection. Finally, selecting the most suitable textbooks for each grade group was recognized as more important than arbitrarily unifying textbooks for the third and fourth grades and for the fifth and sixth grades.

• Composites Research
• /
• v.20 no.4
• /
• pp.31-41
• /
• 2007

Dome shape design methods of Filament Winding (FW) composite pressure vessel, which can suggest various dome contour according to the external loading conditions, were investigated analytically and numerically. The performance indices(PV/W) of the pressure vessels with same cylinder radius and boss opening but different dome shape were evaluated by finite element analysis under the internal pressure loading condition. The analysis results showed that as the dome shape becomes flat, the performance index decreases significantly due to the reduced burst pressure. Especially, for the case of the high value of the parameter ro, the ratio between the radii of the cylinder part and the boss opening, the flat dome is disadvantageous in the aspect of the weight reduction, and additional reinforcing dome design technique should be required to increase the burst pressure. For example, above ro=0.54 condition, the dome shape change according to the loading condition could cause the low burst pressure and increase of composite weight in dome region and is not recommendable except for the special case that maximum inner volume or sufficient space between skirt and dome is the primary design objective. However, at ro=0.35, the dome shape change brings not so significant differences in the performance of FW vessel.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.2
• /
• pp.59-68
• /
• 2009

This paper aims to explore the factors of learner's flow and to develop and validate a scale to measure the flow in Massive Multiplayer Online Role Playing Game(MMORPG) for education. First of all, potential factors were drawn through literature review. The potential stage comprises 6 factors(learner's psychological characteristics, learner's skill, importance of game, environment for learner, instructional design, and instructional environment) and 16 subfactors. With total 48 items developed. a survey was carried out among 293 elementary learners who had been participating in a commercial MMORPG for English skills to measure their flow in the MMORPG by utilizing the potential scale. Using the responses collected from 288 respondents, exploratory factor analysis, reliability analysis, and confirmatory factor analysis were performed. The expository factor analysis showed that items within each sub-factors could be bound into one factor. That is, the variables evaluating learner's flow were divided into six factors(learner's psychological characteristics, learner's skill, importance of game, environment for learner, instructional design, and instructional environment). And these factors were interpreted consisting of 16 sub-ones. Reliability estimates indicated that the evaluation tool had good internal consistency. The confirmatory factor analysis did confirm the model suggested by the expository factor analysis. Over fit measures(CFI, NFI, NNFI) showed the good suitability of the model. Findings of this study confirmed the validity and reliability of the scale to measure learner's flow in MMORPG.

• Korean Journal of Heritage: History & Science
• /
• v.56 no.1
• /
• pp.100-116
• /
• 2023

The Sinamsa Temple was built in the late Goryeo Dynasty and a gilt-bronze seated Buddha is enshrined in Geungnakjeon hall in the precinct. Various damages occurred in the gilt layer of the Buddha, such as peeling of the gilt layer and deteriorating gloss. In the study, the conservation conditions of the inside and outside on the statue were accurately investigated, and the making technique was interpreted through the material characteristics and non-destructive diagnosis of the statue. As a result, it is estimated that gold-gilding layer is pure gold, coloration pigment of black is carbon, green is malachite, atacamite and verdigris, red is red lead and cinnabar, respectively. In the deterioration evaluation, peeling, cracking, break out and exfoliation of the gilt layer are confirmed as damages, but the conservation condition is relatively wholesome. However, the gloss of the gilt layer is calculated to be wider in the poorer part than the maintenance part. The ultrasonic velocity of the statue was calculated to be 1,230 to 3,987 (mean 2,608) m/s and showed a relatively wide range. In infrared thermography, peeling was not confirmed, and no special bonding marks were found. In endoscope, some biological damage and corrosion were observed on the surface of the internal metal, and sealed artifacts were identified. Manufacturing technique based on the study, it is considered that the gilt-bronze seated Buddha was cast at once, and the mold was inverted to inject molten metal.

• Journal of the Korean Society of Food Culture
• /
• v.25 no.2
• /
• pp.179-188
• /
• 2010

In order to aide in the design of an improved menu book, which could play an important role as a marketing tool, the current version of the menu books and managers (subjects) of 295 restaurants in the Incheon area were examined. These were managers of Korean (36.3%), Western (25.8%), Japanese (14.6%), cafeteria (12.5%) and Chinese (10.8%) style restaurants. The level of service (self-evaluation, 3-point scale) was average $2.25{\pm}0.45$. The general colorings of the menu books were green (19.0%), brown (18.6%), black (17.6%), yellow (15.9%), red (13.6%) and blue (13.2%). The material of the menu book cover was mainly leather (35.9%), and the internal material was mainly coated paper (59.7%). Physically, the design was two-panel fold (38.3%), two-panel multi-page (35.6%), die style (10.2%), single panel (8.1%) and tent style (7.8%). The type sizes were unchanged in 49.9% of the menu books and in 61.7% photos were not used. 53.9% of menu books did not explain the menus, and 13.2% did not classify the items into groups. Emphasis of profit-making menus was not done in 66.8%. 51.5% of menu books were irreplaceable in parts. The emphasis of profit-making menus was less among the Korean style restaurants (p<0.001). The possibility of partial replacement of menu books was lower in both Korean and Chinese restaurants (p<0.001). The explanation of the items was lower in the Japanese restaurants (p<0.001). The classification of items into groups was lower in cafeteria (p<0.001). In cases in which there were both seasonal and event menus, the possibility of partial replacements of menu books was higher (p<0.001). Restaurants of which service level was less than ordinary were lower in the differentiation of type sizes (p<0.001), the use of photos (p<0.001), the explanation of menus (p<0.001), the classification of menus by groups (p<0.05), the emphasis of profit-making menus (p<0.001) and the possibility of partial replacement of menu books (p<0.001). If these study findings are applied to the designing of menu books, the role of the menu book as an important tool for marketing could be greatly improved.