• Journal of the Korea Society of Computer and Information
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• v.15 no.9
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• pp.67-76
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• 2010

This paper proposes a image-based water level measurement method, which adapt to the ruler's surface condition. When the surface of a ruler is deteriorated by mud, drifts, or strong light reflection, the proposed method judges the pollution of ruler by comparing distance between two levels: the first one is the end position of horizontal edge region which keeps the pattern of ruler's marking, and the second one is the position where the sharpest drop occurs in the histogram which is construct using image density based on the axis of image height. If the ruler is polluted, the water level is a position of local valley of the section having a maximum difference between the local peak and valley around the second level. If the ruler is not polluted, the water level is detected as the position having horizontal edges more than 30% of histogram's maximum value around the first level. The detected water level is converted to the actual water level by using the mapping table which is construct based on the making of ruler in the image. The proposed method is compared to the ultrasonic based method to evaluate its accuracy and efficiency on the real situation.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.475-483
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• 2019

Special chemical warfare agents are lethal gases that attack the human respiratory system. One of such gases are blood agents that react with the irons present in the electron transfer system of the human body. This reaction stops internal respiration and eventually causes death. The molecular sizes of these agents are smaller than the pores of an activated carbon, making chemical adsorption the only alternative method for removing them. In this study, we carried out a Computational Fluid Dynamics simulation by passing a blood agent: cyanogen chloride gas through an SG-1 gas mask canister developed by SG Safety Corporation. The adsorption bed consisted of a Silver-Zinc-Molybdenum-Triethylenediamine activated carbon impregnated with copper, silver, zinc and molybdenum ions. The kinetic analysis of the chemical adsorption was performed in accordance with the test procedure for the gas mask canister and was validated by the kinetic data obtained from experimental results. We predicted the dynamic behaviors of the main variables such as the pressure drop inside the canister and the amount of gas adsorbed by chemisorption. By using a granular packed bed instead of the Ergun equation that is used to model porous materials in Computational Fluid Dynamics, applicable results of the activated carbon were obtained. Dynamic simulations and flow analyses of the chemical adsorption with varying gas flow rates were also executed.

• Korean Journal of Applied Biomechanics
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• v.31 no.1
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• pp.1-15
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• 2021

Objective: The aim of this study was to investigate 1) the difference in static lower extremity alignment (SLEA) according to a history of lateral ankle sprain (LAS), 2) to identify SLEA factors affecting LAS, and 3) to present the cut-off value and 4) the usefulness and limitations of the SLEA measurement. Method: This case-control study recruited 88 men (age: 27.78±4.69 yrs) and 39 women (age: 24.62±4.20 yrs) subjects with and without LAS. SLEA measurement protocol included Q angle, tibiofemoral angle, genu recurvatum, rear foot (RF) angle, tibal varum and torsion, navicular drop, ankle dorsiflexion range of motion (DF ROM). Independent t-test, logistic regression and receiver operating characteristic (ROC) curve were used for statistical analysis. Results: Men with a history of LAS had significantly smaller Q angles both in standing and in supine position, while women with a history of LAS had significantly greater DF ROM in non-weight bearing (NWB; p < 0.05). Logistic regression model suggests tibial varum (OR = 0.779, p = 0.021) and WB DF ROM (OR = 1.067, p = 0.045) were associated with LAS in men. In case of women, there were no significant SLEA factors for LAS, however, ROC curve analysis revealed standing RF angle (AUC = 0.647, p = 0.028) and NWB DF ROM (AUC = 0.648, p = 0.026) could be affecting factors for LAS. Conclusion: There are differences in SLEA according to the history of LAS, furthermore, the identified items were different by sex. In case of men, tibial varum and WB DF ROM affect LAS occurrence. Standing RF angle and NWB DF ROM of women could be a predictor for LAS. However, since the sensitivity and specificity in most of the SLEA measurements are low, kinematic in dynamic tasks should be considered together for a more accurate evaluation of LAS risk.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.819-825
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• 2020

This study explored the possibility of psychological testing as a way to proactively support underachieving students. Among the four-year college students that participated in our study, 43 students who participated in the academic warning support program for the second semester of 2019 and 30 students who had no academic warning experience used the data from the study personality type test. For data analysis, technical statistics, t-test, and correlation analysis were performed using jambi 1.1.9.0 to obtain the Pearson correlation. Studies have shown that the two classes of students differ in their learning behavior patterns. A student with a bachelor's degree warning scored high in the rest of the class, except for rebelliousness, perfection, mixed thoughts, hard work, satisfaction, single-mindedness and type satisfaction. This can be seen as a factor in the psychological conflict, such as the discrepancy between what one likes and what one studies, and lack of available support. It has been confirmed that psychology, emotional parts and economic support are needed as well as learning skills. In addition, this study is expected to provide basic data for proper preemptive support in schools, such as the prevention of dropouts and counseling programs.

• Journal of Industrial Convergence
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• v.19 no.4
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• pp.95-102
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• 2021

This study aims to verify the effect of mother's career-related behavior on the intention of multicultural youths to school dropout intention and the mediating effect of academic adaptation. To this end, 1,121 middle school seniors were sampled in the 7th (2017) data of the Multicultural Youth Panel Survey, and the influence relationship of the model presented as a three-step method of analysis of the mediated effects of Baron & Kenny and the Sobel test were conducted. First, the analysis showed that mother's support, a subfactor of mother's career-related behavior, had a negative effect on dropout intention, and that mother's interference had a positive effect. Second, academi adaptation has been shown to have a negative effect on dropout intention. Third, mother's support, a subfactor of mother's career-related behavior, showed a positive influence on academi adaptation, and mother's interference showed a negative effect. Fourth, academi adaptation has been shown to be mediated in the relationship between career-related behavior and dropout intention. Based on the above results, practical implications were presented.

• Journal of Marine Life Science
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• v.6 no.2
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• pp.97-105
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• 2021

Tegillarca granosa, is one of the most important fishery resources throughout Asia. However, due to industrialization factories, marine environmental pollution, and global warming, the marine fishery production has drop sharply. In order to understand the genetic factors of the blood clam, which is a major fishery resource on the southern coast of Korea, the whole genome of blood clam was studied. The assembled genome of T. granosa was 915.4 Mb, and 19 chromosomes were identified. 25,134 genes were identified, and 22,745 genes were functionally annotated. As a result of performing gene gain and loss analysis between the blood clam genome and eight other types of shellfish, it was confirmed that 725 gene groups were expanded, and 479 gene groups were contracted. The homeobox gene cluster of blood clam showed a well-preserved genetic structure within lophotrochozoan ancestor. T. granosa genome showed high similarity between three hemoglobin genes with Scarpharca broughtonii. The blood clam genome will provide information for the genetic and physiological characteristics of blood clam adaptation, evolution, and the development of aquaculture industry.

• The Journal of Engineering Geology
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• v.31 no.4
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• pp.589-601
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• 2021

Artificial recharge technology is a method for solving problems such as groundwater level drop and ground subsidence caused by groundwater withdrawal. This study investigated the applicability of using the hydraulic conductivity of an aquifer to predict injection test results for aquifer restoration. Pumping and injection tests were performed under the same conditions as those for the artificial injection facility located in Icheon, Gyeonggi-do. The hydraulic conductivity of the aquifer, which plays a decisive role in restoring the groundwater level, was derived from the pumping test. A numerical model of a simplified on-site aquifer was constructed, and a transient analysis was applied with the same conditions as the pumping test. The correlation between the measured and the resulting model values is strong (R² = 0.78). The injection test was performed in a sedimentary layer composed of silt sand and clay sand. From the results of the injection test, an empirical formula was derived using Theim's formula, which is a common well analysis solution to determine the parameters of the aquifer from time-level data. The model values from the empirical formula have a high degree of correlation (R² = 0.99) with measured values. Under specific conditions, for areas where it is difficult to conduct an injection test, the formula from this study, which relies on the hydraulic conductivity of the aquifer determined through the pumping test, may be used to predict reliable injection rates for groundwater restoration.

• Korean Journal of Applied Biomechanics
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• v.33 no.3
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• pp.110-117
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• 2023

Objective: The purpose of this study was to find out kinematic and kinetic differences the lower extremity joint according to the landing type during vertical jump movement after jump landing, and to present an efficient landing method to reduce the incidence of injury in youth players. Method: Total of 24 Youth players under Korean Sport and Olympic Committee, who used either heel contact landing (HCG) or toe contact landing (TCG) participated in this study (HCG (12): CG height: 168.7 ± 9.7 cm, weight: 60.9 ± 11.6 kg, age: 14.1 ± 0.9 yrs., career: 4.3 ± 2.9 yrs., TCG height: 174.8 ± 4.9 cm, weight: 66.9 ± 9.9 kg, age 13.9 ± 0.8 yrs., career: 4.7 ± 2.0 yrs.). Participants were asked to perform jump landing consecutively followed by vertical jump. A 3-dimensional motion analysis with 19 infrared cameras and 2 force plates was performed in this study. To find out the significance between two landing styles independent t-test was performed and significance level was set at .05. Results: HCG showed a significantly higher dorsi flexion, extension and flexion angle at ankle, knee and hip joints, respectively compared with those of TCG (p<.05). Also, HCG revealed reduced RoM at ankle joint while it showed increased RoM at knee joint compared to TCG (p<.05). In addition, HGC showed greater peak force, a loading rate, and impulse than those of TCG (p<.05). Finally, greater planta flexion moment was revealed in TCG compared to HCG at ankle joint. For the knee joint HCG showed extension and flexion moment in E1 and E2, respectively, while TCG showed opposite results. Conclusion: Compared to toe contact landing, the heel contact landing is not expected to have an advantage in terms of absorbing and dispersing the impact of contact with the ground to the joint. If these movements continuously used, performance may deteriorate, including injuries, so it is believed that education on safe landing methods is needed for young athletes whose musculoskeletal growth is not fully mature.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.365-370
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• 2023

Royalty contributed to the development of the non-fungible token (NFT) ecosystem as a reward system that pays a portion of the sales to the creator whenever transactions occur. This study quantitatively analyzes the impact of the abolition of royalties, which is being expanded by some NFT marketplaces, on the NFT market, and qualitatively analyzes the results of the impact. The analysis results are as follows. First, the number of NFT mints is decreasing by causing creators to leave the NFT market and reducing new entry. Second, major NFT projects have refused to trade with marketplaces that have abolished royalties, leading to a decrease in the number of transactions. Third, the abolition of royalties has undermined the motivation of NFT creators to continue to develop their projects, leading to a drop in NFT floor prices. This study is expected to contribute to reducing the current negative impact in the short term by suggesting how the NFT community provides incentives to owners who voluntarily pay royalties independently of the policy of the NFT marketplace. In addition, it suggests that in the long run, fundamental solutions to the problem of abolishing royalties require improvements in technology related to royalty payments, cooperation between NFT marketplaces and NFT creators, and institutional support related to royalties.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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• pp.191-200
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• 2017

Proper packaging design can meet both the environmental and economic aspects of packaging materials by reducing the use of packaging materials, waste generation, material costs, and logistics costs. Finite element analysis(FEM) is used as a useful tool in various fields such as structural analysis, heat transfer, fluid motion, and electromagnetic field, but its application in the field of packaging is still insufficient. Therefore, the application of FEM to the field of packaging can save the cost and time in the future research because it is possible to design the package by computer simulation, and it is possible to reduce the packaging waste and logistics cost through proper packaging design. Therefore, this study investigated the FEM papers published in Korea for the purpose of helping research design using FEM program in the field of packaging in the future. In this paper, we analyzed the 29 papers that were directly related to the analysis of FEM papers published in domestic journals from 1991 to 2017. As a result, we analyzed the research topic, FEM program, and analysis method using each paper, and presented the direction that can be applied in future packaging field. When the FEM is applied to the packaging field, it is possible to change the structure and reduce the thickness through the stress and vibration analysis applied to the packaging material, thereby reducing the cost by improving the mechanical strength and reducing the amount of the packaging material. Therefore, in the field of packaging research in the future, if the FEM is performed together, economical and reasonable packaging design will be possible.