• Korean Journal of Environment and Ecology
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• v.38 no.3
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• pp.263-276
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• 2024

Fish community characteristics and the influence of sampling gear were investigated in Lake Singal, South Korea, from August 2020 to October 2021. The employed sampling gears included a kick net, cast net, gill net, and fyke net, which are commonly utilized within the lake. Across three survey stations, a total of 18 fish species from seven families, comprising 3,501 individuals and contributing to a total biomass of 117,670 grams, were identified. Dominance among species was assessed based on individual count and biomass. Pseudorasbora parva was the most abundant, constituting 29.9% of the total catch, followed by Zacco platypus (25.1%) and Micropterus salmoides (19.3%). In terms of biomass, Carassius auratus was predominant, accounting for 45.1%, followed by Cyprinus carpio (17.4%) and M. salmoides (14.3%). Among the sampled species, three were identified as endemic to Korea: Squalidus japonicus coreanus, Cobitis nalbanti, and Odontobutis interrupta. Additionally, four exotic species were recorded, including M. salmoides and Lepomis macrochirus, both classified as invasive alien species, along with C. cuvieri and a variant of Cyprinus carpio (nudus type). Analysis of the average standard length (SL) and body weight (BW) revealed significant size variations among species. P. parva, the dominant species, measured 60 ± 24.1 mm (SL) and weighed 4.4 ± 3.42 g (BW). The subdominant species, Z. platypus, exhibited an SL of 82 ± 17.6 mm and a BW of 10.4 ± 7.27 g. M. salmoides, another dominant species, registered 96 ± 25.1 mm (SL) and 24.9 ± 96.02 g (BW), while C. auratus measured 125 ± 77.3 mm (SL) and weighed 168 ± 336.5 g (BW). In terms of gear-specific performance, the kick net captured eight species from three families, totaling 302 individuals with a biomass of 1,269 g. The cast net was more effective in coastal zones, collecting 11 species from four families, amounting to 948 individuals and 31,343 g of biomass. The gill net yielded the highest biomass, capturing 13 species from four families with 682 individuals weighing 69,695 g. The fyke net recorded the highest species diversity and number of individuals, capturing 15 species from seven families, totaling 1,569 individuals and 15,362 g of biomass. The fyke net proved most efficient in species and individual counts, whereas the gill net was superior for biomass collection. Conversely, the kick net demonstrated effectiveness in collecting small benthic species in coastal areas.

• Journal of Korean Elementary Science Education
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• v.43 no.3
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• pp.353-364
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• 2024

The purpose of this study is to analyze the achievement standards for grades 3-4 of the 2022 revised science curriculum and identify the goals of science education for grades 3-4 of the 2022 revised curriculum, as well as provide implications for the development of the science textbooks for grades 3-4 and the direction of teaching for teachers in the field. For this purpose, 57 achievement standards of the Science Department 2022 revised curriculum for grades 3-4 were analyzed as to their knowledge dimensions and cognitive processes according to Bloom's Taxonomy of the New Educational Objectives. In cases where an achievement standard is a double sentence or combines two or more knowledge dimensions or cognitive process dimensions, we separated the sentences after having consulted with a group of experts and divided the achievement standards into 57 sentences. We then analyzed the frequency of the categorization of concepts and descriptors by comparing them with the previously studied elementary science standards from the 2015 revised curriculum. The main findings of the study are as follows. First, in the knowledge dimension, the "factual knowledge" accounted for 50 items (86%), compared to "conceptual knowledge" (10%), and "procedural knowledge" (4%), and "metacognitive knowledge" was not analyzed at all. Second, in terms of the cognitive processes, "Understanding" was the highest at 60% with 34 items. It was followed by "applying" with 11%, "creating" with 19%, "evaluating" with 15%, and "analyzing" and "remembering" with 6%. Third, when analyzing the descriptors, "I can explain" was the highest with 9%, followed by "comparison" with 6%, and "practice" and "classification" with 5%. Fourth, compared to the 2015 revised curriculum, "conceptual knowledge" was reduced and "factual knowledge" was overwhelmingly increased. Fifth, in the cognitive process dimension, "understanding,' has increased significantly, while the other cognitive process dimensions have decreased. Conclusions and implications based on these findings are as follows: the focus of the Science Department for grades 3-4 in the 2022 revised curriculum is heavily weighted toward the "factual knowledge," with "understanding" dominating the cognitive process dimensions. As a result, many concepts and applications have been reduced. Based on the results of the comparison of the descriptors with the results of the 2015 revised curriculum, the implications for the development of the science textbooks for grades 3-4 of the 2022 revised curriculum were discussed, and so were the implications of the curriculum for the field.

• Journal of Venture Innovation
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• v.7 no.3
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• pp.25-43
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• 2024

The rapid advancement of the 4th Industrial Revolution and the ongoing effects of COVID-19 significantly accelerated the adoption of smart work practices, especially in the financial sector. This study aimed to empirically investigate the impact of smart work on job satisfaction among employees in this industry. Specifically, the study examined the effects of time flexibility and workplace flexibility (as quantitative elements of smart work) and work autonomy (as a qualitative element) on job satisfaction. Additionally, the study explored the impact of technostress factors, including techno-overload, techno-invasion, and techno-complexity. Using data from 250 valid survey responses collected from financial sector employees, the study employed structural equation modeling (SEM) with AMOS to analyze the relationships. The findings revealed that time flexibility and work autonomy positively influenced job satisfaction, with work autonomy being the most significant predictor. Conversely, techno-overload and techno-invasion negatively affected job satisfaction. However, workplace flexibility and techno-complexity did not show a significant relationship with job satisfaction, possibly due to the already established norms in the financial sector, where remote work and high-level technology usage were standard practices. A critical aspect of the study was the examination of work-life balance as a mediating factor. The analysis confirmed that work-life balance mediated the relationship between work autonomy, techno-overload, techno-invasion, and job satisfaction. This suggested that maintaining a balance between work and personal life was crucial for enhancing job satisfaction in smart work environments, particularly in the financial sector. Effective management of technostress was essential to preserving this balance and improving overall employee satisfaction. These findings contributed to the academic understanding of how smart work practices and technostress impacted job satisfaction. They offered practical insights for financial sector organizations seeking to optimize smart work environments by emphasizing the importance of work-life balance and carefully managing technostress factors.

• Korean Journal of Heritage: History & Science
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• v.57 no.3
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• pp.90-101
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• 2024

The test answer sheets submitted by examinees in the Joseon Dynasty were called Sigwon (test papers with answers, 試卷), and Siji (blank test papers, 試紙) were generally prepared by the examinees themselves. At that time, paper was not produced as a standard product, so there was no uniformity in size or manufacturing method. Mulberry paper in the Joseon Dynasty was basically transparent, so various paper processing methods were applied for examinees to write answers on both sides. In order for ink lines to be written smoothly, Dochim (hitting paper with a wooden bat on the stone, 搗砧) or surface processing was treated. We found a 19th-century Siji (試紙) that was processed in a unique way, which led to this study. An unusual Sigwon (試卷) is one by Lee Mangi (李晩耆) from 1848 owned by the National Folk Museum of Korea. We found that an opaque white substance was thickly applied between the papers of this Siji (試紙). Through component analysis using infrared spectrophotometry, fluorescence X-ray spectroscopy, optical and polarizing microscopy, and electron microscopy, this white substance was proved to be rice starch. From these analyses, it is presumed that this Siji (試紙) was made by soaking rice flour in water to remove a significant amount of protein, and then applying wet starch containing a small amount of protein between sheets of paper. In addition, with a Siji (試紙) reproduction experiment, we found that the paper reproduced by this processing method was thick and high in whiteness and opacity. This is believed to be a production method designed to produce double-sided paper without using multiple sheets of paper, which was difficult to obtain at that time. In this study, the material processed between the sheets of paper was disclosed only from < Lee Mangi (李晩耆)'s Sigwon (試卷)(Minsok 71745)>, but this appears to be one of several processing methods to treat the paper during the Joseon Dynasty. We hope that more similar Sigwons will be discovered in the future and that extensive research on processing methods will be conducted.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.3
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• pp.71-81
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• 2009

Food waste has been actively used as a composting material in order to reduce the environmental pollution load and to enhance the recycling of resources. In this study, the longterm effects of continuous application of food waste compost to soils on both the crop production and the soil properties were examined to ensure the safety of food waste compost in agricultural use. In addition, we collected the preliminary data for establishing standard application rate of food waste compost for agricultural utilization. Based on conventional nitrogen application rate of chemical fertilizer for crop cultivation, pig manure compost $(24g\;N\;kg^{-1}$, $8g\;P_2O_5\;kg^{-1}$, and $10.4g\;K_2O\;kg^{-1})$ and food waste compost ($20g\;N\;kg^{-1}$, $20.1g\;P_2O_5\;kg^{-1}$, and $6.5g\;K_2O\;kg^{-1}$) were applied to the upland soil in $2{\times}2{\times}2m$ lysimeter in which lettuce (Lactuca sativa var. crispa), Chinese cabbage (Brassica campestris subsp. napus var. pekinensis), red pepper (Capsicum annuum), and potato (Solanum tuberosum) were grown continuously. The crops grown in soils to which food waste compost applied showed better growth responses than the control, whereas some variations were observed in the crops grown in chemical fertilizer treated soils. Continuous application of food waste compost increased the contents of organic matter, nitrogen, and phosphorus, which resulted in improving soil aeration.

• Journal of Korea Water Resources Association
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• v.57 no.9
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• pp.633-643
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• 2024

Many coastal countries have developed and used a wide range of technologies and policy measures to protect freshwater aquifers and groundwater resources from seawater intrusion, and have established and implemented a foundation to legally and institutionally support them. This study covers coastal states in the eastern United States, the Netheland, India and Japan. The goal of this study is to analyze each country's legal and policy measures for coastal groundwater management. By introducing Jeju Island's groundwater standard level system, we aim to provide a basis for future discussions on groundwater management measures not only in Jeju Island but also in coastal areas of Korea. As a result of the analysis, despite the various contents and aspects of coastal groundwater management based on local issues and characteristics around the world, in order to achieve the common goal of securing a stable amount of groundwater withdrawal and preventing seawater intrusion and to maximize the efficiency of groundwater management, it is understood that attempts are being made to establish optimal management measures, laws, systems, and policies based on several key factors. First, considering the hydrogeological characteristics and status of coastal groundwater, a separate special management system is being established and implemented within the scope of the national groundwater management system. In addition, preventing and maintaining groundwater level decline through limiting the amount of groundwater withdrawal and preventing seawater intrusion are key policy goals and policy tools, and it is suppored by research and development. Finally, tt was found that synergy effects are being sought by using various other policy tools and measures in a complex manner.

• Journal of Ginseng Research
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• v.48 no.5
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• pp.504-510
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• 2024

Background: As a physiological function of body, immunity can maintain health by identifying itself and excluding others. With economic development and increasingly fierce social competition, the number of sub-healthy population is gradually increasing, and the most basic problem exposed is human hypoimmunity. Hypoimmunity can be manifested as often feeling tired, catching colds, mental depression, etc. In order to enhance immunity, eating healthy foods with the effect of enhancing immunity may become an effective choice. KRG has pharmacological effects of enhancing immunity. Because the screening and evaluation method of immune population are not unified, there are relatively few KRG immunity tests for sub-health population. It is of great significance to study the effect of KRG on people with hypoimmunity to improve sub-health status. Methods: This was a 180-day, randomized, double-blind, placebo-controlled clinical trial. According to the trial scheme design, 119 qualified subjects were included and randomly divided into the test group taking KRG and the placebo control group. Subjects need to check safety indicators (blood pressure and heart rate, blood routine, liver and kidney function, urine routine and stool routine) and efficacy indicators (main and secondary) inspection at baseline, efficacy indicators inspection during the mid-term of the test (90th days of administration), safety and efficacy indicators inspection after the test (180th days of administration). Results: After the test, the safety indicators of placebo control group and KRG test group were basically within the normal range, and there is no significant difference in fireness score between the two groups. Through follow-up interviews, it was found that the subjects in the test group and the control group had no adverse reactions and allergic reactions such as nausea, flatulence, diarrhea, and abdominal pain during the test period. Self-comparison of the test group, the results of the main efficacy indicators: (1) immune related health scores were significantly improved in the mid-term and after the test (P < 0.01), (2) CD3 and CD4/CD8 increased significantly after the test (P < 0.05), (3) IgG, IgA, IgM and WBC increased significantly in the mid-term and after the test (P < 0.01); the results of the secondary efficacy indicators: (1) TNF-α decreased significantly in the midterm (P < 0.05), IFN-γ decreased significantly in the mid-term (P < 0.01), (2) NK increased significantly in the mid-term and after the test (P < 0.05), (3) monocyte increased significantly in the mid-term and after the test (P < 0.01). Inter-group comparison of the test group and the control group, the results of the main efficacy indicators: (1) immune related health scores were higher than that of the control group in the mid-term and after the test (P < 0.01), (2) IgA of the test group was higher than that of the control group in the mid-term and after the test (P < 0.05); the results of the secondary efficacy indicators: (1) WBC of the test group was higher than that of the control group in the mid-term (P < 0.05); (2) monocytes of the test group were higher than that of the control group in the mid-term and after the test (P < 0.05), neutrophils of the test group were higher than that of the control group in the mid-term (P < 0.05). Conclusion: Taking KRG has no adverse effects on the health of the subjects. According to the standard of clinical trial scheme, the immune related health scores and IgA in the main efficacy indicators were positive, which shows that KRG is helpful in enhancing human immunity.

• Tunnel and Underground Space
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• v.34 no.4
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• pp.374-392
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• 2024

In order to successfully select a site for deep geological disposal of high-level radioactive waste, it is important to perform the stepwise approach along with the systematic selection and survey of evaluation parameters of geological environmental characteristics suitable for the domestic geological environment. In this study, we evaluated the characteristics of hydraulic conductivity, which is considered the most important evaluation parameter in the field of hydrogeology, targeting a deep-depth rock aquifer where actual disposal facilities are expected to be located. In particular, for the first time in Korea, we obtained in-situ pressure-flow data by directly conducting hydraulic tests in boreholes at depths ranging from 500 m to 750 m in various rock types distributed in Korea (granite/volcanic rock/gneiss/mudstone). And we derived hydraulic conductivity values by rock types and depth using verified analytical methods. For this purpose, precision hydraulic testing equipment developed in-house through this study was used, and detailed investigation procedures based on standard test methods were applied to field tests. As a result of the analysis, the average hydraulic conductivity value was found to be in the range of 10^-9 m/s in all granite/volcanic rock/gneiss areas. In the mudstone area, an average hydraulic conductivity value of 10^-11 m/s was derived, which was about 100 times (2 orders of magnitude) lower than that of the fractured rock aquifers. Moreover, permeability tended to slightly decrease with depth in fractured rock aquifers (granite and volcanic rock areas) containing many rock fractures. The gneiss area tended to have large local differences in permeability according to the composition of the stratum and the development of fracture zones rather than depth. In mudstone areas with weak fracture development, there was no significant variation in rock permeability according to depth. The hydraulic conductivity results by various rock types and depth presented in this study are expected to be utilized in building a foundational database for the site selection, design, and construction of disposal facilities in Korea.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.5
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• pp.389-395
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• 2024

This study was conducted to determine the cytotoxicity of the extracts from the human body contact area of the test substance during a test on the Good Laboratory Practice (GLP), which is the medical device safety evaluation standard, using the extracorporeal shock wave therapy (ESWT) cartridge as a sample, using L-929 cells. The test and control substances were extracted with 1xMEM culture medium containing 10% FBS at 37±1℃ for 24±2 hours. The test substance extract (test group), negative control substance extract (negative control group), positive control substance extract (positive control group), and blank test solution extract (solvent control group) were applied to L929 cells and cultured for 48±2 hours in a 37±1℃, 5±1% CO2 incubator. As a result of observing cell reactions under a microscope, the cells to which the blank test solution extract and negative control substance extract were applied were grade 0, the cells to which the positive control substance extract was applied were grade 4, and the cells to which the test substance extract was applied were grade 0. As a result of quantitative evaluation through cell counting, the cell viability rate of the cells to which the negative control substance extract was applied was 106.28% compared to the blank test solution extract, the cells to which the positive control substance extract was applied were 0.00%, and the cells to which the test substance extract was applied were 99.58%. Therefore, when the results of the negative and positive control groups were confirmed, the test process was appropriate, and it was determined that it did not cause cytotoxicity because the qualitative evaluation method was less than grade 2 and the quantitative evaluation method showed a cell viability rate of more than 70%.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.201-209
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• 2004

Extracorporeal life support (ECLS) system is a device for respiratory and/or heart failure treatment, and there have been many trials for development and clinical application in the world. Currently, a non-pulsatile blood pump is a standard for ECLS system. Although a pulsatile blood pump is advantageous in physiologic aspects, high pressure generated in the circuits and resultant blood cell trauma remain major concerns which make one reluctant to use a pulsatile blood pump in artificial lung circuits containing a membrane oxygenator. The study was designed to evaluate the hypothesis that placement of a pressure-relieving compliance chamber between a pulsatile pump and a membrane oxygenator might reduce the above mentioned side effects while providing physiologic pulsatile blood flow. The study was performed in a canine model of oleic acid induced acute lung injury (N=16). The animals were divided into three groups according to the type of pump used and the presence of the compliance chamber, In group 1, a non-pulsatile centrifugal pump was used as a control (n=6). In group 2 (n=4), a single-pulsatile pump was used. In group 3 (n=6), a single-pulsatile pump equipped with a compliance chamber was used. The experimental model was a partial bypass between the right atrium and the aorta at a pump flow of 1.8∼2 L/min for 2 hours. The observed parameters were focused on hemodynamic changes, intra-circuit pressure, laboratory studies for blood profile, and the effect on blood cell trauma. In hemodynamics, the pulsatile group II & III generated higher arterial pulse pressure (47$\pm$ 10 and 41 $\pm$ 9 mmHg) than the nonpulsatile group 1 (17 $\pm$ 7 mmHg, p<0.001). The intra-circuit pressure at membrane oxygenator were 222 $\pm$ 8 mmHg in group 1, 739 $\pm$ 35 mmHg in group 2, and 470 $\pm$ 17 mmHg in group 3 (p<0.001). At 2 hour bypass, arterial oxygen partial pressures were significantly higher in the pulsatile group 2 & 3 than in the non-pulsatile group 1 (77 $\pm$ 41 mmHg in group 1, 96 $\pm$ 48 mmHg in group 2, and 97 $\pm$ 25 mmHg in group 3: p<0.05). The levels of plasma free hemoglobin which was an indicator of blood cell trauma were lowest in group 1, highest in group 2, and significantly decreased in group 3 (55.7 $\pm$ 43.3, 162.8 $\pm$ 113.6, 82.5 $\pm$ 25.1 mg%, respectively; p<0.05). Other laboratory findings for blood profile were not different. The above results imply that the pulsatile blood pump is beneficial in oxygenation while deleterious in the aspects to high pressure generation in the circuits and blood cell trauma. However, when a pressure-relieving compliance chamber is applied between the pulsatile pump and a membrane oxygenator, it can significantly reduce the high circuit pressure and result in low blood cell trauma.