• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.436-445
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• 2023

Methane (CH₄) emissions from rice paddies are mainly observed using the closed chamber method or the eddy covariance method. In this study, a new observation technique combining a portable gas analyzer (Model LI-7810, LI-COR, Inc., USA) and an automatic opening/closing chamber (Model Smart Chamber, LI-COR, Inc., USA) was introduced based on the strengths and weaknesses of the existing measurement methods. A cylindrical collar was manufactured according to the maximum growth height of rice and used as an auxiliary measurement tool. All types of measured data can be monitored in real time, and CH₄ flux is also calculated simultaneously during the measurement. After the measurement is completed, all the related data can be checked using the software called 'SoilFluxPro'. The biggest advantage of the new observation technique is that time-series changes in greenhouse gas concentrations can be immediately confirmed in the field. It can also be applied to small areas with various treatment conditions, and it is simpler to use and requires less effort for installation and maintenance than the eddy covariance system. However, there are also disadvantages in that the observation system is still expensive, requires specialized knowledge to operate, and requires a lot of manpower to install multiple collars in various observation areas and travel around them to take measurements. It is expected that the new observation technique can make a significant contribution to understanding the CH₄ emission pathways from rice paddies and quantifying the emissions from those pathways.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.847-870
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• 2023

The safe disposal of high-level radioactive waste requires accurate predictions of the long-term geochemical behavior of radionuclides. To achieve this, the present study was conducted to model geochemical behaviors of uranium (U), plutonium (Pu), and palladium (Pd) under different hydrogeochemical conditions that represent deep groundwater in Korea. Geochemical modeling was performed for five types of South Korean deep groundwater environment: high-TDS saline groundwater (G1), low-pH CO₂-rich groundwater (G2), high-pH alkaline groundwater (G3), sulfate-rich groundwater (G4), and dilute (fresh) groundwater (G5). Under the pH and Eh (redox potential) ranges of 3 to 12 and ±0.2 V, respectively, the solubility and speciation of U, Pu, and Pd in deep groundwater were predicted. The result reveals that U(IV) exhibits high solubility within the neutral to alkaline pH range, even in reducing environment with Eh down to -0.2 V. Such high solubility of U is primarily attributed to the formation of Ca-U-CO₃ complexes, which is important in both G2 located along fault zones and G3 occurring in granitic bedrocks. On the other hand, the solubility of Pu is found to be highly dependent on pH, with the lowest solubility in neutral to alkaline conditions. The predominant species are Pu(IV) and Pu(III) and their removal is predicted to occur by sorption. Considering the migration by colloids, however, the role of colloid formation and migration are expected to promote the Pu mobility, especially in deep groundwater of G3 and G5 which have low ionic strengths. Palladium (Pd) exhibits the low solubility due to the precipitation as sulfides in reducing conditions. In oxidizing condition, anionic complexes such as Pd(OH)₃^-, PdCl₃(OH)₂^-, PdCl₄^2-, and Pd(CO₃)₂^2- would be removed by sorption onto metal (hydro)oxides. This study will improve the understanding of the fate and transport of radionuclides in deep groundwater conditions of South Korea and therefore contributes to develop strategies for safe high-level radioactive waste disposal.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.695-713
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• 2023

In coastal waters, phytoplankton,suspended particulate matter, and dissolved organic matter intricately and nonlinearly alter the reflectivity of seawater. Neural network technology, which has been rapidly advancing recently, offers the advantage of effectively representing complex nonlinear relationships. In previous studies, a three-stage neural network was constructed to extract the inherent optical properties of each component. However, this study proposes an algorithm that directly employs a deep neural network. The dataset used in this study consists of synthetic data provided by the International Ocean Color Coordination Group, with the input data comprising above-surface remote-sensing reflectance at nine different wavelengths. We derived inherent optical properties using this dataset based on a deep neural network. To evaluate performance, we compared it with a quasi-analytical algorithm and analyzed the impact of log transformation on the performance of the deep neural network algorithm in relation to data distribution. As a result, we found that the deep neural network algorithm accurately estimated the inherent optical properties except for the absorption coefficient of suspended particulate matter (R² greater than or equal to 0.9) and successfully separated the sum of the absorption coefficient of suspended particulate matter and dissolved organic matter into the absorption coefficient of suspended particulate matter and dissolved organic matter, respectively. We also observed that the algorithm, when directly applied without log transformation of the data, showed little difference in performance. To effectively apply the findings of this study to ocean color data processing, further research is needed to perform learning using field data and additional datasets from various marine regions, compare and analyze empirical and semi-analytical methods, and appropriately assess the strengths and weaknesses of each algorithm.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.94-101
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• 2023

In this study, the development performance of the head bars, which is SD700, was experimentally evaluated at the RC (reinforced concrete) or SFRC (steel fiber reinforced concrete external beam-column joint. A total of 10 specimens were tested, and variables such as steel fibers, length of settlement, effective depth of the beam, and stirrups of the column were planned. As a result of the experiment, the specimens showed side-face blowout, concrete breakout, and shear failure depending on the experimental variables. In the RC series experiments with development length as a variable, it was confirmed that the development strength increased by 26.5~42.2% as the development length increased by 25-80%, which was not proportional to the development length. JD-based experiments with twice the effective depth of beams showed concrete breakout failure, reducing the maximum strength by 31.5% to 62% compared to the reference experiment. The S-series experiment, in which the spacing of the shear reinforcement around the enlarged head reinforcement was 1/2 times that of the reference experiment, increased the maximum strength by 8.4 to 9.7%. The concrete compressive strength of SFRC was evaluated to be 29.3% smaller than the concrete compressive strength of RC, but the development strength of SFRC specimens increased by 7.3% to 12.2%. Accordingly it was confirmed that the development performance of the head bar was greatly improved by reinforcing the steel fiber. Considering the results of 92% and 99% of the experimental maximum strength of the experiment arranged with 92% and 110% of the KDS-based settlement length, it is judged that the safety rate needs to be considered even more. In addition, it is required to present a design formula that considers the effective depth of the beam compared to the development length.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.5
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• pp.133-150
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• 2022

The purpose of this study was to develop a female entrepreneurial competency model. For the purpose, two Focus Group Interviews (FGI) were conducted with seven outstanding female entrepreneurs, and three expert reviews were conducted. In addition, in order to verify the validity of the provisional female entrepreneur competency model derived from the FGI and competency modeling expert review, the female entrepreneur competency model was finally confirmed through a survey of 442 female entrepreneurs. The results were as follows. First, a female entrepreneur competency model consisting of 6 competency groups and 25 competencies of entrepreneurship, emotion, business management, relationship management, strategic management, and multitasking, and 75 behavioral indicators describing each competency was developed. Second, sensibility and multitasking are competencies that reflect the characteristics of female entrepreneurs. In particular, 'social sense', which is the ability to be considerate of others in the emotional competency group and the ability to respond well to subtle nuances, and the multitasking competency group's unique strengths are women's ability to perform various tasks at the same time. The 'work-family control ability' of a female entrepreneur who maintains a balance between 'multi-tasking' and work and family is a representative competency of only female entrepreneurs. Third, the developed female entrepreneurship competency model is meaningful in that it not only increases female entrepreneurial competency so that prospective female entrepreneurs can successfully run a business through entrepreneurship education, but it also makes it easy for existing female entrepreneurs to reflect and improve their competencies. If we provide appropriate training programs to female entrepreneurs based on their competency, it will be possible to effectively enhance the entrepreneurial competency, which is the key to strengthening the competitiveness of female entrepreneurs. The female entrepreneur competency model developed through this study can provide a basis for future research on competency diagnosis and education needs analysis.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.125-132
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• 2007

We estimated the distribution of predator-prey interaction strengths for 12 species of herbivores (including amphipods, isopods, gastropods, and sea urchins) and made a regression model that may be applicable to other species. Laboratory experiments were used to determine per capita grazing rate (PCGR; g seaweeds/individual/day). Relationship between the biomass of individual grazers and fourth-root transformed PCGR was fitted to power curve ($y=0.2310x^{0.3290}$, r=0.8864). This finding supported that the grazing efficiency was not even as individual grazers increase in size (biomass). Therefore, the biomass-normalized PCGR was estimated and revealed that smaller size herbivores were more effective grazers. Grazing impact considering density of each taxon was calculated. The sea hare Aplysia kurodai had greatest grazing impact on the seaweed bed and the sea urchin Strongylocentrotus nudus and S. intermedius were ranked in descending order of the impact. The amount of seaweed grazed by the amphipod Elasmopus sp. (>4,000 $ind./m^2$) and Jassa falcata (>2,000 $ind./m^2$) were 3.435 and $1.697mg/m^2/day$ respectively. The combined grazing amount of herbivores was $5,045mg/m^2/day$ in the seaweed bed. Although sea hare and sea urchin had strong impacts on seaweeds, the effects of dense, smaller species could not be seen as negligible. Surprisingly, the calculated grazing potential of sea urchins with a mean density of 3 $ind./m^2$ exceeded the mean production of seaweed cultured in domestic coastal waters in Korea (ca., 5 ton/ha). Small crustaceans were also expected to consume up to 16% of the seaweed production if their densities were rising under weak predation conditions. Considering that the population density of herbivores are strongly controlled by fish, human interference like overfishing may have strong negative effects on persistence of seaweeds communities.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1258-1273
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• 2021

Purpose The balloon-stent technique (BST) has certain strengths as an assisted technique for the treatment of complex aneurysms. After Atlas release, the BST can be executed without an exchange maneuver of the balloon to the stent-delivery catheter. The purpose of this article is to share our experience with the BST using the Scepter-Atlas combination. Materials and Methods Device inspection led us to a simple method to avoid failure in loading Atlas to the Scepter. From March 2018 to December 2019, 57 unruptured distal internal carotid artery (dICA) aneurysms were treated with coil embolization; among which, 25 aneurysms in 23 patients were treated with BST. Clinical and angiographic data were retrospectively collected and reviewed. Results The technical success rate of the Scepter-Atlas combination increased from 50% to 100% after careful inspection. BST angiographic results were comparable to the stent-assisted coil (SAC) group treated during the immediately post-embolization same period (modified Raymond-Roy classification [MRRC] 1 & 2 84% in BST, 96.3% in SAC) and during short-term follow-up (MRRC 1 & 2 95.8% in BST, 88.4% in SAC). A small number of patients showed periprocedural complications, but none had clinical consequences. Conclusion BST using the Scepter-Atlas combination can provide an effective and safe method for the treatment of dICA aneurysms. Scepters can be used as delivery catheters for Atlas.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.187-194
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• 2023

Purpose: A mismatched size in the post and post space is a common problem during post-fixation. Since this discordance affects the bonding strength of the fiber-reinforced composite resin post (FRC Post), a corresponding luting agent is required. The aim of this study was to evaluate the bonding strength of the FRC post according to the fitness of the fiber post and the type of luting agent. Materials and Methods: Thirty mandibular premolar were endodontic-treated and assigned to two groups according to their prepared post space: Fitting (F) and Mismatching (M). These groups were further classified into three subgroups according to their luting agent: RelyX Unicem (ReX), Luxacore dual (Lux), and Duolink (Duo). A push-out test was performed to measure the push-out bond strengths. The fractured surfaces of each cross-section were then examined, and the fracture modes were classified. Results: In the ReX and Duo subgroups, the F group had a higher mean bond strength; however, the Lux subgroup had no significant difference between the F and M groups. In the analysis of the failure modes, the ReX subgroup had only adhesive failures between the cement and dentin. Conclusion: The result of this study showed that the bond strength of an FRC post was influenced by the type of luting agent and the mismatch between the diameter of the prepared post space and that of the post.

• Sim-seong Yeon-gu
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• v.32 no.2
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• pp.122-168
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• 2017

I tried to understand a folk tale "The half-boy" in terms of analytical psychology. In the story, a lady without children prayed to the Buddha. The white old man came and gave three fishes, but the cat ate half of it. So, she ate two and a half. She gave birth to two perfect sons. The third son had one arm, one leg, and one eye. They grew well. Brothers went to take the civil service examinations, and the half-boy followed. But two brothers did not like the half-boy coming along. So, brothers tied the half-boy to the rocks and trees, and he picked them up with force and gave them down to the yard of the house. And the half-boy followed his brothers again, and brothers tied him with kudzu and put him in front of the tiger. The half-boy won the tiger by betting with cutting kudzu. The half-boy stripped off the tiger's skin. The host coveted the tiger skin and they played with janggi. The half-boy won the game and was permitted to take host's daughter. The half-boy went with a string, a drum, a flea, and a bedbug. He teased host's people with these. The half-boy brought a virgin and lived well. "The Half-Boy" folktale is an old story spread throughout the country. There are similar stories in India and Africa. Unilateral figures are universally distributed archetypal images. In numerous cultures gods and spirits are being portrayed as unilateral figures. In the creation mythology, half-figure beings have immortality. In Indonesian and African folk tales, the half-born boy goes to heaven and merges with its half and becomes perfect. Some of one-sided spirits are harmful to humans but some of one-sided birds, chickens, and spirits are helpful to people. Sometimes half being is a cultural hero who steals grain from heaven or gets some advice how to use bamboo. There are stories that half body becomes a whole body afterwards. But in this folktale and most of the similar folktales, half-figure does not change and maintains half-figure to the end. And as a half-figure he does various great things and marries a virgin. The half-boy symbolizes a psychic experience born in the unconscious. The unconscious contents may seem strange and weird at first and the collective consciousness does not want to accept them. But the unconscious exerts greater power and brings vitality and creativity to consciousness. This folk tale seems to have compensated for the stubborn collective consciousness of our society, which was a Confucian class society. It also allows people to change their attitude toward disabled people and recognize strengths and creativity of the handicapped.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.3
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• pp.123-138
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• 2024

Experiential social entrepreneurship education offers participants opportunities for active engagement in social entrepreneurial activities. Highlighting the significance of psychosocial experiences within the program, this study examines work meaningfulness discovered in this process as the antecedent to forming social entrepreneurial intention. Furthermore, drawing on social cognitive career theory that emphasizes the role of agency in career decisions, we propose social entrepreneurial self-efficacy as the underlying mechanism and social class as the moderating factor in the relationship between work meaningfulness and social entrepreneurial intention formation. The propositions were tested with a two-wave survey dataset collected among 145 university students taking part in an experiential social entrepreneurship program in South Korea. Our results indicate that work meaningfulness positively affects social entrepreneurial self-efficacy, which subsequently promotes social entrepreneurial intention. Moreover, when participants' social class, measured by either household income or perceived rank, is lower, the positive effect of work meaningfulness on social entrepreneurial self-efficacy as well as intention is amplified. Theoretically, these findings shed light on the crucial role of work meaningfulness in strengthening potential entrepreneurs' agency in the domain of social entrepreneurship, particularly for those from lower classes. Practically, we provide guidelines for designing an inclusive experiential social entrepreneurship program that allows participants to find meaningfulness by realizing their strengths and justifying their prosocial contribution.