• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.249-254
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• 2022

With the rapid advance of the semiconductor and Information and communication technologies, remote environment monitoring technology, which can detect and analyze surrounding environmental conditions with various types of sensors and wireless communication technologies, is also drawing attention. However, since the conventional remote environmental monitoring systems require external power supplies, it causes time and space limitations on comfortable usage. In this study, we proposed the concept of the self-powered remote environmental monitoring system by supplying the power with the levitation-electromagnetic generator (L-EMG), which is rationally designed to effectively harvest biomechanical energy in consideration of the mechanical characteristics of biomechanical energy. In this regard, the proposed L-EMG is designed to effectively respond to the external vibration with the movable center magnet considering the mechanical characteristics of the biomechanical energy, such as relatively low-frequency and high amplitude of vibration. Hence the L-EMG based on the fragile force equilibrium can generate high-quality electrical energy to supply power. Additionally, the environmental detective sensor and wireless transmission module are composed of the micro control unit (MCU) to minimize the required power for electronic device operation by applying the sleep mode, resulting in the extension of operation time. Finally, in order to maximize user convenience, a mobile phone application was built to enable easy monitoring of the surrounding environment. Thus, the proposed concept not only verifies the possibility of establishing the self-powered remote environmental monitoring system using biomechanical energy but further suggests a design guideline.

• Clean Technology
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• v.28 no.1
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• pp.79-93
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• 2022

In this study, an electronics industrial wastewater activated sludge model (e-ASM) to be used as a Water Digital Twin was calibrated based on real high-tech electronics industrial wastewater treatment measurements from lab-scale and pilot-scale reactors, and examined for its treatment performance, effluent quality prediction, and optimal process selection. For specialized modeling of a high-tech electronics industrial wastewater treatment system, the kinetic parameters of the e-ASM were identified by a sensitivity analysis and calibrated by the multiple response surface method (MRS). The calibrated e-ASM showed a high compatibility of more than 90% with the experimental data from the lab-scale and pilot-scale processes. Four electronics industrial wastewater treatment processes-MLE, A2/O, 4-stage MLE-MBR, and Bardenpo-MBR-were implemented with the proposed Water Digital Twin to compare their removal efficiencies according to various electronics industrial wastewater characteristics. Bardenpo-MBR stably removed more than 90% of the chemical oxygen demand (COD) and showed the highest nitrogen removal efficiency. Furthermore, a high concentration of 1,800 mg L^-1 T MAH influent could be 98% removed when the HRT of the Bardenpho-MBR process was more than 3 days. Hence, it is expected that the e-ASM in this study can be used as a Water Digital Twin platform with high compatibility in a variety of situations, including plant optimization, Water AI, and the selection of best available technology (BAT) for a sustainable high-tech electronics industry.

• Science of Emotion and Sensibility
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• v.24 no.4
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• pp.139-148
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• 2021

This study aimed to verify how a multisensory storytelling-based activity-based intervention affects social interaction in children with cerebral palsy. As a quasi-experimental investigation, this study used a single-blind, two-group pre-post test design. This study comprised 24 children aged 7 to 8 y who had been diagnosed with spastic cerebral palsy and were classified as having GMFCS stages I to III. Twelve children were randomly assigned to experimental and control groups, with neither the children nor their guardians knowing which group they were placed in. The group program comprised 16 sessions of 60 min each, twice a week for eight weeks. The experimental group engaged in an activity-centered intervention centered on multisensory storytelling, whereas the control group engaged in structured physical activity. The activities were assessed using the peer relations skills scale to determine the extent to which social interaction had changed prior to and during the child's intervention. The SPSS 25.0 for Windows (IBM Corp, USA) application was used to analyze the data, and the significance level (α) for statistical verification was set to 0.05. Furthermore, the Wilcoxon Signed-Rank and Mann-Whitney U tests were used to assess the differences in social interaction between the experimental and control groups. Significant differences were observed in the total of the peer relationship skill scale and cooperation and empathy areas of the subtest in the intragroup change of the peer relationship skill scale between the experimental and control groups. However, the experimental group demonstrated a significant difference in the initiative area, whereas the control group demonstrated no significant difference. A significant difference was observed in the amount of change between the two groups in the initiative area and total of the subtest of peer relationship skills but no significant difference in the collaboration and empathy areas. We gave a multisensory storytelling-based activity-based intervention based on multisensory storytelling to children with cerebral palsy and saw a significant improvement in peer relationship skills. It may be proposed as an effective intervention strategy for children with cerebral palsy who struggle with social contact.

• 한국노년학
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• v.40 no.4
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• pp.639-657
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• 2020

The purpose of this study is to analyze the effect of individual differences in recognition of retirement responsibility on financial preparedness for retirement and to examine moderating effect of income-level on the relationships between the two variables, using the 7th Korean Retirement and Income Study(KReIS). Two research methods, descriptive analysis and hierarchical multiple logistic regression(HMLR) analysis, have been conducted. The total number of sample was 3,869 subjects with an average age of 58.9 years and 55.3% males. The results show that only 35.8% of the respondents make financial plans for retirement, and 64.2% did not. Main findings are as follows. First, 65% of respondents take a responsibility for financial preparedness for retirement, compared to 37% in European countries. Second, people with responsibility for their own retirement are more likely to have a financial preparation for retirement than people who think others(family, society, government) have to take a responsibility for retirement instead of them. Third, there is a significant moderating effect of income-level on relationships between recognition of retirement responsibility and financial preparedness for retirement. As income level decreases, the moderating effect reduces the positive effect of recognition of retirement responsibility on financial preparedness for retirement and vice versa. Fourth, as income level increases and educational level is higher, the tendency to prepare financially for retirement is also increasing. Low-income and low-educated people are less likely to have a financial preparation for retirement than their counterparts. The findings suggest that it is necessary to design an effective incentive scheme for financial preparedness for retirement for low-income and low-educated people and to develop various policies and services to encourage them to prepare financially for retirement.

• Korean Journal of Heritage: History & Science
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• v.55 no.2
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• pp.24-48
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• 2022

Bronze mirrors found in pagodas were regarded as simple offerings and thus have received little attention in studies. Furthermore, the few studies on bronze mirrors enshrined in pagodas have focused on the line-engraved mirrors found in the pagodas of the Kingdom of Wuyue; therefore, it is difficult to understand the general characteristics of the bronze mirrors enshrined in the pagodas. This study assumes that the bronze mirrors found in many pagodas in the Kingdom of Wuyue and the Song dynasty were enshrined for a specific purpose. To explore this assumption and accurately understand the artifacts, this study focuses on the location and method of enshrinement. The number of bronze mirrors enshrined in pagodas increased during the Kingdom of Wuyue, with the mirrors expressing statues and inscriptions related to Buddhism rather than being simple offerings. This shows that the purpose of the bronze mirror changed. The influence of the Kingdom of Wuyue continued during the Song dynasty; however, the pattern of bronze mirror enshrinement changed due to the culture and social atmosphere of the time. The most common types of enshrined bronze mirrors were plain, and bronze mirrors from the Dang dynasty were also used consistently. Plain bronze mirrors were used more frequently in this period despite the lingering influence of the Kingdom of Wuyue because it was less laborious to engrave images and inscriptions such as the inscription of Buddha. Additionally, bronze mirrors were valued during this period because of the attention toward the imitation of the archaic bronze(仿古銅器) of the Song dynasty and the influence of the emperor. Moreover, it is believed that bronze mirrors were enshrined in pagodas as offerings as they were deemed valuable at the time. There was a change in the method of enshrining bronze mirrors in pagodas during the Kingdom of Wuyue and the Song dynasty. During this time, bronze mirrors that were positioned on the floor or in iron boxes were intentionally attached to walls or hung from the ceiling. This method was largely divided into two types: attaching to walls or the ceiling(嵌入鏡) and hanging from the ceiling(懸鏡). A typical example of hanging a bronze mirror from the ceiling can be seen in the Jingzhisa Temple Pagoda, and Teng County's Fushengsa Temple Pagoda contains an example of attaching a bronze mirror to the ceiling. The methods of hanging or attaching bronze mirrors to the ceiling were closely related to the methods employed in Chinese tombs. Song dynasty burial chambers had a high and wide structure, so to defend against evil spirits(辟邪用), bronze mirrors were used to protect the burial rooms. Bronze mirrors were, therefore, placed high to illuminate the burial room. This was achieved in the ways mentioned above. As underground chambers became wider and higher, mirrors also protected the important areas of the chambers and illuminated the interiors. Thus, it is believed that the methods of enshrining bronze mirrors in the pagodas during the Kingdom of Wuyue and the Song dynasty arose from the method of enshrining bronze mirrors in tombs at the time. Thereafter, pagodas, such as the Miaojuesa Temple Pagoda, in which the placement of a bronze mirror was actively considered from the design stage were constructed.

• Korean Journal of Heritage: History & Science
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• v.55 no.3
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• pp.46-58
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• 2022

This study analyzed the documentation trend of garden components such as plants, infrastructure, unit facilities, and structures, based on 188 measurement drawings of 94 old houses in a report on the documentation of the national folklore cultural heritage. The findings are as follows. First, it was found that plants and structures continuously appeared as the subject of measurement drawings, while infrastructure was often omitted. It was confirmed that unit facilities, which are smaller than other components, were frequently excluded from the documentation subject as well due to frequent changes such as movement, loss, and expansion. Second, the level of expression in measurement drawings showed different aspects for each component. The unit facilities showed a large change over time with respect to the level of documentation, and the level of documentation was somewhat polarized, particularly toward the latter stage. This suggests that the level of documenting the drawings limited to specific facilities improved, but the overall level of drawings did not improve, such as a lack of diversification of expression techniques suitable for various unit facilities. On the other hand, it was confirmed that the level of documenting the drawings for plants, infrastructure and structures did not change to a significant degree, implying that no improvements were made to the expression of components. Third, as for the technique of detailed expression, in the case of plants, vegetation status was prepared without distinction of old or protected trees that have historical value. Above all, there was no record of the vegetation structure that could help grasp the vegetation landscape of the outer area. As for the infrastructure, there was no consistent expression technique to systematically convey topographic changes such as the height and slope of the land. In addition, since there was no subtype classification defined for unit facilities and structures, there was no subject or method of documentation. This study is meaningful in that it expanded the category of documentation, which has been concentrated on buildings in old houses, to gardens, and called attention to the need for documenting the gardens for the preservation and management of old houses as an integration of the building and outer area.

• Clean Technology
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• v.28 no.3
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• pp.218-226
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• 2022

As a result of the recent social transformation towards a hydrogen economy and carbon-neutrality, the demands for hydrogen energy have been increasing rapidly worldwide. As such, eco-friendly hydrogen production technologies that do not produce carbon dioxide (CO₂) emissions are being focused on. Among them, ammonia (NH₃) is an economical hydrogen carrier that can easily produce hydrogen (H₂). In this study, Ru/Al₂O₃ catalyst coated onmetallic monolith for hydrogen production from ammonia was prepared by a dip-coating method using a catalyst slurry mixture composed of Ru/Al₂O₃ catalyst, inorganic binder (alumina sol) and organic binder (methyl cellulose). At the optimized 1:1:0.1 weight ratio of catalyst/inorganic binder/organic binder, the amount of catalyst coated on the metallic monolith after one cycle coating was about 61.6 g L^-1. The uniform thickness (about 42 ㎛) and crystal structure of the catalyst coated on the metallic monolith surface were confirmed through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Also, a numerical optimization regression equation for NH3 conversion according to the independent variables of reaction temperature (400-600 ℃) and gas hourly space velocity (1,000-5,000 h^-1) was calculated by response surface methodology (RSM). This model indicated a determination coefficient (R²) of 0.991 and had statistically significant predictors. This regression model could contribute to the commercial process design of hydrogen production by ammonia decomposition.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.167-183
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• 2023

Gases originated from the final SNF (spent nuclear fuel) disposal site are very mobile in the barrier and they may also affect the migration of radioactive nuclides generated from the SNF. Mechanisms of gas-nuclide migration in the multi-barrier and their influences on the safety of the disposal site should be understood before the construction of the final SNF disposal site. However, researches related to gas-nuclide coupled movement in the multi-barrier medium have been very little both at home and abroad. In this study, properties of gas generation and migration in the SNF disposal environment were reviewed through previous researches and their main mechanisms were summarized on the hydrogeological evolution stage of the SNF disposal site. Gas generation in the SNF disposal site was categorized into five origins such as the continuous nuclear fission of the SNS, the Cu-canister corrosion, the oxidation-reduction reaction, the microbial activity, and the inflow from the natural barriers. Migration scenarios of gas in porous medium of the multi-barrier in the SNF repository site were investigated through reviews for previous studies and several gas migration types including ① the free gas phase flow including visco-capillary two-phase flow, ② the advection and diffusion of dissolved gas in pore water, ③ dilatant two-phase flow, and ④ tensile fracture flow, were presented. Reviewed results in this study can support information to design the further research for the gas-nuclide migration in the repository site and to evaluate the safety of the Korean SNF disposal site in view points of gas migration in the multi-barrier.

• (The) Research of the performance art and culture
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• no.41
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• pp.219-255
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• 2020

This article was triggered by Victor H. Mair's book 'Painting and performance'. The book explained that Buddhist paintings are common in the area where Buddhism was spread, and there are also performances using them. And although it has nothing to do with Buddhism, it has been shown that this form of performance can be global. However, the problem was not 'Korea'. It was because there was no record or transmission of the corresponding performance soon. In this situation, the landing method of Samcheok stable temple was announced in 2018. On the one hand, the academic community is very pleased, but on the other hand, it is troubled. The worries are summed up as 'synchronic and diachronic universality'. Is the landing method inherited from the Samcheok stable temple a unique type of temple? Otherwise, it is a question of whether it has been passed down or is it universal at the national level. However, prior to this essential question, we do not yet know the full picture of the stable landing method. So this article was prepared to show the overall outline of the stable landing method. There is a 'picture' in common throughout the landing method, and understanding how to operate it in various ways is the first step in understanding the landing method. There are five repertoires (which are called main halls) that are considered important, and more than that. What these repertoires have in common is the narrative structure of a Buddhist character. In this narrative, the most important thing is the revised figure, and it was the earthly method to inform the contents of the revised figure in various ways. In the case of Byeonsangdo, which serves as a clue to the narrative, there was a problem that could not be seen in the evening without light, which required special design. It is the way of shadow play and Yeongdeung. In other words, there are three types of performances in the landing method. The first is the method of using reparation, and the second is the method of using shadow. The third is the way of eternity. This method is not a selection based on the contents of the repertoire, but a selection based on the performance environment. If there is light and you can see the picture, use reparation. However, in the evening, it was impossible to see it dark (when there was no electricity in the past). The use of the visual method as a tool in this method is to confirm the transition to a visual culture that is a step further from the level of culture. Moreover, unlike the epic narrative, the power of the implied image provided an opportunity for viewers to experience the mystery of Buddhism through emotional stimulation.

• Resources Recycling
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• v.31 no.6
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• pp.44-51
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• 2022

In the steelmaking process using an electric arc furnace (EAF), light-burnt dolomite, which is a flux containing MgO, is used to protect refractory materials and improve desulfurization ability. Furthermore, a recarburizing agent is added to reduce energy consumption via slag foaming and to induce the deoxidation effect. Herein, a waste MgO-C based refractory material was used to achieve the aforementioned effects economically. The waste MgO-C refractory materials contain a significant amount of MgO and graphite components; however, most of these materials are currently discarded instead of being recycled. The mass recycling of waste MgO-C refractory materials would be achievable if their applicability as a flux for steelmaking is proven. Therefore, experiments were performed using a target composition range similar to the commercial EAF slag composition. A pre-melted base slag was prepared by mixing SiO₂, Al₂O₃, and FeO in an alumina crucible and heating at 1450℃ for 1 h or more. Subsequently, a mixed flux #2 (a mixture of light-burnt dolomite, waste MgO-C based refractory material, and limestone) was added to the prepared pre-melted base slag and a melting reaction test was performed. Injecting the pre-melted base slag with the flux facilitates the formation of the target EAF slag. These results were compared with that of mixed flux #1 (a mixture of light-burnt dolomite and limestone), which is a conventional steelmaking flux, and the possibility of replacement was evaluated. To obtain a reliable evaluation, characterization techniques like X-ray diffraction (XRD) analysis and X-ray fluorescence (XRF) spectrometry were used, and slag foam height, slag basicity, and Fe recovery were calculated.