• Clean Technology
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• v.28 no.2
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• pp.110-116
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• 2022

In this study, iron oxide (FeO_x) nanoparticles were synthesized using iron (Fe) by-products recovered from NdFeB permanent magnet scraps, and the effect of heat-treatment temperature on the physical properties of the FeO_x nanoparticles was investigated. In order to prepare the FeO_x nanoparticles, 2.0 M ammonia (NH₄OH) solution was added to an iron by-product solution diluted to c.a. 10 wt% in D.I. water, which led to the precipitation of the iron oxide precursor. Then, the FeO_x nanoparticles were synthesized by heat-treatment at 300 ℃, 400 ℃, 500 ℃ and 600 ℃. After that, the physical properties of the FeO_x nanoparticles were investigated in order to understand the effect of the heat-treatment temperature. The results of the X-ray diffraction (XRD) analysis showed that the diffraction peak in accordance with the <104> direction increased as the heat-treatment increased, and a diffraction peak indicating the α-Fe₂O₃ crystal structure was detected at heat-treatment temperatures above 500 ℃. The BET specific surface area analysis revealed that the specific surface area decreased as the heat-treatment temperature increased to above 400 ℃. Observation with a high resolution transmission electron microscope (HRTEM) showed that rod-shaped nanoparticles were formed, and the size of the nanoparticles showed a tendency to increase as the heat-treatment temperature increased.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.85-93
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• 2022

As of the end of 2019, the total population nationwide was 51,849,861, and over the past five years, the population per household has decreased by 1.52% annually from 2.45 in 2015 to 2.31 in 2019. Looking at the current status of population distribution by age group, Busan metropolitan city had the highest proportion of senior citizens aged 65 or older at 18.2%, and Sejong Special Self-Governing city had the lowest at 9.4%. In particular, as of 2019, the population of the mobility handicapped was 15,219,000 nationwide, showing a ratio of about 29.4% of the total population. Therefore, it is important to secure the right to move according to the mobile facilities so that the mobility handicapped can move safely and conveniently. Against this background, this study places value on transportation welfare facilities centered on the mobility handicapped for safe and convenient movement, and in particular, in proposing measures to cope with the entry of an aging society and the continuous increase of the mobility handicapped, the transportation facilities, The purpose of this study is to analyze the impact of welfare facilities on the mobility handicapped and suggest implications. As a research method, the results of statistical analysis methods were presented through major preceding studies and expert surveys.

• Science of Emotion and Sensibility
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• v.26 no.2
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• pp.129-140
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• 2023

Following ISO 20471, in this study, first, two sets of safety clothes and safety vests were made by designing and attaching animal and bird patterns preferred by children to retroreflective films and black fabrics on those fluorescent fabrics and retroreflective materials prescribed by international standards. Second, by mounting a smart photonic device on the safety clothing so that the body can be recognized from a distance even without an ambient light source at night, children can emit three types of light depending on the situation with just one-touch of the button. From a result of comparison with visibility a day and night by dressing a mannequin in the made smart safety clothing, the difference in visibility was evident at night, it was confirmed that we can see the figure of a person even at a distance of approximately 70 m. Therefore, it is expected to contribute to the prevention of traffic and other accidents on the road, as the drivers driving at night or in bad weather can recognize a person from a distance. Third, in case of the energy is exhausted and cannot maintain the stability of the light-emitting function of the optical faber, we can use energy harvesting device, and the light-emitting time will be extended. As a result it comes up to emit light stably for a long time. And this prove that smart photonic safety clothing can also be used for night workers. Therefore, optical fiber safety clothing is expected to be highly wearable not only in real life but also in dark industrial sites due to stable charging by applying the energy harvesting provided by solar cells.

• Journal of Korea Entertainment Industry Association
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• v.13 no.2
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• pp.57-65
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• 2019

This study is a scientific approach to psychological factors such as emotional stability among various effects of forest resources. In order to carry out this study, the experiment was conducted on the subjects by setting the forest healing space as various spaces. The subjects who participated in this experiment were the students in their twenties and the average age was 22±1.25 years. The subjects were assessed for emotional words through subjective sequence evaluation in different designated forest healing spot. In addition, the emotional states that they actually perceived were measured by measuring the bio-signals to their perceived emotions. BMP, SDNN, VLF, LF, HF, Amplitude, and PPI were used for the bio-signal reaction experiment applied to this study. The results of this experiment were measured by Friedman test and Wilcoxon test for statistical analysis. n this study, 'good', 'clear', and 'uncomfortable' words were found statistically significant at the spot of forest healing space for subjective emotional vocabulary. In addition, SDNN, HF and Amplitude were statistically significant in the results of quantitative bio-signal measurement at each spot in the forest healing space. Based on the results of this study, we can suggest the application direction and strategic utilization plan of forest healing spot and forest resource utilization field. This is not only a guide for the users who use the facility through the spatial facilities and physical requirements for the emotion based forest-healing, but also can be used as a personalized emotional space design aspect.

• Journal of Service Research and Studies
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• v.12 no.3
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• pp.1-25
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• 2022

This study was conducted for technology development and industrial and enterprise system design for the sustainable life of mankind. Human society is facing a crisis. As the power of mankind has increased due to the development of nuclear weapons and information and communication technologies, the risk of human society has greatly increased. The value of growth and freedom is increasing due to capitalism and democratic systems, so technological innovation is accelerating, and industries and companies are growing significantly. New technologies and industries can greatly develop human society and put it at risk. This study was conducted with the aim of redesigning technology, industry, and enterprise systems so that humans who live on Earth can be more sustainable for a longer time. It presented a practical alternative for a long-term sustainable human society. It suggested alternatives for what philosophy and methodology should be developed for the whole of humanity and in each individual national society, for developing technologies, fostering industries, and operating corporate systems. First of all, the problems of the technology development system, industrial system, and enterprise system of human society were analyzed. The characteristics and problems were analyzed in terms of sustainability of human society. The necessary and sufficient conditions for an alternative system to solve the raised problems were derived. A system that satisfies these conditions was designed and presented. The alternative system was named as a servicism system as a system based on the service philosophy. The structure, operation model, and implementation plan of the new technology industry enterprise system were presented. In the future, follow-up studies are needed to be concreted at the level of individual countries and human society as a whole.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.449-455
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• 2022

The Colony of Selaginella involvens (Sw.) Spring in Sanyang-myeon, Mungyeong-si, can be divided into five types, and in the past, it was said that Selaginella involvens (Sw.) Spring formed colonies throughout the colony and grew naturally, but now it remains only in some sections. It was found that the Selaginella involvens (Sw.) Spring colony was damaged by artificial and natural factors, and as an artificial factor, the Selaginella involvens (Sw.) Spring was proven to be effective for medicinal and cremation, and many people were damaging the Selaginella involvens (Sw.) Spring colony without permission. Naturally, vines thrive and Selaginella involvens (Sw.) Spring die, and the reality is that the entire colony of Selaginella involvens (Sw.) Spring is in danger of being damaged if maintenance is not performed. On the other hand, there are sections that reproduce with symbiosis with some herbaceous plants, so it is necessary to plan and implement conservation strategies. In order to preserve the Selaginella involvens (Sw.) Spring colony, CCTV is needed to prevent artificial damage, and on the contrary, install facilities such as fences can easily burn up and create worse scenery, so it can preserve the good environment, restore recoverable areas, and install supplementary buffer zones.

• Journal of Broadcast Engineering
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• v.27 no.1
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• pp.91-103
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• 2022

Determination of sound source characteristics such as: sound volume, direction and distance to the source is one of the important techniques for unmanned systems like autonomous vehicles, robot systems and AI speakers. There are multiple methods of determining the direction and distance to the sound source, e.g., using a radar, a rider, an ultrasonic wave and a RF signal with a sound. These methods require the transmission of signals and cannot accurately identify sound sources generated in the obstructed region due to obstacles. In this paper, we have implemented and evaluated a method of detecting and identifying the sound in the audible frequency band by a method of recognizing the volume, direction, and distance to the sound source that is generated in the periphery including the invisible region. A cross-shaped based sound source recognition algorithm, which is mainly used for identifying a sound source, can measure the volume and locate the direction of the sound source, but the method has a problem with "blind spots". In addition, a serious limitation for this type of algorithm is lack of capability to determine the distance to the sound source. In order to overcome the limitations of this existing method, we propose a QRAS-based algorithm that uses rectangular-shaped technology. This method can determine the volume, direction, and distance to the sound source, which is an improvement over the cross-shaped based algorithm. The QRAS-based algorithm for the OSSD uses 6 AITDs derived from four microphones which are deployed in a rectangular-shaped configuration. The QRAS-based algorithm can solve existing problems of the cross-shaped based algorithms like blind spots, and it can determine the distance to the sound source. Experiments have demonstrated that the proposed QRAS-based algorithm for OSSD can reliably determine sound volume along with direction and distance to the sound source, which avoiding blind spots.

• Korea Science and Art Forum
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• v.23
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• pp.95-109
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• 2016

The background and objective of this study are as follows. Gwangheemun, one of the 4 small gates of Seoul Castle is a space to represent ordinary people and it is a valuable cultural heritage that shows the process of technical transition of fortification technology during Chosun Dynasty. It is a place that we can expect to play a role as a field where history and culture mix and communicate together. But currently, the environment and facilities around Gwangheemun have fallen behind and become old, so they need to be reorganized as their local feature is not shown distinctly. We need to vitalize the new traditional space that shows local feature. This study has drawn out the method, contents and the result of study like as follows. This study aims to establish an identity based on the historical and cultural backgrounds and suggest the contents to vitalize the space of Gwangheemun as a traditional cultural heritage. By this, this study aims to create a historical and cultural space where people can enjoy, eat and look around. Therefore, based on the historical and cultural feature, it gives an identity as moonlight street, and it has developed and suggested 5 contents to vitalize space: Gwangheemun maintenance, plan, castle restoration plan, village inside the castle, village outside the castle and fashion art street. Contents to vitalize space has a meaning as a specific developmen method of urban restoration, and we can expect to be used as a direction to develop the area to enhance the cultural quality of life of both inhabitants and visitors by forming the brand identity of surrounding area with traditional cultural heritage.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.569-577
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• 2023

This study selected seven carbon-neutral villages, considering the characteristics of each region, including all five administrative districts of Changwon City, and proposed activation plans based on business evaluations through surveys of local residents and FGIs with leaders. The analysis showed that carbon-neutral education was the most important factor for activating carbon-neutral villages, with a response rate of 91.9% for 17 multiple-choice questions, followed by legal (ordinance) arrangements at 79.3% and village organization building at 74.1%. Based on this, the following activation plans through the participation of residents who are involved in the project of creating a carbon-neutral village in Changwon City were proposed. First, the characteristics of each carbon-neutral village model were classified into a resource circulation-based model, an environmental creation-based model, an environmental education and experience event-based model, and an energy efficiency-based model. Second, it is necessary to create and present carbon-neutral village growth stage guidelines for the growth of carbon-neutral villages. Third, manuals and teaching materials related to carbon neutrality, such as theories, issues, and practices, need to be produced and distributed for leaders and activists to easily apply and access for self-government operation of the village. Finally, if a carbon-neutral support center that is legally installable in Changwon City is established, it is expected that the lives of local residents will become more sustainable for carbon-neutral living in preparation for climate crises.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.2
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• pp.25-32
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• 2023

In this study, a double wall system is introduced, which was invented to simplify the complicated manufacturing process of the existing precast concrete (PC) double wall systems and to remove defects such as laitance that may occur during the production of concrete panels. An experimental study was conducted to investigate the tensile resisting capacity of the steel tube which is embedded in the precast concrete panel to keep the spacing between PC panels and to prevent damage of the PC panels during transportation and casting concrete onsite. The experiment was planned to determine the detail of effective steel tube connection considering the steel plate treatment method according to the formation of the opening, the presence of embedded concrete, and the reinforcement welding for additional dowel action as key variables. As a result, the ultimate tensile strength increased by 20-30% compared to the control specimen (ST) except for the steel tube specimen (ST_CP) which has steel plates bent inward at the end part of the steel tube. Since the specimen (ST_CON) filled with concrete inside the control specimen has no additional process and cost for the steel tube connections compared to the control specimen during the production of the developed double wall system, it is determined to be the appropriate detail of steel tube connection.