• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.152-160
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• 2021

Converter steel slag(BOF slag) is a vast amount of solid waste generated in the steelmaking process which has very low utilization rate in Korea. Due to the presence of free CaO which can derive bad volume stability in BOF slag, it usually land filled. For recycling BOF and identify its applicability as fine aggregate, this study investigates the fundamental characteristics of mortar with cement replaced ferronickel slag(FNS), which has the potential to be used as a binder. The results suggest that the mineral phases of BOF slag mainly include larnite(CaSiO₄), mayenite(Ca₁₂Al₁₄O₃₃) and wuestite(FeO) while olivine crystallines are shown in FNS. The results of flow and setting time reveals that the flowability and process of hardening increased when the amount of FNS and BOF slag incorporated was increased. The length change shows that the amount of change in the length of the mortar was almost constant regardless of mix proportion while compressive strength was reduced. Micro structure test results revealed that FNS or/and BOF slag mix took a long time to react in the cement matrix to form a complete hydration products. To achieve the efficient utilization of B OF slag as construction materials, proper replacement rate is necessary.

• Korean Journal of Heritage: History & Science
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• v.47 no.3
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• pp.160-171
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• 2014

The provision of support for the art of making these items needs to be considered with the focus on the following factors: the local situation of the areas where such traditional handicrafts are still made, the craftspeople involved in their production, and their communities. So far, discussion about how to reinvigorate traditional handicrafts, including those mentioned above, has been concentrated on the measures taken to promote them as part of the handicrafts industry and the allocation of the government's budget for important intangible cultural heritages. The government runs a traditional handicrafts management system and provides financial support for the craftspeople and spaces for exhibiting their work. This form of support has led to systematic management of traditional handicrafts and heightened public interest in cultural heritage, as well as publicizing the country's traditional crafts, but has made little progress in the following areas: the fostering of young people willing to learn traditional skills, diversification of the types of skills to be maintained, or establishment of the networks of collaboration among the craftspeople. The most important aspect among the efforts mentioned above is to maintain cultural traditions that are unique to each region by encouraging local craftspeople to engage in their work with a solid sense of pride backed up by financial support. This study was carried out in connection with the need to reinvigorate the art of making tanggeon (horsehair crown), manggeon (horsehair headband), and gat (black horsehair hat), which few people wear as they are used only for ornamental purposes nowadays. This study examined the circumstances surrounding the artisans engaged in the production of horsehair handicrafts prior to their designation as a cultural heritage, and the changes that occurred in the local communities associated with their production after the designation, in order to assess the status of inheritance of this tradition.

• Journal of Korea Port Economic Association
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• v.35 no.2
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• pp.109-126
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• 2019

The Panmunjom Declaration adopted by the leaders of South and North Korea on April 27, 2018, has created an environment conducive for peace and cooperation in the Korean Peninsula. In the June of last year, South Korea has joined the Organization for Cooperation between Railways (OSJD). The membership of OSJD has established a solid foundation for restoring a multimodal logistics system that connects the Korean peninsula to Eurasia countries, including China and Russia. In this paper, a questionnaire survey targeting working-level experts was conducted to find the barriers in constructing multimodal logistics that efficiently connect the port-continental railways of the Korean peninsula and the Eurasian nations. Survey items were divided into five categories-border crossing procedures, technology, facilities, operation, and government support. As a result, among the most important problems of international multimodal logistics in Eurasia that need to be solved on priority include improving transshipment facilities, eliminating inspection carried out at every country for transit, simplifying documents for customs clearance, and minimizing the changes in freight rates. In conclusion, for vitalizing the connection between the Korean peninsula and the continental railways, it is necessary to develop a transshipment system to facilitate the changes in tracks at the borders by making a joint effort with the international community. Second, railway and operational systems in South Korea, North Korea, China, and Russia should be standardized. Third, international cooperation among South Korea, North Korea, China, and Russia is essential for simplifying customs clearance at borders, priority departure of domestic cargo, sharing information about the changes in freight rates, and so on. Finally, the government should come up with measures to secure the quantity of cargo required to form block trains, while developing new business models.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.2
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• pp.71-79
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• 2021

In this study, we have successfully fabricated the Sn-Ni paste and evaluated the bonding properties for high-temperature endurable EV (Electric Vehicle) power module applications. From evaluating of the micro-structural changes in the TLPS (Transient Liquid Phase Sintering) joints with Sn and Ni contents in the Sn-Ni pastes, a lack of Ni powders and Ni particle agglomerations by Ni surplus were observed in the Sn-20Ni and Sn-50Ni joints (in wt.%), respectively. In contrast, relatively dense microstructures are observed in the Sn-30Ni and Sn-40Ni TLPS joints. From differential scanning calorimetry (DSC) thermal analysis results of the fabricated Sn-Ni paste and TLPS bonded joints, we confirmed that the complete reactions of Sn with Ni to form Ni-Sn intermetallic compounds (IMCs) at bonding temperatures occurred, and there is no remaining Sn in the joints after TLPS bonding. In addition, the interfacial reactions and IMC phase changes of the Sn-30Ni joints under various bonding temperatures were reported, and their mechanical shear strength were investigated. The TLPS bonded joints were mainly composed of residual Ni particles and Ni₃Sn₄ intermetallic phase. The average shear strength tended to increase with increasing bonding temperature. Our results indicated a high shear strength value of approximately 30 MPa at a bonding temperature of 270 ℃ and a bonding time of 30 min.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.3
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• pp.12-21
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• 2011

We investigated the location and surveillance system of fortress using inter-visibility analysis between fortress and the capital of the Silla Dynasty. The digital terrain model(DTM) was generated with $10{\times}10m$ grid in Arcview 3.2. Then three fortresses lines(Myeonghwal-sanseong, Namsan-shinseong, Seohyeong-sanseong) were superimposed on the DTM. 4 results of this study were drew out from the cumulative visibility analysis. First, the most of fortress lines which showed the high visible frequency from the Sila-Capital(538 viewpoints) have a good aspect toward the capital. It means that 3 fortresses secured the visibility to the capital. Second, the cumulative visibility analysis from 3 fortresses generated evenly distributed visible frequency across the inside of fortress. It shows that the inner area of fortress is more advantageous to command during the war. On the contrary, a number of invisible(vulnerable) regions which is scattered on the outside were supplemented by adjacent fortress. Third, the north area of the Sila-captial showed the highest visible frequency generated by sum up the visibility from 3 fortresses. The northern captial is placed within 4km distance easy to support at the Myeonghwal and Seohyeong-sanseong. We proved that the Sila-capital had organized a solid surveillance system by 3 fortresses. Fourth, we could infer the practical process of fortress layout from comparing a cumulative visibility map. For the secure of visibility and defense systems, the fortress line would form a rising shape to the peak. This practical location theory can replace the vague common location theory that the fortress would constructed on two thirds of mountain height. It will be an empirical method in the ancient remains research.

• Resources Recycling
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• v.30 no.4
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• pp.27-34
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• 2021

In this study, the leaching behavior of vanadium (V) was investigated through CaO roasting and sulfuric acid leaching from domestic V-bearing titanomagnetite (VTM). Changes in the phase according to the amount of CaO added and roasting temperature were analyzed. Regardless of the roasting conditions, perovskite (CaTiO₃) was preferred to form. When the CaO content was increased, the calcium ferrite (CaFeO_x) phase was formed; otherwise, ferrite (Fe₂O₃) was preferred. After CaO was roasted, leaching was performed for 6 h with 1M sulfuric acid at 50℃ and a 10% solid-liquid ratio. Results of leaching revealed that when the roasted product was sintered, V was not sufficiently oxidized, and the leaching efficiency decreased. In addition, when the roasting temperature was low, the leaching efficiency of V decreased due to the influence of unreacted excess CaO. To lower the leaching efficiency of iron and titanium in VTM concentrates, suppressing the formation of CaTiO₃ and CaFeO_x was necessary by minimizing the amount of CaO added. Consequently, a leaching efficiency of 86% V, 4.3% Fe, and 6.5% Ti was obtained when the roasted product of 1150℃ and 10 wt% CaO was leached.

• Journal of Christian Education in Korea
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• v.68
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• pp.279-306
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• 2021

This paper intends to say that children's worship as a liturgy for children living in modern society is an important place to support children's personal development and experience of coziness necessary for their personal development. To this end, this thesis first regards modern society as an unstable society, analyzes fluid society and individualism as the causes, and deals with changes in educational style accordingly. In a fluid society, children are not provided with a solid form and lasting environment that supports personality development, and the education style changed under the influence of individualism and pluralism requires a heavy task of determining the direction of one's life and constantly making choices and decisions. Therefore, children need rules and forms that help them live together, and they need a space that can give them comfort that helps them develop their personality. As an argument for this, second, this paper deals with the concept and function of the liturgy in order to understand the worship of children as the liturgy. The third deals with the elements necessary for the development of children's personality that can be experienced in children's worship. First, it deals with the meaning of religious, aesthetic, and communal driving forces that children can experience in children's worship, focusing on Eberhard's research. In addition, it deals with the meaning of language and expression methods provided in children's worship, and finally, it says that children's worship can be a space where you can experience stability and coziness. Through this, it is emphasized that children's worship can play an important role in supporting the personal development of children living in modern times.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.3
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• pp.477-496
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• 2017

A drastic development of modern cities and transportation means as part of a rapid industrialization and urbanization for the past half-century has consistently broaden the boundaries of urban dwellers while, at the same time, raising issues as to establishing relationships among them throughout the society following the materialization of modern urban planning. Within the framework of the postmodern concept, there have been consistent efforts to create a community space in appropriate size and, in particular, the concept of New Urbanism and Urban Village that emerged in mid 1800s along with the effort to build a community by building an ideal city provides an important meaning today when people are seeking to restore a healthy community. Against this backdrop, this study aims to explore the concept of community and to determine its optimal scope of implementation in the sense of healing environment under the premise that organizing a healthy city is based on building a solid urban community. The study findings and conclusions are as follows. First, a community is a subject of constant consideration in the process of historical development of the city and has required us to take a variety of strategic approaches and to determine the scope of implementation. Second, the activities of a healthy community have been conducted under various types of environments, including churches, commercial facilities, urban plazas, parks, and streets in various scales, reflecting their unique characteristics. Third, in the process of designing a healthy and sustainable city, determination of location carries significant implications along with building a community of appropriate size, which requires multidisciplinary considerations in addition to functional approaches. Fourth, the composition and design of a modern urban community need to seek practical ways of its implementation within the concept of healing environment.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.38-53
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• 2022

In this article, I have summarized and reviewed the concepts and terms surrounding the stamped construction technique, focusing on earthen walls in the Three Kingdoms period. This is because confusion is caused by defining the nature of the earthen walls by using various concepts and terms for each researcher regarding the substance and construction method of the earthen walls. The stamped earth method is a representative ancient civil engineering or construction technique in which a frame is made of plates to form a fortress wall, a fence, and the base of a building, and then soil or sand is poured into it layer by layer and then stamped with a bat to make it solid. Therefore, in order to prove that the earthen wall was built by the stamped earth method, evidence such as a narrow plate, a column for fixing it, long horizontal and vertical wood pieces to support the narrow plate, and traces of pounding the soil must be detected. However, in Korea, there are very few cases where such evidence has been fully excavated, so it is necessary to agree on how strictly the standards for the stamped earth method will be applied. The terms related to the stamped technique mobilized for the construction of the earthen walls were explained with actual examples by dividing the terms related to the concept into terms related to the principle and unit of the stamped plate, and the specific stamped technology. In particular, in Pungnabtoseong Earthen wall, a variety of typical and diverse methods of building the ancient stamped earthen wall were identified so that decisive data could be secured to understand the principles and techniques of the stamped earthen wall. In the future, a more general understanding of the stamped technique will be possible only when more evidence related to it is found in relics other than Pungnabtoseong Earthen wall.

• Journal of The Korean Association For Science Education
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• v.27 no.4
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• pp.337-345
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• 2007

The purposes of this study are to investigate and compare the characteristics of classification criteria of secondary school students and science teachers in relation to the three statesof matter. For this research, 76 middle school students in the7th grade who studied microscopic viewpoints about classifying the state of matter for the first time, 69 high school students in the 12th grade who studied Chemistry I and IIcourses successfully, and 130 secondary school science teachers, through a questionnaire. As a result, while having learned the three states of matter in the microscopic viewpoints, the majority of middle school students showed a high percentage of classification in the macroscopic viewpoints. For high school students, their percentage of classification included highmicroscopic viewpoints about solid and gas, the percentage of classification included macroscopic viewpoints about liquid state as alsohigh. The secondary school teachers gave answers in the macroscopic viewpoints and microscopic viewpoints equally, but their answers were just representation of the viewpoints list without the meaningful connection of the two type of viewpoints. To solve these problems, It is necessary to form connective change from the macroscopic viewpoints to the microscopic viewpoints about the criteria for classifying the States of Matter and various educational efforts.