• 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.

• Knowledge Management Research
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• v.24 no.1
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• pp.245-271
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• 2023

The change to the data economy requires a new analysis beyond ordinary research in the management field. Data matching refers to a technique or processing method that combines data sets collected from different samples with the same population. In this study, statistical matching was performed using random hotdeck and Mahalanobis distance functions using 2020 Survey of Korea Venture Firms and 2020 Korea Innovation Survey datas. Among the variables used for statistical matching simulation, the industry and the number of workers were set to be completely consistent, and region, business power, listed market, and sales were set as common variables. Simulation verification was confirmed by mean test and kernel density. As a result of the analysis, it was confirmed that statistical matching was appropriate because there was a difference in the average test, but a similar pattern was shown in the kernel density. This result attempted to expand the spectrum of the research method by experimenting with a data matching research methodology that has not been sufficiently attempted in the management field, and suggests implications in terms of data utilization and diversity.

• 한국체육학회지인문사회과학편
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• v.54 no.5
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• pp.867-876
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• 2015

This study was intended to closely examine an effect that the level of physically challenged person's participation in community sports had on positive psychological capital. In order to accomplish the purpose of study, data on 212 physically challenged persons who lived in B city and participated in community sports were analyzed. Korean version of positive psychological capital created by Taehong Lim (2014) through the reconstruction of scales developed by Luthans, Youssef and Avolio(2007) and Sangwan Jeon and Jonghun Yang's (2009) level of participation in community sports was reconstructed through modification·improvement as measurement instrument. An exploratory factor analysis, reliability test, paired difference test, and multiple regression analysis was carried out by using SPSS 18.0 program for data processing. First, It was shown that there was a significant difference in positive psychological capital according to gender, age, and disability grade among physically challenged persons' socio-demographic characteristics. Second, it was shown that, among sub-variables (period, frequency and intensity) of level of physically challenged persons' participation in community sports, the frequency of participation and the intensity of participation had a significant effect on self efficacy. On the other hand, it was shown that the period of participation didn't have a significant effect. Third, it was shown that the frequency of participation had a significant effect on optimism. On the other hand, it was shown that the period of participation and the intensity of participation didn't have a significant effect. Fourth, it was shown that the frequency of participation and the intensity of participation had a significant effect on hope. On the other hand, it was shown that no significant effect was produced on the period of participation. Fifth, it was shown that the frequency of participation had a significant effect on resilience. On the other hand, it was shown that no significant effect was produced on the period of participation and the intensity of participation. Sixth, it was shown that the frequency of participation and the intensity of participation had a significant effect on positive psychological capital. And it was shown that no significant effect was produced on the period of participation.

• Journal of Christian Education in Korea
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• v.74
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• pp.7-31
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• 2023

The climate crisis threatens Earth's ecosystems and biodiversity. In particular, it can be said that the cause of the global crisis began with human greed. An educational alternative is needed to change the Christian worldview that causes greed. The purpose of this study is to find ways to apply democratic citizenship education to Christian education as an alternative to overcome the climate crisis. The contents of the study to achieve the purpose were first the essence of Christian citizenship education was examined by dividing it into citizenship education, democratic citizenship education, and Christian citizenship education. Second, The model of democratic citizenship education was established by defining its goals, content, methods, and directions within the context of Christian citizenship education. Third, the application plan of Christian education for democratic citizenship education was classified into 7 categories and proposed; environmental education to overcome the climate crisis, ethical education to restore the public role of the church, education to form God's character, education to realize the village education community, education that promotes Christ's peace and Christ education that fosters consideration for multicultural individuals, and literacy education to prevent the negative impacts of digital media culture. Next, the plan to apply democratic citizenship education to Christian education is, first, to reduce human greed and restore God's creation order through environmental education that can overcome the climate crisis. Second, through ethics education to restore the church's public nature, it is necessary to restore the church's role for the church's moral empathy and publicity. Third, through the education that forms the God's character, it is necessary to form a mature character of faith in which personality and faith are harmonious and balanced. Fourth, schools, villages, and churches form a community through education that realizes a village education community so that the members of the village can obtain educational results. Fifth, through education that aims for the peace of the God Christians should be able to live as Christian democratic citizens who achieve peace in the kingdom of God. Sixth, through education that considers multicultural people, faith education that helps them overcome discrimination, exclusion, and hatred toward multicultural people with the love of Jesus Christ and seek a life of coexistence. Seventh, through literacy education that prevents the harmful effects of digital media culture, personal ability to read and write in media should ultimately be improved to the ability to practice socially.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.216-217
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• 2022

Gulpur 수력발전 프로젝트는 전력난을 겪고 있는 파키스탄에 102 MW 규모의 수력발전소를 건설하여 30년 동안 운영 관리한 후 파키스탄 정부로 양도하는 IPP(Independent Power Producing) 형식의 투자사업이다. 남동발전과 DL E&C, 롯데건설이 Sponsor로서 출자한 자본금과, ADB, IFC, K-EXIM 등의 대주단로부터의 차입금을 재원으로 하여 소요 사업비를 조달하고 사업을 개발하였다. DL E&C와 롯데건설이 EPC(Engineering, Procurement, Construction)를 수행하였고, 이산이 Design consultant의 역할을 수행하였다. Gulpur 수력발전 프로젝트의 발전형식은 수로식(run-of-river)으로 201 m³/s의 발전유량과 102 MW의 발전 시설용량을 이용하여 연평균예상발전량은 398 GWh이다. 주요 구조물로는 설계 재현빈도 1년의 유수전환시설(가물막이댐 & 가배수터널)과 콘크리트 중력식댐(H 67 m, L 205 m), 도수터널(D 6.7 m, L 215 m, 2기), 옥외형 발전소 (H 51 m, W 60 m, L 38 m, Kaplan 2기)가 있으며, 2015년 10월 착공하여 2020년 3월 상업발전을 시작하였다. 본 프로젝트는 DL E&C의 첫 번째 EPC 해외수력발전 프로젝트이다. 따라서 프로젝트의 성공적 수행을 위한 경제적 설계, 시공의 효율성 및 안정성 확보 등을 위하여 많은 연구를 수행하는 과정에서 다양한 기술 개선을 이룰 수 있었다. 본고에서는 Gulpur 프로젝트를 통하여 도출된 성공 사례들을 소개 및 공유하고자 한다. 첫 번째로 콘크리트 중력식댐 시공을 위한 유수전환시설의 최적 설계빈도를 산정하였다. 일반적으로 유수전환시설의 규모는 설계기준에 제시된 설계 재현빈도를 이용하는데, 해외 설계기준에서는 10년, 국내 설계기준에서는 1~2년으로 다르게 제시되어 있는 문제점이 있다. 유수전환시설의 규모는 프로젝트의 경제성에 큰 영향을 미치기 때문에 최적 설계빈도의 결정이 필요하며, 위험도분석기법(Risk Analysis)과 기대화폐가치법(Expected Monetary Value)을 이용하여 유수전환시설의 최적 설계 재현빈도와 이에 영향을 미치는 인자를 분석하였다. 위험도는 몬테카를로 시뮬레이션으로 산정된 가물막이댐 파괴확률과 재현빈도를 이용하여 산정된 가물막이댐 월류확률을 고려하였으며, 비용 및 피해액으로는 유수전환시설의 공사비, 가물막이댐 파괴시의 재건설비용과 지체보상금, 가물막이댐 월류시의 복구비용을 고려하였다. 이에 대한 연구결과로, 유수전환시설의 사용기간과 월류시의 복구비용이 유수전환시설의 설계 재현기간 결정에 가장 큰 영향을 미치는 것으로 나타났고, 특히 월류시의 복구비용이 작을수록 낮은 설계 재현빈도를 선택하는 것이 타당한 것으로 나타났다. 예를 들어, 유수전환시설의 사용기간이 3 ~ 5년, 복구비용이 0.5 ~ 1.0 mil USD 이하인 조건에서 가물막이시설의 최적 설계빈도는 1년 ~ 2년인 것으로 나타났다. 또한, 유수전환시설의 사용기간은 본댐의 규모와 시공기간 등을 고려하여 결정되는 사항으로 설계자가 임의 조정할 수 없지만, 복구비용은 시공 관리자에 따라 결정되는 부분으로, 적극적 홍수 피해 저감 및 복구방안을 마련하는 것이 프로젝트의 경제성을 향상시킬 수 있다는 것을 알 수 있었다. 두 번째로 프로젝트의 경제성 향상, 홍수기 댐 시공시의 안전성 확보를 위하여 홍수 조기경보시스템(Early Warning System)을 개발 및 활용하였다. 수로식(Run-of-river) 수력발전댐은 대부분 산악지역에 위치하기 때문에 국지성 강우 및 급한 지형 경사로 인하여 돌발홍수(flash flood)의 발생 가능성이 높다. 따라서 시공 중 홍수(월류) 발생을 미리 감지하고 현장에 전파할 수 있는, 수로식(Run-of-river) 수력발전댐 현장을 위한 홍수 조기경보시스템이 필요하며, 이를 리스크 인식, 모니터링 및 경보, 전파 및 연락, 반응 능력 향상의 4가지 부분으로 나누어 구축하였다. 리스크 인식 부분에서는 가물막이댐 월류 발생 상황에 대한 위험도, 취약성, 리스크를 제시하였으며, 모니터링 및 경보 부분에서는 상류 측정수위에서 유도된 현장 예상수위와 실제 현장 측정 수위를 대상으로 경보홍수위와 위험홍수위로 나누어 관리하였다. 전파 및 연락 부분에서는 현장 시공 조직을 활용하여 홍수시를 대비한 비상연락체계도(Emergency communication flow chart)를 운영하였으며, 반응 능력 향상을 위해 비상연락체계도의 팀별 Action plan을 상세화 하였다. 세 번째로 현장의 지질특성과 50여 차례 발파시험으로 현장 고유의 발파진동감쇄곡선을 도출하였으며, 이를 통해 현장의 시공성과 콘크리트 품질 확보를 동시에 달성할 수 있는 방안을 제시하였다. 콘크리트댐 공사에서는 제한된 공기 내에 공사를 완료하기 위해 사면부 굴착과 콘크리트 타설이 동시에 수행될 수밖에 없는 문제점을 가지고 있다. 그러나 신규 콘크리트 타설면 근처에서 발파를 수행하는 경우 발파로 발생되는 탄성파가 일정 수준을 초과하게 되면, 콘크리트 양생에 영향을 주게 된다. 따라서 다수의 현장 발파시험을 통해 발파거리와 최대진동속도의 상관관계 즉, 발파진동감쇄곡선을 도출함으로써 현장의 발파진동특성을 도출할 수 있었다. 또한, 기존 연구 논문들을 통해 콘크리트 재령기간 별 안전진동속도를 선정하고, 해당 안전진동속도를 초과하지 않는 범위에서 콘크리트 타설면과 발파위치의 거리에 따라 1회 발파 가능한 장약량을 산정하여 적용하였다. 이와 같은 체계적인 접근을 통해 콘크리트 타설과 발파 작업 동시 수행에 대한 논란을 해소할 수 있었다.

• The Mathematical Education
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• v.61 no.2
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• pp.339-357
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• 2022

This study explores pre-service secondary mathematics teachers (PSTs)' noticing competency. 17 PSTs participated in this study as a part of the mathematics teaching method class. Individual PST's essays regarding the question 'what effective mathematics teaching would be?' that they discussed and wrote at the beginning of the course were collected as the first data. PSTs' written analysis of an expert teacher's teaching video, colleague PSTs' demo-teaching video, and own demo-teaching video were also collected and analyzed. Findings showed that most PSTs' noticing level improved as the class progressed and showed a pattern of focusing on each key aspect in terms of the Teaching for Robust Understanding of Mathematics (TRU Math) framework, but their reasoning strategies were somewhat varied. This suggests that the TRU Math framework can support PSTs to improve the competency of 'what to attend' among the noticing components. In addition, the instructional reasoning strategies imply that PSTs' noticing reasoning strategy was mostly related to their interpretation of noticing components, which should be also emphasized in the teacher education program.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.297-306
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• 2023

Saemangeum Lake is the largest artificial lake in Korea. The continuous deterioration of lake water quality necessitates the introduction of novel water quality management strategies. Therefore, this study aims to identify the spatiotemporal water quality characteristics of Saemangeum Lake using data from the National Water Quality Measurement Network and provide basic information for water quality management. In the water quality parameters of Saemangeum Lake, water temperature and total phosphorous content were correlated, and salt, total nitrogen content, pH, and chemical oxygen demand were significantly correlated. Other parameters showed a low correlation. The spatial principal component analysis of Saemangeum Lake showed the characteristics of its four zones. The mid-to-downstream section of the river affected by freshwater inflow showed a high nutrient salt concentration, and the deep-water section of the drainage gate and the lake affected by seawater showed a high salt concentration. Two types of water qualities were observed in the intermediate water area where river water and outer sea water were mixed: waters with relatively low salt and high chemical oxygen demand, and waters with relatively low salt and high pH concentration. In the principal component analysis by time, the water quality was divided into four groups based on the observation month. Group I occurred during May and June in late spring and early summer, Group II was in early spring (March-April) and late autumn (November-December), Group III was in winter (January-February), and Group IV was in summer (July-October) during high temperatures. The water quality characteristics of Saemangeum Lake were found to be affected by the inflow of the upper Mangyeong and Dongjin rivers, and the seawater through the Garuk and Shinshi gates installed in the Saemangeum Embankment. In order to achieve the target water quality of Saemangeum Lake, it is necessary to establish water quality management measures for Saemangeum Lake along with pollution source management measures in the upper basin.

• 한국노년학
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• v.29 no.4
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• pp.1539-1557
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• 2009

The purpose of this study was to analyze the effects of program's participation, self-esteem and depression on quality of life for the elderly participating social welfare using facilities. Therefore, this paper will help improve a life's quality of all the olds by fixing the problems we got in this society and suggesting the better program for the elderly participating social welfare using facilities. The results of the study were as follows. There was no specific difference in statistic that shows the quality of the old's life who have their economic life. In quality of life in neighbors, the male were more friendly to their neighbors and the lower level of education, the higher quality of life. Healthy old people had greater quality of life than unhealthy old people did. If the old were excellent in scholarship, if unmarried couple shared the same house, if both of husband and wife live together when they are married, and if their allowance are full in pocket, the quality of their life was enhanced. Self-esteem influenced the quality of life in economic, but depression influenced negatively. In quality of life in neighbors, feeling depression and joining in program of a work for prosperity in future didn't effect doing well with the neighbors. On the other hand, participating in the social community program effected positively. In quality of life in neighbors, feeling depression and program of rehabilitation effected on the quality of life negatively. Educating refinement program effected positively being a good match, but promoting health program effected negatively.

• (The) Research of the performance art and culture
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• no.23
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• pp.347-368
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• 2011

This article is a review of the composition pattern of Suryukjae, which is one of the Buddhist ceremonies, and a consideration of the performance process. As one of the ceremonies leading the dead to heaven performed in the Buddhist circle, Suryukjae had been performed in Buddhist temples nationwide, but currently, it remains only in several Buddhist temples. Suryukjae is composed as follows. First, the early part of Suryukjae is a stage of preparing Suryukjae and ensuring legitimacy; thus, it has no detailed Jaecha except for Gwanyok. It is made up of Onghoge and Dage, has no Somun, and is centered on Yojabbara. The middle part of Suryukjae is a part in which Suryukjae is performed on a full-scale, which wishes the achievement of the goal of Suryukjae. It is made up of Geobul, Dage, and Somun, and is centered on Sadaranibara. Furthermore, this part delineates the flow of the Jaecha concerned as it contains detailed Jaecha. Meanwhile, in the middle part of Suryukjae, there is only detailed Jaecha called Sajadanman Bongsong (sending off), and the rest parts including Orodan, upper part, middle part, and lower part, in which there is no detailed Jaecha called Bongsong. The fact that there is no Bongsong in this part means all Bongsong is made in Heuihyang Bongsong, which is the last Jaecha. This implies that Saja, which is enshrined in Sajadan, is the essence of the achievement of the goal of Suryukjae. Only when there is Saja, Muju, Yuju, and Gohon (the meaning of all spirits) can be led to heaven. Also, from a rough perspective, this part is connected to other Chundojae (ceremony for sending off the dead to heaven) in Korea. There is a geori(Jaecha) that calls in Saja also in Jinogigut (exorcism) of Seoul. Then, although various gods from the otherworld are coming in in succession, to which Saja enters clearly shows a process in that Saja returns to the next world with the dead through . Just as demonstrates a process in that Saja returns to the next world with the dead in Jinogigut, also in Suryukjae, Saja needs to return to the next world with Gohon; therefore, at least Sajadan has detailed Jaecha called Bongsong. That is, this means that although Suryukjae of Buddhism is different from other Chundojae in terms of the composition of Jaecha, its notion about Saja is the same.

• Asia Marketing Journal
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• v.8 no.3
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• pp.41-74
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• 2006

It is frequently observed that consumers' behavior and performance in their weight control are greatly affected by the degree of self-control by the consumers themselves. In other words, effective weight control behavior is only possible when the consumers invest a substantial amount of endeavors and self-control. The present study empirically investigated the effect of the self-image congruence and subjective norm formed by self- concept reflected in weight control behavior on weight control attitude formation, actual behavior, and performance. For more in-depth research, rather than simply showing differences in performance based on self-control, the present study divided the subjects into high and low self-control groups for a comparative purpose. Based on empirical research employing general consumers and those who were engaged in an actual weight loss program at professional weight control centers as subjects, the study found the following results: First, for both high and low self-control groups, self-image congruence significantly affected attitude toward weight control, but not the actual weight control behavior. The results indicate that in weight control, the actual behavior must be preceded by the attitude. Second, subjective norm directly affected both attitude toward weight control, and behavior for the low self-control group while it affected the behavior only for the high self-control group. The results show that the lower self-control is, the more powerful the effect of referents is. Third, weight control attitude positively affected weight control behavior only for the high self-control group. Fourth, weight control behavior significantly affected the performance for both high and low self-control groups. Compared to the low group, the high self-control group showed more powerful effect of behavior, suggesting the crucial role of self-control in successful weight control. The results also imply that the role of referents is relatively more important for the low self-control group.