• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.198-202
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• 2011

과거의 하천은 이 치수에 주목적을 두고 하천정비를 실시하였으며, 이 때문에 하천은 직선화되거나 하천구조물을 설치하여 원래의 고유한 특성을 상실한 채 자연적인 모습을 찾아보기 어려운 상황에 이르렀다. 과거와 같은 하천의 난개발은 하천 생태계를 교란하였으며, 하천을 서식처로 삼고 살아가던 많은 동식물이 하천환경의 변화와 파괴로 인해 사라졌거나 생존을 위협받고 있다. 그러나, 최근에는 이러한 하천환경을 과거와 같이 생물의 종다양성이 풍부한 곳으로 만들기 위한 노력이 하천 개발과정에서 다양하게 전개되고 있으며, 이를 위한 연구도 진행되고 있다. 본 연구에서는 하천환경에서 어류의 서식처 보전을 위한 하천유지유량을 산정하기 위해 2차원 생태모델인 River2D 모형을 섬진강 송정지점을 대상으로 하여 적용하였다. 모형의 적용을 위해 송정지점에서의 대표어종을 선정하였으며, 서식처 특성 파악을 위해 하천 수리 및 하도특성을 조사하였다. 조사된 결과를 이용하여 River2D 모형을 구축하였으며, 구축된 모형을 이용하여 송정구간에서 대표어종인 피라미와 갈겨니의 서식처 보전을 위한 생태학적 하천유지유량을 추정하였다. 생태학적 하천유지유량은 모델의 결과와 실제 도입 가능수량 등을 검토하여 최종적인 하천유지를 결정하였으며, 그 결과 송정구간은 $7.0\;m^3/s$이상으로 산정되었다. 본 연구에서는 미시서식처 모형에 의해 생태유지유량을 산정하였으나, 진정한 의미의 생태학적하천유지유량은 수리수문학적 특성뿐만 아니라 생화학적 특성을 고려한 거식적인 관점에서 검토하여야 할 것이다.

• Polymer(Korea)
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• v.30 no.1
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• pp.50-55
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• 2006

When the monodisperse polystyrene(PS)/HDDA polymer particles were synthesized via one-step polymerization using polystyrene seed particles by dispersion polymerization, the effects of 1) the molecular weight of seed polymer particles, 2) the ratio of the absorbed HDDA to the seed polymer particles (swelling ratio) and 3) seeded polymerization rate on the surface morphology of PS/HDDA polymer particles were investigated. It was observed that the creation of the crater shaped defect on the surface of PS/HDDA polymer particles was irrespective of the molecular weight of seed polymer ant swelling ratio. But its surface morphology could be controlled by the change of the seeded polymerization rate.

• Polymer(Korea)
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• v.27 no.6
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• pp.603-608
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• 2003

Syndiotactic polystyrene (s-PS) presents a very complex polymorphic behavior depending on the sample preparation history and exhibits a solid-solid phase transition. Each different polymorphic structures of the s-PS sample were prepared by annealing the samples from room temperature to 220 $^{\circ}C$. The structural changes induced by annealing were investigated using FTIR and FT-Raman spectroscopy. Although the crystallization kinetics of s-PS are difficult to investigate with DSC due to its fast crystallization rate, it was possible to determine crystallinity changes in the s-PS sample using infrared characteristic peaks with Beer-Lambert's law.

• Analytical Science and Technology
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• v.21 no.5
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• pp.392-396
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• 2008

Acer tegmentosum is a tree used to treat various liver diseases in Korea. There have been some concern regarding the safety of Acer tegmentosum due to some toxic chemical compounds in its stems. Supercritical fluid extraction (SFE) was employed to develop a removing method of toxic compounds from Acer tegmentosum. The toxic compounds were effectively extracted with ethanol modified supercritical fluid $CO_2$. The optimum condition of SFE was 100 bar of pressure, $40^{\circ}C$ of extraction temperature, 3 mL/min of $CO_2$ flow rate, 0.2 mL/min of modifier (ethanol) flow rate.

• Journal of English Language & Literature
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• v.56 no.5
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• pp.773-796
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• 2010

This essay examines, first, the possibility and limitation of Asian America as a category of identity and its political and cultural implications through various theoretical perspectives. Here, by closely reading David Mura's poem "The Colors of Desire," I will argue that "Asian America" as a category of identity is now on the verge of falling apart and its politics of identity is no longer an effective way of fighting back against racism in the US. It is because Asian America is indeed what might be called a historical block, a product of ad-hoc coalition between different ethnic groups historically situated and constructed. In this sense, it is a kind of phantasmal object that is marked by practical absence. This fabricatedness inherent in Asian America as an identity category signifies that it has no essence that is meant to define the group in a transcendental way. The internal totality and coherence of that identity can thus be achieved only by suppressing differences between various ethnic groups and positing a single 'authentic' Asian American identity and culture. More dangerously, according to Viet Nguyen, such idealization of a single subject position can reinforces ideological rigidity that might threaten the ability of Asian America to represent itself in a unified fashion. Then, he predicts, Asian America will lose its cohesive force and fall apart. Eventually, every group within Asian America will be ethnicized. The only way of escaping from this bleak situation, as Vincent Cheng argues, is to foregroud the fabricatedness and ad-hocness of Asian America and to perform "inauthenticity," because Asian America is nothing but a functional category that is marked by absence of essence or authenticity. If Asian Americans admit that they have no essence and that they are essentially inauthentic, the practice of performing inauthenticity can become what we might call an alternative Asian American culture and identity.

• (The)Study of the Eastern Classic
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• no.68
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• pp.35-67
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• 2017

This paper examines the petition to the king of Doam(陶菴) Leejae(李縡), one of the key figures of 18th century. He wrote a total of 49 he petition to the king, mostly resignation petition to the king. He emphasized the genuine feelings and emphasized the accurate persuasion logic when he was writing a petition to the king. It is not contradictory to these elements, looking at his actual situation he wrote. He wrote the resignation petition to the king three times to resign Daejehak (大提學), he changed his persuasion logic in each of the resignation petition to the king. We can look at the aspect of transforming persuasion logic on the same topic. His resignation petition to the king, for the first time, was particularly well structured in terms of composition, and used a proper accent method. His resignation petition to the king has the beautiful literary art of gomun(古文), such as the expression of the so-called munjongjasoon(文從字順) and the composition of paragraph organically corresponding. The best work of his resignation petition to the king is Maneonso(萬言疏). The contents criticized Yeongjo(英祖)'s tangpyeongchaek(蕩平策) while evaluating Sinimoksa(辛壬獄事). It consists of a total of 5,300 letters. This work repeatedly used the irony, the method of seolui(設疑), and the incremental method to criticize the tangpyeongchaek(蕩平策), and put Yeongjo(英祖)'s position to the corner. This work is an example of other the resignation petition to the king.

• Resources Recycling
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• v.15 no.2 s.70
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• pp.18-23
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• 2006

Foaming of slag is a thermodynamically unstable phenomenon and has significant effects in iron and steelmaking processes. For better recycling method of pulp sludge, the application as an defoaming agent during steelmaking process was adopted and tested. The forming machine has been modified in order to produce the briquettes, which are made of pulp sludge and slag with different weight ratio. Influencing factors on the foaming phenomena have been studied and tested for better understanding of foaming phenomena. Experiments were carried out with $CaO-FeO-SiO_2$ based slags with Ar gas injection and addition of coke particles. The slag basicity and (%FeO) contents adapted as major factors to treasure foaming tendency of the slag system. It was found that foam index (${\Sigma}$) gradually decreased as both the basicity and the (FeO) content increase. Four kinds of antifoaming agent such as aluminium dross, cokes, rice bran and pulp sludge with steelmaking slag have been tested in actual process. Aluminium dross was the most effective, and pulp sludge with steelmaking slag also showed the desired results.

• Journal of the Korean association of regional geographers
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• v.8 no.3
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• pp.326-346
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• 2002

This study examined how the tradition and culture based on the historical experience of the region are regenerated on the making regional identity and symbolic representation in Kurim-ri, Youngam. Kurim has represented the most typical community of the aristocratic class through Daedong-gae of 400 years. But, since 1970's Kurim has undergone a rapid change in regional identity in Kurim ; from the beginning of the spot of Wangin festival to the village of earthenware, the village of pottery culture heritage most recently. The process of history-making around Wangin in Kurim was connected with the strategy of the pottery culture village-making centering around the Youngam Pottery Culture Center. These projects ultimately were resulted in expression the regional identity, 'Kurim of Wang-in'. The regional tradition of Daedong-gae and Wangin in Kurim was linked together solidly through the Wangin festival procedures. And the excavation of a kiln site in Kurim which was going on with the process of history-making at the same time around Wangin in Kurim provided the cultural episode on related 'earthenware' with an archeological foundation. As a consequence of these, the cultural space, the Young-am Pottery Culture Center has came to establish in Kurim finally. However, recently the Kurim of Wangin and Daedong-gae which was representative of regional identity in Kurim is bringing Dosun who was distorted and estranged during the history-making focused on Wangin in Kurim. Now, there are some cultural issues in Kurim ; an authentical settlement of the Youngam Pottery Culture Center in Kurim and how Wangin and Dosun is linked together into the cultural strategy of 'the traditional village, Kurim'.

• (The) Research of the performance art and culture
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• no.18
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• pp.379-412
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• 2009

According to "Jinjak-yigwe(進爵儀軌)", a special banquet was held at Yungyungdang(演慶堂, a kind of royal theatre) to celebrate the 40th birthday of Queen Soonwon(純元王后) in 1828. This banquet is famous for the presentation of nineteen new Jungjae(呈才) repertoires that the Crown Prince Hyomyung(孝明) created. In order to explore the theoretical basis for the reproduction and presentation of Yungyungdang(演慶堂) Jinjak(進爵, a type of royal banquets), in this article, the imagination and experience of the presentation of Yungyungdang Jinjak are pursued, while focussing on audience's reception. In Yungyungdang Jinjak, King Soonjo(純祖), Queen Soonwon and the prince were the special audience; they participated in the procedure of Ye(禮, etiquette of ceremony) and also were considered as the characters of certain repertoire of Jungjae. Hyomyung arranged the spectacles from the myths of Taoist gods and immortal hermits, as well as historic episodes of the past emperors' elegant tastes of music. These mythic and historic images lead the audience toward the imagination and experience on the transcendental world. Hyomyung, managing the administration as the representative of King Soonjo, tried to show absolute royal authority through the splendid performances of Yungyungdang Jinjak, so as to overcome the politicaly difficult situation. He set up the sacred world for his father King Soonjo, distinct from the secular ordinary world, and emphasized his position as the bridge between the two sides. He expressed his filial duty through the devotion of performing arts to display absolute royal authority.

• The Mathematical Education
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• v.62 no.3
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• pp.381-400
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• 2023

As the era of solving various and complex problems in the real world using artificial intelligence and big data appears, problem-solving competencies that can solve realistic problems through a mathematical approach are required. In fact, the 2015 revised mathematics curriculum and the 2022 revised mathematics curriculum emphasize mathematical modeling as an activity and competency to solve real-world problems. However, the real-world problems presented in domestic and international textbooks have a high proportion of artificial problems that rarely occur in real-world. Accordingly, domestic and international countries are paying attention to the reality of mathematical modeling tasks and suggesting the need for authentic tasks that reflect students' daily lives. However, not only did previous studies focus on theoretical proposals for reality, but studies analyzing teachers' perceptions of reality and their competency to reflect reality in the task are insufficient. Accordingly, this study aims to analyze in-service mathematics teachers' perception of reality among the characteristics of tasks for mathematical modeling and the in-service mathematics teachers' competency for designing the mathematical modeling tasks. First of all, five criteria for satisfying the reality were established by analyzing literatures. Afterward, teacher training was conducted under the theme of mathematical modeling. Pre- and post-surveys for 41 in-service mathematics teachers who participated in the teacher training was conducted to confirm changes in perception of reality. The pre- and post- surveys provided a task that did not reflect reality, and in-service mathematics teachers determined whether the task given in surveys reflected reality and selected one reason for the judgment among five criteria for reality. Afterwards, frequency analysis was conducted by coding the results of the survey answered by in-service mathematics teachers in the pre- and post- survey, and frequencies were compared to confirm in-service mathematics teachers' perception changes on reality. In addition, the mathematical modeling tasks designed by in-service teachers were evaluated with the criteria for reality to confirm the teachers' competency for designing mathematical modeling tasks reflecting the reality. As a result, it was shown that in-service mathematics teachers changed from insufficient perception that only considers fragmentary criterion for reality to perceptions that consider all the five criteria of reality. In particular, as a result of analyzing the basis for judgment among in-service mathematics teachers whose judgment on reality was reversed in the pre- and post-survey, changes in the perception of in-service mathematics teachers was confirmed, who did not consider certain criteria as a criterion for reality in the pre-survey, but considered them as a criterion for reality in the post-survey. In addition, as a result of evaluating the tasks designed by in-service mathematics teachers for mathematical modeling, in-service mathematics teachers showed the competency to reflect reality in their tasks. However, among the five criteria for reality, the criterion for "situations that can occur in students' daily lives," "need to solve the task," and "require conclusions in a real-world situation" were relatively less reflected. In addition, it was found that the proportion of teachers with low task development competencies was higher in the teacher group who could not make the right judgment than in the teacher group who could make the right judgment on the reality of the task. Based on the results of these studies, this study provides implications for teacher education to enable mathematics teachers to apply mathematical modeling lesson in their classes.