• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1151-1158
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• 2011

In this study, a galactooligosaccharide (GOS) was synthesized using active ${\beta}$-galactosidase (${\beta}$-gal) inclusion bodies (IBs)-containing Escherichia coli (E. coli) cells. Analysis by MALDI-TOF (matrix-assisted laser desorption/ionization-time of flight) mass spectrometry revealed that a trisaccharide was the major constituent of the synthesized GOS mixture. Additionally, the optimal pH, lactose concentration, amounts of E. coli ${\beta}$-gal IBs, and temperature for GOS synthesis were 7.5, 500 g/l, 3.2 U/ml, and $37^{\circ}C$, respectively. The total GOS yield from 500 g/l of lactose under these optimal conditions was about 32%, which corresponded to 160.4 g/l of GOS. Western blot analyses revealed that ${\beta}$-gal IBs were gradually destroyed during the reaction. In addition, when both the reaction mixture and E. coli ${\beta}$-gal hydrolysate were analyzed by high-performance thin-layer chromatography (HP-TLC), the trisaccharide was determined to be galactosyl lactose, indicating that a galactose moiety was most likely transferred to a lactose molecule during GOS synthesis. This GOS synthesis system might be useful for the synthesis of galactosylated drugs, which have recently received significant attention owing to the ability of the galactose molecules to improve the drugs solubility while decreasing their toxicity. ${\beta}$-Gal IB utilization is potentially a more convenient and economic approach to enzymatic GOS synthesis, since no enzyme purification steps after the transgalactosylation reaction would be required.

• 한국수자원학회논문집
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• 제38권6호
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• pp.505-515
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• 2005

본 논문에서는 두 가지 대표적인 하천수질모형을 비교${\cdot}$분석하였다. 정상상태 모형으로는 QUAL2E, 비정상상태 모형으로는 CE-QUAL-RIV1을 선택하여 동일한 반응계수 및 경계조건 하에서 두 모형의 계산결과를 서로 비교해 보았다. 각 모형에 대하여 수질변동을 계산하기 위해 적용된 방정식을 서로 비교하였으며, 두 가지 수질모형을 이용하여 대청댐 이하 금강본류의 수질을 모의하였다. 두 모형은 기본 알고리듬이 매우 유사하므로, 모형구축에 필요한 입력자료도 매우 비슷하였다. 정상상태로 모의한 경우에 대하여 두 모형의 결과값은 BOD와 DO, 및 $NH_3-N$의 경우에 대하여서는 매우 일치도가 높았다. 그러나 용존인과 같은 특정한 수질인자 항목은 상당한 차이가 있음을 확인하였다. 이러한 모의결과를 바탕으로 두 모형의 민감도 분석을 실시하였으며, 각 수질항목에 대해 지배적으로 작용하는 매개변수를 도표화하여 정리하였다.

• 비교문화연구
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• 제26권
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• pp.405-444
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• 2012

This paper is based on the view that film should be conceived as a form of cultural practice whose meaning is always in the process of being produced within diverse socio-cultural contexts and aims to examine the ways in which the meaning of Korean film is (re)mediated or received in diverse cultural contexts outside the country. In this paper, we employ two theoretical grounds. Firstly, it positions itself in line with the audience studies within the field of cultural studies where the audience is conceived as active agents who produce the meaning of a popular culture text. The recruitment of the theoretical propositions from the audience studies enables recognition of the significance of the reception in film practice which recently seems to be oriented on production and distribution. Secondly, we conceive transnationality of film as that which is being produced in the process of transaction between the film and the audience, that is to say, transnationality is a form of discourse that emerges upon cultural interaction. The empirical work involves examination of a set of reviews of four films--Chihwaseon, Oldboy, Thirt, Poety--that have been published in daily newspapers and some popular film magazines in the U. S., the U. K. and France. Through the analysis of the film reviews, we identify four interpretive schemes or rather discourses recruited via which the Korean films are approached and understood: auteurism, formalism, universal themes, emotional response. We propose that these four kinds of discourse provide a common ground for the audience from different cultural backgrounds to understand Korean film. Furthermore, we also suggest that transnationality of Korean cinema needs to be reconsidered in terms of the reception as the audience from different socio-cultural backgrounds should be understood as active agents who are capable of engaging in Korean cultural texts such as film in their own way producing various meanings and these are also constituent of the meaning of the cultural texts.

• 한국태양에너지학회 논문집
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• 제33권3호
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• pp.58-66
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• 2013

Recently, PV module that the most important part of the photovoltaic system is more widened to lower manufacturing costs for module. However, the broad PV module results to the serious mechanical damage corning from installation circumstances such as snow, wind etc of snow and finally lead to the dramatic degradation of the electrical behavior of PV module. In this paper, 3 kinds of PV modules that consist of the different thickness and area of front glass and the diverse cross sectional structures of the frame are prepared for this experiment. The drooped length and electrical outputs of the PV modules are measured by means of applying 600Pa mechanical load to the PV modules from 1200Pa to 5400Pa base on the mechanical load test procedure of K SC IEG 61215 standard. The simulation data are obtained by the simulation tool as ANSYS and those are validate by comparing with the those experimental results figure out relations between the deformation and the constituent part of PV module.

• 중환자간호학회지
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• 제12권2호
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• pp.39-49
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• 2019

Purpose : The purpose of this study was to identify the extent to which intensive care unit (ICU) nurses' perceptions of life-sustaining treatment decisions and "a good death" affect attitudes toward terminal care. Method : Participants included 109 ICU nurses from three university hospitals. Data were collected using structured questionnaires, and collected data were analyzed using a t-test, ANOVA, the $Scheff{\acute{e}}$ test, Pearson correlation coefficients, and a multiple regression analysis (SPSS 24.0 program). Results : Perceptions of life-sustaining treatment decisions and a sense of closeness (a constituent for the awareness of "a good death") were positively correlated with terminal care attitudes. The factors affecting terminal care attitudes were a clinical career in ICU (${\beta}=.20$, p =.035), a sense of closeness(${\beta}=.19$, p =.041), and the perception of a life-sustaining treatment decision (${\beta}=.22$, p =.017). This finding indicates that more than 10 years of experience in ICU, a greater sense of closeness, and a higher view of life-sustaining treatment decisions results in more positive attitudes toward terminal care. The explanatory power of these variables on terminal care attitudes was 14% (F=6.84, p < .001, Adj $R^2=.140$). Conclusion : A sense of closeness and the perception of life-sustaining treatment decisions were identified as the factors affecting terminal care attitudes. Thus, various programs must be developed to raise awareness among ICU nurses of "a good death" and perceptions of life-sustaining treatment decisions.

• Metals and materials international
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• 제24권6호
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• pp.1376-1385
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• 2018

Ultrasonic melt treatment (UST) was applied to an A390 hypereutectic Al-Si alloy in a temperature range of $750-800^{\circ}C$ and its influence on the solidification structure and the consequent increase in strength was investigated. UST at such a high temperature, which is about $100^{\circ}C$ above the liquidus temperature, had little effect on the grain refinement but enhanced the homogeneity of the microstructure with the uniform distribution of constituent phases (e.g. primary Si, ${\alpha}-Al$ and intermetallics) significantly refined. With the microstructural homogeneity, quantitative analysis confirmed that UST was found to suppress the formation of Cu-bearing phases, i.e., $Q-Al_5Cu_2Mg_8Si_6$, $Al_2Cu$ phases that form in the final stage of solidification while notably increasing the average Cu contents in the matrix from 1.29 to 2.06 wt%. A tensile test exhibits an increase in the yield strength of the as-cast alloy from 185 to 208 MPa, which is mainly associated with the solute increment within the matrix. The important role of UST in the microstructure evolution during solidification is discussed and the mechanism covering the microstructure-strengthening interrelationship of the ultrasonically treated A390 alloy is proposed.

• 대한지구과학교육학회지
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• 제12권2호
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• pp.151-164
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• 2019

이 연구의 목적은 단계별 질문을 활용해 '계절의 변화' 단원을 재구성함으로써 학생들의 오개념 변화에 어떠한 효과가 있는지 확인해 보고자 한 것이다. 대부분의 학생들은 계절 변화의 원인을 설명하는데 자신의 경험을 바탕으로 하여 선개념을 구성하고 있었다. 그래서 개발한 수업에서는 학생들이 갖고 있는 선개념 중 오개념을 조사하고 이에 대한 지도 계획을 '개념 변화를 위한 수업 설계 요소'로 명시하여 핵심 교수 학습 내용이 되도록 단원을 재구성하였다. 연구 결과, 실험 집단의 24명 학생들을 대상으로 과학 개념 검사를 실시하여 통계적으로 유의미한 효과가 있음을 알 수 있었다. 또한 질적 분석을 실시한 결과, 계절 변화를 설명할 때 활성화한 개념적 자원의 수와 계절 변화를 설명하는 구체성의 정도가 비교 집단에 비해 높음을 확인할 수 있었다.

• 생약학회지
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• 제52권3호
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• pp.192-201
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• 2021

Dangguisu-san (DGSS) is widely known traditional herbal medicinal formula in Korea for treatment of traumatic injury by traffic accident, ecchymosis, abdominal distension and anti-thrombosis of blood. This study was conducted to develop the simultaneous analyze method using high performance liquid chromatography (HPLC) and examine the effect of anti-inflammatory activity of DGSS-dry extract (DGSS-DE) and DGSS-mix extract powder (DGSS-MEP). Physicochemical characteristics of DGSS-DE and DGSS-MEP showed that there is no significant difference in pH, titratable acidity, total soluble solid content and browning degree except for color value (L, a, b). 15 functional constituents of DGSS were identified and the correlation coefficient values of DGSS-DE and DGSS-MEP were conformed 0.950. Also, DGSS-DE and DGSS-MEP significantly decreased the secretion of nitric oxide (NO), prostaglandin E₂ (PGE₂), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) through inhibited expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-1β, IL-6, and TNF-α. From these result, DGSS-MEP showed similar chemical composition and anti-inflammatory effect to DGSS-DE. Therefore, DGSS-DE and DGSS-MEP may be useful as potential source of drug to prevent inflammation.

• 대한금속재료학회지
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• 제47권9호
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• pp.523-532
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• 2009

In this study, four API X80 linepipe steel specimens were fabricated with varying cooling rates and finish cooling temperatures, and their microstructures and crystallographic orientations were analyzed to investigate the effects of cooling conditions on their tensile and Charpy impact properties. All the specimens consisted of acicular ferrite, granular bainite, and secondary phases such as martensite and martensiteaustenite constituent. The volume fraction of secondary phases increased with increasing cooling rate, and the higher finish cooling temperature resulted in the reduction in volume fraction and grain size of secondary phases. According to the crystallographic orientation analysis data, the effective grain size and unit crack path decreased as fine acicular ferrites having a large amount of high-angle grain boundaries were homogeneously formed, thereby leading to the improvement of Charpy impact properties. The specimen fabricated with the higher cooling rate and lower finish cooling temperature had the highest upper shelf energy and the lowest energy transition temperature because it contained a large amount of fine secondary phases homogeneously distributed inside fine acicular ferrites, while its tensile properties well maintained.

• 한국추진공학회지
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• 제25권4호
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• pp.43-52
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• 2021

본 연구에서는 기계식 추진 시스템인 CODOG 구조의 통합 제어를 위하여 구성 모듈인 가스터빈 엔진의 성능 모델링 및 시뮬레이션을 수행하였다. 엔진 모델은 상위 제어기 및 타 구성 모듈과의 통합이 용이하도록 MATLAB/Simulink를 이용하였으며, 시스템의 구성 및 목적에 맞는 입/출력 설정이 가능하도록 구성하였다. 일반적으로 엔진 제작사는 엔진 및 구성요소의 성능 데이터를 제공하지 않는다. 따라서 가스터빈 엔진에 대한 모델링 기법으로 구성요소의 맵을 스케일링하여 성능 데이터를 확보하는 CMF 기법을 적용하였다. 생성한 모델 및 시뮬레이션 프로그램을 이용하여 정상상태 및 동적 해석 시험을 수행하였으며, 최종 출력 결과에 대해 최대 오차 5% 이내의 신뢰성을 확보하였다.