• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.1
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• pp.21-42
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• 2020

This study aimed to analyze library anxiety among international users in various aspects and make suggestions for alleviating library anxiety. Subjects were 'international users using the academic library' not only including international students but also including international professors and researchers to analyze library anxiety in various aspects. S university with most international users was selected for the study, and the surveys were distributed. The questionnaires completed by 369 international users were analyzed. The overall average of library anxiety among international users is 2.96, and 'knowledge of the library' appears to be the greatest source of library anxiety among international users. An analysis revealed that variables including status, nationality, library instruction, the reason for using the library, Korean proficiency, and cultural understanding contributed significantly to the library anxiety level. Based on these findings, recommendations for library service, staffing, environment, and resources were made to help alleviate library anxiety.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.37-50
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• 2005

This study analyzes the effect of airport investment on GRDP(Gross Regional Domestic Product) using Regional Production Function with public investment on social infrastructure. Particularly it includes the spillover effect of airport investment on the economies of neighbor regions beyond border. We estimate regional production function with the independent variable of airport investment stock using panel data with regional cross-section and time-series data. In the analysis with aggregate data of all industries, it shows the positive relationship between airport investment and GRDP which implies the affirmative effect of airport investment on regional economy in the aspects of direct and indirect spill-over effects. On the contrary, the research results of each industry do not appear to be the same. With the different characteristics of each industry, the direct and indirect effect may not be the same and the SOC investment contributes to the restructuring of regional economy by altering the industrial organizations of any specific region and its neighbors.

• Current Research on Agriculture and Life Sciences
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• v.33 no.1
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• pp.1-5
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• 2015

This study investigated the chelation of a sorghum bran extract using iron (Fe) as a new natural colorant. The composition of the sorghum bran extract and chelation conditions were both examined. The thermal properties of the chelated colorants were analyzed using differential scanning calorimetry (DSC) and a thermal analyzer system(TGA). The sorghum bran extract solution showed a maximum absorbance at 281 nm based on UV/Vis spectrophotometry. According to the chelation pH conditions, pH 7.5 was the most effective. The chelation of the sorghum bran extract increased rapidly when increasing the iron concentration up to 2 mg/L, with no further chelation at a higher concentration. The particle size distribution curve for the chelated tannin revealed four groups: $4.5{\sim}17{\mu}m$, $20{\sim}42{\mu}m$, $45{\sim}80{\mu}m$, and $83{\sim}160{\mu}m$. In a DSC analysis, endothermic peaks attributed to the pyrolysis of the extract and chelated tannin were found at $318^{\circ}C$ and $415^{\circ}C$, respectively. In a TGA analysis, the chelation was shown to increase the final degradation temperature from $253^{\circ}C$ to $382^{\circ}C$, confirming that the chelation improved the thermal stability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.42-49
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• 2018

In steel industries, cold-rolled sheet manufacturing is one of the links between the front and rear important industries for national competitiveness and high value-added production. In particular, in small and medium-sized enterprises, one of the major problems is the carbonization phenomenon of the steel sheet during the annealing process. Carbonization occurring on the surface of the coil help reduce steel production. After conducting various experiments to identify the cause of carbonization on the surface of a cold-rolled steel, the following results were obtained: (1) An analysis of the rolling oil, which is used in the field, revealed it to contain approximately 40 ppm carbonized material. (2) A comparison of the thermal denaturation characteristics of the fresh rolling oil and using rolling oil by FT-IR analysis showed that thermal denaturation had occurred, as shown by the significant decrease in the relative intensity of the 2900 and $1750cm^{-1}$ peaks. (3) The thermal decomposition of the rolling oil took place for the rolling oil at approximately $220^{\circ}C$. Furthermore, annealing experiments at $200^{\circ}C$ showed that the carbonization phenomenon of the sample was not observed. On the other hand, carbonization was observed at temperatures higher than $240^{\circ}C$.

• Journal of Energy Engineering
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• v.19 no.4
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• pp.221-227
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• 2010

In this study, we consider gas generation characteristics on pyrolysis of eco-fuel which were made by mixing of Pitch Pine and Lauan sawdust as biomass and polyethylene, polypropylene, polystyrene as municipal plastic wastes with catalyst in fixed bed reactor. From the result of higher heating value(HHV) measurement and of ultimate analysis, the heating value of plastic wastes and a hydrogen content in plastic sample are higher than biomass. An activation energy was reduced by a catalyst addition. However the catalyst content influence over 5 wt% was insignificant. The yield of hydrogen from gasification of biomass containing plastic wastes such as polyethylene, polypropylene and polystyrene were obtained higher than that of sole biomass. The high temperature and mixture ratio of catalyst conditions induced to high hydrogen yield in most of the samples. As the influence of catalyst, the hydrogen yield by catalytic reaction was higher than non-catalytic reaction. We confirmed that Ni-$ZrO_2$ catalyst is more active in increasing the hydrogen yield in comparison with that of carbonate catalyst. The maximum hydrogen yield was 65.9 vol.%(Pitch Pine / polypropylene / 20 wt.% Ni-$ZrO_2$(1:9) at $900^{\circ}C$).

• Economic and Environmental Geology
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• v.46 no.2
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• pp.165-178
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• 2013

This study is for the genetic differences of two closed asbestos mines from Jeongjeon and Ocheon areas in Boryoung, Chungnam. They are mined asbestos for past several decades. Host rocks are serpentinites for Jeongjeon mine and dolomites for Ocheon mine. Asbestos samples and their host rocks are collected from the field trips and examined with microscopes and FESEM, and analysed with XRD and EDX to confirm for the type and/or compositions of the minerals. The asbestos occur as layers, cracks and fractures assummed as a pathway of the hydrothermal water, but show different characteristics. The serpentinites from the Jeongjeon mine contain chrysotile, tremolite and actinolite asbestos. Non-asbestos minerals including tremolite and actinolite were also found. The chrysotiles occur as a cross fiber or slip fiber at veins and along cracks of several mm to cm thickness. Tremolite and actinolite asbestos occur along cracks and fractures of several cm to ten cm thickness. It suggests that the asbestos from Jeongjeon area were formed by the reactions between serpentinite and hydrothermal water. The dolomites of the Ocheon mine only contain tremolite and actinolite asbestos. The asbestos occur along layers, cracks and fractures, suggestive of asbestos from Ocheon area formed by the reactions between dolomite and hydrothermal waters influxed along layers, cracks and fractures. Overall results suggest that two asbestos mines showing different host rocks are located in a Boryoung area. They show a different type of asbestos minerals, reflecting variety of petrogeneses.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.3
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• pp.109-121
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• 2024

This paper adopts a resource-based approach to analyze why some universities have a greater number of faculty startups, and how this impacts on performance, in terms of indictors such as the number of employees and revenue sales. More specifically, we propose 9 hypotheses which link institutional resources to faculty startups and their performance, and compare 5 different groups of university resources for cross-college variation, using data from 134 South Korean four-year universities from 2017 to 2020. We find that the institutional factors impacting on performance of faculty startups differ from other categories of startups. The results show that it is important for universities to provide a more favorable environment, incorporating more flexible personnel policies and accompanying startup support infrastructure, for faculty startups, whilest it is more effective to have more financial resources and intellectual property for other categories of startups. Our findings also indicate that university technology-holding company and technology transfer programs are crucial to increase the number of faculty startups and their performance. Our analysis results have implications for both university and government policy-makers, endeavoring to facilitate higher particaption of professors in startup formation and ultimate commercialization of associated teachnologies.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.483-487
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• 2006

본 연구는 비점오염원에 의한 수질오염현상을 억제하기 위한 수변지역의 관리기법 중 하나인 식생여과대를 효과적으로 설치하기 위하여 식생에 의한 오염물질의 저감능력을 파악하고 효율적 설치방안을 모색하기 위하여 수행되었다. 연구결과 T-N과 T-P의 깊이별 오염물질 저감효과는 나대지에서 표면유출이 각각 17.6%, -23.9%, 단면유출이 각각 51.7%, 91.0%, 하부유출이 각각 38.4%, 89.3%인 것으로 나타나 표면층을 통한 유출보다는 토양층에 침투될수록 오염물질의 저감효과가 높아지는 것으로 나타났다. 잔디로 표면층을 식재한 실험에서는 표면, 단면, 하부유출에서의 T-N이 각각 16.0%, 57.1%, 38.4%의 오염물질 저감효과를 보였고, T-P의 저감효과는 각각 -9.7%, 83.6%, 88.8%인 것으로 조사되었다. 또한 돌미나리로 표면층을 식재한 실험에서는 표면, 단면, 하부유출에서의 T-N 처리효율이 각각 -2.6%, 62.1%, 71.2%로 나타났으며, T-P는 각각 -7.2%, 94.5%, 84.5%인 것으로 조사되었다. 결론적으로 식생을 한 경우 전체적으로 오염물질의 저감효율이 비교적 안정되게 유지되는 것으로 나타났으나, T-P의 표면층을 제외하면 전체적인 저감효과에 크게 영향을 미치지 않은 것으로 판단된다. 그러나 일반적으로 알려져 있는 식생에 따른 오염물 저감효과에 대한 순기능 즉 토양입자의 침식방지, 토양용액의 저류작용 및 공극확대에 따른 침투능력 증대, 토성의 개량 등과 같은 기능을 무시할 수 없으므로 오염저감효과를 극대화하기 위해서는 처리대상이 되는 하천유역의 자생적 식생을 보다 효과적으로 활용할 수 있는 방안마련이 비용적 측면이나 생태 보존적 측면에서 유리할 것으로 판단된다.one)을 설치하는 대책이 필요하다. 저수지 관리를 효과적으로 수행하기 위해서는 저수지 내부의 탁도 거동을 정확히 예측할 수 있어야 한다. 따라서 추후 동수역학 및 열역학에 기초한 3차원 수치모형 연구와 성층흐름에 정밀한 밀도류 실험연구 및 이에 대한 적용이 필요할 것으로 판단된다.함으로써 정보의 질적보장과 정보전환의 표준화방안을 제시하는 정보분석시스템이다.이용, 수자원의 지속적 확보기술의 특성에 따른 4개의 평가기준과 26개의 평가속성으로 이루어진 2단계 기술가치평가 모형을 구축하였으며 2개의 개별기술에 대한 시범적용을 실행하였다.하는 것으로 추정되었다.면으로의 월류량을 산정하고 유입된 지표유량에 대해서 배수시스템에서의 흐름해석을 수행하였다. 그리고, 침수해석을 위해서는 2차원 침수해석을 위한 DEM기반 침수해석모형을 개발하였고, 건물의 영향을 고려할 수 있도록 구성하였다. 본 연구결과 지표류 유출 해석의 물리적 특성을 잘 반영하며, 도시지역의 복잡한 배수시스템 해석모형과 지표범람 모형을 통합한 모형 개발로 인해 더욱 정교한 도시지역에서의 홍수 범람 해석을 실시할 수 있을 것으로 판단된다. 본 모형의 개발로 침수상황의 시간별 진행과정을 분석함으로써 도시홍수에 대한 침수위험 지점 파악 및 주민대피지도 구축 등에 활용될 수 있을 것으로 판단된다. 있을 것으로 판단되었다.4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.4
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• pp.29-42
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• 2017

Jeongeuihyanggyo(旌義鄕校) is a kind of traditional, Confucian cultural landscapes that is located in Jeju special self-governing province. Its historical background illustrates that the first erection was started at Goseong-li of Seongsan-eup(城山邑 古城里) at Taejong(太宗) of 16 years(1417) and it moved to the west gate of Hyunseong(縣城) at Heojong(憲宗) of 15 years,(1849) Joseon. The aim at this study is to reveal characters of these Confucian Spatial Composition and Order, which are valuable resources that can be created into the cultural contents. The results demonstrate the characters of the Confucian cultural landscape as followings; the changing process of new building and its relocation, the utilization of antique maps in location interpretation of Jeongeuihyanggyo, Confucian symbolic elements of it, the spatial compositions and layouts of its buildings, physical structures, main buildings and their characters, locational points of topographic profile, changes of axial line at Daeseongjeon(大成殿), the D/H ratio of its courts. This study can show that Jeongeuihyanggyo is a case for realizing the Confucian reformation to enhance Seongeup Hyun's education standard considering the locality of the site which is an isolated island like Jejudo(濟州島). The author can see that the example of Confucian space is applied to various layout techniques, both horizontally and vertically, in a limited space condition of being in the castle. Therefore, it is necessary to revive this point so that it can utilize unique Confucian cultural landscape possessed only by Jeongeuihyanggyo.

• Korean Chemical Engineering Research
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• v.61 no.3
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• pp.419-425
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• 2023

This paper presents the research results of analyzing the high-temperature corrosion characteristics of three currently commercialized heat exchanger tube materials under actual operating conditions of a biomass power plant. In order to precisely analyze the high-temperature corrosion characteristics of these materials, a high-temperature corrosion evaluation device was installed in the power plant equipment, which allows for adjusting the surface temperature of the heat exchanger tubes. Experiments were conducted for approximately 300 hours under various temperature and operating conditions. In this study, the commercialized heat exchanger tube materials used were SA213T12, SA213T22, and SA213T91 alloys. In order to objectively analyze the high-temperature corrosion characteristics of each material, an international standard-based process to remove corrosion products was applied to obtain the weight change of the specimens, and the average thickness loss and corrosion rate were derived. Thus, the high-temperature corrosion results for each condition were quantitatively compared and analyzed. In addition, in order to increase the reliability of the high-temperature corrosion evaluation method introduced in this study, the surface and cross-sectional corrosion of the specimens were confirmed by using scanning electron microscopy and energy-dispersive X-ray analysis. Based on these analysis results, it was found that the corrosion resistance of the commercial heat exchanger materials increases as the content of chrome and nickel in the composition increases. Additionally, it was found that the corrosion phenomenon is rapidly accelerated as the surface temperature increases. Finally, the replacement period (lifetime) of the heat exchanger tubes under each condition could be inferred through this study.