• 한국재료학회지
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• 제32권9호
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• pp.379-383
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• 2022

In this study, Barium Germanium glasses were prepared with a composition of xBaO-(72-x)GeO₂-8La₂O₃-20ZnO where x = 16.0, 18.0, 20.0, 22.0 and 24.0 mol% respectively. Their physical and optical properties, such as refractiveness index, glass transition temperature (T_g), softening temperature (T_s), transmittance and Knoop hardness were studied. The results showed that refractive index, T_g, T_s and coefficient of thermal expansion (CTE) increased with increasing BaO concentration. The refractive index of all the prepared samples was observed between 1.7811 to 1.7881. The Abbe number was calculated by formula using n_d (589.3 nm), n_f (656.3 nm) and n_c (486.1 nm) and observed to be between 38 to 40. The Abbe number of the prepared sample was similar to that of BaO and GeO₂. The transmittance of the prepared glasses was observed to be between 80 ~ 82 % throughout the range from 200 nm to 800 nm. Knoop hardness divided into seven steps were measured 5 class (≥ 450 ~ < 550) of all prepared samples.

• 한국수산과학회지
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• 제15권4호
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• pp.283-290
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• 1982

Sardine and mackerel so called dark muscled fish have been underutilized due to the disadvantages in bloody meat color, high content of fat, and postmortem instability of protein. Recent efforts were made to overcome these defects and develope new types of product such as texturized protein concentrates and dark muscle eliminated minced fish. Approach of this study is based on the rapid dehydration of foamed fish-starch paste by dielectric heating. In process comminuted sardine meat was washed more than three times by soaking and decanting in chilled water and finally centrifuged. The meat was ground in a stone mortar added Ivith adequate amounts of salt, foaming agent, and other ingredients for aid to elasticity and foam stability. The ground meat paste was extruded in finger shape and heated in a microwave oven to give foamed, expanded, and porous solid structure by dehydration. Dielectric onstant $(\varepsilon')$ and dielect.ic loss $(\varepsilon")$ values of sardine meat paste were influenced by wavelength and moisture level. Those values at 100 KHz and 15 MHz were ranged 2.25-9.86; 2.22-4,18 for E' and 0.24-19.24; 0.16-1.20 for E", respectively, at the moisture levels of $4.2-13.8\%$. For a formula for fish-starch paste preparation, addition of $20-30\%$ starch (potato starch) to the weight of fish meat, $2-4\%$ salt, and $5-10\%$ soybean protein was adequate to yield 4-5 folds of expansion in volume when heated. Addition of e99 yolk was of benefit to micronize foam size and better crispness. In order to provide better foaming and dehydration, addition of $0.2-0.5\%$sodium bicarbonate, foaming agent, was proper to result in foam size of 0.5-0.7 mm and foam density of $200-400\;/cm^2$ which gave a good crispness. Heating time was depended upon the moisture level of fish-starch paste. For a finger shaped paste (1.0cm. $D\times10cm.L$) heating for 150-200 sec. in a microwave oven (700W. 2.45GHz) was sufficient to generate foams, expand, and solidify the porous structure of fish-starch paste. When the moisture content was above $55\%$ browning and scorching was deepened due to over-expansion and over-heating whereas the crispness was hardened by insufficient expansion at lower moisture content. In quality evaluation of the product, chemical composition of $30\%$ starch and $3\%$ salt added product was moisture $8.8\%$, lipid $2.4\%$, carbohydrate $46.7\%$, protein $36.1\%$, and ash $6.0\%$. Eleven membered panel test evaluated that fish-starch paste was acceptable in color, crisp-ness, taste, except a trace of fishy odour which could be masked by the addition of spice extracts.

• 교육녹색환경연구
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• 제16권1호
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• pp.1-11
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• 2017

본 연구는 학교 안전교육 7대 표준안에 기초하여 체험위주의 안전교육을 효과적으로 실시할 수 있도록 안전체험교육시설의 현황분석과 수요분석을 통해 학생 안전체험교육시설 설립을 위한 필요 시설수를 제시하고자 하였다. 학교 안전교육 7대 표준안 및 기존 안전체험관의 체험 프로그램을 분석하고, 그 분석을 토대로 학교급별 체험 프로그램을 추출하였다. 도출된 프로그램을 체험 공간화하여 설정하고, 이에 준하여 기존 안전체험시설을 현황분석 하였다. 그리고 이를 바탕으로 시설 확충 수요 산정을 위해 도출한 산출식을 활용하여 필요 시설 수(체험시설 약95개소, 체험차량 약55대)를 제시하였다. 이는 2015년 학령인구를 기준하여 체험차량의 분담비율을 정하고 필요 시설 수를 산정한 결과이다. 장기적으로는 체험시설의 단위 구축비용과 체험차량의 단위 구축비용의 실제적인 비교를 통한 적정비율을 산출하고, 이를 고려한 중 장기적인 필요 시설 및 차량에 대한 구축 계획 및 연차별 확충을 위한 별도 계획 마련이 필요하다.

• 콘크리트학회지
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• 제7권3호
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• pp.199-210
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• 1995

충전형 강관콘크리트 구조는 강관과 콘크리트 두 재료의 이질적인 재료특성을 상호 보완적으로 발휘하여 구조적 성능향상을 꾀한 것으로서 제구조 특성상 우수한 구조형식이라 할 수 있다. 강관으로 구속된 콘크리트가 중심축력을 받게 되면 내부의 콘크리트는 압괴에 의한 체적 팽창을 외부의 강관에 의해 구속 받게 되므로 3축 압축응력 상태로 되어 압축강도가 증대된다. 또한 콘크리트의 압괴에 의한 탈락 현상이 방지되므로서 단면의 결손이 없어져 내력 저하가 작아진다는 잇점을 가진다. 따라서 본 연구에서는 원형강관으로 구속된 내부 콘크리트의 구조적 거동 특성을 규명하기 위한 것으로서 폭두께비와 충전 콘크리트의 강도를 주요 변수로 하여 일련의 실험을 통하여 강관으로 구속(3축 응력)된 콘크리트의 구조적 거동 특성을 고찰하였다. 일련의 실험을 통하여 얻어진 결론을 요약하면 다음과 같다. (1)강관에 의한 콘크리트의 구속효과는 강관의 폭두께비와 충전 콘크리트의 강도가 낮을수록 현저하며, 원형강관으로 구속된 내부 콘크리트는 최대내력시의 변형능력에 있어서 횡방향 구속이 없는 콘크리트보다 4~7배 정도까지 증대시켜 연성효과를 높일 수 있을 것으로 기대된다. (2)콘크리트의 구속계수를 이용하여 강관으로 구속된 내부 콘크리트의 강도와 콘트리트 충전강관 기둥의 최대내력을 산정할 수 있는 식을 제시하였다.

• 대한공업교육학회지
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• 제40권1호
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• pp.23-39
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• 2015

이 연구의 목적은 특성화고 교사를 위한 발명 특허분야 교원 직무연수 프로그램의 효과성을 확인하고 개선 방안을 탐색하는데 있었다. 이 연구의 대상은 2015년도 충남대학교 발명교사교육센터가 주관한 특성화고 교사 대상 발명 특허분야 교원직무연수 참여자 39명을 대상으로 하였다. 자료 수집은 연수가 종료된 시점에 직접 설문지를 배부하고 전량(100%)을 회수하였고, 39명중 불성실한 응답자 2명을 제외한 37명을 자료분석에 활용하였다. 이 연구를 위한 교원연수프로그램 개발은 문헌연구와 전문가 회의를 통해 이루어졌고, 적용에 따른 만족도는 설문지를 개발하여 활용하였다. 연수 프로그램의 효과성은 교육요구도와 교육만족도를 통해 확인하였으며, 교원 직무연수 개선 방안 연구진에 의해 구안된 교원 연수 평가 모형에 의해 모색되었다. 이 연구의 결과는 다음과 같다. 첫째, 특성화고 교원을 위한 발명 특허 교원직무연수의 교육요구도는 높았다. 둘째, 개발된 교원직무연수 프로그램의 만족도는 높게 나타났다. 셋째, 연수 프로그램은 전반적으로 교육효과성이 높게 나타났다. 넷째, 연수 프로그램의 엄격한 개선을 위하여 현상유지, 대안탐색, 전략수정, 기대 확장의 4개 영역으로 구분하였다.

• 한국산학기술학회논문지
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• 제18권1호
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• pp.310-315
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• 2017

대규모 건설공사 현장에서는 발파공사에 대한 표준발파패턴과 시험발파패턴의 발파진동추정식의 상이에 따른 설계변경의 반영 문제로 시공사, 건설사업관리자, 발주처간의 갈등요인을 해소하기 위한 체계적인 자료의 수집 및 분석 과정을 통하여 효율적인 대책수립이 필요한 실정이다. 발파진동에 의한 인접 구조물에 미치는 영향을 여러 각도로 평가하려는 연구들은 계속 되어 왔으나, 노천발파를 수행하면서 현장계측의 진동파형을 분석하여 인접 건축물의 안전성을 확보하고 현장여건에 적합한 발파공법을 연구한 사례는 미미한 실정이다. 따라서 현장여건에 적합하고 경제적이며 효율적인 발파작업을 수행할 수 있도록 시험발파를 통하여 발파패턴 선정의 개선방안을 제시하는 것이 필요하다. 본 연구에서는 실제 도로확장공사 현장에서 시험발파를 통한 표준발파공법 및 진동규제기준별로 적용되는 이격 거리를 기준으로 노천 발파작업을 수행하여 발파진동 값을 계측하고 이를 통한 발파공법별 진동예측식을 회귀분석 전산프로그램을 이용하여 신뢰수준 95%의 K, n, R등을 산출하였다. 시험발파 대상지역의 발파허용진동기준을 0.3cm/sec로 설정하고 노천발파지침의 발파진동추정식과 시험발파의 발파진동추정식에 따른 이격 거리별 장약량과 발파공법을 비교분석한 결과 사업비가 증가하는 요인을 도출할 수 있었다. 또한, 노천발파 작업 중 인접 구조물에 대한 계측 및 분석을 수행하고 노천발파지점과 가장 인접한 구조물을 선정하여 발파진동 계측 및 평가를 시행하여 노천발파공사를 완료하는 과정에서 나타난 노천발파 설계 시공 지침에서의 시험발파 절차 및 해석방법에 대한 문제점을 분석하여 개선방안을 제시하였다.

• 유통과학연구
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• 제12권2호
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• pp.105-112
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• 2014

Purpose - This research undertakes to understand the trade structures of both China and Japan to strengthen Sino-Japan economic cooperation and examines impediments to trade between the 2 countries to analyze causes which affect trade and to examine improvements in these areas to find out ways of trade expansion. Through this survey of a defined period of time, we can identify the structural factors of trade dependence in the relationship between China and Japan. Research design, data, methodology - The data were collected from Korea Traders Association, Korea Customs Office and UN Comtrade, from which whole table indexes are calculated by author. This research methodology uses trade related indexes to focus on analyzing comparative advantages based on time-series analysis statistics data (2000~2012), by using the analysis index of Trade Intensity Index (TII), Revealed Comparative Advantage Index (RCA) and Trade Specialization Index (TSI). Results - The export ratio for China against Japan was a little higher in 2000 at 2.867 and the export ratio for China against Japan was sustained in 2005. However, it diminished gradually and reached 1.263 in 2012. During the whole period of 2000~2012, the indexes were maintained without any significant change. However, they are still moving closer to -1. Especially, in 2012 it is the closest it has been to -1. Therefore, Japan has a comparative advantage toward export specialization. On the other hand, China has a comparative advantage toward import specialization. For the whole research period, all indexes were much smaller than 1, which means that China has comprehensively had a comparative disadvantage against Japan for the past 10 years when compared to other industries, even though it had improved in 2000. Conclusions - The summary of conclusions based on empirical analysis research are as follows: First, per the Trade Intensity Index of industries between the 2 countries, we can conclude that export ratio index is 2.867, based on the formula, in 2000, which means the export ratio of China against Japan is a little bit higher. Furthermore, the ratios of 2.259 and 1.263 are indicated in 2005 and 2012 respectively which mean the export ratio of China against Japan was maintained in 2005 but was diminishing gradually as the index is 1.263 in 2012. Second, per the Trade Specialization Index of the shipping industry between China and Japan, -0.379 is indicated in 2000, -0.368 in 2005 and -0.568 in 2012. Looking at the whole period of 2000~2012, the indexes were maintained without any significant change. However, they are still moving closer to -1. Especially, in 2012 it is the closest it has been to -1. Third, per the Revealed Comparative Advantage Index of the automobile industry between China and Japan, the RCA indexes in 2005 and 2012 are 0.246 and 0.306 respectively which are still far from 1 even though the index is improved compared to 2000's value of 0.0001. Therefore, the Chinese automobile industry is very much at a comparative disadvantage to that of the Japanese automobile industry.

• 한국세라믹학회지
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• 제52권6호
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• pp.410-416
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• 2015

Recently, a new $Y_2O_3$ coating deposited using the EB-PVD method has been developed for erosion resistant applications in fluorocarbon plasma environments. In this study, surface crack formation in the $Y_2O_3$ coating has been analyzed in terms of residual stress and elastic modulus. The coating, deposited on silicon substrate at temperatures higher than $600^{\circ}C$, showed itself to be sound, without surface cracks. When the residual stress of the coating was measured using the Stoney formula, it was found to be considerably lower than the value calculated using the elastic modulus and thermal expansion coefficient of bulk $Y_2O_3$. In addition, amorphous $SiO_2$ and crystalline $Al_2O_3$ coatings were similarly prepared and their residual stresses were compared to the calculated values. From nano-indentation measurement, the elastic modulus of the $Y_2O_3$ coating in the direction parallel to the coating surface was found to be lower than that in the normal direction. The lower modulus in the parallel direction was confirmed independently using the load-deflection curves of a micro-cantilever made of $Y_2O_3$ coating and from the average residual stress-temperature curve of the coated sample. The elastic modulus in these experiments was around 33 ~ 35 GPa, which is much lower than that of a sintered bulk sample. Thus, this low elastic modulus, which may come from the columnar feather-like structure of the coating, contributed to decreasing the average residual tensile stress. Finally, in terms of toughness and thermal cycling stability, the implications of the lowered elastic modulus are discussed.

• 한국식품조리과학회지
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• 제14권2호
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• pp.168-176
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• 1998

메밀분 30%와 강력분 70%의 복합분으로 강력분만을 사용한 이스트 발효빵과 유사하도록 메밀빵을 만들기 위하여 활성 글루텐과 gum 물질을 첨가하였으며 복합분의 제빵 적성에 미치는 그들의 효과를 알아보기 위하여 첨가물별 메밀빵의 물리적, 관능적 검사를 통하여 메밀빵의 품질 특성을 비교하였다. 메밀에 결여된 글루텐의 기능성을 보완하기 위하여 활성 글루텐과 gum물질을 첨가한 결과 메밀빵의 부피와 무게가 모두 증가하였으며 그 효과는 xanthan gum>활성 글루텐>guar gum 순 이었고, 단독 사용시보다는 활성 글루텐과 gum물질을 같이 사용하였을 때 효과가 더욱 증대되어 대조구 밀빵과 유사한 부피를 나타내었다. 빵 껍질색은 guar gum의 첨가로 L, a값이 증가하여 밝아졌고 xanthan gum을 첨가한 경우에는 L, b값이 감소하여 상대적으로 어두운 색을 나타내었다. 빵 내부색은 활성 글루텐과 xanthan gum 첨가로 L, b값이 감소하여 어두워졌다. 관능검사 QDA 결과 메밀빵에 활성 글루텐이나 gum 물질을 첨가함으로써 빵 속의 부서짐성이 유의적으로 감소되었고 그 밖의 탄력성, 촉촉함, 깔깔함 등의 조직감이 개선되었다. Amylograph에서 호화는 밀가루보다 메밀가루가 낮은 온도에서 일찍 시작되었고 최고 점도는 밀가루보다 메밀가루가 현저히 높았다. 메밀가루 30%와 강력분 70%의 복합분에 활성 글루텐과 gum물질을 간이 첨가함으로써 호화 점도가 감소되고 제빵 적성이 개선되었다. 또한 100% 강력분의 호화 점도쪽으로 낮아질수록 관능검사에서 메밀랑은 부드럽고 촉촉하게 나타났으며 부서지는 정도도 감소하였다. 이러한 관점에서 첨가물에 따른 메밀빵의 저장기간 중 노화변화에 대한 연구가 수행되어져야 할 것으로 사려된다.

• Ocean and Polar Research
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• 제31권1호
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• pp.31-50
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• 2009

The demarcation of Maritime Boundary is directly related to the expansion of jurisdiction and the securing of resources. Resource diplomacies of the three countries Korea, China and Japan represent a major task for the national administrations : to secure resources as well as to stablize and sustain resources for future national economies. At the sea area around Korea as well, countries are fiercely competing to secure resources and to expand jurisdiction. This is evidenced by the fact that various principles and logics which are beneficial to each own country are presented through international precedents, agreement between countries and the theories of the international law scholars. They say that the conclusion of demarcation of maritime boundary for the Yellow Sea would be easy from the point that there is no dispute related to island dominion in the waters of the Korean Peninsula especially the Yellow Sea, but still we need to have a strategic approach to this issue from the point that the factors used for claiming maritime boundaries may expand the waters of a country over much. For example, the continental shelf boundary in consideration of the distribution of sedimentary deposits in the Yellow Sea which is being raised by China began from the hypothesis that the inflow of sedimentary deposits to the Yellow Sea through the rivers of China represents absolute majority, but the results of the latest studies raised questions on the hypothesis. Especially, the studies done by Martin and Yang revealed that the inflow of sedimentary deposits to the Yellow Sea from the Yellow River is approximately less than 1% of total sedimentary deposits in the Yellow Sea, and also the result of analysis on the causes and counter policy measures on the environment of Bohai, China supports the reliability of the results of such studies. From a legal aspect, the sedimentary deposits of rivers which are claimed by China represent extremely weak ground for the claim for the title of the continental shelf. The siltline claimed by China seems to be based on the Article 76-4-(a)(i) of UNCLOS. This is, however, not the definition on the title of the continental shelf but it is only a technical formula to utilize in a case where a country desires to expand the continental shelf to over 200 nautical miles. Scientific and Technical Guidelines of the Commission on the Limits of the Continental Shelf also confirm this point through the Article 2.1.2 of the Guideline. The only case in which sedimentary deposits of rivers were referred to as concrete demarcation of maritime boundary was in the which was concluded in 1986 between India and Myanmar at the Andaman Sea. In the said case, India acknowledged the boundary up to the isobath of 200m which Myanmar claimed based on the sedimentary deposits of the Irrawaddy River. It has limits as a case for acknowledging the sedimentary deposits, however, because in fact India's acknowledgment was made in exchange for the condition that Myanmar gave up the dominion of two islands which they had been claiming from India up until that time.