• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.357-365
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• 1998

목적: 치과용 수복재료의 방사선 불투과성은 매우 다양하다. 따라서 다양한 수복재료의 방사선 불투과성을 인지하여 치질과 비교하면 이차우식의 진단에 도움이 될 수 있다. 도재의 방사선 불투과성에 따라 적절한 luting cement의 선택이 가농해진다. 수복재료의 방사선 불투과성은 알루미늄 step wedge 의 후경과 방사선 불투과성과의 상관관계 의해 측정된다. 본 연구의 목적은 CAD/CAM용 도재와 이틀의 접착에 쓰이는 접착재료의 방사선 불투과성을 조사해 적절한 재료의 선택과 이차우식 진단의 효율결정에 도움이 되게 하는데 있다. 방법: 본 실험에서는 CAD/CAM용 도재인 Vita MarkII, Dicor MGC와 이의 접착에 사용되는 Z-100, 그리고 luting cement인 Duo cement, Scotchbond resin cement를 사용해 방사선 불투과성을 측정하였다. 시편 제작을 위해 도재를 저속절단기로 두께 2mm, 3mm로 절단하였으며 Z-100과 cement시편은 두께 2mm와 3mm, 직경 7.0mm의 금속 주형을 제작한 후 재료를 양쪽 면에 유리판을 대고 조임쇠로 압접하였으며 광조사기를 사용하여 각 재료마다 두 가지 두께로 10개씩 100개의 시편을 제작하였다. 치질의 시편을 얻기 위해 교정 목적으로 최근에 발거된 정상적인 상악 소구치를 저속 절단기를 사용하여 협설측 교두정을 기준 삼아 2mm, 3mm 두께로 절단하였으며 방사선 불투과성의 기준을 위해 12개의 step으로 구성된 12mm두께의 aluminum step wedge를 사용하였다. Kodak E-Speed occlusal film에 aluminum step wedge와 시편들을 위치시킨 후 70kVp, 7mA, 2.16mm aluminum filtration으로 고정된 dental X-ray unit을 사용하여 target과 film 사이의 거리는 25cm, 노출시간은 0.2초로 하여 방사선 촬영을 한 다음, 현상된 방사선 사진상에 나타난 방사선 불투과성을 X-rite 301 densitometer를 이용하여 측정한 값들의 평균을 냈다. 얻어진 결과는 one-way ANOVA Duncan test(P<0.01)로 검증하였다. 결론: 1. Dicor MGC의 방사선 불투과성은 법랑질보다 약간 높게 나타났다.(P<0.01) 2. Vita Mark Il는 상아질보다 낮은 방사선 불투과성을 보였다.(P<0.01) 3. Z-100과 Luting cement들의 방사선 불투과성은 법랑질보다 높았다. Duo cement가 방사선 불투과성이 가장 높았고 그 다음이 Z-100, 그리고 Scotchbond resin cement 순이었다. 4. Z-100과 2종류의 방사선 불투과성 luting cement들은 Vita Mark II 와 같이 사용하면 2차우식 진단에 도움이 된다.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.4
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• pp.245-250
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• 1976

A field study was conducted to find out the optimum level of NPK fertilizers for pearl barley (Coix Lacryma-Jobi L.). The results are sumarized as follows. 1. When all of NPK fertilizers were increased together as 0-0-0, 6-3-3, 12-6-6-6 and 18-9-9 kg/10a of NPK, the grain yield also increased lineally. 2. When the level of two other elements were fixed at 12kg/10a for N and 6kg/10a for P and K, maximum yields were obtained at 12kg/10a of N and 6kg/10a of P and K. 3. Accordingly, with present results, it is difficult to point out the optimum levels of NPK. It seemed necessary to conduct another trial with expanded NPK levels. However it can be pc pointed out that the yield of pearl barley can be increased with higher levels of NPK fertilizers than 18-9-9 kg/10a at the similar soil used for present study. 4. The antagonism phenomena were observed between N and K in plant's uptake.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.3
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• pp.266-276
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• 2021

Fundus hemorrhage refers to abnormalities in the retinal tissue and blood vessels. Therefore, when a hemorrhagic change in the fundus occurs, the ophthalmologist orders various ophthalmic tests to evaluate the degree of hemorrhage and determine the progress of the lesion before, during, and after treatment to accordingly establish a treatment plan. Currently, the most useful and universal fundus examination includes optical coherence tomography (OCT), fundus photography (FP), and fluorescein angiography (FAG). Existing fluorescein angiography test methods for establishing a treatment plan for severe fundus bleeding have limitations. The authors propose that peripheral pupil and the 5-quadrant method should be performed using ultra-wide-angle fluorescence fundus angiography (UWFFA). Using this method, it is possible to quickly determine the area to be described, avoid the radius of bleeding as much as possible, and provide the ophthalmologist with a range of damaged tissue and abnormal blood vessels. Nevertheless, there are cases in which ophthalmologists judge that fundus bleeding is so severe that ultra-wide-angle fluorescence fundus angiography is meaningless. In such cases, ophthalmic ultrasound and electroretinogram may be used in that order as alternative methods of examination. Therefore, some clinical situations require the use of ophthalmic ultrasound and electroretinogram and should be performed accurately.

• Review of Culture and Economy
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• v.20 no.3
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• pp.3-33
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• 2017

The present study analyzed movie consumption behavior from the perspective of transaction cost, taking into account the possible incurrence of additional costs in the process of consumers obtaining movie information to choose movies. Regression and multinomial logistic regression analyses were performed in the analysis by taking movie information and the individuals' social demographic characteristics as independent variables and the number and frequency of movies watched as dependent variables, using information from the "2015 movie consumer survey." The results showed that consumers considering elements such as "directors" and "online reviews" were found to be more active in movie consumption. The analysis of movie-watching frequency showed that the information considered when choosing a movie was different for high- and low-frequency movie viewers. Putting these factors together suggests that movie consumption can vary according to an individual's cultural capital, preferences, and their degree of movie information awareness. While existing studies have mostly analyzed the determinants of box office performance, the significance of the present study is its empirical analysis of individual movie information in terms of transaction cost. Based on the results above, it can be inferred that the cyclical structure of trading expenses influences movie consumption and, once preferences are formed through a certain level of consumption, the trading cost expenses decrease, which results in increasing consumption. Therefore, film makers need to establish and execute marketing strategies that appropriately use movie information so that consumers can reduce the trading costs necessary for movie watching.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.331-343
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• 2019

The purpose of this study is to observe the trends of heart age of Koreans by using the predictor of heart age of the Framingham Heart Study. The subjects were 20,012 adults aged 30~74 years who were enrolled in the Korean National Health and Nutrition Examination Survey from 2005~2013. They filled in the determinants data and they had no history of cardiovascular disease (CVD). The heart age was calculated using a non-laboratory based model of prediction. The difference of heart age and chronological age, and the rate of excessive heart age over 10 years were calculated. The annual trend, the difference according to gender, the age bracket and geographic region, the heart age were all evaluated. Data analysis performed using the SAS program (version 9.3). Complex designed analysis was done. The heart age showed differences according to gender, age bracket and geographic region. The heart age is a useful comprehensive indicator for predicting the CVD events in the near future. So, it could be used for the purposes of exercising caution and guidance on CVD for administering medical care. It is strongly recommended to use heart age as an indicator for customized medical management to focus efforts on relatively vulnerable subjects and their factors for CVD. Further study on Koreans' customized heart age is needed.

• Communications of Mathematical Education
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• v.36 no.2
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• pp.287-311
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• 2022

This study was related to the cases in which pre-service elementary teachers designed math lessons tailored to math underachievers with learning trajectories and universal design for learning. Learning trajectories can be a basis to identify students' current state of understanding and development, and make a lesson plan responsively tailored to underachievers' state. And universal design for learning is a framework that removes potential barriers that may exist in math lessons from the time the lessons are planned, and guides the rich learning environment accessible to all learners. In order to provide an experience of designing math lessons considering the characteristics of math underachievers, this study required pre-service elementary teachers to create learning trajectories and make lesson plans with the principles of universal design for learning. The characteristics of the learning trajectories shown in the lesson plans and the results of applying the principles of universal design for learning were analyzed. By discussing the results, implications were derived regarding the necessity of lesson planning for math underachievers and the development of lesson planning competency of pre-service elementary mathematics teachers in teacher education.

• Resources Recycling
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• v.31 no.1
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• pp.29-36
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• 2022

The hydrogen reduction behavior of molybdenum oxides was studied using a horizontal-tube reactor. Reduction was carried out in two stages: MoO₃ → MoO₂ and MoO₂ → Mo. In the first stage, a mixed gas composed of 30 vol% H₂ and 70 vol% Ar was selected for the MoO₃ reduction because of its highly exothermic reaction. The temperature ranged from 550 to 600 ℃, and the residence time ranged from 30 to 150 min. In the second step, pure H₂ gas was used for the MoO₂ reduction, and the temperature and residence time ranges were 700-750 ℃ and 30-150 min, respectively. The hydrogen reduction behavior of molybdenum oxides was found to be somewhat different between the two stages. For the first stage, a temperature dependence of the reaction rate was observed, and the best curve fittings were obtained with a surface reaction control mechanism, despite the presence of intermediate oxides under the conditions of this study. Based on this mechanism, the activation energy and pre-exponential were calculated as 85.0 kJ/mol and 9.18 × 10⁷, respectively. In addition, the pore size within a particle increases with the temperature and residence time. In the second stage, a temperature dependence of the reaction rate was also observed; however, the surface reaction control mechanism fit only the early part, which can be ascribed to the degradation of the oxide crystals by a volume change as the MoO₂ → Mo phase transformation proceeded in the later part.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.273-281
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• 1990

Two rice varieties, Samkangbyeo and Sangpungbyeo, were transplanted on 1/2000a pots at 6 different dates beginning on May 11 with 10 day interval in 1987 and at 4 different dates beginning on May 21 with 10 day interval in a paddy field at the Chungbuk Provincial Rural Development Administration. Dry matter distributions to stem and leaf sheath, leaves and ear at different growth stages were analyzed to provide basic informations neccessary for the development of dynamic growth model. Dry matter production was reduced as transplanting was delayed and the degree of reduction was greater at the transplanting later than June 1. Dry matter distribution to stem and leaf sheath was increased up to 60-70 days after transplanting with the maximum ratio between 60-70%, which were decreased to 37-43% in pots and 27-33% in field at the end of ripening stage. On the other hand, dry matter distribution to leaf blade was decreased from 40-50% at transplanting to 11-17% at harvesting. Ear dry matter distribution increased rapidly after heading and the distribution ratio was 42-49% in pots and 52-62% in field. Although regression equations to predict dry matter distribution to different parts of rice plant were satisfactory for individual experiment, the application to different experiment was not appropriate.

• Issues in Feminism
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• v.10 no.1
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• pp.123-158
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• 2010

For the last several months, abortion debates have sparkled in Korea. The government has escalated the need of active punishment of illegal abortions to solve low fertility problems, while some obstetricians and gynecologist have proclaimed stoppage of illegal abortions suing colleague doctors who has conducted illegal abortions. Women's rights groups and researchers have also responded to the abortion debate claiming that women's decisions over their pregnancy are important in making of abortion policies. To contribute to Korean abortion debates, his paper aims to analyze European experiences of abortion polices in relation to the consequences on women's health. For the analysis of European abortion experiences, three countries - Ireland, U.K, and Netherland -are chosen. These three countries are selected since their legal and social acceptance of abortion and the level of safe abortion system are different. Each country is reviewed by national abortion policy, legal regulation, medical system and the role of civil society. The analysis shows several implications for abortion debates occurring in Korea. Various systematic policy mechanisms - abortion on women' request, abortions without complicated doctor's referrals, transparent and anonymous counseling and information provision regarding abortion, training and education for medical professionals to guarantee high quality abortion, abortions funded publicly for women to improve their access to abortions, steady monitoring and auditing abortion procedures and outcomes for safe abortion and so on - are required in Korean society. Two track procedures - safe abortion on women's request and prevention of unwanted pregnancy - are needed for reproduction of healthy women and society.

• Asia Marketing Journal
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• v.9 no.3
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• pp.209-232
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• 2007

두산은 2001년에 <산> 소주 제품으로 소주시장에 진입하였지만, 2002년도에 6.7%였던 <산> 소주의 시장 점유율이 2004년도 들어서서 5.4% 로 하락하였고, 선호도 역시 매우 낮은 수준으로 조사되어, 원인분석과 함께 새로운 소주에 대한 개발 필요성이 대두되었다. 당시 두산은 시장 선도 브랜드인 <참이슬>의 충성 고객층은 감소하면서 비호감 고객층이 증가하는 등 소주에 대한 고객의 욕구가 변화하고 있다는 시장조사 결과에서 성공의 기회를 엿볼 수 있었다. 그리고 1인당 알코올 소비량은 감소하였으나 소주의 소비량은 연간 70병으로 일정한 소비를 나타나고 있었기 때문에, 소주시장의 매력도는 아직 충분히 존재한다고 판단하였다. 그리하여 두산이 목표로 삼을 표적시장 선정을 위한 시장조사를 대대적으로 시작하였는데, 소주 음용 조사에서 30~40대의 남성들은 소비량이 감소하는 반면 여성들의 소주 소비량은 전 연령대에 걸쳐 증가하는 것으로 나타났다. 여기에서 두산은 새로운 소주시장에 대한 신제품 개발의 기회를 발견하고, 신제품 개발 프로젝트에 착수하게 되었다. 이를 위해 먼저 소주 트렌드의 변화와 소비자들의 라이프 스타일을 살펴보고, 이를 통해 '웰빙'을 신제품의 주요가치로 결정하게 된다. 이후 시장 세분화 조사를 통해 다량음용자(heavy user)가 많은 품질 중시 시장과 도수 및 숙취 중시 시장에 진입하기로 한다. 그 다음 소주에 대한 소비자들의 불만족 요인이 무엇인지 살펴보고 이를 해결하기 위한 대안들을 탐색한다. 그 결과 '목 넘김이 부드럽고, 몸의 산성화를 중화시키며, 숙취 해소'에 뛰어난 '알칼리수'를 신제품의 주원료로 사용한 <처음처럼>을 개발하게 된다. 소주의 주요 속성별 선호도 조사를 실시한 결과, 모든 속성에서 <처음처럼>이 경쟁사 제품보다 뛰어난 것으로 나타나 두산은 <처음처럼>을 시장에 출시하게 되었다. <처음처럼>은 24~35세를 목표 고객으로 설정하고, 유흥업소가 밀집한 중심상권을 집중적으로 공략하였다. 이를 위해 저가 정책을 실시하여 유통업체의 마진을 높였으며, 다양한 광고, 촉진 전략을 통해서 소비자 인지도를 향상시켰다. 그 결과 수도권 및 전국 지역에서 지속적으로 시장점유율이 증가하였으며, 소비자들에게 <참이슬>과 차별화된 이미지를 구축하게 되었다. <처음처럼>이 성공적으로 시장에 진입할 수 있었던 이유로는 알칼리수 사용, 감성적 브랜드명 채택, 차별화된 마케팅 전략 구사, 그리고 조직원의 강력한 성공 의지 등을 들 수 있다. 소주 시장의 독보적 존재였던 <참이슬>과의 경쟁에서 이루어진 결과라는 점에서 <처음처럼>의 사례는 많은 기업들에게 시사점을 제공할 수 있다. 하지만 현재 '대중성'이나 '친근감'같은 이미지가 <참이슬>에 비해 상대적으로 낮고, <참이슬 fresh>의 출시로 인해 목표 고객인 20대가 이탈되는 문제는 앞으로 <처음처럼>이 극복해야 할 과제이다. 이를 위해 <처음처럼>은 무엇보다 '웰빙 소주'로서의 이미지를 확고히 하기 위한 마케팅 전략을 실행하여야 할 것이다.