• 대한화학회지
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• 제54권4호
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• pp.471-478
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• 2010

이 연구는 제 7차 교육과정 화학 I 교과서의 "물" 단원에 사용된 어휘들을 등급별로 분류하고, 그 적절성을 알아보는데 목적이 있다. 이를 위해 화학 I 8종 교과서의 "물" 단원에 사용된 어휘들을 표준국어대사전을 기준으로 한 SWA 프로그램을 이용하여 과학 전문어와 비과학 전문어로 나누고 그 등급을 살펴보았다. 그리고 어휘들이 11학년 학생들의 어휘 발달 수준에 적절한지의 여부를 조사하였다. 연구 결과, 과학 전문어의 등급 분포는 1등급에서 3등급까지 증가하다가 5등급까지 다시 감소하는 경향을 보였으며, 등급 외 어휘가 평균 37%로 가장 큰 비율을 나타냈다. 비과학 전문어는 1등급 어휘가 압도적으로 많았으며 5등급으로 갈수록 감소하였고, 5등급과 등급 외 어휘는 평균 18% 사용 되었다. 교과서에 사용된 부적절한 어휘는 과학전문어의 경우 5등급 6어, 등급 외 82어이며, 비과학 전문어는 5등급 53어, 등급 외 145어로 조사되었다. 그러므로 전체적인 교과서 진술 방식은 타당하나 11학년 학생들의 어휘 수준에 적절하지 못한 어휘가 상당수 있어 그 사용을 최소한으로 하고 1~4등급의 어휘로 바꾸어 진술하여 학생들의 이해 수준에 맞는 적절한 어휘로 교과서를 집필해야 함을 제안한다.

• 대한핵의학회지
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• 제17권1호
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• pp.25-31
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• 1983

Serum thyroglobulin(Tg) was measured by radioimmunoassay in 81 patients with thyroid tumor who were treated in the department of Internal medicine of National Medical Center from January, 1981 to June, 1982. The results were as follows: 1) The mean serum thyroglobulin level in thyroid tumor was significantly higher than normal subjects (p<0.001). 2) The mean serum thyroglobulin level in benign tumor was lower than malignant tumor (p<0.05). 3) The thyroid carcinoma with metastasis had significant high level of serum thyroglobulin than without metastasis (p<0.001). 4) The mean postoperative serum thyroglobulin level was significantly lower than preoperative level (p<0.001). Data from our study show that serum thyroglobulin determination is useful for assessing the presence of malignant thyroid tumor, metastasis and the extent of residual or recurrent thyroid cancer after surgery.

• Journal of Species Research
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• 제2권2호
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• pp.227-244
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• 2013

We investigated the flora of Jang-do (Isl.), an island of the Heuksan archipelago, located in Heuksan-myeon, Shinan-gun, Jeollanam-do and discussed the remarkable plants found there. Thirteen-field trips (total 27 days) were completed from May of 2004 to May of 2013. As a result, we identified the distribution of 423 taxa in Jang-do (Isl.), comprising 104 families, 285 genera, 335 species, 78 varieties and 10 forms. There are a total of 95 taxa of floristic regional indicator plants. The floristic regional indicators are as follows; four taxa of level V such as Impatiens furcillata, four taxa of level IV such as Hosta yingeri, 14 taxa of level III such as Ophioglossum vulgatum, 5 taxa of level II, and 58 taxa of level I. In addition 10 red data plants, 2 vulnerable species (VU) including Calanthe striata for. sieboldii, and 4 least concern species (LC) like Ardisia crenata, 2 not evaluated species (NE) such as Hosta yingeri, were found in the investigated area. An unrecorded species, Fragaria (Rosaceae), was found in a forest of Jang-do (Isl.) for the first time in Korea.

• 한국가시화정보학회지
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• 제22권2호
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• pp.55-62
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• 2024

Using an internal flow noise test bench, this study investigates the variation in internal flow noise at the inlet and outlet monitoring points of a DN100 T-junction pipe under different flow velocities. Results indicate that with increasing flow velocity, both the sound pressure level and total sound pressure level at the inlet and outlet monitoring points increase. The highest total sound pressure level is observed at the vertical outlet monitoring point B, followed by the horizontal inlet monitoring point A, with the lowest at the horizontal outlet monitoring point C. At a constant flow velocity, the sound pressure level at the inlet and outlet points initially increases and then decreases as frequency increases.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권1호
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• pp.34-39
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• 2014

This paper discusses the 3-level charge pumping (CP) method in planar-type Silicon-Oxide-High-k-Oxide-Silicon (SOHOS) and Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) devices to find out the reason of the degradation of data retention properties. In the CP technique, pulses are applied to the gate of the MOSFET which alternately fill the traps with electrons and holes, thereby causing a recombination current Icp to flow in the substrate. The 3-level charge pumping method may be used to determine not only interface trap densities but also capture cross sections as a function of trap energy. By applying this method, SOHOS device found to have a higher interface trap density than SONOS device. Therefore, degradation of data retention characteristics is attributed to the many interface trap sites.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.149-150
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• 2011

본 논문에서는 3-Level Vienna Converter를 간단히 제어 하기 위한 단일 반송파 비교 방식의 전압제어 방법을 제안 한다. 제안된 전압 제어 방식은 Two-Level 전압 변조 방식의 상전압 지령과 단자 전압 지령은 그대로 사용하고, 삼각파 비교부만 비엔나 정류기에 적합하게 단일 반송파를 이용한 방식으로 바꿔 SVPWM을 간단하게 구현할 수 있으며, 기존의 Two-Level 컨버터에서 적용하던 다양한 선형 변조 및 과변조 방식 등 전압제어 알고리듬과 전류제어 알고리듬 등을 Three - Level 컨버터에 쉽게 적용 할 수 있다.

• 한국산림과학회지
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• 제105권4호
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• pp.472-485
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• 2016

이 연구는 산림유전자원보호구역의 관리효과성 증진을 위하여 보호구역 관리 시스템 수준과 현장 수준에서 활용할 수 있는 관리효과성 평가틀을 개발하기 위해 수행되었다. 시스템 수준의 관리효과성 평가틀 개발을 위해 IUCN WCPA에서 개발한 관리효과성 평가틀과 IUCN, 환경부, 국립공원관리공단이 공동 개발한 보호지역 관리효과성 평가틀을 준용하여 산림유전자원보호구역에 적용할 수 있도록 평가지표들을 수정하고, 일부 지표를 추가하였다. 설문조사를 통해 평가지표(안)에 대한 전문가 32명의 의견을 수렴하여 6개 카테고리, 39개 평가지표, 42개 세부 평가항목으로 구성된 시스템 수준의 관리효과성 평가틀을 개발하였다. 현장 수준의 관리효과성 평가틀은 IUCN, 환경부, 국립공원관리공단이 공동으로 개발한 보호지역 관리효과성 평가틀을 바탕으로 산림유전자원보호구역의 특성들에 대한 평가가 가능하도록 수정하고, 관련된 새로운 평가지표들을 추가하였다. 전문가 설문조사, 산림청 및 지방자치단체들의 산림유전자원보호구역 관리 담당 공무원들을 대상으로 워크숍과 설문조사를 통해 의견을 수렴하여 6개 카테고리, 16개 평가지표, 40개 세부 평가항목으로 구성된 현장 수준의 관리효과성 평가틀을 개발하였다.

• Nutritional Sciences
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• 제3권1호
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• pp.11-17
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• 2000

This study was intended to examine whether dehydroepiandrosterone (DHEA) and dietary fat level or source could modulate glutathione utilizing detoxifying system activity and the cytosolic NADPH generation in rat liver. Male Sprague-Dawley rats were fed semipurifed diet containing either 2%(w/w) corn oil (low level of corn oil diet: 5 ca% of fat) 15% corn oil (high level of corn oil diet: 31 cal% of fat) or 13% sardine oil plus 2% corn oil(high level of fish oil diet: 31 cal% of fat) for 9 weeks. Half of the rats in each diet group were fed a diet supplemented with 0.2% DHEA (w/w). DHEA administration increased plasma total cholesterol level in low corn oil diet-fed rats. The high fish oil diet significantly decreased plasma total cholesterol level compared to the high corn oil diet. Plasma triglyceride level was not significantly changed by DHEA administration and dietary fat level and source. Fasting plasma glucose level was increased by DHEA administration and fish oil diet. Glucose 6-phosphate dehydrogenase activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration. DHEA suppressed the glutathione peroxidase, glutathione-dependent enzymes compared to the low corn oil diet, while fish oil diet elevated the activity of glutathione peroxidase and glutathione reductase compared to corn oil diet. These results suggest that DHEA administration and high level of corn oil diet may suppress the cellular detoxifying system activity through reduction of glutathione utilization, while the fish oil diet did not show these effects.

• 한국과학교육학회지
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• 제7권2호
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• pp.1-14
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• 1987

To examine the effect of students' Cognitive level upon their achievement on Science. the students' cognitive levels were tested by using GALT(Group Assessment of Logical Thinking) and examined the Correlation between the cognitive level and achievement According to the results, most students were still in the conerete level. Only 60% of 9th grade students could handle the logic of displacement volume. In case of proportional logic and logic of probability, only 40% of 9th graders could handle them. Only 10% of the students could understand Correlational logic. Cognitive level and students achievement were estimated to be in a very closely related. Students who were in a high cognitive level showed better achievement scores on knowledge, comprehensive, inquiry, and application items than those who were in low cognitive level. Therefore, this study suggests that the content of the current middle school science should be revised in away to match the students' cognitive level.

• 한국초전도ㆍ저온공학회논문지
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• 제24권1호
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• pp.29-33
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• 2022

Recently, development of a cryogenic fluids storage tank for storing or transporting liquid hydrogen is actively in progress. In cryogenic fluids storage tanks, hydrogen evaporates due to the extreme temperature difference inside and outside the tank. As the mass of the cryogenic fluids changes with continuous vaporization, the fluids level also changes. Therefore, there is need for a method of accurately measuring the level change in the storage tank. In the case of general cryogenic fluids, it is difficult to accurately measure the level because the dielectric constant is very low. As a method of measuring cryogenic fluids level with low dielectric constant, it can be used an Millimeter wave (MM wave) FMCW radar sensor. However, the signal sensitivity is very weak and the level accuracy is poor. In this paper, the signal sensitivity is improved by designing the horn lens antenna of the existing 80 GHz FMCW radar sensor. Horn lens antenna is fabricated by FDM/SLA type 3D printer according to horn and lens characteristics. The horn is used to increase the signal gain and the lens improves the signal straightness. This makes it possible to measure the level of cryogenic fluids with a low dielectric constant.