• 한국전기전자재료학회논문지
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• 제23권11호
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• pp.875-879
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• 2010

In this study, we have characterized the roles of $Cr_2O_3$ on the sintering and electrical properties of ZnO. The densification and grain growth of Cr-doped ZnO (ZCr) system was mainly influenced by Cr contents. In the beginning of sintering, the densification of ZnO was retarded as reducing the Zni concentration in ZnO lattice with Cr doping. And the densification and grain growth of ZnO was more retarded due to a formation of spinel phase with increasing the Cr contents. ZCr system revealed varistor behavior with nonlinear coefficient $\alpha$ of 3~23 depending on the sintering temperature, implying double Schottky barrier formation on the grain boundary of ZnO. Especially the best varistor characteristics should be developed with 0.1~0.5 at% Cr contents and under $1100^{\circ}C$ in ZCr systems.

• 한국콘텐츠학회논문지
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• 제22권2호
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• pp.22-34
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• 2022

본 연구는 다양화된 영상 매체 플랫폼을 통한 공연예술 분야의 온라인 공연 콘텐츠 제작 형식과 현황을 고찰한다. 이를 위해 태양의 서커스 엔터테인먼트의 선도적 사례를 연구하여 태양의 서커스만의 브랜드 가치혁신 요소, 디지털 허브 플랫폼인 "Cirque Connect" 배경 및 현황과 오리지널 콘텐츠를 다각화한 다양한 서브 콘텐츠를 분석하였다. 공연예술 분야의 디지털 플랫폼 활용 및 서브 콘텐츠 제작은 미디어 콘텐츠 감상에 익숙한 대중의 니즈를 파악하여 공연기획 초기 단계부터 다방면의 서브 콘텐츠 생성을 고려한 전략적 기획이 필요하다. 이는 서브 콘텐츠의 질적 향상을 도모하고 다양한 문화예술분야 콘텐츠와의 차별성으로 공연예술 디지털 콘텐츠의 상품적 가치를 높일 수 있을 것이다. 온라인 플랫폼을 통해 작품과 관련된 다양한 관점의 정보를 손쉽게 접할 수 있는 환경은 빠르게 변화하는 문화향유 방식에서 공연예술분야의 대중성을 향상 시키며 공연 예술 산업의 저변확대를 가능케 할 것이다. 다변화된 문화의 흐름 속에 공연예술분야가 경쟁력을 갖기 위해서는 작품의 예술적 문화 가치를 높이는 브랜드 가치 혁신과 그것을 기반으로 하는 다양한 서브 콘텐츠 제작이 무엇보다 중요한 과제라 할 것이다.

• 한국재료학회지
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• 제14권1호
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• pp.67-72
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• 2004

The glass-forming conditions are investigated in the $K_2$O-CaO-$SiO_2$ $-P_2$$O_{5}$ system with 10~65 mole% of$ P_2$$O_{5}$. Thermal properties and dissolution properties were investigated according to variation of the SiO and KO contents in selected compositions. The glass formation condition was determined when $K_2$O/$P_2$$O_{5}$ mole ratio 0~0.24, $SiO_2$/($SiO_2$+$P_2$$O_{5}$ ) mole ratio 0～0.29, and CaO/$P_2$$O_{5}$ mole ratio 0~1.00. In the result of the thermal properties, the glass transition temperature($T_{g}$) and softening temperature($T_{s}$ ) were gradually shifted to the lower temperature range with increase of $K_2$O contents. The maximum value of the chemical durability was shown in $K_2$$PO_2$$O_{5}$ mole ratio 0.17 when the $SiO_2$ contents were changed, and $K_2$O was fixed at 10 mole%. Hence the change of the $K_2$O/$P_2$$O_{5}$ mole ratio was found that a new main factor of the chemical durability.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2018년도 춘계 종합학술대회 논문집
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• pp.485-486
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• 2018

In this paper, we consider a binary recovery framework of the Compressed Sensing (CS) problem. We derive an upper bound for $L_0$ recovery performance of a binary sparse signal in terms of the dimension N and sparsity K of signals, the number of measurements M. We show that the upper bound obtained from this work goes to the limit bound when the sensing matrix sufficiently become dense. In addition, for perfect recovery performance, if the signals are very sparse, the sensing matrices required for $L_0$ recovery are little more dense.

• 한국세라믹학회지
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• 제40권11호
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• pp.1132-1137
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• 2003

환경친화적인 유리비료로서의 응용을 위해 인산염계 유리의 용출특성에 대한 연구를 진행하였다. 0.1K₂O-0.1SiO₂-0.6P₂O/sub 5/계 유리를 기본조성으로 하고, CaO와 MgO의 함량변화를 준 다양한 유리조성에 대한 유리 형성 조건을 확인하고자 하였다. 또한 CaO 및 MgO의 함량변화에 따른 열적특성 및 용출 특성 변화를 확인하였다. MgO 함량의 증가에 따라 유리 전이온도 및 연화온도는 증가하였으며, CaO 및 MgO의 함량변화에 따라 용출특성에 큰 영향을 미치는 것을 확인하였다.

• 한국대기환경학회지
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• 제31권4호
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• pp.368-377
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• 2015

Bunker C fuel oil is a high-viscosity oil obtained from petroleum distillation as a residue. The sulfur content of bunker C fuel oil is limited to 4.0% or even lower to protect the environment. Because bunker C fuel oil is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, carbon dioxide is emitted as a result of combustion. The objective of this study is to investigate $CO_2$ emission characteristics of bunker C fuel oil by sulfur contents. Calorific values and carbon contents of the fuels were measured using the oxygen bomb calorimeter method and the CHN elemental analysis method, respectively. Sulfur and hydrogen contents, which were used to calculate the net calorific value, were also measured and then net calorific values and $CO_2$ emission factors were determined. The results showed that hydrogen content increases and carbon content decreases by reducing sulfur contents for bunker C fuel oil with sulfur contents less than 1.0%. For sulfur contents between 1.0% and 4.0%, carbon content increases as sulfur content decreases but there is no evident variation in hydrogen content. Net calorific value increases by reducing sulfur contents. $CO_2$ emission factor, which is calculated by dividing carbon content by net calorific value, decreases as sulfur content decreases for bunker C fuel oil with sulfur contents less than 1.0% but it showed relatively constant values for sulfur contents between 1.0% and 4.0%.

• 한국세라믹학회지
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• 제42권5호
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• pp.346-351
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• 2005

The linear thermal expansions of $UO_2$ and $(U_{1-y}Ce_y)O_2$ pellet were measured from room temperature to $1400^{\circ}C$ as a function of Ce contents (0, 7.63, 14.84, and $21.68 mol\%$) by using the TMA(Thermo-Mechanical Analysis) method. From the measured data, the linear thermal expansion rate, the coefficient of linear thermal expansion and density variation with temperature were calculated, and the best-fitted temperature-dependent equations were recommended. It was shown that the rate and coefficient of $(U_{1-y}Ce_y)O_2$ thermal expansion increased and the density decreased with increasing Ce contents.

• 한국식품영양학회지
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• 제32권1호
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• pp.61-68
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• 2019

In this study, the contents of water-soluble vitamins $B_1$ (thiamin), $B_2$ (riboflavin), $B_3$ (niacin), and $B_{12}$ (cyanocobalamin) in namuls (wild greens), such as salads and side dishes, consumed in Korea were quantified by high-performance liquid chromatography (HPLC) with UV and fluorescence detection. All samples were prepared with recipes used in Korea. All analyses were performed under the quality control of vitamin $B_1$, $B_2$, $B_3$, and $B_{12}$. The vitamin $B_1$, $B_2$, and $B_3$ contents in namuls consumed in Korea were analyzed. The highest content of vitamin $B_1$ was $3.018{\pm}0.016mg/100g$ in Putgochudoenjang-muchim. The highest contents of vitamin $B_2$, $B_3$, and $B_{12}$ were $0.279{\pm}0.003mg/100g$ in Gul-muchim, $12.241{\pm}0.040mg/100g$ in Chamchi-salad, and $8.133{\pm}0.371{\mu}g/100g$ in Pijogae-muchim, respectively. These results showed that animal-based ingredients in salads provided for good intake of vitamin $B_{12}$. These results can be used as basic data for food composition tables and improvement of the national health of Koreans.

• Advances in materials Research
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• 제9권2호
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• pp.99-107
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• 2020

Reinforced aluminum alloy base composites have become increasingly popular for engineering applications, since they usually possess several desirable properties. Recently, Warm Accumulative Roll Bonding (WARB) process has been used as a new novel process to fabricate particle reinforced metal matrix composites. In the present study, TiO₂ particles are used as reinforcement in aluminum metal matrix composites fabricated through warm accumulative roll bonding process. Firstly, the raw aluminum alloy 1060 strips with TiO₂ as reinforcement particle were roll bonded to four accumulative rolling cycles by preheating for 5 min at 300℃before each cycle. The mechanical and bonding properties of composites have been studied versus different volume contents of TiO₂ particles by tensile test, peeling test and vickers micro-hardness test. Moreover, the fracture surface and peeling surface of samples after the tensile test and peeling test have been studied versus different amount of TiO₂ volume contents by scanning electron microscopy. The results indicated that the strength and the average vickers micro-hardness of composites improved by increasing the volume content of TiO₂ particles and the amount of their elongation and bonding strength decreased significantly.

• 현장농수산연구지
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• 제5권1호
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• pp.28-35
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• 2003

화성지역 '캠벨얼리' 포도 포도원의 엽병의 무기성분, 수체생육 및 과실품질을 조사하였다. 토양의 물리·화학성은 Y포도원은 적정기준 농도보다 pH는 높고 유기물 함량은 낮으며 인산은 2.8배, 칼륨은 3.6배 높았으나 칼슘, 마그네슘, 양이 온치환용량은 큰 차이가 없었다. H포도원은 pH와 유기물함량은 낮고 인산, 칼륨, 칼슘 및 마그네슘 함량은 적당하였다. C포도원은 유기물함량은 낮은 편이며 인산은 3.5배 높았으나, pH, 칼륨, 칼슘, 마그네슘 및 양이온치환용량은 적당한 편이었다. 그러나 심토는 배수 잘 안 되는 토양이었다. 엽병의 질소, 칼슘 및 마그네슘 함량은 적당하였으나 인산은 Y 및 C포도원에서 기준치보다 8~6배, 칼리는 Y포도원에서 1.8배 높았다. 포도원간 과실 경도, 착색정도 및 과분발생정도는 큰 차이는 없었으나, 가용성고형물, 주당수량 및 상품과율은 Y와 H포도원에 비하여 C포도원가 현저히 떨어졌다. 생리장해 및 병 발생은 Y포도원에서 동녹 발생이 H포도원은 착색불량과가 C포도원은 수정불량과, 열과 및 탄저병 발생이 많았다.