• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.12-14
• /
• 2022

One of the most negative social changes of the last decade is population aging which leads to 19 times more patients with Mild Cognitive Disorder(MCI). It is well established that MCI is the most important state that can prevent dementia with early diagnosis and intervention. However, the social security system for patients with dementia is not working properly due to the coronavirus pandemic and the limited human power. This article proposes design principles for dementia training programs of extended reality devices. and The findings in this study provide a guide for considering the cognitive and physical and social functions of patients.

• Journal of Engineering Education Research
• /
• v.26 no.2
• /
• pp.45-53
• /
• 2023

This study conducted and evaluated the PBL-based team activity classes in contact and untact learning. Appropriate subject (Engineering communication) was also selected and evaluation methods were improved. In the qualitative evaluation results, in contact learning, similar score ranges were formed for each task, and the variability of scores for each task was not large. In untact learning, the difference in scores for each task was rather large, and the variability of scores for each task was large, indicating a large difference between teams that performed well and teams that did not. In the quantitative evaluation, contact learning showed a little low grades, but untact learning showed relatively high grades, but there were limitations in showing the conclusion that the untact learning effect was very good. As a result of the survey, there were more positive responses to the degree of understanding of the class conducted online, the degree of help to improve competence, and the team activity. However, if untact learning continues, it was analyzed that it is necessary to prepare appropriate measures to enhance learning effects and efficiently conduct team activities.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.167.2-167.2
• /
• 2015

고 이동도(~10 cm/Vs), 낮은 공정온도 및 높은 투과율 등의 특성을 갖는 산화물 반도체는 저 소비전력, 대면적화 및 고해상도 LCD Panel에 적합한 재료로서 현재 일부 Mobile Panel 및 TFT-LCD Panel의 양산에 적용되고 있으나, 향후 UHD급(4 K, 8 K)의 대형, 고해상도 Panel에의 적용을 위해서는 30 cm2/Vs 이상의 고 이동도 재료의 개발 및 저 저항 배선의 적용에 따른 소자 신뢰성의 개선이 필요하다. Cu는 대표적인 저 저항 배선 재료로 일부 양산에 적용되고 있으나, Cu 전극과 산화물 반도체의 계면에서 Cu원자의 확산 및 Cu-O 층의 형성에 의한 소자 특성 저하의 문제가 있다. 본 연구에서는 고 이동도의 In doped-ZTO계 산화물 반도체를 기반으로 채널 층과 Cu source-Drain layer의 계면에서의 Cu element의 거동 및 TFT 소자 특성과의 상관관계를 고찰하고, 계면에 형성된 Cu-O layer에 대해 높은 전자 친화도를 갖는 Ca element를 첨가에 의한 TFT 소자 특성의 변화를 관찰하였다. 본 연구에서는 이러한 효과로 인한 소자 신뢰성의 향상을 기대하였으며, 우선 In doped-ZTO 채널 층에 Cu와 CuCa 2at% source-drain을 적용한 TFT 특성을 확인하였다. 그 결과, Cu는 Field-effect mobility: ~17.67 cm2/Vs, Sub-threshold swing: 0.76 mV/decade 및 Vth:, 4.40 V의 결과가 얻어졌으며 CuCa 2at%의 경우 Field-effect mobility: ~17.84 cm2/Vs, Sub-threshold swing: 0.86 mV/decade 및 Vth:, 5.74 V의 결과가 얻어졌다. 소자신뢰성 측면에서도 Bias Stress의 변화량 ${\delta}Vth$의 경우 Cu : 4.48 V에 대해 CuCa 2at% : 2.81 V로 ${\delta}Vth$:1.67 V의 개선된 결과를 얻었다.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.13 no.5
• /
• pp.235-240
• /
• 2003

The development of large area GaN substrates is one of important issues in expanding of GaN-based applications. In order to investigate the possibility, GaN thick films were grown by a sublimation technique, using MOCVD-GaN films grown on a sapphire as a seed-crystal substrate and a commercial GaN powder as a source material. The pressure in chamber under the fixed flow rate of $N_2$ gas and $NH_3$ gas was kept at 1 atmosphere and the effects of the various processing parameters such as the distance between source material and seed crystal, the temperature of top- and bottom heater and the growth time during the growth of GaN thick film were investigated. The growth feature and microstructure of the GaN thick films were observed by SEM and XRD. The optical bandgap properties and the defects were evaluated by the PL measurement. By these results, the growth conditions such as the distance between the GaN source and the seed substrate, the growth temperature and the growth time were determined for the satisfied growth of GaN thick films.

• Explosives and Blasting
• /
• v.38 no.2
• /
• pp.1-12
• /
• 2020

Digital Image Correlation is a well-established method for displacements, strains and shape measurements of engineering objects. Stereo-camera 3D Digital Image Correlation (3D-DIC) systems have been developed to match the specific requirements for measurements posed by material and mechanical industries. Although DIC method provides the capabilities of scaling a field-of-view(FOV), dimensions of Geotechnical structure objects in many cases are too big to be measured with DIC based on a single camera pair. It can be the most important issue with applying 3D DIC to the measurement of Geotechnical structures. In this paper, We were present stereo vision conditions in a 3D DIC system that can be measured for large FOV(30×20m) and high precisions(z-displacement 0.5mm) of the ground objects with Stereo-camera DIC systems.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.3
• /
• pp.91-98
• /
• 2012

The objective of this study was to analyze the effects on the growth of Sedum species by different soil in shallow green roof module system, and to find the best soil mixture. The experiment used a module system, 7cm soil depth, five types of soil mixture ratio, and it was carried out on 7th Hoar rooftop in December of 2010. The growth status of the plant showed the most superior of the P5C7P2V1, next P10C1P2V1 and P1P1V1, P1 and C1 showed very poor growth. This result showed that the soil mixture ratio (P5C7P2V1) in green roof module system with minimum management can contribute to the proliferation of rooftop greening in urban settings.

• Korean Journal of Plant Resources
• /
• v.14 no.3
• /
• pp.229-234
• /
• 2001

In order to investigate the possibility of utilizing small cermet as a seed corm in taro, the small cermets classified by the weight were planted on April 30,2000. The effect of weight of small cermets(5,10, If,20,25, and 30g) and corms on the growth, yield, and quality of taro was compared to those raised from cermets. The larger the size of cormel was, the more number of leaves developed, and the higher the yield was. Also the growth of small cormel was normal, so we forecast that it is possible to use small cermet as seed corm in mass production of taro.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.32 no.3
• /
• pp.163-185
• /
• 2021

In the face of unprecedented pandemics, School libraries should also seek ways to provide non-face-to-face services in an online environment differentiated from existing services, which were mainly limited to face-to-face activities. This study is a basic study for school library services using the operation of YouTube channels. Thourgh the FGI was conducted on teacher librarians of school libraries who are operating YouTube channel, we investigated the awareness, necessity, and specific requirements of school libraries. Furthermore, The second interview to verify the feasibility of our propose ways to activate the operation of school libraries on YouTube in the future.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.29 no.3
• /
• pp.245-252
• /
• 2009

The grassland establishment under the forest become important, but it comes with a shade for the grass growing among trees. The objective of this study is to select the proper grass-clover mixtures to several shading degrees. The grass-clover mixtures were grown under full sunlights and shade cloths, which reduce sunlight intensity by 35, 50 and 75%. The various types of mixtures were allocated at each shading degrees with three replications. The productivity of mixtures was the highest under full sunlights, and intermediate with 35% degree of shading and least with both 50 and 75% degrees of shading. The 1st mixture (orchardgrass+tall fescue+Kentucky bluegrass+ladino clover+perennial ryegrass+timothy) showed the greatest yield in all treatments. The crude protein (CP) concentration of all mixtures increased with the higher degree of shading, but no CP concentration difference was observed in mixtures within same degree of shading. The lowest neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations and highest relative feed value (RFV) were resulted in the 1st mixture in all treatments. This study indicates that tall fescue, Kentucky bluegrass, ladino clover, perennial ryegrass and timothy can be used as components for mixtures with orchardgrass which is major component for forest-pastures.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2000.02a
• /
• pp.76-76
• /
• 2000

최근 비정질 SiC 박막은 열과 광안정도면에서 비정질 Si 박막에 비해 우수하며 공정변수들을조절함으로써 비교적 쉽고 다양하게 광학적.전기적 특성을 얻을 수 있고, 낮은 광흡수계수 및 105($\Omega$cm)1 이상의 높은 전도도를 가지고 있어 Plasma Enhanced Chemical Vapor Deposition(PECVD)을 통해 가전자제어 (Valency electron control)가 가능한 비정질 SiC 박막이 제작된 이래 대한 많은 연구가 진행되고 있다. 결정성이 없는 비정질 물질은 상대적으로 낮은 온도에서 성장이 가능하며, 특히 glow-sidcharge 방식으로 저온에서 성장시킬 수 있음에 따라 유리등과 같은 다른 저렴한 물질을 기판으로 이용, 넓은 면적의 비정질 SiC 박막을 성장시켜 여러 분야의 소자에 응용되고 있다. 비정질 SiC 박막이 넓은 에너지띠 간격을 갖는 물질이라는 점과 화학적 안정성 및 높은 경도, 비정질성에 기인한 대면적 성장의 용이성 등의 장점이외에, 원자의 성분비 변화에 의해 에너지띠 간격(1.7~3.1eV)을 조절할 수 있다는 점은 광전소자의 응용에 큰 잠재성이 있음을 나타낸다. PECVD 방식으로 성장된 비정질 SiC 박막은 태양전지의 Window층이나 발광다이오드, 광센서, 광트랜지스터 등에 응용되어 오고 있다. 본 연구에서는, RF-PECVD(ULVAC CPD-6018) 방법에 의하여 비정질 Si1-xCx 박막을 2.73Torr의 고정된 압력에서 RF 전력(50~300W), 증착온도(150~30$0^{\circ}C$), 주입 가스량 (SiH4:CH4)등의 조건을 다양하게 변화시켜가며 증착된 막의 특성을 평가하였다. 성장된 박막을 X-ray Photoelectron Spectroscopy(XPS), UV-VIS spectrophotometer, Ellipsometry, Atomic Force Microscopy(AFM)등을 이용하여 광학적 밴드갭, 광흡수 계수, Tauc Plot, 그리고 파장대별 빛의 투과도의 변화를 분석하였으며 각 변수가 변화함에 따라 광학적 밴드갭의 변화를 정량적으로 조사함으로써 분자결합상태와 밴드갭과 광 흡수 계수간의상관관계를 규명하였고, 각 변수에 따른 표면의 조도를 확인하였다. 비정질 Si1-xCx 박막을 증착하여 특성을 분석한 결과 성장된 박막의 성장률은 Carbonfid의 증가에 따라 다른 성장특성을 보였고, Silcne(SiH4) 가스량의 감소와 함께 박막의 성장률이 둔화됨을 볼 수 있다. 또한 Silane 가스량이 적어지는 영역에서는 가스량의 감소에 의해 성장속도가 둔화됨을 볼 수 있다. 또한 Silane 가스량이 적어지는 영역에서는 가스량의 감소에 의해 성장속도가 줄어들어 성장률이 Silane가스량에 의해 지배됨을 볼 수 있다. UV-VIS spectrophotometer에 의한 비정질 SiC 박막의 투과도와 파장과의 관계에 있어 유리를 기판으로 사용했으므로 유리의투과도를 감안했으며, 유리에 대한 상대적인 비율 관계로 투과도를 나타냈었다. 또한 비저질 SiC 박막의 흡수계수는 Ellipsometry에 의해 측정된 Δ과 Ψ값을 이용하여 시뮬레이션한 결과로 비정질 SiC 박막의 두께를 이용하여 구하였다. 또한 Tauc Plot을 통해 박막의 optical band gap을 2.6~3.7eV로 조절할 수 있었다.