• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.30 no.4
• /
• pp.282-285
• /
• 2019

A 100-nm gate-length metamorphic high electron mobility transistor(mHEMT) with a T-shaped gate was fabricated using a two-step gate recess and characterized for DC and microwave performance. The mHEMT device exhibited DC output characteristics having drain current($I_{dss}$), an extrinsic transconductance($g_m$) of 1,090 mS/mm and a threshold voltage($V_{th}$) of -0.65 V. The $f_T$ and $f_{max}$ obtained for the 100-nm mHEMT device were 190 and 260 GHz, respectively. The developed mHEMT will be applied in fabricating W-band monolithic microwave integrated circuits(MMICs).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.272-277
• /
• 2019

In this paper, a manufacturing method of an anti-glare cover glass on LCD for outdoor use is proposed. The main specification of cover glass is hardness and anti-glare. Hardness is achieved by using the tempered glass, and anti-glare(AG) film is laminated to meet anti-glare specification no the tempered glass. However, the AG film is difficult to maintain the AG performance continuously because the abrasion resistance of the PET film itself is as weak as about 3H. Therefore, a novel production procedure using screen printing method is proposed. The proposed coating is implemented by applying $ZnO-B_2O_3-SiO_2$ powder on glass surface and the glass is made with enhanced hardness through tempering process. In order to apply the ZBS powder uniformly on the glass surface, a screen printing process is used. The main parameters to be considered in screen printing are the oil concentration and mesh opening size. Because the amount of ZBS powder applied to the printing process is controlled by these two parameters, the correlativity is confirmed through the experiments. In order to evaluate the performance of the proposed method, the haze, surface roughness and transmittance are selected as the performance index and are compared with the AG film. As a result of comparison, it is verified that the transmittance of the proposed tempered glass is 83.1%, which is slightly lower than 89.5% of AG film, but the hardness is more than double to 7H.

• Journal of the Korea Computer Graphics Society
• /
• v.24 no.5
• /
• pp.31-39
• /
• 2018

In this paper, we propose an automated method for the ground-glass nodule(GGN) classification using GGN-Net based on intensity, texture, and shape-enhanced images in chest CT images. First, we propose the utilization of image that enhances the intensity, texture, and shape information so that the input image includes the presence and size information of the solid component in GGN. Second, we propose GGN-Net which integrates and trains feature maps obtained from various input images through multiple convolution modules on the internal network. To evaluate the classification accuracy of the proposed method, we used 90 pure GGNs, 38 part-solid GGNs less than 5mm with solid component, and 23 part-solid GGNs larger than 5mm with solid component. To evaluate the effect of input image, various input image set is composed and classification results were compared. The results showed that the proposed method using the composition of intensity, texture and shape-enhanced images showed the best result with 82.75% accuracy.

• Journal of Environmental Science International
• /
• v.28 no.1
• /
• pp.85-97
• /
• 2019

Meteorological factors and air pollutants are associated with respiratory diseases, and appropriate use of weather and air quality information is helpful in the management of patients with such diseases. This study was performed to investigate both the utilization of weather and air quality information by, and the needs of, patients with respiratory diseases. Questionnaires were administered to 112 patients with respiratory diseases, 60.7% of whom were female. The rates of bronchial asthma and chronic obstructive pulmonary disease among patients were 67.0% and 10.7%, respectively. The majority of subjects (90%) responded that prevention was important for respiratory disease management and indicated that they used weather and air quality information either every day or occasionally. However, respondents underestimated the importance of weather and air quality information for disease management and were unaware of some types of weather information. The subjects agreed that respiratory diseases were sensitive to weather and air quality. The most important weather-related factors were diurnal temperature range, minimum temperature, relative humidity, and wind, while those for air quality were particulate matter and Asian dust. Information was gleaned mainly from television programs in patients aged 60 years and older and from smartphone applications for those below 60 years of age. The subjects desired additional information on the management and prevention of respiratory diseases. This study identified problems regarding the utility of weather and air quality information currently available for patients with respiratory diseases, who indicated that they desired disease-related information, including information in the form of action plans, rather than simple health- and air quality-related information. This study highlights the necessity for notification services that can be used to easily obtain information, specifically regarding disease management.

• Journal of Climate Change Research
• /
• v.2 no.3
• /
• pp.203-219
• /
• 2011

Greenhouse gas(GHG) inventories were reported recently in various fields. It, however, has been rarely to mention about the accuracy and reliability of the GHG inventory results. Some reliable assessment methods were introduced to judge the accuracy of the GHG inventory results. It is, hence, critical to develop an evaluation methodology. This project was designed 1) to develop evaluation methodology for reliability of inventory results by GHG-CAPSS, 2) to check the feasibility of the developed evaluation methodology as a result of applying this methodology to two emission sources: liquid fossil fuel and landfill, and 3) to construct the technical roadmap for future role of GHG-CAPSS. Qualitative and quantitative assessment methodologies were developed to check the reliability and accuracy of the inventory results. Qualitative assessment methodology was designed to evaluate the accuracy and reliability of estimation methods of GHG emissions from emission and sink sources, activity data, emission factor, and quality management schemes of inventory results. On the other hand, quantitative assessment methodology was based on the uncertainty assessment of emission results. According to the results of applying the above evaluation methodologies to two emission sources, those seem to be working properly. However, it is necessary to develop source-specific rating systems because emission and sink sources exhibit source-specific characteristics of GHG emissions and sinks.

• Korean Journal of Remote Sensing
• /
• v.34 no.6_1
• /
• pp.1101-1117
• /
• 2018

The clear sky radiance (CSR) is one of the baseline products of the Himawari-8 which was launched on October, 2014. The CSR contributes to numerical weather prediction (NWP) accuracy through the data assimilation; especially water vapor channel CSR has good impact on the forecast in high level atmosphere. The focus of this study is the quality analysis of the CSR of the Himawari-8 geostationary satellite. We used the operational CSR (or clear sky brightness temperature) products in JMA (Japan Meteorological Agency) as observation data; for a background field, we employed the CSR simulated using the Radiative Transfer for TOVS (RTTOV) with the atmospheric state from the global model of KMA (Korea Meteorological Administration). We investigated data characteristics and analyzed observation minus background statistics of each channel with respect to regional and seasonal variability. Overall results for the analysis period showed that the water vapor channels (6.2, 6.9, and $7.3{\mu}m$) had a positive mean bias where as the window channels(10.4, 11.2, and $12.4{\mu}m$) had a negative mean bias. The magnitude of biases and Uncertainty result varied with the regional and the seasonal conditions, thus these should be taken into account when using CSR data. This study is helpful for the pre-processing of Himawari-8/Advanced Himawari Imager (AHI) CSR data assimilation. Furthermore, this study also can contribute to preparing for the utilization of products from the Geo-Kompsat-2A (GK-2A), which will be launched in 2018 by the National Meteorological Satellite Center (NMSC) of KMA.

• Korean Journal of Remote Sensing
• /
• v.35 no.2
• /
• pp.337-342
• /
• 2019

This letter describes the development of WRI (Wildfire Risk Index) using GDAPS (Global Data Assimilation and Prediction System) and satellite data, and its application to the Goseong-Sokcho and Gangneung-Donghae wildfires in April 4, 2019. We made sure that the proposed WRI represented the change of wildfire risk of around March 19 and April 4 very well. Our approach can be a viable option for wildfire risk monitoring, and future works will be necessary for the utilization of GK-2A products and the coupling with the wildfire prediction model of the Korea Forest Service.

• Anxiety and mood
• /
• v.15 no.1
• /
• pp.45-52
• /
• 2019

Objective : The objective of this study is to determine the effects of fear of Middle East respiratory syndrome (MERS) on socio-psychological health during an outbreak of MERS and the post-traumatic stress as a mediator on the relationship between stress and socio-psychological health. Methods : Visual Analog Scale, Impact of Event Scale -Revised, Psychosocial well-being index short form was implemented for 150 medical persons who worked at the hospital in which exposure to MERS cases had been confirmed and 96 ordinary people. A Pearson correlation coefficient and a hierarchical multiple regression was carried out to confirm the effect of fear of MERS and the mediating effect of post-traumatic stress between fear and socio-psychological health. Results : The higher the fear, the lower the socio-psychological health in both healthcare workers and the public (r=0.32, p<0.01) and the higher post-traumatic stress (r=0.32, p<0.01). But, the research results showed that only healthcare workers had a partially mediating effect of post-traumatic stress in the relationship between fear and socio-psychological health (${\beta}=0.45$, t=6.33 p<0.001), (${\beta}$ value : 0.39>0.26). Conclusion : This study demonstrated that the post-traumatic stress can indirectly lead to a negative effect on the socio-psychological health of healthcare workers when under the fear of MERS and shows adverse effects on psycho-social wellbeing. This suggests that clinical intervention and psycho-social approach aiming at reducing post-traumatic stress is important to maintain mental health during crisis development.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.5
• /
• pp.60-67
• /
• 2019

In general, a reinforced concrete slabs are known to have a high fire resistance performance due to thermal properties of concrete materials. However, according to previous research, the thermal behavior of voided slabs is reported to be different from that of conventional RC solid slabs, and the differences seem to be caused by the air layer formed inside the voided slab. Therefore, it is difficult to estimate the temperature distribution of the voided slab under fire by using the existing methods that do not take into account the air layer inside the voided slab. In this study, a numerical analysis model was proposed to estimate the temperature distribution of voided slabs under fire, and evaluated. Heat transfer of slabs under fire is generally caused by conduction, convection and radiation, and time-dependent temperature changes of slab can be determined considering these phenomena. This study proposed a numerical method to estimate the temperature distribution of voided slabs under fire based on a finite difference method in which a cross-section of the slab is divided into a number of layers. This method is also developed to allow consideration of heat transfer through convection and radiation in air layer inside of slabs. In addition, the proposed model was also validated by comparison with the experimental results, and the results showed that the proposed model appropriately predicts the temperature distribution of voided slabs under fire.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.32 no.3
• /
• pp.20-31
• /
• 2019

Objectives: The seeds from Arctium lappa have been considered for its various pharmacological properties, which include anti-carcinogenic, anti-inflammatory, anti-diabetic, and anti-viral activities. Methods: In the present study, we investigated the anti-inflammatory effect of the ethanol extract from the seeds of Arctium lappa L (EAL) on cytokine-induced vascular inflammation in human umbilical vein endothelial cells (HUVEC). Results: Pretreatment with EAL significantly decreased tumor necrosis factor alpha ($TNF-{\alpha}$)-induced cell adhesion molecules expression such as intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial-selectin (E-selectin) in a dose-dependent manner. Cell adhesion assay showed that pretreatment with EAL suppressed HUVEC-monocyte adhesion by $TNF-{\alpha}$ over $1{\mu}g/ml$ concentration. We investigated the involvement of nuclear transcription factor kappa-B ($NF-{\kappa}B$) in $TNF-{\alpha}$-induced vascular inflammation. $NF-{\kappa}B$ p65 nuclear expression was induced by $TNF-{\alpha}$, however, pretreatment with EAL was attenuated that nuclear translocation. In cytoplasm, EAL was also attenuated $TNF-{\alpha}$-induced decrease of inhibitor of ${\kappa}B-{\alpha}$ ($I{\kappa}B-{\alpha}$) expression. Moreover, EAL significantly decreased $TNF-{\alpha}$-induced production of intracellular reactive oxygen species (ROS). Conclusions: Taken together, our findings suggest that seeds of Arctium lappa L could be a therapeutic herb for prevention of cardiovascular diseases throughout the inhibition of vascular endothelial inflammation.