대면적 저누설 커패시터를 위한 최적화 블레이드 코팅 기반 고분자 유전체 프린팅

서경호 ( Kyeong-ho Seo ),배진혁 ( Jin-hyuk Bae ) 한국센서학회 2021 센서학회지 Vol.30 No.1

We demonstrated a polymer dielectric with low leakage characteristics through an optimal blade coating method for low-cost and large-scale fabrication of metal-insulator-metal (MIM) capacitors. Cross-linked poly(4-vinylphenol) (C-PVP), which is a typically used polymer dielectric, was coated on a 10 × 10 cm indium-tin-oxide (ITO) deposited glass substrate by changing the deposition temperature (T_D) and coating velocity (V_C) in the blade coating. During the blade coating, the thickness of the thin c-PVP varied depending on T_D and V_C owing to the ‘Landau-Levich (LL) regime’. The c-PVP-dielectric-based MIM capacitor fabricated in this study showed the lowest leakage current characteristics (10^-6 A/cm² at 1.2MV/cm², annealing at 200 °C) and uniform electrical characteristics when TD was 30 °C and V_C was 5mm/s. In addition, at T_D = 30 °C, stable leakage characteristics were confirmed when a different electric field was applied. These results are expected to positively contribute to applications with next-generation electronic devices.

GIS 및 MODIS 영상을 활용한 행정구역별 도시열섬강도 분석

서경호 ( Kyeong-ho Seo ),박경훈 ( Kyung-hun Park ) 한국지리정보학회 2017 한국지리정보학회지 Vol.20 No.2

This study was conducted to analyze the urban heat island(UHI) intensity of South Korea by using Moderate Resolution Imaging Spectroradiometer(MODIS) satellite imagery. For this purpose, the metropolitan area was spatially divided according to land cover classification into urban and non-urban land. From the analysis of land surface temperature(LST) in South Korea in the summer of 2009 which was calculated from MODIS satellite imagery it was determined that the highest temperature recorded nationwide was 36.0℃, lowest 16.2℃, and that the mean was 24.3℃, with a standard deviation of 2.4℃. In order to analyze UHI by cities and counties, UHI intensity was defined as the difference in average temperature between urban and non-urban land, and was calculated through RST1 and RST2. The RST1 calculation showed scattered distribution in areas of high UHI intensity, whereas the RST2 calculation showed that areas of high UHI intensity were concentrated around major cities. In order to find an effective method for analyzing UHI by cities and counties, analysis was conducted of the correlation between the urbanization ratio, number of tropical heat nights, and number of heat-wave days. Although UHI intensity derived through RST1 showed barely any correlation, that derived through RST2 showed significant correlation. The RST2 method is deemed as a more suitable analytical method for measuring the UHI of urban land in cities and counties across the country. In cities and counties with an urbanization ratio of < 20%, the rate of increase for UHI intensity in proportion to increases in urbanization ratio, was very high; whereas this rate gradually declined when the urbanization ratio was > 20%. With an increase of 1℃ in RST2 UHI intensity, the number of tropical heat nights and heat wave days was predicted to increase by approximately five and 0.5, respectively. These results can be used for reference when predicting the effects of increased urbanization on UHI intensity.

VaRTM과 VAP 공정의 수지 충진실험 및 해석에 관한 연구

윤동환,서경호,권유정,최진호,Dong-Hwan Yoon,Kyeong-Ho Seo,Yu-Jung Kwon,Jin-Ho Choi 한국복합재료학회 2023 Composites research Vol.36 No.5

VaRTM(Vacuum assisted resin transfer molding) and VAP(Vacuum assisted process) processes are a type of RTM(Resin transfer molding) process, and are typical out-of-autoclave (OOA) processes that can manufacture large structures at low cost. In this paper, a resin filling test was conducted to compare the VaRTM and VAP processes, and the filling process and dimensional stability were compared. In addition, an analysis method to simulate the filling process was developed, and a dielectric sensor was used to detect the flow front of the resin, which was compared with the analysis results. From the resin filling test, the total filling time of the composite plate was measured to be 48 minutes for the VAP process and 145 minutes for the VaRTM process, and the filling time by the VAP process was reduced by about 67%. In addition, it was confirmed that the VAP process was superior to the VaRTM process in the thickness control ability and uniformity of the composite plate.

3-차원 보강 복합재 체결부의 피로강도 특성 연구

김지완,안우진,서경호,최진호,Kim, Ji-Wan,An, Woo-Jin,Seo, Kyeong-Ho,Choi, Jin-Ho 한국복합재료학회 2022 Composites research Vol.35 No.5

Composite lap joints have been extensively used due to their excellent properties and the demand for light structures. However, due to the weak mechanical properties in the thickness direction, the lap joint is easily fractured. various reinforcement methods that delay fracture by dispersing stress concentration have been applied to overcome this problem, such as z-pinning and conventional stitching. The Z-pinning is reinforcement method by inserting metal or carbon pin in the thickness direction of prepreg, and the conventional stitching process is a method of reinforcing the mechanical properties in the thickness direction by intersecting the upper and lower fibers on the preform. I-fiber stitching method is a promising technology that combines the advantages of both z-pinning and the conventional stitching. In this paper, the static and fatigue strengths of the single-lap joints reinforced by the I-fiber stitching process were evaluated. The single-lap joints were fabricated by a co-curing method using an autoclave vacuum bag process and I-fiber reinforcing effects were evaluated according to adherend thickness and stitching angle. From the experiments, the thinner the composite joint specimen, the higher the I-fiber reinforcement effect, and Ifiber stitched single lap joints showed a 52% improvement in failure strength and 118% improvement in fatigue strength.

K-POP 커버댄스 운동이 청소년 폭력 관련 심리 변인 및 혈중 호르몬 농도에 미치는 영향

서태범(Tae-Beom Seo),김영숙(Young-Sook Kim),김유미(Yu-mi Kim),강민정(Min-Jeong Kang),서경호(Kyeong-Ho Seo),박해찬(Hae-Chan Park) 한국생활환경학회 2015 한국생활환경학회지 Vol.22 No.5

The purpose of this study was to examine the effect of K-POP cover dance on violence related psychological factors, blood hormones, and neurotransmitters in adolescents. Participants in this study were 30 males and females taken blood sample and surveyed. All participants were performed K-POP cover dance (50~75%MHR, 80 min/day, 3days/week) during 8 weeks. School stress, assumed stress, interpersonal stress, ego stress were composed the stress factors. Body and verbal aggression, propriety, anger were composed aggression factors. School stress, assumed stress, interpersonal stress, ego stress were decreased significantly on K-POP cover dance. Also, body and verbal aggression, propriety, doubt, anger were decreased significantly on K-POP cover dance. Cortisol, melatonin, beta-endorphin, serotonin, dopamin were composed violence related blood factors. Cortisol were decreased significantly, but melatonin and dopamin were no significantly on K-POP cover dance. It is concluded that K-POP cover dance caused positive effects on violence and stress, stress related blood hormones.

GIS 공간내삽법을 활용한 PM_2.5 분포 특성 분석 - 창원시 도시지역을 대상으로 -

문한솔 ( Han-sol Mun ),송봉근 ( Bong-geun Song ),서경호 ( Kyeong-ho Seo ),김태형 ( Tae-hyeung Kim ),박경훈 ( Kyung-hun Park ) 한국지리정보학회 2020 한국지리정보학회지 Vol.23 No.2

The purpose of this study was to analyze the distribution characteristics of spatial and temporal PM_2.5 in urban areas of Changwon-si, and to identify the causes of PM_2.5 by comparing the characteristics of land-use, and to suggest the direction of reduction measures. As the basic data, the every hour average from September 2017 to August 2018 of Airpro data, which has measurement points in kindergartens, elementary schools, and some middle and high schools in Changwon-si was used. Also, by using IDW method among spatial interpolation methods of GIS, monthly and time-slot distribution maps were constructed, and based on this, spatial and temporal PM_2.5 distribution characteristics were confirmed. First, to verify the accuracy of the Airpro data, the correlation with AirKorea data managed by the Ministry of Environment was confirmed. As a result of the analysis, R² was 0.75~0.86, showing a very high correlation and the data was judged that it was suitable for the study. In the monthly analysis, January was the highest year, and August was the lowest. As a result of analysis by time-slot, The clock-in time at 06-09 was the highest, and the activity time at 09-18 was the lowest. By administrative district, Sangnam-dong, Happo-dong, and Myeonggok-dong were the most severe regions of PM_2.5 and Hoeseong-dong was the lowest. As a result of analyzing the land-use characteristics by administrative area, it was confirmed that the ratio of traffic area and commercial area is high in the serious area of PM_2.5. In conclusion, the results of this study will be used as basic data to grasp the characteristics of PM2.5 distribution in Changwon-si. Also, it is thought that the severe regions and the direction of establishing reduction measures derived from this study can be used to prepare more effective policies than before.

UAV 열적외 영상을 활용한 피복재질별 표면온도 특성 분석

송봉근 ( Bong-geun Song ),김경아 ( Gyeong-ah Kim ),서경호 ( Kyeong-ho Seo ),이승원 ( Seung-won Lee ),박경훈 ( Kyung-hun Park ) 한국지리정보학회 2018 한국지리정보학회지 Vol.21 No.3

The purpose of this study was to analyze the surface temperature of surface fabrics using UAV TIR images, to mitigate problems in the thermal environment of urban areas. Surface temperature values derived from UAV images were compared with those measured in-situ during the similar period as when the images were taken. The difference in the in-situ measured and UAV image derived surface temperatures is the highest for gray colored concrete roof fabrics, at 17℃, and urethane fabrics show the lowest difference, at 0.3℃. The experiment power of the scatter plot of in-situ measured and UAV image derived surface temperatures was 63.75%, indicating that the correlation between the two is high. The surface fabrics with high temperature are metal roofs(48.9℃), urethane(43.4℃), and gray colored concrete roofs(42.9℃), and those with low temperature are barren land(30.2℃), area with trees and lawns(30.2℃), and white colored concrete roofs(34.9℃). These results show that accurate analysis of the thermal characteristics of surface fabrics is possible using UAV images. In future, it will be necessary to increase the usability of UAV images via comparison with in-situ data and linkage to satellite imagery.

유산소성 운동이 노인들의 신체조성과 등속성 슬관절 근력 및 요부근력에 미치는 영향

한종우(Jong Woo Han),이상석(Sang Sug Lee),송분도(Bun Do Song),지용석(Yong Suk Ji),김난수(Nan Su Kim),서경호(Kyeong Ho Seo) 한국사회체육학회 2000 한국사회체육학회지 Vol.13 No.-

This study was designed to investigate the effect of a year aerobic exercise training on body composition, isokinetic knee and trunk muscular strength of elders. The subjects for this study were eighty healthy elderly people who were members of seniors tower at Song-Do Hospital and didn`t have any history of cardiorepiratory disease. Subjects have been trained three times a week for a year. The exercise program was made up of a 15-minute warm-up, cool-down. Stretching was performed every eight minutes for the prevention of injuries which could occur during the main exercise and quick recovery of the used muscle. Aerobic training was performed for each 15-20minutes using the treadmill and cycle ergometer at the intensity of 50-70% HRmax. For the data, all the measurements were represented by mean and standard deviation using SAS package(version 6.12). Statistical techniques for data analysis were paired t-test to determine the difference between pre and post exercise program. The 5% level of significance was used as the critical level for acceptance of hypotheses for the study. The following results were obtained from this study. 1. There is a statistically significant difference in the VO_2max, fat mass, lean mass and %body fat both old men and women after a year training. 2. There is not a statistically significant difference in the weight, WHR and thigh circumference both old men and women after a year training. 3. There is a statistically significant difference in the right knee flexor/extensor peak torque, peak torque % body weight, total work and total work % body weight both old men and women after a year training. 4. There is a statistically significant difference in the left knee flexor/extensor peak torque, peak torque % body weight, total work and total work % body weight both old men and women after a year training.

UAV를 활용한 고해상도 지도 제작 및 농업지역 비점오염 영향 인자 조사

김경아(Gyeong-Ah Kim),박경훈(Kyung-Hun Park),문병현(Byung-Hyun Moon),배은택(Eun-Taek Bae),이승원(Seung-Won Lee),김성현(Seoung-Hyeon Kim),박건웅(Geon-Ung Pack),서경호(Kyeong-Ho Seo),송봉근(Bong-Geun Song) 대한공간정보학회 2018 한국지형공간정보학회 학술대회 Vol.2018 No.11

장기간 복합운동이 고령자의 심폐기능과 신체조성에 미치는 영향

김성수(Sung Soo Kim),심영제(Young Jae Sim),황문현(Moon Hyeon Hwang),변재종(Jae Jong Byeon),최요섭(Yo Seob Choi),서경호(Kyeong Ho Seo),김만겸(Man Kyeom Kim) 한국사회체육학회 2000 한국사회체육학회지 Vol.13 No.-

This study was designed to investigate the effect of a year aerobic combined with resistance weight training on cardiorespiratory function and body composition of elders. The subjects for this study were thirty healthy elderly people who were members of seniors tower at Song-Do hospital and didn`t have any history of cardiorepiratory disease. The subjects were divided into two groups: aerobic combined with resistance weight training group(n=16), and aerobic training group(n=14). Both groups have been trained three times a week for a year. The exercise program for both groups was made up of a 15-minute warm-up, cool-down. Stretching was performed every ten minutes for the prevention of injuries which could occur during the main exercise and quick recovery of the used muscle. Aerobic training was performed for each 10-20minutes using the treadmill and cycle ergometer at the intensity of 50-70% HRmax. The resistance weight training was performed for each 3set using the reg press, reg extension, reg curl, back extension, abdominal flexion, and torso at 60% of one-repetition maximum. One repetition maximum(1RM) of each person in all the six terms measured prior to training performance. For the data, all the measurements were represented b, mean(M) and standard deviation(SD) using SAS Package(version 6.12). Statistical techniques for data analysis were ANCOVA to determine the difference among groups. The 5% level of significance was used as the critical level for acceptance of hypotheses for the study. The following results were obtained from this study. 1. In the aerobic exercise group and the aerobic combined with resistance weight training group, rest RPP decreased significantly after a year training. 2. In the aerobic exercise group and the aerobic combined with resistance weight training group, there wasn`t a significant difference in rest HR after a year training. 3. In the aerobic exercise group and the aerobic combined with resistance weight training group, there wasn`t a significant difference in V02max after a year training. 4. In the aerobic exercise group and the aerobic combined with resistance weight training group, there wasn`t significant difference in rest systolic blood pressure while diastolic blood pressure decreased significantly after a year training. 5. In the aerobic exercise group and the aerobic combined with resistance weight training group, waist to hip ratio decreased significantly while fat mass(kg), %body fat, and lean body mass(kg) weren`t significant difference after a year training. In conclusion, the result of this study suggests that this kind of aerobic combined with resistance weight training can contribute to the better improvement in the cardiorespiratory function. In the changes of body composition, though there was only decreased significant waist to hip ratio between the two groups. Although the statistical significance of the change was not discovered, aerobic combined with resistance weight training group showed that the tendency of fat mass(kg), %body fat loss and lean body mass(kg) were increased after a year training. Therefore, carrying out a long period of aerobics and resistance weight training at the same time is considered to be proper exercise programs to the development risk of heart disease and to prevent all kinds of regressive diseases and reduce body fat in elderly people. More effective and various exercise programs should be developed in the near future to be helpful with the elderly people.