• Title/Summary/Keyword: Lee Ji-Ham

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Patrol Monitoring Plan for Transmission Towers with a Commercial Drone and its Field Tests (상용화 드론을 이용한 송전선로 점검방안 및 현장시험)

  • Kim, Seok-Tae;Park, Joon-Young;Lee, Jae-Kyung;Ham, Ji-Wan;Choi, Min-Hee
    • KEPCO Journal on Electric Power and Energy
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    • v.4 no.2
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    • pp.115-123
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    • 2018
  • Various types of robots running on power transmission lines have been developed for the purpose of line patrol monitoring. They usually have complex mechanism to run and avoid obstacles on the power line, but nevertheless did not show satisfactory performance for going over the obstacles. Moreover, they were so heavy that they could not be easily installed on the lines. To compensate these problems, flying robots have been developed and recently, multi-copter drones with flight stability have been used in the electric power industry. The drones could be remotely controlled by human operators to monitor power distribution lines. In the case of transmission line patrol, however, transmission towers are huge and their spans are very long, and thus, it is very difficult for the pilot to control the patrol drones with the naked eye from a long distance away. This means that the risk of a drone crash onto electric power facilities always resides. In addition, there exists another danger of electromagnetic interference with the drones on autopilot waypoint tracking under ultra-high voltage environments. This paper presents a patrol monitoring plan of autopilot drones for power transmission lines and its field tests. First, the magnetic field effect on an autopilot patrol drone is investigated. Then, how to build the flight path to avoid the magnetic interference is proposed and our autopilot drone system is introduced. Finally, the effectiveness of the proposed patrol plan is confirmed through its field test results in the 154 kV, 345 kV and 765 kV transmission lines in Chungcheongnam-do.

Effect of Korea red ginseng on nonalcoholic fatty liver disease: an association of gut microbiota with liver function

  • Hong, Ji Taek;Lee, Min-Jung;Yoon, Sang Jun;Shin, Seok Pyo;Bang, Chang Seok;Baik, Gwang Ho;Kim, Dong Joon;Youn, Gi Soo;Shin, Min Jea;Ham, Young Lim;Suk, Ki Tae;Kim, Bong-Soo
    • Journal of Ginseng Research
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    • v.45 no.2
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    • pp.316-324
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    • 2021
  • Background: Korea Red Ginseng (KRG) has been used as remedies with hepato-protective effects in liver-related condition. Microbiota related gut-liver axis plays key roles in the pathogenesis of chronic liver disease. We evaluated the effect of KRG on gut-liver axis in patients with nonalcoholic statohepatitis by the modulation of gut-microbiota. Methods: A total of 94 patients (KRG: 45 and placebo: 49) were prospectively randomized to receive KRG (2,000 mg/day, ginsenoside Rg1+Rb1+Rg3 4.5mg/g) or placebo during 30 days. Liver function test, cytokeraton 18, and fatigue score were measured. Gut microbiota was analyzed by MiSeq systems based on 16S rRNA genes. Results: In KRG group, the mean levels (before vs. after) of aspartate aminotransferase (53 ± 19 vs. 45 ± 23 IU/L), alanine aminotransferase (75 ± 40 vs. 64 ± 39 IU/L) and fatigue score (33 ± 13 vs. 26 ± 13) were improved (p < 0.05). In placebo group, only fatigue score (34 ± 13 vs. 31 ± 15) was ameliorated (p < 0.05). The changes of phyla were not statistically significant on both groups. In KRG group, increased abundance of Lactobacillus was related with improved alanine aminotransferase level and increased abundance of Clostridium and Intestinibacter was associated with no improvement after KRG supplementation. In placebo group, increased abundance of Lachnospiraceae could be related with aggravation of liver enzyme (p < 0.05). Conclusion: KRG effectively improved liver enzymes and fatigue score by modulating gut-microbiota in patients with fatty liver disease. Further studies are needed to understand the mechanism of improvement of nonalcoholic steatohepatitis. ClnicalTrials.gov: NCT03945123 (www.ClinicalTrials.gov).

Study on the relevance of dietary behavior and oral management by periodontal assessment and survey (치주검사와 설문조사를 통한 성인의 구강건강관리행태 및 식이행태와 치주질환과의 관련성)

  • Moon, Sang-Eun;Hong, Sun-Hwa;Kim, Hui-Jeong;Seo, Ga-hye;Park, Jin-Ah;Lee, Ji-Yeon;Jeong, Ju-Yeong;Choi, Jong-Im;Park, Seon-Mi;Park, Jin-A;Han, In-Hwa
    • Journal of Korean society of Dental Hygiene
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    • v.20 no.6
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    • pp.949-961
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    • 2020
  • Objectives: This study investigated the relevance of dietary behavior and oral management for oral heath in adults to extend the recognition of the importance of food intake in oral health and to provide basic information for oral health management. Methods: A survey and clinical assessment were conducted for 119 adults over 20 years of age. The chi-square test and logistic regression analysis were carried out using SPSS Statistics 20.0. Results: Gingivitis was influenced less when ham and sausage in the sub-area of meat, fish, egg, and bean were consumed once a week rather than the cases when consumed rarely (3.47 times) or when consumed two times or more a week (7.87 times) (p<0.05). Periodontitis was influenced more in the groups of 30s and 40s age than in that of over 50 years of age (14.97 times, 7.73 times) and in the group without drinking experience than in group with that (4.17 times) (p<0.05). Conclusions: The results verified the close relationship between food intake frequency and oral health in patients with periodontitis and gingivitis. Thus, it would be necessary to study the relationship between dietary behavior and oral health continuously.

The effect of Temperature Reduction of Green Roof using Rainwater Storage Tank (빗물 저류 시스템을 활용한 옥상 녹화의 온도 저감 효과)

  • Yun, Seok-Hwan;Kim, Eun-Sub;Piao, Zheng-Gang;Jeon, Yoon-Ho;Kang, Hye-Won;Kim, Sang-Hyuck;Kim, Ji-Yeon;Kang, Han-Min;Ham, Eun-Kyung;Lee, Dong-Kun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.24 no.6
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    • pp.109-119
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    • 2021
  • Thermal environment of city is getting worse due to severe urban heat island caused by climate change and urbanization. Green roof improves the urban thermal environment and save the cooling energy in buildings. This study presented a green roof combined with a storage system that stores rain-water and supplies water through a wick and evaluated the temperature reduction effect as surface temperature and amount of evapotranspiration. For about a week, the surface temperature using a infrared thermal imager and the evapotranspiration by recording change of module weight were measured at intervals of 30 minutes from sunrise to sunset. The results show that the mean surface temperature of the green roof was 15.4 degrees lower than that of the non-green roof from 12:00 P.M. to 14:00 P.M. There was no significant difference between mean surface temperature of green roof with and without storage system immediately after rain, but more than a week after rain, there was a difference with average of 2.49 degrees and maximum of 4.72 degrees. The difference in daily amount of evapotranspiration was measured to be 1.66 times on average. As drought stress increased over time, the difference in daily amount of evapotranspiration and surface temperature between with/without storage system increased simultaneously. The results of the study show a more excellent cooling effect of green roof combined with the rainwater storage system.

Isolation and Identification of Fungi Associated with Decay of Quercus mongolica (신갈나무의 부후에 관여하는 곰팡이 분리 및 동정)

  • HAM, Youngseok;AN, Ji-Eun;LEE, Soo Min;CHUNG, Sang-Hoon;KIM, Sun Hee;PARK, Mi-Jin
    • Journal of the Korean Wood Science and Technology
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    • v.49 no.3
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    • pp.234-253
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    • 2021
  • The Quercus mongolica has a high utilization value in industrial economic sector. The species is distributed throughout Korea, however, the damage caused by deterioration such as discoloration and decay is severe. For this reason, the deterioration of Q. mongolica is an obstacle to its use as wood, but research on deterioration factors is insufficient. In this study, we focused on fungi as a factor influencing the deterioration of Q. mongolica, and isolated and identified the fungi from the deteriorated Q. mongolica. In additions, in order to confirm whether the identified fungi actually affects wood deterioration, enzyme activities of the identified fungi were evaluated and related mass loss of wood treated with the fungi was measured by wood decay test. As a result of sequencing analysis using the ITS region of the genomic DNA of the fungi isolated from Q. mongolica, Mucor circinelloides, Cunninghamella elegans, and Umbelopsis isabellina 3 species belonging to Mucoromycota phylum, and Ophiostoma piceae and Aureobasidium melanogenum 2 species belonging to Ascomycota phylum were identified. These five fungi had enzyme (i.e. cellulase, laccase) activities related to wood decay and reduced the mass of heartwood and sapwood of Q. mongolica in practice. In particular, O. piceae and A. melanogenum, which have both cellulase and laccase activities, showed 6.9% and 1.5% mass loss, respectively. These results indicated that five fungi identified in this study influence the deterioration of Q. mongolica and are wood decaying fungi for Q. mongolica potentially.

Assessing systemic, developmental, and reproductive toxicity and estrogenicity of Korean red ginseng extract G1899 in juvenile Sprague-Dawley Rats

  • Sangyun Kim;Ji-Seong Jeong;Woojin Kim;Onju Ham;Yixian Quah;Soontag Jung;Dong-Ju Park;Min Jae Kim;Byung-Cheol Han;Eunji Kim;Seung-Jin Lee;Wook-Joon Yu
    • Journal of Ginseng Research
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    • v.48 no.3
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    • pp.333-340
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    • 2024
  • Background: Korean red ginseng (KRG) is a product from ginseng roots, which is enriched with ginsenosides and has been utilized for a long time as an adaptogen to alleviate various physiological or disease conditions. While KRG is generally considered safe, conducting a thorough toxicological assessment of the spray-dried powder G1899 during the juvenile period is essential to establish its safety profile. This study aimed to assess the safety of G1899 during the juvenile period using Sprague-Dawley rats. Methods: Two studies were conducted separately: a juvenile toxicity study and a uterotrophic bioassay. To assess the potential toxicity at systemic, postnatal developmental, and reproductive levels, G1899 was orally gavaged once a day in post-weaning juvenile Sprague-Dawley (SD) rats at 0, 1250, 2500, or 5000 mg/kg/day. Estrogenicity was assessed by orally gavaging G1899 in immature female SD rats at 0, 2500, or 5000 mg/kg/day on postnatal days (PND) 19-21, followed by a uterotrophic bioassay. These studies were conducted in accordance with the Good Laboratory Practice (GLP) regulations and regulatory test guidelines. Results: Regarding juvenile toxicity, no abnormalities related to the G1899 treatment were observed in any group during the experiment. Moreover, no uterotrophic responses were observed in the dosed female group. Based on these results, the no observed adverse effect level (NOAEL) of G1899 was determined to be at least 5000 mg/kg/day for general systemic function, developmental/reproductive function, and estrogenic activity. Conclusion: Our results suggest that G1899 is not toxic to juveniles at doses of up to 5000 mg/kg/day.

Development and application of non-invasive drug delivery systems utilizing pulse power, and its application to mouse models (펄스파워를 적용한 비침습 약물 전달기 개발 및 마우스 모델로의 적용)

  • Hwi-Chan Ham;Kyu-Sik Kim;Ji-Hwan Lee;Hyung-Jin Choi;Do-Nyun Kim;Jai-Ick Yoh
    • Journal of IKEEE
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    • v.28 no.1
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    • pp.97-103
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    • 2024
  • Some drugs can offer far better medical effectiveness as it is injected through the intradermal layer of the skin, known as a needle-free injection. However, conventional needle-free devices might deliver a relatively large amount of drug in a just single spot of skin, splitting open the tissue layer structure, which might cause bruising and bleeding. By injecting the small volume with a fast repetition rate in a large surface area of skin, the patient may get much fewer injuries and pain. To achieve that specification, the driving force must be instantaneous and short-pulsed. Such a form of an injection device has been developed but the efficacy of those devices has been rarely examined. Therefore, this study developed the laser-induced microjet device that ejects microjet whose speed is ~310 m/s, during the 400~800 ㎲ of pulse time. The device can eject ~1 µL of the drug at the rate at which each shot repeated 10 shots per second. Using this specification, we evaluated the efficacy of drug injection onto mouse models. After injecting the insulin solution into the mouse model, the blood insulin level is detected, resulting in 20 % of blood insulin level with the ordinary needle syringe injection method.

Relationship between Systemic Inflammatory Marker, Oxidative Stress and Body Mass Index in Stable COPD Patient (안정된 만성폐쇄성폐질환 환자에서 신체질량지수와 전신 염증인자, 산화 스트레스와의 관련성)

  • Ham, Hyun Seok;Lee, Hae Young;Lee, Seung Jun;Cho, Yu Ji;Jeong, Yi Young;Kim, Ho Cheol;Ham, Jong Ryeal;Park, Chan Hoo;Lee, Jong Deok;Sohn, Hyun Joon;Youn, Hee Shang;Hwang, Young Sil
    • Tuberculosis and Respiratory Diseases
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    • v.61 no.4
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    • pp.330-338
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    • 2006
  • Background: The main factors associated with weight loss in patients with COPD are not well known. Since chronic inflammation and oxidative stress play a major pathogenic role in COPD, these factors may be responsible for the patients' weight loss. Therefore, this study measured the body mass index (BMI) in COPD patients and evaluated the variables, such as systemic inflammatory marker, oxidative stress and lung function, that correlate with the BMI. Method: The stable COPD patients (M:F=49:4, mean age=$68.25{\pm}6.32$) were divided into the lower (<18.5), normal (18.5-25) and higher (>25) BMI group. The severity of the airway obstruction was evaluated by measuring the $FEV_1$. The serum IL-6 and TNF-$\alpha$ levels were measured to determine the degree of systemic inflammation, and the carbonyl protein and 8-iso-prostaglandin $F_2{\alpha}$ level was measured to determine the level of oxidative stress. Each value in the COPD patients and normal control was compared with the BMI. Results: 1) Serum 8-iso-prostaglandin $F_2{\alpha}$ in COPD patients was significantly higher ($456.08{\pm}574.12pg/ml$) than that in normal control ($264.74{\pm}143.15pg/ml$) (p<0.05). However, there were no significant differences in the serum IL-6, TNF-$\alpha$, carbonyl protein between the COPD patients and normal controls. 2). In the COPD patients, the $FEV_1$ of the lower BMI group was significantly lower ($0.93{\pm}0.25L$) than that of the normal BMI ($1.34{\pm}0.52L$) and higher BMI groups ($1.72{\pm}0.41L$) (p<0.05). The lower $FEV_1$ was significantly associated with a lower BMI in COPD patients (p=0.002, r=0.42). The BMI of very severe COPD patients was significantly lower ($19.8{\pm}2.57$) than that of the patients with moderate COPD ($22.6{\pm}3.14$) (p<0.05). 3). There were no significant differences in the serum IL-6, TNF-$\alpha$, carbonyl protein and 8-iso-prostaglandin $F_2{\alpha}$ according to the BMI in the COPD patients. Conclusion: The severity of the airway obstruction, not the systemic inflammatory markers and oxidative stress, might be associated with the BMI in stable COPD patients. Further study will be needed to determine the factors associated with the decrease in the BMI of COPD patients.

Antioxidant and Anti-Proliferative Activities of Oats under Different Solvent Extraction Conditions (추출용매별 귀리의 항산화 및 암세포 증식 억제 활성)

  • Ham, Hyeonmi;Woo, Koan Sik;Park, Ji-Young;Lee, Byongwon;Choi, Yong-Hwan;Lee, Choonwoo;Kim, Wook Han;Lee, Junsoo;Lee, Yu-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.6
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    • pp.918-922
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    • 2016
  • The objective of this study was to determine the antioxidant and anti-proliferative activities of methanol, ethanol, acetone, and ethyl acetate extracts from oats (Avena sativa L.). Total polyphenol contents of extracts were analyzed by Folin-Ciocalteu assay. The antioxidant activities of extracts were determined by 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and reducing power. The anti-proliferative activities of colon (HCT116), lung (NCI-H460), and breast (MCF7) cancer cells were investigated. Among solvents, methanol extract showed the highest amount of total polyphenols, which was 8.2 mg gallic acid equivalents/g residue. High levels of ABTS radical [12.1 mg Trolox equivalent antioxidant capacity (TEAC)/g residue] and DPPH radical (4.4 mg TEAC/g residue) scavenging activity and reducing power ($A_{700}=0.39$) were found in methanol extracts. Moreover, methanol extracts indicated higher anti-proliferative activities against HCT116 (69.5%), NCI-H460 (75.2%), and MCF7 (84.8%) cells compared with other extracts. The results show that methanol was the best solvent for extraction of antioxidant and anti-proliferative compounds from oats. Moreover, notable antioxidant and anti-proliferative activities of oats could have significant health benefits.

Antioxidant Compounds and Activities of Methanolic Extracts from Oat Cultivars (품종별 귀리 메탄올 추출물의 항산화 성분 및 항산화 활성)

  • Ham, Hyeonmi;Woo, Koan Sik;Lee, Byongwon;Park, Ji-Young;Sim, Eun-Yeong;Kim, Byung Joo;Lee, Choonwoo;Kim, Si-Ju;Kim, Wook Han;Lee, Junsoo;Lee, Yu-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.11
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    • pp.1660-1665
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    • 2015
  • Oats (Avena sativa L.) were evaluated in recent years as a promising crop for increasing the nutritional quality of foods, due to their abundance in many bioactive compounds. The objectives of this study were to determine antioxidant compounds and antioxidant activities of nine oat cultivars and investigate the relationships between antioxidant compounds and antioxidant activities in oat cultivars. The contents of total polyphenolics and vitamin E in oat cultivars were analyzed by spectrophotometric methods and normal phase HPLC, respectively. 2,2'-Azino-bis-(3-ethylbenzothiazoline- 6-sulphonic acid) (ABTS) radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities, reducing power, and chelating effects were used to compare the relative antioxidant activities of oat cultivars. In this study, total polyphenolic and vitamin E contents of oat cultivars ranged from 83.41 to 130.59 mg gallic acid equivalents/100 g and 0.54 to 1.90 mg/100 g, respectively. High levels of ABTS radical (116.14 mg Trolox equivalent antioxidant capacity (TEAC)/100 g) and DPPH radical (38.58 mg TEAC/100 g) scavenging activities and reducing power ($A_{700}=0.922$) were found in Daeyang. Significant correlation was evaluated between total polyphenolic contents and their antioxidant activities, namely ABTS and DPPH radical scavenging activities and reducing power. A low correlation was observed between vitamin E contents and their antioxidant activities. The results of this study could have an impact on oat consumption by enhancing consumer awareness of the health benefits of oats.