• Title/Summary/Keyword: Hwang Kyung-Ha

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Conceptual Design of 100 MW Turbogenerator (가스터빈 구동 공냉식 100 MW 발전기의 개념설계)

  • Park, Doh-Young;Hwang, Don-Ha;Ha, Kyung-Duck;Kim, Yong-Joo
    • Proceedings of the KIEE Conference
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    • 1998.07a
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    • pp.88-90
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    • 1998
  • The conceptual design of turbine-driven air-cooled 100 MW generator is presented. The generators rating is 100 MW 3-phase 2pole 13.8 kV 0.85 pf 60 Hz. The conceptual design is described by the process of designing the stator, rotor, and obtaining some of equivalent circuit parameters. The design process starts from the output coefficient G, and utilizes the classical design equations with parameters used in the modern designs. The slot dimensions of the stator and rotor are obtained with their respective winding dimensions.

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Study on characteristics of CSOs in urban area -Focus on Pyungchang catchment of Hongje basin (도시지역 합류식 하수관거 월류수 발생특성 연구 - 홍제천 평창배수분구을 중심으로)

  • Oh Kyung-Seok;Ho Jong-Kwang;Hwang Byung-Gi
    • Proceedings of the KAIS Fall Conference
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    • 2004.11a
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    • pp.284-287
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    • 2004
  • 홍제천 유역의 평창 배수분구를 대상으로 합류식 하수관거 월류수의 발생특성을 파악하고자 유량 및 오염물질 발생경향, 오염물질별 상관관계, 연간 강우유출 오염부하량 등에 대하여 살펴보았다. 강우시 오염물질의 초기세척현상은 누적오염 부하량비를 이용하여 분석하였으며, 모든 수질항목에 대하여 초기유출현상이 나타났으며, 초기 $20\%$ 유출 유량에서 오염부하가 $30\%$ 정도로 유출되고 있는 것으로 분석되었다. 또한 수질항목별 상관계수를 보면, 건기시의 상관계수는 COD와 SS가 0.4857, 월류수의 경우에는 SS와 TN의 상관계수가 0.7723으로 가장 크게 나타났다. 연간 강우에 의하여 방류선으로 배출되는 면적당 오염부하는 COD 1,202kg/ha/yr SS 494kg/ha/yr로 산정되었다.

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Primary Malignant Fibrous Histiocytoma of the Pleura

  • Cho, Kyung-Hwa;Park, Chul;Hwang, Ki-Eun;Hwang, Yu-Ri;Seol, Chang-Hwan;Choi, Keum-Ha;Lee, Mi-Kyung;Choi, Soon-Ho;Kim, Hak-Ryul;Jeong, Eun-Taik
    • Tuberculosis and Respiratory Diseases
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    • v.74 no.5
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    • pp.222-225
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    • 2013
  • Malignant fibrous histiocytoma, a type of sarcoma, is a malignant neoplasm with uncertain origin that arises in both the soft tissues and the bone. The occurrence of primary malignant fibrous histiocytoma of the pleura is extremely rare. We report a case of a 65-year-old Korean man who is being diagnosed with primary malignant fibrous histiocytoma of the pleura.

Herbicidal activity of a new benzenesulfonylurea compound, KSC-13906 (신규 benzenesulfonylurea 계 화합물 KSC-13906의 제초활성)

  • Hwang, I.T.;Choi, J.S.;Ko, Y.K.;Choi, Y.S.;Kim, M.H.;Kim, D.W.;Cho, K.Y.
    • The Korean Journal of Pesticide Science
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    • v.3 no.1
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    • pp.1-12
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    • 1999
  • Herbicidal activities of newly synthesized experimental compound, KSC-13906 [Erythro N-{(4,6-dimethoxy pyrimidin-2-yl)aminocarbgnyl}-2-(2-fluoro-1- hydroxy-n-propyl)benzenesulfonamide, US Patent 5,461,025], were investigated in greenhouse and field for development as a paddy herbicide. KSC-13906 exihibited excellent weeding effects and selectivity to rice under submerged paddy condition in geenhouse. At the application rate of $2.5{\sim}5$ g ai/ha treated on surface of water, KSC-13906 effectively controlled three annual weeds such as Echinochloa crus-galli var. oryzicola. Scirpus juncoides, and Monochoria vaginalis as well as five perennial weeds such as Cyperus serotinus, Sagittaria pygmaea, Eleocharis kuroguwai, Potamogeton distinctus, and S. trifolia. However, there was no effect on Aneilema keisak and Lindernia procumbens. Especially, KSC-13906 effectively controlled Echinochloa crus-galli var. oryzicola at growth stages ranging from pre-emergence to 3-leaf stage. Antagonistic interaction was found between pyrazosulfuron-ethyl and mefenacet, but not between KSC-13906 ana mefenacet. KSC-13906 had high selectivity to transplanted rice, but caused phytotoxic effect on direct-seeded rice when treated before 3-leaf stage. Herbicidal activity of KSC-13906 on the Echinochloa crus-galli var. oryzicola was 7-folds greater than that of pyrazosulfuron-ethyl in terms of relative dose ratio of the herbicides. These results suggest that KSC-13906 possesses selective herbicidal potency in rice.

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Surface characteristics of a novel hydroxyapatite-coated dental implant

  • Jung, Ui-Won;Hwang, Ji-Wan;Choi, Da-Yae;Hu, Kyung-Seok;Kwon, Mi-Kyung;Choi, Seong-Ho;Kim, Hee-Jin
    • Journal of Periodontal and Implant Science
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    • v.42 no.2
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    • pp.59-63
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    • 2012
  • Purpose: This study evaluated the surface characteristics and bond strength produced using a novel technique for coating hydroxyapatite (HA) onto titanium implants. Methods: HA was coated on the titanium implant surface using a super-high-speed (SHS) blasting method with highly purified HA. The coating was performed at a low temperature, unlike conventional HA coating methods. Coating thickness was measured. The novel HA-coated disc was fabricated. X-ray diffraction analysis was performed directly on the disc to evaluate crystallinity. Four novel HA-coated discs and four resorbable blast medium (RBM) discs were prepared. Their surface roughnesses and areas were measured. Five puretitanium, RBM-treated, and novel HA-coated discs were prepared. Contact angle was measured. Two-way analysis of variance and the post-hoc Scheffe's test were used to analyze differences between the groups, with those with a probability of P<0.05 considered to be statistically significant. To evaluate exfoliation of the coating layer, 7 sites on the mandibles from 7 mongrel dogs were used. Other sites were used for another research project. In total, seven novel HA-coated implants were placed 2 months after extraction of premolars according to the manufacturer's instructions. The dogs were sacrificed 8 weeks after implant surgery. Implants were removed using a ratchet driver. The surface of the retrieved implants was evaluated microscopically. Results: A uniform HA coating layer was formed on the titanium implants with no deformation of the RBM titanium surface microtexture when an SHS blasting method was used. Conclusions: These HA-coated implants exhibited increased roughness, crystallinity, and wettability when compared with RBM implants.

Investigation of the Effect of Sappan Lignum and Brazilin on Expression of Tight Junction Related-genes in Human Keratinocyte (소목(蘇木)과 그 지표물질인 brazilin이 인간 유래 각질 형성 세포의 tight junction 유전자 발현에 미치는 영향)

  • Cheon, Seong Hye;Choi, Sun Kyung;Cho, Nam Joon;Kim, Kee Kwang;Lee, Woong Hee;Hwang, Hyung Seo;Kim, Kyoon Eon;Han, Hyosang
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.32 no.2
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    • pp.106-112
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    • 2018
  • The aim of this research was to determine the diverse effects of Sappan Lignum extract and brazilin on human keratinocyte HaCaT cells. We confirmed the antioxidant effect of Sappan Lignum extract and brazilin was analyzed by using an ABTS assay, confirming the efficacy of water extraction method. Also, we examined effect of Sappan Lignum extract and brazilin on the cell viability, using the MTS assay in HaCaT cells. mRNA expression levels of tight junction-related genes associated with skin barrier in HaCaT cells were analyzed using quantitative real-time PCR analysis. Sappan Lignum extract increased the cellular activity of HaCaT cells and the expression of the tight junction-related genes claudin 3, claudin 6, and ZO-2. Brazilin displayed the same effects as that of the extract on HaCaT cells activity and tight junction-related genes expression. Furthermore, dispase assay demonstrated altered cell-cell adhesion strength of Sappan Lignum extract or brazilin treated HaCaT cells. Sappan Lignum extract or brazilin might be an useful ingredient in skin-mosturizinng and anti-wrinkle cosmetics, given its effects of altering mRNA expression of tight junction-related genes and enhancing cell-cell adhesion strength of HaCaT cells.

Evaluation and Comparison Yield and Feed Value of Pasture Species and Varieties by Spring Sowing in High-Latitude Regions

  • Dong-Geon Nam;Sun-Kyung Kim;Sun-Kyung Kim;Geon-Ho Lee;Tae-Young Hwang
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.92-92
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    • 2022
  • In preparation for the ever-changing climate and unification of North Korea and South Korea, it is necessary to increase the grain self-sufficiency rate by selecting crops with good utilization in high-altitude regions. The principle is to sow pastures at the end of August. However, sowing occurs in spring because the sowing period is missed when the weather is bad or when the workforce is insufficient. Sometimes when the grassland is completely devastated, it is frequently sowed in spring. In addition, North Korea consists of a high-altitude regions, and has been devastated in a general mountainous region. As a result, the landscape is not good and it is vulnerable to natural disasters such as landslides. Therefore, to prevent this, pasture must be sowed in the high-altitude regions. The goal of this study was to evaluate and compare yield and feed value of pasture species and varieties by spring sowing in high-latitude regions. The study was conducted in Pyeongchang, Gangwon-do, which is 700m height above sea level. The pasture species and varieties was sown on April 24, 2022. Each treatment was carried out by sowing 30 kg/ha, the experiment field size was 1 m2(1m×1m), and randomized block design with tri-repeat. The total of 14 varieties was used in the study, 6 varieties of Orchardgrass (OG), 6 varieties of Tall fescue (TF) and 2 varieties of Perennial ryegrass (PRG). The grassland composition fertilization using (N:P2O5:K2O at 80:200:70 kg/ha) was conducted and management fertilizer was N:P2O5:K2O at 210:150:180 kg/ha. The first harvest was June 26,2022 and the second harvest was on August 16, 2022. For statistical analysis of the data, an Analysis of Variance (ANOVA) was performed using the R3.6.3 software program, and all data was subjected to analysis using Duncan's multiple range test. Significance was set at the 5% level. The dry matter yield at the first harvest was the highest in PRG, and second harvest was the highest in TF (p < 0.05). Overall, PRG showed a trend of gradually decreasing growth, OG and TF showed a trend of gradually improving growth. This showed that PRG was considerably weaker to summer depression than other pasture species. Comparing the total dry matter yield, TF was the highest (4,565.45 kg/ha), but there was no significance difference with PRG (4,487.24 kg/ha) (p < 0.05). In addition, comparing the total TDN (total digestible nutrient) yield, TF was the highest (3147.33 kg/ha), second in PRG (2975.67 kg/ha) and third in OG (2052.33 kg/ha). Since this result is the data of the second harvests, if the result is derived by the end of next year, it will be provided as basic data for selection of pasture species and varieties suitable for spring seeding in high-altitude regions.

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Aboveground Carbon Storage of Quercus acuta Stands by Thinning Intensity (붉가시나무 간벌강도에 따른 지상부 탄소고정량에 관한 연구)

  • Lee Sang-Tae;Son Yeong-Mo;Lee Kyung-Jae;Hwang Jaehong;Choi Jae-Chae;Shin Hyeon-Chul;Park Nam-Chang
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.4
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    • pp.282-288
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    • 2005
  • This study was carried out to estimate aboveground carbon contents associated with four years of thinning treatment of Quercus acuta stands in Wando Arboretum, Jeonnam. Stand thinning was conducted over four years using stand table projection for each thinning treatment. Ten sample trees were cut in the surveyed area. Estimation of aboveground biomass was made using the equation model $W=aD+bD^2$ where W is oven dry weight and D is DBH in cm. The total aboveground biomass for each intensity treatment area was : control (148.4 ton/ha), light (105.6 ton/ha), moderate (68.7 ton/ha) and heavy (39.1 ton/ha). Aboveground carbon storage for Quercus acuta stands was found by multiplying dry weigh t (ton/ha) by 0.5. Carbon storage and increment after four years was: control (74.2 tonC/ha), light (52.8 tonC/ha), moderate (34.3 tonC/ha) and heavy thinning intensity area (38.2tonC/ha).

Hesperidin Suppresses Melanosome Transport by Blocking the Interaction of Rab27A-Melanophilin

  • Kim, Bora;Lee, Jee-Young;Lee, Ha-Yeon;Nam, Ky-Youb;Park, JongIl;Lee, Su Min;Kim, Jin Eun;Lee, Joo Dong;Hwang, Jae Sung
    • Biomolecules & Therapeutics
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    • v.21 no.5
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    • pp.343-348
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    • 2013
  • We investigated the inhibitory effects of hesperidin on melanogenesis. To find melanosome transport inhibitor from natural products, we collected the structural information of natural products from Korea Food and Drug Administration (KFDA) and performed pharmacophore-based in silico screening for Rab27A and melanophilin (MLPH). Hesperidin did not inhibit melanin production in B16F10 murine melanoma cells stimulated with ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH), and also did not affect the catalytic activity of tyrosinase. But, hesperidin inhibited melanosome transport in melanocyte and showed skin lightening effect in pigmented reconstructed epidermis model. Therefore, we suggest that hesperidin is a useful inhibitor of melanosome transport and it might be applied to whitening agent.

Characteristics of Digital Infrared Thermal Imaging and Quantitative Evaluations for Patients with Burning Mouth Syndrome: a Cross Sectional Study (구강작열감증후군 환자의 적외선체열검사와 정량적 평가 특성 : 단면조사연구)

  • Ko, Whee-hyoung;Nam, Seong-uk;Ha, Na-yeon;Hwang, Mi-ni;Baek, So-young;Kim, Dong-yoon;Kim, Jin-sung
    • The Journal of Internal Korean Medicine
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    • v.39 no.4
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    • pp.699-707
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    • 2018
  • Objectives: This study was designed to investigate characteristics of digital infrared thermal imaging (DITI) and quantitative evaluations in patients with burning mouth syndrome (BMS). Methods: We reviewed the clinical records of 38 patients with BMS who visited the Oral Diseases Clinic of Kyung Hee University Korean Medicine Hospital from March 1st, 2018 to June 30th, 2018. The subjects were evaluated with digital infrared thermal imaging (DITI) and for heart rate variability (HRV), unstimulated salivary flow rate (USFR), and the proportion of coated tongue. Results: Most patients showed higher temperatures on the central part of the tongue (T2) than on the middle of the forehead (T1). The patients tended to have a high Low frequency/High frequency (LF/HF) ratio. Statistically significant negative correlations were noted between the age of patients and the temperature of T1 and T2. Statistically significant negative correlations were also observed between the LF/HF ratio and 'T1-T2' values. Conclusions: This study suggests that DITI and HRV are useful for the validation of patients with BMS. Correlations between the result values suggest that sympathetic function acceleration is related to temperature distribution and, ultimately, to symptoms.