• Title/Summary/Keyword: GK2

Search Result 162, Processing Time 0.03 seconds

Enhancing GEMS Surface Reflectance in Snow-Covered Regions through Combined of GeoKompsat-2A/2B Data (천리안 위성자료 융합을 통한 적설역에서의 GEMS 지표면 반사도 개선 연구)

  • Suyoung Sim;Daeseong Jung;Jongho Woo;Nayeon Kim;Sungwoo Park;Hyunkee Hong;Kyung-Soo Han
    • Korean Journal of Remote Sensing
    • /
    • v.39 no.6_1
    • /
    • pp.1497-1503
    • /
    • 2023
  • To address challenges in classifying clouds and snow cover when calculating ground reflectance in Near-UltraViolet (UV) wavelengths, this study introduces a methodology that combines cloud data from the Geostationary Environmental Monitoring Spectrometer (GEMS) and the Advanced Meteorological Imager (AMI)satellites for snow cover analysis. The proposed approach aims to enhance the quality of surface reflectance calculations, and combined cloud data were generated by integrating GEMS cloud data with AMI cloud detection data. When applied to compute GEMS surface reflectance, this fusion approach significantly mitigated underestimation issues compared to using only GEMS cloud data in snow-covered regions, resulting in an approximately 17% improvement across the entire observational area. The findings of this study highlight the potential to address persistent underestimation challenges in snow areas by employing fused cloud data, consequently enhancing the accuracy of other Level-2 products based on improved surface reflectivity.

Gene Cloning and Expression of Trehalose Synthase from Thermus thermophilus HJ6 (Thermus thermophilus HJ6 유래 내열성 Trehalose Synthase의 유전자 클로닝 및 발현)

  • Kim, Hyun-Jung;Kim, Han-Woo;Jeon, Sung-Jong
    • Microbiology and Biotechnology Letters
    • /
    • v.36 no.3
    • /
    • pp.182-188
    • /
    • 2008
  • A hyperthermophilic bacteria (strain HJ6) was isolated from a hot springs located in the Arima-cho, Hyogo, Japan. The cells were long-rod type ($2-4{\mu}m$), about $0.4{\mu}m$ in diameter. The pH and temperature for optimal growth were 6.5 and $80^{\circ}C$, respectively. Phylogenetic analysis based on the 16S rDNA sequence and biochemical studies indicated that HJ6 belonged to the genus Thermus thermophilus (Tt). The gene encoding the Trehalose synthase (TS) was cloned and sequenced. The open reading frame (ORF) of the TtTS gene was composed of 2,898 nucleotides and encoded a protein (975 amino acids) with a predicted molecular weight of 110.56 kDa. The deduced amino acid sequence of TtTS showed 99% and 83% identities to the Thermus caldophilus TS and Meiothermus ruber TS, respectively. TtTS gene was expressed in Escherichia coli cells, and the recombinant protein was purified to homogeneity. The optimal temperature and pH for Trehalose synthase activity were found to be $80^{\circ}C$ and 7.5, respectively. The half-life of heat inactivation was about 40 min at $90^{\circ}C$. The maximum trehalose conversion rate of maltose into trehalose by the enzyme increased as the substrate concentration increased, and reached 55.7% at the maltose concentration of 500 mM, implying that the enzyme conversion was dependent of the substrate concentration.

Estimation of Fire Emissions Using Fire Radiative Power (FRP) Retrieved from Himawari-8 Satellite (히마와리 위성의 산불방사열에너지 자료를 이용한 산불배출가스 추정: 2017년 삼척 및 강릉 산불을 사례로)

  • Kim, Deasun;Won, Myoungsoo;Lee, Yangwon
    • Korean Journal of Remote Sensing
    • /
    • v.33 no.6_1
    • /
    • pp.1029-1040
    • /
    • 2017
  • Wildfires release a large amount of greenhouse gases (GHGs) into the atmosphere. Fire radiative power (FRP) data obtained from geostationary satellites can play an important role for tracing the GHGs. This paper describes an estimation of the Himawari-8 FRP and fire emissions for Samcheock and Gangnueng wildfire in 6 May 2017. The FRP estimated using Himawari-8 well represented the temporal variability of the fire intensity, which cannot be captured by MODIS (Moderate Resolution Imaging Spectroradiometer) because of its limited temporal resolution. Fire emissions calculated from the Himwari-8 FRP showed a very similar time-series pattern compared with the AirKorea observations, but 1 to 3 hour's time-lag existed because of the distance between the station and the wildfire location. The estimated emissions were also compared with those of a previous study which analyzed fire damages using high-resolution images. They almost coincided with 12% difference for Samcheock and 2% difference for Gangneung, demonstrating a reliability of the estimation of fire emissions using our Himawari-8 FRP without high-resolution images. This study can be a reference for estimating fire emissions using the current and forthcoming geostationary satellites in East Asia and can contribute to improving accuracy of meteorological products such as AOD (aerosol optical depth).

Production of Fructose 6-Phoschate from Starch Using Thermostable Enzymes (내열성 효소를 이용한 전분으로부터 6-인산과당의 제조)

  • Kwun, Kyu-Hyuk;Cha, Wol-Suk;Kim, Bok-Hee;Shin, Hyun-Jae
    • KSBB Journal
    • /
    • v.22 no.5
    • /
    • pp.345-350
    • /
    • 2007
  • Phosphosugars are found in all living organisms and are commercially valuable compounds with possible applications in the development of a wide range of specialty chemicals and medicines. In carbohydrate metabolism, fructose 6-phosphate (F6P) is an essential intermediate formed by phosphorylation of 6' position of fructose in glycolysis, gluconeogenesis, pentose phosphate pathway and Calvin cycle. In glycolysis, F6P lies within the glycolysis metabolic pathway and is produced by isomerisation of glucose 6-phosphate. For large-scale production, F6P could be produced from starch using many enzymes such as pullulanase, starch phosphorylase, isomerase and mutase. In enzymatic reactions carried out at high temperatures, the solubility of starch is increased and microbial contamination is minimized. Thus, thermophile-derived enzymes are preferred over mesophile-derived enzymes for industrial applications using starch. Recently, we reported the production of glucose 1-phosphate (G1P) from starch by Thermus caldophilus GK24 enzymes. Here we report the production of F6P from starch through three steps; from starch to glucose 1-phosphate (glucan phosphorylase, GP), then glucose 6-phosphate (phosphoglucomutase, GM) and then F6P (phosphoglucoisomerase, GI). Using 200 L of 1.2% soluble starch solution in potassium phosphate buffer, 1,253 g of G1P were produced. Then, 30% yields of F6P were attained at the optimum reaction conditions of GM : G1 (1 : 2.3), 63.5$^{\circ}C$, and pH 6.85. The optimum conditions were found by response surface methodology and the theoretical values were confirmed by the experiments. The optimum starch concentrations were 20 g/L under the given conditions.

Rainfall Intensity Estimation Using Geostationary Satellite Data Based on Machine Learning: A Case Study in the Korean Peninsula in Summer (정지 궤도 기상 위성을 이용한 기계 학습 기반 강우 강도 추정: 한반도 여름철을 대상으로)

  • Shin, Yeji;Han, Daehyeon;Im, Jungho
    • Korean Journal of Remote Sensing
    • /
    • v.37 no.5_3
    • /
    • pp.1405-1423
    • /
    • 2021
  • Precipitation is one of the main factors that affect water and energy cycles, and its estimation plays a very important role in securing water resources and timely responding to water disasters. Satellite-based quantitative precipitation estimation (QPE) has the advantage of covering large areas at high spatiotemporal resolution. In this study, machine learning-based rainfall intensity models were developed using Himawari-8 Advanced Himawari Imager (AHI) water vapor channel (6.7 ㎛), infrared channel (10.8 ㎛), and weather radar Column Max (CMAX) composite data based on random forest (RF). The target variables were weather radar reflectivity (dBZ) and rainfall intensity (mm/hr) converted by the Z-R relationship. The results showed that the model which learned CMAX reflectivity produced the Critical Success Index (CSI) of 0.34 and the Mean-Absolute-Error (MAE) of 4.82 mm/hr. When compared to the GeoKompsat-2 and Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks (PERSIANN)-Cloud Classification System (CCS) rainfall intensity products, the accuracies improved by 21.73% and 10.81% for CSI, and 31.33% and 23.49% for MAE, respectively. The spatial distribution of the estimated rainfall intensity was much more similar to the radar data than the existing products.

Experimental Investigation of Aerodynamic Force Coefficients and Flutter Derivatives of Bridge Girder Sections (교량단면의 공기력계수 및 플러터계수에 관한 실험적 연구)

  • Cho, Jae-Young;Lee, Hak-Eun;Kim, Young-Min
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.5A
    • /
    • pp.887-899
    • /
    • 2006
  • The aim of this study is to investigate a correlation between fundamental data on aerodynamic characteristics of bridge girder cross-sections, such as aerodynamic force coefficients and flutter derivatives, and their aerodynamic behaviour. The section model tests were carried out in three stages. In the first stage, seven deck configurations were studied, namely; Six 2-edge girders and one box girder. In this stage, changes in aerodynamic force coefficients due to geometrical shape of girders, incidence angle of flow, wind directions and turbulence intensities were studied by static section model tests. In the second stage, the dynamic section model tests were carried out to investigate the relativity of static coefficients to dynamic responses. And finally, the two-dimensional (lift-torsion) aerodynamic derivatives of three bridge deck configurations were investigated by dynamic section model tests. The aerodynamic derivatives can be best described as a representation of the aerodynamic damping and the aerodynamic stiffness provided by the wind for a given deck geometry. The method employed here to extract these unsteady aerodynamic properties is known as the initial displacement technique. It involves the measurement of the decay in amplitude with time of an initial displacement of the deck in heave and torsion, for various wind speeds, in smooth flow. It is suggested that the proposed aerodynamic force coefficients and flutter derivatives of bridge girder sections will be potentially useful for the aeroelastic analysis and buffeting analysis.

Effects of quercetin derivatives from mulberry leaves: Improved gene expression related hepatic lipid and glucose metabolism in short-term high-fat fed mice

  • Sun, Xufeng;Yamasaki, Masayuki;Katsube, Takuya;Shiwaku, Kuninori
    • Nutrition Research and Practice
    • /
    • v.9 no.2
    • /
    • pp.137-143
    • /
    • 2015
  • BACKGROUND/OBJECTIVES: Mulberry leaves contain quercetin derivatives, which have the effects of reducing obesity and improving lipid and glucose metabolism in mice with obesity. It is not clear whether or not mulberry leaves can directly affect metabolic disorders, in the presence of obesity, because of the interaction between obesity and metabolic disorders. The aim of the current study was to assess the direct action of quercetin derivatives on metabolic disorders in non-obese conditions in short-term high-fat diet fed mice. MATERIALS/METHODS: C57BL/6N mice were fed a high-fat diet, supplemented with either 0% (control), 1%, or 3% mulberry leaf powder (Mul) or 1% catechin powder for five days. Anthropometric parameters and blood biochemistry were determined, and hepatic gene expression associated with lipid and glucose metabolism was analyzed. RESULTS: Body and white fat weights did not differ among the four groups. Plasma triglycerides, total cholesterol, and free fatty acids in the 1%, 3% Mul and catechin groups did not differ significantly from those of the controls, however, plasma glucose and 8-isoprostane levels were significantly reduced. Liver gene expression of gp91phox, a main component of NADPH oxidase, was significantly down-regulated, and PPAR-${\alpha}$, related to ${\beta}$-oxidation, was significantly up-regulated. FAS and GPAT, involved in lipid metabolism, were significantly down-regulated, and Ehhadh was significantly up-regulated. Glucose-metabolism related genes, L-PK and G6Pase, were significantly down-regulated, while GK was significantly up-regulated in the two Mul groups compared to the control group. CONCLUSIONS: Our results suggest that the Mul quercetin derivatives can directly improve lipid and glucose metabolism by reducing oxidative stress and enhancing ${\beta}$-oxidation. The 1% Mul and 1% catechin groups had similar levels of polyphenol compound intake ($0.4{\times}10^{-5}$ vs $0.4{\times}10^{-5}$ mole/5 days) and exhibited similar effects, but neither showed dose-dependent effects on lipid and glucose metabolism or oxidative stress.

Adsorption Characteristics Evaluation of Natural Zeolite for Heavy-metal Contaminated Material Remediation (중금속 오염물질 정화를 위한 천연제올라이트의 흡착특성)

  • Shin, Eun-Chul;Park, Jeong-Jun;Jeong, Cheol-Gyu;Kim, Sung-Hwan
    • Journal of the Korean Geosynthetics Society
    • /
    • v.13 no.2
    • /
    • pp.59-67
    • /
    • 2014
  • The amount of the contaminants that can be adsorbed on the drain was evaluated for the effective remediation of the contaminated soil, and the contaminants adsorptivity of the drain was evaluated by comparing the isothermal adsorption model after carrying out the contaminants adsorption test of the reactants coated on the surface of the drain. The reactant used in the experiment is a natural zeolite, and the contaminants are copper, lead and cadmium. The results that Freundlich and Langmuir adsorption isotherm model are compared to the adsorption amount according to the change of the initial concentration by the contaminants. As a result of the component analysis, because Si, Al and O are contained approximately 28%, 11% and 48%, respectively, it is identified that the material coated on the surface of the drain is the component of the zeolite which is the reactant for the adsorption of the heavy-metal (Cu, Pb, Cd) contaminants. The heavy-metal adsorption kinetic of the zeolite which is the reactant was decreased in order of lead, copper and cadmium. The important factor of the performance evaluation of the adsorbent is the reaction rate, and if zeolite is used as the reactant in the relationship between the maximum amount of adsorption and reaction rate, it can be utilized as the design factor that determine the removal order of the complex heavy-metal. In other words, because the maximum adsorption quantity of lead is smaller compared to copper but the reaction rate is relatively fast, it can be primarily removed, and copper can be removed after removing the lead. It was analyzed that Cadmium can be finally removed after that other heavy-metal is removed.

Liberalization of Telemedicine in Germany (독일 원격의료 합법화와 법개정 논의)

  • Kim, SooJeong
    • The Korean Society of Law and Medicine
    • /
    • v.21 no.2
    • /
    • pp.3-33
    • /
    • 2020
  • Until recently the German and the South Korean medical associations reacted cautiously to the introduction of telemedicine between doctor and patient which is exclusively on the platform conducted. But the General Assembly of German Physicians voted to lift the ban on remote treatment with the amendment to Section 7 (4) MBO-Ä(Medical Association's Professional Code of Conduct) in 2018 and the situation has been fundamentally changed in Germany. From then until now 16 of 17 rural medical associations have changed their professional code to allow telemedicine. In addition the legislature started to prepare the basis for the introduction of the electronic health card (eGK) and the telematics infrastructure. So far, various laws such as Medicinal Products Act, Drug Advertisement Act and Social Code have been changed to support legalization of telemedicine and digitalization of health care. Unlike in Germany, the social circumstances such as excessive centralization of the big hospitals in Seoul and the resulting concern of small medical practices for profitability are the main obstacles to the introduction of telemedicine. However the German approach how to legalise the telemedicine and to prepare for legal and technical infrastructure is also interesting in South Korea. The discussions for and against the changes in the law and the telematics infrastructure attempted by the German government for several years indicate that not only lifting the ban on remote treatment, but also harmonization of all the related legal system could guarantee successful implementation of telemedicine.

Chlorogenic Acid Enhances Glucose Metabolism and Antioxidant System in High-fat Diet and Streptozotocin-induced Diabetic Mice (고지방식이와 스트렙토조토신으로 유도한 당뇨마우스에서 Chlorogenic Acid의 혈당강하 및 항산화 효과)

  • Lee, Jin;Seo, Kwon-Il;Kim, Myung-Joo;Lee, Su-Jin;Park, Eun-Mi;Lee, Mi-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.41 no.6
    • /
    • pp.774-781
    • /
    • 2012
  • This study investigated dose-response effects of chlorogenic acid (CA) on glucose metabolism and the antioxidant system in streptozotocin (STZ)-induced diabetic mice with a high-fat diet (HFD). Male ICR mice were fed with a HFD (37% calories from fat) for 4 weeks prior to intraperitoneal injection with STZ (100 mg/kg body weight). Diabetic mice were supplemented with two doses of CA (0.02% and 0.05%, wt/wt) for 6 weeks. Both doses of CA significantly improved fasting blood glucose level, glucose tolerance and insulin tolerance without any changes in plasma insulin and C-peptide levels. Plasma leptin concentration was significantly higher in the CA-supplemented groups than in the diabetic control group. Both doses of CA significantly increased hepatic glucokinase activity and decreased glucose-6-phosphatase activity compared to the diabetic control group. The ratio of glucokinase/glucose-6-phosphatase was dose-independently higher in CA-supplemented mice than in diabetic control mice. CA supplementation dose-independently elevated superoxide dismutase and catalase activities, whereas it lowered lipid peroxide levels compared to the diabetic control mice in the liver and erythrocyte. These results suggest that low-dose CA may be used as a hypoglycemic agent in a high-fat diet and STZ-induced diabetic mice.