• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1843-1846
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• 1997

This paper describes the fault reducing effects of the 154 kV transmission tower by auxiliary grounding from the top of the tower to ground. The grounding surge impedance of the auxiliary grounding system is calculated by CDEGS(:Current Distribution Electromagnetic Interference Grounding and Soil Structure Analysis), and the critical lightning back flashover current and arcing horn dynamic characteristics are simulated by EMTP/TACS(:Electromagnetic Transient Program/Transient Analysis of Control Systems). The calculated results of total LFOR(Lightning Flashover Rate) shows that the LFOR can be reduced from 5.2(count/100km. year) to 3.4 by auxiliary grounding on the 154 kV transmission tower with one ground wire shielding system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1281-1282
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• 2007

Effect of tension coating on reducing iron losses of thin grain-oriented 3% Si-Fe steel sheets was investigated. Conventional grain-oriented electrical steel sheets have a forsterite coating layer and a tension coating layer in order to apply tensile stress to the rolling direction of the sheets. However the proposed coating method in this paper is to form only a tension coating layer on the both surfaces of the sheets. Iron losses with the tension coating were reduced by 8% under the condition of 1.7 T and 60 Hz. Consequently the proposed tension coating is applicable to $80{\mu}m$-thick 3% Si-Fe steel sheets.

• 한국산림과학회지
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• 제102권4호
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• pp.566-570
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• 2013

정금나무의 기능성 품종을 육성하기 위하여 정금나무 선발 5개체의 열매에 대한 항산화 활성을 측정하였으며, 항산화 성분인 총 페놀 함량을 측정하였다. 총 페놀 함량은 gallic acid를 기준물질로 하여 분석한 결과 15.8~19.9 mg/g 범위로 전체 평균 17.9 mg/g을 나타냈으며, DPPH free radical 소거활성은 400 ppm의 농도에서 69.1~91.4% 범위로 전체평균 84.2%를 나타내었다. 환원력은 0.56~0.96 범위로 전체 평균 0.79를 나타내었다. 상관분석 결과 DPPH free radical 소거활성과 환원력에서 상관계수가 0.969로 매우 높은 정의 상관관계를 나타내었다.

• 한국식품조리과학회지
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• 제18권6호
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• pp.603-612
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• 2002

The study was carried out to compare the relation between the color intensity and antioxidant activity of caramelization products using xylose(XY), glucose(GL). sucrose(SU), glucose＋citric acid(GLCA), glucose＋sodium citrate(GLSC), heated at 80, 120 and 140$\^{C}$ for 24hrs, respectively. The color intensity(absorbance at 490nm) of the browning mixtures increased as the browning temperature and time increased. But the degrees of color intensity of SU and GLCA changed very little. The hydrogen donating ability(HDA) of browning reaction products was generally enhanced as the browning temperature and time increased. When browning mixtures were heated at 80$\^{C}$, the HDA of GLGC was the highest, but the HDA of GLSC was the highest when heated at 120 and 140$\^{C}$. The antioxidant activities for the corn oil substrate containing the anhydrous ethanol extracts from the browning mixtures was inferior to that of SU, but was superior to that of GLCA. The relations among the color intensity, the antioxidant activity, and the hydrogen donating ability(HDA, reducing power) of the browning reaction mixtures were as follows: As the color intensity increased, the antioxidant activity decreased. The correlation coefficient of the color intensity and the antioxidant activity by regression equation was -0.73 ∼ -0.82. As the reducing power increased, the antioxidant activity decreased. The correlation coefficient between the reducing power and the antioxidant activity by regression equation was -0.98 ∼ -0.99. Therefore, the antioxidant activity of browning reaction mixtures seemed not correlated with the color intensity and the reducing power.

• 한국식품조리과학회지
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• 제27권3호
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• pp.39-49
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• 2011

This study was conducted to evaluate the effects of adding unrefined oil on the antioxidant activity of a tuna oil-enriched emulsion by determining DPPH radical scavenging activity, reducing power, and inhibition of low-density lipoprotein (LDL) oxidation in vitro. The emulsion consisted of tocopherol-stripped canola (18.3 g) and tuna (9.1 g) oil, one of the unrefined oils (4.6 g), such as extra virgin olive, mustard, perilla, or sesame oil, 0.5% acetic acid (64 g), and egg yolk powder (4 g). The control emulsion contained only canola (21.4 g) and tuna oil (10.6 g), as oil sources,with the same composition of the remaining ingredients. The emulsion with added unrefined oil, particularly mustard oil, showed higher radical scavenging activity and reducing power than those of the control emulsion. The radical scavenging activity and reducing power of the emulsion with added unrefined oil were higher at 1,000 ppm than at 500 ppm thus, the effect was concentration-dependent. Adding sesame or perilla oil to the tuna oil-enriched emulsion resulted in higher inhibition of LDL oxidationwhereas adding olive oil increased LDL oxidation. The results clearly showed that adding roasted mustard, sesame, or perilla oil improved the antioxidant activity of a tuna oil-enriched emulsion by increasing free radical scavenging activity, reducing power, and inhibiting LDL oxidation. The results also suggest that adding unrefined oils produces a healthier fish oil-enriched salad dressing recipe.

• 대한지역사회영양학회지
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• 제13권1호
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• pp.91-99
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• 2008

The present study was conducted to examine metabolic risk factors and total antioxidant capacity (TAC) of Korean females living in Seoul and to investigate the relationship between the metabolic risk factors and serum TAC. A total of 353 females aged between 20 and 64 participated in the study. Obesity indicators, blood pressure, serum lipid profile and fasting blood glucose were measured as metabolic risk factors. Ferric reducing antioxidant power (FRAP) assay was employed to determine serum TAC of subjects. Obesity indicators such as body mass index, waist circumference and waist-hip ratio were significantly higher in the participants aged $\geq$ 50 y (older group) than in the participants aged 20-49 y (younger group) (p < 0.001). Blood pressure, serum total cholesterol (TC), triglyceride (TG) and fasting blood glucose were also significantly higher in the older group than in the younger group (p < 0.001), demonstrating significant positive correlations between age and MS risk factors. The association between FRAP and MS risk factors were also investigated. FRAP values showed significant positive correlations with age (p = 0.001), serum TG (p = 0.002) and TC (p = 0.03). A tendency of positive association between FRAP and waist circumference was observed without any significant difference (p = 0.06). Increased serum FRAP with central obesity and serum lipids may be interpreted as results of activation of antioxidant defense system against oxidative stress induced by metabolic syndrome (MS) constituent factors. However, to verify the function of FRAP as a potential biomarker of susceptibility to MS various contributors to the plasma antioxidant capacity and their biological relevance related to MS should be elucidated further.

• KSBB Journal
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• 제30권4호
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• pp.155-160
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• 2015

The present study was to investigate the antioxidant activity in ethanol and water extracts of root and stem of Sargassum coreanum. Antioxidant activities were evaluated by total polyphenol contents, DPPH radical scavenging activity, chelating effect, reducing power, and rancimat method. Total polyphenol contents of ethanol and water extracts were 32.79 mg/g and 15.55 mg/g, respectively. Ethanol extract showed higher DPPH radical scavenging activity than water extract and similar activity to BHT. Reducing power of extracts was increased in a concentration-dependent manner and ethanol extract had more reducing power than water extract. Ethanol and water extracts have little chelating effect at all concentrations. Antioxidant index (AI) of ethanol extract measured by Rancimat was higher than that of water extract, but their AI was lower than that of BHT. These results indicate that ethanol extract of S. coreanum root and stem has more potent antioxidant activity than water extract through DPPH radical scavenging and reducing power, and could potentially be used as a good source of natural antioxidants.

• 대한본초학회지
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• 제28권3호
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• pp.25-31
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• 2013

Objectives : To develop a natural antioxidant and anti-hemolytic agents, we investigated the effects of ethanol extracts of Carpesii Fructus and Farfarae Flos. Methods : Aerial parts of Carpesii Fructus and Farfarae Flos were extracted with 80% ethanol. Antioxidant activity of Carpesii Fructus or Farfarae Flos extract was evaluated by employing three different assays, i.e., 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-suphonic acid) diammonium (ABTS) scavenging and reducing power activities. Also, anti-hemolytic activity of Carpesii Fructus or Farfarae Flos extract was determined using [2,2'-azobis (2-methylpropionamidine) dihydrochloride (AAPH)]-induced hemolysis, glutathione (GSH) depletion and malondialdehyde (MDA) formation in normal rat red blood cells (RBC) or plasma. Results : The extracts obtained from Carpesii Fructus and Farfarae Flos dose-dependently increased the scavenging activity on DPPH- or ABTS-induced radicals and the reducing power activities. Carpesii Fructus and Farfarae Flos were similar to the scavenging activity and the reducing power of butylated hydroxy anisole effect at high concentration ($1,000{\mu}g/mL$). RBC oxidative hemolysis and plasma MDA formation induced by AAPH were significantly suppressed by the extracts of Carpesii Fructus and Farfarae Flos in a dose-dependent manner. Also, Carpesii Fructus and Farfarae Flos extracts prevented the depletion of cystosolic antioxidant GSH in RBCs. Carpesii Fructus generally had better than the free radical scavenging activity, the reducing power and anti-hemolytic effects of Farfarae Flos. Conclusions : These results suggest that Carpesii Fructus and Farfarae Flos may have value as the potential antioxidant and anti-hemolytic medicinal plant.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.397-398
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• 2013

Fairchild Green Mode off line buck switch for low standby power consumption and high reliability is presented. By reducing operating current and optimizing switching frequency, 20mW power consumption is achieved. High performance trans-conductance amplifier and green mode function improve the ripple and regulation in the output voltage. The conventional $FPS^{TM}$ buck and novel Fairchild buck switch are compared to show the improvement of performance. Experimental results are showed using 2W evaluation board.

• ETRI Journal
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• 제38권5호
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• pp.885-895
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• 2016

The lowest power mode (passive-standby mode) was proposed for reducing the power consumption of set-top boxes in a standby state when not receiving content. However, low-power set-top boxes equipped with the lowest power mode have been rarely commercialized because of their low-quality user experience. In the lowest power mode, they deactivates almost all of operational modules and processes, and thus require dozens of seconds for activation latency (that is, the latency for activating all modules of the set-top boxes in a standby state). They are not even updated in a standby state because they deactivate their network interfaces in a standby state. This paper proposes an adaptive standby mode scheduling method for improving the user experience of such boxes. Set-top boxes using the proposed method can analyze the activation pattern and find the frequently used time period (that is, when the set-top boxes are frequently activated). They prepare for their activation during this frequently used time period, thereby reducing the activation latency and enabling their update in a standby state.