• Asian-Australasian Journal of Animal Sciences
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• 제20권9호
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• pp.1438-1443
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• 2007

The experiment was conducted to evaluate the effects of Ligustrum lucidum (LL) and Schisandra chinensis (SC) on the growth, antioxidative metabolism and immunity of laying strain male chicks. The results showed that diets supplemented with 1% of either LL or SC had no effects on the growth performance of chicks compared with the control. Furthermore, both LL and SC significantly reduced malondialdehyde (MDA) concentration of serum and heart of chicks (p<0.05). In addition, superoxide dismutase (SOD) activity of serum of the birds was significantly elevated by supplementation with SC (p<0.05). Glutathione reductase (GR) activity of heart and serum of the birds was significantly elevated by supplementation with LL or SC (p<0.05). LL supplementation significantly elevated antibody values against Newcastle Disease virus (NDV)(p<0.05) and lymphoblastogenesis (p<0.05) of the birds. The results suggest that diets supplemented with 1% of either LL or SC may improve immune function and antioxidant status of chicks.

• 한국구조물진단유지관리공학회 논문집
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• 제8권4호
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• pp.257-264
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• 2004

공동주택 수익모델의 가치를 형성하는 요소 중 영향도가 큰 물리적 요소는 주택의 평형변화로서 이를 중심으로 리모델링의 대안을 제안한다. 이에 따라 본 연구에서는 공동주택의 가치형성요인과 공간구성기법을 이용한 큰 평형의 세대를 작은 평형의 세대로 분할하는 모델과 작은 평형의 세대를 통합하여 큰 평형의 세대로 변환하는 모델의 수익모델을 설정하여 경제성은 '보통'이상 '양호'한 것으로 나타났으며, 경제성 평가값은 할인율이 증가함에 따라 감소하며 리모델링의 경제성이 우수해지는 것으로 나타남을 알 수 있다.

• 한국연초학회지
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• 제8권2호
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• pp.19-27
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• 1986

This experiment was carried out to investigate the effect of circulating air volume to chemical composition of tobacco leaves during the bulk curing. The results were as follows : The decrease of circulating air volume prolonged curing time as the case of a 0.058m3/min. kg; but, no remarkable changes with a 0.11m3/min. kg and a 0.083m3/min. kg. When the circulating air volume was decreased, compared with 0.11m3/min. kg, sugar content was increased while total nitrogen and nicotine content showed a reduced values. In case of a 0.058m3/min. kg and a 0.083m3/min.kg, solanone and damascenone were high. Some of volatile neutral constituents and volatile organic acids were increased during curing process ; especially, their quantities were remarkably increased during the midrib drying stage. As circulating air volume decreased the equilibrium moisture content was increased, while leaf shatter index and filling capacity were decreased.

• Preventive Nutrition and Food Science
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• 제8권4호
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• pp.349-355
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• 2003

Effects of extraction conditions, gamma-irradiation and storage conditions on bioactivities of Citrus (Citrus unshiu) peel extract were investigated. The Hunter color $L^{*}$- and $a^{*}$-values of the extract increased but $b^{*}$-value decreased with an increase in absorbed irradiation dose. DPPH radical scavenging, tyrosinase inhibition and nitrite scavenging activities were not affected by irradiation but reduced by increased storage time. Nitrite scavenging activity of the extract was the highest at pH 1.2 followed by pH 4.2 and 6.0 and not changed by storage. Results indicated that there is potential for using citrus peel byproducts as a bioactive ingredient, and that gamma irradiation brightens the color of the extract without adversely altering its biological activity.ity.

• 국토계획
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• 제53권7호
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• pp.39-48
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• 2018

The purpose of this study is to verify the stable flight conditions of drones within a limited urban area by using the ICAO(International Civil Aviation Organization) reich model which is using to evaluate civil aircraft stability. The results of the study are summarized as follows. First, in order for the drones flying stably, the horizontal safety separation distance between a drone and another should be at least 1,852M. Second, assuming that no obstacles within 1,852M of horizontal space, two drones can be fly into upper and lower spaces. However there are obstacles such as buildings, it is impossible to secure a 1,852M distance between drones. Third, sensitivity analysis point out that the separation interval($s_x$) of drone aviation has the greatest influence on the TLS(Target Level of Safety). If future research is conducted to lower the numerical values, the safety distance between a drone and another drone will be drastically reduced, allowing more detailed urban space division, and will be presented as a scientific numerical value for establishing a dedicated path for the drones.

• Corrosion Science and Technology
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• 제22권3호
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• pp.164-174
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• 2023

Electropolishing technology uses an electrochemical reaction and improves surface roughness, glossiness, and corrosion resistance. In this investigation, electropolishing was performed to improve the corrosion resistance of super austenitic stainless steel. As a result of electropolishing, surface roughness (0.16 ㎛) was improved by about 76.5% compared to mechanical polishing (0.68 ㎛). In addition, the electropolished surface was smooth because the average and variance values of the depth histogram were small. Tafel analysis was performed after a potentiodynamic polarization experiment with seawater temperature, and the microstructure was compared and analyzed. The corrosion current density at 30 ℃, 60 ℃, and 90 ℃ was reduced by 0.083 ㎂/cm², 0.296 ㎂/cm², and 0.341 ㎂/cm², respectively. Pitting occurred in the mechanical polished specimen at 30 ℃, but partial intergranular corrosion was observed in the electropolished specimen, and pitting occurred predominantly at both 60 ℃ and 90 ℃. In addition, the damage depths of the electropolished specimen were shallower than those of mechanical polishing at 30 ℃ and 60 ℃, but the opposite result was seen at 90 ℃.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.160-163
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• 2001

In order to investigate the role of bacterial chemotaxis in root colonization, the chemotaxis potential of bacteria isolated from spinach roots was compared with that of bacteria from nonhizosphere soil, with reference to the plant age (1,000 isolates), soil moisture conditons (1,400 isolates), and part of the root (200 isolates). The % CT (% occurrence of chemotaxis (+) isolates among total bacterial isoltes) of the root isolates significantlyfluctuated during the plant growth period, reaching a maximum after 10-15 days of growth. At this time period, the maximum % CT for the root isolates was around 70-80% CT under a soil moisture 50% WFP (% volume of water-filled pores in total soil pores), and then gradually reduced with an increasing % WFP. The results of the chemotaxis potential of each of the 100 islates from the spinach roots and nonrhizosphere soil under various % WFP demonstrated that the % CT of the root isolates were significantly higher than those of solates from the nonrhizosphere soil under a wide range of soil moisture content (35-80% WFP). Furthermore, the % CT value (80%) from the upper root was significantly higher than tht (55%) from the lower root. Compared with the % CT values of the roots, the values from the nonrhizosphere soil did not significantly vary relative to the plant age of % WFP. These results indicate that chemotaxis would appear to be a major factor in bacterial root colonization.

• 전기학회논문지
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• 제60권1호
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• pp.205-213
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• 2011

The Long Term Evolution (LTE) system is designed to provide a high quality data service for fast moving mobile users. It is based on the Orthogonal Frequency Division Multiplexing (OFDM) and relies its channel estimation on the training samples which are systematically built within the transmitting data. Either a preamble or a lattice type is used for the distribution of training samples and the latter suits better for the multipath fading channel environment whose channel frequency response (CFR) fluctuates rapidly with time. In the lattice-type structure, the estimation of the CFR makes use of the least squares estimate (LSE) for each pilot samples, followed by an interpolation both in time-and in frequency-domain to fill up the channel estimates for subcarriers corresponding to data samples. All interpolation schemes should rely on the pilot estimates only, and thus, their performances are bounded by the quality of pilot estimates. However, the additive noise give rise to high fluctuation on the pilot estimates, especially in a communication environment with low signal-to-noise ratio. These high fluctuations could be monitored in the alternating high values of the first forward differences (FFD) between pilot estimates. In this paper, we analyzed statistically those FFD values and propose a postprocessing algorithm to suppress high fluctuations in the noisy pilot estimates. The proposed method is based on a localized adaptive moving-average filtering. The performance of the proposed technique is verified on a multipath environment suggested on a 3GPP LTE specification. It is shown that the mean-squared error (MSE) between the actual CFR and pilot estimates could be reduced up to 68% from the noisy pilot estimates.

• 한국식생활문화학회지
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• 제22권3호
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• pp.330-335
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• 2007

알로에 베라 원액 첨가량을 달리하여(0, 3, 6, 9, 12%) 제조한 알로에 설기떡을 4일간 저장하면서 기계적, 관능적 품질특성을 평가하였다. 수분함량은 제조 직후 대조군이 33.79%였고, 알로에 원액 12% 첨가군에서는 다시 감소하는 현상을 보였다. 저장기간별로는 대조군과 첨가군 모두 저장기간이 길어질수록 수분함량은 감소하였다. 물성측정에서는 응집성, 탄력성, 점착성, 부착성, 씸힘성은 알로에 원액 첨가량이 증가할수록 감소하는 경향을 보였다. 색도에서 L값은 설기떡에 첨가한 알로에 원액의 양이 많을수록 유의적으로 감소하였고, a값의 경우 제조 직후 대조군은 -0.56이었으나, 알로에 원액 첨가량이 늘어날수록 음의 값을 나타내는 것을 볼 수 있었고, b값은 알로에 원액 첨가량에 따라 유의적으로 증가하였다. 관능검사에서는 색, 향, 맛, 부드러움, 촉촉함 및 전반적인 기호도에서 모두 9% 첨가군이 가장 높은 것으로 나타났을. 따라서 설기떡에 알로에 원액을 사용함으로써 떡의 품질특성이 향상되어 건강 기능성 상품개발이 가능할 것으로 예상된다.

• 환경생물
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• 제27권3호
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• pp.306-313
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• 2009

In the Upo wetland, physico-chemical factors were observed during the period from March 2005 to December 2007 on a monthly basis. In the Upo wetland, water temperatures ranged $3.4{\sim}34.5^{\circ}C$. Conductivities were in the range of 133~806 ${\mu}S\;cm^{-1}$, which showed about 140 ${\mu}S\;cm^{-1}$ below in comparison with the precedent studies. The pH levels were between 6.7~9.1 with lower level in summertime. The dissolved oxygens were between 0.06~18.23 mg $L^{-1}$. COD ranged 4.9~20.8 mg $L^{-1}$, and showed a tendency to decrease every year. Nitrogen nutrients such as nitrate nitrogen ($NO_3-N$), ammonia nitrogen ($NH_3-N$) and total nitrogen (T-P) showed that they were generally decreased in comparison with those in the precedent studies. However the total nitrogen (T-N) is still considerably higher than the standard concentration level of eutrophication and algal blooming. Phosphate phosphorus ($PO_4-P$) and total phosphorus (T-P) were also shown as to be reduced considerably comparing with the values in the precedent studies. However, It was found out that total phosphorus (T-P) was dissolved over the criteria concentration of eutrophication. The average of TN/TP ratio was 18 in the Upo wetland, which proved that phosphorus was the limiting factor to the growth of phytoplankton in the Upo wetland. The chl-$\alpha$ was the highest in wintertime and the lowest in summertime, and especially in 2006 summer when the cyanobacterial bloom developed, it showed extremely high concentration.