• 대한전기학회논문지:시스템및제어부문D
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• 제54권7호
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• pp.423-427
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• 2005

In this paper, we proposed a new ARMA model identification which estimate the parameters to make the current prediction error uncorrelated with the past one. As good properties of the proposed method, we show the uniqueness, consistency of the estimate and asymptotic normality of the estimation error. Via simulation results, we show that the proposed method give good estimates for various systems which have different power spectrum. Moreover, the estimation of gyroscope random errors shows that the proposed method is applicable to the real data.

• 생명과학회지
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• 제24권5호
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• pp.485-490
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• 2014

백복령(Poria cocas)은 전통적으로 민간에서 피부미백에 효과가 있다고 보고되어 있다. 지금까지 melanin 합성에 대한 백복령의 직접적인 효과는 과학적으로 잘 연구되어 있지 않다. 따라서 멜라닌 합성에 대한 백복령 주정 추출물(PCEE)의 직접적인 효과를 밝히기 위해, 쥐의 B16F1 세포를 이용하여 DOPA synthesis assay, tyrosinase activity assay, Western blotting for melanogenic proteins [tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2]를 수행하였다. 본 연구에서 PCEE가 3,4-dihydroxyindole-2-carboxylic acid (DOPA) 합성을 차단함으로써 농도 의존적으로 melanin형성을 억제한다는 것이 밝혀졌다. 비록 tyrosinase의 활성은 영향을 받지 않았지만 TRP-1 과 TRP-2의 단백질 발현 수준은 PCEE에 의해 조절되었다. 따라서 이러한 결과는 PCEE가 미백 효능을 가지고 있어 미백 화장품 개발을 위해 이용될 수 있다는 것을 시사하고 있다.

• 한국통신학회논문지
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• 제9권2호
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• pp.62-69
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• 1984

DS대역확산 통신 수신기의 성능은 디지털 백색화 여파기를 사용하여 개선시킬 수 있다. 본 연구에서는 출력의 hard-limiter에서 검출한 신호를 입력으로 궤환시켜 간섭과 잡음성분만을 백색화하는 디지털 궤환 백색화 여파기를 제안하고 여파기의 계수계산 방법에 관하여 기술하였다. SNR과 BER에 관한 식을 유도하였으며 종래의 디지털 백색화 여파기와 비교하였다. 컴퓨터 시뮬레이션 결과 오율특성은 종래의 방식에 비해 크게 향상된 것으로 나타났다.

• 펄프종이기술
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• 제43권4호
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• pp.76-81
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• 2011

This study was carried out in order to develop a speciality functional coated paper, which can be recognized under a ultraviolet lamp. The special fluorescent whitening agent (FWA) which absorbs ultraviolet light (397~410 nm) and emits it as yellowish light (570~500nm) was used. The special FWA was applied in a coating color in two ways: (1) direct application to a coating color as a FWA; (2) application on pigment surface, drying it and application it as a fluorescence whitening pigments (colored pigments). The effects of the special FWA on coating color properties were tested and the distribution of colored pigments in coated paper was evaluated under a ultraviolet lamp. The results showed that the colored pigments didn't affect on coating color properties. Experimental results showed the possibility of producing a security coated paper using the special FWA. To produce a speciality functional paper, it was found to be proper to apply the special FWA in the form of colored pigment.

• Journal of Ginseng Research
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• 제39권1호
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• pp.1-6
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• 2015

Abnormal changes in skin color induce significant cosmetic problems and affect quality of life. There are two groups of abnormal change in skin color; hyperpigmentation and hypopigmentation. Hyperpigmentation, darkening skin color by excessive pigmentation, is a major concern for Asian people with yellowe-brown skin. A variety of hypopigmenting agents have been used, but treating the hyperpigmented condition is still challenging and the results are often discouraging. Panax ginseng has been used traditionally in eastern Asia to treat various diseases, due to its immunomodulatory, neuroprotective, antioxidative, and antitumor activities. Recently, several reports have shown that extract, powder, or some constituents of ginseng could inhibit melanogenesis in vivo or in vitro. The underlying mechanisms of antimelanogenic properties in ginseng or its components include the direct inhibition of key enzymes of melanogenesis, inhibition of transcription factors or signaling pathways involved in melanogenesis, decreasing production of inducers of melanogenesis, and enhancing production of antimelanogenic factor. Although there still remain some controversial issues surrounding the antimelanogenic activity of ginseng, especially in its effect on production of proinflammatory cytokines and nitric oxide, these recent findings suggest that ginseng and its constituents might be potential candidates for novel skin whitening agents.

• 펄프종이기술
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• 제47권6호
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• pp.106-112
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• 2015

Many researchers have proposed analytical methods to measure the adsorption of di-sulpho fluorescent whitening agents (D-FWAs), but practical methods for D-FWA utilization in an actual paper mill have not been established. In particular, the D-FWA adsorption behavior must be monitored in paper mills to ensure the effective use of D-FWAs. This study used the zeta-potential of pulps as an indicator of the adsorption behavior of a D-FWA. We identified the relationship between the actual adsorption of the D-FWA and the zeta-potential of the pulps as a function of D-FWA addition. zeta-potential measurements were then used to analyze the D-FWA adsorption behavior under different conditions of pulp type, conductivity, and pH. The actual adsorption of a D-FWA was proportional to the ${\Delta}zeta-potential$ of the pulps (i.e., the difference between the zeta-potential of a pulp containing no D-FWA and one containing the D-FWA). The ${\Delta}zeta-potential$ of the pulps was therefore adopted for adsorption analysis. A higher adsorption of the D-FWA was observed onto Hw-BKP than onto Sw-BKP because of the shorter fiber length and higher fines content of Hw-BKP. A high conductivity and an acidic pH decreased the D-FWA adsorption because of direct effects of high ion concentrations and low pH on the D-FWA solubility. Therefore, a D-FWA must be added to Hw-BKP under low conductivity conditions and at neutral or alkaline pH to optimize the D-FWA adsorption.

• 약학회지
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• 제56권6호
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• pp.395-400
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• 2012

To investigate the possibility of development as a whitening agent using arctigenin, we measured DPPH assay, NBT/XO assay, intracellular ROS scavenging assay, tyrosinase assay and MSH-induced melanin production in B16 melanoma cells. Arctigenin dose-dependently had anti-oxidant activity in DPPH, NBT/XO and intracellular ROS assay. Although arctigenin did not inhibit purified tyrosinase activity, it dose-dependently inhibited tyrosinase activity and melanin production in B16 melanoma cells stimulated by $1{\mu}M$ ${\alpha}$-MSH. In particular, arctigenin at a concentration $100{\mu}M$ inhibited ${\alpha}$-MSH-stimulated tyrosinase activity and melanin production by $50.9{\pm}2.9%$ and $69.0{\pm}6.5%$ respectively. And typical tyrosinase inhibitor, arbutin, inhibited $57.7{\pm}2.9%$ and $65.1{\pm}5.0%$ respectively. Such an similar inhibitory effect of arctigenin and arbutin in B16 melanoma cells may be due to the inhibition of MSH signal pathway rather than the direct inhibition of tyrosinase. Therefore, these results suggest that arctigenin may be useful for the development as whitening agents.

• 생명과학회지
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• 제22권7호
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• pp.936-942
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• 2012

매실나무(Carthamus tinctorius L.)는 한국, 일본과 중국에서 전통적으로 약효가 있는 음식으로 사용되어 왔다. 특히 과일은 위염증 및 위궤양에 도움이 되는 생물학적 효과가 있다고 보고되었다. 그러나 피부미백과 관련된 효능에 대한 연구는 이직까지 미진하다. 따라서, 본 연구에서는 항산화 및 피부미백에 대한 매실추출물의 효능이 조사되었다. MTT assay를 이용한 세포생존에 대한 결과로 매실추출물은 0.1% 이하의 농도에서 세포독성이 없는 것으로 나타났다. 다음에 매실추출물의 환원력 뿐만 아니라 DPPH radical, hydrogen peroxide 및 superoxide에 대한 직접적인 소거효과가 in vitro에서 평가되었다. 그것은 이상의 활성산소종에 대한 소거효과를 발휘하게 하는 우수한 환원력을 가지고 있다. 더욱이 산화적 스트레스와 연관된 genomic DNA 손상에 대한 보호효과가 농도에 따라 증가하는 것이 관찰 되었다. 뿐만 아니라 L-dopa에 의하여 유발되는 멜라닌 생성에 대한 억제효과를 나타내었다. 그것은 또한 Western blot 분석에서 항산화와 괸련된 NRF-2, SOD-1 및 SOD-2 발현수준을 감소시킨다는 것이 발견되었다. 이러한 결과들은 매실추출물이 항산화에 의한 멜라닌생성의 억제를 통하여 피부 미백효과를 발휘할 수 있다는 것을 암시한다.

• 한국정밀공학회지
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• 제27권7호
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• pp.87-93
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• 2010

This paper presents an evaluation of efficiency on glass precision machining by using abrasive water-jet machine. In this study, problems of conventional water-jet machining are examined experimentally and are analysized numerically. Especially, the reason of whitening on the machined surface of biochip glass is determined. It is found that the mass flow rate of abrasive input and transverse speed of water-jet are key parameters to control the direct machining of micro hole and channel on a glass substrate. Based on results of experimental analysis, possibility of direct fabrication of micro holes and channels on a glass substrate is successfully confirmed.

• Journal of Biosystems Engineering
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• 제1권1호
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• pp.17-48
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• 1976

In analyzing the operational characteristics of a rice whitening machine, the internal radial pressure of the machine was measured using strain gage equipment. Changes in cylinder and feed screw configurations, screen type, cylinder speed and counter-pressure levels were examined to determine their impact on the quality and quantity of milled rice and the performance of the machine. The results are summarized as follows: 1. The internal radial pressure in the whitening chamber varied with the surface condition of the grain being processed. During the first or second pass through the machine, pressure was relatively low, reached a maximum after two to three passes with combinations I and II, three to six with combination III and then began to fall. 2. The pitch of the feed screw and the size of the feed gate opening which determine the rate of entry of grain into the whitening chamber, appeared to be the most important factor aff-::cting the degree of radial pressure, quality and quantity of milled rice and the efficiency of the machine. Using a feed screw with a wide pitch (4.8cm), radial pressure was relatively high and head rice recovery ratio \vere quite low. In this case capacity and machine effic\ulcorneriency were much higher than obtained when using a feed screw with a narrow pitch (2.3cm). Very significant responses in radial pressure, head rice recovery rates and machine capacity were observed with changes in cylinder speed and counter-pressure levels when using the wide pitch feed screw. 3. The characteristics of the screen which surrounds the whitening chamber had an important effect on whitening efficiency. The existence of small protuberances on the original screen resulted in significant increases in both machine capacity and efficiency but without a significant decrease in head rice recovery or development of excessive radial pressure. Further work is required to determine the effects of screen surface conditions and the shape of the cylinderical steel roller on the rate of bran removal, machine efficiency and recovery rates. The size of the slotted perforations 0:1 the screen affects total milled rice recovery. The opening size on the original screen was fabricated to accommodate the round shape of Japonica rice varieties but was not suitable for the more slender Indica type. Milling Indica varieties with this screen resulted in a reduction in total milled rice recovery. 4. An increase in cylinder speed from 380 to 820 rpm produced a positive effect on head rice recovery for all machine combinations at every level of counter-pressure used in the tests. Head rice recovery was considerably lower at 380rpm using a wide screw pitch when compared to the results obtained at speeds from 600 to 820 r.p.m. The effects of cylinder speed On radial pressure, capacity and machine efficiency showed contrasting results, depending on the width of the feed screw pitch. With a narrow feed screw pitch (2.3cm), a direct proportional relationship was observed bet\ulcornerween cylinder speed and both radial pressure and machine efficiency. In contrast, using a 4.8 centimeter pitch feed roller produced a series of inverse relationships between the above variables. Based on the results of this study it is recommended when milling Indica type long grain rice varieties that the cylinder speed of the original machine be increased from 500-600 rmp up to a minimum of 800 rpm to obtain a greater abrasive effect between the grain and the screen. The pitch of the feed screw should be also reduced to decr\ulcornerease the level of internal radial pressure and to obtain higher machine efficiency and increased quality of milled rice with increased cylinder speeds. Further study on the interaction between cylinder speed and feed screw pitch is recommended. 5. An increase in the counter pressure level produced a negative effect On the head rice recovery with an increase in radial pressure, capacity, and machine efficiency over all combinations and at every level of cylinder speed. 6. Head rice recovery rates were conditioned primarily by the pressure inside the whitening chamber. According to the empirical cha racteristics curve developed in this study, the relationships of head rice recovery ($Y_h$) and machine capacity ($Y_c$/TEX>) to internal radial pressure ($X_p$) followed an inverse quadratic function and a linear function respectively: $$Y_h^\Delta=\frac{1}{{1.4383-0.2951X_p^\ast+0.1425X_p^{\ast\ast}}^2} , (R^2=0.98)$$ $$Y_c^\Delta=-305.83+374.37X_p^{\ast\ast}, (R^2=0.88)$$ The correlation between capacity and power consumption per unit of brown rice expressed in the following exponential function: $$Y_c^\Delta=1.63Y_c^{-0.7786^\{\ast\ast}, (R^2=0.94)$$ These relationships indicate that when radial pressure increases above a certain range (1. 6 to 2.0 kg/$cm^2$ based On the results of the experiment) head ricerecovery decrea\ulcornerses in a quadratic relation with a inear increase in capacity but without any decrease in power consump tion per unit of brown rice. On the other hand, if radial pressure is below the range shown above, power consumption increases dramatically with a lin\ulcornerear decrease in capacity but without significant increases in head rice recovery. During the operation of a given whitening machine, the optimum radial pressure range or the correct capacity range should be selected by controlling the feed rate and/or counter-pressure keeping in mind the condition of the grain, particulary the hardness. It was observed that the total number of passes is related to radial pessure level, feed rate and counter-pressure level. The higher theradial pressure the fewer num\ulcornerber of pass required but with decreased head rice recovery. In particular, when using high feed rates, the total number of passes should be increased to more than three by reducing the counter-pressure level to avoid decreaseases in head rice recovery (less than 65 percent head rice recovery on the basis of brown rice) at every cylinder speed. 7. A rapid rise in grain temperature seemed to have a close relationship with the pressure generated inside the whitening chamber and, subsequently with head rice reco\ulcornervery rates. The higher the rate of increase, the lower were the resulting head rice recoveries.