• 천문학회보
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• 제39권2호
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• pp.63.1-63.1
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• 2014

The galaxy disk warp is a common phenomenon, yet their properties and formation mechanism(s) are still unclear. Here, we introduce a new automatic measurement method for the warp properties of stellar disks in nearby edge-on galaxies, including warp's angle, shape, and asymmetry. We obtain isophotal maps of edge-on galaxies and express each of isophote contours in polar coordinates (${\Phi}$, R) centered on the galaxy centers. Two peaks in the ${\Phi}$-R diagram correspond to the outermost tips of each isophote. The locations of peaks, in turn, inform us of the misalignment between their inner and outer galactic planes, i.e., the warp. We apply this method to SDSS Stripe 82 co-added data and discuss its reliability and validity. Based on the measurement of warp properties, we also investigate their correlations with both intrinsic and environmental properties of warped galaxies.

• 한국토양비료학회지
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• 제15권2호
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• pp.89-94
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• 1982

1. 벼수량(收量)에 미치는 인산시용효과(燐酸施用効果)가 현저(顯著)하지 않은 화강암유래(花崗岩由來) 보통답(普通畓)과 시용효과(施用効果)가 현저(顯著)한 현무암유래중점질답(玄武岩由來重粘質畓)에 있어서 담수(湛水)에 따라 용출(溶出)되는 인산염(燐酸塩)을 추정(推定)하기 위해 solubility diagram법(法)을 사용(使用)했다. 2. 토양용액중(土壤溶液中) 인산농도(燐酸濃度), 양(陽)이온농도(濃度), pH치(値)의 담수(湛水)에 따른 변화(変化)를 측정(測定)했다. 그 변화양상(変化樣相)은 어느 토양(土壤)에서도 비슷했다. 보통답(普通畓)의 인산시용구(燐酸施用区), 무시용구(無施用区)의 값은 비슷했으나 중점질답(中粘質畓)에서는 차이(差異)가 보였다. 3. 보통답(普通畓), 중점질답(重粘質畓) 공(共)히 담수(湛水)에 따라 용출(溶出)되는 인산농도(燐酸濃度)는 담수후(湛水後) 얼마동안은 시용인산(施用燐酸)과 토양중(土壤中)알루미늄인산(燐酸)에 의해 지배(支配)되고, 그후 환원발달(還元発達)에 따라 토양중(土壤中) vivianite계(系) 인산(燐酸)에 의해 지배(支配)되는 것으로 추정(推定)되었다.

• 천문학회지
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• 제48권6호
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• pp.343-355
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• 2015

There is much observational evidence that active star formation is taking place in the Hii regions Sh 2-255 – 257. We present a photometric study of this star forming region (SFR) using imaging data obtained in passbands from the optical to the mid-infrared, in order to study the star formation process. A total of 218 members were identified using various selection criteria based on their observational properties. The SFR is reddened by at least E(B −V ) = 0.8 mag, and the reddening law toward the region is normal (R_V = 3.1). From the zero-age main sequence fitting method it is confirmed that the SFR is 2.1 ± 0.3 kpc from the Sun. The median age of the identified members is estimated to be about 1.3 Myr from a comparison of the Hertzsprung-Russell diagram (HRD) with stellar evolutionary models. The initial mass function (IMF) is derived from the HRD and the near-infrared (J, J −H) color-magnitude diagram. The slope of the IMF is about Γ = −1.6 ± 0.1, which is slightly steeper than that of the Salpeter/Kroupa IMF. It implies that low-mass star formation is dominant in the SFR. The sum of the masses of all the identified members provides the lower limit of the cluster mass (169M_⊙). We also analyzed the spectral energy distribution (SED) of pre-main sequence stars using the SED fitting tool of Robitaille et al., and confirm that there is a significant discrepancy between stellar mass and age obtained from two different methods based on the SED fitting tool and the HRD.

• Journal of Dairy Science and Biotechnology
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• 제21권2호
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• pp.81-87
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• 2003

우유의 여러 가지 품질 평가방법 중에서 소비자의 입장에서 중요한 기준이 되는 관능검사를 통해서 ESL우유와 non-ESL우유의 품질을 비교하여 그 차이점을 확인하였다. ESL우유의 1개사 제품과 non0ESL우유 4개사 제품을 $5^{\circ}C$ 와 $10^{\circ}C$에서 시료의 pH 및 적정산도는 그 변화가 크지 않았으며, 유성분인 fat, protein, lactose의 변화 역시 크지 않았다. 반면에 관능적으로 평가된 신섬함은 보존 5일차에 가장 신선하게 나타났다. ESL우유와 non-ESL우유의 QDA(quantitative descriptive analysis) diagram에 따르면, 동일한 조건상에서 저장지간 중 non-ESL우유의 관능적 품질 저하가 ESL우유보다 컸으며, 그 정도는 $10^{\circ}C$에서 두드러졌다. 우유의 신선도 평가 기준인 FFA(free fatty acid)와 관능적으로 느끼는 신선도 상의 상관분석을 통해서, 우유의 신선도는 FFA보다 우유의 풍미 및 미생물적 부패와 상관관계가 크다는 것으로 확인되었다. 결론적으로 우유의 신선도 결정에는 관능적 풍미가 가장 중요한 기준이 되며, non-ESL우유보다 ESL우유가 보존기간 중 신선함이 오래 지속되는 것으로 확인되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.313-315
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• 2005

In a power system, an out-of-step condition causes a variety of risk such as serious damage to system elements, tripping of loads and generators, mal-operation of relays, etc. Therefore, it is very important to detect the out-of-step condition and take a proper measure. Several out-of-step detection methods have been employed in relays until now Mo,;t common method used for an out-of-step detection is based on the transition time through the blocking impedance area in R-X diagram. Also, the R-R dot out-of- step relay, the out-of-step prediction method and the adaptive out-of-step relay using the equal area criterion (EAC) and Global Positioning Satellite (GPS) technology have been developed. This paper presents the out-of-step detection algorithm using the time variation of the complex power. The complex power is calculated and the mechanical power of the generator is estimated by using the electrical power, and then the out-of-step detection algorithm, which is based on the complex Power and the estimated mechanical power, is presented. This algorithm, may detect the instant when the generator angle passes the Unstable Equilibrium Point (UEP). The proposed out-of-step algorithm is verified and tested by using Alternative Transient Program/Electromagnetic Transient Program (ATP/EMTP) MODELS.

• Journal of Pharmaceutical Investigation
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• 제32권1호
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• pp.27-33
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• 2002

A self-microemulsifying drug delivery system(SMEDDS) composed of Cremophor $EL^{\circledR},\;Labrasol^{circledR}$, and Lauroglycol $FCC^{circledR}$ was prepared for the enhancement of solubility, dissolution rate and bioavailability of ibuprofen(IBP), which is water-insoluble but soluble in oils and surfactants. Phase diagram with various regions including microemulsion area was depicted. The SMEDDS was encapsulated in soft gelatin capsules and their dissolution characteristics in various media were observed in comparison to the generic products commercially available in the market. Soft capsules of SMEDDS formulation showed better dissolution profiles, especially in acidic condition, than the others. For the period of 1 hr dissolution in pH 1.2 medium, it reached over 70% dissolution from soft capsules, compared to less than 40% dissolution from commercial reference tablets. On the other hand, in vivo pharmacokinetic parameters were obtained after oral administrations of different IBP preparations to Sprague Dawley rats. SMEDDS formulation showed higher $C_{max}$ and greater $AUC_{0-5hr}$ than the suspension of reference tablet or IBP powder. Therefore, it is possible to conclude that a newly developed soft capsules employing SMEDDS provides an alternative preparation to improve oral bioavailability of IBP.

• 천문학회지
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• 제38권4호
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• pp.429-435
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• 2005

We present BV CCD photometry for the open clusters Czernik 24 and Czernik 27. These clusters have never been studied before, and we provide, for the first time, the cluster parameters; reddening, distance, metallicity and age. Czernik 24 is an old open cluster with age $1.8{\pm}0.2Gyr$, metallicity $[Fe/H]=-0.41{\pm}0.15dex$, distance modulus $(m-M)_0=13.1{\pm}0.3mag$ ($d=4.1{\pm}0.5kpc$), and reddening $E(B-V)=0.54{\pm}0.12mag$. The parameters for Czernik 27 are estimated to be $age=0.63{\pm}0.07Gyr$, $[Fe/H]=-0.02{\pm}0.10dex$, $(m-M)_0=13.8{\pm}0.2mag$ ($d=5.8{\pm}0.5kpc$), and $E(B-V)=0.15{\pm}0.05mag$. The metallicity and distance values for Czernik 24 are consistent with the relation between the metallicity and the Galactocentric distance of other old open clusters. We find the metallicity gradient of 51 old open clusters including Czernik 24 to be ${\Delta}[Fe/H]/{\Delta}R_{gc}=-0.064 {\pm}0.009dex\;kpc^{-1}$.

• 한국광학회지
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• 제4권2호
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• pp.220-225
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• 1993

이 연구에서는 4d 전이원소인 rhodium 이온을 첨가한 유리의 광학적 특성을 조사하였다. Rhodium이 첨가된 phosphate유리의 광흡수, photoluminescence, 수명시간 등을 측정하고 여기에 Sugano-Tanabe의 strong-field scheme을 적용하여 해석한 결과 phosphate유리 속에서 rhodium은 R$h^{2+}$ 상태로 존재하며 이때 10Dq는 약$20,000cm^1$였다. $^2 E{\rightarrow}^2 T_1$과 $^2 E{\rightarrow}^2 T_2$ 천이에 의한 흡수대는 460nm에 중첩되어 나타나고, $^2 T_1{\rightarrow}^2 E$와 $^2 T_1{\rightarrow}^2 E$천이에 의한 luminescence대는 각각 650nm와 580nm에 나타났다.

• 약학회지
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• 제49권4호
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• pp.268-274
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• 2005

Paclitaxel is an effective antineoplastic agent against ovarian, colon and breast tumors. But there have been many difficulties to formulate this drug due to the extremely low aqueous solubility. Paclitaxel is currently formulated in a vehicle composed of Cremophor EL and absolute ethanol mixture which is $5\~20$ fold diluted in normal saline or $5\%$ dextrose solution before I.V. injection. However, this formulation has many problems such as allergic reactions and drug precipitation on aqueous dilution. To overcome these problems, we prepared the micelle and microemulsion systems for parenteral administration of paclitaxel by using glycofurol, $Soluto^{(R)}lHS$ 15 and oleic acid. Phase diagram, pH-rate stability, particle size distributions and pharmacokinetics of the systems were studied. Micelles and microemulsions formulated as nano-particle delivery system were physically and chemically stable. Therefore, these formulations might be the promising alternative candidate for the parenteral delivery of paclitaxel.

• 천문학회지
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• 제43권5호
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• pp.141-152
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• 2010

UBV I CCD photometry is obtained for the open clusters NGC 4609 and Hogg 15 in Crux. For NGC 4609, CCD data are presented for the first time. From new photometry we derive the reddening, distance modulus and age of each cluster - NGC 4609 : E(B-V ) = $0.37{\pm}0.03$, $V_0-M_V=10.60{\pm}0.08$, log $\tau$= 7.7 $\pm$ 0.1; Hogg 15 : E(B - V ) = 1.13 $\pm$ 0.11, $V_0-M_V$ = 12.50 $\pm$ 0.15, log $\tau$ $\lesssim$ 6.6. The young age of Hogg 15 strongly implies that WR 47 is a member of the cluster. We also determine the mass function of these clusters and obtain a slope $\Gamma$ = -1.2 ($\pm$0.3) for NGC 4609 which is normal and a somewhat shallow slope (${\Gamma}=-0.95{\pm}0.5$) for Hogg 15.