• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.39.1-39.1
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• 2016

The cosmic distance can be precisely determined using a 'standard ruler' imprinted by primordial baryon acoustic oscillation (hereafter BAO) in the early Universe. The BAO at the targeted epoch is observed by analyzing galaxy clustering in redshift space (hereafter RSD) of which theoretical formulation is not yet fully understood, and thus makes this methodology unsatisfactory. The BAO analysis through full RSD modeling is contaminated by the systematic uncertainty due to a non--linear smearing effect such as non-linear corrections and uncertainty caused by random viral velocity of galaxies. However, BAO can be probed independently of RSD contamination using the BAO peak positions located in the 2D anisotropic correlation function. A new methodology is presented to measure peak positions, to test whether it is also contaminated by the same systematics in RSD, and to provide the radial and transverse cosmic distances determined by the 2D BAO peak positions. We find that in our model independent anisotropic clustering analysis we can obtain about 2% and 5% constraints on $D_A$ and $H^{-1}$ respectively with current BOSS data which is competitive with other analysis.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.72.1-72.1
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• 2016

Current and planned large-volume surveys such as the Sloan Digital Sky Survey extended Baryon Oscillation Spectroscopic Survey (SDSS IV-eBOSS) or the Dark Energy Spectroscopic Instrument (DESI) will use Luminous Red Galaxies (LRGs) and Emission Line Galaxies (ELGs) to map the cosmic web up to z~1.7, and will allow one to accurately constrain cosmological models and obtain crucial information on the nature of dark energy and the expansion history of the Universe in novel epochs - particularly by measuring the Baryon Acoustic Oscillation (BAO) feature with improved accuracy. To this end, we present here a study of the spatial distribution and clustering of a sample of LRGs and ELGs obtained from a sub-volume of the MultiDark simulation complemented by different semi-analytic prescriptions, and investigate how these two different populations trace the cosmic web at different redshift intervals - along with their synergy. This is the first step towards the interpretation of upcoming ELG and LRG data.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.72.2-72.2
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• 2016

The SDSS-IV extended Baryon Oscillation Spectroscopic (eBOSS) will provide new photometry and spectroscopy of an unprecedented number of quasars in a novel redshift range, along with some re-observations of SDSS DR12 objects. We present here an observational study of the geometry, spatial distribution, luminosity function, and clustering of a sample of low- and high-z quasars obtained from the first SDSS-IV data release (DR13). In particular, we characterize the amount of overlapping between different data releases, and then focus on the synergy among high- and low-z quasars as tracers of the cosmic web, particularly considering their cross-correlations and cosmological implications.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.794-799
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• 2011

In order to reduce the oil consumption for a 2 stroke free piston hydrogen fueled engine, the behaviors of residual lubricant oil of the cylinder wall surface were visualized and oil mass emitted into exhaust port was measured by using research engine with cross-head and eccentric crankshaft. As the results, it was shown that characteristics of residual lubricant oil such as oil thickness and distribution were remarkably different from a conventional 4 stroke engine. It was also analyzed that these tendencies relied on the configuration and installed position of the exhaust port, piston pin boss and so on.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.810-812
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• 2000

Superconducting transmission cable is one of interesting part in power application using high temperature superconducting wire as transformer. One important parameter in HTS cable design is transport current distribution because it is related with current transmission capacity and loss. In this paper, we calculate inductance and current distribution for 4-layer cable using the electric circuit model and compare calculation results of transport current losses by monoblock model and Norris equation

• Journal of Sensor Science and Technology
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• v.22 no.5
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• pp.321-326
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• 2013

In this paper, the usability of a compact silicon strain gauge load cell in a weighting disdrometer for measuring the impact load of a falling raindrop is introduced for application in a multi-meteorological sensor. The silicon strain gauge load cell is based on the piezoresistive effect, which has a high linearity output from the momentum of the raindrop and the simplicity of signal processing. The weighting disdrometer shows a high sensitivity of 7.8 mV/g in static load measurement when the diaphragm thickness of the load cell is $250{\mu}m$.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.2
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• pp.77-88
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• 1993

This paper shows the methods about an improvement of the sound quality, which is improvement for automobil market recently. Especially, the rumble noise in the passenger compartment makes driver uncomfortable. For an improvement of the rumble noise, in this paper, the increase of the number of balance weight of the crank shaft(from 4 to 8), the vibration constrainer of cylinder block and the flexible flywheel were applied to power plant. Among those kinds of applications, the application of the flexible flywheel to power plant makes not only the vibration of the engine mount boss reduce most effectly but also the interior noise. It also improves the sound quality and the rumble noise disappears in the passenger compartment.

• The Journal of Information Technology
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• v.2 no.1
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• pp.91-101
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• 1999

In today's firms, there is an increasing awareness amongst managers and executives on the importance of secretary's role. This is a study on the profile of the corporate executive secretary's job responsibilities with emphasis on communication skills, interpersonal and foreign language fluency, which I deem relevant to their position. As a result, I believe that an executive secretary must obtain at least a two-year secretarial degree, Furthermore, I propose that their education must include and stress emphasis in foreign languages. Nevertheless, I feel that in today's global economy, it is important that executive secretaries are fluent in at least two(2) foreign languages that would enable him/her to write his/her boss' speeches, editing dictated materials and creating corresspondences. This study is believed to contribute to the education of the future executive secretaries and the managers etc.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.446-450
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• 1996

본 논문은 Computer Aided Software Engineering (CASE) Tool을 이용할 경우의 Safety Critical 소프트웨어 개발 방법론인 구조적 분석 및 구조적 설계 모델링 방법론을 Teamwork CASE tool의 예를 중심으로 제안하고자 한다. 제시된 사례는 NSIS(Nuclear Safety Information System)으로서 Essential Modeling과 Implementation Modeling을 제시하였는데 Teamwork CASE 환경하에서의 분석 및 설계 절차, 지침 등을 제시하였다. Essential Modeling에서는 NSIS의 MMIS 분석범위 및 External Interface를 제시하는 환경 모델(Environmental Model)과 MMIS의 기능을 계층구조적으로 분할하는 행위모델링(Behaviroal Modeling)을 각각 Context Diagram과 Data Flow Diagram (DFD)으로 그 과정을 제시하였다. Implementation Modeling에서는 Essential Modeling으로 부터 나온 결과물을 토대로 Boss Rule, Transform Rule과 Transaction Rule 등을 거쳐 NSIS MMIS의 설계 근간이 되는 Structured Chart(SC)를 제시하였다. 본 논문에서 제시된 모델링 방법론을 통하여 Safety Critical 소프트웨어 개발시 Teamwork CASE Tool을 활용할 수 있음과 동시에 분실 및 설계의 일치성을 통하여 Safety Critical 소프트웨어의 안전성 확립과 품질보증 목표에 기여할 수 있다.

• Archives of Pharmacal Research
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• v.27 no.7
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• pp.730-733
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• 2004

Bioassay-guided fractionation has led to the isolation of triterpenoid saponins such as Acutoside A (3-O-[O-${\beta}$-D-glucopyrano$yl-(1${\to}$2)-O-${\beta}$-D-glucopyranosyl] oleanolic acid) from the whole plants of Viola hondoensis. Among them, Saponin 1 exhibited potent inhibitory activity against matrix metalloproteinase (MMP)-1, and prevented the UV-induced changes in the MMP-1 expression. In addition, compound was isolated from this plant for the first time.