• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.254-257
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• 2002

As the large Coolant amount used of a machine holds mass serious trouble recently, an environment pollution is increased, and a machine is conquering large specific gravity in an empty cost plane. It is the stage that must reexamine the parts washing that processing is later with this current way or a problem of a liquid waste treatment back. The environmental problems by using coolant demanded the new cooling methods. As one of them, the studies on the grinding with compressed cold air and oil mist have been done. The cooling method using compressed cold air was effective through going down the temperature of compressed air supplied below -$25^{\circ}C$ and increasing the amount of compressed cold air, but had not enough cooling effect due to the low performance of lubrication. Therefore, the cooling methods using oil mist newly were suggested. This method can satisfy both cooling effect and lubrication with only small amount of coolant, also have the benefit in the point of decreasing the environmental pollution. This paper focused on analyzing the grinding characteristics of the cooling method using oil mist. The grinding test according to compressed cold air and oil mist supply direction were done.

• 한국수산과학회지
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• 제41권6호
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• pp.409-413
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• 2008

A simple method for the purification of porphyran from laver Porphyra yezoensis was developed to obtain information for the development of food materials with biological functionality. Crude porphyran (CP) was extracted from dried laver in boiling water for 3 h, and then fractionated using cetylpyridinium chloride into an acidic fraction (CP-F1) and a neutral fraction (CP-F2). CP-F1 was fractionated further by fractional ethanol precipitation. Fraction CP-F1-70, precipitated at an ethanol concentration of 61-70% was the major fraction containing 68.1% of the yield from the initial fraction CP-F1. The CP-F1-70 fraction displayed a single band on Sepharose CL-4B with a molecular mass of 550 kDa, indicating a homogeneous polysaccharide. The molar ratio of galactose, 3,6-anhydro-L-galactose, 6-0-methyl-D-galactose and ester sulfate of CP-F1-70 was 1:0.32:0.07:0.53. This method is very useful for rapid and large-scale preparation of purified porphyran because it is compatible with mass production.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4275-4280
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• 2011

Present study describes the optimization of disk type sorptive extraction using monolithic material (Mono Trap) for the analysis of volatile aroma compounds from Lantana camara L. in combination with gas chromatography/mass spectrometry (GC/MS). Monolithic material sorptive extraction (MMSE) is a new sampling technique using a monolithic hybrid adsorptive disk (O.D. 10 mm, 1 mm thickness) made of high purity silica and activated carbon having a large surface area chemically bonded with octadecyl silane (ODS). The experimental parameters that may influence the MMSE efficiency have been optimized. Linearity, accuracy, precision and detection limits were evaluated to assess the performance of the proposed method. The method was validated with real plant samples of Lantana camara L. Twenty eight compounds including the main representative compounds of ${\alpha}$-curcumene and ${\beta}$-caryophyllene were found in analyzed samples. Results proved that proposed method could be used as a good alternative for the analysis for such volatile aroma compounds in plant samples.

• 반도체디스플레이기술학회지
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• 제5권4호
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• pp.29-34
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• 2006

In order to design an OLED(Organic Luminescent Emitting Device) evaporation system, geometric simulation of film thickness distribution profile is required. For the OLED evaporation process, thin film thickness uniformity is of great practical importance. In this paper, a geometric modeling algorithm is introduced for process simulation of the OLED evaporating process. The physical fact of the evaporating process is modeled mathematically. Based on the developed method, the thickness of the thin-film layer can be successfully controlled.

• 한국해양공학회지
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• 제10권2호
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• pp.136-145
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• 1996

The theory is based on two thermodynamic equations for the air mass in the air column and bydrodynamic equation for the relation between the response of the air in the water column and the incident wave. The numerical model is experimented in a two dimensional water tank and the caisson model with sloped front wall is tested in the large towing tank.

• 대기
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• 제23권4호
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• pp.501-511
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• 2013

In this study, we estimate the background concentration of black carbon (BC) mass concentration measured at Gosan Climate Observatory from January 2008 to December 2011 by applying six methods: (1) Mean and Median (2) Trimmed mean method deployed in Interagency Monitoring of Protected Visual Environments (IMPROVE) network program (hereafter, IMPROVE method), (3) Concentration-frequency distribution analysis method, (4) Advanced Global Atmospheric Gases Experiment (AGAGE) method (hereafter, AGAGE method), (5) Kaufman et al. (2001) method (hereafter, Kaufman method), and (6) Airmass sector analysis. The background concentration of BC mass concentrations is estimated to be about 400~900 ng $m^{-3}$, but each method shows a large difference. The estimated background concentration, in general, is arranged in the order of: mean > IMPROVE method > median > Kaufman method > concentration-frequency distribution analysis method > AGAGE method. The background concentration estimated by the airmass sector analysis is found to be about 550 ng $m^{-3}$ which is lower than those estimated by other methods. When we apply the same analytical period (i.e., 4-day and 6-day) to both AGAGE and Kaufman methods, the estimated background concentrations are quite similar. However, further researches on the development of statistical method for estimating background concentration for various gas-phase and particulate pollutants under different environment are needed.

• Macromolecular Research
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• 제11권6호
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• pp.437-443
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• 2003

A series of alternating and alternating block copolycarbonates containing the constituent groups of polysulfone was synthesized through a multi-step solution condensation method. For the regulation of block length, monodisperse oligomers were prepared by using a large excess of the bisphenols and were subsequently incorporated into the copolymer chains. Separating the unreacted bisphenols from the oligomers by dissolution/precipitation steps took advantage of solubility differences. The structures of the monomers, oligomers, and copolymers were characterized and confirmed by GPC, NMR spectroscopy, mass spectrometry, and elemental analysis. Monodispersity of the oligomers, which is critical for control over the block length in the copolymers, was confirmed by GPC and mass spectrometry. Of the two constituent groups of the polysulfone, the sulfone linkage stiffens the polycarbonate copolymer chain, while the ether linkage softens it.

• 한국해안해양공학회지
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• 제1권1호
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• pp.87-92
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• 1989

극지에서의 충돌 빙하중의 크기를 구하기 위해 지반, 구조 및 구조물을 일체로 하는 동적 모델을 제시하였다. 지반은 감쇠 효과를 고려한 비선형 스프링으로 이상화하였으며, 부빙과 구조물의 상호작용은 얼음의 특성을 고려한 비선형 스프링으로 이상화하였다. 이 모델에 의한 여름과 겨울의 부빙의 질량과 속도에 따른 영향을 모래지반과 시일토지반에 대해 각각 해석하여 에너지 평형 방법과 비교하였다. 해석 결과 모래지반의 경우는 대체적으로 에너지 평형 방법에 의한 값이 동적 모델에 의한 값보다 작게 나타났으며, 시일 토지반의 경우는 그 반대로 나타났다.

• 천문학회보
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• 제39권1호
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• pp.42.1-42.1
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• 2014

A gravitational weak-lensing map provides a weighted "picture" of the projected surface mass density and is to be an important tool for identifying "mass-selected" clusters of galaxies. However, weak-lensing maps have a limitation due to the projection of large-sclae structure along the line-of-sight. Geller et al. (2010) and Kurtz et al. (2012) compared massive clusters identified in a dense redshift survey with significant weak-lensing map convergence peaks. Both assessments of the efficiency of weak-lensing map for cluster identification did not draw a general conclusion, because the sample is so small. Thus, we additionally perform deep imaging observations of fields in a dense galaxy redshift survey that contain galaxy clusters at z~0.2-0.5, using CFHT Megacam. Our study will provide an important opportunity to examine the efficiency and completeness of a weak-lensing selection, and further to improve the method of cluster identification in future weak-lensing surveys.

• 천문학회보
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• 제41권1호
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• pp.71.2-71.2
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• 2016

Merging galaxy clusters, such as PLCKG287.0+32.9, provide a window into the formation process of the large scale structure of the universe. PLCKG287.0+32.9 is an enormous merging galaxy cluster with mass estimated to be ~10^15 Msun. It hosts a pair of mega-parsec sized radio relics with projected offsets from the X-ray center of approximately 350kpc and 2.7Mpc, suggesting a NW-SE merging scenario with relics originating from two separate passes (Bonafede et al. 2014). A detected radio halo coincides with the center of x-ray emission. We present the motivation for our weak lensing study of the merging galaxy cluster PLCKG287.0+32.9 using recent Subaru optical imaging. We discuss the basics of weak-lensing and the criteria for source selection. In addition, we describe our method of PSF modeling and mass reconstruction.