• 천문학회보
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• 제40권1호
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• pp.80.3-81
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• 2015

Globular clusters (GCs) are known to have a very small amount of or no dark matter (DM). Several studies propose that GCs may have formed in individual dark halos. Thus, some of the current GCs might have a non-negligible DM content. Using the Fokker-Planck (FP) calculations, we investigate the dynamical evolution of the Galactic GCs residing in mini DM halo. We trace the initial amount of DM of 47 Tuc, NGC 1851, and M15, which is a 'disk/bulge' cluster, an 'old halo' cluster, and a 'young halo' cluster, respectively. We find that the three GCs have initially insignificant amounts of DM, less than 20 percent of the initial stellar mass of the each cluster.

• 천문학논총
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• 제27권4호
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• pp.345-346
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• 2012

Starting from an infrared selected GALEX-SDSS-2MASS-AKARI sample of local star forming galaxies, we built mock samples from redshift 0 to 2.5 to investigate star formation rate (SFR) calibrations using WISE luminosities. We find W3 and W4 band fluxes can indicate SFRs with small scatters when the rest-frame wavelengths are longer than ${\sim}6{\mu}m$. When the wavelength becomes shorter, the observed luminosities are more tightly connected to the emission of old stellar populations than dust, therefore lose the reliability to trace the SFR. The current SFR calibrations are consistent with previous studies.

• Bulletin of the Korean Chemical Society
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• 제27권7호
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• pp.991-994
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• 2006

Herein, insoluble single-walled carbon nanotube (SWNT) was successfully dispersed into water in the presence of a special kind of surfactant-dicetyl phosphate (DCP), subsequently, a SWNT-DCP composite film coated glassy carbon electrode (GCE) was fabricated. The electrochemical behaviors of 6-benzylaminopurine (6-BAP) at the unmodified GCE and SWNT-DCP modified GCE were examined. It is found that the SWNT-DCP modified GCE remarkably enhances the oxidation peak current of 6-BAP, indicating great potential in the determination of trace level of 6-BAP. Finally, a sensitive and simple voltammetric method with a good linear relationship in the range of ${\times}5.0\;\;10^{-8}\sim 2.5\;{\times}\;10^{-6}$ mol/L, was developed for the determination of 6-BAP. The detection limit is as low as $2.0\;{\times}\;10^{-8}$ mol/L for 3-min accumulation. This newly-proposed method was successfully demonstrated with practical samples.

• 한국세라믹학회지
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• 제29권4호
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• pp.253-258
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• 1992

ZnO varistors were prepared by the organochemical method which used citric acid and ethylene glycol as gelling agents. The microstructure of the sintered specimens exhibited small grains, uniform grain size distribution, and few intragranular pores. Thermal decomposition of the organic resin formed during the powder preparation process was completed around 450$^{\circ}C$. No significant changes were observed in microstructure and current voltage characteristic with respect to calcination temperatures. A major advantage of the organochemical method used in this experiment is a possible uniform mixing of trace amounts of dopants. Therefore, this powder preparation method seems promising in investigating the effect of Li or In ion, which is added in ppm level to ZnO varistors, on the pulse respose characteristic.

• 한국생산제조학회지
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• 제7권6호
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• pp.72-79
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• 1998

In this paper, image processing algorithm is studied to enhance the preciseness of the geometry while converting captured images to CAD data. A program is developed as a result. The code, in the image processing, utilizes outline trace, point data smoothing algorithm. It is capable of automatically generating design data by converting input image data to the CAD data. The output can be made in DXF, IGES formats. The current research can be utilized as a base data for the development of factory automation or flexible manufacturing system which adopt image processing based automatic inspection and measuring system.

• 한국통신학회논문지
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• 제22권6호
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• pp.1266-1272
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• 1997

Due to the price and performanceof uniprocessor workstations and off-the shelf networking, network of workstations(NOW) ae now a cost-effective parallel processing platform tht is competitive with supercomputers. Meanwhile, current network fiile system protocols rely heavily on a central server to coordinate file activity among client workstations. This central server can become a bottleneck that limits scalibility for environments with large numbers of clients. In this paper, we propsoe a highly reliable and effective software RAID file system on the network of workstation environment. We present results form a trace-driven simulation study that shows that the designed software RAID file system is more effective in the aspect of elapsed time when compared with client/server file systems.

• 대기
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• 제20권1호
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• pp.49-61
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• 2010

Atmospheric aerosols play a crucial role for changing climate, resulting in a wide range of uncertainty for future climate prediction. In this paper we review current international research status and trend of climate-related aerosol science. There have been carried out a number of campaigns (including ACE-Asia, TRACE-P, ABC, and so on) and special experiments with some modeling studies over Korea, East Asia, and the Northwestern Pacific to characterize the various properties (physical, chemical, optical, and radiative) of Asian aerosols and evaluate their climate forcing impacts. But some parts of the aerosol research may need to be improved, advanced, or newly launched. Especially, a chemical transport model (CTM) embedded by a general circulation model (GCM) should be developed by the national scientific community with a high research priority, actively collaborating with international community in order to estimate direct and indirect global radiative forcing due to anthropogenic and natural aerosols.

• Asian Journal of Innovation and Policy
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• 제6권2호
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• pp.170-191
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• 2017

Inclusive innovation refers to different types and forms of innovation activities or performance by which we can get more for lesser cost and which could cater and meet the needs and demands of more people. The essence of inclusive innovation is to help poor, marginalized and underprivileged sections of society to improve their livelihoods and enable them to climb up the socio-economic ladder. In the current phase of economic slowdown, increasing unemployment and inequalities, World Bank, OECD and various governments are turning towards inclusive innovation as a new source of optimism or even as a new innovation strategy. Whilst it is being reframed or packaged as a novel or a new strategy, one can trace its historical roots to the AT movement and the Gandhian ideas of economy and society in the 1940s and 1950s. These ideas have inspired and influenced a range of individuals, institutions and civil society groups in inclusive innovation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1360-1363
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• 1996

EPD(End Point Detection) is used to decide etching degree of layer which must be removed at wafer etching process in plasma etching process which is one of the most important process in semiconductor manufacturing. In this thesis, the method which detects malfunction of etching process in real-time will be discussed. Several EPD signal traces are collected in normal plasma etching condition and used as reference EPD signal traces. Critical points can be detected by applying differentiation and zero-crossing techniques to reference EPD signal. Mean and standard deviation of critical parameters which is memorized from reference EPD signal are calculated and these determine the lower and higher limit of control chart. And by applying statical control chart to EPD signals which are collected in real etching process malfunctions of process are detected in real-time. By means of applying this method to the real etching process we prove our method can accurately detect the malfunction of etching process and can compensate disadvantage of current industrial method.

• 전자공학회논문지D
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• 제34D권7호
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• pp.45-55
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• 1997

Electircal characteristics of HgCdTe photodiodes with a heterostructure to achieve high performance are analyzed numerically. A two-dimensional device simulator which can handle a HgCdTe heterostructure, was developed for this work. The effects of band nonparabolicity, carrier degeneracy, and band-offset of heterointerace are included in a carrier transport model. A unified generation-recombination model includes simultaneously phonon-assisted tunneling and pure tunneling of carriers via traps is newly employed for describing the electric field and temperature dependency of dark current effectively. Furthermore, to accurately predict the effect mole fraction variations on genration rates, ray-trace algorithm is incorporated in the our simulator. Under the various circumstances such as dark, illumination, and surface states, electrical properties of planar heterostructure photodiode are presented and those of homojunction are compared. These results serve as a explanation of cap layer's role on performance.