• Journal of the Korean Society of Combustion
• /
• v.7 no.4
• /
• pp.36-44
• /
• 2002

Carbon molecules with closed-cage structures are called fullerenes $(C_{60},\;C_{70})$, whose applications include super-conductors, sensors, catalysts, optical and electronic device, polymer composites, and biological and medical materials. The synthesis of fullerenes has been recently studied with low-pressure benzene/argon/oxygen flames. The formation of fullerene is known as molecular weight growth processes of PAHs (polycyclic aromatic hydrocarbon). This study presents results of PAHs and fullerene measurements performed in a low-pressure benzene/argon/oxygen normal co-flow laminar diffusion flame. Through the central tube of the burner, benzene vapors carried by argon are injected. The benzene vapors are made in a temperature-controlled bubbler. The burner is located in a chamber, equipped with a sampling system for direct collection of condensable species from the flame, and exhausted to a vacuum pump. Samples of the condensable are analyzed by HPLC (High Performance Liquid Chromatography) to determine the yields of PAHs and fullerene. Also, we computed mole fraction of fullerene and PAHs in a nearly sooting low pressure premixed, one-dimensional benzene/argon/oxygen flame (equivalence ratio ${\Phi}=2.4$, pressure=5.33kPa). The object of computation was to investigate the formation mechanism of fullerenes and PAHs. The computations were performed with CHEMKIN/PREMIX. As a result of this study, fullerenes were synthesized in a low pressure (20torr) $C_6H_6/Ar/O_2$ flames and the highest concentration of fullerene was detected just above the visible surface of a flame.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.03a
• /
• pp.88-88
• /
• 2003

Optical Emission Spectroscopy(OES) is a very important technology for real-time monitoring of plasma in a reactor during dry etching process. OES technology is non-invasive to the plasma process. It can be used to collect information on excitation and recombination between electrons and ions in the plasma. It also helps easily diagnose plasma intensity and monitor end-point during plasma etch processing. We studied high density planar inductively coupled BCl$_3$ and BCl$_3$/Ar plasma with an OES as a function of processing pressure, RIE chuck power, ICP source power and gas composition. The scan range of wavelength used was from 400 nm to 1000 nm. It was found that OES peak Intensity was a strong function of ICP source power and processing pressure, while it was almost independent on RIE chuck power in BCl$_3$-based planar ICP processes. It was also worthwhile to note that increase of processing pressure reduced negatively self-induced dc bias. The case was reverse for RIE chuck power. ICP power and gas composition hardly had influence on do bias. We will report OES results of high density planar inductively coupled BCl$_3$ and BCl$_3$/Ar Plasma in detail in this presentation.

• The Korean Journal of Applied Statistics
• /
• v.27 no.7
• /
• pp.1163-1170
• /
• 2014

The concepts and structure of intermittent panel time series data are introduced. We suggest a Wald test statistic for the test of homogeneity for intermittent panel first order autoregressive model and its limit distribution is derived. We consider the fitting the model with pooling data using sample mean at the time point if homogeneity for intermittent panel AR(1) is satisfied. We performed simulations to examine the limit distribution of the homogeneity test statistic for intermittent panel AR(1). In application, we fit the intermittent panel AR(1) for panel Mumps data and investigate the test of homogeneity.

• Korean Chemical Engineering Research
• /
• v.43 no.6
• /
• pp.728-739
• /
• 2005

An experiment and simulation were performed for hydrogen separation of mixtures by PSA (pressure swing adsorption) process on activated carbon. The binary ($H_2/Ar$; 80％/ 20％) and ternary ($H_2/Ar/CH_4$; 60％/ 20％/ 20％) mixtures were used to study the effects of feed composition. The cyclic performances such as purity, recovery, and productivity of 2bed-6step PSA process were experimentally and theoretically compared under non-isothermal and non-adiabatic conditions. The develped process produced the hydrogen with 99％ purity and 75％ recovery from both processes. Therefore, optimal separation condition was referred multicomponent gas mixtures.

• Economic and Environmental Geology
• /
• v.49 no.2
• /
• pp.97-104
• /
• 2016

Here we firstly present that a timing of reactivated event of Yangsan fault, the major fault in the southeastern Korean Peninsula, by using combined approaches of the optimized illite-polytype quantification, the K-Ar age-dating, and the recently developed illite-age-analysis (IAA) approach for the fault clays from Sangcheon-ri area of Yangsan main fault line. Two chronological record of brittle fault-activation event at about 41.5~43.5 and 50.7 Ma were determined from 3 fault gouges suggesting a crucial reactivation time-scheme. Furthermore, the regional processes that drive tectonics to form and reactivate the Yangsan fault may be explained from the chronological analysis for additional sites along the Yangsan fault.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.24 no.4
• /
• pp.1-12
• /
• 1999

This paper presents a DEA-AHP hybrid model to evaluate and select R&D projects. AHP collects and processes information on the weights of evaluation criteria. The processed information is used as an input for DEA/AR model. Only desirable number of projects are selected by the hybrid model. The model is examined by an example generated from a real data set.

• Journal of the Korean Statistical Society
• /
• v.30 no.1
• /
• pp.31-39
• /
• 2001

For estimating parameters of possibly nonlinear and/or non-stationary seasonal autoregressive(AR) processes, we introduce a new instrumental variable method which use the direction vector of the regressors in the same period as an instrument. On the basis of the new estimator, we propose new seasonal random walk tests whose limiting null distributions are standard normal regardless of the period of seasonality and types of mean adjustments. Monte-Carlo simulation shows that he powers of he proposed tests are better than those of the tests based on ordinary least squares estimator(OLSE).

• Journal of the Korean Statistical Society
• /
• v.36 no.4
• /
• pp.447-456
• /
• 2007

On the basis of marginal likelihood of the residual vector which is free of nuisance mean parameters, we propose new Lagrange Multiplier seasonal unit root tests in seasonal autoregressive process. The limiting null distribution of the tests is the standardized ${\chi}^2-distribution$. A Monte-Carlo simulation shows the new tests are more powerful than the tests based on the ordinary least squares (OLS) estimator, especially for large number of seasons and short time spans.

• Applied Biological Chemistry
• /
• v.20 no.1
• /
• pp.10-25
• /
• 1977

The photobiological receptors of phototactic, phototropic, and photomorphogenic responses of various organisms have been described in terms of spectroscopic, photophysical and photochemical properties which may be relevant in elucidating the energy transduct ion mechanism(s) in photobiology. The photoreceptors discussed include carotenoids, flavins, stentorin and phytochrome. Although the molecular modes of their photobiological action still remain largely unexplained, it is possible to suggest several primary molecul ar processes of the photoreceptors in eliciting responses of various organisms to light.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2012.05a
• /
• pp.128-128
• /
• 2012

Korea institute of materials science (KIMS) has researched an anode layer linear ion source (ALIS) for various roll-to-roll treatment processes. The ALIS can be used to Ar ion beam (1~2 keV) treatment, and diamond-like carbon coating and so on. The treatment width of ALIS is 500 mm with a uniformity below 5 % (=(Max-min)/(Max+min)). We also demonstrate the status of development of ALIS in a roll-to-roll industry.