• Journal of the Korean Chemical Society
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• v.57 no.2
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• pp.172-175
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• 2013

We compare the relative usefulness of common basis functions and numerical integration methods in representing complex resonance state encountered in the molecular scattering problem of aluminum dimer electronic predissociation. Specifically, the basis set size and computing CPU times are monitored in order to find the minimum requirement for ensuring the modest accuracy of calculated resonance energies (0.1 $cm^{-1}$) for more than 100 resonance states. The combination of the so-called one-dimensional box eigenfunctions and energy-dependent boundary functions are found to be most efficient if integration is done using the basis set quadrature rules.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.134-137
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• 2006

The equipment of PV system is composed of PV Modules, inverters, DC combiner boxes, transformer protective equipment etc,. And, These equipment be combined Power transformation, Monitoring, Protect ive function The primary concern in designing any PV system is the determination of its optimum size and combination.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.197-198
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• 2018

This paper proposes a novel hybrid converter topology suitable for electric vehicle on-board battery chargers, which is a combination of the full-bridge (FB) and half-bridge (HB) LLC circuits. A full load controllability under wide output voltage range can be achieved with a small resonant inductance, which increases the efficiency and lowers the size and cost. Simulation results are shown to evaluate the dynamic performance of the proposed converter.

• Particle and aerosol research
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• v.9 no.3
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• pp.133-137
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• 2013

Measuring particle size distribution is one of the primary concerns in aerosol studies. For a nano-particle size distribution measurement, many scientists use a combination of a differential mobility analyzer (DMA) and a condensation particle counter (CPC) system, which is a called scanning mobility particle sizer (SMPS). Although it has a very high particle size resolution, some issues still remain. These problems include residence time between a DMA and a CPC, discontinuity of a CPC, and disturbance due to long scanning time during the precise measurement of particles. In particular, long scanning time is not adequate for measuring particle size distribution since the particle concentration is changing during the measurement. In this study, we developed radial exhaust multi-port system (REM-system) with no scanning time and high resolution to measure real-time particle size distribution. As a result of the REM-system performed using mono-disperse particle, it is expected that this system will be suitable for measuring continuously changing aerosol. If the counting efficiency of multi-condensation particle counter (M-CPC) and data inversion matrix are completed, REM-system will be a very adequate system for unsteady aerosol, which changes for SMPS scanning time.

• Journal of the Korean Dietetic Association
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• v.26 no.2
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• pp.153-173
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• 2020

The purpose of this study was to objectively quantify the effects of nutrition and dietary life education on preschoolers through meta-analysis. In addition, it provides basic data for the implementation of nutrition education and development of systematic nutrition and dietary life education programs. In this study, a meta-analysis of 27 papers was conducted that conformed to the selection criteria in the study conducted from January 2012 to August 2019 to derive objective data on the effects of education. As a result of the analysis, the overall effective size of nutrition and dietary life education for preschoolers was 0.829, which indicates a strong effect. According to the education method, the effect size of general education was 0.562, which indicates a medium effect size, the vegetable playing-based experience education was 0.685, which indicates a medium effect size, and cooking activity-based experience education was 1.101, which indicates a large effect size. Judging from this result, experience activity education was more effective than general nutrition education. In addition, the combined size of convergence education conducted through a combination of general and experience education was found to be the most effective at 1.301. In terms of educational effect, it was confirmed that the effect size was 0.898 for improving nutrition knowledge, 0.858 for improving dietary habits, 0.836 for improving unbalanced diet, and 0.756 for improving food preference and intake, and the sizes of effects were all found to be large. As frequency of education increased, the number of education participants decreased and the effect of education increased.

• Journal of electromagnetic engineering and science
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• v.5 no.3
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• pp.126-131
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• 2005

To increase the efficiency of an applicator during microwave hyperthermia therapy, first, the length from the antenna end to a slot is varied to get the optimal matching of the characteristic impedance at the frequency of 2.45 GHz. Using the electric and thermal constants of biological tissue, we compose a phantom to calculate temperature increment as well as the resonance characteristics and the SAR distributions. The proposed 3-slot sleeve antenna inserted in an applicator plays an effective role in increasing the therapy size in the view of heating performance as electromagnetic energy tends to concentrate on not feed point direction but treatment area. The SAR is then used in combination with a finite difference heat transfer equation to determine the temperature distribution. Also, in order to shorten treatment time and increase therapy size, a square-array structure is suggested and analyzed.

• Particle and aerosol research
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• v.10 no.2
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• pp.45-51
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• 2014

Fine particle capture is facing a challenge since traditional filtration which relies on the combination of impaction, interception, diffusion has a limited efficiency for fine particle capture particularly in size from 0.1 to $0.5{\mu}m$. This paper reviewed the collection efficiency of above mechanisms, as well as magnetic mechanisms for ferromagnetic particles, and mainly studied the influencing factors of magnetic filtration. Filtration velocity, magnetic field intensity and fiber size were found to be the most important parameters for magnetic filtration.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.12
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• pp.73-86
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• 1993

This paper proposes an automatic variable block truncation coding (BTC) method. It selects the block size automatically based on the mode of the discontinutiy measure of blocks. The combination of an automatic block-size determination scheme and the conventional BTC results in the proposed automatic variable BTC techniques. For color images, subsampling in I and Q chrominance components is adopted along with the variable BTC. To show the effectiveness of the proposed algorithm, its simulation results are compared to those of the several conventional BTC algorithms for monochrome and color test images. Computer simulation shows that the proposed algorithm gives better performance than the conventional ones based on the subjective and objective performance evaluation.

• Fibers and Polymers
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• v.6 no.3
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• pp.263-268
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• 2005

Alpaca fibers have some distinct properties such as softness and warmth, which have not been fully understood in combination with the fiber internal structures. In the present investigation, the internal structures of alpaca fibers have been closely examined under the scanning electron microscope (SEM), especially in the longitudinal direction. The results showed that numerous pigment granules reside loosely inside pockets in brown and dark-brown alpaca fibers. These pigment granules were mainly distributed inside the cortical cells, the medullation regions as well as underneath the cuticles. Their size in the brown alpaca fibers was smaller and more uniformly round than in the dark-brown fibers. These granules in colored alpaca fibers loosen the bundle of cortical cells, providing many crannies in the fibers which may contribute to the superior flexibility, warmth and softness of the fibers. Moreover, there are no heavy metal elements found in the granules. The mordant hydrogen peroxide bleaching employed could eliminate the pigment granules and create many nano-volumes for further dyeing of fibers into more attractive colors.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.630-633
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• 2005

Some gases can be formed into hydrate by physical combination with water under appropriate temperature and pressure condition. Besides them, it was found that the pore size of the sediments can affect the formation and dissociation of hydrate. In this study, formation temperatures of carbon dioxide and methane hydrate have been measured using isobaric method to investigate the effects of flow rates of gases on formation condition of hydrate in porous rock samples. The flow rates of gases were controlled using a mass flow controller. To minimize Memory effect, system temperature increased for the dissociation of gas hydrates and re-established the initial saturation. The results show that the formation temperature of hydrate decreases with increasing the injection flow rate of gas. This indicates that the velocity of gas in porous media may act as kinds of inhibitor for the formation of hydrate.