• Journal of Digital Convergence
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• v.15 no.1
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• pp.393-401
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• 2017

This article aims to suggest a principle frame and direction for the development of the character education program using Maumgram. Maumgram is said to clearly illustrate step-by-step structures of character education, for which the human mind is classified as four types(indulged type, rage-type, competition type, selfishness type) on the basis of the existing analytical psychology and Yogacara Thought. The design of the mind type program is composed of three steps. The first step is the 'discovery' step to awaken the cause of self-consciousness through observation, and the second is the 'conversion' step. Learning process to control the negative desires in a positive desire, and the third is the 'relationship'-oriented step to promote a sense of community with other people.

• Journal of the Korean Ceramic Society
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• v.51 no.6
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• pp.533-538
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• 2014

Today, silicon and epoxy resin are used as materials of conversion lenses for white LEDs on the basis of their good bonding and transparency in LED packages. But these materials give rise to long-term performance problems such as reaction with water, yellowing transition, and shrinkage by heat. These problems are major factors underlying performance deterioration of LEDs. In this study, in order to address these problems, we fabricated a conversion lenses using glass, which has good chemical durability and is stable to heat. The fabricated conversion lenses were applied to a remote phosphor type. In this experiment, the conversion lens for white LED was coated on a glass substrate by a screen printing method using paste. The thickness of the coated conversion lens was controlled during 2 or 3 iterations of coating. The conversion lens fabricated under high heat treatment temperature and with a thin coating showed higher luminance efficiency and CCT closer to white light than fabricated lenses under low heat treatment temperature or a thick coating. The conversion lens with $32{\mu}m$ coating thickness showed the best optical properties: the measured values of the CCT, CRI, and luminance efficiency were 4468 K, 68, and 142.22 lm/w in 20 wt% glass frit, 80 wt% phosphor with sintering at $800^{\circ}C$.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.653-657
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• 2011

Conversion characteristics of $CH_4$ and $CO_2$ was studied using an atmospheric pressure plasma for the preparation of synthesis gas composed of $H_2$ and CO. The effects of delivered power, total gas flow rate, and gas residence time in the reactor on the conversion of $CH_4$ and $CO_2$ were evaluated in a plasma reactor with the type of dielectric barrier discharge. The increase of reactor temperature did not affect on the increase of conversion if the temperature does not reach to the appropriate level. The conversion of $CH_4$ and $CO_2$ largely increased with increasing the delivered power. As the $CH_4/CO_2$ ratio increased, the $CH_4$ conversion decreased, whereas the $CO_2$ conversion increased. Generally, the $CH_4$ convesion was higher than the $CO_2$ conversion through the variation of the process parameters.

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.11a
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• pp.95-95
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• 1996

• Korean Journal of Optics and Photonics
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• v.19 no.3
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• pp.199-207
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• 2008

Wavelength converting devices with a ridge-type waveguide in periodically poled $MgO:LiNbO_3$ are made and characterized. The experimental results are compared with theoretical analysis on the effects of waveguide dimension and duty ratio of the periodically poled structure. To show the relationship of the conversion efficiency to those factors, a new measurement system is configured. That experimental results show that the center wavelength, normalized conversion efficiency and full width half maximum of the conversion efficiency curve are 1067.45 nm, 90.7%/$Wcm^2$ and 0.17 nm, respectively. Also, the estimated results of the duty period and full width half maximum of the conversion efficiency from theoretical calculations agreed well with experimental results with the errors of 0.016 ${\mu}m$ and 0.01 nm.

• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.100-101
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• 2007

• The Korean Journal of Ecology
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• v.27 no.4
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• pp.217-224
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• 2004

The purpose of this study is to clarify the effects of the conversion of the forest management type from a natural deciduous broad-leaved forest to an artificial evergreen coniferous forest based on organic matter dynamics. We investigated the amounts and carbon contents of the forest floor and the litterfall, soil chemical characteristics and cellulose decomposition rates in the natural deciduous broad-leaved forest and adjacent artificial evergreen coniferous forest. In the artificial evergreen coniferous forest were planted Japanese cypress (Chamaecyparis obtusa) on the upper slope and Japanese cedar (Cryptomeria japonica) on the lower slope. The soil carbon and nitrogen contents, CEC and microbial activity had decreased due to the conversion of the forest management type from a natural deciduous broad-leaved forest to an artificial Japanese cypress forest, and were almost the same for the conversion to a Japanese cedar forest. Under the same conditions, it is considered that the soil fertility was different by planting specific tree species because the organic matter dynamics were changed by them.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1166-1177
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• 2014

A new type of topology with medium-frequency-transformer (MFT) isolation for medium voltage wind power generation systems is proposed in this paper. This type of converter is a high density power conversion system, with high performance features suitable for next generation wind power systems in either on-shore or off-shore applications. The proposed topology employs single-phase cascaded multi-level AC-AC converters on the grid side and three phase matrix converters on the generator side, which are interfaced by medium frequency transformers. This avoids DC-Link electrolytic capacitors and/or resonant L-C components in the power flow path thereby improving the power density and system reliability. Several configurations are given to fit different applications. The modulation and control strategy has been detailed. As two important part of the whole system, a novel single phase AC-AC converter topology with its reliable six-step switching technique and a novel symmetrical 11-segment modulation strategy for two stage matrix converter (TSMC) is proposed at the special situation of medium frequency chopping. The validity of the proposed concept has been verified by simulation results and experiment waveforms from a scaled down laboratory prototype.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.37-41
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• 2004

In this paper, a reflector type frequency doubler for local oscillator at 24GHz is designed and fabricated with ne71300-N MESFET. Optimum source and load impedances are decided through a multiharmonic load pull simulation technique. A conversion gain can be improved using the reflector and fundamental and third harmonics are well suppressed with open stub of $\lambda$/4 length Measured results show output power at 0dBm of input power is -3.776dBm, conversion gain 0.736dB, harmonic suppression 41.064dBc, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.2
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• pp.115-122
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• 1997

Diurnal variation of $PM_{10}$ concentration was investigated for 24 sites in library including reading room, bookstock room, lobby, office and so on, and 9 sites in student building at Kangwon National University using scattering light integrated type digital dust indicator. The dimensional conversion factors for mass concentrations (K) were determined by comparing between the $PM_{10}$ concentrations collected by $PM_{10}$ hig volume air sampler and the digital dust indicator. The dimensional conversion factor (K) was 3.33 for indoor air in this experiment. The highest concentrations were 649 $\mug/m^3$/day for smoking room in the library and 242 $\mug/m^3$/day for circle room in the student building. Most of spaces in the library except a office and bookstock rooms were over 150 $\mug/m^3$/day of $PM_{10}$ concentrations and 6 indoor spaces were over the guideline for indoor air quality in student building except a health center and two restaurants. Therefore, it should be required to make an improvement on the indoor air quaility for public facilities in the university buildings.