• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.46.2-46.2
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• 2012

The black hole mass-stellar velocity dispersion ($M_{BH}-{\sigma}_*$) relation observed in the present-day universe has motivated numerous studies on the black hole-galaxy co-evolution. It is crucial to define the$M_{BH}-{\sigma}_*$ local active galaxies since cosmic evolution of the correlations is calibrated based on the local relation. However, stellar velocity dispersion is difficult to measure in active galaxies due to much higher AGN continuum than stellar pseudo-continuum, resulting in a small sample with reliable velocity dispersion measurements for studying the AGN $M_{BH}-{\sigma}_*$ relation. To increase the sample size and improve the measurements, we obtained high S/N near-IR spectra for 3 local AGNs, i.e., NGC 3227, Akn 120, 3C 390.3, for which reverberation black hole masses are measured, using the TripleSpec at the Palomar 5-m Telescope. By investigating aperture effect and correcting for rotation component, we determine the luminosity-weighted ${\sigma}_*$, based on the spatially resolved kinematics and compare them with optical measurements from literature. Combining our new measurements with literature data, we present an improved $M_{BH}-{\sigma}_*$ relation for the enlarged sample of reverberation-mapped AGNs.

• Structural Engineering and Mechanics
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• v.53 no.6
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• pp.1241-1251
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• 2015

Faced with the growing needs of material resources and requirements of environmental protection for achieving sustainable development, it has become necessary to study and investigate all possibilities of exploring crushed and dune sand, reusing industrial wastes and by-product, and also applying new technologies including sand concrete which can replace the conventional concretes in certain structures to surmount the deficit on construction materials, conserve natural resources, lessen the burden of pollutants to protect the environment and reduce the consumption of energy sources. This experimental study is a part of development and valorization of local materials project in Skikda region (East of Algeria). It aims at studying the effects of partial replacement of sand with marble waste as fines on several fresh and hardened properties of sand concrete in order to reuse these wastes in the concrete manufacturing, resolve the environmental problems caused by them and find another source of construction materials. To achieve these objectives, an experimental program has been carried out; it was consisted to incorporate different percentages of marble waste fines (2, 4, 6, 8, 10 and 12%) in the formulations of sand concrete and study the development of several mechanical and rheological properties. We are also trying to find the optimal percentage of marble waste fine replaced in sand concrete that makes the strength of the concrete maximum. Obtained results showed that marble waste fines improve the properties of sand concrete and can be used as an additive material in sand concrete formulation.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.319-330
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• 2005

The information infrastructure between all the elementary and middle schools of the nation have made it possible to build an environment to breed competent students for our future society. However, since the focus of computer education has been mostly on utilization, it has created many problems such as limitation of creativity, weakening the self-studying skill and many other. Consequently this study is for the development of the textbooks of the computer principles in education and shows the affirmative effect of the improvement of creativity through their application.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.89-92
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• 2008

Lecture room, space for student to study, need to get exactly information and show up what students are required So, problems for illuminated environments are low effect of studying, and that students may get weak-sighted. Research is required to get enough lighting for lecture room which students spend most their time. If we compare lighting system for recent college lecture room with computer simulation, lighting system at the lecture room with down light will be improve intensity of illumination. Therefore we can get economical benefit and save energy.

• Computers and Concrete
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• v.24 no.6
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• pp.513-525
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• 2019

In this work, an experimental research has been performed on Steel Fiber-Steel Reinforced Concrete (SFSRC)specimens subjected to four-point bending tests to evaluate the feasibility of mutual replacement of steel fibers and conventional reinforcement through studying failure modes, load-deflection curves, stiffness of characteristic points, stiffness degradation curves and damage analysis. The variables considered in this experiment included steel fiber volume percentage with and without conventional reinforcements (stirrups or steel fibers) with shear span depth ratios of S/D=2.5 and 3.5. Experimental results revealed that increasing the volume percentage of steel fiber decreased the creation and propagation of shear and bond cracks, just like shortening the stirrups spacing. Higher crack resistance and suturing ability of steel fiber can improve the stability of its bearing capacity. Both steel fibers and stirrups improved the stiffness and damage resistance of specimens where stirrups played an essential role and therefore, the influence of steel fibers was greatly weakened. Increasing S/D ratio also weakened the effect of steel fibers. An equation was derived to calculate the bending stiffness of SFSRC specimens, which was used to determine mid span deflection; the accuracy of the proposed equation was proved by comparing predicted and experimental results.

• Carbon letters
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• v.9 no.3
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• pp.200-202
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• 2008

In order to improve the thermal stability of PAN-based electrospun fibers, AP-PER-MEL and $TiO_2$ were added in to the fibers as additives. The polymer composite with uniformly mixed additional agents was obtained. In case of non-treated sample, the fibers were burn off completely with high rate within $620^{\circ}C$. But in case of treated samples (EF-M and EF-MT), it is sure that the thermal stability was improved by studying TGA data and ISO flammability test about 20 and 30%, respectively. A synergy effect of adding two kinds of agents (AP-PER-MEL and $TiO_2$) into PAN-based electrospun fibers was confirmed. Through SEM images, it is confirmed that the fiber shape can be kept even after addition of agents (AP-PER-MEL and $TiO_2$). Finally the thermal stability of fibers was largely developed with keeping the nature of PAN-based fibers effectively.

• Journal of Fashion Business
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• v.18 no.3
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• pp.29-44
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• 2014

As there is a growing interest in natural ingredients, they are actively being studied to improve damaged skin However, the lip cosmetics are still being inadequately studied on the exposure of lips to several stimuli and easy flow of chemical on the lips into the body. This study was conducted to make a clinical evaluation on the real effect of lip balm on lips, by extracting oil from Chamaecyparis obtusa and Lithospermum erythrorhizon that are known to play a positive role on skin. The following three natural lip balms were produced: lip balm made with Chamaecyparis obtusa(LBWCO), lip balm made with both Chamaecyparis obtusa and Lithospermum erythrorhizon(LBWCOLE), lip balm made without Chamaecyparis obtusa or Lithospermum erythrorhizon(LBWICOLE). The quality of LBWCO or LBWCOLE was evaluated to be higher than that of LBWICOLE. LBWCO and LBWCOLE had the highest satisfaction and purchase intention, respectively. As stated above, Chamaecyparis obtusa and Lithospermum erythrorhizon could be the ingredients of lip balm, and they were effective in improving damaged lips. Consequently, this study will provide opportunities to explore excellent ingredients to be used in natural lip balm. Also, studying lip cosmetics using only the natural ingredients will provide opportunities to expand positive images of ingredients for producing lip cosmetics.

• Journal of Power Electronics
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• v.19 no.1
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• pp.234-243
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• 2019

Studying the control strategy of a microgrid under the load unbalanced state helps to improve the stability of the system. The magnitude of the power fluctuation, which occurs between the power supply and the load, is generated in a microgrid under the load unbalanced state is called negative sequence reactive power $Q^-$. Traditional power distribution methods such as P-f, Q-E droop control can only distribute power with positive sequence current information. However, they have no effect on $Q^-$ with negative sequence current information. In this paper, a stationary-frame control method for power sharing and voltage unbalance compensation in islanded microgrids is proposed. This method is based on the proper output impedance control of distributed generation unit (DG unit) interface converters. The control system of a DG unit mainly consists of an active-power-frequency and reactive-power-voltage droop controller, an output impedance controller, and voltage and current controllers. The proposed method allows for the sharing of imbalance current among the DG unit and it can compensate voltage unbalance at the same time. The design approach of the control system is discussed in detail. Simulation and experimental results are presented. These results demonstrate that the proposed method is effective in the compensation of voltage unbalance and the power distribution.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.39-50
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• 2020

The current number of international students is gradually increasing in the world due to their passion for study or exchange students programs related to be affiliated with their universities. Many international students have great hope for their successful life of studying abroad. The factors that play a key role in successful study abroad can be seen as life satisfaction in host country and career commitment. Therefore, this study suggested the way to improve students' life satisfaction and career commitment among Chinese international students in Korea. It focused on social identification as a core factor in improving international student life satisfaction and career commitment. In addition, it also focused on social support as a factor to increase social identification. According to the results of empirical analysis, it was verified that perceived social support improves social identification among international students. In addition, social identification improves their life satisfaction and career commitment. Therefore, the mediating effect of social identification was found to be significant in the relationship between perceived social support and life satisfaction and career commitment. This study was verified that if international students perceive social support, they can experience social identification. This process can eventually lead to life satisfaction and career commitment. Based on these results, it emphasized that the role and importance of social identification. Finally, the practical implications and future research directions were discussed.

• Journal of the Korean institute of surface engineering
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• v.54 no.1
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• pp.37-42
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• 2021

Electrodeposition is a synthetic method that allows fine control of the nucleation and growth factors of metals and is a suitable method for studying the nucleation and growth of Ni(OH)2. Hexa-methylenetetramine (HMT) helps to form Ni(OH)2 nanosheets by increasing the OH- of the nickel precursor solution and helps to improve the electrochemical properties of the electrode. In this study, the structural properties of Ni(OH)2 nanosheets according to the HMT concentration change using electrodeposition were studied. As the concentration of HMT increased, the size and thickness of the Ni(OH)2 nanosheet adsorbed on the surface increased and porosity increased. Also, the Scharifker-Hills nucleation theory model and experimental data were compared. In conclusion, the nanosheet shape of the HMT 7.5 mM sample electrodeposited with -0.85 V vs. Ag/AgCl grew most uniformly, and the best result was obtained as an electrode material for a pseudocapacitor.