• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2227-2236
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• 2017

In order to solve the neutral-point voltage fluctuation problem of three-phase three-level T-type inverters (TPTLTIs), the unbalance characteristics of capacitor voltages under different switching states and the mechanism of neutral-point voltage fluctuation are revealed. Based on the mathematical model of a TPTLTI, a feed-forward voltage balancing control strategy of DC-link capacitor voltages error is proposed. The strategy generates a DC bias voltage using a capacitor voltage loop with a proportional integral (PI) controller. The proposed strategy can suppress the neutral-point voltage fluctuation effectively and improve the quality of output currents. The correctness of the theoretical analysis is verified through simulations. An experimental prototype of a TPTLTI based on Digital Signal Processor (DSP) is built. The feasibility and effectiveness of the proposed strategy is verified through experiment. The results from simulations and experiment match very well.

• Journal of Korea Game Society
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• v.4 no.4
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• pp.25-30
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• 2004

Recently, it is increasing a users requiring actually and a variety of service due to a growth of wet based technique and network technique. In services, the interest in web and mobile contents domain is increasing rapidly. The most contents supported point or a E-Money as result of contents's usage. But, the point system be in name only due to a lack of a contents using a point or a related service. As a solution for this problem, this paper designed a supported system that integrated a point system supporting others contents and can associated to a game using that point. we made a simple game and supporting contents in web for simulating the designed system. Also, we realized the mobile system for communicating a data causing in web.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2000.04a
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• pp.235-241
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• 2000

This article suggests integrated neural network models for the interest rate forecasting using change point detection. The basic concept of proposed model is to obtain intervals divided by change point, to identify them as change-point groups, and to involve them in interest rate forecasting. the proposed models consist of three stages. The first stage is to detect successive change points in interest rate dataset. The second stage is to forecast change-point group with data mining classifiers. The final stage is to forecast the desired output with BPN. Based on this structure, we propose three integrated neural network models in terms of data mining classifier: (1) multivariate discriminant analysis (MDA)-supported neural network model, (2) case based reasoning (CBR)-supported neural network model and (3) backpropagation neural networks (BPN)-supported neural network model. Subsequently, we compare these models with a neural networks (BPN)-supported neural network model. Subsequently, we compare these models with a neural network model alone and, in addition, determine which of three classifiers (MDA, CBR and BPN) can perform better. This article is then to examine the predictability of integrated neural network models for interest rate forecasting using change-point detection.

• Journal of Acupuncture Research
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• v.15 no.2
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• pp.455-478
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• 1998

The result as following one was founded that investigate cause and acupuncture point for symptoms of headache; 1. Headache in distinction from doo-pung(頭風.) was defined that it' period is short and treatment is easy. 2. The cause of headache was classified according to the interior and exterior cause of the body. 3. Total number of used acupuncture point was one hundred and six, and in order of using time acupuncture point was appeared as LI4(15), LU7(12), GB20(12), BL2(11), GV20(9), TE23(9), SI3(7), GV24(7), GV23(7) 4. The meridian distribution of acupuncture point is appeared as Bladder Meridian(21points), Gallbladder Meridian(18points), Governer vesseI(14points), Triple Energizer meridian(12points), Large Intestine Meridian(9points), Small Intestine Meridian(7points), Stomach Meridian(7points) 5. According to headache position, the distribution of acupuncture point $Yangmy\check{o}ng\;Ky\check{o}ng$ and Governer vessel was used to frontal headache, Soyang $Ky\check{o}ng$ to migraine, Taeyang $Ky\check{o}ng$ and Governer vessel to occipital headache. 6. LI4(合谷) and LU7(列缺) was used to general headache as basic acupuncture point.

• Journal of Haehwa Medicine
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• v.11 no.1
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• pp.111-135
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• 2002

The result as following one was founded that investigate cause and acupuncture point for symptoms of headache, 1. Headache in distinction from doo-pung(頭風) was defined that it' period is short and treatment is easy. 2. The cause of headache was classified according to the interior and exterior cause of the body. 3. Total number of used acupuncture point was one hundred and six, and in order of using time acupuncture point was appeared as LI4(15), LU7(12), GB20(12), BL2(11), GV20(9), TE23(9), SI3(7), GV24(7), GV23(7) 4. The meridian distribution of acupuncture point is appeared as Bladder Meridian(21points), Gallbladder Meridian(18points), Governer vessel(14points), Triple Energizer meridian(12points), Large Intestine Meridian(9points), Small Intestine Meridian(7points), Stomach Meridian(7points) 5. According to headache position, the distribution of acupuncture point was appeared that $Yangmy\breve{o}ng$ $Ky\breve{o}ng$ and Governer vessel was used to frontal headache, Soyang $Ky\breve{o}ng$ to migraine, Taeyang $Ky\breve{o}ng$ and Governer vessel to occipital headache. 6. LI4(合谷) and LU7(列缺) was used to general headache as basic acupuncture point.

• Journal of Korea Game Society
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• v.8 no.3
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• pp.51-59
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• 2008

This article focuses on perspectives of game in terms of interactivity between game texts and players. There are many points of view which have been discussed, such as first person point of view, third person point of view, top-down point of view, side-view point of view, quarter-view point of view, and isometric point of view, but they are too insufficient to fully explain the perspectives of game from the viewpoint of the interactivity. This paper examines the function of player and game manufacturer as implied authors on interactive point of view, and discusses the perspectives of game through a sense of distance between players as implied author and player characters.

• Fire Science and Engineering
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• v.29 no.6
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• pp.45-50
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• 2015

The flash point is one of the most important properties for characterizing the fire and explosion hazard of liquid solutions. In this study, a Tag open-cup apparatus was used to measure the flash points of two flammable binary mixtures, n-decane + n-octanol and acetic acid + n-butanol. The flash point temperature was estimated using the UNIFAC (Universal Functional Activity Coefficient) group contribution model and optimization method. The experimentally derived flash point was also compared with the predicted flash point. The two methods can estimate the flash point fairly well for the n-decane + n-octanol and acetic acid + n-butanol systems.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.136.1-136.1
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• 2011

This paper proposes the method to implement the railroad switching point heating system using the hybrid of the photovoltaic and wind power. The goal of the implementation of the railroad switching point heating system is to prevent freezing of the snow in the winter. The heating system of railway used to supply electricity through photovoltaic and wind power to prevent freezing. Hot wires of the railroad switching point heating system are used about 2kW of electric energy at the day. The electric energy of 2kW used the length of the hot wires about 3m. As the ON and/or OFF mode considering the tracks temperature and the ambient temperature, so the way the use of power-saving effect. In addition, the system can be used the railroad switching point heating system in winter and railway signal and street lights around the track in summer. In experiment, we acquired the power data according to time at the day of photovoltaic and wind power. We confirmed the temperature rise using the heating cable for 3m of $85^{\circ}C$, 30W/m. The temperature rise of the heating cable changes the temperature of $5^{\circ}C$ after 10 minutes and $11^{\circ}C$ after 10 minutes. We have confirmed the possibility of the railroad switching point heating system using the hybrid of the photovoltaic and wind power.

• Journal of the Korean Ceramic Society
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• v.42 no.12 s.283
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• pp.793-799
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• 2005

A composite cathode of LSCF$(La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3)\;and\;GDC\; (Gd_2O_3-doped\;CeO_2:Ce_{0.9}Gd_{0.1}O_{1.95_})$ was characterized in terms of an electrode response, using a point contact in an Yttria-Stabilized Zirconia (YSZ) electrolyte incorporated into AC two-point impedance spectroscopy. The point-contacted configuration amplifies the responses occurring near the YSZ/cathode interface through the aligned point contact on the planar LSCF/GDC electrode. The point contact interface increases the bulk resistance allowing the estimation of the point contact geometry and resolving the electrode-related responses. The resultant impedance spectra are analyzed through an equivalent circuit model constructed by resistors and constant phase elements. The bulk responses can be resolved from the electrode-related portions in terms of spreading resistance. The electrode-related polarizations are measured in terms of temperature and oxygen partial pressure. The modified impedance spectroscopy is discussed in terms of methodology and analytical aspects, toward resolving the electrode-polarization issues in solid oxide fuel cells.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.6
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• pp.457-467
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• 2019

Because non-point source pollution is very closely related to hydrological characteristics, its importance is highly emphasized nowadays along with accelerating climate change. Especially for Korea, the non-point source pollution and its control are entirely depending on runoff, precipitation, drainage, land use or development, based on geographical and topographical reasons of Korea. Many studies reported the physical (e.g., apparatus- and natural-type facilities, etc.) and chemical methods (e.g., organic and inorganic coagulants, etc.) of controling non-point pollutant source pollution, however, those are needed to be reconsidered along with climate change causing the unexpected patterns and amounts of precipitation and strengthen complexity of social community. The objectives of this study are to assess recent situations of non-point source pollution in Korea and its control means and to introduce possible effective ways of non-point source pollution against climate change in near future.