• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.223-225
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• 2007

The contact-less inductive power transformer (IPT) uses principle of electromagnetic induction. Generally, there were many methods to improve the transfer performance of traditional transformer. But, though the principle of IPT is similar to that of general transformer, it is impossible to apply the methods because of large air-gap. Consequently, many linear numerical formulas for analysis of performance and design of traditional transformer cannot be used in development of IPT. The concept of the IPT for vehicle like PRT(Personal Rapid Transit) system is suggested and some suggestions for power collector(core & winding) design of IPT to improve power transfer performance arc presented in this paper. The characteristic of power delivery with these novel methods in design is presented by simulation and examination.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.3
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• pp.143-148
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• 2004

This paper shows property conversion of water and removing characteristics of Escherichia coli for discharge tube with $ZrO_2$ beads. At the result of the removal characteristic experiments of Escherichia coli using the discharge tube with $ZrO_2$ beads, because the electric field is also increased when input voltage is increased, the removal characteristic of Escherichia coli was appeared relation connection to input voltage. And if a passing number of test water in discharge tube with $ZrO_2$beads is increased, the removal ratio of Escherichia coli is to be increased because passing number of electric field section is increased. And if diameter of $ZrO_2$beads is increased, the removal time of Escherichia coli is to be decreased because dielectric polalization of $ZrO_2$beads. Also, the removal ratio of Escherichia coli of the discharge tube with $ZrO_2$beads. is appeared higher than the removal ratio of the discharge tube without $ZrO_2$beads. And a satulation punt of ozone and $H_2$ $O_2$generation density inner water was appeared near 60[min].

• Journal of the Korean Solar Energy Society
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• v.32 no.4
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• pp.90-95
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• 2012

Of school buildings, university building requires various case analysis unlike buildings in the elementary, middle and high schools in accordance with its characteristic for variables such as characteristic of department, construction structure and material, the number of persons admitted and schedule. Through the case research on the 'D' university located in Daejeon, this study made a comparison on the monthly and yearly consumption of gas and electricity of the most recent 3 years and implemented analysis on the usage pattern and standby power of air conditioning and heating by the hour and month using PCCS(Power Consumption Consulting System) as respects electricity that is considered to have a possibility of energy-saving. The result of analysis showed that enormous amount of electric power was used during the night time for freeze protection and burst in winter season and standby power was increased in winter season as a result.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.282-287
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• 2011

Of school buildings, university building requires various case analysis unlike buildings in the elementary, middle and high schools in accordance with its characteristic for variables such as characteristic of department, construction structure and material, the number of persons admitted and schedule. Through the case research on the 'D' university located in Daejeon, this study made a comparison on the monthly and yearly consumption of gas and electricity of the most recent 3 years and implemented analysis on the usage pattern and standby power of air conditioning and heating by the hour and month using PCCS(Power Consumption Consulting System) as respects electricity that is considered to have a possibility of energy-saving. The result of analysis showed that enormous amount of electric power was used during the night time for freeze protection and burst in winter season and standby power was increased in winter season as a result.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.71-75
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• 2015

The flow and noise characteristics of the regenerative blower are evaluated experimentally. To decrease the noise of regenerative blower at a high frequency, we arrange the impeller vanes unevenly by special formula. The uneven pitch formular consists of the combination of trigonometric function. The magnitude of degree between each vanes and the control parameters of trigonometric functions are main design parameters for the uneven pitch. The flow characteristics of even and uneven impellers are tested by the fan tester and compared each results. The efficiency of a blower is calculated by the axial power using a dynamo system. The noise property of designed impeller is measured in an anechoic room. In this study, we certify that the uneven pitch impeller is effective in the noise reduction at a high frequency.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1059-1060
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• 2007

In this paper analysis of the characteristics in the three phase induction motor for the electric forklift truck is researched. There are two kinds of the Finite element analysis method. First thing is time domain analysis by the time transient method. Second thing is frequency domain analysis by method which assumes applied voltage and current sinusoidal. Especially in case of the characteristic studies, electromagnetic analysis is performed about each prototype motors. The obtained results are compared and the result of the test is examined. We could know characteristics of each prototypes and verify the design program of the motor through FEM. Finally this paper shows the factors of discord results of the analysis.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.3
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• pp.591-599
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• 2024

This paper presents the configuration and characteristic analysis of the protection system to improve the safety of the building integrated photovoltaic(BIPV) system. BIPV is a solar power system installed in buildings. Since the BIPV system is installed in buildings, there is a high risk of electric shock and fire accidents. Therefore, in order to improve the safety of BIPV, a protective system is required to block or quickly detect risk factors. In this paper, as a protection system to improve the safety of the BIPV system, it is composed of a rapid shutdown (RSD) that can quickly separate the PV system to prevent fire and electric shock accidents and a system to detect Arc faults that cause PV system fires. RSD and Arc Fault Detector analyzed the operating characteristics according to each condition and confirmed that the safety of the BIPV system can be improved through this.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.1-7
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• 2007

Generally, an electric railroad feeding system has many problems due to the different characteristics in contrast with a load of general three-phase AC electric power system. One of them is harmonics problem caused by the switching device existing in the feeding system, and moreover, the time-varying dynamic loads of rail way is inherently another cause to increase this harmonics problem. In Korea power systems, the electric railroad feeding system is directly supplied from the substation of KEPCO. Therefore, if voltages fluctuation or unbalanced voltages are created by the voltage and current distortion or voltage drop during operation, it affects directly the source of supply. The trainloads of electric railway system have non-periodic but iterative harmonic characteristics as operating condition, because the electric characteristic of the electric railroad feeding system is changed by physical conditions of the each trainload. According to the traditional study, the estimation of harmonics has been performed by deterministic way using the steady state data at the specific time. This method is easy to analyze harmonics, but it has limits in some cases which needs an assessment of dynamic load and reliability. Therefore, this paper proposes the probabilistic estimation method, moments matching method(MW) in order to overcome the drawback of deterministic method. In this paper, distributions for each harmonics are convolved to obtain the moments and cumulants of TDD(Total Demand Distortion), and this can be generalized for any number of trains. For the case study, the electric railway system of LAT(Intra Airport Transit) in Incheon International Airport is modeled using PSCAD/EMTDC dynamic simulator. The raw data of harmonics for the moments matching method is acquired from simulation of the LAT model.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2089-2097
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• 2014

Negative corona onset characteristics of the stranded conductors based on the ultra-high voltage (UHV) corona cage were studied in the paper. Based on the corona self-sustaining criterion in extreme uneven electric fields and the secondary emission process of the photoelectrons, the corona onset calculation model in the UHV corona cage is established and the corona current tests of the single LGJ900-75, 6 bundle LGJ900-75, 8 bundle LGJ400-35 conductors in dry and rain conditions were done in the UHV corona cage, and the rain rates are 2.4 mm/h, 20 mm/h and 30 mm/h. Corona onset electric field strength is gained by E-I tangent method, and the onset electric field strength in dry condition proves that the calculation model can be used to calculate the corona onset characteristics of the bundle conductors in the UHV corona cage. A further analysis proves that: the negative corona onset voltage of the conductor increases with the bundle number and the diameter of the sub conductor, but decreases with the bundle space in the corona cage. The onset electric field strength is influenced little by bundle space and bundle number, but decreases with the increase of the diameter of the sub-conductor. The surface irregularity coefficient decreases with the rain rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6799-6806
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• 2015

Electric energy consumption is always followed by the introduction of diversity scale-up and state-of-the-art equipments in logistic centers. In order to analyze the status and the characteristic of the electric energy consumption quantitatively, and also to evaluate the efficiency of the electric energy, this research aims to develop an estimation model of standard electric energy consumption for logistic centers. The proposed model applies the thermodynamics theory so as to effectively reflect the peculiarity that the temperature in the logistic center influences the electric energy consumption. And the model consists of the energy consumed by the refrigerator, which can be subdivided into the heat conducted through the wall, the heat convected by the open doors and the heat lost into the goods, and the electric consumption of the machinery equipments. The model also includes a variety of explanatory variables to support an operator of logistics centers in evaluating the efficiency of energy consumption and establishing improvement strategies for energy efficiency. Application of the model developed in this study is discussed with observed data on energy consumption of a logistics center.