• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.781-783
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• 2002

In this paper, the experiment results of the Boost converter for PFC(power factor correction) are presented. The performance of the 1kW class PFC rectifier with the average current mode control are evaluated. A 1kW, 100kHz system prototype was built and experimental results are presented to verify the design. As a results, power conversion efficiency above $95\%$ and power factor above $99\%$ were obtained.

• The KSFM Journal of Fluid Machinery
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• v.15 no.1
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• pp.64-69
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• 2012

Currently axial flow compressor is used primarily in a large power generation gas turbine. In this paper,the main factors to be considered when designing a axial flow compressor were compared to those of a small power generation gas turbine(DGT-5). The main design parameters was examined in the aspect ratio, solidity, as well as reaction, diffusion factor, incidence angle, etc. The results in case of a small compressor are showed a regular pattern but there were not found any specific design patterns for a large class compressor.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.534-535
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• 2012

The characteristics of wireless power transfer is achieved at high frequencies in short range magnetic resonant wireless power transfer system. Use PFC pre-regulator for power supply of high frequency inverter. Supplied power to high power factor and high efficiency. Accordingly, the input voltage is 110V-220V. The designed of 175W Class with the output voltage of 385V. As a experiment result, maximum power factor and maximum efficiency measured 99% and 97% respectively. Therefore, in this paper, the design of a inductor which is the most important element in PFC converter for short range magnetic resonance wireless power transfer system was studied. Used an CS330125 core through the designed of 175W class. Examination results power loss was 0.2%.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2099-2101
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• 2005

The problem of observer design for a class of Lipschitz nonlinear systems is considered. We propose a new observer design method which takes into account the structure of perturbed nonlinear terms with a scaling factor ${\epsilon}$. An example is provided to demonstrate the usefulness of our result over the existing method.

• Communications for Statistical Applications and Methods
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• v.14 no.3
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• pp.497-506
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• 2007

Coverage-based NHPP SRGMs have been introduced in order to incorporate the coverage growth behavior into the NHPP SRGMs. The coverage growth function representing the coverage growth behavior during testing is thus an essential factor of the coverage-based NHPP SRGMs. This paper proposes a class of discrete time coverage growth functions and illustrates its application to real data sets.

• Journal of the Korean Home Economics Association
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• v.32 no.2
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• pp.255-263
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• 1994

The objectives of this study were : 1) to find research trends on lifestyles 2) to analyze the lifestyle patterns of middle class residents in Seoul and 3) to develop a standarized instrument to measure lifestyles. Questionnaires were administered to 1615 homemakers in Seoul, The statistics with the SPSS software package was used for factor analysis. The major findings were as follows: the lifestyles of middle class residents in Seoul were categorized into six patterns : Fashion oriented Interior Design Oriented Economy Concerned Simplicity in Eating Hobby Oriented and Health Concerned. A standarized instrument using validity and reliability testes for lifestyles was developed.

• Journal of the Korean Mathematical Society
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• v.38 no.2
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• pp.485-501
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• 2001

In this paper we express analytic Feynman integral of the first variation of a functional F in terms of analytic Feynman integral of the product F with a linear factor and obtain an integration by parts formula of the analytic Feynman integral of functionals on abstract Wiener space. We find the Fourier-Feynman transform for the product of functionals in the Fresnel class F(B) with n linear factors.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.211-221
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• 2023

The purpose of this study is to improve the validity of the evaluation by adding the factor of academic achievement to the subject of evaluation, and to improve the reliability of the evaluation by verifying the legitimacy of control of in-class attitude and developing the correction index of satisfaction of teaching. The results of the study are as follows. Firstly, it was confirmed that the students' in-class attitude had a significant effect on satisfaction of teaching. The more positive the in-class attitude, the higher the satisfaction of teaching, and vice versa. Secondly, it was confirmed that the students' in-class attitude had a significant effect on academic achievement. The more positive the in-class attitude, the higher the academic achievement, and vice versa. Thirdly, it was confirmed that satisfaction of teaching did not have a significant effect on academic achievement. High satisfaction of teaching does not mean that the quality of the teaching is high, and vice versa. Fourthly, the correction index of satisfaction of teaching was developed to correct the results of satisfaction of teaching that may be distorted due to the students' negative in-class attitude. In conclusion, academic achievement should be added as the subject of evaluation in addition to the satisfaction of teaching to improve the validity of evaluation and the correction index of satisfaction of teaching should be applied to improve the reliability of evaluation.

• BMB Reports
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• v.38 no.5
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• pp.602-608
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• 2005

As a crucial transcription factor family, heat-shock factors were mainly analyzed and characterized in tomato and Arabidopsis. In this study, we isolated two putative heat shock factors OsHSF6 and OsHSF12 that interact specifically with heat-shock element (HSE) from Oryza sativa L by yeast one-hybrid method. The full-length cDNA of OsHSF6 and OsHSF12 have 1074bp and 920bp open reading frame (ORF), respectively. Analysis of the deduced amino acid sequences revealed that OsHSF6 was a class A heat shock factor (HSF) with all the conserved sequence elements characteristic of heat stress transcription factor, while OsHSF12 was a class B HSF with C-terminal domain (CTD) lacking of AHA motif. Bioinformatic analysis showed that the sequences and structures of two HSFs' DNA binding domain (DBD) had a high similarity with LpHSF24. The results of RT-PCR indicated OsHSF6 gene was expressed immediately after rice plants exposure to heat stress, and the transcription of OsHSF6 gene accumulated primarily in immature seeds, roots and leaves. However, we did not find the transcription of OsHSF12 gene in different organs and growth periods. Our results implied that OsHSF6 might be function as a HSF regulating early expression of stress genes in response to heat shock, and OsHSF12 might be act as a synergistic factor to regulate the expression of down-stream genes.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.151-161
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• 2013

An active power factor correction (PFC) circuit is presented which employs a newly proposed input voltage sensor-less control technique operated in continuous conduction mode (CCM) and critical conduction mode (CRM). The conventional PFC circuit with input voltage sensor-less control technique degrades the power factor (PF) under the light load condition due to DCM operation. In the proposed PFC circuit, the switching frequency is basically 70KHz in CCM operation. In light load condition, however, the PFC circuit operates in CRM and the switching frequency is increased up to 200KHz. So CCM/CRM operation of the PFC circuit alleviates the decreasing of the PF in light load condition. The proposed PFC controller IC has been implemented in a $0.35{\mu}m$ BCDMOS process and a 240W PFC prototype is built. Experimental results shows the PF of the proposed PFC circuit is improved up to 10% from the one employing the conventional CCM/DCM dual mode control technique. Also, the PF is improved up to 4% in the light load condition of the IEC 61000-3-2 Class D specifications.