• Journal of Power Electronics
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• v.13 no.1
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• pp.113-121
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• 2013

This paper introduces a simple core loss calculation method for output filter inductor in pulse width modulation (PWM) DC-AC inverter. Amorphous C-core (AMCC-320) is used to analyze the core loss. In order to measure core loss of the output filter inductor and validate the proposed method, a single-phase half-bridge inverter and a calorimeter are used. By changing switching frequency and modulation index (MI) of the inverter, core loss of the AMCC-320 is measured with the lab-made calorimeter and the results are compared with calculated core loss. The proposed method can be easily extended to other core loss calculation of various converters.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.389-403
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• 2011

Studies on effects of human action on the destruction of ecosystems and changes in biodiversity are being processed actively from the view point of landscape ecology. This study investigated present distribution status of the naturalization plant by disturbance of natural ecosystem which could be seen on 35 rural villages in Korea. The study made a landuse map on the study area then quantified the landscape ecologic characteristic using landscape index based on this landuse map. Correlation between landscape index on the study area and distribution characteristic of naturalization plant was analyzed. The landscape index was calculated by FRAGSTATS, a spatial analysis program, and naturalization index and urbanization index were used in the distribution characteristic of naturalization plant. As a result, naturalization index and patch density, naturalization index and edge density, naturalization index and area-weighted mean shape index were shown as having positive correlation, and naturalization and core area percentage of landscape, naturalization index and mean core area were displayed as having negative correlation.

• Korean Journal of Environment and Ecology
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• v.18 no.2
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• pp.158-166
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• 2004

For the zoning of natural ecosystem, Vegetation Index is calculated from the vegetation data surveyed on Baekdudaegan (from Namdeogyusan to Sosagogae). Five factors-biodiversity, conservation value of the stand, environmental quality, longevity of the stand, site productivity- are considered in the calculation of Vegetation Index. Vegetation Index might be a useful zoning tool for management of Baekdudaegan. For Vegetation Index I, 8 sample plots 12.l％ of total 66 sample plots are belong to core area, 21 sample plots 31.8％ and 37 sample plots 56.l％ are belong to buffer zone and transition area, respectively. For Vegetation Index II, 37 sample plots 41.9% of total 60 sample plots are belong to core area, 19 sample plots 28.8％ and 19 sample plots 28.8% are belong to buffer zone and transition area, respectively.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.135-141
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• 2002

An optimization of KTF thorium fuel assembly design was performed on the basis of the design parameter studies. Optimization goals ware to make the core have both proliferation resistance and fuel cycle economics. Four kinds of proliferation resistance indexes were used; SNS, TG, BCM, Toxicity. A new index, FEI was regarded as a limiting index for the maximization of fuel cycle economics. Optimized thorium fuel design was applied for APR-1400 reactor core. Nuclear core design procedures were examined to solve the thorium fuel reactor problems. It was shown that heterogeneous thorium fuel core option is acceptable in safety and economics aspects.

• The Korean Journal of Health Service Management
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• v.13 no.4
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• pp.253-263
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• 2019

Objectives: This study evaluated the perception on importance of interprofessional core competencies (PI-ICCP) scale. Methods: Data were collected from 353 college students of health. Content validity was tested using the content validity index for individual items(I-CVI) and for scale(S-CVI). Criterion validity was tested using the professional competencies scale developed by Choi. Reliability was evaluated using Cronbach's coefficient alpha. The goodness-of-fit of the construct validity was determined through exploratory and confirmatory factor analyses. Results: The I-CVI of each item was .8 or higher for all items, and the S-CVI was .98. The reliability of the PI-IPCC was Cronbach's α=.98. The goodness-of-fit indices of the model were χ2=1811.54(p<.001), the comparative fit index (CFI)=.91, and root mean square error of approximation (RMSEA)=.08, which satisfied the criteria. Conclusions: The construct and criterion-related validity of the perception for PI-ICCP scale were a good fit, so the instrument is appropriate for measuring perception on importance of interprofessional core competencies. Further research will be required using this instrument to investigate perception of interprofessional core competencies of health professionals.

• Current Optics and Photonics
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• v.3 no.3
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• pp.199-203
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• 2019

The characteristics of a photonic crystal fiber sensor with reuleaux triangle are studied by using the finite element method. The wavelength sensitivity of the designed optical fiber sensor is related to the arc radius of the reuleaux triangle. Whether the core area is solid or liquid as well as the refractive index of the liquid core contributes to wavelength sensitivity. The simulation results show that larger arc radius leads to higher sensitivity. The sensitivity can be improved by introducing a liquid core, and higher wavelength sensitivity can be achieved with a lower refractive index liquid core. In addition, the specific channel plated with gold film is polished and then analyte is deposited on the film surface, in which case the position of the resonance peak is the same as that of the complete photonic crystal fiber with three analyte channels being filled with analyte. This means that filling process becomes convenient with equivalent performance of designed sensor. The maximum wavelength sensitivity of the sensor is 10200 nm/RIU and the resolution is $9.8{\times}10^{-6}RIU$.

• Korean Journal of Environment and Ecology
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• v.16 no.3
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• pp.223-232
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• 2002

For the zoning of natural ecosystem, Vegetation Index is calculated from the vegetation data surveyed on Baekdudaegan (Pijae-Doraegijae). Five factors -biodiversity, conservation value of the stand, environmental quality, longevity of the stand, site productivity- are considered in the calculation of Vegetation Index. Vegetation Index might be a useful zoning tool for management of Baekdudaegan. For Vegetation Index I, 59 sample plots 52.2% of total 113 sample plots are belong to core area, 34 sample plots 30.l% and 20 sample plots 17.7% are belong to buffer zone and transition area, respectively. For Vegetation Index II, 49 sample plots 43.4% of total 113 sample plots are belong to core area, 38 sample plots 33.6% and 26 sample plots 23.0％ are belong to buffer zone and transition area, respectively.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.292-300
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• 2023

This paper proposes a patent discovery method and strategy for Generative AI-related patents by utilizing qualitative evaluation indicators established based on the core components of the technology. Currently, the evaluation of patent quality relies on quantitative indicators, but existing quantitative indicators cannot represent the characteristics of Generative AI technology, making it difficult to accurately evaluate. Therefore, there is a need for additional qualitative indicators that consider technical characteristics based on patent claims, which can reveal the actual strength of the patent. In this paper, we propose a new evaluation index considering the technical characteristics of Generative AI. Core patents were selected using the proposed evaluation index, and the appropriateness of the proposed index was verified through the existing quantitative evaluation method for the selected core patents.

• Proceedings of the Optical Society of Korea Conference
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• 2006.02a
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• pp.87-88
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• 2006

Bragg fibers, consisting of a low index core (including air) surrounded by a series of periodic layers of alternate high and low refractive index materials, each being higher than that of the core, form a 1D photonic bandgap (PBG). In view of the multitude of individual physical parameters that characterize a Bragg fiber, they offer a wide choice of parametric avenues to tailor their propagation characteristics. Owing to their unique PBG guidance mechanism, Bragg fibers indeed exhibit unusual dispersion characteristics that are otherwise nearly impossible to achieve in conventional silica fibers. Solid core Bragg fibers, amenable to fabrication by the highly mature MCVD technology, could be designed to realize broadband supercontinuum light. This talk would review our recent works on modeling of propagation characteristics, dispersion tailoring in them for applications as metro as well as dispersion compensating fibers and also as supercontinuum light generators.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.9
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• pp.739-745
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• 1998

The objective of this paper is to provide experimental data of Er(rare- earth)doped $SiO_2$thin film made by sputtering methods. The deposition rate of silica glass by sputtering method was 55$\AA$/min. In EDD measurements, the average Er concentration in the deposited film was 0.77(wt%). After annealing at $900^{\circ}C$, the Cl concentration decreased from 3.79(wt%) to 1.52(wt%). The refractive indices of the core $n_1$, cladding $n_2$ were 1.458, 1.558 respectively at 632.8 nm. The refractive index difference between core and cladding, $\Delta$n was 0.1. The refractive index profile of core and cladding interface shows step profile. In the study, $SiO_2$ glass films of Si wafer were successfully doped with active erbium. Therefore, this experimental data will be applicable for fabrications of Er doped planar integrated optical device.