• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.333-336
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• 2001

This paper reports that the Lambert W function applies to a non-iterative design of minimum mean square-error scalar quantizers for a Laplacian source. The contribution of the paper is in the reduction of the time needed for the design and the increased accuracy in resulting quantization points and thresholds, because the algorithm is non-iterative and the Lambert W function can be evaluated as accurately as desired.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2003년도 춘계 학술발표회 논문집
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• pp.20-23
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• 2003

Low-sulfidation style ore deposits, the major source of Au, Ag, and Hg, are formed from neutral-pH, reduced hydrothermal solutions close to equilibrium with their host rocks. The waters are low-salinity (〈1 wt % NaCl equiv.) but relatively gas rich (1-2 wt % $CO_2$), and are largely meteoric water. However, the contribution of magmatic components to the epithermal system, its temporal importance, and its relation to the source of ore metals are largely controversial. (omitted)

• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.161-164
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• 1989

When an electric (or a magnetic) line source is located near the surface, surface wave type field is generated and the energy associated with this field is guided very close to the impedance surface. In this paper, field strength is calculated by the exact modal and ray methods for a line source excited parallel plate waveguide. The surface wave contribution to the modal and ray solutions is anticipated very strong and must be included in both solutions.

• 수산경영론집
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• 제54권2호
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• pp.77-90
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• 2023

This study employed the Gini coefficient decomposition analysis to classify and examine fishery household income inequality according to income sources. The raw data from the Fisheries Economic Survey by the National Statistical Office were used for the analysis after equalization according to the recommended method of the OECD. In particular, the Gini coefficient was decomposed by classifying with and without public subsidies, and the contribution, correlation, and marginal effect by income source were presented.As a result of the analysis, the inequality of fishing income and non-fishing income of fishermen was worsening, and the inequality of transfer income was continuously easing. Among them, fisheries subsidies have been analyzed to have the greatest contribution to the Gini coefficient of gross income and the highest relative marginal effect, although distribution inequality has been alleviated. On the other hand, other subsidies, including public pensions, were found to have the opposite contribution, correlation, and marginal effect to fisheries subsidies. The results of this analysis showed that even within public subsidies, the contribution to income redistribution might differ depending on the nature of the subsidy. In addition, in the case of other public subsidies, it can be seen that the transition from selective welfare to universal welfare occurs.

• Nuclear Engineering and Technology
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• 제49권8호
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• pp.1600-1609
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• 2017

The accelerator-driven subcritical system (ADS) is driven by a neutron source from spallation reactions introduced by the injected proton beam. Part of the neutron source has energy as high as a few hundred MeV to a few GeV. The effects of high-energy source neutrons ($E_n$ > 20 MeV) are usually approximated by energy cut-off treatment in practical core calculations, which can overestimate the predicted proton beam current in the ADS design. This article intends to quantize this effect and propose a way to solve this problem. To evaluate the effects of high-energy neutrons in the subcritical core, two models are established aiming to cover the features of current experimental facilities and industrial-scale ADS in the future. The results show that high-energy neutrons with $E_n$ > 20 MeV are of small fraction (2.6%) in the neutron source, but their contribution to the source efficiency is about 23% for the large scale ADS. Based on this, a neutron source efficiency correction factor is proposed. Tests show that the new correction method works well in the ADS calculation. This method can effectively improve the accuracy of the prediction of the proton beam current.

• 한국대기환경학회지
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• 제26권1호
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• pp.21-33
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• 2010

The objective of this study was to estimate the $PM_{2.5}$ source apportionment at the Pinnacles National Monument IMPROVE site in western coastal USA. The PMF was applied to identify the existing sources and apportion the $PM_{2.5}$ mass to each source. To analyze local source impacts from various wind directions, the NPR analysis was performed using source contribution results with the wind direction values measured at the site. Also, PSCF was applied to identify the locations by point sources relative to the back trajectories. A total of 1,634 samples were collected from March 1988 to May 2004 by IMPROVE sampler and 32 chemical species were analyzed by PIXE, PESA, XRF, IC, and TOR methods. The PMF modeling identified seven sources and the average mass was apportioned to gasoline vehicle, secondary sulfate, aged sea salt, secondary nitrate, wood/field burning, diesel emission, and soil, respectively. In this study, the average mass was apportioned to gasoline vehicle (33.0%), secondary sulfate (25.7%), aged sea salt (17.8%), and secondary nitrate (10.1%). Also, this study suggests the possible role for source apportionment study of $PM_{2.5}$ at similar areas such as wildness, national park, and coastal areas in Korea.

• 한국대기환경학회지
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• 제16권5호
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• pp.477-485
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• 2000

The data set was collected on fifty-eight different days with a 24-h sampling period from October 27, 1995 through August 25, 1996. From the chemical mass balance (CMB) analysis of $PM_{2.5}$ in the Chongju area, the contributions from soil, gasoline, diesel, light and heavy oil combustion were 2.6%, 15.4%, 9.0%, 28.8% and 1.5%, respectively. Residual $NO_{3}^{-}$), residual $SO_{4}^{2-}$ and residual OC, possibly formed in the atmosphere. represented additional 8.0, 10.2, and 1.6% of the $PM_{2.5}$, respectively. Other unidentified sources constituted the remaining 22.9%. From the CMB analysis, the $PM_{2.5}$ source contribution for fall, winter, spring and summer were 92, 76.8, 77.5 and 59.2%, respectively.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.229-233
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• 2007

This study is to test the applicability of QuickBird image for non-point source pollution assessment. SWAT (Soil and Water Assessment Tool) model was adopted and the model was calibrated for a stream watershed of 255.4 $km^2$ Landsat land use data. For model application with QuickBird image, a precise agricultural land use map of 1.16 $km^2$ area located in the upstream watershed was produced by field investigation. The model was run with the combination of land use and soil map scales (1:5,000, 1:25,000 and 1:50,000). The results were compared and analyzed for the contribution of non-point source pollution by the land use scale and contents.

• 한국환경보건학회지
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• 제41권1호
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• pp.49-60
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• 2015

Objectives: Pine needles were used as a passive air sampler (PAS) of atmospheric persistent organic pollutants (POPs). This study was performed to investigate concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) deposited on pine needles near a waste incinerator and PCDD/Fs source contributions using principal component analysis (PCA). Methods: Two-year-old pine needles were sampled at 11 points with respect to distance and wind direction from the incinerator. PCDD/Fs deposited on pine needles were analyzed with HRGC/HRMS. The source contribution of PCA was calculated with SPSS. Results: The average concentration of PCDD/Fs deposited on pine needle was 0.79 (0.27-1.76) pg TEQ/g dry, PCDDs with 0.24 (0.01-0.95) pg TEQ/g dry and PCDFs with 0.56 (0.27-0.82) pg TEQ/g dry, respectively. The average concentration fraction of PCDDs was 29.7%, that of PCDFs was 70.3%, and PCDFs were more prevalent than PCDDs. The contributions of PCDD/Fs sources were estimated as incineration at 58.3% and automobiles at 28.4%. However, a relation and regulation between PCDD/Fs concentrations deposited on pine needles and distance from incinerator or wind direction was not shown. Conclusion: It was concluded that atmospheric PCDD/Fs concentrations near an industrial complex with a waste incinerator were affected by multiple sources. However, PCDD/Fs concentrations were lower than in other inland cities with the exception of background area.

• 한국대기환경학회지
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• 제22권1호
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• pp.85-97
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• 2006

The PAMS data collected at four sites in Seoul metropolitan area in 2004 were analyzed using the positive matrix factorization (PMF) technique, in order to identify the possible sources and estimate their contributions to ambient VOCs. Ten sources were then resolved at Jeongdong, Bulgwang, Yangpyeong, and Seokmo, including vehicle exhaust, LPG vehicle, petroleum evaporation, coating, solvent, asphalt, LNG, Industry & heating, open burning, and biogenic source. The PMF analysis results showed that vehicle exhaust commonly contributed the largest portion of the predicted total VOCs mass concentration, more than $30\%$ at four sites. The contribution of other resolved sources were significantly different according to the characteristics of site location. In the case of Jeongdong and bulgwang located in urban area, various anthropogenic sources such as coating, solvent, asphalt, residual LPG, and petroleum evaporation contributed about $40\%$ of total VOCs mass. On the other hand, at yangpyeong and Seokmo located in rural and remote area, the portion of these anthropogenic sources was reduced to less than $30\%$ and the contribution of natural sources including open burning and biogenic source clearly observed. These results were considerably corresponding to the emission inventory investigated in this region.