• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.9
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• pp.947-955
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• 2002

In this paper, we derive an outage probability for the Erlang capacity and the link margin respectively, calculate them with the same parameters and outage probability, and then analyze a capacity and cell coverage in city, suburban, and open area. So, the Erlang capacity is more real than in a cell, and the cell coverage can be calculated with high reliability by the margin. When the $E_b/N_o$ decreases from 7 dB to 5 dB within the outage probability of 5 %, it is observed that the capacity is increased from 18 Erlang to 31 Erlang with the same margin of 2.8 dB, then the coverage is increased to 0.4 km, 1 km, and 2.5 km in city, suburban, and open area respectively. Also if the outage probability is decreased from 5 % to 2 % in case of $E_b/N_o$ of 5 dB, the result shows a very reliable link with additional increment of 0.88 dB in the margin and a high QoS (quality of service) within decrement of 0.15 km, 0.5 km, and 1.5 km for the same areas with decrement of 3 Erlang from 31 Erlang.

• Journal of The Korean Astronomical Society
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• v.45 no.5
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• pp.117-125
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• 2012

We present $^{12}CO$ J = 2-1 line observations of G54.1+0.3, a composite supernova remnant with a mid-infrared (MIR) loop surrounding the central pulsar wind nebula (PWN). We map an area of $12^{\prime}{\times}9^{\prime}$ around the PWN and its associated MIR loop. We confirm two velocity components that have been proposed to be possibly interacting with the PWN/MIR-loop; the +53 km $s^{-1}$ cloud, which appears in contact with the eastern boundary of the PWN and the +23 km $s^{-1}$ cloud, which has CO emission coincident with the MIR loop. However, we have not found a direct evidence for the interaction in either of these clouds. Instead, we detected an 5'-long arc-like cloud at +15-+23 km $s^{-1}$ with a systematic velocity gradient of ~3 km $s^{-1}$ $arcmin^{-1}$ and broad-line emitting CO gas with widths (FWHM) of ${\leq}7km\;s^{-1}$ in the western interior of the supernova remnant. We discuss their association with the supernova remnant.

• Korean Journal of Optics and Photonics
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• v.6 no.2
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• pp.156-164
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• 1995

Based on the scalar wave equation of optical fibers, the dispersion characteristics of arbitrarily profiled fibers were analyzed. We used the I-D FEM employing quadratic interpolation fucntions to solve the scalar wave equation. We simulated the DC optical fibers as objects, and searched for the refractive index distribution to minimize the total dispersion. In DC fibers, we found the design parameters for which the total dispersion was almost zero at $\lambda=1.3{\mu}m and 1.55{\mu}m$ simultaneously. We also found the design parameters where the dispersion was flattened, less than 1.0 ps/km.nm for$\lambda=1.4~1.7{\mu}m$1. and the dispersion was as low as 0.65 ps/km.nm at $\lambda=1.55{\mu}m$..

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.331-331
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• 2017

2011 년부터 2014 년까지 4 년간의 여름철에 한반도에 비교적 많은 강수를 남긴 23 개의 중규모 저기압-구름무리 집중호우 사례를 선정하여, 이들 사례에서의 중규모 저기압 발생과 이동 그리고 그것에 동반된 강수계에 의한 강수 발생을 수치예측하는 실험을 수행하였다. WRF 모델을 이용하여 12 km와 4 km 수평격자 크기로 수치실험을 진행하였으며, 각 사례에 대해 중규모 저기압이 발생한 시점을 초기 시각으로 하여 수치적분을 수행하였다. 수치실험 결과와 AWS 강수량 관측 자료를 $0.1^{\circ}{\times}0.1^{\circ}$ 격자에 각각 내삽한 후 비교하였다. 12 km 격자 실험에서는 25 mm/12h 문턱값에 대해 23개의 사례 중 9개 (39 %)만이 0.3이 넘는 성공임계지수(TS)를 나타냈고, 50 mm/12h 문턱값에 대해서는 17개 사례 중 7개 (41 %)의 사례에서 0.3이 넘는 TS가 나타났다. 4 km 실험에서는 25 mm/12h 문턱값에 대해 23개의 사례 중 10개 (43 %) 사례에서 0.3이 넘는 TS 값이 나타났고, 50 mm/12h 문턱값에 대해서는 17개 사례 중 7개 (41 %)로 나타나 WRF 모델의 수평격자 크기와 관계없이 비슷한 성능을 보였다. 중규모 저기압이 진행하는 경로에 따라 예측 능력에 차이가 나타났다. 23개 사례를 중규모 저기압 발생지점으로부터의 이동경로에 따라 준 직선 경로 사례 그룹, 곡선형 경로 사례 그룹, 정체사례 그룹으로 분류하여 각 그룹에 대해 예측 능력을 조사한 결과, 직전 경로 사례들에 대한 4km 격자 모델 예측은 55 %의 사례에서 0.3보다 큰 TS값을 보여, 30 %의 사례에서 0.3 이상의 TS 값을 보인 곡선형 경로 사례들에 대한 예측보다 상대적으로 높은 예측 신뢰도를 보여 주었다.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.06a
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• pp.165-169
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• 2004

Marine magnetic survey were carried out at Sokotra Basin offshore Korea between latitudes $31^{\circ}$ 42'32' N and $32^{\circ}$ 46'29' N, and longitudes $123^{\circ}$ 56'26" E and $125^{\circ}$ 49'16" E in order to estimate the depth of basement complex and as well as to configure it surface and produce the thickness of sedimentary sequence at the study area. Two methods have been used for depth estimation and basement configuration: the power spectrum and the 3-D analytical signal. The estimated depths resulted from the power spectrum method range from 1.4 km to 6.0 km for deep sources (basement troughs), and from 0.3 km to 1.75 km for shallow source (basement peaks). An isopach map was prepared for estimating the thickness of the sedimentary sequence at the study area; it ranges from 1.2 to 4.66 km. The estimated depths resulted from the analytic signal method range from 1.0 to 6 km. A basement configuration map was constructed for the study area in the basin. They show a well agreement with the geology of the study area.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.3
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• pp.104-118
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• 2018

This study is to evaluate the accuracy improvement of the model using SWAT(Soil and Water Assessment Tool) model and multi - point hydrological observation data. The watershed is located in the Yongdam Dam($930.4km^2$), the Donghyang($165.5km^2$), the Chuncheon($290.9km^2$), the Juchun($57.8km^2$) and the Seokjeong($80.5km^2$). The watershed covers 70.0 % forest. In order to improve the accuracy of the model, precipitation data were used from two weather stations(Jangsu, Geumsan) and 16 AWS stations daily precipitation data(2003~2011) managed by KMA, MLIT, and K-water. Based on the reliable data of the Yongam test basin in 2003~2011, the runoff of single point (Yongdam dam) and multi-point (Donghyang, Chuncheon, Jucheon, Seokjeong). Simulation results show that the $R^2$ of the single subwatershed (Donghyang, Chuncheon, Jucheon, Seokjeong) is single point(0.84) and multipoint(0.88). For model efficiency coefficient of Nash-Sutcliffe at single point(0.45) and multipoint(0.70).

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.459-460
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• 2011

한전의 가공 송전선로는 2010년 기준으로 약 12,990km(765 kV 송전선로 354 km, 345 kV 송전선로 약 3,868 km, 154 kV 송전선로 8,173 km, 66 kV 송전선로 : 약 595 km)가 설치되어 운전되고 있다. 이러한 송전선로는 평지, 구릉, 산악지 등에 설치됨으로써 자연환경에 크게 영향을 받는다. 특히 전 세계적으로 낙뢰에 의한 송전선로의 트립 고장이 전체 고장의 약 60%를 점유하는 것으로 보고되고 있으며, 낙뢰에 의한 고장을 최소화하기 위한 내뢰 설계를 시행하고 있다. 한전에서도 전압별 계통의 신뢰도와 경제성을 고려하여 765 kV 송전선로의 목표 사고율은 0.35[건/100 km 년], 345 kV 송전선로의 경우는 1.0[건/100 km.년], 154 kV 송전선로의 경우는 2.0[건/100 km 년] 이하의 목표 사고율을 설정하여 설계 운영하고 있다. 그러나 2000년 이후 낙뢰발생 빈도가 증가하고 있으며, 낙뢰에 의한 고장 점유율도 약 75%로서 고품질 전력공급을 위한 내뢰 대책 수립의 검토가 요구되고 있다.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.6
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• pp.105-114
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• 2007

This study is to predict the spatial expansion of urban areas by applying CA(Cellular Automata)-Markov technique considering MCE(multi-criteria evaluation) and MOLA(multi-objective land allocation) of factor analysis. For the 10 administration districts$(3677.3km^2)$ including the whole Anseong-cheon watershed, the past six temporal land use data(1973, 1981, 1985, 1990, 1994, 2000) from Landsat satellite images were prepared. During this period, the urban area increased $233.71km^2$. Using the 36 indices composed of topological characteristics, population and land use change, the final factor map of MOLA was produced through 5 maps of MCE. Using 1990 and 1994 land use data, the 2000 predicted urban area of CA-Markov with factor map showed 0.06% improvement of absolute error comparing with that of CA-Markov without factor map. By the CA-Markov technique considering factor map, the 2030 and 2060 urban area increased $58.94km^2(0.78%)\;and\;60.14km^2(0.81%)$ respectively comparing with 2000 urban area$(313.19km^2)$. The 2030 and 2060 paddy area decreased $93.28km^2(2.54%)\;and\;93.65km^2(2.55%)$ respectively comparing with 2000 paddy area$(1383.23km^2)$.

• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.70-77
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• 2020

A feeding experiment was conducted to investigate the effects of replacement of dietary fish meal by frozen whole krill (FWK) and/or krill meal (KM) on growth performance and body composition of juvenile black rockfish, Sebastes schlegeli. The basal experimental diet (ED) contained 58.4% fish meal (FM) as a control, the other five EDs were formulated with the protein replacement ratio of fish meal by as 0, 10, 20, 30, and 40%, respectively (FWKM0, FWK10, FWK20, FWK20KM10, FWK20KM20 and FWK20KM20HP). Each diet was fed to juvenile rockfish initially weighing 3.09±0.02 g/fish in a flow-through system. The control ED containing 58.4% FM and 10% FWK diet showed significantly higher weight gain and feed efficiency than all the other EDs containing 20, 30, and 40% FWK and/or KM. But the survivals, whole-body moistures, crude proteins and lipids of black rockfish fed all EDs were similar in all EDs. The only whole-body ashes of juvenile black rockfish were significantly differentiated by feeding the various EDs containing different levels of FWK and/or KM with a protein and lipid levels adjustment. These results suggest that dietary frozen whole Antarctic krill and/or krill meal inclusions could not improve the growth but change the whole-body ashes in juvenile black rockfish. Therefore, this study further indicates that dietary more than 20% of FWK and/or KM supplementation could not be a potential source of animal protein to replace fishmeal in juvenile black rockfish.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.4
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• pp.66-76
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• 2021

The purpose of this study was to analyze the transition process of Gyeongpo lake and to analyze the viewing characteristics of each period in the pavilion. The view characteristics at pavilion were analyzed by overlapping classification maps of landscape types by period with the view range map from pavilion. The circumference and area of Gyeongpo lake have been reduced to 15.2km and 3.9km² in the 1750s, 9.0km and 1.7km² in the 1933, and now 4.41km and 1.0km². By period, the largest decrease in the proportion of Gyeongpo lake viewed from Pavilion was Hwanseonjeong, which decreased by 48.0% from the 1750 to 2017. Hwallaejeong, Haeunjeong, and Hohaejeong were found to be impossible to view Gyeongpo lake as some of the adjacent lakes were changed to agricultural land. Pavilion has great significance as a space for traditional culture created in the background of humanities and natural environments. For the succession and development of Pavilion culture, it is necessary to use it as a cultural resource, to continuously manage the building, and to partially restore Gyeongpo lake considering the function of each pavilion.