• Journal of Environmental Science International
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• v.6 no.1
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• pp.9-16
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• 1997

We investigated and analysed the actual conditions and characteristics of railroad noise levels for 17 sites in the vicinity of the Seoul-Pusan Line. The results i,we summarized as follows : 11 Railroad noise level ranged to 64 ~ 74 $L_{eq}$ dB(A) at day time and ranged to 60 ~ 72 $L_{eq}$ dB(A) at night time. 21 Increased night noise level depend on the increase of trains passing at night time. 31 The major factor of Increased noise level in the vicinity of stations are using loudspeakers and stream whistle on trains. 4) Decreased effect of noise according to distance is able to be described quantitatively using regression equations of multiplicative model. $L_{eq}$=$78.59^{X-0.056}$, n =25, r=-0.994, s.e. =1.007 $P_{av}$ = $105.68X^{-0.073}$, n =25, r =-0.997, s.e. = 1.007 Also increased and decreased effect of noise according to floor in apartment Is able to be described quantitatively using regression equations of multiplicative model. $L_{eq}$ = $64.238X^{0.0567}$, n = 39, r = 0.787, s.e. = 1.004 $P_{av}$ =79.963X0.0524, n =39, r =0.689, s.e. = 1.056 5) Average noise level in high floor is over 70 $L_{eq}$ dB(A) at day and night time. so more detailed soundproofing countermeasured in high floors apartment is required.

• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.109-120
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• 2018

The distributional characteristics of fault segments in Cretaceous and Tertiary rocks from southeastern Gyeongsang Basin were derived. The 267 sets of fault segments showing linear type were extracted from the curved fault lines delineated on the regional geological map. First, the directional angle(${\theta}$)-length(L) chart for the whole fault segments was made. From the related chart, the general d istribution pattern of fault segments was derived. The distribution curve in the chart was divided into four sections according to its overall shape. NNE, NNW and WNW directions, corresponding to the peaks of the above sections, indicate those of the Yangsan, Ulsan and Gaeum fault systems. The fault segment population show near symmetrical distribution with respect to $N19^{\circ}E$ direction corresponding to the maximum peak. Second, the directional angle-frequency(N), mean length(Lm), total length(Lt) and density(${\rho}$) chart was made. From the related chart, whole domain of the above chart was divided into 19 domains in terms of the phases of the distribution curve. The directions corresponding to the peaks of the above domains suggest the directions of representative stresses acted on rock body. Third, the length-cumulative frequency graphs for the 18 sub-populations were made. From the related chart, the value of exponent(${\lambda}$) increase in the clockwise direction($N10{\sim}20^{\circ}E{\rightarrow}N50{\sim}60^{\circ}E$) and counterclockwise direction ($N10{\sim}20^{\circ}W{\rightarrow}N50{\sim}60^{\circ}W$). On the other hand, the width of distribution of lengths and mean length decrease. The chart for the above sub-populations having mutually different evolution characteristics, reveals a cross section of evolutionary process. Fourth, the general distribution chart for the 18 graphs was made. From the related chart, the above graphs were classified into five groups(A~E) according to the distribution area. The lengths of fault segments increase in order of group E ($N80{\sim}90^{\circ}E{\cdot}N70{\sim}80^{\circ}E{\cdot}N80{\sim}90^{\circ}W{\cdot}N50{\sim}60^{\circ}W{\cdot}N30{\sim}40^{\circ}W{\cdot}N40{\sim}50^{\circ}W$) < D ($N70{\sim}80^{\circ}W{\cdot}N60{\sim}70^{\circ}W{\cdot}N60{\sim}70^{\circ}E{\cdot}N50{\sim}60^{\circ}E{\cdot}N40{\sim}50^{\circ}E{\cdot}N0{\sim}10^{\circ}W$) < C ($N20{\sim}30^{\circ}W{\cdot}N10{\sim}20^{\circ}W$) < B ($N0{\sim}10^{\circ}E{\cdot}N30{\sim}40^{\circ}E$) < A ($N20{\sim}30^{\circ}E{\cdot}N10{\sim}20^{\circ}E$). Especially the forms of graph gradually transition from a uniform distribution to an exponential one. Lastly, the values of the six parameters for fault-segment length were divided into five groups. Among the six parameters, mean length and length of the longest fault segment decrease in the order of group III ($N10^{\circ}W{\sim}N20^{\circ}E$) > IV ($N20{\sim}60^{\circ}E$) > II ($N10{\sim}60^{\circ}W$) > I ($N60{\sim}90^{\circ}W$) > V ($N60{\sim}90^{\circ}E$). Frequency, longest length, total length, mean length and density of fault segments, belonging to group V, show the lowest values. The above order of arrangement among five groups suggests the interrelationship with the relative formation ages of fault segments.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.210-211
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• 2012

본 논문에서는 N-Device 환경의 인증, 지불, 전자서명을 스마트폰에 탑재된 스마트지갑앱을 이용하여, 동일한 UX로 편리하게 이용할 수 있게 해주는 스마트채널 기술을 제안한다. 스마트채널 기술은 스마트 TV등 클라이언트 디바이스에서 스마트폰으로 인증, 지불 등의 트랜잭션을 이관하는 트랜잭션 트랜스밋 기술과 클라이언트 디바이스의 웹브라우저와 웹서버 간에 e2e 메시지 보안을 플러그인 없이 제공하는 메시지 보안 기술로 구성된다. 스마트채널 기술을 적용하면 서비스 제공자는 단일한 웹페이지를 이용해 모든 디바이스에 서비스할 수 있으며, 일체의 플러그인이 필요없게 된다. 이용자는 스마트지갑에만 크리덴셜을 저장 관리하고 이용하면 된다.

• 한국해양학회지
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• v.19 no.1
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• pp.11-17
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• 1984

The abnormal cooling phenomenon occurred in the coastal areas of East Sea of Korea in summer, 1981 is studied on the basis of the oceanographical data obtained by the National Fisheries University of Pusan, in July, 1981 and by Fisheries Research and Development Agency of Korea during 1961 to 1981 and by Japan Meteorological Agency in 1975 and 1981. Th vertical section of temperature along 130 E showed that the warmer waters more than 10 C occupied at upper layer of about 75m depth in south of 35 30'N the layer changed rapidly thinner as 20m th 30m depth. In the areas of East Sea during 1966 to 1981, the temperature fluctuations at 100m depth ranged greatly in standard deviation from 2 C to 4 C. The temperature anomaly in 1981 was about 1.5 times of the standard deviation and at the upper layer of 150m depth the temperatures became colder by 5 -10 C than average values in August, 1961-1975. The 10 C isotherm at 100m depth in 1981 appeared between 35 and 36 N, shifting southward 20 to 120 miles than mean year. These results showed that the abnormal cooling phenomenon in the areas of East Sea of Korea in summer occurred mose predominantly in 1981 in period from 1966 to 1981

• Polymer(Korea)
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• v.36 no.3
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• pp.344-350
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• 2012

New pressure sensitive adhesives (PSAs) for polarizer film were prepared by electron beam (e-beam) radiation to acrylic copolymers, and their adhesive properties were investigated. The acrylic copolymers were synthesized by free radical polymerization of $n$-butylacrylate (BA), 2-hydroxyethyl methacrylate (HEMA), and acrylic acid (AA). The acrylic copolymers were coated on PET release films to a thickness of 25 ${\mu}m$, laminated to polarizer films, and then radiated with e-beam at room temperature. Gel fractions of all the acrylic copolymers after e-beam radiation at 50 kGy were higher than 93%, and their crosslinking densities were increased with increasing the content of HEMA units. PSA prepared by e-beam radiation of acrylic copolymer synthesized with a feed ratio of BA/HEMA/AA = 89.5/10/0.5 (w/w/w) at a dose of 50 kGy exhibited the best adhesion performances in terms of peel strength, creep resistance, durability and reliability, and light leakage. It is expected that the preparation method of PSAs via e-beam irradiation will improve the producibility and workability of polarizer film for liquid crystal display.

• Korean Journal of Materials Research
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• v.8 no.7
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• pp.591-595
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• 1998

In this work, the freestanding GaN single crystalline substrates without cracks were grown by hydride vapor phase epitaxy (HVPE) and its some properties were investigated. The GaN substrate, having a current maximum size of 350 $\mu\textrm{m}$-thickness and 100$\textrm{mm}^2$ area, were obtained by HVPE growth of thick film GaN on sapphire substrate and subsequent mechanical removal of the sapphire substrate. A lattice constant of $C_o$= 5.18486 $\AA$ and a FWHM of DCXRD was 650 arcsec for the single crystalline GaN substrate. The low temperature PL spectrum consist of three excitonic emission and a deep D- A pair recombination at 1.8eV. The Raman E, (high) mode frequency was 567$cm^{-1}$ which was the same as that of strain free bulk single crystals. The Hall mobility and carrier concentration was 283$cm^3$<\ulcornerTEX>/ V.sand 1.1$\times$$10^{18}cm^{-3}$, respectively.

• Communications of Mathematical Education
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• v.22 no.1
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• pp.79-89
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• 2008

In this study, we study on various positions and equations of trisectors of angle. We analyze article related with trisector's equation of angle. We elaborate the article, investigate various case of angles, and find out new equations of trisectors of angle.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.75.1-75.1
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• 2021

MSE (Maunakea Spectroscopic Explorer)는 11.25m 구경의 망원경과 최대 4,000 개의 천체를 한 번에 관측할 수 있는 분광기를 통해 다천체 분광학 연구를 이끌 차세대 관측기기이다. 경희대학교는 망원경에 장착되는 다천체 분광기의 성능 요구사항을 바탕으로 노출 시간 소프트웨어 ETC (Exposure Time Calculator)를 개발하고 있다. ETC는 대기에 의한 연속선 소광, 방출선과 흡수선, 망원경 및 광학 기기의 투과율, 검출기의 암전류와 읽기 잡음을 바탕으로 신호 대 잡음비 S/N (Signal to Noise)을 도출하여 천체를 분광 관측하기 위한 적절한 노출 시간을 계산한다. MSE-ETC는 저분산 LR (Low Resolution, R=3,000), 중분산 MR (Moderate Resolution, R =6,000) 및 고분산 HR (High Resolution, R=40,000)의 관측 모드로 가시광선과 근적외선 영역의 S/N과 파장, 그리고 S/N과 AB등급 간의 상관관계를 보여준다. 본 포스터에서는 개발 중인 MSE-ETC 프로그램의 구조와 작동 알고리즘 및 사용 예를 발표한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.331-334
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• 2001

In this study, the magnetic properties for Ni-Zn ferrite were investigated as the function of $Co_3$ $O_4$ additive contents which was predicted to improve the resonance frequency. Toroid specimens with the composition of N $i_{0.8-x}$Z $n_{0.2+x}$F $e_2$ $O_4$(x = 0, 0.05, 0.1, 0.15) ferrites were preparation by conventional ceramic processing technique. The maximum resonance frequency of 19.905 MHz and the permeability of 90.88 in 10 MHz were attained to the N $i_{0.8}$Z $n_{0.2}$F $e_2$ $O_4$with $Co_3$ $O_4$0.3 wt%. Both of the permeability in 10 MHz and the resonance increased to 107.11 and 19.005 MHz respectively for the N $i_{0.8}$Z $n_{0.2}$F $e_2$ $O_4$with $Co_3$ $O_4$wt% than the N $i_{0.8}$Z $n_{0.2}$F $e_2$ $O_4$/ with the free $Co_3$ $O_4$composition.composition.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.255-255
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• 2020

아프리카 대륙에서 존재하는 가장 큰 사하라 사막(Sahara desert)의 면적은 지난 1세기 동안 기후변화로 인하여 10% 정도 증가하였고, 미래에도 기온상승으로 인하여 증가할 것으로 판단된다. 사하라 사막 면적의 증가로 인하여 아프리카의 자연식생과 수자원뿐만 아니라 아프리카에 거주하는 사람들의 삶에 많은 영향을 미치기에 사막의 면적 또는 경계선의 위치를 예측함은 매우 중요하다. 본 연구에서는 Coupled Model Intercomparison Project Phase 5 (CMIP5)의 36개 Global Climate Models (GCMs)과 ERA-interim 재분석 자료의 1979~2000년 강수 자료들을 이용하여 사헬(Sahel) 지대 서쪽(15W~15E, 10N~20N)과 동쪽(15E~35E, 10N~20N)의 강수량과 사막경계선을 비교하였다. 또한, 각 모델의 과거 모의 성능을 평가하여 미래 기후 예측성을 판단하고자 한다. 본 연구에서는 22년 평균 강수량이 200mm 이하인 지역을 사막이라 정의하고, 모델별로 연평균 강수량과 사막경계선에 대한 root mean square error(RMSE)를 산정하여 평가하였다. 또한, 습윤 정적 에너지(Moist. Static Energy; MSE), 바람(풍속 및 풍향) 자료를 이용하여 각 모델의 사막경계선의 오차에 대한 이유를 분석하였다. 이 연구를 바탕으로 하여 사헬 지대의 강수량 및 사막면적 모의의 불확실성 요소를 이해하고, 미래 상세 지역 수문기후 변화 예측에 활용 가능한 GCMs을 선별할 수 있을 것으로 판단한다.