• Korean Journal of Crystallography
• /
• v.6 no.1
• /
• pp.43-48
• /
• 1995

The crystal structure of P-toluenesulfonanilide, C13H13NO2S is monoclinic, space group P21/c, a=8.777(1)Å, b=9.784(2)Å, c=15.139(2)Å, β=99.00(1)°, Z=4, V=1284.0(6)Å3, Dc=1.28g/cm33, λ(Mo-Kα)=0.71069Å, μ=2.3cm-1, F(000)=520, Temperature : 293±3K, R=0.038 for 711 Fo<3.0σ unique observed reflection. The structure was determuned by direct method and refined by full-matrix least squares refinement. Two benzene rings have the dihedral angle of 68.4°. Moleculs are accumulated according to the c axis with two fold screw and contacted by van der Walls force.

• Journal of the Korean Magnetics Society
• /
• v.4 no.2
• /
• pp.154-159
• /
• 1994

The magneto-optical Kerr spectra(${\lambda}=250~700nm$) of amorphous RE-Co(RE=Ce, Nd, Pr, Gd, Tb, Er, Ho) are compared with those of Y-Co films. It has been found that the Kerr rotation of RE-Co is mainly due to Co in the long wavelength region, whereas at short wavelength Ce, Pr, Nd, and Gd contribute positively, and Tb, Ho, and Er contribute negatively to the Kerr rotation of RE-Co amorphous films. In the interesting energy region(1.5~5.0 eV), the magneto-optical contribution of Pr and Nd are thought to be related with $4f{\uparrow}->5d{\uparrow}$ interband transition, and the contribution of Ce and Gd might be concerned with d->p interband transition. The magneto-optical effect of Tb in the short wavelength region might be related with $4f{\downarrow}->5d{\downarrow}$ and/or $5d{\downarrow}->4f{\downarrow}$, and that of Ho and Er can be explained by $4f{\downarrow}->5d{\downarrow}$ magneto-optical interband transition.

• Annual Conference on Human and Language Technology
• /
• 2021.10a
• /
• pp.439-443
• /
• 2021

기계 독해는 단락과 질의가 주어졌을 때 단락 내 정답을 찾는 자연어 처리 태스크이다. 최근 벤치마킹 데이터셋에서 사전학습 언어모델을 기반으로 빠른 발전을 보이며 특정 데이터셋에서 인간의 성능을 뛰어넘는 성과를 거두고 있다. 그러나 이는 단락 내 범위(span)에서 추출된 정보에 관한 것으로, 실제 연산을 요구하는 질의에 대한 응답에는 한계가 있다. 본 논문에서는 기존 범위 내에서 응답이 가능할 뿐만이 아니라, 연산에 관한 이산 추론을 요구하는 단락 및 질의에 대해서도 응답이 가능한 기계 독해 모델의 효과성을 검증하고자 한다. 이를 위해 영어 DROP (Discrete Reasoning Over the content of Paragraphs, DROP) 데이터셋으로부터 1,794개의 질의응답 쌍을 Google Translator API v2를 사용하여 한국어로 번역 및 정제하여 KoDROP (Korean DROP, KoDROP) 데이터셋을 구축하였다. 단락 및 질의를 참조하여 연산을 수행하기 위한 의미 태그를 한국어 KoBERT 및 KoELECTRA에 접목하여, 숫자 인식이 가능한 KoNABERT, KoNAELECTRA 모델을 생성하였다. 실험 결과, KoDROP 데이터셋은 기존 기계 독해 데이터셋과 비교하여 단락에 대한 더욱 포괄적인 이해와 연산 정보를 요구하였으며, 가장 높은 성능을 기록한 KoNAELECTRA는 KoBERT과 비교하여 F1, EM에서 모두 19.20의 월등한 성능 향상을 보였다.

• Korean Journal of Remote Sensing
• /
• v.38 no.5_2
• /
• pp.685-694
• /
• 2022

Building information is essential for various urban spatial analyses. For this reason, continuous building monitoring is required, but it is a subject with many practical difficulties. To this end, research is being conducted to extract buildings from satellite images that can be continuously observed over a wide area. Recently, deep learning-based semantic segmentation techniques have been used. In this study, a part of the structure of the context-based ResU-Net was modified, and training was conducted to automatically extract a building from a 30 cm Worldview-3 RGB image using SpaceNet's building v2 free open data. As a result of the classification accuracy evaluation, the f1-score, which was higher than the classification accuracy of the 2nd SpaceNet competition winners. Therefore, if Worldview-3 satellite imagery can be continuously provided, it will be possible to use the building extraction results of this study to generate an automatic model of building around the world.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.3 no.1
• /
• pp.18-25
• /
• 1978

The 1/f noise spectrum of short-circuited output drain current due to the Shockley-Read-Hal] recombination centers with a single lifetime in homogeneous nondegenerate MOS-field effcte transtors with n-type channel is calculated under the assumptions that the quasi-Fermi level for the carriers in each energy band can not be defined if we include the fluctuation for time varying quantities. and so 1/f noise is a majority carrier effect. Under these assumptions the derived 1/f noise in this paper show some essential features of the 1/f noise in MOS-field effect transistors. That is, it has no lowfrequency plateau and is proportionnal to the channel cross area A and to the driain bias voltage Vd and inversely proportional to the channel length L3 in MOS field effect transistors. This model can explain the discrepancy between the transition frequency of the noise spectrum from 1/f- response to 1/f2 and the frequency corresponding to the relaxation time related to the surface centers in p-n junction diodes. In this paper the results show that the functional form of noise spectrum is greatly influenced by the functional forms of the electron capture probability cn (E) and the relaxation time r (E) for scattering and the case of lattice scattering show to be responsible for the 4 noise in MOS fold effect transistors. So we canconclude that the source of 1/f noise is due to lattice scattering.

• Journal of the Mineralogical Society of Korea
• /
• v.14 no.1
• /
• pp.73-84
• /
• 2001

티타늄과 산소의 함량이 서로 다른 4가지의 합성 페롭스카이트형(perovskite-type) 광물(($K_2$$La_2$$Ti_{n}$/$O_{2n+4}$, n=3, 4, 5, 6; 14/mcm, 14/mmm, I42 m)을 대상으로 리트벨트(Rietveld)구조분석법을 실시하여 결정구조를 밝히고 티타늄함량에 따른 층상형 구조를 연구하였다. 4가지 합성시료에 대하여 구조분석을 실시한결과 대표적인 페롭스카이트형 광물인 토소나이트(taustonite, $La_{1-x}$ //$K_{x}$ /$TiO_3$, x<0.4)가 주성분으로 나타났으며 토스나이트내에 12개의 산소를 배위하는 A자리 양이온은 자리점유율에 의해 $La^{3+}$ 와 $K^{+}$ /의 치환관계를 보여준다 공간군은 14/mcm, 단위포는 a=5.505(1)~5.510(1)$\AA$, c=7.793(1)~7.796(1)$\AA$ V=236.25~236.66 $\AA^3$ 범위의 값을 갖는다. 구조의 정밀도를 나타내는 R지수를 살펴보면 $R_{B}$ 값은 5.31~9.10 S(GofF)값은 0.86~1.24로 각각 계산되었다. 12배위를 하는 A자리 양이온인 란탄과 산소의 평균거리는 2.755$\AA$이고 6배위를 하는 B자리 양이온인 티타늄과 산소의 평균거리는 1.948 $\AA$의 결과를 얻었다. 합성된페롭스카이트형 광물의 층상구조가 알려져 있지 않아 시뮬레이션을 통해 구조모델을 결정하였으며 그결과 n=3인 R-38시료에서만 두 종류의 층상 페롭스카이트($La_2$$K_2$$Ti_3$$O_{10}$ ) 구조 (A-type: 14/mmm, a=3.8178 $\AA$, c=29.9189 $\AA$, V=436.04 $\AA^3$, B-type: 142 m, a =3.8376 $\AA$, c=28.023 $\AA$, V=412.6 $\AA^3$)가 존재함을 확인하였으나 다른 시료에서는 토소나이트, 금홍석 외에 새로운 합성광물로 제파이트의 존재를 확인하였다.

• Journal of the Society of Naval Architects of Korea
• /
• v.30 no.1
• /
• pp.134-144
• /
• 1993

Sandwich plate is consisted of equal two isotropic, thin, stiff and strong sheets of dense material separated symmetrically by an isotropic thick layer which may be much less stiff and strong. This study analyzed the dependency of the natural frequencies and mode shapes of sandwich plates on material properties, thicknesses of faces and cores, and various boundary conditions using Rayleigh-Ritz method. E-glass Woven Roving and another two kinds of materials were selected as a face, P.V.C. and another kinds of materials were selected as a core. Natural frequencies and mode shapes obtained by Rayleigh-Ritz method were compared with F.E.M. solutions using ADINA program.

• Journal of Korean Society of Forest Science
• /
• v.96 no.1
• /
• pp.40-47
• /
• 2007

The objectives of this study were to derive site index and stem volume prediction equation based on stem analysis data for Larix leptolepis in Jinan region. The function for site index was developed by algebraic difference equation method. Polymorphic site index family curves with base age of 40 were presented based on the Schumacher height equation. The best stem volume prediction equation was suggested as $V=0.00260+0.00000399D^2H$. The simultaneous F-test using this equation showed that the estimated tree stem volumes were not significantly different (${\alpha}=0.05$ level) from the observed stem volumes for model evaluation. Therefore, site index and volume prediction equations prepared in this study could provide an indication of site quality and basic information for making of yield table, and could be used for rational forest management of Larix leptolepis stands grown in Jinan region.

• Korean Journal of Ecology and Environment
• /
• v.39 no.4 s.118
• /
• pp.450-461
• /
• 2006

In this study, sorption kinetics of lead (Pb) and cadmium (Cd) onto coastal sediments were investigated at pH 5.5 using laboratory batch adsorbers. Four different models: one-site mass transfer model (OSMTM), pseudo-first-order kinetic model (PFOKM) ,pseudo-second-order kinetic model (PSOKM) and two compartment first-order kinetic model (TCFOKM) were used to analyze the sorption kinetics. As expected from the number of model parameters involved, the three-parameter TCFOKM was better than the two-parameter OSMTM, PFOKM and PSOKM in describing sorption kinetics of Pb and Cd onto sediments. Most sorption of Pb and Cd was rapidly completed within the first three hours, followed by slow sorption in the subsequent period of sorption. All models predicted that the sorbed amount at the apparent sorption ($q_{e,s}$) equilibria increased as the CEC and surface area of the sediments increased, regardless of initial spiking concentration ($C_0$) and heavy metal and the sediment type. The sorption rate constant ($k_s,\;hr^{-1}$) in OSMTM also increased as the CEC and BET surface area increased. The rate constant of pseudo-first-order sorption ($k_{p1,s},\;hr^{-1}$) in PFOKM were not correlated with sediment characteristics. The results of PSOKM analysis showed that the rate constant of pseudo-second-order sorption ($k_{p2,s},\;g\;mmol^{-1}\;hr^{-1}$) and the initial sorption rate ($v_{o,s},\;mg\;g^{-1}\;hr^{-1}$) were not correlated with sediment characteristics. The fast sorption fraction ($f_{1,s}$) in TCFOKM increased as CEC and BET surface increased regardless of initial aqueous phase concentrations. The sorption rate constant of fast fraction ($k_{1,s}=10^{0.1}-10^{1.0}\;hr^{-1}$) was much greater than that of slow sorption fraction ($k_{2,s}=10^{-2}-10^{-4}\;hr^{-1}$) respectively.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.11 no.1 s.53
• /
• pp.67-77
• /
• 2007

Site coefficients in IBC and KBC codes have some limits to predict the rational seismic responses of a structure, because they take into account only the effect of the soil amplification without the effects of the structure-soil interaction. In this study, upper and lower limits of the site coefficients are estimated through the pseudo 3-D elastic seismic response analyses of structures built on the linear or nonlinear soil layers taking Into account the effects of the structure-soil interaction. Soil characteristics of site classes of A, B and C were assumed to be linear, and those of site classes of D and E were done to be nonlinear and the Ramberg-Osgood model was used to evaluate shear modulus and damping ratio of a soil layer depending on the shear wave velocity of the soil layer, Seismic analyses were performed with 12 weak or moderate earthquake records scaled the peak acceleration to 0.1g or 0.2g and deconvoluted as earthquake records at the bedrock located at 30m deep under the outcrop. With the study results of the elastic seismic response analyses of structures, new standard response spectrum and upper and lower limits of the site coefficients of $F_{a}\;and\;F_{v}$ at the short period range and the period of 1 second are suggested including the effects of the structure-soil interaction, and new site coefficients for the KBC code are also suggested.