• Journal of Magnetics
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• v.12 no.4
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• pp.152-155
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• 2007

Spin dependent transport was investigated in lateral $Py(Ni_{81}Fe_{19})/Au/Py$ spin valve devices. Clear spin valve effect was observed in conventional four-terminal measurement geometry. Higher resistance was found in antiparallel magnetization field of two Py electrodes which is determined by anisotropy magnetoresistance (AMR) measurements. The rectangular shape of spin signal together with good agreement of switching field convinces observed spin valve signal is resulted from effective spin injection and detection. The magnetoresistance ratio decays exponentially with channel length by which spin diffusion length of Au channel was estimated to be 76 nm.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2001.05a
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• pp.29-34
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• 2001

The purpose of this study is to provide a practical planning guide for the actual conditions and the preference by user characteristics in one-room housing. The data collected through questionnaire surveys from the residents of one-room housing in kangnam & sinchon. 259 samples we collected and are analyzed by using SPSS-PC. The results are follows : 1) Students: Students prefer monthly rent, down town, of officetel type, 8-l0py room size, and semi-furnished 2)Business men: They prefer multi function housing mixed office and residence, down town, officetel type, 11-l5py, and fully furnished housing. 3)Newly marriged couples: Ordinary habitation site, apt type, 16-l8py ,and 5: 5 division of space(bedroom:others) 4) Old age: normal habitation site, residence-commerce complex building type, middle corridor type, and 11-l5py. 5)Couple+child: lease of deposit basis, apt complex site, and 16-l8py.

• Convergence Security Journal
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• v.22 no.4
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• pp.129-133
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• 2022

Deep learning frameworks are still evolving, and there are various frameworks. Typical deep learning frameworks include TensorFlow, PyTorch, and Keras. The Deepram framework utilizes optimization models in image classification through image learning. In this paper, we use the TensorFlow and PyTorch frameworks, which are most widely used in the deep learning image recognition field, to proceed with image learning, and compare and analyze the results derived in this process to know the optimized framework. was made.

• Journal of the Korean Chemical Society
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• v.33 no.3
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• pp.295-303
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• 1989

Tetradentate Schiff base cobalt(II) complex; Co(SND) and Co(SOPD) were synthesized, and these complexes were allowed to react with dry oxygen to form oxygen adducts cobalt(III) complexes such as $[Co(SND)(Py)]_2O_2$ and $[Co(SOPD)(Py)]_2O_2$ in pyridine. These complexes have been identified by IR specta, T.G.A., magnetic susceptibilities measurements and elemental analysis. It has been found that the oxygen adducts coblat(III) complexes have hexacoordinated octahedral configuration with tetradentate Schiff base cobalt(II), pyridine and oxygen, and the mole ratio of oxygen to cobalt(II) complexes are 1;2. The redox reaction processes of $Co(SND)(Py)_2$ and $Co(SOPD)(Py)_2$ complexes were investigated by cyclic voltammetry with glassy carbon electrode in 0.1M TEAP pyridine. The result of redox reaction processes of Co(III)/Co(II) and Co(II)/Co(I) for $Co(SND)(Py)_2$ and $Co(SOPD)(Py)_2$ complexes are reversible or quasi reversible process but oxygen adducts complexes are irreversible processes. Redox process for oxygen of oxygen adducts complexes was quasi reversible and redox range of potential was $E_{pc}\;=\;-0.96{\sim}-1.03V$ and $E_{pa}\;=\;-0.78{\sim}-0.80V.$

• Textile Coloration and Finishing
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• v.28 no.2
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• pp.92-100
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• 2016

To chemically prepare polypyrrole(pPy) coated fabrics(silk, cotton and nylon fabrics), the fabrics were first soaked in 0.4M oxidant $FeCl_3$/0.06M dopant anthraquinone-2-sulfonic acid solution for 5min at room temperature, and subsequently soaked in a 0.4M monomer pyrrole aqueous solution for 5min at room temperature. The content(wt%) of coated pPy in the coated fabrics was controlled by the number of treatments(these two steps). This study examined the effect of the number of treatments/pPy content on the sheet resistance, mechanical/bending properties and color behaviors of pPy coated fabrics. The coated pPy content, sheet resistance(${\Omega}$/square) and color strength(K/S) of pPy coated fabrics increased sharply with increasing number of treatments up to 20 times, while the increase slowed down afterward. The tensile strength, elongation at break and lightness($L^*$) decreased with increasing number of treatments. The tensile modulus and bending rigidity of coated fabrics increased significantly with increasing number of treatments/coated pPy content. This indicated that the flexibility of coated fabrics decreased considerably.

• Journal of Korean Society for Atmospheric Environment
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• v.6 no.1
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• pp.22-30
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• 1990

The contents of benzo(a)pyrene (Bap.), Pyrene(Py) and Perylene(Pery) were determined by one-dimensional dual band thinlayer chromatogragphy and spectrofluorophotometer in soil samples from road at 36 places of Ulsan and 6 places of Seoul from April to May, 1984. The concents were as follows: 1. Ulsan city : Bap. 0.05-3.66 $\mu$g/g ; mean 1.07 $\mu$g/g Py. 0.60-11.01 $\mu$g/g ; mean 4.34 $\mu$g/g Pery. 0.94-5.48 $\mu$g/g ; mean 1.83 $\mu$g/g 1) Industrial area : Bap. 0.03-3.66 $\mu$g/g ; mean 5.28 $\mu$g/g Py. 2.34-9.07 $\mu$g/g ; mean 5.28 $\mu$g/g Pery. 1.01-3.69 $\mu$g/g ; mean 2.09 $\mu$g/g 2) Commercial area : Bap. 0.15-2.27 $\mu$g/g ; mean 0.29 $\mu$g/g Py. 0.06-11.0 $\mu$g/g ; mean 4.04 $\mu$g/g Pery. 1.03-5.48 $\mu$g/g ; mean 1.84 $\mu$g/g 3) Residential area : Bap. 0.05-0.05 $\mu$g/g ; mean 0.29 $\mu$g/g Py. 1.34-5.53 $\mu$g/g ; mean 2.74 $\mu$g/g Pery. 0.94-2.15 $\mu$g/g ; mean 1.18 $\mu$g/g 2. Commerical area in Seoul : Bap. 0.35-1.01 $\mu$g/g ; mean 0.74 $\mu$g/g Py. 9.37-24,44 $\mu$g/g ; mean 18.64 $\mu$g/g Peay. 1.47-2.24 $\mu$g/g ; mean 1.87 $\mu$g/g 3. The areas that had high contents of Benzo(a)pyrene had also high contents of Pyrene and Perylene. 4. The industrial area had the highest contents of polynuclear aromatic hydrocarbons, followed by commercial area and residential area. 5. The contents of Bap. and Pery. in the commercial area were similar in Seoul and Ulsan, while the content of Py. in Seoul was 4 times higher than in Ulsan.

• Clean Technology
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• v.18 no.3
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• pp.280-286
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• 2012

The dry etching of sacrificial $SiO_2$ was performed in supercritical carbon dioxide. The etching of boron phosphor silica glass (BPSG), tetraethyl orthosilicate (TEOS), thermal $SiO_2$, and Si-nitride (SiN) was investigated by using a two chamber system with HF/py etchant and alcohol additives. The etch rate of sacrificial $SiO_2$ increased upon the addition of methanol. The etch selectivity of BPSG with respect to SiN was highest with IPA although the highest etch rate was resulted from methanol except BPSG. The etch rate increased with the temperature in HF/py/MeOH system. Especially the increase of the etch rate was much higher for BPSG with an increase in the reaction temperature. The etch residue was not reduced apparently upon the addition of alcohol cosolvents to HF/py. While the etch rate in HF/$H_2O$ was higher than HF/py/alcohol system, the rate decreased with the addition of alcohols to HF/$H_2O$. The cantilever beam structure of high aspect ratios was released by the dry ething in supercritical carbon dioxide without damage.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.643-659
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• 2022

Geologic sequestration technologies such as CCS (carbon capture and storage), EGS (enhanced geothermal systems), and EOR (enhanced oil recovery) have been widely implemented in recent years, prompting evaluation of the mechanical stability of storage sites. As fluid injection can stimulate mechanical instability in storage layers by perturbing the stress state and pore pressure, poroelastic models considering various injection scenarios are required. In this study, we calculate the pore pressure, stress distribution, and vertical displacement along a surface using commercial finite element software (COMSOL); fault slips are subsequently simulated using PyLith, an open-source finite element software. The displacement fields, are obtained from PyLith is transferred back to COMSOL to determine changes in coseismic stresses and surface displacements. Our sequential use of COMSOL-PyLith-COMSOL for poroelastic modeling of fluid-injection and induced-earthquakes reveals large variations of pore pressure, vertical displacement, and Coulomb failure stress change during injection periods. On the other hand, the residual stress diffuses into the remote field after injection stops. This flow pattern suggests the necessity of numerical modeling and long-term monitoring, even after injection has stopped. We found that the time at which the Coulomb failure stress reaches the critical point greatly varies with the hydraulic and poroelastic properties (e.g., permeability and Biot-Willis coefficient) of the fault and injection layer. We suggest that an understanding of the detailed physical properties of the surrounding layer is important in selecting the injection site. Our numerical results showing the surface displacement and deviatoric stress distribution with different amounts of fault slip highlight the need to test more variable fault slip scenarios.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.2
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• pp.289-298
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• 2011

TMAH-based Py-MS has been investigated to apply for a real-time classification of biological agents in the field. Acquiring reproducible data from mass spectrometry is a key to biological detection in the field. Nevertheless, it has been little studied on what factors could affect to the reproducibility of the TMAH-based Py-MS spectrum patterns. Given the TMAH-based Py-MS applied to the field system, several factors which could affect to the reproducible pattern of TMAH-based Py-MS spectra are needed to be examined, including changes in TMAH injection volume, growth temperature for microorganism, and number of cells collected in pyrolyzer, and implication of stabilizer used for lyophilization. This study showed that the reproducibility of the spectrum patterns was significantly hindered by changes in TMAH concentration and cell number, and stabilizer implication but not by growth temperature. Among those at low TMAH concentration(0.015m) was not observed the significant alterations of the spectrum pattern even when its injection volume was changed, yet was in different cell numbers and stabilizer implication.

• BMB Reports
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• v.37 no.4
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• pp.416-421
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• 2004

The antioxidant activities of NADH and of its analogue, 1,4-dihydro-2,6-dimethyl-3,5-dicarbethoxy-pyridine ($PyH_2$), were evaluated in vitro. NADH was found to be oxidized by the peroxyl radical derived from 2,2-azobis-(2-amidinopropane) dihydrochloride (AAPH) decomposition, in a pH-dependent manner. Both NADH and $PyH_2$ inhibited the peroxidation of egg yolk lecithin (EYL) liposomes, although $PyH_2$ was more effective than NADH when 2,2'-azobis-4-methoxy-2,4-dimethyl-valeronitrile (methoxy-AMVN) was employed to induce EYL liposome peroxidation. The antioxidant activities of NADH and $PyH_2$ were also evaluated by measuring their influences on 1,3-diphenylisobenzofuran (DPBF) fluorescence decay in the presence of peroxyl radicals. NADH and $PyH_2$ were much more effective at inhibiting DPBF quenching in Triton X-100 micelles than in liposomes. These results indicate that NADH can inhibit lipid peroxidation despite being hydrophilic. Nevertheless, membrane penetration is an important factor and limits its antioxidant activity.