• Korean Institute of Interior Design Journal
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• v.22 no.5
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• pp.68-77
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• 2013

'The Third space,' which is the concept that embraces sociological, spatial, and marketing concepts, refers to the place which is other than the home and the workplace and which is a comfortable frequented place where meditation, psychological relaxation, and social needs can be satisfied. 'The Third space' has the characteristics of comfort, openness, interactivity, playfulness, and diversity. In modern times, most of consumption spaces play the role of 'the Third space,' and the typical example is $Caf{\acute{e}}$. $Caf{\acute{e}}$ began from its origin with the characteristics of 'the Third space,' and recently it has become the complex cultural space of urban dwellers. $Caf{\acute{e}}$ as 'the Third space' has the characteristics of a healing space, communication space, personalized space, value-expressive space, culture and consumption space, nomad space. Such characteristics of $Caf{\acute{e}}$ are well represented in the cafes around the regions where 'street culture' has recently been formed. As examined through the examples, $Caf{\acute{e}}$ as 'the Third space' can be more strategically produced by establishing themes through storytelling, giving spatial identity through style creation, diversifying the sequence through complex space organization, and establishing interaction devices through experience elements.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.05a
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• pp.38-40
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• 1988

This paper was a study on dielectic characteristics of polypropylen film which were annealled in air and qunched in nitorgen after aging for 5[Hr]. Dielectric characteristics of specimen were measured in temperature of the range of 15-120[$^{\circ}C$], and in frequency of the range of $30-1{\times}10^6$[Hz.] As the result, for dielectric relaxation $\beta$-peak was observed in 20[$^{\circ}C$], and $\alpha$-peak was observed in 90[$^{\circ}C$]. Also, it was explained that $\alpha$-peak attributed due to armorphous region and $\beta$-peak attributed due to crystalline region and activation energy from dielectric loss spectra was obtained 34.5[kcal/mole] for $\alpha$-peak and 80.5[Kcal/mole] for $\beta$-peak, respectively.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.66-72
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• 1995

Using the Si/SiGe layer grown by solid source molecular beam epitaxy(SSMBE) on the LOCOS-patterned wafers, an emitter-base self-aligned hterojunction biplar transistor(HBT) with the polysilicon-emitter and the silicon germanium(SiGe) base has been fabricated. Trech isolation process, planarization process using a chemical-mechanical poliching, and the selectively implanted collector(SIC) process were performed. A titanium disilicide (TiSi$_{2}$), as a base electrode, was used to reduce an extrinsic base resistance. To prevent the strain relaxation of the SiGe epitaxial layer, low temperature (820${^\circ}C$) annealing process was applied for the emitter-base junction formation and the dopant activation in the arsenic-implanted polysilicon. For the self-aligned Si/SiGe HBT of 0.9${\times}3.8{\mu}m^{2}$ emitter size, a cut-off requency (f$_{T}$) of 17GHz, a maximum oscillation frequency (f$_{max}$) of 10GHz, a current gian (h$_{FE}$) of 140, and an emitter-collector breakdown voltage (BV$_{CEO}$) of 3.2V have been typically achieved.

• Bulletin of the Korean Chemical Society
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• v.29 no.4
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• pp.811-816
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• 2008

2,5-Di-(2'-hydroxyethoxy)benzylidenemalononitrile (3) was prepared and polymerized with 2,4-toluenediisocyanate and 3,3'-dimethoxy-4,4'-biphenylenediisocyanate to yield novel T-type polyurethanes 4 and 5 containing 2,5-dioxybenzylidenemalononitrile, nonlinear optical (NLO)-chromophores as part of the polymer backbones. Polyurethanes 4 and 5 were soluble in common organic solvents such as acetone and N,Ndimethylformamide and showed a thermal stability up to $250{^{\circ}C}$ with glass-transition temperatures ($T_g$) in the range $119-146{^{\circ}C}$. The second harmonic generation (SHG) coefficients ($d_{33}$) of poled polymer films at 1064 nm fundamental wavelength were around $5.82{\times}10^{-9}$ esu. The dipole alignment exhibited high thermal stability up to $T_g$, and there was no SHG decay below $140{^{\circ}C}$ due to the partial main-chain character of the polymer structure, which was acceptable for nonlinear optical device applications.

• Journal of the Korean Chemical Society
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• v.38 no.9
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• pp.628-631
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• 1994

We have studied the paramagnetic $CuF_2$ using the techniques of pulsed nuclear magnetic resonance (NMR). The powder sample revealed two well-separated lines from the distinct $^{19}F$ sites at room temperature. One of the lines showed little frequency shift. However, the other showed a large frequency shift, suggesting electron transfers. Furthermore, the two sites have very short spin-lattice relaxation times $(T_1).$ The frequency-shifted site has the shorter $T_1$ than the unshifted one, reflecting the difference of the electron environments of the two sites.

• Journal of the Korean Magnetics Society
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• v.22 no.3
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• pp.73-78
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• 2012

We calculated the electron spin resonance (ESR) line-profile function. The line-width of single-walled carbon nanotube (SWNT) was studied as a function of the temperature at a frequency of 9.5 GHz in the presence of external electromagnetic radiation. The temperature dependence of the line-widths is obtained with the projection operator method (POM) proposed by Argyres and Sigel. The scattering is little affected in the low-temperature region (T < 200 K). We conclude that the calculation process presented in this method is useful for optical transitions in SWNT.

• Current Photovoltaic Research
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• v.1 no.1
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• pp.27-32
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• 2013

We investigated the growth mechanism of amorphous-phase Si thin films in order to improve the film characteristics and circumvent photo-degradation effects by implementation of hot-wire chemical vapor deposition. Amorphous silicon thin films grown in a silane/hydrogen mixture can be decomposed by a resistive heat filament. The structural properties were observed by Raman spectroscopy, FTIR, SEM, and TEM. The electrical properties of the films were measured by photo-conductivity, dark-conductivity, and photo-sensitivity. The contents of Si-H and $Si-H_n$ bonds were measured to be 19.79 and 9.96% respectively, at a hydrogen flow rate of 5.5 sccm, respectively. The thin film has photo-sensitivity of $2.2{\times}10^5$ without a crystalline volume fraction. The catalyst behavior of the hot-wire to decompose the chemical precursors by an electron tunneling effect depends strongly on the hydrogen mixture rate and an amorphous Si thin film is formed from atomic relaxation.

• Journal of the Korean Magnetics Society
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• v.5 no.3
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• pp.171-174
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• 1995

We have studied the paramagnetic $CuF_{2}$ using the techniques of pulsed nuclear magnetic resonance(NMR). The powder sample revealed two well-separated lines from the distinct $^{19}F$ sites at room temperature and at 77 K. The distinct frequency shifts of the two lines appear to arise from electron transfers. Furthermore, the two sites have very short spin-lattice relaxation times ($T_{1}$). The frequency-shifted site has the shorter $T_{1}$ than the unshifted one, reflecting the difference of the electron environments of the two sites.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.99-106
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• 2013

Polyaniline-yttrium trioxide (PAni-$Y_2O_3$) composites were synthesized by the in-situ polymerization of aniline in the presence of $Y_2O_3$ The composite formation and structural changes in these composites were investigated by X-ray diffraction (XRD), Fourier transform infra red spectroscopy (FTIR), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The direct current (DC) electrical conductivity of the order of $0.51{\times}10^{-2}\;S\;cm^{-1}-0.283\;S\;cm^{-1}$ in the temperature range 300 K-473 K indicates semiconducting behavior of the composites. Room temperature AC conductivity and dielectric response of the composites were studied in the frequency range of 10 Hz to 1 MHz. The variation of AC conductivity with frequency obeyed the power law, which decreased with increasing weight percentage (wt %) of $Y_2O_3$. Studies on dielectric properties shows the relaxation contribution coupled by electrode polarization effect. The dielectric constant and dielectric loss in these composites depend on the content of $Y_2O_3$ with a percolation threshold at 20 wt % of $Y_2O_3$ in PAni. Electromagnetic interference shielding effectiveness (EMI SE) of the composites in the frequency range 100 Hz to 2 GHz was in the practically useful range of -12.2 dB to -17.2 dB. The observed electrical and shielding properties were attributed to the interaction of $Y_2O_3$ particles with the PAni molecular chains.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.217-220
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• 2016

Phytoestrogens are one of quasi-estrogens which are not generated within the endocrine system, but consumed by intaking phytoestrogenic plants. Phytoestrogens, also called as "dietary estrogens", are various botanic chemical compound groups naturally occurring nonsteroidal plant compounds of spontaneous generation. Due to their structural similarities to estrogone, they may provide desirable health benefits for reducing the menopausal symptoms. In this paper, various phytoestrogens were extracted from sophora root, pomegranate and kudzu by ultrasonic extraction process. In this study, the amount of extracted phytoestrogens at various ultrasonic power strengths and extraction times were compared, which could be used as basic data in the study of biology and chemistry related to natural products.