• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.291-299
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• 2021

In 2019, SUV sales surpassed sedans in the domestic sales market with phenomenal domestic sales. The strength of SUVs around the world is expected to continue in the future. South Korea's K-company aggressively launched small SUVs in the SUV market. Its simple lineup is recognized as a brand image, not as a SUV. It is time to evaluate this. Therefore, it influences the purchasing decisions of potential customers and buyers of small SUVs through the evaluation of design images of small SUVs in Korea. Rather than the functional properties of the SUV model, it is purchased by emotional characteristics, brand symbolism, and image. Subconsciousness of the purchasing psychology of the end consumer was used by metaphor extraction techniques. Customers wanted to study the evaluation of small SUV design images that fit their needs. We wanted to see if consumers who intend to purchase or purchase small SUVs in Korea had a connection with the image of design of small SUVs in Korea. The conclusion of the study was extracted through ZMET, a metaphor extraction technique, with the latent consciousness of the primary ambiguous message from the consumer's feeling and representation of the image. Therefore, based on the results of this study, we hope that the images presented in SUVs in the future will be used as a design guide in the development of small SUVs to influence customer thinking and behavior.

• Journal of Korea Foundry Society
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• v.41 no.3
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• pp.235-240
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• 2021

We present the effect of the critical cooling rate during rapid solidification on the nucleation of precipitates in an Fe₇₅B₁₃P₅Nb₂Hf₁C₄ (at.%) alloy. The thermophysical properties of the rapidly solidified Fe₇₅B₁₃P₅Nb₂Hf₁C₄ liquids, which were obtained at various cooling rates with various sizes of gas-atomized powder during a high-pressure inert gas-atomization process, were evaluated. The cooling rate of the small-particle powder (≤20 ㎛) was 8.4×10⁵ K/s, which was 13.5 times faster than that of the large-particle powder (20 to 45 mm; 6.2×10⁴ K/s) under an atomized temperature. A thermodynamic calculation model used to predict the nucleation of the precipitates was confirmed by the microstructural observation of MC-type carbide in the Fe₇₅B₁₃P₅Nb₂Hf₁C₄ alloy. The primary carbide phase was only formed in the large-particle gas-atomized powder obtained during solidification at a slow cooling rate compared to that of the small-particle powder.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1308-1314
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• 2018

$Er^{3+}$ and $Yb^{3+}$ co-doped $Y_3Ga_5O_{12}$ polycrystalline powders were prepared by using a solid-state reaction method, and their crystallinities were measured using X-ray diffraction. According to the results of X-ray diffraction, the powders showed a polycrystalline tetragonal structure. The photoluminescence and the upconversion luminescence properties of the $(Y_{0.85-x}Yb_{0.15})_3Ga_5O_{12}:Er^{3+}_x$ (x = 0.03, 0.06, 0.09, 0.12 and 0.15) phosphors were investigated in detail. Green and red upconversion emissions were observed for the phosphors excited by 980 nm radiation from a semiconductor laser. The powders exhibited strong green and weak red upconversion emission peaks at 553 and 660 nm, respectively. Also, their upconversion processes were explained using an energy-diagram analysis and the strongest upconversion intensity was emitted by the powder with a 0.12 mol $Er^{3+}$ ion concentration.

• Korean Journal of Metals and Materials
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• v.47 no.3
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• pp.147-154
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• 2009

The effect of carbon addition on the microstructures and mechanical properties of $Ni_3Al$ and TiAl intermetallic alloys have been characterized. It is shown that carbon is not only an efficient solid solution strengthener in $Ni_3Al$ and TiAl, it is also an efficient precipitation strengthener by fine dispersion of carbide. Transmission electron microscope investigation has been performed on the particle-dislocation interactions in $Ni_3Al$ and TiAl intermetallics containing various types of fine precipitates. In an $L1_2$-ordered $Ni_3Al$ alloy with 4 mol.% of chromium and 0.2~3.0 mol.% of carbon, fine octahedral precipitates of $M_{23}C_6$ type carbide, which has the cube-cube orientation relationship with the matrix, appear during aging. Typical Orowan loops are formed in $Ni_3Al$ containing fine dispersions of $M_{23}C_6$ particles. In the L10-ordered TiAl containing 0.1~2.0 mol.% carbon, TEM observations revealed that needle-like precipitates, which lie only in one direction parallel to the [001] axis of the $L1_0$ matrix, appear in the matrix and preferentially at dislocations. Selected area electron diffraction (SAED) patterns analyses have shown that the needle-shaped precipitate is $Ti_3AlC$ of perovskite type. The orientation relationship between the $Ti_3AlC$ and the $L1_0$ matrix is found to be $(001)_{Ti3AlC}//(001)_{L10\;matrix}$ and $[010]_{Ti3AlC}//[010]_{L10\;matrix}$. By aging at higher temperatures or for longer period at 1073 K, plate-like precipitates of $Ti_2AlC$ with a hexagonal structure are formed on the {111} planes of the $L1_0$ matrix. The orientation relationship between the $(0001)_{Ti2AlC}//(111)_{L10\;matrix}$ is and $[1120]_{Ti2AlC}//[101]_{L10\;matrix}$. High temperature strength of TiAl increases appreciably by the precipitation of fine carbide. Dislocations bypass the carbide needles at further higher temperatures.

• Journal of Life Science
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• v.31 no.5
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• pp.496-501
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• 2021

In this study, the marine agar-degrading bacterium Pseudoalteromonas sp. JH-1 was isolated, and its growth and agarase properties were investigated. Seawater was collected from the offshore of the Yonggung Temple in Busan, and agar-degrading bacteria were isolated and cultured with marine agar medium. The bacterium Pseudoalteromonas sp. JH-1 was isolated through 16S rRNA gene sequencing. The extracellularly secreted enzyme was obtained from the culture broth of Pseudoalteromonas sp. JH-1 and was used to characterize its agarase. The extracellular agarase exhibited a maximum activity of 116.6 U/l at 50℃ and pH 6.0 of 20 mM Tris-HCl buffer. Relative activities were 31, 59, 94, 100, 45, and 31% at 20, 30, 40, 50, 60, and 70℃, respectively. Relative activities were 49, 85, 100, 86, 81, and 67% at pH 4, 5, 6, 7, 8, and 9, respectively. Residual activity was more than 85% after exposure at 20, 30, and 40℃ for 2 hr, and more than 82% after exposure at 50℃ for 2 hr. Zymogram analysis confirmed that Pseudoalteromonas sp. JH-1 produced at least two agarases of 55 and 97 kDa. As the products of α-agarase and β-agarase have antioxidation, antitumor, skin-whitening, macrophage activation, and prebiotic effects, further studies are needed on the agarase of Pseudoalteromonas sp. JH-1.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.870-882
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• 2021

Coptis chinensis has been used in the treatment of various diseases such as soothing, anti-inflammation, antimicrobial and antipyretic in oriental traditional medicine. In this study, we investigated the effect of hot water extract of Coptis chinensis(CCW) on skin barrier and inflammation-related factors in UVB and TNF-α/IFN-γ-induced HaCaT cells and evaluated its potential as a moisturizing and anti-inflammatory material. Based on result, the amount of HA (Hyaluronic acid) production and protein and mRNA expression of filaggrin were measured. In TNF-α/IFN-γ-induced HaCaT cells, CCW increased the amount of HA production in a concentration-dependent manner. In the measurement of protein and mRNA expression of filaggrin, the expression rate increased as the concentration of CCW increased. In UVB-induced HaCaT cells, CCW decreased the production of ROS and showed significant results with EGCG ((-)-epigallocatechin-3-gallate), a positive control. In addition, CCW inhibited the expression of inflammatory cytokines TNF-α, IL-1β, IL-6, and IL-8 in TNF-α/IFN-γ-induced HaCaT cells. It was confirmed that the protein and mRNA expression of COX-2, a major factor in skin inflammation, was decreased in a concentration-dependent manner. These results suggest that hot water extract from Coptis chinensis can be used as a cosmetic material having a moisturizing and anti-inflammatory effect.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.1
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• pp.55-60
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• 2021

In order to produce wearable displays with high adhesion while maintaining flexible characteristics, the adhesive method using electro plating method was carried out. Laser lift-off (LLO) transcription was also used to remove sapphire substrates from LEDs bonded to fibers. Afterwards, the SEM and EDS data of the sample, which conducted the adhesion method using electro plating, confirmed that copper actually grows through the lattice of the fiber fabric to secure the light source and fiber. The adhesion characteristics of copper were checked using Universal testing machine (UTM). After plating adhesion, the characteristics of the LLO transcription process completed and the LED without the transcription process were compared using probe station. The electroluminescence (EL) according to the enhanced current was measured to check the characteristics of the light source after the process. As the current increases, the temperature rises and the bandgap decreases, so it was confirmed that the spectrum shifted. In addition, the change in the electrical characteristics of the samples according to the radius change is confirmed using probe station. The radius strain also had mechanical strength that copper could withstand bending stress, so the Vf variation was measured below 6%. Based on these results, it is expected that it will be applied to batteries, catalysts, and solar cells that require flexibility as well as wearable displays, contributing to the development of wearable devices.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.1-6
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• 2022

As the demand for wearable devices increases, many studies have been studied on the development of flexible electrode materials recently. In particular, the development of high-performance flexible electrode materials is very important for wearable sensors for healthcare because it is necessary to continuously monitor and accurately detect body information such as body temperature, heart rate, blood glucose, and oxygen concentration in real time. In this study, we fabricated the nonenzymatic glucose sensor based on polyaniline/carbon nanotube fiber (PANI/CNT fiber) electrode. PANI layer was synthesized on the flexible CNT fiber electrode through electrochemical polymerization process in order to improve the performance of a flexible CNT fiber based electrode material. Surface morphology of the PANI/CNT fiber electrode was observed by scanning electron microscopy. And its electrochemical characteristics were investigated by chronoamperometry, cyclic voltammetry, electrochemical impedance spectroscopy. Compared to bare CNT fiber electrode, this PANI/CNT fiber electrode exhibited small electron transfer resistance, low peak separation potential and large surface area, resulting in enhanced sensing properties for glucose such as wide linear range (0.024~0.39 and 1.56~50 mM), high sensitivity (52.91 and 2.24 ㎂/mM·cm²), low detection limit (2 μM) and good selectivity. Therefore, it is expected that it will be possible to develop high performance CNT fiber based flexible electrode materials using various nanomaterials.

• The Journal of the Acoustical Society of Korea
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• v.41 no.4
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• pp.426-434
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• 2022

Bubbles generated by various causes in the ocean are known to persist for long periods of time. Although the volume occupied by bubbles in the ocean is small, the presence of bubbles in ocean due to resonance and attenuation greatly affects the acoustic properties. Accordingly, bistatic reverberation experiment was performed in the ocean where artificial bubbles exist. A number of transducers and receivers were installed on 6 buoys arranged in a hexagonal shape, and blowing agents were dropped in the center of the buoy to generate bubbles. For reverberation modeling that reflects acoustic characteristics changed by bubbles, the spatial distribution of bubbles was estimated using video data and received signals. A measurement-based bubble spectral shape was used, and it was assumed that the bubble density within the spatial distribution of the estimated bubble was the same. As a result, it was confirmed that the bubble reverberation was simulated in a time similar to the measured data regardless of the bubble density, and the bubble reverberation level similar to the measured data was simulated at a void fraction of about 10^-7 ~ 10^-6.8.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.143-148
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• 2022

The subject of this paper is the practical examples of technoculture that critically thinks network technology, a strong material foundation in the era of data capitalism in the 21st century, and appropriates its socio-cultural metaphor as an artistic potential. In order to analyze its alternatives and the meaning of cultural politics, this paper examines the properties and influence of data capitalism after the 2008 global financial crisis, and the cultural and artistic context formed by its reaction. The first case considered in this paper, Furtherfield's workshop, provided a useful example of how citizens can participate in social change through learning and education in which art and technology are interrelated. The second case, Greek hackerspace HSGR, developed network technology as a tool to overcome the crisis by proposing a new progressive cultural commons due to Greece's financial crisis caused by the global financial crisis and a decrease in the state's creative support. The third case, Paolo Cirio's project, promoted a critical citizenship towards the state and community systems as dominant types of social governance. These technoculture cases can be evaluated as efforts to combine and rediscover progressive political ideology and its artistic realization tradition in the context of cultural politics, paying attention to the possibility of signifying practices of network technology that dominates the contemporary economic system.