• Journal of Sensor Science and Technology
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• v.30 no.4
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• pp.250-254
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• 2021

A highly sensitive and selective non-dispersive infrared (NDIR) carbon dioxide gas sensor requires achieving high transmittance and narrow full width at half maximum (FWHM), which depends on the interface of the optical filter for precise measurement of carbon dioxide concentration. This paper presents the design, simulation, and fabrication of a Fabry-Perot filter based on a distributed Bragg reflector (DBR) for a low-cost NDIR carbon dioxide sensor. The Fabry-Perot filter consists of upper and lower DBR pairs, which comprise multilayered stacks of alternating high- and low-index thin films, and a cavity layer for the resonance of incident light. As the number of DBR pairs inside the reflector increases, the FWHM of the transmitted light becomes narrower, but the transmittance of light decreases substantially. Therefore, it is essential to analyze the relationship between the FWHM and transmittance according to the number of DBR pairs. The DBR is made of silicon and silicon dioxide by RF magnetron sputtering on a glass wafer. After the optimal conditions based on simulation results were realized, the DBR exhibited a light transmittance of 38.5% at 4.26 ㎛ and an FWHM of 158 nm. The improved results substantiate the advantages of the low-cost and minimized process compared to expensive commercial filters.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.173-173
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• 2000

Multilayered films (MLF) consisting of transition metals and semiconductors have drawn a great deal of interest because of their unique properties and potential technological applications. Fe/Si MLF are a particular topic of research due to their interesting antiferromagnetic coupling behavior. although a number of experimental works have been done to understand the mechanism of the interlayer coupling in this system, the results are controversial and it is not yet well understood how the formation of an iron silicide in the spacer layers affects the coupling. The interpretation of the coupling data had been hampered by the lack of knowledge about the intermixed iron silicide layer which has been variously hypothesized to be a metallic compound in the B2 structure or a semiconductor in the more complex B20 structure. It is well known that both magneto-optical (MO0 and optical properties of a metal depend strongly on their electronic structure that is also correlated with the atomic and chemical ordering. In order to understand the structure and physical properties of the interfacial regions, Fe/Si multilayers with very thin sublayers were investigated by the MO and optical spectroscopies. The Fe/si MLF were prepared by rf-sputtering onto glass substrates at room temperature with a totall thickness of about 100nm. The thicknesses of Fe and Si sublayers were varied from 0.3 to 0.8 nm. In order to understand the fully intermixed state, the MLF were also annealed at various temperatures. The structure and magnetic properties of Fe/Si MLF were investigated by x-ray diffraction and vibrating sample magnertometer, respectively. The MO and optical properties were measured at toom temperature in the 1.0-4.7 eV energy range. The results were analyzed in connection with the MO and optical properties of bulk and thin-film silicides with various structures and stoichiometries.

• Journal of the Korean Society of Costume
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• v.51 no.2
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• pp.149-167
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• 2001

Today, every culture has taken on the compromise form by means of the cultural difference, variety, and pluralism according to the internationalization and the advance so that it has been developed toward the half-blooded and multilayered the aspect. In accordance with this current of the times, this thesis observed the feminism found in the multiculturism of the end of the 20th century, the third world, and technology with the side of the tendency of modern fashion, considered the hybride phenomenon which is pulling down the wall between culture and genre due to the social diversification. and predicted the fashion trend do 21st century serf on it. Multiculturism is the movement that began to arise in the academic world of America and the literary world form the close of 1980's in accepting the variety of culture and regarding the culture with the more balanced and wide view and just as it is, it means the attitude of accepting one or more cultures of variely and the position of taking interest in the culture of minority race not the culture of a governing race. It is the fashion of feminism adapts dualism like unisex, androgynous look, etc of bisexual lendency in the 1980's, it shows new style with crossover of liberal sense because there is not the difference of sex in fashion. The eco-feminism pursues the natural sexuality not being instrumental and dismantling and expressed it in the Gender expression of an integrated human being. The trend of ethnic fashion in the close of 20th century is that the element of hippie is working so strongly. By adding embroidery of Oriental style, accessories of Indian style, feathers, beads, a hempen hood to the ethnic costumes of Asia and Latin, is shows the figure of ethnic hippie. As the cycler fashion is the future clothes through technology of computer, it uses a cool glass material bringing up the image of a spacesuit in order to expresses cyber image through artificial color combination of sheen colors, Though this techno-color fashion has established the fresh stimulation and the innovative aspect with ultramodern materials and image of futurism, it transmits a hope of estranged people and the natural elements. Hybride means a cross and mixture of animal and plant in Korean and is also called fusion. The phenomenon of hybrid predicts to comes the period of a cross and variation because something completely new comes into the world by contamination, mixture and compromise through meeting something different each other and it has on advantage of developing something existing to one more stage. It is prospected that in the society of 21st century, the borderline of traditional gender will be disappeared, variety and individuality will determine the individual behavior, and the masculine value will be substituted by feminine value. In the society giving priority to feminine value, a fashion stuck closely to women is what must reflect lives of woman under the proposition of woman's beauty, being on original function. So, it is considered that a fashion with added convenience and practicality having the function which is easy to put on, comfortable to act, able to express solves so much, and able to show various appearances according to T.P.O will get into the spotlight.