• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.334-334
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• 2013

In the past decade, the infrared detectors based on intersubband transition in quantum dots (QDs) have attracted much attention due to lower dark currents and increased lifetimes, which are in turn due a three-dimensional confinement and a reduction of scattering, respectively. In parallel, focal plane array development for infrared imaging has proceeded from the first to third generations (linear arrays, 2D arrays for staring systems, and large format with enhanced capabilities, respectively). For a step further towards the next generation of FPAs, it is envisioned that a two-dimensional metal hole array (2D-MHA) structures will improve the FPA structure by enhancing the coupling to photodetectors via local field engineering, and will enable wavelength filtering. In regard to the improved performance at certain wavelengths, it is worth pointing out the structural difference between previous 2D-MHA integrated front-illuminated single pixel devices and back-illuminated devices. Apart from the pixel linear dimension, it is a distinct difference that there is a metal cladding (composed of a number of metals for ohmic contact and the read-out integrated circuit hybridization) in the FPA between the heavily doped gallium arsenide used as the contact layer and the ROIC; on the contrary, the front-illuminated single pixel device consists of two heavily doped contact layers separated by the QD-absorber on a semi-infinite GaAs substrate. This paper is focused on analyzing the impact of a two dimensional metal hole array structure integrated to the back-illuminated quantum dots-in-a-well (DWELL) infrared photodetectors. The metal hole array consisting of subwavelength-circular holes penetrating gold layer (2DAu-CHA) provides the enhanced responsivity of DWELL infrared photodetector at certain wavelengths. The performance of 2D-Au-CHA is investigated by calculating the absorption of active layer in the DWELL structure using a finite integration technique. Simulation results show the enhanced electric fields (thereby increasing the absorption in the active layer) resulting from a surface plasmon, a guided mode, and Fabry-Perot resonances. Simulation method accomplished in this paper provides a generalized approach to optimize the design of any type of couplers integrated to infrared photodetectors.

• Journal of the Korean Wood Science and Technology
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• v.27 no.2
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• pp.15-22
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• 1999

Polymeric meterials that are used for noise and vibration damper in wood/polymer/wood sandwich composites, must have a high loss factor(tan ${\delta}$), and at the same time the storage modulus(E) of $5{\times}10^7$ to $10^9$ dyne/$cm^2$ must withstand over a wide temperature and frequency ranges. In this study, the series of epoxy resinlpolyacrylate interpenetrating polymer networks(IPNs) were synthesized by simultaneous polymerization. Their dynamic tensile properties were measured at 110Hz using Rheovibron instrument. Composite damping factor(tan ${\delta}_c$) and dynamic bending modulus($E_c,\;E_^{\prime\prime}c$) of wood/polymer/wood sandwich composites were measured at 110Hz using a Rheovibron in bending mode of vibration. These dynamic tensile studies indicated that cured epoxy resin/polyacrylates IPNs were semicompatible in the sense that both the shifting of T($E^{\prime\prime}_{max}$) or T(tan ${\delta}_{max}$) and the broadening of glass transition temperature range were observed. Especially, the cured Epikote871/P(n-BMA) IPNs of composition 70/30 to 50/50 showed a relatively high tan a and appropriate E' value over a wide temperature range; consequently the tan a e curves of wood/IPNs/wood sandwich composites was broadened over a wide temperature range.

• Journal of Technology Innovation
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• v.22 no.3
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• pp.135-166
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• 2014

'Creative Economy' has been announced as the new paradigm of socio-economic development strategy of newly elected President Geun-Hye Park's administration. By explicitly defining people as a major player in creative activity, it seems to depart from expert-driven or science & technology-focused development paradigms of previous administrations. Yet, its interpretation and operation in terms of government policy does not seem to show any differences. This study aims to explicate the nature of Creative Economy as a development paradigm by clarifying the differences between people's creativity and that of scientists and engineers through extensive literature review. People can contribute to the creative activity not just as users but also as living persons who make everyday yet independent choices based on their humanistic, philosophical, ethical and experiential capabilities which are clearly different from the sources of scientists' & engineers' creativity. People's creative activity does involve value judgement about life and can often accelerate the system innovation or transition by changing consumer behaviour and lifestyle, and hence destruct technological lock-in user lock-in of the existing system. People's creativity can thus present 'User/Field-driven Innovation Paradigm which clearly differs from existing expert- or science & technology-driven innovation paradigm. The Creative Economy with focus on people's creativity therefore faces new socio-economic development challenges of fulfilling the User/Field-driven Innovation Paradigm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.2
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• pp.157-166
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• 2020

The city of Suwon has introduced a dockless bike for the first time in Korea. In this study, a questionnaire was conducted for citizens to suggest improvement through satisfaction analysis. As a result of the survey, 88 % of respondents awarded the presence of a bike, and 90 % answered positively in terms of bike policy; whereas mature civic ethics showed an low satisfaction. For the purpose of usage, approximately 75 % of users mainly used for commuting, business, shopping, and the connection with mass transit. In the result of the primary means of a trip, a private car was most preferred before operation; However, it was found that mode transition has been actively carried out. This suggests significant implications for implementing sustainable urbanism. Meanwhile, The level of satisfaction significantly differed in the field of payment method, charge, usage guidance and publicity by an occupation and age groups commonly. Satisfaction in bike maintenance was statistically differed by an occupation. Satisfaction in Rental-return and registration procedures showed differences by an age groups. The results of this study will contribute to establishment related policies and to more activate dockless shared bike.

• Journal of the Korean Society of Clothing and Textiles
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• v.11 no.2 s.24
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• pp.37-55
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• 1987

Pasul (Herein after referred to Korean-styled Pasul) to cover up the secrets, which has originated from Bool-an original mode of clothes is to put around a belt with a kind of towel. With the development of culture, it has been handed down the parts of ornamental and symbolic functions, losted its particular and original one. In general, we cannot exactly show when the Pasul has been used as a ritual dress, but, dare to maintain in this thesis, which has been used in Koguryu era. This thesis is summarized as follows: 1. The Bool, which is the first dress of all has its origin in the prehistory, and gradually has developed to a ceremonial dress with the help of man's intelligence. 2. Korean-styled Pasul has continuously been handed down from generation to generation (to adding up, from Koguryu era to Yi dynasty). Today, the color of the Pasul is known as a pink one, but I, herein, would like to refer that king Kojong in Yi dynasty had on a yellow-colored Pasul. 3. With becoming to be a form of ceremonial dress, the Bool has become to be complicated in style. For example, in the Koguryu era, the style is in the form of 'U,' and in Koryu era, it is the echelon formation tinting a pink color and weaving a mountain and flare shaped designs, and its dimension, the upper is one ja (a ja means a unit of length, 0.33 M), the lower, two ja, its length three ja. The Bool of Yi dynasty tints a pink color, and weaves a seaweeds, rices, axes and shaped designs. The Pasul which King Kojong in Yi dynasty put in, was a yellow-colored one weaving dragons and fire shaped design. 4. The Pasul is a ceremonial dress used a ritual or court dress. The purposes of wearing it are to distinguish the upper from the lower classes, to make them abide by regulations, and to respect courtesy. Accordingly, the Pasul. as the dress for special occassions does make us review the old and learn the new. 5. The reason that Pasul has been handed down are: 1) richness and fecundity. 2) symbol mark to represent classicalism. 3) to symbolize the authority by putting on it, for it is necessary to distinguish the upper from the lower classes along with the class consciousness in society. 6. On the basis of the study, the Pasul transition is to be handed down the function of the ornament and symbol. after losted its original functions, with the development of culture.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.593-598
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• 2013

In this study, we have evaluated the water absorption phenomenon of photoresist dry film, which is commonly used to build circuits on PCB (Printed Circuit Board) by photolithography, by using ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared). We have firstly observed significant change in fracture mode of dry film with respect to temperature and humidity, which we assumed the material transition from ductile to brittle. Secondly, we have established the process of absorption test for determining the diffusion coefficients of water into the dry film both with gravimeter and ATR-FTIR. We have successfully calculated the diffusion coefficients for each environmental conditions from the results which we achieved by gravimeter and ATR-FTIR. Compared to the gravimeter which is a conventional method for absorption test, the ATR-FTIR method in this study has been found to be very easy to use and have the same accuracy as gravimeter. Moreover, we are expecting to use the ATR-FTIR as an appropriate method to study the absorption phenomena related to any kinds of solvent and polymer system.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.95-99
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• 2018

High thermal conductivity films with electrically insulating properties have a great potential for the effective heat transfer as substrate and thermal interface materials in high density and high power electronic packages. There have been lots of studies to achieve high thermal conductivity composites using high thermal conductivity fillers such alumina, aluminum nitride, boron nitride, CNT and graphene, recently. Among them, hexagonal-boron nitride (h-BN) nano-sheet is a promising candidate for high thermal conductivity with electrically insulating filler material. This work presents an enhanced heat transfer properties of ceramic/polymer composite films using h-BN nano-sheets and PVA polymer resins. The h-BN nano-sheets were prepared by a mechanical exfoliation of h-BN flakes using organic media and subsequent ultrasonic treatment. High thermal conductivities over $2.8W/m{\cdot}K$ for transverse and $10W/m{\cdot}K$ for in-plane direction of the cast films were achieved for casted h-BN/PVA composite films. Further improvement of thermal conductivity up to $13.5W/m{\cdot}K$ at in-plane mode was achieved by applying uniaxial compression at the temperature above glass transition of PVA to enhance the alignment of the h-BN nano-sheets.

• Analytical Science and Technology
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• v.24 no.5
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• pp.345-351
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• 2011

A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) method was developed and validated for the determination of finasteride in human serum. Beclomethasone was used as internal standard (IS) and liquid-liquid extraction (LLE) using methyl tert-butyl ether (MTBE) was carried out to isolate analyte. The mass transitions monitored in multiple reaction monitoring (MRM) in positive ion mode were m/z 373.2${\rightarrow}$305.2 for finasteride and m/z 409.3${\rightarrow}$391.2 for IS. Retention times of finasteride and IS were 5.81 and 5.46 min, respectively. The limit of quantitation (LOQ) was 0.1 ng/mL and the calibration curve showed good linearity in the range of 0.1~20.0 ng/mL ($R^2$=0.9997). The intra-day assay precision and accuracy were in the range 6.3~10.6% and 97.3~103.6%, respectively, and the inter-day assay precision and accuracy were in the range 0.8~5.2% and 99.8~102.5%, respectively. The sample extract recovery of the method was 80~83%.

• Sijohaknonchong
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• v.25
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• pp.175-209
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• 2006

This study focuses on Korean-American writer Hong-Eun$(1880{\sim}1951)'s$ American travel gasaes and sis who played an active role under the rule of Japanese imperialism. This study also investigates Hong-Eun's experience and expression on American travel and culture and discusses his changes in stream of consciousness. According to American travel sigaes which were published in the New Koren Times in 1936. 1937, and 1949, his consciousness can be summarized as follows. First travel siga depicts his inner conflict as a refugee who lost one's home country. That is to say. by observing Indians' losing identity and their miserable labor conditions, he developed his own critical eyes on American society. Eventually he missed his country desperately and sought for the ways of his returning there. Second travel sijo reveals his own agony about not be able to return his home country where he could Possibly visit. In other words, after suffering from his agony, it is evident that he started to take positive attitude towards American society and establish his own identity. Based upon Hong-Eun's changes in consciousness as a writer, the researcher hypothesizes that there exists Diaspora-Consciousness in his work. His consciousness is strongly related with his attitude towards his home country whether it Is positive or vice versa. When his home country declared her independence. his attitude towards immigrant society was positively changed, which was quite contradictory from his previous one. In this transition period, not only he accepted American ideology and life, but he re-conceptualized them as a Korean mode. In sum, Hong-Eun's mental traces lie on the core of hybrid and diaspora which Post-Colonial literature values highly of.