• Journal of IKEEE
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• v.23 no.3
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• pp.917-924
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• 2019

This paper presents a wideband low noise amplifier (LNA) that is suitable for LTE-Advanced and 5G communication standards employing carrier aggregation (CA). The proposed LNA encompasses a common input stage and a dual output second stage with a buffer at each distinct output. This architecture is targeted to operate in both intra-band (contiguous and non-contiguous) and inter-band CA. In the proposed design, the input and second stages employ a gm enhancement with resistive feedback technique to achieve self-biasing, enhanced gain, wide bandwidth as well as reduced noise figure of the proposed LNA. An up/down power controller controls the single input single out (SISO) and single input multiple outputs (SIMO) modes of operation for inter-band and intra-band operations. The proposed LNA is designed with a 45nm CMOS technology. For SISO mode of operation, the LNA operates from 0.52GHz to 4.29GHz with a maximum power gain of 17.77dB, 2.88dB minimum noise figure and input (output) matching performance better than -10dB. For SIMO mode of operation, the proposed LNA operates from 0.52GHz to 4.44GHz with a maximum voltage gain of 18.30dB, a minimum noise figure of 2.82dB with equally good matching performance. An $IIP_3$ value of -6.7dBm is achieved in both SISO and SIMO operations. with a maximum current of 42mA consumed (LNA+buffer in SIMO operation) from a 1.2V supply.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.414-420
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• 2001

A 30-kV plasma immersion ion implantation setup (P $I^3$) has been equipped with a self-developed 6'-magnetron to perform hard coatings with enhanced adhesion by P $I^3$D(P $I^3$ assisted deposition) process. Using ICP source with immersed Ti antenna and reactive magnetron sputtering of Ti target in $N_2$/Ar ambient gas mixture, the TiN films were prepared on Si substrates at different pulse bias and ion-to-atom arrival ratio ( $J_{i}$ $J_{Me}$ ). Prior to TiN film formation the nitrogen implantation was performed followed by deposition of Ti buffer layer under A $r^{+}$ irradiation. Films grown at $J_{i}$ $J_{Me}$ =0.003 and $V_{pulse}$=-20kV showed columnar grain morphology and (200) preferred orientation while those prepared at $J_{i}$ $J_{Me}$ =0.08 and $V_{pulse}$=-5 kV had dense and eqiaxed structure with (111) and (220) main peaks. X-ray diffraction patterns revealed some amount of $Ti_{x}$ $N_{y}$ in the films. The maximum microhardness of $H_{v}$ =35 GN/ $M^2$ was at the pulse bias of -5 kV. The P $I^3$D technique was applied to enhance wear properties of commercial tools of HSS (SKH51) and WC-Co alloy (P30). The specimens were 25-kV PII nitrogen implanted to the dose 4.10$^{17}$ c $m^{-2}$ and then coated with 4-$\mu\textrm{m}$ TiN film on $Ti_{x}$ $N_{y}$ buffer layer. Wear resistance was compared by measuring weight loss under sliding test (6-mm $Al_2$ $O_3$ counter ball, 500-gf applied load). After 30000 cycles at 500 rpm the untreated P30 specimen lost 3.10$^{-4}$ g, and HSS specimens lost 9.10$^{-4}$ g after 40000 cycles while quite zero losses were demonstrated by TiN coated specimens.s.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.485-496
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• 2019

The current study examined the latent mean analysis and path analysis comparison between male and female groups in the structural relationships among parent-child conversation, peer attachment, satisfaction in teacher at a community child care center, ego-resiliency, self-esteem, and career identity in adolescents who attend a community child care center. For this purpose, 438 adolescents who participated in the 4th(2017) questionnaire in the 2nd child panel of the community child care center were used. From the analysis results, first, peer attachment and satisfaction in teacher at a community child care center increased ego-resiliency and career identity, but parent-child conversation did not predict ego-resiliency and career identity. Peer attachment and satisfaction in teacher at a community child care center was fully mediated by ego-resiliency and self-esteem to career identity. Second, in the latent mean analysis, male students showed significantly higher latent mean values in ego-resiliency and self-esteem than female students, while female students showed significantly higher latent mean values in parent-child conversation than male students. Third, multi-group analysis revealed different paths to career identity between the genders. Peer attachment can buffer the effect of ego-resiliency and self-esteem on career identity of male students, but satisfaction in teacher at a community child care center buffers more on the ego-resiliency of female students. The results of this study suggest that social support for enhancing ego-resiliency and self-esteem is needed to encourage career identity, and that gender needs to be considered.

• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.189-196
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• 2004

Most of the recent researches for ATM switches have been based on multistage interconnection network known as regularity and self-routing property. These networks can switch packets simultaneously and in parallel. However, they are blocking networks in the sense that packet is capable of collision with each other Mainly Banyan network have been used for structure. There are several ways to reduce the blocking or to increase the throughput of banyan-type switches: increasing the internal link speeds, placing buffers in each switching node, using multiple path, distributing the load evenly in front of the banyan network and so on. Therefore, this paper proposes the use of recirculating shuffle-exchange network to reduce the blocking and to improve hardware complexity. This structures are recirculating shuffle-exchange network as simplified in hardware complexity and Rank network with tree structure which send only a packet with highest priority to the next network, and recirculate the others to the previous network. after it decides priority number on the Packets transferred to the same destination, The transferred Packets into banyan network use the function of self routing through decomposition and composition algorithm and all they arrive at final destinations. To analyze throughput, waiting time and packet loss ratio according to the size of buffer, the probabilities are modeled by a binomial distribution of packet arrival. If it is 50 percentage of load, the size of buffer is more than 15. It means the acceptable packet loss ratio. Therefore, this paper simplify the hardware complexity as use of recirculating shuffle-exchange network instead of bitonic sorter.

• Journal of Digital Convergence
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• v.15 no.10
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• pp.211-219
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• 2017

Currently, enterprises are in a rapid flow of comvergence of industries in the ear of the 4th Industrial Revolution. Under this circumstances, change of economic condition, change of industrial structure, increase of women's advance into society. Based on such background of the times, the aim of this study is to examine the effect of work-home conflict on burnout and the moderating effect of self-efficacy in that relation. The research samples were obtained from nurses at hospitals in Daejeon-si, Sejong-si, Chungcheongnam-do and Chungcheongbuk-do. Total 360 copies of valid questionnaire was used for analysis. Specific analysis results from the research are as follows. Firstly, it was found that Work Interference with Family(WIF) had positive (+) impact on physical burnout. Family Interference with Work (FIW) had no impact on physical burnout. Secondly, it was found that Work Interference with Family(WIF) had positive (+) impact on emotional burnout and Family Interference with Work (FIW) had negative (-) impact on emotional burnout. Thirdly, self-efficacy had a buffer effect on the negative impact of Work Interference with Family upon emotional burnout. However, there was no moderating effect of self-efficacy in the relationship between Family Interference with Work (FIW) and emotional burnout. Therefore, it needs to consider a plan to reduce conflicts between work and family according to the causes of conflicts and it also needs to consider relevant results.

• Journal of Pharmaceutical Investigation
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• v.22 no.2
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• pp.97-104
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• 1992

The purpose of this study was (i) to determine whether protease inhibition by medium chain fatty acids such as sodium caprate, sodium caprylate and sodium laurate led to suppression of insulin proteolysis over a range of insulin concentrations and (ii) elucidate preventing effect of the enhancers on molecular self-association of insulin in pH 7.4 phosphate buffer isotonic solution. To this end, the rate of insulin proteolysis in nasal tissue supernatants of the albino rabbits was determined in the presence of $0.1{\sim}2%$ sodium caprylate, sodium caprate and sodium laurate at insulin concentrations ranging from $5\;to\;100\;{\mu}M$. At fatty acid salts concentration lower than 0.5%, insulin proteolysis was accelerated but the enhancers of high concentration (>1%) reduced the rate of insulin proteolysis. These effects were dependent upon insulin concentration and chain length of fatty acid salts. Circular dichroism spectra of insulin solutions were then determined. Monomer fraction of insulin was increased with increasing sodium caprate. Therefore, half-life decrease of insulin at low concentrations of the enhancers was attributed to deaggregation of insulin by the enhancers, increasing the proportion of monomers available for nasal proteolysis. And the increase of half-life at high concentration of the enhancers was attributed to inhibitory effect on protease rather than the effect of monomer fraction.

• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.1-6
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• 2007

Mercaptopropionic acid(mpa) has been used to make self-assembled monolayer(SAMs) on the surface of graphite electrode incorporating gold nano particles, which are subsequently modified with dopamine(dopa). Such modified electrodes haying types of Gr(Au)/mpa-dopa were employed in the electrocatalytic oxidation of NADH. The responses of such modified electrodes were studied in terms of electron transfer kinetics and reaction procedure in the reaction. The reaction of the surface immobilized dopa with NADH was studied using the rotating disk electrode technique and a value of $5.06{\times}10^5M^{-1}s^{-1}$ was obtained for the second-order rate constant in 0.1 M phosphate buffer(pH=7.0), which was a $EC_{cat}$ and kinetic controlled procedure. But, the modified electrodes were diffusion controlled reaction having $4.64{\times}10^{-4}cm^2s^{-1}$ of the coefficient within $10^{-3}s$ after starting the reaction.

• Journal of Sensor Science and Technology
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• v.15 no.4
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• pp.237-244
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• 2006

Atomic force microscope (AFM) has become a common tool for the structural and physical studies of biological macromolecules, mainly because it provides the ability to perform experiments with samples in a buffer solution. In this study, structure of proteins and nucleic acids has been studied in their physiological environment that allows native intermolecular complexes to be formed. Cr and Au were deposited on p-Si (100) substrate by thermal evaporation method in sequence with the thickness of $200{\AA}$ and $500{\AA}$, respectively, since Au is adequate for immobilizing biomolecules by forming a self-assembled monolayer (SAM) with semiconductor-based biosensors. The SAM, streptavidin and biotin interacted each other with their specific binding energy and their adsorption was analyzed using the Bio-AFM both in a solution and under air environment. A silicon nitride tip was used as a contact tip of Bio-AFM measurement in a solution and an antimony doped silicon tip as a tapping tip under air environment. Actual morphology could also be obtained by 3-dimensional AFM images. The length and agglomerate size of biomolecules was measured in stages. Furthermore, $R_{a}$ (average of surface roughness) and $R_{ms}$ (mean square of surface roughness) and surface density for the adsorbed surface were also calculated from the AFM image.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.52-53
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• 2005

$Y_2O_3$ film was directly deposited on Ni-3at%W substrate using DC reactive sputtering technique. Metallic yttrium was used for DC sputtering target and water vapor was used for oxidizing the deposited metallic Yttrium atoms on the substrate. The window of the water vapor turned out to be broad. The minimum partial pressure of water vapor was determined by sufficient oxidation of the $Y_2O_3$ film, and the maximum partial pressure of water vapor was determined by the non-oxidation of the target surface. As the sputtering power was increased, The deposition rate increased without narrowing the window. The fabricated $Y_2O_3$ films showed good texture qualities and surface morphologies. The YBCO film deposited directly on the $Y_2O_3$ buffered Ni-3at%W substrate showed $T_c$, $I_c$ (77 K, self field), and $J_c$ (77 K, self field) of 89 K, 64 A/cm and 1.l $MA/cm^2$, respectively.

• Korean Journal of Materials Research
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• v.18 no.10
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• pp.535-541
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• 2008

Growth behavior of InGaN/GaN self-assembled quantum dots (QDs) was investigated with respect to different growth parameters in low pressure metalorganic chemical vapor deposition. Locally formed examples of three dimensional InGaN islands were confirmed from the surface observation image with increasing indium source ratio and growth time. The InGaN/GaN QDs were formed in Stranski-Krastanow (SK) growth mode by the continuous supply of metalorganic (MO) sources, whereas they were formed in the Volmer-Weber (V-W) growth mode by the periodic interruption of the MO sources. High density InGaN QDs with $1{\sim}2nm$ height and $40{\sim}50nm$ diameter were formed by the S-K growth mode. Dome shape InGaN dots with $200{\sim}400nm$ diameter were formed by the V-W growth mode. InN content in InGaN QDs was estimated to be reduced with the increase of growth temperature. A strong peak between 420-460 nm (2.96-2.70 eV) was observed for the InGaN QDs grown by S-K growth mode in photoluminescence spectrum together with the GaN buffer layer peak at 362.2 nm (3.41 eV).