• ETRI Journal
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• v.36 no.3
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• pp.510-513
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• 2014

A Q-band pHEMT image-rejection low-noise amplifier (IR-LNA) is presented using inter-stage tunable resonators. The inter-stage L-C resonators can maximize an image rejection by functioning as inter-stage matching circuits at an operating frequency ($F_{OP}$) and short circuits at an image frequency ($F_{IM}$). In addition, it also brings more wideband image rejection than conventional notch filters. Moreover, tunable varactors in L-C resonators not only compensate for the mismatch of an image frequency induced by the process variation or model error but can also change the image frequency according to a required RF frequency. The implemented pHEMT IR-LNA shows 54.3 dB maximum image rejection ratio (IRR). By changing the varactor bias, the image frequency shifts from 27 GHz to 37 GHz with over 40 dB IRR, a 19.1 dB to 17.6 dB peak gain, and 3.2 dB to 4.3 dB noise figure. To the best of the authors' knowledge, it shows the highest IRR and $F_{IM}/F_{OP}$ of the reported millimeter/quasi-millimeter wave IR-LNAs.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.97-102
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• 2004

In this paper, a new predistorter controlling modified individual order jntermodulation distortion signals is proposed. The proposed predistorter generates and controls predistorted third and high order IM signals independently. Using predistorted signals, jntermodulation distortion signals of power amplifier are suppressed effectively. The predistortion linearizer has been implemented to operate in Korean PCS basestation transmitting band (1840～1870MHz). The test results show that IMD3 and IMD5 (C/I) of power amplifier are improved more than 40dB and 23dB for CW two tone signals, respectively. The predistorter improves the adjacent channel power ratio (ACPR) more than 10dB at 885KHz offset point for CDMA (IS-95) signals.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.7
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• pp.593-598
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• 2003

In this paper, 3rd overtone mode energy-trapped filter using modified PbTiO$_3$ system ceramics was manufactured to apply for intermediate frequency(IF) SMD type fillet with splitted electrode and gap size. To investigate the effects of splitted electrode and gap size on filter characteristics of 3rd overtone mode energy-trapped filter, ceramic wafers were fabricated by etching splitted rectangular electrode size(b$\times$d) of b=0.4, 0.6, 0.8, 1mm, d=0.3, 0.4, 0.5, 0.6mm and gap size(c) c=0.2, 0.3, 0.4, 0.6mm, respectively. And then, SMD type ceramic filter were fabricated with the size of 3.7$\times$3.1$\textrm{mm}^2$. SMD type ceramic filter with the size of b=0.8mm, d=0.4mm and gap(c)=0.4mm, which showed insertion loss of 2.951dB, 3dB bandwidth of 54.7kHz and 20dB stop bandwidth of 129.27kHz, was suitable for IF bandpass filter application.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.451-460
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• 2015

An enantioselective recognition of D- and L-tryptophan (Trp)-b-cyclodextrin (CD) inclusion complex was performed using electrochemical and FT-Raman spectroscopic analysis. From the electrochemical analysis, the selectivity coefficient ($K_{DL}$) of b-CD inclusion complexes was found higher than that of the D- and L-Trp in phosphate buffered saline (PBS, pH=7.0) solution. The percentage of enantioselectivity ($I_{%{ee}}$) for peak current of D-Trp-b-CD inclusion complexes was observed higher than that of L-Trp-b-CD inclusion complexes in PBS solution. From Raman spectroscopy, chemical shift difference (D, $cm^{-1}$) for the C=C stretch, ring vibration, and ring breathing of D-Try-b-CD inclusion complex were observed higher than that of L-Trp-b-CD inclusion complex. The electrochemical and Raman spectroscopic analyses were found very useful for chiral detection of racemic amino acid in the presence of b-CD.

• Korean Journal of Poultry Science
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• v.38 no.4
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• pp.331-338
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• 2011

The study was conducted to evaluate the production and the performance test of egg-type commercial Korean Native Chickens. A total of 360 female layers were produced from CY${\times}$C (A), CL${\times}$C (B), CG${\times}$C (C) and CW${\times}$C (D) crossbreds kept at National Institute of Animal Science, Korea, and breed during 20~64 weeks to investigate the productivity and the performance. Layers were divided into 4 crossbreds (6 replications/crossbred, 15 heads/replication). Age and egg weight at first egg was no significantly different among crossbreds. Body weight (BW) at first egg of D crossbred was significantly lower compared to that of other crossbreds (P<0.05). Weekly BW of B crossbred was the highest at 20, 30 and 40 weeks of age, but BW of D crossbred was the lowest among crossbreds. Feed intake (FI) of B crossbred was significantly higher compared to the other crossbreds at 20~24, 32~44 and 52~60 weeks of age. FI of D crossbred was significantly lower compared to other crossbreds after the age of 44 weeks (P<0.05). Average egg weight of B crossbred was significantly higher than the other crossbreds at the age of 24~60 weeks (P<0.05). Egg production ratio (%) of C crossbred was significantly higher compared to the other crossbreds for whole test periods (P<0.05). Hen-housed egg production number at 64 weeks of age for A, B, C and D crossbreds resulted in 241.4, 235.6, 232.3 and 227.0, respectively. Feed conversion ratio of A and C crossbreds was lower compared to the other crossbreds at the age of 20~24 weeks and C crossbred was the lowest among the crossbreds at the age of 60~64 weeks. These results provide the basic data which will be helpful to develope the new strains of commercial Korean Native Chickens.

• Applied Biological Chemistry
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• v.29 no.4
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• pp.375-380
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• 1986

The result of analysis of ingredient of Kochujang is as follows. The experiments were prepared with wheat flour (WF) and glutinous rice(GR) ; the experimental A type is made of full WF, B type, WF 75% and GR 25%, C type, WF 50% and GR 50% and D type, only full GR. The N content of crude protein and amino type N is higher in the order of A, B, C, and D types, ethyl alcohol is higher in the order of D, C, B, and A types in aging process. The pH is some what higher in A type but in moisture and NaCl, not much difference were shown in the experimental types. The isolated sugars of Kochujang ripened for 90 days analyzed out glucose, fructose, maltose and rhamnose with glucose being the largest in quantity. Glucose is higher in A type, fructose in B type. The alcohols of the ripened Kochujang analyzed out n-propyl, iso-butyl, and iso-amyl alcohol, the content of which is below 3.2mg% and did not show much difference in each experimental types.

• Korean Journal of Optics and Photonics
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• v.16 no.3
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• pp.196-200
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• 2005

A 40 channel arrayed-waveguide grating (AWG) filter operating in C-band and L-band wavelength regions has been fabricated using PLC (Planar Lightwave Circuit) processes with 0.75 refractive index difference. Its design was optimized for matching the center wavelength with the ITU-recommended wavelength. The characteristics of the fabricated C-band AWG are as follows; average insertion loss < 2.5 dB, polarization-dependent loss < 0.3 dB, non-adjacent crosstalk >35dB, and the loss uniformity of 0.8 dB. In the L-band AWG, wavelength accuracy is below 0.02nm.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.215-220
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• 2002

In this paper, the 100 watt unit ower amplifier using temperature independent biasing for DTV (Digital Television) repeater application is designed and fabricated. The DC operation point of this unit power amplifier at temperature variation from $20^{\circ}C$ to $100^{\circ}C$ is fixed by active bias circuit. The variation of current consumption in the 100 watt unit power amplifier has an excellent characteristics of less than 0.6A. The implemented unit power amplifier has the gain over 12dB, the gain flatness of less than 0.5dB and input and output return, loss of than 15dB over the DTV repeater frequency range (470~806MHz). This unit power amplifier yields intermodulation distortion(IMD) of more than 32dBc at 2MHz offset, which satisfies the IMD at output power of 100 watt (50dBm).

• BMB Reports
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• v.41 no.1
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• pp.62-67
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• 2008

The present study was aimed to elucidate the mechanism of stabilization of tubulin by deuterium oxide ($D_2O$). Rate of decrease of tryptophan fluorescence during aging of tubulin at 4$^{\circ}C$ and 37$^{\circ}C$ was significantly lower in $D_2O$ than in $H_2O$. Circular dichroism spectra of tubulin after incubation at 4$^{\circ}C$, suggested that complete stabilization of the secondary structure in D2O during the first 24 hours of incubation. The number of available cysteine measured by DTNB reaction was decreased to a lesser extent in $D_2O$ than in $H_2O$. . During the increase in temperature of tubulin, the rate of decrease of fluorescence at 335 nm and change of CD value at 222 nm was lesser in $D_2O$. Differential Scanning calorimetric experiments showed that the $T_m$ values for tubulin unfolding in $D_2O$ were 58.6$^{\circ}C$ and 62.17$^{\circ}C$, and in $H_2O$. those values were 55.4$^{\circ}C$ and 59.35$^{\circ}C$.

• International Journal of Industrial Entomology and Biomaterials
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• v.23 no.1
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• pp.147-153
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• 2011

The Pseudorabies (PR), also called Aujeszky's disease (AD), is an infectious viral disease caused by an alpha herpes virus and has domestic and wild pigs, as well as a wide range of domestic and wild animals, as the natural host. Pseudorabies virus (PRV) virions contain several envelope glycoproteins. Among them, gB, gC and gD are regarded as the major immunogenic proteins. We expressed these glycoproteins using the bacterial expression system and analyzed recombinant proteins. Expression of glycoproteins gC and gD were observed on SDS-PAGE or Western blot analysis, but gB was not. Optimal concentration of IPTG and inducing time were determined as 1.0 mM and 4 h, respectively, for the expression of both gC and gD in E. coli. A sodium dodecyl sulfate (SDS) was the most efficient detergent in solubilizing insoluble recombinant protein.