• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.151-155
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• 1999

본 논문에서는 개구 급전 마이크로스트립 야기 배열에 의한 빔 틸팅 안테나를 제안하고, Ansoft사의 Ensemble 5.1을 이용하여 설계 변수들의 값을 추출하고 제작된 안테나의 성능을 측정 분석하였다. 제안된 안테나는 북반구 대부분 지역에서 고정위성 지향을 위해 3dB 빔 폭은 45$^{\circ}C$ 를 중심으로 +/- 2$0^{\circ}C$ 정도의 빔 커버리지를 가지며, 2.51GHz ~ 2.59GHz의 동작 대역을 가진다. 안테나의 구조는 반사기, 구동기, 유도기의 3개 구형 패치로 구성된다. 2.56GHz에서 제작된 안테나의 최대 이득은 앙각 42$^{\circ}C$ 에서 6.2dB, 그리고 Front-to-Back 비는 약 13dB 이상을 얻었다.

• Journal of Animal Science and Technology
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• 제56권7호
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• pp.25.1-25.6
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• 2014

This study was carried out to investigate the association of POU1F1 (POU domain, class 1, transcription factor 1, Pit1, renamed as POU1F1) gene with backfat thickness (mm), carcass weight (kg), pH, and color values ($L^*$, $a^*$, $b^*$) in crossbred pigs (Landrace ${\times}$ Yorkshire ${\times}$ Duroc). Frequency of the AA genotype indel was at the highest level (66.67%). Frequency of A allele (0.81) was higher than that of b allele (0.19). This population followed Hardy-Weinberg equilibrium. Carcass weights and $a^*$ values of the three genotypes were all significantly different (p < 0.05), respectively. However, backfat thickness, $L^*$, $b^*$, visual color, and pH of the three genotypes were not significantly different (p > 0.05). Visual color was negatively correlated with $L^*$ (r = -0.521) and $b^*$ (r = -0.390) values, $L^*$ value was correlated with $b^*$ (r = 0.419) value, and $a^*$ value was positively correlated with $b^*$ (r = 0.612) value. These results indicate that the POU1F1 gene affected carcass weight and meat redness.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.570-572
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• 2012

In this paper, a three-dimensional (3-D) low-loss and wide-band BPF based on low-temperature co-fired ceramic (LTCC) has been presented for mm-wave wireless communication applications. The proposed BPF is designed in a 6-layer LTCC substrate. The double patch resonators are fully integrated into the LTCC dielectrics and vertical via and planar CPW transitions are designed for interconnection between embedded resonators and in/output ports and MMICs, respectively. The designed BPF was fabricated in a 6-layer LTCC dielectric. The fabricated BPF shows a centre frequency (fc) of 53.23 GHz and a 3dB bandwidth of 14.01 % from 49.5 to 56.9 GHz (7.46 GHz). An insertion loss of -1.56 dB at fc and return losses below -10 dB are achieved. Its whole size is $4.7{\times}1.7{\times}0.684mm^3$.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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• pp.231-234
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• 2001

위성방송 수신을 위한 S-band용 LNB를 유전율3.48, 기판두께 0.762mm의 기판을 사용하여 NF=0.9 dB, 변환이득 56dB, Gain Flatness +0.7dB/27MHz을 만족하도록 설계하였으며 대역통과필터는 원하는 대역내에서 삽입손실 -2dB, 반사계수 -l2dB 이하의 결과를 얻었다. 발진기는 3.62GHz에서 6.17dBm의 출력을 나타내었으며 위상잡음은 중심주파수 3.62GHz의 100kHz offset 지점에서 -98 dBc/Hz의 특성을 얻었다.

• 한국인터넷방송통신학회논문지
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• 제23권5호
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• pp.109-114
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• 2023

본 논문에서는 Ka-대역 소형 레이더에 적용하기 위한 65-nm CMOS 기반 2채널 이미지 제거 수신기를 기술하였다. 설계된 수신기는 Low-Noise Amplifier (LNA), IQ mixer 및 Analog Baseband (ABB) 회로로 구성된다. ABB 내에 complex filter를 포함하여 원하지 않는 이미지 성분을 억제할 수 있으며, RF 및 ABB의 가변 이득 증폭기 (VGA)에서 이득을 4.5-56 dB 범위에서 조절할 수 있어 수신기의 동적 영역을 확보할 수 있다. 이득 조절은 수신기에 내장된 SPI 컨트롤러를 통해 수행된다. 수신기 칩은 Ka-대역 목표주파수 내 이득 36 dB에서 잡음지수 <15 dB, OP1dB >4 dBm, 이미지 제거비 >30 dB, 채널 간 격리도 >45 dB 특성을 보였다. 본 수신기는 1.2 V 공급전압에서 420 mA를 소모하며, 칩 면적은 4000×1600 ㎛ 이다.

• 한국전자파학회논문지
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• 제23권5호
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• pp.624-631
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• 2012

본 논문은 Guanella의 1:1 transmission-line transformer와 harmonic filtering 방식을 이용한 13.56 MHz 고효율 전류 모드 D급(CMCD) 전력증폭기를 제안한다. 출력 정합 네트워크에 기존의 D급 전력증폭기의 부하 네트워크를 변형하여 harmonic filtering 방식을 포함시킴으로써 낮은 2차와 3차 고조파 특성을 얻었다. 제작된 CMCD 전력증폭기는 13.56 MHz의 CW 입력 신호를 사용하여 측정하였을 때, 13.4 dB의 전력 이득을 가지며, 44.4 dBm의 출력에서 84.6 %의 높은 PAE 특성을 나타내었다. 같은 출력에서 2차 3차 고조파는 각각 -50.3 dBc와 -46.4 dBc를 나타냈다.

• 대한화학회지
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• 제56권4호
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• pp.448-458
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• 2012

In order to develop alloy resistance in aggressive sulphat ion, the corrosion behavior of metallic glasses $Ni_{92{\cdot}3}Si_{4.5}B_{32}$, $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ (at %) at different concentrations of $H_2SO_4$ solutions was examined by electrochemical methods and Scanning Electron Microscope (SEM) and X-ray Photoelectron Microscopy (XPS) analyses. The corrosion kinetics and passivation behavior was studied. A direct proportion was observed between the corrosion rate and acid concentration in the case of $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ alloys. Critical concentration was observed in the case of $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ alloy. The influence of the alloying element is reflected in the increasing resistance of the protective film. XPS analysis confirms that the protection film on the $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ alloy was NiS which is less protective than that formed on Cr containing alloys. The corrosion rate of $Ni_{82,3}Cr_7Fe_3Si_{4.5}B_{3.2}$ and $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$. alloys containing 7% and 13% Cr are $7.90-26.1{\times}10^{-3}$ mm/y which is lower about 43-54 times of the alloy $Ni_{92{\cdot}3}Si_{4.5}B_{32}$ (free of Cr). The high resistance of $Ni_{75.5}Cr_{13}Fe_{4.2}Si_{4.5}B_{2.8}$ alloy at the very aggressive media may due to thicker passive film of $Cr_2O_3$ which hydrated to hydrated chromium oxyhydroxide.

• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1728-1735
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• 2014

Scrub typhus, caused by infection with Orientia tsutsugamushi, is a mite-borne zoonotic disease endemic to the Asian-Pacific region. In Korea, the incidence of this disease has increased with climate changes, and over 10,000 cases of infection were reported in 2013. Although this infection is treatable with antibiotics such as doxycycline and azithromycin, an effective prophylactic vaccine against O. tsutsugamushi would be more desirable for preventing scrub typhus in endemic areas. In this study, we investigated the 56-kDa type-specific antigen (TSA56), which is a major outer membrane protein of O. tsutsugamushi, as a vaccine candidate. Intranasal immunization of recombinant TSA56 (rec56) induced a higher level of TSA56-specific IgG than that induced by intramuscular immunization of tsa56-expressing DNA (p56). Both types of immunization induced a cell-mediated immune response to TSA56, as demonstrated by the splenic cell proliferation assay. Mice immunized with p56, followed by rec56 plus heat-labile enterotoxin B subunit from E. coli, had a stronger protection from a homologous challenge with the O. tsutsugamushi Boryong strain than with other combinations. Our preliminary results suggest that an effective human vaccine for scrub typhus can include either recombinant TSA56 protein or tsa56-expressing DNA, and provide the basis for further studies to optimize vaccine performance using additional antigens or different adjuvants.

• Journal of Korean Neurosurgical Society
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• 제56권5호
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• pp.375-382
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• 2014

Objective : To assess the effect of bone marrow mononuclear cells (BMMNCs) transplantation in the expression of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) in spinal cord injury (SCI) in rats. Methods : BMMNCs were isolated from tibia and femur by a density gradient centrifugation. After establishment of acute transection SCI, rats were divided into experiment (BMMNCs), experiment control (0.1 M PBS infused) and sham surgery groups (laminectomy without any SCI). Locomotor function was assessed weekly for 5 weeks post-injury using BBB locomotor score and urinary bladder function daily for 4 weeks post-injury. Activity of NF-${\kappa}B$ in spinal cord was assessed by immunohistochemistry and reverse transcriptase polymerase chain reaction. Results : At each time point post-injury, sham surgery group had significantly higher Basso, Beattie, Bresnahan locomotor and urinary bladder function scores than experiment and experiment control group (p<0.05). At subsequent time interval there were gradual improvement in both experiment and experiment control group, but experiment group had higher score in comparison to experiment control group (p<0.05). Comparisons were also made for expression of activated NF-${\kappa}B$ positive cells and level of NF-${\kappa}B$ messenger RNA in spinal cord at various time points between the groups. Activated NF-${\kappa}B$ immunoreactivity and level of NF-${\kappa}B$ mRNA expression were significantly higher in control group in comparison to experiment and sham surgery group (p<0.05). Conclusion : BMMNCs transplantation attenuates the expression of NF-${\kappa}B$ in injured spinal cord tissue and thus helps in recovery of neurological function in rat models with SCI.

• 한국작물학회지
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• 제56권4호
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• pp.413-419
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• 2011

This study was conducted to determine the physicochemical properties of a giant embryo rice 'P47JB-4-B-5-B' derived from the cross between 'P47', a mutant of 'Hwayoung' induced by T-DNA insertion, and 'Junam'. The grain appearance and chemical components of the embryo were analyzed and compared with a donor cultivar, 'Hwayoung'. The proportion of embryo weight to grain weight of 'P47 JB-4-B-5-B' was 2.2 times heavier (6.7%) than that (3.1%) of 'Hwayoung'. Total free amino acid content (75.81 mg/100 g) of 'P47JB-4-B-5-B' was 2.1 times higher than that of 'Hwayoung'. The GABA content in brown rice was 14.06 mg/100 g in 'P47JB-4-B-5-B' and 6.8 mg/100 g in 'Hwayoung'. Especially, the GABA content in brown rice of 'P47JB-4-B-5-B' remarkably increased (about 33 times from 1.48 mg to 44.81 mg/100 g) 2 days after germination. Continuous frequency distributions and transgressive segregation in embryo length and width were observed in the $F_2$ population of the cross between 'P47' and 'Cheongcheong', indicating that the giant embryo was controlled by quantitative trait loci. However, embryo length and width demonstrated high broad sense heritability, implying that giant embryonic traits could be selected in earlier generations in comparison with other quantitative traits.