• JSTS:Journal of Semiconductor Technology and Science
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• 제16권5호
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• pp.675-681
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• 2016

A 41dB gain control range $6^{th}$-order band-pass receiver front-end (RFE) using CMOS switched frequency translated impedance (FTI) is presented in a 40 nm CMOS technology. The RFE consists of a frequency tunable RF band-pass filter (BPF), IQ gm cells, and IQ TIAs. The RF BPF has wide gain control range preserving constant filter Q and pass band flatness due to proposed pre-distortion scheme. Also, the RF filter using CMOS switches in FTI blocks shows low clock leakage to signal nodes, and results in low common mode noise and stable operation. The baseband IQ signals are generated by combining baseband Gm cells which receives 8-phase signal outputs down-converted at last stage of FTIs in the RF BPF. The measured results of the RFE show 36.4 dB gain and 6.3 dB NF at maximum gain mode. The pass-band IIP3 and out-band IIP3@20 MHz offset are -10 dBm and +12.6 dBm at maximum gain mode, and +14 dBm and +20.5 dBm at minimum gain mode, respectively. With a 1.2 V power supply, the current consumption of the overall RFE is 40 mA at 500 MHz carrier frequency.

• 한국인터넷방송통신학회논문지
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• 제22권6호
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• pp.129-135
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• 2022

본 논문에서는 10 W급 전력증폭 GaN MMIC(Microwave Monolithic Integrated Circuit)를 16개 전력 결합하여 100 W급 Ka대역 SSPA(Soild State Power Amplifier)를 개발하였다. 개발된 SSPA를 하나의 안테나를 이용하여 송수신을 하는 Ka 대역 소형 레이다에 적용을 위해 수신 구간에 MMIC 게이트 전원을 제어하여 SSPA 잡음이 수신기에 미치는 영향을 최소화 하였다. 또한 근접한 표적의 큰 수신신호에 의해 수신기가 포화되는 것을 막기 위해 SSPA의 출력 전력을 약 20 dB 감소시키는 기능을 추가하였다. 개발된 SSPA는 10%, 40% 듀티비의 펄스 조건에서 각각 52.4 dBm, 51.6 dBm 이상의 첨두전력을 출력하였으며, 이때 전력효율은 각각 19.2%, 15.8% 이상이다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.406-409
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• 2003

TFF(Thin Film Fille.) 방식의 2$\times$2 OADM을 이용하여 1510nm 파장과 1530nm 파장의 광원을 첨가하여 add/drop시킨 4 파장 광 모듈을 구성하였고 이 광모듈을 채택하여 PCS(personal communication system) 및 셀룰러 (cellular) 이동 통신뿐만 아니라 차세대 이동 통신 방식은 IMT-2000 서비스와 다중 링크 시켜 광선로를 재활용하는 방식의 4 파장 광 트랜시버를 구현하였다. OADM을 이용한 4파장 optical signal stream을 구성하여 1510 nm, 1530 nm, 1550 nm, 1570 nm 파장에서 각각 -1.6 dBm, -1.7 dBm, -5.6 dBm, -5.8dBm의 광출력을 얻었다. 제작된 광 트랜시버의 LD 모듈에 12 V의 바이어스 전압을 사용하여 약 1.5dBm의 광 출력 특성을 얻었으며, PD 모듈의 증폭단에는 two-stage 저 잡음 증폭기를 제작하여 1.66dB의 잡음지수와 25.7 dB의 이득을 얻었다. 또한 S$_{11}$과 S$_{22}$ 그리고 입ㆍ출력 정재파비는 각각 -5.47dB, -20 dB 그리고 3.27 : 1, 1.22 : 1의 결과 값을 얻었다.다.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권2호
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• pp.235-239
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• 2004

Drosophila melanogaster heat shock protein 70 gene promoter (Dhsp70p) is widely used in transgenic insect to drive exogenous gene, and the homologous region 3 from Bombyx mori nucleopolyhedrovirus (BmNPVhr3) functions as an enhancer for several promoters. To test whether BmNPVhr3 can enhance the Dhsp70ps transcriptional activity, the reporter plasmids, which contain the Dhsp70p, the reporter $\beta$-galactosidase gene with SV40 terminator and BmNPVhr3 fragment, are constructed and transfected into the insect cell lines (Bm-N cells and Sf-21 cells) by lipofectin-mediated method. The results from the transient expression assay show that BmNPVhr3 significantly increases transcriptional activity of Dhsp70p both under the normal condition and under the heat-shock treatment, although the effects are significantly different between in Bm-N cells and in sf-21 cells. The enhancing behavior of BmNPVhr3 on the Dhsp70p is in an orientation-independent manner. Meanwhile, the effects of heat-shock treatment on Dhsp70p alone or Dhsp70p/BmNPVhr3 combination present no significant difference, indicating that BmNPVhr3 only enhances the transcriptional activity of Dhsp70p, but cant alter its characteristic of the response to the heat-shock stress. The above results suggest that the Dhsp70p/BmNPVhr3 combination is more effective one to drive exogenous gene for transgene or stable cell expression system in insects.

• Journal of Food and Nutrition Research
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• 제10권1호
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• pp.32-40
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• 2022

Diabetes is a chronic metabolic disease with a high prevalence worldwide. Beet (Beta vulgaris) is a plant that is widely used in many countries and has various biological activities. In this study, we aimed to evaluate the antidiabetic effect of a B. vulgaris mixture (BM). In the in vitro evaluation, we measured the inhibitory activities of α-amylase and α-glucosidase, performed the oral starch tolerance test (OATT) and oral sucrose tolerance test (OSTT) in Sprague Dawley (SD) rats, and evaluated the clinical symptoms, oral glucose tolerance test (OGTT), number of blood cells, and insulin resistance in db/db mice. BM showed an inhibitory effect against α-amylase and α-glucosidase activity and decreased the blood glucose increased in the OATT and OSTT. In the diabetes mouse model, BM alleviated the general symptoms of diabetes and OGTT results showed a decrease in the increased blood sugar level. Regarding diabetes-related tissue weight, BM decreased the reduced pancreatic weight and showed an effect on diabetes-related factors of blood. Histological analysis indicated that BM decreased insulin concentration, insulin resistance, and insulin secretion ability in serum, and increased insulin concentration in the islets of Langerhans. These results demonstrate that BM has an antidiabetic effect through the regulation of glycolytic enzymes and β cell activity in the pancreas.

• 동의생리병리학회지
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• 제17권5호
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• pp.1315-1320
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• 2003

The purpose of this research was to investigate effects of Bambusae Caulis in Liquamen (BCL) on the synthesis of basement membrane proteins during proliferation and differentiation of 3T3-L1 cells. BCL has been used to relieve the cough and asthma, and remove phlegm in traditional oriental medicines. In recent years. it was studied for its antiinflammatory, antiallergenic. immune-modulating and anticarcinogenic capabilities. We have previously observed that glycyrrhizin stimulates the adipose conversion of 3T3-L1 cells. To investigate effects of BCL on the basement membrane proteins during proliferation and differentiation of 3T3-L1 cells, we have analyzed synthetic amounts of basement membrane components such as type IV collagen and BM40. BCL stimulated the synthesis and secretion of type IV collagen from both 3T3-L1 preadipocytes and adipocytes. The synthesis and secretion of BM40 was not affected by BCL. The continuous addition of BCL markedly stimulated cell growth and increased cell density. These results suggest an important role for type IV collagen in adipocyte differentiation.

• Asian Pacific Journal of Cancer Prevention
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• 제13권3호
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• pp.909-914
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• 2012

Background: Gefitinib, a tyrosine kinase inhibitor (TKI) of epidermal growth factor receptor (EGFR), is used both as a single drug and concurrently with whole brain radiotherapy (WBRT) the standard treatment for brain metastases (BM), and is reported to be effective in a few small studies of patients with BM from non-small-cell lung cancer (NSCLC). However, no study has compared the two treatment modalities. This retrospective analysis was conducted to compare the efficacy of gefitinib alone with gefitinib plus concomitant WBRT in treatment of BM from NSCLC. Methods: We retrospectively reviewed 90 patients with BM from NSCLC who received gefitinib alone (250mg/day, gefitinib group) or with concomitant WBRT (40Gy/20f/4w, gefitinib-WBRT group) between September 2005 and September 2009 at Sun Yat-Sen University Cancer Center. Forty-five patients were in each group. Results: The objective response rate of BM was significantly higher in gefitinib-WBRT group (64.4%) compared with gefitinib group (26.7%, P<0.001). The disease control rate of BM was 71.1% in gefitinib-WBRT group and 42.2% in gefitinib group (P=0.006). The median time to progression of BM was 10.6 months in gefitinib-WBRT group and 6.57 months in gefitinib group (P<0.001). The median overall survival(OS) of gefitinib-WBRT and gefitinib alone group was 23.40 months and 14.83 months, respectively (HR, 0.432, P=0.002). Conclusion: Gefitinib plus concomitant WBRT had higher response rate of BM and significant improvement in OS compared with gefitinib alone in treatment of BM from NSCLC.

• 전자공학회논문지A
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• 제30A권5호
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• pp.45-51
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• 1993

An erbium doped fiber amplifier(EDFA) pumped by aingle 1.48$\mu$m LD was fabricated, and its gain and noise characteristics were measured. As a signal source, 1548 nm wavelength DFB LD was used. The small signal net gain of the EDFA module was 21.8 dB with maximum gain coefficient 0.7dB/mW for the erbium fiber length of 17.6 m, the pump power of 58 mW, and an input signal power of -25 dBm, respectively. The saturation power of the EDFA was 1 dBm for the input signal power of -5 dBm and the noise figure, measured by using an optical spectrum analyzer, was 5.8 dB for the input signal power of -40 dBm.

• Journal of applied mathematics & informatics
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• 제40권5_6호
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• pp.813-830
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• 2022

The generating functions of the divisor function σ_s(n) = Σ_0<d|n d^s are quasimodular forms. In this paper, we find the basis of the space of quasimodular forms of weight 6 on Γ₀(10) consisting of Eisenstein series and η-quotients. Then we evaluate the convolution sum Σ_ak+bl+cm=n σ(k)σ(l)σ(m) with lcm(a, b, c) = 10 and Σ_al+bm=n lσ(l)σ(m) and Σ_al+bm=n σ₃(l)σ(m) with lcm(a, b) = 10.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.136-139
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• 2003

A clock recovery circuit for a 40 Gb/s optical receiver has been designed and implemented. The clock recovery circuit consists of signal amplifiers, a nonlinear circuit with diodes, and a bandpass filter Before implementing the 40 Gb/s clock recovery circuit, a 10 Gb/s clock recovery circuit has been successfully implemented and tested. With the 40 Gb/s clock recovery circuit, when a 40 Gb/s NRZ signal of -10 dBm was applied to the input of the circuit, the 40 GHz clock was recovered with the -20 dBm output power after passing through the nonlinear circuit. The output signal from the nonlinear circuit passes through a narrow-band filter, and then amplified. The implemented clock recovery circuit is planned to be used for the input of a phase locked loop to further stabilize the recovered clock signal and to reduce the clock jitter.