• Journal of Life Science
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• v.26 no.3
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• pp.325-330
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• 2016

In this study, we evaluated the antidiabetic effect of submerged culture of Ceriporia lacerata mycelium (CL01) on glucose uptake and the expression of mRNA and protein of major signal markers of insulin signaling pathway in 3T3-L1 adipocytes. After 3T3-L1 adipocytes were pre-treated by CL01 (0, 2, 10 mg/ml) for 8 hours, followed with treatment of insulin, the glucose uptake levels significantly increased by more 55.1%, 94.4% than negative control respectively (p<0.01, 0.001) in a dose-dependent manner. However, in case of CL01 pre-treatment without insulin, the glucose uptake did not increase compared with insulin-treated 3T3-L1. Also we demonstrated that the protein expression levels of pIR β, pAkt, pPI3K and pAMPK and the mRNA expression levels of GLUT4 in adipocytes inducing insulin resistance increased in CL01-treated group compared with negative control. These results demonstrated that CL01 affected glucose metabolism and the protein and gene expression through insulin signaling pathway, and increased glucose uptake levels effectively. More than 90% of those who have suffered for type 2 diabetes are more likely to have from hyperinsulinemia, hypertension, obesity and etc. because of altered insulin signaling pathway. So, it is probably considered that intake of CL01 may treat type 2 diabetes by normalization of insulin signaling pathway, and it will provide useful evidences regarding a mechanism for cure of type 2 diabetes.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.41-48
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• 2019

This paper deals with the design of the L-band rotary joint, which is a core part of the tracking radar system. The rotary joint is a part that is mounted on the rotating parts of the tracking system antenna, which smoothly transmits RF signals with minimizing signal insertion loss. To improve the insertion loss of rotary joint, 1) dielectric materials, 2) design of distribution ring and 3)dielectric shape are studied. The performance of proposed rotary joint is compared with the conventional product. The prototype rotary joint showed a max insertion loss of 0.68dB, that is improved about 46% compare with conventional product which insertion loss was 1.26dB.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.2
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• pp.93-97
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• 2009

An advantage of a magnetostrictive strip transducer for a long-range guided wave inspection is that the wave patterns are relatively clear and simple when compared to a conventional piezoelectric ultrasonic transducer. Therefore, if we can characterize the evolution of defect signals, it could be a promising tool for a structural health monitoring of pipes for a long period of time as well as an identification of flaws. However, when evaluating a signal during a realistic field examination, it should be careful because of some spurious signals or false indications, such as signals due to a directionality, multiple reflections, mode conversion, geometrical reflections etc. Mode converted signals from a realistic piping mockup were acquired and analysed. We found mode conversions between a torsional guided wave T(0,1) mode and a flexural F(1,3) or longitudinal L(0,2) mode generated by a magnetostrictive strip transducer. Based on the experimental observations, an interpretation of the source of the mode conversion is discussed in a viewpoint of electromagnetic properties and structure of the strip transducer.

• Journal of Advanced Navigation Technology
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• v.26 no.2
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• pp.85-90
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• 2022

In this study, in order to test the performance of the aircraft system, a threat signal simulator that can transmit a signal similar to the actual threat to the aircraft under test with high power was designed. The high-power threat signal simulator should be able to transmit broadband (UHF band, L band, S band, X band) communication signals and radar signals, and control to transmit signals accurately directed to the aircraft through interfacing tracking radar. The signal strength of the developed equipment is 63 dBm to 93 dBm or more depending on type of signal, and the tracking precision is less than 0.1 degree, which satisfies the required performance. And it was confirmed that the antenna of the high-power threat signal simulator can accurately direct the signal to the aircraft position through the tracking radar interfacing.

• Korean Journal of Optics and Photonics
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• v.16 no.5
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• pp.411-416
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• 2005

We have designed an extended L-band Erbium-doped fiber amplifier to amplify 1625 nm optical time domain reflectometry signal for a long distance monitoring system. The proposed amplifier has a dual-stage structure without an isolator. Gain improvement of 5.1 dB has been achieved by adding a fiber Bragg grating and a narrow band pass filter. As a result, the 16.3 dB gain and 7.1 dB noise figure has been successfully accomplished.

• Journal of Life Science
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• v.33 no.11
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• pp.859-867
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• 2023

Lupeol is a type of pentacyclic triterpene that has been reported to have therapeutic effects for treating many diseases; however, its effect on insulin resistance is unclear clear. This study examined the inhibitory effect of lupeol on the serine phosphorylation of insulin receptor substrate-1 in insulin resistance-induced 3T3-L1 adipocytes. 3T3-L1 cells were cultured and treated with tumor necrosis factor-α (TNF-α) for 24 hours to induce insulin resistance. Cells treated with different concentrations of lupeol (15 μM or 30 μM) or 100 nM of rosiglitazone were incubated. Then, lysed cells underwent western blotting. Lupeol exhibited a positive effect on the negative regulator of insulin signaling and inflammation-activated protein kinase caused by TNF-α in adipocytes. Lupeol inhibited the activation of protein tyrosine phosphatase-1B (PTP-1B)-a negative regulator of insulin signaling-and c-Jun N-terminal kinase (JNK); it was also an inhibitor of nuclear factor kappa-B kinase (IKK) and inflammation-activated protein kinases. In addition, Lupeol downregulated serine phosphorylation and upregulated tyrosine phosphorylation in insulin receptor substrate-1. Then, the downregulated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway was activated, the translocation of glucose transporter type 4 was stimulated to the cell membrane, and intracellular glucose uptake increased in the insulin resistance-induced 3T3-L1 adipocytes. Lupeol may improve TNF-α-induced insulin resistance by downregulating the serine phosphorylation of insulin receptor substrate 1 by inhibiting negative regulators of insulin signaling and inflammation-activated protein kinases in 3T3-L1 adipocytes.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.1
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• pp.56-63
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• 2012

In this study, a field applicability of reboiler tube was evaluated by comparing ECT signal with IRIS signal about wall loss rate and remaining wall thickness using worked austenite STS 316L ASME standard calibration tube. In the case of wall-loss rate, as a result, tolerance about $20%{\times}4$ flat bottom hole and 10% O D groove(ECT), 80% defect and 10% O D groove(IRIS) occurred up to ${\pm}15%$. In the case of remaining wall thickness, ECT was satisfied with the both tolerance, but tolerance about 80% defect occurred up to ${\pm}15%$ in IRIS. Therefore, if the IRIS is performed for interpretation of non-relevant indication and measurement of wall-loss rate after ECT, reliability is supposed to be improved.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.651-657
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• 1995

고리원자력1호기에서 각각 2주기, 4주기동안 연소한 핵연료봉 G33-N2(평균연소도:3464MWD/MTU) 및 G23-14(평균연소도:13917MWD/MTU)에 대하여 와전류시험을 수행한 결과 G33-N2 핵연료봉 하단으로부터 각각 2290mm, 2878mm 위치에 관통결함신호와 내부결함신호를 얻었다. 또한 G23-l4 핵연료봉에서는 ridge 와전류신호를 획득하였다. 비파괴적 와전류시험을 통하여 관통결함 및 내부결함으로 예측된 위치에서 파괴적 금속조직시험을 수행하여 얻은 결과는 와전류시험결과와 잘 일치하였다 G23-l4 핵연료봉에서 획득한 ridge 와전류신호는 직경측정시험결과와 비슷한 경향을 보여 주었다. 따라서 와전류시험을 통하여 핵연료봉에 대한 건전성 평가 도구로서의 그 신뢰성이 양호함을 실증하였으며 핵연료봉의 ridge 정보도 제공할 수 있음을 입증하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.319-320
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• 2011

이 연구에서는 국토해양부 해양교통시설과 위성항법중앙사무소가 운영하고 있는 DGNSS 기준국의 신호수신환경을 파악하기 위해 관측자료의 TEQC 품질평가와 현장조사를 병행하였다. TEQC는 GPS 수신기로 관측한 원시자료를 RINEX형식으로 변환 편집하고, 관측자료의 품질을 점검하는데 이용하는 GPS 전처리 소프트웨어이다. TEQC 품질점검 기능을 통해 GPS 관측자료의 데이터수신율, L1과 L2 신호의 의사거리 다중경로오차, 사이클슬립에 관한 지수를 산출하였고, 이를 현장조사결과와 상호 비교하였다. 장기 관측 자료의 TEQC 품질지수 결과를 통하여 시간변화에 따른 관측소의 주변환경 및 장비변화 시점을 간접적으로 확인하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1071-1077
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• 2010

The six-port phase correlator using lumped elements was designed and fabricated in this paper, also the receiving performance of L-band direct conversion receiver using lumped six-port phase correlator element was analyzed. The proposed L-band lumped six-port phase correlator element was composed of a resistive power divider and the twist-wire coaxial cables. The proposed lumped six-port structure provides the small-sized configuration and wide-band characteristics. The performance of the L-band lumped direct conversion receiver structure was measured under the conditions of 1.69 GHz frequency for LO-CW signal and RF-QPSK signal, which are input signals for the lumped six-port phase correlator element. The direct conversion receiving structure using the proposed lumped six-port phase correlator element can recovered the good digital I/Q signal.