• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2166-2168
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• 2001

Reactor Noise is defined as the fluctuations of measured instrumentation signals during full-power operation of reactor which have informations on reactor system dynamics such as neutron kinetics. The Reactor internal structures which consist of many complex components are subjected to flow-induced vibration due to high temperature and pressure in reactor coolant system. The above flow-induced vibration causes degradation of structural integrity of the reactor and may result in loosing mechanical binding component which might impact other equipment and component or cause flow blockage. It is important to analyze reactor noise signal for the early detection of potential problem or failure in order to diagnosis reactor integrity in the point of view of safety and plant economics. Detailed design of hardware diagnostic system reactor internal structures using neutron noise(RIDS).

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2020년도 정기학술대회 발표논문집
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• pp.219-219
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• 2020

Kaempferol (3,4',5,7-tetrahydroxyflavone), a flavonoid found in beans, broccoli, garlic, etc., has been used in natural medicine as an anti-inflammatory and antioxidant. This experiment was carried out to evaluate the anti-apoptotic effect of kaempferol in 12-O-tetradecanoylphorbol 13-acetate (TPA)-treated Normal Human Dermal Fibroblast (NHDF). Kaempferol inhibited the production of intracellular Reactive Oxygen Species (ROS) induced by TPA in NHDF. Kaempferol significantly blocks the phosphorylation of extracellular signal-regulated kinase responsible for the activation of nuclear factor-kappa B. In addition, kaempferol significantly attenuated the expression of Bax and cleaved caspase-3 as regulated by the phosphorylation of nuclear factor-kappa B during its blockage of TPA-induced apoptotic cell death. These findings suggest that kaempferol protects the apoptotic signaling pathway induced by TPA through modulating intracellular ROS in NHDF.

• Journal of Applied Biological Chemistry
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• 제56권2호
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• pp.61-67
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• 2013

Due to their diversity and abundancy, marine resources have emerged as important biological resources to compensate the limited sources of terrestrial biological materials. Phaeodactylum tricornutum (PT) is one of classical model diatoms most widely studied for its ecology, physiology, biochemistry and molecular biology. In this study, four different PT extracts on lipopolysaccharide (LPS)-stimulated macrophages were compared for anti-inflammatory effect and investigated for the underlying mechanisms. The extracts of PT inhibited nitric oxide production from LPS stimulated RAW 264.7 cells in a dose dependent manner. These extracts also inhibited the expression of mRNA and production of proteins of pro-inflammatory cytokines such as interleukin (IL)-$1{\beta}$, IL-6 and tumor necrosis factor-${\alpha}$. These inhibitory effects were found to be caused by blockage of nuclear factor-${\kappa}B$ activation and phosphorylation of p38 mitogen-activated protein kinases, extracellular signal-regulated kinases 1 and 2 and c-Jun N-terminal kinase.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.667-671
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• 2016

Oridonin, an ent-kaurane diterpenoid compound isolated from the traditional Chinese herb Rabdosia rubescens, has shown various pharmacological and physiological effects such as anti-tumor, anti-bacterial, and anti-inflammatory properties. However, the effect of oridonin on human ovarian cancer cell lines has not been determined. In this study, we demonstrated that oridonin inhibited ovarian cancer cell proliferation, migration and invasion in a dose-dependent manner. Furthermore, we showed oridonin inhibited tumor growth of ovarian cancer cells (SKOV3) in vivo. We then assessed mechanisms and found that oridonin specifically abrogated the phosphorylation/activation of mTOR signaling. In summary, our results indicate that oridonin is a potential inhibitor of ovarian cancer by blocking the mTOR signaling pathway.

• Natural Product Sciences
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• 제15권1호
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• pp.32-36
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• 2009

Glutamate causes neurotoxicity through formation of reactive oxygen species and activation of mitogen-activated protein kinase (MAPK) pathways. MAPK phosphatase-1 (MKP-1) is one of the phosphatases responsible for dephosphorylation/deactivation of three MAPK families: the extracellular signal-regulated kinase-1/2 (ERK-1/2), the c-Jun N-terminal kinase-1/2 (JNK-1/2), and the p38 MAPK. In this report, the potential involvement of MKP-1 in neuroprotective effects of curcumin, the active ingredient of turmeric (Curcuma longa), was examined using HT22 cells. Glutamate caused cell death and activation of ERK-1/2 but not p38 MAPK or JNK-1/2. Blockage of ERK-1/2 by its inhibitor protected HT22 cells against glutamate-induced toxicity. Curcumin attenuated glutamate-induced cell death and ERK-1/2 activation. Interestingly, curcumin induced MKP-1 activation. In HT22 cells transiently transfected with small interfering RNA against MKP-1, curcumin failed to inhibit glutamate-induced ERK-1/2 activation and to protect HT22 cells from glutamate-induced toxicity. These results suggest that curcumin can attenuate glutamate-induced neurotoxicity by activating MKP-1 which acts as the negative regulator of ERK-1/2. This novel pathway may contribute to and explain at least one of the neuroprotective actions of curcumin.

• KSBB Journal
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• 제11권2호
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• pp.165-172
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• 1996

자신의 3차구조를 가진 인체 프로인슐린을 얻기 위하여 Staphylococcal 프로테인 A(SPA)의 신호 랩타이드를 이용하여 대장균내에서 분비 발현을 시도하였다. 분비 발현을 위해 T7 프로모터, SPA 리보좀 바인팅 부위, SPA 신호 랩타이드, 프로인슐린 유전자를 연속적으로 연결하여 분비 벡터를 구성하였다. 이 벡터를 대장균에 넣은후 발현을 유도했으 나 면역적으로 반응하는 인체 프로인슐린은 배양액이나 페리프라스믹 공간에서 거의 존재하지 않았으며 세포 내에도 존재하지 않았다. 그러나 말현 유도시 세포 내에 프로인슐린 RNA가 급격히 증가하였으며 구성한 벡터는 실험실적으로 프로인슐린을 전 사(transcription) , 번역 (translation) 할 수 있었다. 이는 프로인슐린이 번역 후 급히 세포내에서 분 해됨을 의미하며 이로 인해 분비된 프로인슐린을 거의 얻을 수 없게 된 것으로 생각된다. 그러나 프로인 슐린의 세포내 안정성을 위해 말토즈 바인딩 프로테인을 융합짝으로 프로인슐린에 연결한 경우 과량의 분비된 인체 프로인슐린을 검출할 수 있었다.

• 한국정보통신학회논문지
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• 제18권9호
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• pp.2298-2306
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• 2014

본 논문에서는 정지궤도 위성을 운용하는 위성통신환경에서 이동형 위성단말의 송신전력제어를 위한 개루프 전력제어 알고리즘을 제안한다. 제안하는 알고리즘은 위성체로부터 전송되는 비콘 신호를 기준으로 현재 위성채널 상태가 장애물에 의해 LOS가 제한되는 상황인지, 안테나의 위성추적 오차로 인해 발생되는 손실인지 판별한다. 판별된 신호감쇄 원인을 기준으로 안테나 위성추적 오차 시는 RF 출력을 멈추며, 장애물에 의한 채널 단절이 발생될 경우는 전력제어 없이 확산을 통해 데이터 수신 확률을 향상시킨다. 제안하는 알고리즘의 성능분석을 위해 인접위성 간섭 수준과 채널 아웃티지 확률을 분석하였으며, 분석결과 제안하는 알고리즘이 더 높은 성능을 보임을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.69-73
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• 2014

The effects of erlotinib combined with celecoxib in a lung cancer xenograft model were here explored with a focus on possible mechanisms. A xenotransplanted lung cancer model was established in nude mice using the human lung cancer cell A549 cell line and animals demonstrating tumour growth were randomly divided into four groups: control, erlotinib, celecoxib and combined (erotinib and celecoxib). The tumor major axis and short diameter were measured twice a week and after 40 days tissues were collected for immunohistochemical analyses of Bcl-2 and Bax positive cells and Western-blotting analyses for the epidermal growth factor recepto (EGFR), P-EGFR, and cyclooxygenase-2 (COX-2). Tumor size in the combined group was smaller than in the others (p<0.01) and the percentage of Bcl-2 positive cells was fewer in most cases (p<0.01), while that of Bax positive cells was greater than in the erlotinib and celecoxib groups (P>0.05). Western blotting showed decreased expression of P-EGFR and COX-2 with both erlotinib and celecoxib treatments, but most pronouncedly in the combined group (P<0.05). Simultaneous blockage of the EGFR and COX-2 signal pathways exerted stronger growth effects in our human xenotransplanted lung cancer model than inhibition of either pathway alone. The anti-tumor effects were accompanied by synergetic inhibition of tumor cell apoptosis, activation of p-EGFR and expression of COX-2.

• Journal of Positioning, Navigation, and Timing
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• 제1권1호
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• pp.35-43
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• 2012

The UGV is one of the special field robot developed for mine detection, surveillance and transportation. To achieve successfully the missions of the UGV, the accurate and reliable navigation data should be provided. This paper presents design and implementation of multi-sensor-based open architecture integrated navigation for localization of UGV. The presented architecture hierarchically classifies the integrated system into four layers and data communications between layers are based on the distributed object oriented middleware. The navigation manager determines the navigation mode with the QoS information of each navigation sensor and the integrated filter performs the navigation mode-based data fusion in the filtering process. Also, all navigation variables including the filter parameters and QoS of navigation data can be modified in GUI and consequently, the user can operate the integrated navigation system more usefully. The conventional GPS/INS integrated system does not guarantee the long-term reliability of localization when GPS solution is not available by signal blockage and intentional jamming in outdoor environment. The presented integration algorithm, however, based on the adaptive federated filter structure with FDI algorithm can integrate effectively the output of multi-sensor such as 3D LADAR, vision, odometer, magnetic compass and zero velocity to enhance the accuracy of localization result in the case that GPS is unavailable. The field test was carried out with the UGV and the test results show that the presented integrated navigation system can provide more robust and accurate localization performance than the conventional GPS/INS integrated system in outdoor environments.

• 한국항공우주학회지
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• 제37권7호
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• pp.678-684
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• 2009

GNSS 반송파 위상 측정치를 사용하는 정밀 측위 혹은 자세결정에서 미지정수의 결정이 반드시 필요하며 많은 연구가 진행되었다. 그러나 한번 구해진 미지정수는 위성 추적상태가 변화하지 않으면 상수로 계속 사용할 수 있으므로 미지정수 검색과정을 통하지 않고 이미 구해진 미지정수를 사용할 수 있다. 본 논문에서는 ARCE를 변형하여 한번 구해진 미지정수와 새로운 측정치를 이용하여 환경 변화에서도 미지정수를 재구성할 수 있는 미지정수 전파기법을 제안하였다. 초기 미지정수는 LAMBDA로 구하며 신뢰도 향상을 위하여 여러 epoch 동안 연속해서 비율검사를 통과한 미지정수를 사용한다. 한번 구해진 미지정수는 위성의 배치, 위성 신호의 단락 등의 변화에도 미지정수 검색기법을 통하지 않고 제안한 기법을 사용하여 계속 유지될 수 있다. 이로 인하여 미지정수 결정의 성공률이 향상되며 계산량이 감소되는 효과를 얻을 수 있다. 실제 측정치를 이용한 실험으로 제안한 방법은 효과적인 방법임을 확인하였다.