• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.31.2-31.2
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• 2010

편대비행 위성이 공동의 임무를 수행하기 위해서는 편대를 이루는 위성의 각기 다른 초기 오차와 다양한 외란 환경에서도 자세 동기화를 이룰 수 있는 기법이 필요하다. 이 연구에서는 편대비행위성의 자세 동기화를 위하여 비선형 시스템에 대한 준최적 제어기법인 SDRE(State-Dependent Riccati Equation)에 기반한 추적 제어기가 사용되었다. 반작용 휠이 포함된 위성의 자세 동역학이 SDRE 추적 제어기를 구성하는데 이용된다. 이를 Leader/Follower 편대비행 시스템에 적용하며, 기준 자세를 추적하는 Leader 위성의 자세를 Follower 위성이 추적하여 자세 동기화를 이룰 수 있다. MATLAB과 SIMULINK를 이용한 수치해석적 시뮬레이션으로 추적 제어기의 성능을 검증하였으며, 이에 대한 실시간 HIL(Hardware-In-the-Loop) 시뮬레이션이 수행되었다. 무중력 환경을 모사하는 에어베어링시스템과 세 개의 반작용 휠을 장착한 자세제어 HILS(Hardware-In-the-Loop Simulator)는 PC104 타입의 임베디드 컴퓨터에서 SIMULINK의 xPC Target을 이용한 실시간 시뮬레이션 환경을 제공하며, 이에 적용되는 SDRE 추적 제어기는 이산화되어 설계되었다. 또한 SDRE 추적 제어기에 대한 안정성을 보장하는 영역이 추정되어 위 추적 제어기가 위성 편대비행에 적합한 자세 동기화 기법임을 보였다.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.43-44
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• 2012

비 절연형 PCS를 사용하였을 때 절연을 할 수 없기 때문에 안전에 대한 위험이 있고 손실이 커서 전체적인 효율이 낮다. 본 논문에서 듀얼 풀 브릿지 컨버터를 사용하여 구현하였다. 각 소자들의 전압, 전류 정격을 줄일 수 있으며 전기적인 절연으로 인하여 안전하다. 또한 승압 비가 홀로 사용했을 때 보다 높으며 고주파 변압기의 턴비를 줄일 수 있다. 본 논문은 1.5[kW]급 듀얼 풀 브릿지 컨버터와 단상 인버터를 이용한 PCS를 설계하고 설계한 파라미터를 구현하여 실험을 통해 검증하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.276-279
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• 2004

CdS thin films on polymer substrates such as polycarbonate(PC) and polyethylene terephthalat(PET) have many merits such as light weight, small volume and can make the obtained devices folded, easily carried. In present work, CdS thin films on glass, PC, and PET substrates have been prepared by chemical bath deposition. The structural and optical propertied of the films depending on substrate types have been investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.125-126
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• 2006

ZnO Films have been prepared on polycarbonate (PC), polyethylene terephthalate (PET), and Coming 7059 substrates by r.f. magnetron sputtering technique. A comparison of the properties of the films deposited on polymer and glass substrates was performed. In addition, the effect of the sputter power on the structural and optical properties of these films was evaluated.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.781-784
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• 2012

스마트폰의 사용이 늘어나면서 스마트폰의 취약점을 노리는 악성코드들도 많이 발생되고 있다. 특히 악성코드를 숨겨주는 루트킷이 최근 캐리어IQ사태를 통해 이슈가 되면서 루트킷에 대한 관심이 늘어가고 있다. 루트킷은 동작방식에 따라 유저모드 루트킷과 커널모드 루트킷으로 나눌 수 있는데 PC처럼 운영체제를 통해 자원 및 프로세스를 제어하는 스마트폰도 루트킷의 위협에 안전하지 못하다. 본 논문은 PC환경에서 동작하는 루트킷의 동작원리를 파악하고 스마트폰 환경 특히 안드로이드 환경의 유저모드 루트킷의 동작과 위협을 주지시키고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1075-1078
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• 2009

Web 2.0 시대가 도래하면서부터 새로운 소프트웨어 배포 방식인 SaaS가 등장하였다. 보안 분야에서도 기존의 소프트웨어적인 보안 방식이 아닌 하드웨어적인 보안 방식을 위해 TPM이라는 보안 칩이 개발되었다. 본 논문에서는 TPM 칩을 사용하여 보다 신뢰적인 측면이 강조된 신뢰 컴퓨팅 기반 SaaS 모델을 설계하고, 설계된 모델의 가장 기본적인 기능인 로컬 PC 레벨의 PCR 값 인증 프로그램과 로컬 PC 레벨 어플리케이션 무결성 측정 프로그램을 구현하고 이를 평가한다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.105-106
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• 2023

In project projects where various factors arise, the construction company's initial establishment of a reasonable process plan reduces various variables and potential risks. In order to create a densely written initial process plan, it is necessary to compare the economic feasibility of time and money by reflecting Slack time. Through this, site managers can lead a successful project based on reasonable and stable construction.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.4
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• pp.61-76
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• 2006

Purpose : This study examined the non-toxic and the anti-oxidative effect of Dioscoreae Rhizoma on PC12 cells. Sanyak(Dioscoreae Rhizoma; chinese yam, shan yao) is well-known for its curing power for kidney, lung, spleen. Tonifies and augments the spleen and stomach. Tonifies the lung gi and augments the kidney yin. Tonifies the kidneys and also stabilizes and binds. it also binds the essence and treats spermatorrhea, frequent urination, and vaginal discharge. We are therefore interested in whether Dioscoreae Rhizoma is capable of causing abnormal apoptosis processes, and whether this condition can be rectified through Dioscoreae Rhizoma herb treatment. Methods : We used aqueous extract to treat PC12 cells with different concentrations treated with a water or a MeOH extract of Dioscoreae Rhizoma (0, x10, x20, x40, x80). The MTT (3, (4, 5-dimethyl-thiazol) 2, 5-diphenyl-tetraxolium bromide) reduction assay was employed to quantify the differences in cell activity and viability. The Bax expression level was monitored using western-blotting techniques. The patterns of the changes in expression were scanned and analyzed. Results : Bax and GSK-3${\beta}$ promotes cell death and down-regulated during the development of the PC12 cells. This is indicated that Dioscoreae Rhizoma is capable of inducing apoptosis in PC12 cells. The induced cell death and significantly inhibited by Dioscoreae Rhizoma, which can be explained by the increase in the inhibition of Bax and GSK-3${\beta}$ expression. It was also shown that Dioscoreae Rhizoma inhibits the release of $H_2O_2$ and prevents lipid peroxidation. Furthermore, the accumulation of wild type Bax protein significantly downregulated in a dose-dependent manner upon treatment with Dioscoreae Rhizoma. Conclusion : In conclusion, Dioscoreae Rhizoma can induce apoptosis via a Bax-dependent pathway or GSK-3${\beta}$ dependent pathway in PC12 cells into anti-oxidant and protective effect.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.10
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• pp.4469-4475
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• 2015

Transient receptor potential melastain 7 (TRPM7) is a bifunctional protein with dual structure of both ion channel and protein kinase, participating in a wide variety of diseases including cancer. Recent researches have reported the mechanism of TRPM7 in human cancers. However, the correlation between TRPM7 and prostate cancer (PCa) has not been well studied. The objective of this study was to investigate the potential the role of TRPM7 in the apoptosis of PC-3 cells, which is the key cell of advanced metastatic PCa. In this study, we demonstrated the influence and potential function of TRPM7 on the PC-3 cells apoptosis induced by TNF-related apoptosis inducing-ligand (TRAIL). The study also found a novel up-regulated expression of TRPM7 in PC-3 cells after treating with TRAIL. Suppression of TRPM7 by TRPM7 non-specific inhibitors ($Gd^{3+}$ or 2-aminoethoxy diphenylborate (2-APB) ) not only markedly eliminated TRPM7 expression level, but also increased the apoptosis of TRAIL-treated PC-3 cells, which may be regulated by the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway accompany with up-regulated expression of cleaved Caspase-3, (TRAIL-receptor 1, death receptors 4) DR4, and (TRAIL-receptor 2, death receptors 5) DR5. Taken together, our findings strongly suggested that TRPM7 was involved in the apoptosis of PC-3 cells induced by TRAIL, indicating that TRPM7 may be applied as a therapeutic target for PCa.

• Environmental and Resource Economics Review
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• v.14 no.1
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• pp.75-100
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• 2005

This study attempts to empirically investigate the respondents' preference uncertainty involved in stating their willingness to pay (WTP). In the contingent valuation (CV) survey, we employed two approaches using two split samples. The respondents of one sample were given the opportunity to express intensity of preference through polychotomous choice (PC) WTP question. Those of the other sample were given a follow-up question of confidence measure (0~100%). By incorporating the two elicited degrees of preference uncertainty into examining the WTP responses, we take a comparison of the two approaches in terms of the goodness-of-fit of the examination and the efficiency of the mean WTP estimates. In comparing the DC model with the PC models, the DC model provides more efficient estimates. Moreover, the conventional DC model give some gains in terms of the goodness-of-fit and efficiency in comparing with the PC model most similar to this model. In this specific study, incorporating the preference uncertainty in DC model results greater estimates than conventional DC model without loss of goodness-of-fit and efficiency. This implies that the consideration of preference uncertainty on DC model could correct underestimating. We conclude that DC model provides a better estimate of WTP and preference uncertainty could be a critical information on the DC-CV estimation.