흰쥐 경동맥 손상 모형에서 체외 방사선조사에 의한 신내막 과증식억제 : Intercellular Adhesion Molecule-1과 Vascular cell Adhesion Molecule-1의 역할 The Possible Role of Intercellular Adhesion Molecule-1 and Vascular Cell Adhesion Molecule-1

강동헌,승기배,장기육,임상현,정해억,임효영,김연실,채장성,김재형,홍순조,최규보 대한순환기학회 1999 Korean Circulation Journal Vol.29 No.9

친환경 비납계 Sodium potassium niobate 압전세라믹스의 조성 최적화

姜東憲 水原大學校 2012 論文集 Vol.26 No.-

Lead-free piezoelectric [(Na0.5K0.5)1-x(A)x][(Nb)1-y-z(B)y(Mn)Z]O3 (A:Ag or Li, B=Ta) specimens prepared by the conventional ceramic processing. Their crystal structure, microstructure, dielectric and piezoelectric properties were investigated with different compositions (substituents and contents). Electrical properties of the specimens increased up to 0.075 mol Ag or Li addition and Ta addition improved their piezoelectric properties. The maximum values, d33, Qm, kp obtained were 153(pC/N), 351, 0.43 for Ag/Ta and 201(pC/N), 141, 0.4 for Li/Ta based NKN systems, respectively. When 0.005 mol Mn was added in Ag/Ta or Li/Ta based specimens, dielectric loss was effectively suppressed below 1.5% and piezoelectric constant, d33 was improved, although dielectric constant and Qm were somewhat lowered. These results were explained in terms of the formation of morphotropic phase boundary, sinterability, grain size, formation of oxygen vacancy and change of transition temperature.

무연계 (Bi0.5Na0.5)TiO3 박막의 강유전특성 연구

강동헌 水原大學校 2013 論文集 Vol.27 No.-

(Bi0.5Na0.5)TiO3 (BNT) is well known as an excellent candidate for the lead free ferroelectric and piezoelectric materials due to its relatively high Tc, Pr and Ec, compared with other lead free materials. For BNT material, it is well known that Bi and Na have relatively low melting and boiling points compared with those of other elements, and are vaporized easily. In this study, BNT thin films were fabricated by the sol-gel method and their dielectric properties were investigated as a function of excess Bi and Na contents. As the content of excess Bi and Na increased, their properties were improved. For 0.1 mol addition, it showed the highest dielectric constant, remanant polarization and pyroelectric coefficient regardless annealing condition. While their properties were degraded with further excess Bi and Na addition. These results were explained in terms of phase present by XRD and surface morphology by SEM and AFM

PCFN-PZW계의 마이크로파 유전 특성에 미치는 Pb계 Flux의 영향

강동헌,설충의,차훈주,김영호,길상근,조봉희 한국전기전자재료학회 2002 전기전자재료학회논문지 Vol.15 No.12

(Pb$\_$0.4/Ca$\_$0.6/)(Fe$\_$1/2/Nb$\_$1/2/)O$_3$ system was modified by 10 mol% Pb(Zn$\_$1/2/W$\_$1/2/)O$_3$ addition and their sinterability and microwave properties were investigated as a function of the amount of flux (0.975PbO-0.025SnO$_2$). With increasing flux content, single perovskite phase was maintained up to 3 wt% flux addition and further addition led to the presence of Pb-rich second phase which was confirmed by EDS analysis. The apparent densities of PCFN-PZW specimen increased and showed maximum values at 2.5 wt% flux addition for the Ts=1000$^{\circ}C$ and 2.0wt% flux addition for the Ts=1050$^{\circ}C$, respectively. The dielectric constant and Q$.$f values strongly depended on the variation of density and microstructure, where the optimum values of $\varepsilon$$\_$r/ = 91.95, Q$.$f = 5938GHz, TCF = +8.15ppm/$^{\circ}C$ were obtained for the 2.5wt% flux added PCFN-PZW specimen sintered at 1000$^{\circ}C$ for 4h.

Lead Magnesium Niobate 계 세라믹스의 전왜성에 미치는 미세구조 의존성

姜東憲 수원대학교 산업기술연구소 1993 산업기술연구소논문집 Vol.8 No.-

Pb(Mg_1/3Nb_2/3)O_3 and Pb(Mg_1/3Nb_2/3)O_3 - PbTiO_3 ceramics were prepared by the columbite precursor method and their electrostrictive properties were investigated as a function of sintering temperature and excess MgO content. For the PMN ceramics, the longitudinal field induced strain, x increased with increasing sintering temperature and the addition of 5 mol% excess MgO led to the further increases in the maximum dielectric constant and electrostrictive strain. For the PMN-PT ceramics, larger strain value, compared to that of the PMN ceramics, was induced at room temperature and also electrostrictive coefficient, Q slightly increased with the addition of PbTiO_3. These results were explained by microstructure analysis.

LTCC적층형 대역통과필터의 공정 및 특성 최적화 연구

강동헌,차훈주 수원대학교 산업기술연구소 2003 산업기술연구소논문집 Vol.18 No.-

Multi-layered ceramic chip bandpass filter for 2.4 GHz ISM band was fabricated by using LTCC (Low Temperature Co-fired Ceramics) technology, and related processing parameters such as lamination condition, sintering temperature, time and electrode condition were investigated in terms of filters characteristics. The BPF consists of coupled stripline resonators and coupling capacitors. The sintering shrinkages was affected substantially by lamination pressure and sintering temperature. And insertion loss with inner conductor thickness has been discussed and realized. Insertion losses in the passband were less than 2 dB and the attenuation more than 25 dB at 2.1 GHz. The frequency response characteristics of the chip BPF is well acceptable for bluetooth application.

로버스트 의사결정을 이용한 영산강유역 종합치수계획 재평가

강동헌,김영오,박준형 한국수자원학회 2017 한국수자원학회논문집 Vol.50 No.2

This research adopted a Robust Decision Making framework to re-evaluate four alternative strategies proposed by the Comprehensive Flood Management Plan for the Yeongsan River Basin report (MLTM, 2005) considering uncertainties of future floods under condition of climate change. To reflect the uncertainties, multiple sets of future flood scenarios were used with three uncertainty factors: the change in rainfall intensity based on the RCP climate change scenarios and the changes in the temporal and the spatial flood distributions. With combinations of these factors, 216 plausible flood scenario sets were generated and the performances of the four alternatives under different future states were evaluated. From the results, the most robust alternative among the strategies was identified. Moreover, the key factors which made the tested alternatives poor were discovered through assessment of the uncertainty factors. This information can provide detailed insights to decision makers and can be utilized to overcome alternatives' potential vulnerabilities by modifying the strategy to be more robust. 본 연구에서는 미래 기후변화로 인한 미래 홍수의 불확실성을 고려하여 영산강유역 종합치수계획 보고서(MLTM, 2005)에서 제시한 4가지 홍수방어대안들을 재평가하였다. 불확실성을 반영하기 위해 미래 RCP 기후 시나리오에 따른 확률강우량 값의 변화, 홍수의 시간적 분포, 그리고 공간적 분포 등 세가지 불확실성 요소를 고려하였다. 이 요소들의 조합을 통해 각기 다른 특성을 갖는 216개의 홍수 시나리오가 생성되었으며 생성된 홍수 시나리오 하에서 대안들의 수행능력이 평가되었다. 평가 결과를 통해 4개의 대안들 중 가장 로버스트한(혹은 강건한) 대안이 선별되었다. 또한, 불확실성 요소 평가를 통해 대안들이 좋지 못한 수행능력을 보이게 하는 주 원인 요소를 파악하였다. 이러한 정보는 의사결정자에게 대안들에 대한 더 상세한 통찰력을 제공하며 이후 선정한 대안의 로버스트함을 증대시키는데 있어 중요한 단서로 활용될 수 있다.

자체 정화용 고분자 필름에 적용 가능한 무기계 코팅소재 연구

강동헌 水原大學校 2020 論文集 Vol.34 No.-

A wide range of transparent and self-cleaning materials such as glass, outdoom r billboard, traffic sign board or building wall tile, are already commercially available. But, some practical limitations still restrict their widespread use in the outdoor sector due to difficulty of their replacements. In this study, we prepared the coating solutions with hydrophilic property by using different organic and inorganic materials, which wiill be applicable to the flexible polymer film. TiO2 nano solutions were prepared and their crystal structure, powder morphology and transmittance were analyzed. After modifying to alcohol based solutions, their wettability and photoactivity were characterized in terms of coating solution on polymer film.

압전세라믹스를 이용한 이산화탄소 감지센서 제조 및 특성

강동헌 水原大學校 2015 論文集 Vol.29 No.-

According to recent environmental pollution problem, more efficient carbon dioxide sensors containing lead zirconium titanate (PZT) compositions have been actively studied and released. In this study, PZT ceramics such as 0.8Pb(Zr1-xTx)O3-0.05b(Sn0.5Sb0.5)O3-0.15MnO2 (x=0.65~0.85) were well-mixed, formed and sintered respectively in the ranges of 1230oC ~ 1290 oC for 2 hours. Their crystal structure, sinterability, microstructure and dielectric (pyroelectric) properties were investigated. The 0.8Pb(Zr0.65T0.3)O3 – 0.05b(Sn0.5Sb0.5)O3 - 0.15MnO2 (Zr/Ti=65/30) specimen sintered at 1270 oC showed the highest properties, which were explained in terms of different Zr/Ti ratios. Also it's sensor characteristics, output voltage via CO2 concentration showed good linearity with very few deviations from the theoretical value, which means the highly effective NDIR type gas sensor application.

경수 손상 장애인을 위한 호흡운동프로그램의 만족도 조사

강동헌,박현주,은선덕,박지영 대한인간공학회 2017 대한인간공학회 학술대회논문집 Vol.2017 No.4