• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.129-129
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• 2010

The conjugated oligomers with rigid and fused-ring structures are of interest for the solution-processable organic thin film transistors (OTFTs) due to their well defined structure and high purity. In this study, alkyl substituted benzothiophene based oligomers were synthesized by a novel route, the key point of which is the acid-induced intermolecular cyclization reaction of aromatic methyl sulfoxides, and were confirmed by $^1H$-NMR and FT-IR studies. The obtained oligomers showed the good solubility in common organic solvents such as hexane, chloroform, and dimethylchloride at room-temperature, which is due to the introduced alkyl chain. The physical and optical properties of the oligomers were studied using differential scanning scalorimetry (DSC), cyclic-voltammetry (CV), UV-visible and PL spectra studies. Solution processed OTFT device based on synthesized oligomers show a high hole mobility of up to $0.01\;cm^2V^{-1}s^{-1}$, $I_{on}/I_{off}$ of $10^5$ and threshold voltage of -14V.

• 한국환경과학회지
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• 제20권4호
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• pp.511-517
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• 2011

Ti-SBA-15 catalysts doped with samarium ion were synthesized using conventional hydrothermal method. The physical properties of Sm/Ti-SBA-15 catalysts have been characterized by XRD, FT-IR, DRS and PL. In addition, we have also examined the activity of these materials on the photocatalytic decomposition of methylene blue. The Sm/ Ti-SBA-15 was shown to have the mesoporous structure regardless of Sm ion doping. With doping amount of 1% lanthanide ion, the pore size and pore volume of Sm(Er, Cs)/Ti-SBA-15 decreased and the surface area increased. For the purpose of vibration characteristics on the Ti-SBA-15 and Sm/Ti-SBA-15 photocatalysts, the IR absorption at 960 $cm^{-1}$ commonly accepted the characteristic vibration of Ti-O-Si bond. 1% of Sm/Ti-SBA-15 had the highest photocatalytic activity on the decomposition of methylene blue but the catalysts doped with Er ions had lower activity in comparison with pure Ti-SBA-15 catalyst.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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• pp.251-259
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• 2002

The design concept of diesel engines for sea-going ships has been directed to Low-speed/Long-Stroke type to improve the efficiencies of combustion and propelling. But the time-delay property inevitable at such low speed engines gives much difficulties for governors to control the engine speed because they would be apt to go into unstable region especially when operating at low speed. The purpose of this paper is to study the problem of how the governor gain can be calculated dynamically in accordance with the variance of engine speed at least for an engine to be stable. In this study, the property of diesel engine was described as composed of combustion element including dead time and rotating element, and the ultimate gain for the speed control system to be located on the condition of stability limit was proposed based on the frequency characteristics. And the target gains with optimized stability also were proposed by giving proper margin to these ultimate conditions. The results were applied to a model system and the availability was confirmed to be satisfactory.

• 공업화학
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• 제8권4호
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• pp.637-639
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• 1997

본 연구에서는 고상반응에 의하여 $Tm^{3+}$를 도핑한 $YTa_7O_{19}$를 제조하고, 이들에 대한 빛발광 특성을 조사하였다. 시료의 특성평가에는 XRD, SEM 및 PL을 사용하였다. 359 nm의 여기하에서, $Tm^{3+}$를 도핑한 $YTa_7O_{19}$의 발광 스팩트럼은 455 nm에서 피크를 나타내며, 매우 좁은 발광밴드를 갖는 청색 형광체가 얻어졌다. $YTa_7O_{19}$의 최대발광강도는 $Tm^{3+}$의 농도를 0.12몰 도핑하였을 때 얻어졌으며, 이는 발광강도의 농도퀀칭과 관련이 있다.

• Journal of Information Display
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• 제11권3호
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• pp.109-112
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• 2010

The solid phase compositions and dielectric properties of silicon nitride ($SiN_x$) films prepared using the plasma enhanced chemical vapor deposition (PECVD) technique at a low temperature ($200^{\circ}C$) were studied. Controlling the source gas mixing ratio, R = $[N_2]/[SiH_4]$, and the plasma power successfully produced both silicon-rich and nitrogen-rich compositions in the final films. The composition parameter, X, varied from 0.83 to 1.62. Depending on the film composition, the dielectric properties of the $SiN_x$ films also varied substantially. Silicon-rich silicon nitride (SRSN) films were obtained at a low plasma power and a low R. The photoluminescence (PL) spectra of these films revealed the existence of nano-sized silicon particles even in the absence of a post-annealing process. Nitrogen-rich silicon nitride (NRSN) films were obtained at a high plasma power and a high R. These films showed a fairly high dielectric constant ($\kappa$ = 7.1) and a suppressed hysteresis window in their capacitance-voltage (C-V) characteristics.

• 한국소음진동공학회논문집
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• 제13권1호
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• pp.10-18
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• 2003

This paper presented a design and control of a biped walking RGO(robotic gait orthosis) and its simulation. The biped walking RGO was distinguished from the other one by which had a very light-weight and a new RGO system will be made of 12-servo motors and 12-controllers. The vibration evaluation of the dynamic PLS(posterior leaf splint) on the biped walking RGO was used to access by the 3-axis accelerometer with a low frequency vibration of less than 30 Hz. The galt of the biped walking RGO depends on the constrains of mechanical kinematics and the initial posture. The stability of dynamic walking was investigated by analyzing the ZMP (zero moment point) of the biped walking RGO. It was designed according to the human wear type and was able to accomodate itself to the environments of S.C.I. Patients. The Joints of each leg were adopted with a good kinematic characteristics. To analyse joint kinematic properties. we made the strain stress analysis of the dynamic PLS and the analysis study of FEM with a dynamic PLS.

• Transactions on Electrical and Electronic Materials
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• 제3권4호
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• pp.16-20
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• 2002

The high bias voltage associated with the thick layer (typically 500-1000 ㎛) of selenium required to have an acceptable x-ray absorption in radiography and fluoroscopy applications may have some practical inconvenience. A hybrid x-ray detector with zinc sulfide-amorphous selenium structure has been developed to improve the x-ray sensitivity of a a-Se based flat-panel digital imaging detector. Photoluminescence(PL) characteristic of a ZnS:Ag phosphor layer showed a light emission peak centered at about 450 nm, which matches the sensitivity spectrum of selenium. The dark current of the hybrid detector showed similar characteristics with that of a a-Se detector. The x-ray sensitivity of hybrid and a-Se x-ray detector was 345 pC/㎠/mR and 295 pC/㎠/mR at an applied voltage of 10 V/㎛, respectively. The purpose of this study was to evaluate the pertinence of a solution using a thin selenium layer, as a photosensitive converter, with a thick coating of silver doped zinc sulfide phosphor.

• 한국전기전자재료학회논문지
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• 제19권8호
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• pp.744-748
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• 2006

Emission characteristics of terbium-activated $InBO_3$ under cathode-ray(c.r.) and vacuum ultra violet(v.u.v.) irradiation have been investigated as a functions of norminal compositions and firing conditions. From the x-ray analysis, it was found that some of the synthesized samples contained excess $In_2O_3$ and the amount of the excess $In_2O_3$ varied with the norminal composition and heat treatment conditions. The samples with remanent excess $In_2O_3$ showed lower luminescence intensities than the ones free of excess $In_2O_3$. The phosphors of norminal composition of $InBO_3+10mol%B_2O_3:2mol%Tb$ synthesized at $1250^{\circ}C$ showed excellent CL and PL properties.

• 산업진흥연구
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• 제1권1호
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• pp.7-11
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• 2016

IGZO의 접합특성을 조사하기 위해서 진공 중에서와 대기 중에서 열처리를 하여, 전지적인 특성을 조사하였다. 진공 중에서 열처리를 한 IGZO는 비정질특성을 나타내었지만 대기 중에서 열처리를 하면 결정질 특성을 가졌다. 열처하는 방법에 따라서 산소공공의 함량이 달라지기 때문이다. 대기 중에서 열처리를 하면 IGZO의 산소공공이 증가하였다. 산소공공은 전류를 증가시키고 따라서 대기 중에서 열처리를 한 IGZO는 오믹 접합을 나타내었다. 그러나 진공 중에서 열처리를 한 IGZO는 쇼키접합을 나타냈다.

• 대한간호학회지
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• 제46권1호
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• pp.1-18
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• 2016

Purpose: This study was conducted to synthesis the results of research on relationships of cognitive impairment with multi-dimensional correlates of rheumatic disease through a systematic literature review and meta-analysis. Methods: For the study purpose, 23 studies were selected through a systematic process of searching the literature. Results: The study results showed that among general characteristics, age and education were the variables having a significant relationship with cognitive impairment. Among health risk factors, obesity appeared to have a significant positive relationship with cognitive impairment. For past history, diabetes and hypertension were shown to have a significant positive relationship with cognitive impairment. It was noted also that aPL, one of the physiological factor, had significant association with cognitive impairment. None of the medication related factors had a significant relationship with cognitive impairment. Results showed that among disease related factors, disease activity had the highest relationship with cognitive impairment. Depression, among psychological factors, was the only variable having a significant relationship with cognitive impairment. Conclusion: The findings indicate that the variables strongly impacting on cognitive impairment in rheumatic disease are depression and disease activity.