• Applied Science and Convergence Technology
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• 제23권5호
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• pp.261-264
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• 2014

$SrTiO_3$ (STO) single crystal irradiated with a 3-MeV proton beam exhibits blue and green mixed luminescence. However, the same proton beam when used to irradiate STO with a very thin layer of deposited Pt does not show any luminescence. This Pt layer prevents any damage which may otherwise be caused by arcing, which stems from the accumulated surface voltage of tens of kV due to the charge induced by secondary electrons on the surface of the insulator during the ion beam irradiation process. Hence, the luminescence of ion-irradiated STO originates from the modification of the STO surface layer caused by arcing rather than from any direct ion beam irradiation effect. STO treated with atmospheric-pressure plasma, a simple and cost-effective method, also exhibits the same type of blue and green mixed luminescence as STO treated with an ion beam, as the plasma also creates a layer of surface damage due to arcing.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권6호
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• pp.628-634
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• 2008

The purpose of this study is to examine reproducibility of operation plan and 3-dimentional jaw movement patterns by comparing jaw position of STO with post-operative jaw position. Twenty patients with class III dental and skeletal malocclusion who were treated with Le-Fort I osteotomy and B-SSRO were reviewed. Lateral cephalometric radiographs were taken within two weeks before operation and two days after operation. Cephalometric radiographs were compared and analyzed with orthognathic computer program '$V-Ceph^{TM}$'. Post-operative maxillary advancement was insufficient compared to maxillary advancement through STO. Post-operative setback movement was over compared to mandibular setback movement through STO. But statistically this is not significant. Maxillary vertical location is insignificant on the whole. Especially post-operative maxillary clockwise rotation is significant compared to maxillary rotation through STO. Post-operative maxillary clockwise rotation tendency is generally observed in all patients. So surgeons and staffs must consider this tendency when operation plan is established ans operation is being performed. Using intra or extra oral marking points, face bow, and bite plate will make exact surgery possible.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 1999년도 High Temperature Superconductivity Vol.IX
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• pp.71-74
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• 1999

접지면을 가지는 정사형 조셉슨 결합을 제작하기 위한 기본 단계로 YBCO/STO/YBCO 구조의 다층 박막을 제작하였다. 상하부 YBCO 박막은 그 사이에 존재하는 STO 절연층에 형성된 홀을 통해 서로 연결되어 있으며 이것의 저항-온도 특성을 측정한 결과 임계 온도가86 K로 나타났다. 이 결과는 시편을 매우 장시간동안 열처리한 후 얻은 결과로서 YBCO/STO/YBCO 다층 구조의 박막 제작시 하부 YBCO 박막의 특성이 많이 저하되고 이를 복원하기 위해서는 열처리 공정이 매우 중요함을 알 수 있었다. 현재 우수한 특성을 가지는 YBCO/STO/YBCO 다층 구조의 제작 공정을 최적화하기 위한 연구를 계속 수행 중에 있다.

• 한국세라믹학회지
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• 제36권2호
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• pp.116-121
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• 1999

MgO 단결성 (100) 기판 위에 0.5 wt% Nb 첨가된 전기전도성의 SrTiO3 (Nb:STO) 박막을 Pulsed Laser Deposition 법으로 제조하였다. 산소압력, 타겟과 기판거리, 기판온도, 박막증착시간 등의 박막형성 조건을 다양하게 변화시켜 Nb:STO박막의 격자상수와 박막두께의 변화를 조사하였다. $700^{\circ}C$에서 제작한 0.5 wt% Nb doped SrTiO3 박막의 배향성은 산소분압변화에 따라(100), (110)과 (111)배향이 관찰되었고, 박막제조시의 산소분압이 79.8 Pa로 증가됨에 따라 격자상수는 감소하여 벌크값인 0.390 nm에 근접하였다. 증착시간증가에 따른 박막의 두께는 증착시간에 비례하여 증가하였고, 격자상수의 변화는 거의 없었다. 타겟과 기판사이의 거리가 멀어짐에 따라 박막의 두께는 감소하였으나, 격자상수에는 큰 변화가 없었고 박막두께분포의 균일성이 향상되었다.

• 한국전기전자재료학회논문지
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• 제11권6호
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• pp.436-441
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• 1998

$Pt/SrTiO_3/Pb_x(Zr_{0.52}, Ti_{0.48})O_3/SrTiO_3/Si$ structure was prepared by rf-magnetron sputtering method for use in nondestructive read out ferroelectric RAM(NDRO-FEAM). PBx(Zr_{0.52}Ti_{0.48})O_3}$(PZT) and $SrTiO_3$(STO) films were deposited respectively at the temperatures of $300^{\circ}C and 500^{\circ}C$on p-Si(100) substrate. The role of the STO film as a buffer layer between the PZT film and the Si substrate was studied using X-ray diffraction (XRD), Auger electron spectroscopy (ASE), and scanning electron microscope(SEM). Structural analysis on the interfaces was carried out using a cross sectional transmission electron microscope(TEM). For PZT/Si structure, mostly Pb deficient pyrochlore phase was formed due to the serious diffusion of Pb into the Si substrate. On the other hand, for STO/PZT/STO/Si structure, the PZT film had perovskite phase and larger grain size with a little Pb interdiffusion. the interfaces of the PZT and the STO film, of the STO film and the interface layer and $SiO_2$, and of the $SiO_2$ and the Si substate had a good flatness. Across sectional TEM image showed the existence of an amorphous layer and $SiO_2$ with 7nm thickness between the STO film and the Si substrate. The electrical properties of MIFIS structure was characterized by C-V and I-V measurements. By 1MHz C-V characteristics Pt/STO(25nm)/PZT(160nm)/STO(25nm)/Si structure, memory window was about 1.2 V for and applied voltage of 5 V. Memory window increased by increasing the applied voltage and maximum voltage of memory window was 2 V for V applied. Memory window decreased by decreasing PZT film thickness to 110nm. Typical leakage current was abour $10{-8}$ A/cm for an applied voltage of 5 V.

• 대한전자공학회논문지TC
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• 제47권8호
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• pp.1-8
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• 2010

본 논문에서는 Cyclic prefix 형태의 보호구간을 갖는 비동기 MC-CDMA 상향 링크 시스템의 시간 옵셋의 영향을 주파수 선택적 다경로 페이딩 채널에 대하여 분석하였다. 분석을 위하여 시간 옵셋을 보호구간 및 최대 접속 지연 시간 (maximum access delay time)과 관련하여 모델링하였다. 수식적 분석을 통하여 시간 옵셋이 원하는 신호성분의 전력 누수와 자기 간섭성분을 발생시키는 것을 확인하였다. 이러한 시간 옵셋이 유효 SNR 및 평균 오류율에 미치는 영향을 분석하였다. 근사화를 통하여 평균 오류율 및 SNR 감쇄를 닫혀진 형태로 유도하였다. 분석결과의 정확성은 모의실험 결과와의 비교를 통해 다양한 시간 옵셋 및 SNR에 대해 검증하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.597-597
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• 2013

The resistive switching behaviors of Pt nanodisk on Nb-doped SrTiO3 single-crystal have been studied with conductive atomic force microscopy in ultra-high vacuum. The nanometer sizes of Pt disks were formed by using self-assembled patterns of silica nanospheres on Nb-doped SrTiO3 single-crystal semiconductor film using the Langmuir-Blodgett, followed by the metal deposition with e-beam evaporation. The conductance images shows the spatial mapping of the current flowing from the TiN coated AFM probe to Pt nanodisk surface on Nb：STO single-crystal substrate, that was simultaneously obtained with topography. The bipolar resistive switching behaviors of Pt nanodisk on Nb：STO single-crystal junctions was observed. By measuring the current-voltage spectroscopy after the forming process, we found that switching behavior depends on the charging and discharging of interface trap state that exhibit the high resistive state (HRS) and low resistive state (LRS), respectively. The results suggest that the bipolar resistive switching of Pt/Nb:STO single-crystal junctions can be performed without the electrochemical redox reaction between tip and sample with the potential application of nanometer scale resistive switching devices.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권4호
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• pp.323-330
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• 2011

Purpose: The present study examined the reproducibility of an operation plan by comparing the jaw position of STO with the postoperative mandibular set back measurement in sagittal split ramus osteotomy. Methods: Thirty patients with class III dental and skeletal malocclusion and who were treated with BSSRO were reviewed. Three plain radiographs such as the panoramic view, the lateral cephalogram and the submentovertex view were taken before and after operation. Also, paper surgery for STO and model surgery were used to evaluate the amount of mandibular set back. Results: On the panoramic view, the amount of mandibular set back in STO was similar to the postoperative results of model surgery, but the amount of mandibular set back on the lateral cephalogram was smaller than the postoperative result of model surgery and then the amount of set back on submentovertex view was similar to the postoperative result of model surgery. Conclusion: Precise tracing and paper surgery should be performed for a combined expected STO in order to predict the exact amount of preoperative mandibular set back.

• ETRI Journal
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• 제42권3호
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• pp.324-332
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• 2020

In this paper, a blind symbol timing offset (STO) estimation method is proposed for offset quadrature phase-shift keying (OQPSK) modulated signals, which also works for other linearly modulated signals (LMS) such as binary-PSK, QPSK, 𝜋/4-QPSK, and minimum-shift keying. There are various methods available for blind STO estimation of LMS; however, none work in the case of OQPSK modulated signals. The popular cyclic correlation method fails to estimate STO for OQPSK signals, as the offset present between the in-phase (I) and quadrature (Q) components causes the cyclic peak to disappear at the symbol rate frequency. In the proposed method, a set of close and approximate offsets is used to compensate the offset between the I and Q components of the received OQPSK signal. The STO in the time domain is represented as a phase in the cyclic frequency domain. The STO is therefore calculated by obtaining the phase of the cyclic peak at the symbol rate frequency. The method is validated through extensive theoretical study, simulation, and testbed implementation. The proposed estimation method exhibits robust performance in the presence of unknown carrier phase offset and frequency offset.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.35-35
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• 2012

Most grid-based distributed hydrologic models are complex in terms of data requirements, parameter estimation and computational demand. To address these issues, a simple grid-based hydrologic model is developed in a geographic information system (GIS) environment using storage-release concept. The model is named GIS Storage Release Model (GIS-StoRM). The storage-release concept uses the travel time within each cell to compute howmuch water is stored or released to the watershed outlet at each time step. The travel time within each cell is computed by combining the kinematic wave equation with Manning's equation. The input to GIS-StoRM includes geospatial datasets such as radar rainfall data (NEXRAD), land use and digital elevation model (DEM). The structural framework for GIS-StoRM is developed by exploiting geographic features in GIS as hydrologic modeling objects, which store and process geospatial and temporal information for hydrologic modeling. Hydrologic modeling objects developed in this study handle time series, raster and vector data within GIS to: (i) exchange input-output between modeling objects, (ii) extract parameters from GIS data; and (iii) simulate hydrologic processes. Conceptual and structural framework of GIS StoRM including its application to Pleasant Creek watershed in Indiana will be presented.