일반화된 누적손상모형에 관한 연구

Thesis (master`s)--서울대학교 대학원 :통계학과,1998.Maste

A Study of stock price response of sales information in value added tax final return

학위논문(박사)--서울대학교 대학원 :경영학과 경영학전공,1998.Docto

비동질적인 포아송과정에서 베이지안 모형 선택

Thesis (doctoral)--서울대학교 대학원 :통계학과,2002.Docto

플라즈마 처리가 사파이어 기판 표면과 결정화된 알루미나의 결정성에 미치는 영향 분석

학위논문 (석사)-- 서울대학교 대학원 : 공과대학 재료공학부, 2018. 2. 윤의준.GaN-based LEDs, which are a group III-nitride compound semiconductors, are emerging as next-generation lighting technologies due to their superior energy efficiency and loger luminescent life than conventional incandescent lamps and fluorescent lamps. Generally, a GaN-based compound semiconductors are grown on a sapphire substrate by a hetero-epiaxy. However, there are problem of high threading dislocation density due to lattice constant mismatch, wafer bow due to difference in the thermal expansion coefficients between substrate and GaN film, and the low light extraction efficiency due to difference in the refractive index. In order to improve these problems, researches have been carried out to insert a patterns on the sapphire substrate surface to enable lateral overgrowth of GaN film and increase diffuse reflection. Our research group has also developed a CES (cavity-engineered sapphire substrate) which inserts an air cavity arrays on a sapphire substrate surface. When GaN film is grown on a CES, the threading dislocation density decreased due to lateral overgrowth, and the light extraction efficiency increased because of the diffuse reflection. Also, the air cavity arrays reduce the stress inside the thin film, thereby reducing the wafer bow phenomenon. The CES is fabricated by crystallization of alpha-alumina through thermal treatment of amorphous-alumina deposited on a sapphire substrate. Therefore, in order to obtain a high-quality GaN film, the crystallinity of alumina layer is important. During the CES fabrication process, plasma treatment is performed before depositing the amorphous-alumina layer to remove the PR residue after the photolithography process and to obtain the desired shape pattern. This study was conducted to analyze the effect of plasma treatment on the surface of the sapphire substrate and the crystallinity of the crystallized alumina. Plasma treatment was performed by adjusting parameters. In this study, plasma treatment was carried out using oxygen (O2) and argon (Ar) gas. Also, experiments were conducted by controlling the power applied to the plate which the substrate is placed. Fluorine (F) impurities were detected in both the oxygen and argon plasma treatment and about 1% of argon impurities were detected in the case of argon plasma treatment. The oxygen ratio on the surface of the sapphire substrate was increased during the oxygen plasma treatment, and the opposite result was obtained in the case of the argon plasma treatment. Also, as the plate power increases, the stoichiometry of the sapphire substrate surface became more broken. As a result of analysis using AFM technique, the surface morphology and roughness of plasma-treated samples did not much change much, but the crystallized samples showed that nano-sized grains appeared on the surface, and the surface roughness also increased greatly. As a result of the crystallinity analysis, the crystallinity of both gamma-alumina and alpha-alumina was degraded in comparison with the samples that not plasma-treated. Therefore, this study can be used to experminetally examine the effect of plasma treatment on the sapphire substrate surface and the crystallized alumina.Chapter 1. Introduction 1 1.1. Background theory 1 1.1.1. GaN-based LEDs 1 1.1.2. Technical issues in GaN-based LEDs 4 1.2. Cavity Engineered Sapphire substrate (CES) 9 1.2.1. Advantages of CES 9 1.2.2. Fabrication process of CES 11 1.2.3. Necessity of plasma treatment 13 1.2.4. Solid-phase-epitaxy (SPE) of alumina 15 1.3. Purpose of the study 17 Chapter 2. Experimental and analysis tools 19 2.1 CES fabrication techniques 19 2.1.1 Atomic layer deposition (ALD) 19 2.1.2 Inductively coupled plasma etcher (ICP-etcher) 21 2.2 Characterization techniques 23 2.2.1 Atomic force microscopy (AFM) 23 2.2.2 X-ray photoelectron spectroscopy (XPS) 23 2.2.3 High resolution X-ray diffraction (HR-XRD) 23 Chapter 3. Experimental results and discussion 25 3.1. Experimental setup 25 3.1.1 Plasma treatment 25 3.1.2 Amorphous alumina deposition 27 3.1.3 Thermal treatment 29 3.2. AFM analysis (roughness, morphology) 31 3.2.1 Bare sapphire surface 31 3.2.2 Amorphous alumina 31 3.2.3 Crystallized alumina (gamma-phase, alpha-phase) 34 3.2.4 Summary 37 3.3. XPS analysis (stoichiometry, impurities) 39 3.3.1 Oxygen plasma treated 39 3.3.2 Argon plasma-treated 41 3.3.3 Summary 43 3.4. XRD analysis (crystalline quality) 44 3.4.1 Crystallized gamma-phase alumina 44 3.4.2 Crystallized alpha-phase alumina 46 3.4.3 Summary 50 Chapter 4. Conclusion 51 Reference 52Maste

Nonpharmacological Interventions for Alzheimer`s Disease

Although acetylcholinesterase inhibitors (e.g., tacrine, donepezil, rivastigmine, and galantamine) and NMDA receptor antagonists (e.g., memantin) have demonstrated efficacy in the temporal symptomatic control of cognitive decline and daily function in Alzheimer`s disease (AD) patients, their effect is not good enough to restore premorbid function, nor is it maintained in the later stages. Therefore, nonpharmacological interventions are being increasingly advocated in order to optimize the cognition, affect and global functioning of AD patients. We reviewed the current nonpharmacological interventions for AD. Nonpharmacological interventions can be divided into two groups. One is cognitive interventions (e.g., Memory rehabilitations, Reality orientation, Reminiscence therapy and so on) and the other is behavioral interventions (e.g., unmet needs interventions, learning and behavioral interventions, environmental vulnerability and reduced stress-threshold interventions). Cognitive interventions are aimed to slow and compensate cognitive decline of AD patients. On the other hand, behavioral interventions are aimed to reduce neuropsychiatric symptoms (depression, anxiety, agitation, wandering, aggression and so on) of AD patients. Although many of the nonpharmacological interventions have proven beneficial for AD patients, their efficacy was still ambiguous. Randomized and controlled study with a larger sample size is needed to confirm efficacy of non pharmacological interventions.Lee SB, 2009, ARCH GERONTOL GERIAT, V49, P289, DOI 10.1016/j.archger.2008.10.005Teasdale TW, 2009, J NEUROL NEUROSUR PS, V80, P781, DOI 10.1136/jnnp.2008.162966Rothi LJG, 2009, J INT NEUROPSYCH SOC, V15, P311, DOI 10.1017/S1355617709090201Guetin S, 2009, DEMENT GERIATR COGN, V28, P36, DOI 10.1159/000229024Nguyen QA, 2008, INT J GERIATR PSYCH, V23, P337, DOI 10.1002/gps.1886Vance DE, 2008, J NEUROSCI NURS, V40, P96Provencher V, 2008, AM J ALZHEIMERS DIS, V23, P47, DOI 10.1177/1533317507307228Bier N, 2008, NEUROPSYCHOL REHABIL, V18, P343, DOI 10.1080/09602010701694723Lin PWK, 2007, INT J GERIATR PSYCH, V22, P405, DOI 10.1002/gps.1688Ayalon L, 2006, ARCH INTERN MED, V166, P2182Wang PS, 2005, NEW ENGL J MED, V353, P2335, DOI 10.1056/NEJMoa052827Ruis C, 2005, AGING CLIN EXP RES, V17, P514Metzler-Baddeley C, 2005, J CLIN EXP NEUROPSYC, V27, P1070, DOI 10.1080/13803390490919164Schneider LS, 2005, JAMA-J AM MED ASSOC, V294, P1934Briesacher BA, 2005, ARCH INTERN MED, V165, P1280Hochhalter AK, 2005, EXP AGING RES, V31, P101, DOI 10.1080/03610730590914976Sink KM, 2005, JAMA-J AM MED ASSOC, V293, P596Spector A, 2005, COCHRANE DB SYST REV, DOI 10.1002/14651858.CD001119.pub2WOODS B, 2005, COCHRANE DB SYST REV, DOI DOI 10.1002/14651858.CD001120.PUB2LEE SY, 2005, TAEHAN KANHO HAKHOE, V35, P303Snow AL, 2004, J ALTERN COMPLEM MED, V10, P431, DOI 10.1089/1075553041323696Feliciano L, 2004, J APPL BEHAV ANAL, V37, P107Baker R, 2003, J ADV NURS, V43, P465Kessels RPC, 2003, J CLIN EXP NEUROPSYC, V25, P805Wilson BA, 2003, NEUROREHABILITATION, V18, P3NEAL M, 2003, COCHRANE DB SYST REV, DOI DOI 10.1002/14651858.CD001394Hart T, 2002, J HEAD TRAUMA REHAB, V17, P556Ballard CG, 2002, J CLIN PSYCHIAT, V63, P553Kixmiller JS, 2002, BRAIN COGNITION, V49, P237, DOI 10.1006/brcg.2001.1476Yaffe K, 2002, JAMA-J AM MED ASSOC, V287, P2090GRAY SG, 2002, AM J ALZHEIMERS DIS, V17, P169Moniz-Cook E, 2001, INT J GERIATR PSYCH, V16, P45RAGNESKOG H, 2001, INT J NURS PRACT, V7, P146van den Broek MD, 2000, BRAIN INJURY, V14, P455Clare L, 2000, J CLIN EXP NEUROPSYC, V22, P132SPECTOR A, 2000, COCHRANE DB SYST REV, P1120Heard K, 1999, J APPL BEHAV ANAL, V32, P381Palmer CV, 1999, J SPEECH LANG HEAR R, V42, P312Evans JJ, 1998, J INT NEUROPSYCH SOC, V4, P399CLARK ME, 1998, J GERONTOLOGICAL NUR, V24, P10HOPE KW, 1998, J PSYCHIATR MENT HLT, V5, P377MACMAHON S, 1998, AUST J HOLIST NURS, V5, P47CohenMansfield J, 1997, J GERONTOL A-BIOL, V52, pM369Lyketsos CG, 1997, J NEUROPSYCH CLIN N, V9, P556Wilson BA, 1997, J NEUROL NEUROSUR PS, V63, P113Hope K, 1997, J ADV NURS, V25, P780Stern Y, 1997, JAMA-J AM MED ASSOC, V277, P806HOLTKAMP CC, 1997, TIJDSCHR GERONTOL GE, V28, P124KRAGT K, 1997, VERPLEEGKUNDE, V12, P227LOVELL BB, 1995, PSYCHIAT RES, V57, P7SNYDER M, 1995, GERIATR NURS, V16, P60THOENE AIT, 1995, J INT NEUROPSYCH SOC, V1, P29HEISS WD, 1994, DEMENTIA, V5, P88BAKKE BL, 1994, J APPL BEHAV ANAL, V27, P175HITCH S, 1994, J CLIN NURS, V3, P49BALDELLI MV, 1993, ARCH GERONTOL GERIAT, V17, P211ABRAHAMS JP, 1993, CLIN GERONTOLOGIST, V12, P57GERDNER LA, 1993, ARCH PSYCHIAT NURS, V7, P284ODONOVAN S, 1993, NURS ELDER, V5, P27MCKITRICK LA, 1992, J GERONTOL, V47, P337DIESFELDT HFA, 1991, TIJDSCHR GERONTOL GE, V22, P221CAMP CJ, 1990, CLIN GERONTOLOGIST, V10, P58GLISKY EL, 1988, J LEARN DISABIL, V21, P333GLISKY EL, 1986, J CLIN EXP NEUROPSYC, V8, P292GRAF P, 1985, J EXP PSYCHOL LEARN, V11, P501YESAVAGE JA, 1981, J AM GERIATR SOC, V29, P164FEIL NW, 1967, GERONTOLOGIST, V7, P192

Seawater filtration mechanism of mangrove roots

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Spontaneous water filtration through the root of mangrove

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맹그로브 뿌리의 물 정화 기작

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