근접장 광학 현미경 탐침을 이용한 빛의 전기장 성분의 3차원 매핑

학위논문(박사)--서울대학교 대학원 :자연과학대학 물리·천문학부,2015. 2. 김대식.In this thesis, I measured the direction of local electric field vectors in three-dimensional space with 100 nm resolution. A radial polarized light is generated by using a radial polarization converter and is focused by an objective lens. Gold nanoparticle functionalized probes are used as the local probes which scatter the focused field into the far-field region. The optical scattering properties of the gold nanoparticle functionalized probes are characterized by determining the polarizability tensors of them. I used rotational analyzer ellipsometry and Stokes parameters to reconstruct the local polarization states of the focused radial polarized light. Two distinct methods give consistent results with each other. I performed near-field measurements of transmission through nanometer-sized gaps at near infrared frequencies with varying the gap size from 1 nm to 10 nm. Field enhancement factors of the nanogaps were quantified by measuring transmission of the nanogaps using NSOM. The near-field measurements produce consistent result to the far-field measurement on quantifying the field enhancement factors of the nanogaps. In spite of the consistency, the near-field measurements have advantages of low background and accessibility to a single nanostructure. I demonstrated the mapping of optical magnetic field of the focused radial polarized light. Subwavelength apertures on metal films and on the apex of tapered fiber probes used as the local probes of the optical magnetic field. By scanning the apertures at the focal plane, I measured the optical magnetic field distribution of the focused radial polarized light. I compared the scattered signal from the apex of the conical probe and the collected signal through the aperture on the apex of the probe. From the measurements, I conclude that subwavelength apertures on the apex of the conical probe are sensitive to the horizontal components of the optical magnetic field. I fabricated near-field scanning optical microscopy (NSOM) probes with different geometrical factors which determine the selective sensitivity to the electric field and the magnetic field of light. The physical parameter dominating the preferential sensitivity is found to be the width of the metal rim surrounding aperture. I quantified the coupling ratio of the NSOM probes to the optical electric and magnetic field by measuring the scattering polarization of the probes. Using the characterized NSOM probes, I measured electromagnetic field distribution of vertical standing wave formed upon reflection at oblique incidence on a metal film. The vertical profiles of the collection signal from two different kinds of probes, the electric probes and the magnetic probes, appear to be out-of-phase.Table of Contents Chapter 1 Introduction ............................................................. 1 Chapter 2 Fabrication of near-field probes ................................................................... 7 2.1 Fabrication of gold nanoparticle functionalized probes ................................................................... 7 2.2 Fabrication of metal-coated apertured probes ................................................................. 10 Chapter 3 Experimental Setups ................................................................. 13 3.1 Near-field Scanning Optical Microscopy .......................................................... 13 3.1.1 Feed-back and Scanning system ................................................................ 13 3.1.2 Optical detection system ................................................................ 15 3.2 Three-dimensional optical vector field mapping setup ................................................................... 19 3.2.1 Optical illumination and Scanning system ................................................................ 19 3.2.2 Optical detection system ................................................................ 22 Chapter 4 Theoretical descriptions ......................................................... 25 4.1 Dipole radiation .............................................................. 25 4.2 Field distribution of radially polarized light .................................................................... 29 4.3 Field distribution at the nanogap ............................................................. 33 Chapter 5 Three dimensional optical vector field mapping ............................................................. 51 5.1 Analysis of local polarization state ................................................................... 51 5.2 Tip characterization.................................................... 57 5.3 Three-dimensional vector field mapping of focused radially polarized light .................................................................... 59 Chapter 6 Quantification of field enhancement factor of nanometer-sized gaps ................................................................... 65 6.1 Fabrication of nanogap samples .............................................................. 65 6.2 Far-field transmission measurements...................................................... 69 6.3 Near-field transmission measurements ..................................................... 73 Conclusion .......................................................... 81 Appendices .......................................................... 83 Chapter A.1 Optical magnetic field mapping of radial polarized light ..................................................................... 83 A.1.1 Bethe-Bouwkamp aperture on a metal film ...................................................................... 83 A.1.2 Bethe-Bouwkamp aperture on the apex of the conical probe ................................................................... 89 Chapter A.2 Selective detection of transverse component of electric and magnetic field of light ..................................................................... 97 A.2.1 Discrimination of Electric Probe and Magnetic Probe ................................................................... 97 A.2.2 Quantitative Estimation of Electric and Magnetic Field Coupling Coefficients ...........................................................101 A.2.3 Origin of Selective Electric and Magnetic Field Sensitivity of NSOM Probes ..................................................................105 A.2.4 Mapping Hertzs standing wave at optical frequency .............................................................109 References .......................................................... 113 요약 (국문초록) ...................................................................... 119 List of publications ................................................ 120 Conferences ........................................................ 122Docto

A study on generating Population Density Surfaces using Digital Base Maps under Internet GIS environment

이 연구에서는 수치지형도와 인터넷GIS서비스를 활용하여, GIS자료모형으로 표현되는 인구밀도면을 제작하고 제공하는 방안을 마련하였다. 인구밀도면 제작방안은 수치지형도가 제공하는 공간정보를 활용하여 센서스 자료의 분해(disaggregation)에 초점을 두었다. 이는 센서스자료가 담고 있는 정보가 수치지형도자료가 담고 있는 건물유형별 정보를 통합하는 방법이다. 인구 밀도면의 특징을 살펴보기 위해서는 센서스 단위로 집계되어 있는 자료와 인구 밀도면으로 추정된 자료를 비교하여 오차의 특징을 살펴보았다. 또한 해상력과 매개변수에 따른 인구 밀도면의 변화양상을 살펴보았다. 이와 더불어, 수치고도모형에 사용되던 가시화도구를 사용할 수 있는 표현상의 특징을 살펴보았다. 이러한 인구 밀도면 자료를 제작하고 제공하는 방안으로서 웹 기반기술을 활용한 인구 밀도면 자료 서비스시스템을 설계하고 구현하였다. 이는 웹 기반 기술과 GIS시스템 개발기술을 근거로, 컴포넌트GIS구조를 갖고 자바애플릿으로 구성된 오브젝트 웹(Object wed)단계의 서비스시스템이다. This research attempts to generate PDS(Population Density Surface) data, associated with socio-economic data derived from census under GIS internet environment. The method focused on maximizing application of spatial information and disaggregating of census data is developed. PDS data is supposed to combine contents of census data with Digital Base Map drawn from each type of bulding entities. For the purpose of catching up the characteristic and tolerating Mean Absolute Error in PDS it is required to compare actual census data value to the value estimated from PDS according to the band width and resolution is included. PDS service system is designed and implemented to facilitate PDS. PDS service system is objet-oriented web based GIS service system organized by JAVA applet based on the GIS system-developing technology

Clinical Outcomes and Contributors in Contemporary Kidney Transplantation; Single Center Experience

연구배경: 효과적인 면역억제제의 발달과 이들의 적용으로 근래의 신장이식의 임상성적은 향상되었다. 본 연구에서는 최근의 신장이식성적과 이에 관련된 인자들에 대하여 보고하고자 한다. 방법: 1998년 7월부터 2016년 6월까지 울산대학교병원에서는 총 354예 (생체 신이식 182예, 사체 신이식 172예)의 신장이식이 시행되었다. 저자는 신장이식환자들의 임상적 특성과 성적을 후향적으로 분석하여 환자 생존율과 이식신 생존율과 이에 영향을 미치는 위험요인들을 평가 하였다. 결과: 관찰 기간의 중간값은 53개월 (범위 3-220개월)이었다. 신장이식 수혜자와 공여자의 평균 나이는 각각 45.0±12.5세, 44.7±13.6세이었다. 관찰 기간 동안 이식 신 기능 소실은 18예에서 발생했으며, 5년 및 10년 이식 신 생존율은 각각 96.7%, 91.5%였다. 급성 거부반응은 총 71예에서 발생하였으며, 55예가 급성 T세포 거부반응이었고, 16예가 급성 항체 매개 거부반응이었다. Cox 회귀분석에서 급성 거부반응의 여부가 이식 신 생존율에 영향을 미치는 독립적인 인자로 확인되었다(hazard ratio [HR] 14.38, 95% confidence interval [CI]: 3.79-54.53 P<0.001). 15명의 환자가 사망했고, 5년 및 10년 환자 생존율은 각각 97.2%, 91.9%이었다. 환자 생존율에 영향을 미치는 요인으로는 나이 60세 이상과 (HR 6.03, 95% CI 1.12 – 32.61, P=0.037), 당뇨병 (HR 6.18, 95% CI 1.35 – 28.22, P=0.019)이 유의한 인자로 분석되었다. 결론: 울산대학교병원에서 시행한 신장이식 성적은 상대적으로 높은 사체 신이식 비율에도 불구하고, 이식 신 생존율 및 환자 생존율 모두 국내외 타 기관에 비해 우수한 경향을 보였다. 이러한 분석결과로 근래의 신장이식에서 단기간 성적뿐 아니라 장기간 성적 역시 향상된 것으로 판단 할 수 있다.Maste

Exploratory Space-Time Analysis : Geo-visual analytics approach based on geovisualization and knowledge discovery

학위논문(박사) --서울대학교 대학원 :지리학과,2007.Docto

인터넷 GIS 서비스와 수치지형도를 활용한 인구밀도면 제작에 관한 연구

학위논문(석사)--서울대학교 대학원 :지리학과,1999.Maste

Clinical Outcomes of Large (> 10 mm) Unruptured Posterior Circulation Aneurysms and Their Predictors

Objective : The treatment of large aneurysms of the posterior circulation is complicated and remains challenging. We here analyzed our institutional clinical outcomes of large unruptured aneurysms of the posterior circulation. Methods : This study included 56 patients who presented with a large (>10 mm) unruptured aneurysm of the posterior circulation between 2002 and 2018. Results : There were 18 (32.1%) male and 38 (67.9%) female patients, with a mean age of 53.4 years. The most common location was the vertebral artery, followed by the basilar tip and posterior cerebral artery. The median follow-up duration was 29 months. Eighteen patients (32.1%) were treated by transcranial surgery and 38 (67.9%) were treated by endovascular treatment (EVT). Post-treatment complications occurred in 16 patients (28.6%), with there being no significant difference between the transcranial surgery and EVT groups. Complete obliteration was achieved in 30 patients (53.6%), with there being no statistically significant difference between the transcranial surgery and EVT groups. Recurrence occurred in 17 patients (30.4%), and the rate of recurrence was higher in the EVT group than in the transcranial surgery group (39.5% vs. 11.1%, p=0.03). Forty-four (84%) of 56 patients showed a favorable functional outcome. In saccular aneurysm, EVT was negative predictor of worsening of functional status. Conclusion : Treatment of these aneurysms harbors an inherent high risk of morbidity. No superiority was found between transcranial surgery and EVT in terms of complications and complete obliteration, but transcranial surgery showed a higher treatment durability than EVT