A Study on Activation of Sanbokdoro Renaissance Project

본 연구는 마을만들기 사업이 활발히 추진하고 있는 부산광역시를 대상으로 대표적인 마을만들기 사업인 산복도로 르네상스 1차년도 사업으로 만들어진 거점시설들의 운영상황을 마을만들기 구성요소인 주민참여, 지역자원활용, 네트워크형성, 지속성에 대하여 분석하고, 인근 지역주민을 포함 타 지역 주민의 운영에 대한 인식 조사를 통하여 문제점 도출 및 활성화 방안을 제안하였다. 살펴본 결과다음과 같다. 첫째, 계획 당시 전문가와 행정이 추진주체가 되어 마을만들기에 대한 인식이 부족한 주민들의 참여를 이끌어 내었고 추후 운영 및 관리에서 주민들을 인력으로써 참여 하였다. 과정 속에 운영에 대한 주민교육이 부족하여 추후 시설에 대한 운영부분이 미흡하였다. 거점시설 전반적으로 주민들의 참여를 이끌 수 있는 프로그램이 부족하였고, 다양한 주민참여 프로그램 및 운영교육 프로그램이 필요하다. 둘째, 거점시설에서의 지역자원활용이 낮으며 산복도로만의 지역자원의 도출과 컨텐츠화 및 프로그램 개발이 필요하다. 특히 산복도로에서 바라보는 해양경관에 대한 만족도가 높고, 필요성에 대한 부분이 높아 해양경관을 살린 다양한 시설과 프로그램이 필요하다. 셋째, 각 시설의 운영 및 관리가 타부서로 산개되어있어 각거점시설의 네트워크형성이 이루어지지 않았다. 지원 및 운영체계가 행정에서 주민으로 지원과 도움을 주는 하향식 운영체제로 되어있어 각거점시설의 운영기관과 운영주민과의 네트워크가 이루어지지 않았다. 물리적연결 또한 이뤄지지 않고 있어으며, 이를 해결하고 초량이바구길 거점시설을 효율적 운영을 위해서는 민·관의 협력 체계를 구축하여 초량이바구길 통합운영 조직이 필요하다. 넷째, 거점시설 전반적으로 환경적 지속성이 고려되고 있지 않고, 지속적으로 사업을 운영할 경제적 재원이 넉넉지 않아 경제적인 지속성 또한 힘들다는 점이다. 이를 해결하기 위해서는 지속적인 수익구조를 형성할 필요가 있다.The subject of this study is Choryang Ibagu-gil base facilities of Sanbokdoro Renaissance first project that is one of the representative community building business in Busan. This study analyzed the operating situations of base facilities in Ibagu-gil, Choryang for citizen participation, utilization of regional resource, network formation, and persistence. Also by investigating recognition of residents for operation, it deduced problem and proposed activation plan. Examined results are as follows. First, the experts and administration elicited participation of citizens who lack recognition for community building business. And after finishing plan, citizens have been participating in operation and management of facilities. However, in process, due to the insufficient training for citizens, facilities management was unsatisfying, and even, program that can lead to citizen participation was shortage. To solve these problems, various programs for management training and citizen participation are needed. Second, the rate of utilization of regional resources in base facilities was low, it is needed to develop programs and deduce regional resources of the only for Sanbokdoro. Especially, due to the high satisfaction and needs for the marine scenery viewed from Sanbokdoro, various facilities and programs utilizing marine scenery are needed. Third, because management and operation of each facilities were scattered to other departments, network formation of base facilities was not built. The network between organizations and citizens of each base facilities was not built due to the top-down operating system, also physical connection has not been built as well. To solve these problems, first of all, the organization for the integrated operation is required by establishing cooperation with public-private. Fourth, base facilities in Ibagu-gil, Choryang generally lack environmental persistence. Also, because of the shortage of financial resources for consistent operation of business, it is hard to maintain. To solve the problem above, create programs that are able to make a profit, and form a continuous revenue structure through the connection between base facilities.List of Tables iii List of Figures v Abstract vii 1. 서 론 1.1. 연구의 배경 및 목적 1 1.2. 연구의 내용 및 범위 2 2. 마을만들기 사업의 이론적 고찰 2.1. 마을만들기사업 3 2.1.1. 마을만들기의 개념 및 등장배경 3 2.1.2. 마을만들기의 구성요소 4 2.1.3. 마을만들기의 유형 11 2.2. 산복도로 르네상스 사업 20 2.2.1. 산복도로 르네상스 사업의 배경 및 목적 20 2.2.2. 사업의 내용 및 추친 현황 21 2.2.3. 산복도로 르네상스 1차년도 사업의 개요 23 2.3. 선행연구 고찰 26 2.3.1. 마을만들기 사례 관련 선행연구 26 3. 초량이바구길 거점시설 운영 사례 분석 3.1. 초량이바구길 거점시설의 현황 29 3.1.1. 초량이바구길 거점시설의 개요 29 3.1.2. 초량이바구길 거점시설의 운영현황 30 3.2. 초량이바구길 거점시설의 현황 분석 50 3.2.1. 초량이바구길 거점시설의 주민참여 51 3.2.2. 초량이바구길 거점시설의 지역자원활용 53 3.2.3. 초량이바구길 거점시설의 네트워크 형성 55 3.2.4. 초량이바구길 거점시설의 지속성 56 3.3. 초량이바구길 거점시설의 만족도 분석 57 3.3.1. 산복도로 르네상스 1차 사업의 만족도 57 3.3.2. 초량이바구길 거점시설 만족도 61 3.3.3. 만족도 종합 분석 72 3.4 거점시설 분석과 만족도와의 상관관계 73 4. 초량이바구길 거점시설 활성화 방안 4.1. 통합 운영조직 구성을 통한 운영 및 관리 방안 75 4.1.1. 통합 운영조직 구성을 통한 운영 및 관리 방안 75 4.2. 해양경관자원을 활용한 구역별 쌈지공원 조성 77 4.2.1. 해양경관자원을 활용한 구역별 쌈지공원 조성 77 4.3. 지역자원을 활용한 가로 정비 방안 78 4.3.1. 지역자원을 활용한 가로 정비 방안 78 4.4. 거점시설 운영프로그램 활성화 및 연계방안 79 4.4.1. 거점시설 운영프로그램 연계방안 79 4.4.2. 각 거점시설 운영프로그램 활성화 80 5. 결론 참고문헌 110 부록 11

Evaluation of deposited silicon oxide with post-deposition annealing for gate oxide of MOS capacitors on 4H-SiC

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 재료공학부, 2018. 2. 김형준.Silicon carbide (SiC) is one of the promising materials being developed for the application of power devices. The 4H-SiC metal-oxide-semiconductor field effect transistors (MOSFETs) using 4H-SiC as substrate are expected to play a major role as a power semiconductor device. However, carbon clusters, which are formed in the oxidation process, increase interface states, and thus deteriorate device performance. Many researches have reported that the efficient method to remove the interfacial traps is the post-oxidation annealing (POA) using nitric oxide (NO) gas, which has become common process to remove interface traps. Although NO POA is effective on reducing interface traps, it is necessary to find the alternative and advanced methods to reduce interface traps effectively: deposition is one of them, because the most of carbon clusters are formed during oxidation process. The deposition of oxide films has been usually carried out by chemical vapor deposition (CVD) and atomic layer deposition (ALD). ALD oxide with NO post-deposition annealing (PDA) showed excellent performance was reported, but the MOSFET, which was fabricated with the ALD oxide, consisted of thin oxide less than 30 nm. However, the commercial products commonly used thicker than 50 nm. In this dissertation, oxide films thicker than 40 nm were deposited by ALD or sputtering, and then MOS capacitors were fabricated to evaluate their electrical and physical properties. And the effects of PDA conditions on the deposited oxide were also investigated. In addition, to evaluate the feasibility of oxide deposition without PDA, the oxides, which were deposited on the thermal buffer oxide, were also investigated. In order to densify the 50 nm SiO2 oxide film deposited with plasma-enhanced ALD (PEALD), the PDA was performed using Ar gas, which is an inert gas. At this time, the PDA was operated at 400, 600, 800, 1000, and 1200°C for 2 h. HF etch test and leakage current analysis showed that the oxide film was stabilized after densifying at 1000°C or higher. However, in the capacitance‒voltage (C‒V) characteristics, the densified sample at 1000°C was found to be in a less stable state, but a stable oxide film was formed only at 1200°C. In addition, the NO PDA, known to be effective at 30 nm, was conducted for 2 h at 1200°C on PEALD oxide. The C‒V hysteresis decreased significantly compared to the as-dep oxide, but the flat-band voltage (VFB) shifted significantly in the negative direction. This is because the thicker the oxide film, the greater the positive charging by nitrogen atoms. On the other hand, sputtering is a traditional physical vapor deposition (PVD) method, but it has not been often used to deposit the gate insulating films. To evaluate whether this sputtering SiO2 oxide film can be used as an insulating film, MOS capacitors with sputtered oxide were fabricated and their electrical properties and physical properties were also analyzed. N2, NH3, O2, and NO PDA were conducted to stabilize the sputtered oxide. All the samples were found to be sufficiently densified through refractive index measurement and HF etching test, and in the case of O¬2 PDA, an additional oxidation reaction occurred. As a result of the insulation property evaluation, N2 and NH3 did not have good insulation characteristics, which seems to be the result of the chemical reaction of nitrogen, increasing the leakage current. In the case of O2 and NO, they showed insulation characteristics but it was insufficient compared to thermal oxide. For the optimization of NO PDA for sputtering oxide, the 30, 60, and 90 min of NO PDAs were also investigated. As PDA time increased, VFB was negatively shifted and hysteresis decreased. As a result of normalized conductance‒frequency (GP‒ω) and Dit characteristics, the lowest interface traps were shown in the 60 min NO PDA among three conditions. Since both PEALD and sputtering use plasma, it is necessary to judge whether the plasma damage affects the substrate and interface characteristics. A passivation layer was formed through pre-oxidation before deposition, and then an oxide film was formed through PEALD and sputtering. As-deposition oxide without PDA showed poor insulating properties and large leakage current. However, pre-oxidation greatly reduced the leakage current and allowed a normal C‒V curve to be obtained. Although the leakage current is not as good as that of the thermal oxide, the overall characteristics are sufficiently improved for both PEALD and sputtering oxide. Based on these results, pre-oxidations using NO and N2O were conducted, and showed superior C‒V characteristics when using N2O and NO/O2 mixed gas. In this dissertation, whether the deposition SiO2 can be used as the gate oxide was investigated. To improve characteristics of PEALD and sputtering SiO2, post-deposition annealing and pre-oxidation were conducted. The applicability of PEALD and sputtering oxide was investigated through PDA and pre-oxidation under various conditions. If the deposition and annealing conditions were optimized, deposition oxide will have competitive enough to be used as a gate oxide for 4H-SiC MOS device.Chapter 1. Introduction 1 1.1 SiC Power Device 1 1.1.1 Power device 1 1.1.2 Conventional MOS Device 5 1.1.3 Application of SiC for power device and SiC MOS device 7 1.2. Material Properties of SiC 9 1.2.1 Structural properties 9 1.2.2 Thermal properties 12 1.2.3 Optical properties 14 1.2.4 Electrical properties 16 1.3 Gate Oxide Issue for SiC MOS Device 20 1.3.1 Conventional SiC MOSFET 20 1.3.2 The formation of defect between SiO2/SiC interface 23 Chapter 2. Literature Review 27 2.1 Fabrication Method of Gate Oxide 27 2.1.1 Thermal oxide on SiC 27 2.1.2 CVD oxide 31 2.1.3 ALD oxide 33 2.1.4 PVD oxide 35 2.2 Nitridation of SiO2 on SiC for MOS device 37 2.2.1 NO and N2O post-oxidation annealing 39 2.2.2 N2 post-oxidation annealing 43 2.2.3 Other nitridation methods 45 2.3 Basic of Device Measurement 49 2.3.1 C‒V measurement 49 2.3.2 Interface state density measurement 54 2.3.3 J‒E measurement 58 2.4 Electrical Characteristics of Gate Oxide on SiC 60 2.4.1 Thermal oxide 60 2.4.2 CVD oxide 63 2.4.3 ALD oxide 67 2.4.4 PVD oxide 73 Chapter 3. Experiment and Analysis 78 3.1 Sample Preparations 78 3.1.1 4H-SiC wafer information 78 3.1.2 Wafer cleaning process 78 3.2 Gate Oxide Deposition and Oxidation 79 3.2.1 Plasma-enhanced atomic layer deposition system 79 3.2.2 PEALD conditions of gate oxide deposition 80 3.2.3 Sputtering system and deposition condition 82 3.2.4 Dry oxidation process 83 3.3 Post-deposition annealing process 85 3.3.1 Apparatus of furnace for PDA 85 3.3.2 Ar post-deposition annealing 85 3.3.3 NO post-deposition annealing 86 3.3.4 N2, NH3, O2 Post-deposition annealing 86 3.4 MOS Capacitor Fabrication 88 3.5 Measurement and Analysis 89 3.5.1 Physical and chemical analysis of gate oxide 89 3.5.2 Electrical properties measurement of MOS capacitor 90 Chapter 4. Results and Discussions 92 4.1 Characteristics of PEALD Oxide with PDA 92 4.1.1 Effects of Ar PDA 92 4.1.2 Effects of NO PDA on 50nm SiO2 99 4.2 Characterisitcs of Sputtered Oxide with PDA 102 4.2.1 Physical and chemical properties 102 4.2.2 J‒E and oxide breakdown characteristics 108 4.2.3 C‒V and Dit characteristics 111 4.3 Analysis of Sputtered Oxide with NO PDA 117 4.3.1 C–V curve analysis 117 4.3.2 Modeling of charging in near interface traps 121 4.3.3 G–ω and Dit analysis 124 4.4 Deposited Oxide with Thermal Oxide Interlayer 127 4.4.1 PEALD oxide with dry thermal oxide 127 4.4.2 PEALD oxide with NO thermal oxide 132 4.4.3 PEALD oxide with NO/O2 and N2O thermal oxide 135 4.4.4 Sputtering Oxide with dry thermal oxide 140 4.5 Experiments Summary 144 Chapter 5. Conclusions 146 CURRICULUM VITAE 148 REFERENCES 154 LIST OF PUBLICATIONS 163 국문 초록 171Docto

2006년 우수 졸업논문 지원 사업

서울대학교 교수학습개발센터 글쓰기교실에서 2006년 1학기부터 시행하고 있는 '우수 졸업논문 지원 사업'은 단순한 요식 절차에 그칠 수도 있는 학부 졸업논문쓰기에 좀더 적극적인 의의를 부여하기 위해 마련되었다. 이 지원사업을 통해 졸업 예정자들이 졸업논문을 보다 성실히 주비하고 집필할 수 있는 동기를 부여함은 물론, 졸업논문 쓰기 과정에 대한 실제적인 자료를 수지하여 글쓰기 교욱에 활용할 수 있다

마우스 위암과 간암 모델에서 Osteopontin의 역할

학위논문 (박사)-- 서울대학교 대학원 : 수의학과, 2017. 2. 김대용.Osteopontin (OPN), coded by secreted phosphoprotein 1 (Spp1) gene, plays a variety of roles in pathophysiological processes, including inflammation and carcinogenesis. Clinically, the elevated OPN levels in plasma or tissue from patients were identified in inflammatory diseases such as Crohns disease and rheumatoid arthritis, and in various cancers. In this study, we demonstrated the role of OPN in Helicobacter pylori (H. pylori)-induced gastritis, gastric cancer and chemically induced hepatocellular carcinoma using C57BL/6-Spp1tm1Blh(-/-) (OPN KO) mice and OPN knockdown human cancer cell lines. In H. pylori-induced gastritis model, the degree of inflammation of OPN KO mice was lower compared to that of WT mice, with a significant reduction in infiltratied macrophages and the expression of IL-1β, TNF-α, and IFN-γ. Similar to these results, mRNA expression of the pro-inflammatory cytokines was reduced in OPN KD gastric cancer cell lines exposed to H. pylori, and the conditioned media (CM) from these cells decreased the migration of monocytic and macrophage-like cell lines. Furthermore, H. pylori-infected OPN KO mice had a lower number of proliferative gastric epithelial cells than WT mice, in association with a reduction in mitogen-activated protein kinase (MAPK) pathway activation. OPN KD gastric cancer cell lines also showed the suppression of the G1/S cell-cycle after H. pylori co-culture and reduced MAPK activation after IL-1β and TNF-α treatment. In H. pylori and chemical-induced gastric cancer model, the overall incidence of gastric tumors was significantly decreased in OPN KO mice compared to WT mice. Apoptotic cell death was significantly enhanced in OPN KO mice, and was accompanied by upregulation of signal transducer and activator of transcription 1 (STAT1) and inducible nitric oxide synthase (iNOS). In AGS and THP-1 cells, OPN suppression also caused STAT1 upregulation and iNOS overexpression, which resulted in apoptosis of AGS cells. In addition, a negative correlation was clearly identified between expression of OPN and iNOS in human gastric cancer tissues. Our data demonstrate that loss of OPN decreases H. pylori-induced gastric carcinogenesis by suppressing pro-inflammatory immune response and augmenting STAT1 and iNOS-mediated apoptosis of gastric epithelial cells. Furthermore, the overall incidence of chemically induced hepatic tumors at 36 weeks was significantly decreased in OPN KO mice compared to WT mice. Consistent with the result of gastric cancer model, apoptosis was significantly enhanced in OPN KO mice and was accompanied by downregulation of epidermal growth factor receptor (EGFR). In Hep3B and Huh7, OPN suppression also caused the decreased mRNA and protein levels of EGFR with the downregulation of c-Jun, which resulted in the increased apoptotic cell death of both cell lines. In addition, a positive correlation was clearly identified between expression of OPN and EGFR in human HCC tissues. Taken together, these data demonstrate that the loss of OPN decreases the degree of H. pylori-associated gastritis, which resulting in the suppression of gastric cancer development. In addition, it can be concluded that loss of OPN inhibits gastric and hepatic carcinogenesis through promotion of apoptotic cell death in cancer cells.Literature Review 1 CHAPTER I. 14 CHAPTER II. 58 CHAPTER III. 112 국문초록 157 REFERENCES 161Docto

교육 개선을 위한 단과대학 교무부학장과의 좌담회

좌담회 진행 방식은 교수학습개발센터 부서별 교육 프로그램 안내 (교수자, 학부학생, 대학원생 대상 교육 지원 프로그램 안내 및 각 단과대 학과의 협력 사례 소개)와 각 단과대학별 교육 개선을 위한 요구 사항 전 달 및 협력 방안에 대한 논의로 진행되었다. 다음의 내용은 양일에 걸쳐 진행된 좌담회 내용을 주제 중심으로 재구성한 것이다

Posttransplant Lymphoproliferative Disorder without Epstein-Barr Virus Presented as Small Bowel Perforation in Renal Transplant Recipient: A Case Report

Posttransplant lymphoproliferative disorder (PTLD) is documented as one of the serious complications leading to mortality particularly in organ transplant recipients receiving immunosuppressive therapy. Extant literature confirms beyond doubt that the most common site of involvement of PTLD is lymph nodes, and rarely involved is the gastrointestinal tract. It is a well-known fact that Epstein-Barr virus (EBV) is a risk factor for PTLD development. In this study, we report a case of PTLD presented as small bowel perforation without EBV infection after long-term immunosuppressive therapy in a renal transplant recipient.ope

Clinical Characteristics and Risk Factors for Renal Cell Carcinoma after Kidney Transplantation

Background The occurrence of malignancy following kidney transplantation has been estimated three to five times the incidence compared to that of the general population. It is estimated that particularly in renal cell carcinoma (RCC), the relative risk increases. The aim of this study was to analyze the characteristics, risk factors, and prognosis of RCC following kidney transplantation. Methods Total number of 3,272 kidney recipients who underwent transplantation from April 1979 to December 2012 and patients who had RCC following kidney transplantation were retrospectively reviewed and analyzed. Results We found that among 232 cases of posttransplant malignancies, 25 recipients were diagnosed with RCC. We have observed in our study that it took an average of 175.2±71.0 months to develop RCC after their first kidney transplantation. However, with longer follow up period, interval incidence of RCC increased. Fourteen patients (56%) were diagnosed with RCC 15 years after transplantation. We also found that with reference to the risk factor analysis for posttransplant RCC, the long-term follow-up period was the only independent risk factor. In our study, 21 patients with RCC were treated with radical nephrectomy. Of them, 16 patients survived, and four RCC-related deaths occurred. Furthermore, the patient survival rate of RCC recipients was lower than that of the nonmalignancy group despite the graft survival rate were not different. Conclusions We conclude that the incidence of RCC increased in a time-dependent manner following kidney transplantation. Therefore, we strongly recommend the procedure of regular-interval screening for the patients who are on compulsive long-term immunosuppression.ope

Comparison of the usability of dental composite resin systems as a direct core material

치의학과/석사[한글] 코어(core)는 광범위하게 손상받은 치아를 고정성 보철수복을 위한 지대치 삭제에 적합한 형태로 재건하는데 사용되어지는 수복물로 정의할 수 있다. 레진 필러(filler)의 입자 크기 및 조성을 달리하여 다양한 흐름성과 조작성을 가지게 한 여러 가지 충전용 복합 레진을 비롯하여, 레진 시멘트(resin cement) 및 코어 축조를 위한 전용 복합 레진 등 다양한 복합 레진 시스템이 코어 축조를 위해 혼용되어지고 있다. 본 연구의 목적은, 다양한 조성과 물성을 가진 여러 종류의 치과용 복합 레진 시스템의 직접 코어 축조를 위한 재료로서의 유용성을 알아보는 것이며, 이를 위하여 압축 강도(Compressive strength), 탄성 계수(Elastic modulus), 전단 결합 강도(Shear bond strength)를 측정하여 비교하였다.실험을 위해 7가지 복합 레진 시스템을 사용하였다. 압축 강도와 탄성 계수 측정을 위해 높이 12.0 mm, 지름 6.0 mm의 원통 모양 시편을 제작하였으며, 각 군당 40개씩의 시편을 배정하고 이를 다시 무작위로 두 개 조로 나누었다. 한 조는 측정 전 1시간 동안 실온에서 증류수에 보관하였으며, 나머지 한 조는 1200회 thermocycling(5, 55 ℃, 저류시간: 30초씩)을 시행 한 후 crosshead speed 1.5 mm/min 하에서 Universal testing machine을 이용하여 압축 강도 및 탄성 계수를 측정하였다. 전단 결합 강도의 측정을 위해, 140개의 우식에 이환되지 않은 최근에 발치된 사람의 상하악 대구치를 남아있는 연조직을 제거한 후 지름과 높이가 25 mm인 원통 모양의 테플론 몰드를 이용하여 cold-cured acrylic resin에 함입시켰다. 치아의 상아질을 노출시키고, 도말층(smear layer)을 형성한 후 각 군당 20개씩의 시편을 무작위로 배정하였다. 각 adhesive system별로 제조사의 지시에 따라 표면을 처리한 후 Ultradent test assemble을 이용하여 resin rod를 만들었다. 시편을 1시간 동안 실온에서 증류수에 보관한 후 crosshead speed 1.0 mm/min 하에서 Universal testing machine을 이용하여 전단 결합 강도를 측정하였다. Thermocycling을 시행한 후의 측정값을 얻기 위해, 실험을 마친 시편을 약 0.5~1.0 mm 정도 갈아낸 후 앞서 행한 과정을 반복하여 새로운 140개의 시편을 얻어냈다. 이를 1200회 thermocycling을 시행한 후 같은 방법으로 전단 결합 강도를 측정하였다. SPSS™ Ver 12.0(SPSS Inc., Chicago, IL, USA)을 이용하여 통계 처리를 시행하였다. 압축 강도, 탄성 계수, 전단 결합 강도 각각에 대해 동일한 재료 내에서 thermocycling 전과 후의 통계적 유의성을 t-test(5% 유의수준)로 검정하였다. 또한 압축 강도, 탄성 계수, 전단 결합 강도 각각에 대한 재료간의 통계적 유의성을 thermocycling 전과 후로 나누어 one-way ANOVA(5% 유의수준)로 검정하였고 Duncan''s multiple range test로 사후 검정하였다.실험 과정상의 한계점내에서 본 연구를 통해 다음과 같은 결과를 얻었다.1. Thermocycling 시행 전 Filtek™P60과 Z100™Restorative는 대조군인 Bisfil™Core에 비해 유의성 있게 높은 압축 강도를 나타내었고, 반면 Panavia™F는 유의성 있게 낮은 측정값을 나타내었다. Thermocycling 시행 후에도 Filtek™P60과 Z100™Restorative는 대조군인 Bisfil™Core에 비해 유의성 있게 높은 측정값을 나타내었고, 반면 CharmFil Flow와 Panavia™F는 유의성 있게 낮은 측정값을 나타내었다(p<0.05).2. Thermocycling에 의해 Bisfil™Core와 Filtek™P60은 압축 강도가 유의성 있게 증가하였고, CharmFil Flow, LuxaCore&#9415;와 Panavia™F는 유의성 있는 감소를 보였다(p<0.05).3. Thermocycling 시행 전 Filtek™P60, Z100™Restorative와 SureFil은 대조군인 Bisfil™Core에 비해 유의성 있게 높은 탄성 계수를 나타내었고, 반면 LuxaCore&#9415;, CharmFil Flow, Panavia™F는 유의성 있게 낮은 측정값을 나타내었다. Thermocycling 시행 후 모든 실험군이 대조군인 Bisfil™Core에 비해 유의성 있게 높은 측정값을 나타내었다(p<0.05).34. Thermocycling에 의해 Bisfil™Core를 제외한 나머지 재료들은 모두 탄성 계수가 유의성 있게 증가하였고, Bisfil™Core는 유의성 있는 감소를 보였다(p<0.05).5. 탄성 계수는 7개 재료 모두가 상아질에 비해 전반적으로 낮은 탄성 계수값을 나타내었다. 비록 thermocycling 시행 후 Bisfil™Core를 제외한 나머지 6개 재료가 모두 그 값이 유의성 있게 증가하였지만, 그 중 가장 높은 값을 갖는 Z100™Restorative(6151 MPa)도 상아질과는 상당한 차이를 갖는다.6. CharmFil Flow와 Panavia™F는 thermocycling 시행 전과 후 모두에서 다른 재료들에 비하여 유의성 있게 낮은 전단 결합 강도를 나타내었다(p<0.05).7. Thermocycling에 의해 Bisfil™Core, Filtek™P60, 그리고 SureFil의 결합 강도는 유의성 있게 증가되었다(p<0.05). .8. 전단 결합 강도 실험에 따른 상아질과 코어 재료 사이의 결합 실패 양상(failure mode)은 Panavia™F를 제외한 대부분이 상아질과 재료사이의 계면에서 발생(adhesive failure)하였으며, 반면 Panavia™F의 실패 양상은 mixed failure(adhesive failure를 동반한 cohesive failure)가 대부분이었다..이상의 결과로 Bisfil™Core, Filtek™P60, LuxaCore&#9415;, SureFil, Z100™Restorative는 직접 코어 재료로서 유용성이 있으며, 그에 비해 CharmFil Flow와 Panavia™F는 직접 코어 재료로서의 유용가치가 상대적으로 낮은 것으로 사료된다. 본 연구에서 측정한 압축 강도, 탄성 계수, 전단 결합 강도 외에도 이상적인 코어 재료가 갖추어야 할 여러 다른 요소들의 관점에서의 추가적인 연구가 필요하리라 사료된다. [영문]A core can be defined as a restoration used to build-up extensively damaged teeth to a form suitable for crown preparation. Different composite resin systems such as composite resins with various flowability and manipulability by altering its filler particle size and components, resin cement and core build-up resin are used for direct core build-up procedure. The purpose of this study is to find out the usabilities of different dental composite resin systems with various composition and physical properties as materials for direct core build-up procedure. For this study, compressive strength, elastic modulus and shear bond strength of different dental composite resin systems were measured and compared.Seven different composite resin systems were used in this study. For measurement of compressive strength and elastic modulus, cylindrical specimens of height 12.0 mm and diameter 6.0 mm were made. Each group consisted of randomly selected 40 specimens and bisected into two groups once more. One group was stored in distilled water under room temperature one hour prior to measurement and the other group was thermocycled 1200 times(5, 55 ℃, dwell time: 30 seconds). Compressive strength and elastic modulus of both groups were measured using a Universal testing machine under crosshead speed of 1.5 mm/min. For measurement of shear bond strength, 140 recently extracted caries-free upper and lower human molars were inserted into cold-cured acrylic resin using a cylindrical teflon mold of diameter and height 25 mm after removal of its soft tissues. After dentin was exposed and smear layers were formed, radomly selected 20 specimens were arranged to each group. The surface was treated with each adhesive system according to the manufacturer''s instructions and then resin rods were made with Ultradent test assemble. Shear bond strength was measured using Universal testing machine under crosshead speed of 1.0 mm/min after the specimen was stored in distilled water for an hour at room temperature. In order to obtain post-thermocycling measurement values, about 0.5-1.0 mm were removed from the post-experimental specimens and previous procedures were repeated leaving newly made 140 specimens. After thermocylcing the specimens for 1200 times, shear bond strength was measured with the same method. Statistical analysis was performed using SPSSTM Ver 12.0. Statistically significant differences about each compressive strength, elastic modulus and shear bond strength between pre and post thermocycled specimens within the same material were conformed to t-test(p<0.05). Similarly statistically significant differences about each compressive strength, elastic modulus and shear bond strength between materials of pre and post thermocycled materials was conformed with one-way ANOVA(p<0.05). Duncan''s multiple range test was used for the post hot analysis.Within experimental limits, the following results were obtained from this study. .1. Before thermocycling, the compressive strengths measurement values of Filtek™P60 and Z100™Restorative were statistically significantly higher than Bisfil™Core which was used as a control of this study, on the other hand Panavia™F was statistically significantly lower than Bisfil™Core. Similarly, the post thermocycled compressive strength measurement values of Filtek™P60 and Z100™Restorative were statistically significantly higher than Bisfil™Core, on the other hand CharmFil Flow and Panavia™F values were statistically significantly lower than Bisfil™Core (p<0.05).2. The compressive strength of Bisfil™Core and Filtek™P60 showed a statistically significant increase by thermocycling whereas CharmFil Flow, LuxaCore&#9415; and Panavia™F showed a statistically significant decrease(p<0.05).3. Before thermocycling, the elastic modulus of Filtek™P60, Z100™Restorative and SureFil were statistically significantly higher than Bisfil™Core which was used as a control of this study, on the other hand LuxaCore&#9415; , CharmFil Flow and Panavia™F were statistically significantly lower than Bisfil™Core(p<0.05).4. The elastic modulus of all materials except Bisfil™Core showed a statistically significant increase by thermocycling. Bisfil™Core showed a statistically significant decrease (p<0.05).5. All values of elastic modulus of the seven materials showed a lower value compared to dentin. Although all six materials except Bisfil™Core showed a statistically significant increase, Z100™Restorative which showed the highest value still showed a significantly lower value compared to dentin.6. The shear bond strengths of CharmFil Flow and Panavia™F showed a statistically significantly lower than other materials from both the pre and post thermocycling(p<0.05).7. The shear bond strengths of Bisfil™Core, Filtek™P60 and Surefil showed a statistically siginificant increase by thermocycling(p<0.05).8. The bonding failure between dentin and core material in the shear strength test occurred as an adhesive failure in most materials except Panavia™F, whereas the bonding failure of Panavia™F was adhesive failure accompanied by cohesive failure.To conclude, It seems that Bisfil™Core, Filtek™P60, LuxaCore&#9415;, Surefil, and Z100™Restorative were appropriate to use as a direct core build material whereas CharmFil Flow and Panavia™F were not appropriate as a direct core build up material. However, additional studies of different properties other than compressive strength, elastic modulus and shear bond strength discussed in this study seems to be required in order to approve the results obtained from this study.ope

The Linkage Between South-North Korean Politics and Great Power Politics in Northeast Asia

이 글의 목적은 동맹정치의 관점에서 한미동맹과 북중동맹이 남북한의 한반도 정치에 미치는 영향과 역으로 미·중 동북아 강대국 정치가 남북한의 한반도 정치에 미치는 영향을 비교·분석하는 것이다. 한미동맹과 북중동맹이 남북한의 한반도 정치에 미치는 영향은 다음과 같다. 우선적으로 한미동맹이 남북한의 한반도 정치에 미치는 영향은 북한 문제의 국제적 쟁점을 둘러싸고 남-북-미라는 삼각관계를 형성하면서 포기와 연루라는 동맹 딜레마를 주기적으로 표출시켜 왔다고 볼 수 있다. 반면, 북중동맹이 남북한의 한반도 정치에 미치는 영향은 한미동맹과는 달리 북중동맹 차원에서의 동맹 딜레마가 거의 존재하지 않는다는 점이다. 또한 한미동맹 관계에서 남북한의 한반도 문제가 국제화될수록 한국의 안보 자율성이 제약을 받는 것과는 대조적으로 북중동맹의 북한에게 있어서 한반도 문제의 국제화는 커다란 제약으로 작용하기보다는 자신의 자율성을 제고할 수 있는 하나의 전략적 카드로 작용하는 측면을 보여주고 있다는 점이다. 한편, 미-중 동북아 강대국 정치가 남북한의 한반도 정치에 미치는 영향은 기본적으로 미중 관계의 변화 양상에 따라 달리 나타날 가능성이 높다는 것이다. 즉, 미중 강대국 정치의 관여와 통합 성격이 부각될 경우, 남북한의 한반도 정치는 강대국 동맹정치의 파열음으로부터 어느 정도 벗어나 남북한 당사자가 보다 자율적이고 적극적으로 한반도 정치를 운영해 나갈 수 있는 공간을 확보할 개연성이 높다. 반면, 미-중 강대국 정치의 균형 성격이 부각될 경우, 남북한의 한반도 정치는 강대국 동맹정치의 구도로 편입되어 한반도 정치의 자율성이 극히 제약될 수 있다는 점이다. 그러나 균형 성격이 강조되는 미-중 강대국 정치는 한미동맹 및 한국과 북중동맹 및 북한에 사뭇 다른 영향을 미치는 것으로 나타났다.This study analyzes the linkage between South-North Korean politics and great power politics in Northeast Asia in perspective of alliance politics. South and North Korea has formed alliance with its parter, U.S. and China respectively. Thus an interplay of South-North Korean politics has impacted on great power politics in Northeast Asia after the end of the Cold War and the reverse is true. In this context, I show several aspects of alliance politics embedded in South-North Korean politics and great power politics between the United States and China in Northeast Asia. My point is that great power politics has heavily influenced on South-North Korean politics but its impact on South and North Korea is very different. So, the main purpose of this study is to review alliance types of South and North Korea and correlations between great power politics and security autonomy of South-North Korea and to identify some important reasons why North Koreas autonomy is relatively high than South Koreas autonomy

쓸 말을 찾아내는 글쓰기

예전에 국어 교과서에서 좋은 글쓰기란쓰고 싶을 때, 쓰고 싶은 말을 쓰는 것이라는 취지의 수필을 읽은 기억이 난다. 맞는 말이다. 그런데 이를 쓰고 싶지 않거나 쓰고 싶은 말이 없을 때에는 글을 쓸 수 없다는 뜻으로 이해해도 될까? 그러나 우리는 아주 현실적인 이유에서 그다지 쓰고 싶지도 않고 또 굳이 쓰고 싶은 말도 없지만 글을 써야 할 경우를 적지 않게 만나게 된다. 이 경우 우리는 글을 쓰지 않으면 될까? 아마도쓰고 싶을 때, 쓰고 싶은 말을 쓰는 것이라는 좋은 글쓰기의 요건은 다소 보완될 필요가 있을 것이다. 사실, 아무런 준비도 안 하고 있는데 불현듯 뭔가가 쓰고 싶어지는 사람은 거의 없다고 봐도 무방하다. 중요한 것은 어떤 준비 과정을 통해 쓸 말을 찾거나 만들어가는 과정이다. 예를 들어, 대학에서 대중문화에 관한 강의를 듣는다고 생각해 보자. 강의가 어느 정도 진행된 후 그 주제와 관련된 리포트를 제출하라는 요구를 받을 수 있다. 혹은 그 주제와 관련된 책을 읽고 서평을 써 오라는 요구를 받을 수 있다. 모르긴 해도 수강생 중 열에 아홉은 별로 쓰고 싶지도 않고, 또 쓸 말도 없을 것이다. 쓰고 싶지 않은 것이야 억지로 쓰고 싶도록 만들 수는 없지만, 적어도 쓸 말을 찾는 과정은 반드시 필요하다