중심기업(Focal Firm) 제품에 대한 사회적 조명도가 경쟁 기업의 대응제품 출시에 미치는 영향: 제도론과 Competitive Dynamics 관점에서

학위논문 (석사)-- 서울대학교 대학원 : 경영학과, 2012. 2. 박철순.본 연구는 중심기업(Focal firm)의 제품에 대한 사회적 조명도가 경쟁 기업의 대응제품 출시에 미치는 영향을 살펴보았다. 2005년부 터 2011년까지 국내 휴대폰 시장에서의 대응 관찰치 138개를 분석 해본 결과, 중심기업(Focal firm)의 제품에 대한 사회적 조명도가 높 을수록 경쟁 기업이 출시하는 대응 제품의 수가 증가하였다. 또한 이러한 영향은 중심기업의 성장성이 높을 때, 더욱 강하게 나타났 다. 이러한 결과는 Competitive Dynamics 연구에서도 실질적으로 경쟁이 일어나는 제도적 환경에 대한 이해가 중요함을 시사한다.This paper examines how the social interest on a focal firms product affect its competitors new product launch. By analyzing a sample of the Korean cell phone market from 2005 to 2011, the results show that the greater the degree of social interest on a focal firms product, the more aggressively competitors respond. Furthermore, this effect appears stronger when the focal firm is growing rapidly. These results imply that the understanding of the institutional environment is also important in competitive dynamics research.Maste

Optimal Surgical Treatment Strategy for T1b Gallbladder Carcinoma : Multinational multicenter study and meta-analysis

학위논문(박사)--서울대학교 대학원 :의과대학 의학과,2019. 8. 장진영.배경 및 목적: T1b 담낭암에 대한 최적의 수술 범위는 논란의 여지가 남아있다. 단순 담낭 절제술이 T1b 담낭암에 대해 충분한 치료라는 주장이 있는 반면, 몇 가지 진료 지침에서는 T1b 담낭암에 대한 확대 담낭절제술을 권장한다. 그러나 T1b 담낭암의 최적 수술 범위에 관한 증거는 부족하다. 본 연구는 장기 생존과 관련하여 T1b 담낭암의 최적 수술 범위를 체계적으로 평가하기 위해 다빈도 발생국가 중심의 다국가 다기관 연구를 시행하고 이를 바탕으로 메타분석을 시행하는 것을 목적으로 하였다. 대상 및 방법: 한국, 일본, 칠레 및 미국의 전문적 간담췌외과 및 병리학자를 갖춘 14개 센터에서 외과적 절제술을 시행 받은 T1b 담낭암 환자 272명을 대상으로 자료를 수집하여 분석을 시행하였다. 수술 종류에 따른 질병 특이 생존율(disease specific survival, DSS)을 포함한 임상 결과를 분석하였다. 또한 메타분석을 위해 1990년부터 MEDLINE, EMBase에 영문으로 등재된 논문을 대상으로 포괄적인 문헌 검색을 수행하여 선정기준에 따라 조직학적으로 확진된 T1b 담낭암 환자를 대상으로 생존 데이터가 있는 적합한 연구를 확인하였다. T1b 담낭암 환자 군을 단순 담낭절제술 군과 확대 담낭절제술 군으로 나누어 이에 따른 생존율에 관한 자료를 추출하여 위험 비율, 위험 차이 및 95 % 신뢰 구간을 확인하였다. 결과: 단순 담낭절제술 (simple cholecystectomy, SC)은 121 명 (51.1 %)에서 시행되었으며 확대 담낭절제술 (EC)을 116 명 (48.9 %)에서 시행하였다. 전체 5년 DSS는 94.6 % 였고 SC와 EC 환자에서 유사한 결과를 보였다 (93.7 % 대 95.5 %, P = 0.496). 5년 DSS는 아메리카대륙 국가(82.3 % vs.100.0 %, P = 0.249)와 아시아대륙 국가(98.6 % vs 95.2 %, P = 0.690)로 나누어 분석하여도 SC와 EC 환자 간에 유사한 결과를 보였다. 또한 5년 DSS는 림프절 전이 (P = 0.688) 또는 종양 위치 (P = 0.474)에 따라 유의한 차이가 없었다. 메타분석 결과는 총 951 명의 환자를 포함한 18 개의 간행물이 최종 분석에 포함되었다. T1b 담낭암 환자에서 단순 담낭절제술과 확대 담낭절제술의 위험 차이(risk difference)는 0.04 (95 % 신뢰 구간, -0.12~0.03)였다. 위험 정도의 차이는 수술 방법에 따라 통계적으로 유의한 차이를 보이지 않았다 (P = 0.13). 또한 T1b 담낭암 환자에서 단순 담낭절제술과 확대 담낭절제술의 두 가지 수술적 개입 사이의 위험 비(risk ratio)는 1.26 (95 % 신뢰 구간, 0.73~2.20)이었으며 이 역시 통계적으로 유의하지 않았다 (P = 0.34) 결론: 단순 담낭절제술과 확대 담낭절제술은 T1b 담낭암 환자에서 비슷한 생존 결과를 보였다Background: The optimal surgical extent for T1b gallbladder cancer (GBC) remains controversial. Although some studied showed simple cholecystectomy is a sufficient treatment for T1b gallbladder cancer, but several guidelines recommend extended cholecystectomy for T1b GBC. However, evidence regarding the optimal surgical extent for T1b GBC is still lacking. This study aims to systematically evaluate the optimal surgical extent for T1b GBC with regard to long-term survival. Methods: 1. A total of 272 patients with T1b GBC who underwent surgical resection at 14 centers with specialized hepatobiliary-pancreatic surgeons and pathologists in Korea, Japan, Chile, and the United States were studied. Clinical outcomes including disease specific survival (DSS) rates according to the types of surgery were analyzed. 2. A comprehensive literature search in MEDLINE and EMBase was performed to identify studies with histologically proven GBC and survival data. A total of 18 articles with a total of 951patients were included in the final analysis. Dichotomous data regarding survival in T1b GBC cases were extracted. Risk ratios, risk differences, and 95% confidence intervals (CIs) were pooled. Results: 1. After excluding patients, the 237 qualifying patients consisted of 90 men and 147 women. Simple cholecystectomy (SC) was performed in 116 patients (48.9%) and extended cholecystectomy (EC) in 121 patients (51.1%). The overall 5-year DSS was 94.6%, and it was similar between SC and EC patients (93.7% vs. 95.5%, P = 0.496). The 5-year DSS was similar between SC and EC patients in America (82.3% vs. 100.0%, P = 0.249) as well as in Asia (98.6% vs. 95.2%, P = 0.690). The 5-year DSS also did not differ according to lymph node metastasis (P = 0.688) or tumor location (P = 0.474). 2. The pooled risk difference between simple cholecystectomy and extended cholecystectomy was 0.04 (95% confidence interval (CI), -0.12 ~ 0.03) in patients with T1b GBC. There was no statistically significant difference in the degree of risk according to the surgical method (P = 0.13). And the pooled risk ratio between the two surgical interventions of T1b GBC was 1.26 (95% CI, 0.73 ~ 2.20), which was also not statistically significant (P = 0.34). Conclusion: Simple and extended cholecystectomy showed comparable survival outcomes in T1b GBC patients초록 - i 목차 - iv 표 목차 - v 그림 목차 - vi 배경 및 목적- 1 방법 - 3 결과 - 8 고찰 - 16 참고문헌 - 23 영문 초록 - 50Docto

고려전기 國政의 결정과 회의

This study dealts with the decision of state affairs and conference in the early Koryo period. It was the king the most important thing in the carrying-out of the state affairs. Without the king, it was impossible to carry out of the state affairs. But he couldn't decide all thing on his own authority. Usually he referred to conference with ministers. Jaesang(宰相) was the men who took counsel with the king lawfully. They examined the king's order in the Jeongsadang (政事堂) and discussed with king's inquiry and conferred with state affairs without king's inquiry. Sometimes they discussed state affairs with king. Chumil(樞密") couldn't confer with state affairs by themselves. They should come together with Jaesang in order to confer with state affairs. There were a example in the 11th century, but many in the 12th century. They discussed on urgent state affairs with king's inquiry. Bosin(輔臣)-conference was consist of 14-17 ministers and conferred with state affairs in the commission of king. The conference with Sikmokdogamsa(式目都監使) was consist of about 15 ministers and discussed state affairs with the king's inquiry after the proposal of Sikmokdogam. Gunsin(群臣) -conference was consist of Jaechu(宰樞), literary and military officer above the third class, Sangchamgwan(常參官). They discussed with king's inquiry and in the commission of king. These conferences could know a little more in the system of the state affairs carrying-out. The carrying-out of state affairs was consist of ministers' proposal, king's decision, ministers' execution. Jaesang took counsel with the king lawfully. Jaesang, Jaechu, Bosin, Ministers with Sikmokdogamsa, Gunsin conferred with the state affairs with king's inquiry. This system reflected on ministers' interest that state affairs were determined on the agreement of king and mininsters

Graphene and its nanocomposites as a platform for environmental applications

Graphene is a two-dimensional nanomaterial with unique characteristics that can be used to efficiently remove organic pollutants in the aqueous system via adsorption and photocatalytic degradation. This review was organized to offer valuable insights into the mechanisms regulating the graphene and its related nanomaterials as the platform for the treatment of various organic pollutants in aqueous media. To this end, the performance variables of graphene, functionalized graphene, and graphene-supported materials are evaluated for such applications in some respects. Our discussion is extended further to describe regeneration and reuse of these nanomaterials along with future challenges encountered in their applications, especially on toxicity and stability aspects. (C) 2017 Elsevier B.V. All rights reserved.This work was supported by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology (MEST) (No. 2016R1E1A1A01940995). JWP also acknowledges the support made by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, & Future Planning (NRF-2015R1A2A1A09005838)

Study on Jaechu organization and polity carrying-out system in early Koryo period

학위논문(박사)--서울대학교 대학원 :국사학과,2000.Docto

Phthalocyanine Tetrasulfonate를 이용한 Aβ의 세포독성 제어책 개발에 관한 연구

Thesis(masters) --서울대학교 대학원 :화학생물공학부,2009.8.Maste

3차원 악안면 CT영상의 기준좌표계 설정

Thesis(doctor`s)--서울대학교 대학원 :치의학과 치과교정학전공,2006.Docto

Change of nutritional index, pancreas function and quality of life after pancreatectomy: prospective clinical trial

학위논문 (석사)-- 서울대학교 대학원 : 의학과, 2012. 2. 장진영.Background Data: Pancreatectomy is major treatment modality for various pancreas and periampullary diseases. But still there are a few studies concerning with nutritional index, pancreas function and quality of life after pancreatectomy. Objective: To assess change of nutritional index, pancreas function and quality of life after pancreatectomy Methods: From 2007 to 2011, we analyzed 157 consecutive pancreatectomy patients with at least finish 1 year follow up. Relative body weight (RBW), Triceps skinfold thickness (TSFT), Serum protein/albumin, transferrin, fasting blood sugar (FBS), Oral glucose tolerance test (oGTT), HbA1c, EORTC QLQ-C30 questionnaire were collected serially (preoperative, discharge, 3month, 6month, 12month). Results: RBW (107.7, 102.0, 101.0, 102.8, 103.6; respectively preoperative, discharge, 3 month, 6 month, 12 month) TSFT (13.3, 13.0, 12.0, 12.5, 12.3) recover at 6month, whereas transferrin, albumin, protein recover at 3month. DM or impaired fasting glucose (IFG)/impaired glucose tolerance (IGT) was severe at 6 month and recover at 12 month (32.1, 58.5, 57.4, 63.2, 51.7; % of total numbers). Also steatorrhea and diarrhea show recovery at 3 month (4.7, 16.7, 7.4, 5.7, 6.9%; 7.4, 25.9, 12.3, 14.8, 10.8). Global health status/QoL and functional scales recover to preoperative score at 3 month and improve to higher than preoperative score (61.7, 41.2, 63.4, 67.4, 71.3). Multivariate analysis reveals extensive operation, adjuvant therapy, chronic pancreatitis and malignant disease have significant impact on nutritional index, pancreas function and quality of life (p<0.05) Conclusions: Nutritional index, pancreas function and quality of life recover at 3 month and 6 month after pancreatectomy. Patients with risk factor need more careful follow-up and supportive management.연구목적: 췌장 절제 수술은 다양한 췌장과 팽대부 주위의 질환에 대한 주요 치료 법 중 하나이며 최근 장기 생존 환자들이 많아 졌으나 여전히 췌장 절제술 이후의 영양학적 지표, 췌장 기능 그리고 환자의 삶의 질에 관한 연구는 많지 않은 실정이다. 본 연구에서는 췌장 절제술 이후의 영양학적 지표, 췌장 기능 및 삶의 질의 변화에 대해 분석하는 하였으며, 또한 이에 영향을 미치는 인자들을 찾아 보았다. 대상 및 방법: 2007년 10월부터 2010년 3월까지 본 기관에서 췌장 절제술을 시행 받고 1년 이상 외래 추적 진료를 시행한 연속적인 157명의 환자를 대상으로 분석하였으며 상대 몸무게(relative body weight, RBW), 삼두근피부두겹두께(triceps skinfold thickness, TSFT), 혈청 단백질, 알부민, 트랜스페린, 공복혈당, 경구 포도당 내성 검사, 당화혈색소 그리고 EORTC QLQ-C30/PAN26 설문조사를 전향적이고 연속적으로 측정하였다(수술 전, 퇴원 시, 수술 후 3개월, 6개월, 12개월). 결과: 상대몸무게 (107.7, 102.0, 101.0, 102.8, 103.6; 각각 수술 전, 퇴원 시, 수술 후 3개월, 6개월, 12개월)와 삼두근피부두겹두께 (13.3, 13.0, 12.0, 12.5, 12.3)는 수술 후 6개월 추적 검사에서 회복되는 양상을 보인 반면, 트랜스페린, 알부민, 단백질은 3개월 추적 검사에서 회복되는 양상이었다. 당뇨와 공복혈당 장애/내당능 장애는 수술 후 6개월에 가장 심하였으며 12개월 추적에서는 회복되는 양상이었다 (32.1, 58.5, 57.4, 63.2, 51.7; % 환자수). 또한 지방변과 설사는 3개월 추적에서 회복을 보였으며 (4.7, 16.7, 7.4, 5.7, 6.9%; 7.4, 25.9, 12.3, 14.8, 10.8) 삶의 질과 기능적 항목들에서는 3개월 추적에서 수술 전의 상태까지 회복되고 그 이후 수술 전 상태 이상의 삶의 질 향상을 보였다 (61.7, 41.2, 63.4, 67.4, 71.3). 다변량 분석을 통하여 수술의 방법, 수술 후 보조적 치료 여부, 수술 전 췌장염 여부, 질병의 악성도가 환자의 영양학적 지표, 췌장의 기능 및 삶의 질에 영양을 주는 인자로 밝혀졌다(p<0.05). 결론: 영양학적 지표, 췌장의 기능 그리고 삶의 질의 지표는 수술 후 3개월과 6개월에서 회복을 보였다. 그러나 기능적인 부전을 보일 수 있는 요소를 가지고 있는 환자들에서는 더 주의 깊은 추적관찰과 보조적인 처치가 필요하다.Maste

The study on the measurement error of the 3d digital model made by laser scan method Laser scan으로 제작된 3차원 진단모형의 계측치오차에 대한 연구

Thesis (master`s)--서울대학교 대학원 :치의학과 치과교정학,2003.Maste

미세조류 내 바이오디젤 생산을 정량화하는 미세유체 플랫폼 개발

학위논문 (박사)-- 서울대학교 대학원 : 기계항공공학부, 2015. 2. 전누리.Microfluidics always has been appealed to biologist because of the capability to control the cellular microenvironment in both a spatial and temporal manner. These system can generate a biological relevant stimulus including concentration gradient, nutrient conditions and physical and chemical stresses by taking advantage of basic characteristics of laminar flow and diffusion. Moreover, microfluidic techniques have been presented a novel paradigm for screening system with their small volume fractions and high-throughputs. Unfortunately, there are several considerable things for applying microalgae to microfluidic system. This research presents microalgae research into microfluidic platform by offering each solutions at every limiting steps. First, quantification of lipid droplet (LD) which is one of the major product of carbon conversion in microalgae is required for developing and optimizing microalgal bioprocess engineering. This report describes new fluorescence probes for LDs stainingSeoul-Fluor (SF) and JC-1 (5,5′,6,6′-Tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide). We validated that lipophilic fluorescence probe has a specific interaction with LDs and optimized staining conditions with each probes via systematic variations of physicochemical conditions. A protocol for quantitative measurement of accumulation kinetics of LDs in Chlamydomonas reinhardtii was developed using spectrofluorimeter and the accuracy of LD size measurement was confirmed by transmission electronmicroscopy (TEM). Second, unlike mammalian cells, investigation of microalgae in microfluidic system has been limited due to their small size and motility. Here, we present a simple surface immobilization method using gelatin coating as the biological glue. We have continuously monitored single microalgal cells for up to 6 days. Surface immobilization allowed high-resolution, live-cell imaging of mitotic process in real time-which followed previously reported stages in mitosis and LDs accumulation of suspension cultured cells. Third, PDMS (polydimethylsiloxane), which is the main component of microfluidic system, is hard to observe and manipulate cellular behavior with adsorption of hydrophobic fluorescence probes. Here, we present a new simple method for preventing unwanted hydrophobic absorption on PDMS device using Teflon coating. Throughout the clearing considered issues, we suggested a novel paradigm, never discussed, which could guarantee the most promising method for achieving economics of biodiesel. Based on miniaturized continuous culture system, we could generate various combinations of carbon and nitrogen source for measuring single cell behavior. This result indicate that single cell behavior under continuous culture system did not show similar result of conventional flask culture system. Throughput the result, cell size were affected by nitrogen concentration as well as intracellular lipid content were maximized by half deprivation of nitrogen. Especially, in mass (or continuous) culture system, it would be better to reduce only half of nitrogen source by considering economics of biodiesel. We hope that the applications of developed microfluidic platform become a useful tool for biodiesel research as well as system biology by helping high-throughput screening and biological relevant stimulus. This thesis also describes a new method for enhancing microalgal growth and intracellular lipid accumulation using vibration. As we previously mentioned, conventional microaglal biodiesel researches are only focused on the nutrient starvation that activates biosynthesis of lipid formation. However, these approaches slow down microalgal growth and development. Although these unfavorable conditions lead high lipid productivity at single cell level, their low growth rate are a major bottleneck considering commercial biodiesel production in the point of view at whole culture system. Due to this reason, we represent new concept for improving economics of biodiesel by realizing high growth rate and lipid productivity. Chlamydomonas reinhardtii were treated in the presence of various frequencies under mechanical vibrations and sounds. Mechanical vibration enhanced proliferation and we assumed that the cell displacement is the crucial factor for maximizing growth and development. The most interest thing is mechanical vibration boosts proliferation via enhanced carbon conversion ability. Although mechanical vibration system cause stress on photosynthetic system, all frequencies enhances growth yield. In cases of sound, except for 1000 Hz, all frequencies boosts proliferation as well as lipid production. Our results presented here confirmed that vibration can be a new method not only for boosting intracellular lipid formation but also for enhancing cell proliferation in normal condition. We hope that these properties could be an applicable condition for algal cultivation during biodiesel production.Chapter 1 Introduction 1 1.1 Microalgae as an alternative energy source 1 1.1.1 Recent energy crisis and global warming 1 1.1.2 Microalgae as a solution for current issues 2 1.2 Microfluidics for microalgal research 4 1.2.1 Issues on microalgae into microfluidics 4 Chapter 2 Quantitative measurement of lipid droplets with fluorescnce probe 8 2.1 Introduction 8 2.2 Materials and methods 11 2.2.1 Materials 11 2.2.2 Culture conditions 12 2.2.3 Visualization of LDs in C. reinhardtii 12 2.2.4 Optimization of SF44 and JC-1 staining 13 2.2.5 Viability assay 14 2.2.6 Liposome concentration measurement 14 2.2.7 Determination of LDs contents 15 2.2.8 LDs purification and size measurement 15 2.3 Results 16 2.3.1 Optimization of SF44 staining for microalgae 16 2.3.2 Quantification of lipid contents using SF44 21 2.3.3 Kinetics measurement of intracellular LDs using SF44 23 2.3.4 Optimization of JC-1 staining for microalgae 27 2.3.5 Quantification of lipid contents using JC-1 31 2.3.6 Kinetics measurement of intracellular LDs using JC-1 33 2.4 Conclusions 35 Chapter 3 Immobilization of microalgae 39 3.1 Introduction 39 3.2 Materials and methods 40 3.2.1 Materials 40 3.2.2 Culture conditions 40 3.2.3 Microfluidic device fabrication 41 3.2.4 Surface immobilization optimization 41 3.2.5 Patterned substrate preparation 42 3.2.6 Viability assay 42 3.2.7 Wall shear stress induced detachment assay 44 3.2.8 Live cell imaging of C. reinhardtii mitosis 44 3.2.9 Imaging and quantification of lipid accumulation in C. reinhardtii as single cell level 45 3.3 Results 45 3.3.1 Surface immobilization of C. reinhardtii using gelatin 46 3.3.2 Validation for microfluidic application 52 3.3.3 Live cell imaging of C. reinhardtii mitosis and lipid accumulation 55 3.4 Conclusions 60 Chapter 4 Preventing small hydrophobic molecule absorption on PDMS microchannel 63 4.1 Introduction 63 4.2 Materials and methods 64 4.2.1 Materials 64 4.2.2 Microfluidic device fabrication 65 4.2.3 Teflon coating method 65 4.2.4 Visualization of hydrophobic molecule absorption on PDMS microchannels 65 4.2.5 Measurement of gas permeability 67 3.2.6 Transparency measurement of PDMS 67 4.3 Results 68 4.3.1 PDMS microchannel that resist hydrophobic molecule absorption 68 4.3.2 Characteristics of Teflon coated PDMS microchannel 70 4.3.3 Cell imaging of C. reinhardtii on Teflon coated-PDMS microchannel 74 4.4 Conclusions 76 Chapter 5 Quantitative measurement of Chlamydomonas reinhardtii on gradient generation system 80 5.1 Introduction 80 5.2 Materials and methods 82 5.2.1 Materials 82 5.2.2 Culture conditions 83 5.2.3 Microfluidic device fabrication 83 5.2.4 Gradient generation with flow system 84 5.2.5 Visualization and quantification of C. reinhardtii 84 5.3 Results 85 5.3.1 Device design and validation for gradient generation 86 5.3.2 Carbon source dependent quantitative measurement 88 5.3.3 Nitrogen source dependent quantitative measurement 93 5.3.4 Combinations of carbon and nitrogen sources dependent quantitative measurement 95 5.4 Conclusions 97 Chapter 6 Effect of mechanical vibration and sound on Chlamydomonas reinhardtii 100 6.1 Introduction 100 6.2 Materials and methods 101 6.2.1 Materials 101 6.2.2 Culture conditions 101 6.2.3 Mechanical vibration generation system 101 6.2.4 Sound generation system 102 6.2.5 Measurement of growth for solid culture system 102 6.2.6 Measurement of growth kinetics for liquid culture system 102 6.2.7 Fv/Fm measurement 103 6.2.8 Measurement of intracellular lipid contents 103 6.3 Results 103 6.3.1 Mechanical vibration generation 103 6.3.2 Mechanical vibration effect on microlagal proliferation 106 6.3.3 Sound generation 110 6.3.4 Sound effect on microalgal proliferation and development 113 6.4 Conclusions 121 Chapter 7 Concluding remarks 123 Bibliography 127 Abstract 138Docto