압력 순환 흡착과 막 분리공정을 이용한 다성분 기체의 분리공정 조업 최적화 및 경제성 평가

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Examining the different types of sport content consumption on bridging and bonding social capital

학위논문(석사) -- 서울대학교대학원 : 사범대학 체육교육과,글로벌스포츠매니지먼트전공, 2021.8. 김기한.The current study elucidates the potential social impact of mediated sport consumption, in particular the role of social connection and its influence in accumulating social capital. Although, social connection is an important research construct in understanding social capital, previous scholarly attention in sport literature has been limited, especially in the context of mediated sports. Therefore, this study was conducted to bridge this gap in literature by examining the interrelationships among mediated sport consumption (i.e., sport events, pre.post sport events and sport news), opportunity for social connection, and social capital (i.e., bridging and bonding). More specifically, the role of opportunity for social connection was examined to explain the relationship between mediated sport consumption and social capital. To test the proposed research model, data was collected through a questionnaire survey from a total of 369 respondents. For data analysis, Structural Equation Modeling (SEM) was adopted using the statistical program STATA. Results indicated that opportunity for social connection varied depending on the different types of sport content consumed. While sport events and pre.post sport events both showed positive impact on opportunity for social connection, consumption of sport news did not show any statistical significance. Furthermore, opportunity for social connection indicated a positive relationship to both bridging and bonding social capital with greater impact shown for bridging than bonding social capital. Findings of this study contribute further the theoretical understanding of the relationship between mediated sport consumption and social capital. From both a sport management and communication perspective, results of the present study provide statistical evidence to support the social potential of mediated sport consumption and demonstrate how consuming different types of sport content can influence the level of opportunity for social connection and also social capital. With content in the sport media landscape continuously diversifying and growing, understanding the different types of content available for consumers and the associated impact of consuming such content can be beneficial to the sport management and communication literature. Theoretical and practical implications are also discussed.최근 연구에서는 스포츠 미디어 소비의 사회적 효과, 특히 사회적 교류의 역할과 사회적 자본에 대한 영향을 밝혀내고 있다. 사회적 교류(social connection)는 사회적 자본을 이해하는 데 중요한 변인이지만, 체육학 분야 그중 스포츠 미디어 분야에서는 이와 관련된 연구가 부족한 실정이다. 따라서, 본 연구의 목적은 스포츠 미디어 소비(스포츠 이벤트, 스포츠 이벤트 전.후 콘텐츠, 스포츠 뉴스)와 사회적 교류, 사회적 자본의 관계를 규명하는 데 있다. 구체적으로, 스포츠 미디어 소비가 사회적 교류에 미치는 영향, 사회적 교류가 사회적 자본에 미치는 영향을 분석하고자 한다. 이를 검증하기 위해 본 연구에서는 설문조사를 실시하였으며, 총 369명의 응답자로부터 데이터를 수집하였다. 데이터 분석은 통계프로그램 STATA를 이용하였고, 변인 간의 구조적 관계 분석을 위해 구조방정식분석(SEM)을 실시하였다. 본 연구의 결과는 다음과 같다. 첫째, 스포츠 미디어의 콘텐츠 유형에 따라 사회적 교류에 미치는 영향이 달라지는 것으로 나타났다. 스포츠 이벤트와 스포츠 이벤트 전.후 콘텐츠는 사회적 교류에 정(+)의 영향을 미쳤지만, 스포츠 뉴스는 통계적으로 유의한 영향이 나타나지 않았다. 둘째, 사회적 교류는 교량적 사회자본과 결속적 사회자본에 정(+)의 영향을 미치는 것으로 나타났다. 그중 사회적 교류는 사회적 자본의 교량(bridging)에 더 큰 영향을 미치는 것으로 나타났다. 본 연구를 통해 스포츠 미디어 소비와 사회적 자본의 관계를 밝혀낼 수 있었다. 스포츠매니지먼트와 커뮤니케이션의 관점에서 보았을 때, 본 연구의 결과는 스포츠 미디어 소비의 사회적 효과를 뒷받침한다. 스포츠 미디어 콘텐츠가 지속적으로 다양화되고 성장함에 따라, 각 스포츠 미디어 콘텐츠의 특성과 이들이 어떠한 영향을 미치는지 파악한다면 스포츠매니지먼트와 커뮤니케이션 학문의 발전에 이바지할 수 있을 것이다.I. INTRODUCTION 1 1. Research Background 1 2. Research Objective 4 II LITERATURE REVIEW 5 1. Mediated Sport Consumption 5 1.1. Motivations for Mediated Sport Consumption 5 1.2. Different Types of Sport Content 8 1.2.1. Sport Events 10 1.2.2. Pre.Post Sport Events 12 1.2.3. Sport News 13 2. Social Connection 14 2.1. Defining Social Connection 14 2.2. Antecedents of Social Connection 16 2.2.1. Sense of Similarity 16 2.2.2. Affective Connection 18 2.2.3. Individuality and Culture 20 3. Social Captial 21 3.1. Conceptualizing Social Capital 21 3.1.1. Bridging Social Capital 23 3.1.2. Bonding Social Capital 23 4. Interrelationship Between Mediated Sport Consumption, Opportunity for Social Connection and Social Capital 24 4.1. Social Penetration Theory 24 4.2. Role of Social Connection 25 4.2.1. Opportunity for Social Connection via Mediated Sport Consumption 25 4.2.2. Impact of Opportunity for Social Connection on Social Capital 28 III. RESEARCH MODEL & HYPOTHESES 30 1. Research Model 30 2. Research Hypotheses 31 IV. METHOD 32 1. Participants and Data Collection 32 2. Item Development 33 3. Data Analysis Procedure 36 3.1. Descriptive Statistical Analysis 36 3.2. Reliability Analysis 36 3.3. Confirmatory Factor Analysis 37 3.4. Structural Equation Modeling Analysis 37 V. RESULTS 38 1. Respondent Demographics 38 2. Descriptive Analysis 40 3. Confirmatory Factor Analysis 42 4. Structural Equation Modeling 46 VI. DISCUSSION 51 1. Opportunity for Social Connection via Mediated Sport Consumption 51 2. Influence of Opportunity for Social Connection on Social Capital 54 3. Theoretical and Managerial Implications 55 4. Limitations and Future Research 56 VII. CONCLUSION 58 BIBLIOGRAPHY 60 APPENDIX 82 KOREAN ABSTRACT 86석

Histogram Analysis of Hepatobiliary Phase MR Imaging as a Quantitative Value for Liver Cirrhosis: Preliminary Observations

PURPOSE: To investigate whether histogram analysis of the hepatobiliary phase on gadoxetate enhanced-MRI could be used as a quantitative index for determination of liver cirrhosis. MATERIALS AND METHODS: A total of 63 patients [26 in a normal liver function (NLF) group and 37 in a cirrhotic group] underwent gadoxetate-enhanced MRI, and hepatobiliary phase images were obtained at 20 minutes after contrast injection. The signal intensity of the hepatic parenchyma was measured at four different regions of interest (ROI) of the liver, avoiding vessels and bile ducts. Standard deviation (SD), coefficient of variation (CV), and corrected CV were calculated on the histograms at the ROIs. The distributions of CVs calculated from the ROI histogram were examined and statistical analysis was carried out. RESULTS: The CV value was 0.041±0.009 (mean CV±SD) in the NLF group, while that of cirrhotic group was 0.071±0.020. There were statistically significant differences in the CVs and corrected CV values between the NLF and cirrhotic groups (p<0.001). The most accurate cut-off value among CVs for distinguishing normal from cirrhotic group was 0.052 (sensitivity 83.8% and specificity 88.5%). There was no statistically significant differences in SD between NLF and cirrhotic groups (p=0.307). CONCLUSION: The CV of histograms of the hepatobiliary phase on gadoxetate-enhanced MRI may be useful as a quantitative value for determining the presence of liver cirrhosis.ope

제조업 분야 중소기업에 대한 분석을 중심으로

학위논문(석사)--서울대학교 대학원 :사회과학대학 경제학부,2019. 8. 김영식.본 연구는 우리나라의 제조업 분야 중소기업을 대상으로 은행의 위험감수 대출행태가 기업의 재무제약을 완화하여 기업성장에 긍정적인 영향을 미치는지를 분석하였다. 분석결과 단순한 은행의 대출규모 증대보다는 은행의 위험감수가 존재하는 대출규모의 증대가 기업의 재무제약 완화 경로를 통한 기업성장에 큰 긍정적 효과를 가져옴을 알 수 있었다. 특히 규모가 작고 업력이 짧은 기업에서 그 효과가 더 큰 것으로 나타났다. 결론적으로 은행이 보신주의에서 탈피하여 보다 위험을 감수하더라도 중소기업의 투자기회를 늘려주는 방향으로 대출행태를 변화시킨다면 우리나라 제조업 분야의 중소기업의 성장에 재무제약 완화경로를 통한 긍정적인 효과를 가져올 것으로 기대되며, 이러한 효과는 신생기업과 소기업에게 더 크게 나타날 것으로 기대된다.This paper examines the effects of the risk taking loan of private bank on firm growth via alleviation of financial constraints using data from small and medium sized manufacturing firms in South Korea. The key finding is the risk taking loan of private bank for small and medium sized firms had larger positive effects on the growth of firm than the total loan. In particular, the younger and smaller firms are more positively affected than the older and bigger ones. As a result, the small and young firms are expected to grow further if private banks increase the risk profile.1. 서론 01 2. 선행연구 개괄 및 본 연구의 차별성 06 3. 데이터 및 분석 방법론 10 4. 실증분석 결과 14 5. 결론 29Maste

Essential Items for Structured Reporting of Rectal Cancer MRI: 2016 Consensus Recommendation from the Korean Society of Abdominal Radiology

High-resolution rectal MRI plays a crucial role in evaluating rectal cancer by providing multiple prognostic findings and imaging features that guide proper patient management. Quality reporting is critical for accurate effective communication of the information among multiple disciplines, for which a systematic structured approach is beneficial. Existing guides on reporting of rectal MRI are divergent on some issues, largely reflecting the differences in overall management of rectal cancer patients between the United States and Europe. The Korean Society of Abdominal Radiology (KSAR) study group for rectal cancer has developed an expert consensus recommendation regarding essential items for structured reporting of rectal cancer MRI using a modified Delphi method. This recommendation aims at presenting an up-to-date, evidence-based, practical, structured reporting template that can be readily adopted in daily clinical practice. In addition, a thorough explanation of the clinical and scientific rationale underlying the reporting items and their formats is provided. This KSAR recommendation may serve as a useful tool to help achieve more standardized optimal care for rectal cancer patients using rectal MRI.ope

Reversing the intractable nature of pancreatic cancer by selectively targeting ALDH-high, therapy-resistant cancer cells

Human pancreatic ductal adenocarcinoma (PDAC) is a cancer with a dismal prognosis. The efficacy of PDAC anticancer therapies is often short-lived; however, there is little information on how this disease entity so frequently gains resistance to treatment. We adopted the concept of cancer stem cells (CSCs) to explain the mechanism of resistance and evaluated the efficacy of a candidate anticancer drug to target these therapy-resistant CSCs. We identified a subpopulation of cells in PDAC with CSC features that were enriched for aldehyde dehydrogenase (ALDH), a marker expressed in certain stem/progenitor cells. These cells were also highly resistant to, and were further enriched by, treatment with gemcitabine. Similarly, surgical specimens from PDAC patients showed that those who had undergone preoperative chemo-radiation therapy more frequently displayed cancers with ALDH strongly positive subpopulations compared with untreated patients. Importantly, these ALDH-high cancer cells were sensitive to disulfiram, an ALDH inhibitor, when tested in vitro. Furthermore, in vivo xenograft studies showed that the effect of disulfiram was additive to that of low-dose gemcitabine when applied in combination. In conclusion, human PDAC-derived cells that express high levels of ALDH show CSC features and have a key role in the development of resistance to anticancer therapies. Disulfiram can be used to suppress this therapy-resistant subpopulation.ope

Mouse Hepatic Tumor Vascular Imaging by Experimental Selective Angiography.

PURPOSE: Human hepatocellular carcinoma (HCC) has unique vascular features, which require selective imaging of hepatic arterial perfusion and portal venous perfusion with vascular catheterization for sufficient evaluation. Unlike in humans, vessels in mice are too small to catheterize, and the importance of separately imaging the feeding vessels of tumors is frequently overlooked in hepatic tumor models. The purpose of this study was to perform selective latex angiography in several mouse liver tumor models and assess their suitability. MATERIALS AND METHODS: In several ectopic (Lewis lung carcinoma, B16/F10 melanoma cell lines) and spontaneous liver tumor (Albumin-Cre/MST1fl/fl/MST2fl/fl, Albumin-Cre/WW45fl/fl, and H-ras12V genetically modified mouse) models, the heart left ventricle and/or main portal vein of mice was punctured, and latex dye was infused to achieve selective latex arteriography and/or portography. RESULTS: H-ras12V transgenic mice (a HCC and hepatic adenoma model) developed multiple liver nodules that displayed three different perfusion patterns (portal venous or hepatic artery perfusion predominant, mixed perfusion), indicating intra-tumoral vascular heterogeneity. Selective latex angiography revealed that the Lewis lung carcinoma implant model and the Albumin-Cre/WW45fl/fl model reproduced conventional angiography findings of human HCC. Specifically, these mice developed tumors with abundant feeding arteries but no portal venous perfusion. CONCLUSION: Different hepatic tumor models showed different tumor vessel characteristics that influence the suitability of the model and that should be considered when designing translational experiments. Selective latex angiography applied to certain mouse tumor models (both ectopic and spontaneous) closely simulated typical characteristics of human HCC vascular imaging.ope

Increased hepatic FDG uptake on PET/CT in hepatic sinusoidal obstructive syndrome

PURPOSE: Imaging features of sinusoidal obstruction syndrome (SOS), an increasingly common drawback of chemotherapy, were evaluated via 18F-fluorodeoxyglucose (FDG) positron emission tomography computed tomography (PET/CT). EXPERIMENTAL DESIGN: This retrospective study was approved by our Institutional Review Board, with a waiver of informed consent. FDG PET/CT studies of 35 patients (male, 24; female, 11; median age, 53.2 years) obtained between January, 2005 and December, 2012 were analyzed before and after systemic chemotherapy. Diagnosis of SOS was based on histologic (n=13) or gadoxetic acid-enhanced MRI (n=22) findings. On PET/CT images, ROIs drawn on non-tumorous liver generated mean standardized uptake value (SUVliver). Total lesion glycolysis of liver (TLGliver) was calculated as: SUVliver × CT-derived hepatic volume. Paired t-test was applied to compare changes before and after SOS. RESULTS: Mean (±standard error [SE]) values of hepatic volume (baseline, 1307.7±46.2 cm3; SOS, 1395.4±41.3 cm3; p=0.004), SUVliver (baseline, 2.08±0.06; SOS, 2.27±0.07; p=0.02), and TLGliver (baseline, 2697.5±114.5; SOS, 3170.2±134.2; p=0.001) significantly increased with development of SOS. In contrast, mean SUVaorta was unchanged (baseline, 1.53±0.04; SOS, 1.50±0.04; p=0.52). CONCLUSIONS: Hepatic FDG uptake on PET/CT intensified after onset of SOS and thus may be an inappropriate reference in this setting, potentially skewing chemotherapeutic responses gauged by lesion-to-liver SUV ratio.ope

Histogram analysis of gadoxetic acid-enhanced MRI for quantitative hepatic fibrosis measurement.

PURPOSE: The diagnosis and monitoring of liver fibrosis is an important clinical issue; however, this is usually achieved by invasive methods such as biopsy. We aimed to determine whether histogram analysis of hepatobiliary phase images of gadoxetic acid-enhanced magnetic resonance imaging (MRI) can provide non-invasive quantitative measurement of liver fibrosis. METHODS: This retrospective study was approved by the institutional ethics committee, and a waiver of informed consent was obtained. Hepatobiliary phase images of preoperative gadoxetic acid-enhanced MRI studies of 105 patients (69 males, 36 females; age 56.1±12.2) with pathologically documented liver fibrosis grades were analyzed. Fibrosis staging was F0/F1/F2/F3/F4 (METAVIR system) for 11/20/13/15/46 patients, respectively. Four regions-of-interest (ROI, each about 2 cm2) were placed on predetermined locations of representative images. The measured signal intensity of pixels in each ROI was used to calculate corrected coefficient of variation (cCV), skewness, and kurtosis. An average value of each parameter was calculated for comparison. Statistical analysis was performed by ANOVA, receiver operating characteristic (ROC) curve analysis, and linear regression. RESULTS: The cCV showed statistically significant differences among pathological fibrosis grades (P<0.001) whereas skewness and kurtosis did not. Univariable linear regression analysis suggested cCV to be a meaningful parameter in predicting the fibrosis grade (P<0.001, β = 0.40 and standard error  = 0.06). For discriminating F0-3 from F4, the area under ROC score was 0.857, standard deviation 0.036, 95% confidence interval 0.785-0.928. CONCLUSION: Histogram analysis of hepatobiliary phase images of gadoxetic acid-enhanced MRI can provide non-invasive quantitative measurements of hepatic fibrosis.ope

Erlotinib monotherapy for stage IIIB/IV non-small cell lung cancer: a multicenter trial by the Korean Cancer Study Group

BACKGROUND: Erlotinib (Tarceva, OSI Pharmaceuticals, Melville, NY) is an oral, epidermal growth factor receptor tyrosine kinase inhibitor that has antitumor activity and good tolerability in non-small cell lung cancer (NSCLC). In particular, higher response rates have been reported in Asian patients than in Western patients. The aim of this study conducted by the Korean Cancer Study Group was to evaluate the efficacy and tolerability of erlotinib monotherapy as a palliative treatment for advanced NSCLC patients in Korea. PATIENTS AND METHODS: Patients with histologically or cytologically confirmed stage IIIB or IV NSCLC including recurrent or metastatic disease, with performance status from 0 to 3, were eligible either if they had received any anticancer treatment except epidermal growth factor receptor inhibitors or if they were unsuitable for chemotherapy because of poor performance status. Enrolled patients were treated with oral erlotinib at a dose of 150 mg daily until disease progression or development of intolerable toxicity. RESULTS: A total of 120 patients were enrolled between January 2005 and May 2006. Forty-four patients (36.7%) were female and 72 patients were current or former smoker. Fifty percent of patients had received one prior palliative chemotherapy regimens and 34.2% had two or more prior palliative regimens. The overall tumor response rate was 24.2% (95% confidence interval [CI], 16.8-32.8%) with 4 complete responses and 25 partial responses, and the disease control rate was 56.7%. The favorable clinical variables for tumor response were female (P = 0.001), never smokers (P = 0.041), and adenocarcinoma (P = 0.001). The most common adverse event was skin rash (78% of which grade 3 or 4 skin rash occurred in 13.3% of the patients). With a median follow-up of 23.6 months, the median time to progression was 2.7 months (95% CI, 2.2-3.2), and the median overall survival was 12.9 months (95% CI, 6.9-18.8). By multivariate analysis, female and development of skin rash were significantly associated with longer time to progression and overall survival. CONCLUSION: Erlotinib monotherapy showed significant antitumor activity and an acceptable tolerability profile as a palliative treatment in advanced NSCLC patients in Korea, especially in females, never smokers, and patients with adenocarcinoma histology.ope