용인-서울 구간을 중심으로

학위논문(석사) -- 서울대학교대학원 : 행정대학원 공기업정책학과, 2022. 8. 김동욱.Since highways are guaranteed free movement rights, they can be seen as basic public goods. The role of the state is important because highways as public goods must be supplied and managed by the state. Until now, the government has built highways with the aim of balanced regional development and economic growth. However, the highway policy has been changed to improve publicity, such as connecting to the outer cities of large cities and the construction of bypass roads to distribute existing highway traffic. Most of the studies related to highway traffic demand are studies in engineering fields such as changes in traffic volume and the calculation of benefits according to technology and system application. This study analyzes how the Private Financed Highways built for the purpose of distributing traffic volume affect the transportation demand of the Government Funded Highways. Oil prices and number of automobile registered vehicles related to traffic demand were set as detailed contents, and an empirical analysis was conducted by creating a research model between the opening of the Private Financed Highways and the demand for its traffic. In other words, the research model was set as the independent variable was whether launching status to the Private Financed Highways, and the dependent variable was the Government Funded Highways traffic volume. As for the control variables are oil prices, the number of automobile registered vehicles, and the Private Financed Highways traffic. The variable setting of oil prices and the number of automobile registered vehicles in this research model means traffic demand. The variables of the Private Financed Highways traffic demand and whether launching status the Private Financed Highways are considered to confirm the positive and negative impact of highway traffic demand. First of all, a tollgate office was selected to be included in the section from Yongin to Seoul of the Gyeongbu highways, a Government Funded Highways directly affected by the Yongin Seoul highways, a Private Financed Highways built for the purpose of distributing traffic. The period was divided before and after the opening of the Yongin Seoul highways (July 2009), and this study analyzed the monthly traffic volume from 2006 to 2019. The oil prices were calculated at the national average monthly price of gasoline. The number of automobile registered vehicles per month was calculated by dividing its by the population for Hwaseong city, Yongin city, Suwon city, and Seongnam city, which are administrative districts that include the Yongin Seoul highway and the Gyeongbu highway. Prior to the actual analysis, multicollinearity between variables was tested to confirm that there was no correlation, and the results of the regression analysis are as follows. First, it was found that the opening of the Private Financed Highways significantly reduced the demand for the Government Funded Highways traffic. This means that the traffic congestion on the Gyeongbu highways section from Yongin to Seoul was alleviated, and the government policy for the construction of the Yongin-Seoul highway, which was built to disperse the increased traffic demand due to new town development, was effective. Second, the impact of the decrease in demand for Government Funded Highways traffic volume due to the opening of the Private Financed Highways did not differ by time zone. Both peak hour (rush hour) and off-peak hour reduced traffic demand. Oil prices and the number of automobiles registered vehicles per capita during non-commuting hours were not statistically significant. According to the study of "Baek Seung-gul and Jeong So-young Study (2008)", the elasticity of highway traffic demand is hardly affected by oil prices, and the increase in short-distance traffic is judged to be the biggest cause of the increase in short-distance car traffic due to wide-area cities such as the metropolitan area. Finally, the impact of the decrease in demand for the Government Funded Highways traffic volume due to the opening of the Private Financed Highways did not differ by vehicle type. Both passenger and non-commercial vehicles have reduced traffic demand. Looking at the regression coefficient values of the passenger car group and the emergency vehicle group, it was found that the regression coefficient value of the non-passenger car group was relatively less affected by the opening of the Yongin Seoul highways. The emergency vehicle group consisting of buses and trucks has a stronger purpose of driving long distances than the passenger car group. In the case of emergency vehicles, it is believed that they used the Gyeongbu highways, the Government Funded Highways with excellent network effects due to the organization of all routes, rather than using the single route the Yongin Seoul highways for long-distance movement. The highway traffic has strong seasonal characteristics, resulting in a deviation in traffic volume from month to month. In addition, the factors that cause traffic demand are various such as the value of travel time and the traffic situation and quality of roads. In other words, for the accuracy of statistical analysis, it is necessary to devise a data correction plan and consider various variables. This study is meaningful in that despite the limitations of the research, the impact of traffic between Private Financed Highways and Government Funded Highways was analyzed.고속도로는 자유로운 이동권이 보장되어 있어 기본적인 공공재로 볼 수 있다. 공공재로서의 고속도로는 국가가 공급하고 관리해야 하기에 국가 역할이 중요하다. 그간 정부는 지역간 균형발전과 경제성장을 목표로 고속도로를 건설하였다. 하지만 수도권의 인구집중 심화와 지속적인 자동차의 증가, 신도시 건설 등으로 인한 교통개선 대책으로 대도시의 외곽 연결, 기존 고속도로 교통량 분산을 위한 우회도로 건설 등과 같이 공공성을 향상시키는 방향으로 고속도로 정책이 변화되어 왔다. 고속도로 교통수요와 관련한 연구는 주로 기술과 제도 적용에 따른 통행변화, 편익산출 등과 같은 공학적인 분야가 대다수를 차지한다. 하지만 본 연구는 교통량 분산을 목적으로 건설한 민자고속도로가 재정고속도로 교통수요에 어떤 영향을 미치는지 교통수요와 관련한 유가, 자동차등록대수를 설정하고 이와 더불어 민자고속도로 개통 여부와 민자고속도로 교통량 수요를 변수에 포함시켜 재정고속도로 교통량 수요 간의 연구모형을 만들어 실증분석을 수행하였다. 즉, 독립변수는 민자고속도로 개통여부, 종속변수는 재정고속도로 교통량, 통제변수는 유가, 자동차등록대수, 민자고속도로 교통량으로 연구모형을 설정하였다. 이 연구모형의 유가와 자동차등록대수의 변수는 자연적인 교통량 수요를 의미하며, 민자고속도로 교통량 수요와 개통 여부의 변수는 재정고속도로 교통량 수요 간의 영향도 크기와 정과 부의 영향성 확인을 고려한 것이다. 먼저 교통량 분산으로 건설된 민자고속도로인 용인서울고속도로의 직접적인 영향을 받는 재정고속도로인 경부고속도로 용인-서울구간의 영업소를 선정하여 용인서울고속도로 개통(2009년 7월) 전과 후로 나누어 2006년부터 2019년까지 월 교통량을 분석하였다. 또한 유가는 전국 휘발유 월 평균 가격, 자동차등록대수는 용인서울고속도로와 경부고속도로 용인-서울구간의 행정구역인 화성시, 용인시, 수원시, 성남시를 대상으로 인구수로 나누어 월별로 산출하였다. 실제적인 분석에 앞서 변수들 간의 다중공선성을 검정하여 상관관계가 없음을 확인하였으며, 회귀분석 결과는 다음과 같다. 첫째, 민자고속도로의 개통은 재정고속도로 교통량 수요를 유의미하게 감소시킨 것을 알 수 있었다. 이는 만성적인 경부고속도로 용인과 서울구간의 교통체증을 완화하고 신도시 건설로 증가되는 교통수요를 분산하기 위해 정부의 용인서울고속도로 건설 정책이 효과적이었음을 의미한다. 둘째, 민자고속도로의 개통으로 인한 재정고속도로 교통량 수요 감소 영향은 시간대별로 차이가 없었다. 출퇴근시간대와 비출퇴근시간대 모두 교통량 수요를 감소시켰다. 비출퇴근시간대의 유가와 1인당 자동차등록대수는 통계적으로 유의한 결과가 나오지 않았는데, 백승걸·정소영(2008)에 따르면 고속도로 통행수요 탄력성은 유가의 영향을 거의 받지 않는다 하였으며, 단거리 통행의 증가추세는 유가 상승에 의한 것이라기보다는 수도권 등 대도시 주변 도시광역화로 단거리 자동차 통행의 증가가 가장 큰 원인으로 판단한다고 하였다. 마지막으로, 민자고속도로 개통으로 인한 재정고속도로 교통량 수요 감소 영향은 차종별로 차이가 없었다. 승용차군과 비승용차군 모두 교통량 수요를 감소시켰다. 승용차군과 비승용차군의 회귀계수 값을 살펴보면 회귀계수 값이 비승용차군이 승용차군보다 작은 것은 상대적으로 용인서울고속도로 개통으로 인한 영향이 적은 것으로 나타났다. 버스, 화물차 등으로 구성된 비승용차군은 승용차군보다 장거리 운행이 목적이 강하다. 비승용차군의 경우 원거리 지역 이동을 위해 단일 노선인 용인서울고속도로를 이용하기보다는 모든 노선들이 유기적으로 연결되어 네트워크 효과가 우수한 재정고속도로인 경부고속도로를 이용했을 것으로 판단된다. 고속도로 교통량은 계절성이 강해 월별로 교통량의 편차가 발생된다. 또한, 교통수요를 유발하는 요인은 통행시간의 가치, 도로의 교통상황과 품질 등 다양하다. 즉, 통계분석의 정확성을 위해 데이터 보정방안을 강구하고 다양한 변수를 고려해야 할 것이다. 본 연구는 연구 수행의 한계에도 불구하고 민자고속도로와 재정고속도로 간 교통량 영향성 분석을 수행하였다는 데 의미가 있다.제 1 장 서 론 1 제 1 절 연구의 배경 및 목적 1 제 2 절 연구의 범위 및 방법 4 1. 연구의 범위 4 2. 연구의 방법 5 제 2 장 이론적 배경과 선행연구 검토 6 제 1 절 이론적 배경 고찰 6 1. 고속도로 공공성의 특성 6 2. 고속도로 교통수요 8 3. 고속도로 통행료 제도 12 제 2 절 선행연구 검토 17 1. 교통수요에 관한 선행연구 검토 17 2. 통행료에 관한 선행연구 검토 18 제 3 장 연구설계 21 제 1 절 연구의 가설 21 제 2 절 연구의 모형 23 1. 단절적 시계열 설계 23 2. 통계적 분석 24 제 3 절 변수의 정의 및 측정 24 1. 단절적 시계열 설계 24 2. 회귀분석 26 3. 변수의 정의 27 제 4 절 자료의 수집 및 분석방법 31 제 4 장 연구결과 33 제 1 절 단절적 시계열 설계 33 1. 월 교통량 33 2. 시간대별 교통량 37 3. 차종별 교통량 40 제 2 절 통계적 방법 43 1. 기초통계량 분 43 2. 상관관계분석 48 제 3 절 가설검증 49 1. 가설1의 검증 49 2. 가설2의 검증 51 3. 가설3의 검증 54 4. 가설검증내용 정리 57 제 5 장 결론 58 제 1 절 연구결과 요약 58 제 2 절 정책적 시사점 60 제 3 절 연구의 한계 62 참고문헌 63 부록 67 Abstract 78석

Baseline Cardiovascular Characteristics of Adult Patients with Chronic Kidney Disease from the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD)

Cardiovascular disease (CVD) is the most common cause of death in patients with chronic kidney disease (CKD). We report the baseline cardiovascular characteristics of 2,238 participants by using the data of the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD) study. The cohort comprises 5 subcohorts according to the cause of CKD: glomerulonephritis (GN), diabetic nephropathy (DN), hypertensive nephropathy (HTN), polycystic kidney disease (PKD), and unclassified. The average estimated glomerular filtration rate (eGFR) was 50.5 ± 30.3 mL/min⁻¹/1.73 m⁻² and lowest in the DN subcohort. The overall prevalence of previous CVD was 14.4% in all patients, and was highest in the DN followed by that in the HTN subcohort. The DN subcohort had more adverse cardiovascular risk profiles (higher systolic blood pressure [SBP], and higher levels of cardiac troponin T, left ventricular mass index [LVMI], coronary calcium score, and brachial-ankle pulse wave velocity [baPWV]) than the other subcohorts. The HTN subcohort exhibited less severe cardiovascular risk profiles than the DN subcohort, but had more severe cardiovascular risk features than the GN and PKD subcohorts. All these cardiovascular risk profiles were inversely correlated with eGFR. In conclusion, this study shows that the KNOW-CKD cohort exhibits high cardiovascular burden, as other CKD cohorts in previous studies. Among the subcohorts, the DN subcohort had the highest risk for CVD. The ongoing long-term follow-up study up to 10 years will further delineate cardiovascular characteristics and outcomes of each subcohort exposed to different risk profiles.ope

Permissive fluid volume in adult patients undergoing extracorporeal membrane oxygenation treatment

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is a cardiorespiratory support technique for patients with circulatory or pulmonary failure. Frequently, large-volume fluid resuscitation is needed to ensure sufficient extracorporeal blood flow in patients initiating ECMO. However, excessive overhydration is known to increase mortality in critically ill patients. Therefore, in order to define a tolerant volume range in patients undergoing ECMO treatment, the association between cumulative fluid balance (CFB) and outcome was evaluated in patients undergoing ECMO. METHODS: This retrospective multicenter cohort study was conducted with 723 patients who underwent ECMO in three tertiary care hospitals between 2005 and 2016. CFB was calculated as total fluid input minus total fluid output during the first 3 days from ECMO initiation. The patients were divided into groups that initiated ECMO owing to cardiovascular disease (CVD)-related or non-cardiovascular disease (non-CVD)-related causes. The primary endpoint was mortality within 90 days after ECMO commencement. RESULTS: Totals of 406 and 317 patients were included in the CVD and non-CVD groups, respectively. In the CVD group, the mean age was 58.4 ± 17.7 years, and 68.2% were male. The mean age was 55.7 ± 15.7 years, and 65.3% were male in the non-CVD group. The median CFB values were 64.7 and 53.5 ml/kg in the CVD and non-CVD groups, respectively. Multivariable analysis using Cox proportional hazards models revealed a significantly increased risk of 90-day mortality in patients with higher CFB values in both the CVD and non-CVD groups. However, the risks were elevated only in the two CFB quartile groups with the largest CFB amounts. Cubic spline models showed that mortality risk began to increase significantly when CFB was 82.3 ml/kg in the CVD group. In patients with respiratory diseases, the mortality risk increase was significant for those with CFB levels above 189.6 ml/kg. CONCLUSIONS: Mortality risk did not increase until a certain level of fluid overload was reached in patients undergoing ECMO. Adequate fluid resuscitation is critical to improving outcomes in these patients.ope

Drainage Failure Because of Spontaneous Fracture of the Peritoneal Dialysis Catheter

ope

Circulating Fibroblast Growth Factor-23 Levels are Associated with an Increased Risk of Anemia Development in Patients with Nondialysis Chronic Kidney Disease

Fibroblast growth factor-23 (FGF23) is an established biomarker of adverse outcomes in patients with chronic kidney disease (CKD). Several cross-sectional studies have suggested a possible association between FGF23 and anemia in these patients. In this large-scale prospective cohort study, we investigated this relationship and examined whether high FGF23 levels increase the risk of incident anemia. This prospective longitudinal study included 2,089 patients from the KoreaN cohort study for Outcome in patients With CKD. Anemia was defined as hemoglobin level <13.0 g/dl (men) and <12.0 g/dl (women). Log-transformed FGF23 significantly correlated with hepcidin but inversely correlated with iron profiles and hemoglobin. Multivariate logistic regression showed that log-transformed FGF23 was independently associated with anemia (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.04-1.24, P = 0.01). Among 1,164 patients without anemia at baseline, 295 (25.3%) developed anemia during a median follow-up of 21 months. In fully adjusted multivariable Cox models, the risk of anemia development was significantly higher in the third (hazard ratio [HR], 1.66; 95% CI, 1.11-2.47; P = 0.01) and fourth (HR, 1.84; 95% CI, 1.23-2.76; P = 0.001) than in the first FGF23 quartile. In conclusion, high serum FGF23 levels were associated with an increased risk for anemia in patients with nondialysis CKD.ope

Electrolyte and mineral disturbances in septic acute kidney injury patients undergoing continuous renal replacement therapy

Electrolyte and mineral disturbances remain a major concern in patients undergoing continuous renal replacement therapy (CRRT); however, it is not clear whether those imbalances are associated with adverse outcomes in patients with septic acute kidney injury (AKI) undergoing CRRT. We conducted a post-hoc analysis of data from a prospective randomized controlled trial. A total of 210 patients with a mean age of 62.2 years (136 [64.8%] males) in 2 hospitals were enrolled. Levels of sodium, potassium, calcium, and phosphate measured before (0?hour) and 24 hours after CRRT initiation. Before starting CRRT, at least 1 deficiency and excess in electrolytes or minerals were observed in 126 (60.0%) and 188 (67.6%) patients, respectively. The excess in these parameters was greatly improved, whereas hypokalemia and hypophosphatemia became more prevalent at 24 hours after CRRT. However, 1 and 2 or more deficiencies in those parameters at the 2 time points were not associated with mortality. However, during 28 days, 89 (71.2%) deaths occurred in patients with phosphate levels at 0?hour of ≥4.5?mg/dL as compared with 49 (57.6%) in patients with phosphate levels <4.5?mg/dL. The 90-day mortality was also significantly higher in patients with hyperphosphatemia. Similarly, in 184 patients who survived at 24 hours after CRRT, hyperphosphatemia conferred a 2.2-fold and 2.6-fold increased risk of 28- and 90-day mortality, respectively. The results remained unaltered when the serum phosphate level was analyzed as a continuous variable. Electrolyte and mineral disturbances are common, and hyperphosphatemia may predict poor prognosis in septic AKI patients undergoing CRRT.ope

Electrocardiographic left ventricular hypertrophy and outcome in hemodialysis patients

BACKGROUND AND AIMS: Electrocardiography (ECG) is the most widely used initial screening test for the assessment of left ventricular hypertrophy (LVH), an independent predictor of cardiovascular mortality in patients with end-stage renal disease (ESRD). However, traditional ECG criteria based only on voltage to detect LVH have limited clinical utility for the detection of LVH because of their poor sensitivity. METHODS: This prospective observational study was undertaken to compare the prognostic significance of commonly used ECG criteria for LVH, namely Sokolow-Lyon voltage (SV) or voltage-duration product (SP) and Cornell voltage (CV) or voltage-duration product (CP) criteria, and to investigate the association between echocardiographic LV mass index (LVMI) and ECG-LVH criteria in ESRD patients, who consecutively started maintenance hemodialysis (HD) between January 2006 and December 2008. RESULTS: A total of 317 patients, who underwent both ECG and echocardiography, were included. Compared to SV and CV criteria, SP and CP criteria, respectively, correlated more closely with LVMI. In addition, CP criteria provided the highest positive predictive value for echocardiographic LVH. The 5-year cardiovascular survival rates were significantly lower in patients with ECG-LVH by each criterion. In multivariate analyses, echocardiographic LVH [adjusted hazard ratio (HR): 11.71; 95% confidence interval (CI): 1.57-87.18; P = 0.016] and ECG-LVH by SP (HR: 3.43; 95% CI: 1.32-8.92; P = 0.011) and CP (HR: 3.07; 95% CI: 1.16-8.11; P = 0.024) criteria, but not SV and CV criteria, were significantly associated with cardiovascular mortality. CONCLUSIONS: The product of QRS voltage and duration is helpful in identifying the presence of LVH and predicting cardiovascular mortality in incident HD patients.ope

Stepwise Treatment Using Corticosteroids Alone and in Combination with Cyclosporine in Korean Patients with Idiopathic Membranous Nephropathy

PURPOSE: We undertook an observational study to investigate the effects of immunosuppressive treatment on proteinuria and renal function in 179 Korean idiopathic membranous nephropathy patients with nephrotic syndrome. MATERIALS AND METHODS: The primary outcome was regarded as the first appearance of remission and the secondary outcomes as a decline in estimated glomerular filtration rate (eGFR) >50% or initiation of dialysis, and all-cause mortality. Seventy-two (40.2%) and 50 (27.9%) patients were treated with corticosteroids alone (C) and corticosteroids plus cyclosporine (C+C), respectively, whereas 57 (31.8%) did not receive immunosuppressants (NTx). Cyclosporine was added if there was no reduction in proteinuria of >50% from baseline by corticosteroids alone within 3 months. RESULTS: There were no differences in baseline renal function and the amount of proteinuria among the three groups. Overall, complete remission (CR) was achieved in 88 (72.1%) patients by immunosuppressants. In a multivariate analysis adjusted for covariates associated with adverse renal outcome, the probability of reaching CR was significantly higher in the C [hazard ratio (HR), 4.09; p<0.001] and C+C groups (HR, 2.57; p=0.003) than in the NTx group. Kaplan-Meier analysis revealed that 5-year CR rates of C, C+C, and NTx groups were 88.5%, 86.2%, and 56.7% (p<0.001). Ten-year event-free rates for the secondary endpoints in these three groups were 91.7%, 79.9%, and 57.2% (p=0.01). CONCLUSION: Immunosuppressive treatment was effective in inducing remission and preserving renal function in these patients. Therefore, stepwise treatment using corticosteroids alone and in combination with cyclosporine is warranted in these patients.ope

Preservation of renal function by thyroid hormone replacement therapy in chronic kidney disease patients with subclinical hypothyroidism

CONTEXT: Subclinical hypothyroidism is not a rare condition, but the use of thyroid hormone to treat subclinical hypothyroidism is an issue of debate. OBJECTIVE: This study was undertaken to investigate the impact of thyroid hormone therapy on the changes in estimated glomerular filtration rate (eGFR) in subclinical hypothyroidism patients with stage 2-4 chronic kidney disease. PATIENTS: A total of 309 patients were included in the final analysis. MAIN OUTCOME MEASURE: The changes in eGFR over time were compared between patients with and without thyroid hormone replacement therapy using a linear mixed model. Kaplan-Meier curves were constructed to determine the effect of thyroid hormone on renal outcome, a reduction of eGFR by 50%, or end-stage renal disease. The independent prognostic value of subclinical hypothyroidism treatment for renal outcome was ascertained by multivariate Cox regression analysis. RESULTS: Among the 309 patients, 180 (58.3%) took thyroid hormone (treatment group), whereas 129 (41.7%) did not (nontreatment group). During the mean follow-up duration of 34.8 ± 24.3 months, the overall rate of decline in eGFR was significantly greater in the nontreatment group compared to the treatment group (-5.93 ± 1.65 vs. -2.11 ± 1.12 ml/min/yr/1.73 m(2); P = 0.04). Moreover, a linear mixed model revealed that there was a significant difference in the rates of eGFR decline over time between the two groups (P < 0.01). Kaplan-Meier analysis also showed that renal event-free survival was significantly lower in the nontreatment group (P < 0.01). In multivariate Cox regression analysis, thyroid hormone replacement therapy was found to be an independent predictor of renal outcome (hazard ratio, 0.28; 95% CI, 0.12-0.68; P = 0.01). CONCLUSION: Thyroid hormone therapy not only preserved renal function better, but was also an independent predictor of renal outcome in chronic kidney disease patients with subclinical hypothyroidism.ope

Vitamin D deficiency is significantly associated with depression in patients with chronic kidney disease

BACKGROUND: Depression is reported to be the most common psychological problem in patients with chronic kidney disease (CKD). Several studies have reported that lower levels of serum vitamin D are significantly associated with depression. Both vitamin D deficiency and depression are prevalent in patients with CKD, yet the relationship between these two factors remains poorly understood. This study aimed to investigate the association between vitamin D levels and depression among CKD patients. METHODS: Totally, 21,257 individuals who participated in the Korean National Health and Nutrition Examination Survey (KNHANES V, VI) from 2010-2014 were screened for the study; 533 CKD patients were included. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D3 [25(OH)D3] ≤10 ng/mL. Patients were divided into vitamin D deficient or sufficient groups. Depression was screened for using the Korean version of the WHO Composite International Diagnostic Interview-Short Form. The association between vitamin D deficiency and depression was evaluated by multivariate logistic regression analysis. RESULTS: The mean participant age was 70.1±9.4 years; 262 patients (49.2%) were male. The median 25(OH)D3 level was 19.1±6.9 ng/mL. The prevalence of depression was higher in CKD patients than in the general population (14.3 vs. 11.1%, P = 0.03). Additionally, the prevalence of depression was significantly higher in CKD patients with (vs. without) vitamin D deficiency (32.5% vs. 50.0%, P<0.001). Multivariate logistic regression analysis showed that vitamin D deficiency was a significant independent predictor of depression after adjusting for confounding factors (adjusted odds ratio, 6.15; 95% confidence interval, 2.02-8.75; P = 0.001). CONCLUSION: Depression was highly prevalent in CKD patients, in whom vitamin D deficiency was a significant independent predictor of depression. Therefore, management of vitamin D deficiency might help prevent depression in CKD patients.ope