버스 공급수준의 변화가 도시철도 수요예측에 미치는 영향

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 건설환경공학부, 2018. 2. 고승영.The problem of misleading forecasts on the road is less severe and less one-sided than for rail. As the cause of this severe and nonrandom error of rail demand forecasting, this study focuses on the unexpected increase of bus supply level and the modal share prediction errors caused by the unexpected bus supply level change in the process of mode split. If a new rail line is planned for an area where large land developments are expected, the level of bus supply at the time of development planning and level of bus supply at the time of development completion would be different, and this may cause overestimation of rail demand. Therefore, this study developed a model to forecast the bus supply level and suggested a method to apply the model in the urban rail demand forecasting process. To consider the effect of change of future bus supply level, post-processing analysis which re-estimates urban rail demand by using cross-elasticity and the differential rate between bus supply level of existing model and the proposed model. By using the proposed model, four cases of previous urban rail demand forecasting studies were re-reviewed. In Shinbundang-line, Yongin light rail, Gimpo metro line and Byollae-line case studies, the impacts of bus supply level change on the rail demand forecasts ranged from 16% to 41%. In this proposed model, the error was less than 5% and showed high predictability except for the case of Byollae-line. In Byollae-line case, the results of both of the existing model and proposed model showed large error rate to the observed demand. The source of this relatively large error of Byeollae-line case is supposed that several land development plans are neighboring, and buses running through the districts may be overlapped. It is assumed that the overlapping buses cause errors in several districts, as a result, causing relatively large errors. This study suggests the unexpected change of bus supply level as a major source of rail demand forecasting error, which has been failed to be considered in previous studies and guidelines. This study is distinct from previous studies regarding the impact of change of bus supply level on urban rail demand forecast was quantified, and a model to forecast the bus supply level was developed and applied to improve the reliability of demand forecasting.Chapter 1. Introduction 1 1.1. Background 1 1.2. Purpose of this study 10 1.3. Research flow 12 Chapter 2. Literature Review 13 2.1. Studies on sources of errors in demand forecasting 13 2.2. Guidelines for travel demand forecasting 30 2.2.1. A Study on Standard Guidelines for Pre-feasibility 30 2.2.2. Transport Analysis Guidance 35 2.2.3. Passenger Demand Forecasting Handbook 37 2.3. Studies on bus supply level 40 2.4. Review result and direction of this study 45 Chapter 3. Framework 48 3.1. Outline of methodology 48 3.2. The choice of transportation mode 50 3.2.1. A behavioral model for mode choice 50 3.2.2. Proposed methodology 55 3.3. Bus supply level forecasting model 60 3.4. Post-processing of rail demand 64 Chapter 4. Case Study 69 4.1. Overview of case study 69 4.2. Shinbundang-line project 71 4.2.1. Overview of the project 71 4.2.2. Comparison of predicted and observed rail demand 74 4.2.3. Analysis of bus supply level change 76 4.2.4. Scenario analysis 77 4.2.5. Result of scenario analysis 81 4.3. Yongin light rail Project 85 4.3.1. Overview of the project 85 4.3.2. Comparison of predicted and observed rail demand 88 4.3.3. Analysis of bus supply level change 90 4.3.4. Scenario analysis 91 4.3.5. Result of scenario analysis 95 4.4. Gimpo metro line project 99 4.4.1. Overview of the project 99 4.4.2. Analysis of bus supply level change 102 4.4.3. Scenario analysis 104 4.4.4. Result of scenario analysis 108 4.5. Byeollae-line Project 112 4.5.1. Overview of the project 112 4.5.2. Analysis of bus supply level change 118 4.5.3. Scenario analysis 120 4.5.4. Result of scenario analysis 124 Chapter 5. Conclusion 128 5.1. Summary and conclusion 128 5.2. Further research 132Docto

중소기업의 재무성과와 고용창출효과를 중심으로

학위논문(석사) -- 서울대학교대학원 : 행정대학원 공기업정책학과, 2022. 8. 김봉환.In the 2010s, as Korea’s potential growth rate fell below 3% and youth unemployment and job losses emerged as important social problems, the urgency to foster new growth engines other than the existing main industries such as semiconductors, automobiles, and shipbuilding prevailed in the society. It has become our task to discover a new growth engine rather than the traditional heavy industry that has led the growth of Korea. In this process, fostering the 4th industrial revolution, which was introduced by Klaus Schwab at the World Economic Forum in 2016 and has since become a global trend, has rapidly emerged as a core agenda. Accordingly, the Korea Credit Guarantee Fund has provided credit guarantee since 2017 in accordance with the ‘Common Standards for Innovation Growth’ related to the 4th Industrial Revolution established by the Innovation Growth Policy and Finance Council. This study was conducted to see the effectiveness of it. In this study, the companies newly supported by the Korea Credit Guarantee Fund in 2017 and 2018 were classified into innovative growth companies or generally guaranteed companies. They are analyzed in terms of financial performances(growth potential, profitability, stability) and employment growth rate. The performances of years t+1, t+2, and integrated year(t+1, t+2) were analyzed through DID analysis. As a result of the analysis, the financial impact of the credit guarantee on innovative growth companies showed generally higher than that of generally guaranteed companies, but the employment growth rate was somewhat insignificant. In terms of growth potential, both the sales growth rate and the total asset growth rate showed that innovative growth companies performed better than generally guaranteed companies did. However, In terms of profitability, the results were mixed by the types of company. In terms of stability, the result of debt ratio of t+2 year was not statistically significant, but the results of year t+1 and consolidated year(t+1, t+2) showed positive impacts on credit guarantee for innovative growth companies. However, the times interest earned ratio was turned out to be positive impacts in all years. As for the employment growth rate, the effect of credit guarantee for innovative growth companies was not statistically significant. The effect of credit guarantee support for the innovative growth is generally more positive than that of generally guaranteed companies, raising the needs of strengthened support for innovative growth sectors in the future. By increasing investment in innovative growth companies that are in the introduction or growth stage, we could see the possibility of future growth engine in Korea. Although there is a limitation in that the performance was statistically insignificant in terms of the employment growth rate, additional research is needed in that innovative growth companies are not labor-intensive industries and the effects on employment may vary.2010년대 들어서 대한민국 잠재성장률이 3% 이하로 떨어지고, 청년실업과 일자리 문제가 중요한 사회문제로 대두되면서, 반도체, 자동차, 선박 등 기존 주력산업 외의 새로운 성장동력 산업을 육성해야 한다는 절박함이 사회 전반에 팽배하였다. 기존 대한민국 성장을 이끌었던 전통적인 중후장대 산업이 아닌 새로운 성장동력 발굴이 우리의 과제가 되었다. 이 과정에서 2016년 ‘세계경제포럼’에서 클루우스 슈밥에 의해 제기되고, 이후 세계적인 트렌드로 자리잡은 4차 산업혁명 육성이 핵심 아젠다로 급부상하였다. 이에 따라, 신용보증기금은 혁신성장정책금융협의회에서 수립한 4차 산업혁명 관련 ‘혁신성장공동기준’에 따라 2017년부터 신용보증 지원을 하였는데, 이에 대한 효과성을 보고자 본 연구를 진행하게 되었다. 본 연구는 신용보증기금이 2017년, 2018년에 신규로 신용보증 지원한 업체를 혁신성장기업과 일반 보증기업으로 구분하여 분석대상으로 하였으며, 재무적 성과(성장성, 수익성, 안정성)와 고용증가율 측면에서 t+1년, t+2년 및 통합(t+1, t+2) 기간의 성과를 DID분석을 통해 살펴보았다. 분석 결과, 혁신성장기업에 대한 신용보증의 효과는 재무적 측면에서는 양호한 것으로 산출되었으나 고용증가율 측면에선 다소 미흡한 것으로 나왔다. 성장성 측면에서 매출액증가율과, 총자산증가율 모두 혁신성장기업에 대한 신용보증 지원의 성과는 일반 보증기업보다 양호하였다. 그러나 수익성 지표 중 매출액영업이익률은 혁신성장기업에 대한 신용보증 지원의 효과가 좋지 못한 반면, 총자산순이익률은 혁신성장기업이 양호한 성과를 보이는 것으로 나타나 결과가 엇갈리고 있었다. 안정성 측면에선 부채비율은 t+2년 결과는 통계적으로 유의하지 않은 것으로 나왔으나 t+1년과 통합(t+1, t+2)은 성과가 양호한 것으로 나왔으며, 이자보상배율은 모든 연도에 성과가 좋은 것으로 산출되었다. 고용증가율은 혁신성장기업에 대한 신용보증 지원의 효과가 일반 보증기업보다 좋을 것이라는 가설이 기각되었다. 혁신성장기에 대한 신용보증 지원의 효과는 일반 보증기업보다 대체로 양호하므로 앞으로 더욱 혁신성장 부문에 대한 지원 강화 필요성이 제기된다. 기업 성장단계상 도입기 혹은 성장기 단계인 혁신성장기업에 대한 투자 제고를 통해 대한민국의 미래성장동력으로 자리잡을 수 있는 가능성을 엿볼 수 있었다. 다만, 고용증가율 측면에서 성과가 미흡했다는 한계가 있으나 혁신성장기업이 노동집약적 산업이 아니고, 고용에 미치는 효과는 다양할 수 있다는 점을 고려할 때 추가적인 연구가 필요할 것으로 보인다. 주요어 : 혁신성장기업, 4차산업혁명, 신용보증, 재무성과, 고용증가율제 1 장 서 론 1 제 1 절 연구의 배경 및 필요성 1 제 2 절 연구의 대상과 방법 4 제 2 장 이론적 논의와 선행연구 검토 5 제 1 절 이론적 논의 5 1. 4차 산업혁명 5 2. 산업정책 6 3. 혁신성장공동기준 8 4. 혁신성장기업에 대한 신용보증 지원 10 제 2 절 선행연구 검토 12 1. 신용보증 지원 효과성에 관한 연구 12 2. 4차 산업혁명에 대한 연구 15 3. 선행연구와의 차별성 17 제 3 장 연구설계 및 분석방법 19 제 1 절 연구문제 19 제 2 절 연구가설 19 제 3 절 연구모형 23 제 4 절 변수의 개념적 정의 25 제 5 절 변수의 조작적 정의 26 1. 독립변수 26 2. 종속변수 26 3. 통제변수 29 제 6 절 연구방법 30 1. 자료수집방법 30 1. 분석방법 30 제 4 장 실증분석 결과 32 제 1 절 분석대사 및 기술통계 32 1. 분석대상 및 표본 32 2. 빈도분석 32 3. 기술통계량 분석 39 제 2 절 상관관계 분석 41 제 3 절 혁신성장기업과 일반 보증기업의 보증지원 효과 분석 45 1. 성장성에 미치는 효과 분석 45 2. 수익성에 미치는 효과 분석 49 3. 안정성에 미치는 효과 분석 53 4. 고용에 미치는 효과 분석 57 제 5 장 결론 59 제 1 절 연구결과 요약 59 제 2 절 시사점 61 제 3 절 연구의 한계 및 향후 과제 63 참고문헌 65 부 록 69 Abstract 78석

Development of a Mother-Preschool Child Interaction Scale

Purpose: This study was done to develop the self-report Mother-Preschool Child Interaction Scale (MPIS) for mothers of preschool children. Methods: The scale was based on items derived from literature review and in-depth interviews. A methodological study was used to check reliability and validity and participants were 334 mothers of preschool children enrolled in kindergarten or nursery. Data were analyzed using principal component factor analysis for construct validity, t-test for contrasted group validity, Pearson correlation for criterion related validity and test-retest reliability and Cronbach's alpha for reliability. Results: In the final MPIS 34 items identified through factor analysis were included, 6 constructs were derived, and explanatory power was 64.2%. Items on the MPIS were verified through correlation with the interaction observation scale of Kim Mahoney and MPIS. Results were significant as mothers in the normal group exhibited MPIS scores that were significantly higher than those of mothers in the depressed group. Reliability of MPIS was .96 and test-retest reliability was .92. Conclusion: MPIS has the advantage of being easy to use, economical, and useful. Consequently, it is expected to be used as a screening tool for promptly and simply identifying the mother-preschool child interaction in diverse nursing practice and research.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/2008003875/3SEQ:3PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:2008003875ADJUST_YN:YEMP_ID:A078492DEPT_CD:811CITE_RATE:.352FILENAME:2013-JKAN-43-1-59-박성희 방경숙.pdfDEPT_NM:간호학과EMAIL:[email protected]_YN:NCONFIRM:

Evaluation of a Career Ladder Program for Nurses in a Hospital

Purpose: The purposes of this study were to assess the efficacy and usefulness of the career ladder program in a hospital and to evaluate nurses satisfaction with the program. Methods: The study was conducted using a survey consisting of 14 questions on the appropriateness, necessity and usefulness of the career ladder program. The data were gathered from 403 nurses in a hospital. We assessed differences in responses according to the participants workplace, age, educational background, marital status, experience (total years and years at current working place). We analyzed the data using SPSS/WIN 12.0. Results: Nurses acknowledged that the career ladder program is necessary and profitable within the nursing field, but they worried about the appropriateness of the nurse's role at each career level and rationality of the portfolio. The study also identified nurses characteristics that were significant factors in explaining nurses satisfaction with the career ladder program. Finally, we identified complaints and improvements for the program. Conclusion: We assessed differences in attitude towards the career ladder program according to nurses' characteristics

Ductal carcinoma in situ diagnosed using an ultrasound-guided 14-gauge core needle biopsy of breast masses: can underestimation be predicted preoperatively?

PURPOSE: This study was designed to determine the rate of ductal carcinoma in situ (DCIS)underestimation diagnosed after an ultrasound-guided 14-gauge core needle biopsy (US-14G-CNB) of breast masses and to compare the clinical and imaging characteristics between trueDCIS and underestimated DCIS identified following surgical excision. METHODS: Among 3,124 US-14G-CNBs performed for breast masses, 69 lesions in 60 patients were pathologically-determined to be pure DCIS. We classified these patients according to the final pathology after surgical excision as those with invasive ductal carcinoma (underestimated group) and those with DCIS (non-underestimated group). We retrospectively reviewed and compared the clinical and imaging characteristics between the two groups. RESULTS: Of the 69 lesions, 21 were shown after surgery to be invasive carcinomas; the rateof DCIS underestimation was 30.4%. There were no statistically significant differences withrespect to the clinical symptoms, age, lesion size, mammographic findings, and ultrasonographic findings except for the presence of abnormal axillary lymph nodes as detected on ultrasound. The lesions in 2 patients in the non-underestimated group (2/41, 4.9%) and 5 patients in the underestimated group (5/19, 26.3%) were associated with abnormal lymph nodes on axillary ultrasound, and the presence of abnormal axillary lymph nodes on ultrasound was tatistically significant (P=0.016). CONCLUSION: We found a 30.4% rate of DCIS underestimation in breast masses based on a US-14G-CNB. The presence of abnormal lymph nodes as detected on axillary ultrasound may be useful to preoperatively predict underestimation.ope

Differentiation of adrenal adenoma and nonadenoma in unenhanced CT: New optimal threshold value and the usefulness of size criteria for differentiation

Objective To determine the optimal threshold for the attenuation values in unenhanced computed tomography (CT) and assess the value of the size criteria for differentiating between an adrenal adenoma and a nonadenoma. Materials and Methods The unenhanced CT images of 45 patients at our institution, who underwent a surgical resection of an adrenal masses between January 2001 and July 2005, were retrospectively reviewed. Forty-five adrenal masses included 25 cortical adenomas, 12 pheochromocytomas, three lymphomas, and five metastases confirmed by pathology were examined. The CT images were obtained at a slice thickness of 2 mm to 3 mm. The mAs were varied from 100 to 160 and 200 to 280, while the 120 KVp was maintained in all cases. The mean attenuation values of an adrenal adenoma and nonadenoma were compared using an unpaired t test. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy at thresholds of 10 Hu, 20 Hu, and 25 HU were compared. The diagnostic accuracy according to the size criteria from 2 cm to 6 cm was also compared. Results The twenty-five adenomas showed significantly lower (p 90% but a specificity < 70%. Size criteria of 2 or 3 cm had a high specificity of 100% and 80% but a low sensitivity of 20% and 60%. Conclusion The threshold attenuation values of 20 or 25 HU in the unenhanced CT appear optimal for discriminating an adrenal adenoma from a nonadenoma. The size criteria are of little value in differentiating adrenal masses because of their low specificity or low sensitivity.ope

FDG Uptake in PET by Bladder Hernia Simulating Inguinal Metastasis

A 70-year-old man with past history of hemicolectomy due to colon cancer underwent a follow-up abdominal/pelvic CT scan. CT revealed a right adrenal metastasis and then he underwent FDG-PET/CT study to search for other possible tumor recurrence. In PET images, other than right adrenal gland, there was an unexpected intense FDG uptake at right inguinal region and at first, it was considered to be an inguinal metastasis. However, correlation of PET images to concurrent CT data revealed it to be a bladder herniation. This case provides an example that analysis of PET images without corresponding CT images can lead to an insufficient interpretation or false positive diagnosis. Hence, radiologists should be aware of the importance of a combined analysis of PET and CT data in the interpretation of integrated PET/CT and rare but intriguing conditions, such as bladder herniation, during the evaluation of PET scans in colon cancer patients.ope

Anaplastic thyroid carcinoma arising from a calcified thyroid mass

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Cyclosporin A에 의해 유도된 치은 과성장에 대한 azithromycin의 억제 효과 및 작용기전에

Dept. of Dental Science/박사[한글] 목적 : 치은 과성장을 일으키는 대표적인 약물로는 면역억제제로 많이 사용되고 있는 cyclosporin A (CsA), 항경련제로 쓰이는 phenytoin, 고혈압치료제로 사용되는 nifedipine을 들 수 있다. 보통 이러한 치은 과성장은 통상적으로 치은 절제술을 통해 치료하고 있지만 잦은 재발로 인해 정기적인 수술을 필요로 하여 환자들이나 의사들에게 큰 부담을 주고 있다. 최근 임상연구를 통해서 CsA 에 의한 치은 과성장이 macrolide 계열의 항생제인 azithromycin (AZI)에 의해 효과적으로 억제된다는 결과가 보고되었다. 그러나 현재까지 CsA에 의한 치은 과성장의 유도기전과 AZI에 의한 억제기전은 명확히 밝혀지지 않고 있다. 이에 본 연구에서는 CsA에 의한 치은 과성장의 유도기전과 AZI에 의한 억제기전을 분자 생물학적 관점에서 밝혀보고자 한다.방법 : 치은 섬유아세포는 과거에 CsA를 복용하여 치은과성장을 보인 환자와 CsA를 복용한 경험이 없는 건강한 환자의 치은에서 explant culture로 분리하였다. CsA에 대한 치은 섬유아세포의 증식률과 AZI에 의한 억제율은 MTT assay에 의해 측정하였다. CsA에 의한 세포증식률이 가장 높은 치은섬유아세포에 CsA를 처리한 후 differential display-reverse transcriptase-polymerase chain reaction(DDRT-PCR) 방법을 수행하고 DNA sequence를 조사하여 유전자 발현의 변화를 조사하였다. 의미있다고 여겨지는 세가지 유전자, prolyl 4-hydroxylase의 subunit (P4HB), ribosomal protein L24 (RPL24), ribosomal protein L30 (RPL30)의 발현을 RT-PCR로 확인하였으며, CsA에 의해 증가된 이들 유전자의 발현에 대한 AZI의 영향을 RT-PCR로 조사하였다.결과 : CsA에 의한 세포의 증식률은 건강한 환자보다 CsA를 복용한 경험이 있는 환자로부터 분리한 치은 섬유아세포에서 뚜렷하게 증가되었다. 그러므로 이후의 연구는 CsA를 복용한 경험이 있는 환자의 치은 섬유아세포로 진행하였다. 5일간 CsA(10ng/ml)와 AZI을 함께 처리한 경우, AZI의 농도에 비례하여 치은 섬유아세포의 증식률이 감소하였다. CsA를 처리한 치은 섬유아세포에서의 DDRT-PCR 결과 collagen 생합성과 세포의 증식에 영향을 미치는 P4HB, RPL24, RPL30 유전자의 발현양이 CsA에 의해 현저하게 증가됨을 볼 수 있었다. 그러나, CsA와 함께 AZI을 처리했을 경우에는 CsA에 의해 증가된 이러한 유전자의 발현양이 AZI에 의해 억제되는 것으로 관찰되었다.결론 : AZI이 CsA에 의해 증가된 세포증식과 P4HB 유전자의 발현양을 감소시켜 collagen의 합성을 감소시킴으로써 CsA에 의해 유도된 치은과성장을 억제하는 것으로 사료된다. [영문]A frequent side effect of cyclosporin A (CsA) administration is gingival overgrowth (GO). Many previous reports have demonstrated that GO can be effectively treated by azithromycin (AZI), a macrolide antibiotic of the azalide subclass. However, the mechanism by which AZI suppresses CsA-induced GO (CIGO) has not yet been elucidated. In the present study, we examined the inhibitory effect of AZI on CIGO and its mechanism of action, and we also investigated the mechanism of CIGO.Human gingival fibroblasts were isolated from the gingival tissues of healthy subjects and patients exhibiting CIGO. The cell proliferation was significantly increased by CsA exposure for 5 days in fibroblasts isolated from gingival tissue of patients taking CsA. In contrast, AZI significantly inhibited CsA-induced cell proliferation. To identify the differentially expressed genes associated with CsA-induced proliferation in CIGO-GFs, we used differential display-reverse-transcriptase-polymerase chain reaction (DDRT-PCR). In our experimental findings, seven genes were upregulated by CsA treatment. Among them, the mRNA expression levels of subunit of the prolyl 4-hydroxylase (P4HB), ribosomal protein L24 (RPL24), ribosomal protein L30 (RPL30) were confirmed by RT-PCR. Upregulated mRNA levels of P4HB, RPL24 and RPL30 by CsA treatment were inhibited dose-dependantly by AZI. The overexpression of P4HB mRNA by CsA shown in our data indicate that CsA may increase the collagen production by stabilizing prolyl 4-hydroxylase, a key enzyme in collagen synthesis and delaying the intracellular degradation of procollagen I. These results suggest that AZI may inhibit CIGO by decreasing CsA-induced cell proliferation and collagen synthesis through downregulation of P4HB in human gingival fibroblasts.ope

초음파 유도하 14-게이지 핵생검에서 관상피내암으로

Dept. of Medicine/석사[한글] [영문] The purpose of this study was to determine the underestimation rate of ductal carcinoma in situ (DCIS) diagnosed after an ultrasound guided 14-gauge core-needle biopsy (US-14G-CNB) of breast masses and to compare the clinical and imaging characteristics between DCIS lesions and underestimated DCIS lesions identified following surgical excision. Among 3124 US-14G-CNBs performed for breast masses, 69 lesions in 60 patients were pathologically determined as pure DCIS. We classified patients with these lesions according to the final pathology after surgical excision as patients with invasive ductal carcinoma (IDC) (upgrade group) and DCIS (non-upgrade group). We retrospectively reviewed and compared the clinical and imaging characteristics between the patients in the two groups. The imaging characteristics analyzed included ultrasound findings according to the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) lexicon and mammographic findings. Of the 69 lesions, 21 lesions were upgraded to invasive carcinoma and the underestimation rate was 30.4%. There were no statistically significant differences for the mammographic findings, sonographic findings, size, age or clinical symptoms except for the presence of pathological axillary lymph nodes as detected on ultrasound. Lesions in two patients in the non-upgrade group (2/41, 4.9%) and five patients in the upgrade group (5/19, 26.3%) were associated with pathological lymph nodes as detected on axillary ultrasound and this finding was statistically significant (p = 0.016). The DCIS underestimation rate after a US-14G-CNB of breast masses was 30.4% in this study. The presence of pathological lymph nodes as detected on axillary ultrasound may be useful to predict underestimation preoperatively.restrictio