임원 연봉 공개 법이 기업의 성과와 연봉 수준 변화에 미치는 영향

학위논문 (석사) -- 서울대학교 대학원 : 경영대학 경영학과, 2020. 8. 이관휘.The 2013 FISCMA (Financial Investment Services and Capital Markets Act) in Korea required firms to disclose individual pay information of executives receiving more than 500 million KRW. Using a large panel data of 1,341 unique firms in Korea over the 2011-2016 period, this paper investigates whether the amended disclosure law has affected firms executive compensation level, firm performance and pay-performance sensitivity. Using a difference-in-differences regression analysis, I find that executive compensation increases in the bottom ranked group (bottom 30%) firms and decreases in the top ranked group (top 30%) firms, where group rankings are based on the level of average executive compensation in the pre-law period. In addition, while firm performance of the bottom ranked group firms increased, firm performance of the top ranked group firms decreased following the passage of the FISCMA. The results are similar for pay–performance sensitivity. The academic literature on the determinants of executive pay has been divided between two contrasting viewpoints: managerial entrenchment and tournament theory. Overall, the results of this paper supports the latter view. This paper examines a positive correlation between the change in executive compensation and firm performance in both ranked firm groups, which identifies that the level of compensation packages in Korea reflects the tournament theory.2013년에 새롭게 개정된 자본시장법은 상장 기업 등기 임원중 5억 이상의 보수를 지급받는 경영진에 대해 개인 보수 정보를 공개하도록 요구했다. 한국의 상장 기업 1,341개를 2011년부터 2016년까지 분석한 결과, 법 개정 이전의 연봉수준이 상위 30%인 기업은 평균 임원 연봉이 줄어들고 기업 가치 또한 줄어드는 결과를 보였다. 반대로 하위 30%인 기업은 평균 임원 연봉이 증가하고 기업 가치 또한 증가하는 결과를 보였다. 경영진 보수에 관련해서 선행연구는 두 가지의 반대되는 시사점을 제공한다. 지대 추구 가설은 경영자가 성과에 비해 과한 연봉을 받는 다는 가설이고 토너먼트 이론은 경영자의 보수가 그 성과를 정확하게 반영하고 있다는 가설이다. 선행연구에서는 연봉 수준의 변화와 기업가치의 변화가 양(+)의 상관관계를 가지면 토너먼트 이론, 음(-)의 상관관계를 가지면 지대추구 가설을 지지한다고 주장한다. 결과적으로 이 논문은 한국의 임원 연봉 수준이 토너먼트 이론을 지지 하고 있다는 결과를 나타냈다. 이러한 결과는 기업들이 받는 정치적 부담에서 나온다는 점을 시사한다.1. Introduction 7 2. Literature Review 15 3.1 Sample Construction 19 3.2 Research Specification 21 3.3 Empirical Model 23 4. Empirical Results 27 5. Political Pressure 37 6. Conclusion and Discussion 40 7. References 42 Abstract in Korean 46 Table 1 48 Table 2 49 Table 3 50 Table 4 52 Table 5 54 Table 6 56 Table 7 57 Table 8 59Maste

Island Biogeography of the South Korean Coleoptera

학위논문 (석사)-- 서울대학교 대학원 : 사회과학대학 지리학과, 2018. 2. 박정재.Since Island Biogeography that physical environment of islands such as island size or island distance affects biodiversity of them come to the fore, many biogeographers have tried to apply the Island Biogeographic rules to several isolated environments. Besides physical environment, however, human disturbance can also affect insular biota if island is not far from mainland and has undergone human disturbance, such as many South Korean islands. In this research, therefore, I comprehended distribution pattern of the South Korean insular Coleoptera and calculated the effect of the relationship between physical environment of islands and species diversity of Coleoptera. I also speculated the specific mechanism of distribution pattern of Coleoptera through collecting samples and testing the hypothesis. Nestedness analysis result showed high nestedness value of South Korean islands for Coleoptera species and the possibility of geographical region of Coleopetran type species. The west coast generally tends to show higher nestedness than the southeast coast so that the west coast seems that undergoes less outside disturbance (human disturbance) such as invasive species from Korean peninsula. Island size was directly proportional to species diversity. However, it was also inversely proportional in big inhabited islands. It is because the islands can support larger human population and undergo severe and continuous human disturbance. Island distance was not correlated with species diversity. However, island distance was directly proportional to the number of macropterous species in the high-nestedness regions. It suggests that macropterous species have advantage over brachypterous species in terms of reaching far islands and colonizing on their own in case of less outside disturbance. To test the difference of distribution of Coleoptera with different wing length, four islands around Boryeong city in Chungcheongnamdo province were surveyed. 755 samples were collected using pitfall-trap and sweeping and identified. Identification result showed the tendency that dominance index was inversely proportional to island distance and the rate of macropterous species. It may be originated from the characteristic of macropterous species such as slow colonization and fewer individuals in restricted area. Therefore, the difference of dispersal ability with wing length may affect species composition of islands. In this research, I calculated and speculated the effect size of classical Island Biogeographic theory and human disturbance in South Korean islands, and also found distribution pattern and the mechanism of the South Korean Coleoptera. This research can be used as base data when predicting species composition and species diversity of uninvestigated islands.Chapter 1. Introduction 1 1.1. Study Background 1 1.2. Regional and Temporal Settings: Sapsido, Hodo, Nokdo and Oeyondo on the West Coast of South Korea 5 1.3. Research Purpose and Structure 9 Chapter 2. Literature Review 10 2.1. Introduction to Coleoptera 10 2.2. Studies on Island-Biogeographic Approach in South Korea and Abroad 13 Chapter 3. Methodology 15 3.1. Coleoptera sampling 15 3.2. Identification 17 3.3. Data analysis 18 Chapter 4. Research Results and Analysis 26 4.1. Identification Results 26 4.2. Ecological indices results 31 4.3. Nestedness temperature results 33 Chapter 5. Discussion 34 5.1. The Characters of Insular Coleopteran Communities of Study Area 34 5.2. Distributional Characteristics of South Korean Insular Coleopteran species 34 Chapter 6. Conclusion 49 Bibliography 52 APPENDIX 57 Appendix 1. The set-up time and location of pit-fall trap 57 Appendix 2. Calculated nestedness temperature for each site 59 Appendix 3. Calculated nestedness temperature for each species 62 Appendix 4. Multicolinearity between island size and island distance 66 Appendix 5. Difference between rate of increase of the number of Coleoptera species in relation to island size 67 국 문 초 록 70Maste

Electroanatomical characteristics of idiopathic left ventricular tachycardia and optimal ablation target during sinus rhythm: significance of preferential conduction through Purkinje fibers

PURPOSE: We hypothesized that Purkinje potential and their preferential conduction to the left ventricle (LV) posteroseptum during sinus rhythm (SR) are part of reentrant circuits of idiopathic left ventricular tachycardia (ILVT) and reentry anchors to papillary muscle. MATERIALS AND METHODS: In 14 patients with ILVT (11 men, mean age 31.5±11.1 years), we compared Purkinje potential and preferential conduction during SR with VT by non-contact mapping (NCM). If clear Purkinje potential(SR) was observed in the LV posteroseptum and the earliest activation site (EA) of preferential conduction at SR (EA(SR)) was well matched with that of VT (EA(VT)), EA(SR) was targeted for radiofrequency catheter ablation (RFCA). Also, the anatomical locations of successful ablation sites were evaluated by echocardiography in five additional patients. RESULTS: 1) All induced VTs exhibited clear Purkinje potential(VT) and preferential conduction in the LV posteroseptum. The Purkinje potential(VT) and EA(VT) was within 5.8±8.2 mm of EA(SR). However, the breakout sites of VT were separated by 30.2±12.6 mm from EA(VT) to the apical side. 2) Purkinje potential(SR) demonstrated a reversed polarity to Purkinje potential(VT), and the interval of Purkinje potential(SR)-QRS was longer than the interval of Purkinje potential(VT)-QRS (p<0.02) 3) RFCA targeting EA(SR) eliminated VT in all patients without recurrence within 23.3±7.5 months, and the successful ablation site was discovered at the base of papillary muscle in the five additional (100%) patients. CONCLUSION: NCM-guided localization of EA(SR) with Purkinje potential(SR) matches well with EA(VT) with Purkinje potential(VT) and provides an effective target for RFCA, potentially at the base of papillary muscle in patients with ILVT.ope

A case of Long QT syndrome type 3 aggravated by beta-blockers and alleviated by mexiletine: the role of epinephrine provocation test.

Long QT syndrome (LQTs) is an uncommon genetic disease causing sudden cardiac death with Torsade de Pointes (TdP). The first line drug treatment has been known to be β-blocker. We encountered a 15-year-old female student with LQTs who had prolonged QTc and multiple episodes of syncope or agonal respiration during sleep. Although her T wave morphology in surface electrocardiography resembled LQTs type 1, her clinical presentation was unusual. During the epinephrine test, TdP was aggravated during β-blocker medication, but alleviated by sodium channel blocker (mexiletine). Therefore, she underwent implantable cardioverter defibrillator implantation.ope

Prolonged PR Interval Predicts Clinical Recurrence of Atrial Fibrillation After Catheter Ablation

BACKGROUND: A prolonged PR interval is known to be a poor prognostic factor in cardiovascular disease. The aim of this study was to investigate the association between PR interval and clinical outcome in patients undergoing radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). METHODS AND RESULTS: We prospectively included 576 patients with AF (75.5% male, 57.8±11.6 years old, 68.8% paroxysmal AF) who underwent RFCA. We analyzed preprocedural sinus rhythm ECGs obtained in the absence of antiarrhythmic drug, and all enrolled patients were categorized into 4 groups based on the quartile values of the PR interval (166, 182, and 202 ms), and were analyzed according to the left atrium (LA) volume (CT; Computed tomography), LA voltage (NavX), and clinical outcome of AF ablation. Based on quartile value of PR interval, the highest quartile of PR interval (Q4; PR ≥202 ms) was oldest (P<0.001), and most likely to have persistent AF (P<0.001) and hypertension (P=0.013) compared with the other groups. However, there was no significant difference in LA conduction velocity and atrial effective refractory period. Q4 had the greatest LA dimension (P<0.001) and volume index (P<0.001), and lowest LA appendage-emptying velocity (P<0.032) and LA voltage (P<0.001) compared with the others. For 13.1±7.5 months, the classification based on the PR interval was a significant predictor of AF recurrence after RFCA of AF (HR=1.969, 95% CI 1.343 to 2.886, P=0.001). CONCLUSIONS: The PR interval was closely associated with advanced LA remodeling due to AF, and had a noninvasive significant predictive value of clinical recurrence of AF after RFCA.ope

A Thin Left Atrial Antral Wall Around the Pulmonary Vein Reflects Structural Remodeling by Atrial Fibrillation and is Associated with Stroke

PURPOSE: Circumferential pulmonary (PV) vein isolation (CPVI) is the most important treatment strategy for atrial fibrillation (AF). While understanding left atrial wall thickness around PVs (PVWT) prior to catheter ablation is important, its clinical implications are not known. This study aimed to evaluate PVWT characteristics according to underlying disease and to identify associations between PVWT and reconnections of PV potentials (PVPs) in redo ablation. MATERIALS AND METHODS: In 28 patients who underwent redo-AF ablation, PVWT and reconnected PVPs were evaluated at 12 sites (1-12 o'clock) around each PV. Clinical characteristics including stroke and CHA₂DS₂-VASc scores were analyzed according to the PVWT. RESULTS: The PVWT was thicker in males than females (p0.6 mm predicted PV reconnections with a sensitivity of 76.7% and specificity of 52.2% with an area under the curve of 0.695. CONCLUSION: Thick PVWs were associated with diabetes and heart failure, and also showed significant inverse correlations with stroke and the CHA₂DS₂-VASc score. Thick PVWs were associated with reconnected PVPs after the CPVI, which were related to AF recurrence.ope

Endoscopic Treatment of a Pediatric Patient with Acute Pancreatitis Caused by Anomalous Union of Pancreaticobiliary Duct Combined with Incomplete Pancreatic Divisum

The most common causes of acute pancreatitis are microlithiasis and alcohol. In pediatrics, anomalies in pancreaticobiliary system should be considered as possible causes. Among many anomalies, pancreas divisum associated with anomalous pancreaticobiliary ductal union (APBDU) is very rare. APBDU is associated with acute pancreatitis, choledochal cyst, and gallbladder cancer. Pancreas divisum is also a well known cause of acute recurrent pancreatitis. In adult cases with such conditions, the role of endoscopic management including sphincterotomy or stenting through the Santorini duct is well documented. However, it is still controversial to perform endoscopic retrograde cholangiopancreatography in pediatrics. Herein, we experienced a case of 4 year 7 month old female patient suffered from recurrent attacks of acute pancreatitis, which were caused by APBDU and incomplete pancreas divisum. She was treated by endoscopic sphincteretomy of both openings to the Santorini`s and Wirsung`s ducts. Thus, we report this interesting case with literature review.ope

Clinical Significance of Additional Ablation of Atrial Premature Beats after Catheter Ablation for Atrial Fibrillation

PURPOSE: The clinical significance of post-procedural atrial premature beats immediately after catheter ablation for atrial fibrillation (AF) has not been clearly determined. We hypothesized that the provocation of immediate recurrence of atrial premature beats (IRAPB) and additional ablation improves the clinical outcome of AF ablation. MATERIALS AND METHODS: We enrolled 200 patients with AF (76.5% males; 57.4±11.1 years old; 64.3% paroxysmal AF) who underwent catheter ablation. Post-procedure IRAPB was defined as frequent atrial premature beats (≥6/min) under isoproterenol infusion (5 μg/min), monitored for 10 min after internal cardioversion, and we ablated mappable IRAPBs. Post-procedural IRAPB provocations were conducted in 100 patients. We compared the patients who showed IRAPB with those who did not. We also compared the IRAPB provocation group with 100 age-, sex-, and AF-type-matched patients who completed ablation without provocation (No-Test group). RESULTS: 1) Among the post-procedural IRAPB provocation group, 33% showed IRAPB and required additional ablation with a longer procedure time (p=0.001) than those without IRAPB, without increasing the complication rate. 2) During 18.0±6.6 months of follow-up, the patients who showed IRAPB had a worse clinical recurrence rate than those who did not (27.3% vs. 9.0%; p=0.016), in spite of additional IRAPB ablation. 3) However, the clinical recurrence rate was significantly lower in the IRAPB provocation group (15.0%) than in the No-Test group (28.0%; p=0.025) without lengthening of the procedure time or raising complication rate. CONCLUSION: The presence of post-procedural IRAPB was associated with a higher recurrence rate after AF ablation. However, IRAPB provocation and additional ablation might facilitate a better clinical outcome. A further prospective randomized study is warranted.ope

Comparison of optical coherence tomographic assessment between first- and second-generation drug-eluting stents

PURPOSE: There is a lack of sufficient data in comparison of optical coherence tomographic (OCT) findings between first- and second-generation drug-eluting stents (DES). Compared to first-generation (i.e., sirolimus- or paclitaxel-eluting stents), second-generation DESs (i.e., everolimus- or biolinx-based zotarolimus-eluting stents) might have more favorable neointimal coverage. MATERIALS AND METHODS: Follow-up OCT findings of 103 patients (119 lesions) treated with second- generation DESs were compared with those of 139 patients (149 lesions) treated with first-generation DESs. The percentage of uncovered or malapposed struts, calculated as the ratio of uncovered or malapposed struts to total struts in all OCT cross-sections, respectively, was compared between the two groups. RESULTS: Both DES groups showed similar suppression of neointimal hyperplasia (NIH) on OCT (mean NIH cross-sectional area; second- vs. first-generation=1.1±0.5 versus 1.2±1.0 mm², respectively, p=0.547). However, the percentage of uncovered struts of second-generation DESs was significantly smaller than that of first-generation DESs (3.8±4.8% vs.7.5±11.1%, respectively, p<0.001). The percentage of malapposed struts was also significantly smaller in second-generation DESs than in first-generation DESs (0.4±1.6% vs.1.4±3.7%, respectively, p=0.005). In addition, intra- stent thrombi were less frequently detected in second-generations DESs than in first-generation DESs (8% vs. 20%, respectively, p=0.004). CONCLUSION: This follow-up OCT study showed that second-generation DESs characteristically had greater neointimal coverage than first-generation DESs.ope

Low Left Atrial Compliance Contributes to the Clinical Recurrence of Atrial Fibrillation after Catheter Ablation in Patients with Structurally and Functionally Normal Heart

Stiff left atrial (LA) syndrome was initially reported in post-cardiac surgery patients and known to be associated with low LA compliance. We investigated the physiological and clinical implications of LA compliance by estimating LA pulse pressure (LApp) among patients with atrial fibrillation (AF) and structurally and functionally normal heart. Among 1038 consecutive patients with LA pressure measurements before AF ablation, we included 334 patients with structurally and functionally normal heart (81.7% male, 54.1±10.6 years, 77.0% paroxysmal AF) after excluding those with hypertension, diabetes, and previous ablation or cardiac surgery. We measured LApp (peak-nadir LA pressure) at the beginning of the ablation procedure and compared the values with clinical parameters and the AF recurrence rate. AF patients with normal heart were younger and more frequently male and had paroxysmal AF, a lower body mass index, and a lower LApp compared to others (all p<0.05). Based on the median value, the low LA compliance group (LApp≥13 mmHg) had a smaller LA volume index and lower LA voltage (all p<0.05) compared to the high LA compliance group. During a mean follow-up of 16.7±11.8 months, low LA compliance was independently associated with two fold-higher risk of clinical AF recurrence (HR:2.202; 95%CI:1.077-4.503; p = 0.031). Low LA compliance, as determined by an elevated LApp, was associated with a smaller LA volume index and lower LA voltage and independently associated with higher clinical recurrence after catheter ablation in AF patients with structurally and functionally normal heart.ope