Investigation into the Market Viability of Bitcoin: Measuring the Digital Currency's Speculative Nature

학위논문 (석사)-- 서울대학교 대학원 : 경영학과, 2016. 2. 유병준.Ever since its creation by the presumed pseudonymous Satoshi Nakamoto, Bitcoin has garnered significant attention as an innovative online payment system. The purpose of this paper is to empirically confirm the existence of speculative nature within Bitcoin as posed in the previous literature, discover the degree to which the participation of a Bitcoin user is dependent on the speculative opportunities in the Bitcoin market and, accordingly, test Bitcoins chance against traditional currency. Using a panel data set from one of the largest Bitcoin traders in Asia, we find that $1 increase in arbitrage between market prices is associated with 0.1 more log-ins of users, thus confirming the existence of speculative nature among users. However, the paper also suggests that such a portion of speculative users might not be as much as dominating the entire user population. The findings of the paper show that there is considerable number of users who treat Bitcoin not as a short term investment vehicle, but as something that they intend to watch over for a longer period of time. Also, the findings report that the actual reason for Bitcoins incompetence as a form of currency against the conventional tools of trade may be attributable to its low level of network effects, not yet fully formulated.1. INTRODUCTION 1 2. LITERATURE REVIEW 5 3. DATA AND HYPOTHESES 9 3.1 DATA DESCRIPTION 9 3.2 HYPOTHESES 12 4. MODEL 17 5. RESULT 19 6. DISCUSSION AND CONCLUSION 25 REFERENCES 29 Appendix 32 Appendix 1: Bitcoin Trading Volume of Korbit Trading Exchange 32 Appendix 2: Existence of Price Gap 33 국문 초록 34Maste

Molecular Mechanisms Mediating Gibberellin-Induced Parthenocarpic Fruit Development in Grapevines (Vitis spp.)

학위논문 (박사)-- 서울대학교 대학원 : 식물생산과학부, 2014. 8. 이희재.The concept that gibberellin (GA) application on seeded grapevines induces parthenocarpy has been known for decades in viticulture, but the molecular mechanism underlying this induction is poorly understood. GA was applied to inflorescence clusters of seeded diploid grapevine cultivar Tamnara (Vitis spp.) at 14 days before full bloom (DBF). Morphological and molecular effects of GA application were examined on the induction of parthenocarpic fruit development. With GA application, ovaries were enlarged and pollen tube growth was completely inhibited. Vitis GA oxidases, the key determinants for GA level, were characterized through phylogenetic analysis with Arabidopsis GA oxidase. Five VvGA 20-oxidase (VvGA20ox), three VvGA 3-oxidase (VvGA3ox), and nine VvGA 2-oxidase (VvGA2ox) family proteins, and one VvGA methyltransferase (VvGAMT) and one Vitis cytochrome P450 (VvCYP) 714A proteins were identified, and their expression patterns were analyzed during inflorescence development from 14 DBF to 5 days after full bloom (DAF). VvGA2ox1, VvGA20ox3, and VvGA3ox2 transcripts were most abundantly expressed in each gene family at 7, 5, and 2 DBF, respectively. Following GA application at 14 DBF inducing seedlessness, GA catabolic genes such as VvGAMT2, VvGA2ox3, and VvGA2ox4 were up-regulated at 12 DBF, full bloom, and 5 DAF, respectively. Conversely, GA biosynthetic genes, VvGA20oxs and VvGA3oxs, were down-regulated at near full bloom, and the timing of their peak expression was changed. These results suggest that GA application at pre-bloom changes the GA biosynthesis into GA catabolic pathway at near full bloom by altering the transcript level and timing of GA oxidase genes expression during grapevine inflorescence development. In addition, the transcriptional levels of the putative negative regulators of fruit set initiation, including Vitis auxin/indole-3-acetic acid transcription factor 9 (VvIAA9), Vitis auxin response factor 7 (VvARF7), and VvARF8 were also monitored during inflorescence development. Without GA application, VvIAA9, VvARF7, and VvARF8 were expressed at a relatively high level before full bloom, but decreased thereafter following pollination. However, after GA application at 14 DBF, the expression levels of VvIAA9 and VvARF7 declined at 5 DBF prior to pollination. The effects of GA application on auxin levels or auxin signaling were also analyzed by monitoring the expression patterns of auxin-biosynthetic and -responsive genes with or without GA application. Transcript levels of the auxin biosynthetic genes of Vitis anthranilate synthase β subunit (VvASB1-like), Vitis YUCCA2 (VvYUC2), and VvYUC6 were not significantly changed by GA application. However, the expressions of Vitis Gretchen Hagen3.2 (VvGH3.2) and VvGH3.3, auxin-responsive genes, were up-regulated from 2 DBF to full bloom with GA application. Furthermore, the Vitis GA signaling gene, VvDELLA was up-regulated by GA application during 12 to 7 DBF, prior to down-regulation of VvIAA9 and VvARF7. These results suggest that VvIAA9 and VvARF7 are negative regulators of fruit set initiation in grapevines, and GA signaling is integrated with auxin signaling via VvDELLA during parthenocarpic fruit development in grapevines.CONTENTS ABSTRACT i CONTENTS iv LIST OF TABLES vii LIST OF FIGURES viii ABBREVIATIONS xi GENERAL INTRODUCTION 1 LITERATURE REVIEW 4 Gibberellin metabolism 4 Hormones and parthenocarpic fruit set 6 Use of gibberellin in viticulture 11 LITERATURE CITED 14 CHAPTER 1. Transcriptional Changes of Gibberellin Oxidase Genes in Grapevines with or without Gibberellin Application during Inflorescence Development ABSTRACT 26 INTRODUCTION 28 MATERIALS AND METHODS 31 Plant material and GA application 31 Histological analysis 31 Protein identification 32 Phylogenetic analysis 36 Total RNA isolation and cDNA synthesis 36 Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis 36 RESULTS 40 Morphological changes in inflorescence in response to GA application 40 Identification of Vitis GA metabolic genes 40 GA-induced transcriptional changes in Vitis GA biosynthetic genes 43 GA-induced transcriptional changes in Vitis GA catabolic genes 47 DISCUSSION 53 Characterization of Vitis GA metabolic genes 53 VvGA2ox1, VvGA20ox3, and VvGA3ox2 are sequentially expressed during inflorescence development without GA application 54 GA application at pre-bloom alters transcription levels of Vitis GA metabolic genes at near full bloom 55 GA application and seedlessness 56 LITERATURE CITED 60 CHAPTER 2. Gibberellin Application at Pre-bloom in Grapevines Down-regulates the Expressions of VvIAA9 and VvARF7, Negative Regulators of Fruit Set Initiation, during Parthenocarpic Fruit Development ABSTRACT 71 INTRODUCTION 73 MATERIALS AND METHODS 76 Plant material and GA application 76 Protein identification 76 Phylogenetic analysis 77 Total RNA isolation and cDNA synthesis 78 Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis 78 RESULTS 81 Characterization and identification of Vitis ARF7 and ARF8 81 Down-regulation of VvIAA9 and VvARF7 with GA application 84 Up-regulation of VvGH3.2 and VvGH3.3 with GA application 86 Up-regulation of VvDELLA with GA application 87 DISCUSSION 91 GA application induces parthenocarpy by early down-regulation of negative regulators of fruit set initiation 91 Integration of GA and auxin signalings during parthenocarpic fruit development via VvDELLA 93 LITERATURE CITED 98 CONCLUSIONS 108 ABSTRACT IN KOREAN 111Docto

고추에서 PVY와 PMMV 저항성 유전자와 연관된 분자 표지의 개발

학위논문(석사)--서울대학교 대학원 :원예학과,2002.Maste

한국 자동차 보험시장의 정보비대칭에 관한 연구

학위논문 (석사)-- 서울대학교 대학원 : 경영학과, 2017. 2. 박소정.This article draws on a set of data from the Korean automobile insurance industry to investigate the presence of asymmetric information and learning. I find that there exists a conditional correlation between the choice of Collision and Comprehensive coverage and the probability of accidents. This finding implies that the better insured actually cause more claims, although the difference in the number of claims seems less significant in economic contexts. I confirm that the degree of information asymmetry is more significant in contracts with new policyholders, young drivers with less than 3 years of driving experience, and senior drivers with more than 7 years of experience. Tests using premiums provide results consistent with tests considering variables related to the characteristics of policyholders, characteristics of their vehicles, and the contract choices they make.I. Introduction 1 II. Hypothesis Development 5 A. Related Literature 5 B. Predictions 9 III. Background Information and Data 12 A. Car Insurance in Korea 12 B. Sample Selection 14 C. Summary Statistics 15 IV. Empirical Analysis 18 A. The Presense of Asymmetric Information 18 B. Asymmetric Learning on Private Information 21 V. Conclusion 25 References 28 Abstract (Korean) 31Maste