Digital sketchpad: A Portable scetching device

The thesis discusses the problems of sketching on paper and in using existing products that are currently on the market for hand drawing. A new display technology, electronic paper display, is introduce

Current-Induced Resonant Motion of a Magnetic Vortex Core: Effect of Nonadiabatic Spin Torque

The current-induced resonant excitation of a magnetic vortex core is investigated by means of analytical and micromagnetic calculations. We find that the radius and the phase shift of the resonant motion are not correctly described by the analytical equations because of the dynamic distortion of a vortex core. In contrast, the initial tilting angle of a vortex core is free from the distortion and determined by the nonadiabaticity of the spin torque. It is insensitive to experimentally uncontrollable current-induced in-plane Oersted field. We propose that a time-resolved imaging of the very initial trajectory of a core is essential to experimentally estimate the nonadiabaticity.Comment: 4 pages, 4 figure

Emerging roles of desumoylating enzymes

AbstractPosttranslational modification by small ubiquitin-like modifier (SUMO) controls diverse cellular processes including transcriptional regulation, nuclear transport, cell-cycle progression, DNA repair, and signal transduction pathway. Sumoylation is a highly dynamic process that is reversed by a family of Sentrin/SUMO-specific proteases (SENPs). Thus, desumoylation process must be important for regulation of the fate and function of SUMO-conjugated proteins as well as SUMOylation process. SENPs catalyze the removal of SUMO from SUMO-conjugated target proteins as well as the cleavage of SUMO from its precursor proteins. Since the first report of yeast desumoylating enzymes, many studies have revealed the structural and cellular biological properties of SENP family. This review focuses on the specificity of the SENPs' catalytic activities with regard to SUMO isoforms and their emerging roles as cellular regulators

Anti-anxiety effect of methanol extract of Pericarpium zanthoxyli using a strychnine-sensitive glycine receptor model

Purpose: To determine if the methanol extract of Pericarpium zanthoxyli exerts anti-anxiety effects and also to explore any probable anti-anxiety mechanism in vivo.Methods: The staircase test, elevated plus maze test, rota-rod treadmill test and convulsions induced by strychnine and picrotoxin on mice were tested to identify potential mechanism of anti-anxiety activity of the plant extract.Results: The plant extract (10 mg/kg, p.o.) significantly reduced rearing numbers in the staircase test while it increased the time spent in the open arms as well as the number of entries to the open arms in the elevated plus maze test, suggesting that it has significant anti-anxiety activity. Furthermore, the extract inhibited strychnine-induced convulsion. However, it had little effect on picrotoxin-induced convulsion, suggesting that its anti-anxiety activity may be linked to strychnine-sensitive glycine receptor and not GABA receptor.Conclusion: These results suggest that the Pericarpium zanthoxyli extract may be beneficial for the control of anxiety.Keywords: Anti-anxiety, Pericarpium zanthoxyli, Glycine Receptor, GABA Recepto

Galatheoid squat lobsters (Crustacea: Decapoda: Anomura) from Korean waters

Abstract Ten species of Galatheoidea (squat lobsters), belonging to two families, were collected in the Korean exclusive economic zone: Galathea balssi Miyake and Baba, 1964, Galathea orientalis Stimpson, 1858, Galathea pubescens Stimpson, 1858, and Galathea rubromaculata Miyake and Baba, 1967 belonging to Galatheidae; Bathymunida brevirostris Yokoya, 1933, Cervimunida princeps Benedict, 1902, Munida caesura Macpherson and Baba, 1993, Munida japonica Stimpson, 1858, Munida pherusa Macpherson and Baba, 1993, and Paramunida scabra (Henderson, 1885) belonging to Munididae. The present study comprises the morphological description of these ten species, including drawings and color photographs, a brief review of their regional records, and a key for their identification. Although all species are common in Japanese waters, G. balssi, G. rubromaculata, B. brevirostris, C. princeps, M. caesura, and M. pherusa are new to Korean marine fauna

우리나라 식물원의 기원과 진화

학위논문 (박사)-- 서울대학교 대학원 : 조경학, 2017. 2. 조경진.식민지 시대 일본에 의해 조성된 창경원 식물원이 한국 식물원의 효시라는 설명에 대한 비판적 고찰을 비롯해, 한국 식물원의 기원과 진화 과정을 밝히는 역사적 고찰은 지금껏 없었다. 이에 본 논문은 창경원 식물원이 조성되기 이전에 발현한 식물원의 맹아를 찾아 서술함으로써 한국 식물원의 태동 과정에 대한 총체적 양상과 그 함의를 제시하고자 하였다. 이를 위해 식물원의 탄생을 추적할 수 있는 키워드로 근대 과학의 탄생에 주목하고, 한국 식물학의 역사에서 두드러진 변화를 보인 네 가지 시기를 중심으로 식물원의 역사를 살펴보았다. 2장에서는 여말선초인 13세기부터 15세기 사이에 본초학과 향약(鄕藥)에 대한 관심 속에서 등장한 약초원을 살펴보았다. 고려 말에는 성리학적 자연관의 영향으로 향약론이 대두하면서 토산 약초를 구해 약포(藥圃)를 가꾸는 경향이 나타나기 시작했다. 이후 의료가 국정 운영의 핵심으로 인식되었던 조선 전기에 이르러 향약 정책과 제도 시행이 이루어졌는데, 그 중 하나가 약초의 확보·증식·토산화 등을 위한 종약전(種藥田)이라는 의료 시설이었다. 결국 종약전을 통해 의약학의 발달, 지리에 대한 재인식과 함께 일어난 토산 약초에 대한 관심, 그리고 강력한 왕권의 정책에 의해 15세기경부터 한반도에 왕립 약초원이 운영되고 있었다고 말할 수 있다. 3장에서는 조선 후기인 18세기 후반, 박물학적 경향 속 정원 문화의 변화 양상을 검토하였다. 조선 후기에는 사물의 이치를 탐구해 지식을 넓힐 수 있다는 격물치지(格物致知)가 바람직한 학문 태도로 인식되기 시작하였다. 이러한 사회 분위기는 사물에 대한 몰두를 가리키는 벽(癖) 예찬론을 낳고, 수집가와 박물학자를 배태하였다. 정원과 원예 문화에서도 박물학적 경향이 나타났는데, 새로운 화훼 풍속으로 기화이초 애호와 수집 열기가 확인되며, 더 나아가 화훼 고증·관찰·명명과 같은 탐구 경향도 엿보인다. 따라서 조선 후기 애호가의 정원은 화훼 수집과 탐구라는 식물원의 몇 가지 역할을 내포하고 있었던 것으로 해석할 수 있다. 4장에서는 개화기인 19세기 후반, 박물학 교육이 제도화되던 시대의 식물원 개념과 그 형성 과정을 밝혔다. 사회 개혁의 일환으로 대두된 개화(開化)사상은 문명국에 이르기 위해 서구 문물의 도입이 필요하다는 논리를 형성했다. 이에 따라 서양을 통해 박물학 교육을 비롯해 각종 근대 문물이 유입되었으며, 식물원의 유입 경로 역시 마찬가지 양상을 보였다. 사절단과 유학생 등 개화기 조선의 지식인들이 해외 유수의 식물원을 견문하는 과정을 통해 식물원의 정의, 특성, 역할 뿐 아니라 필요성을 인식하였던 것이다. 그러므로 현대적인 의미의 식물원 개념이 적어도 19세기 후반 국내에 도입되어 논의되고 있었다고 판단할 수 있다. 5장에서는 20세기 초 식물분류학의 여명기에 설립된 식민지 식물원, 창경원 식물원을 재고하였다. 창경원 식물원은 과학 탐구 기관을 표방했으나 당시 식물학계에서 연구 기관으로서 두각을 나타내지 못했다. 창경원 식물원의 탄생은 오히려 한·일 양국에서 정치적 혹은 문화적으로 계몽된 상태를 가리켰던 취미 담론의 출현과 관련해 이해할 수 있다. 이러한 결과는 창경원 식물원이 식물에 대한 취미를 제공함으로써 대중을 교양 시민(혹은 신민)으로 양성하는 전시와 교육 기관으로 논의되어야 할 필요성을 제시하는 것이라 하겠다. 연구 결과 한국 식물원의 기원과 진화에 대해 내릴 수 있는 결론은 다음과 같다. 첫째, 일제 강점기 이전에 식물원의 씨앗이 싹트고 있었다고 말할 수 있다. 우선 식물 연구와 교육 및 전시 기능은 확인되지 않으나, 의료기구 종약전에서 약초라는 범주에 속한 식물을 수집한 사실이 확인되었다. 식물 교육 및 전시 기능은 엿보이지 않으나, 애호가의 정원에서 약초라는 범위 이상의 보다 다양한 식물을 수집한 양상을 비롯해 박물학적 탐구 경향이 나타났다. 게다가 식물원이라는 단어가 쓰이기 시작한 때가 일제 강점기 이전인 개화기이고, 비록 담론에 불과했으나 이때 식물원에 대한 인식이 형성되어 있었으며 더 나아가 필요성이 제기된 사실이 드러났다. 따라서 일제 강점기 이전에 이미 약초원으로서, 화훼 탐구 정원으로서, 혹은 담론으로서 식물원은 태동했다고 결론내릴 수 있다. 둘째, 식물원은 하나의 조상으로부터 진화한 것이 아니다. 종약전, 애호가의 정원, 개화기의 식물원 논의, 그리고 창경원 식물원의 조성 주체와 탄생 맥락은 서로 달랐다. 결국 한국 식물원의 진화 과정은 불연속적이며 산발적인 궤적을 보인다고 말할 수 있다. 우리는 종약전, 애호가의 정원, 개화기 지식인의 식물원 견문록, 창경원 식물원으로의 한국 식물원의 탄생에 대한 지적 여정을 통해 이들이 오늘날의 식물원에 전하는 메시지를 읽을 수 있었다. 그것은 바로 식물원의 존재의 이유이다. 식물원은 지식을 생산하고 확산시키는 발판이며, 구체제를 혁신하기 위해 모색하거나 도입한 새로운 패러다임의 산물이고, 안목과 교양을 쌓는 수단이었다. 다시 말해, 한국 식물원의 역사는 식물원이 더 나은 삶을 향한 플랫폼(platform)이라는 존재임을 증명해보인 궤적이었다.There has been no historical study on the origin and development of Korean botanical gardens until now, although there have been criticisms of the viewpoint that acknowledges the Changgyeongwon Botanical Garden, which was established during the Japanese colonial period, as the first botanical garden of Korea. Thus, in an effort to examine the background of the birth of Korean botanical gardens and its significance, this paper studies the botanical gardens that existed before the founding of the Changgyeongwon Botanical Garden. Particular attention is given to the birth of modern science in tracing the root of botanical gardens. The history of botanical gardens is examined, while an analysis of the four periods that saw significant changes in Koreas history of botany is also provided in this paper. The attributes of physic gardens that emerged with the increase in interest in herbal medicine study and hyangyak (鄕藥, native herbs) between the thirteenth and fifteenth centuries at the end of the Goryeo dynasty and the beginning of the Joseon dynasty are studied in chapter 2. At the end of the Goryeo dynasty, finding native herbs and creating yakpo (藥圃, kitchen garden for medicinal herbs) became popular with the rise of the hyangyak theory, which was influenced by the Neo-Confucianist view of nature. Hyangyak policy and system was put in place as medical service became essential for government administration at the beginning of the Joseon dynasty. Jong-yakjeon (種藥田), a medical facility, was part of the system that was established for the collection, production and localization of herbs. Thus, it may be said that the development of the study of medicine and pharmacy, a new understanding of geography, increase in the interest in local herbs, and royal authority contributed to the establishment of a physic garden in Korea around the fifteenth century. Gardening culture which developed with the rise of natural history that prevailed at the end of the Joseon dynasty in the late eighteenth century is analyzed in chapter 3. Gewuzhizhi, the belief that one could acquire knowledge through the study of matters, which was widely discouraged until the latter part of the Joseon dynasty, started to gain recognition as good practice. Such change of perception led to the birth of byeok (癖, obsession) and to the rise of collectors and naturalists. Aspects of natural history were found in gardening culture and horticulture, as flower collection became widespread and rare flowers and plants gained popularity. Conducting historical research into flowers, observing and naming of flowers also became popular. Thus, it may be said that toward the end of the Joseon dynasty, functions of botanical gardens, such as flower collection and research, were carried out at the gardens owned by aficionados. The concept and development of botanical gardens in the early modern period toward the end of the nineteenth century, in light of the institutionalization of natural history education, are examined in chapter 4. Gaewha thought, which was regarded as part of the effort directed toward national development, contributed to creating the notion that Korea must adopt Western culture to become a civilized country. Natural history education and other forms of Western culture were introduced to Korea, and the concept of botanical gardens found its way into Korean society via a similar route. The definition, characteristics, functional purposes of botanical gardens, as well as the need to establish botanical gardens were widely shared after the intellectuals of the Joseon dynasty visited Western countries during the early modern period. Thus, it may be said that the idea of botanical gardens, in the modern sense, was introduced and discussed at least in the latter part of the nineteenth century. The Changgyeongwon Botanical Garden of the Japanese colonial period that was founded in light of the rise of plant taxonomy at the beginning of the twentieth century is studied in chapter 5. The purpose of the Changgyeongwon Botanical Garden was to further scientific research. However, it was not recognized as a prominent research institute in the academic circle at the time. The birth of the Changgyeongwon Botanical Garden can be understood in relation to the development of the discussion about taste (chwimi or shumi) and its relevance to the state of political or cultural enlightenment of Korea and Japan. Consequently, it may be said that the evolution of the Changgyeongwon Botanical Garden is less associated with the development of botany. The Changgyeongwon Botanical Garden, therefore, may be understood as a display and research institute that contributed to the enlightenment of the public by providing taste (chwimi or shumi) in relation to botany. Research into the origin and development of Korean botanical gardens has led to the following conclusion. First, the idea of botanical gardens had already blossomed before the Japanese colonial period. Although such functions as botany research, education and display were not carried out by Jong-yakjeon, the royal medicinal herb farms work of collecting herbal plants has been brought to light. Moreover, although such functions as botanical education and display were not present in the features of the gardens owned by aficionados, the gardens collection of a wide variety of plants, including herbal plants, and their characteristic of providing opportunities to explore natural history have been identified. Also, it has been found that the term botanical garden (sikmulwon) appeared in the early modern period before the Japanese colonial period. Furthermore, although it remained as a discussion, the idea of botanical gardens was formed, and claims made in support of establishing a botanical garden before the Japanese colonial period have been identified. Thus, it may be said that the physic gardens, gardens used for exploring flowers, and the discussions on the idea of botanical gardens provide evidence in support of the claim that the concept of botanical gardens blossomed before the Japanese colonial period. Second, botanical gardens did not evolve from one entity. Circumstances that led to the development of Jong-yakjeon, gardens owned by aficionados, discussions about botanical gardens in the early modern period, principal agents that led the construction of the Changgyeongwon Botanical Garden, and the birth of the garden itself were not the same. Thus, it may be said that the development process of Korean botanical gardens was discontinuous and sporadic. The study of identifying the origin of Korean botanical gardens, involving the Jong-yakjeon, aficionados gardens, intellectuals writings on trips to Western botanical gardens during the early modern period, and the creation of the Changgyeongwon Botanical Garden carries a message for contemporary botanical gardenswhich is, the botanical gardens reason for existence. Indeed, botanical gardens provided the basis for knowledge production and knowledge dissemination. They were the product of efforts directed toward revolutionizing old systems and adopting new ideas and new systems, and a means for promoting good taste and cultural refinement. In other words, the history of Korean botanical gardens is proof supporting the botanical gardens role as a platform aimed at creating a better life.Chapter 1. Introduction 1 1. Research Background and Purpose 1 2. Research Scope and Method 6 3. Related Literature and Studies 16 Chapter 2. Physic Gardens in the Age of Herbal Medicine Study, 13-15 Century 21 1. Herbal Study and Systems in Ancient Times 21 Medicine and Herbal Study 21 The Interest in Native Herbs and Yakpo in the Late Goryeo Dynasty 26 2. The Jong-yakjeon in the Joseon Dynasty 32 King Sejongs Hyangyak Policy 32 Jong-yakjeon: Increase and Localization of Medicinal Herbs 37 3. Conclusion: Benevolent Kings Medicinal Herb Garden 47 Chapter 3. Gardens of Aficionados in the Age of Natural History, 18-19 Century 50 1. The Emergence of Natural History and Aficionados 50 New Intellectual Paradigm: Natural History 50 The Pursuit of Byeok: From Wawusangzhi to Gewuzhizhi 58 The Emergence of Aficionados: Dilettantes and Connoisseurs 61 2. Gardens of Aficionados 68 Changes in Gardens and Horticulture in the Late Joseon Dynasty 68 Byeok for Flowers: Collection and Observation 72 Ryu Bak and Baekhwaam 83 3. Conclusion: Gentlemens Repository of Flowers and Knowledge 102 Chapter 4. Visits to Botanical Gardens in the Age of Enlightenment, 1876-1910 105 1. The Civilization and Enlightenment Movement and the Expansion of Knowledge 105 The Rise of Natural History as a New Thought 105 The Rise and Spread of Gaehwa Thought 109 Exploration of the West and the Pursuit of Civilization 112 2. Visits to Botanical Gardens in the World 120 Korean Delegations' Visits to Botanical Gardens 120 Overseas Students' Visits to Botanical Gardens 137 3. Conclusion: Western Gardens and Models of Civilization 147 Chapter 5. The Changgyeongwon Botanical Garden in the Age of Plant Taxonomy, 1910-1945 150 1. Botanical Research at the Changgyeongwon Botanical Garden 150 Establishment of the Changgyeongwon Botanical Garden 150 The Rise of Korean Botany and Botanists 159 2. Developing Taste at the Changgyeongwon Botanical Garden 173 Shumi: Colonial Politics and Botanical Gardens 176 Chwimi: Men of Culture and Botanical Gardens 184 3. Conclusion: Colonial People, Modern Citizens and the Changgyeongwon Botanical Garden 195 Chapter. 6 Conclusion 198 KOREAN VERSION 207 BIBLIOGRAPHY 372 ABBREVIATIONS 393 GLOSSARY 394 국문초록 397Docto

Study on Growth of Two-Dimensional Transition Metal Dichalcogenides on Graphene: The Interface-Driven Defects and Properties Relationship

Department of Materials Science and EngineeringVertically stacked heterostructures based on the different types of two-dimensional (2D) materials via van der Waals (vdW) interaction have been extensively researched due to their novel properties beyond the limitations of individual 2D materials. The development of chemical vapor deposition (CVD) method enables the fabrication of various vdW heterostructures with clean interface and mass production, compared to the conventional multiple transfer method. Given the 2D nature of these materials, the interface intrinsically plays an important role in modulating or modifying their properties. For example, graphene placed on hexagonal boron nitride shows high charge carrier mobility, but a non-negligible interaction leads to the observation of ???Hofstadter???s butterfly???. In addition, in the case of transition metal dichalcogenides (TMDs), the transition from the direct band gap to the indirect band gap is apparent when the thickness increases due to the interface effect. Therefore, a systematic understanding of the impact of the interface on the intrinsic characteristics and performances of the vdW heterostructures is required in order to design desirable properties and expand the scope of applications of the vdW heterostructure. It is well known that the structural features of the underlying substrate significantly affect the growth behavior and even the unique properties of the heterostructures. Therefore, in this dissertation, I studied novel defects in TMDs induced by an underlying graphene template with various structural features. For this research, I prepared 3 types of graphene templates: 1) Pristine, 2) wrinkle-rich, and 3) nanocrystalline graphene (ncG). Pristine graphene is a good substrate for synthesizing TMDs without dangling bonds and without friction. In addition, when TMDs grow on pristine graphene, the anti-phase boundaries (APBs) of the TMDs are generated more predominantly than the tilted grain boundaries (GBs) due to vdW epitaxial growth. Using this heterostructure, we discovered the anisotropic features of the APBs according to transition-metal-facing (saw-toothed) or chalcogen-facing (straight) APBs, and both types of APBs show metallic properties despite different in-plane charge mobility. Wrinkles in graphene cause significant friction due to out-of-plane deformation and result in AB/AC stacking boundaries (SBs) in epi-TMD layer driven by Shockley partial dislocations. AB/AC SB has a buckled structure for releasing in-plane strain and results in monolayer-like behavior by reducing interlayer coupling. Finally, ncG has lots of dangling bond based active sites for multilayer growth. Due to the diffusion limited growth regime on the ncG template, the synthesized WSe2 domain shows a fractal morphology with many Se-terminated edge states. The WSe2/ncG heterostructure shows a downshifted work function similar to the valence band maximum of WSe2, resulting in a small Schottky barrier height at the metal-semiconductor-junction. Interface-driven novel defects and their corresponding properties are mainly observed using multi-mode of transmission electron microscopy (TEM) and other surface analysis tools (e.g. Raman, x-ray spectroscopy, atomic force microscopy). Theoretical density functional theory (DFT) calculations and TEM image simulations were supported to identify thermodynamically stable defect configurations and to confirm the exact atomic structures of novel defects. These studies could provide a systematic understanding of defect engineering, especially interface-driven defect formation mechanisms, atomic configurations, and their corresponding properties. It could pave the way for achieving and expanding the manipulation and commercialization of 2D material-based devices via defect engineering.clos