Education and political ideology in North Korea : a critical analysis of educational policy, aims, and nationalism

Sung UMI 1990 국내박사

Hug2Go : The Development of Indoor Smart Driving Personal Mobility

Sung-ho Lee Graduate School of UNIST 2019 국내석사

This paper presents an initial study on the acceptance of indoor PMVs through providing design and development of a new PMVs (Personal Mobility Vehicles). Hug2Go is the indoor personal mobility, finding passenger through self-driving and going to place by a new way of steering. The personal mobility vehicles (PMVs) emerged as a new category of transportation device in the early 2000s. PMVs offers several potential benefits to consumers and society. Many researchers focused on performance or acceptability of use. However, most of PMVs regarded as outdoor mobility. Recently, popular PMVs has been moved to sharing service area. We thought it opportunity area for the mobility market. In this research, we suppose a new model of indoor mobility and examine it possible to build on the market through the usability test. First, we discovered the context of indoor mobility with existing PMVs driving. Through the observation, we found meaningful insights. Second, we designed and developed indoor PMVs. Third, we conducted a usability evaluation with fifteen participants by using Hug2Go. Experimental results with fifteen participants regarding the acceptance of indoor PMVs validated the proposed latent needs. Finally, we discussed findings and opportunities for improvements. The purpose of this study and the development of PMVs is to provide a comprehensive background for initial research of indoor PMVs.

Understanding Design Process from a Perspective of Framing: Exploring the Concept of Frames for Designing

Sung, Hye Rin Hongik University 2017 국내석사

The journey of progressing this study was not possible without all my bright friends and incredible professors at IDAS, Hongik University. Though the journey rather brought a seemed endless cycle of agony-frustration-eureka-enthusiasm, at the end of every day I could be full of excitement for the following steps because of these people. Thank you. My supervising professor Dr. Ken Nah, who has been always inspiring with his insights, is the definite first person I would like to acknowledge. I could keep on track while I have been consistently shifting my frames, thanks to his interest and keen advices. I owe Dr. Junhong Park an enormous gratitude for all those discussions and guidance. This journey has been startlingly fun because of his serious knowledge with wrong humour. And my indescribably beautiful friend Seoyoung Kim, who is always there inspiring and considerate, has kept me in eagerness by sharing unexpected perspectives throughout the course of this research. I feel that it is not enough to express my gratefulness and affection in words, but I only dream of the near day when we could unfold our curiosity together for it to be interwoven wonderfully. I would like to acknowledge Soojung Jun and all my fellow researchers at IDTC lab in Hongik University, for them to exchange invaluable feedbacks. And every one of my research mates from IDAS, especially the residents at room #504, gave me a lot of intriguing points of view which helped me to push my study, I appreciate all immensely. Also, I owe the team from Beyond Design Inc. a huge gratitude for such great inspirations and insights, particularly, Michael Prince for his encouragement and support. And my outstandingly thoughtful and explorative friend Holly Prouty, I would love to thank her for continuously inspiring my mindset and being supportive and attentive from another continent regardless of the distance. Finally, I owe the biggest thankfulness to my adorable family, especially my parents, I would not have come this far without their endless love and support. Seoul, July 2017 Hyerin Sung p.8.oft-Systmes guide to creativity, problem-solving and the process of reaching goals, challenging situations and arrive at satAbstract Design, as a problem-solving process, has been recognised to be thoroughly human-centred. Since the initial move aimed for a major shift from design artefacts to people, the discipline has been progressing forward by developing diverse approaches and methodologies. On the other hand, it has been discussed that the increasing complexity in our world and society is an unprecedented case. Regarding these matters, this study began with two prime questions: 1) when design claims to be the appropriate discipline for human-centred problem solving, why so? 2) how can designers enhance fundamental understanding on people, in response to the slogan ‘designing for people’? Hence, this study aimed to find opportunities for improvement in design in terms of understanding people and dealing with various perspectives, by exploring the concept of frames which is known to be fundamentally related to how we perceive the world differently. The study was implemented in two directions: reviewing literature on both design and frames to extract the essentials for synthesis and analysing a case study to understand design process from a perspective of framing. As a result, design process was reinterpreted with a scope of designers’ framing actions in handling various perspectives and a guidebook was designed to inform designers on useful aspects about the notion of frames. 문제해결 프로세스로서의 디자인은 지금껏, 사람에 초점을 맞춘다는 점에서 큰 관심을 받아왔다. 디자인 인공물 자체에 맞춰져 있던 초점을 디자인을 사용하는 사람으로 이동시키기 위한 시도와 움직임 이래, 디자인 학문은 다양한 접근법과 방법론들을 전개하며 발전해왔다. 한 편으론, 전례 없이 빠르게 복잡해지고 있는 사회에 대한 이슈가 대두되고 있다. 이러한 사항들을 토대로, 본 연구는 두 가지 근본적인 질문에서 출발하였다. 1) 디자인 분야가 사람 중심의 문제해결에 적합한 방법으로 각광받고 있는데, 어떤 면에서 그러한가? 2) 어떻게 하면 디자이너들이 ‘사람을 위해 디자인 한다’는 슬로건에 대응하여, 사람에 대한 근본적인 이해를 높일 수 있을까? 이러한 배경을 바탕으로 본 연구의 목적은, 개개인이 세상을 각기 다른 시각으로 보게 되는 현상에 밀접한 관계가 있는 ‘프레임’이라는 개념의 탐구를 통하여, 사람에 대한 이해와 다양한 시각들을 다뤄야하는 디자인 분야의 발전 방향과 기회의 탐색에 있다. 연구의 방향은 두 가지로 나뉘었다. 첫째로는, 디자인과 프레임에 대한 개별적 문헌 연구를 통하여 디자인 분야에 유용할 수 있는 프레임 개념 관련 요소들을 검토하고 종합하는 연구가 진행되었다. 둘째로는, 사례연구 분석을 통하여 디자인 프로세스를 프레임의 관점에서 해석하고 이해하는 방향으로 진행되었다. 본 연구는 결과적으로, 디자이너들이 사람들의 다양한 시각을 다루는 과정에서 행하는 ‘프레이밍’ 활동에 초점을 맞춰 디자인 프로세스를 재해석하였고, 문헌 연구 등을 바탕으로 추출된 ‘프레임’ 관련 유용 개념 및 핵심 사항 등을 디자이너에게 전달하기 위한 안내 소책자를 디자인하였다.

Laser Development for Photo Therapy and Cartilage Reshaping

Sung Ho Lee Graduate School of UNIST 2018 국내석사

I designed laser systems for Laser Cartilage Reshaping (LCR). To flexible usage, I have de-signed a fiber laser system with outputs at 3 wavelengths, 808nm, 1064nm, 1470nm. We used fiber type laser which provide cost, space, flexibility. The main feature of the fiber laser system is that it can be operated tunable and high power –the loss is less than 20%. This laser system is suitable for more portable applications with limited power output. Following recommendation of Health Care Laser System (HCLS) that invisible laser power for medical approach it cannot pro-duce more than 500mW. We already have enough power to adopt at medical approach. We have tested both laser systems by reshaping septal cartilage samples freshly excised from rabbits.

Understanding embrittlement in heat-resistant steels and prevention of cracking by precipitation control

성현제 Pohang University of Science and Technology 2018 국내박사

The use of advanced heat-resistant steels in coal-fired fossil power plants has increased significantly in efforts to increase thermal efficiency and reduce environmentally damaging gases. In particular, the alloying of tungsten for solid solution strengthening and carbo-nitride formers for precipitation hardening has remarkably enhanced the performance of low chromium heat-resistant steel, comparable to high chromium steels. However, its weakness, showing inevitable phase transformation during welding procedures, causes eventual intergranular cracking and premature failure. Although various interpretations of embrittlement have been suggested in previous studies, the understanding of intergranular cracking still remains a subject for discussion, and fundamental questions considering the cracking mechanisms have remained. Here, direct evidence from transmission electron microscopy is reported, showing the active M23C6 precipitation reaction accelerated by tungsten. Also, Auger electron spectroscopy and Nano secondary ion mass spectrometry are used to show that detrimental phosphorus and sulfur segregate at grain boundaries due to absence of carbon repelling them during post-weld heat treatment or under operation condition. The present study also provides the thermodynamic calculation results showing the changes in the Gibbs free energy of M23C6 formation and precipitation kinetics with increasing vanadium content. The experimental results compared with simulation show that the selection of the appropriate vanadium content makes it possible to reduce cracking susceptibility by precipitation control and grain boundary segregation engineering. The present work also develops new low chromium heat-resistant alloys even surpassing the creep rupture life of conventional 9 wt. % chromium steels by vanadium content modification and the subsequent elimination of unstable M23C6 carbides. Sub-boundaries of bainite microstructure can be stabilized by fine MX, so movement and agglomeration of neighboring sub-boundaries are effectively suppressed. Therefore, sub-grain hardening is effectively maintained and it leads to promising results for advanced power plant applications.

Synthesis and characterization of layer structured transition metal chalcogenides with 2D metallic transport

Yu, Hosung Sungkyunkwan university 2018 국내박사

1.1 Motivation and representative research works Since transition metal chalcogenide (TMC) have attracted much attention because of their unique physical properties with two dimensional character. There are lots of materials which crystal structure is already reported but their physical properties are not discovered fully. I have mainly focused on synthesis and characterization of materials which can be applicable to find new phenomena. Here I describes two representative research works. One is ternary layered transition metal chalcogenide Ti2PTe2 with 2D metallic transport and the other is enhanced electropositivity of dense metallic cuboid in layer structured transition metal-rich chalcogenide Hf3Te2. 1.2 Ternary layered transition metal chalcogenide Ti2PTe2 with 2D metallic transport Recently transition metal dichalcogenides (TMDs) have attracted stimulated interest in diverse fields of study in physics and materials science because of their unique physical properties and high potential for applications derived by their weak interlayer attraction, allowing exfoliation into atomically thin layers. But most researches have been focused on the binary compounds with TmCh2 composition (Tm: transition metal, Ch: chalocogen element), and the properties of TMCs are confined to the semiconducting field. So it is necessary to study diverse compound TMCs and their physical properties. Based on the synthesis of high quality single crystal Ti2PTe2, we successfully measured the anisotropic resistivity down to 1.8 K, verifying quasi-2D transport in a weakly disordered metallic regime along the in-plane direction. Combining with Hall coefficient and heat capacity measurements, it is confirmed that the electron-electron interaction is dominant in a bipolar electronic feature. From angle-resolved photoemission spectroscopy (ARPES) measurement combined with DFT calculations, the large electron pockets which have a quasi-2D character and a small hole pocket in the first Brillouin zone center are clearly demonstrated. These results strongly support that quasi-2D metallic nature originates from 2D Ti-network that constructs quasi-2D conducting channels in a ternary Ti2PTe2 crystal. 1.3 Quasi-high-pressure effects in transition-metal-rich dichalcogenide, Hf3Te2 Considering monolayer transition metal chalcogenides with MX2 composition, the trigonal prismatic phase 1H and the octahedral prismatic phase 1T are obtainable consisting of three atoms in an intralayer space. In case of transition metal-rich chalcogenide Hf3Te2, there are five atoms in the intralayer and a hafnium cuboid is sandwiched between outer tellurium atoms. Changes of physical properties are expected due to the chemical pressure induced by structural deformation. To sustain transition metal-rich composition, hafnium metals form cuboid which is comparable with bcc phase of hafnium at high pressure which cause changes in physical properties such as exceeding heat capacity over Dulong-Petit limit and reduced work function. Density functional theory calculations verify that the compressed cuboid in Hf3Te2 has a key role resulting from the intrinsic pressure induced s-d transfer in covalent electrons between Hf-Hf bonding. This transition metal-rich dichalcogenide can guide a route to realize a high pressure element under ambient condition and offer an opportunity to explore a new layered two-dimensional material.

(The) effects of flashlight guidance on performance for chest compression of cardiopulmonary resuscitation in a noisy environment

유제성 Graduate School, Yonsei University 2012 국내석사

Introduction In real cardiopulmonary resuscitation (CPR) situations, noise can arise from instructional voices and from environmental sounds in places such as the battlefield, industrial, commercial shopping and high traffic areas. The World Health Organization (WHO) suggested guideline limits for community noise in specific environments. In the specific environments mentioned above, noise levels were measured to be >70 dB, which can induce annoyance and hearing impairment. A simple feedback device using flashlight stimulus was designed for overcoming noise-induced stimulus saturation during CPR. This study was conducted to determine whether flashlight guidance influences CPR performance in a simulated noisy setting. Materials and Methods We recruited 30 senior medical students with no previous experience using flashlight-guided CPR participated in this prospective, simulation-based, cross-over study. In a simulated noisy situation, the experiment was conducted using a cardiac arrest model without ventilation. Noise was artificially generated as patrol car and fire engine sirens. Siren noise intensity was adjusted to 80 ± 5 dB, with 60 pitches/minute. The flashlight guidance emitted light pulses at the rate of 100 flashes/minute from a light-emitting diode (LED). Participants also received the instruction that suited a target rate of 100 compressions/minute. CPR was randomly performed in one of two sequences. Compression rate and depth and percentage of compression with correct hand position were recorded with a Resusci Anne? manikin with a PC skill-reporting system. Participants were asked to report rescuer’s fatigue on a visual analog scale (VAS) of 0-10. A linear mixed model for 2×2 cross-over design and evaluating changes in chest compression rate across time were used. Results There were significant differences between the control and flashlight groups for mean compression rate (MCR), MCR/minute, and VAS. However, there were no significant differences for corrected compression depth (%), mean compression depth (mm), corrected hand position (%), and correctly released compression (%). The flashlight group MCR closely maintained the target 100 compressions/minute. However the control group MCR was distributed over a much wider range. The flashlight group had a tendency to maintain constant MCR, whereas the control group had a tendency to decrease MCR after 60 seconds Conclusion Flashlight guidance is effective low-cost CPR feedback system for maintaining desired MCR. Flashlight-guided CPR is particularly advantageous in maintaining desired MCRs during compression-only CPR in noisy environments where metronome-pacing might not be clearly heard.

Essays on capital market and portfolio performance

박성준 Graduate School, Yonsei University 2018 국내박사

본 학위논문은 포트폴리오 성과를 중심으로 자본시장을 분석하였다. 제1장에서는 미국 애널리스트들의 평균적인 투자의견을 반영하여 구축한 포트폴리오의 성과를 살펴보았다. 표본 기간은 1994년 1월부터 2016년 12월이다. 포트폴리오의 성과는 Carhart의 4요인 모형의 상수항으로 정의하였다. 기존 논문과 마찬가지로 애널리스트들이 가장 선호하는 주식으로 구성된 포트폴리오와 롱-숏 전략으로 구성된 포트폴리오는 전체 표본 기간 동안 통계적으로 유의미한 초과 수익을 거두는 반면, 거래비용을 고려하는 경우 이러한 초과 수익률은 대부분 사라지는 것으로 나타났다. 다만, 이들 포트폴리오의 초과 수익률은 시간에 따라 변동하는 것으로 나타났으며, 거래비용을 고려하더라도 2000년대 초중반에 예외적으로 높은 수준을 보였다. 제2장에서는 미국 애널리스트들이 가장 선호하는 주식으로 구성된 포트폴리오의 무위험 자산 및 시장 대비 수익률이 과연 금융 및 거시 변수들에 의해 예측될 수 있는지를 살펴보았다. 추정 결과 배당 수익률 및 산출갭(output gap)이 다양한 기간에 걸쳐서 포트폴리오의 무위험 자산 대비 수익률을 표본 내와 표본 외에서 예측할 수 있는 것으로 나타났다. 그러나 실증분석에 사용된 예측 변수들은 대부분 포트폴리오의 시장 대비 수익률을 예측하는 데 실패하였다. 제3장에서는 미국 애널리스트들의 평균적인 산업별 투자의견을 포트폴리오 최적화 과정에 반영함으로써 다양한 포트폴리오 전략의 성과를 개선할 수 있는지를 살펴보았다. 산업별 투자의견은 추가적인 제약식의 형태로 최적화 과정에 포함되었다. 실증분석에는 Fama-French 산업별 포트폴리오가 사용되었다. 분석 결과, 보다 세밀한 산업 분류가 사용되는 경우 산업별 투자의견을 반영한 포트폴리오가 그렇지 않은 포트폴리오에 비해 통계적으로 유의미하게 향상된 성과를 내는 것으로 나타났다. 또한 기존의 포트폴리오 성과가 산업 분류의 정도에 따라 변동하는 반면, 산업별 투자의견을 반영한 포트폴리오의 성과는 산업 분류의 정도에 별다른 영향을 받지 않는 것으로 나타났다. This dissertation consists of three chapters that examine capital market and portfolio performance. The first chapter examines whether investors can benefit from consensus recommendations of the stock analysts using U.S.\ financial market data from January 1994 to December 2016. The abnormal return from the four-factor model is used as performance measure. Consistent with existing literature, the portfolios of most recommended stocks and the long-short strategy exhibit significantly positive abnormal returns, although some of them disappear when the transactions cost is taken into account. Furthermore, the performance of both portfolios varies over time, and is exceptionally good in the early and mid 2000's regardless of the transactions cost. The second chapter investigates the predictability of the excess return of the portfolio consisting of most highly recommended stocks. The consensus recommendations of the analysts are used to construct the portfolio. The predictability of excess return of the portfolio over the risk-free rate and over the market return at various horizons is tested using predictors widely used in the literature. The estimation results show that the dividend yield and output gap measure, among others, predict the excess return of the portfolio over the risk-free rate both in-sample and out-of-sample at various horizons. But the performances of the predictors are not good for the excess return of the portfolio over the market index. The last chapter examines if one can improve the out-of-sample performance of the industry portfolios by incorporating industry consensus recommendations into the optimization process. The consensus recommendations enter the optimization process as an additional constraint. The idea is tested using Fama-French industry portfolios. The empirical results show that the optimization strategies involving consensus recommendations tend to outperform their counterparts especially when more detailed industry classifications are considered. Moreover, it is also shown that their out-of-sample performances don't fluctuate much when the industry classification changes, in contrast with the traditional optimization strategies.

Effects of coffee consumption on liver metastasis of colon cancer and host microenvironment in a mouse model

이성배 Daejeon University 2020 국내박사

The most harmful behavior of cancer is metastases that make a difficulty to complete cure up to now. In colon cancer, liver metastasis is most commonly observed, and its colon-liver metastatic rate is approximately 30 to 40 % worldwide. On the other hand, coffee is a one of most popular drink globally and it is daily consumed more than 2.25 billion cups in the world. Coffee generally shows the positive pharmacological actions on colon cancer, either stage of development or patients’ survival. It however didn’t reveal how coffee affects to colon-liver metastasis yet. In order to answer the questions regarding to coffee’ effects on colon -liver metastasis, this study conducted four experiments: 1) coffee’ effects on tumor metastasis in “seeding phase”, 2) coffee’ effects on tumor metastasis in “soiling phase”, 3) fluorescence tracking assay for chase of “early seeding phase” and 4) coffee’ effects on “host microenvironment”. C57BL/6 male mice were divided into 3 groups: Control, Coffee 0.2 g/kg, and Coffee 1 g/kg, respectively. The colon-liver metastasis animal model adapted spleen injection of MC38, a mouse colon cancer cell line. In results, the pre-administration of coffee (seeding phase) significantly decreased the nodule numbers of tumor, liver weight and the fluorescence cancer cells in hepatic tissue comparing to the control (p < 0.01). The post-administration of coffee (soiling phase) slightly reduced the nodule numbers of tumor and liver weight but was not statistically significant comparing to control (p > 0.05). In addition, coffee administration suppressed both pro- and anti-inflammatory cytokines (IL-1β, TNF-α, INF-γ, IL-10) and adhesion molecule (VCAM1) significantly comparing to the control (p < 0.01). Immune cells in blood and hepatic tissue weren’t changed by administration of coffee. Interestingly, TGF-β levels was decreased in serum but increased in hepatic tissue by administration of coffee. Taken together, coffee administration evidently inhibits liver metastasis of colon cancer via modulations of hepatic microenvironments, likely reductions of adhesion molecules, and pro-inflammatory cytokines, and reverse regulation of TGF-β1 in blood and hepatic tissue.

Epigallocatechin-3-gallate (EGCG) enhances TRAIL-induced apoptosis through DR5 upregulation in human colon cancer cells

권오성 Kyung Hee University 2018 국내박사

Though epigallocatechin-3-gallate (EGCG), a major component of green tea, was known to exhibit anti-inflammatory, anti-diabetes, anti-obesity, and antitumor effect, the underlying antitumor molecular mechanism of EGCG was not fully understood. Here the sensitizing effect of EGCG to TRAIL was examined in colon cancers. Combination of EGCG and TRAIL exerted synergistic cytotoxicity in SW480 and HCT116 cells. Also, combination of EGCG and TRAIL increased early and late apoptotic portion, sub G1 accumulation, the number of TUNEL positive cells in SW480 and HCT116 cells. Also, this combination enhanced the cleavages of poly (adenosine diphosphate-ribose) polymerase (PARP), caspase-8 activation compared to TRAIL or EGCG alone in SW480 and HCT116 cells. Of note, cotreatment of EGCG and TRAIL enhanced the expression of death receptor 5 (DR5) at protein and mRNA levels and attenuated anti-apoptotic proteins in SW480 and HCT116 cells. Conversely, depletion of DR5 by siRNA transfection blocked the apoptotic activity of combination of EGCG and TRAIL to increase cytotoxicity, sub-G1 accumulation and PARP cleavages in SW480 and HCT116 cells. Overall, our study suggests that EGCG can be a sensitizer of TRAIL via DR5 mediated apoptosis in colorectal cancer cells.