Recent progress in computational discovery of Heusler alloys

Jin Taewon,Yousung Jung 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.4

Heusler alloy is an intermetallic alloy with a wide range of compositional space. Due to this compositional tunability, novel Heusler alloys have been studied for a variety of applications including permanent magnets, thermoelectric, and catalysis. Recently, computational approaches have been actively used to aid the fast discovery of novel Heusler alloys by identifying stable compositions with desired properties. In this mini-review, we briefly overview several computational approaches used for Heusler alloys, namely, density functional theory (DFT) calculations, high-throughput virtual screening (HTVS), and machine learning (ML) to further accelerate these screening processes. Future directions for the computational screening of Heusler alloy in other application fields are discussed.

Adiponectin Upregulates Filaggrin Expression via SIRT1-Mediated Signaling in Human Normal Keratinocytes

( Taewon Jin ),( Kui Young Park ),( Seong Jun Seo ) 대한피부과학회 2017 Annals of Dermatology Vol.29 No.4

Background: Filaggrin (FLG) is the major component of the epidermal granular layer and binds to and condenses the ker-atin cytoskeleton. FLG thus contributes to cell compaction and serves as a natural moisturizing factor by promoting un-folding and degradation into hygroscopic amino acids. Loss or downregulation of FLG has been shown to result in a weak stratum corneum, which causes water loss and increases the possibility of skin barrier-related seizure. Adiponectin (Acrp30) contributes to the functional recovery of somatic cells, including human normal epidermal keratinocytes (NHEKs). Objective: To investigate the effect of Acrp30 in FLG expression and identifying its signal transduction mechanism. Methods: Normal human keratinocytes were treated with Acrp30 and the levels of FLG were examined. Silent mating type information regulation 2 homolog (SIRT)-targeting siRNA and aryl hydrocarbon receptor nu-clear translocator (ARNT)-targeting siRNA were used to iden-tify the role of various signal transduction pathway components. Results: Acrp30 upregulated SIRT1 and ARNT expression in NHEKs, resulting in increased FLG expression. Treatment with both SIRT1-targeting siRNA and ARNT-tar-geting siRNA blocked Acrp30 stimulation and silenced FLG expression. Conclusion: Adiponectin upregulates FLG ex-pression through a SIRT1-mediated pathway. Our results suggest that Acrp30 is a promising agent for skin barrier per-meability improvement. (Ann Dermatol 29(4) 407∼413, 2017)

Fisetin Up-regulates the Expression of Adiponectin in 3T3-L1 Adipocytes via the Activation of Silent Mating Type Information Regulation 2 Homologue 1 (SIRT1)-Deacetylase and Peroxisome Proliferator-Activated Receptors (PPARs)

Jin, Taewon,Kim, Oh Yoen,Shin, Min-Jeong,Choi, Eun Young,Lee, Sung Sook,Han, Ye Sun,Chung, Ji Hyung American Chemical Society 2014 Journal of agricultural and food chemistry Vol.62 No.43

<P>Adiponectin, an adipokine, has been described as showing physiological benefits against obesity-related malfunctions and vascular dysfunction. Several natural compounds that promote the expression and secretion of adipokines in adipocytes could be useful for treating metabolic disorders. This study investigated the effect of fisetin, a dietary flavonoid, on the regulation of adiponectin in adipocytes using 3T3-L1 preadipocytes. The expression and secretion of adiponectin increased in 3T3-L1 cells upon treatment with fisetin in a dose-dependent manner. Fisetin-induced adiponectin secretion was inhibited by peroxisome proliferator-activated receptor (PPAR) antagonists. It was also revealed that fisetin increased the activities of PPARs and silent mating type information regulation 2 homologue 1 (SIRT1) in a dose-dependent manner. Furthermore, the up-regulation of adiponectin and the activation of PPARs induced by fisetin were prevented by a SIRT1 inhibitor. Fisetin also promoted deacetylation of PPAR γ coactivator 1 (PGC-1) and its interaction with PPARs. SIRT knockdown by siRNA significantly decreased both adiponectin production and PPARs–PGC-1 interaction. These results provide evidence that fisetin promotes the gene expression of adiponectin through the activation of SIRT1 and PPARs in adipocytes.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2014/jafcau.2014.62.issue-43/jf502849j/production/images/medium/jf-2014-02849j_0007.gif'></P>

박형 디스플레이를 위한 도광판의 광학설계

공태원(Taewon Gong),최규진(Gyu Jin Choi),권진혁(Jin Hyuk Kwon),박인식(In Shik Park),이선묵(Sunmook Lee),우동진(DongJin Woo),곽진석(Jin Seog Gwag) 한국표면공학회 2014 한국표면공학회지 Vol.47 No.5

In this paper, in order to achieve slim and light liquid crystal display, we examine the optical conditions that can obtain uniform light with higher optical efficiency over whole light guide plate (LGP) through simulation. Furthermore, to overcome the issues of hot spot in front of red, green, and blue light emitting diodes (RGB LEDs) source and non-uniform color mixing, we propose four shaped color mixing bars tied up with the LGP and check the optical characteristics of the LGP with them by simulation. Consequently, we could know the optical conditions of improving optical efficiency and optical uniformity in the LGP through the optical design. Also we confirmed that the issues of the hot spot and non-uniform color mixing in edge type LED could be solved by using the ∧-shaped window color mixing bar.

한반도 평화체제의 (탈)구축을 위하여 : 을의 민주주의의 관점에서

진태원(Jin, Taewon) 부산대학교 인문학연구소 2019 코기토 Vol.- No.88

이 글은 한반도 평화체제의 문제를 ‘을(乙)의 민주주의’의 관점에서 재고찰하는 것을 목표로 삼는다. 2018년 세 차례의 남북정상회담 및 최초의 북미정상회담이 이루어지면서 현재 우리나라에서는 한반도 평화체제에 대한 기대가 한층 높아져 있다. 1953년 정전체제가 수립된 이후 전개된 한반도 평화에 관한 담론은 크게 세 가지로 구별될 수 있다. 전통적인 안보담론이 하나이고, 김대중․노무현 정권 이후 본격화된 평화지향적 안보담론이 두 번째 담론이며, 마지막 세 번째가 평화운동 단체들을 중심으로 전개된 적극적 평화담론이다. 나는 이 세 번째 담론을 지지하는 입장을 제시하되, 을의 민주주의의 관점에서 적극적 평화담론을 (탈)구축 할 필요성을 제기하고자 한다. 그 핵심은 착취(또는 불평등), 배제(또는 차별), 리프리젠테이션의 문제를 평화담론 속에 포함시키는 것이다. This paper aims to reconsider the question of peace system in the Korean Peninsula from the viewpoint of democracy of ul(乙). After three South Korea-North Korea Summits and the first North Korea-USA Summit in 2018, expectations for a peace system on the Korean Peninsula are higher than ever before. Since the armistice in 1953, the discourses on peace in the Korean Peninsula have been largely distinguished in three ways; traditional discourse of national security is the first, and a discourse of peaceful security in Kim Dae-jung and Roh Moo-hyun administrations is the second, and a discourse of positive peace which is raised by the active groups of the peace movement in South Korea. I support this last one, but at the same time, I would like to raise the necessity to (de)construct it from the viewpoint of democracy of ul. The point is to include the issues of exploitation (or inequality), exclusion (or discrimination), and representation into the discourses on peace in the Korean Peninsula.

저성장 시대의 조세정책 방향에 대한 연구

곽태원(Kwack Taewon),최명근(Choe Myung Keun),현진권(Hyun Jin Kwon),이영(Lee Young),전영준(Chun Young Jun),조성진(Cho Seong Jin),김상겸(Kim Sang Kyum) 한국경제연구원 2006 한국경제연구원 연구보고서 Vol.2006-02 No.-

This volume is an outcome of collaborate work by several Korean public finance economists on various issues on the tax system in Korea. During the past twelve months we have conducted in-depth analysis on various tax issues, and had regular workshop to share results and ideas. As a result, we produced ten issue papers. Though independently dealing with different issues, these ten papers share the perspective that we provide rational strategy to overcome fundamental challenges that the Korean economy is facing. Chapter 2 overviews future directions for the tax system from the long-term perspective. Key challenges of the Korean economy are rapid aging and a consequent sharp drop in economic growth rates. Considering also the ever-intensifying international competition, the long-term key object of tax reforms should be the enhancement of potential economic growth rates. Equity can be also improved with adequately rapid economic growth, and problems associated aging population can be also alleviated when the old can find a job. Chapter 3 summarizes the key issues on the fundamental tax reforms in the United States. Tax systems of the 20th century can be characterized as taxation based on income, which increasingly reveals their weakness in terms of efficiency as globalization is intensified. Fundamental tax reforms toward more growth-friendly tax systems based on the consumption tax have been seriously considered as an alternative to the current income-based system with double taxations. Chapter 4 analyzes theories and practices of flat taxes. Simplicity of flat taxes has attracted interests of many public finance economists. Recently transitional economies in Eastern Europe adopted flat taxes. Initial outcome of the introduction of flat taxes appears promising. Chapter 5 reviews roles and characteristics of value-added taxes in Korea, and evaluates recent reform measures on VAT. It examines VAT as a tool to move toward the fundamental tax reform. Chapter 6 empirically examines how the correlation between corporate tax rates and revenue changes as openness increases. It is found that the positive correlation between the tax rates and revenues become weak in a more opened economy, suggesting that keeping corporate tax rates high in open economy accompany high efficiency cost. On the other hand, the correlation between individual income tax rates and revenues does not become weaker in more opened economies. The results suggest that corporate income bases are more mobile and elastic than individual income bases are, and hence, that relatively lower corporate tax rates are optimal policies in open economy. Chapter 7 examines the income redistribution and taxes. As the economy becomes more open, the effectiveness of taxes as income redistribution tools becomes weaker and involves high efficiency cost. Chapter 8 reviews issues related to environmental taxes. Strengthening environmental taxes is a worldwide trend, and Korea cannot be an exception. We suggest that strengthening environmental elements in existing taxes is a better measure than introducing new environmental taxes. Chapter 9 reviews issues related to estate and inheritance taxes in developed countries. Estate and inheritance taxes have been criticized for their ineffectiveness in enhancing equity and their distortionary effect on saving and investment from double taxation on income. The author suggests various ways to streamline the current estate and inheritance tax system in Korea. Chapter 10 evaluates the level of fiscal decentralization in Korea by comparing the actual values with predicted values from cross-country regressions of decentralization level on its determinants, such as the size of country, the level of democratization, and corruption. Contrary to common belief that the current level of fiscal decentralization in Korea is low, the authors find that the current level is not lower than the predicted values. The authors also point out

Synthesis and Photovoltaic Properties of Low-Band Gap Copolymers Containing Perylene Diimide Derivatives

Jin, Sung-Ho,Ban, Taewon,Park, Juhyeon,Gal, Yeong-Soon,Wook Lee, Jae Informa UK (TaylorFrancis) 2013 MOLECULAR CRYSTALS AND LIQUID CRYSTALS - Vol.578 No.1

Optimization of a redundantly actuated 5R symmetrical parallel mechanism based on structural stiffness

Jin, Sangrok,Kim, Jongwon,Seo, TaeWon Cambridge University Press 2015 Robotica Vol.33 No.9

<B>SUMMARY</B><P>A redundantly actuated parallel kinematic machine (PKM) can be used to avoid singularities, normalize manipulability, and increase the stiffness of anon-redundant mechanism. In this study, a redundantly actuated symmetrical PKM with five revolute (5R) joints is optimized for isotropic stiffness in the workspace. The stiffness of the 5R symmetrical PKM is calculated by the superposition of the actuator stiffness and the structural stiffness. We compared the stiffness of anon-redundant PKM and a redundant PKM. Compliance ellipses of the actuator stiffness and the structural stiffness of the non-redundant PKM resulted in the same configurations in the workspace, while those of the redundant PKM resulted in very different configurations. Optimization was performed by determining the optimal actuator torques that are needed to maximize the conditioning index. Optimal results considering structural stiffness can provide a more uniform directional stiffness than optimal results considering the index. When the strength of the linkages in a PKM is weak, the structural stiffness affects the actual stiffness considerably. We believe that the results of this study can be used to help design and control redundant PKMs.</P>

Paper as a Substrate for Inorganic Powder Electroluminescence Devices

Jin-Young Kim,Shang Hyeun Park,Taewon Jeong,Min Jong Bae,Sunjin Song,Jeonghee Lee,In Taek Han,Donggeun Jung,SeGi Yu IEEE 2010 IEEE transactions on electron devices Vol.57 No.6

<P>Alternating-current-type inorganic powder electroluminescence (PEL) devices were successfully fabricated on four kinds of paper substrates, i.e., glossy paper, sticker paper, magazine paper, and newspaper. To protect the paper from wet chemical and heating processes during the formation of the PEL device, the paper substrate was coated with a spin-on-glass layer that served as a buffer layer. In spite of the fragility of paper, quite satisfactory results were obtained-the performance of paper-based PEL devices was almost equivalent to that of PEL devices on a plastic substrate. Extension of a substrate to paper, even to flimsy daily newspaper, will widen the opportunity of PEL devices as one of flexible and disposable displays.</P>

Field-Enhancement Effect of Short Carbon Nanotubes Using an Electrical Aging Treatment on Inorganic Electroluminescence

Jin-Young Kim,Min Jong Bae,Taewon Jeong,Shang Hyeun Park,Sunjin Song,Jeonghee Lee,Intaek Han,Donggeun Jung,SeGi Yu IEEE 2010 IEEE electron device letters Vol.31 No.11

<P>AC inorganic electroluminescence (EL) devices were fabricated using the emitting layer composed of phosphor-single-walled carbon nanotubes (SWCNTs) composite (PSC) to utilize the local field enhancement of SWCNTs. In order to enhance the electric field in an emitting layer with minimized current paths, bare long SWCNTs were shortened by cryogenic crushing method. After electrical aging treatment of the PSC device, partly formed short SWCNT networks in the emitting layer were effectively removed during the electrical aging treatment. High performance of 60% and 43% increase in efficiency and luminance, respectively, was achieved. This PSC device with short SWCNTs could lead to high brightness due to increased electron tunneling into phosphor. The PSC device reveals the importance of high electric field by SWCNTs leading to high EL performance.</P>