Large anomalous Hall current induced by topological nodal lines in a ferromagnetic van der Waals semimetal

Kim, Kyoo,Seo, Junho,Lee, Eunwoo,Ko, K.-T.,Kim, B. S.,Jang, Bo Gyu,Ok, Jong Mok,Lee, Jinwon,Jo, Youn Jung,Kang, Woun,Shim, Ji Hoon,Kim, C.,Yeom, Han Woong,Il Min, Byung,Yang, Bohm-Jung,Kim, Jun Sung Springer Science and Business Media LLC 2018 NATURE MATERIALS Vol.17 No.9

Effect of food on the pharmacokinetics of YH4808, a potassium-competitive acid blocker, after single- and multiple-oral dosing in healthy subjects

Kim, Eunwoo,Kim, Anhye,Yi, Sojeong,Kim, Yu Kyong,Jang, Seong Bok,Byun, Hae Mi,Yoon, Seo Hyun,Cho, Joo-Youn,Jang, In-Jin,Yu, Kyung-Sang,Lee, SeungHwan Springer-Verlag 2018 European journal of clinical pharmacology Vol.74 No.10

High-resolution Classifier Ensemble for Defect Inspection of Display Panels

Eunwoo Kim(김은우),Jaewon Kim(김재완) 제어로봇시스템학회 2021 제어·로봇·시스템학회 논문지 Vol.27 No.8

DL(Deep Learning) has been applied to various tasks, and image classification is one of the most active areas where DL is applied. While the majority of DL approaches have focused on achieving improvements in classification accuracy by innovating a network structure with standard datasets in low resolution, detailed features in a high-resolution dataset are crucial to enhance classification accuracy, especially for practical datasets in the industry. We proposed a DL classifier structure that fully utilizes high-definition information for an OLED (Organic Light-Emitting Diode) panel inspection, and, for verification, we performed the task of classifying the authenticity of the actual OLED panel defects. The authenticity inspection of panel defects requires a precise analysis of high-resolution information. We confirmed that the application of the proposed classifier structure improved the performance of the classification. The proposed method includes an object detection method optimized for panel inspection and displays stable performance by utilizing an ensemble structure. The proposed method has been applied and is being used in actual production lines.

Efficient <tex> $l_{1}$</tex>-Norm-Based Low-Rank Matrix Approximations for Large-Scale Problems Using Alternating Rectified Gradient Method

Eunwoo Kim,Minsik Lee,Chong-Ho Choi,Nojun Kwak,Songhwai Oh IEEE 2015 IEEE transactions on neural networks and learning Vol.26 No.2

<P>Low-rank matrix approximation plays an important role in the area of computer vision and image processing. Most of the conventional low-rank matrix approximation methods are based on the l(2)-norm (Frobenius norm) with principal component analysis (PCA) being the most popular among them. However, this can give a poor approximation for data contaminated by outliers (including missing data), because the l(2)-norm exaggerates the negative effect of outliers. Recently, to overcome this problem, various methods based on the l(1)-norm, such as robust PCA methods, have been proposed for low-rank matrix approximation. Despite the robustness of the methods, they require heavy computational effort and substantial memory for high-dimensional data, which is impractical for real-world problems. In this paper, we propose two efficient low-rank factorization methods based on the l(1)-norm that find proper projection and coefficient matrices using the alternating rectified gradient method. The proposed methods are applied to a number of low-rank matrix approximation problems to demonstrate their efficiency and robustness. The experimental results show that our proposals are efficient in both execution time and reconstruction performance unlike other state-of-the-art methods.</P>

New fMRI analysis method for multiple stimuli using reference estimation

Kim, Eunwoo,Han, Yeji,Park, Hyunwook Wiley Subscription Services, Inc., A Wiley Company 2011 INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHN Vol.21 No.4

<P><B>Abstract</B></P><P>The stimulation paradigms of a functional MRI (fMRI) usually consist of one or more stimulations and a resting state in the block‐based and event‐related designs. To localize the activation areas in the human brain, each voxel is statistically analyzed using the fMRI data measured with the stimulation. The conventional method can be inefficient for experiments with multiple stimuli because of measuring the resting‐state signals repeatedly, causing redundancy in the scanning process. Although the phase mapping method can be applied to reduce the redundant resting‐state measurements, there are still limitations in the detection of regions activated by multiple stimuli and the periodic sequence of the multiple stimuli. In this article, a new fMRI data analysis method is presented that enables the detection of functional activations without the resting‐state images. This method estimates the reference signal from the signals acquired during multiple stimuli, and a random sequence and various durations of the multiple stimuli can be applied. Therefore, it can be used in the event‐related design as well as the block‐based design. The results of simulation and fMRI experiments show that the proposed method can correctly detect the activation regions of multiple stimuli, even for overlap regions, and can reduce the imaging time by skipping the resting‐state imaging. © 2011 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 21, 315–322, 2011</P>

Robust Elastic-Net Subspace Representation

Kim, Eunwoo,Lee, Minsik,Oh, Songhwai IEEE 2016 IEEE TRANSACTIONS ON IMAGE PROCESSING - Vol.25 No.9

<P>Recently, finding the low-dimensional structure of high-dimensional data has gained much attention. Given a set of data points sampled from a single subspace or a union of subspaces, the goal is to learn or capture the underlying subspace structure of the data set. In this paper, we propose elastic-net subspace representation, a new subspace representation framework using elastic-net regularization of singular values. Due to the strong convexity enforced by elastic-net, the proposed method is more stable and robust in the presence of heavy corruptions compared with existing lasso-type rank minimization approaches. For discovering a single low-dimensional subspace, we propose a computationally efficient low-rank factorization algorithm, called FactEN, using a property of the nuclear norm and the augmented Lagrangian method. Then, ClustEN is proposed to handle the general case, in which the data samples are drawn from a union of multiple subspaces, for joint subspace clustering and estimation. The proposed algorithms are applied to a number of subspace representation problems to evaluate the robustness and efficiency under various noisy conditions, and experimental results show the benefits of the proposed method compared with existing methods.</P>

Fabrication of Microgratings and their IR Diffraction Spectra

Kim, In Cheol,Choi, Eunwoo,Kim, Seong Kyu,Kang, Young Il,Kim, Taeseong,Bae, Hyo-Wook,Park, Do-Hyun Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.3

Microgratings whose diffracted field at a fixed angle generate IR spectra of $SF_6$ or $NH_3$ were fabricated by MEMS techniques for the purpose of IR correlation spectroscopy. Each micrograting was composed of 1441 reflecting lines in the area of $19.2{\times}19.2mm^2$. The depth profile of the line elements was determined with a gradient searching method that was described in our previous publication (J. Mod. Opt. 2013, 60, 324-330), and was discretized into 16 levels between 0 and $6.90{\mu}m$. The diffraction field from a given depth profile was calculated with Fraunhofer equation. The fabricated microgratings showed errors in the depth and the width within acceptable ranges. As the result, the diffracted IR spectrum of each micrograting matched well with its target reference spectrum within spectral resolution of our optical setup.

능동 롤 제어에 의한 차량 운동 성능 향상에 대한 연구

라은우(Eunwoo Na),김경호(Kyungho Kim),이상호(Sangho Lee),최장한(Janghan Choi),김충(Choong Kim),박준홍(Joonhong Park) 한국자동차공학회 2009 한국자동차공학회 부문종합 학술대회 Vol.2009 No.4

ARC (Active Roll Control) system operates the actuators either in the middle of the stabilizer bar (Rotary type) or at one end of stabilizer bar (Linear type) in order to reduce the roll angle. Here we apply ARC technology to a sedan and simulate it, in which the stabilizer bar stiffness changes along with the actuator stroke related to the lateral acceleration. Besides the roll angle reduction, it can improve the yaw rate behavior, too. The control logic of the linear ARC consists of three modules, 'Active Roll Compensation', 'Active Roll Damping' and 'Moment Distribution'.

공동제작 방식의 문제점과 해결방안

김은우(Eunwoo Kim),곽주영(Jooyoung Kwak) 연세대학교 경영연구소 2013 연세경영연구 Vol.50 No.2

보통 거래비용은 해외 진출을 지분투자에 기반한 진입 모드로 설명하지만 중국 영화 산업은 법규상 조인트벤쳐만 외국기업의 진입 모드로 허용하고 있다. 이러한 단일 진입 모드에 비하여 실제로 제작에 참여하는 방식은 복수의 선택이 있는데, 본고는 중국 시장의 진입 모드를 지분투자 방식으로 설명해온 기존 논문과는 달리 프로젝트 단위의 협업에 초점을 맞추었다. 국내 영화사는 대기업 한두 곳을 제외하고는 대부분 중소영화사이기 때문에 우리나라의 기업은 프로젝트 단위의 협업을 선호하고, 이러한 현실적 여건을 반영하고자 본 논문을 쓰게 되었다. 궁극적으로 본 연구는 중한 공동 제작상 문화콘텐츠를 창작하는데에 어떠한 어려움이 있고 이를 어떻게 극복했는지 <묵공>과 <전처의 결혼식>을 분석대상으로 하여 관련자들을 인터뷰하였다. 거래비용이론에서 설명하듯이, 중국에서의 협업도 파트너간 역할분담을 둘러싼 갈등의 문제가 많았다. 결국 국내 기업은 중국 영화시장에서 공동 제작에 성공하기 위해서는 무슨 역할을 어떻게 해야할 것인가가 관건인데, 한국이 강점이 있는 콘텐츠 개발에 주력하고 투자비율에 의한 수익의 배분을 약속받기 보다는 판권을 보유하는 방식이 파트너들과 갈등의 요소가 적음을 발견하였다. 중국 제작사들의 협상력이 지배적인 상황에서 한국의 중소영화제작사는 영화제작에 있어서 보다 특수화된 역할분담을 하는 방식으로 국제 협업에 참여하는 방안이 영화산업에서 한중간 국제협업의 모델로 제기된다. While transaction-cost theory explains entry mode using the level of equity investment, the entry of movie industry in China has been allowed only in a form of joint venture among the varying types of equity investment. In contrast, there are several ways to participate in production. Given the fact, we focus on the participation perspective, which is usually project-based. This approach gains theoretical and managerial supports because most production agencies in Korea are small or middlesized(except a couple of large firms), and most papers regarding entry mode to China adopts equity investment approach. Our study addresses the challenges of coproduction between Korea and China and the responses to overcome the challenges, with an in-depth examination of Mogong and Lianaiba. As transaction-cost theory proposes, international cooperation in movie coproduction has raised conflicts over the role of division with the Chinese partner. The reasons for success, after all, seem to lie in the clearly defined responsibilities and the following payoff. Our study finds that Korean agency needs to concentrate on content creation and to claim copyrights rather than profit split in order to reduce tension with Chinese partner. We suggest that as Chinese partner possesses dominant bargaining power, small or middle-sized Korean production agency should undertake more specific and specialized tasks for international co-production.

Post-growth process for flexible CdS/CdTe thin film solar cells with high specific power

Cho, Eunwoo,Kang, Yoonmook,Kim, Donghwan,Kim, Jihyun The Optical Society 2016 Optics express Vol.24 No.10