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Machine‐Engineered Active Disorder for Digital Photonics

Jungmin Kim, Seungkyun Park, Sunkyu Yu, Namkyoo Park
2022 Advanced Optical Materials  
doi:10.1002/adom.202102642 fatcat:mcn3ujuyindqddepmg6rdvhmti

Identifying intrinsic and extrinsic mechanisms of anisotropic magnetoresistance with terahertz probes [article]

Ji-Ho Park, Hye-Won Ko, Jeong-Mok Kim, Jungmin Park, Seung-Young Park, Younghun Jo, Byong-Guk Park, Se Kwon Kim, Kyung-Jin Lee, Kab-Jin Kim
2021 arXiv   pre-print
Identifying the intrinsic and extrinsic origins of magneto-transport in spin-orbit coupled systems has long been a central theme in condensed matter physics. However, it has been elusive owing to the lack of an appropriate experimental tool. In this work, using terahertz time-domain spectroscopy, we unambiguously disentangle the intrinsic and extrinsic contributions to the anisotropic magnetoresistance (AMR) of a permalloy film. We find that the scattering-independent intrinsic contribution to
more » ... MR is sizable and is as large as the scattering-dependent extrinsic contribution to AMR. Moreover, the portion of intrinsic contribution to total AMR increases with increasing temperature due to the reduction of extrinsic contribution. Further investigation reveals that the reduction of extrinsic contribution is caused by the phonon/magnon-induced negative AMR. Our result will stimulate further researches on other spin-orbit-interaction-induced phenomena for which identifying the intrinsic and extrinsic contributions is important.
arXiv:2107.01770v1 fatcat:ggt6xyxmovhqdnxyrozvarji4a

Hearing the shape of a drum for light: isospectrality in photonics

Seungkyun Park, Ikbeom Lee, Jungmin Kim, Namkyoo Park, Sunkyu Yu
2021 Nanophotonics  
Seungkyun Park and Ikbeom Lee contributed equally to this work. Figure 1 : 1 Figure 1: Concept of isospectrality.  ... 
doi:10.1515/nanoph-2021-0614 fatcat:fy7sgylv2nbpto45ehgcxr575e

Lightweight Image Enhancement Network for Mobile Devices Using Self-Feature Extraction and Dense Modulation [article]

Sangwook Baek, Yongsup Park, Youngo Park, Jungmin Lee, Kwangpyo Choi
2022 arXiv   pre-print
Convolutional neural network (CNN) based image enhancement methods such as super-resolution and detail enhancement have achieved remarkable performances. However, amounts of operations including convolution and parameters within the networks cost high computing power and need huge memory resource, which limits the applications with on-device requirements. Lightweight image enhancement network should restore details, texture, and structural information from low-resolution input images while
more » ... ng their fidelity. To address these issues, a lightweight image enhancement network is proposed. The proposed network include self-feature extraction module which produces modulation parameters from low-quality image itself, and provides them to modulate the features in the network. Also, dense modulation block is proposed for unit block of the proposed network, which uses dense connections of concatenated features applied in modulation layers. Experimental results demonstrate better performance over existing approaches in terms of both quantitative and qualitative evaluations.
arXiv:2205.00853v1 fatcat:tvc5xiqr3rgdhclidqfotuq5bm

Clinical significance of tumor size in Gastric cancer

Hakjin Kim, Youjin Jang, Jonghan Kim, Sungsoo Park, Sungheum Park, Seungjoo Kim, Youngjae Mok, Jongsuk Kim, Jungmin Park, Kyungsook Yang
2010 Korean Journal of Clinical Oncology  
doi:10.14216/kjco.10006 fatcat:e6zb5zu6wngutlgqrmq74t6a3e

Study on User Interface of Pathology Picture Archiving and Communication System

Dasueran Kim, Peter Kang, Jungmin Yun, Sung-Hye Park, Jeong-Wook Seo, Peom Park
2014 Healthcare Informatics Research  
tal management including patient management, general administration, clinical examination, healthcare management, information management, and the storage and delivery of medical images. Moreover, the variety of medical information systems, such as Electronic Medical Record (EMR) systems, Order Communication Systems (OCSs), and Picture Archiving and Communication Systems (PACS), as well as telemedicine has been developing rapidly. Even though the introduction of various medical information
more » ... s has increased, the development of a user experience-based medical information system should be considered because various studies on the healthcare systems have focused mainly on functional aspects rather than on user experience. User experience refers to the overall experience that is gained from direct and indirect use of a system, product, or service, and is a new approach to developing the technology in terms of improving the quality of Objectives: It is necessary to improve the pathology workflow. A workflow task analysis was performed using a pathology picture archiving and communication system (pathology PACS) in order to propose a user interface for the Pathology PACS considering user experience. Methods: An interface analysis of the Pathology PACS in Seoul National University Hospital and a task analysis of the pathology workflow were performed by observing recorded video. Based on obtained results, a user interface for the Pathology PACS was proposed. Results: Hierarchical task analysis of Pathology PACS was classified into 17 tasks including 1) pre-operation, 2) text, 3) images, 4) medical record viewer, 5) screen transition, 6) pathology identification number input, 7) admission date input, 8) diagnosis doctor, 9) diagnosis code, 10) diagnosis, 11) pathology identification number check box, 12) presence or absence of images, 13) search, 14) clear, 15) Excel save, 16) search results, and 17) research. And frequently used menu items were identified and schematized. Conclusions: A user interface for the Pathology PACS considering user experience could be proposed as a preliminary step, and this study may contribute to the development of medical information systems based on user experience and usability.
doi:10.4258/hir.2014.20.1.45 pmid:24627818 pmcid:PMC3950265 fatcat:xncexcjidzdg3mofrsxong5rtm

Transcanal Endoscopic Ear Surgery for Congenital Cholesteatoma

Joo Hyun Park, Jungmin Ahn, Il Joon Moon
2018 Clinical and Experimental Otorhinolaryngology  
Objectives. As endoscopic instrumentation, techniques and knowledges have significantly improved recently, endoscopic ear surgery has become increasingly popular. Transcanal endoscopic ear surgery (TEES) can provide better visualization of hidden areas in the middle ear cavity during congenital cholesteatoma removal. We aimed to describe outcomes for TEES for congenital cholesteatoma in a pediatric population. Methods. Twenty-five children (age, 17 months to 9 years) with congenital
more » ... a confined to the middle ear underwent TEES by an experienced surgeon; 13 children had been classified as Potsic stage I, seven as stage II, and five as stage III. The mean follow-up period was 24 months. Recurrence of congenital cholesteatoma and surgical complication was observed. Results. Congenital cholesteatoma can be removed successfully via transcanal endoscopic approach in all patients, and no surgical complications occurred; only one patient with a stage II cholesteatoma showed recurrence during the followup visit, and the patient underwent revision surgery. The other patients underwent one-stage operations and showed no cholesteatoma recurrence at their last visits. Two patients underwent second-stage ossicular reconstruction. Conclusion. Although the follow-up period and number of patients were limited, pediatric congenital cholesteatoma limited to the middle ear cavity could be safely and effectively removed using TEES.
doi:10.21053/ceo.2018.00122 pmid:29940721 pmcid:PMC6222188 fatcat:agf63mrlyfar5ldktfvnmkwkum

Distributive and Processive Exonucleases Characterized by Single Molecule FRET

Sangmi Jee, Jungmin Yoo, Suyeon Park, Gwangrog Lee
2014 Biophysical Journal  
Yoo, Suyeon Park, Gwangrog Lee.  ...  the strand cleavage for the Flp-FRT system but affect the synapsis for Cre-loxP system. 392-Pos Board B147 Distributive and Processive Exonucleases Characterized by Single Molecule FRET Sangmi Jee, Jungmin  ... 
doi:10.1016/j.bpj.2013.11.479 fatcat:h6xfjhh62jcbjlczycvle6nzru

Antiviral Efficacy of Pralatrexate against SARS-CoV-2

Joon-Yong Bae, Gee Eun Lee, Heedo Park, Juyoung Cho, Jeonghun Kim, Jungmin Lee, Kisoon Kim, Jin Il Kim, Man-Seong Park
2021 Biomolecules & Therapeutics  
Novel coronavirus (SARS-CoV-2) has caused more than 100 million confirmed cases of human infectious disease (COVID-19) since December 2019 to paralyze our global community. However, only limited access has been allowed to COVID-19 vaccines and antiviral treatment options. Here, we report the efficacy of the anticancer drug pralatrexate against SARS-CoV-2. In Vero and human lung epithelial Calu-3 cells, pralatrexate reduced viral RNA copies of SARS-CoV-2 without detectable cytotoxicity, and
more » ... replication was successfully inhibited in a dose-dependent manner. In a time-to-addition assay, pralatrexate treatment at almost half a day after infection also exhibited inhibitory effects on the replication of SARS-CoV-2 in Calu-3 cells. Taken together, these results suggest the potential of pralatrexate as a drug repurposing COVID-19 remedy.
doi:10.4062/biomolther.2021.032 pmid:33731494 pmcid:PMC8094065 fatcat:5k5bpvoe6vdrzpgdh4zl5ws5he


Min-Joong Lee, Jungmin Lee, Jaimie Yejean Park, Ryan Hyun Choi, Chin-Wan Chung
2012 Proceedings of the 21st international conference on World Wide Web - WWW '12  
The betweenness centrality of a vertex in a graph is a measure for the participation of the vertex in the shortest paths in the graph. The Betweenness centrality is widely used in network analyses. Especially in a social network, the recursive computation of the betweenness centralities of vertices is performed for the community detection and finding the influential user in the network. Since a social network graph is frequently updated, it is necessary to update the betweenness centrality
more » ... iently. When a graph is changed, the betweenness centralities of all the vertices should be recomputed from scratch using all the vertices in the graph. To the best of our knowledge, this is the first work that proposes an efficient algorithm which handles the update of the betweenness centralities of vertices in a graph. In this paper, we propose a method that efficiently reduces the search space by finding a candidate set of vertices whose betweenness centralities can be updated and computes their betweenness centeralities using candidate vertices only. As the cost of calculating the betweenness centrality mainly depends on the number of vertices to be considered, the proposed algorithm significantly reduces the cost of calculation. The proposed algorithm allows the transformation of an existing algorithm which does not consider the graph update. Experimental results on large real datasets show that the proposed algorithm speeds up the existing algorithm 2 to 2418 times depending on the dataset.
doi:10.1145/2187836.2187884 dblp:conf/www/LeeLPCC12 fatcat:gt4lxd4mcnfqdfeirxrcwbep4i

A Case of Lipoma in the Middle Ear

Song I Park, Min Hae Park, Jungmin Ahn, Won Ho Chung
2019 Korean Journal of Otorhinolaryngology - Head and Neck Surgery  
Lipoma is a common benign tumor found at various sites in the body, but it is rarely encountered in the middle ear. We report a case of a 5-month-old girl who presented a middle ear lipoma, which was successfully removed by canal wall up mastoidectomy. To the best our knowledge, this is the youngest case of rare middle ear lipoma, which has ever been reported in the literature. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License
more » ... which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
doi:10.3342/kjorl-hns.2018.00227 fatcat:m33uelzz2bembduavacbcf6buu

Preparation and Characterization of Superabsorbent Polymers Based on Starch Aldehydes and Carboxymethyl Cellulose

Jungmin Lee, Soohee Park, Hyun-gyoo Roh, Seungtaek Oh, Sunghoon Kim, Myounguk Kim, Donghyun Kim, Jongshin Park
2018 Polymers  
Superabsorbent polymers (SAPs) are crosslinked hydrophilic polymers that are capable of absorbing large amounts of water. Commercial SAPs are mostly produced with acrylic acid that cannot be easily biodegraded. Therefore, in this study, polysaccharide-based SAPs using carboxymethyl cellulose as a major component were prepared. Starch aldehydes and citric acid were selected due to their environment-friendly, non-toxic, and biodegradable properties compared to conventional crosslinking agents.
more » ... rch aldehydes were prepared by periodate oxidation, which forms aldehyde groups by taking the places of C⁻OH groups at C-2 and C-3. Furthermore, starch aldehydes were analyzed through the change in FT-IR spectra, the aldehyde quantitation, and the morphology in FE-SEM images. In the crosslinking of polysaccharide-based SAPs, the acetal bridges from starch aldehydes led to a large amount of water entering the network structure of the SAPs. However, the ester bridges from citric acid interfered with the water penetration. In addition, the swelling behavior of the SAPs was analyzed by the Fickian diffusion model and the Schott's pseudo second order kinetics model. The relationship between swelling behavior and morphology of the SAPs was analyzed by FE-SEM images. In conclusion, polysaccharide-based SAPs were well prepared and the highest equilibrium swelling ratio was 87.0 g/g.
doi:10.3390/polym10060605 pmid:30966639 pmcid:PMC6404157 fatcat:pn6fjqn7tjf3tirxep2x54f4wi

Flexible Sensory Systems: Structural Approaches

Chan Park, Byeongjun Lee, Jungmin Kim, Haran Lee, Jeongbeom Kang, Jongwon Yoon, Jonghyeon Ban, Chiwon Song, Seong J. Cho
2022 Polymers  
Biology is characterized by smooth, elastic, and nonplanar surfaces; as a consequence, soft electronics that enable interfacing with nonplanar surfaces allow applications that could not be achieved with the rigid and integrated circuits that exist today. Here, we review the latest examples of technologies and methods that can replace elasticity through a structural approach; these approaches can modify mechanical properties, thereby improving performance, while maintaining the existing material
more » ... integrity. Furthermore, an overview of the recent progress in wave/wrinkle, stretchable interconnect, origami/kirigami, crack, nano/micro, and textile structures is provided. Finally, potential applications and expected developments in soft electronics are discussed.
doi:10.3390/polym14061232 pmid:35335562 pmcid:PMC8955130 fatcat:ab62c7i7dnd2fe7ws77itnhiee

Usage Trends of Open Access and Local Journals: A Korean Case Study

Jeong-Wook Seo, Hosik Chung, Jungmin Yun, Jin Young Park, Eunsun Park, Yuri Ahn, Pablo Dorta-González
2016 PLoS ONE  
Articles from open access and local journals are important resources for research in Korea and the usage trends of these articles are important indicators for the assessment of the current research practice. We analyzed an institutional collection of published papers from 1998 to 2014 authored by researchers from Seoul National University, and their references from papers published between 1998 and 2011. The published papers were collected from Web of Science or Scopus and were analyzed
more » ... g to the proportion of articles from open access journals. Their cited references from published papers in Web of Science were analyzed according to the proportion of local (South Korean) or open access journals. The proportion of open access papers was relatively stable until 2006 (2.5~5.2% in Web of Science and 2.7~4.2% in Scopus), but then increased to 15.9% (Web of Science) or 18.5% (Scopus) in 2014. We analyzed 2,750,485 cited references from 52,295 published papers. We found that the overall proportion of cited articles from local journals was 1.8% and that for open access journals was 3.0%. Citations of open access articles have increased since 2006 to 4.1% in 2011, although the increase in open access article citations was less than for open access publications. The proportion of citations from local journals was even lower. We think that the publishing / citing mismatch is a term to describe this difference, which is an issue at Seoul National University, where the number of published papers at open access or local journals is increasing but the number of citations is not. The cause of this discrepancy is multi-factorial but the governmental / institutional policies, social / cultural issues and authors' citing behaviors will explain the mismatch. However, additional measures are also necessary, such as the development of an institutional citation database and improved search capabilities with respect to local and open access documents.
doi:10.1371/journal.pone.0155843 pmid:27195948 pmcid:PMC4873189 fatcat:3urmykcqrvhp3lybiag2lo6nxq

RTL-PSC: Automated Power Side-Channel Leakage Assessment at Register-Transfer Level [article]

Miao He, Jungmin Park, Adib Nahiyan, Apostol Vassilev, Yier Jin, Mark Tehranipoor
2019 arXiv   pre-print
Power side-channel attacks (SCAs) have become a major concern to the security community due to their non-invasive feature, low-cost, and effectiveness in extracting secret information from hardware implementation of cryto algorithms. Therefore, it is imperative to evaluate if the hardware is vulnerable to SCAs during its design and validation stages. Currently, however, there is little-known effort in evaluating the vulnerability of a hardware to SCAs at early design stage. In this paper, we
more » ... pose, for the first time, an automated framework, named RTL-PSC, for power side-channel leakage assessment of hardware crypto designs at register-transfer level (RTL) with built-in evaluation metrics. RTL-PSC first estimates power profile of a hardware design using functional simulation at RTL. Then it utilizes the evaluation metrics, comprising of KL divergence metric and the success rate (SR) metric based on maximum likelihood estimation to perform power side-channel leakage (PSC) vulnerability assessment at RTL. We analyze Galois-Field (GF) and Look-up Table (LUT) based AES designs using RTL-PSC and validate its effectiveness and accuracy through both gate-level simulation and FPGA results. RTL-PSC is also capable of identifying blocks inside the design that contribute the most to the PSC vulnerability which can be used for efficient countermeasure implementation.
arXiv:1901.05909v1 fatcat:endf7phqzfeddppeh3stcyas5a
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