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Nano-Micro Letters 2023年第6期15卷 1-23页

作者： Horim lee Seung Han Ryu suk Jin Kwon Jae Ryung Choi Sang‑bok lee Byeongjin Park Composites Research Division Korea Institute of Materials Science797 ChangwondaeroSeongsan‑GuChangwonGyeongsangnam‑Do 51508Republic of Korea

Although there is a high demand for absorption-dominant electromagnetic interference(EMI) shielding materials for 5G millimeter-wave(mmWave) frequencies, most current shielding materials are based on reflection-dominant conductive materials. While there are few absorption-dominant shielding materials proposed with magnetic materials, their working frequencies are usually limited to under 30 GHz. In this study, a novel multi-band absorption-dominant EMI shielding film with M-type strontium ferrites and a conductive grid is proposed. This film shows ultralow EMI reflection of less than 5% in multiple mmWave frequency bands with sub-millimeter thicknesses, while shielding more than 99.9% of EMI. The ultralow reflection frequency bands are controllable by tuning the ferromagnetic resonance frequency of M-type strontium ferrites and composite layer geometries. Two examples of shielding films with ultralow reflection frequencies, one for 39 and 52 GHz 5G telecommunication bands and the other for 60 and 77 GHz autonomous radar bands, are presented. The remarkably low reflectance and thinness of the proposed films provide an important advancement toward the commercialization of EMI shielding materials for 5G mmWave applications.

关键词： 5G communication MmWave EMI shielding M-type ferrites

Self-motivated,thermally oxidized hematite nanoflake photoanodes:Effects of pre-polishing and ZrO_(2) passivation layer

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Journal of Energy Chemistry 2022年第2期31卷 415-423页

作者： Love Kumar Dhandole Hyun Hwi lee Weon-Sik Chae Jum suk Jang Jae Sung lee Department of Energy Engineering School of Energy and Chemical EngineeringUlsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea Division of Biotechnology College of Environmental and Bioresource SciencesChonbuk National UniversityIksan 54596Republic of Korea Pohang Accelerator Laboratory Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Daegu Center Korea Basic Science InstituteDaegu 41566Republic of Korea

High-temperature thermal oxidation of an Fe foil produces a high-quality,crystalline hematite nanoflake suitable as a photoanode for the photoelectrochemical(PEC)water oxidation.Physical pre-polishing of the foil surface has a profound effect in the formation of a vertically-aligned nanoflakes of hematite phase with extended(110)planes by removing the loosely-bonded oxide layer.When the surface of the photoanode is modified with a ZrO_(2) passivation layer and a cobalt phosphate co-catalyst,the charge recombination at the photoanode-electrolyte interface is greatly suppressed to improve its overall PEC activity.As a result,the photocurrent density at 1.10 VRHE under 1 sun condition is enhanced from 0.22 mA cm^(-2) for an unmodified photoanode to 0.59 mA cm^(-2) for the fully modified photoanode,and the photocurrent onset potential is shifted cathodically by 400 mV.Moreover,the photoanode demonstrates outstanding stability by showing steady production of H_(2) and O_(2) gases in the stoichiometric ratio of 2:1 in a continuous PEC operation for 10 h.

关键词： Fe foil Thermal oxidation Nanoflakes Photoelectrochemical water splitting Surface modifications

基于高光谱成像技术应用光谱及纹理特征识别柑橘黄龙病（英文）

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光谱学与光谱分析 2016年第7期36卷 2344-2350页

作者：马淏吉海彦 Won Suk Lee 中国农业大学现代精细农业系统集成研究教育部重点实验室北京100083 河南科技大学农业工程学院河南洛阳471003 Department of Agricultural and Biological Engineering University of FloridaGainesvilleFL32611USA

讨论了基于高光谱成像技术光谱及纹理特征在识别早期柑橘黄龙病中的应用。使用一套近地高光谱成像系统采集了176枚柑橘叶片的高光谱图像作为实验样品,其中健康叶片60枚,黄龙病叶片60枚,缺锌叶片56枚。手工选取每幅叶片高光谱图像的病斑... 详细信息

讨论了基于高光谱成像技术光谱及纹理特征在识别早期柑橘黄龙病中的应用。使用一套近地高光谱成像系统采集了176枚柑橘叶片的高光谱图像作为实验样品,其中健康叶片60枚,黄龙病叶片60枚,缺锌叶片56枚。手工选取每幅叶片高光谱图像的病斑位置作为样品感兴趣区域（regions of interest,ROI）,计算其平均光谱反射率,并以此作为样品的反射光谱,光谱范围为396～1 010nm。样品光谱分别经过主成分分析（PXA）及连续投影算法（SPA）进行数据降维,再结合最小二乘支持向量机（LS-SVM）分类器建立分类模型。相比原始光谱,由PCA选取的前四个主成分及SPA选取的一组最佳波长组合（630.4,679.4,749.4和899.9 nm）建立的模型拥有更好的分类识别能力,其对三类柑橘叶片平均预测准确率分别为89.7%和87.4%。同时,从被选四个波长的每幅灰度图像中提取6个灰度直方图的纹理特征以及9个灰度共生矩阵的纹理特征再次构建分类模型。经SPA优选的10个纹理特征值进一步提高了分类效果,对三类柑橘叶片的识别正确率达到了100%,93.3%和92.9%。实验结果表明,同时包含光谱信息及空间纹理信息的高光谱图像在柑橘黄龙病的识别中显示了很大的潜力。

关键词：柑橘黄龙病高光谱成像分类纹理特征连续投影算法

Rationally designed bioactive milk-derived protein scaffolds enhanced new bone formation

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Bioactive Materials 2023年第2期20卷 368-380页

作者： Min Suk Lee Jin Jeon Sihyeon Park Juhan Lim Hee Seok Yang Department of Nanobiomedical Science&BK21 FOUR NBM Global Research Center for Regenerative Medicine Dankook UniversityCheonan31116Republic of Korea Medical Laser Research Center College of MedicineDankook UniversityCheonan31116Republic of Korea Center for Bio-Medical Engineering Core-Facility Dankook UniversityCheonan31116Republic of Korea

Recently,a number of studies reported that casein was composed of various multifunctional bioactive peptides such as casein phosphopeptide andβ-casochemotide-1 that bind calcium ions and induce macrophage chemotaxis,which is crucial for bone homeostasis and bone fracture repair by cytokines secreted in the process.We hypothesized that the effects of the multifunctional biopeptides in casein would contribute to improving bone regeneration.Thus,we designed a tissue engineering platform that consisted of casein and polyvinyl alcohol,which was a physical-crosslinked scaffold(milk-derived protein;MDP),via simple freeze-thaw cycles and performed surface modification using 3,4-dihydroxy-L-phenylalanine(DOPA),a mussel adhesive protein,for immobilizing adhesive proteins and cytokines for recruiting cells in vivo(MDP-DOPA).Both the MDP and MDP-DOPA groups proved indirectly contribution of macrophages migration as RAW 264.7 cells were highly migrated toward materials by contained bioactive peptides.We implanted MDP and MDP-DOPA in a mouse calvarial defect orthotopic model and evaluated whether MDP-DOPA showed much faster mineral deposition and higher bone density than that of the no-treatment and MDP groups.The MDP-DOPA group showed the accumulation of host M2 macrophages and mesenchymal stem cells(MSCs)around the scaffold,whereas MDP presented mostly M1 macrophages in the early stage.

关键词： Casein Bioactive peptides Bone regeneration Protein based scaffold Physical crosslinking

Modeling and Hardware-in-the-Loop System Realization of Electric Machine Drives-A Review

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CES Transactions on Electrical Machines and Systems 2021年第3期5卷 194-201页

作者： Jae Suk Lee Gilsu Choi the Jeonbuk National University JeonjuJeonbukKorea Inha University IncheonKorea

This paper presents a state-of-the-art review in modeling approach of hardware in the loop simulation(HILS)realization of electric machine drives using commercial real time machines.HILS implementation using digital signal processors(DSPs)and field programmable gate array(FPGA)for electric machine drives has been investigated but those methods have drawbacks such as complexity in development and verification.Among various HILS implementation approaches,more efficient development and verification for electric machine drives can be achieved through use of commercial real time machines.As well as implementation of the HILS,accurate modeling of a control target system plays an important role.Therefore,modeling trend in electric machine drives for HILS implementation is needed to be reviewed.This paper provides a background of HILS and commercially available real time machines and characteristics of each real time machine are introduced.Also,recent trends and progress of permanent magnet synchronous machines(PMSMs)modeling are presented for providing more accurate HILS implementation approaches in this paper.

关键词： Hardware-in-the-loop machine modeling permanent magnet synchronous machine(PMSM) model based design

Increased incidence of indeterminate pancreatic cysts and changes of management pattern: Evidence from nationwide data

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Hepatobiliary & Pancreatic Diseases International 2023年第3期22卷 294-301页

作者： Jaewoo Park Jinkyeong Park Yoon Suk Lee Kwangrok Jung In Ho Jung Jong-Chan lee Jin-Hyeok Hwang Jaihwan Kim Department of Internal Medicine Seoul National University Bundang HospitalSeoul National University College of MedicineSeongnamKorea Department of Internal Medicine Kyung Hee University Hospital at GangdongSeoulKorea Department of Internal Medicine Inje University College of MedicineIlsan Paik HospitalGoyangKorea

Background:Pancreatic cysts are common.However,most studies are based on data collected from individual centers.The present study aimed to evaluate the changes of management patterns for pancreatic cystic lesions(PCLs)by analyzing large epidemiologic data.Methods:Between January 2007 and December 2018,information regarding pancreatic cystic lesions was acquired from the nationwide Health Insurance Review and Assessment Service database in Korea.Results:The final number of patients with pancreatic cysts was 165277 among the total claims for reimbursement of 855983 associated with PCLs over 12 years.The total number of claims were increased from 19453 in 2007 to 155842 in 2018 and the prevalence increased from 0.04%to 0.23%.For 12 years,2874(1.7%)had pancreatic cancer and 8212(5.0%)underwent surgery,and 36 had surgery for twice(total 8248 pancreatectomy).After ruling out claims from the first 3 years of washout period,the incidence increased from 9891 to 24651 and the crude incidence rate of PCLs expanded from 19.96 per 100000 to 47.77 per 100000.Compared to specific neoplasm codes(D136 or D377),the use of pancreatic cyst code(K862)has been remarkably increased and the most common since 2010.The annual number of pancreatectomies increased from 518 to 861 between 2007 and 2012,and decreased to 596 until 2018.The percentage of pancreatic cancer in patients who received pancreatectomy increased from 5.6%in 2007 to 11.7%in 2018.Conclusions:The incidence of PCLs is rapidly increasing.Among PCLs,indeterminate cyst is increasing outstandingly.A trend of decreasing in the number of resections and increasing cancer rates among resected cysts may be attributed to the updated international guidelines.

关键词： Pancreatic cyst Incidence Prevalence Pancreatectomy Big data

Changing strategies for target therapy in gastric cancer

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World Journal of Gastroenterology 2016年第3期22卷 1179-1189页

作者： suk-young lee Sang Cheul Oh Department of Internal Medicine College of MedicineKorea UniversityGuro-guSeoul 08308South Korea

In spite of a worldwide decrease in the incidence of gastric cancer, this malignancy still remains one of the leading causes of cancer mortality. Great efforts have been made to improve treatment outcomes in patients with metastatic gastric cancer, and the introduction of trastuzumab has greatly improved the overall survival. The trastuzumab treatment took its first step in opening the era of molecular targeted therapy, however several issues still need to be resolved to increase the efficacy of targeted therapy. Firstly, many patients with metastatic gastric cancer who receive trastuzumab in combination with chemotherapeutic agents develop resistance to the targeted therapy. Secondly, many clinical trials testing novel molecular targeted agents with demonstrated efficacy in other malignancies have failed to show benefit in patients with metastatic gastric cancer, suggesting the importance of the selection of appropriate indications according to molecular characteristics in application of targeted agents. Herein, we review the molecular targeted agents currently approved and in use, and clinical trials in patients with metastatic gastric cancer, and demonstrate the limitations and future direction in treatment of advanced gastric cancer.

关键词： Advanced gastric cancer target therapy chemotherapy strategy signal pathway

Late Quaternary Paleoclimatic Change in the Ulleung Basin,East Sea,Korea

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Acta Geologica Sinica(English Edition) 2017年第1期91卷 263-269页

作者： Young-suk BAK Young-Up lee The Earth and Environmental System Research Center Chonbuk National University Jeonju 54896 South Korea

Paleoclimatic changes in the late Quaternary sediments deposited in the East Sea were analyzed by studying diatoms. A total of 95 species belonging to 47 genera were identified from the Core02GHP-02 of the Ulleung Basin in the East Sea, Korea. In the Core 02GHP-02, U-Oki（169–181 cm; 9.3 ka）, AT（464–465.5 cm; 22 ka） and U–Ym（556–559 cm; 33 ka） tephra layers were recognized. The chronological divisions of 02GHP-02 may be correlated with the climatic changes from the glacial interval（730–620 cm; MIS3）, to interstadial（620–500 cm; MIS3）, to the last glacial maximum（500–390 cm; MIS 2）, to the deglaciation（390–290 cm; MIS 2）, to the late glacial（290–190 cm; MIS 1）, and to the Holocene（190–10 cm; MIS 1）. It is speculated that diatoms were rarely found during the glacial interval when the 02GHP-02 core was deposited; during the interstadial（MIS 3） and deglaciation, a mixture of warm-water and cold-water species were found. In particular, Fragilariopsis doliolus seems to have appeared in the East Sea after 8 ka BP. In the lower layers of the Holocene deposits, cold-water species such as Neodenticula seminae were frequently found, while in the upper layers, warm-water species such as Hemidiscus cuneiformis were found in relatively large abundance. Therefore, the findings indicate that the climate became warmer during the transition from the lower layer to the upper layer of the Holocene deposits.

关键词： diatoms paleoclimatic change late Quaternary glacial interval MIS

SUBic:A Scalable Unsupervised Framework for Discovering High Quality Biclusters

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Journal of Computer Science & Technology 2013年第4期28卷 636-646页

作者： Jooil lee Yanhua Jin Won Suk Lee Department of Computer Science Yonsei University

A biclustering algorithm extends conventional clustering techniques to extract all of the meaningful subgroups of genes and conditions in the expression matrix of a microarray dataset. However, such algorithms are very sensitive to input parameters and show poor scalability. This paper proposes a scalable unsupervised biclustering framework, SUBic, to find high quality constant-row biclusters in an expression matrix effectively. A one-dimensional clustering algorithm is proposed to partition the attributes, that is, columns of an expression matrix into disjoint groups based on the similarity of expression values. These groups form a set of short transactions and are used to discover a set of frequent itemsets each of which corresponds to a bicluster. However, a bicluster may include any attribute whose expression value is not similar enough to others, so a bicluster refinement is used to enhance the quality of a bicluster by removing those attributes based on its distribution of expression values. The performance of the proposed method is comparatively analyzed through a series of experiments on synthetic and real datasets.

关键词： biclustering clustering expression matrix frequent itemset sub-matrix

Impact of Spectral Nudging on the Downscaling of Tropical Cyclones in Regional Climate Simulations

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Advances in Atmospheric Sciences 2016年第6期33卷 730-742页

作者： suk-Jin CHOI Dong-Kyou lee Atmospheric Sciences Program School of Earth and Environmental SciencesKorea-USA Weather and Climate Research Center Seoul National University

This study investigated the simulations of three months of seasonal tropical cyclone （TC） activity over the western North Pacific using the Advanced Research WRF Model. In the control experiment （CTL）, the TC frequency was considerably overestimated. Additionally, the tracks of some TCs tended to have larger radii of curvature and were shifted eastward. The large-scale environments of westerly monsoon flows and subtropical Pacific highs were unreasonably simulated. The overestimated frequency of TC formation was attributed to a strengthened westerly wind field in the southern quadrants of the TC center. In comparison with the experiment with the spectral nudging method, the strengthened wind speed was mainly modulated by large-scale flow that was greater than approximately 1000 km in the model domain. The spurious formation and undesirable tracks of TCs in the CTL were considerably improved by reproducing realistic large-scale atmospheric monsoon circulation with substantial adjustment between large-scale flow in the model domain and large-scale boundary forcing modified by the spectral nudging method. The realistic monsoon circulation took a vital role in simulating realistic TCs. It revealed that, in the downscaling from large-scale fields for regional climate simulations, scale interaction between model-generated regional features and forced large-scale fields should be considered, and spectral nudging is a desirable method in the downscaling method.

关键词： tropical cyclone spectral nudging technique dynamic downscaling regional climate simulation