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High linear HBT MMIc power amplifier with partial RF coupling to bias circuit for W-cDMA portable application

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High linear HBT MMIC power amplifier with partial RF couplin...

2002 3rd International conference on Microwave and Millimeter Wave Technology

作者： Joon.H.Kim Ji.H.Kim Y.s.Noh c.s.park school of Engineering Information and Communications University(ICU)58-4 HwaamYusongDaejon 305-732Korea

This paper proposes a high linear two-stage InGaP/GaAs heterojunction bipolar transistor(HBT) power amplifier monolithic microwave integrated circuit (MMIc) using a new on-chip linearizer for 1.95 GHz wide-band code division multiple-access(W-cDMA) *** linearizer consists of the base-emitter junction diode of the bias transistor and the RF coupling *** proposed linearizer remarkably improves gain compression of 18 dB and phase distortion of 20°, and negligibly has little insertion power loss,and more importantly it requires no additional die area and no additional Dc *** HBT MMIc power amplifier with the integrated linearizer exhibits an maximum output power(P) of 30.5 dBm,the power gain of 25 dB,the power added efficiency(PAE) of 51% at the maximum output power under the operation voltage of 3.4 V,and adjacent channel power ratio (AcPR) of-56dBc at P of 27 dBm.

关键词： wide-band code division multiple access heterojunction bipolar transistor power amplifier

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乳腺特异性伽玛成像特征预测乳腺恶性病变

国际医学放射学杂志 2019年第1期 126-127页

作者： E.K.choi J.J.Im c.s.park Y.A.chung K.Kim J.K.Oh 周健 Department of Radiology Incheon St. Mary ’s HospitalCollege of MedicineThe Catholic University of Korea

摘要目的本研究旨在探讨近期诊断为恶性乳腺癌病人的乳腺特异性伽玛成像(BsGI)摄取特征。方法回顾性分析231例近期诊断为乳腺癌病人的术前BsGI数据。特征分

关键词：恶性病变乳腺钼靶摄影特异性

Omni-functional simultaneous interfacial treatment for enhancing stability and outgassing suppression of lithium-ion batteries

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Journal of Energy chemistry 2024年第7期94卷 677-687页

作者： Youbean Lee chanjoo park Kyoungmin Min Kwangjin park Department of Mechanical Engineering Gachon UniversityGyeonggi-do 13120Republic of Korea Department of Battery Engineering Gachon UniversityGyeonggi-do 13120Republic of Korea school of Mechanical Engineering Soongsil UniversitySeoul 06978Republic of Korea

Ni-rich layered oxides in lithium-ion batteries have problems with gas generation and electrochemical performance reduction due to residual lithium's reaction on the surface with the *** address this issue,in this study,the Acid solvent evaporation(AsE)method has been proposed as a potential method to remove residual lithium while promoting the formation of a new LiNO_(3)-derived coating layer on the cathode *** reduction of residual lithium using the AsE method and the construction of a LiNO_(3)-derived coating layer suppresses gas evolution caused by the side effects of the electrolyte,improves electrochemical performance,and improves thermal stability by facilitating the smooth movement of lithium ***,the structural stability and resistance change due to the LiNO_(3)-derived coating layer effects is guaranteed through cycling and DcIR of the pouch *** a result,compared to Pristine,the capacity retention of coin cells increased by 8%after 100 cycles,and pouch cells increased by 25%after 160 *** addition,after cycling the pouch cell,cO_(2) gas has significantly reduced by about 30%compared to Pristine using gas *** AsE method effectively forms a robust LiNO_(3)-derived coating layer on the cathode active material,which helps minimize electrolyte reactivity,suppress ,cO_(2) emissions,enhance surface structure stability,improve thermal stability,and improveoverallbatteryperformance.

关键词： Lithium-ion batteries Ni-rich NcM Acid solvent evaporation LiNO_(3)-derived coating Gasevolution

Non-interleaved chiral metasurfaces and neural networks enhance the spatial resolution of polarimetry

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Light(science & Applications) 2024年第3期13卷 396-398页

作者： Jaewon Jang Minsu park Yeonsang park Department of Physics Chungnam National UniversityDaejeon 34134Korea Institute of Quantum systems Chungnam National UniversityDaejeon 34134Korea

Non-interleaved chiral metasurfaces for high-spatial-resolution polarimetry are proposed and ***,a convolutional neural network is incorporated to analyze interferometric images with the polarization state of light,an... 详细信息

关键词： parameters chiral resolution

Efficient Object segmentation and Recognition Using Multi-Layer Perceptron Networks

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computers, Materials & continua 2024年第1期78卷 1381-1398页

作者： Aysha Naseer Nouf Abdullah Almujally saud s.Alotaibi Abdulwahab Alazeb Jeongmin park Department of computer science Air UniversityIslamabad44000Pakistan Department of Information systems College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Information system Department Umm Al-Qura UniversityMakkahSaudi Arabia Department of computer science College of Computer Science and Information SystemNajran UniversityNajran55461Saudi Arabia Department of computer Engineering Tech University of KoreaGyeonggi-do15073South Korea

Object segmentation and recognition is an imperative area of computer vision andmachine learning that identifies and separates individual objects within an image or video and determines classes or categories based on their *** proposed system presents a distinctive approach to object segmentation and recognition using Artificial Neural Networks(ANNs).The system takes RGB images as input and uses a k-means clustering-based segmentation technique to fragment the intended parts of the images into different regions and label thembased on their ***,two distinct kinds of features are obtained from the segmented images to help identify the objects of *** Artificial Neural Network(ANN)is then used to recognize the objects based on their *** were carried out with three standard datasets,MsRc,Ms cOcO,and caltech 101 which are extensively used in object recognition research,to measure the productivity of the suggested *** findings from the experiment support the suggested system’s validity,as it achieved class recognition accuracies of 89%,83%,and 90.30% on the MsRc,Ms cOcO,and caltech 101 datasets,respectively.

关键词： K-region fusion segmentation recognition feature extraction artificial neural network computer vision

Iso-propagation vortices: a breakthrough in optical communication technology

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Advanced Photonics 2024年第3期6卷 13-15页

作者： cherry park Junsuk Rho Pohang University of science and Technology (POsTEcH) Department of Mechanical Engineering Pohang University of science and Technology (POsTEcH) Department of Chemical Engineering Pohang University of science and Technology (POsTEcH) Department of Electrical Engineering POscO-POsTEcH-RIsT convergence Research center for Flat Optics and Metaphotonics

The rapid advance of optical communication technology requires improvements in data transmission capacity and efficiency. conventional methods of increasing the transmission capacity such as polarization,wavelength, and spatial mode division multiplexing have shown significant promise, while spatial mode division multiplexing(sDM) offers a new approach through the use of orthogonal spatial modes as distinct communication channels.

关键词： communication optical polarization

Electrochemically Deposited cZTsse Thin Films for Monolithic Perovskite Tandem solar cells with Efficiencies Over 17%

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Energy & Environmental Materials 2024年第1期7卷 147-152页

作者： sun Kyung Hwang Ik Jae park se Won seo Jae Hyun park so Jeong park Jin Young Kim Department of Materials science and Engineering Seoul National UniversitySeoul 08826Korea Department of Applied Physics Sookmyung Women's UniversitySeoul 04310Korea Research Institute of Advanced Materials and systems Sookmyung Women's UniversitySeoul 04310Korea Research Institute of Advanced Materials(RIAM) Seoul National UniversitySeoul 08826Korea

In spite of the high potential economic feasibility of the tandem solar cells consisting of the halide perovskite and the kesterite cu2Znsn(s,se)4(cZTsse),they have rarely been demonstrated due to the difficulty in implementing solution-processed perovskite top cell on the rough surface of the bottom ***,we firstly demonstrate an efficient monolithic two-terminal perovskite/cZTsse tandem solar cell by significantly reducing the surface roughness of the electrochemically deposited cZTsse bottom *** surface roughness(R_(rms))of the cZTsse thin film could be reduced from 424 to 86 nm by using the potentiostatic mode rather than using the conventional galvanostatic mode,which can be further reduced to 22 nm after the subsequent ion-milling *** perovskite top cell with a bandgap of 1.65 eV could be prepared using a solution process on the flattened cZTsse bottom cell,resulting in the efficient perovskite/cZTsse tandem solar *** the current matching between two subcells involving the thickness control of the perovskite layer,the best performing tandem device exhibited a high conversion efficiency of 17.5%without the hysteresis effect.

关键词： cZTsse monolithic tandem solar cells perovskite solution process surface roughness control

Environmentally adaptive reshaping of plant photomorphogenesis by karrikin and strigolactone signaling

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Journal of Integrative Plant Biology 2024年第5期66卷 865-882页

作者： Young-Joon park Bo Eun Nam chung-Mo park Department of smart Farm science Kyung Hee UniversityYongin 17104Korea Departmentof Biological sciences Seoul National UniversitySeoul 08826Korea Department of chemistry Seoul National UniversitySeoul 08826Korea

coordinated morphogenic adaptation of growing plants is critical for their survival and propagation under fluctuating *** morphogenic responses to light and warm temperatures,termed photomorphogenesis and thermomorphogenesis,respectively,have been extensively studied in recent *** photomorphogenesis,plants actively reshape their growth and developmental patterns to cope with changes in light ***,photomorphogenesis is closely associated with diverse growth hormonal ***,accumulating evidence indicates that light-directed morphogenesis is profoundly affected by two recently identified phytochemicals,karrikins(KARs)and strigolactones(sLs).KARs and sLs are structurally related butenolides acting as signaling molecules during a variety of developmental steps,including seed *** receptors and signaling mediators have been identified,and associated working mechanisms have been explored using gene-deficient mutants in various plant *** particular interest is that the KAR and sL signaling pathways play important roles in environmental responses,among which their linkages with photomorphogenesis are most comprehensively studied during seedling *** this review,we focus on how the phytochemical and light signals converge on the optimization of morphogenic *** also discuss molecular mechanisms underlying the signaling crosstalks with an aim of developing potential ways to improve crop productivity under climate changes.

关键词： karrikins morphogenic adaptation photomorphogenesis seedling establishment strigolactones

An Investigation on Open-RAN specifications:Use cases,security Threats,Requirements,Discussions

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computer Modeling in Engineering & sciences 2024年第10期141卷 13-41页

作者： Heejae park Tri-HaiNguyen Laihyuk park Department of computer science and Engineering Seoul National University of Science and TechnologySeoul01811Republic of Korea Faculty of Information Technology School of TechnologyVan Lang UniversityHo Chi Minh City70000Vietnam

The emergence of various technologies such as terahertz communications,Reconfigurable Intelligent surfaces(RIs),and AI-powered communication services will burden network operators with rising infrastructure ***,the Open Radio Access Network(O-RAN)has been introduced as a solution for growing financial and operational burdens in Beyond 5G(B5G)and 6G networks.O-RAN promotes openness and intelligence to overcome the limitations of traditional *** disaggregating conventional Base Band Units(BBUs)into O-RAN Distributed Units(O-DU)and O-RAN centralized Units(O-cU),O-RAN offers greater flexibility for upgrades and network ***,this openness introduces new security challenges compared to traditional *** existing studies overlook these security requirements of the O-RAN *** gain deeper insights into the O-RAN system and security,this paper first provides an overview of the general O-RAN architecture and its diverse use cases relevant to B5G and 6G *** then delve into specifications of O-RAN security threats and requirements,aiming to mitigate security vulnerabilities *** providing a comprehensive understanding of O-RAN architecture,use cases,and security considerations,thisworkserves as a valuable resource for future research in O-RAN and its security.

关键词： O-RAN architecture use cases security issues security requirements security discussions