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Approximate contact solutions for non-axisymmetric homogeneous and power-law graded elastic bodies:A practical tool for design engineers and tribologists

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Friction 2024年第2期12卷 340-355页

作者： Valentin L.popov Qiang LI Emanuel WILLERT Institute of Mechanics Technische Universität BerlinBerlin 10623Germany

In two recent papers,approximate solutions for compact non-axisymmetric contact problems of homogeneous and power-law graded elastic bodies have been suggested,which provide explicit analytical relations for the force–approach relation,the size and the shape of the contact area,as well as for the pressure distribution *** solutions were derived for profiles,which only slightly deviate from the axisymmetric *** the present paper,they undergo an extensive testing and validation by comparison of solutions with a great variety of profile shapes with numerical solutions obtained by the fast Fourier transform(FFT)-assisted boundary element method(BEM).Examples are given with quite significant deviations from axial symmetry and show surprisingly good agreement with numerical solutions.

关键词： normal contact non-axisymmetric indenter extremal principle generalized method of dimensionality reduction(MDR) functional elastic grading

Improved organs at risk segmentation based on modified U‐Net with self‐attention and consistency regularisation

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CAAI Transactions on Intelligence Technology 2024年第4期9卷 850-865页

作者： Maksym Manko Anton popov Juan Manuel Gorriz Javier Ramirez Electronic Engineering Department Igor Sikorsky Kyiv Polytechnic InstituteKyivUkraine Department of Signal Theory Telematics and CommunicationsUniversity of GranadaGranadaSpain

Cancer is one of the leading causes of death in the world,with radiotherapy as one of the treatment *** planning starts with delineating the affected area from healthy organs,called organs at risk(oAR).A new approach to automatic oAR seg-mentation in the chest cavity in Computed Tomography(CT)images is *** proposed approach is based on the modified U‐Net architecture with the ResNet‐34 encoder,which is the baseline adopted in this *** new two‐branch CS‐SA U‐Net architecture is proposed,which consists of two parallel U‐Net models in which self‐attention blocks with cosine similarity as query‐key similarity function(CS‐SA)blocks are inserted between the encoder and decoder,which enabled the use of con-sistency *** proposed solution demonstrates state‐of‐the‐art performance for the problem of oAR segmentation in CT images on the publicly available SegTHoR benchmark dataset in terms of a Dice coefficient(oesophagus-0.8714,heart-0.9516,trachea-0.9286,aorta-0.9510)and Hausdorff distance(oesophagus-0.2541,heart-0.1514,trachea-0.1722,aorta-0.1114)and significantly outperforms the *** current approach is demonstrated to be viable for improving the quality of oAR segmentation for radiotherapy planning.

关键词： 3‐D computer vision deep learning deep neural networks image segmentation medical image processing object segmentation

Physiological strategies in wild rodents:immune defenses of commensal rats

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Integrative Zoology 2024年第3期19卷 350-370页

作者： Ivana MIRKoV Dina TUCoVIC Jelena KULAS Anastasija MALESEVIC Dragan KATARANoVSKI Milena KATARANoVSKI Aleksandra.popov ALEKSANDRoV Immunotoxicology Group Department of EcologyInstitute for Biological Research“Sinisa Stankovic”—National Institute of Republic of SerbiaUniversity of BelgradeBelgradeSerbia

The importance of issues associated with urban/commensal rats and mice(property damage,management costs,and health risks)press upon research on these *** the demography of commensal rodents is mostly studied,the need for understanding factors influencing their natural morbidity/mortality is also *** this respect,more attention is expected to be paid to immunity,the physiological mechanism of defense against host survival threats(pathogens,parasites,diseases).Commensal rats and mice carry numerous pathogens that evoke diverse immune *** state of immunity in commensal house mice is studied in great detail,owing to the use of laboratory strains in biomedical *** commensal rats are,compared to mice,carriers of more zoonotic agents,rats’immunity is studied mainly in that *** of these zoonotic agents cause chronic,asymptomatic infections,which justified studies of immunological mechanisms of pathogen tolerance versus clearance regulation in *** of some infections in specific tissues/organs pressed upon analysis of local/regional immune responses and/or immunopathology.A survey of immunological activity/responses in commensal rats is given in this review,with mention of existing data in commensal *** should throw some light on the factors relevant to their morbidity and lifespan,supplementing the knowledge of commensal rodent ecology.

关键词： commensal rats and mice immunopathology infection inflammation tolerance

Security and Privacy Challenges in SDN-Enabled IoT Systems: Causes, Proposed Solutions,and Future Directions

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Computers, Materials & Continua 2024年第8期80卷 2511-2533页

作者： Ahmad Rahdari Ahmad Jalili Mehdi Esnaashari Mehdi Gheisari Alisa A.Vorobeva Zhaoxi Fang Panjun Sun Viktoriia M.Korzhuk Ilya.popov Zongda Wu Hamid Tahaei Institute of Artificial Intelligence Shaoxing UniversityShaoxing312000China Department of Computer Engineering Gonbad Kavous UniversityGonbad-e Kavus49717-99151Iran Faculty of Computer Engineering K.N.Toosi University of TechnologyTehran196976-4499Iran Department of Computer Science and Engineering Saveetha School of EngineeringSaveetha Institute of Medical and Technical SciencesChennai602105India Secure Information Technologies Department National Research University ITMOSt.Petersburg197101Russia School of Electrical and Computer Engineering Shiraz UniversityShiraz71946–84334Iran Department of Computer Science and Engineering Islamic Azad UniversityDamavand***Iran Department of R&D Shenzhen BKD Co.Ltd.Shenzhen518000China

Software-Defined Networking(SDN)represents a significant paradigm shift in network architecture,separating network logic from the underlying forwarding devices to enhance flexibility and centralize ***-rently,the Internet of Things(IoT)connects numerous devices to the Internet,enabling autonomous interactions with minimal human ***,implementing and managing an SDN-IoT system is inherently complex,particularly for those with limited resources,as the dynamic and distributed nature of IoT infrastructures creates security and privacy challenges during SDN *** findings of this study underscore the primary security and privacy challenges across application,control,and data planes.A comprehensive review evaluates the root causes of these challenges and the defense techniques employed in prior works to establish sufficient secrecy and privacy *** investigations have explored cutting-edge methods,such as leveraging blockchain for transaction recording to enhance security and privacy,along with applying machine learning and deep learning approaches to identify and mitigate the impacts of Denial of Service(DoS)and Distributed DoS(DDoS)***,the analysis indicates that encryption and hashing techniques are prevalent in the data plane,whereas access control and certificate authorization are prominently considered in the control plane,and authentication is commonly employed within the application ***,this paper outlines future directions,offering insights into potential strategies and technological advancements aimed at fostering a more secure and privacy-conscious SDN-based IoT ecosystem.

关键词： Security privacy-preserving software-defined network internet of things

NSVS 2569022:a peculiar binary among W UMa stars with extremely small mass ratios

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Research in Astronomy and Astrophysics 2018年第10期18卷 123-130页

作者： Diana P.Kjurkchieva Velimir a.popov Nikola I.Petrov Department of Physics and Astronomy Shumen University Institute of Astronomy and NAo Bulgarian Academy of Sciences

Photometric observations of the W UMa binary NSVS 2569022 are presented. The light curve solution reveals that both components are of F spectral type （temperatures T1 = T2 = 6100 K）. NSVS 2569022 undergoes a total eclipse of W subtype and the mass ratio is well-determined. Its extremely small value of only 0.077 implies that the target will probably experience instability and a possible merger. This value ranks NSVS 2569022 in sixth place among binaries with the smallest mass ratio. Based on an empirical relation of ＂period - total mass＂ for low mass-ratio binaries, we estimate the global parameters of NSVS 2569022： masses M1 = 1.17 M⊙ and M2 = 0.09 M⊙; radii R1 = 1.19 R⊙ and R2 = 0.38 R⊙; luminosities L1 = 1.73 L⊙ and L2 = 0.17L⊙. An analysis of the characteristics of binaries with extremely low-mass ratios is made. NSVS 2569022 turns out to be a peculiar binary among W UMa stars with extremely small mass ratios due to its unexpectedly small fill-out factor of only 0.014 （slightly overcontact configuration）.

关键词： binaries eclipsing - binaries close - stars fundamental parameters - stars individual(NSVS 2569022)

New observations and transit solutions of the inflated exoplanets HAT-P-40b and HAT-P-51b

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Research in Astronomy and Astrophysics 2021年第2期21卷 157-160页

作者： Diana P.Kjurkchieva Nikola I.Petrov Velimir a.popov Department of Physics and Astronomy Shumen University115 Universitetska str.9700 ShumenBulgaria Institute of Astronomy and NAo Bulgarian Academy of SciencesTsarigradsko shossee 721784 SofiaBulgaria

We present high-precision photometric observations of the transiting exoplanets HAT-P-40 b and HAT-P-51 b by the Rozhen 2-m *** newly-observed transit of HAT-P-40 b is the first one with a complete *** orbital periods of the two targets were *** modeled the observed transits and found bigger stellar radii than those derived from the stellar *** planet radii of HATP-40 b and HAT-P-51 b obtained from our transit solutions are bigger than the values calculated by the empirical relations for Jupiter-mass and Saturn-mass planets *** values reveal the highlyinflated nature of the two targets,especially that of HAT-P-51 *** established that the best transit solutions correspond to a quadratic limb-darkening *** fitted limb-darkening coefficients of HAT-P-40 are close to the theoretical ones while those of HAT-P-51 are a little *** precise astrometric Gaia distances of the two targets are smaller by 6%–7%than the calculated values from the stellar *** propose the Gaia distances to be used for improvement of the stellar models as well as for more reliable calculation of the parameters of the known exoplanets.

关键词： (Stars )planetary systems-techniques photometric-Stars individual(HAT-P-40 and HAT-P-51)

Atherosclerosis originating from childhood:Specific features

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Journal of Biomedical Research 2024年第3期38卷 233-240页

作者： Anastasia V.Poznyak Alexey A.Yakovlev MikhailА.popov Elena B.Zhigmitova Vasily N.Sukhorukov Alexander N.orekhov Institute for Atherosclerosis Research Moscow 121609Russia Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology Moscow 109240Russia Department of Cardiac Surgery Moscow Regional Research and Clinical InstituteMoscow 129110Russia Laboratory of Angiopathology Institute of General Pathology and PathophysiologyMoscow 125315Russia

Atherosclerosis is extremely ***,it is considered a disease of older people,who most often experience problems with the heart and blood *** much attention from the scientific community has been paid to studying the association between aging and atherosclerosis,as well as its consequences,there is evidence that atherosclerosis occurs at an early *** may form both during intrauterine development and in *** plays an important role in childhood atherosclerosis,along with previous infectious diseases and excess weight of both the child and the *** the present review,we examined the development of atherosclerosis and the prerequisites in childhood.

关键词： atherosclerosis childhood pediatrics cardiovascular disease

Prompt neutron emission in ^(250)No spontaneous fission associated with ground and isomeric state decays

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Chinese Physics C 2024年第6期48卷 112-117页

作者： R.S.Mukhin A.V.Isaev A.V.Andreev M.L.Chelnokov V.I.Chepigin H.M.Devaraja I.N.Izosimov A.A.Kuznetsova o.N.Malyshev A.G.Popeko Yu.a.popov A.Rahmatinejad B.Sailaubekov T.M.Shneidman E.A.Sokol A.I.Svirikhin M.S.Tezekbayeva M.A.Bychkov A.V.Yeremin o.Dorvaux B.Gall K.Kessaci K.Hauschild A.Lopez-Martens Joint Institute for Nuclear Research Dubna141980Russia Dubna State University Dubna141982Russia Institute of Nuclear Physics Almaty050032Kazakhstan L.N.Gumilyov Eurasian National University Astana010008Kazakhstan Kazan Federal University Kazan420008Russia Universitéde Strasbourg CNRSStrasbourg67000France IJCLab IN2P3-CNRSUniversitéParis-SaclayOrsay91400France

The complete-fusion reaction^(204)Pb(^(48)Ca,2n)^(250)No was used to study two activities of^(250)No with distinct half-lives.A total of 1357 events were observed in the SFiNx neutron detection *** average number of neutrons emitted per spontaneous fission of^(250)No was determined to be(4.1±0.1).The unusually symmetrical shape of the prompt neutron multiplicity distribution was restored and presented for the first *** tests were performed to compare the prompt neutron multiplicity distributions associated with the ground state and K-isomer state decays.

关键词： spontaneous fission prompt neutrons actinide

V2551 Cyg:a pulsating star with enigmatic peculiarities

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Research in Astronomy and Astrophysics 2017年第7期17卷 57-66页

作者： Diana P.Kjurkchieva Velimir a.popov Dragomir V.Marchev Kenneth T.Menzies Nikola I.Petrov Department of Physics Shumen University IRIDA observatory Rozhen NAO Tigh Speuran observatory Institute of Astronomy and NAo Bulgarian Academy of Sciences

Intensive photometric and spectral observations of the variable star V2551 Cyg are *** light curve shape reveals that the target is a pulsating star, contrary to its previous classification as an eclipsing binary. The period and amplitude of the light curve, the amplitudes of color changes and the radial velocity curve of V2551 Cyg are similar to those of a high-amplitude δ Scuti variable. The target seems to pulsate with the fundamental mode. However, V2551 Cyg exhibits several important peculiarities：（i） the decreasing branch of its light curve is steeper than the increasing one;（ii） the radial velocity curve has a flat section in the phase range 0.7-1.2 and short increase of the negative radial velocity at phase 0.7;（iii） the rotational velocity is quite big for a HADS star;（iv） the Fourier coefficients of V2551 Cyg are quite different from those of HADS stars. The target classification is difficult due to these peculiarities.

关键词： stars variables delta Scuti - stars variables RR Lyrae - stars individual (V2551 Cyg)