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Tensionless contact of a finite circular plate

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Acta Mechanica Sinica 2012年第5期28卷 1374-1381页

作者： Yin Zhang kevin d.murphy State Key Laboratory of Nonlinear Mechanics(LNM) Institute of MechanicsChinese Academy of Sciences department of Mechanical Engineering the University of Connecticut

A general formulation is developed for the contact behavior of a finite circular plate with a tensionless elastic foundation. The gap distance between the plate and elastic foundation is incorporated as an important parameter. Unlike the previous models with zero gap distance and large/infinite plate radius, which assumes the lift-off/separation of a flexural plate from its supporting elastic foundation, this study shows that lift-off may not occur. The results show how the contact area varies with the plate radius, boundary conditions and gap distance. When the plate radius becomes large enough and the gap distance is reduced to zero, the converged contact radius close to the previous ones is obtained.

关键词： Tensionless contact Elastic foundation Plate Lift-off

Tensionless contact of a finite beam:Concentrated load inside and outside the contact zone

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Acta Mechanica Sinica 2013年第6期29卷 836-839页

作者： Yin Zhang kevin d.murphy State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences department of Mechanical Engineering University of ConnecticutStorrsCT 06268USA

For a finite beam with a nonzero gap distance, an asymmetric concentrated load can be either inside or outside of the contact zone. A new governing equation is given for the case of a concentrated load outside the contact zone. By numerically solving the left-side and right-side contact lengths of the beam, a criterion is established to determine whether the concentrated load is inside or outside the contact zone. A more general approach on the tensionless contact of a beam is thus presented.

关键词： Tensionless contact Lift-off Beam

Nonlinear dynamic response of beam and its application in nanomechanical resonator

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Acta Mechanica Sinica 2012年第1期28卷 190-200页

作者： Yin Zhang Yun Liu kevin d.murphy State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences100190 BeijingChina Faculty of Information and Automation Kunming University of Science and Technology650051 KunmingChina department of Mechanical Engineering The University of ConnecticutStorrsCT 06269USA

Nonlinear dynamic response of nanomechanical resonator is of very important characteristics in its application. Two categories of the tension-dominant and curvaturedominant nonlinearities are analyzed. The dynamic nonlinearity of four beam structures of nanomechanical resonator is quantitatively studied via a dimensional analysis approach. The dimensional analysis shows that for the nanomechanical resonator of tension-dominant nonlinearity, its dynamic nonlinearity decreases monotonically with increasing axial loading and increases monotonically with the increasing aspect ratio of length to thickness; the dynamic nonlinearity can only result in the hardening effects. However, for the nanomechanical resonator of the curvature-dominant nonlinearity, its dynamic nonlinearity is only dependent on axial loading. Compared with the tension-dominant nonlinearity, the curvature-dominant nonlinearity increases monotonically with increasing axial loading; its dynamic nonlinearity

关键词： Resonator. dynamic response. dynamic nonlinearity - dimensional analysis

BUCKLING LOAdS ANd EIGENFREQUENCIES OF A BRACEd BEAM RESTING ON AN ELASTIC FOUNdATION

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Acta Mechanica Solida Sinica 2011年第6期24卷 510-518页

作者： Yin Zhang Yun Liu Peng Chen kevin d murphy State Key Laboratory of-Nonlinear Mechanics （LN M） Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China Faculty of Information and Automation Kunming University of Science and Technology Kunming 650051 China department of Civil Engineerning Guangdong Technical College of Water Resources and Electric Engineering Guangzhou 510635 China department of Mechanical Engineering University of Connecticut Storrs CT 06269 USA

The eigenvalue problems of the buckling loads and natural frequencies of a braced beam on an elastic foundation are investigated. sented. The eigenvalues vary with the different The exact solutions for the eigenvalues are preparameters and are especially sensitive to the brace location. As the beam of a continuous system has infinite eigenvalues and these eigenvalues are influenced differently by a brace, the eigenvalues show rich variation patterns. Because these eigenvalues physically correspond to the structure buckling loads and natural frequencies, the study on the eigenvalues variation patterns can offer a design guidance of using a lateral brace of translation spring to strengthen the structure.

关键词： beam elastic foundation buckling eigenfrequency curve crossing curve veering

Erratum to:Tensionless contact of a finite circular plate

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Acta Mechanica Sinica 2013年第2期29卷 309-309页

作者： Yin Zhang kevin d. murphy State Key Laboratory of Nonlinear Mechanics (LNM) Institute of MechanicsChinese Academy of Sciences department of Mechanical Engineering the University of Connecticut

In the electronic version of the original article, the issue number shown in the header of the article opening page was wrong. It should be Issue 5 as in Acta Mechanica Sinica (2012) 28(5): 1374-1381.

关键词： Erratum to

depressive semantic awareness from vlog facial and vocal streams via spatio-temporal transformer

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digital Communications and Networks 2024年第3期10卷 577-585页

作者： Yongfeng Tao Minqiang Yang Yushan Wu kevin Lee Adrienne Kline Bin Hu School of Information Science and Engineering Lanzhou UniversityLanzhouChina The School of Accounting Auditing and TaxationBusiness SchoolUNSW SydneyAustralia department of Preventive Medicine Northwestern UniversityChicagoILUnited States

With the rapid growth of information transmission via the Internet,efforts have been made to reduce network load to promote *** such application is semantic computing,which can extract and process semantic *** media has enabled users to share their current emotions,opinions,and life events through their mobile ***,people suffering from mental health problems are more willing to share their feelings on social ***,it is necessary to extract semantic information from social media(vlog data)to identify abnormal emotional states to facilitate early identification and *** studies do not consider spatio-temporal information when fusing multimodal information to identify abnormal emotional states such as *** solve this problem,this paper proposes a spatio-temporal squeeze transformer method for the extraction of semantic features of ***,a module with spatio-temporal data is embedded into the transformer encoder,which is utilized to obtain a representation of spatio-temporal ***,a classifier with a voting mechanism is designed to encourage the model to classify depression and non-depression *** are conducted on the d-Vlog *** results show that the method is effective,and the accuracy rate can reach 70.70%.This work provides scaffolding for future work in the detection of affect recognition in semantic communication based on social media vlog data.

关键词： Emotional computing Semantic awareness depression recognition Vlog data

dynamics of Advantageous Mutant Spread in Spatial death-Birth and Birth-death Moran Models

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Communications on Applied Mathematics and Computation 2024年第1期6卷 576-604页

作者： Jasmine Foo Einar Bjarki Gunnarsson kevin Leder david Sivakoff School of Mathematics University of MinnesotaTwin CitiesMN55455USA department of Industrial and Systems Engineering University of MinnesotaTwin CitiesMN55455USA departments of Statistics and Mathematics The Ohio State UniversityColumbusOH43210USA

The spread of an advantageous mutation through a population is of fundamental interest in population genetics. While the classical Moran model is formulated for a well-mixed population, it has long been recognized that in real-world applications, the population usually has an explicit spatial structure which can significantly influence the dynamics. In the context of cancer initiation in epithelial tissue, several recent works have analyzed the dynamics of advantageous mutant spread on integer lattices, using the biased voter model from particle systems theory. In this spatial version of the Moran model, individuals first reproduce according to their fitness and then replace a neighboring individual. From a biological standpoint, the opposite dynamics, where individuals first die and are then replaced by a neighboring individual according to its fitness, are equally relevant. Here, we investigate this death-birth analogue of the biased voter model. We construct the process mathematically, derive the associated dual process, establish bounds on the survival probability of a single mutant, and prove that the process has an asymptotic shape. We also briefly discuss alternative birth-death and death-birth dynamics, depending on how the mutant fitness advantage affects the dynamics. We show that birth-death and death-birth formulations of the biased voter model are equivalent when fitness affects the former event of each update of the model, whereas the birth-death model is fundamentally different from the death-birth model when fitness affects the latter event.

关键词： Spatial death-birth models Spatial birth-death models Spatial evolutionary models Spatial cancer models Evolutionary graph theory Stochastic processes Biased voter model dual process Fixation probability Shape theorem

Asbestos Exposure during Gasket Removal from Aircraft Engine

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Occupational diseases and Environmental Medicine 2024年第2期12卷 59-67页

作者： Charles L. Blake kevin M. Guth Raymond d. Harbison Apex Companies Marietta USA Center for Environmental and Occupational Risk Analysis and Management College of Public Health University of South Florida Tampa USA

We have previously evaluated asbestos exposure associated with various maintenance procedures on light aircraft. The purpose of this study was to evaluate asbestos exposure during engine maintenance on light aircraft. This test was designed to evaluate the potential for asbestos exposure to mechanics and others who remove asbestos-containing engine gaskets from reciprocating style aircraft engines. Utilized in this test was an air cooled, horizontally opposed, aviation gasoline burning engine, assembled during 1986 and operated intermittently up into 2015, having accumulated 1680 hours run time. Nearly 75% of the asbestos-containing gaskets installed during 1986 were still in place at the time of testing. Chrysotile asbestos contents of such gaskets ranged from 55% to 60% by area, for those of sheet style and 5% by area, for the spiral wound metal/asbestos style. despite the levels of effort required to effect gasket removals, the professional aircraft mechanic was not exposed to airborne asbestos fibers at the lower limits of sampling and analytical detection achieved;all of which were substantially less than the current Occupational Safety and Health Administration Permissible Exposure Limits for asbestos. The results of this testing indicate an absence of gasket related asbestos exposure risk to mechanics who work with light aircraft engines, including those having asbestos-containing gaskets. These results are consistent with the findings of Mlyarek and Van Orden who studied the asbestos exposure risk occasioned during overhaul of larger radial style reciprocating aircraft engines [1].

关键词： Asbestos Exposure Gaskets Aircraft Engine Friction Materials

Pharmacological methods for ovarian function and fertility preservation in women with cancer:A literature review

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Oncology Research 2024年第8期32卷 1309-1322页

作者： ANA S.CVETANOVIC MATTEO LAMBERTINI kevin PUNIE GORANA G.MATOVINA BRKO NIKOLA d.ZIVKOVIC MAJA J.POPOVIC MARIJANA M.MILOVIC KOVACEVIC LAZAR S.POPOVIC department for Oncology Medical Faculty NisUniversity of NisNis18000Serbia Clinic of Oncology University Clinical Centre NisNis18000Serbia department of Internal Medicine and Medical Sciences(diMI) School of MedicineUniversity of GenovaGenova16100Italy department of Medical Oncology U.O.C Clinica di Oncologia MedicaIRCCS Ospedale Policlinico San MartinoGenova16100Italy department of General Medical Oncology and Multidisciplinary Breast Centre Leuven Cancer InstituteUniversity Hospitals LeuvenLeuven3001Belgium department of Medical Oncology Oncology Institute of VojvodinaSremska Kamenica21208Serbia department for Pathology Medical Faculty NisUniversity of NisNis18000Serbia Center for Pathology University Clinical Centre NisNis18000Serbia Faculty of Medicine University of Novi SadNovi Sad21000Serbia department of Medical Oncology Institute of Oncology and Radiology SerbiaBelgrade11000Serbia

Oncofertility is an extremely signiﬁcant topic that is increasingly being discussed owing to increased evidence indicating that fertility preservation does not affect the treatment outcomes of patients with cancer but signiﬁcantly contributes to preserving life *** effect of chemotherapy can range from minimal effects to complete ovarian *** data are available on the effects of monoclonal antibodies and targeted therapies on the ovaries and *** ovarian suppression by administering a gonadotropin-releasing hormone agonist(GnRHa)during chemotherapy decreases the gonadotoxic effect of chemotherapy,thereby diminishing the chance of developing premature ovarian insufﬁciency(POI).At present,the concomitant administration of GnRH analogs during chemotherapy is the only accepted pharmacological method for preserving ovarian ***,most randomized studies on the effectiveness of luteinizing hormone-releasing hormone agonists during chemotherapy in preventing POI have been conducted in women with breast cancer,with a considerably small number of studies on patients with hematological ***,most randomized controlled trials on breast cancer have revealed a decrease in treatment-induced POI risk,regardless of the hormone receptor *** addition,studies on hematological malignancies have yielded negative results;nevertheless,theﬁndings must be interpreted with caution owing to numerous *** guidelines from the American Society of Clinical Oncology and ESMO Clinical Practice Guidelines recommend sperm,oocyte,and embryo cryopreservation as a standard practice and only offering GnRHa to patients when proven fertility preservation methods are not *** this manuscript,we present a comprehensive literature overview on the application of ovarian suppression with GnRHa during chemotherapy in patients with cancer by addressing preclinical and clinical data,as well as future perspectives in thisﬁeld

关键词： Gonadotropin-releasing hormone agonists(GnRHa) Fertility preservation Premature ovarian insufficiency(POI) Premenopausal patients