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Connection Between Damping Torque Analysis and Energy Flow Analysis in Damping Performance Evaluation for Electromechanical Oscillations in Power Systems

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Journal of Modern Power Systems and Clean Energy 2022年第1期10卷 19-28页

作者： Yong Hu Siqi Bu Xin Zhang Chi yung Chung Hui Cai Department of Electrical Engineering and Research Institute for Smart Energy The Hong Kong Polytechnic UniversityHong KongChina Shenzhen Research Institute The Hong Kong Polytechnic UniversityShenzhenChina Centre for Energy Systems and Strategy Cranfield UniversityCranfieldUK Department of Electrical and Computer Engineering University of SaskatchewanSaskatoonCanada State Grid Jiangsu Economic Research Institute NanjingChina

The damping performance evaluation for electromechanical oscillations in power systems is crucial for the stable operation of modern power systems.In this paper,the connection between two commonly-used damping performance evaluation methods,i.e.,the damping torque analysis(DTA)and energy flow analysis(EFA),are systematically examined and revealed for the better understanding of the oscillatory damping mechanism.First,a concept of the aggregated damping torque coefficient is proposed and derived based on DTA of multi-machine power systems,which can characterize the integration effect of the damping contribution from the whole power system.Then,the pre-processing of measurements at the terminal of a local generator is conducted for EFA,and a concept of the frequency-decomposed energy attenuation coefficient is defined to screen the damping contribution with respect to the interested frequency.On this basis,the frequency spectrum analysis of the energy attenuation coefficient is employed to rigorously prove that the results of DTA and EFA are essentially equivalent,which is valid for arbitrary types of synchronous generator models in multi-machine power systems.Additionally,the consistency between the aggregated damping torque coefficient and frequency-decomposed energy attenuation coefficient is further verified by the numerical calculation in case studies.The relationship between the proposed coefficients and the eigenvalue(or damping ratio)is finally revealed,which consolidates the application of the proposed concepts in the damping performance evaluation.

关键词： Electromechanical oscillation damping performance damping torque analysis(DTA) energy flow analysis(EFA) frequency spectrum

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Prediabetes in children and adolescents:An updated review

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World Journal of Clinical Pediatrics 2023年第5期12卷 263-272页

作者： Hak yung Ng Louis Tsz Wang Chan Department of Paediatrics and Adolescent Medicine Tseung Kwan O HospitalHong KongChina

Prediabetes,the precursor of type 2 diabetes mellitus,is an intermediate stage between normal glucose homeostasis and overt diabetes.This asymptomatic metabolic state is increasingly prevalent in pediatric population and is very difficult to detect without appropriate screening.Studies have shown that a certain proportion of children with prediabetes will develop diabetes in a few years.Even more alarming is the evidence that youth-onset diabetes has a more aggressive clinical course with progressive beta-cell decline and accelerated endorgan damage.Despite its importance,several aspects involving prediabetes in childhood are disputed or unknown.This review presents the latest insights into this challenging entity and outlines a simplified screening approach to aid clinical practice.In summary,childhood prediabetes is an important clinical condition indicating the need for proper screening and timely intervention.

关键词： Prediabetes Screening Diagnosis Management Obesity Type 2 diabetes mellitus Children

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Nonlinear Algebraic Equations Solved by an Optimal Splitting-Linearizing Iterative Method

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Computer Modeling in Engineering & Sciences 2023年第5期135卷 1111-1130页

作者： Chein-Shan Liu Essam REl-Zahar yung-Wei Chen Center of Excellence for Ocean Engineering Center of Excellence for the OceansTaiwan Ocean UniversityKeelung202301Taiwan Department of Mathematics College of Sciences and Humanities in Al-KharjPrince Sattam bin Abdulaziz UniversityAlkharj11942Saudi Arabia Department of Basic Engineering Science Faculty of EngineeringMenofia UniversityShebin El-Kom32511Egypt Department of Marine Engineering Taiwan Ocean UniversityKeelung202301Taiwan

How to accelerate the convergence speed and avoid computing the inversion of a Jacobian matrix is important in the solution of nonlinear algebraic equations(NAEs).This paper develops an approach with a splitting-linearizing technique based on the nonlinear term to reduce the effect of the nonlinear terms.We decompose the nonlinear terms in the NAEs through a splitting parameter and then linearize the NAEs around the values at the previous step to a linear system.Through the maximal orthogonal projection concept,to minimize a merit function within a selected interval of splitting parameters,the optimal parameters can be quickly determined.In each step,a linear system is solved by the Gaussian elimination method,and the whole iteration procedure is convergent very fast.Several numerical tests show the high performance of the optimal split-linearization iterative method(OSLIM).

关键词： Nonlinear algebraic equations novel splitting-linearizing technique iterative method maximal projection optimal splitting parameter

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Axial control for nonlinear resonances of electrostatically actuated nanobeam with graphene sensor

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Applied Mathematics and Mechanics(English Edition) 2017年第4期38卷 527-542页

作者： Canchang LIU Qian DING Qingmei GONG chicheng MA Shuchang YUE School of Transportation and Vehicle Engineering Shandong University of Technology School of Mechanical Engineering Tianjin University

The nonlinear resonance response of an electrostatically actuated nanobeam is studied over the near-half natural frequency with an axial capacitor controller. A graphene sensor deformed by the vibrations of the nanobeam is used to produce the voltage signal. The voltage of the vibration graphene sensor is used as a control signal input to a closed- loop circuit to mitigate the nonlinear vibration of the nanobeam. An axial control force produced by the axial capacitor controller can transform the frequency-amplitude curves from nonlinear to linear. The necessary and sufficient conditions for guaranteeing the system stability and a saddle-node bifurcation are studied. The numerical simulations are conducted for uniform nanobeams. The nonlinear terms of the vibration system can be transformed into linear ones by applying the critical control voltage to the system. The nonlinear vibration phenomena can be avoided, and the vibration amplitude is mitigated evidently with the axial capacitor controller.

关键词： graphene sensor nanobeam nonlinear vibration electrostatic force

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Human-Animal Interactions in Disaster Settings:A Systematic Review

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International Journal of Disaster Risk Science 2023年第3期14卷 369-381页

作者： Haorui Wu Lindsay K.Heyland Mandy yung Maryam Schneider School of Social Work Faculty of HealthDalhousie UniversityHalifaxNS B3H 4R2Canada Department of Psychology Mount Saint Vincent UniversityHalifaxNSB3M2J6Canada

This systematic review aimed to assess the current knowledge of human-animal interactions(HAIs)in disaster settings and identify areas for future research.A Preferred Reporting Items for Systematic Reviews and Meta-Analyses search was conducted on three multidisciplinary databases,identifying English-language journal articles published between January 2000and February 2022 that explored the benefits of and challenges associated with HAI in disasters and emergencies.The review analyzed 94 articles using both quantitative and qualitative methods.The review found a paucity of universal terminology to describe the bidirectional relationship between humans and animals during disasters and a failure to include all animal types in every stage of disaster and emergency management.Additionally,research predominantly focused on the health and well-being benefits of HAI for humans rather than animals.Efforts to promote social and environmental justice for humans and their co-inhabitants should support the welfare of both humans and animals in disaster settings.Four recommendations were developed based on these findings to increase the inclusion of HAI in research,policy,and practice.Limitations of the review included the exclusion of pre-2000 articles and all grey literature,limited research examining different combinations of animal and disaster types,and limited research outside of North America.

关键词： Emergency management Hazards and disaster research Human-animal bonds Human-animal interactions Human-animal welfare Inclusive Literature review

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Flow Management Mechanism in Software-Defined Network

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Computers, Materials & Continua 2022年第1期70卷 1437-1459页

作者： Eugene Tan yung-Wey Chong Mohammed F.R.Anbar National Advanced IPv6 Centre Universiti Sains MalaysiaUSMPenangMalaysia

Software-defined networking(SDN)is a paradigm shift in modern networking.However,centralised controller architecture in SDNimposed flow setup overhead issue as the control plane handles all flows regardless of size and priority.Existing frameworks strictly reduce control plane overhead and it does not focus on rule placement of the flows itself.Furthermore,existing frameworks do not focus on managing elephant flows like RTSP.Thus,the proposed mechanism will use the flow statistics gathering method such as random packet sampling to determine elephant flow and microflow via a predefined threshold.This mechanism will ensure that the control plane works at an optimum workload because the controller only manages elephant flows via reactive routing and rule placement respectively.Reactive routing has reduced link bandwidth usage below the pre-defined threshold.Furthermore,rule placement has increased average throughput and total transfer to 238%.Meanwhile,the data plane switches will be able to forward microflows via multipath wildcard routing without invoking controller in greater responding time by 85 ms faster in two Transmission Control Protocol(TCP)traffic and achieved 11%and 12%higher total transfer size and throughput respectively.Hence,the controller’s workload reduced significantly to 48%in two TCP traffic.

关键词： Software-defined network controller flow management

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Human amniotic fluid stem cell therapy can help regain bladder function in type 2 diabetic rats

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World Journal of Stem Cells 2022年第5期14卷 330-346页

作者： Ching-Chung Liang Steven W Shaw yung-Hsin Huang Tsong-Hai Lee Female Urology Section Department of Obstetrics and GynecologyLinkou Chang Gung Memorial HospitalCollege of MedicineChang Gung UniversityTaoyuan 333Taiwan Division of Obstetrics Department of Obstetrics and GynecologyTaipei Chang Gung Memorial HospitalTaipei 105Taiwan Prenatal Cell and Gene Therapy Group Institute for Women’s HealthUniversity College LondonLondon WC1E 6BTUnited Kingdom Stroke Center and Department of Neurology Linkou Chang Gung Memorial HospitalCollege of MedicineChang Gung UniversityTaoyuan 333Taiwan

BACKGROUND Diabetes mellitus(DM)is a serious and growing global health burden.It is estimated that 80%of diabetic patients have micturition problems such as poor emptying,urinary incontinence,urgency,and urgency incontinence.Patients with diabetic bladder dysfunction are often resistant to currently available therapies.It is necessary to develop new and effective treatment methods.AIM To examine the therapeutic effect of human amniotic fluid stem cells(hAFSCs)therapy on bladder dysfunction in a type 2 diabetic rat model.METHODS Sixty female Sprague-Dawley rats were divided into five groups:Group 1,normal-diet control(control);group 2,high-fat diet(HFD);group 3,HFD plus streptozotocin-induced DM(DM);group 4,DM plus insulin treatment(DM+insulin);group 5,DM plus hAFSCs injection via tail vein(DM+hAFSCs).Conscious cystometric studies were done at 4 and 12 wk after insulin or hAFSCs treatment to measure peak voiding pressure,voided volume,intercontraction interval,bladder capacity,and residual volume.Immunoreactivities and/or mRNA expression of muscarinic receptors,nerve growth factor(NGF),and sensory nerve markers in the bladder and insulin,MafA,and pancreatic-duodenal homeobox-1(PDX-1)in pancreatic beta cells were studied.RESULTS Compared with DM rats,insulin but not hAFSCs treatment could reduce the bladder weight and improve the voided volume,intercontraction interval,bladder capacity,and residual volume(P0.05).The immunoreactivities and mRNA expression of M2-and M3-muscarinic receptors(M2 and M3)were increased mainly at 4 wk(P<0.05),while the number of beta cells in islets and the immunoreactivities and/or mRNA of NGF,calcitonin gene-related peptide(CGRP),substance P,insulin,MafA,and PDX-1 were decreased in DM rats(P<0.05).However,insulin and hAFSCs treatment could help to regain the expression of M2,M3,NGF,CGRP,substance P,MafA,and PDX-1 to near the levels of controls at 4 a

关键词： Amniotic fluid Bladder dysfunction Diabetes Insulin Stem cells

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Comparative transcriptome analysis reveals molecular adaptations underlying distinct immunity and inverted resting posture in bats

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Integrative Zoology 2023年第3期18卷 493-505页

作者： Jinwei WU Libiao ZHANG Chao SHEN Simon yung Wa SIN Caoqi LEI Huabin ZHAO Engineering Research Center of Eco-environment in Three Gorges Reservoir Region of Ministry of Education China Three Gorges UniversityYichangChina Guangdong Key Laboratory of Animal Conservation and Resource Utilization Guangdong Public Laboratory of Wild Animal Conservation and UtilizationInstitute of ZoologyGuangdong Academy of SciencesGuangzhouChina College of Life Sciences Wuhan UniversityWuhanChina School of Biological Sciences The University of Hong KongHong Kong SARChina

Understanding how natural selection shapes unique traits in mammals is a central topic in evolutionary biology.The mammalian order Chiroptera(bats)is attractive for biologists as well as the general public due to their speciﬁc traits of extraordinary immunity and inverted resting posture.However,genomic resources for bats that occupy key phylogenetic positions are not sufﬁcient,which hinders comprehensive investigation of the molecular mechanisms underpinning the origin of speciﬁc traits in bats.Here,we sequenced the transcriptomes of 5 bats that are phylo-genetically divergent and occupy key positions in the phylogenetic tree of bats.In combination with the available genomes of 19 bats and 21 other mammals,we built a database consisting of 10918 one-to-one ortholog genes and reconstructed phylogenetic relationships of these mammals.We found that genes related to immunity,bone remodeling,and cardiovascular system are targets of natural selection along the ancestral branch of bats.Further analyses revealed that the T cell receptor signaling pathway involved in immune adaptation is speciﬁcally enriched in bats.Moreover,molecular adaptations of bone remodeling,cardiovascular system,and balance sensing may help to explain the reverted resting posture in bats.Our study provides valuable transcriptome resources,enabling us to tentatively identify genetic changes associated with bat-speciﬁc traits.This work is among theﬁrst to advance our understanding of the molecular underpinnings of inverted resting posture in bats,which could provide insight into healthcare applications such as hypertension in humans.

关键词： adaptation bats immunity resting posture transcriptome

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Endoscopic salvage therapy after failed biliary cannulation using advanced techniques:A concise review

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World Journal of Gastroenterology 2022年第29期28卷 3803-3813页

作者： yung-Kuan Tsou Kuang-Tse Pan Mu Hsien Lee Cheng-Hui Lin Department of Gastroenterology and Hepatology Chang Gung Memorial HospitalTaoyuan 333Taiwan Department of Medicine Chang Gung UniversityTaoyuan 333Taiwan Department of Medical Imaging and Intervention Chang Gung Memorial HospitalTaoyuan 333Taiwan

Therapeutic endoscopic retrograde cholangiopancreatography(ERCP)begins with successful biliary cannulation.However,it is not always be successful.The failure of the initial ERCP is attributed to two main aspects:the papilla/biliary orifice is endoscopically accessible,or it is inaccessible.When the papilla/biliary orifice is accessible,bile duct cannulation failure can occur even with advanced cannulation techniques,including double guidewire techniques,transpancreatic sphincterotomy,needle-knife precut papillotomy,or fistulotomy.There is currently no consensus on the next steps of treatment in this setting.Therefore,this review aims to propose and discuss potential endoscopic options for patients who have failed ERCP due to difficult bile duct cannulation.These options include interval ERCP,percutaneous-transhepatic-endoscopic rendezvous procedures(PTE-RV),and endoscopic ultrasound-assisted rendezvous procedures(EUS-RV).The overall success rate for interval ERCP was 76.3%(68%-79% between studies),and the overall adverse event rate was 7.5%(0-15.9% between studies).The overall success rate for PTE-RV was 88.7%(80.4%-100%between studies),and the overall adverse event rate was 13.2%(4.9%-19.2% between studies).For EUS-RV,the overall success rate was 82%-86.1%,and the overall adverse event rate was 13%-15.6%.Because interval ERCP has an acceptably high success rate and lower adverse event rate and does not require additional expertise,facilities,or other specialists,it can be considered the first choice for salvage therapy.EUS-RV can also be considered if local experts are available.For patients in urgent need of biliary drainage,PTE-RV should be considered.

关键词： Difficult biliary cannulation Endoscopic ultrasound Rendezvous Endoscopic retrograde cholangiopancreatography Percutaneous transhepatic biliary drainage Interval

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得利丧失抗辩研究——以《民法典》第986条为中心

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华东政法大学学报 2022年第6期25卷 177-192页

作者：黄赤橙北京交通大学法学院

《民法典》第986条规定了得利丧失抗辩,作为限制不当得利返还义务的工具,其目的在于保护得利人自主决定利益,避免得利人因承担返还义务而处于比得利之前更糟糕的地位。该条规定了得利丧失抗辩成立的“得利丧失”与“善意”要件,解释上... 详细信息

《民法典》第986条规定了得利丧失抗辩,作为限制不当得利返还义务的工具,其目的在于保护得利人自主决定利益,避免得利人因承担返还义务而处于比得利之前更糟糕的地位。该条规定了得利丧失抗辩成立的“得利丧失”与“善意”要件,解释上应当加上因果关系要件。得利丧失应该以得利人因得利而提升的整体财富做判断;因果关系指要不是得利,则不会丧失得利;善意既包含不知道且不应当知道不当得利,还包含虽知道或应当知道不当得利但其行为或不行为表明打算将得利返还给失利人。得利丧失抗辩处理的实质问题是因得利丧失所造成的损失应当如何分配,过错作为损失分配的常见因素应当在决定抗辩能否被阻却时纳入考虑。失利人可以针对得利丧失抗辩提出得利人对于不当得利的发生具有过错的再抗辩;得利人则可以进一步提出失利人对于不当得利发生具有更大过错的再再抗辩。

关键词：不当得利返还得利丧失地位变更抗辩

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