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Truly optimal semi-active damping to control free vibration of a single degree of freedom system

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Theoretical & Applied Mechanics Letters 2024年第2期14卷 142-145页

作者： Viet Duc la Ngoc Tuan Nguyen Institute of Mechanics Vietnam Academy of Science and TechnologyHanoi 10000Vietnam Graduate University of Science and Technology Vietnam Academy of Science and TechnologyHanoi 10000Vietnam

This paper studies a single degree of freedom system under free vibration and controlled by a general semiactive damping.A general integral of squared error is considered as the performance index.A one-time switching damping controller is proposed and *** pontryagin maximum principle is used to prove that no other form of semi-active damping can provide the better performance than the proposed one-time switching damping.

关键词： Analytical optimization Quadratic integral Lyapunov equation Pontryagin maximum principle

A convolutional neural network to detect possible hidden data in spatial domain images

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Cybersecurity 2024年第1期7卷 37-52页

作者： Jean De la Croix Ntivuguruzwa Tohari Ahmad Department of Informatics Institut Teknologi Sepuluh Nopember(ITS)Kampus ITS Keputih SukoliloSurabaya60111Indonesia African Center of Excellence in the Internet of Things College of Science and TechnologyUniversity of Rwanda3900KigaliRwanda

Hiding secret data in digital multimedia has been essential to protect the ***,attackers with a steganalysis technique may break *** steganalysis methods have good results with conventional Machine Learning(ML)techniques;however,the introduction of Convolutional Neural Network(CNN),a deep learning paradigm,achieved better performance over the previously proposed ML-based *** the existing CNN-based approaches yield good results,they present performance issues in classification accuracy and stability in the network training *** research proposes a new method with a CNN architecture to improve the hidden data detection accuracy and the training phase stability in spatial domain *** proposed method comprises three phases:pre-processing,feature extraction,and ***,in the pre-processing phase,we use spatial rich model filters to enhance the noise within images altered by data hiding;secondly,in the feature extraction phase,we use two-dimensional depthwise separable convolutions to improve the signal-to-noise and regular convolutions to model local features;and finally,in the classification,we use multi-scale average pooling for local features aggregation and representability enhancement regardless of the input size variation,followed by three fully connected layers to form the final feature maps that we transform into class probabilities using the softmax *** results identify an improvement in the accuracy of the considered recent scheme ranging between 4.6 and 10.2%with reduced training time up to 30.81%.

关键词： Information security Spatial domain steganalysis Deep learning Convolutional neural network Infrastructure

ZnSb/Ti_(3)C_(2)T_(x)MXene van der Waals heterojunction for flexible near-infrared photodetector arrays

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Journal of Semiconductors 2024年第5期45卷 99-105页

作者： Chuqiao Hu Ruiqing Chai Zhongming Wei la Li Guozhen Shen State Key laboratory for Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronic Engineering University of Chinese Academy of SciencesBeijing 100049China School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China

Two-dimension(2D)van der Waals heterojunction holds essential promise in achieving high-performance flexible near-infrared(NIR)***,we report the successful fabrication of ZnSb/Ti_(3)C_(2)T_(x)MXene based flexible NIR photodetector array via a facile photolithography *** single ZnSb/Ti_(3)C_(2)T_(x)photodetector exhibited a high light-to-dark current ratio of 4.98,fast response/recovery time(2.5/1.3 s)and excellent stability due to the tight connection between 2D ZnSb nanoplates and 2D Ti_(3)C_(2)T_(x)MXene nanoflakes,and the formed 2D van der Waals *** polyethylene terephthalate(PET)substrate enables the ZnSb/Ti_(3)C_(2)T_(x)photodetector withstand bending such that stable photoelectrical properties with non-obvious change were maintained over 5000 bending ***,the ZnSb/Ti_(3)C_(2)T_(x)photodetectors were integrated into a 26×5 device array,realizing a NIR image sensing application.

关键词： ZnSb nanoplates Ti_(3)C_(2)T_(x)MXene van der Waals heterojunction flexible photodetector image sensing

High Seebeck Coefficient Thermally Chargeable Supercapacitor with Synergistic Effect of Multichannel Ionogel Electrolyte and Ti_(3)C_(2)T_(x)MXene-Based Composite Electrode

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Energy & Environmental Materials 2024年第6期7卷 367-377页

作者： Zhongming Chen Zhijian Du la Li Kai Jiang Di Chen Guozhen Shen School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China Faculty of Hepato-Pancreato-Biliary Surgery Chinese PLA General HospitalInstitute of Hepatobiliary Surgery of Chinese PLA&Key Laboratory of Digital Hepetobiliary SurgeryChinese PLABeijing 100853China

Thermally chargeable supercapacitors can collect low-grade heat generated by the human body and convert it into electricity as a power supply unit for wearable ***,the low Seebeck coefficient and heat-to-electricity conversion efficiency hinder further *** this paper,we designed a high-performance thermally chargeable supercapacitor device composed of ZnMn_(2)O_(4)@Ti_(3)C_(2)T_(x)MXene composites(ZMO@Ti_(3)C_(2)T_(x)MXene)electrode and UIO-66 metal–organic framework doped multichannel polyvinylidene fluoridehexafluoro-propylene ionogel electrolyte,which realized the thermoelectric conversion and electrical energy storage at the same *** thermally chargeable supercapacitor device exhibited a high Seebeck coefficient of 55.4 mV K^(−1),thermal voltage of 243 mV,and outstanding heat-to-electricity conversion efficiency of up to 6.48%at the temperature difference of 4.4 *** addition,this device showed excellent charge–discharge cycling stability at high-temperature differences(3 K)and low-temperature differences(1 K),*** two thermally chargeable supercapacitor units in series,the generated output voltage of 500 mV further confirmed the stability of *** a single device was worn on the arm,a thermal voltage of 208.3 mV was obtained indicating the possibility of application in wearable electronics.

关键词： ionogel electrode Soret effect thermally chargeable supercapacitor Ti_(3)C_(2)T_(x)MXene UIO-66 MOF

The Influence of Significant Public Health Events on Offline Consumption and Its Pathways

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Journal of Systems Science and Systems Engineering 2024年第5期33卷 627-648页

作者： Baile Lu Kewei Zhou Shuai Hao la Ta Hongyan Dai Weihua Zhou College of Systems Engineering National University of Defense TechnologyChangsha 410073China Business School Central University of Finance and EconomicsBeijing 100081China Department of Marketing and Operations Management College of BusinessSouthern University of Science and TechnologyShenzhen 518055China School of Management Zhejiang UniversityHangzhou 310058China

In the face of a significant public health event,consumers may either increase their panic buying or decrease their willingness to make *** study focuses on the impact of a significant public health event on offline store sales and consumer consumption,utilizing data from chain convenience stores in Hefei and Wuhu during early 2019 and early 2020 in *** a difference-in-differences model,the study investigates the effect of the significant public health event outbreak on weekly store sales,order numbers,and consumer consumption in terms of product quantities,transaction amount,average amount per order,and transaction *** from prior literature that finds hoarding behavior of consumers online,the findings of this paper indicate a significant reduction in stores’offline weekly sales and order numbers,as well as consumers’offline weekly consumption across the four dimensions,as a result of the significant public health event ***,employing a mediation model,the study explores the pathway of population mobility through which the significant public health event adversely affects offline ***,subset analysis is conducted for stores located in different areas and consumers with varying characteristics,revealing that the aforementioned conclusions predominantly apply to stores situated in office areas and residential areas,as well as consumers with either no apparent preference for different product categories or a noticeable preference for food.

关键词： Significant public health event offline consumption population mobility mediating effect

Polarization Study of Swift J151857.0–572147 with IXPE Observation

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Research in Astronomy and Astrophysics 2024年第9期24卷 60-65页

作者： Yu-Shan Ling Fei Xie Ming-Yu Ge Fabio la Monaca Guangxi Key laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China Key laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China INAF Istituto di Astrofisica e Planetologia Spaziali Via del Fosso del Cavaliere 10000133 RomaItaly Dipartimento di Fisica Universitàdegli Studi di Roma“Tor Vergata”Via della Ricerca Scientifica 100133 RomaItaly Dipartimento di Fisica Universitàdegli Studi di Roma“La Sapienza”Piazzale Aldo Moro 500185 RomaItaly

We present an analysis of the Imaging X-ray Polarimetry Explorer observation from a newly discovered transient source:Swift *** obtained polarization degree(PD)and angle are 0.3%±0.3% and -24°±26°respectively in 2-8 keV within 68%confidence level errors,and polarization results are below MDP99in all energy bins,with the upper limit on PD of 0.8% in the 2-8 keV energy *** quasi-periodic oscillations(QPOs)are detected in this *** polarization and QPO analyses support the hypothesis that the source was in the high soft state,and the results are consistent with predictions for a thin accretion disk model.

关键词： stars:black holes polarization X-rays:bursts

Challenges and pitfalls of youth-onset type 2 diabetes

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World Journal of Diabetes 2024年第5期15卷 876-885页

作者： lavinia la Grasta Sabolic Sanda Marusic Maja Cigrovski Berkovic Department of Pediatric Endocrinology and Diabetology University Hospital Centre Sestre MilosrdniceZagreb 10000Croatia School of Medicine Catholic University of CroatiaZagreb 10000Croatia Department for Sport and Exercise Medicine University of Zagreb Faculty of KinesiologyZagreb 10000Croatia

The incidence and prevalence of youth-onset type 2 diabetes mellitus(T2DM)are *** rise in frequency and severity of childhood obesity,inclination to sedentary lifestyle,and epigenetic risks related to prenatal hyperglycemia exposure are important drivers of the youth-onset T2DM epidemic and might as well be responsible for the early onset of diabetes ***,youth-onset T2DM has a more extreme metabolic phenotype than adult-onset T2DM,with greater insulin resistance and more rapid deterioration of beta cell ***,intermediate complications such as microalbuminuria develop in late childhood or early adulthood,while end-stage complications develop in *** to the lack of efficacy and safety data,several drugs available for the treatment of adults with T2DM have not been approved in youth,reducing the pharmacological treatment *** this mini review,we will try to address the present challenges and pitfalls related to youth-onset T2DM and summarize the available interventions to mitigate the risk of microvascular and macrovascular complications.

关键词： Youth-onset type 2 diabetes mellitus Insulin resistance Beta cell failure Risk factors Therapy Complications

Game changer:How Janus kinase inhibitors are reshaping the landscape of ulcerative colitis mana

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World Journal of Gastroenterology 2024年第35期30卷 3942-3953页

作者： Antonio M Caballero-Mateos Guillermo Arturo Cañadas-de la Fuente Department of Gastroenterology and Hepatology San Cecilio University HospitalGranada 18014Spain Department of Nursing Faculty of Health SciencesUniversity of GranadaGranada 18004Spain

Recent advancements in the treatment landscape of ulcerative colitis(UC)have ushered in a new era of possibilities,particularly with the introduction of Janus kinase(JAK)-signal transducer and activator of transcription *** novel agents offer a paradigm shift in UC management by targeting key signaling pathways involved in inflammatory *** approved JAK inhibitors(JAKis),such as tofacitinib,filgotinib,and upadacitinib,clinicians now have powerful tools to modulate immune responses and gene expression,potentially revolutionizing the treatment algorithm for *** trials have demonstrated the efficacy of JAKis in inducing and maintaining remission,presenting viable options for patients who have failed conventional ***-world data support the use of JAKis not only as first-line treatments but also in subsequent lines of therapy,particularly in patients with aggressive disease phenotypes or refractory to biologic *** rapid onset of action and potency of JAKis have broadened the possibilities in the management strategies of UC,offering timely relief for patients with active disease and facilitating personalized treatment *** safety concerns,including cardiovascular risks and infections,ongoing research and post-marketing surveillance will continue to refine our understanding of the risk-benefit profile of JAKis in UC management.

关键词： Ulcerative colitis Janus kinase inhibitors Filgotinib Tofacitinib Upadacitinib

Comparison of corona effect prediction criteria on sphere-plane configuration

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High Voltage 2024年第4期9卷 957-969页

作者： Manuel De la Hoz Petrus Jacobus Pieterse Agurtzane Etxegarai Diego Gonzalez Angel Javier Mazon Dirk Uhrlandt University of the Basque Country BilbaoSpain University of Rostock RostockGermany Leibniz Institute for Plasma Science and Technology GreifswaldGermany

When designing high-voltage elements,knowing if the corona effect will be present during their life cycle is ***,designers consider several prediction criteria based on physical features related to breakdown discharge principles to predict the corona *** introduced practical set-up consists of a concave cone electrode with a hemispheric tip above a plate to evaluate selected corona prediction *** hemisphere has a fixed diameter of 7 mm,and the electrode separation ranges from 2.5 to 39 *** about the corona mode inception under different voltage sources was extracted using an intensified charge-coupled device camera and a partial discharge *** prediction criteria were connected to a specific corona mode depending on the main discharge structure behind its *** average deviation between these criteria and experimental results was around eight *** assumptions in criteria are also discussed in light of the experimental results.

关键词： effect. electrode effect