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DEEP NEURAL NETWORKS COMBINING MULTI-TASK LEARNING FOR SOLVING DELAY INTEGRO-DIFFERENTIAL EQUATIONS 被引量:1
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作者 WANG Chen-yao SHI Feng 《数学杂志》 2025年第1期13-38,共26页
Deep neural networks(DNNs)are effective in solving both forward and inverse problems for nonlinear partial differential equations(PDEs).However,conventional DNNs are not effective in handling problems such as delay di... Deep neural networks(DNNs)are effective in solving both forward and inverse problems for nonlinear partial differential equations(PDEs).However,conventional DNNs are not effective in handling problems such as delay differential equations(DDEs)and delay integrodifferential equations(DIDEs)with constant delays,primarily due to their low regularity at delayinduced breaking points.In this paper,a DNN method that combines multi-task learning(MTL)which is proposed to solve both the forward and inverse problems of DIDEs.The core idea of this approach is to divide the original equation into multiple tasks based on the delay,using auxiliary outputs to represent the integral terms,followed by the use of MTL to seamlessly incorporate the properties at the breaking points into the loss function.Furthermore,given the increased training dificulty associated with multiple tasks and outputs,we employ a sequential training scheme to reduce training complexity and provide reference solutions for subsequent tasks.This approach significantly enhances the approximation accuracy of solving DIDEs with DNNs,as demonstrated by comparisons with traditional DNN methods.We validate the effectiveness of this method through several numerical experiments,test various parameter sharing structures in MTL and compare the testing results of these structures.Finally,this method is implemented to solve the inverse problem of nonlinear DIDE and the results show that the unknown parameters of DIDE can be discovered with sparse or noisy data. 展开更多
关键词 delay integro-differential equation Multi-task learning parameter sharing structure deep neural network sequential training scheme
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Integrated Optical True Time Delay Phased Array Antenna Systems 被引量:1
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作者 Qi Zihang Yang Linhui +1 位作者 Zhao Wenyu Li Xiuping 《China Communications》 2025年第5期152-172,共21页
The integrated optical true time delay phased array antenna system has the advantages of high bandwidth,small size,low loss and strong antiinterference capability,etc.The high integration of the optically controlled p... The integrated optical true time delay phased array antenna system has the advantages of high bandwidth,small size,low loss and strong antiinterference capability,etc.The high integration of the optically controlled phased array antenna system is a necessary trend for the future development of the phased array,and it is also a major focus and difficulty in the current research of integrated microwave photonics.This paper firstly introduces the basic principle and development history of optical true time delay phased array antenna system based on microwave photonics,and briefly introduces the main implementation methods and integration platform of optical true time delay.Then,the application and development prospect of optical true time delay technology in beam control of phased array antenna system are mainly presented.Finally,according to the current research progress,the possible research directions of integrated optically controlled phased array antenna systems in the future are proposed. 展开更多
关键词 microwave photonics optical switch optical true time delay phased array antenna siliconbased integration
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Periodic Traveling Wave Solutions of a Single Population Model with Advection and Distributed Delay
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作者 GUO Zilin YU Tao TANG Xiaosong 《应用数学》 北大核心 2025年第4期988-995,共8页
In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave so... In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave solutions for this model under the influence of advection term and distributed delay.The obtained results indicate that weak kernel and strong kernel can both deduce the existence of periodic traveling wave solutions.Finally,we apply the main results in this paper to Logistic model and Nicholson’s blowflies model. 展开更多
关键词 Single population model Advection Distributed delay Periodic traveling wave solution
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Effect of retinoic acid on delayed encephalopathy after acute carbon monoxide poisoning:Role of the lncRNA SNHG15/LINGO-1/BDNF/TrkB axis
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作者 HUANG Fangling WANG Su’e +2 位作者 PENG Zhengrong HUANG Xu BAI Sufen 《中南大学学报(医学版)》 北大核心 2025年第6期955-969,共15页
Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid... Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid(RA)can suppress the neurotoxic effects of CO.This study further explores,in vivo and in vitro,the molecular mechanisms by which RA alleviates CO-induced central nervous system damage.Methods:A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO,and a DEACMP animal model was established in adult Kunming mice.Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay and Annexin V/propidium iodide(PI)double staining.The transcriptional and protein expression of each gene was detected using real time fluorescence quantitative PCR(RT-qPCR)and Western blotting.Long noncoding RNA(lncRNA)SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes.In DEACMP mice,SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression.Results:RA at 10 and 20μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes,downregulation of SNHG15 and LINGO-1,and upregulation of brain-derived neurotrophic factor(BDNF)and tyrosine kinase receptor B(TrkB)(all P<0.05).Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity(all P<0.05).Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels(all P<0.05).Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP(all P<0.05).Conclusion:RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes,thereby reducing central nervous system injury and exerting neuroprotective effects.LncRNA SNHG15 and LINGO-1 are key molecules mediating RA induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway.These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms. 展开更多
关键词 delayed encephalopathy after acute carbon monoxide poisoning apoptosis retinoic acid NEUROPROTECTION LINGO-1 lncRNA SNHG15
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Effects of potential field delay and coupling delay on collective behavior of a fractional-order coupled system in a dichotomous fluctuating potential
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作者 Yangfan Zhong Xi Chen +1 位作者 Maokang Luo Tao Yu 《Chinese Physics B》 2025年第5期270-287,共18页
The collective dynamic of a fractional-order globally coupled system with time delays and fluctuating frequency is investigated.The power-law memory of the system is characterized using the Caputo fractional derivativ... The collective dynamic of a fractional-order globally coupled system with time delays and fluctuating frequency is investigated.The power-law memory of the system is characterized using the Caputo fractional derivative operator.Additionally,time delays in the potential field force and coupling force transmission are both considered.Firstly,based on the delay decoupling formula,combined with statistical mean method and the fractional-order Shapiro–Loginov formula,the“statistic synchronization”among particles is obtained,revealing the statistical equivalence between the mean field behavior of the system and the behavior of individual particles.Due to the existence of the coupling delay,the impact of the coupling force on synchronization exhibits non-monotonic,which is different from the previous monotonic effects.Then,two kinds of theoretical expression of output amplitude gains G and G are derived by time-delay decoupling formula and small delay approximation theorem,respectively.Compared to G,G is an exact theoretical solution,which means that G is not only more accurate in the region of small delay,but also applies to the region of large delay.Finally,the study of the output amplitude gain G and its resonance behavior are explored.Due to the presence of the potential field delay,a new resonance phenomenon termed“periodic resonance”is discovered,which arises from the periodic matching between the potential field delay and the driving frequency.This resonance phenomenon is analyzed qualitatively and quantitatively,uncovering undiscovered characteristics in previous studies. 展开更多
关键词 potential field delay coupling delay FRACTIONAL-ORDER collective behavior
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Compact Ultra-Low Loss Optical True Delay Line on Thin Film Lithium Niobate
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作者 Yuan Ren Bo-Yang Nan +6 位作者 Rong-Bo Wu Yong Zheng Rui-Xue Liu Xue-Wen Wang Yun-Peng Song Min Wang Ya Cheng 《Chinese Physics Letters》 2025年第7期145-149,共5页
We report the fabrication of an 8-meter-long thin-flm lithium niobate optical true delay line using the photolithography-assisted chemomechanical etching technique,showing a low transmission loss of 0.036 dB/cm in the... We report the fabrication of an 8-meter-long thin-flm lithium niobate optical true delay line using the photolithography-assisted chemomechanical etching technique,showing a low transmission loss of 0.036 dB/cm in the conventional telecom band. 展开更多
关键词 conventional telecom band COMPACT transmission loss optical true delay line true delay line thin film ultra low loss lithium niobate
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Continuously Tunable Thin-Film Lithium Niobate Optical Delay Line with 293 ps Tuning Range
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作者 Lv-Bin Song Yong Zheng +8 位作者 Yuan Ren Bo-Yang Nan Rui-Xue Liu Hao-Zong Zhong Lin Li Min Wang Jin-Ming Chen Rong-Bo Wu Ya Cheng 《Chinese Physics Letters》 2025年第9期62-67,共6页
We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with du... We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount. 展开更多
关键词 continuous tunable thin film lithium niobate optical delay line wide range continuous tunability delay tuning optical delay line odl unbalanced Mach Zehnder interferometer synchronized control coupling coefficientscorresponding dual tunable couplers cm path difference interfe
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Optimization of reheating furnace rolling delay strategies based on a minimum energy consumption principle
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作者 Jing-qi Qiu Jun-xiao Feng +1 位作者 Xian-mo Huang Zhi-feng Huang 《Journal of Iron and Steel Research International》 2025年第3期707-719,共13页
To provide an energy-efficient and slab-demand-compliant rolling delay strategy,the simulation software is utilized to calculate the rolling delay process of the reheating furnace.Based on energy consumption evaluatio... To provide an energy-efficient and slab-demand-compliant rolling delay strategy,the simulation software is utilized to calculate the rolling delay process of the reheating furnace.Based on energy consumption evaluation,two optimization methods were employed.The bisection approach uses the needs of the slab to estimate the rolling delay temperature,and the golden section search method uses the energy consumption analysis of the slab to determine the high-temperature insulation duration.Generally,the slab closest to the discharge position in the control zone is selected as the optimization target.The optimized slab does not show a significant temperature rise after the end of the rolling delay process.When comparing the optimized rolling delay strategies with the traditional ones,the optimized rolling delay strategies not only meet the output requirements for slabs but also offer significant advantages in terms of energy efficiency,and this advantage increases with rolling delay time. 展开更多
关键词 Rolling delay strategy Rolling delay process Bisection method Golden section search method Energy consumption analysis
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Impact of low vision and blindness on characteristics of developmental delay in children younger than 6 years
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作者 Prakasit Wannapaschaiyong Suksri Chotikavanich +12 位作者 Sureelak Sutchritpongsa Pat Rojmahamonkol Amornrat Penphattarakul Piangporn Saksiriwutto Akarawit Eiamsamarng Simaporn Setthawong Theerajate Phongsuphan Piyaphat Jaruniphakul Rungtip Yingyong Nattapon Sarinak Ekpipat Eksupapan Saranya Sagan Pridaporn Onlamul 《World Journal of Clinical Pediatrics》 2025年第4期304-314,共11页
BACKGROUND Visual impairment during early childhood can hinder motor,language,and social development,yet data on its developmental impact across common pediatric ocular diseases remain limited.AIM To investigate the d... BACKGROUND Visual impairment during early childhood can hinder motor,language,and social development,yet data on its developmental impact across common pediatric ocular diseases remain limited.AIM To investigate the developmental impact of low vision and blindness on children under six with common ocular diseases.METHODS This retrospective study reviewed records of new patients under six with visual impairment at Siriraj Hospital’s low vision rehabilitation center(January 2017-October 2022).We collected ocular,systemic,and developmental data;recorded visual acuity in the better-seeing eye after refractive correction;and assessed developmental domains with the DenverⅡ.Univariable and multi-variable logistic regression identified factors associated with developmental delay.RESULTS A total of 161 pediatric patients(mean age 24.9±18.9 months)were enrolled and evaluated based on their ability to fix on and follow an object or light source.Some were further assessed using the Allen picture chart and all had visual acuity worse than 1.07±0.58 LogMAR,and 83.2%were identified as having global developmental delay(GDD).The three most common ocular causes were cortical visual impairment(CVI),optic neuropathy/atrophy,and optic nerve hypoplasia.Extremely poor visual acuity(inability to fixate and follow)was significantly associated with GDD[adjusted odds ratio(AOR)41.0]and delays in all developmental domains:Gross motor(AOR 10.0),fine motor(AOR 12.8),language(AOR 5.3),and personal-social skills(AOR 13.4)(P≤0.002).Multiple disabilities,most often visual impairment with cerebral palsy,were also significantly associated with gross motor delays(AOR 7.7)and fine motor delays(AOR 4.0)(P<0.05).CVI was also related to delays in language and personal-social skills(AOR 9.1 each)(P<0.05).CONCLUSION This study underscores the developmental issues in children with visual impairment,especially those with poorer acuity,CVI,and multiple disabilities.Significant delays were observed in all domains,including GDD.A timely referral to specialists is strongly recommended. 展开更多
关键词 CHILDREN Developmental delay Low vision Thailand Visual impairment
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The Global Attractor of 2D g-Navier- Stokes Equations with Damping and Delay
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作者 WANG Xiaoxia JIANG Jinping ZHANG Fukun 《Wuhan University Journal of Natural Sciences》 2025年第3期269-275,共7页
In this article,the global attractors of 2D g-Navier-Stokes equations are obtained in the space of C_(Hg) and CVg respectively.When the external force f is sufficiently small,the studies indicate that the global attra... In this article,the global attractors of 2D g-Navier-Stokes equations are obtained in the space of C_(Hg) and CVg respectively.When the external force f is sufficiently small,the studies indicate that the global attractor in C_(Hg) is equal to the global attractor in C_(Vg). 展开更多
关键词 global attractor g-Navier-Stokes equation DAMPING delay
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Modified Fixed-Time Synchronization Criteria of Complex Networks with Time-Varying Delays via Continuous or Discontinuous Control
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作者 WU Huan WU Ailong ZHANG Jin'e 《Wuhan University Journal of Natural Sciences》 2025年第2期150-158,共9页
This paper investigates modified fixed-time synchronization(FxTS)of complex networks(CNs)with time-varying delays based on continuous and discontinuous controllers.First,for the sake of making the settling time(ST)of ... This paper investigates modified fixed-time synchronization(FxTS)of complex networks(CNs)with time-varying delays based on continuous and discontinuous controllers.First,for the sake of making the settling time(ST)of FxTS is independent of the initial values and parameters of the CNs,a modified fixed-time(FxT)stability theorem is proposed,where the ST is determined by an arbitrary positive number given in advance.Then,continuous controller and discontinuous controller are designed to realize the modified FxTS target of CNs.In addition,based on the designed controllers,CNs can achieve synchronization at any given time,or even earlier.And control strategies effectively solve the problem of ST related to the parameters of CNs.Finally,an appropriate simulation example is conducted to examine the effectiveness of the designed control strategies. 展开更多
关键词 complex networks settling time fixed-time synchronization controllers time-varying delays
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Communication delay-aware cooperative adaptive cruise control with dynamic network topologies——A convergence of communication and control
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作者 Jihong Liu Yiqing Zhou Ling Liu 《Digital Communications and Networks》 2025年第1期191-199,共9页
Wireless communication-enabled Cooperative Adaptive Cruise Control(CACC)is expected to improve the safety and traffic capacity of vehicle platoons.Existing CACC considers a conventional communication delay with fixed ... Wireless communication-enabled Cooperative Adaptive Cruise Control(CACC)is expected to improve the safety and traffic capacity of vehicle platoons.Existing CACC considers a conventional communication delay with fixed Vehicular Communication Network(VCN)topologies.However,when the network is under attack,the communication delay may be much higher,and the stability of the system may not be guaranteed.This paper proposes a novel communication Delay Aware CACC with Dynamic Network Topologies(DADNT).The main idea is that for various communication delays,in order to maximize the traffic capacity while guaranteeing stability and minimizing the following error,the CACC should dynamically adjust the VCN network topology to achieve the minimum inter-vehicle spacing.To this end,a multi-objective optimization problem is formulated,and a 3-step Divide-And-Conquer sub-optimal solution(3DAC)is proposed.Simulation results show that with 3DAC,the proposed DADNT with CACC can reduce the inter-vehicle spacing by 5%,10%,and 14%,respectively,compared with the traditional CACC with fixed one-vehicle,two-vehicle,and three-vehicle look-ahead network topologies,thereby improving the traffic efficiency. 展开更多
关键词 Communication delay Cooperative adaptive Cruise control Network topology String stability
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Delay-Calibrated Compressed Sensing for MIMO-OFDM Channel Estimation with Inter-Cell Interference
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作者 Ou Zhihao Jiang Wenjun +2 位作者 Yuan Xiaojun Wang Li Zuo Yong 《China Communications》 2025年第8期102-113,共12页
This paper considers the fundamental channel estimation problem for the multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM)system in the presence of multi-cell interference.Specificall... This paper considers the fundamental channel estimation problem for the multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM)system in the presence of multi-cell interference.Specifically,this paper focuses on both channel modelling and receiver design for interference estimation and mitigation.We propose a delay-calibrated block-wise linear model,which extracts the delay of the dominant tap of each interference as a key parameter and approximates the residual channel coefficients by the recently developed blockwise linear model.Based on the delay-calibrated block-wise linear model and the angle-domain channel sparsity,we further conceive a message passing algorithm to solve the channel estimation problem.Numerical results demonstrate the superior performance of the proposed algorithm over the state-of-the-art algorithms. 展开更多
关键词 channel estimation compressed sensing delay calibration inter-cell interference
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Patient and physician factors contributing to delays in inflammatory bowel diseases:Enhancing timely diagnosis
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作者 Horia Minea Ana-Maria Singeap +3 位作者 Laura Huiban Cristina Maria Muzica Carol Stanciu Anca Trifan 《World Journal of Gastroenterology》 2025年第6期115-120,共6页
In this article,we comment on the article by Blüthner et al.The article provides a comprehensive analysis of the factors contributing to the late detection of Crohn’s disease and ulcerative colitis within a Germ... In this article,we comment on the article by Blüthner et al.The article provides a comprehensive analysis of the factors contributing to the late detection of Crohn’s disease and ulcerative colitis within a German cohort.It highlights the conse-quences on patient outcomes,particularly disease progression and the increased risk of developing complications.The study identifies specific predictors asso-ciated with both patient-related and physician-related delays,offering a detailed exploration of the initial approach.Additionally,the article delves into the distinct patterns observed in the German population,stressing the unique aspects of diagnostic delays that may differ from those reported in other regions.This detailed examination offers valuable insights into the specific challenges faced within the German healthcare system and underscores the necessity of targeted interventions to facilitate early diagnosis.The importance of improved screening tools,patient education,and better healthcare infrastructure is emphasized as crucial steps toward improving patient care in inflammatory bowel disease. 展开更多
关键词 Inflammatory bowel disease Diagnostic delay Disease awareness Healthcare system Screening tools
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Global asymptotic stability in a delay stage structured model for mosquito population suppression
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作者 HUANG Mu-gen YU Jian-she 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第1期122-136,共15页
A promising avenue to control mosquito-borne diseases such as dengue,malaria,and Zika involves releasing male mosquitoes carrying the bacterium Wolbachia in wild areas to drive female sterility by a mechanism called c... A promising avenue to control mosquito-borne diseases such as dengue,malaria,and Zika involves releasing male mosquitoes carrying the bacterium Wolbachia in wild areas to drive female sterility by a mechanism called cytoplasmic incompatibility(CI).In this work,we initiate a preliminary assessment of how the combined impact of dispersal,incomplete CI and mating competitiveness on mosquito population suppression by a delay differential equation model.Our theoretical analyses indicate that the immigration of eggs plays a significant role in the suppression dynamics.For the case without egg immigration,we identify a threshold dispersal rate v*of adult mosquitoes,threshold CI densityξ*,and threshold release ratio r*.A successful mosquito suppression would be established only when v<v*,ξ>ξ*,and r(t)≥r*uniformly.The immigration of eggs causes the threshold dynamics to be invalid,and warns an absolute failure of population suppression.The monotonicity of the adult steady-state in the dispersal rate and CI intensity indicates that choosing a suitable Wolbachia strain with strong CI intensity,or bringing down the dispersal rate of mosquitoes by blocking the suppression zones is a feasible strategy to obtain a better suppression level. 展开更多
关键词 dengue fever WOLBACHIA cytoplasmic incompatibility population suppression delay differential equations
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Symbol Labeling for LDPC Coded Delayed BICM in a Two-Way Relay Channel
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作者 Zhang Zhe Zhou Liang +1 位作者 Du Junyi Zhou Zhiheng 《China Communications》 2025年第10期170-178,共9页
This paper is concerned with design-ing symbol labeling for a low-density parity-check(LDPC)-coded delayed bit-interleaved coded modu-lation(DBICM)scheme in a two-way relay channel(TWRC).We first present some properti... This paper is concerned with design-ing symbol labeling for a low-density parity-check(LDPC)-coded delayed bit-interleaved coded modu-lation(DBICM)scheme in a two-way relay channel(TWRC).We first present some properties of symbol labeling within a phase shift keying(PSK)modula-tion.These properties reduce the candidate labeling search space.Based on this search space,we take DBICM capacity as the cost function and propose a general method for optimizing symbol labeling by em-ploying the differential evolution algorithm.Numeri-cal results show that our labeling obtains a signal-to-noise ratio(SNR)gain up to 0.45 dB with respect to Gray labeling. 展开更多
关键词 delayed BICM LDPC symbol labeling two-way relay channel
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Optimizing Contrast-Enhanced Magnetic Resonance Neurography of the Brachial Plexus With Delayed Scanning
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作者 Jun Xu Xiaoli Hu +7 位作者 Xiaoyun Su Shen Gui Ziqiao Lei Xiaoming Liu Xiangzhi Zhou Lixia Wang Wenjun Wu Xiangchuang Kong 《iRADIOLOGY》 2025年第2期168-175,共8页
Background:Contrast-enhanced magnetic resonance neurography(ceMRN)can enhance brachial plexus visualization and quality of imaging.However,the interval between contrast injection and scanning that provides the highest... Background:Contrast-enhanced magnetic resonance neurography(ceMRN)can enhance brachial plexus visualization and quality of imaging.However,the interval between contrast injection and scanning that provides the highest-quality images is not known.Methods:Fifteen patients underwent brachial plexus imaging using the 3D T2-NerveView sequence with a scanning duration of 5 min.A consecutive six-phase scan was initiated immediately at the start of contrast agent injection.Subsequently,all patients'images were classified into six groups according to the phases:group A(phase 1,delay 0 min),group B(phase 2,delay 5 min),group C(phase 3,delay 10 min),group D(phase 4,delay 15 min),group E(phase 5,delay 20 min),and group F(phase 6,delay 25 min).The image quality in each group was assessed based on nerve signal(signalnerve),muscle signal(signalmuscle),lymph node signal(signallymph node),background noise(BN),signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),and subjective score.Results:Signalnerve,signalmuscle,BN,and SNR did not significantly differ among the six groups(p>0.05).However,significant differences(p<0.05)were observed in signallymph node(F=16.067),CNR(F=9.495),and subjective score(χ^(2)=23.586).As the scanning delay increased,signallymph node intensity gradually increased whereas the CNR gradually decreased.The subjective score was significantly higher in groups B(4.830.24),C(4.900.21),D(4.870.30),E(4.830.31),and F(4.830.31)than in group A(4.470.30).Conclusion:We recommend performing brachial plexus ceMRN 5 min after contrast injection.With this delay,the brachial plexus can be visualized optimally with minimal interference from background signals. 展开更多
关键词 brachial plexus compressed sensing delayed scanning image quality magnetic resonance neurography
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MEROMORPHIC SOLUTIONS OF DELAY SCHWARZIAN DIFFERENTIAL EQUATIONS
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作者 Xiaotang NIE Jiaxing HUANG +1 位作者 Yuefei WANG CHENGFA WU 《Acta Mathematica Scientia》 2025年第4期1514-1528,共15页
In this paper,we focus on the admissible transcendental meromorphic solutions of the following delay Schwarzian differential equations with rational coefficients f(z+1)-f(z-1)+a(z)S(f,z)=P(z,f(z))/Q(z,f(z)).We obtain ... In this paper,we focus on the admissible transcendental meromorphic solutions of the following delay Schwarzian differential equations with rational coefficients f(z+1)-f(z-1)+a(z)S(f,z)=P(z,f(z))/Q(z,f(z)).We obtain the necessary conditions on the degree of R(z,f)for these delay differential equations and give a classification of the delay Schwarzian differential equations according to the multiplicities of the root of Q(z,f)on f.Finally,we provide some examples to illustrate that all cases occur. 展开更多
关键词 meromorphic functions delay differential equations Nevanlinna theory Schwarzian derivatives minimal hyper-type
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Diagnosis delays associated with mortality among patients with haemorrhagic fever in Upper Southern Thailand:A hospital-based case control study
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作者 Siraphat Chokumnuaysit Somkiattiyos Woradet Bhunyabhadh Chaimay 《Asian Pacific Journal of Tropical Medicine》 2025年第3期122-130,共9页
Objective:To investigate the association between diagnosis delays and mortality in patients with haemorrhagic fever in Upper Southern Thailand.Methods:A hospital-based case control study was conducted between December... Objective:To investigate the association between diagnosis delays and mortality in patients with haemorrhagic fever in Upper Southern Thailand.Methods:A hospital-based case control study was conducted between December 2019 and January 2020.Cases were defined as patients who had been diagnosed with haemorrhagic fever and died during hospitalization,while controls were patients with similar conditions who survived.Medical records were retrospectively reviewed,with the primary variable being a diagnosis delay of more than three days after the onset of illness.The outcome of interest was mortality during hospitalization.Data analysis involved descriptive statistics and multiple logistic regression.Results:A total of 38815 haemorrhagic fever cases were reported from 2014 to 2019.The case-to-control ratio was 1:3,comprising 66 cases and 198 controls.Among 66 cases and 198 controls,the median(IQR)time from illness onset to diagnosis was 4(4)days in cases vs.1(0)day in controls.Diagnosis delays significantly increased mortality risk[adjusted OR(aOR)5.60,95%CI 2.74-11.46].Other risk factors for mortality included age≤5 years(aOR 16.15,95%CI 3.70-70.42)and overweight status(aOR 3.43,95%CI 1.57-7.52).Conclusions:Delayed diagnosis in patients with haemorrhagic fever was strongly associated with higher mortality rates.These findings highlight the critical importance of early diagnosis to reduce mortality in haemorrhagic fever cases. 展开更多
关键词 Diagnosis delays MORTALITY Haemorrhagic fever Dengue haemorrhagic fever Dengue shock syndrome
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Wave attenuation in a metamaterial beam with time delay control
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作者 Xiaochen Mao Xia Tong +1 位作者 Liufei Zhang Youheng Dong 《Acta Mechanica Sinica》 2025年第4期130-141,共12页
This paper studies the bandgap characteristics of a locally resonant metamaterial beam with time delays.The dispersion relations are addressed based on transfer matrix method.The governing equations of motion of the b... This paper studies the bandgap characteristics of a locally resonant metamaterial beam with time delays.The dispersion relations are addressed based on transfer matrix method.The governing equations of motion of the beam in the frequency domain are given according to spectral element method.The amplitude-frequency responses of the forced beam are determined by solving linear algebraic equations.The obtained results show that the time-delayed feedback control has great relationships with the location,width and number of the bandgaps.It is interesting that the time delay can change the direction of the movement of the bandgap and give rise to the generation of multiple bandgaps.The influences of different combinations of control parameters on the bandgap properties are shown,such as broadening effects. 展开更多
关键词 Wave characteristics Time delays Spectral element method Frequency shift Multiple bandgaps
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