R0 Values Research Articles

The effects of the abamectin and spirodiclofen mixture on life history and population parameters of Amblyseius swirskii

In this study, three sublethal concentrations (LC5, LC15, and LC25) of Envidor®speed (Abamectin and Spirodiclofen mixture, 24% SC, Bayer co.) on the biological parameters of the predatory mite Amblyseius swirskii Athias-Heneroit (Acari: Phytoseiidae) fed on Tetranychus urticae Koch (Acari: Tetranychidae) was assessed based on the Two-sex life table theory under laboratory conditions (25 ± 1°C, 70 ± 5% RH and 16:8 (L: D) hours). The data were analyzed based on a two-sex life table procedure. Increasing the sublethal concentration did have a significant effect on some life table parameters. The total lifespan of both males and females treated mites had a decreasing trend, for the females, it increased from 22.10 days in LC25 treatment to 42.67 days in control. The oviposition days of the predatory mite had the most differences between the LC15 and LC25 treatments compared to LC5 and control. Based on our results, the total fecundity is also affected by the acaricidal doses, which changed from 19.10 eggs per individual in LC25 to 37.17 eggs per individual in control. The net reproductive rate (R0), as well as the gross reproductive rate (GRR), were all significantly reduced with increasing the acaricide concentration. The control treatment had the maximum value, and the higher concentration treatment (LC25) had the slowest value of R0 and GRR. On the contrary, the intrinsic rate of increase (r) and finite rate of increase (λ) showed no significant differences with the increasing concentration of acaricide from the control to LC25 treatments. Eventually, with due attention to the large range value of each LCs for predatory mites concerning recommended concentration for T. urticae based on the active ingredient, the recommended concentration of Envidorspeed in IPM programs is unobstructed.

Optimal Parking Path Planning and Parking Space Selection Based on the Entropy Power Method and Bayesian Network: A Case Study in an Indoor Parking Lot

According to the vehicle dynamics model and the requirements of reliable safety and minimal time, the path planning problem of parking in different types of parking spaces is solved by obstacle avoidance analysis and motion analysis in the case of the optimal solution, and the parking trajectory from the initial position to the designated parking space is obtained. In the static situation, different parking spaces in the parking space are occupied; analyze the parking space type, parking space left and right occupancy situation, and the distance between the vacant parking space and the starting point location of unoccupied cars; and establish the attribute information matrix R0 of the vacant parking space and calculate the KMO value of the matrix R0. This is completed to determine the weak correlation between the attributes of the vacant parking space and use the matrix R0 as the original evaluation matrix of the entropy weight method, using the entropy weight method to calculate the three attributes of parking space type, parking space left and right occupancy situation, and distance between starting point and parking space. These results are weighted in the optimal parking space selection process, the difficulty score of the vacant parking space is determined, and the optimal parking space is determined through the ranking of the scores. In the dynamic case, the number of parking spaces and parking space usage will change over time, with the help of the Bayesian network, the existing parking spaces and number of spaces in the parking lot at the previous moment are learned according to the computer clock, which can be used to reason about the number of parking spaces and parking space availability in the parking lot at the next moment. The weights of the three attributes of parking space type, parking space left and right situation, and distance between the starting point and parking space are updated in the case of a dynamic change of parking space, and then the parking difficulty score of a new vacant parking space using the entropy weight method is used to select the optimal parking space in the dynamic situation. The optimized parking path planning and parking space selection method could contribute to enhancing parking efficiency for the sustainable management of indoor parking lots.

Modeling criminal careers of different levels of offence

We set up and analyse a mathematical model, the Serious Crime Model, which describes the interaction of mild and serious offenders and potential criminals. However we get more complete results for a simpler version of this model, the Mild Crime Model, with no serious offenders. For the full Serious Crime Model there are two key parameters R01 and R02 corresponding to the basic reproduction number in the mathematics of infectious diseases, which determine the behaviour of the system. For the Simpler Mild Crime Model there is just one such parameter R01. Both forward and backward bifurcation can occur for this second model with two subcritical non-trivial equilibria possible for R01<1 in the backwards case. For backwards bifurcation there is another threshold value R0* such that the upper non-trivial equilibrium is unstable for R01<R0* and stable for R01>R0*. For forwards bifurcation there is a second additional threshold value R0** such that the stability of the unique non-trivial equilibrium switches from unstable to stable as R01 passes through R0**. At the end we return to the full Serious Crime Model and discuss the behaviour of this model. The results are meaningful and interesting because in all of the other epidemiological and sociological models of which we are aware, analogous thresholds to R0* and R0** do not exist. For forwards bifurcation the unique non-trivial equilibrium, and for backwards bifurcation with two subcritical endemic equilibria the higher non-trivial equilibrium, are also usually always locally asymptotically stable. So our models exhibit unusual and interesting behaviour.

The Influence of Nonlinear Cannibalism to Logistic Equation

A single species model with Holling II type cannibalism term is proposed and studied in this paper. Local and global stability property of the system are investigated. By applying the iterative method, we show that the system always admits the unique globally asymptotically stable positive equilibrium. A threshold value R0, which depends on the cannibalism rate and the transform rate, is obtained. Depending on R0 &gt; 1, R0 = 1 or R0 &lt; 1, the final density of the species will smaller or equal to or bigger than the system without cannibalism. Our study shows that if the cannibalism rate is too large, and transform rate is too small, then R0 &gt; 1 and cannibalism has negative effect on the final density of the species, which increase the extinction property of the species.

Monocular spatial geometrical measurement method based on local geometric elements associated with out-of-view datum

In the field of industrial inspection, visual non-contact measurement of the radial dimension of the extension end of the long pole structure is a difficult problem. Utilizing the principle of telecentric vision measurement, we propose a monocular spatial geometrical measurement method based on local geometric elements associated with out-of-view datum, focusing on key techniques such as visual calibration and global unification of separate dimensions. Firstly, the designed associated target is used to establish the conversion relationship between the measurement reference space and the camera FOV space. Singular Value Decomposition (SVD) is used to obtain the initial values R0 and T0 of the rotation matrix and translation vector during the three-dimensional coordinate system conversion. Then the initial values are linearized based on the Rodrigues iterative transformation to obtain the optimized R and T, thereby achieving the high-precision conversion of the coordinate system, realizing the global unification of the coordinates of the separated size elements. In order to verify the effectiveness of the method, an experimental measurement device was constructed. The experimental results show that the measurement uncertainty (95% confidence level) of the space radial dimension is ±10.37 µm, and the %R&R index is 12.91%. This method is suitable for applications such as rapid and precise measurement of narrow and long workpieces such as partial visible elements in vitro or cross-scale measurement.

Effect of the type of citrus fruit on the biological parameters of Panonychus citri (Acari: Tetranychidae) under laboratory conditions

The citrus red mite, Panonychus citri (McGregor, 1916), is considered a very important pest in most citrus-growing countries. The developmental periods, reproduction rates, and population growth parameters of P. citri were evaluated using the fruit peel under experimental conditions (25 ± 1 °C, 50 ± 5% RH and 14:10 h photoperiod) on five Citrus species: Mexican lime (C. ×aurantiifolia (Christm.) Swingle), grapefruit (C. ×paradisi Macfad.), sweet orange (C. ×sinensis (L.) Osbeck), mandarin (C. reticulata Blanco), and tangelo fruit (C. ×tangelo J.W. Ingram & H.E. Moore). The developmental period of the immature stages of P. citri averaged 26.64, 25.93 and 25.75 d for sweet orange, mandarin, and tangelo fruit, respectively. The adult stage was not achieved in Mexican lime and grapefruit. Immature survival was less than 50% in mandarin and tangelo fruit, in contrast, in sweet orange it was 57%. On average, oviposition was 3.55, 4.95 and 5.00 eggs female-1, on sweet orange, mandarin, and tangelo fruit, respectively. The intrinsic natural growth rate (rm), net reproduction rate (R0), generation time (T), and finite growth rate (λ) of P. citri showed significant differences among the tested species (p < 0.05). The rm and R0 values were 0.005 and 1.209 for sweet orange, 0.026 and 2.474 for mandarin and 0.020 and 2.000 for tangelo fruit. The results indicated that mandarin was the most suitable species for the P. citri population growth, whereas sweet orange was less suitable to proliferate. These differences are important in the integrated management of P. citri on citrus.

Mathematical Modeling of COVID-19 with Vaccination Using Fractional Derivative: A Case Study

Vaccination against any infectious disease is considered to be an effective way of controlling it. This paper studies a fractional order model with vaccine efficacy and waning immunity. We present the model’s dynamics under vaccine efficacy, the impact of immunization, and the waning of the vaccine on coronavirus infection disease. We analyze the model under their equilibrium points. The model under the equilibrium points is discussed and proven that it is locally asymptotically stable if Rv is lesser than unity. We present the backward bifurcation hypothesis of the model and show that there is a parameter β2 that causes the backward bifurcation in the imperfect vaccine model. We show certain assumptions when ψ=1 for the imperfect vaccine case; the model is both stable globally asymptotically at the disease-free (R0≤1) and endemic cases (R0&gt;1). By using infected cases from the recent wave throughout Pakistan, we shall estimate the model parameters and calculate the numerical value of the basic reproductive number R0≈1.2591. We present the comprehensive graphical results for the realistic parameter values and show many useful suggestions regarding the elimination of the infection from society. The vaccination efficacy that provides an important role in disease elimination is discussed in detail.

New Method to Investigate the Impact of Independent Quadratic α-Stable Poisson Jumps on the Dynamics of a Disease under Vaccination Strategy

Long-run bifurcation analysis aims to describe the asymptotic behavior of a dynamical system. One of the main objectives of mathematical epidemiology is to determine the acute threshold between an infection’s persistence and its elimination. In this study, we use a more comprehensive SVIR epidemic model with large jumps to tackle this and related challenging problems in epidemiology. The huge discontinuities arising from the complexity of the problem are modelled by four independent, tempered, α-stable quadratic Lévy processes. A new analytical method is used and for the proposed stochastic model, the critical value R0🟉 is calculated. For strictly positive value of R0🟉, the stationary and ergodic properties of the perturbed model are verified (continuation scenario). However, for a strictly negative value of R0🟉, the model predicts that the infection will vanish exponentially (disappearance scenario). The current study incorporates a large number of earlier works and provides a novel analytical method that can successfully handle numerous stochastic models. This innovative approach can successfully handle a variety of stochastic models in a wide range of applications. For the tempered α-stable processes, the Rosinski (2007) algorithm with a specific Lévy measure is implemented as a numerical application. It is concluded that both noise intensities and parameter α have a great influence on the dynamical transition of the model as well as on the shape of its associated probability density function.

Anticipating the transmissibility of the 2022 mpox outbreak.

An ongoing outbreak of monkeypox virus (MPXV) was first reported in the United Kingdom on 6 May 2022. As of 17 November, there had been a total of 80 221 confirmed MPXV cases in over 110 countries. Based on data reported between 6 May and 30 June 2022 in the United Kingdom, Spain, and Germany, we applied a deep learning approach using convolutional neural networks to evaluate the parameters of the 2022 MPXV outbreak. The basic reproduction number (R0 ) of MPXV was estimated to be 2.32 in the United Kingdom, which indicates the active diffusion of MPXV since the beginning of the outbreak. The data from Spain and Germany produced higher median R0 values of 2.42 and 2.88, respectively. Importantly, the estimated R0 of MPXV in the three countries tends to the previously calculated R0 of smallpox (3.50 to 6.00). Furthermore, the incubation (1/ε) and infectious (1/γ) period was predicted between 9 and 10 days and 4-5 days, respectively. The R0 value derived from MPXV is consistent with the significantly increasing number of cases, indicating the risk of a rapid spread of MPXV worldwide, which would provide important insights for the prevention and control of MPXV epidemic.

Comparing the transmission potential from sequence and surveillance data of 2009 North American influenza pandemic waves.

Technological advancements in phylodynamic modeling coupled with the accessibility of real-time pathogen genetic data are increasingly important for understanding the infectious disease transmission dynamics. In this study, we compare the transmission potentials of North American influenza A(H1N1)pdm09 derived from sequence data to that derived from surveillance data. The impact of the choice of tree-priors, informative epidemiological priors, and evolutionary parameters on the transmission potential estimation is evaluated. North American Influenza A(H1N1)pdm09 hemagglutinin (HA) gene sequences are analyzed using the coalescent and birth-death tree prior models to estimate the basic reproduction number (R 0 ). Epidemiological priors gathered from published literature are used to simulate the birth-death skyline models. Path-sampling marginal likelihood estimation is conducted to assess model fit. A bibliographic search to gather surveillance-based R 0 values were consistently lower (mean≤1.2) when estimated by coalescent models than by the birth-death models with informative priors on the duration of infectiousness (mean≥1.3 to ≤2.88 days). The user-defined informative priors for use in the birth-death model shift the directionality of epidemiological and evolutionary parameters compared to non-informative estimates. While there was no certain impact of clock rate and tree height on the R 0 estimation, an opposite relationship was observed between coalescent and birth-death tree priors. There was no significant difference (p=0.46) between the birth-death model and surveillance R 0 estimates. This study concludes that tree-prior methodological differences may have a substantial impact on the transmission potential estimation as well as the evolutionary parameters. The study also reports a consensus between the sequence-based R 0 estimation and surveillance-based R 0 estimates. Altogether, these outcomes shed light on the potential role of phylodynamic modeling to augment existing surveillance and epidemiological activities to better assess and respond to emerging infectious diseases.

A REE-based zircon geothermometer based on improved lattice strain modeling of zircon-melt REE partition coefficients

Several methods for tracing geological processes based on the rare earth element (REE) concentrations in zircon have been proposed in recent years. Application of these methods requires quantitative knowledge of the partition coefficients (D) for the REE between zircon and co-existing phases, which may be melt, fluid, or other minerals. Precisely determining the DREE of zircon, however, is challenging. This is especially true for the light rare earth elements, which generally occur in very low concentrations in zircon. This difficulty can be overcome by modeling DREE using a prediction function based on the crystal lattice strain model. The prediction function is defined by three empirically derived lattice strain parameters: the apparent Young's Modulus E of the Zr site in which the REE resides; the ionic radius r0 of a (fictive) REE optimally fitting into this site; and the maximum partition coefficient D0 of this optimally fitting REE. In principle, these three parameters can be determined by fitting the prediction function to sets of measured DREE. The ionic radii of the REE, however, are all larger than r0 for zircon, commonly resulting in strain model fits yielding physically unrealistic values of r0, in particular. Here, we use a compilation of zircon-melt REE partition coefficients from the literature to establish a new empirical relationship between r0 and E, which is used as an additional constraint during lattice strain model curve fitting. Lattice strain parameters for literature DREE data sets of natural and synthetic zircon samples are calculated using our constraint resulting in a new parametrization of the inverse temperature dependence of D0. This parametrization enables quantitative estimates of REE-based crystallization temperatures of magmatic zircons, complementing estimates based on Ti-in-zircon geothermometry.

Analysis of COVID-19 mathematical model for predicting the impact of control measures in Rwanda

This paper shows the impact of control measures on the predictive COVID-19 mathematical model in Rwanda through sensitivity analysis of the basic reproduction number R0. We have introduced different levels of the control measures in the model, precisely, 90%, 80%, 60%, 40%, 20%, 0% and studied their effects on the variation of the model variables. The results from numerical simulations reveal that the more the adherence to the control measures at the percentage of 90%, 80%, 60%, 40%, 20%, 0%, the more the number of COVID-19 cases, hospitalized and deaths reduces which indicates the reduction of the spread of the pandemic in Rwanda. Moreover, It was shown that the transition rate from the infectious compartment is very sensitive to R0 as the increase/decrease in its value increases/decreases the value of R0 and this leads to the high spread or the containment of the pandemic respectively.

Comparison of the Basic Reproduction Numbers for COVID-19 through Four Waves of the Pandemic in Vietnam

Estimating the basic reproduction number (R0) of an infectious disease is a crucial step to describe the contagiousness and provides suggestions for interventions. To lift the effectiveness of preventive measures for the COVID-19 pandemic, we need to minimize the newly infected cases by reaching adequate herd immunity. This study thus aimed to compare the R0 through four waves of COVID-19 outbreaks in Vietnam and to calculate the minimal vaccination coverage in different populations. The data on the number of daily confirmed COVID-19 patients were collected from 21 January 2020 to 16 November 2021 from the daily reports through the four waves of the pandemic in Vietnam. The R0 values were estimated by exponential growth and the maximum likelihood methods to range from 1.04 to 3.31 from the first to the third wave. The fourth wave was the most severe, especially in the southern provinces, and the highest R0 was in Ho Chi Minh City. The herd immunity would range from 43.50% to 95.76% by various R0 values from different populations. Overall, the presence of new viral mutants increased the infectiousness and the vaccination coverage was higher to establish the required herd immunity in a high-density population. The results provide the basis for policy recommendations and resource allocation for vaccine management and distribution at a time when the COVID-19 pandemic is not yet over.

FOCAL PARAMETERS of CRIMEAN-BLACK SEA REGION EARTHQUAKES in 2016–2017

Focal parameters of twenty-one 2016–2017 earthquakes of the Crimean-Black sea region with KП=6.5–13.1 have been recovered. Solutions of focal mechanisms have been obtained for the four strongest earthquakes. The dynamic source parameters – scalar seismic moment M0, the radius of circular dislocation r0, released stress , shear deformation , apparent stress ησ, radiation friction r, average slip along fault ū, energy of dislocation formation in the source ЕU, moment magnitude Mw – have been restored for twenty-one earthquakes by 149 amplitude spectra using Brune theoretical dislocation model. The type of slip in the source of May 13, 2016, felt an earthquake, which happened near the southern coast of Crimea, is a strike-slip. The June 28, July 22 and October 15, 2016 earthquakes occurred in the Black sea basin under the action of horizontal compressive stress, the type of slip in the source is a reverse fault. In the source of the June 16, 2017 earthquake, a thrust of active rupture wing occurred under the action of horizontal compression stress of the meridional direction. This type of movement is typical for earthquakes in the eastern part of the Crimean-Black Sea region. The mechanism parameters of these earthquakes were used to determine the direction of the source radiation to the recording station to account for relevant amendments in the calculation of the seismic moment M0. In general, average values of M0 and r0 for 2016–2017 earthquakes were within the confidence intervals of long-term dependencies M0(KП), r0(KП). The best correspondence of seismic moment values to the long-term dependencies was obtained for the earthquakes of the June 28, July 22, October 15, 2016 and June 16, 2017, with known focal mechanisms because the corrections for real radiation direction Rφ were introduced in the formula for M0 calculation. For reliable estimates of the spectral and dynamic source parameters of the 2016–2017 Crimean earthquakes, only very clear records of body waves at seismic stations with reliable characteristics of recording equipment were used. The averaging of the source dynamic parameters was done by 2–10 station definitions, which provided a small value of standard deviations. In this regard, quantitative estimates of focal parameters can be classified as reliable for further use for scientific and scientific-applied problems, in particular, for the development of geodynamic models.

An SIS epidemic model in a patchy environment with pulse vaccination and quarantine

An SIS epidemic model in an m-patch environment with pulse vaccination and quarantine at two different fixed moments is formulated by impulsive differential equations in this paper. The sufficient conditions for the extinction and persistence of the disease are derived and the threshold value R0 is obtained by using the persistence theory of impulsive systems, the impulsive-type Floquet theory and the perturbation techniques. That is, the infection-free periodic solution is globally asymptotically stable if R0<1, and the impulsive system becomes uniformly persistent if R0>1. When m=2, two special cases are considered to illustrate joint impact of the pulse vaccination and quarantine and population mobility on the disease dynamics. Numerical simulations are given to show the effectiveness of the theoretical results.

Estimation of the herd-level basic reproduction number for African swine fever in Vietnam, 2019.

African swine fever (ASF) is a notifiable viral disease of pigs and wild boars that causes severe economic losses to the swine industry. The pig industry in Vietnam was recently attacked by the ASF virus (ASFV) for the first time in history. However, we lack information regarding the transmissibility of ASF within indoor production systems communities, such as those in Vietnam. Therefore, we aimed to estimate the basic reproduction number (R0) for ASF during the early stages of transmission between farms in indoor production system communities from local and national data in Vietnam. The linear regression model approach for the susceptible infectious method was used in this study to estimate the transmission rate and, consequently, the R0 value. The R0 values between-farm of ASF ranged from 1.41 to 10.8 in different scenarios of infectious period duration, from 15 to 30 days at the national and local levels. These results help to understand the scale and speed of ASF infection in Vietnam and to provide a scientific basis to implement control measures to restrict the spread of ASFV in other locations.

Multi-frame blind deconvolution and phase diversity with statistical inclusion of uncorrected high-order modes

Context. Images collected with ground-based telescopes suffer blurring and distortions from turbulence in the Earth’s atmosphere. Adaptive optics (AO) can only partially compensate for these effects. Neither multi-frame blind deconvolution (MFBD) methods nor speckle techniques perfectly restore AO-compensated images to the correct power spectrum and contrast. MFBD methods can only estimate and compensate for a finite number of low-order aberrations, leaving a tail of uncorrected high-order modes. Restoration of AO-corrected data with speckle interferometry depends on calibrations of the AO corrections together with assumptions regarding the height distribution of atmospheric turbulence. Aims. We seek to develop an improvement to MFBD image restoration that combines the use of turbulence statistics to account for high-order modes in speckle interferometry with the ability of MFBD methods to sense low-order modes that can be partially corrected by AO and/or include fixed or slowly changing instrumental aberrations. Methods. We modify the MFBD image-formation model by supplementing the fitted low-order wavefront aberrations with tails of random high-order aberrations. These tails follow Kolmogorov statistics scaled to estimated or measured values of Fried’s parameter, r0, that characterize the strength of the seeing at the moment of data collection. We refer to this as statistical diversity (SD). We test the implementation of MFBD with SD with noise-free synthetic data, simulating many different values of r0 and numbers of modes corrected with AO. Results. Statistical diversity improves the contrasts and power spectra of restored images, both in accuracy and in consistency with varying r0, without penalty in processing time. Together with focus diversity (FD, or traditional phase diversity), the results are almost perfect. SD also reduces errors in the fitted wavefront parameters. MFBD with SD and FD seems to be resistant to errors of several percentage in the assumed r0 values. Conclusions. The addition of SD to MFBD methods shows great promise for improving contrasts and power spectra in restored images. Further studies with real data are merited.

Monkeypox and Pregnancy: Latest Updates.

Monkeypox virus (MPXV) has emerged as a threatening zoonosis. Its spread around the world has been growing fast over the last 2 years, particularly in 2022. The reasons for this sudden spread are probably multifactorial. The R0 values of the two MPXV clades are rather low, and a massive pandemic is considered unlikely, although the increase in the number of single-nucleotide polymorphisms found in the 2022 MPXV strain could indicate an accelerated human adaptation. Very little is known about the risks of an infection during pregnancy for both the mother and the fetus. Further observations must be made to create clear, adapted, evidence-based guidelines. This article summarizes the current knowledge about MPXV infections and similar pregnancy virus infections.

NUMERICAL SIMULATION OF CORONAVIRUS DISEASE EPIDEMIC BASED ON ESTABLISHED SUSCEPTIBLE-EXPOSED-INFECTIOUS-RECOVERED-UNDETECTABLE-SUSCEPTIBLE MODEL

Coronavirus (COVID-19) is the virus which has killed so many people in the world. The spread of COVID-19 within a region in South East Asia has been modelled using a compartment model called SEIR (Susceptible, Exposed, Infected, Recovered). Actual number of sick people needing treatments, or the number active case data was used to obtain realistic values of the model parameter such as the reproduction number (R0), incubation, and recovery periods. It is shown that at the beginning of the pandemic where most people were still not aware, the R0 was very high as seen by the steep increase of people got infected and admitted to the hospitals. Few weeks after the lockdown of the region was in place and people were obeying the regulation and observing safe distancing, the R0 values dropped significantly and converged to a steady value of about 3. Using the obtained model parameters, fitted on a daily basis, the maximum number of active cases converged to a certain value of about 2500 cases. It is expected that in the early June 2020 that the number of active cases will drop to a significantly low level. We Implement SEIR model to enumerate the infected Population and the number of casualties of this pandemic. Numerical Simulations was carried out to set off the analytical results in investigating the effect of the implementation of Isolation and social distancing as a function of time.

State of charge estimation of ultracapacitor based on forgetting factor recursive least square and extended Kalman filter algorithm at full temperature range

State of charge (SOC) of ultracapacitor plays an important role in the energy management optimization of hybrid energy storage system for electric vehicles. In addition to the perfection of the model and the SOC estimation algorithm, the parameter identification method and temperature factor should also be considered. In this paper, an ultracapacitor test platform is established, the characteristic parameters of ultracapacitor at full temperature range are obtained. This paper uses the forgetting factor recursive least squares algorithm (FFRLS) to identify the parameters of the second-order equivalent circuit model of ultracapacitor online. The extended Kalman filter (EKF) algorithm is used to estimate the SOC of ultracapacitor cell. The results show that: (1) FFRLS algorithm can identify R0, R1, R2, C1, and C2 values of ultracapacitor at full temperature range. Under the hybrid pulse power characterization working condition, the average mean absolute error between the estimated voltage and the actual voltage is about 0.0132 V. (2) EKF algorithm has a good adaptability to estimate SOC of ultracapacitor under different temperatures and working conditions. The SOC estimation error under different working conditions is low. From the perspective of mean square error, the estimation error at −20°C is the lowest. (3) FFRLS and EKF joint estimation algorithm with good robustness and reliability can be used to estimate the SOC of ultracapacitor under different temperatures and working conditions. This study can provide a useful guidance for the parameter identification and SOC estimation of ultracapacitor for electric vehicle at different temperatures.