期刊文献+
任意字段
题名或关键词
题名
关键词
摘要
作者
第一作者
机构
刊名
分类号
参考文献
作者简介
基金资助
栏目信息
共找到71篇文章
< 1 2 … 4 >
每页显示 20 50 100
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
显示方式：
The relationship between compartment models and their stochastic counterparts:A comparative study with examples of the COVID-19 epidemic modeling 认领 引用 被引量：1
1
作者 Ziyu Zhao Yi Zhou +6 位作者 Jinxing Guan Yan Yan Jing Zhao Zhihang Peng Feng Chen Yang Zhao Fang Shao 《Journal of Biomedical Research》 CAS CSCD 2024年第2期175-188,I0016-I0018,共14页
Deterministic compartment models(CMs)and stochastic models,including stochastic CMs and agent-based models,are widely utilized in epidemic modeling.However,the relationship between CMs and their corresponding stochast... Deterministic compartment models(CMs)and stochastic models,including stochastic CMs and agent-based models,are widely utilized in epidemic modeling.However,the relationship between CMs and their corresponding stochastic models is not well understood.The present study aimed to address this gap by conducting a comparative study using the susceptible,exposed,infectious,and recovered(SEIR)model and its extended CMs from the coronavirus disease 2019 modeling literature.We demonstrated the equivalence of the numerical solution of CMs using the Euler scheme and their stochastic counterparts through theoretical analysis and simulations.Based on this equivalence,we proposed an efficient model calibration method that could replicate the exact solution of CMs in the corresponding stochastic models through parameter adjustment.The advancement in calibration techniques enhanced the accuracy of stochastic modeling in capturing the dynamics of epidemics.However,it should be noted that discrete-time stochastic models cannot perfectly reproduce the exact solution of continuous-time CMs.Additionally,we proposed a new stochastic compartment and agent mixed model as an alternative to agent-based models for large-scale population simulations with a limited number of agents.This model offered a balance between computational efficiency and accuracy.The results of this research contributed to the comparison and unification of deterministic CMs and stochastic models in epidemic modeling.Furthermore,the results had implications for the development of hybrid models that integrated the strengths of both frameworks.Overall,the present study has provided valuable epidemic modeling techniques and their practical applications for understanding and controlling the spread of infectious diseases. 展开更多
关键词 compartment models agent-based models compartment-agent mixed models comparative study COVID-19
暂未订购 下载PDF
Real-Time Analytical Solutions as Series Formulas and Heaviside off/on Switch Functions for Multiple Intermittent Intravenous Infusions in One- and Two-Compartment Models 认领 引用 被引量：2
2
作者 Michalakis Savva 《Journal of Biosciences and Medicines》 2022年第1期150-189,共40页
Pharmacokinetic compartment models are the only models that can extract pharmacokinetic parameters from data collected in clinical studies but their estimates lack accuracy, explanations and physiological significance... Pharmacokinetic compartment models are the only models that can extract pharmacokinetic parameters from data collected in clinical studies but their estimates lack accuracy, explanations and physiological significance. The objective of this work was to develop particular solutions to drug concentration and AUC in the form of mathematical series and Heaviside functions for repetitive intermittent infusions in the one- and two-compartment models, as a function of dose number and total time using differential calculus. It was demonstrated that the central and peripheral compartment volumes determined from regression analysis of the aminoglycoside antibiotic Sisomicin concentration in plasma represent the actual physiological body fluid volumes accessible by the drug. The drug peak time and peak concentration in the peripheral compartment were also calculated as a function of dose number. It is also shown that the time of intercompartmental momentary distribution equilibrium can be used to determine the drug’s apparent volume of distribution within any dosing interval in multi-compartment models. These estimates were used to carry out simulations of plasma drug concentration with time in the one-compartment model. In conclusion, the two-compartment open mammillary pharmacokinetic model was fully explained for the aminoglycoside antibiotic sisomicin through the new concept of the apparent volume of distribution. 展开更多
关键词 Pharmacokinetics Intermittent Intravenous Infusion Multiple Doses Compartment Models Heaviside Function Apparent Volume of Distribution
暂未订购 下载PDF
The Presence of Phases and the Inability of the Classical Compartment Models to Provide Pharmacokinetic Parameters of Physiological Significance for Lipophilic Drugs 认领 引用
3
作者 Michalakis Savva 《Journal of Biosciences and Medicines》 2022年第4期1-13,共13页
The first biphasic open one-compartment pharmacokinetic model is described. Its analytical solutions to drug concentration were developed from parameters of an open two-compartment pharmacokinetic model. The model is ... The first biphasic open one-compartment pharmacokinetic model is described. Its analytical solutions to drug concentration were developed from parameters of an open two-compartment pharmacokinetic model. The model is used to explain the unusually large compartment volumes and apparent volumes of distribution of lipophilic drugs, as well as to identify which of the pharmacokinetic parameters of the classical compartment models are biologically relevant. 展开更多
关键词 Lipophilic Drugs Pharmacokinetic Compartment Model Apparent Volume of Distribution Clearance Prazosin Doxazosin Digoxin Pindolol
暂未订购 下载PDF
A Tutorial on Common Differential Equations and Solutions Useful for Modeling Epidemics Like COVID-19: Linear and Non-Linear Compartmentation Models 认领 引用
4
作者 Robert V. Mulkern Reyhaneh Nosrati 《Journal of Applied Mathematics and Physics》 2022年第10期3053-3071,共19页
Purpose: To review some of the basic models, differential equations and solutions, both analytic and numerical, which produce time courses for the fractions of Susceptible (S), Infectious (I) and Recovered (R) fractio... Purpose: To review some of the basic models, differential equations and solutions, both analytic and numerical, which produce time courses for the fractions of Susceptible (S), Infectious (I) and Recovered (R) fractions of the population during the epidemic and/or endemic conditions. Methods: Two and three-compartment models with analytic solutions to the proposed linear differential equations as well as models based on the non-linear differential equations first proposed by Kermack and McKendrick (KM) [1] a century ago are considered. The equations reviewed include the ability to slide between so-called Susceptible-Infected-Recovered (SIR), Susceptible-Infectious-Susceptible (SIS), Susceptible-Infectious (SI) and Susceptible-Infectious-Recovered-Susceptible (SIRS) models, effectively moving from epidemic to endemic characterizations of infectious disease. Results: Both the linear and KM model yield typical “curves” of the infected fraction being sought “to flatten” with the effects of social distancing/masking efforts and/or pharmaceutical interventions. Demonstrative applications of the solutions to fit real COVID-19 data, including linear and KM SIR fit data from the first 100 days following “lockdown” in the authors’ locale and to the total number of cases in the USA over the course of 1 year with SI and SIS models are provided. Conclusions: COVID-19 took us all by surprise, all wondering how to help. Spreading a basic understanding of some of the mathematics used by epidemiologists to model infectious diseases seemed like a good place to start and served as the primary purpose for this tutorial. 展开更多
关键词 COVID-19 Differential Equations Modelling Compartment Model
暂未订购 下载PDF
A Comprehensive Comparison of Transition Point Detection Methods for Monkeypox--Africa,2024-2025 认领 引用
5
作者 Mengshou Wang Zibin Yu +1 位作者 Ling Yin Liu Hong 《China CDC weekly》 SCIE CSCD 2026年第20期604-608,I0004-I0007,共5页
Introduction:Global mpox outbreaks pose a significant public health challenge.Accuracy predicting transition points can guide containment measures.However,different forecasting methods identified distinct types of tra... Introduction:Global mpox outbreaks pose a significant public health challenge.Accuracy predicting transition points can guide containment measures.However,different forecasting methods identified distinct types of transition points,making it essential to clarify their applicability.Methods:Using World Health Organization(WHO)mpox outbreak data,this study employed both compartmental epidemic models and network models for simulation.Four transition point detection methods,dynamic network biomarkers(DNB),Network Information Gain(NIG),Temporal Change Point Detection(TCD),and Spatial-Temporal Principal Component Analysis(stPCA),were applied for predictions.Results:The study revealed that NIG-and DNBbased methods were more suitable for detecting the peak timing of new cases,the epidemiological inflection point,while TCD and stPCA were more applicable for identifying the point of maximum acceleration in case incidence.These findings were validated in three African countries with high outbreak intensities too.Conclusion:NIG and DNB can predict the peak timing of new mpox cases,whereas TCD and stPCA are suitable for forecasting the point of maximum acceleration in case incidence.These approaches enable more rational allocation of epidemic control resources and timely adjustment of containment measures,offering critical insights for managing mpox outbreaks. 展开更多
关键词 compartmental epidemic models network biomarkers dnb network network models transition point detection transition point monkeypox dynamic network biomarkers network information gain
PERTURBATION SOLUTION FOR COMPARTMENT MODEL OF VARIABLE EXTRACELLULAR VOLUME 认领 引用
6
作者 张凤宝 张国亮 +1 位作者 李明 王淑兰 《Transactions of Tianjin University》 CAS 1997年第2期72-76,共5页
The two compartment model with variable extracellular volume is presented and solved by using both perturbation and analytical method. The computation for both creatinine and urea show that the perturbation solution i... The two compartment model with variable extracellular volume is presented and solved by using both perturbation and analytical method. The computation for both creatinine and urea show that the perturbation solution is not only simple but also accurate enough and is a good substitute for the more exact analytical solution. 展开更多
关键词 hemodialysis two compartment model ultrafiltration perturbation solution
暂未订购 下载PDF
Estimating Hydrogeological Parameters in Covered Carbonate Rocks Using a Discrete-State Compartment Model and Environmental Tritium 认领 引用 被引量：1
7
作者 马志远 周寅康 Matthias Hinderer 《Journal of China University of Mining and Technology》 2002年第1期30-34,共5页
Nowadays, isotope environmental technique tends to be used as a reconnaissance tool , both qualitative and quantitative, to calculate the aquifer parameters particularly in carbonate rock aquifers. But, the heterogene... Nowadays, isotope environmental technique tends to be used as a reconnaissance tool , both qualitative and quantitative, to calculate the aquifer parameters particularly in carbonate rock aquifers. But, the heterogeneous flow is still problematic when Lumped parameter Models are usually used to calculate the residence times and hydraulic parameters. However, Discrete State Compartment Model can provide a powerful model to heterogeneous medium. One such study was carried on in Dazha valley, where the environmental tritium was used as a tracer for determining hydrogeological parameters based on a discrete state compartment model 展开更多
关键词 discrete state compartment model environmental tritium covered carbonate rocks hydraulic parameters residence time concentration of tritium tracer
暂未订购 下载PDF
A Reevaluation of Prazosin Pharmacokinetics in a Two-Compartment Model, the Apparent Volume of Distribution and Comparative Simulations in the One-Compartment Model 认领 引用 被引量：2
8
作者 Michalakis Savva Xudong Yuan 《Journal of Biosciences and Medicines》 2022年第1期108-140,共33页
Published clinical data of Prazosin were reevaluated pharmacokinetically using explicit solutions to drug concentration as a function of total time for IV bolus injection, intermittent intravenous infusion and oral ro... Published clinical data of Prazosin were reevaluated pharmacokinetically using explicit solutions to drug concentration as a function of total time for IV bolus injection, intermittent intravenous infusion and oral routes of administration in an open two-compartment model. In a novel way, the apparent volume of distribution was estimated from a two-compartment model and found to be close to the total body water suggesting that Prazosin is distributed in all tissues both extracellularly and intracellularly. In addition, extracting the value of the apparent volume of distribution from a two-compartment model allowed comparative simulations in the one-compartment model. It is shown that dosage calculations of Prazosin intermittent infusion can be safely performed using the simpler one-compartment model equations. Lastly, several additional time-dependent pharmacokinetic parameters e.g., the peak time in the central and peripheral compartment and non-steady state and steady state peak concentration and AUC were determined using series equations for all three routes of administration, as a function of dose number and total time upon multiple drug administrations in the two-compartment model. It is also the first time that steady-state plasma drug concentration equations were derived in a two-compartment mammillary model. 展开更多
关键词 Prazosin Pharmacokinetics Intravenous Bolus Intermittent Infusion Oral Dose Multiple Doses Compartment Model Apparent Volume of Distribution
暂未订购 下载PDF
A compartmental model of variant coexistence,dynamics and dominance in infectious diseases:Case for SARS-CoV-2 in Abu Dhabi 认领 引用
9
作者 Mauricio Patón Mireille Hantouche +3 位作者 Farida Al-Hosani Amrit Sadani Jorge Rodríguez Rowan Abuyadek 《Infectious Disease Modelling》 CSCD 2026年第1期310-324,共15页
In recent years,the rapid mutation of SARS-CoV-2 has led to the emergence of new variants.Despite advancements in pandemic control,these new variants could pose substantial public health issues.This study introduces a... In recent years,the rapid mutation of SARS-CoV-2 has led to the emergence of new variants.Despite advancements in pandemic control,these new variants could pose substantial public health issues.This study introduces a comprehensive compartmental model that can handle multiple virus variants and population groups.The model also factors the influence of international visitors,per variant and group,on the population,which is pertinent for populations with a high ratio of incoming travellers.The model was applied to simulate the coexistence of different variants in the Emirate of Abu Dhabi from August 2022 until March 2023.Calibration was conducted using the data available from Abu Dhabi health authorities and international data from GISAID to estimate the prevalence of each variant.The model seems to effectively depict the temporal coexistence of multiple strains and,ultimately,the rise of a dominant variant.The simulation results from Abu Dhabi indicate that the XBB variant became the dominant strain by the end of the simulation period.The calibrated parameters for the XBB variant suggest that its dominance can be attributed to its superior ability to evade immunity and its increased infectiousness,estimated to be approximately 15%more than the BQ.1 variant.The introduction of the XBB variant through infected visitors further amplified its emergence. 展开更多
关键词 dynamics variant coexistence comprehensive compartmental model compartmental model SARS CoV Abu Dhabi international visitors dominance
Nitrogen cycle of a typical Suaeda salsa marsh ecosystem in the Yellow River estuary 认领 引用 被引量：16
10
作者 Xiaojie Mou Zhigao Sun +1 位作者 Lingling Wang Chuanyuan Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第6期958-967,共10页
The nitrogen（N） biological cycle of the Suaeda salsa marsh ecosystem in the Yellow River estuary was studied during 2008 to 2009.Results showed that soil N had significant seasonal fluctuations and vertical distribu... The nitrogen（N） biological cycle of the Suaeda salsa marsh ecosystem in the Yellow River estuary was studied during 2008 to 2009.Results showed that soil N had significant seasonal fluctuations and vertical distribution.The N/P ratio（15.73±1.77） of S.salsa was less than 16,indicating that plant growth was limited by both N and P.The N absorption coefficient of S.salsa was very low（0.007）,while the N utilization and cycle coefficients were high（0.824 and 0.331,respectively）.The N turnover among compartments of S.salsa marsh showed that N uptake from aboveground parts and roots were 2.539 and 0.622 g/m2,respectively.The N translocation from aboveground parts to roots and from roots to soil were 2.042 and 0.076 g/m2,respectively.The N translocation from aboveground living bodies to litter was 0.497 g/m2,the annual N return from litter to soil was far less than 0.368 g/m2,and the net N mineralization in topsoil during the growing season was 0.033 g/m2.N was an important limiting factor in S.salsa marsh,and the ecosystem was classified as unstable and vulnerable.S.salsa was seemingly well adapted to the low-nutrient status and vulnerable habitat,and the nutrient enrichment due to N import from the Yellow River estuary would be a potential threat to the S.salsa marsh.Excessive nutrient loading might favor invasive species and induce severe long-term degradation of the ecosystem if human intervention measures were not taken.The N quantitative relationships determined in our study might provide a scientific basis for the establishment of effective measures. 展开更多
关键词 compartment model nitrogen biological cycle Suaeda salsa Yellow River estuary
暂未订购 下载PDF
Numerical simulation of flow regions in red mud separation thickener's feedwell by analysis of residence-time distribution 认领 引用 被引量：10
11
作者 周天 李茂 +3 位作者 李秋龙 雷波 周谦 周孑民 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第4期1117-1124,共8页
The residence-time distribution （RTD） and the compartment model were applied to characterizing the flow regions in red mud separation thickener’s feedwells. Combined with the experimental work, validated mathematic... The residence-time distribution （RTD） and the compartment model were applied to characterizing the flow regions in red mud separation thickener’s feedwells. Combined with the experimental work, validated mathematical model as well as three-dimensional computational fluid dynamics （CFD） model was established to analyze the flow regions of feedwells on an industrial scale. The concept of RTD, although a well-known method for the characterization of mixing behavior in conventional mixers and reactors, is still a novel measure for the characterization of mixing in feedwells. Numerical simulation results show that the inlet feed rate and the aspect ratio of feedwells are the most critical parameters which affect the RTD of feedwell. Further simulation experiments were then carried out. Under the optimal operation conditions, the volume fraction of dead zone can reduce by10.8% and an increasement of mixing flow volume fraction by 6.5% is also observed. There is an optimum feed inlet rate depending on the feedwell design. The CFD model in conjunction with the RTD analysis then can be used as an effective tool in the design, evaluation and optimization of thickener feedwell in the red mud separation. 展开更多
关键词 computational fluid dynamics residence-time distribution compartment model feedwell
暂未订购 下载PDF
A high performance liquid chromatography method for the quantitative determination of ribavirin in human plasma and its application in a pharmacokinetics study 认领 引用 被引量：4
12
作者 张华 王桂玲 +2 位作者 李可欣 张烜 张强 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2013年第4期361-364,共4页
The clinical pharmacokinetics of ribavirin after a single oral dose of 600 mg ribavirin tablets in healthy Chinese volunteers was studied. A rapid and simple high performance liquid chromatography （HPLC） method was ... The clinical pharmacokinetics of ribavirin after a single oral dose of 600 mg ribavirin tablets in healthy Chinese volunteers was studied. A rapid and simple high performance liquid chromatography （HPLC） method was developed to determine the ribavirin concentration in human plasma. C18 column was used for separation with a column temperature of 25℃, the mobile phase was ultrapure water adjusted to pH 3 with acetic acid at the flow rate of 1 mL/min, and the detection wavelength was set at 207 rim. The linear range of the standard curves was 50.4-2016.0 ng/mL and the lower limit of quantification （LLOQ） was 50.4 ng/mL. The relative recoveries of ribavirin were more than 90% in plasma. The RSD of the intra-day precision was less than 10% and that of inter-day was less than 15%. The pharmacokinetic parameters of ribavirin were calculated by WinNonlin. Results indicated that the two-compartment model was a better model for describing the pharmacokinetics profile of ribavirin than one-compartment model. The AUC0-t was 10807.8 h.ng/mL, the CL/F was 64879.5 mL, and the Cmax was 525.1 ng/mL. These results provided the experimental data for the development of ribavirin dosage form. 展开更多
关键词 Ribavirin HPLC Pharmacokinetics Compartmental model
暂未订购 下载PDF
Nitrogen cycling of atmosphere-plant-soft system in the typical Calamagrostis angustifolia wetland in the Sanjiang Plain,Northeast China 认领 引用 被引量：13
13
作者 SUN Zhi-gao LIU Jing-shuang 《Journal of Environmental Sciences》 SCIE EI CAS 2007年第8期986-995,共10页
The nitrogen （N） distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland （TMCW） and marsh meadow Calamagrostis angustifolia wetland （MMCW） in the Sanjian... The nitrogen （N） distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland （TMCW） and marsh meadow Calamagrostis angustifolia wetland （MMCW） in the Sanjiang plain were studied by a compartment model. The results showed that the N wet deposition amount was 0.757 gN/（m^2·a）, and total inorganic N （TIN） was the main body （0.640 gN/（m^2·a））. The ammonia volatilization amounts of TMCW and MMCW soils in growing season were 0.635 and 0.687 gN/m^2, and the denitrification gaseous lost amounts were 0.617 and 0.405 gN/m^2, respectively. In plant subsystem, the N was mainly stored in root and litter. Soil organic N was the main N storage of the two plant-soil systems and the proportions of it were 93.98% and 92.16%, respectively. The calculation results of N turnovers among compartments of TMCW and MMCW showed that the uptake amounts of root were 23.02 and 28.18 gN/（m^2·a） and the values of aboveground were 11.31 and 6.08 gN/（m^2·a）, the re-translocation amounts from aboveground to root were 5.96 and 2.70 gN/（m^2·a）, the translocation amounts from aboveground living body to litter were 5.35 and 3.38 gN/（m^2·a）, the translocation amounts from litter to soil were larger than 1.55 and 3.01 gN/（m^2·a）, the translocation amounts from root to soil were 14.90 and 13.17 gN/（m^2·a）, and the soil （0-15 cm） N net mineralization amounts were 1.94 and 0.55 gN/（m^2·a）, respectively. The study of N balance indicated that the two plant-soil systems might be situated in the status of lacking N, and the status might induce the degradation of C. angustifolia wetland. 展开更多
关键词 compartment model nitrogen cycling Calamagrostis angustifolia wetland ecosystem Sanjiang Plain
暂未订购 下载PDF
Assessment of the Benefits of Targeted Interventions for Pandemic Control in China Based on Machine Learning Method and Web Service for COVID-19 Policy Simulation 认领 引用 被引量：3
14
作者 WU Jie Wen JIAO Xiao Kang +7 位作者 DU Xin Hui JIAO Zeng Tao LIANG Zuo Ru PANG Ming Fan JI Han Ran CHENG Zhi Da CAI Kang Ning QI Xiao Peng 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2022年第5期412-418,共7页
Taking the Chinese city of Xiamen as an example,simulation and quantitative analysis were performed on the transmissions of the Coronavirus Disease 2019(COVID-19)and the influence of intervention combinations to assis... Taking the Chinese city of Xiamen as an example,simulation and quantitative analysis were performed on the transmissions of the Coronavirus Disease 2019(COVID-19)and the influence of intervention combinations to assist policymakers in the preparation of targeted response measures.A machine learning model was built to estimate the effectiveness of interventions and simulate transmission in different scenarios.The comparison was conducted between simulated and real cases in Xiamen.A web interface with adjustable parameters,including choice of intervention measures,intervention weights,vaccination,and viral variants,was designed for users to run the simulation.The total case number was set as the outcome.The cumulative number was 4,614,641 without restrictions and 78 under the strictest intervention set.Simulation with the parameters closest to the real situation of the Xiamen outbreak was performed to verify the accuracy and reliability of the model.The simulation model generated a duration of 52 days before the daily cases dropped to zero and the final cumulative case number of 200,which were 25 more days and 36 fewer cases than the real situation,respectively.Targeted interventions could benefit the prevention and control of COVID-19 outbreak while safeguarding public health and mitigating impacts on people’s livelihood. 展开更多
关键词 COVID-19 Intervention policy simulation Machine learning Compartment model
暂未订购 下载PDF
Parameter optimization of pharmacokinetics based on artificial immune network 认领 引用 被引量：2
15
作者 刘丽 周少丹 +2 位作者 卢红文 谢芬 须文波 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第4期549-558,共10页
A new method for parameter optimization of pharmacokinetics based on an artificial immune network named PKAIN is proposed. To improve local searching ability of the artificial immune network, a partition-based concurr... A new method for parameter optimization of pharmacokinetics based on an artificial immune network named PKAIN is proposed. To improve local searching ability of the artificial immune network, a partition-based concurrent simplex mutation is developed. By means of evolution of network cells in the PKAIN artificial immune network, an optimal set of parameters of a given pharmacokinetic model is obtained. The Laplace transform is applied to the pharmacokinetic differential equations of remifentanil and its major metabolite, remifentanil acid. The PKAIN method is used to optimize parameters of the derived compartment models. Experimental results show that the twocompartment model is sufficient for the pharmacokinetic study of remifentanil acid for patients with mild degree of renal impairment. 展开更多
关键词 artificial immune network pharmacokinetics compartment model simplex remifentanil
暂未订购 下载PDF
Sorption and desorption kinetics of phthalates and phenol on water/sediment interface 认领 引用 被引量：1
16
作者 Ye Changming, Zhao Wushan, Li Tie, Lei Zhifang, Yan Hai Research Center for Eco Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China 《Journal of Environmental Sciences》 SCIE CAS 1997年第3期84-91,共8页
The sorption and desorption kinetics of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP) and phenol on water and sediment interface were studied using two compartment model in this paper. The... The sorption and desorption kinetics of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP) and phenol on water and sediment interface were studied using two compartment model in this paper. The results showed that the sorption coefficients of DMP, DEP, DBP and phenol measured by batch equilibrium method were 16.79, 24.55, 132 and 0.65μg 1-1 · g -1 · ml -1 , the sorption and desorption kinetic constants of DMP, DEP, DBP, phenol were 0.0248, 0.0357, 0.0727, 0.014ml·cm -2 ·h -1 and 0.000512, 0.000754, 0.00127, 0 000899h -1 at static condition respectively; and the sorption and desorption kinetics constants of above chemicals were 0 279, 0.382, 0.496, 0.0904ml·cm -2 ·h -1 and 0.0442, 0.0031, 0.00116, 0.00247h -1 at flow water condition respectively. 展开更多
关键词 sorption desorption kinetics phthalate esters phenol two compartment model.
暂未订购 下载PDF
Approximations of Quasi-Stationary Distributions of the Stochastic SVIRModel for the Measles 认领 引用 被引量：1
17
作者 Moussa Seydou Moussa Tessa 《Journal of Applied Mathematics and Physics》 2021年第9期2277-2289,共13页
In this paper, we analyze the quasi-stationary distribution of the stochastic SVIR (Susceptible, Vaccinated, Infected, Recovered) model for the measles. The quasi-stationary distributions, as discussed by Danoch and S... In this paper, we analyze the quasi-stationary distribution of the stochastic SVIR (Susceptible, Vaccinated, Infected, Recovered) model for the measles. The quasi-stationary distributions, as discussed by Danoch and Seneta, have been used in biology to describe the steady state behaviour of population models which exhibit discernible stationarity before to become extinct. The stochastic SVIR model is a stochastic SIR (Susceptible, Infected, Recovered) model with vaccination and recruitment where the disease-free equilibrium is reached, regardless of the magnitude of the basic reproduction number. But the mean time until the absorption (the disease-free) can be very long. If we assume the effective reproduction number Rp , the quasi-stationary distribution can be closely approximated by geometric distribution. β and δ stands respectively, for the disease transmission coefficient and the natural rate. 展开更多
关键词 Compartment Models SIR Markov Chains Stochastic Simulation Basic Reproduction Number Quasi-Stationary Distribution Measles
暂未订购 下载PDF
A Bayesian model calibration framework for stochastic compartmental models with both time-varying and timeinvariant parameters 认领 引用 被引量：2
18
作者 Brandon Robinson Philippe Bisaillon +4 位作者 Jodi D.Edwards Tetyana Kendzerska Mohammad Khalil Dominique Poirel Abhijit Sarkar 《Infectious Disease Modelling》 CSCD 2024年第4期1224-1249,共26页
We consider state and parameter estimation for compartmental models having both timevarying and time-invariant parameters.In this manuscript,we first detail a general Bayesian computational framework as a continuation... We consider state and parameter estimation for compartmental models having both timevarying and time-invariant parameters.In this manuscript,we first detail a general Bayesian computational framework as a continuation of our previous work.Subsequently,this framework is specifically tailored to the susceptible-infectious-removed(SIR)model which describes a basic mechanism for the spread of infectious diseases through a system of coupled nonlinear differential equations.The SIR model consists of three states,namely,the susceptible,infectious,and removed compartments.The coupling among these states is controlled by two parameters,the infection rate and the recovery rate.The simplicity of the SIR model and similar compartmental models make them applicable to many classes of infectious diseases.However,the combined assumption of a deterministic model and time-invariance among the model parameters are two significant impediments which critically limit their use for long-term predictions.The tendency of certain model parameters to vary in time due to seasonal trends,non-pharmaceutical interventions,and other random effects necessitates a model that structurally permits the incorporation of such time-varying effects.Complementary to this,is the need for a robust mechanism for the estimation of the parameters of the resulting model from data.To this end,we consider an augmented state vector,which appends the time-varying parameters to the original system states whereby the time evolution of the time-varying parameters are driven by an artificial noise process in a standard manner.Distinguishing between time-varying and time-invariant parameters in this fashion limits the introduction of artificial dynamics into the system,and provides a robust,fully Bayesian approach for estimating the timeinvariant system parameters as well as the elements of the process noise covariance matrix.This computational framework is implemented by leveraging the robustness of the Markov chain Monte Carlo algorithm permits the estimation of time-invariant parameters while nested nonlinear filters concurrently perform the joint estimation of the system states and time-varying parameters.We demonstrate performance of the framework by first considering a series of examples using synthetic data,followed by an exposition on public health data collected in the province of Ontario. 展开更多
关键词 Time-varying parameter estimation Bayesian inference Stochastic compartmental models
Temporal patterns of storage and flux of N and P in young Teak plantations of tropical moist deciduous forest,India 认领 引用 被引量：2
19
作者 Kaushalendra Kumar Jha 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第1期75-86,共12页
Teak （Tectona grandis Linn. f.） ranks among the top five tropical hardwood species and is being promoted for use in plantations in its non-native range due to its high economic value. However, there is a general lac... Teak （Tectona grandis Linn. f.） ranks among the top five tropical hardwood species and is being promoted for use in plantations in its non-native range due to its high economic value. However, there is a general lack of data on ecosystem functioning of teak plantations. We aimed at understanding storage and flux of nutrients related to young plantations of teak. Cycling of nitrogen （N） and phosphorus （P） in a chronosequence of plantations （1, 5, 11, 18, 24 and 30 years） was studied in the Moist Deciduous Forest Region of North India with the objective of investigating the nutrient cycling pattern at younger age since the current trend of harvesting age of the species in several tropical countries is being drastically reduced for quick return from this high value crop. Standing state, nutrient uptake, nutrient return and nutrient retransloca-tion in these plantations were estimated by tree harvesting and chemical analysis methods. The range of total standing nutrient across all these plantations was 20.3 to 586.6 kg？ha-1 for N and 5.3 to 208.8 kg？ha-1 for P. Net uptake of N ranged from 19.4 to 88.9 kg？ha-1？a-1 and P from 3.8 to 18.1 kg？ha-1？a-1. Retranslocation of N and P among all the stands ranged from 8.7 to 48.0 kg？ha-1？a-1 and 0.01 to 3.5 kg？ha-1？a-1, respectively. Range of total nutrient return was 25.8 to 91.3 kg？ha-1？a-1 for N and 2.7 to 10.1 kg？ha-1？a-1 for P. N and P use efficiency was between 107.4 and 192.5 g dry organic matter （OM） g-1N, and 551.9 and 841.1 g OM g-1P, respec-tively. The turnover time ranged from 2.04-13.17 years for N and be-tween 2.40-22.66 years for P. Quantity of N and P in the soil nutrient pool ranged from 2566.8 to 4426.8 kg？ha-1 and 372 to 520 kg？ha-1, re-spectively. Storage and flux of components in different plant parts of different aged plantations were assessed and depicted in compartment models. Percentage storage in soil, litter and vegetation ranged from 82% to 99%, 0.6% to 2.4% and 0.5% to 15% for N, respectively, and from 63% to 98%, 0.5% to 2% and 1% to 35% for P, respectively. This infor-mation could be useful in managing external nutrient manipulation to crops of different ages for optimum biomass production or carbon se-questration. 展开更多
关键词 nutrient uptake standing state return turnover time nutrient use efficiency compartment model harvest loss Tectona grandis
暂未订购 下载PDF
Switched forced SEIRDV compartmental models to monitor COVID-19 spread and immunization in Italy 认领 引用
20
作者 Erminia Antonelli Elena Loli Piccolomini Fabiana Zama 《Infectious Disease Modelling》 CSCD 2022年第1期1-15,共15页
This paper presents a new hybrid compartmental model for studying the COVID-19 epidemic evolution in Italy since the beginning of the vaccination campaign started on 2020/12/27 and shows forecasts of the epidemic evol... This paper presents a new hybrid compartmental model for studying the COVID-19 epidemic evolution in Italy since the beginning of the vaccination campaign started on 2020/12/27 and shows forecasts of the epidemic evolution in Italy in the first six months.The proposed compartmental model subdivides the population into six compartments and extends the SEIRD model proposed in[E.L.Piccolomini and F.Zama,PLOS ONE,15(8):1e17,082020]by adding the vaccinated population and framing the global model as a hybridswitched dynamical system.Aiming to represent the quantities that characterize the epidemic behaviour from an accurate fit to the observed data,we partition the observation time interval into sub-intervals.The model parameters change according to a switching rule depending on the data behaviour and the infection rate continuity condition.In particular,we study the representation of the infection rate both as linear and exponential piecewise continuous functions.We choose the length of sub-intervals balancing the data fit with the model complexity through the Bayesian Information Criterion.We tested the model on italian data and on local data from Emilia-Romagna region.The calibration of the model shows an excellent representation of the epidemic behaviour in both cases.Thirty days forecasts have proven to well reproduce the infection spread,better for regional than for national data.Both models produce accurate predictions of infected,but the exponential-based one perform better in most of the cases.Finally,we discuss different possible forecast scenarios obtained by simulating an increased vaccination rate. 展开更多
关键词 Compartmental model with vaccine SEIRDV Switched model Hybrid model Forcing function Model calibration
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
上一页 1 2 … 4 下一页 到第 页
在线咨询 使用帮助 返回顶部 意见反馈