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Total 29 records

    Descriptive epidemiology of traumatic injuries in 18890 adults: A 5-year-study in a tertiary trauma center in Iran

    , Article Asian Journal of Sports Medicine ; Volume 6, Issue 1 , 2015 ; 2008000X (ISSN) Mehrpour, S. R ; Nabian, M. H ; Oryadi Zanjani, L ; Foroughmand Araabi, M. H ; Shahryar Kamrani, R ; Sharif University of Technology
    Abstract
    Background: Basic epidemiological data can provide estimates when discussing disease burden and in the planning and provision of healthcare strategies. There is little quantitative information in the literature regarding prevalence of traumatic injuries from developing countries. Objectives: The aim of the current preliminary study was to reveal the prevalence and age and gender distribution of various traumatic injuries in a tertiary referral orthopedic hospital in Iran. Patients and Methods: In a prospective descriptive study, all traumatic injured patients attending the Orthopedic Trauma Unit of our center in a five year period were included. Demographic details, the cause of injury,... 

    Control of diseases epidemic spreading through metapopulation models

    , Article International Journal of Control Theory and Applications ; Volume 8, Issue 2 , 2015 , Pages 769-784 ; 09745572 (ISSN) Afshar, M ; Razvan, M. R ; Sharif University of Technology
    International Sciences Press  2015
    Abstract
    We study a system of ordinary differential equations which describes the metapopulation SIR model. The main target is to control the epidemic spreading using the structure of connections between cities. For this purpose, we formulate optimal control strategy that the control represents a drug treatment and Prevention strategies . Some methods are given in numerical example section such as control through spectral radius of movement matrix or optimal control through travelling between cities. Existence results for the optimal control are studied  

    Global trends of hand and wrist trauma: A systematic analysis of fracture and digit amputation using the Global Burden of Disease 2017 Study

    , Article Injury Prevention ; 2020 Crowe, C. S ; Massenburg, B.B ; Morrison, S.D ; Chang, J ; Friedrich, J.B ; Abady, G.G ; Alahdab, F ; Alipour, V ; Arabloo, J ; Asaad, M ; Banach, M ; Bijani, A ; Borzì, A.M ; Briko, N.I ; Castle, C.D ; Cho, D.Y ; Chung, M.T ; Daryani, A ; Demoz, G.T ; Dingels, Z.V ; Do, H.T ; Fischer, F ; Fox, J.T ; Fukumoto, T ; Gebre, A.K ; Gebremichael, B ; Haagsma, J.A ; Haj-Mirzaian, A ; Handiso, D.W ; Hay, S.I ; Hoang, C.L ; Irvani, S.S.N ; Jozwiak, J.J ; Kalhor, R ; Kasaeian, A ; Khader, Y.S ; Khalilov, R ; Khan, E.A ; Khundkar, R ; Kisa, S ; Kisa, A ; Liu, Z ; Majdan, M ; Manafi, N ; Manafi, A ; Manda, A.-L ; Meretoja, T.J ; Miller, T.R ; Mohammadian Hafshejani, A ; Mohammadpourhodki, R ; Mohseni Bandpei, M.A ; Mokdad, A.H ; Naimzada, M.D ; Ndwandwe, D.E ; Nguyen, C.T ; Nguyen, H.L.T ; Olagunju, A.T ; Olagunju, T.O ; Pham, H.Q ; Pribadi, D.R.A ; Rabiee, N ; Ramezanzadeh, K ; Ranganathan, K ; Roberts, N.L.S ; Roever, L ; Safari, S ; Samy, A.M ; Sanchez Riera, L ; Shahabi, S ; Smarandache, C.-G ; Sylte, D.O ; Tesfay, B.E ; Tran, B.X ; Ullah, I ; Vahedi, P ; Vahedian Azimi, A ; Vos, T ; Woldeyes, D. H ; Wondmieneh, A. B ; Zhang, Z. J ; James, S. L ; Sharif University of Technology
    BMJ Publishing Group  2020
    Abstract
    Background: As global rates of mortality decrease, rates of non-fatal injury have increased, particularly in low Socio-demographic Index (SDI) nations. We hypothesised this global pattern of non-fatal injury would be demonstrated in regard to bony hand and wrist trauma over the 27-year study period. Methods: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 was used to estimate prevalence, age-standardised incidence and years lived with disability for hand trauma in 195 countries from 1990 to 2017. Individual injuries included hand and wrist fractures, thumb amputations and non-thumb digit amputations. Results: The global incidence of hand trauma has only modestly... 

    Global analysis of a model of differential susceptibility induced by genetics

    , Article Nonlinear Analysis: Real World Applications ; Volume 12, Issue 4 , 2011 , Pages 2183-2197 ; 14681218 (ISSN) Razvan, M. R ; Yasaman, S ; Sharif University of Technology
    2011
    Abstract
    This paper is concerned with global analysis of an SIS epidemiological model in a population of varying size with two dissimilar groups of susceptible individuals. We prove that this system has no periodic solutions and use the Poincar index theorem to determine the number of rest points and their stability properties. It has been shown that multiple equilibria (bistability) occurs for suitable values of parameters. We also give some numerical examples of all possible bifurcations of this system  

    Global analysis of a delay SVEIR epidemiological model

    , Article Iranian Journal of Science and Technology, Transaction A: Science ; Volume 37, Issue A4 , 2013 , Pages 483-489 ; 10286276 (ISSN) Farajzadeh Tehrani, N ; Razvan, M. R ; Yasaman, S ; Sharif University of Technology
    2013
    Abstract
    This paper is concerned with global analysis of a delay SVEIR epidemiological model in a population of varying size. By using Lyapunov stability method and LaSalle's invariance principle for delay systems, we prove that when there is no endemic equilibrium, the disease free equilibrium is globally asymptotically stable, otherwise the endemic equilibrium is globally stable  

    Global dynamics of a differential susceptibility model

    , Article International Journal of Biomathematics ; Volume 5, Issue 5 , September , 2012 ; 17935245 (ISSN) Razvan, M. R ; Yasaman, S ; Sharif University of Technology
    2012
    Abstract
    An SIS epidemiological model in a population of varying size with two dissimilar groups of susceptible individuals has been analyzed. We prove that all the solutions tend to the equilibria of the system. Then we use the Poincaré Index theorem to determine the number of the rest points and their stability properties. It has been shown that bistability occurs for suitable values of the involved parameters. We use the perturbations of the pitchfork bifurcation points to give examples of all possible dynamics of the system. Some numerical examples of bistability and hysteresis behavior of the system has been also provided  

    Finding Influential Nodes in Complex Networks

    , M.Sc. Thesis Sharif University of Technology Barazandeh Shirvan, Amin (Author) ; Jalili, Mahdi (Supervisor)
    Abstract
    The modern science of networks helps us to have a better understanding of complex systems. Networked systems can be found everywhere and many systems can be represented by a complex network. A networked structure consists of a number of nodes and links connecting to them. Networks’ ability in information propagation is one of their amazing features that have attracted lots of scholars to work on. It has potential applications in many fields ranging from marketing to biology, epidemiology and sociology. Information propagation studies how information such as computer viruses, contagion, rumor, or new product’s interest propagates over a network. Percolation theory and various epidemic models... 

    Epidemiology and Networks

    , M.Sc. Thesis Sharif University of Technology Ashrafi Amineh, Rasa (Author) ; Haji Sadeghi, Mir Omid (Supervisor) ; Razvan, Mahammad Reza (Supervisor)
    Abstract
    Networks and the epidemiology of directly transmitted infectious diseases are fun-damentally linked. The foundations of epidemiology and early epidemiological models were based on population wide random-mixing, but in practice each individual has a finite set of contacts to whom they can pass infection; the ensemble of all such contacts forms a network. Knowledge of the structure of the network allows models to compute the epidemic dynamics at the population scale from the individual-level behaviour of infections.Motivated by the analysis of social networks, we study a model of random net-works that has both a given degree distribution and a tunable clustering coefficient.We consider two... 

    Global analysis of an SAIS model

    , Article Journal of Biological Dynamics ; Volume 6, Issue 2 , 2012 , Pages 457-474 ; 17513758 (ISSN) Razvan, M. R ; Yasaman, S ; Sharif University of Technology
    2012
    Abstract
    This paper is concerned with global analysis of an SAIS epidemiological model in a population of varying size introduced by Busenberg and van den Driessche. In this model the population is divided into three subgroups of susceptible, asymptomatic and infective individuals. It has been shown that this system has no periodic solutions and all its trajectories tend to the equilibria of the system. We use the Poincaré Index theorem to determine the number of the equilibria and their stability properties. We have shown that bistability occurs for suitable values of parameters and found a set of examples of all possible dynamics of the system  

    A new immunization algorithm based on spectral properties for complex networks

    , Article 2015 7th Conference on Information and Knowledge Technology, IKT 2015, 26 May 2015 through 28 May 2015 ; May , 2015 , Page(s): 1 - 5 ; 9781467374859 (ISBN) Zahedi, R ; Khansari, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    Nowadays, we are facing epidemic spreading in many different areas; examples are infection propagation, rumor spreading and computer viruses in computer networks. Finding a strategy to control and mitigate the spread of these epidemics is gaining much interest in recent researches. Due to limitation of immunization resources, it is important to establish a strategy for selecting nodes which has the most effect in mitigating epidemics. In this paper, we propose a new algorithm that minimizes the worst expected growth of an epidemic by reducing the size of the largest connected component of the underlying contact network. The proposed algorithm is applicable to any level of available resources... 

    Temporal dynamics of connectivity and epidemic properties of growing networks

    , Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 93, Issue 1 , 2016 ; 15393755 (ISSN) Fotouhi, B ; Khani Shirkoohi, M ; Sharif University of Technology
    American Physical Society  2016
    Abstract
    Traditional mathematical models of epidemic disease had for decades conventionally considered static structure for contacts. Recently, an upsurge of theoretical inquiry has strived towards rendering the models more realistic by incorporating the temporal aspects of networks of contacts, societal and online, that are of interest in the study of epidemics (and other similar diffusion processes). However, temporal dynamics have predominantly focused on link fluctuations and nodal activities, and less attention has been paid to the growth of the underlying network. Many real networks grow: Online networks are evidently in constant growth, and societal networks can grow due to migration flux and... 

    Prevalence of hepatitis e infection in the general population of Iran: a systematic review and meta-analysis

    , Article Future Virology ; Volume 12, Issue 4 , 2017 , Pages 227-236 ; 17460794 (ISSN) Hadifar, S ; Sedighi, M ; Mostafaei, S ; Miri, A ; Amiri, H ; Abiri, R ; Babaei, F ; Kabir, K ; Moghoofei, M ; Sharif University of Technology
    Abstract
    Aim: Hepatitis E is a form of acute viral hepatitis, which is caused by hepatitis E virus (HEV). The study objective was to evaluate the prevalence of HEV to provide an overall relative frequency in Iran. Methods: In this study, databases such as PubMed and Scopus were searched using the following keywords according to MeSH, "Hepatitis E virus", "Epidemiology", "Enzyme-linked immunosorbent assay (ELISA)" and "Iran". Then studies which had reported prevalence of HEV were selected. Results: We selected 36 researches out of 9246 for our study. From all the samples, the pooled estimated prevalence of HEV positive was 9.7%. It should be noted that HEV infection's relative frequency varied from... 

    Nonlinear robust adaptive sliding mode control of influenza epidemic in the presence of uncertainty

    , Article Journal of Process Control ; Volume 56 , 2017 , Pages 48-57 ; 09591524 (ISSN) Sharifi, M ; Moradi, H ; Sharif University of Technology
    Elsevier Ltd  2017
    Abstract
    In this paper, a nonlinear robust adaptive sliding mode control strategy is presented for the influenza epidemics in the presence of model uncertainties. The nonlinear epidemiological model of influenza with five state variables (the numbers of susceptible, exposed, infected, asymptomatic and recovered individuals) and two control inputs (vaccination and antiviral treatment) is considered. The objective of the proposed controller is decreasing the number of susceptible and infected humans to zero by tracking the desired scenarios. As a result of this decreasing, the number of exposed and asymptomatic individuals is also decreased and converged to the zero. Accordingly, it is shown that the... 

    Obesity and spinal loads; a combined MR imaging and subject-specific modeling investigation

    , Article Journal of Biomechanics ; 2017 ; 00219290 (ISSN) Akhavanfar, M. H ; Kazemi, H ; Eskandari, A. H ; Arjmand, N ; Sharif University of Technology
    Abstract
    Epidemiological studies have identified obesity asa possible risk factor for low back disorders. Biomechanical models can help test such hypothesis and shed light on the mechanism involved. A novel subject-specific musculoskeletal-modelling approach is introduced to estimate spinal loads during static activities in five healthy obese (BMI>30kg/m2) and five normal-weight (20

    Obesity and spinal loads; a combined MR imaging and subject-specific modeling investigation

    , Article Journal of Biomechanics ; Volume 70 , March , 2018 , Pages 102-112 ; 00219290 (ISSN) Akhavanfar, M. H ; Kazemi, H ; Eskandari, A. H ; Arjmand, N ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Epidemiological studies have identified obesity as a possible risk factor for low back disorders. Biomechanical models can help test such hypothesis and shed light on the mechanism involved. A novel subject-specific musculoskeletal-modelling approach is introduced to estimate spinal loads during static activities in five healthy obese (BMI > 30 kg/m2) and five normal-weight (20 < BMI < 25 kg/m2) individuals. Subjects underwent T1 through S1 MR imaging thereby measuring cross-sectional-area (CSA) and moment arms of trunk muscles together with mass and center of mass (CoM) of T1-L5 segments. MR-based subject-specific models estimated spinal loads using a kinematics/optimization-driven... 

    Scalable performance analysis of epidemic routing considering skewed location visiting preferences

    , Article 27th IEEE International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems, MASCOTS 2019, 22 October 2019 through 25 October 2019 ; Volume 2019-October , 2019 , Pages 201-213 ; 15267539 (ISSN); 9781728149509 (ISBN) Rashidi, L ; Dalili Yazdi, A ; Entezari Maleki, R ; Sousa, L ; Movaghar, A ; Sharif University of Technology
    IEEE Computer Society  2019
    Abstract
    This paper investigates the performance of epidemic routing, in mobile social networks (MSNs), which makes use of the store-carry-forward paradigm for communication. Real-life mobility traces show that people have skewed location visiting preferences, with some places visited frequently and some others infrequently. In order to model epidemic routing in MSNs, we first analyze the time taken for a node to meet the first node belonging to a set of nodes restricted to move in a specific subarea. Afterwards, a monolithic stochastic reward net (SRN) is proposed to evaluate the delivery delay and the average number of transmissions under epidemic routing by considering skewed location visiting... 

    Characterizing the effect of traffic density on ambient CO, NO2, and PM2.5 in Tehran, Iran: an hourly land-use regression model

    , Article Transportation Letters ; Volume 11, Issue 8 , 2019 , Pages 436-446 ; 19427867 (ISSN) Hassanpour Matikolaei, S. A. H ; Jamshidi, H ; Samimi, A ; Sharif University of Technology
    Taylor and Francis Ltd  2019
    Abstract
    Economic development and population growth in Tehran has increased demand for goods movement and road transportation. This trend has increased mobile source emissions and citizens’ exposure, imposing severe health risks. We used the framework of Land-Use Regression models to quantify the effect of real-time traffic, within buffer distance, on hourly exposure of CO, NO2, and PM2.5. Effect of residential, industrial, and governmental land-use in addition to the effect of pollution sources, such as construction sites and airport were assessed on air pollution. Meteorological variables were also employed to adjust between day variations. R-squared of the models were 38, 27, and 38% for CO, NO2,... 

    Performance evaluation of epidemic content retrieval in DTNs with restricted mobility

    , Article IEEE Transactions on Network and Service Management ; Volume 16, Issue 2 , 2019 , Pages 701-714 ; 19324537 (ISSN) Rashidi, L ; Entezari Maleki, R ; Chatzopoulos, D ; Hui, P ; Trivedi, K. S ; Movaghar, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    In some applicable scenarios, such as community patrolling, mobile nodes are restricted to move only in their own communities. Exploiting the meetings of the nodes within the same community and the nodes within the neighboring communities, a delay tolerant network (DTN) can provide communication between any two nodes. In this paper, two analytical models based on stochastic reward nets (SRNs) are proposed to evaluate the performance of the epidemic content retrieval in such multi-community DTNs. Performance measures computed by the proposed models are the average retrieval delay and the average number of transmissions. The monolithic SRN model proposed in the first step is not scalable, in... 

    Modeling epidemic routing: capturing frequently visited locations while preserving scalability

    , Article IEEE Transactions on Vehicular Technology ; Volume 70, Issue 3 , 2021 , Pages 2713-2727 ; 00189545 (ISSN) Rashidi, L ; Dalili Yazdi, A ; Entezari Maleki, R ; Sousa, L ; Movaghar, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    Abstract
    This paper investigates the performance of epidemic routing in mobile social networks considering several communities which are frequently visited by nodes. To this end, a monolithic Stochastic Reward Net (SRN) is proposed to evaluate the delivery delay and the average number of transmissions under epidemic routing by considering skewed location visiting preferences. This model is not scalable enough, in terms of the number of nodes and frequently visited locations. In order to achieve higher scalability, the folding technique is applied to the monolithic model, and an approximate folded SRN is proposed to evaluate performance of epidemic routing. Discrete-event simulation is used to... 

    How do the smart travel ban policy and intercity travel pattern affect COVID-19 trends? Lessons learned from Iran

    , Article PLoS ONE ; Volume 17, Issue 10 October , 2022 ; 19326203 (ISSN) Nassiri, H ; Mohammadpour, S. I ; Dahaghin, M ; Sharif University of Technology
    Public Library of Science  2022
    Abstract
    COVID-19, as the most significant epidemic of the century, infected 467 million people and took the lives of more than 6 million individuals as of March 19, 2022. Due to the rapid transmission of the disease and the lack of definitive treatment, countries have employed non-pharmaceutical interventions. This study aimed to investigate the effectiveness of the smart travel ban policy, which has been implemented for non-commercial vehicles in the intercity highways of Iran since November 21, 2020. The other goal was to suggest efficient COVID-19 forecasting tools and to examine the association of intercity travel patterns and COVID-19 trends in Iran. To this end, weekly confirmed cases and...