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    Robust Markov Decision Processes and Applications in Mathematical Finance

    , M.Sc. Thesis Sharif University of Technology Soori, Mohammad (Author) ; Fotouhi Firouzabadi, Morteza (Supervisor) ; Salavati, Erfan (Supervisor)
    Abstract
    Dynamic portfolio optimization is one of the prominent problems in financial mathematics, for which numerous theories have been proposed to solve it. One of the solutions to this problem is the use of reinforcement learning. The main challenge with this method is that most reinforcement learning algorithms require a large amount of data, and therefore, the necessary data is often obtained not from the real world, but through simulations by estimating the parameters of a model. However, the approximation error of the parameters can propagate through the final solution, leading to inaccurate results. One approach to addressing this issue is the use of robust Markov processes and robust... 

    A Process Mining Approach to Analyze Customer Journeys to Improve Customer Experience

    , M.Sc. Thesis Sharif University of Technology Akhavan, Fatemeh (Author) ; Hassannayebi, Erfan (Supervisor)
    Abstract
    With the growth of the number of online service providers and the need to innovate in these services, in this study, the processes and the journeys taken by visitors of a website that provides employment services and employment insurance has been analyzed. In this research, process mining techniques and predictive process monitoring were implemented. With the use of a supervised and unsupervised learning algorithm, it attempted to identify the customer journeys' output and the existing patterns that lead to the complaint. In the first step, the website event log is extracted. Afterward, by using frequency-based encoding methods, the journeys traveled by users were clustered based on the... 

    Predictive Business Process Monitoring Using Machine Learning Algorithms

    , M.Sc. Thesis Sharif University of Technology Feiz, Roya (Author) ; Hassannayebi, Erfan (Supervisor)
    Abstract
    In order to survive in today's business world, which is changing at a very fast pace, organizations can detect deviations even before they occur, quickly and with a high percentage of confidence, by analyzing their processes, in order to prevent disruptions in the processes. by monitoring the information systems that automatically execute business processes, it is possible to ensure the correct implementation of the existing processes. For this purpose, various techniques for monitoring business processes have been presented so that managers have a comprehensive and real view of how implement processes and be able to identify possible deviations in the future and try to fix them because the... 

    Data-Driven Prediction for Monitoring Business Process Pperformances Based on Classification Algorithms

    , M.Sc. Thesis Sharif University of Technology Taheriyan, Zahra (Author) ; Hassannayebi, Erfan (Supervisor)
    Abstract
    In recent years, several studies have been conducted in the field of data mining techniques in the field of process mining with the aim of improving the performance of organizations. Predictive process monitoring is a data-driven approach that helps business managers to improve the status and conditions of their organization. In this approach, the event log, which includes a set of completed examples of a process, is received as input, and machine learning methods are used to predict the outcome and results of the organization's processes before the process is completed. This prediction can include the prediction of the final result, the next event, the time remaining until the completion of... 

    Operations Optimization in Supply Chain Systems using Simulation and Reinforcement Learning

    , M.Sc. Thesis Sharif University of Technology Mahmoudi, Farzaneh (Author) ; Hassan Nayebi, Erfan (Supervisor)
    Abstract
    The inventory costs constitute a significant portion of the supply chain costs. Therefore, choosing an optimal inventory policy for orders is of great importance. The aim of this research is to find the optimal inventory policy for a distribution center in a three-tier supply chain consisting of a manufacturer, a distribution center, and a retailer. This research simulates a supply chain in agent-based framework and optimizes it using reinforcement learning. The optimization KPI in this research is the mean daily cost of the supply chain. Finally, the result obtained from reinforcement learning is compared with the optimized result of AnyLogic and the mean daily cost in the model optimized... 

    Predictive Process Monitoring Based on Optimized Deep Learning Methods

    , M.Sc. Thesis Sharif University of Technology Alibakhshi, Alireza (Author) ; Hassannayebi, Erfan (Supervisor)
    Abstract
    Business processes are an essential part of every business as they provide insights on how to optimize and make them more efficient. Predictive Business Process Monitoring has garnered significant attention in recent years due to its capability to forecast process outcomes and predict the next activity within an ongoing process. In the last few years, there have been works that focused on deep learning and its applications in predicting the next activity. Some research used Long Term Short Memory, while others used Convolutional Neural Networks. However, long term short term memory models have the constraint of relatively slow training, while Convolutional Neural Networks are fast but may... 

    A maximal inequality for pth power of stochastic convolution integrals

    , Article Journal of Inequalities and Applications ; Volume 2016, Issue 1 , 2016 ; 10255834 (ISSN) Salavati, E ; Zangeneh, B. Z ; Sharif University of Technology
    Springer International Publishing  2016
    Abstract
    We prove an inequality for the pth power of the norm of a stochastic convolution integral in a Hilbert space. The inequality is stronger than analogous inequalities in the literature in the sense that it is pathwise and not in expectation  

    Continuous dependence on coefficients for stochastic evolution equations with multiplicative lévy noise and monotone nonlinearity

    , Article Bulletin of the Iranian Mathematical Society ; Volume 42, Issue 1 , 2016 , Pages 175-194 ; 10186301 (ISSN) Salavati, E ; Zangeneh, B. Z ; Sharif University of Technology
    Iranian Mathematical Society  2016
    Abstract
    Semilinear stochastic evolution equations with multiplicative Lévy noise are considered. The drift term is assumed to be monotone nonlinear and with linear growth. Unlike other similar works, we do not impose coercivity conditions on coefficients. We establish the continuous dependence of the mild solution with respect to initial conditions and also on coefficients. As corollaries of the continuity result, we derive sufficient conditions for asymptotic stability of the solutions, we show that Yosida approximations converge to the solution and we prove that solutions have Markov property. Examples on stochastic partial differential equations and stochastic delay differential equations are... 

    Stochastic evolution equations with multiplicative Poisson noise and monotone nonlinearity

    , Article Bulletin of the Iranian Mathematical Society ; Volume 43, Issue 5 , 2017 , Pages 1287-1299 ; 10186301 (ISSN) Salavati, E ; Zangeneh, B. Z ; Sharif University of Technology
    2017
    Abstract
    Semilinear stochastic evolution equations with multiplicative Poisson noise and monotone nonlinear drift in Hilbert spaces are considered. The coefficients are assumed to have linear growth. We do not impose coercivity conditions on coefficients. A novel method of proof for establishing existence and uniqueness of the mild solution is proposed. Examples on stochastic partial differential equations and stochastic delay differential equations are provided to demonstrate the theory developed. © 2017 Iranian Mathematical Society  

    Customer Journey Analytics using Process Mining Based on the Markov Model

    , M.Sc. Thesis Sharif University of Technology Torabi Ardekani, Saba (Author) ; Hassan Nayebi, Erfan (Supervisor)
    Abstract
    The analysis of customer journeys has gained significant attention due to the critical role of customer behavior data in enhancing business decision-making and formulating strategies for customer acquisition and retention. By segmenting customers based on their journey patterns, businesses can offer personalized recommendations, thereby improving customer engagement and loyalty. Additionally, predicting the next steps in a customer’s journey based on historical data allows for timely and appropriate interventions at various touchpoints. By understanding where customers are in their journey, businesses can provide targeted recommendations that increase the likelihood of converting potential... 

    A System Dynamic Simulation Approach to Investigate Economic And Environment Factors Based on VUCA framework: A Case Study in Petrochemical Industry

    , M.Sc. Thesis Sharif University of Technology Monfaredi Jafarbagi, Aoun (Author) ; Hassannayebi, Erfan (Supervisor)
    Abstract
    To maintain adaptability, businesses should anticipate changes in their environment. The commonly employed forecasting method within corporate circles is the bottom-up approach, which relies on historical data for projecting future trends. However, research suggests that this approach often falls short of accurately reflecting real-world events. This has led to the adoption of dynamic systems modeling, a technique grounded in the assumption of stable conditions. This method effectively replicates the system's current state, thereby assisting in predicting future behaviors over a longer timeframe. The dynamic systems modeling approach was employed in this study, underscoring the imperative... 

    Discovering and Improving the Processes of an Iranian Psychiatric Hospital Using Process Mining

    , M.Sc. Thesis Sharif University of Technology Roshan, Mohammad Amin (Author) ; Hassan Nayebi, Erfan (Supervisor)
    Abstract
    Providing quality hospital services depends on the efficient and correct implementation of processes. Therapeutic care processes are a set of activities that are carried out with the aim of diagnosing, treating and preventing any disease in order to improve and promote the patient's health. The purpose of this study is to use process mining techniques to discover and improve healthcare processes. The case study of this research is a psychiatric hospital in Shiraz. The approach implemented in this research consists of three main stages including data pre-processing, model discovery phase, and analysis phase. Three algorithms including Heuristic Miner, Inductive Miner, and ILP Miner were used... 

    Investigation the Effects of Parking Pricing and Improving Public Transportation Policies on Private Car Use Reduction in Central Business District

    , M.Sc. Thesis Sharif University of Technology Salavati, Mohammad Ali (Author) ; Kermanshah, Mohammad (Supervisor)
    Abstract
    Nowadays, with population growth and vehicle traffic increase, only providing transportation supply couldn’t answer the transportation demand. One of the most important solutions to reduce traffic is transportation demand management (TDM). In this research, the effects of parking pricing and improving public transportation services on private car demand reduction in city center are examined. The data are collected from private cars users in the city center of Isfahan through interviews. By stated preference method, the impacts of parking price and public transit travel time and other related factors were investigated. For this purpose, binary logit, multinomial logit and nested logit models... 

    Semilinear Stochastic Evolution Equations with Lévy Noise

    , Ph.D. Dissertation Sharif University of Technology Salavati, Erfan (Author) ; Zohuri Zangeneh, Bijan (Supervisor)
    Abstract
    Semilinear stochastic evolution equations with multiplicative Lévy noise and monotone nonlinear drift are considered. A novel method of proof for establishing existence and uniqueness of the mild solution is proposed. We also prove the continuous dependence of the mild solution with respect to initial conditions and also on coefficients. As corollaries of the continuity result, we derive sufficient conditions for asymptotic stability of the solutions, we show that Yosida approximations converge to the solution and we prove that solutions have Markov property. Examples on stochastic partial differential equations and stochastic delay differential equations are provided to demonstrate the... 

    The investigation of natural super-cavitation flow behind three-dimensional cavitators: Full cavitation model

    , Article Applied Mathematical Modelling ; Volume 45 , 2016 , Pages 165-178 ; 0307904X (ISSN) Kadivar, E ; Kadivar, Erfan ; Javadi, K ; Javadpour, S. M ; Sharif University of Technology
    Elsevier Inc  2016
    Abstract
    In this study, natural super-cavitating flow around three different conical cavitators with wedge angles of 30°, 45° and 60° is investigated. We apply the k−ϵ turbulence model and the volume of fluid (VOF) technique to numerically study the three-dimensional cavitating flow around the cavitators. The turbulence approach is coupled with a mass transfer model which is implemented into the finite-volume package. Simulations are performed for different cavitation numbers. Finally, the effects of some important parameters such as the cavitation index, inlet velocity, Froude number and wedge angle of cavitators on the geometrical characteristics of the super-cavities are discussed. Our numerical... 

    Analysis and Improvement of Agile Software Development Process Using Process Mining and Machine Learning Algorithms

    , M.Sc. Thesis Sharif University of Technology Fardipour Asl, Mohsen (Author) ; Hassan Nayebi, Erfan (Supervisor)
    Abstract
    In the competitive world of software development, IT product development teams face numerous challenges and issues within business processes. In recent years, the combination of process mining and machine learning algorithms to optimize software development processes has gained attention. However, there is still a lack of a comprehensive model for identifying and conducting root-cause analysis of problems and providing solutions based on them in agile software development systems. The aim of this research is to find a solution for identifying and addressing issues in the software development process by modifying the change request workflow and examining various aspects of incidents. To... 

    Improve Performance of Process Mining Algorithms in Low-Level Event Log with Machine Learning Methods

    , M.Sc. Thesis Sharif University of Technology Choopannezhad, Mahsa (Author) ; Hassan Nayebi, Erfan (Supervisor)
    Abstract
    This thesis abstract addresses the use of process mining techniques when event data is stored at varying levels of granularity. While most techniques assume that events have the same level of granularity, real data is often stored differently. Pre-processing techniques allow for appropriate summarization of the data, which simplifies the output while retaining important process details. The goal is to ensure an interpretable output for stakeholders and different business teams without losing critical process points. However, adding new data as a feature to the dataset can be expensive, and at times, infeasible. Therefore, existing data is the only solution. To overcome this challenge, this... 

    Application of [M(en)3]3[Fe(ox)3]2 (M = Zn, Cd, Ni) complexes as new precursor for the synthesis of ferrite micro/nanostructures

    , Article Advanced Powder Technology ; Volume 27, Issue 2 , 2016 , Pages 388-394 ; 09218831 (ISSN) Hashemi, M ; Mohandes, F ; Salavati Niasari, M ; Sharif University of Technology
    Elsevier B.V  2016
    Abstract
    This work presents solid-state thermal decomposition synthesis of transition metal ferrites (MFe2O4, M = Zn, Ni, Cd). In this method, binary complexes of [Zn(en)3]3[Fe(ox)3]2, [Cd(en)3]3[Fe(ox)3]2 and [Ni(en)3]3[Fe(ox)3]2 (where en = ethylenediamine and ox = oxalate) are introduced as new single-source precursors to fabricate ZnFe2O4, CdFe2O4 and NiFe2O4 micro/nanostructures, respectively. X-ray powder diffraction (XRD) patterns show that pure CdFe2O4 and NiFe2O4 are formed by thermal decomposition of the single-source precursors at 800°C. When thermal decomposition of [Zn(en)3]3[Fe(ox)3]2 complex is carried out at 700 and 800°C, the final products are composed of ZnFe2O4 and metal oxides.... 

    Simulation-Based Optimization for IoT-Enabled Epidemic Patients Care Systems

    , M.Sc. Thesis Sharif University of Technology Bisheh Niasar, Mohammad Amir (Author) ; Hassan Nayebi, Erfan (Supervisor)
    Abstract
    This research focuses on examining and improving healthcare systems, particularly during crises and pandemics. Following disasters such as natural calamities and pandemics like COVID-19, healthcare systems face significant challenges due to the increased demand for medical services, creating a substantial threat to the population in the affected regions. This study emphasizes the importance of utilizing modern technologies such as the Internet of Things (IoT) and telemedicine systems in alleviating the pressure on healthcare systems. A combined approach of prediction and multi-objective optimization based on simulation is proposed in this study to improve resource allocation and demand... 

    An ant based rate allocation algorithm for media streaming in peer to peer networks

    , Article 33rd IEEE Conference on Local Computer Networks, LCN 2008, Montreal, AB, 14 October 2008 through 17 October 2008 ; 2008 , Pages 456-463 ; 9781424424139 (ISBN) Salavati, A. H ; Goudarzi, H ; Pakravan, M. R ; Sharif University of Technology
    2008
    Abstract
    In this paper, we propose a novel algorithm for rate allocation in multiple-source media streaming peer to peer networks. Our algorithm is based on ant-colony optimization and capable of handling network changes which occur quite often in unstructured P2P networks. The suggested algorithm does not need any information about the topology of the network. Moreover, it could get over uncertainties in network state information, particularly the rate of media provider nodes that could happen due to lack of accurate measurements. We show that our algorithm will reach the maximum achievable rate of the network quite fast and with relatively little overhead. In our simulations, we have demonstrated...