Loading...
Search for: abdollahi-azgomi--m
0.234 seconds

    Efficient evaluation of CSAN models by state space analysis methods

    , Article 2006 International Conference on Software Engineering Advances, ICSEA'06, Tahiti, 29 October 2006 through 3 November 2006 ; 2006 , Pages 57-62 ; 0769527035 (ISBN); 9780769527031 (ISBN) Abdollahi Azgomi, M ; Movaghar, A ; Sharif University of Technology
    IEEE Computer Society  2006
    Abstract
    We have recently introduced a high-level extension for stochastic activity networks (SANs) called coloured stochastic activity networks (CSANs). CSANs have several distinguishing properties, which make them quite appropriate for modeling and evaluation of software performance and dependability. CSANs have introduced a construct called coloured place for data manipulation. A coloured place holds a list of tokens of a userdefined token type. CSAN models can be evaluated by state space analysis techniques or discrete-event simulation. However, their state spaces will become very large, even for a small CSAN model. For efficient evaluation of these models by state space analysis methods, we will... 

    Modeling and evaluation of software systems with object stochastic activity networks

    , Article 2006 International Conference on Software Engineering Advances, ICSEA'06, Tahiti, 29 October 2006 through 3 November 2006 ; 2006 , Pages 58-63 ; 0769527035 (ISBN); 9780769527031 (ISBN) Abdollahi Azgomi, M ; Movaghar, A ; Sharif University of Technology
    IEEE Computer Society  2006
    Abstract
    Stochastic activity networks (SANs) are a stochastic generalization of Petri nets. SAN models have been used to evaluate a wide range of systems and are supported by several modeling tools. We have introduced object stochastic activity networks (OSANs) to overcome some restrictions of these models. OSANs integrate the concepts of object-orientation into SAN models. Elements of OSANs and their submodels are defined as classes. OSANs are more appropriate that most other objectoriented or high-level extensions of Petri nets for application on software systems. In this paper, we will present the definitions, behavior and an example of OSAN models. The objectorientation of OSANs and the... 

    A modeling tool for a new definition of stochastic activity networks

    , Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 29, Issue 1 B , 2005 , Pages 79-92 ; 03601307 (ISSN) Abdollahi Azgomi, M ; Movaghar, A ; Sharif University of Technology
    2005
    Abstract
    Stochastic activity networks (SANs) are a powerful and flexible extension of Petri nets. Modeling and analysis with Petri nets and their extensions need a software tool to help to construct and analyze the models. The original definition of SANs has been used as a modeling formalism in several tools. In this paper, we introduce a modeling tool called SharifSAN, which is based on a new definition of SANs. This modeling tool is useful for both the verification and performance evaluation of systems. The functional aspects of a system are verified by model checking branching temporal logic formulas, whereas its performance aspects are evaluated using some analytic and simulative methods. The... 

    Modeling and evaluation with object stochastic activity networks

    , Article Proceedings - First International Conference on the Quantitave Evaluation of Systems, QEST 2004, Enschede, 27 September 2004 through 30 September 2004 ; 2004 , Pages 326-327 ; 0769521851 (ISBN) Abdollahi Azgomi, M ; Movaghar, A ; Sharif University of Technology
    2004
    Abstract
    Stochastic activity networks (SANs) are a stochastic generalization of Petri nets. SAN models have been used for performance, dependability and performability evaluation and are supported by several powerful modeling tools. We have recently introduced object stochastic activity networks (OSANs) to overcome some restrictions of these models. OSANs integrate the concepts of object-orientation into SAN models. Elements of OSANs and their submodels are defined as classes. In this paper, we briefly introduce OSANs and SANBuilder tool for modeling and evaluation with these models. © 2004 IEEE  

    A modelling tool for hierarchical stochastic activity networks

    , Article Simulation Modelling Practice and Theory ; Volume 13, Issue 6 , 2005 , Pages 505-524 ; 1569190X (ISSN) Azgomi, M. A ; Movaghar, A ; Sharif University of Technology
    2005
    Abstract
    Hierarchical stochastic activity networks (HSANs) are a newly introduced extension of stochastic activity networks (SANs). HSAN models encapsulate hierarchies and a key benefit of these models is the possibility of automatic employment of composition techniques by their modelling tools. For modelling and evaluation with HSANs, we have developed a software tool called SANBuilder. This tool has an integrated development environment (IDE) for construction, animation, simulation and analytic solution of SAN-based models. We have implemented in this tool some state-of-the-art methods for the simulation and analytic solution of SAN and HSAN models. In addition to an introduction to HSANs, this... 

    Hierarchical stochastic activity networks: Formal definitions and behaviour

    , Article International Journal of Simulation: Systems, Science and Technology ; Volume 6, Issue 1-2 , 2005 , Pages 56-66 ; 14738031 (ISSN) Azgomi, M. A ; Movaghar, A ; Sharif University of Technology
    UK Simulation Society  2005
    Abstract
    Stochastic activity networks (SANs) are a powerful and flexible extension of Petri nets. These models can be used for the modelling and analysis of various kinds and different aspects of distributed real-time systems. Similar to other classical extensions of Petri nets, SANs have some limitations for modelling complex and large-scale systems. In order to remove some of these limitations and provide high-level modelling constructs, we have defined a new extension for SANs, called hierarchical stochastic activity networks (HSANs). HSAN models provide a construct for composing a hierarchy of SAN submodels that is called macro activity. HSANs encapsulate hierarchies and a key benefit of these... 

    Transformation of UML models into analyzable OSAN models

    , Article Electronic Notes in Theoretical Computer Science ; Volume 159, Issue 1 , 2006 , Pages 3-22 ; 15710661 (ISSN) Kamandi, A ; Abdollahi Azgomi, M ; Movaghar, A ; Sharif University of Technology
    2006
    Abstract
    The unified modelling language (UML) is a de facto standard for object-oriented modelling. However, the formal semantics for the notations included in UML are not provided, which are a key requirement for the verification and evaluation purposes. To solve this problem, Petri net formalism has been used as a complement to UML in several research projects. However, there is not a complete transformation technique for all concepts and diagrams of UML to an extension of Petri nets. We have recently introduced object stochastic activity networks (OSANs). OSANs are a high-level modelling formalism that integrates object-orientation into stochastic activity networks (SANs). In this paper, we... 

    A new hybrid heuristic technique for unit commitment considering spinning reserve probability

    , Article AIP Conference Proceedings, 1 June 2009 through 3 June 2009, Bali ; Volume 1159 , 2009 , Pages 262-267 ; 0094243X (ISSN) ; 9780735406964 (ISBN) Abdollahi, A ; Ehsan, M ; Rashidinejad, M ; Purakbari Kasmaie, M ; Sharif University of Technology
    2009
    Abstract
    This paper proposes a new approach for solving generation scheduling and ramp rate constrained unit commitment with considering spinning reserve probability. In order to simulate the probability of reserve in the formulation, the estimated probability that spinning reserve is called and generated has been considered. A hybrid heuristic method between genetic algorithm and lambdad iteration method is applied to solve the problem. The proposed approach is applied to two different cases such as a 10-unit base problem without considering probability of reserve and 10-unit problem with considering probability of reserve. The results are compared with other approaches results to exhibit the... 

    Cost-based unit commitment considering prohibited zones and reserve uncertainty

    , Article International Review of Electrical Engineering ; Volume 4, Issue 3 , 2009 , Pages 425-433 ; 18276660 (ISSN) Abdollahi, A ; Ehsan, M ; Rashidinejad, M ; Pourakbari Kasmaei, M ; Sharif University of Technology
    2009
    Abstract
    Generation scheduling is a crucial challenge in power systems especially under new environment of liberalization of electricity industry. This paper is focused on the economical aspect of UC problem, while the next load demand as a very important issue and prohibited operation zones and spinning reserve uncertainty as practical constraints have been taken in to account. The impacts of hot/cold start-up cost have been considered in this paper. Numerical results show a significant improvement in the solutions of a cost-based unit commitment in comparison with the other studies. © 2009 Praise Worthy Prize S.r.l  

    Stochastic security-constrained unit commitment with arma-based wind modelling considering network uncertainties

    , Article International Journal of Renewable Energy Research ; Volume 3, Issue 1 , 2013 , Pages 132-137 ; 13090127 (ISSN) Abdollahi Mansoorkhani, H ; Kia, M ; Sahebi, M. M ; Pishvaie, M ; Sharif University of Technology
    2013
    Abstract
    This paper proposes a short-term stochastic SCUC model that simultaneously schedules generating units' energy and spinning reserve in presence of wind energy. It should be noted that system uncertainties, wind farm output uncertainties and power generators and lines outages are also considered in optimization process. The proposed stochastic SCUC model is formulated as a two-stage stochastic mixed-integer programming model. Performance of the proposed formulation is proved through test systems and the results are also presented  

    Synthesis, characterization and comparison of PAM, cationic PDMC and P(AM-co-DMC) based on solution polymerization

    , Article Journal of Industrial and Engineering Chemistry ; Volume 17, Issue 3 , 2011 , Pages 580-586 ; 1226086X (ISSN) Abdollahi, Z ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
    2011
    Abstract
    High molecular weight homopolymers of acrylamide (PAM) and (2-methacryloyloxyethyl) trimethyl ammonium chloride (PDMC) and copolymer of DMC with acrylamide (P(AM-co-DMC)) were synthesized using solution polymerization technique. The synthesized polymers were characterized by Fourier transform infrared (FTIR), 1HNMR, 13CNMR spectroscopy and differential scanning calorimetry (DSC) and viscometery. 1HNMR and 13CNMR studies confirmed the structure of the synthesized polymers. The behavior of the synthesized polymers was investigated in water-acetone and water-methanol mixtures. The plot of intrinsic viscosity of either PAM or P(AM-co-DMC) with respect to acetone (methanol)/water ratio in... 

    Study of atmospheric muons using a cosmic ray telescope

    , Article Journal of Physics G: Nuclear and Particle Physics ; Volume 40, Issue 2 , 2013 ; 09543899 (ISSN) Abdollahi, S ; Bahmanabadi, M ; Purmohammad, D ; Sharif University of Technology
    2013
    Abstract
    The charge ratio of cosmic muons holds important information for both the atmospheric neutrino anomaly and hadronic interaction models. In this paper we measured the muon charge ratio () in the cosmic ray flux in the momenta range 0.76-1.60 GeV/c by using a cosmic ray telescope. The delayed coincidence method is used based on the reduced mean lifetime of negative muons due to nuclear capture in matter. The systematic time-dependent effects of the muon charge ratio are considered by grouping the decay data into different time intervals. We compared the experimental data with the predictions of CORSIKA simulations using a high energy interaction model (QGSJET-II) and two low energy interaction... 

    Highly Efficient and Revocable CP-ABE with Outsourcing Decryption for IoT∗∗

    , Article ISeCure ; Volume 15, Issue 1 , 2023 , Pages 113-126 ; 20082045 (ISSN) Abdollahi, S ; Mohajeri, J ; Salmasizadeh, M ; Sharif University of Technology
    Iranian Society of Cryptology  2023
    Abstract
    Ciphertext-policy attribute-based encryption(CP-ABE) is considered a promising solution for secure data sharing in the cloud environment. Although very well expressiveness in ABE constructions can be achieved using a linear secret sharing scheme(LSSS), there is a significant drawback in such constructions. In the LSSS-based ABE construction, the number of heavy pairing operations increases with an increase in the number of required attributes in the decryption. In this paper, we propose an LSSS-based CP-ABE scheme with a fixed number of pairings(four pairings) during the decryption process. In our scheme increasing the number of required attributes in the decryption does not affect the... 

    Oxidation pretreatment for enhancing desulfurization of coal with sodium butoxide

    , Article Minerals Engineering ; Volume 17, Issue 4 , 2004 , Pages 545-552 ; 08926875 (ISSN) Jorjani, E ; Rezai, B ; Vossoughi, M ; Osanloo, M ; Abdollahi, M ; Sharif University of Technology
    2004
    Abstract
    A sample of Tabas coal from Iran was oxidized using air, peroxyacetic acid (PAA), and PAA+air as a pretreatment for desulfurization with sodium butoxide in a batch reactor. The effects of air oxidation temperature, PAA oxidation time, sodium butoxide reaction time and temperature, solvent concentration and particle size on the reduction of sulfur were investigated. The PAA+air oxidation pretreatment was the most effective method for enhancing sulfur removal. This procedure increased pyritic sulfur removal by approximately 15% and organic sulfur removal by 20% in leaching with sodium butoxide. Increasing the temperature from 25 (unoxidized) to 100 °C on air oxidized samples, increased sulfur... 

    Granulated copper oxide nano-catalyst: A novel and efficient catalyst for C-N cross-coupling of amines with iodobenzene

    , Article Monatshefte fur Chemie ; Volume 142, Issue 8 , 2011 , Pages 801-806 ; 00269247 (ISSN) Ahmadi, S. J ; Sadjadi, S ; Hosseinpour, M ; Abdollahi, M ; Sharif University of Technology
    2011
    Abstract
    Nano-structured CuO granules catalyze the C-N cross-coupling of amines with iodobenzene in excellent yields. The reaction is simple, efficient, and operates in air under ligand-free conditions  

    Joint transfer of energy and information in a two-hop relay channel

    , Article IWCIT 2017 - Iran Workshop on Communication and Information Theory, 3 May 2017 through 4 May 2017 ; 2017 ; 9781509047833 (ISBN) Abdollahi Bafghi, A. H ; Mirmohseni, M ; Aref, M. R ; Sharif University of Technology
    2017
    Abstract
    We study the problem of joint information and energy transfer in a two-hop channel with a Radio frequency (RF) energy harvesting relay. We consider a finite battery size at the relay and deterministic energy loss in transmitting energy. In other words, to be able to send an energy-contained symbol, the relay must receive multiple energy-contained symbols. Thus, we face a kind of channel with memory. We model the energy saved in battery as channel state with the challenge that the receiver does not know the channel state. First, we consider the problem without any channel noise and derive an achievable rate. Next, we extend the results to the case with an independent and identically... 

    The energy hub: An extensive survey on the state-of-the-art

    , Article Applied Thermal Engineering ; Volume 161 , 2019 ; 13594311 (ISSN) Sadeghi, H ; Rashidinejad, M ; Moeini Aghtaie, M ; Abdollahi, A ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Today's world energy-related challenges, ranging from anthropogenic climate change to continuous growth of demand for different energy forms, have enforced planners of energy systems (ESs) to concentrate on more optimal and eco-friendly operation and/or expansion planning methodologies. In this context, increased interdependencies of gas, heat and electricity ESs have recently encouraged the planners to design operation and/or expiation strategies in an integrated manner in favor of a new concept, the so-called “Energy Hub” (EH). Although this concept has been employed so far in a multitude of studies, but its real nature, advantages, difficulties, importance or inevitability aspect, and... 

    Heat and electricity supply chain expansion planning under the umbrella of energy hub: A case study of Iran

    , Article Scientia Iranica ; Volume 29, Issue 4 D , 2022 , Pages 1983-2006 ; 10263098 (ISSN) Sadeghi, H ; Rashidinejad, M ; Moeini Aghtaie, M ; Abdollahi, A ; Sharif University of Technology
    Sharif University of Technology  2022
    Abstract
    Reinforcing the correlation between Gas and Electricity Systems (G&ESs) susceptible to diverse factors ranging from anthropogenic climate change to the advent of new conversion/generation technologies has remarkably brought into focus the co-expansion of G&ESs using a new concept so-called Energy Hub (EH) as well as the potential of storage systems. To assess the effectiveness of EH approach and the role of storages in the coordinated plans of G&ES, this study proposes a comprehensive EH-based planning model for co-expansion of G&ES supply chains with respect to the role of Gas Storage Systems (GSSs). As a Mixed-Integer Linear Programming (MILP) problem, the model is applied to a real... 

    Degrees of freedom of a k-user interference channel in the presence of an instantaneous relay

    , Article Entropy ; Volume 24, Issue 8 , 2022 ; 10994300 (ISSN) Abdollahi Bafghi, A. H ; Mirmohseni, M ; Nasiri Kenari, M ; Sharif University of Technology
    MDPI  2022
    Abstract
    In this paper, we study the degrees of freedom (DoF) of a frequency-selective K-user interference channel in the presence of an instantaneous relay (IR) with multiple receiving and transmitting antennas. We investigate two scenarios based on the IR antennas’ cooperation ability. First, we assume that the IR receiving and transmitting antennas can coordinate with each other and that the transmitted signal of each transmitting antenna can depend on the received signals of all receiving antennas, and we derive lower and upper bounds for the sum DoF of this model. In an interference alignment scheme, we divide receivers into two groups called clean and dirty receivers. We design our scheme such... 

    Liver-on-a-chip

    , Article Principles of Human Organs-on-Chips ; 2023 , Pages 195-249 ; 978-012823536-2 (ISBN); 978-012823610-9 (ISBN) Mirzababaei, S ; Navaei Nigjeh, M ; Abdollahi, M ; Shamloo, A ; Sharif University of Technology
    Elsevier  2023
    Abstract
    The liver is the most metabolically active organ in the human body whose role is of high importance to maintain homeostasis. Drug-induced liver injury and liver diseases such as fatty liver diseases, cancer, or hepatitis are the main reasons for malfunctioning in this organ. In this regard, developing physiologically relevant models could be remarkably useful both for the pharmaceutical industry and the study of (patho)physiology of the liver. Among different in vitro cell cultures, organ-on-a-chip (OOC) could be a promising candidate for liver studies. Liver-on-a-chip (LOC) models propose high-fidelity in vitro models by incorporating perfusion, different cell types, and 3D environment....