The Effects of Intentional Process Models on Goal Modeling and Process Conformance Checking

, M.Sc. Thesis Sharif University of Technology Farsayyad, Nazi (Author) ; Rafiei, Majid (Supervisor) ; Khedmati, Majid (Supervisor)

Abstract

In recent years, requirement engineering and goal modeling have gained more attention among different organisations. Therefore, different methods have been designed to discover stakeholders’ requirements and translate them into process and organizational goals. Various goal models have been introduced to represent these goals and their relations towards each other. Still, these methods are manual representations of different process scenarios and do not relate to the actual behavior. In 2014, Map Miner Method (MMM) was introduced to discover intentional process models from event logs. MMM uses Hidden Markov Model (HMM) as a means to represent the process as a map model of strategies and...

A Trajectory Recommendation System for Efficient Finding of Passengers

, M.Sc. Thesis Sharif University of Technology Aledavood, Ebrahim (Author) ; Khedmati, Majid (Supervisor) ; Rafiee, Majid (Supervisor)

Abstract

Recommending routes to city taxis in order to improve their performance in finding passengers can reduce traffic, pollution and waiting time for passengers, as well as this, increasing the efficiency of taxis can increase their income. In this study, by analyzing trajectory data obtained from 536 taxis in San Francisco over a period of one month, we generated networks of cells, each of which has time-dependent characteristics such as the probability of finding a passenger, the capacity of each cell, or the amount of demand exists is in the cell and the average speed of passing through that cell. also, the connections between these cells in order to make more use of the experiences of taxi...

Improving Artificial Neural Network Predictive Performance Using Panel Data

, M.Sc. Thesis Sharif University of Technology Alirezaei, Hamid Reza (Author) ; Khedmati, Majid (Supervisor) ; Rafiee, Majid (Supervisor)

Abstract

The purpose of the present study is to develop neural network estimation method for hybrid or panel data which have a combination of two cross-sectional and time series structures and because of the features of both structures, their use in different sciences offers many advantages; and the analytical methods for this data structure are also different from other one-dimensional structures, so different and specific regression models are presented for this data structure. However, in the artificial neural network method, modeling the development for this data structure is neglected, so in the present study, using the concepts of panel regression methods and their application to the...

An exploration in acoustic radiation force experienced by cylindrical shells via resonance scattering theory

, Article Ultrasonics ; Vol. 54, issue. 4 , April , 2014 , pp. 971-980 ; ISSN: 0041624X Rajabi, M ; Behzad, M ; Sharif University of Technology

2014

Abstract

In nonlinear acoustic regime, a body insonified by a sound field is known to experience a steady force that is called the acoustic radiation force (RF). This force is a second-order quantity of the velocity potential function of the ambient medium. Exploiting the sufficiency of linear solution representation of potential function in RF formulation, and following the classical resonance scattering theorem (RST) which suggests the scattered field as a superposition of the resonant field and a background (non-resonant) component, we will show that the radiation force is a composition of three components: background part, resonant part and their interaction. Due to the nonlinearity effects, each...

On the contribution of circumferential resonance modes in acoustic radiation force experienced by cylindrical shells

, Article Journal of Sound and Vibration ; Vol. 333, issue. 22 , October , 2014 , p. 5746-5761 Rajabi, M ; Behzad, M ; Sharif University of Technology

2014

Abstract

A body insonified by a constant (time-varying) intensity sound field is known to experience a steady (oscillatory) force that is called the steady-state (dynamic) acoustic radiation force. Using the classical resonance scattering theorem (RST) which suggests the scattered field as a superposition of a resonance field and a background (non-resonance) component, we show that the radiation force acting on a cylindrical shell may be synthesized as a composition of three components: background part, resonance part and their interaction. The background component reveals the pure geometrical reflection effects and illustrates a regular behavior with respect to frequency, while the others...

Point source stimulated acoustic radiation of cylindrical shells: Resonance and background fields

, Article Acta Acustica united with Acustica ; Vol. 100, issue. 2 , 2014 , pp. 215-225 ; ISSN: 16101928 Rajabi, M ; Behzad, M ; Sharif University of Technology

2014

Abstract

Objective: The method of wave function expansion in association with the spatial Fourier transform technique is adopted to study the steady-state sound radiation characteristics of a cylindrical component of infinite length subjected to an arbitrary time-harmonic on-surface concentrated radial drive. Method: Presenting the acoustical radiated coefficient as an exact function of modal accelerance function of the shell and following the classical Resonance Scattering Theory (RST), postulate that the radiated field can be synthesized as a superposition of the resonance response of the shell and a background signal within each partial wave. Utilizing the inherent background approach, we...

Interaction of a plane progressive sound wave with anisotropic cylindrical shells

, Article Composite Structures ; Vol. 116, issue. 1 , September–October , 2014 , pp. 747-760 ; ISSN: 02638223 Rajabi, M ; Behzad, M ; Sharif University of Technology

2014

Abstract

An exact analysis based on the wave function expansion is carried out to study the scattering of a plane harmonic acoustic wave incident at an arbitrary angle upon an arbitrarily thick helically filament-wound (anisotropic) cylindrical shell submerged in and filled with compressible ideal fluids. Using the laminated approximation method, a modal state equation with variable coefficients is set up in terms of appropriate displacement and stress functions and their cylindrical harmonics to present an analytical solution based on the three-dimensional exact equations of anisotropic elasticity. Taylor's expansion theorem is then employed to obtain the solution to the modal state equation,...

Efficient aerobic oxidation of alcohols using a novel combination N-hydroxy phthalimide (NHPI) and a recyclable heterogeneous cobalt complex

, Article Journal of Molecular Catalysis A: Chemical ; Volume 232, Issue 1-2 , 2005 , Pages 95-99 ; 13811169 (ISSN) Rajabi, F ; Karimi, B ; Sharif University of Technology

2005

Abstract

A novel combination between N-hydroxy phthalimide (NHPI) and a silica based cobalt (II) interphase catalyst (1) efficiently catalyzes the aerobic oxidation of various types of alcohols to the corresponding carbonyl compounds. The catalyst 1 shows high thermal stability and also could be recovered and reused in combination with NHPI for at least five reaction cycles without considerable loss of reactivity. © 2005 Elsevier B.V. All rights reserved

Modeling and Developing a Control System for Centrifigual Compressors

, M.Sc. Thesis Sharif University of Technology Rajabi, Alireza (Author) ; Ghorbanian, Kaveh (Supervisor)

Abstract

Compression systems are widely used in industry. Dynamic Modeling is a necessary step in design procedure of a safe compression system. A dynamic model should be adequate and simulate dominant elements of system. One important element of industrial compression systems is downstream pipelines. In this work, a dynamic model including pipeline acoustics is developed. It is accepted that changes of working gas molecular weight can cause inception of instabilities in compression systems. The dynamic model used to study mechanisms of these instabilities. A conventional control system is modeled and tuned for the compression system. The ability of this control system to prevent such instabilities...

Risk Management for DG Owners

, M.Sc. Thesis Sharif University of Technology Karimi, Ahmad (Author) ; Rajabi, Abbas (Supervisor)

Abstract

Distributed generation (DG) and its utilization have some benefits and risks for its owner and power network. From owner perspective, benefits of DG include selling energy, reducing costs related to fuel, and other economic benefits. However, there are some risk factors for the owner including risk of supplying fuel, risk of selling generated power, and other risk factors related to establishment of the DG unit. Utilizing risk-reduction tools such as signing agreements for selling power, purchasing fuel, and related economic tools are necessary for risk management of the owners of DG units. The purpose of this thesis is to investigate the economic situation of the DG units and optimize the...

Synthesis, Characterization and Emission Study of Bis-cyclometalated Platinum(II) Complexes Containing 2-Phenylpyridine Ligand and its Derivatives

, M.Sc. Thesis Sharif University of Technology Rajabi, Sheida (Author) ; Jamali, Sirous (Supervisor)

Abstract

The bis(cyclometalated) platinum(II) complexes of the type [Pt(ppy)(p′py)], in which ppy = p′py = 2-(p-tolyl)pyridine, 6; ppy = 2-(3-bromophenyl)pyridine, p′py = 2-(p-tolyl)pyridine, 7; ppy = 2-(2,4-difluorophenyl)pyridine, p′py = 2-(p-tolyl)pyridine, 8; ppy = 2-(2,4-difluorophenyl)pyridine, p′py = 2-(2,4-difluorophenyl)pyridine, 9, have been prepared from the reaction of the cyclometalated platinum(II) complex [Pt(ppy)Me(SMe2)] with one equiv p′py and one equiv B(C6F5)3. The structure of 6, 7 and 10 determined using X-ray crystallography in solid state. However NMR spectroscopy methods have been used for structural characterization of the complexes in solution phase. The bis(cyclometalated)...

Theoretical Development of Resonance Acoustic Spectroscopy Technique and Its Applications for Non-destructive Evaluation of Thick-walled Cylindrical Shells

, Ph.D. Dissertation Sharif University of Technology Rajabi, Majid (Author) ; Behzad, Mehdi (Supervisor)

Abstract

Resonance acoustic spectroscopy (RAS) is one of the techniques used for monitoring the production quality and evaluation of mechanical properties of cylindrical components, due to their non-destructivity, high precision and quickness.
In this technique, the resonance effects are caused by the excitation of eigenvibrations of structure by an incident acoustic wave located in far-field. The resonance spectroscopy (isolation and identification of the resonance features) is performed on the far-field scattered pressure field which contains valuable information about the characteristics of the target. Appropriate exploitation of these resonance informations from the theoretical model and...

An Investigation on Photocatalytic Properties of Sol-Gel Produced TiO2-SiO2-Ni Nanocomposite Coatings

, M.Sc. Thesis Sharif University of Technology Rajabi, Shabnam (Author) ; Ghorbani, Mohammad (Supervisor)

Abstract

Titania is one of the photocatalytic materials , but low quantum yield and relatively high band gap of TiO2 limited its applications.There are several ways to improve the photocatalytic properties of this material relied on narrowing the band gap,by doping TiO2 with other metals and oxides or increasing its specific surface area.In this work ,TiO2-SiO2-Ni coating have been made by sol-gel process and deposited on quartz substrate by using of dip-coating method .Effect of increasing Nickel content in nanocomposite and primary sol on crystalline structure,morphol ogy, photocatalytic properties and specific surface area have been investigated by means of X-Ray diffraction method, FT-IR, SEM,...

Causal Discovery and Generative Neural Networks to Identify the Functional Causal Model

, M.Sc. Thesis Sharif University of Technology Rajabi, Fatemeh (Author) ; Bahraini, Alireza (Supervisor)

Abstract

Causal discovery is of utmost importance for agents who must plan and decide based on observations. Since mistaking correlation with causation might lead to un- wanted consequences. The gold standard to discover causal relation is to perform experiments. However, experiments are in many cases expensive, unethical or impossible to perform. In these situations, there is a need for observational causal discovery. Causal discovery in the observational data setting involves making significant assumptions on the data and on the underlying causal model. This thesis aims to alleviate some of the assumptions and tries to identify the causal relationships and causal mechanisms using generative neural...

Climate Classification of the MENA (Middle East and North Africa) by Introducing a New Index for Clustering Validation

, M.Sc. Thesis Sharif University of Technology Rajabi, Reza (Author) ; Moghim, Sanaz (Supervisor)

Abstract

Clustering presents valuable information in discovery of the climatic zones. To use clustering approaches, similarity measure, clustering algorithm, and clustering validity index should be determined. To find climatic zones over Middle East nad North Africa (MENA), this study performs k-means clustering with Euclidean distance as the similarity measure on four monthly precipitation datasets (CRU, GPCC, UDEL, and PREC/L) and two monthly temperature datasets (CRU, NOAA GHCN-CAMS). This study aims to validate clustering results and find a proper number of clusters. For this purpose, five traditional validity indices are examined on experimental datasets. Results show significant differences...

Acoustic resonance scattering from a multilayered cylindrical shell with imperfect bonding

, Article Ultrasonics ; Volume 49, Issue 8 , 2009 , Pages 682-695 ; 0041624X (ISSN) Rajabi, M ; Hasheminejad, S. M ; Sharif University of Technology

2009

Abstract

The method of wave function expansion is adopted to study the three dimensional scattering of a time-harmonic plane progressive sound field obliquely incident upon a multi-layered hollow cylinder with interlaminar bonding imperfection. For the generality of solution, each layer is assumed to be cylindrically orthotropic. An approximate laminate model in the context of the modal state equations with variable coefficients along with the classical T-matrix solution technique is set up for each layer to solve for the unknown modal scattering and transmission coefficients. A linear spring model is used to describe the interlaminar adhesive bonding whose effects are incorporated into the global...

A cheap, simple, and versatile method for acetylation of alcohols and phenols and selective deprotection of aromatic acetates under solvent-free condition

, Article Synthetic Communications ; Volume 35, Issue 3 , 2005 , Pages 483-491 ; 00397911 (ISSN) Rajabi, F ; Saidi, M. R ; Sharif University of Technology

2005

Abstract

Acyclic and cyclic acetates of various alcohols and phenols were obtained in excellent yields under mild reaction conditions in the presence of a catalytic amount of sodium hydroxide under solvent-free conditions and microwave irradiation. Selective deprotection of acetate group from the corresponding phenolic compounds was carried out in the presence of LiClO4· 2H2O. Copyright © Taylor & Francis, Inc

Solid lithium perchlorate-mediated conjugate addition of thiols and indoles to α,β-unsaturated carbonyl compounds

, Article Journal of Sulfur Chemistry ; Volume 26, Issue 3 , 2005 , Pages 251-259 ; 17415993 (ISSN) Rajabi, F ; Saidi, M. R ; Sharif University of Technology

2005

Abstract

A simple, efficient, and general synthetic strategy has been developed for the synthesis of Michael adducts in the presence of solid lithium perchlorate under solvent-free conditions. Nucleophilic addition of thiols and indoles gave the corresponding Michael adducts in high yields. © 2005 Taylor & Francis

Microwave-assisted methylation of carboxylic acids and phenolic compounds with dimethyl-carbonate under solvent-free condition

, Article Synthetic Communications ; Volume 34, Issue 22 , 2004 , Pages 4179-4188 ; 00397911 (ISSN) Rajabi, F ; Saidi, M. R ; Sharif University of Technology

2004

Abstract

Phenolic compounds and carboxylic acids are methylated with dimethyl carbonate in the presence of a catalytic amount of BF3· OEt2, DBU, or KOH, in good to excellent yields under microwave irradiation and solvent-free conditions

Local Community Detection in Social

, M.Sc. Thesis Sharif University of Technology Rajabi, Arezoo (Author) ; Rabiee, Hamid Reza (Supervisor)

Abstract

The fast growth of social networks and their wide range of applications have made the anal-ysis of them an interesting field of research. The growth of concern in modeling large social networksand investigation of their structural features leads studies towards community detec-tion in such networks. In recent years, a great amount of effort has been done for introducing community detection algorithms, many of which are based on optimization of a global cri-terion which needs network’s topology. However, because of big size of most of the social networks , accessing their global information tends to be impossible. Hence, local commu-nity detection algorithms have been introduced. In this...