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...

Impelementation of Numerical Method For Hydrodynamic Behavior for Salvage of a Sunken Ship

, M.Sc. Thesis Sharif University of Technology Jelodari, Ehsan (Author) ; Abbaspour, Majid (Supervisor)

Abstract

One of the utmost important factors during salvage operation of drowned ships is raising velocity. Uncontrolled raise is a dynamic phenomenon which can lead to the sudden tensions, collapse in airbags or ships. Studing this issue helps the engineers which kinds of problems are more important during salvage operations. This study focus on modeling and analysis of raising movment of the ship with FLOW-3D and ABAQUS software.
In FLOW-3D environment, hydrodynamic analysis of rising movment of drowned ship has been done. We should mention that applied forces and velocities and other parameters from the FLOW-3D output should be passed IMCA Criteria to avoid uncontrollable raise. In ABAQUS...

The Application of Profile Monitoring in Healthcare for Disease Monitoring- case Study

, M.Sc. Thesis Sharif University of Technology Chabok, Sheyda (Author) ; Rafiee, Majid (Supervisor)

Abstract

Profile Monitoring is a new research topics in the field of statistical process control. In many applications of statistical quality control, sometimes quality of a process or product described by a relationship between a response variable and one or more independent variables.The researchers call this relationship profile. The study seeks to demonstrate that monitoring profiles In addition, the industry can be effective in medical field and improves control of the patient's condition by a doctor. Profiles are usually modeled with a linear regression equation, non-linear or polynomial. finally, the results of this study, using actual data, models and methods to predict and control...

Experimental Study on Extracting Clean Energy from Vortex Induced Vibration

, M.Sc. Thesis Sharif University of Technology Mohtat, Pouya (Author) ; Abbaspour, Majid (Supervisor)

Abstract

Two experimental models were designed and tested to extract energy from vortex induced vibrations of a elastically mounted one degree of freedom rigid cylinder in the Reynolds range of 120000 < Re <220000. In the first model the amplitude and frequency of the movement was measured then a second model was designed to be tested in the Emam Hossein marine laboratory. The model was designed in a way that many of its properties like mass ratio, spring constant and damping coefficient were able to be altered. In this study the vortex induced vibration of an elastically mounted cylinder was scrutinized in high Reynolds and very low mass ratios for the first time and an amplitude ratio of 2.49 were...

Optimization of Radiotherapy Plan under Uncertainty

, M.Sc. Thesis Sharif University of Technology Amir, Atabeiki (Author) ; Rafiee, Majid (Supervisor)

Abstract

As a method of cancer treatment or improvement of cancer-related complications, external radiation therapy is prescribed by physicians, in case of detection of a tumor in a region of patient’s body. Over time, various techniques have been developed for external beam radiation therapy. Among which, Intensity Modulated Radiation Therapy (IMRT), due to its ability to adjust the intensity of radiation beams, has a higher capacity to generate appropriate dose distribution based on tumor size and volume and it is one of the most widely used techniques in cancer treatment centers.The core process in treatment planning is using appropriate computer algorithms which results in posing enough damage to...

Location and Relocation of Ambulances under Uncertainty Conditions

, M.Sc. Thesis Sharif University of Technology Firooze, Saeed (Author) ; Rafiee, Majid (Supervisor)

Abstract

The aim of Emergency Medical Services (EMS) is to provide fast medical care and to transport patients to hospitals at the earliest possible time, so as to reduce injury and fatality rate. Healthcare managers try to improve healthcare systems by reducing the response time to demands. In this thesis, we present mathematical models for the problem of location and relocation of emergency vehicles after the end of their service time or after they have returned to a hospital. We believe that implementing these models can help managers improve the performance of emergency medical services. In the first part of this study, we present a two-level deterministic optimization model considering demand...