Parallel machine scheduling problem with preemptive jobs and transportation delay

, Article Computers and Operations Research ; Vol. 50, issue , Oct , 2014 , p. 14-23 Shams, H ; Salmasi, N ; Sharif University of Technology

2014

Abstract

In this research the parallel machine scheduling problem with preemption by considering a constant transportation delay for migrated jobs and minimization of makespan as the criterion i.e., Pm|pmtn(delay)|Cmax is investigated. It is assumed that when a preempted job resumes on another machine, it is required a delay between the processing time of the job on these two machines. This delay is called transportation delay. We criticize an existing mathematical model for the research problem in the literature [Boudhar M, Haned A. Preemptive scheduling in the presence of transportation times. Computers & Operations Research 2009; 36(8):2387-93]. Then, we prove that there exists an optimal schedule...

Experimental study of two-phase oil – Polymer flow in horizontal flow path

, Article Experimental Thermal and Fluid Science ; Volume 100 , 2019 , Pages 62-75 ; 08941777 (ISSN) Shams, R ; Shad, S ; Sharif University of Technology

Elsevier Inc 2019

Abstract

Two-phase flow inside the oil and gas wells and flow path lines is a usual occurrence in petroleum and petrochemical studies. Due to its complexity, flow transfer parameters such as hold up and pressure drop and their dependency on the flow regime maps are not well understood yet. This study is aimed at analyzing holdup for oil- water system and evaluation of this parameter by means of Image processing under different available flow regime conditions. In addition, different oil-polymer systems have been studied to evaluate the impact of polymer concentration on transport criteria. The experimental setup used for this study is consisted of a 12 m long Plexiglas pipe with an inner diameter of...

Experimental study of two-phase oil – Polymer flow in horizontal flow path

, Article Experimental Thermal and Fluid Science ; Volume 100 , 2019 , Pages 62-75 ; 08941777 (ISSN) Shams, R ; Shad, S ; Sharif University of Technology

Elsevier Inc 2019

Abstract

Two-phase flow inside the oil and gas wells and flow path lines is a usual occurrence in petroleum and petrochemical studies. Due to its complexity, flow transfer parameters such as hold up and pressure drop and their dependency on the flow regime maps are not well understood yet. This study is aimed at analyzing holdup for oil- water system and evaluation of this parameter by means of Image processing under different available flow regime conditions. In addition, different oil-polymer systems have been studied to evaluate the impact of polymer concentration on transport criteria. The experimental setup used for this study is consisted of a 12 m long Plexiglas pipe with an inner diameter of...

Seismic Design of Substation Structures with Consideration of IEEE-693

, M.Sc. Thesis Sharif University of Technology Shams, Mohammad (Author) ; Mofid, Massoud (Supervisor)

Abstract

The Reliability of substation structures with consideration of earthquake uncertainties is one of the most important subjects in structural analysis in recent years. In this project we first introduce IEEE-693-2005, which is the most effective and comprehensive seismic design code for electronic substations. Also in second chapter the rudimentary aspects of Reliability Theory and methods for evaluating the reliability of substation structures is introduced. Then with modeling the most common and most important electronic substation devices in Iran, with consideration of all seismic parameters and their uncertainties, the reliability of these structures evaluated. In this project for...

Scheduling on Parallel Machines with Preemption and Transportation Delays using a Particle Swarm Optimization (PSO)-Based Algorithm

, M.Sc. Thesis Sharif University of Technology Shams, Hesam (Author) ; Shadrokh, Shahram (Supervisor)

Abstract

This research deals with the problem of scheduling independent preemptive jobs on identical parallel machines, to minimize the total completion time (makespan). The transportation of an interrupted job from a machine to another machine requires considering a constant transportation delay i.e., Pm|prmp(delay)| Cmax. This delay is called transportation delay. We propose a Mixed Integer Linear Programming formulation for the research problem in case of two machines i.e., P2|prmp(delay)| Cmax. Since the research problem is shown to be NP-hard, a particle swarm optimization (PSO) algorithm is applied to solve the problem approximately. Based on the frequency of using local search procedure, three...

Speaker Adaptation in Eigen Voice Space for Statistical Parametric Speech Syntheis

, M.Sc. Thesis Sharif University of Technology Shams, Boshra (Author) ; Sameti, Hossein (Supervisor)

Abstract

Recently various speaker adaptation methods in HMM-based speech synthesis are proposed. The importance of adaptation techniques is that we can design a system in which speech is generated with high quality and target speaker characteristics through limited adaptation data sets.
In this research, we focus on adaptation based on clustering and develop a new and novel method using eigenvoices in order to adapt a new speaker. We employ this approach for the first time in HSMM-based speech synthesis systems and its goal is to reduce the parameters and adaptation data of the system. In our proposed method, first some speaker dependent models are trained. For each model we combine the...

A Simulation for Better Understanding of Integrin Clustering and Activation

, M.Sc. Thesis Sharif University of Technology Shams, Shahab (Author) ; Motahhari, Abolfazl (Supervisor)

Abstract

Today, computer simulations are employed prevalently by researchers to understand biological processes. The tendency to use computational methods has been increased recently due to the high costs and errors of experimental methods. Integrins are membrane proteins that mechanically attach cells to the extra cellular matrix (ECM) and derive some behaviors such as cell migration. Moreover, integrins have biochemical functions. They transduce environment signals and trigger chemical pathways. As a result, integrins regulate cell shape, motility, etc. The investigation of integrin behavior in a real environment is very difficult due to the presence of many other proteins that interfere with the...

Modeling Propagation of Cardiac Action Potential at Cellular Level

, M.Sc. Thesis Sharif University of Technology Farahani, Mojtaba (Author) ; Jahed, Mehran (Supervisor)

Abstract

Heartbeat is the result of contractions of over 10 billion cardiac cells. These cells’ cytoplasms are connected to each other by gap junctions which are arrays of intercellular protein channels. Thus action potential can propagate from one cell to another and cause its contraction. In core-conductor model, one-dimensional microscopic representation of cardiac tissue, cells are attached to each other to form a ladder network. The parallel elements are connected to each other by series resistors which represent gap junctions. These resistors are nearly always considered as static elements. In this thesis I have investigated the effects of incorporating the dynamicity of gap junction resistors...

Distributed Cardiovascular System Modeling

, M.Sc. Thesis Sharif University of Technology Khani, Mehrdad (Author) ; Jahed, Mehran (Supervisor)

Abstract

Simulation of cardiovascular system functionality during various physiological conditions is essential at different diagnostic and clinical levels. A first step in studying the roots of cardiovascular diseases and abnormal activity is to study a practical yet complete model of the cardiovascular system. In this thesis we introduced a new approach for defining the distributed model of the cardiovascular system. Initially, we chose an appropriate subsystem, namely Arch of Aorta, and proposed a distributed model for it. The elements of the proposed model were nonlinear RLC elements that simulate resistance, blood viscosity and vessel elasticity respectively. To minimize the system complexity,...

Risk Breakdown Structure (RBS) Identification and Designing for projects

, M.Sc. Thesis Sharif University of Technology Abdi, Mehdi (Author) ; Sepehri, Mehran (Supervisor)

Abstract

To actualize and making the outputs of a project effectual, it is necessary to conduct an effective management during a project. This case may not be possible without accurately planning for activities, management and controlling all phases of a project ignoring the risk management of that project. If risks of a project cannot be detected before conducting a project, it is possible to challenge the performance and even effectiveness of the project. In current conditions, the most important problem of managers and executives of construction projects through the country is risk management of projects, not acknowledging with definitions of risk, models of risk management and lack of a model for...

Introducing a suitable Controller for Rowing Activity in Patients with Spinal CordInjuries using FES

, M.Sc. Thesis Sharif University of Technology Zarei, Mohammad (Author) ; Jahed, Mehran (Supervisor)

Abstract

Disconnections in neural paths from the central nervous system to the muscles or vice versa cause different neuropathies, thus paralysis in different limbs may occur. As a result of the lack of muscular activity and the decrease in blood perfusion in paralyzed limbs, problems like osteoporosis, increase in the risk of breaking, decline in muscle size, cardiovascular diseases, renal dysfunction, bedsores, etc may happen. In order to induce movement in paralyzed limbs, thus preventingmentioned problems, rowing exercise through Functional Electrical Stimulation (FES) may be utilized. In FES, electrical Stimulation using current stimulating pulses is applied to contracting and relaxing muscles,...

Performance Management of HSE Management System based on BSC Framework-the Case Study of Mapna Corporation

, M.Sc. Thesis Sharif University of Technology Naseri, Amin (Author) ; Sepehri, Mehran (Supervisor)

Abstract

A Balanced Scorecard (BSC) model is proposed to evaluate performance of Health, Safety and Environment (HSE) management systems. This model includes key performance indicators at three integrated levels. It has been tested and verified in a project-based organization in Iran, active in the area of power and energy. Results show that the company has done well in implementing HSE management processes, but no so well in growth and learning. This model may be used as a basis for comparing different companies and various proposed programs in the field of HSE management systems. The model includes indicators and sub-indicators in each category particularly related to stakeholders, processes, and...

Functional Modeling of Normal and CHF Heart and Control of Total Artificial Heart- An Optimizing Approach

, Ph.D. Dissertation Sharif University of Technology Ravanshadi, Samin (Author) ; Jahed, Mehran (Supervisor)

Abstract

World-wide, Congestive Heart Failure (CHF) takes hundreds of thousands of lives each year. This chronic heart disease causes poor performance of the heart and insufficient blood pumping to the organs. A significant percentage of patients with CHF require heart transplants for their survival. The high cost of heart transplant, shortage of donor hearts and possibility of its rejection by recipients are serious problems of this type of treatment. Therefore a large number of heart patients are potential beneficiaries of artificial blood pumps such as Ventricular Assist Device (VAD) and Total Artificial Heart (TAH). Performance of these systems must be compliant and complementary to the existing...

Identifying Affecting HR Factors on Unsuccessful Reengineering Projects

, M.Sc. Thesis Sharif University of Technology Kordrostami, Melika (Author) ; Sepehri, Mehran (Supervisor)

Abstract

In this study, factors which lead in failures in reengineering processes in project based companies have been investigated. The research used qualitative methods, and finally using theme analysis to identify the main factors.Consequently, the main causes of failure of re-engineering projects have been identified and classified in six basic categories including: organizational leadership, planning, human resources management, mental models causing resistance, culture and organizational climate and communication. That each of these themes includes some subset of the agents it represents. In this study, a suitable pattern for organizations which intend to perform reengineering has been...

Applying Tandem CONWIP Policy to Assembly Supply Chain

, M.Sc. Thesis Sharif University of Technology Shokoohyar, Sina (Author) ; Sepehri, Mehran (Supervisor)

Abstract

Supply chain management has been developed extensively in second half of last century and the development has been continued up to present century. Nowadays Development and conformity of production and inventory control methods with JIT philosophy in production line level is one of the topics that received much attention from researchers. An increasing interest in the scope of JIT philosophy is on the extension and adaptation of Pull policies such as Kanban and CONWIP for materials and production control. In a real-life environment, companies are subjected to various types of uncertainties such as stochastic processing times and variable demand. This uncertain environment could cause lots...

Joint Segmentation and Motion Estimation of Cardiac Cine MR Image Sequences

, Ph.D. Dissertation Sharif University of Technology Eslami, Abouzar (Author) ; Jahed, Mehran (Supervisor)

Abstract

In this study a variational framework for joint segmentation and motion estimation is provided for inspecting heart in Cine MRI sequences. In the first work, a functional including Mumford-Shah segmentation and optical flow based dense motion estimation is proposed. However, the motion estimation technique is replaced with warping estimation in the second work to reach in more regular and smooth motion field based on tracking of cardiac boundaries. Both of these functionals are then approximated by using the phase-field method to make them suitable for extracting Euler-Lagrange equations. Numerical solution to the optimization problem, when the time and image spaces are discretized by finite...

Dynamics and Control of Needle Movement in Percutaneous Interaction with Prostate Tissue

, Ph.D. Dissertation Sharif University of Technology Maghsoudi, Arash (Author) ; Jahed, Mehran (Supervisor)

Abstract

In many modern medical procedures, needle insertion is an inevitable part of the diagnosis or treatment protocols. The accuracy of the needle insertion is adversely affected by a number of factors. A needle, frequently assumed to be flexible, is inserted into a soft tissue and induces complex mechanical interactions that may result in considerable uncertainties. Tissue intrinsic characteristics as well as its deformation and rotation may cause dramatic complexities. This work considers the needle movement inside the tissue from the dynamics and control point of view. The proposed approach can be regarded as an initial step towards automation of needle insertion procedures; it can also be...

Needle Steering in Soft Tissue

, M.Sc. Thesis Sharif University of Technology Haghighi, Payam (Author) ; Jahed, Mehran (Supervisor)

Abstract

Medical needle interventions are a common technique for accessing tissue structures.In these procedures, needles are used, for example, to extract biopsy samples, brachytherapy, and to insert drugs. In TRUS guided prostate brachytherapy application, Physicians used ulterasound imaging to steer the needle and insert radioactive seeds into cancerous tumors to irradiate surrounding tissue over several months. Prostate rotation, deformation, and unavailability of imaging data during part of the insertion path result in misplaced seeds. To overcome these problems, in this research, we modeled the prostate, its membrane and the surrounding fatty tissue as linearly elastic homogenous material, and...

Considering Lessons Learned and Ascertaining Their Roadmap in Project Management (Case Study: Sepanir Company)

, M.Sc. Thesis Sharif University of Technology Aftabi, Meysam (Author) ; Sepehri, Mehran (Supervisor)

Abstract

Evolutions in the economy, society and politics has raised knowledge as a key element in the development and competitiveness and knowledge management is considered one of the essential elements in this field. By taking temporary nature of the project into account, dynamics and competition in the project-oriented organizations business world makes the preservation and management of knowledge in project-based organizations more important. Lesson learned system is one of the knowledge management tools that can propose strategic solutions which avoid wasting of time and money and make perfect use of knowledge management accomplishments.In this study, by using literature review, interview and...

Pathology Analysis and Multi-Class Discrimination for Laryngeal Disorders

, M.Sc. Thesis Sharif University of Technology Pakravan, Mansooreh (Author) ; Jahed, Mehran (Supervisor)

Abstract

Ability to speak lucidly plays a key role in social relations. Consequently the role of larynx is quite important and timely diagnosis of laryngeal diseases has proved to be crucial. Since conventional diagnostic methods of the larynx are usually expensive or bothersome, the aim of this project is to analyze and classify diseases of the larynx with the aid of signal processing which tend to be faster and easier to implement and quite economical. This study utilizes the vowel sound /a/ and a well referenced database, namely MEEI (Massachusetts Eye and Ear Infirmary) which includes 53 normal and 213 abnormal voices in 7 classified diseases. In this work, using existing signal modeling and...