Sharif Digital Repository

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... 

The mankind has always utilized vision as the most essential tool in evaluating his environment. Currently, one of the most important research areas in computer vision is to characterize a three dimensional object through its features in a natural scene. This task may be conducted through a stereo vision system. The objective of this study is to introduce a quantitative measure in order to evaluate the operation of an automatic recognition system for selected hand postures. A key application of our proposed system is to train a prosthetic hand through surface electromyogram (sEMG) signals. At the onset of this process, the patient conducts a certain posture through application of sEMG... 

Ultrasound hyperthermia is a commonly used noninvasive approach to destroy cancer tumors. High Intensity Focused Ultrasound (HIFU) is a technique based on hyperthermia. It creates short and local elevations of temperature at a focus site within the tissue of interest. The main goal of HIFU is to maintain the temperature between 50 and 100 °C for a few seconds (typically less than 10 s), in order to cause tissue necrosis. In order to predict the effects of hyperthermia, accurate and effective modeling is needed. This study considers a 3D simulation of the hyperthermia based on HIFU method in the liver tissue. Temperature distribution and lesion volume changes, with a temperature of above... 

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... 

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... 

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,... 

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... 

Gesture and motion evaluation are needed for a variety of applications. The use of human hand motions as a natural interface tool has motivated researchers to conduct research in the modeling, analysis and evaluation of various hand movements. In particular, human-computer intelligent interaction has been a focus of research in vision-based gesture recognition. In this work, we introduce a 3-D hand model evaluation method that offers flexible and elaborate representation of hand motion. We used landmarked points on tips and joints of the fingers and calculated the 3-D coordinates of these points through a stereo vision system followed by an HMM (Hidden Markov Model) to recognize hand... 

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... 

Despite a rather long history of bureaucratic public administration, Iranian public sector has failed to catch up with the ever developing knowledge of fighting corruption in “public procurement”, a critical field of governmental management which accounts for at least 15 percent of GDP around the world. While international organizations like TI and OECD have been broadly active in globalizing the standards of integrity and calling for improvements in the national frameworks of procurement, a reductionist agenda might take the safest path of change by following whatever prescribed by those international bodies. However, there have also been some deeper reflections on the complexities of... 

Wireless Body Area Network (WBAN) is one of the emerging technological trends that paves the way for the next generation medical systems by offering proactive wellness management and early detection of diseases. WBAN, as standardized by IEEE 802.15.6, is a network composed of intelligent, miniaturized, low power sensors that are strategically implanted in, placed on, or in close proximity to the human body. The sensors have responsibility for recording vital physiological signals and wirelessly transmitting them to a central hub for further processing. In this study, we have first investigated the applicable channel models for a typical WBAN. Considering various scenarios with different... 

This study is a report on the fabrication of a novel single-chamber micro-structure microbial fuel cell consisting of spiral anode chamber. A 3×3 cm plexiglass plate with 1 mm thickness was used as main body. A spiral microchannel (1 mm in width and 226 mm in length) was cut using a laser beam as an anodic compartment. Two types of microbial fuel cells with the same anode electrode (stainless steel mesh) and different cathode electrodes (stainless steel mesh and carbon cloth) were constructed in order to investigate the effect of cathode electrode material on microbial fuel cell performance. In both batch and continuous mode, higher power density was obtained by microbial fuel cell with... 

Physiotherapy is a major part of the rehabilitation process that is used to retrieve patients' physical ability. The recuperation feedback in the physiotherapy process has a twofold significance for both physiotherapists and patients. It helps patients regain their ability to recover more quickly, prevent recurrence of injury to the treated area and other areas, and motivate the patient to continue treatment. It also helps the physiotherapist to monitor the process of rehabilitation and ensure the correctness of the procedure. Meanwhile, many patients cannot maintain continuous workouts due to lack of access to the physiotherapist at home and inability to provide required feedback.In this... 

In the literature of motor behavior, rapid and harmonious human movements and adaptation to limb dynamics are described with reference to internal models. Concepts of internal models in neuroscience cognitive sciences and computational modeling have been investigated and their structure and performance have been evaluated by behavioral, neurophysiological and medical imaging data. The purpose of the theory of internal models is to explain the mechanism of human movement. Based on this theory, the central nervous system uses internal models to predict and adjust movements and reduce uncertainty. Uncertainty refers to the unknown dynamics of the system due to the lack of access to accurate... 

The goal of this research is to study the effective factors in order to overcome resistance to change. In today’s competitive world, change is the most critical competitive advantage of an organization to adapt to new circumstances. The failure rate of change projets is more than 70% and there are various factors responsible for this high rate. One of the most important factors is resistance to change. In this research, traditional studies of change starting in the 19’s by Kurt Lewin is the strat point, who had initiated the studies of this field with his three-step model. In recent decades, newer models have emerged which in contrast with previous versions, focused on an individual as the... 

Motor imagery causes Event related Synchronization/Desynchronization (ERS/ERD) in Electroencephalogram (EEG) signal. These potentials can be used as an input for a Brain Computer Interface (BCI) system. To do so, it is necessary for these inputs to be correctly classified. The quality of classification is severely affected by the features extracted. Common Spatial Patterns (CSP) algorithm is often used for this task. Some of this method disadvantages are neglecting non-stationary properties of EEG signal and its proneness to overfitting. Additionally, its success is highly dependent on the frequency band that the algorithm is performed in. The most suitable sub band is interchangeable... 

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... 

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... 

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...