Sharif Digital Repository

Parkinson's disease is a progressive neurodegenerative disease in which balance disorders are a common symptom. Clinical and non-clinical methods have been developed to evaluate the quality of maintaining balance. Clinical methods include questionnaires and tests that are scored by the therapist and therefore depend on the examiner's skill. On the other hand, there are biomechanical methods that do not depend on the therapist's skill. Posturography -based methods are among the biomechanical tests used today to assess balance. In these methods, some indicators are extracted from the patient's foot center of pressure that can measure the quality of balance. These studies usually examine the... 

Parkinson's disease, after Alzheimer's, is the most important and common progressive neurodegenerative disorders. There are various methods for assessing the quality of patients’ movements. One of them is biomechanical methods. The application of these methods in telerehabilitation has been considered by many researchers. Telerehabilitation improves the efficiency of the therapists and reduces problems such as commute costs, traffic stress, and patient fatigue.In the present study, 21 Parkinson patients were treated and evaluated remotely using SANA system. This study aimed to investigate the effects of the therapist absence during the tele-assessment and its impact on the validity and... 

Background: Parkinson’s disease (PD) patients seriously suffer from instability and impaired postural control. Rehabilitation exercises help them to recover their ability through long-term practical sessions. For designing optimal tasks in each session, and in agreement with each patient’s state, it is essential to employ computational models and approaches.Objective: The goal of this study is to develop a computational postural control model of Parkinson’s disease in order to provide new understanding of the postural control in PD, and to gain insight on the effect of balance trainings on PD (the learning dynamics), from the view of this model.Methods: In the first phase of this study, the... 

High-Speed Crafts’ motion has lots of hydrodynamic complexities, so analytical study of their motion is not feasible. Meanwhile, experimental analysis of their reactions in water is not time-consuming & cost-effective. In spite of code generating & developing problems and complexities in the primary stage of numerical modeling of such problems, this method is the most popular & efficient one. On the other hand, flow around high-speed craft bodies has a turbulent nature and needs special cares to predict reasonable results. In the present study, after representing an introduction about the turbulence modeling, we discissed about governing equation such as momentum, volume fraction and rigid... 

Multilateral wells are relatively new alternatives in field development and because they can increase the productivity per well and reduce the cost of field development, they are rapidly replacing old methods. In order to predict the performance of well, three methods are usually used: Analytical methods which use closed-forms models, semi-analytical methods which entails line-source model and numerical methods which is based on techniques such as finite volume or finite difference. In this thesis, line-source model is extended from two dimensional forms to three dimensional forms in order to be used to optimize the path of multilateral wells. Optimization entails direct optimization... 

With occurring severe earthquakes, damages of columns in RC buildings can lead to overall failure and collapse. So retrofitting of such columns that do not comply with the design requirements is necessary to prevent such phenomena. A variety of methods has been introduced so far for retrofitting. The key factors in determining the retrofitting methods are being economic and easily implemented in the design. Confining concrete columns with pre-stressed steel strips is a new technique that is simple and economic. Previous experimental experiments have shown that this method can enhance ductility and overall seismic behavior of such columns.
In the present study three and six story frames... 

Digital image analysis of histological datasets is a currently expanding field of research. Histological images are inherently complex in nature and contain a wide variety of visual information. Graph-based methods have recently gained immense popularity, as these methods can effectively describe tissue architecture and provide adequate numeric information for subsequent computer-based analysis. Graphs have the ability to represent spatial arrangements and neighborhood relationships of different tissue components, which are essential characteristics observed visually by pathologists during the investigation of specimens. In this thesis, we proposed an automatic approach for classification... 

Engineering of properties was previously not possible. With the advent of additive manufacturing, it became possible to produce structures with architected microstructures, known as lattice structures. The popularity of these structures, due to their lightweight and tunable properties, has increased the importance of their optimal mechanical analysis. Since direct analysis of these structures is computationally prohibitive due to their high level of detail, homogenization methods have been proposed as an alternative. Since these methods couldn't capture size effects, higher-order homogenization methods were introduced. However, despite their good accuracy, these methods are still rarely used... 

Reinforcement Learning (RL) is a branch of machine learning that tries to improve agent’s behaviour through interaction with environment and receiving reinforcement signal. As the size of environment increases, decision-making would be more difficult and learning time will increase. On of the main approaches for decreasing learning complexity is to define skills. Skill is a behavioural unit consists of primitive actions. Humans learn and use a lot of skills in their life. Walking, eating, passing the door to reach kitchen and going to airport for travelling are examples of such skills that humans utilize them for daily activities. Agent can learn skills once and then uses them in other... 

The concurrent flow of oil and water is a common occurrence in the field of multiphase flow in different fields including petroleum industry. In oil and gas, production engineers often face a situation in which more than one phase is flowing through the producers. In such conditions an accurate assessment of pressure loss inside the well plays a vital role in efficient and effective production planning. Changes in well orientation, wellbore diameter, reservoir and fluid properties as well as fluid flow rates are among parameters in which will affect the flow patterns that can occur inside a well during its life time. These flow patterns are created as a result of a competition between... 

Casing design is one of the most expensive parts in the drilling of oil wells, and any cost reduction with the basic design of these casing strings will significantly reduce the total cost of the operation. In recent years, occurring scenarios-based casing design has become popular; Because in many cases, it eliminates non-occurring scenarios such as gas kick and saves on drilling costs. In this study, we have tried to investigate all scenarios that may occur during the lifetime of the well, whether drilling or production, and for each well, based on its own field information, possible scenarios for each casing part are selected separately and the applying loads are calculated. For this...