Sharif Digital Repository

The use of super-swelling polymers is steadily increasing and the applications in industry are continuing to grow. With the authorization of the superabsorbents in food packaging by the Food and Drug Administration recently, demand may soon take off in the market. The worldwide production of SAPs is more than one million tons per year, representing a multibillion-dollar market. However, the increase in prices of petroleum products in recent years may be a drawback for these acrylic-based materials. Thus, there is now a need to develop natural-based super-swelling hydrogels which are more economical and environment friendly. In addition, the super-swelling gels are promising novel functions... 

Nowadays, BDI architecture is of the most well known agent’s architectures. BDI architecture or the architecture in which the system is viewed as rational agents based on the attitudes of belief, desire and intention represents an abstraction of human deliberation based on a theory of rational action in the human cognition process. BDI logic introduced by Rao and Georgeff have been widely used as the theoretical basis of specification and implementation of rational agents. BDI logic is limited to deal with crisp assertion, while the assertions encountered in real world are not precise and thus cannot be treated simply by using yes or no. Moreover, In order to obtain more human like agents we... 

Although rural inhabitants constitute a large portion of developing countries’ population, they have always been neglected in many ways. Expansion of equity, calls for a new concern in adequacy of rural development. The problem could be considered in two aspects: Firstly, there is a great tendency for immigration to nearby cities, hoping for a better life. This would result in more crowded cities, extended poverty and an increasing rate of crime mainly in suburban areas. On the other hand, the evacuation of farms and fertilized lands imposes great economical loss to the country. Therefore, development of rural facilities should be integrated into national policies to assure a homogeneous and... 

As the size and complexity of software increase, the number of software vulnerabilities also increases. An examination of vulnerability reports shows that in addition to the fact that a large number of unknown vulnerabilities still exist in software, there is still no proper solution for identifying vulnerabilities that have been observed one sample of them exit in real-world software. The main reason for such an event is the lack of a suitable template for recognized vulnerabilities, which ultimately makes searching for them in other software a problem of scalability and high search cost. This thesis, recognizing the importance of the issue, presents a framework for extracting robust and... 

Airports are one of the most important elements of the aviation system that provide the ground infrastructure that is required for enabling or flight across the globe. Master Planning is currently the dominant approach to airport strategic planning. However, history shows that this approach can often result in costly mistakes. Because there are many stakeholders with conflicting objectives, deep uncertainty about the future, and many potential strategies, planners often narrow their scope by using a single forecast for the future, leaving out alternative strategies, and excluding stakeholders, resulting in a Master Plan that quickly becomes obsolete and may be opposed by some stakeholders.... 

In order to perform laparoscopic surgery of large intra-abdominal organs with minimum trauma on patient’s body, an endoscopic tool is designed, analyzed and fabricated in this project. This instrument is capable of passing through a 10mm incision point on patient’s abdomen and then be opened to grasp and hold large organs up to 80mm in diameter. It acts as a miniature hand with three fingers which are opened and closed parallel with each other. Using this tool, there will be no need for a 7-9 cm incision for entering surgeon hand which is required in hand assisted laparoscopic surgery method. In order to evaluate the capability of the tool in grasping and manipulating large organs, the... 

Walking on legs using orthosis for spinal cord injury patients has many advantages and decreases the physiological and psychological problems comparing with wheelchair application, however high energy consumption and early exhaustion of patients are disadvantages of orthosis usage. The most important group of orthosis for spinal cord injury patients is RGO (Reciprocating Gait Orhtosis) which a reciprocating cable mechanism links two hip joints motion. So swinging of mobile leg gets easier and stability of patient in standing and walking step increases. Regarding to existent reports about high energy consumption in walking by orthosis, this project has been fulfilled to design an improved... 

Common fracture treatments include open reduction and intramedullary nailing technology. However, these methods have disadvantages such as intraoperative X-ray radiation, delayed union or nonunion and postoperative rotation. Robots provide a novel solution to the aforementioned problems while having new challenges. The robotic system used in the study by providing more precise motion and exerting higher amount of forces makes the operation procedure more straightforward. In a normal operation 300-400 N of extension force would be needed which is fully provided by the surgen which leads to physical his/her (khastegi), by using the robotic system however, this force is simply provided without... 

In recent years, computer haptics research area have gradually grown all around the world. It deals with displaying the rendered contact properties in a virtual environment to a human user while interaction to a haptic interface. In general, a haptic interface provides essential haptic feedback information of a remote environment to a human user. The human operator, as a part of computer haptic system, will usually make an interaction by the haptic interface in a real environment which is usually limited to the end-effector of the physical device. On the other hand, the virtual tool in the virtual environment will interact by the virtual based remote environment which is generated from the... 

Sina surgical system is a telesurgery robotic system which is capable of using the conventional laparoscopic tools. In order to provide the wrist degree of freedom and increase the surgical maneuverability, a mechanism is introduced here which enables Sina to use and activate the wristed laparoscopic instrument Laparo-Angle. At first, the kinematics and dynamics characteristics of Laparo-Angle were identified experimentally. This tool contains 4 degrees of freedom, pitch, yaw, grasp and distal Roll. Activation of pitch and Yaw degrees of freedom requires a mechanism which at least has two rotational degrees of freedom to move the tool handle in a cone shape workspace with an apex angle of 36... 

A popular way for performing minimally invasive heart surgery is to use cardiac stabilizers that fix the heart during surgery. In the recent years several research works have been conducted to develop effective cardiac stabilizers. While these developments have attempted to improve fixation of the heart, there are reports indicating that a rigid cardiac stabilization may induce injury to heart muscle tissues due to restricting the heart motion in all directions. A more efficient approach than rigid cardiac stabilization might be to use a flexible cardiac stabilizer in combination with a surgical robot having motion compensation capability. The scope of this research is designing a device to... 

2D-3D image registration has been adopted in many clinical applications such as kinematic analysis of bones in knee and ankle joints. Because it is not possible to take dynamic images in 3D and 2D dynamic images such as fluoroscopic images lack spatial information. For comparing two images it’s necessary to make their dimensions the same. So in this research we prepared a code in MATLAB to generate digitally Reconstructed Radiograph (DRR) from the CT image in different positions and then be compared with 2D fluoroscopic image. Registering two images could be done either with comparing their intensities or their mutual features. We combined these two methods and developed a cost function with... 

In this study, pyrolysis features and corresponding kinetic behavior of non-metallic fractions of the paper-laminated phenol resin printed circuit boards (P-PCB) and fiberglass-reinforced epoxy resin printed circuit boards (E-PCB) were investigated by the use of simultaneous thermogravimetric analysis (TGA/DTG). The kinetic parameters of the P-PCB abs E-PCB during pyrolysis process were estimated from the experimental data by means of three iso-conversional kinetic models, including Friedman, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) methods. The activation energy range obtained for P-PCB and E-PCB utilizing the Friedman method was within 117–594.1 and 88.42-295.3 kJ.mol-1,... 

Every year, a significant number of people around the world suffer from anterior cruciate ligament injury. Rapid and low-cost diagnosis of anterior cruciate ligament injury is important to prevent further complications as well as timely treatment. Due to the disadvantages of each diagnostic methods, the development of alternative methods for diagnosing anterior cruciate ligament injury is still of interest to researchers. Meanwhile, several studies have shown that the kinematics of the knee joint are different for injured and healthy anterior cruciate ligament. Due to the capability of inertial sensors for kinematic measurement of joints, their use to diagnose damaged anterior cruciate... 

Human body movements are achieved by activating a number of muscles. It has been shown that the central nervous system (CNS) plays the main role in controlling rhythmic activities (including walking, chewing, etc.). However, the way the central nervous system works in controlling different parts of the body has always been discussed due to the excess degrees of freedom to perform certain tasks. Controlling a group of muscles (under the name of muscle synergy analysis) instead of each one of them has been one of the most attractive and efficient recent ideas to better understand the CNS function. Also, a similar concept can be expressed for kinematic synergies (by the degrees of freedom of... 

The mechanical interaction of a tilting anchor and cancellous bones of various densities was simulated using finite element modeling. The model enjoyed a sophisticated representation of the bone, as an elasto-plastic material with large deformation capability. The anchor’s tilting action during implantation phase, as well as its fixation stiffness during pull-out test, were predicted by the model, and a parametric study was performed to investigate the effects of the anchor’s distal width, corner fillet radius and bone engagement edge’s coefficient of friction (COF) on these measures. The model predictions were validated against the results of an experimental test on ovine humerus specimens.... 

Cerebral Palsy is the most common motor disability in childhood. It’s caused by an injury or impaired development of brain. As result, CP children have disability in motor system. All people with cerebral palsy have problem with movement. The symptoms of CP vary from person to person. Therefore, gait analysis was used to investigate those child’s problems and help therapist to find better therapy. Given that, we analyze stance phase of gait cycle of CP children. Also, we calculate and compare variability between traditional development (TD) children and CPs to find a better understanding of how central nerves system (CNS) work. Kinematic Data during walking were collected from 100 CP and TD... 

One of the most important problems in the field of robotic surgery is the measurement of the laparoscopic instrument Tip force. Many efforts have been made with the use of distal sensors to issues such as high cost and need to be disinfected, but the use of proximal sensors for estimating the Tip force of the tool is very rare, which can improve distal sensor problems.In this project, first, using data obtained from simulating a set-up for the Sina robot, two static MLP, and dynamic NARX neural networks are trained to evaluate the use of machine learning algorithms to determine whether the Tip force neural network can be used. Did the robot estimate Sina's surgeon? Then, by comparing this...