Sharif Digital Repository

In the present study, a new version of haptic devices is presented in which user’s hand is in contact with the device just while collision with virtual surface. In this system, the position of user’s finger can be traced by using a camera and the haptic device follows user’s finger at the distance of about two centimeters. While the haptic device approaches to the virtual surface, gradually reduces its speed and stops about two centimeters distant of virtual plane. Then user’s hand collides with the haptic device which is static. Greater fidelity, transparency, more stability and also no need to large actuators are of the advantages of this system. In this project, first we present a new... 

Let G be a graph. We call G an odd graph if all its vertices have odd degrees. Caro conjectured that for every graph G and every integer k, k > 2, there exists a Zk-coloring for the vertices of G so that for all v 2 V (G), the sum of the colors of all vertices in N[v] is not congruent to 0 modulo k. This thesis is mainly devoted to determining a lower bound for the number of vertices of the largest odd induced subgraph of a given graph with no isolated vertices. Another focus of this thesis is to find an upper bound for the number of odd induced subgraphs, as well as odd induced forests, needed to partition V (G), where G is a given graph with even order. At the end, two variations of Caro’s... 

In recent decades, the air pollution issue and fuel resource constraints have compelled researchers to find ways to replace fossil fuels or reduce their consumption. Since the Vehicles are one of the most important sources of pollution and energy consumer, efforts to reduce vehicles fuel consumption can be an effective action to reduce air pollution. A proper powertrain system has an important task to reduce fuel consumption and air pollution.
Uses of continuously variable transmission system (CVT) and infinitely variable transmission (IVT), which makes the internal combustion engine to operate in optimal condition, can help to achieve this goal. In this thesis, the target is find... 

The main goal of this thesis is the design and development of a rehabilitation device for helping patients “to improve blood circulation” & retain and recover their abilities if possible that were lost during the stroke or a accident like that (my research in karaj/iran shows that it is possible by just movement of the specific body part). The focus is on hand in this thesis because Injuries to the hand are common and can be very debilitating since our hands are our primary means for interacting with our world. For rehabilitation in case of human hand there are several practices that should be done for patients either in home or in a rehabilitation center, time and money that is supposed to... 

In the past few decades, shaking tables are widely used to evaluate system response of structures under seismic excitations. These devices are used without any fundamental research performed on a shaking table system as an entity model. In most of these studies for simplicity, it is assumed that there exist no considerable vibration and displacement around the shaking tables, and no attention is paid to the peripheral substances such as soil settled under the foundation.
In this thesis, result of ambient vibration test on shaking table system (solid deck, concrete foundation and soil layer) has been presented. Precise sensors known as low frequency and high accuracy accelerometers have... 

Out of several ground improvement techniques available, stone columns have been widely used. This technique has been successfully applied to increase the bearing capacity and to reduce the settlement for foundation of structures like liquid storage tanks, earthen embankments, raft foundations, etc., where a relatively large settlement is permissible. This technique has, generally, been proven successful in increasing the stiffness of weak soils, upgrading their safe bearing capacity, and reducing their total and differential settlements, as well as speeding up their consolidation process. The beneficial effects of stone column installation in weak deposits is manifested in the form of...