Sharif Digital Repository

This thesis presents a dynamic multidimensional data structure, which is called Improved Skip Quadtree for peer-to peer networks. This data structure is the Improved version of Skip Quadtree which originally presented jointly by D.Eppstein, M.T.Goodrich, and J.Z.Sun. It tries to combine the best features of two well-known data structures; hieracical structure search quadtree, and skip list. In this thesis, it is tried to focus on algorithms for inserting and deleting points in both skip quadtree and Improved skip quadtree, which is fast method for performing point location and approximate range queries. The result of experimentation and implementation of this structure shows that it can be... 

Rehabilitation science has been proved that, in most cases, manipulation of injured body part, repeatedly, can help in returning the performance of that part. So robots can be useful for rehabilitation applications. Rehabilitation robots can record physical parameters such as position, velocity and force, so can play important role in developmentof making decisions on exercise types. Among the existing robots, cable-driven robots have specifications such as vast workspace, low cost, flexibility and light weight which make them suitable for rehabilitation applications.
The purpose of this research is kinematic design of a multi-link cable-driven robot for arm rehabilitation.In the most of... 

In the recent years, emerging vehicular ad hoc networks offer a wide variety of applications, including safety, convenience and entertainment. One of the beneficial applications in these fields is video streaming. However, according to the features like high mobility and loss of links, establishment of video streaming which requires stringent Quality of Service is a daunting task. In this thesis, the goal is introducing approaches in two levels, one for resilient video coding and the other one for network routing. For resilient video coding, the concentration is on the scalable video coding, which supports various applications for users with different requirements. The introduced approach... 

Olefin/ paraffin separation is one of the most important processes in the petrochemical industries.In the last decades, adsorption and membrane processes are a new technology considered significantly for this purpose. In order to synthesizeof zeolite powder (pure silica zeolite STT and CHA), raw materials were made by two methods and their HNMR spectrum was recorded and thenzeolite powder was synthesized. X ray diffraction(XRD) and scanning electron microscopy (SEM) images were taken,showing the same results as the refference structure.To consider synthesized zeolite powdersand olefin/ paraffin interactions, surface adsorption ofthose gases was accomplished on two zeolite powders. After... 

Nanotechnology is an emerging field in technology that exploits the chemical and physical properties created by careful manipulation of materials at atomic and molecular levels. These properties lead to abilities created by this technology, which many scientists regard as the next industrial revolution. Although Nanotechnology promises bright future, today, researchers having learned from the history of technology are trying to predict its unwanted aspects and negative effects to decrease its potential issues. Researchers of Nano-ethics are trying to enable us to encounter Nanotechnology’s achievements in a reasonable way, by studying its ethical and social obligations. Since in our country,... 

Causation is one of the most old and difficult problems of Metaphysics which is also important in Science and Philosophy of Science. There are three different views in the Ontology of Causation—Eliminativism, Fundamentalism and Reductionism. Also we know that the Ontology of Causation can be equated with the question of the difference between Causal and Non-Causal series of events, such that the answers to this question are correspondent to the mentioned views: 1)Eliminativism: There is not any difference between those two series and the concept of Causation does not have any objective or external being. 2)Primitivism: There is a difference between them but it can not be explained in any... 

Philosophy of Chemistry: The missed piece of Philosophy of Science’s tower. This thesis is intended to bring in this recently emerged branch of Philosophy of science. In section 1, some trends of Philosophizing in chemistry by some scientist and philosopher have been investigated. Why Philosophy of Chemistry had been turned off until recently? Section 2 deals with this question. In section 3 some problems in Philosophy of Chemistry have been introduced  

Bruno Latour is one of the well-known contemporary philosophers in the field of science and technology studies. He is specially famouse for his work in laboratory studies and also for rejecting the dualities of modernity. By rejecting subject/object division, Latour opens new perpectives in Ontology. Ontology is one of the most important contributions of Latour to philosophy. He is also one of the primary developers of actor-network theory.In this research, I elaborate on ontological ideas of Latour. First, I will clarify his position in regard to modernity and show how he withdraws from dualities of modernity. Then I will explain his ontological pluralism. Based on this approach, I will... 

The need for service passenger cars, like taxies and governmental vehicles, to work in central Tehran that can produce less emission has been the main drive behind this research. A series and a parallel hybrid pneumatic vehicle based on Iran manufactured Samand Passenger car and different driving cycles were developed using commercially available components. The idea is to use as many standard parts as possible to reduce the development and manufacturing costs. The vehicle space, weight limitations and the fixed geometry have been the main constraints in components adoption. In addition, the dynamic performance of both series and parallel designed vehicles were evaluated with chosen... 

Today, several centuries after the time when science began to flourish of science, everybody is familiar with destroying consequences of modern science and technology, in addition to its achievments. Besides, domination and exclusive position of science in educational system and government organizations have marginalized alternative knowledge. Thus, some people found this trend dangerous for humankind’s fate and tried to change this situation. Nasr and Feyerabend are two philosophers that despite their different work area both criticise modern science and try to establish their own ideal scientific community.Nasr’s approach is regeneration of traditional science which was prevalent before...