Sharif Digital Repository

Due to enhancements in medical world, some medical instruments have been developed in order to assist surgeons. Navigation systems as one of the progressive ones make a virtual environment to simplify the surgeons. Three-dimensional registration is a necessary step through these systems and widely used in shape analysis, surface representation, and medical image-aided surgery. In addition, It’s relevance to medical imaging is that there is much useful anatomical information in the form of collected surface points which originate from complimentary modalities. In this study, the kinematic relations between two point clouds with different coordinate definitions have been generated. Using... 

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... 

A fullerene graph is a cubic and 3-connected plan graph that has exactly 12 faces of size5 and other faces of size 6, which can be regarded as the molecular graph of fullerene.In the irst part of this thesis we study some important deinitions and theorems whichused in the other parts.A matching of a graph G is a set M of edges of G such that no two edges of M sharean end-vertex; further a matching M of G is perfect if any vertex of G is incident with anedge of M. A matching M of G is maximum if |M| ? |N| for any other matching N in G. Amatching M is maximal if it is not a proper subset of some other matching in G. Obviously,any maximum matching in G is also a maximal matching. An... 

Gamma irradiation systems are used extensively in the industry in order to sterilize medical devices, disinfect hygienic materials or increase the shelf life of agricultural produce. The method of gamma irradiation is superior to the older methods of heat or chemical treatment because it is by far a simpler operation. In this method only a single parameter of time is controlled whereas in the other mentioned methods five or six different parameters need to be controlled. The design of irradiation systems including the size, location of products and arrangement of source rack pencils. In order to optimize the design it is needed to study the products dose distribution in a wide range of... 

The Internet was originally designed for host-to-host communications but is currently being used for data dissemination and retrieval. This structural mismatch makes the Internet an inefficient architecture. To overcome these inefficiencies, NDN has been proposed as a promising architecture over the Internet. One of the fundamental characteristics of this novel architecture is in-network caching. In this thesis, by focusing on the in-network cache management challenge of NDN, we first formally state the problem of social welfare maximization subject to the cache capacity constraint for the cache-enabled nodes, and then propose a distributed in-network caching algorithm based on matching... 

Cloud computing is a paradigm for scalable processing infrastructure which combines distributed software concepts, networks and IT management. Virtualization techniques help to increase productivity from resources. Services are adjusted based on service level agreement with a contract between users and service providers for specifying quality service. In this way, the level of customer satisfaction will be improved. Reliable and flexible management of service level agreements is very important for users and providers. This agreement model is used to prevent the payment of the penalty by providers and minimized interaction between users and providers. Migration from the traditional model to a... 

The government in special schools tries to offer a higher quality of education than public schools, and get less tuition than private schools. If the achievements of these schools are positive, it can be expanded as a supportive policy for low-income families in order to raise the educational skills of deprived students. This study conducted on the basis of data from an internet-based survey, in which 130,000 volunteers, which were enrolled in the National university entrance examinations in 1389, answered the questionnaire. By using the propensity score matching method, assumed that the unobservable variables for the two groups, one is enrolled in a special school and the other is enrolled... 

Matching theory plays an important role in analyzing economic behavior in social networks. The matching theory has application in marriage problems, kidney exchange, allocating workers to firms and etc. The main problem in matching theory is to design a mechanism such that it results in maximizing the welfare and it is incentive compatible, to tell the truth for each individual. In this thesis, we introduce a measure for comparing any two matchings and we investigate two matchings mechanisms under certain domains  

Online ride-hailing platforms aim to match drivers and riders instantly by receiving ride requests from riders and sending them to drivers nearby. However, the low acceptance rate of offers by drivers leads to friction in the process of driver and rider matching. Various factors influence drivers' decisions to accept or reject offers. Specifically, drivers are more likely to turn down a ride offer when they know that by rejecting it, they can quickly receive another offer or find a passenger traditionally. To examine the factors influencing drivers' decisions in online ride-hailing markets, we focus on the behavior of drivers employed by Tapsi ride-hailing platform, and by specifying a...