Sharif Digital Repository

In this thesis we introduce the objective method for solving combinatorial probability problems and combinatorial optimization. For introducing this method, we consider its application in solving problems such as graphs maximal partial matching problem. Then we introduce mean-field model, which has a close relationship with this method. Finally we use this method to discuss perfect mathching with minimal cost in complete graphs, and using obtaind theorems and concepts from solving this problem, like involution invariance and standard construction, we find an answer for random assigment problem, which is one of the most practical problems in the class of optimization problems  

With the development of technology and growing interest in using high performance and low price products, Wireless Sensor Networks (WSNs) are being dramatically deployed as an emerging technology. The main concern in WSNs is energy consumption that has an effect on sensor’s life time. In order to minimize the energy consumption, Data aggregation, which obtains aggregated values from WSNs, is an important functionality but yet time consuming. On the other hands, Emerging applications of Wireless Sensor Networks (WSNs) such as real-time detection of events need high-rate data collection, which is now an important challenge in WSNs. Multi-channel communication is one of the efficient methods to... 

Nowadays, image registration is considered as one of usual issues in medical researches whose new findings are expanding outstandingly and it has reached a high level of maturity. Generally speaking, image registration is a task to reliably estimate the geometric transformation such that two images can be precisely aligned. With respect to different uses of image registration in medical applications, it has attracted the attention of many scholars and there has been made significant improvement in this realm. Image registration is still one of the active branches in medical image processing due to its wide applications and problems. Graphs, thanks to their geometric structures and intuitive... 

Traffic assignment model, as the last step to the well-known four-step planning models, have been under a special research focus to better capture the uncertainty in the decision-making process of the users. Researchers' use of fuzzy cost for travel time and stochastic assignment models have each aimed at considering the variation in perception of users and uncertainty in their route choices. This thesis has proposed two route-based stochastic assignment models that exploit the fuzzy theory to model network users' perception of travel time and stochastic assignment to model their route choice process. A simulation approach has been exploited to generate the routes prior to the assignment... 

One of the most important targets in bio-informatics is the analysis of biological networks. These networks are modeled by graphs. Comparing networks with mapping is a useful tool for analyzing. The mapping between the nodes of a network that preserves some topological and functional structures, is called network alignment. Network alignment has various applications in different fields; such as pattern recognition, social networks, biological networks, and etc. The alignment of the protein-protein interaction network is one of the substantial problems. There are many static algorithms for the alignment of PPI networks. Because of the developments of computer science in recent years,... 

One of the newest approaches in optimization fields under uncertainty which absorb many scientists is robust optimization. This approach uses uncertain data instead of stochastic distributions and its goal is to find a solution which is robust under uncertainty of input data.
Assignment problem is one of the most applicable problems in real world which its parameter is faced uncertainty. Because of this reason, the aim of this thesis is to find a method for solving generalized assignment problem robustly which the coefficients of costs and use of resources by agents for performing the jobs is undetermined. These parameters are interval data and have just lower and upper bound.
For... 

One most important industry in developing countries is the construction industry and essential component of any construction project is the construction site. According to studies, proper construction site planning will increase productivity, reduce cost, time and risk of the project. Facility layout planning and warehouse location are the most important problems in the construction site. Project activity scheduling, ordering and delivery of material known as project logistics have been investigated by several researchers. In this thesis, two problems including material procurement scheduling and warehouse allocation are simultaneously considered, a hybrid problem, which due to its... 

Machine-to-machine communication (M2M) can be considered as one of the most important types of high-density communication in the Internet of Things (IoT). Therefore, how to send data using the cooperation of machines with each other and selecting the appropriate relay can play an effective role in improving the quality of network communication, especially when communication between sources and their destinations is weak. Since in the real world some of the applications used on a set of IoT machines require the similar bandwidth, we also followed this assumption. For this purpose, we went through three steps in this thesis. First, two new relay selection algorithms with static RF interface...