Sharif Digital Repository

Classification is one the contrivesial problems in machine vision and pattern recongnition. Traditional feature extraction methods which are based on low level feature extraction do not have high classification accuracy, thus they do not have the ability to represent images in feature space in discriminative way. In this thesis we have proposed a grid base method and used hidden Markov model (HMM) to include topological and spatial information in feature vectors. Then the classifiers created based on HMM feature extraction are combind. Combination of classifiers is based on designing a convex goal function. The goal of this optimization is to determine the wight of each classifier for... 

In this study a mathematical model has been presented for multi depots, continuous location-routing problem with inventory restrictions. In this problem, a three-echelon supply chain was assumed and a factory which is producing one product and with unlimited capacity is on the first echelon of supply chain. In the second echelon of supply chain, several distribution centers distribute products. In the third echelon, there is a set of customers who are scattered in different geographical locations. Location of customers is pre-specified, but distribution centers should be located. In this problem, location of distribution centers will be determined in a continuous space. As the leader of this... 

Concrete filled double-steel-plate (CFDSP) composite wall is a new lateral resisting system that recently used in design and strengthening of high-rise buildings. This CFDSP composite wall is composed of concrete filled steel tubular columns at the two boundaries and concrete filled double-steel-plate wall body. The main advantage of this system is the interaction between steel and concrete which delays local buckling of steel plates. Also, steel jacket increases the strength of concrete in result of confinement effects. Furthermore, these systems have lower thickness compared to ordinary concrete shear walls. Hence, they have less structural weight which reduces the earthquake force.... 

The significant growth of wind generation in power systems, in form of wind farms connected to transmission networks, is changing the present transmission reinforcement planning in the mid-term horizon and transmission expansion planning in the long-term horizon approaches. In this thesis, the optimal wind farms integration to the power system and uncertainty of wind farms output power are considered as two major items in the proposed models and the novel transmission reinforcement and expansion planning models considering optimal wind farms integration are presented. According to these models, the optimal capacity of wind farms and wind farms lines, and the new transmission lines of the... 

In Iran, titanium dioxide is still not produced and imports of titanium dioxide are required by various industries, including dyeing, electrodeposition, plastics and Therefore, according to the Ministry of Industries and Mines objectives, to obtain the technology of extraction Ti and TiO2, a research was carried out on titanomagnetite concentrate, extracted from the minerals of the plancher titanumitent and low-grade kahnoj. In this research, titanium dioxide is produced by sulfate method. Solid state recovery and magnetic separation were used to isolate titanium and iron. The dissolution process was then performed to achieve maximum dissolution. At this stage, the effects of temperature,... 

In this study, the effects of adding rubber particles to reinforced concrete beams were investigated. In recent years, the use of recycled materials in concrete production has emerged as a method to reduce environmental impacts and costs in the construction industry. In this context, the use of waste rubber particles from worn tires as a partial replacement for fine aggregates in concrete production can contribute to improving the technical properties of concrete. This research examines the simultaneous effects of rubber particles, concrete compressive strength, and the tensile steel reinforcement ratio on the flexural strength of reinforced concrete beams under four-point loading. Sixteen... 

Software architecture has been known as one of the fundamental elements of effective software development process. In order to improve and optimize the software architecture design, many attempts have been made among which are introducing architectural patterns. Because of high advantages of service-oriented architecture, it is considered as one of the main interests of software developers. It should be noted, however, that getting advantages from service-oriented architecture is not possible without having an efficient management within its processes. In other words, using service-oriented architecture without considering its process management challenges, can lead to increased costs and... 

In this thesis departure programming are studied in general state and takeoff programming studied in special state. Departure programming consists of several parts that decisions for each part may influence in the other parts. Because of unforeseen delays this problem is a dynamic problem. Holding area is a part that overtaking operations performance before takeoff. An initial sequence obtained from ground controller. A heuristic algorithm that used in this thesis is a hybrid of constraint satisfaction and dynamic programming for minimizing sum of the total delays. The performance of the heuristic algorithm is compared with tabu search algorithm. The result shows that the proposed algorithm... 

Ising model in nano systems are studied, in the presence of a magnetic field. For a one-dimensional(1-D) array of spins interacting via nearest-neighbor and next-nearest-neighbor interactions we calculated the heat capacity , the surface energy, the finite-size free energy, and bulk free energy per site. The heat capacity versus temperature exhibited a common wide peak for systems of any size. A small peak also appears at lower temperatures for small arrays when the ratio of magnetic field- spin interaction energy over the nearest-neighbour spin-spin interaction energy f is within and size. The peak becomes smaller for longer array and eventually vanishes for long arrays, disappearing when... 

This research conducted to achieve a pragmatic approach for the demand forecasting of ICU beds which is the one of most important services are provided by hospitals and medical centers and always has been challenging associated with capacity planning in many countries. Attaining such a method, ICU patients identified and categorized according to patients age and duration of hospitalization period. Then, as a case study, demanded ICU beds in Iran's hospitals predicted for three time horizons in 2021, 2031 and 2041 by use of regression model to forecast the population of identified patient categories which was extracted from Iran's demographic data in a 30-year period. The results indicated... 

Numerical simulation of air-water annular two-phase flow in a tube is carried out by using level set method for determining position of interface between two phases. Governing equations include continuity, momentum and level set equations that considered for each phase. The finite difference scheme is used to discretize the differential equations. The SIMPLE algorithm is adopted to solve the discretized equations for linking continuity and momentum equation. An unequally spaced staggered grid size for flow field is adopted. The Level Set method is used to capture interface position between two phases. To increase the accuracy of solution at level set equation, 5th order finite difference and... 

In today’s world, people’s tendency to use their own vehicles is relatively high since private cars provide more convenience, better safety, and better time management than public transportation, but cause more traffic in the streets. Ride-sharing is one of the management tools that has attracted a lot of attention in recent years to mitigate the traffic congestion. Also, electric vehicles are used for public transportation in many parts of the world to achieve a sustainable environment. In this study, we assume that passengers’ origin, destination, and preferred time windows for pick-up and drop-off are known in advance. The aim of the study is to determine the sequence of visiting travel... 

Over the past few years, deep reinforcement learning(DRL) has been given a lot of attention in finance for portfolio management. With the help of experts’ signals and historical price data, we have developed a new reinforcement learning(RL) method. The use of experts’ signals in tandem with DRL has been used before in finance, but we believe this is the first time this method has been used to solve the financial portfolio management problem. As our agent, we used the Proximal Policy Optimization(PPO) algorithm to process the reward and take actions in the environment. Our framework comprises a convolutional network to aggregate signals, a convolutional network for historical price data, and...