Sharif Digital Repository

With the growing use of machine learning algorithms, especially in deep neural networks, the need for annotated data for supervised learning has also increased. In many cases, it is possible to collect data widely, but annotating all of these data is usually very time-consuming, expensive, and even impossible in some cases. The goal of active learning algorithms is to maximize the model’s performance with the least annotated data. Active learning algorithms are iterative algorithms that train the model in each iteration with the current annotated data. Then, using the results of the model on the remaining data without annotation, select some new data to annotate. This process usually... 

In this thesis, free vibration of composite conical sandwich panel with a flexible is presented. Simply supported boundary condition are applied on the face’s edge only. Hamilton principle and energy method are used to derive equilibrium equations. In the mathematical formulation higher-order sandwich panel theory (HSAPT) was used. First shear deformation theory (FSDT) is used for faces.
Core displacement in various directions is modeled by polynomial function with indeterminate coefficient. It is assumed that the core is able to sustain shear and in-plane stresses. Temprature and humidity effects are neglected. Equations solved using generalized differential quadrature (GDQ) method.... 

Iran plateau is situated over the Alpide-Himalaya earthquake belt. Tectonic studies indicate that this plateau has a very high density of active and recent faults; as a result, Iran is at risk of damaging earthquakes. Experience of past severe earthquakes shows previous designed structures do not have enough strength instead of real earthquake forces, therefore vulnerability study of existing structures and give a technical and economical retrofitting plan of them is required. Conventional methods of seismic rehabilitation for example using concrete shear walls or steel braces are not suitable for some buildings. Nowadays, passive control systems have been successfully used for reducing the... 

The possibility of time travel in modern physics based on the theory of relativity has led to the study of this issue from various aspects. In this research, the metaphysical possibility of time travel will be examined and therefore its physical and technological possibility is out of the subject of this research. Metaphysical possibility is also considered to mean the compatibility of time travel with the laws of metaphysics. The metaphysical possibility of time travel is challenged by the paradoxes that arise from it. These paradoxes, despite their great diversity, fall into four general categories: Temporal Paradoxes, The paradoxes of freedom, The paradoxes of Causal, and The paradoxes of... 

The silicon vacancy in silicon carbide is a strong emergent candidate for applications in quantum information processing. 4H, 6H and 3C polytypes of SiC all host coherent and optically addressable defect spin states. Electron paramagnetic resonance (EPR) and optically detected magnetic resonance (ODMR) investigations suggest that silicon vacancy point defects in SiC possess properties similar to those of the NV center in diamond. We provide a new theoretical frame to explain a wider range of experimental results. Employing a proposed generalized Hubbard model, with the help of electronic structure programs, DFT, second quantization, and various computational approaches, we obtain new... 

In recent years, boundary control (BC) approach for distributed parameter systems and their applications has demonstrated that it can be a well-intentioned candidate for control system design. In this approach, the main focus is on the boundary actions, where the actuators are aligned on the boundaries of the media. BC may be considered as an ideal approach, especially from applied and engineering point of view, because it deals only with actuators and sensors along the boundaries. Moreover, the problem of boundary stabilization and motion control of flexible crane systems has been one of the remarkable problems for control engineers. In this research, we contemplate the boundary control... 

The Present Study Deals With The Numerical Modeling Of Free Surface Flows Using Unstructured Grids, That Is An Extension Of Later Studies At Research Institute Of Marine Engineering With The Goal Of Developing A Robust CFD Code. One Of The Most Applicable Aspects Of This Software Is Simulation Of Ship Maneuver And Calculation Of Hydrodynamic Resistance Of Floating Structures That Arises From Combination Of Equations Governing The Flow And 6DOF Rigid Body Equations. This Study Represents Some Proposed Algorithms For Solving Navier-Stokes Equations, Volume Fraction Equation And Rigid Body Equations In A Time Marching Manner. These Equations Are Discretized Based On A Collocated Arrangement For... 

Liver metastasis is the leading cause of death in patients with colorectal cancer (CRC). An increasing number of studies have shown that mRNAs, miRNAs, can play an important role in various biological processes that are related to cancer. Identifying and determining the relationship between them can help to diagnose and treat cancer.The aim of this study is to identify miRNA and molecular mRNA markers in the stage of polyp formation in order to diagnose colorectal cancer early and also to introduce therapeutic targets in the stage of metastasis.In this study, two microarray data sets GPL15207 and GPL16384 were analyzed to identify different miRNAs and mRNAs from the GEO database in three... 

Obtaining polymers with desired properties is very important from industrial point of view. Weight average molecular weight and polydispersity are two important polymer properties. It is also important to obtain a high monomer conversion. In this thesis production of polyvinyl acetate is considered. Under special conditions, the vinyl acetate reactor dynamics become oscillatory which makes the reactor control difficult. For obtaining polymer with desired properties, an objective function which includes weight average molecular weight, polydispersity and monomer conversion has been defined. Then by minimizing this objective function the optimal temperature trajectory is obtained. In this... 

In recent years there is a growing trend in designing efficient health care systems. The applications of operations research have been instrumental in advancing this growing trend too. The blood management issue has raised concerns for human on the other hand. Blood is one of the vital commodities in the field of health. Despite significant advances in the field of medicine, a suitable replacement for this vital commodity has not been found yet. Collecting and managing the distribution of blood that is discussed in the blood supply chain management, requires careful planning and managing. In this research blood inventory management in hospitals considering the uncertainty of supply, demand... 

Generally, the costs of logistics and distribution are included in the significant share of the product price. Hence, choosing appropriate decisions and reducing these costs can have an important effect in reducing the price of products and services, increasing the competitiveness of enterprises. One of the most important measures, in order to achieve this goal, is to integrate location of distribution centers and the routing paths of goods. That how these decisions are made in the networks and discrete problems seriously has been taken into consideration but in continuous areas due to the complexity has not been studied a lot by scholars. In this study, we try to develop a model for...