Sharif Digital Repository

Due to safety critical applications of the embedded systems, reliability is one of the most important properties of these systems. Wireless networks also have error prone data transmission channels and limited power consumption. Therefore reliability and power conservation are two vital characteristics of the wireless network especially in embedded applications. Since achieving to a desirable level of data reliability is power consuming, we must consider a trade-off between power consumption and data reliability. In wireless networks power consumption can be categorized into: power consumption in wireless devices and power consumption in data transmission. For decrement of wireless devices... 

In recent years, there has been a trend toward outsourcing data to the cloud provider. These companies must tackle the data security challenges. Generally these parties are assumed to be honest but curious. In past years, the research communities have been investigating different solution to ensure confidentiality.
In addition to data confidentiality access and pattern confidentiality is a high-priority issue in some cases so. potential adversary should be unable to drive information from the observed access pattern to the outsourced data. Despite the fact that there are more investigation in the field of data confidentiality, concern over data security are the rise in outsourcing data,... 

In this thesis we want to discuss about a new approach about information. Using this approach, Scott Muller builds his formalism on two basic concepts: distinguishablity and symmetry. His claim is that there is an inverse relation between symmetry and information. It means that if we have a symmetric system we need less information (Than an asymmetric system) to describe it. Here, we are going to explore the role and significance of symmetry in probabilistic distributions of the double-slit experiment, and we want to show if there is a predetermined relation between symmetry and information or not.
 

Spoken language understanding unit is one of the most important parts of a spoken dialogue system. The input of this system is the output of speech recognition unit. The main function of this unit is to extract the semantic information from the input utterances. There are two main types of approaches to do this task: rule-based approaches, and data-driven approaches. Today data-driven approaches are of more interest because they are more flexible and robust compared to the rule-based approaches. The main drawback of these methods is that they need a large amount of fully annotated or in some cases Treebank data. Preparing such data is time consuming and expensive. The goal of this thesis is... 

Superconducting Rapid Single Flux Quantum (RSFQ) Logic, is very fast (up to about THz) and ultra low power circuit technology and is the most recent and fastest superconducting logic family. So far one of the difficulties in RSFQ logic is associated to reading the circuit states in particular flip flops. In prevalent RSFQ logic using T1 Flip Flop gate instead of the T Flip Flop, the non-destructive reading of the registered bit is possible. Through this approach, it also has some limits in particular circuits. Another idea of resolving this issue, is considering the very new bi-directional RSFQ logic, which is based on alternative changing the bias current through the Josephson junctions.... 

In this thesis the problem of optimal robust fault detection has been studied. Optimal Fault Detection Filter (FDF) design, by using a Linear Matrix Inequality (LMI) structure for both linear systems with polytopic uncertainties and nonlinear Lipschitz systems has been considered. In this regard, a novel LMI is introduced which is capable of calculating the maximum lower bound of H− index with great accuracy.Then, based on the parameter-dependent Lyapunov function and the property of having convexity in combination of certain state space equations, the result is extended to polytopic uncertain systems. Afterward the design of an optimal observer-based residual generator, in the sense of... 

To answer how large the welfare gains from international trade are, this thesis uses two main ideas: linkages and complementarity. A problem along the production chain can sharply reduce output under complementarity. In such a circumstance, international trade and importing in the sectors which are the weak links of the production chain, help solve this problem. Using a general equilibrium model, it is shown that, the complementarity of the intermediate goods assumption results in much higher welfare gains from international trade compared to similar international trade models which assume the substitutability of the intermediate goods  

In this paper, a new method for handling power plants preventive maintenance scheduling problem is proposed in which a decentralized framework is applied in order to help the electricity markets to prevent data sharing. The new approach is the extension of alternating direction method of multipliers (ADMM) along with several heuristics and refinements to omit the effect of non-convexity of the problem. Since, the new methodmerely needs minimal information exchange, it is completely practical. In order to evaluate the performance of the proposed method, a case study based on generating system of Iran is presented. It is shown that the proposed model obtains acceptable results  

Because of unique features and numerous advantages, the fluidized bed has been considered as one of the most widely used process equipment in various industries. However, many aspects of the hydrodynamic behavior of the equipment are unknown. In this study, using simulation tool, hydrodynamic behavior and mixing process of binary solids particle mixture in the tapered fluidized bed with a jet at the entrance were studied. Eulerian – Eulerian multifluid model incorporating the kinetic theory of granular flow is used to simulate the gas-solid multiphase flow with open-source MFIX software. To increase the accuracy of the results standard k-ε turbulence model was used. Validation of results was... 

Cooling sandwich panels are one of the components of the heat exchangers used to cool the components of the sandwich panels . One of the applications of TLP Bonding for steel can be called cooling sandwich panels. In this research , TLP of 304 Stainless Steel , using Fe-base interlayer at 1200 C has been investigated . Cross section of bonded samples were examined by optical and scanning electron microscopes. Microscopy results revealed that 2h is sufficient for completion of isothermal solidification and there is no eutectic compound at bonding zone . Bonding in this condition resulted in the free precipitates in the diffusion affected area. By analyzing eutectic phase in bonding areas at... 

Hydroxyurea is an anticancer drug that is commonly used to treat chronic myeloid leukemia (white blood cell cancer in bone marrow), polycythemia vera (red blood cell cancer), sickle cell anemia, solid tumors, and in particular leukemia. In this research, in addition to analyzing all available methods for synthesis of hydroxyurea, the most economical method for synthesis of hydroxyurea which is Hantzsch method was chosen; then we synthesized hydroxyurea crystals using a precipitation or crystallization process. To do so, two hydroxylamine hydrochloride and potassium cyanate reactants have been used in the semi batch reactor. Since the reaction efficiency and purity of the synthesized...