Sharif Digital Repository

Many of the existing or under-construction buildings in Iran and the world belong to masonry materials buildings. These buildings are more popular among owners and employers in non-urban, rural, and small towns than in large metropolitan areas. In addition to residential buildings, current schools and office buildings in Iran have been built or are being built using this building system. The most important factors in acceptance of these building systems are economic matters, availability of materials, simplicity of production technology of building blocks, and lack of any dependence on skilled technical personnel to build these structures. Experiences of past earthquakes show the very... 

Recently, the tradeoff between low energy consumption and high fault-tolerance has attracted a lot of attention as a key issue in the design of real-time embedded systems. Dynamic Voltage Scaling (DVS) is known as one of the most effective low energy techniques for real-time systems. Control-theoretic DVS techniques, which have been exploited recently for DVS-enabled systems, are able to adapt well to dynamic workload. In this thesis, we have combined the above two important issues i.e., the control-theoretic DVS and fault-tolerance, and investigated reducing the energy consumption of fault-tolerant hard real-time systems using feedback control theory. Our proposed feedback-based DVS method... 

Event-based embedded systems are usually energy-constrained and also have to be highly reliable. This thesis presents a novel energy-efficient standby-sparing technique for eventbased embedded systems. It speculatively pre-executes reaction tasks prior to events, resulting in a high available slack time for energy management. Although the prediction might be wrong, we will show that in average the proposed speculative standby-sparing technique (SSS) consumes less energy compared to non-speculative techniques. We present some real-life examples of event-based embedded systems to justify practical use for the proposed technique. To evaluate SSS extensive experiments were conducted on a variety... 

According to statistics published by the World Health Organization, 9.6% of men and 18% of women over the age of 60 exhibit symptoms of osteoarthritis(OA). Cur- rently, there is no cure for OA, but there are medications that have shown promising results. Drug delivery methods to the cartilage include oral and injectable adminis- tration, neither of which deliver sufficient amounts of the drug to the cartilage unless administered in high doses, which can cause toxicity. High-Intensity Focused Ultra- sound (HIFU) can play a role in drug delivery to the cartilage by creating a pressure field. HIFU application to the body is non-invasive as it is applied externally. Ad- ditionally, HIFU can... 

In recent years, there have been huge advancements in fabrication of micron-sized devices such that they enabled engineers to create a wide range of miniaturized systems, each of which is utilized in mechanical, electrical, and thermal applications. Micromixers are one of these devices with the role of mixing various micro flows. These devices are broadly used for chemical, biological, and biomedical assays. Among variety of micromixers, one that employs electrokinetic transport phenomenon is of great popularity. For instance, mixing under electroosmotic flow enables accurate process control and eliminates the need for moving components inside micromixer. The very complex nature of electric... 

This research concerns investigating the behavior of two-phase flow in the inlet and outlet of the microchannels.Both the droplet based and the continuous microfluidics are considered. For the continuous system whenthe minor fluid enters the microchannel, due to ratio of viscosity of two fluids, viscous folding occurs.Viscous folding phenomena is similar to the buckling phenomena in solids.This means that the viscosity of the fluid, which is applied to two sides of the fluid layer, causes folding the fluid layer and changing the shape of it. For the study we employ a VOF based numerical routine. In order to verify numerical results, the grid and the time step independenciesare checked. In... 

Trip demand analysis is among the most important parts in comprehensive transportation studies. Developing four stage models including trip generation, trip distribution, mode choice, and assignment are so common in demand analyzing. In this study, trip generation models have been studied and to analyze data, two different methods including OLR and GWR are utilized. This study aims to examine relationship between aggregate zones in order to forecast future trips. Moreover, results of modeling trip generation with two different methods, OLR and GWR, are compared. Comparing different levels of aggregation reveals that as the number of zones decreases, the results get better. Decreasing number... 

One of the important questions in mathematics is generalized. In case of metric spaces, one of the questions is: Can we extend notions of Riemannian geometry to arbitrary metric spaces smoothly? Ricci curvature is one of the most important concepts in differential geometry. Ricci curvature is defined for the Riemannian manifold and has many applications in mathematics and physics like Einstein’s equation in relativity theory. There is a good notion for a metric space having “sectional curvature bounded below by K” or “sectional curvature bounded above by K”, due to Alexandrov. Can we define the concept of Ricci curvature in metric space? A motivation for this question comes from Gromov’s... 

Iran has the third largest reservoirs of oil and the second largest reservoirs of gas and has the greatest hydrocarbon reservoirs worldwide. Considering the fact that production of oil is highly dependent on gas injection, Iran is facing a great challenge in determining proper strategy for consuming natural gas. Due to the lack of proper strategy form the point of view of economical as well as scientific evaluation in political and social aspects, it has resulted in weakening Iran’s place in international markets and also reduction of oil wells’ productions.In this study, after a review of relevant literature, characteristics of oil and gas projects effective on modeling them were...