Sharif Digital Repository

Due to 18000 MW power consumption of cooling systems from the total Iranian electricity consumption in 2016 and hitting a new peak in 2017, the need for finding other alternatives that consume less electrical energy is inevitable. Hence, instead of buildings new power plants, only to meet the demand at the peak of power consumption, using new solutions to reduce consumption seems more beneficial. One way to reduce consumption is to switch to ejector refrigeration systems. One of the main advantages of these systems is their ability to cooling using low-grade waste energies or solar energy (as a heat source below 80℃). However, in absorption systems, the minimum temperature of the heat source... 

Ever-increasing development and growth of information volume is an unprecedented phenomenon. Analyzing and saving such enormous volume of information calls for innovative ideas capable of processing and managing this information. One of the successful projects in this regard done by Apache is known as Hadoop.Hadoop is a popular open-source implementationof MapReduce processing schemefor analysis of large datasets. The heart of Hadoop is MapReduce that is a parallel programming model for data processing on clusters. To handle storage resources across the cluster, Hadoop employs a distributeduser-level filesystem. The Hadoop Distributed File System (HDFS) is written in Java and is designed for... 

Hayek is one of the most impressive figures of Austrian School of Economics established by Carl Menger. The Thinkers of this school of thought believed that governments should not intervene in the market process. They argued that such interventions would spoil the market performance in resource allocation. Hayek believes that the order which emerges from the market is a spontaneous one; it means no one has designed it, but it has evolutionarily evolved by distinctive agents' actions who had no plan to make it. Hayek's arguments for spontaneous order are based on some epistemological presuppositions such as: "methodological individualism", "methodological subjectivism", "tacit knowledge" and... 

So far, several studies have been conducted on the endurance time method. In general, these studies can be categorized into two categories. The first group of studies are based on the theoretical foundations of this methodology and the second group of researches that use the method of endurance time in different engineering issues of earthquake and engineering, and also compare the results of this method with other conventional methods of seismic analysis.The purpose of this study, which is more in the first category of research, is to optimize the acceleration functions using various Transform, such as Fourier and Wavelet, as well as the use of various optimization algorithms. In optimizing... 

As application demands for online convex optimization accelerate, the need for design-ing new methods that simultaneously cover a large class of convex functions and im-pose the lowest possible regret is highly rising. Known online optimization methods usually perform well only in specific settings, e.g., specific parameters such as the diam-eter of decision space, Lipschitz constant, and strong convexity coefficient, where their performance depends highly on the geometry of the decision space and cost functions. However, in practice, the lack of such geometric information leads to confusion in using the appropriate algorithm. To address these issues, some adaptive methods have been proposed... 

The widespread use of the Android operating system has made it an attractive target for attackers. In the field of malware identification and mitigation, the use of machine learning methods has seen significant advancements due to their ability to identify unknown malware. One of these methods is graph-based techniques in constructing malware detection systems, which have achieved high success rates in identifying malware. However, machine learning methods suffer from the vulnerability of being misled by adversarial examples. One important aspect in both malware detection systems and adversarial attacks is the limitations imposed on software modification. Any changes made to the application... 

The main goal of this thesis is the design and development of a rehabilitation device for helping patients “to improve blood circulation” & retain and recover their abilities if possible that were lost during the stroke or a accident like that (my research in karaj/iran shows that it is possible by just movement of the specific body part). The focus is on hand in this thesis because Injuries to the hand are common and can be very debilitating since our hands are our primary means for interacting with our world. For rehabilitation in case of human hand there are several practices that should be done for patients either in home or in a rehabilitation center, time and money that is supposed to... 

In the past few decades, shaking tables are widely used to evaluate system response of structures under seismic excitations. These devices are used without any fundamental research performed on a shaking table system as an entity model. In most of these studies for simplicity, it is assumed that there exist no considerable vibration and displacement around the shaking tables, and no attention is paid to the peripheral substances such as soil settled under the foundation.
In this thesis, result of ambient vibration test on shaking table system (solid deck, concrete foundation and soil layer) has been presented. Precise sensors known as low frequency and high accuracy accelerometers have...