Sharif Digital Repository

Coming to the generation of technology, where everything is possible through the Internet contributes a significant proportion to privacy protection. Several Privacy protection technologies have been launched to maintain the confidentiality of user information. Tor, also known as an Onion Router, is indeed the largest global anonymized network technology, including over 7000 distinct domain controller endpoints located all over the globe. Various kinds of wrongdoings are increasing day by day such as terrorism, abuse of the child is increasing using the network. To stop this monitoring plan is needed to develop. To enable this all the hacking mechanisms along with the architecture were... 

Iris segmentation is an essential step in a medical imaging-based automated diagnosis system. The operation of dividing a digital image into areas with different characteristics and setting objectives is known as image segmentation. The extraction of the iris from unnecessary sections of the image is very important for any biometric device. Eyelid / eyelash obstruction, special reflections, intensity heterogeneity, and an irregular iris border, are considered as noise which affect the iris segmentation process. Focusing on Fuzzy C-Means (FCM) clustering and Grasshopper Optimization Algorithm (GOA), we present a new and efficient method for dividing iris-filled, annoying, and iris limits that... 

Classification of Traffic Internet obtained early interest in the computer science community. Various methods have been presented for classifying the traffic of Internet to manage both security and Quality of Service (QoS). Nonetheless, traditional methods of classification including scheme of Transmission Control Protocol/Internet Protocol (TCP/IP) have not been accepted because of their complicated management. Classification method of network through learning algorithms of machine is the most popular classification method of traffic at this time. ELM was proposed as a modern algorithm of learning for the Single-hidden Layer Feed Forward Neural Networks (SLFNs). Meanwhile, learning process... 

Simulation of biophysical neural networks enables the interpretation and integration of fast-growing and different experimental datasets. The widely used NEURON simulator allows molecular-to-network simulation. However, it is still a very hard challenge to create large-scale models and operate parallel simulations applying NEURON. SUNY Downstate developed the NetPyNE means networks using Python and NEURON, which was funded by the New York State Department of Health and some other institutions. NetPyNE is a Python-based tool that enables the development of data-driven multi-scale network models in NEURON through both programmatic and graphical interfaces. It is a powerful tool for parallel... 

Today, with the development of technology, cyberattacks are on the rise. Personal and corporate computer systems can be exposed to various threats and dangers of hackers and malware, including information theft, forgery, and denial of service, which can cause great material and moral damage to individuals and organizations. So, it is necessary to take security measures in this regard. Many security mechanisms are available to prevent security vulnerabilities against various threats. In this study, first, after carefully studying network attacks, we identify the criteria for identifying attacks that can be executed in network traffic and explain how to calculate them. The current research... 

Frequently using Personal Identification Information has escalated the security concerns of bank accounts, emails, daily transactions, and other activities. Therefore, user access to such apps must be controlled. Traditional personal verification methods offer limited security because they might need to be remembered or stolen. Therefore, Biometric authentication, which identifies persons by their unique biological information, is gaining popularity. However, palm vein identification is highly secure because the vein patterns are not duplicated in other people, even in monozygotic twins. Moreover, it has a liveness detection and is convenient since the vein pattern cannot be faked,... 

Since the classical continuum theory fails to deal with the problems associated with defects, stress concentrators, and relevant deformation phenomena in solids, alternative approaches that can detect the atomistic nature of materials' fracture are required. The deficiency of the capture the size effect which yields delusively high values for some components of the stress field right on the edge of the stress concentrators, and its weakness in describing the complex interaction between small inhomogeneities, cracks and the like when they are only a few nanometers apart, are among some of the disadvantages of the classical approach. In recent years, however, atomistic methods are emerging to... 

Aluminum Bronzes have many applications in marine environments. These alloys suffer from both hot cracking and cold cracking. In order to overcome the hot cracking and cold cracking, Semisolid Stir Joining method and a proper thermal cycle was used respectively. Effects of temperature, stirring rate, and tool type were investigated in Semisolid Stir joining method. In this method, butt joint design was used in order to place specimens, and the specimens were heated up to specific temperatures (920, 925, 930°C). A stirrer (Cylindrical and Grooved tool) with three rotational speeds (800, 1200, 1600 RPM) was introduced into the stir weld seam. Welded specimens were cooled to the 900°C... 

The low female labor force participation rate in the Iranian labor market relative to the global average and even to countries that do not differ significantly from the socio-economic characteristics of our country is one of the important questions of the Iranian labor market. In this study, we seek to answer the question of whether the economic participation rate of married women will increase if the gender gaps in wages, job findings and job losses among women and men are eliminated in the Iranian labor market. To answer this question using household expenditure and income data and labor force data, we show that between the two categories of occupations, in terms of the share of women's... 

Shot peening is a cold-working process commonly used in industry to improve the fatigue performance, stress corrosion resistance and surface nano-crystallization of metallic parts. This process extends fatigue life via two mechanisms: Preventing the crack growth due to compressive residual stresses and, preventing the crack initiation because of increased material hardness. These mechanisms are the results of the bombardment of the component's surface with small spherical particles. In this research, an analytical model is developed for estimating the residual stress distribution induced by shot peening process. The modifications of the developed analytical model are related to... 

Solid-State Drives (SSDs) provide high performance, low power consumption, and hence are widely used in the I/O cache of enterprise storage systems and high performance servers. Although employing high performance SSDs in the I/O cache of storage systems significantly improves system performance, it comes with significant reliability threats for write operations upon power failures. In order to provide high level of reliability, storage architectures employ SSDs in I/O cache with RAID-1 configuration, however, such configuration only partially mitigates the reliability issues of the SSDs. In this thesis, we analyze the reliability of SSD-based I/O caches against power outage and high...