Sharif Digital Repository

Insider threat is a significant security risk for organizations and hard to detect. Most of introduced detection methods need contextual data entries about users, or preprocessed user activity logs to detect insider threats while it is costly and time-consuming. In this thesis, we introduce a behavior analysis method that learns its context and detects multiple types of insider threats from raw logs and network traffic in real-time. This method, named XABA, learns user roles and exclusive behaviors, through analyzing raw logs related to each network session of the user. Then it checks for some abnormal patterns, and if so, triggers the appropriate alert. XABA is implemented on the big-stream... 

Modern microwave and wireless communications systems are too complex today to permit the complete simulation of the nonlinear behavior at the transistor level of description. This problem presents a significant productivity bottleneck for design engineers. At the bridge between the transistor circuit and the multichip module or RF integrated circuit (RFIC) we use “behavioral models” to describe the nonlinear circuit blocks or ICs in the system. The behavioral models are simplified models of the essential nonlinear behavior of the complex sub-circuits; this simplification means that these models will execute more quickly, and use much less memory than if an entire complex subsystem was... 

During 1980s Additive Manufacturing technologies for the purpose of prototyping with fast and less expensive, under the name of Rapid Prototyping was invented. But nowadays under the vast progress made in this field, it possesses a notable place in different industries such as automobile manufacturing, aerospace, architecture, medicine and so on for part manufacturing. In all AM machines, the CAD model design part is manufactured by adding layered to each other. In this research, at first by explaining manufacturing process and current different technologies, the place of this manufacturing process in today and future industry, is analyzed. For discussing replacement of this method instead... 

Capacitive deionization (CDI) is a suitable method for water desalination with low energy consumption and high efficiency, which does not have secondary pollution and is environmentally friendly. The hybrid capacitive deionization uses a faradaic electrode next to the carbonaceous electrode, taking advantage of both electrodes, and high capacities have also been reported. Titanium carbide Mxene is an important candidate in CDI due to its high electrical conductivity and tunable interlayer distance, but Mxene suffers from low oxidation resistance. Therefore, in this research, molybdenum disulfide (MoS2) that is an essential member of the 2D transition metal dichalcogenides family, was used as... 

Recently, fluorescence resonance energy transfer (FRET) based assay through employing gold nanoparticles have been developed for sensitive and selective detection of various analytes [1,2]. These are due to the extremely high extinction coefficient of Au NPs, which induces fluorescence quenching of the attached fluorophores as a result FRET ; a process which is inversely proportional to the sixth power of the distance between fluorophore and quencher [3]. Upon the addition of the analytes with much stronger affinity for Au NPs, the fluorophore molecules are detached from the surface of the Au NPs results in an increase of fluorescence intensity, which is in direct relation with... 

Each year about 23 thousand people will be death in the road accidents in our country. According to the Legal Medicine Organization of Iran, about 24 percent of pedestrian fatalities in road accidents are the result of a collision with a car and because of that studying the different parameters that reduce pedestrian injury became an important issue to study. There are different techniques such as simulating crash tests on cadavers, experiments on pedestrian dummy and numerical simulation. The purpose of this project is simulating the car-pedestrian crash with numerical software called Madymo. Then optimize of the various parameters such as the height of the front bumper height, hood,... 

Today, several centuries after the time when science began to flourish of science, everybody is familiar with destroying consequences of modern science and technology, in addition to its achievments. Besides, domination and exclusive position of science in educational system and government organizations have marginalized alternative knowledge. Thus, some people found this trend dangerous for humankind’s fate and tried to change this situation. Nasr and Feyerabend are two philosophers that despite their different work area both criticise modern science and try to establish their own ideal scientific community.Nasr’s approach is regeneration of traditional science which was prevalent before... 

With increasing demand levels in recent years, transmission congestion is considered as one of the most important power system constraints. This limitation can result in higher operational costs and load curtailment. Furthermore, in power systems with high penetration of wind power, a significant amount of wind curtailment may occur due to congestion of transmission lines. Thus, in order to guarantee a reliable and economic operation of the power system, new transmission lines should be constructed with a rational plan. Very high investment costs are required for building new transmission lines to meet the growing demand. This fact as well as the other associated difficulties emphasize the...