Sharif Digital Repository

Reconfigurable devices are a popular platform invarious computational fields due to having high performance and flexibility and low non-recurring engineering cost. Generous flexibility of Look-up Tables (LUTs) in implementing arbitrary functions comes withsignificant area and performance overheads as compared with their Application Specific Integrated Circuit (ASIC) equivalent. One approach to alleviate such overheads is to use less flexible logic elements capable to implement majority of logic functions. In this thesis, we first investigate the most frequently used functions in standard benchmarks and then design a set of less-flexible but area-efficient logic cells, called Hard Logics... 

Because of increase in use of cars in recent years, demands for parking spaces have also dramatically grown. To resolve this issue construction of multi-storey underground car parks has sharply increased. Due to the high level of contaminants emitted by cars in parking lots and also the continuous presence of humen within them, the control of pollution level and parking indoor air quality is a vital matter. Type of ventilation systems including modern and conventional used for ventilating parking lots and also exhaust and supply vents locations are the most important factors affecting contaminants distribution. Thus investigation the performance of the conventional and modern ventilation... 

Propylene is one of the key material in petrochemical industries. In recent years, as propylene demand increases, development of new methods alongside traditional ways in production of propylene seems essential. The production of propylene from methanol using zeolitic catalysts is as one of this new methods. This method in recent years has got attention. H-ZSM-5 zeolite is one of the best catalysts appropriate for this process. However, rapid deactivation is the main problem this catalyst at the present time. Therefore, more research in order to increase stability and lifetime has been performed. The uses of promoters are as one of the simplest improvement methods of H-ZSM-5 zeolite.... 

In this project photocatalysts TiO2, H3PW12O40, H3PMo6W6O40, H3PW12O40 / TiO2, H3PMo6W6O40 / TiO2, K2.5H0.5PW12O40, Cs2.5H0.5PW12O40, (NH4) 2.5H0.5PW12O40 and H3PW12O40 / M-TiO2 that M = La , Ce, Cr, Fe, Co were characterized by techniques DRS, FT-IR, BET, 31P NMR, SEM and XRD. The results of SEM and XRD particle size and page crystalline nanoscale catalysts, with size less than 40nm, respectively. FT-IR analysis confirmed the structure of heteropolyacid was produced. DRS analysis of the degradation reactions during wavelenght longer upheld. Degradation of methylene blue and pollutants such as Tinopal CBS-x to the polyoxometalates keggin is homogeneous and composite titanium dioxide two... 

Steganography is method for communicating confidential information through a non-trustworth in way which hides the existence of communication. For improving the security of steganography statistical detectability must decrease as such as possible. Despite the fact, that the quality of the relation between statistical detectability and amount of distortion engendered by embedding is still an open problem, problem of detectability reduces to problem of management of pixel embedding in order to minimization of distortion. As in wet paper coding methods, an optimum (or approximately optimum) algorithm proportioned to Pixel-cost has been offered, the current problem of steganography is to find... 

In recent years, Intelligent Transportation Systems (ITS) have received special attentions both in research and in commercial areas. Increased infrastructure facilities, like surveillance cameras, has made this concept even more attainable than before. In this respect, the ability to automatically extract information from traffic images, as one of the key inputs of ITSs, is of great importance. With an increased number of surveillance cameras and the need for more accurate information regarding the road users and their interactions, in order to better city traffic management, building and repairing roads, trip time estimation, number of people per roads estimation and etc, using human... 

In today's world we are dealing with many devices and processes with the goal of efficiency and performance improvement. In many processes particularly chemical ones, the goal is to control the output according to its constraints in the way that the performance is economically efficient, such as reducing energy consumption and energy loss and increasing efficiency. In order to control a process with economical goals, an economical cost function is used and after determination of optimal values a controller is used to guide the process so can achieve them. Model predictive control (MPC) is very common in this economic control Due to advantages such as considering the problem constraints. In... 

With the advent of technology, small in size sensors, memory, speeding up the processor and lowering the cost, it is possible to build an embedded camera system. The goal of this project is to design and build an embedded camera system so it can execute any set of necessary algorithms as depending on the application. In this project, two models of embedded camera systems have been presented as an integrated system and a system with independent units. To design the integrated embedded system, ZYNQ processor is used and two structures are presented in the form of hardware-software and hardware design. In hardware-software design, image processing operations are done by software and in hardware... 

Smartphone sensors like accelerometer, gyroscope and magnetometer are very common nowadays. This gives us the opportunity for sensor-based activity recognition. This thesis's goal is to collect data from different smartphone sensors and then extract hand-crafted features and classify them using machine learning algorithms. Metro, bus, taxi, bicycle, running, upstairs, walking and standing are studied activities in this thesis. All above steps are covered in this research, later we want to present an activity recognition model and then test it through a web server, after that, we modify the model by proposing to change learning coefficient to gain better accuracy. Finally, an Android app was... 

The importance and vitality of focusing on sustainable transition and reducing carbon dioxide emissions are clear to everyone today. However, until recently, the impact of digitization as a major global trend involving the application of digital technologies to change and optimize various elements of business, society, and daily life on the environment and carbon dioxide emissions has been underestimated. Despite the growing amount of research in this field, according to current studies, the connection between digitization and carbon dioxide emissions is not clear. To achieve environmental and sustainable development goals, fossil fuel consumption and greenhouse gas (GHG) emissions must be... 

Artificial intelligence is a field that has made another revolution in the Fourth Industrial Revolution and has become one of the most widely used emerging technologies in the present era. Further investigation of the trends in this field shows that it has shown increasing growth in recent years. Also, in the future, this trend will continue and fundamental changes will occur in societies. For this reason, countries must definitely pay the necessary and sufficient attention to this field in their growth and development path. To achieve this growth path, it is intended to evaluate the status of leading countries in the field of artificial intelligence using two key variables in technological... 

This research examines the impact of indirect network effects in platforms on the likelihood of success for platform complements. The main question addressed by this study is: How does a larger number of complements in a platform ecosystem, through access to diverse resources and knowledge, influence the enhancement of innovation and the likelihood of success for platform complements? While the expansion of indirect networks creates more opportunities for innovation and access to resources on one hand, it may also lead to negative effects such as increased competition among complements and user confusion on the other. The goal of this research is to provide a comprehensive answer to these... 

Current Global Positioning Systems (GPS) are unreliable for indoor positioning, leading to an increased demand for indoor navigation and tracking services. This research utilizes wireless technologies such as Bluetooth and Wi-Fi to provide these services by installing devices in the environment that connect to objects or individuals. To ensure the system's practicality, attention must be given to hardware optimization, cost reduction, and easy installation. The system should be applicable in large indoor environments such as hospitals and buildings, assisting with navigation. Key challenges include positioning accuracy, implementation costs, and energy consumption. This thesis presents... 

Social learning approach in economic policymaking is introduced against conflict-based approach in the similar context. Helco, 1973 first studied the effects of such a learning in economic policymaking and said ”men collectively wondering what to do… Governments not only ‘power’… they also puzzle.” The important point in studying policymaking through social learning approach is paradigm shifts in peoples’ mental models. In this approach, policies are not only the result of conflict between different interests but also are the output of a learning process. In this research we first assume that social learning has not occurred in policymaking community and that individual learning has... 

In this thesis, two kind of Kirchhoff type equations are investigated. for each of them we prove existence and uniqueness of weak solution by letting hypothesizes on problems functions and initial conditions and using Faedo-Galerkin method and some theorems in functional analysis. It is should be mentioned that one of the problems has unique strong solution according to compactness theorems. In the nest step stability of these equations are investigated. for this purpose it is showed that total energy of systems will tend to zero as time goes to infinity. Furthermore at the end of each chapter numerical results are presented to illustrate accuracy of obtained theoretical results. Finally we...