Sharif Digital Repository

Long-term deactivation of a commercial K-promoted Fe2O3 catalyst used in the dehydrogenation of ethylbenzene to styrene monomer was studied using thirty months of operating data of three industrial SM radial fixed bed adiabatic reactors. The Langmuir-Hinshelwood, Hougen-Watson model (LHHW) was used for reaction kinetics modeling. The kinetics of coking from ethylbenzene and styrene and the short-term deactivation function due to the quick coke formation were also considered in the model. The kinetics of long-term deactivation of the catalyst for ethylbenzene dehydrogenation to styrene between 550 and 630 °C were determined by allowing the effects of temperature and time on the catalyst... 

Automation of the software development process is the software engineers' final goal, but with the current facilities and knowledge in software engineering, it is not possible to automatically generate the whole software. Usually all the software in a specific domain contain common behaviors, which by careful exploration of these common behaviors and automation of code generation in these sections, the cost and time of projects' execution can be reduced. According to Model Driven Development (MDD), the first step in software development is creating appropriate models. For creating models, metamodel is required; therefore, we need to create a specific motamodel for the chosen domain or use... 

With the growth of the urban population and the increase in private car ownership, negative implications of transportation, such as traffic congestion and environmental pollution has increased. A good solution to this problem is development of traffic infrastructures. However, it is not sufficient by itself and better management strategies for solving these problems are needed. One of the related approaches, is high occupancy toll lane. The main purpose of this study is modeling user’s mode choice behavior in the presence of high occupancy toll lane and pricing some highway lanes in Tehran. Another important purpose of this study is to find affective factors that have an influence on users... 

The cosmic ray astronomy was born in 1937 when Victor Hess flied with his balloon to the height of 17,500 feet. He found that the cosmic rays come from out of atmosphere. There are three fundamental questions from that time. The goal of all cosmic ray's experimental activities and related theories is finding out the answer of these questions. The first question is about the energy and composition spectrum of cosmic rays. The second one is finding the sources which can product the very high energy particles such as the protons with the energy of 1021eV found in some observatory such as AGASA and Haverah Park. The last question is the process of diffusion of cosmic rays in the galaxy. One of... 

This study focused on the investigation of bioleaching of heavy metals from incinerator ash using Thiobacillus thiooxidans. Eight factors were examined for their significance on bioleaching using a Placket-Burman factorial design. Four significant variables (pulp density, Initial pH, sulfur Concentration and inoculation amount) were selected for the optimization studies. The combined effect of these variables on metal bioleaching was studied using a central composite design. Second order polynomials were established to identify the relationship between the recovery percent of the metals and the four significant variables. The optimal values of the variables for maximum metals bioleaching... 

Underground water is one of major resources of drinking water in Iran and thus, its quality (in terms of absence of pollutants) is a matter of great importance. The main goal of this research was to investigate the pollution concentration in underground water and soil in two regions: Dasht-e-naz in Sari and the fields near Sarkhoun gas refinery. The second goal was to determine the source and measure the distribution of the pollutants (in case of presence) and determine potential risks caused by them. The first step was to perform experimental tests in the two regions. In Sari's Dasht-e-naz region, a number of wells were chosen for sampling according to the direction of underground water... 

The objective of OCR systems is to retrieve machine-encoded text from a raster image. Despite the abundance of powerful OCR algorithms for English, there are not many for Farsi. Our proposed algorithm is comprised of pre-processing, line detection, sub-word detection and segmentation, feature extraction and classification. Furthermore, hardware implementation and acceleration of this system on a GPGPU is presented. This algorithm was tested on 5 fonts including Titr, Lotus,Yekan, Koodak and Nazanin and an average accuracy above 90% was achieved  

Spiking Neural Networks(SNN) are networks which are consisted of layers of neurons, like other typical artificial neural networks. The main difference between SNN and other neural networks is the type of data transportation among neurons which is done by spikes. Spiking neural networks and their models are considered as the nearest networks and neurons to animals’ nervous systems. In aspects of hardware implementation, the type of data transportation in SNN causes them to be ultra-low power. So, implementation of these networks on chips like FPGA and also usage of SNN in applications with high processing load have startling germination, recently. In this work, we have tried to propose some... 

There have been many works on generative networks and image generation in the past few years, but the problem with this work is that there is no control over the generated images. The goal of disentangled image synthesis is to generate new images with specific detail and have control over the generated images. Image-based virtual try-on aims to synthesize the customer image with an in-shop clothes image to acquire seamless and natural try-on results, which have attracted increasing attention. The main procedures of image-based virtual try-on usually consist of clothes image generation and try-on image synthesis. In contrast, prior arts cannot guarantee satisfying clothes results when facing... 

Many mobile applications running on smartphones, wearable devices, tiny autonomous robots and IoT devices would potentially benefit from the accuracy and scalability of deep CNN-based machine learning algorithms. However,performance and energy consumption limitations make the execution of such computationally intensive algorithms on embedded mobile devices prohibitive.We present a GPU-accelerated engine, dubbed mCNN, for execution of trained deep CNNs on mobile platforms. The proposed solution takes the trained model as input and automatically optimizes its parallel implementation on the target mobile platform for efficient use of hardware resources such as mobile GPU threads and SIMD units.... 

Many chip manufacturers have recently introduced high-performance deep-learning hardware accelerators. In modern GPUs, programmable tensor cores accelerate the heavy operations involved in deep neural networks. This paper presents a novel solution to re-purpose tensor cores in modern GPUs for high-throughput implementation of turbo decoders. Turbo codes closely approach Shannon’s limit on channel capacity, and are widely used in many state-of-the-art wireless systems including satellite communications and mobile communications. Experimental evaluations show that the proposed solution achieves about 1.2 Gbps throughput, which is higher compared to previous GPU-accelerated solutions  

In the current era, artificial intelligence and machine learning have become vital and widely used technologies across various industries. These technologies enable companies and organizations to optimize processes, predict trends, and uncover hidden patterns in data with high accuracy and speed. However, fully leveraging the capabilities of AI and ML requires the effective and efficient deployment of ML models in production environments. MLOps, a combination of DevOps and ML concepts, aids in managing the lifecycle of ML models from development to deployment and maintenance. In this research, due to international sanctions and limited access to external services such as Google Vertex AI,... 

Laboratory experiments were carried out to investigate the effect of influent alkalinity and reactor pH on microbial species, morphology and performance efficiency of aerobic granules. The experiments were conducted in two L sequencing batch reactors (R1-R2) with different influent alkalinity and pH medium. pH in R1 ,with high influent alkalinity, was in the range of 7-7.5 and pH in R2 was adjusted in 4.5-5.5. The experimental results demonstrated that the dominated microbial species and structure of granules were different in two rectors. Acidic environment of R2 provide favorable condition for fungal growth and granules formed within first week of operation. On the other hand in R1,... 

In this project, a method is emoloyed to implement a Viterbi decoder on GPGPU. This method is based on combining all steps of the algorithm. This combination has some challenges that are related to differences between different steps of the algorithm. So in this project, some solutions are found to handle these challenges and a high-throughput Viterbi decoder is acheived  

Today air pollution has become one of the major urban management concerns. Air pollution could have dangerous effects on human health in short time or long time in many situations. Numerical modelling is one of the most applicable among different ways for predicting pollutant concentration like field measurement, physical model in wind tunnel, and simulation. Modelling of pollutant dispersion is a way for estimating concentration and aggregation of the pollutant near the surface and with different distances from pollution source. In different dispersion models, one of simplest is the Gaussian model. In this approach it is supposed that emission plume obeys from Gaussian distribution and is... 

• Brachiation robot is a kind of under-actuated robots. A brachiating robot is a type of a mobile arm that is capable of moving from branch to branch similar to a long-armed ape. The purpose of this thesis is control of a two link Brachiation robot. The purpose of this thesis is control of a two link Brachiation robot using neural network and geometry control. For this purpose a genetic algorithm based training Neural Network is used to produce a suitable path for the second link of the robot and then using input-output linearization method, the second link is controlled to follow the path. The simulations shows that the Nero Controller designed in this thesis is suitable. The controller can... 

The purpose of this study was to find the optimal position and slip force of friction dampers, for improving the seismic performance of regular and irregular steel structures and comparison of dampers final pattern of these buildings.In this regard, one to six floor regular and irregular buildings were designed. These buildings were modeled three-dimensionally in the OpenSees Software, and were subjected to horizontal components of seven far field accelerogram in order to investigate the need for their rehabilitation. The results of the time history analysis of these buildings showed that inter-story drifts exceeds the acceptance criteria which has been assumed 2.5% according to the Life...