Sharif Digital Repository

International Data Company (IDC) has reported, at the end of 2020, the total amount of digital data stored in the entire world will reach 40 thousand Exabytes. The idea of accessing this volume of data, anywhere at any time by exploiting commodity hardware, led into the introduction of cloud storage. The abounded rate and variety of failures in the equipment used in cloud storage systems, placed fault tolerance, at top of the challenges in these systems. HDFS layer in Hadoop has provided cloud with reliable storage. Replication is the conventional method to protect data against failures in HDFS. But the storage overhead is a big deal and therefore designers are tending towards erasure codes.... 

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  

Reliable communication has become very crucial in the transmission applications. Hence, to design hardware to handle reliability is the most important part of communication. In this work, we propose a new secured ALU (Arithmetic and Logic Unit) against fault attacks that is used in ARM processor which can correct any 5-bit error in any position of 32-bit input registers of ALU. We also designed a BCH (Bose, Chaudhuri, and Hocquenghem) codec (encoder, decoder) using the prototyping FPGA. Further, in this thesis we designed (63, 36) the BCH encoding and decoding system to tolerate the 5-bit faults. The codec system and ALU system are based on using Verilog description language. Since... 

In recent years, techniques in articial intelligence have become an important tool in the analysis of physiological signals. While the application of machine learning techniques has proved useful in other elds, researchers have had difficulty proving its utility for the analysis of physiological signals. A major challenge in applying such techniques to the analysis of physiological signals is dealing effectively with inter-patient differences. The morphology and interpretation of physiological signals can vary dep ending on the patient. This poses a problem, since statistical learning techniques aim to estimate the underlying system that produced the data. If the system (or patient) changes... 

One of the important issues in the field of telecommunications is the optimization of coding algorithms. Especially, in the field of the Internet of Things (IoT) due to the low processing power and the limitation in the energy storage of devices, the needs for such optimized algorithms are more essential. One effective method to improve coding algorithms in the transmission of messages is obtained by paying more attention to the amount of information contained in each part of the message and transmit information accordingly. Some coding methods have addressed this issue indirectly, but they do not pay enough attention to this practical issue. Based on the simple but practical idea mentioned... 

Grobner bases were introduced by Bruno Buchberger in 1965. The terminology acknowledges the influence of Wolfgang Grobner on Buchberger’s work. He introduced a specific generator for ideals in the ring of polynomials over a field and then gave an algorithm for computing of that generator. It leads to solutions to a large number of algorithmic problems that are related to polynomials in several variables. Most notably, algorithms that involve Grobner basis computations allow exact conclusions on the solutions of systems of nonlinear equations, such as the (geometric) dimension of the solution set,the exact number of solutions in case there are finitely many, and their actual computation with... 

In the upward trend of advancing technologies in chips manufacturing, utilizing Network on Chip (NOC) solutions is a sensible approach towards overcoming challenges in System on Chip (SOC). The most common form of NOC is the Wired NOC. The continuous physical size reduction of electronic circuits has led to bandwidth deficiency as well as increased temperature in various parts of these circuits. The vast advancement in chips manufacturing industry has made it possible to embed and adapt telecommunication equipment into chips, giving rise to Wireless NOC (WNOC) manufacturing. However, wireless communication increases fault rate; thereby, the system becomes more vulnerable against transient... 

The representation concept links the information processed by the brain back to the world and enables us to understand what the brain does at a functional level.Representational models specify how activity patterns in the population of neurons relate to sensory stimuli, motor responses, or cognitive processes. In an experimental context, representational models can be defined as hypotheses about the distribution of activity profiles across experimental conditions. Three different methods are currently being used to test such hypotheses: encoding analysis, pattern component modeling (PCM), and representational similarity analysis (RSA). All three evaluate the second moment of the distribution...