Loading...
Search for:
rajabzadeh-oghaz--hamidreza
0.127 seconds
Proposing and Numerical Modeling of Novel Surgical Procedures in Order to Increase Pulsatility Style of TCPC Blood Flow, Using FSI Approach
, M.Sc. Thesis Sharif University of Technology ; Firoozabadi, Bahar (Supervisor) ; Saidi, Mohammad Said (Co-Advisor)
Abstract
Single ventricle anomaly is a congenital heart disease which is characterized by anatomical malformations. The main abnormality that a patient faces is desaturated blood flow, which, without any treatment increases the risk of death. The classical treatment is based on a three stage palliative procedure which should begin from the first few days of patient’s life. The final stage is known as Fontan procedure which directly connects inferior vena-cava to pulmonary arteries without going through the ventricle.This connection is known as Total Cavo Pulmonary Connection (TCPC). After surgery, the single ventricle could supply adequate and saturated systemic blood flow for the body, but TCPC...
Evaluation of a novel extra-cardiac Fontan procedure with implantation of a biocompatible membrane
, Article IRBM ; Volume 36, Issue 5 , 2015 , Pages 287-292 ; 19590318 (ISSN) ; Firoozabadi, B ; Saidi, M. S ; Monjezi, M ; Navabi Shirazi, M. A ; Malakan Rad, E ; Sharif University of Technology
Elsevier Masson SAS
2015
Abstract
Fontan operation is a final palliative surgical treatment for patients with a single ventricle (SV) physiology. One of the common disadvantages of Fontan operation is to generate a non-pulsatile flow instead of the normal pulsatile flow produced by contraction of the ventricle. Theoretically, in SV patients, maintaining the antegrade flow through pulmonary valve can produce flow pulsatility in the right and left pulmonary arteries. However, it not only increases the energy loss in the Fontan of total cavopulmonary pathway (TCPC), but also imposes an extra load on pulmonary arteries as well as the ventricle. In this study, the potential capability of pulmonary valve of the patient that can be...
Pulsatile blood flow in total cavopulmonary connection: a comparison between Y-shaped and T-shaped geometry
, Article Medical and Biological Engineering and Computing ; Volume 55, Issue 2 , 2017 , Pages 213-224 ; 01400118 (ISSN) ; Firoozabadi, B ; Saidi, M. S ; Monjezi, M ; Navabi Shirazi, M. A ; Malakan Rad, E ; Sharif University of Technology
Springer Verlag
2017
Abstract
Single-ventricle anomaly is a hereditary heart disease that is characterized by anatomical malformations. The main consequence of this malformation is desaturated blood flow, which without proper treatment increases the risk of death. The classical treatment is based on a three-stage palliative procedure which should begin from the first few days of patient’s life. The final stage is known as Fontan procedure, in which inferior vena cava is directly connected to pulmonary arteries without going through the ventricle. This connection is called total cavopulmonary connection (TCPC). After surgery, the single ventricle supplies adequate and saturated systemic blood flow to the body; however,...
Comparison of Switching Stream Cipher Systems
, M.Sc. Thesis Sharif University of Technology ; Daneshgar, Amir (Supervisor)
Abstract
In this thesis, we analyze and compare switching and CPSP cryptography systems. CPSP is a dynamic system which can act as synchronized or self-synchronized stream cipher under specific conditions. To do the comparison, first we have a brief review of cryptography fundamentals like stream cipher systems, synchronized stream ciphers, and self-synchronized ones. Then, we consider chaos systems in general form and then we present their role in cryptography systems, and in continue by introducing switching cryptography systems and also CPSP cryptography systems, and analyzing their relation with self-synchronized stream ciphers, we do our statistical tests on them
Investigating One-pot Three Component Synthesis of ß-Amino Carbonyl Compounds Exploiting Hydrolases: Protein Splicing Enzyme and N-Acetylmuramide Glycanhydrolase
, M.Sc. Thesis Sharif University of Technology ; Kalhor, Hamidreza (Supervisor)
Abstract
The application of biocatalysts in organic reactions refers to the use of enzymes, purified or crude, to increase the reaction rate. The usage of biocatalysts in organic reactions have many advantages, including biocompatibility, ease of separation, high yield, reusability without losing activity, high selectivity, and the use of water as the solvent. Furthermore, the carbon–carbon bond formation is one of the most important reactions in the synthesis of organic compounds, drugs, and biomolecules. Using enzymes in organic reactions can provide insightful information about the enzymes catalytic activities and paves the way for systematic investigation of their mechanisms. The enzymes...
Application of Semi-Supervised Learning in Image Processing
, M.Sc. Thesis Sharif University of Technology ; Rabiee, Hamidreza (Supervisor)
Abstract
In recent years, the emergence of semi-supervised learning methods has broadened the scope of machine learning, especially for pattern classification. Besides obviating the need for experts to label the data, efficient use of unlabeled data causes a significant improvement in supervised learning methods in many applications. With the advent of statistical learning theory in the late 80's, and the emergence of the concept of regularization, kernel learning has always been in deep concentration. In recent years, semi-supervised kernel learning, which is a combination of the two above-mentioned viewpoints, has been considered greatly.
Large number of dimensions of the input data along with...
Large number of dimensions of the input data along with...
A General Theorem For Portfolio Generating Functions
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Hamidreza (Supervisor)
Abstract
Portfolio generating functions are positive twice continuously differentiable functions of the common or ranked market weights. The return on such portfolios related to the market with a stochastic differential equation that has two components: the logarithmic change in the value of the generating function, and a drift process that is of bounded variation. The goal of this study is to generalized portfolio generating functions theorem for ’ functions, in order to cover some important functions in economic such as Gini coefficients
An Application of Algebraic Topology to Computer Sciences
, M.Sc. Thesis Sharif University of Technology ; Fanai, HamidReza (Supervisor)
Abstract
In this thesis we study one of the applications of algebraic topology to computer science and define some tools to analyze concurrent programs. For this purpose a geometric space is corresponded to every concurrent program and a partial order is considered on this space, so every path on it corresponds to an execution of the program. Some of these paths which are dihomotop (homotop in partial ordered spaces) with each other induce the same execution of the program. By defining “Fundamental Category” in which objects are points of the space and morphisms are dihomotopy classes, the space that should be analyzed shrinks to a smaller one. By defining component category in the next step, without...
A Survey Of Topological,Algebraic And C ∗-Algebraic K-Theory
, M.Sc. Thesis Sharif University of Technology ; Fanai, Hamidreza (Supervisor)
Abstract
In this thesis we study three versions of K−theory. The most well-known vesrsion is topological K−theory, a generalization of Grothendieck works on algebraic varieties to the topological setting by Atyiah and Hirzebruch. Since its birth it has been an indespensible tool in topology,differential geometry and index theory. In the early 1970s C∗−algebraic version of K−theory introduced through associating two abelian groups,K0(A)and K1(A)to a C∗−algebra like A. These functors proved to be a powerful machine, making it possible to calculate the K−theory of a great many C∗−algebras. At last,algebraic K−theory is dealig with linear algebra over a ring R by associating it, a sequence of abelian...
An Application of Stochastic Optimal Control in Solving the Mean-variance Portfolio Selection Problem
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Hamidreza (Supervisor)
Abstract
In this essay, by putting in the framework of linear-quadratic optimal control (LQ),we study and solve the mean-variance portfolio selection problem. Two models will be studied in our work; in one we assume that the price process satisfies a diffusion stochastic differential equation, while in the second model, we assume it to satisfy a jump-diffusion stochastic differential equation. In both models, a formula for the efficient frontier is obtained. This essay is mainly obtained from the works of the following articles and books:
1)X.Y. Zhou and D. Li, Continuous-Time Mean-Variance Portfolio Selection:A Stochastic LQ Framework. Applied Mathematics and Optimization. 42(2000),...
1)X.Y. Zhou and D. Li, Continuous-Time Mean-Variance Portfolio Selection:A Stochastic LQ Framework. Applied Mathematics and Optimization. 42(2000),...
Customer Churn Prediction in Therapy Policy in Iran
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor) ; Arian, Hamidreza (Supervisor)
Abstract
Using customer relationship management systems has led to the formation of databases containing businesses customer information. Increased competition in the markets, limited resources and high costs of attracting new customers compared to retaining existing customers have made customer retention an inevitable subject for business owners. Meanwhile, insurance companies, which due to their long history have suitable databases of product information and their customers, have resorted to using their databases to manage the relationship with their customers. In this research, while predicting customers churn in health insurance, as one of the most widely used products of domestic insurance...
Feature specific control flow checking in COTS-based embedded systems
, Article Proceedings - 3rd International Conference on Dependability, DEPEND 2010, 18 July 2010 through 25 July 2010 ; July , 2010 , Pages 58-63 ; 9780769540900 (ISBN) ; Miremadi, S.G ; IARIA ; Sharif University of Technology
2010
Abstract
While the Control Flow Checking (CFC) methods are using the ordinary instruction set and general Arithmetic and Logic Unit (ALU) features to protect the programs against the transient faults, this paper presents a new kind of CFC method, called feature specific CFC. The idea behind this method is using a specific internal hardware in modern processors which provides the ability to monitor internal various parameters of the program. This method is a pure software method and the external hardware overhead is zero. Other overheads have been measured experimentally by executing the workloads on a Pentium system. The execution time overhead is between 42% and 67% and the program size overhead is...
Transient detection in COTS processors using software approach
, Article Microelectronics Reliability ; Volume 46, Issue 1 , 2006 , Pages 124-133 ; 00262714 (ISSN) ; Miremadi, S. G ; Sharif University of Technology
2006
Abstract
This paper presents a software-based error detection scheme called enhanced committed instructions counting (ECIC) for embedded and real-time systems using commercial off-the-shelf (COTS) processors. The scheme uses the internal performance monitoring features of a processor, which provides the ability to count the number of committed instructions in a program. To evaluate the ECIC scheme, 6000 software induced faults are injected into a 32-bit Pentium® processor. The results show that the error detection coverage varies between 90.52% and 98.18%, for different workloads. © 2004 Elsevier Ltd. All rights reserved
CFCET: A hardware-based control flow checking technique in COTS processors using execution tracing
, Article Microelectronics Reliability ; Volume 46, Issue 5-6 , 2006 , Pages 959-972 ; 00262714 (ISSN) ; Miremadi, S. G ; Sharif University of Technology
2006
Abstract
This paper presents a behavioral-based error detection technique called control flow checking by execution tracing (CFCET) to increase concurrent error detection capabilities of commercial off-the-shelf (COTS) processors. This technique traces the program jumps graph (PJG) at run-time and compares it with the reference jumps graph to detect possible violations caused by transient faults. The reference graph is driven by a preprocessor from the source program. The idea behind the CFCET is based on using an external watchdog processor (WDP) and also the internal execution tracing feature available in COTS processors to monitor the addresses of taken branches in a program, externally. This is...
A hardware approach to concurrent error detection capability enhancement in COTS processors
, Article 11th Pacific Rim International Symposium on Dependable Computing, PRDC 2005, Changsha, Hunan, 12 December 2005 through 14 December 2005 ; Volume 2005 , 2005 , Pages 83-90 ; 0769524923 (ISBN); 9780769524924 (ISBN) ; Miremadi, S. G ; Sharif University of Technology
2005
Abstract
To enhance the error detection capability in COTS (commercial off-the-shelf) -based design of safety-critical systems, a new hardware-based control flow checking (CFC) technique will be presented. This technique, Control Flow Checking by Execution Tracing (CFCET), employs the internal execution tracing features available in COTS processors and an external watchdog processor (WDP) to monitor the addresses of taken branches in a program. This is done without any modification of application programs, therefore, the program overhead is zero. The external hardware overhead is about 3.5% using an Altera Flex 10K30 FPGA. For different workload programs, the execution time overhead and the error...
Experimental Removal of Diesel in Soil Using Indigenous Microorganisms Isolated Iran
, M.Sc. Thesis Sharif University of Technology ; Kariminia, Hamidreza (Supervisor) ; Yaghmaei, Soheila (Supervisor)
Abstract
Crude oil and petroleum products at the time of extraction, production and transportation cause serious contaminations in soil, water and environment. Biological methods have shown a promising effect for the cleanup of these hydrocarbon pollutants. Bioremediation employs the metabolic activity of microorganisms capable of using oil as their energy and carbon source. Biological methods are also less expensive than other cleanup technologies such as incineration and landfill. Large number of microbial stains have been discovered in nature, capable to degrade oil and petroleum products. Biological cleaning of oil contamination by microorganisms occurs naturally in the environment. It has been...
A Fine Grained Access Control Mechanism for Hybrid Mobile Applications in Android
, M.Sc. Thesis Sharif University of Technology ; Kharrazi, Mehdi (Supervisor) ; Rabiee, HamidReza (Co-Advisor)
Abstract
Hybrid mobile applications combine the features of Web technologies and native mobile apps. Like Web applications, they are implemented in portable, platform independent languages such as HTML and JavaScript. Like native apps, they have direct access to local device resources. In these programs, web contents are loaded into a web component, called WebView, which can render HTML5 pages and execute JavaScript code. In order for the web content to access the system resources, which are isolated from the content inside Web-View due to its sandbox, bridges need to be built between JavaScript and the native code. developers usually use third party plug-ins for native side of application. hybrid...
Estimation of a Portfolio's Value-at-Risk Using Variational Auto-Encoders
, M.Sc. Thesis Sharif University of Technology ; Arian, Hamidreza (Supervisor) ; Talebian, Masoud (Supervisor)
Abstract
One of the most crucial aspects of financial risk management is risk measurement. Advanced AI-based solutions can provide the proper tools for assessing global markets, given the complexity of the global economy and the violation of typical modeling assumptions. A new strategy for quantifying stock portfolio risk based on one of the machine learning models known as Variational Autoencoders is provided in this dissertation. The suggested method is a generative model that can learn the stocks' dependency structure without relying on assumptions about stock return covariance and produce various market scenarios using cross-sectional stock return data with a higher signal-to-noise ratio. We...
Error detection enhancement in COTS superscalar processors with event monitoring features
, Article Proceedings - 10th IEEE Pacific Rim International Symposium on Dependable Computing, Papeete Tahiti, 3 March 2004 through 5 March 2004 ; 2004 , Pages 49-54 ; 0769520766 (ISBN); 9780769520766 (ISBN) ; Mohandespour, M ; Miremadi, G ; Sharif University of Technology
2004
Abstract
Increasing use of commercial off-the-shelf (COTS) superscalar processors in industrial, embedded, and real-time systems necessitates the development of error detection mechanisms for such systems. This paper presents an error detection scheme called Committed Instructions Counting (CIC) to increase error detection in such systems. The scheme uses internal Performance Monitoring features and an external watchdog processor (WDP). The Performance Monitoring features enable counting the number of committed instructions in a program. The scheme is experimentally evaluated on a 32-bit Pentium® processor using software implemented fault injection (SWIFI). A total of 8181 errors were injected into...
Fabrication of Appropriate Membrane for Treatment and Reuse of Grey Water
, M.Sc. Thesis Sharif University of Technology ; Mousavi, Abbas (Supervisor) ; Kariminia, Hamidreza (Supervisor)
Abstract
In this study preparation of polymeric membrane for grey water treatment is examined. Grey water is the wastewater that is produced by household activities such as baths, showers and sinks. These sources make 50 to 80 percent of total household wastewater. Because of low contamination of these kind of wastewater, they can be treated with Nanofiltration membrane process. Membrane used for treatment is thin composite polyamide membrane. This membrane is made with interfacial polymerization reaction of Piperazine and m-phenylenediamine as amine monomer and trimesoyl chloride as chloride acid monomer on a Polysulfone ultrafiltration membrane. In order to promote the flux, Polyethylene glycol is...