, M.Sc. Thesis Sharif University of Technology Razieh, Azad (Author) ; Farzaneh, Forouhar (Supervisor)

Abstract

In recent years due to the advances in semiconductor technology and the ability to implement small-scale manufacturing, communication at 60 GHz band receive more attention than ever has been. The use of this frequency band is not only about 7-9 GHz unlicensed broadband access provided, but getting smaller devices make it possible to use multiple antennas at the transmitter and receiver, and thus taking advantage of multiple input – multiple output systems. Antennas used in these systems should have features such as small size , low weight, high gain and bandwidth and also they should keep their high efficiency and gainat high frequency range (about a few GHz ). To achieve these features...

Design and Implementation of 6-18 GHz Driver Amplifier

, M.Sc. Thesis Sharif University of Technology Piri, Milad (Author) ; Medi, Ali (Supervisor)

Abstract

Nowadays, application of microwave integrated circuits in commerce and humanitarian military measures plays an important role. When integrated microwave circuits emerged, the dream of producing high quality and low cost amplifiers and mass productionhas been fulfilled. Power amplifiers which are the last block in a communication systemare one of the most important circuits in this field.
Since driver amplifiers are interstage between high and low power sections of a system, should have good specificationsfor both small and large signal analysis. Thus, designing such a circuit can be very challenging. In order to get the desired bandwidth, high-order filters are used as interstage...

Numerical Investigation of Nano-Particles Dispersion and Deposition in Crossing of Elliptical Obstacles Networkusing Lattice Boltzmann Method

, M.Sc. Thesis Sharif University of Technology Piri, Salman (Author) ; Moosavi, Ali (Supervisor)

Abstract

Investigation of transport and deposition of aerosol particles has been of interest to researchers in many branches of science. Various numerical and experimental methods has been utilized in particulate fluid flows studies. In recent relevant researches lattice Boltzmann method has been widely used and is reported to be a robust and efficient method. In present study, numerical investigation of dispersion and deposition of aerosol particles is studies in the channel, containing elliptical obstacles geometry using Lattice Boltzmann Method. Fluid flow simulations are performed using LBM while for the study of particle transport and deposition, tracking and the motion equations of them,...

Studying the Role of Distraction of Men and Women in Accidents Using Structural Equation Modeling

, M.Sc. Thesis Sharif University of Technology Piri, Mehran (Author) ; Kermanshah, Mohammad (Supervisor)

Abstract

Crash severity is among the fundamental safety indicators in transportation. In recent years, distracted driving has been one of the biggest concerns in road crashes. Many scholars have evaluated the effects of distraction in crash severities and injuries. This study uses the latest general estimates system (GES) crash dataset, which is a subset of the US National Automotive Sampling System (NASS) and the structural equation model (SEM) approach to explore the relationships between distraction factors and crash severity in male and female drivers. Using SEM for modeling about 22 thousand observations offers the opportunity to simultaneously examine complex relationships between variables by...

Design and Preparation of a Persian Semantic Corpus Using Abstract Meaning Representation

, M.Sc. Thesis Sharif University of Technology Takhshid, Reza (Author) ; Bahrani, Mohammad (Supervisor) ; Shojaie, Razieh (Supervisor)

Abstract

To keep in line with the day to day advancements in the fields of computational linguistics and natural language processing, and the growing attention of researchers to semantic processing, this thesis presents the design and preparation of a Persian semantic corpus using Abstract Meaning Representation (AMR). This semantic representation pairs each sentence with a single rooted, acyclic, directed graph, which is human and computer readable. Moreover, this representation paves the way for the creation of large semantic corpora. In order to bring such benefits to Persian, in this thesis we present solutions for representing Persian sentences in the framework of AMR. Moreover, a corpus of 150...

Ezafe Recognition Using Dependency Parsing

, M.Sc. Thesis Sharif University of Technology Nassajian, Minoo (Author) ; Bahrani, Mohammad (Supervisor) ; Shojaei, Razieh (Co-Supervisor)

Abstract

Ezafe is regarded as one of the most controversial and challenging issues in different Persian Language Processing (NLP) fields. It is recognized and pronounced but usually not written. So, this results in a high degree of ambiguity in Persian texts. Dependency grammar plays a significant role in optimization problems. So, to recognize the position of Ezafe in a sentence, this grammar is used in this current study. This method helps speed up computer operations and use low memory. Within this framework, first we take a close look at Ezafe distribution in Persian text. We use Uppsala Persian Dependency Corpus (2015) to analyze parsed sentences. The Ezafe constructions under study include...

An approach for refining JML specification to object oriented code

, Article 2009 14th International CSI Computer Conference, 20 October 2009 through 21 October 2009 ; 2009 , Pages 1-9 ; 9781424442621 (ISBN) Piri, R ; Mirian Hosseinabadi, S. H ; Sharif University of Technology

2009

Abstract

JML is a behavioral interface specification language which has Java as its target implementation language. It combines the idea of using Java expressions from Eiffel language with the model-based approach to specify a program. Refinement calculus is a framework to produce executable code from a specification by preserving the correctness of programs. In this paper some constructs of JML concerning object creation, feature call, exceptional behavior and concurrency constructs are studied and some refinement rules are proposed to obtain an object oriented code in Java from a JML specification containig these constructs. The correctness of these rules is proved by weakest precondition predicate...

Integrated Dynamic Pricing and Ordering in a Supply Chain With Demand Learning

, M.Sc. Thesis Sharif University of Technology Piri, Saeed (Author) ; Modarres Yazdi, Mohammad (Supervisor)

Abstract

In this study, four pricing models in a supply chain are developed. The first model includes a retailer. The second model also includes a retailer. However in this model we apply the learning technique to update the stochastic demand. In the third model, we consider a supply chain consisting of a retailer and a manufacturer. Finally, in the fourth model we consider a supply chain consisting of a retailer and a manufacturer and like the second model; we apply the learning technique to update the stochastic demand. In all models we assume that a single product is sold in a monopoly market. In this study we seek to simultaneously determine decisions about production, pricing and ordering to...

Novel Approach Towards Mechanical and Thermal Resistant Capillary Microextraction by Sol-Gel Technique in On-Line Combination with High Performance Liquid Chromatography

, Ph.D. Dissertation Sharif University of Technology Piri-Moghadam, Hamed (Author) ; Bagheri, Habib (Supervisor)

Abstract

In this thesis, a new approach was developed to achieve mechanical and chemical resistant capillary microextraction (CME) in on-line combination with high performance liquid chromatography (HPLC) based on sol-gel technology. This thesis is divided into three chapters:
First chapter contains of two parts. Overcoming the lack of mechanical stability of the substrate of CME by replacing the fused silica by copper tubings was the main objective of the first part. Self-assembled monolayers technique was employed to functionalize the copper tube followed by chemical bonding of the sorbent on the inner surface of the copper tube by sol-gel technology. The prepared copper tube containing the...

Simulation of the Influence of Hypertension on Low Density Lipoprotein (Ldl) Permeation into Multilayer Coronary Bifurcation

, M.Sc. Thesis Sharif University of Technology Moniri Piri, Mohammad (Author) ; Firoozabadi, Bahar (Supervisor)

Abstract

Atherosclerosis, due to the penetration of low-density lipoprotein particles (LDL) into the arterial wall, is one of the most common and death-leading diseases in today's world. Due to its importance, extensive research has been conducted on the factors that affect this disease. In this thesis, a numerical study of the effects of Wall Shear Stress (WSS), non-Newtonian behavior of blood, different hematocrit values, and blood pressure on LDL permeation through the artery wall layers are investigated in a 4-layer wall model of a coronary bifurcation. To obtain the velocity and concentration fields in the domain, momentum, Brinkman, and mass transport equations are solved in the lumen and wall...

A Semantic Valency Lexicon for Persian Predicates and Visualization of their Relations

, M.Sc. Thesis Sharif University of Technology Salimifar, Saeedeh (Author) ; Khosravi Zadeh, Parvaneh (Supervisor) ; Shojaei, Razieh (Supervisor)

Abstract

The highest and most difficult layer of Natural Language Processing, is the understanding of meaning. As a result, lexicons and annotated corpora are of the utmost importance in this area. However, the lack of such semantic resources, especially in Abstract Meaning Representation (AMR), is one of the main issues in this field for Persian Language. This work by modeling PropBank, a semantic valency lexicon for English predicates, is the first step towards building such lexicons for Persian Language with the focus on AMR. Thus, a guideline describing how to annotate the Persian predicates is provided which first evaluates the common structures between the two languages and then focuses on the...

Persian Causative/Inchoative Alternation from an LFG Perspective

, M.Sc. Thesis Sharif University of Technology Jamshidi, Naser (Author) ; Khosravizadeh, Parvaneh (Supervisor) ; Shojaee, Razieh (Supervisor)

Abstract

This study attempts to describe and analyze Persian speakers’ linguistic knowledge of different types of causative and inchoative constructions within the framework of Lexical Functional Grammar (LFG). In order to do so, different studies on Persian causative alternations within theories other than LFG as well as causative alternations in other languages within LFG are reviewed. Next, different types of causative constructions are categorized conceptually and structurally after they are extracted from Bijankhan corpus (2005). Then they are analyzed syntactically and semantically. In this regard, we represent syntactic and semantic structures based on LFG as a monostratal theory. After that,...

On-line micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofibers

, Article Chromatographia ; Vol. 77, issue. 9-10 , May , 2014 , p. 723-728 Bagheri, H ; Asgari, S ; Piri-Moghadam, H ; Sharif University of Technology

2014

Abstract

An on-line extraction/determination set up was designed for micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofiber mats. The prepared mats were packed in a stainless steel tube which conveniently acted as a high-performance liquid chromatography injection loop. Influential parameters affecting the extraction efficiency were optimized using a distilled water sample fortified with 25 μg L-1 of clodinafop propargyl. An enrichment factor of 440 was achieved for clodinafop propargyl indicating the ability of the whole procedure. Under the optimum conditions, the linearity for the analyte was in the range of 6-700 μg L-1, while...

Grafting the sol-gel based sorbents by diazonium salts: A novel approach toward unbreakable capillary microextraction

, Article Journal of Chromatography A ; Volume 1318 , November , 2013 , Pages 58-64 ; 00219673 (ISSN) Bagheri, H ; Bayat, P ; Piri Moghadam, H ; Sharif University of Technology

2013

Abstract

The present work deals with a novel approach for grafting a sol-gel based sorbent, using diazonium salts for preparation of an unbreakable capillary microextraction (CME) device in on-line combination with high performance liquid chromatography (HPLC). The use of diazonium salts modifier allowed all types of metallic and non-metallic substrates to be used without any limitation. Substrates including copper, brass, stainless steel and polytetrafluoroethylene (PTFE) were chosen to be functionalized by chemical or electrochemical reduction of 4-amino phenyl acetic acid. Then, 3-(trimethoxysilyl)propylamine (3TMSPA) was selected as the precursor and the only reagent for preparation of the...

Refning Object Oriented Formal Specifcation To Object Oriented Code

, M.Sc. Thesis Sharif University of Technology Piri, Razieh (Author) ; Mirian Hosseinabadi, Hassan (Supervisor)

Abstract

The presented work provides a calculus for refining an object oriented formal specification to an object oriented code. A refinement calculus provides a framework to produce executable code from a specification while preserving its correctness. Eiffel Refinement Calculus is the most complete work in this domain which is studied in this research.
The Formal specification language which is considered for this purpose is .JML to specify executable code in .Java language. For this calculus some refinement laws are pre- sented and their proofs is given by weakest precondition predicate transformer, a work which was not considered in Eiffel Refinement Calculus. The constructs which are used in...

Persian Compound Verb Database with the Verbal Element: “Shodan”

, M.Sc. Thesis Sharif University of Technology Hashemnejad, Zeinab (Author) ; Khosravizadeh, Parvaneh (Supervisor) ; Shojaie, Razieh (Supervisor)

Abstract

Compound verbs (CVs) and its components, have been widely discussed in previous linguistics' researches as one of the most important and fundamental constructions of Persian language. Nevertheless most of the arguments and assumptions in those researches align with each other and studying CVs from another aspect with a different viewpoint has not been considered very much in order to solve nodes and issues in this area. We have endeavored in this thesis to review and criticize the portrayed definitions of the CVs, reconsider this construction and the syntactical and semantical roles of verbal and non-verbal elements in this combination from another point of view, and revise the previous...

Wavelet Applications in Pattern Recognition

, M.Sc. Thesis Sharif University of Technology Piri Pishekloo, Bijan (Author) ; Mahdavi Amiri, Nezameddin (Supervisor)

Abstract

We study wavelet transformation for use in pattern recognition. Feature extraction is a crucial processing step for pattern recognition. Feature extraction is based on finding mathematical methods for reducing dimensionality of pattern representation. Two most important features to be extracted are edges and textures. Edges and textures are not absolute concepts and change with scale. Moreover, local characteristics of edges are needed. In recent decades, wavelet transformation as a mathematical tool has captured the attention of many scientists in signal processing and mathematics. Wavelet basis can provide efficient and useful description of a function or signal since it has local...

Resorcinol-formaldehyde xerogel as a micro-solid-phase extraction sorbent for the determination of herbicides in aquatic environmental samples

, Article Journal of Separation Science ; Volume 38, Issue 13 , 2015 , Pages 2305-2311 ; 16159306 (ISSN) Es Haghi, A ; Zare, M ; Piri Moghadam, H ; Bagheri, H ; Sharif University of Technology

2015

Abstract

In this study, organic aerogels were synthesized by the sol-gel polycondensation of mixed cresol with formaldehyde in a slightly basic aqueous solution. Carbon aerogels and xerogels are generated by pyrolysis of organic aerogels. The novel sol-gel-based micro-solid-phase extraction sorbent, resorcinol-formaldehyde xerogel, was employed for preconcentration of some selected herbicides. Three herbicides of the aryloxyphenoxypropionate group, clodinafop-propargyl, haloxyfop-etotyl, and fenoxaprop-P-ethyl, were extracted from aqueous samples by micro-solid-phase extraction and subsequently determined by gas chromatography with mass spectrometry. The effect of different parameters influencing the...

A combined micro-solid phase-single drop microextraction approach for trace enrichment of volatile organic compounds

, Article Analytical Methods ; Volume 7, Issue 16 , Jun , 2015 , Pages 6514-6519 ; 17599660 (ISSN) Bagheri, H ; Zare, M ; Piri Moghadam, H ; Es haghi, A ; Sharif University of Technology

Royal Society of Chemistry 2015

Abstract

An attempt was made to combine μ-solid phase extraction and headspace single drop microextraction techniques and use their advantages for trace determination of some volatile organic compounds in aqueous samples. After performing the two-step preconcentration approach, the desired analytes were determined by gas chromatography-mass spectrometry. A resorcinol-formaldehyde-based xerogel was used as the extraction medium in the μ-solid phase extraction (μ-SPE) method. Then, the extracted BTEX was eluted with a rather large amount of methanol. To remove the laborious process including solvent evaporation and further reconstitution, which is usually accompanied by loss of analytes and accuracy,...

Experimental and theoretical studies on the synergistic effect of P and Se co-doped g-C3N4 loaded with Ag nanoparticles as an affective photocatalyst under visible light irradiation

, Article Journal of Molecular Liquids ; Volume 369 , 2023 ; 01677322 (ISSN) Nematollahi, R ; Fahimirad, B ; Eshaghi Malekshah, R ; Elhampour, A ; Piri, M ; Heravi, M. M ; Sharif University of Technology

Elsevier B.V 2023

Abstract

In this work, in order to improve drawbacks of bare (pure) carbon graphite nitride (g-C3N4), phosphorus-selenium doped carbon nitride was synthesized to enhance light absorption in visible region. Then Ag nanoparticles loaded onto P-Se co-doped g-C3N4, as a result, the surface plasmonic resonance effect was created. In addition, the photocatalytic activity of samples was improved by suppression of charge carriers’ recombination. Synthesized photocatalyst was characterized by XRD, FT-IR, EDS, BET, XPS, FE-SEM, ICP, TEM, and DRS and PL analysis. All prepared samples were applied in the degradation of Rhodamine B as an azo dye under irradiation of visible light. According to the obtained...