Sharif Digital Repository

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... 

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 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... 

The Ni-base superalloy CM88Y has good hot corrosion resistance, high stability and strength at elevated temperature; accordingly, the alloy is used in manufacturing of gas turbine hot components. In most applications, heat treatment is required in order to achieve the desired mechanical properties and corrosion resistance of the working conditions; often three stages of heat treatment is designed for precipitation hardening nickel-base superalloy. In general, the effective parameters of heat treatment cycles includes temperature, time, heating rate and the cooling rate. In this study, the effect of cooling rate from partial solution temperature (second stage of heat treatment) on the... 

Numerical simulations and large eddy simulations (LES) of turbulent flow downstream of diversion dam , pool-riffle bedform in different geometrical ratios (different lengths of riffle and pool) with flow Reynolds number of 3.0 E+04 to 3.3E+04, downstream of special case study "Mill and Moghan diversion dam" with Froude number of 0.5 are presented The calculations are performed using a computational fluid dynamics model, FLOW-3D, which solves the Navier-Stokes equations in three dimensions with finite volume method. Numerical simulations are validated by comparing the numerical results of time-averaged flow patterns downstream of pool-riffle sequence with that of the experimental... 

RF Receivers are one of the main components of telecommunication systems, which can be composed of many parts and circuits according to their working frequency and application.In this thesis, the design and simulation of an X-band Receiver in 0.15um GaAs technology has been discussed. The receiver chain, in the order of receiving the signal, includes the main blocks of limiter, attenuator, low noise amplifier and mixer. It also includes a number of filters. The attenuator has two digital bits and the receiving chain filters are implemented in such a way to provide more than 20dB attenuation in the frequency band of the image signal. In this research, the limiter is implemented with a... 

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... 

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,... 

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... 

Evolutionary game theory is a relatively new branch of game theory (in contrast to the classical game theory) which has overcome some of the common problems of the classical version such as highly rational agents assumption. Because of this, it has gained popularity among different sciences. On the other hand, social network as one of the branches of complex networks is a pretty novel research area and has application in several fields. Networks are everywhere and most real-world networks are complex ones. Group formation and evolution are among important subjects in studying social networks and some works has been done in analyzing and modeling them. In this thesis we have presented a... 

Liquide phase catalytic exchange (LPCE) between liquid water and hydrogen is an important reaction for separation of the hydrogen isotope from liquid water. One of the application of this reaction is heavy water production. This method is mainly used hydrophobic catalysts with Pt active metal. The use of hydrophobic catalyst is necessary, because liquid water in the LPCE reaction, resulted in block the catalyst pores and loss of catalyst activity. Design of experiment has been done by using of Design Expert 7.0.0 for determination of number of tests and optimization of Pt weight percent. Alumina and carbon (included graphene, single-walled and multi-walled carbon nanotube) supported 5% wt Pt... 

Heart failure is a chronic and significant disease that affects millions of people worldwide. Despite advances in medical technology and treatment options, heart failure remains a leading cause of death globally. This has led to a growing interest in developing new diagnostic tools and therapeutic strategies that can improve the control of this disease. One promising field is bioimpedance spectroscopy, which is a non-invasive method for measuring the electrical properties of biological tissues in the body. Monitoring the condition of fluid accumulation in the lungs of heart failure patients is effective in reducing the death rate caused by this disease. In this thesis, a portable device for...