, 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...

Simulation of welding residual stresses in resistance spot welding, FE modeling and X-ray verification

, Article Journal of Materials Processing Technology ; Volume 205, Issue 1-3 , 26 August , 2008 , Pages 60-69 ; 09240136 (ISSN) Ranjbar Nodeh, I ; Serajzadeh, S ; Kokabi, A. H ; Sharif University of Technology

2008

Abstract

In the present study, an electro-thermo-mechanical model is utilized to predict electrical potential, temperature and residual stress distributions during different stages of resistance spot welding. In order to improve accuracy, material properties including physical, thermal and mechanical properties supposed to be temperature-dependent. The employed model is capable of considering the effects of welding parameters such as heat input and welding time on residual stress distribution. The model results are then compared with the measured residual stresses and good agreement is observed. Predictions show that maximum tensile residual stresses are located at the weld center while they are...

Exploiting Non-Volatile Approximate Memories in Embedded Systems

, Ph.D. Dissertation Sharif University of Technology Teimoori Nodeh, Mohammad Taghi (Author) ; Ejlali, Alireza (Supervisor)

Abstract

Due to recent prevalence of error resilient applications (e.g., multimedia, artificial intelligence, etc.), approximate computing (AC) has become a promising paradigm for low power and high performance designs. A significant amount of research in AC has been focused on improving the power and performance by approximating arithmetic units. However, memories i) are also a major contributor to the overall energy consumption (e.g., 30% to 60%) and response time of a system, and ii) result in perceivable quality degradation when used approximately. In this thesis, we employ the predictability potential of embedded systems in order to enable quality-aware exploitation of the advantages of the...

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...

Preparation of cobalt-ruthenium nanocatalysts supported on nitrogen-doped graphene aerogel and carbon nanotubes in Fischer-Tropsch synthesis

, Article Arabian Journal of Chemistry ; Volume 16, Issue 8 , 2023 ; 18785352 (ISSN) Rezaei Kafrani, M ; Aghababai Beni, A ; Pournuroz Nodeh, Z ; Sharif University of Technology

Elsevier B.V 2023

Abstract

In this study, cobalt-ruthenium nanocatalysts supported on nitrogen-doped graphene aerogel (NGA) and carbon nanotubes (CNT) were synthesized using the wet impregnation method for Fischer-Tropsch process with a cobalt to ruthenium ratio of 1:50. The synthesized catalysts underwent various characterizations such as FTIR, ICP, BET, XRD, EDX, TPR and TEM. The performance of the synthesized catalysts was compared to that of a cobalt-ruthenium nanostructured catalyst supported on NGA and CNTs. The catalysts were evaluated in a fixed-bed reactor at 25 bar, with a gas ratio H2/CO: 2 and Gas Hourly Space Velocity (GHSV) 10,000 mlg-1h-1, at temperatures of 260 °C and 280 °C. The use of NGA as a cobalt...

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,...

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...

Applacation of Zinc Oxide Nanoparticles in Lichen Removal from the Historical Stone Surfaces

, M.Sc. Thesis Sharif University of Technology Nodeh, Razieh (Author) ; Khorashe, Farhad (Supervisor) ; Sohrabi, Mohammad (Co-Advisor) ; Baghalha, Morteza (Co-Advisor)

Abstract

There are many archeological sites, historic building monuments and inscriptions in Iran and other countries in the world which have been damaged by environmental as well as biological causes. Lichens are one of the biological causes which, through their growth, bring about change and damage to the stones. Different methods, each of which has both advantages and disadvantages, have been used in order to deal with the problem. Since there are many historic buildings in our country which have been damaged by different biological causes including the lichens, doing a research on the topic seems to be quite significant and necessary. The Persepolis is among one of the most important historic...

Loving Country is Part of Faith; Investigating the Relationship between Religious Factors and Sacrifice

, M.Sc. Thesis Sharif University of Technology Jafari Nodeh, Negin (Author) ; Yousefi, Kowsar (Supervisor) ; Rahmati, Mohammad Hossein (Supervisor)

Abstract

Wars are destructive and ruin lives. However, when it comes to defending one’s home country and religion, the brilliant aspects of sacrifice are highlighted. The 1980 war between Iran and Iraq, which lasted eight years and cost more than 200,000 lives, is a prime example of such sacrifices. Religions demand sacrifices and create club goods like altruism, cooperation, and effort, which are crucial on the battlefield. Religious institutions, like the Imamzadehs in Iran, strengthen people’s faith and play a significant role in these sacrifices. About eight thousand Imamzadehs in Iran are tombs of the grandchildren of Prophet Muhammad, who left the Arab land seeking a peaceful life among...