Sharif Digital Repository

These days, according to increasing requirement to the applications of clean rooms in industries in and within the developing industry of computer, positive indicators that show a real need to a compere comprehensive study and research about the Clean rooms, in oder to predict the distribution and dispersal of the particles. Correct determination of indoor airflow and particle concentration distribution results in new standard development for Clean rooms. As computational fluid dynamics has become a powerful tool for indoor airflow studies, in this research, influence of effective parameters on the flow and concentration distribution in clean rooms has been... 

It has been realized that the raft (mat) foundations are capable of bearing very large loads when they are assisted with a pile group. The contribution of both raft and piles to carry the surcharge loads is taken into account, considering the stiffness and strength of involved elements in the system, i.e. piles, raft and surrounding soil. Piles are usually required to ensure the stability of the foundation and to act as settlement reducers especially for high rise buildings. The present study focuses on both kinematic and inertial effects of piled foundations and piled raft foundations under earthquake loading. The Finite Element Method (FEM) via ABAQUS will be used as an appropriate tool to... 

The Iran-China 25-year Cooperation Program on the further economic development particularly energy area signed on 27 March 2021 by Iran, which suffered from many years of political and economic isolation and China, the second global economy. Energy transition is an essential issue in both country's energy systems which calls for a medium energy carrier that will be the natural gas. China is seeking for new natural gas resources in order to achieve its ambitious net-zero goals and Iran has targeted 50% reduction in its energy intensity. The necessity of supplying the natural gas for Pakistan and China through the CPEC (China-Pakistan Economic Corridor) by Iran is an important criterion in the... 

The main function of respiratory system is to exchange gasses between air and blood. However selection of the suitable geometry and solution of the fluid flow precede all other phenomena in the lung, including particle deposition and gas exchange. The most complicated phenomena take place at the terminal generations of the lung which is known as acinar region. Due to small dimensions and inability to use experimental measurements, numerical simulations are adequate methods in this region. In the first part of this thesis a method is proposed to reduce the computational space and make it possible to model all acinar region, simultaneously. Results show that the characteristic of streamlines... 

The DNA Molecule carries genetic information in almost all living organisms. The information coded on DNA is an instruction which organizes and conducts all living activities of the living organism. The role of DNA in biological processes is so fundamental that life, as we know, is not possible without DNA. Therefore, studying the biological properties of DNA is crucial for understanding the nature of life. In biological conditions, DNA molecule can be found in highly packed configurations. Since the DNA is a rather stiff molecule, the formation of these configurations cost a considerable amount of energy. The elasticity of DNA plays an important role here. The important question is: how... 

Prosodic annotations are used for locating and characterizing prominent parts in utterances as well as identifying and describing boundaries of coherent stretches of speech. Automatic detection and labeling of prosodic events in speech has received much attention in recent years since prosody is intricately bound to the semantics of the utterance. Recognition of prosodic events is important for spoken language applications such as automatic understanding and translation of speech. Moreover, corpora labeled with prosodic markers are essential for building speech synthesizers that use data-driven approaches to generate natural speech. Such databases are important to reach a better... 

This study investigates the intonational properties of vocative structure in standard Persian in the framework of Auto-segmental-metrical phonology. Pitch accent is one of the elements whithin this framework, that refers to the prominence in the utterance. In Persian all lexical units are stressed in their final syllable and there is a language-specific feature in Persian according to which pitch accents are aligned with lexically stressed syllables. Contrary to the said feature, previous studies claim that in vocative structure, it is the first syllable that is accented, due to the difference existed between intonation pattern of vocative structure compared to its citation form. The data... 

Treebanks are useful in many applications of natural language processing such as machine translation, speech recognition, information extraction, and etc. They are also being used in theoretical linguistics to study languages. For instance, they are valuable for development of different syntactic theories, calculation of frequency of syntactic rules, evaluation and comparison of statistical models and etc.
The most treebanks are based on phrase structure grammar or dependency grammar. In a phrase structure treebank, a sentence is divided to phrases. In this representation, a phrase is composed of several words. But in the dependency treebank, connection between two words is based on the... 

In this research, we investigate shape fitting problems in high dimensional streams and we provide lower bounds for the problems of minimum enclosing spherical shell and minimum enclosing cylindrical shell in streaming model. We will prove that no streaming algorithm can approximate these problems with constant factor with storage sub-exponential in dimension. More precisely, we will prove that every streaming algorithm that can solve these problems with storage sub-exponential in dimension, does not have an approximation factor better than√28 d1/3, where d is dimension of the input points. This is the first lower bound that has been proved for these two problems in high dimensional streams  

The observations of the cosmic background radiation and large-scale structures show that the standard cosmological model is in good agreement with observational data. The standard model is based on the cosmological constant, dark matter, and Gaussian, nearly scale-invariant, adiabatic, and isotropic initial conditions. Although this model has been phenomenologically successful, but the problems of dark energy, dark matter, missing baryons and early universe remain unresolved. One of the most important theoretical questions in cosmology is whether the cosmological constant is the reason for accelerated cosmic expansion. In other words, is Einsteinian gravity the correct theory on the cosmic...