Sharif Digital Repository

In this thesis, the theoretical foundation, the way of implementation and the uses of Pars Morph, a Persian morphological analyzer is introduced. Pars Morph is a rule-based Persian morphological analysis system, which analyzes the internal structure of word in Persian and determines the grammatical category and function of the word parts. Pars Morph being in link with a lexicon covering about 45000 lexemes and based on morphological rules in Persian can analyze the structure of complex lexemes and their possible inflected forms and even out-of-lexicon words.
Accuracy rate of the first version of Pars Morph is about 95% which could be enhanced to 100% by applying the regulations on... 

Derivation and lexicalization are two critical subjects in morphology and word-formation processes. Although wide studies have been taken place about derivation, which is one of the most productive processes of word-formation along with composition, there has been no proper attention to lexicalization, which sometimes happens after derivation. One of the applications of this thesis is developing dictionaries. With regard to this issue that there is no scientific and complete method for recording lexical units in Persian dictionaries, we decided to propose a scientific method to do the mentioned activity by studying derivational processes, affixes and lexicalization phenomena and its relation... 

In this project we have investigated the distribution of distinctive features in Persian lexicon. According to our hypothesis the distribution of distinctive features should be compliant with the amount of perceptibility of acoustic cues to those features in their contexts. The results show that the Sonority Sequencing Principle and the Syllable Contact Law which are previously explained via phonological constraints have a phonetic (perceptual) basis. The more acoustic cues to a distinctive features are perceptually strong in a context the more the consonant is diversed using different values of that feature in that context. The results of intelligibility tests show that consonants are... 

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... 

This study is a research on Persian Intonational System, which was carried out within the Autosegmental-Metrical framework.The intonational elements of Persian are represented by two distinctive levels (High and Low). Persian intonation system enjoys three main elements: pitch accents, Phrase accents and boundary tones. Every intonational element has its own meaning. The data of study is about 200 utterances produced by two Persian native speaker one male and one female. These utterances have been annotated in four levels in PToBI: phoneme level, word level, tone level and break index level. In this study we aimed to formulate the acoustic representation of the intonational elements by three... 

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... 

This study aims at classifying outputs of Reduplication (Total and Partial Reduplication) in Persian, in order to demonstrate the types and processes which lead to the lexicalization of some reduplicated forms and assign them lexical position in lexicography as individual lexical entries. There are distinct phonological, morphological and semantic evidences behind the lexicalization of some types of reduplicated items in Persian. Approximately about 269 totally reduplicated words and 293 partially reduplicated words have been collected and analyzed according to the said morphological, phonological and semantic considerations. Partial and Total Reduplication process is one of the productive... 

Prepositions are considered as frequent linguistic units whose role in computational linguistics cannot be neglected. These units are often thought to have no lexical meaning; moreover, it is a widely held belief that prepositions are solely used for sentence cohesion. On the other hand, in some cases the substitution of one particular preposition with another one would change the meaning of sentences.
The main question which is concerned in this thesis is “Whether prepositions should be regarded as meaningful units or semantically empty units?” In order to achieve this goal, the present study is conducted as a library research and a field research. In the library research, 1000... 

Theoretically, it has been proved that pitch changes has an specific phonological system in Persian and the main intonational elements (i.e. pitch accent, phrase tone and boundary tones) have a known independent identity and can change independently. These changes give different intonational forms to utterances. In addition, it has been demonstrated that sound pattern of Persian syntax units follow HAP (Head Avoidance Principle) and Always, the farthest argument from the head takes the pitch accent. In the present thesis, phonetic values of intonational elements in 5 emotions of PESD database utterances (i.e. Anger, Disgust, Sadness, Happiness and Fear) are quantified and then, they are... 

The stress positions of the words are determined according to the type of their morphological elements. Persian Words often have a fixed position for stress. However, Persian wordforms show different stress positions, based on their morpheme types or in the other words, their bound-non derivational affixes. Inflectional affixes accept stress, whereas clitics do not. In the present research we studied both types of non derivational affixes considering their phonetic features meaning fundamental frequency and duration. The phonetic representation of the pitch accent as the phonemic- intonational element was given as a result of this study, as well. The differences in the phonetic... 

Inrush Current is a form of over-current that occurs during energization of a transformer. For power transformers, the magnitude of the first peak of inrush current is initially several times the rated load current but slowly decreases until it finally reaches the normal exciting current value. This process typically takes several minutes. Time-variant axial and radial electromagnetic forces under inrush current and short-circuit current are calculated (by finite element method; FEM), and compared. An analytic method is presented for computation of inrush current in transformer. The simulation results obtained by this proposed method are compared with the measured values. A compact... 

In this study a variational framework for joint segmentation and motion estimation is provided for inspecting heart in Cine MRI sequences. In the first work, a functional including Mumford-Shah segmentation and optical flow based dense motion estimation is proposed. However, the motion estimation technique is replaced with warping estimation in the second work to reach in more regular and smooth motion field based on tracking of cardiac boundaries. Both of these functionals are then approximated by using the phase-field method to make them suitable for extracting Euler-Lagrange equations. Numerical solution to the optimization problem, when the time and image spaces are discretized by finite... 

Variation in value and initial cost of construction contracts in many cases lead to considerably increasing the finalized price. These increases are sometimes so big enough that the 25 percent of limitation which could be added to contracts couldn't make them to be finalized and exploitable, so the necessity of a new contract sometimes up to 100 percent or even up to 200 percent of initial cost for completing the same project is inevitable. Although in some specific and rare cases we couldn't avoidance from these changes, but observing the growth of these changes in public construction projects of Iran increase the requirement of special attention in order to find the main causes, prevention... 

Integrity of closed-loop systems with integral action control is characterized by using a series of successively more difficult to obtain conditions: Integral Stabilizable (IS), Integral Controllable (IC), Integral Controllable with Integrity (ICI), and Decentralized Integral Controllability (DIC). The IS condition requires that for a Linear Time-Invariant (LTI) finitedimensional (FD) plant, G(s), one finds a stabilizing decentralized controller with integral action. For G(s) to be IC, in addition to being IS, one should be able to reduce the gain of
all control loops by the same factor from a finite value to (but not including) zero without introducing instabilities. ICI requires that... 

Transportation of heavy and super heavy equipment is one of the issues that have been discussed in recent years. High cost and required expertise of Transportation for oil and gas projects has caused many organizations and Iranian companies turn to outsourcing strategy and have invested a lot of money in this field without regard to its Risks. Unfortunately, the lack of risk management in transportation projects has led to an increase in refractive index. In this thesis, have been identified the risks of heavy and super-heavy transport equipment in the oil, gas and petrochemical industries then prioritize the risks identified. Finally, each of the identified risks in Iran is investigated....