Persian pronoun resolution using data driven approaches

, Article 23rd International Conference on Information and Software Technologies, ICIST 2017, 12 October 2017 through 14 October 2017 ; Volume 756 , 2017 , Pages 574-585 ; 18650929 (ISSN); 9783319676418 (ISBN) Nourbakhsh, A ; Bahrani, M ; Sharif University of Technology

Springer Verlag 2017

Abstract

Pronoun resolution is one of the challenges of natural language processing (NLP). The proposed solutions range from heuristic rule-based to machine learning data driven approaches. In this article, we follow a previous machine learning approach on Persian pronoun anaphora resolution. The primary goal of this paper is to improve the results, mainly by extracting more balanced data through using heuristic rules in instance sampling, and utilizing more relevant features in classification. Using PCAC2008 dataset, we consider noun phrase structure as a way to extract more suitable training data. Incorporated features include syntactic and semantic information. Finally, we train and test different...

Pronoun Resolution with Data Driven Approaches

, M.Sc. Thesis Sharif University of Technology Nourbakhsh, Aria (Author) ; Bahrani, Mohammad (Supervisor)

Abstract

Pronoun resolution is one of the challenges of natural language processing. The proposed solutions range from heuristic rule-based to machine learning data driven approaches. In this thesis, we followed a previous machine learning base work to Persian pronoun anaphora resolution. The primary goal of this thesis was to improve results, mainly by extracting more balanced data and to add more features to the extracted feature vectors used in classification. Using PCAC2008 dataset, we considered noun phrase structure as a way to extract more suitable training data. Features added to the extracted data include syntactic and semantic features. Then, we trained and tested different machine learning...

WordPars: A tool for orthographic and phonological neighborhood and other psycholinguistic statistics in Persian

, Article Behavior Research Methods ; 2021 ; 1554351X (ISSN) Esmaeelpour, E ; Saneei, S ; Nourbakhsh, M ; Sharif University of Technology

Springer 2021

Abstract

This paper presents a Windows program providing statistics on word and non-word stimuli in Persian, including word frequency, orthographic and phonological length, orthographic and phonological neighbors, and transposed-letter neighbors. It also generates possible non-words that are orthographic neighbors of the target word. Persian is an under-represented Indo-European language that has historically been influenced by Arabic and adopted certain characteristics in its writing, e.g., the omission of short vowels. This tool aims to help researchers in psycholinguistics, specifically with regard to isolated word recognition in Persian. This downloadable program computes the aforementioned...

WordPars: A tool for orthographic and phonological neighborhood and other psycholinguistic statistics in Persian

, Article Behavior Research Methods ; Volume 54, Issue 4 , 2022 , Pages 1902-1911 ; 1554351X (ISSN) Esmaeelpour, E ; Saneei, S ; Nourbakhsh, M ; Sharif University of Technology

Springer 2022

Abstract

This paper presents a Windows program providing statistics on word and non-word stimuli in Persian, including word frequency, orthographic and phonological length, orthographic and phonological neighbors, and transposed-letter neighbors. It also generates possible non-words that are orthographic neighbors of the target word. Persian is an under-represented Indo-European language that has historically been influenced by Arabic and adopted certain characteristics in its writing, e.g., the omission of short vowels. This tool aims to help researchers in psycholinguistics, specifically with regard to isolated word recognition in Persian. This downloadable program computes the aforementioned...

FoM Optimization in Class-C Oscillators

, M.Sc. Thesis Sharif University of Technology Nourbakhsh, Alireza (Author) ; Safarian, Amin Ghasem (Supervisor)

Abstract

A key point in designing class-C oscillators is maximizing the Figure-of-Merit (FoM). For this purpose, changing the oscillator’s structure or adjusting its bias current may be used. Previous literatures mostly limit their efforts to the first case, leaving the issue of determining the proper bias current almost untouched. In this work, a new approach recruiting DC voltage of the common source node of the switching pair transistors as an indicator has been presented. Using theoretical analysis, it has been shown that maximizing this voltage will optimize the oscillator in term of the FoM. The proposed indicator has the advantages of not introducing any loading effect to the output node, and...

Chaos Quantities and Computational Challenges

, M.Sc. Thesis Sharif University of Technology Nourbakhsh Marvast, Mohammad (Author) ; Razvan, Mohammad Reza (Supervisor)

Abstract

Chaos in dynamical systems refers to the presence of extreme sensitivity to initial conditions in the system’s behavior, which renders the long-term prediction of the sys- tem’s behavior either impossible or highly challenging. This chaotic behavior is also present in deterministic systems. The observation of this concept, besides philosophical changes it has brought about, has been scrutinized in various domains and has provided an explanation for many observed physical, chemical, and biological phenomena. This phenomenon has been studied in diverse sectors such as fluid dynamics, neuronal dy- namics, and chemical reactions. In this research, we intend to analyze chaotic dynamical systems...

Geometric Control of Tethered Satellite Formations by Controlling the Tether Length

, M.Sc. Thesis Sharif University of Technology Makarem, Hadi (Author) ; Alasty, Aria (Supervisor)

Abstract

Satelites formation which is a specic spatial conguration of satellites, is of great importance in design and control of satellite systems. Reducing the required power to maintain that conguration, while imposing complicated dynamics on the system, connecting satelites through tethers has recently attracted researchers' attention. Developing a new model based on which the motion of the satellite formation will be expressed through simple equations, followed by the study of how the tether length control participates in the orientation control of the system, are the principal aims of current research. First, a new model is proposed for a group of tethered satellite for- mations, and based on...

Environment Identification by Experimental Swarm Agents

, M.Sc. Thesis Sharif University of Technology Navvabi, Hamed (Author) ; Alasty, Aria (Supervisor)

Abstract

Swarm is coordinated group action that usually done with little communication among its members. Using several simple members instead of the complicated ones reduces cost, simplifies system and increases the reliability. On the other hand, the mission can be done faster. This thesis is done in two general sections; theoretical and experimental parts. At first some important missions are simulated in MATLAB/Simulink such as aggregation, dispersion, flocking, obstacle detection, obstacle collision avoidance and orbiting around the obstacle. Orbiting around the obstacle is simulated formation flying and a constellation of satellites (such as GPS systems). The methodology is artificial potential...

Design, Dynamic Analysis and Fabrication of a Ring-like Robot with Deformable Shell

, M.Sc. Thesis Sharif University of Technology Firouzeh, Amir (Author) ; Alasty, Aria (Supervisor)

Abstract

In this research application of Ionic Polymer Metal Composite (IPMC) as actuator in a deformable ring capable of locomotion is studied. Such a deformable ring moves as a result of gravitational force acting on its body when its shape changes. A deformable robot made of IPMC can be used in exploration, search and rescue missions in future, where using conventional robots with rigid bodies and actuators is impossible. Large deformation induced by small stimulating voltage, low stiffness and the sensing characteristics that in future work can be used in feedback control make IPMC a good choice for such an application. In this work first a model for IPMC is introduce that can be used in...

Real-Time Hybrid Motion Planning For Autonomous Uavs in Dynamic Environments

, M.Sc. Thesis Sharif University of Technology Mashayekh, Ehsan (Author) ; Alasty, Aria (Supervisor)

Abstract

This study is about real-time hybrid motion planning for autonomous UAVs in dynamic environments. The algorithm is based on system dynamic quantization to trim trajectories and maneuvers, constructing a library of primitives which guarantee the controllability of the system. Random algorithms introduced in literature of motion planning have an offline phase, reducing the computational complexity of online phase. By using dynamic quantization, we have achieved a new totally online algorithm, increasing the probability of finding a solution. Dynamic programming is the core of this algorithm, instead of offline calculations in before random algorithms. In order to decrease the exponential...

Modeling, Control and Simulation of a Swarm of Robots with Shell Structure

, M.Sc. Thesis Sharif University of Technology Rezaei, Sina (Author) ; Alasty, Aria (Supervisor)

Abstract

Swarm robotics has attracted a lot of researches in recent decades due to its ability to overcome complexities despite of simple hardware used in each member of swarm. Developing control algorithms which can address connection, consensus and average consensus, position control, formation and swarm movement, is one of the main problems in the study of multi-agent systems and swarm robotics. Even though such methods have been developed and used by researchers for a few years, theoretical and operational issues still exist in the use of robotic swarms. For example, in leader-follower method, presence of repellent coordinator agent results in disruption in movement of other agents. Also...

Control of Experimental Swarm Robots for Identification, Imaging & 3D Modeling Purposes

, M.Sc. Thesis Sharif University of Technology Moeini, Mohammad (Author) ; Alasty, Aria (Supervisor)

Abstract

The aim of this project is decentralized control of a group of robots (swarm robots); such that the aggregation maneuver, leader following, Identification and imaging the target, will be performed so good as to make a three-dimensional model of the target from these images. Swarm robots consist of a number of similar and limited features robots which interaction in a group of robots, will lead to special features for the group. Any agent of group decides what to do only with its local information from the environment. Swarm robots are more applicable for the jobs in which a distributed perception from the environments needed, for example space exploration and military operations.In this...

Self-Tuning PID via a Hybrid Neural Structure for Attitude Control of Quadcopter

, M.Sc. Thesis Sharif University of Technology Sharifi, Iman (Author) ; Alasty, Aria (Supervisor)

Abstract

Proportional-Integrator-Derivative (PID) controller is used in a wide range of industrial and experimental processes. There are a couple of offline methods for tuning PID gains. However, due to the uncertainty of model parameters and external disturbances, real systems need more robust and reliable PID controllers. A compelling example of these types of systems is Quadrotor. In this article, a self-tuning PID controller using Reinforcement Learning for attitude control of a quadrotor has been investigated. In the proposed method, an Incremental PID, which contains constant and variable gains, has been used, and only the variable ones have been tuned.In this research, the model-free...

Modeling and Control of One-legged Somersaulting Robot

, M.Sc. Thesis Sharif University of Technology Zabihi, Mehdi (Author) ; Alasty, Aria (Supervisor)

Abstract

Inspired by the agility of animal and human locomotion, the number of researchers studying and developing legged robots has been increasing at a rapid rate over the last few decades. In comparison to multi-legged robots, single-legged robots only have one type of locomotion gait, i.e., hopping, which represents a highly nonlinear dynamical behavior consisting of alternating flight and stance phases. Hopping motion should be dynamically stabilized and therefore, presents challenging control problems. A large fraction of studies on legged robots have focused on modeling and control of single-legged hopping machines. In this research, somersaulting is introduced as a kind of hopping motion for...

Real-time Area Measurement of Agricultural Fields from Aerial Robotic Images

, M.Sc. Thesis Sharif University of Technology Karimi, Farzam (Author) ; Alasty, Aria (Supervisor)

Abstract

The aim of this research is to measure the area of agricultural lands using realtime aerial images. This project is divided into two parts. In the first part of the project, five segmentation neural networks based on YOLOv8 models were designed. After collecting 734 images of agricultural lands, they were trained, and among them, the nano model was selected with 89% accuracy, 88% recall, and an inference time of 49.8 milliseconds. In the second part of this project, the internal characteristics and distortion elements of the camera used were identified through the calibration process using a chessboard. This process was carried out using 81 images and hadan RMS of 1.178. Also, the elements...

Path Planning and Control of Aerial-Terrestrial Swarm Robots Using Image Processing and Artificial Intelligence

, M.Sc. Thesis Sharif University of Technology Mirfakhar, Amin (Author) ; Alasti, Aria (Supervisor)

Abstract

Nowadays, there are various applications for swarm robots in different fields such as agriculture, healthcare, and entertainment. Among these, the field of agriculture is of greater importance due to the increasing population and the growing need for food resources. To address this need, industrialization of agriculture and the use of swarm robots have been proposed as a solution in most developed countries. Despite extensive research in this area, there are still challenges in implementing swarm robots. In many of the mentioned applications, determining the position and orientation of the robots relative to each other at long distances and accurately perceiving their surroundings are vital...

Web graph compression by edge elimination

, Article Data Compression Conference, DCC 2006, Snowbird, UT, 28 March 2006 through 30 March 2006 ; 2006 , Pages 459- ; 10680314 (ISSN) Mahdian, A ; Khalili, H ; Nourbakhsh, E ; Ghodsi, M ; Brandeis University ; Sharif University of Technology

2006

Properties Evaluation of Self-Consolidating Concrete Containing Rice Husk Ash

, M.Sc. Thesis Sharif University of Technology Nourbakhsh, Ali (Author) ; Jahanshahi, Mohsen (Supervisor) ; Shams, Mohammad Reza (Co-Advisor)

Abstract

The Self-Consolidating (Compacting) Concrete (SCC) is a high performance concrete. Due to preventing it from segregation, SCC is known by its need to higher dosage of super plasticizer and viscose modifying agents. This increases the cost and reduces the popularity of SCC in construction industry. In this thesis, the production of Rice Husk Ash (RHA) from a controlled burning process using a special designed furnace, and cement replacement feasibility in the concrete mixture by low cost RHA, as an active pozzulanic additive have been investigated. Finding an appropriate ratio of replacement with cement for RHA and further effects on mechanical properties of SCC have been evaluated. The...

Control and Optimization of Robotic Swarm Flocking Using Naturally Inspired Methods

, M.Sc. Thesis Sharif University of Technology Vatankhah, Ramin (Author) ; Alasty, Aria (Supervisor)

Abstract

The idea of using groups of simple autonomous robots instead of one or limited number of very sophisticated robots is inspired by flocking behaviors of animals. Distributed control structures and artificial swarming have attracted lots of studies in robotics. There are many applications for robotic swarms in which members are very simple robots with low communication capabilities. These robots communicate only within very limited distances. In this thesis, a homogenous robotic swarm with at least two robots is assumed. Swarm robots are considered to be dimensionless with no time delay, which is a normal assumption in this field of studies. Robots move in planar space and their behaviors are...

Vibration Control of Nonclassical Microbeams Using Boundary Control Theory of Partial Differential Equations

, Ph.D. Dissertation Sharif University of Technology Vatankhah, Ramin (Author) ; Alasty, Aria (Supervisor)

Abstract

Nowadays, continuous systems such as strings, bars, beams and plates have become widespread in science and engineering applications. To achieve the control purposes of continuous systems, most of engineers use discretization techniques to reduce the governing partial differential equation (PDE) into a set of ordinary differential equations (ODEs). From practical point of view, this model reduction can cause many problems such as in-domain measurement and actuation and control spillover. This thesis attempts to investigate the problem of vibration control of nonclassical microscale beams using the partial differential equation control theory which eliminates spillover instabilities. To this...