Sharif Digital Repository

The injection process on cell is a very accurate and sensitive operation. This method is used for several new invented approaches such as tracytoplasmic Cell Injection or drug delivery. Controlling the injection force in micro scale is one of the problems of mentioned operations. Current huge and expensive laboratorial devices are helping the operators to do injection operation with :nore success. In this study a simple and novel microelectromechanical (MEMS) mechanism for doing injection process automatically on the biological cells is proposed. In order to controlling this device properly, we should model and simulate the operation condition from initial position to final condition. This... 

Cardiovascular diseases are one of the major causes of mortality in humans. One way to diagnose heart diseases and abnormalities is processing of cardiac signals such as ECG.In many of these processes, inter-beat and intra-beat features of ECG signal must be extracted. These features include peak, onset and offset of ECG waves,meaningful intervals and segments that can be defined for ECG signal. ECG fiducial point (FP) extraction refers to identifying the location of the peak as well as the onset and offset of the P-wave,QRS complex and T-wave which convey clinically useful information. However, the precise segmentation of each ECG beat is a difficult task, even for experienced... 

In this thesis, an enhanced local mean-field (MF) model that is suitable for simulating the electroencephalogram (EEG) in different depths of anesthesia is presented. The main building elements of the model (e.g. excitatory and inhibitory populations) are taken from two pioneer MF models designed by Steyn-Ross et al and Bojak & Liley, and then a new slow ionic mechanism is included in the main model. Generally, in mean-field models, some sigmoid-shape functions determine firing rates of neural populations according to their mean membrane potentials. In the enhanced model, the sigmoid function corresponding to excitatory population is redefined to be also a function of the slow ionic... 

Focusing on developing the EEPS (Energy Electric and Power System) based on the SG (Smart Grid) infrastructure to achieve implementation of EI (Energy Internet) ultimately, in order to analyze and manage the energy/power consumption, requires a robust embedded EMS (Energy Management System) to implement real-time LF (Load Forecasting), prevent the power waste and realize consumption management which eventually leads toward the smart industries/buildings. STLF (Short Term Load Forecasting) is an essential component that an industrial plant requires to manage the power, regarding the load fluctuations during production, and compulsory requirement of cost mitigation. This thesis, in order to... 

Providing quality hospital services depends on the efficient and correct implementation of processes. Therapeutic care processes are a set of activities that are carried out with the aim of diagnosing, treating and preventing any disease in order to improve and promote the patient's health. The purpose of this study is to use process mining techniques to discover and improve healthcare processes. The case study of this research is a psychiatric hospital in Shiraz. The approach implemented in this research consists of three main stages including data pre-processing, model discovery phase, and analysis phase. Three algorithms including Heuristic Miner, Inductive Miner, and ILP Miner were used... 

In the field of cancer diagnosis, particularly brain tumors, the priority is to achieve highly accurate tumor detection. Deep learning has shown remarkable potential in object detection tasks, making it a valuable tool for identifying brain tumors. We have proposed a new method for combining the strength of Faster R-CNN in detecting objects and the ability of Vision Transformer’s (Faster-VIT) ability to extract essential features. The proposed method significantly improves the accuracy and efficiency of brain tumor detection in MRI images. We have called the proposed combination Faster-VIT. To assess the effectiveness of the proposed method, we have utilized the Br35H dataset, comprising... 

Introducing the basic concepts of solar desalination systems, improving the performance and efficiency of the solar system under vacuum has been investigated. Further, according to the classification of the types of solar desalination systems, the details of their existing designs have been discussed. The solar desalination system under vacuum is classified into two types of solar systems under natural vacuum and under forced vacuum. The solar system under natural vacuum is divided into one-story and multi-story, while the solar system under forced vacuum is classified into two types, single-effect and multi-effect. Previous studies as well as the most important recent developments in this... 

The stock market is vital to the economy as it serves as a key indicator of economic health. AI algorithms can process vast amounts of market data at high speeds, identifying patterns and trends that are often invisible to human analysts. Forecasting future stock trends poses significant challenges due to the complex inter-stock and intra-stock dynamics that influence stock prices. Recently, graph neural networks have shown promising results by modeling multiple stocks as graph-structured data. However, many of these approaches depend on manually defined factors to construct static stock graphs, which fail to capture the rapidly changing interdependencies between stocks. In this work,... 

Supervision is considered one of the fundamental pillars in the construction of building projects within the country's engineering system. Enhancing the supervision process for construction projects can significantly improve the quality of buildings nationwide. However, in many cases, the supervision process has not effectively fulfilled its assigned responsibilities and has encountered numerous challenges. This study aims to identify and prioritize the challenges present in the operational processes of supervisors within the engineering system. The primary objective of this research is to identify and analyze these challenges and propose solutions to enhance supervisors' performance and... 

This study investigates the performance of the Reinforced Concrete column and Steel beam (RCS) structural system at the system level, with a focus on evaluating seismic design coefficients (R-factor, Ω₀, and Cd) using FEMA P-695 methodology. The RCS system provides a more efficient alternative to conventional steel and reinforced concrete moment-resisting frames, offering higher damping and lateral stiffness in RC columns along with greater energy dissipation in steel beams. Although several studies have examined the RCS system's performance, most have concentrated on the connection level. In this study, 32 archetypes are designed with variations in building heights, span lengths, concrete... 

The construction system, as a fundamental pillar of any country's development, requires meticulous oversight and the employment of qualified professionals. The introduction of qualified contractors in Iran as a measure to enhance the quality of construction projects and eliminate unqualified individuals from this field has been a valuable step. However, legal and operational shortcomings, as well as challenges in the contracts between contractors and employers, have hindered the effectiveness of this role. This study aimed to identify and prioritize the challenges in the workflows of qualified contractors and propose solutions for their improvement. Key identified challenges include... 

Text summarization and classification are two important tasks in natural language processing. Text summarization involves condensing a piece of text into its main points, making it easier to understand. On the other hand, text classification involves categorizing a text into predefined categories based on its content. Text summarization can be achieved through various methods, such as extractive summarization, where key sentences or phrases are extracted from the original text. The present research aims to classify and summarize news texts in the Persian Daily News dataset. This objective is carried out in two stages. First, the texts in this dataset are classified using the ParsBERT... 

Solvatochromic parameters (ETN: normalized polarity parameter, π*: dipolarity/polarizability, β: hydrogen-bond acceptor basicity, α: hydrogen-bond donor acidity) have been determined for binary mixtures of propan-2-ol, propan-1-ol, ethanol, methanol and water with recently synthesized ionic liquid (2-hydroxyethylammonium formate) at 25 ◦C. The applicability of nearly ideal combined binary solvent/Redlich-Kister equation was proved for the correlation of various solvatochromic parameters with solvent composition. Solute-solvent and solvent-solvent interactions were applied to interpret the results. Heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by Pt/Al2O3, was carried out in... 

In this thesis, we study security features of the networks which use linear network coding to multicast information to some nodes of the network in presence of a wiretapper and also an active intruder. We consider information theoretic security in which we assume no computation limits for enemy. Thus, we take advantage of the essence of network coding instead of cryptographic tools to improve security features of the network. First, we show how providing shannon security for such networks in presence of wiretapper, leads to different cost in multicast rate, depending on initial network code designed. Based on this, we present a modified secure network code design which can provide perfect... 

Gelcasting is a new ceramic forming technique getting worldwide attention. The process is based on casting of slurry; containing powder, water and water-soluble organic monomers. The premix solution was prepared using Acrylamide as a monomer and Methylene bisacrylamide as a crosslinker with AM:MBAM ratio of 25:1, and Poly Acrylic Acid Sodium as a dispersant (1 wt% based on ceramic powders weight). A series of Al2O3/ZrO2 ceramic nanocomposites with 15, 17.5 and 20 wt% content of ZrO2 and 40, 43, 45, 47, 50, 53 and 55 vol.% of solid loading were fabricated by gelcasting. After casting the mixture, the monomer was polymerized to form gel parts. Drying, burning out and sintering completed the... 

Compressors are one of the most important components of gas turbines and turbomachinery processes. Thus some precise and quick tools are needed for design and analysis purposes. Despite of vast development of Computational Fluid Dynamics (CFD) tools, Through-Flow Streamline Curvature Methods (SCM) has retained their position. 2D and quasi-3D forms of SCM in combination with CFD results nowadays make more than 80% of turbomachinery design process of axial and radial compressors and turbines. In this thesis, the basics of developing a tool for axial-flow compressor analysis are introduced. As will be seen, this analysis tool can be used for design purposes too. The method that is chosen for... 

In this research, direct synthesis of dimethyl ether (DME) from CO2 hydrogenation in three phase slurry reactor was investigated. Bifunctional catalysts composed of Cu- ZnO-Al2O3-ZrO2 as hydrogenation component and zeolite Na-Mordenite as dehydration component, with different Al2O3 and ZrO2 contents were synthesized by coprecipitating sedimentation and influences of Al2O3 and ZrO2 on CO2 conversion and DME selectivity were evaluated. Results show, both Al2O3 and ZrO2 enhanced conversion, but Al2O3 markedly increase selectivity of DME. However, when the total contents of Al2O3 and ZrO2 was increased up to 16 wt% , CO2 conversion and DME selectivity remarkably decreased. BET and XRD analyzes... 

In this thesis, we considered several types of the visibility problem. These problems include computing the visibility polygon of a point observer inside a polygonal domain, maintaining visibility polygon of a moving point observer, visibility coherence in space, maintaining visibility polygon of a moving segment observer and visibility dependent simplification. Furthermore, we considered these problems in both offline and streaming settings. These problems arise in different practical areas, such as computer graphics, machine vision, robotics, motion planning, geographic information systems (GIS) and computational geometry. We obtained effective theoretical results as well as superior... 

In this research work an analytical instrument has been developed for assessment of energy technologies, R&D resource allocation and technology development. Development of new technologies has been considered according to the specific conditions of developing countries. The analytical instrument includes two models interlinked with each other: energy technology assessment and optimal control of innovation activities. Energy technology assessment and prioritization of new energy technologies are provided by the model of the energy supply system that contains a detailed representation of current and emerging technologies characterized in terms of their technical indices. The results of this...