Sharif Digital Repository

This research develops a simulation model and algorithm to calculate the thermal demand of a one-hectare Venlo greenhouse and explores the impact of using phase change materials (PCMs) on this type of greenhouse. The algorithm controls variables like solar irradiance, artificial lighting, greenhouse humidity, carbon dioxide levels, ventilation rates, injected CO2, and shading systems, alongside greenhouse temperatures to create a system that closely mimics a real greenhouse environment. Subsequently, this model integrates with a PCM model to investigate the effects of these materials comprehensively. In this research, the heat demand of the greenhouse is calculated and compared for the... 

The field of learning from demonstration is the field in which researchers seek to create methods by which a robot can learn and reproduce a skill simply by using the demonstration of the skill. One of the main drawbacks of learning from demonstration methods is their inability to improve the learned skills. To answer this question, the reinforcement learning method can be used. The reinforcement learning approach has the potential to improve the initial skill due to the use of the experience of interacting with the environment. In this project, the dynamic movement primitives algorithm is considered as the learning from demonstration method. The research approach is that first, the dynamic... 

Today, with the reduction of world oil prices and the development of competing energy sources, fossil fuels such as nuclear energy, electricity, wind, etc., in order to increase the economic efficiency of oil sales, we must Reduce production costs to a minimum. If the components of oil extraction costs are examined, the cost of drilling production wells is one of the main economic components that affect the cost of producing oil. Therefore, according to the above explanations, the cost of drilling wells should be reduced.To reduce the cost of drilling a well to be drilled, it is better to predict the drilling parameters (for example ROP) before starting the drilling process. For this... 

Additive manufacturing (AM), also known as Rapid prototyping or D printing, is a new technology for the manufacturing of the physical parts through an additive manner. In the AM process, the orientation pattern of the part is one of the most important factors that significantly affects the product properties such as the build time, the surface roughness, the mechanical strength, the wrinkling, and the amount of support material. The build time and the surface roughness are the more imperative criteria than others that can be considered to find the optimum orientation of parts. In this research, Two method is used to optimize part build orientation (PBO). In the first method a new combined... 

Parkinson’s disease is considered as a progressive neurodegenerative disease that hasn’t any certain treatment. In Iran until 1390, there were about 150 thousand patient struggling with this disease. Rehabilitation is known as an effective treatment to decrease destructive progress of the disease. Because of motional problems of PD patients, it is hard to come to the clinics. So developing remote rehabilitation would be interested by researchers and occupational therapists. Therefore in the recent years, an activity recognition system has been developed in Mowafaghian research center. This system is based on IMU sensors and a NM classifier.These systems are challenging with some problems,... 

This mixed-method study explored the intercultural competence of a group of engineering university students in Sharif University of Technology enrolling in a “Listening and Speaking” class, minoring in English. The aims of this study were first to assess the initial ICC level of the participants, second to evaluate the effect of a culture-based syllabus on ICC development of the learners, third to measure the variation of their L1 cultural identity of the students after the course, fourth to discover recursive themes in the assignments and recorded interviews with the participants and fifth to measure the learners’ satisfaction with the developed syllabus. Quantitative data was derived from... 

In presence of epistemic and aleatoric uncertainties of the structural systems, it is better to investigate the events in probabilistic manner. Bayesian inference is an approach that can update the current knowledge of probabilities with new evidence. The main objective of this study was evaluating the advanteges of using Bayesian approach in two main area of structural health monitoring, model calibration and decision making. In each of these two areas, one case study was conducted. First case study was prediction of crack growth life in a pre-cracked aluminum plate and the results showed that using Bayesian approach in calibration of crack growth model and measurement model of health... 

Increasing the speed of marine transportation services for specific mission and rapidly movement of persons or product always have been considered major issue in maritime industry. In recent years different technology have been used by high speed vessels manufacturer for increasing the safety of crew and passengers at sea. Catamaran is one of the most important high speed craft in marine transportation industry. High speed catamaran nonlinear behavior in high velocity is causing longitudinal instability and large motions. Active control surfaces like hydrofoil and interceptor can be used for reducing high speed catamaran motions in waves. This control surfaces react an adequate action... 

Clogging of the pores of the porous medium occurs in different processes such as geothermal injection pumps, hydrocarbon wells, and underground water extraction wells. We need a model that can simulate these blockages in order to predict how fundamental variables of the porous medium change under different flow regimes and different particle sizes in the fluid (for example, the relationship between porosity and permeability changes). The aim is to simulate clogging in a porous medium using a pore network model. Simulations should model pore clogging and show how the permeability of the sample changes due to pore clogging. In the pore network, there are often thousands (or millions) of pores... 

Self-Assembly (SA) plays a critical role in the formation of different phenomena in nature. This phenomenon can be defined as an arrangement of meaningful patterns with the aggregate behavior of simpler structures. One of the examples of Self-Assembly can be considered of the formation of ice crystals from ice molecules. Previous works mainly focus on graph grammar and self-assembly in fully observable environments. These algorithms mainly consist of two main stages: first, constructing simpler structures and then joining these simpler structures to form a complex structure. The challenges of the previous work can be considered as the necessity of a central controller in the formation of... 

According to the increasing need of the world to increase the speed of existing technologies such as computers, cars, urban transport, etc. The need to carry goods at higher speeds is also a concern that due to its cost It can make a significant contribution to the economy. In the maritime industries, in addition to the commercial and economic orientation, there is also military capability the speed factor and the ability to navigate is very important for military vessels. The power in the sea is inevitably dependent to speed, so for Increasing the speed of vessels with regard to military and economic objectives needs optimized Propulsion systems which There are also limitations for them.... 

The current research is one of the sections of the project for the design and construction of an Unmanned Surface vehicle (USV) , with the goal of extracting the dynamic model of the float using experimental tests. Initially, a literature review on system identification methods and the development of a dynamic model of the float has been conducted. Following that, the process of constructing and equipping a Catamaran platform for conducting tests and collecting suitable data for extracting the dynamic model has been described. Subsequently, tests have been conducted on the constructed float.Using the data obtained from the experimental tests, an artificial neural network has been employed to... 

Rehabilitation usually involves physical therapy, occupational therapy and counseling for the patient's morale to help to restore his power and performance. Considering the economic outlook and the costs of rehabilitation methods and due to the increasing prevalence of stroke and the need to recover the patients in a short period, only the use of robotic systems opens the door to the medical community. Since a large rehabilitation robots designed and built and each been used according to their advantages and shortcomings. In this project, the major shortcomings examined and exoskeleton designed on two major features including portability and covering shoulder workspace. Shoulder movement was... 

Today, acidizing is one of the most important methods for stimulation and increasing the productivity of oil and gas wells. In Iran and other oil-rich countries, a large amount of money is invested every year in acidizing operations. Due to complex nature of acidizing of an oil formation, it’s very difficult to design an optimized and successful operation. Therefore, many research projects have been performed for understanding the physics of the dissolution of reservoir rock by acid and the behavior of wormholes and secondary reactions. The most important prerequisite of these researches is the perfect knowledge of acid and mineral reaction kinetics. One of the most common experiments to... 

The process of separating cells from a laboratory sample, is a crucial step in biotechnology and medical science. Cells separation is important for various reasons, including the identification and treatment of diseases, as an example, separation of Circulating Tumor Cells (CTCs) from patient blood sample. CTCs are cells that shed from a tumor and diffuse into blood vessels. These cells are the starters of metastasis, the process in which cancer spreads in body, and are main reason of deaths caused by cancer. Extremely low percentages of target cells in the blood, clarify the importance of highly accurate and sensitive separation. Currently, conventional separation methods are of macro-order... 

Transport phenomena in porous media play important role in many areas of subsurface hydrology, geo-physics, environment, energy and petroleum. The work in the field of numerical modeling of fractured porous media is yet an open area of research. The classic finite element method (FEM) has some limitations in modeling of discontinuities like fracture. FEM mesh should conform with the geometry of the fracture. Presence of fracture imposes discontinuity in pressure field of fluid phases and displacement field of solid phase (rock). To represent the fractures, the extended finite element method (X-FEM) can be used in which the standard finite element approximation of the field variables is... 

Interpreting data of infrastructures monitored to detect damage of a structural is one of the most challenging issues of structural health monitoring (SHM). Especially, when environmental factors such as temperature, wind and humidity affect the data and the situation become more complicated. In this study, two methods of analysis free model of moving principal components analysis (MPCA) and robust regression analysis (RRA) have recently been considered for monitoring infrastructures compared with a variety of methods of data interpretation and results are presented. In this study, the performance of different ways in different loading conditions and arrangement of sensors have been... 

The vital and influential role of railways in the socio-economic growth and development of countries, along with the high costs of rehabilitation and maintenance of its infrastructure, has made the existence of a comprehensive maintenance management system a necessity to not only elevate the level of service, reliability, and safety but also to minimize such repair costs. Accurate modeling of track deterioration is essential as one of the components of such systems.In this study, a large database from outputs of EM120, track recording machine, was provided for the years 2009 to 2018 and for all 18 railway zones of Iranian Railways (approximately 13,000 km railway track and 80 GB of data).... 

Currently, one of the most important problems in the field of drilling is the issue of drilling fluid loss in different formations. The problem of mud loss has been evident since the beginning of oil and gas well drilling operations, so that oil companies spend millions of dollars annually to solve the problem of mud loss. Problems such as pipe jamming, loss of rig production time, well blowout, loss of a large volume of drilling mud and damage to reservoir formations due to loss of drilling fluid are caused. Regarding the drilling variables, many factors cause the decrease or increase of the loss, the most important of which are the weight on the drill bit, drilling speed, the rate of...