Sharif Digital Repository

One of the most important stages to designing a process plant is layout of equipment in unit area. There are plenty of routine procedures to find out equipment arrangement and their separation distances based on process and cost criteria. One of this Procedures is the use of codes and standards. Although some studies have been carried out to enter safety parameters to conventional procedures, the problem complexity because of the number of involved equipment is still of concern. To clear these ambiguities, the new approach presented in this thesis is aimed at quantifying the effects of adjacent equipment on each other. In this way, fire radiation and explosion have been selected as the major... 

Searching for images of the same object or scene in a large number of images is a major problem in computer vision. It has many applications specially in the search engines.For the goal of efficient image search, we need descriptors that are not only discriminative, but also short and need small amount of memory.In this thesis we analyze the image search methods in two categories: The first methods are based on converting the existed descriptors such as gist into a compact binary code. The second methods are based on building short descriptors, especially by some modifications in the framework of bag of features descriptor.Finally we will introduce a novel descriptor "bag of codes" which... 

One of the important branches in machine learning is finding patterns and hidden features, which is useful for prediction and decision making in many cases. Finding patterns and features of financial data and particularly stock market data may play an important role in guidance, development and proper decision making related to such data sets. In this thesis, we focus on discovering and collecting appropriate methods in machine learning which can be helpful for gathering proper information from financial data and applying them on actual data  

3D reconstruction of digital images is one of the sub- branches of computer vision which is used in various fields such as computer graphics, compute animation, etc. in general, two approaches exist for solving 3D structure problem. In the first approach to obtain the model, we need a certain distance of the whole object level at a certain point and to do so, a sensor is used which is directly interacting with the object. For instance, we use lasers and estimate the depth using that depth to make 3 D model. In the second approach we use the images we have at different instaces of an object (sensor is the camera that is sensitive to light). Using these data and the machine learning... 

Transglutaminase 2 enzyme is expressed in various parts of the human body and is present in almost all tissue cells. The function of this enzyme is multiple and it catalyzes different reactions depending on where it is located in the cell. The most important activities of this enzyme are: isopeptide bond formation between the side chains of two proteins (transamidation reaction), diamidation reaction (hydrolysis of amide bond), esterification, kinase activity. The hen egg white lysozyme protein is another natural antimicrobial protein that has been extensively studied. The muramidase activity of egg white lysozyme against highly gram-positive bacteria is well known, and this property has... 

The nuclear pore complex mediates all transport between the cell cytoplasm and the nucleus. Being inspired by this biological system, in this project we intended to design an artificial gate by using polyelectrolyte brushes in a cylindrical nanochannel, which will be opened by applying a tangent electrical field and will close by eliminating the field. Grafted polyelecrolyte brushes have the potential to be useful for the design of advanced gating systems for many applications like functional and conrolleble MEMS devices. In order to design the desired gating system we have employed the ESPResSo software to conduct a coarse-grained molecular dynamics simulation in NVT ensemble to simulate... 

Smart heat-sensitive polymers play a unique role in drug delivery systems due to reversible behavior in response to environmental changes, especially temperature changes. Among the heat-sensitive polymers, UCST polymers due to their specific behavior and very little-known polymers with this feature are the subject of many new researches. In the present study, New designed temperature-sensitive polymers with UCST capability based on acrylamide and vinyl acetate were synthesized. These copolymers were synthesized in different percentages of acrylamide by free radical polymerization in solution conditions. All polymers compounds were characterized by H-NMR, FT-IR, DSC and GPC measurements. The... 

Knot theory is the study of ambient isotopy classes of compact 1–manifolds in a 3-manifold. In classical knot theory this 3-manifold is R3 or S3. This field has experienced a great transformative advances in recent years because of its strong connections with and a number of other mathematical disciplines including topology of 3-manifolds and 4-manifolds, gauge theory, representation theory, categorification, morse theory, symplectic geometry and the theory of pseudo-holomorphic curves. In this thesis we start with classical knot theory, introducing some of its (classical) invariants like unknotting number, Seifert genus and slice genus of a knot, knot group and finally Alexander Polynomial... 

There are several methods for measuring thin film thickness, however, for the analysis of liquid film motors [1] we need a method which is capable of measuring the thickness using a single image of the film. In this work, we use the colors that appear on thin films, such as soup bubbles, which is a result of light interference to calculate the thickness of the layer  

Thermal relaxation time is the time when maximum temperature of a particle get to 1/e of it’s initial value. The destruction of a tissue depends to this important parameter. This parameter has studied by Monte Carlo simulation of pulsed laser in to environment as healthy and cancerous tissue. The main goal of this method is providing proper temperature in a special area so that minimize thermal destruction around that area. In this thesis, temperature distribution of tissue that is caused by pulsed laser, has solved by new method;in this new method the pulse duration uses for Monte Carlo simulation. Also using the solution of radiation transfer equation by Discretes Ordinate Method, new... 

By direct and alternating electric field applied to thin film of liquid suspended in the air we can spin out and control it. Rotation pattern depends on the geometry of the electrodes and the applied magnetic field. This is called a rotating liquid film (Liquid Film Motor). To determine the cause of rotation, different models have been proposed. In this project we have tried to check the accuracy of any of the models. Using particle velocimetry using the photo, we calculate the velocity pattern. Then, using the Navier-Stokes equation calculate the acceleration and viscosity from the velocity. Then, for a special arrangement using a finite diffrent method, electric potential and the electric... 

Ultrasound waves have attracted substantial attention due to their potential for trapping the small particles, which cannot be handled by usual tweezers. The acoustic tweezer is a technology that is able to tarp and control the movement of micrometer to millimeter objects by standing or focused sound waves. Acoustic tweezers are the subject of many researches around the world, due to simplicity, cost-effective, biocompatibility and most important better performance in non-transparent optical environments, compared with optical tweezers.In this project, by using a ring piezoelectric and a power amplifier, an acoustic tweezer was designed and constructed. Moreover, the polystyrene particles... 

Climate change impacts especially on temperature and precipitation, may have various effects on agriculture and water demand of agriculture sector in different regions around the world. Based on numerous researches, these effects may be positive in a region while another region might endure negative effects. Therefore carrying out researches and developing methods to predict these impacts as well as mitigating strategies seem to be essential. The most worldwide accepted method is using global circulation models (GCMs) outputs under different greenhouse gases emission scenarios, and according to Intergovernmental Panel on Climate Change (IPCC) assessments. IPCC claims that the most recent... 

The citizens’ dissatisfaction with the decreased life and residential care quality is increasing as a result of the rapid growth and development of cities. To find an effective solution to reduce and control these harmful effects is one of the main concerns of urban managers and planners in most countries. In this research, various ecological and sustainability criteria were selected through library-based studies and relative recognition of the region. The Maps were mostly provided through satellite imagery and some by using synoptic data collected from the official aerology website of the country, Iran. Through surveying the experts, different criteria were evaluated and based on the...