Sharif Digital Repository

Gene expression microarrays include thousands of probes spotted on their surface to measure the expression level of a set of genes. Identifying the amount of a transcript level by hybridization, each probe is complementary to a fragment of a specific gene transcripts. Although probes are designed to avoid crosshybridization to non-specific transcripts, occurrences of cross-hybridizations is inevitable due to massive probes that are spotted on microarrays. The main question is whether these non-specific cross-hybridization have significant effect on the downstream analysis of gene expression microarray datasets. This thesis aims at answering to this question by considering datasets from... 

Human facial activity recognition is one of the endeavors to improve human-computer interaction. Recognition of excitements and emotions on human face by machine and makinga corresponding reaction is essential for man machine intraction.The purpose of this project is recognizingactivities such as speaking, eating, laughing, agree and disagree which have more complexity than usualemotions such as fear and happinesscontained in common datasets.So, adataset in accordance with the above mentioned 5 activities was collected and the appropriate feature vector for analyzing these face activities were implemented.Distance between the interest points located on the face were used as parameters in... 

Magnetic resonance imaging is one of non-invasive methods to measure the hemodynamic and morphologic parameters of tissues, especially brain tissues. Hemodynamic parameters monitoring in brain tissue is of significant importance in many majors such as detection of tumor occurrence, brain abnormalities, and track of treatment procedures. Blood is a suspension, comprised of plasma, red blood cells, white blood cells, platelet, etc. Plasma is a Newtonian fluid which is composed of proteins and has a constant viscosity in body temperature. Rheological properties of blood are highly dependent on mechanical and rheological properties of its cells and this dependence is multiplied in narrow vessels... 

Due to the intensification of competition in real markets and the increase in customer needs, manufacturers are forced to implement value-adding techniques in their production management. Many companies begin their improvement efforts without considering the need for a comprehensive plan. As a result, their improvement efforts are not carried out in an integrated and complete manner and do not lead to complete and desirable results. The main objective of this study is to provide a framework that proposes a detailed vision of lean implementation in the machine-woven carpet industry, considering the value stream map as a tool to achieve improvement strategies in this industry. This framework... 

In this study, the influence of eutectic modification, grain refining and cooling rate on amount of shrinkage porosity in aluminium A356 alloy were investigated. Modification process for changing the morphology of eutectic silicon from needle like to fibrous like, use in aluminium – silicon alloys. This process often leads to increasing porosity in melt and affect harmfully on mechanical properties. For studying shrinkage porosity, the melt degassed completely to minimizing amount of gas in the melt. For modification, strontium in Al-10Sr master alloy and sodium in NaF salt used and for grain refining Al-10Ti and Al-5Ti-1B master alloys used. To study the effect of cooling rate, three mold... 

Nowadays, increasingly improvements in the digital technology and the advantages of using digital signal processing methods lead engineers to use digital signal processing instead of analog processing in variant domains. However, speed limitations in analog to digital converters (ADCs) and data transfer ports prevent its penetration to high frequency signals region. In this thesis, an Instantaneous Frequency Measurement (IFM) system that can measure frequency in the range of 2-18 GHz is implemented fully digital (DIFM) on FPGA. To do so, monobit sampling technique with the sampling rate of 10 GHz is selected, and GTX high speed serial port is configured to transfer digital data into FPGA.... 

The trip demand information in the form of the origin-destination (OD) matrix is of significant importance in the transportation studies. Obtaining such a matrix by conventional methods requires a considerable amount of time, cost, and human resources. Traffic count and cellphone network data are two relatively inexpensive data that can be used for estimation of OD matrices as well as correction of prior matrices. The trip demand estimation problem is a bi-level model, and the gradient algorithm is one way to solve it. This study, by generalizing the gradient algorithm, attempts to a better use of the available data. In this algorithm, a complementary algorithm is used to solve the traffic... 

In this study, investigated the simulation flow over a double-delta wing. The flow field was simulated by three dimension grid and RANS flow equation by K-ω-SST model. In order to investigate effect of AOA and leading edge flap simulated variable AOA and leading edge flap angle. The results shows created two vortex in inside and outside the wing. The vortex burst at high AOA and the Lift decrease after vortex bursting. The using leading edge flap effect on the vortex power and postpone vortex bursting and increasing wing lift coefficient in the high AOA. Also the leading edge flap effect on the pitch moment coefficient and change the pitch moment coefficient curve slope. The other effects of... 

Recent developments in space industry and the great tendency for definition of efficient, precise and low cost missions are the main reasons for the growing interest in satellites formation flight. Regarding the aforementioned, the study of the multiple satellite control methods is the subject of the present project. In this project, the governing equations of motion of satellite formation flight are developed. Based on this development, it is shown that the satellite linear equations of motion like many other linear system presentations, can not sufficiently model the real system. Therefore, some of the most famous uncertainties in space dynamics such as semimajor axis and eccentricity...