Sharif Digital Repository

Grammar-based software's are the software's that their input can be expressed according to the grammars for example, reverse engineering software's, evolutional counting's, adjustable programming in product line and XML controllers are in this category; so we can use this capability of the software in its testing .In the field of criteria for the test coverage of the grammar-based software, 5 criteria have been offere so far, which contain rule coverage criterion, context-dependant rule coverage criterion, length-n successor coverage criterion, loop-K coverage criterion and full coverage criterian, any of which have benefits and defeats. The first questions which are asked in this field is... 

This study presents a comprehensive investigation into the characterization of three distinct homogeneous multilayer self-standing thin films, composed of stacked reduced graphene oxide (rGO) planes, which were synthesized using a modified Hummer’s method. In order to investigate their structural, electrical, and optical properties, the samples were characterized by field emission scanning electron microscopy (FESEM), Raman spectroscopy, four-point probe measurements, Impedance measurements, Fourier-transform infrared spectroscopy (FTIR), and Time domain Terahertz Spectroscopy (TDS). The FESEM images obtained from the samples reveal a smooth sheet-like surface with few wrinkles.... 

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... 

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... 

In this research, we investigate shape fitting problems in high dimensional streams and we provide lower bounds for the problems of minimum enclosing spherical shell and minimum enclosing cylindrical shell in streaming model. We will prove that no streaming algorithm can approximate these problems with constant factor with storage sub-exponential in dimension. More precisely, we will prove that every streaming algorithm that can solve these problems with storage sub-exponential in dimension, does not have an approximation factor better than√28 d1/3, where d is dimension of the input points. This is the first lower bound that has been proved for these two problems in high dimensional streams  

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...