Sharif Digital Repository

Inelastic analysis of frames is considered in many researches to obtain the capacity of strength and deformation and also to predict of their realistic behavior. The yielded inelastic zones in the frames, usually occur in the limited length of the beams or columns. One of the inelastic analysis methods is the inelastic hinge method, where the inelastic behavior of elements is concentrated at the hinges, while the other regions are assumed to be elastic. Existing in the inelastic zones, the internal forces are not independent from the each other, and against the elastic zones, the interaction among them are important, too. In the present research, by using of the inelastic hinge concept, a... 

This project aims to determine seismic performance coefficients of Off-Center Braced lateral load resisting system (OBS) equipped with Buckling-Restrained Braces (BRBs), along with comparing its seismic performance in extreme seismicity level with those of Special Moment Frame (SMF). For this intent, the structural design of 24 regular-in-height residential OBS-BRB models was first carried out following ASCE7-16. Then, Static (Pushover) and Incremental Dynamic Analysis (IDA) were performed on the models using the methodology of FEMA P-695 to obtain the target coefficients. Furthermore, the coefficients were used for Pushover and IDA analysis of 27 irregular-in-height OBS-BRB models with soft... 

Mixed matrix membranes (MMMs) are new generation of membranes which possess simple processability of polymeric membranes and high separation ability of zeolitic membranes. The present study, concentrates on the fabrication of MMM for CO2/CH4 separation in a combined method as encompasses not only higher permeability but also superior selectivity in comparison with conventional polymeric membranes. The most appropriate technique for MMM making, is the process which provides participation of distributed zeolite particles in separation efficiently while the polymeric matrix acts just like a particle support and dose not play an effective role in separation. Investigations demonstrates that... 

Nowadays recommender systems are one of the most important parts of big websites. These systems help users to find their intended items among enormous amounts of data. Traditionally, recommender systems are designed and implemented using different methods such as content based, collaborative and demographic filtering. Each of these methods had some problems that lead to emergence of a new kind of recommender systems called hybrid recommender systems. This kind of recommender systems try to combine the other methods and make them better. In this thesis, we have selected some previous recommender systems and then, we have made a new system by combining and reforming them. The resulted... 

In this project, graphene oxide was produced by chemical method (modified hummers method) because of simplicity and reproductiblity in the manufacuring process. Zinc nanoparticles were produced from pure zinc anode in the graphene oxide solution (anodic dissolution). Nanocomposite coating of reduced graphene oxide – zinc was created by electrochemical reduction with voltage pulse. Optimization of corrosion current density of the coating was done by design of experiments software (central composite design). To achieve this goal, several parameters such as cycles of zinc dissolution, frequency, duty cycle, total time of coating and applied voltage were examined. Using analysis of variance... 

An autonomous method for attitude and position determination of a satellite without using data from ground stations and also without the need for human interference is proposed using the image that the satellite has taken at each moment. The proposed method is based on recognition of stable features in the image and using them in order to match the satellite image with a source image from the Earth and the latitude and longitude of the features become known.SIFT and SURF algorithms have been examined. Using the perspective equation and camera coordinate system, a model has been developed that relates the coordinates of a point in the image with its equivalent coordinates in the real world.... 

This paper presents a novel method for satellite attitude determination, using Electrostatically Suspended gyroscope (ESG). In this method, two superconducting rings rotated around a spherical rotor, which causes a variable flux in rings. So according to faraday’s law of induction, a voltage will be induced in the rings. Using this voltage and a kalman filter, attitude of satellite will be determined. ESG works precisely, when the rotor is maintain at the center of gyroscope cavity, between three pairs of circular electrode, so a backstepping control algorithm will be designed In order to this purpose. The performance of attitude determination using this ESG and designed control algorithm is... 

Passive bistatic radars (PBR) using transmitters of opportunity have attracted a lot of attention recently. Advantages of these radars include the covert operation as well as the low cost of their building and maintenance. Such radars are intended to use signals in the environment as transmitters. These transmitters can be terrestrial transmitters such as TV broadcasts or even satellite transmitters such as global positioning system (GPS) satellites.Satellite transmitters have global coverage and their signal is available at all times, but the design of these transmitters for non-radar applications causes the reduction of the reception power at receivers. So BR systems have attempted to use... 

In this study, a number of chloro and nitro cobaloxime complexes with triphenylarsine and triphenylstibine synthesized from dichloro precursor and their structure were studied. These complexes were identified by FT-IR and 1H-NMR methods also their solid state structure studied by X-ray crystallography of single crystals. Intramolecular interactions of these complexes analyzed and studied by NCIPLOT 3.0 and VMD 1.9.3 programs which has different kind of intramolecular interactions which can be identified by their colors. All these complexes have strong hydrogen bond between hydrogen of oxime group and oxygen of other dimethylglyoxime ligand. Also coordinate covalent bond among ligands and... 

Demand estimation has always been one of the most important components of marketing in all industries. Because the profitability of any organization depends on the demand for the product or service that the organization offers to the market. On the other hand, in order to optimize the performance of the organization and better planning, we need to have an estimate of demand in order to avoid wasting the available facilities by optimally allocating resources. Another issue that shows the importance of demand estimation is the dependence of optimal pricing on the amount of demand, which can be said to be the most important tool of the organization to manage its revenue. Optimal pricing can be...