Sharif Digital Repository

Collaborative fltering (CF) is one of the best and widely employed approaches in Recommender systems (RS). This approach tries to fnd some latent features for users and items so it would predict user rates with these features. Early CF methods used matrix factorization to learn users and items latent features. But these methods face cold start as well as sparsity problem. Recent years methods employ side information along with rating matrix to learn users and items latent features. On the other hand, deep learning models show great potential for learning effective representations especially when auxiliary information is sparse. Due to this feature of deep learning, we use deep learning to... 

Herein a simple tow step method is developed to design hierarchical binder free structure of binary nickel cobalt carbonate hydroxide decorated hydrothermal carbon sphere. First carbon sphere were synthesized on nickel foam via hydrothermal process using glucose solution followed by carbonization process. Ni Co carbonate hydroxide core shell array were directly grown on binder free carbon spheres using hydrothermal method. The synthesized electrode afforded high specific capacitance (497/83 mAhg-1 at a current density of 1/4 A g-1) and good cyclic stability (85% after 1500 charge / discharge cycles). EIS measurement showed negligible internal resistance (0.638 Ω) which is attributed to the... 

Wind energy is one of the fastest-growing renewable energy sources around the world. Nowadays, the use of offshore wind turbines has increased due to the high and uniform wind at sea, as well as resolving environmental issues such as making noise and sound pollution. Advances in wind energy technology has been effective in wind turbine control systems. Because the offshore wind turbines are affected by the turbulent wind and wave profiles, the control system should be designed to increase the output power quality, as well as alleviating the mechanical loads on different parts of the turbine. In this research, multiple model predictive control method is used to control offshore wind turbines,... 

Performance-based design (PBD) has been accepted as one of the most reliable design methods in the past few decades. PBD can overcome inherent deficiencies associated with force-based design (FBD) and has advantages over this traditional method. Various PBD methods have been developed, which Displacement-based design (DBD) has been considered as one of the effective design approaches of the PBD method. In this study, the Displacement coefficient method (DCM) is developed for stub-type integral abutment bridges (IABs). For this purpose, two coefficients are proposed to determine the target displacement of these types of bridges. Validation of this method by nonlinear time-history analysis... 

Triboelectric nanogenerator (TENG) works based on the accumulation of electrostatic charges produced on the surface of two dissimilar materials while they are brought into physical contact. When the surfaces are separated by a mechanical force, the induced triboelectric charges generate a potential drop, which can lead to generate an electrical current. Since their invention in 2012, TENGs have shown a rapid development in diversity of structure, amount of output power and range of applications, such as self-powered sensors, touch pads, and smart skin. Various kinds of mechanical force can be used for producing electrical energy: human motion, walking, vibration, rotating tire, wind, flowing... 

When we consider Klein-Gordon and Maxwell perturbation fields on the constant gravitational background, the Einstein-Maxwell equations solution will lead to Reissner-Nordstrom black hole which has decreasing mass because of Hawking radiation of bosons from its outer horizon; by reaching this balck hole to extremal case the evaporation will be stoped. The evaporation time is infinite. But String theory equations solution in General Relativity approximation shows that [11] if a Dilaton field ϕ has a exp⁡(-αϕ) coupling with electromagnetic field, the rate of reaching to extremal case will depend on α. We show that by increasing α from 0 to 1, the evaporation time will be initially infinite... 

The primary purpose of this research is to model, control and simulate a flexible and fully actuated satellite, equipped with twelve on-off thruster actuators, in rendezvous and docking maneuver. Flexibility of the satellite is modeled by considering two flexible and asymmetrical multi section solar panels with rotational springs and dampers in joints, attached to a central rigid body. Solar panel sections have been modeled in the form of Euler-Bernoulli beam by using assumed mode method and taking into account finite bending mode-shapes. The governing differential equations are obtained using Lagrange method. Then, the dynamic model is validated by comparing the simulation results of the... 

In the current situation, kidney transplantation is the most appropriate and least costly treatment for patients with end-stage renal disease (ESRD). Related or altruistic living donors, as well as deceased donors, are considered as a supply source for donated kidneys. Researches have shown deceased donor kidney may not work as well as a living donor kidney because the deceased donor kidney is outside the donor's body for a longer time. If the donor has an incompatibility with the patient (in terms of the blood group, HLA, etc.), a kidney exchange between the pairs can be used to resolve the issue and make the transplantation possible. Pairs with blood group compatibility have also...