Sharif Digital Repository

This paper studies the problem of secure and resilient distributed cooperative control for autonomous vehicles under false data injection attacks on the vehicular communication net-work. We propose a model-based scheme to detect unknown data falsification attacks using the predicted traj ectory in a distributed nonlinear model predictive control problem. First, as a local agent, each autonomous vehicle stores the information received from its neighboring vehicles to clarify anomalies. The recorded data is investigated over a temporal moving observation window which contains different prediction sequences of the distributed nonlinear model predictive control problem in the previous times. In... 

Three preconditioners proposed by Eriksson, Choi and Merkel, and Turkel are implemented in a 2D upwind Euler flow solver on unstructured meshes. The mathematical formulations of these preconditioning schemes for different sets of primitive variables are drawn, and their eigenvalues and eigenvectors are compared with each other. For this purpose, these preconditioning schemes are expressed in a unified formulation. A cell-centered finite volume Roe's method is used for the discretization of the preconditioned Euler equations. The accuracy and performance of these preconditioning schemes are examined by computing steady low Mach number flows over a NACA0012 airfoil and a two-element... 

A novel molecularly imprinted xerogel (MIX) based on organically modified silica (ORMOSIL) was successfully prepared for on-line capillary microextraction (CME) coupled with high-performance liquid chromatography (HPLC). The sol-gel-based xerogel was prepared using only one precursor and exhibited extensive selectivity towards triazines along with significant thermal and chemical stability. Atrazine was selected as a model template molecule and 3-(trimethoxysilyl)propylmethacrylate (TMSPMA) as a precursor in which the propylmethacrylate moiety was responsible for van der Waals, dipole-dipole, and hydrogen-bond interactions with the template. This moiety plays a key role in creation of... 

Preconditioned characteristic boundary conditions (BCs) are implemented at artificial boundaries for the solution of the two- and three-dimensional preconditioned Euler equations at low Mach number flows. The preconditioned compatibility equations and the corresponding characteristic variables (or the Riemann invariants) based on the characteristic forms of preconditioned Euler equations are mathematically derived for three preconditioners proposed by Eriksson, Choi and Merkle, and Turkel. A cell-centered finite volume Roe's method is used for the discretization of the preconditioned system of equations on unstructured meshes. The accuracy and performance of the preconditioned characteristic... 

This review is mostly focused on the recently emerged methodologies for preparing the appropriate extracting media with enhanced capacity, stability and selectivity, which could be used in capillary microextraction (CME). We particularly consider conductive polymers, sol-gel-based materials, monolithic coatings, molecularly-imprinted polymers and xerogels. Moreover, we discuss recent advances in configuration of CME, array capillaries and unbreakable substrates  

Recently, Ghanbari and Mahdavi-Amiri (Appl Math Model 34:3363–3375, 2010) gave the general compromised solution of an LR fuzzy linear system using ABS algorithm. Here, using this general solution, we solve quadratic programming problems with fuzzy LR variables. We convert fuzzy quadratic programming problem to a crisp quadratic problem by using general solution of fuzzy linear system. By using this method, the crisp optimization problem has fewer variables in comparison with other methods, specially when rank of the coefficient matrix is full. Thus, solving the fuzzy quadratic programming problem by using our proposed method is computationally easier than the solving fuzzy quadratic... 

In this work, flow stress behavior, softening mechanisms and processing maps during deformation of aluminum-magnesium alloy i.e. AA5052, were investigated. Firstly, tensile tests were carried out in the range of room temperature up to 450 °C under different strain rates between 0.001 s-1 to 0.05 s-1. Then, neural network algorithms together with dynamic materials modeling were employed for determination of stain rate sensitivity parameter and processing maps under different working conditions. Moreover, the governing constitutive equations as well as the activation energies of dynamic strain aging and hot deformation were defined. Accordingly, the processing maps were developed for different... 

Ciprofloxacin is a widely used antibiotic that is also a persistent contamination that causes major health and environmental risks. This study investigated the electrochemical removal of ciprofloxacin using a boron-doped diamond anode and a non-supportive electrode to get an accurate understanding of the anode's performance. The effects of current density, initial ciprofloxacin concentration, time, pH, and electrolyte concentration on the removal efficiency of ciprofloxacin were investigated. Additionally, ANN and LSSVM models were used to predict ciprofloxacin removal. The results showed that the BDD anode was effective in removing ciprofloxacin from water, with complete removal of 10 mg... 

In this paper, a cooperative approach for control heterogeneous connected and autonomous vehicles (CAVs) platoon considering lane-change maneuvers is proposed. In complex dynamic traffic environment, the speed of the surrounding vehicles of CAVs changes dynamically. Thus, the lane changing vehicle requires considering velocity fluctuations to achieve safe driving. The aim of this study is to combine dynamic path planning based on a cubic curve and model predictive control (MPC) with collision avoidance constraint to track an optimally generated path. The proposed control performs as a maneuver switching model including the vehicle's continuous states and discrete maneuver transition rule for... 

The raising trend both in violent and property crime are of major concern in Iran. Using a panel data modeling (province wide), the paper provides an econometrics assessment of the relationship between crime against properties and violent crimes as functions of deterrent, social, economic and demographic factors in Iran, in the framework of Becker-Ehrlich crime supply theory. The findings indicate that, although deterrence hypothesis is not confirmed for burglary and assault, it explains the variations of murders and threats. Economic factors play key role in burglary and threat explanation, but they do not affect willful murders, however, Literacy explains both murders and threats. Average... 

A novel rotary magnetohydrodynamic (MHD) (RMHD) micropump is presented in this paper in order to both benefit exclusive advantages from the MHD micropumps and eliminate the current obstacles in their implementation. Lorentz force, which is the actuation mechanism in RMHD, is used to propel a mercury slug in a circular microchannel in order to suck the working fluid from the inlet and pump it to the outlet. This idea is integrated with a valve which prevents the working fluid from passing through, while allowing the mercury slug to pass, during each pumping loop. The performance of a fabricated RMHD is evaluated, considering parameters such as pressure difference, running duration, electric... 

Position sensorless control of ac machines at zero and low speed is possible using high-frequency carrier injection methods. These methods utilize anisotropic properties of rotor. Therefore, they may lose their efficiency for nonsalient machines or machines with small rotor saliency. In these machines, measurement noise and offset, existing delays, as well as model uncertainties may lead to inaccurate estimation of rotor position. Stator resistance which is usually neglected in these methods may also lead to a considerable error especially in machines with small rotor saliency. In this paper, a new position estimation method is presented, and it is shown that in comparison to conventional...