Sharif Digital Repository

A comprehensive dynamic model of a catenary anchor leg mooring system has been developed and the governing equations of notion were derived. The equations of motion are found to be nonlinear parametric ordinary differential ones of the order two. The necessary and sufficient conditions, for the existence of a stable periodic response of this system, were found using the Green's function and Schauder's fixed-point theorem. The validity of the assumptions has been fully demonstrated with a few case studies. Results obtained from the dynamic modeling reiterate the presence of inherently nonlinear and time-varying characteristics of the system and hence a stability condition in terms of the... 

A comprehensive dynamic model of a catenary anchor leg mooring system has been developed and the governing equations of notion were derived. The equations of motion are found to be nonlinear parametric ordinary differential ones of the order two. The necessary and sufficient conditions, for the existence of a stable periodic response of this system, were found using the Green's function and Schauder's fixed-point theorem. The validity of the assumptions has been fully demonstrated with a few case studies. Results obtained from the dynamic modeling reiterate the presence of inherently nonlinear and time-varying characteristics of the system and hence a stability condition in terms of the... 

It has been shown that there exists the necessary and sufficient condition for the existence of stable periodic response for a type of catenary anchor leg mooring system, (CALM). The mathematical model shows that the governing equation of motion for the system is a non-linear parametric second-order ordinary differential equation. The above-mentioned conditions have been obtained using the Schauder's fixed-point theorem. The validity of the assumptions has been fully demonstrated by analyzing a few examples. © 2001 Elsevier Science Ltd  

A new optimal control law for direct yaw moment control, to improve the vehicle handling, is developed. Although, this can be considered as part of a multi-layer system, for the traction control of a motorized wheels electric vehicle, but the results of this study are quite general and can be applied to other types of vehicles. The dynamic model of the vehicle system is initially developed and, using the well-known optimal control theory, an optimal controller is designed. Two different versions of control laws are considered here and the performance of each version of the control law is compared with the other one. The numerical simulation of the vehicle handling with and without the use of... 

The innovative powertrain configuration of modern electric vehicles with four-wheel independent drive (4WID) provides the possibility of simple and exact yaw moment control by controlling the electric motor of every wheel independently. In this study, a genuine control strategy for optimum direct yaw moment control is proposed. Although this can be considered as a global control system for traction control of 4WID electric vehicles, the analysis is quite general and can be applied to other types of vehicle. The directional vehicle model is derived and, in accordance with the optimal control theory, an optimum yaw moment controller is designed. Two versions of the control law are developed... 

A comprehensive new dynamic model of a four-wheel independent drive electric vehicle has been developed and different types of the motor control laws were addressed. The first part of this study deals with the full description of the model scope in which the structure of the model including the sub-models has been fully developed. Subsequently, the sub-models including the tire sub-model, the body motion, and the motor dynamics were investigated, and the computer model of the vehicle has been simulated. Finally, the proposed motor control laws and the vehicle dynamic behavior of the vehicle were presented. Detailed analyses of the vehicle performance and comparison of the simulation results... 

A comprehensive dynamic model of a four motorized wheels electric vehicle has been developed and different types of motor control laws were addressed. The first part of this study deals with the full description of the model scope in which the structure of the model, including the sub-models, has been expressed. Subsequently, the sub-models including the fire sub-model, the body motion, and the motor dynamics are fully investigated, and with the use of simulink software, the computer model of the vehicle is simulated. Finally, the motor control laws are presented and the vehicle dynamic behavior studied under different driving conditions. Detailed analyses and comparison of the simulation... 

The inadequacy of traditional theory of elasticity in describing such a phenomenon as dispersion associated to a propagating wave with wavelength comparable to the intrinsic length of the medium of interest is well-known. Moreover, under certain circumstances it is incapable of capturing all the propagating waves. A remedy to such dilemmas is the employment of the more accurate higher order continuum theories which give rise to the appearance of at least one new characteristic length in the formulation. The experimental evidences as well as lattice dynamic analysis suggest that, although higher order continuum theories result in some improvements, but cannot fully overcome the... 

A comprehensive new dynamic model of a four-wheel independent drive electric vehicle has been developed and different types of the motor control laws were addressed. The first part of this study deals with the full description of the model scope in which the structure of the model including the sub-models has been fully developed. Subsequently, the sub-models including the tire sub-model, the body motion, and the motor dynamics were investigated, and the computer model of the vehicle has been simulated. Finally, the proposed motor control laws and the vehicle dynamic behavior of the vehicle were presented. Detailed analyses of the vehicle performance and comparison of the simulation results... 

Silk fibroin (SF) as a natural biopolymer holds great potential in biomedical research because of its biocompatibility, easy processability and high strength properties. However, slow gelation time has narrowed its applications, specifically in cell-laden microparticle production due to insufficient crosslinkable moieties. This study aimed to develop cell-laden silk fibroin-phenol (SF-Ph) microparticle through co-flow microfluidic system using SF conjugated Ph moieties whereas covalent crosslinking is mediated with horseradish peroxidase (HRP) in the presence of hydrogen peroxide (H2O2). For this, the SF-Ph was synthesized through carbodiimide condensation crosslinking reaction. Aqueous...