Ackermann Principle and its Implementation in Modern Cars

The Ackermann principle was developed when it became possible to separately control the four wheels of a moving object in the process of turning. In this case, two tasks arose. The first task was to control the wheels to ensure their pure rolling when the object is turned. The solution of this problem was in the Ackermann principle. The second task was to implement this principle in a specific mechanism. The paper analyzes the mechanisms common in modern cars in order to assess their compliance with the Ackermann principle. The method of analysis was in generating and modeling a finite-difference equation describing the process of transferring the movement of the steering wheel to the movement required to turn the wheels.

Delay Approximation Model for Prime Speed Interconnects in Current Mode

There is enormous demand for high speed VLSI networks in present days. The coupling capacitance and interconnect delay play a major role in judging the behavior of on chip interconnects. There is an on chip inductance effect as we switch to low technology that leads to delay in interconnecting. In this paper we are attempting to apply second order transfer function designed with finite difference equation and transform Laplace at the ends of the source and load termination. Analysis shows that the current signaling mode in VLSI interconnects provide better time delay than the voltage mode

Optimal 25-Point Finite-Difference Subgridding Techniques for the 2D Helmholtz Equation

We present an optimal 25-point finite-difference subgridding scheme for solving the 2D Helmholtz equation with perfectly matched layer (PML). This scheme is second order in accuracy and pointwise consistent with the equation. Subgrids are used to discretize the computational domain, including the interior domain and the PML. For the transitional node in the interior domain, the finite difference equation is formulated with ghost nodes, and its weight parameters are chosen by a refined choice strategy based on minimizing the numerical dispersion. Numerical experiments are given to illustrate that the newly proposed schemes can produce highly accurate seismic modeling results with enhanced efficiency.

A finite difference approach to find exact solution of differential equations

This paper contains the background and samples of an approach to construct exact solutions of a wide range of differential equations (DEs). This approach is based on the finite difference equation which corresponds to the given DE. There are three cases considered: linear partial differential equation (PDE) with constant coefficients and at least one non-zero root of characteristic equation, linear PDE with constant coefficients and completely zero roots of the characteristic equation, and a case of nonlinear autonomous dynamical system of second order. Each of these cases is illustrated by an example.

Simulation Study on Laser Welding of High Strength Steel to Vehicle

Based on quasi-stable state heat-transfer control mode, finite difference equation of thermal conductivity in laser welding is deduced. Physical parameter (specific heat) substitutes for phase-changing latent heat, then critical temperature of thermal conductivity welding is determined, so finite difference equation can be solved by MATLAB software. Temperature field distribution is simulated to weldment.Influence of technological parameters such as laser power and welding speed on temperature field are investigated systematically by numerical simulation, these can establish theoretical basis for optimization of technological parameters in laser welding.

Priority queueing model with balking and reneging

This investigation deals with two levels, single server preemptive priority queueing model with discouragement behaviour (balking and reneging) of customers. Arrivals to each level are assumed to follow a Poisson process and service times are exponentially distributed. The decision to balk / renege is made on the basis of queue length only. Two specific forms of balking behaviour are considered. The system under consideration is solved by using a finite difference equation approach for solving the governing balance equations of the queueing model, with infinite population of level 1 customer. The steady state probability distribution of the number of customers in the system is obtained.