Alexandar Djordjevich

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—Tool wear condition monitoring has the potential to play a critical role in ensuring the dimensional accuracy of the workpiece and prevention of damage to cutting equipment. It could also help in automating cutting processes. In this paper, the feed cutting force estimated with the aid of an inexpensive current sensor installed on the ac servomotor of a(More)
Using the power-flow equation, we have examined the state of mode coupling in step-index plastic optical fibers with different numerical apertures. Our results confirm that the coupling rates vary with the coupling coefficient of the fibers as the dominant parameter, especially in the early stage of coupling near the input fiber end. However, we show that(More)
The power-flow equation is employed to calculate bandwidth of step-index plastic optical fibers (POFs) for different launch conditions. The outcome specifies bandwidth as a function of the mean input angle and width of the launch-beam distribution. For small distribution widths, bandwidth is shown to decrease with increasing mean input angle of the(More)
Using the time-independent power-flow equation, we have examined the mode coupling caused by intrinsic perturbation effects of step-index plastic clad silica fiber carrying more than 10(5) modes. Result show that the equilibrium mode distribution for this fiber is achieved at a length of approximate 550 m, which is longer than reported previously. While(More)
For different depth and width of the intermediate layer, a power flow equation is used to calculate spatial transients and steady state of power distribution in W-type optical fibers (doubly clad fibers with three layers). A numerical solution has been obtained by the explicit finite difference method. Results show how the power distribution in W-type(More)
The coupling coefficient in a strained step index plastic optical fiber is determined using our recent simplified method. This enabled the calculation of the length z(s) at which the steady-state distribution (SSD) is achieved. Results are in good agreement with measurements reported earlier. The strained fiber shows a much stronger mode coupling than the(More)
Using the power flow equation, the state of mode coupling in 100-400 μm core step-index silica optical fibers is investigated in this article. Results show the coupling length L(c) at which the equilibrium mode distribution is achieved and the length z(s) of the fiber required for achieving the steady-state mode distribution. Functional dependences of these(More)
A theoretical evaluation of the properties and processes affecting the radon transport from subsurface soil into buildings is presented in this work. The solution of the relevant transport equation is obtained using the explicit finite difference method (EFDM). Results are compared with analytical steady-state solution reported in the literature. Good(More)