Ground clutter from cultivated land was measured using an L-band long range air-route surveillance radar (ARSR) at very low grazing angles, between 0.21 and 0.32. It is shown that the Weibull-distributed ground clutter obeys a Weibull distribution in the frequency domain after processing by the discrete Fourier transform (DFT). Thus the new Weibull-CFAR should be considered to suppress such clutter in the frequency domain.

A model for computation of the transmission delay distribution in infinite population nonpersistent CSMA/CD is presented, together with computational approximations. Recent extensions of the use of CSMA/CD to heavy load realtime applications, such as packet voice communication and process control, motivated this work. The realtime condition demands quantiles of packet delay distributions, which in turn requires that the entire distribution be calculated rather than representative values such as mean delay and coefficient of variation. The model decomposes into two submodels describing channel state and delay distribution, respectively. The channel model is of infinite population justifying the assumption that the channel behavior affects an individual station's behavior, whereas the converse does not take place. The formulation is by discrete time Markov chain; time is grained into slots or backoff unit time. An arbitrary packet size distribution is allowed. The solution is obtained in closed form; measures such as throughput and probability of trial success are also available in closed form. The delay model assumes that channel access trials are independent of each other; the calculation consists of convolutions and weighted sum of distributions. Because this computation is rather heavy, approximations are included.

Gamma ferric oxide thin film media with a thickness of 0.190.27 µm were prepared by a reactive RF sputtering. Signal output loss with increasing temperature at high recording density was studies. Heating a medium-head system to 55 results in a 16% loss of signal output at 790 bpm (D_{-6 dB}) of recording density for a medium having a 0.19 µm thickness; a 40% loss of signal output for a conventional-coated medium having a 0.7 µm thickness at 400 bpm (D_-6dB), accompanying a decrease of a saturation write current value, I_W(k-1) (an optimum write current). Increments of medium thickness and write current enhanced the thermal signal output loss. An over-saturated recording in the write process was suggested to cause the thermal signal output loss, especially for the thicker media. From the perspective of thermal stability of signal output at high recording density, sputtered γ-Fe₂O₃ thin film media are advantageous because of their thinness and small write current dependence of signal output.

An iterative decomposition method with mesh refinement strategies is presented for the numerical solution of nonlinear two-point boundary value problems. It is shown that this method is more efficient than the traditional finite difference methods and shooting methods.