In Adaptive Ground-Implemented Phased Array (AGIPA) system, signals received with each element of the array on-board a satellite are transferred to the Earth station for further adaptive processing to form a radiation pattern. For transmission from the satellite to the Earth station, a certain signal multiplex method will be applied. Among the multiplex methods, the simplest one is a frequency-division-multiplex (FDM) technique. This paper deals with the effect of satellite-borne transmitter non-linearity when FDM technique is applied to the AGIPA system. Analysis, assuming a two-element array, shows that for the FDM-AGIPA sysmte, the nonlinearity causes spurious interferences which seriously affect the performance of AGIPA system for interference rejection.

This paper presents an approach to the realization of low-sensitivity second-order digital filters. In contrast to existing methods, which use amplitude sensitivity as a criterion, the proposed method uses pole sensitivity. Pole sensitivity is quite useful for evaluating and comparing the performance of various types of filters because it is not a function of frequency. The relation between pole sensitivity and amplitude sensitivity is clarified, and it is shown that the minimization of amplitude sensitivity is equivalent to that of absolute value of pole sensitivity. For the minimization of pole sensitivity, the denominator polynomial of a second-order transfer function is expressed in a general form including two multiplier coefficients and some arbitrary integer parameters. Under certain constraints on the range of the parameters, which limit the filter complexity, the values of the parameters are determined through an exclusive search such that the pole sensitivity is minimized. The optimum set of the parameters are fully dependent on the given specifications, i.e. locations of the poles. Therefore the z-plane can be partitioned into some regions, in each of which a single set of the parameters is chosen. The resultant map enables one to realize low-sensitivity digital filters having any given characteristics. Finally, two illustrative examples are included.

Realizability criteria for infinite dimensional time-varying linear dynamical systems are studied. We set up the problem of realization and obtain some necessary and sufficient conditions for given matrix weighting patterns to be realized by the above mentioned systems in which state spaces are Banach spaces or Hilbert spaces. Moreover, we show that the problem of realization in infinite dimensional systems is not trivial, that is, there are realizable weighting patterns which are not realized by finite dimensional time-varying systems. The theory of evalution operators in Banach spaces plays an important role in our study.

This paper reports on the overflow process for a trunk reservation system which has two kinds of Poisson inputs. The Laplace-Stieltjes transforms of the interoverflow distributions for each of priority calls and ordinary calls are derived, respectively. The overflow process for priority calls is renewal. The Laplace-Stieltjes transform of the interoverflow distribution for priority calls is represented by the recurrences, and the variance of overflow traffic can be easily obtained by the theory of GI/M/ model. The overflow process for ordinary calls is semi-Markovian, since it depends on the number of busy trunks. The Laplace-Stieltjes transform for the semi-Markovian kernel, depending on the number of busy trunks, is derived. The variance can be obtained by the theory of semi-Markovian inputs model, SM/M/. The total overflow process for both priority and ordinary calls is also derived, but in this case the semi-Markovian kernel is more complicated than that for the overflow process for ordinary calls. The variance of the total overflow traffic being analyzed, the covariance for the two kinds of overflow traffic can be easily obtained. Moreover, some numerical results are shown and characteristics of the overflow traffic are discussed.

The amount of memory space required by a branch-and-bound algorithm depends on the search strategy used in the algorithm. From the viewpoint of implementing branch-and-bound algorithms, it is desirable that the amount of memory space can be bounded to some feasible size. In this paper, we propose two new search strategies for branch-and-bound algorithms, by which the amount of required memory space is controllable. These strategies are named pdfs (parallel depth-first search)" and blis (breadth limited search)", respectively. One of the main results of this paper is that (a) the amount of required memory space of any of these strategies is a linear function of the size of the given problem and (b) the amount of required memory space is controllable by adjusting appropriate parameter. That is, these search strategies are adaptable to the available memory space. Another result of this paper is that the computational performance of a branch-and-bound algorithm, using any of these strategies, can be improved by adjusting appropriate parameters.

This paper considers a multi-base single repair station problem which is a reliability analysis for a system with a large number of equipments operated in their own bases and some repairmen in the repair station. In this problem, all the failed equipments are repaired in the repair station and are sent back to their own bases after completions of repair. The mean and the variance of the number of operative equipments in each base are obtained by a diffusion approximation method. Numerical examples of an approximation solution and a simulation solution are presented.

All of the characteristics of the batwing rediator, which is the heart of the superturnstile antenna system, are theoretically calculated by using the Moment Method. The original type, based on this antenna, and the modified batwing antennas, types I, II and III in total of four were examined. The modified batwing antenna type I is used as a horizontally polarized wave antenna among the circularly polarized wave antennas developed by RCA in the U.S.A. as a countermeasure for the ghost phenomena, while type II is used as an antenna having wide band characteristics for IFF receiving. Type III is a combination of types I and II. The characteristics of the above stated four types of antennas are analyzed theoretically by the use of the Moment Method and the results are compared through the use of measurement. Furthermore, the matching condition is obtained on the basis of the characteristics in the cases of changing the shape of the jumper and of changing the distance between the support mast and the antenna elements.

An electronic model, which can simulate a scotopic electroretinogram (ERG), has been manufactured for trial. And we have obtained the effective clues to clarify technologically the mechanism of the generation of the scotopic ERG components.

A mathematically rigorous treatment of the electromagnetic scattering problem of dielectric cylinders based upon the finite element method is presented. The problem is formulated in the variational terms in two different forms depending upon the matching condition at the artificial boundary.