This letter analyzes the performance of a virtual-token passing scheme, fair BRAM, for local area networks. A Markovian model of the system is developed and analyzed by the equilibrium point analysis. The throughput and average message delay characteristics are shown.

in this paper, the steady-state and dynamic analyses of the continuous and the discontinuous conduction mode of the uk converter with nonzero mutual inductance by the state-space averaging method are described. For the analysis of the discontinuous conduction mode of the uk converter, the critical duty ratio is used. The analysis of the dynamic responses is presented for both the open- and closed-loop cases. The obtained results are useful for the optimum design of the uk converters.

In the design of high speed, fine pitch wire matrix print heads, magnetic characteristics and the structure of the armature are studied. Design conditions are proposed for minimizing the equivalent mass. Several armature models are evaluated empirically and non-grooved armatures are found to be suitable for large magnetomotive forces, while grooved armatures offer a slight performance advantage for small magnetomotive forces. The armature magnetic circuit model is then analyzed numerically. As the average flux density increases, magnetic saturation occurs first at the root of the core, and then extends to the inner core portions and the armature. The magnetic attractive force acting on the armature is calculated taking magnetic saturation into account. In order to minimize the mass of the armature, lever, and wire, the lever ratio, which is the ratio of wire rotation radius to armature rotation radius, is taken as a design parameter. It is shown that there exists an optimum lever ratio which minimizes the equivalent mass, and the effects of lever shapes are clarified.

This paper introduces a space bounded alternating one-way multihead Turing machine with only universal states, and investigates fundamental properties of this machine. We show for example that for any function L such that [L(n)/n]0, (1) there is a set in [U2-HTM(0)], but not in [Nk-HTM(L(n))], and there is a set in [N2-HTM(0)], but not in [Uk-HTM(L(n))], (2) for each k1, [Uk-HTM(L(n))][U(k+1)-HTM(L(n))], and (3) [Uk-HTM(L(n))][Nk-HTM(L(n))][Dk-HTM(L(n))], where [Uk-HTM(L(n))] denotes the class of sets accepted by L(n) space bounded alternating one-way k-head Turing machines with only universal states, and [Nk-HTM(L(n))]([Dk-HTM(L(n))] denotes the class of sets accepted by L(n) space bounded nondeterministic (deterministic) one-way k-head Turing machines.

Temperature dependence of a SAW-controlled optical wavelength demulti-/multiplexer has been discussed. The device consists of ZnS/Ta2O5/Nb2O5 thin-films on a Y-cut LiNbO3 substrate. The tuning SAW frequency for the optical switching shifted with temperature by -0.20 MHz/. It is theoretically found that a temperature-independent demulti-/multiplexer can be realized when two waveguides possess the similar temperature properties. When the device is used in a narrow wavelength range, the device constituted of nearly degenerated waveguides exhibits small temperature dependence. These results were experimentally verified. In a nearly degenerated device, the temperature dependence was approximately +0.02 MHz/. The other device having small temperature-dependence was fabricated with a ZnS/Ta2O5/Ti-diffused waveguide on a Y-cut LiNbO3, whose temperature dependence was +0.02 MHz/.

Recently, the development of the micro-computer has been remarkable. Many techniques that were impossible a few years ago are now possible. Superimposition is one of those techniques. Meanwhile, many visual teaching materials have been developed, for example video tapes and micro-computers, but teachers are not yet prepared to make a good use of them. This letter describes applications to audiovisual instruction by video superimposition using a microcomputer. In this system, as well as video aids can be used. This letter show four examples that are supported by video superimposition using a micro-computer. It is concluded that superimposition by a micro-computer is extremely useful for audiovisual instruction. This system is inexpensive, quite simple, and useful even with only a little knowledge of programming. The superimposition system is helpful not only if used by teachers but also if used directly by students.

The present paper derives a sampling basis in the signal space spanned by spline functions of degree 2 with equidistantly spaced knots. It also analyzes properties of the sampling basis. The spline signal space is defined as the space spanned by B-spline basis composed of normalized B-splines. As the norm is , L norm is adopted. The existence of a sampling basis is examined by functional analytic approach. The discrete signal space K[b] corresponding to the B-spline basis and the discrete signal space K[s] corresponding to the sampling basis are defined. As the norm in K[b] and K[s], l norm is adopted. B-spline transform B is defined as the operator which transforms a discrete signal in K[s] into one in K[b]. It is shown that the sampling basis exists in if and only if B has a bounded unit-pulse response in the sense of l1 norm. The sampling basis in is derived using the unit-pulse response of B which is derived by z-transform. As properties of the sampling basis in the time domain, its symmetric property, its shift-invariant property and the exponential attenuation of its amplitude are shown. As properties in the frequency domain, the frequency response of the interpolation by spline functions of degree 2 is shown by the Fourier transform of the sampling basis. It is clarified that the frequency response is of low-pass type, and it has no phase delay in the pass band and the transition band.

Data comparison and trigger skip methods are proposed to extract truly synchronized trigger from a high speed repetitive waveform to be observed on a CRT or to be written in a partially sequential digital sampling storage circuit. So far, there have been no way to automatically extract truly synchronized trigger from the input repetitive waveform in a multi-period sampling system, when an external synchronizing signal is not accompanied. Trigger extraction mechanisms from various kinds of repetitive waveform, for which, especially, a number of triggers can generate during its fundamental period are theoretically analysed. Based on the results, the principle and effectiveness of this system for various types of the waveform are described. The input waveform is taken twice in the sampling storage circuit, and successively taken two sample value streams are compared with each other. These two should agree if both are taken in the same portion of the waveform fundamental period. If they do not agree, it is judged to be due to incorrect trigger extraction, and the trigger skip number is increased. Data taking and comparison is repeated by increasing the trigger skip number untill two successively taken data streams agree with each other. Performance estimation tests of fabricated data comparison and trigger skip circuits were made using computer produces test signal, and the results showed the reliable digital data storage and simple operation.

We propose a new definition of the k-tail for a tree with respect to a tree set and show how it can be used to infer a frontier-to-root tree automaton from a finite set of trees. The behavior of the inference algorithm for varying values of k is also studied.

We are given a set of rectilinear blocks without any overlap in the plane. We may move any block in the horizontal direction unless it intersects any other block. Then, the problem is to determine the minimum width of a rectangle which includes all of the blocks without any overlap and how much we should move each block in order to pack them into the rectangle. An O(n log n) time algorithm is presented, Where n is the total number of vertices of given blocks.

The performance of the Forward Error Correction (FEC) with interleaving was evaluated by computer simulation with the field experimental data and its usefulness in land mobile communications is confirmed.

This paper presents an analysis for a multi-server system with batch arrivals of queueing and non-queueing types of customers. Customers of two types are assumed to arrive in two independent batch Poisson streams and to have exponentially distributed service times. This situation can be seen in the Facsimile Intelligent Communication System (FICS). The existing studies on the service systems which dealt with two types of customers, however, were limited to the case of Poisson arrivals. By using the generating function technique, a recursive scheme for the steady-state probabilities in the system is obtained. Traffic measures, e.g., loss probability, mean waiting time, and the probability that the number of customers in the system is zero, are deduced without any truncated error. It is shown that the above-mentioned traffic measures can be represented by only a finite set of the steady-state probabilities in spite of the infinite state space. In some special cases, it is seen that the results obtained here are consistent with the previous works. Numerical examples are shown and traffic characteristics are also discussed.

We are given a polygonal region P with holes and one point q is specified in the region. The problem is how fast we can find the portion of the boundary of P that is visible from q. For this problem an efficient algorithm is presented which runs in time O(n log h) in the worst case and in time O(n+h log h) if every hole is a convex polygon, where n is the total number of vertices of P and h is the number of holes.

An error-correcting parsing method for context-sensitive languages is described, which finds all sentences ω's in a language with the minimum weighted Levenshtein distance WLD (ω, T) for input string T. The method is obtained by adding an error-correction mechanism to the Adachi-Kamata's parsing method for context-sensitive languages. By introducing the notion of a WLD-graph we can split the error-correction mechanism from the derivation of sentence i.e., the construction of derivation graphs. This makes the algorithm conceptually simple and easy to understand.

This letter presents a method for removing undesirable push actions introduced by a lookahead solution from stack-controlling LALR(1) parsers. By this method, the same parsing algorithm can be surely used for all stack-controlling LALR(1) parsers.

A laser diode wavelength-division demultiplexer is first proposed. The worst crosstalk level in the 1.30 µm-channel is measured to be less than -33 dB for 0.88 µm, 1.30 µm and 1.55 µm wavelength signals. The free-carrier absorption loss is found to play a significant role in the crosstalk improvement.

Mass transport was first employed in an OMVPE system for 1.55 µm GaInAsP/InP laser. The wafers grown by OMVPE were treated at 700 under cracked PH3 and H2+N2 atmosphere for 1 hr, resulting in buried structure and the BH laser showed low threshold current of 50 mA (pulsed) without optimization.

This letter presents a method for analyzing single server queueing models having two classes of customers. This method, based on the conservation laws, makes it possible to analyze queueing models for various types of queueing disciplines.

Assuming a perfect circulary polarized radar system, the cancellation ratio limitations were evaluated using the Sekine-Lind rain-drop distribution. Numerical methods were used and the cancellation limitation was plotted against rainfall rate for various wind velocities.

This paper reports an on-line recognition method of Thai characters being composed of curves, and having many complicated and similar shapes. A character stroke is segmented into clockwise and counter clockwise arcs according as the stroke tracing is clockwise or counter clockwise, by making use of eight directional codes and directional differences of stroke tracing. Intuitively described features such as the sequence of stroke arcs, types of arc and relative positions of arcs are utilized for classifying characters. A multi-step classification method is introduced to achieve a good recognition rate. By applying the method to 69 categories (414 data) of Thai characters, a recognition rate of 100% for learning data, and a recognition rate of 96.4% for test data have been obtained.