In this paper, two synthesis methods of fuzzy membership function circuits with multiple inputs are proposed. By using bounded-differences expressions, membership function representations suitable for logic circuits in current mode is obtained. In bounded-difference expressions, bounded-difference, switch function and algebraic sum are used. Since these operations can be realized by MOS current-mirrors, MOS pass-transistors and wired-sum connections, the membership function circuits with multiple inputs can be built with these circuit elements. Therefore the synthesized circuits can be implemented in MOS IC forms. The potential applications of the membership function circuits with multiple inputs are real-time inference engine and fuzzy ROM.

This paper presents several statistical and empirical approaches to estimating circuit area required for laying out a given number of random-logic gates. The approaches are developed for MOS layout methods in which terminals for load and driver devices account for independent wiring tracks. For placements and interconnections, two statistical models involving (a) linear superposition of one-dimensional placements and (b) uniform, diffused connections of terminals on a wiring track, are introduced. Block width dependent wiring track requirements are determined by incorporating one-dimensional logic partitioning across the block. An empirical relationship for the spatial partitioning is established from a collection of placements done with a manual layout method.

Reliability of single-loop networks can be improved using double loops: forward loops advancing to the neighboring node and backward loops skipping by a certain distance. In this type of double loop networks, when some nodes break down, threre exist possibilities that a message can not be transmitted to some nodes, and some other messages must take a roundabout route. Then, the delay may happen in data transmission. This phenomenon depends on the configulation of the network and the fault location. This paper investigates, first, the number of available communications, and next the maximum distance between any computer pair when two or more computers break down in the network. Finally routing algorithm to find a route where a message can be transmitted to the destination node is presented.

This paper proposes a circuit configuration for realizing third-order CR oscillator, and studies its oscillation characteristics. It is shown that the oscillator can be realized by using an inverter type D-R mutator, transforming a resistor into a frequency dependent negative conductance with Ys2D, and a positive type second generation current conveyor as a noninverting amplifier. Since the inverter type D-R mutator consists of two current conveyors which are basically voltage controlled current sources, an analysis has been carried out based on actual characteristics of current conveyors and an equivalent circuit has been derived. The oscillation condition of oscillator circuit consisting of D-R mutator and noninverting amplifier is derived. The frequency of oscillation of this oscillator is tunable over a wide range by single grounded resistor, and the condition of oscillation is shown to be very simple. Theoretical and experimental results have been compared and discussed, and usefulness of proposed circuit is confirmed.

A 12-GHz-band GaAs monolithic dual-gate FET mixer using a novel circuit configuration has been demonstrated. Adoption of a negative feedback circuit has reduced the output impedance of the mixing dual-gate FET down to 330 Ω, which is approximately one fourth that of conventional dual-gate FET mixers, resulting in good matching to the next state. An experimental MMIC mixer, which included an IF buffer amplifier, exhibited a 3.4-4.2-dB conversion gain with a 11.3-11.6-dB SSB noise figure in the 11.7-12.2-GHz RF band.

This paper describes a newly-developed 4 GHz 135 Mbps 256 QAM system with a rolloff factor of 20%, which can attain a spectrum efficiency of 6.75 bps/Hz. The key techniques are theoretically investigated to realize this system. It was predicted theoretically that the simultaneous incorporation of 7-tap transversal equalizers (TEQL) and a recursive slope equalizer (SEQL) would be required as countermeasure for multipath fading. The 256 QAM system was designed considering the results of the theoretical investigation. Excellent BER performance was obtained with the aid of forward error correction and pilot carrier injection. Since remarkable improvement in the signature was obtained by the simultaneous user of TEQL and SEQL, the 256 QAM system with a very low rolloff factor is promising.

Sea clutter was measured using an X-band shipboard radar of horizontal polarization, pulse with 250 ns, azimuth beamwidth with 1.0 and grazing angles between 4.2 and 13.4. It is shown that sea clutter amplitude statistics obey a log-normal distribution or a Weibull distribution for different azimuth sectors.

In this paper, effectiveness and applicability of the models presented in the preceding paper are discussed. First, a collection of manually placed blocks employed for a 32-bit CPU design have been examined. Postulated linearities of the placement and partitioning are seen to be acceptable with reasonable statistical accuracy. One finding is that the extrapolation of the linear partitioning model gives a statistical 'first-order' value of the circuit area for custom chip design, typically done automatically on long one-dimensional rows of standard cells or gate arrays. Several statistical properties of terminals in a manually placed block are also presented.

A relaxation-based technique exploiting latency and multirate behaviors is proposed for electrical simulation of MOS digital circuits. An efficient window size control scheme is also developed.

A new method to obtain the availability of a cold standby series system with spare units is presented. Two models are considered. The first one is a series system with spare units. The other is m series systems with common spare units. The availabilities are solutions of nonlinear simultaneous equations and are obtained numerically.

This paper describes an experimental system for designing three-dimensional solid objects through three-view orthographic drawings, using automatic three-dimensional interpretation in cooperating with a set of interactive drawing-oriented design utilities. In the design process based on the system approach, an object is viewed as being consisting of several volumetric instances, each of which is further composed a number of simple subvolumes. In the system, whereas the automatic interpretation is employed to construct the instances from their orthographic projections, the design utilities are provided to allow modifications of a solid-object model being composed of the constructed instances. Once a solid-object model is created from a drawing containing the projections of an instance, modifications on the drawing can be performed for addition of new instances into the existing solid-object model, and changes and deletion of the instances existing in the model. Being aimed at a two-dimensional interface for the Constructive Solid Geometry, or CSG method, the system provides the user with design interaction procedures which let the user manipulate the projections of the instances in terms of two-dimensional graphical primitives, such as straight lines, arcs, and circles, obtain and display a solid object constructed from the projections being designed. In addition, more complex three-dimensional object shapes can be achieved using this alternative approach after the interpretation concept.

Markov renewal process (MRP) is widely used in communication theory, OR, physics and so on. This paper is concerned with the mathematically rigorous construction of the stationary MRP with finite states on the whole time axis. A joint (forward and backward) invariant probability exists uniquely for an irreducible MRP. A stationary MRP on the whole time axis is defined by setting the joint invariant probability at the point of origin and by forming the MRP in the positive direction and the reverse MRP in the negative direction. An elementary proof of the stationarity of the defined process is given by showing directly that any finite-dimensional distribution is invariant under the shift of time. The proof of the existence and uniqueness of the joint invariant probability is also presented. Once the stationarity of the defined MRP is established, various stochastic processes generated thereof can easily be shown to be stationary as well.

The convolutional coding combined with continuous phase modulation (CPM) is well known for its good tradeoff between coding gain and bandwidth. On the other hand, the multi-h modulation i.e., the scheme in which plural modulation indices are in cyclically use, is also introduced to obtain the higher power efficiency. However the study of the combination of convolutional coding multi-h scheme is not reported yet. In this study, we consider the combination of convolutional coded CPM with multi-h modulation to achieve larger Euclidean distance. We found that, in some cases, our proposed convolutional coded multi-h CPM can give considerable gains compared with those of conventional single-h scheme.

There exist two basic methods to interconnect n processors under the condition where the relation among each processor and its directly connected neighboring processors is perfectly regular: 1-dimensional and multi-dimensional topological connections. This paper treats three types of general topological connections, and investigates the optimal connections with a smaller number of data transmission steps. It is concluded that two kinds of them have a smaller number of data transmission steps and the smallest number of data transmission steps depends on the number n.

This paper presents queueing analysis methods for mixed loss and delay systems. The queueing models considered here are an extension of the previously analyzed models and are applicable to the Facsimile Intelligent Communication System (FICS). First, assuming compound Poisson arrivals and a single server, an exact result for performance measures of the model is obtained by the supplementary variable technique. Second, assuming general batch arrivals and many servers, a diffusion process approximation with the elementary return boundary is developed. A new recursive scheme for the steady-state distribution of the number of customers in the system is derived. Some numerical examples are provided and compared with exact and simulated results, which demonstrate the accuracy of the approximation.

The M(m)/M/K and M(m)/M/ models with synchronous fluctuation of traffic intensity are considered. The phase process is assumed to make changes according to an irreducible m-phase Markov chain. In contrast to the model with asynchronous fluctuation of parameters, phase changes may occur in synchronization with an arrival or beginning of a customer's service. We study mainly the steady-state regime of our models, and observe that, in general, closed form solutions for the limiting probabilities are difficult to obtain but their numerical computation is rather straightforward. We give a necessary and sufficient condition for the steady-state to be attained. For the model M(m)/M/K, it is shown that, for the case where the traffic intensity of one phase is greater than one (even if the average traffic intensity is less than one) the average queue length approaches infinity as the fluctuations among phases gets more sluggish. However, for the case where the traffic intensity for all phases is less than one, the queue length is moderate and not dependent as much on the rate of fluctuation among phases. Numerical examples are given and discussed. Finally, we point out that, our models may be more tractable than the asynchronous ones, when we try to generalize them to the case of general inter-arrival, service, or sojourn time distribution.

The two-dimensional spatial image transmission characteristics of the optical graded-index fiber with a refractive index distribution including fourth and sixth order terms in the core region are investigated. Since the GRIN fiber for image transmission has a large core radius, the most field is tightly confined to the center of the core. The effect of the core-clad interface on the image transmission characteristics is approximately evaluated. Therefore the GRIN fiber is assumed to have an infinitely-extended index profile. The propagation constants and the electric field distributions in the core region are strongly affected by the coefficient of the fourth order term, D4, but, are only slightly affected by the sixth order term. The optimum value of D4 is found to be 0.8, because the deviation of the difference between the propagation constants of the two consecutive modes becomes minimum. For the graded-index fiber with D40.8, the on-axis and off-axis transmission characteristics show that the two dimensional image can be transmitted for a length of more than 50 m and the beam waist of the output image becomes 1.3 times of that of the input for spatial impulse image signal.

The shortest path from some vertex v to some other vertex w in edge weighted graph G(V, E, W) is the path from v to w with the minimum distance. Shortest path problem is defined to be the problem of finding the shortest path in G(V, E, W). In this paper a different version of shortest path problem is considered. The length of a path is defined to be the number of edges in the path here. The problem considered in this paper is the average length of the shortest paths in G(V, E, W) with non-negative edge distances. It is proved that the upper bound of the average length of a shortest path in G(V, E, W) is O(log N) when G(V, E, W) is a complete graph with N vertices and the distances associated to the edges in G are identically distributed on [0, 1] mutually independent random variables. A concept called shortest path spanning tree that is used in proving the upper bound is also given. Combining with an appropiate data structure, the upper bound proved in this paper implies that there is a shortest path enquiry system with response time O(log N) at the cost of O(N2) space requirement.

This letter describes design and performance of a multicore fiber connector with a plastic-molded ferrule. Discussing ferrule fabrication errors, the connector loss and crosstalk were evaluated. The constructed connector for joining and fanouting multimode two-core fibers showed an insertion loss of 0.4 dB and a crosstalk of less than 35 dB.

Introducing temperature-dependent terms into the propagation constant and its derivatives, and extinction coefficient of a core material of optical fiber, the equation of pulse propagation in a multimode fiber is derived, allowing us to evaluate the temperature dependence of a pulse waveform such as the peak-intensity, the pulse duration or width and the pulse delay-time at the peak as a function of ambient temperature. Using the weighting function for higher order modes in the above equation, the theoretically calculated waveforms are compared with the mode-locked He-Ne 3.39 µm laser pulses propagated through As-S fiber over the range from room temperature to 220, being in good agreement each other.