A uniquely-structured Usage Parameter Control (UPC) method named Virtual-shaping is proposed which considers cell arrival time jitter between user and UPC point. The method uses a modified Dangerous Bridge UPC circuit (Sliding window type) and virtually (logically) shapes cell traffic using cell arrival time compensation to offset cell delay variation (CDV). In addition, the proposed method is based on a cell-buffer-less structure and can be realized with reasonable hardware. The method yields precise and accurate monitoring. Computer simulations show that the method offers higher network utilization than the conventional Leaky Bucket based UPC method. The proposed method will make it possible to create more effective B-ISDNs, and more cost-effective broadband VBR services.

A new gloss-extracting method is proposed in this study. A spatial filter with variable resolution is used for the extraction of glossiness. Various spheres and cylinders with curvature radii from 4 to mm are used as the specimens. In all samples, a strong correlation, with a correlation coefficient of more than 0.98, has been observed between psychological glossiness Gph perceived by the human eye and glossiness Gfm extracted by this method. This method is useful for plane specimens as well as spherical and cylindrical ones.

In this paper, we present a method for extracting the Japanese printed characters from unformatted document images. This research takes into account the multiple general features specific to the Japanese printed characters. In our method, these features are thought of as the constraints for the regions to be extracted within the constraint satisfaction approach. This is achieved by minimizing a constraint function estimating quantitative satisfaction of the features. Our method is applicable to all kinds of the Japanese documents because it is no need of a priori knowledge about the document layout. We have favorable experimental results for the effectiveness of this method.

This paper describes an O(log3n) time O(n/log n) processors parallel algorithm for determining the congruence (exact matching) of two point sets in three-dimensions on a CREW PRAM, where n is the maximum size of the input point sets. Although optimal O(n log n) time sequential algorithms were developed for this problem, no efficient parallel algorithm was known previously. In the algorithm, the original problem is reduced to the two-dimensional congruence problem by computing a three-dimensional point set cps(S) for each input point set S, where cps(S) satisfies the following conditions: 0|cps(S)|12; cps(T(S))T(cps(S)) for all isometric transformations T. The two-dimensional problem can be solved efficiently in parallel using a parallel version of a previously-known sequential algorithm. cps(S) is computed recursively in the following way: the size of a point set is reduced by a constant factor in each recursive step. To reduce the size of a point set, a convex hull is constructed and then it is regarded as a planar graph, so that combinatorial properties of a planar graph are used effectively. A sequential version of the algorithm works in O(n log n) time, so that this paper gives another optimal sequential algorithm. The presented algorithm can be applied for graphs such that each vertex corresponds to a point and each edge corresponds to a line segment connecting its endpoints. Moreover, the algorithm can be modified for computing the canonical form of a point set or a graph.

Circuit design techniques for linearizing adaptively biased differential pairs are described. An emitter-and source-coupled pair is adaptively biased by a squaring circuit to linearize its transconductance, one of whose inputs is divided by resistors. An input signal for a differential pair or a squaring circuit is set to an adequate amplitude by a resistive divider without sacrificing linearity. Therefore, a differential pair is biased by the output current of a squaring circuit and they are coupled directly. There are three design techniques for squaring circuits. One is the transistor-size unbalance technique. Another is the bias offset technique. A third is the multitail technique. The bipolar and MOS squaring circuits discussed in this paper were proposed by the author previously, and consist of transistor-pairs with different transistor size (i.e., the emitter areas or gate W/L values are different), transistor-pairs with the same bias offset, or a multitail cell(i.e., a triple-tail cell or quadritail cell). Several kinds of squaring circuits consisting of such transistor-pairs are applied to produce the quadratic bias currents for compensating the nonlinearity of an emitter-and source-coupled pair. Therefore, four circuits using emitter-coupled pairs with adaptive-biasing current and four circuits using source-coupled pairs with adaptive-biasing current are proposed and analyzed in depth. Furthermore, a circuit configuration for low voltage operation is also introduced and verified with bipolar transistor-arrays on a breadboard.

We study the correspondence between problem descriptions and requirements specification documents derived from them. Based on the results of this investigation, a model that integrates the problem space and the requirements specification space is developed. This integration is based on a semantic network representation. We also propose a model of the requirements elicitation process that is consistent with our empirical studies of traceability in requirements documents. In this process, analysts derived requirements specifications from incomplete and ambiguous problem descriptions given by customers, identify missing information, completed it, and then decide the system boundaries that define which part of the problem descriptions to implement as the target system. The model can be used to complete problem descriptions given by customers and determine the system boundaries.

In the actual sound environmental systems, it seems to be essentially difficult to exactly evaluate a whole probability distribution form of its response fluctuation, owing to various types of natural, social and human factors. We have reported a unified probability density expression in the standard expansion form of Hermite type orthonormal series taking a well-known Gaussian probability density function (abbr. p.d.f.) as the basis for generally evaluating non-Gaussian, non-linear correlation and/or non-stationary properties of the fluctuation phenomenon. However, in the real sound environment, there still remain many actual problems on the necessity of improving the above standard type probability expression for practical use. First, a central point in this paper is focused on how to find a new probabilistic theory of practically evaluating the variety and complexity of the actual random fluctuations, especially through newly introducing an equvivalence transformation toward the standard type probability expression mentioned above in the expansion form of Hermite type orthonormal series. Then, the effectiveness of the proposed theory has been confirmed experimentally too by applying it to the actual problems on the response probability evaluation of various sound insulation systems in an acoustic room.

Switched-capacitor chaotic neurons fabricated in a full-custom integrated circuit are used to investigate the behavior of 2- and 3-neuron chaotic neural networks. Various sets of parameters are used to visualize the dynamical responses of the networks. Hysteresis of the network is also demonstrated. Lyapunov exponents are approximated from the measured data to characterize the state of each neuron. The effect of the finite length of data and the rounding effect of data acquisition system to the computation of Lyapunov exponents are briefly discussed.

First, the necessity of examining the numerical calculation of the Bessel function Jν(x) of complex order ν is explained. Second, the possibility of the numerical calculation of Jν(x) of arbitrary complex order ν by the use of the recurrence formula is ascertained. The rounding error of Jν(x) calculated by this method is investigated next by means of theory and numerical experiments when the upper limit of recurrence is sufficiently large. As a result, it was known that there is the possibility that the rounding error grows considerably when ν is complex. Counterplans against the growth of the rounding error will be described.

This paper deals with an efficient radix-2 divider design theory that uses carry-propagation-free adders based on redundant binary{1, 0, 1} representation. In order to compute the division fast, we look ahead to the next step quotient-digit selection embedded in the current partial remainder calculation. The solution is a function of the four most significant digits of the current partial remainder, when scaling the divisor in the range [1, 9/8). In gate depth, this result is better than the higher radix-4 case without the look-ahead quotient-digit selection and the design is simple.

A graph G is said to be universal for a family F of graphs if G contains every graph in F as a subgraph. A minimum universal graph for F is a universal graph for F with the minimum number of edges. This paper considers a minimum universal graph for the family Fkn of graphs on n vertices with path-width at most k. We first show that the number of edges in a universal graph Fkn is at least Ω(kn log(n/k)). Next, we construct a universal graph for Fkn with O(kn log(n/k)) edges, and show that the number of edges in a minimum universal graph for Fkn is Θ(kn log(n/k)) .

Many combinatorial problems can be efficiently solved for partial k-trees (graphs of treewidth bounded by k). The edge-coloring problem is one of the well-known combinatorial problems for which no NC algorithms have been obtained for partial k-trees. This paper gives an optimal and first NC parallel algorithm to find an edge-coloring of any given partial k-tree with bounded degrees using a minimum number of colors. In the paper k is assumed to be bounded.

A low power bus architecture with Local and Global Charge-Recycling Bus (Local-CRB and Global-CRB) techniques, featuring virtual stacking of the individual bus-capacitance and the dummy capacitor into a series configuration between supply voltage and ground, has been proposed. These Local and Global CRB schemes make it possible to reduce not only each bus-swing but also a total equivalent bus-capacitance of the ultra multi-bit buses running in parallel. The voltage swing of each bus is given by the recycled charge-supplying from the upper adjacent bus capacitance or the dummy capacitor, instead of the power line. The dramatical power reduction was verified by the simulated and measured data. According to these data, if employing the combination of those CRB schemes in a practical chip, the ultra-high data rate of 25 Gb/s can be achieved while maintaining the power dissipation to be less than 300 mW at Vcc3.6 V for the bus width of 512 bit with the bus-capacitance of 14 pF per bit operating at 50 MHz.

We investigated performance of routing schemes in B-ISDN, for heterogeneous traffic flows under various bandwidths. In particular, we compared the simulated performance of these schemes by evaluating their blocking probabilities. To achieve high performance, these schemes use special kinds of routing algorithm, one which is pre-selection algorithm and one which is cyclic algorithm. We investigated the efficiency of the pre-selection algorithm and the robustness of the cyclic algorithm for nonuniform traffic and network resources. We found that these routing algorithm schemes can compensate for errors in resource design.

This paper proposes a novel updating technique, dynamically updating, for achieving extension or modification of functions in a distributed system. Usual updating technique requires synchronous suspension for multiple processes for avoiding unspecified reception caused by the conflict of different versions of processes. Thus, this technique needs very high overhead and it must restrict the types of distributed systems, to which it can be applied, to RPC (remote procedure call) type or client-server type. Using the proposed dynamically updating technique, updating management can be invoked asynchronously by each process with assurance of correct execution of the system, i.e., the system can cope with the effect of unspecified reception caused by mixture of different version processes. Therefore, low overhead updating can be achieved in partner type distributed systems, that is more general type including communications systems or computer networks. Dynamically updating technique is implemented by using a novel distributed algorithm that consists of group communication, checkpoint setting, and rollback recovery. By using the algorithm proposed in this paper, rollback recovery can be achieved with the lowest overhead, i.e., a set of checkpoint determines the last global state for consistent rollback recovery and a set of processes that need to rollback simultaneously is the smallest one. This paper also proves the correctness of the proposed algorithm.

We propose a new concept of network dimensioning, which is based not only on the grade of service but also on profit. In traditional network dimensioning methodology, the number of circuits on links is designed under a cost-minimization concept with grade of service constraints. Recently, telecommunication markets have become very large and competitive; therefore, we believe that a profit viewpoint is now essential. However, it is difficult to calculate profit in almost all the dimensioning methods currently used, because they mainly employ peak-hour traffic data, while profit depends on all the hourly traffic data which contain both peak and off-peak data. In this paper, we propose using all the hourly traffic data in network dimensioning. From these data and telephone charges for each hour, revenues will be estimated. On the other hand, facility costs will be estimated from the number of circuits. Finally, we can estimate profit from the difference between revenues and facility costs. Focusing on both quality and profits in network dimensioning leads to more advanced quality management and quality control in telecommunications networks than with traditional methodology. This paper outlines a dimensioning method based on profit, and describes its properties, some applications of it, and summarizes further studies.

This paper proposes a practical training algorithm for artificial neural networks, by which both the optimally pruned model and the optimally trained parameter for the minimum prediction error can be found simultaneously. In the proposed algorithm, the conventional information criterion is modified into a differentiable function of weight parameters, and then it is minimized while being controlled back to the conventional form. Since this method has several theoretical problems, its effectiveness is examined by computer simulations and by an application to practical ultrasonic image reconstruction.

Calls using different media which require different transfer quality will arrive at ATM networks. Therefore it is important to develop a method for allocating network resources efficiently to individual calls by judging admission of calls. Various call admission control schemes have been already proposed, and these schemes assume that users specify values of traffic descriptors when they originate calls. However, it is sometimes difficult for users to specify these values accurately. This paper proposes a new ATM call admission control scheme based on cell transfer state monitoring which does not require that users specify values of traffic descriptors in detail when they originate calls. In this proposed scheme, the acceptance or rejection of calls is judged by comparing the monitored cell transfer state value with a threshold prepared in advance. This threshold must be adjusted according to changes in the characteristics of traffic applied to ATM networks. This is one of the most serious problems in the control scheme based on the monitoring of cell transfer state. Herein, this paper proposes neural network application to the control scheme in order to resolve this problem and improve performance. In principle, the threshold can be adjusted automatically by the self-learning function of the neural network, and the control can be maintained appropriately even if the characteristics of traffic applied to ATM networks change drastically. In this paper, the effectiveness of the application of a neural network is clarified by showing the configuration of this proposed control scheme with the neural network, a method for deciding various parameter values needed to implement this control scheme, and finally the results of a performance evaluation of the control scheme. Inputs required by the neural network are also discussed.

A number of flexible control mechanisms used in buffer management, congestion control and bandwidth allocation have been proposed to improve the performance of ATM networks by introducing parameters, such as threshold, push-out probability and incremental bandwidth size of a virtual path, which are adjustable by network providers. However, it is difficult to adaptively adjust these parameters, since the traffic in ATM networks is further complicated by accommodating various kinds of services. To overcome the problem, we propose in this paper a control scheme based on the genetic algorithms and the neural estimator. The neural estimator forecasts the future QOS values for each candidate parameter set, and the genetic algorithms select the best one to control the real network. An example of buffer management in an ATM switch is examined in this paper. Simulation results show the effectiveness of the proposed control scheme in adaptively adjusting the parameter set even when the traffic environment and the QOS requirements are dynamically changing.

The recent progress of B-ISDN signaling systems has enabled networks to handle calls which require a wide variety of ATM connection sets. This paper is concerned with the circuit group which handles calls requesting asymmetric forward and backward multi-connections, and has the capability of both bandwidth negotiation and bandwidth reservation as a traffic control for enhancing call blocking performance. A model of the circuit group is first established focusing on the call level characteristics of the group, and then a method based on the reduced load approximation and an approximate analysis of a multirate group is proposed for calculating approximate blocking probabilities. The accuracy of the approximation method is evaluated numerically by comparing with an exact method and simulation. Further the impact of bandwidth negotiation and reservation on call blockings is examined based on numerical examples.