This paper addresses output regulation for nonlinear systems driven by a time varying parameter. The derivative information of the time varying parameter is necessary for the improved regulation performance but it is not readily available in general. In this paper, we propose a velocity estimation of the time varying parameter for use in the control law without amplifying noise signals.

This paper presents a new fuzzy dynamic output feedback controller design technique for the Takagi Sugeno (T-S) fuzzy model with unknown-but-bounded time-varying modeling error. It is shown that the quadratic stabilization problem of the T-S fuzzy modeled system can be converted into an H control problem of the scaled polytopic Linear Parameter Varying (LPV) system. Then, a controller satisfying a prescribed H performance is designed for the stabilization of the T-S fuzzy modeled system.

Today's complicated and heterogeneous telecommunication network environments need fully-integrated, cost-effective, user-friendly management systems. When developing such management systems in distributed environments, many telecommunication companies are carefully adopting CORBA and Java technologies. CORBA technology enables developers to create and manipulate distributed management system components easily while Java technology liberates human users from complicated and proprietary management system interfaces. In this paper, we propose a TMN-based integration framework for distributed network management by combining both CORBA and Java technologies. The framework generalizes a logically-layered architecture from the management agents layer to the user interface layer. It also provides generalized TMN management interfaces using inter-domain gateway systems for coordinating heterogeneous management protocols. By using these interfaces, TMN management function components can be easily constructed as CORBA objects to provide powerful TMN management services to administrators via user-friendly Web browsers. On the basis of this framework, we have designed and implemented a TMN alarm surveillance system which realizes our framework.

We propose a new technique that is able to extract the small-signal equivalent-circuit elements of high electron mobility transistors (HEMTs) without causing any gate degradation. For the determination of extrinsic resistance values, unlike other conventional techniques, the proposed technique does not require an additional relationship for the resistances. For the extraction of extrinsic inductance values, the technique uses the R-estimate, which is known to be more robust relative to the measurement errors than the commonly used least-squares regression. Additionally, we suggest an improved cold HEMT model that seems to be more general than conventional cold HEMT models. With the use of the improved cold HEMT model, the proposed technique extracts the extrinsic resistance and inductance values.

The initial cell search procedure of a terminal in an asynchronous wideband CDMA (WCDMA) system is discussed. The procedure consists of the following steps (not necessarily in this order): chip and frame synchronization; identification and synchronization of the long scrambling code; and determination of the target base station identity. Higuchi et al. proposed a cell search method for such a system. We propose a modification of that scheme which offers substantial terminal complexity reductions with the same performance. The price is a slight increase in delay. Furthermore, we study the impact on performance and complexity for different parameter settings for these methods.

Experiment is reported of enhanced backscattering of light in binary and ternary suspensions of rutile and/or alumina particles. With a conventional CCD camera system for observing the phenomena, the angular line shape and the enhancement factor were agreed with the theoretically predicted curve and value. Observation of the angular distribution scattered at the backscattered direction supported the hypothesis proposed by Pine et al. , in which the transport mean free path of the polydisperse mixture can be expressed in terms of summing its reciprocal values weighted over the particle sizes.

This paper deals with a method of estimating the parameters and the order of a linear system using differential digital filters and the resultant. From the observed signals of the input and output of an objective system, we extract the differential signals from the zero order to an appropriate high order with the same phase characteristics, using several digital filters. On the assumption that the system order is known, we estimate the parameters of the transfer function and evaluate the estimation error bounds. We propose a criterion function generated by the product of the highest order coefficients and the resultant of the numerator and denominator of the estimated transfer function. Applying this criterion function, we can estimate the order of the objective system. The threshold corresponding to this criterion function is evaluated from the deviation in the frequency characteristics of the used differential filters and the error bound of the estimated parameters. In order to demonstrate the propriety of the proposed method, some numerical simulations are presented.

In this paper we propose a heterogeneous agents model that represents speculative dynamics by using the synergetic approach. We consider the markets for three securities (a stock, a bond, and a foreign currency). Each market consists of two typical types of investors: fundamentalists and bandwagon traders. We show the characteristic patterns of speculative prices (speculative bubbles and speculative chaos) which are generated by trading between the fundamentalists and bandwagon traders.

It is an important problem in signal processing, system realization and system identification to find linear discrete-time systems which are consistent with given covariance parameters. This problem is formulated as a problem of finding discrete-time positive real functions which interpolate given covariance parameters. Various investigations have yielded several significant solutions to the problem, while there remains an important open problem concerning the McMillan degree. In this paper, we use more general input-output characteristics than covariance parameters and consider finding discrete-time positive real matrix functions which interpolate such characteristics. The input-output characteristics are given by the coefficients of the Taylor series at some complex points in the open unit disk. Thus our problem is a generalization of the interpolation problem of covariance parameters. We reduce the problem to a directional interpolation problem with a constraint and develop the solution by a state-space based new approach. The main results consist of the necessary and sufficient condition for the existence of the discrete-time positive real matrix function which interpolates the given characteristics and has a limited McMillan degree, and a parameterization of all such functions. These are a contribution to the open problem and a generalization of the previous result.

An approach to an MPEG decoding system with reduced memory capacity will be presented. This method relies on the simple technique of one-dimensional DPCM to recompress reconstructed Macro Block (MB) prior to being stored on frame memory. Simulation results suggest that image quality is subjectively acceptable when using approximately one-half of the memory size required by that of conventional decoder. The degradation in the signal-to-noise ratio introduced by this compression method ranged from 0.1 dB to 0.7 dB for MPEG MP@ML standard test sequences at 4 Mbps. This technique can be implemented to achieve a cost effective MPEG decoder.

In this paper, a new feature which is characterized by the extrema density of 2-D wavelet frames estimated at the output of the corresponding filter bank is proposed for texture segmentation. With and without feature selection, the discrimination ability of features based on pyramidal and tree-structured decompositions are comparatively studied using the extrema density, energy, and entropy as features, respectively. These comparisons are demonstrated with separable and non-separable wavelets. With the three-, four-, and five-category textured images from Brodatz album, it is observed that most performances with feature selection improve significantly than those without feature selection. In addition, the experimental results show that the extrema density-based measure performs best among the three types of features investigated. A Min-Min method based on genetic algorithms, which is a novel approach with the spatial separation criterion (SPC) as the evaluation function is presented to evaluate the segmentation performance of each subset of selected features. In this work, the SPC is defined as the Euclidean distance within class divided by the Euclidean distance between classes in the spatial domain. It is shown that with feature selection the tree-structured wavelet decomposition based on non-separable wavelet frames has better performances than the tree-structured wavelet decomposition based on separable wavelet frames and pyramidal decomposition based on separable and non-separable wavelet frames in the experiments. Finally, we compare to the segmentation results evaluated with the templates of the textured images and verify the effectiveness of the proposed criterion. Moreover, it is proved that the discriminatory characteristics of features do spread over all subbands from the feature selection vector.

We have developed a low-latency, error-correcting-code-(ECC-)adaptable skew-compensation technique, which is needed for high-speed and long-distance parallel optical interconnections. A new frame-coding technique called shuffled mB1C encoding, which requires no clock-rate conversion circuit and no data buffering, and a new skew-measurement method which is suitable for ECC adaptation have been developed for the compensation. Full-digital skew-compensation circuits using these new techniques were able to compensate for a two-clock-cycle skew, even when one transmission channel was removed. The maximum latency for skew compensation was only five clock cycles.

We have developed a low-latency, error-correcting-code-(ECC-)adaptable skew-compensation technique, which is needed for high-speed and long-distance parallel optical interconnections. A new frame-coding technique called shuffled mB1C encoding, which requires no clock-rate conversion circuit and no data buffering, and a new skew-measurement method which is suitable for ECC adaptation have been developed for the compensation. Full-digital skew-compensation circuits using these new techniques were able to compensate for a two-clock-cycle skew, even when one transmission channel was removed. The maximum latency for skew compensation was only five clock cycles.

A novel millimeter-wave on-wafer CAT(Computer-Aided-Testing ) system has been developed for measurement of S-parameters and NF ( Noise figure ). For the S-parameter test system, we have developed a holder setup and installed it in a semi-automatic wafer prober so that the waveguide-based T/R module can be directly connected to a probe-head through fixed waveguides, which feature low insertion loss of less than 2 dB, from 75 GHz to 98 GHz. The accuracy of the developed test system was confirmed by measuring, with this system, a co-planar offset short pattern then comparing measured and simulated results. A good agreement between the measured and calculated, in both return loss and return phase successfully demonstrated the superiority of the system. A W-band NF test system with a system noise of less than 8 dB has been also developed to provide an on-wafer NF measurement capability with an accuracy of 0.3 dB. These S-parameter and NF test systems possess great advantages to achieve high-speed automatic MMIC testing up to W-band.

This paper presents a new approach to computer image generation via three proposed methods for translating the evolution of a Petri net into fractal image synthesis. The idea is derived from the concept of fractal iteration principles in the escape-time algorithm and chaos game. The approach uses a Petri net as a powerful abstract modeling tool for fractal image synthesis via its duality, deadlock, inhibitor arc, firing sequence and marking reachability. The objective of this approach is to enhance the analysis technique of a Petri net and use it as a novel technique for fractal image synthesis. Generating fractal images via the dynamics of a Petri net allows an easy and direct proof for the similarity and correspondence between the dynamics of complex quadratic fractals by the recursive procedure of the escape-time algorithm and the state of a Petri net via a reachability problem. The reachability problem will be manipulated in terms of the dynamics of the fractal in order to generate images via three proposed methods. Validation of our approach is given by discussion and an illustration of some experimental results.

When designing microwave amplifiers, it is the task to select values of the source (input generator) and load reflection coefficients for the transistor, to achieve certain amplifier performance requirements and ensure stability. For unconditionally stable transistors, simultaneous conjugate matching can be achieved using well-known design formulae. Under this condition, the gain is maximised, and the input and output ports are matched. On the other hand when the transistor is conditionally stable, source and load reflection coefficients are selected using graphical design methods, involving gain and stability circles. To eliminate the reliance on graphical techniques, this paper shows the derivation of explicit design formulae that ensure maximum gain for a minimum specified safety margin, with one port matched. In this work, the safety margin is the distance between the chosen source or load reflection coefficient and its respective stability circle. In a production environment, where the circuit and transistor parameters are subject to random variations, the safety margin therefore makes allowance for such variations. This paper shows that the design problem for conditionally stable transistors can be reduced from the selection of values for two complex variables (port terminations) to the selection of the value for just one scalar variable.

High-temperature superconductor (HTS) receiving filter subsystem for mobile telecommunication base station has been developed. An 11-pole HTS filter using YBa2Cu3O7-δ (YBCO) thin films and a low noise amplifier were cooled to 70 K by a small cryocooler. Total noise figure of this subsystem was measured to be 0.5 dB. Furthermore the effect of using the subsystem in the receiver front-end of Code Division Multiple Access (CDMA) cellular base station was investigated. The transmitting power reduction of handy terminal was estimated to be about 35%.

An upper bound on frame error rate (FER) for generalized concatenated convolutional codes (GCCC's) with iterative decoding is presented. The GCCC is a generalized concatenated code which consists of an inner binary convolutional code and outer Reed-Solomon codes. The FER bound is derived from the average weight enumerator of the inner code. We can optimize the configuration of the outer code since the FER bound can be easily computed. Some optimum outer code profiles will be shown. The results show that combination of GCCC and iterative decoding attains fairly small frame error probability (PB 10-13, Eb/N0 = 6 dB) with relatively simple component code (16-state convolutional code and Reed-Solomon code of length 32).

An advanced characterization method for sub-micron DRAM cell transistors has been proposed for the analysis of transistor test structures using memory cell patterns. When the actual memory cell layout is used as a test structure, the parasitic source and drain resistance of the test structure affected conventional transistor parameters such as threshold voltage. To solve this problem, reduced drain current measurement methods have been proposed to suppress the parasitic resistance voltage drop. In these measurements, two new transistor parameters, Vgoff and Vgsat, have been proposed which are related to off-leakage and full writing, respectively. These parameters are found to be good parameters for monitoring DRAM bit failures. A new threshold voltage measurement methodology has also been proposed for test structures with high parasitic resistance.

This paper proposes a traffic-adaptive dynamic routing method, which we have named RAG, for connectionless packet networks. Conventional traffic control methods discard the packets which cause congestion. Furthermore, conventional routing methods propagate control messages all over the network for gathering global topology information, and this causes more congestion. In contrast, RAG estimates traffic conditions all over a network without any communication between nodes and makes the best use of free links so that packets make detours to avoid congestive sites. RAG adopts distributed control based on game theory (non-communication, non-zero-sum, two-person). With RAG, nodes play a packet-forwarding game without any communication with each other, and each node controls ordering and routing of the forwarding packets based on the node's individual payoff table which is dynamically reconstructed by observation of surrounding nodes. Nodes cooperate with each other, except for punishment for disloyalty. Repetition of these local operations in nodes aims at the emergence of the gradual network-global traffic balancing. The results of experiments in comparison with the conventional shortest path first (SPF) routing method show that the throughput is about 1.58 times higher with the new method.