Wavelength division multiplexed (WDM) routed optical networks represent the direction towards future high-capacity wide-area network applications. A serious issue in WDM-routed networks, though, is light-path allocation which requires a combination of optical routing and wavelength assignment. While near-optimal-routing and wavelength-assignment algorithms aimed at minimizing network wavelength requirements have been reported, the practicability of wavelength-routed optical networks depends on the number of wavelengths required to satisfy a given traffic demand. In this paper, we proposed two symmetrical routing and wavelength-assignment methods for optical networks with a Grid or ShuffleNet physical topology. Here, we consider the case of non-adaptive wavelength routing systems, where the operations performed in nodes are independent of the network traffic load. In this case, the routing differs somewhat from that in adaptive routing networks where the routing function may produce different results at different times. The path followed by a wavelength never changes in non-adaptive wavelength-routing networks. When all N(N-1) node-pairs are to be connected, our methods lower the wavelength requirement to (or close to) its calculated minimum. Symmetry is a basic feature of both these regular topologies, but there are differences in the features within the topologies. Our goal has been to try to make use of the symmetry, and the differences in the native symmetry features, of these regular topologies to yield a lower wavelength requirement.

Polyurea thin films containing azo-based nonlinear optical (NLO) chromophore were prepared by co-deposition of 4,4'-diphenylmethane diisocyanate and 2,4-diamino-4'-nitroazobenzene monomers using the ionization-assisted method. The co-deposited film reacted to form polyurea after annealing in the air. The dichroic optical absorption spectra indicated the preferential orientation of dipole moments in the as-deposited film. The substrate bias voltage influenced the optical anisotropy. Maker fringe measurement showed that the films have NLO activity without the poling process.

This paper introduces the concept of hierarchical testability of data paths for delay faults. A definition of hierarchically two-pattern testable (HTPT) data path is developed. Also, a design for testability (DFT) method is presented to augment a data path to become an HTPT one. The DFT method incorporates a graph-based analysis of an HTPT data path and makes use of some graph algorithms. The proposed method can provide similar advantages to the enhanced scan approach at a much lower hardware overhead cost.

The understanding of instruction set usage in typical DOS/Windows applications plays a very important role in designing high performance x86 compatible microprocessors. This paper presents the tools to such analysis, the analysis results, and their implications on the design of a RISC-based superscalar processor for efficient x86 instruction execution. The analyzed results are used to optimize the execution of frequently executed instructions and micro operations.

It have been one open and significant topic for real-time applications to enhance the processing-speed of Boltzmann machines for long time. One effective way of solution of this problem is the augmentation of probability of neurons' state move. In this paper, a novel method, called a rejectionless method, was proposed and introduced into the Boltzmann machines for this augmentation. This method has a feature of independence on the ratio of neurons' state move. The efficiency of this method for speed-up was confirmed with the experiments of TSP and graph problem.

This paper proposes a new blocking artifact reduction algorithm using an adaptive filter based on classifying the block boundary area. Generally, block-based coding, such as JPEG and MPEG, introduces blocking and ringing artifacts to an image, where the blocking artifact consists of grid noise, staircase noise, and corner outliers. In the proposed method, staircase noise and corner outliers are reduced by a 1D low-pass filter. Next, the block boundaries are divided into two classes based on the gradient of the pixel intensity in the boundary region. For each class, an adaptive filter is applied so that the grid noise is reduced in the block boundary regions. Thereafter, for those blocks with an edge component, the ringing artifact is removed by applying an adaptive filter around the edge. Finally, high frequency components are added to those block boundaries where the natural characteristics have been lost due to the adaptive filter. The computer simulation results confirmed a better performance by the proposed method in both the subjective and objective image qualities.

This paper studies the anticontrol problem of making a continuous-time system chaotic by using impulsive control. The controller is designed to ensure the controlled orbit be bounded and, meanwhile, the controlled system have positive Lyapunov exponents, which are achieved near a stable limit cycle of the system. One illustrative example is given.

This paper presents a child verb learning model mainly based on syntactic bootstrapping. The model automatically learns 4-5-year-old children's linguistic knowledge of verbs, including subcategorization frames and thematic roles, using a text in dialogue format. Subcategorization frame acquisition of verbs is guided by the assumption of the existence of nine verb prototypes. These verb prototypes are extracted based on syntactic bootstrapping and some psycholinguistic studies. Thematic roles are assigned by syntactic bootstrapping and other psycholinguistic hypotheses. The experiments are performed on the data from the CHILDES database. The results show that the learning model successfully acquires linguistic knowledge of verbs and also suggest that psycholinguistic studies of child verb learning may provide important hints for linguistic knowledge acquisition in natural language processing (NLP).

We proposed the conduction mechanism of organic light-emitting diode (OLED) using a one-dimensional discontinuous model. We assumed that each emitting molecule corresponds to a hopping site according to the actual charge transfer between adjacent molecules. Both carrier mobility of Alq3 and barrier heights for each carrier were derived from experimental data. We calculate transient behavior of carrier, field, and exciton distribution. Both carrier injections assumed the Schottky injection. In the previous results, when we assumed that calculated current density fit the experimental one in the current density field curve, calculated light-emission intensity did not fit the experimental one in the light-emission field curve. Furthermore, the slope of the calculated light emission-field curve is too small to fit the experimental one. In the previous study, hopping distance was assumed to be 1 nm. In this study, it is assumed to be 1.7 nm. We consider that field dependence of electron injection is too weak to explain only the Schottky emission. When the electron injection is assumed to be both Schottky emission and Fowler-Nordheim emission calculated light-emission field as well as the current-density field curves were fit to the curve of each experimental characteristics.

It has been known that the cell loss ratio (CLR) characteristics of the multiplexed traffic depend on the arrangement of I-picture starting times of individual variable bit rate (VBR) MPEG video sources. In this paper, we propose a simple yet accurate traffic model for the multiplexed VBR MPEG video to calculate the CLR at an ATM multiplexer when the arrangement of the I-picture starting times of individual sources is given. In the proposed model, in order to represent the arrangement of the I-picture starting times, each picture type (I-, P-, or B-picture) of individual source is modeled by the arrival rate histogram, and the multiplexed video traffic is modeled by the convolution of the arrival rate histograms of the pictures that comprise the multiplexed traffic. Using the proposed traffic model, we propose an analytical method to calculate the CLR of the multiplexed VBR MPEG video at an ATM multiplexer. Simulation results show that the proposed method can calculate the CLR more precisely and efficiently than other existing methods.

An efficient algorithm is proposed for the adaptive sizing of a tracking window in correlation-based video tracking. Since a tracking window specifies a support region when estimating a target displacement, the ability to adapt the window size relative to a moving target significantly influences the performance of video tracking. The basic strategy of the proposed algorithm is to maintain the occupancy rate of the target in the tracking window within a specified range. As such, the proposed algorithm measures the occupancy rate using the ratio of the power of the spatial gradients in the edge subwindows, which edge the tracking window, to that in the tracking window. In addition, the level of any complex background and additive white noise is also evaluated to reduce their effect on the gradients. Experimental results using various artificial and real sequences confirm that the proposed algorithm can effectively adjust a tracking window to a moving target and is robust to a complex background and noise.

This paper presents a formal verification method based on logic simulation. In our method, some restricted class of circuits which include data paths can be verified without abstraction of data paths by using symbolic values. Our verifier extracts a transition relation from the state graph (given as a specification) which is expressed using symbolic values, and verifies based on simulation using those symbolic values if the circuit behaves correctly with respect to each transition of the specification. If the verifier terminates with "correct," then it can be guaranteed that for any applicable input vector sequence, the circuit and the specification behaves identically. We have implemented the proposed method on a Unix workstation and verified some FIFO and LIFO circuits by using it.

This paper presents a new DSP-oriented code optimization method to enhance performance by exploiting the specific architectural features of digital signal processors. In the proposed method, a source code is translated into the static single assignment form while preserving the high-level information related to loops and the address computation of array accesses. The information is used in generating hardware loop instructions and parallel instructions provided by most digital signal processors. In addition to the conventional control-data flow graph, a new graph is employed to make it easy to find auto-modification addressing modes efficiently. Experimental results on benchmark programs show that the proposed method is effective in improving performance.

This paper proposes a fast method for the calculation of exponential B-splines sampled at regular intervals. This algorithm is based on a combination of FIR and IIR filters which enables a fast decomposition and reconstruction of a signal. When complex values are selected for the parameters of the exponentials, complex trigonometric functions are obtained. Only the real part of these functions are used for the interpolation of real signals, leading less bandlimited signals when they are compared with the polynomial B-spline counterparts. These characteristics were verified with 1-D and 2-D examples. This paper also discusses the effectiveness of exponential B-splines, when they are applied to image processing.

In this paper, the efficient signal enhancement scheme for an adaptive antenna array under the Nakagami fading channel is proposed. The proposed signal enhancement scheme is the modified linear signal estimator with Toeplitz Matrix Approximation (TMA) method. The underlying principle of the proposed signal enhancement scheme is to reduce a noise component using not only the Lagrangian method of the constrained minimization but also a signal-plus-noise subspace method. TMA is also used to have the theoretical property of noise-free signal. These functions greatly enhance the performance of an adaptive antenna array by removing the all undesired noise effects from the post-correlation received signal. The proposed signal enhancement scheme is applied at the Wiener Maximal Ratio Combining (MRC) method which has been widely used as the conventional adaptive antenna array. Also, we investigated the effect of the power control error (PCE) for the proposed scheme over the Nakagami multipath fading channel. Several computer simulation examples are provided for illustrating the effectiveness of the proposed scheme.

Self-ordered mesoporous silicate films from organic-inorganic compound materials are successfully fabricated into the surface photo voltage (SPV) type gas sensor device as a gas adsorption insulator layer. These kinds of gas sensors device exhibit NO gas sensing property dependent on their mesoporous film structure. We are succeeded in indication about a possibility of mesoporous silicate film for the SPV type gas sensor application.

Wyner and Ziv considered the rate-distortion function for source coding with side information at the decoder (we call the Wyner-Ziv problem). In this paper we show an information-spectrum approach to the Wyner-Ziv problem for general class of nonstationary and/or nonergodic sources with side information at the decoder, where the distortion measure is arbitrary and may be nonadditive. We show that a general formula for the rate-distortion function of the Wyner-Ziv problem for general sources with the maximum distortion criterion under fixed-length coding by using the information spectrum approach.

This paper presents a refined model for the fuzzy logic implementation of an available bit rate (ABR) flow control switch. This refined model is named fuzzy explicit rate (FUER) switch mechanism. FUER switch mechanism is designed to effectively perform congestion control on ABR traffic in asynchronous transfer mode (ATM) networks. The performance of FUER scheme is evaluated against those of two other explicit rate (ER)-based switch mechanisms using simulation in particular local area network (LAN) and wide area network (WAN) environments. On the whole, FUER scheme performs better than the other schemes. Although it has the smallest control parameter set, it is a more efficient and scalable ER-based switch mechanism.

A novel power spectral density accumulation (PSDA) method for estimating the bandwidth of the clutter spectra is proposed, based on a priori knowledge of the shape of the clutter spectra. The comparison of the complexity and the performance between the PSDA method and the general ones is presented. It is shown that the PSDA method is effective for the short-time clutter data in the practical application.

A method for estimating propagation characteristics is described that uses the characteristics of pilot-data-inserted orthogonal frequency division multiplexing (OFDM) signal and is suitable for high-mobility OFDM transmission scheme. Several pilot data are inserted periodically along the frequency axis before the inverse fast Fourier transformation (IFFT) process in the transmitter. At the receiver, the received OFDM signal is correlated with a prepared distinctive OFDM signal in which several pilot data are inserted in the same positions as in the transmitted OFDM symbols and zeros are inserted in the other positions. The propagation characteristics can be estimated precisely and used to cancel any interference caused by delayed waves. Computer simulation shows that this method can estimate the propagation characteristics, which can then be used to cancel the interference caused by delayed waves before the FFT at the receiver under fast multipath fading conditions.