Recently, biometrics such as a person's fingerprint, face, and voice has come to be used for personal authentication. At present, most biometrics authentication systems depend on verification (one-to-one matching) because such verification takes a short period of time and is expected to provide a quick response. In these systems, however, every single user has to enter an ID number for each authentication session and might feel incovenienced as a result. To improve the operation efficiency, identification (one-to-many matching) is required, but identification is currently assumed to require much more time than verification (i.e., the response time is not practical). After probing these problems, we developed a new method to achieve identification in a short period of time. This method shortens the response time by using a matching score matrix, which is constructed in the enrollment phase. The proposed method is shown to need only about 45 one-to-one matchings to identify data in a database with two thousand fingerprints, a count much less than by conventional methods.

The diffraction of a plane electromagnetic wave by an impedance wedge whose boundary is described in terms of the skew coordinate systems is treated by using the Wiener-Hopf technique. The problem is formulated in terms of the simultaneous Wiener-Hopf equations, which are then solved by using a factorization and decomposition procedure and introducing appropriate functions to satisfy the edge condition. The exact solution is expressed through the Maliuzhinets functions. By deforming the integration path of the Fourier inverse transform, which expresses the scattered field, the expressions of the reflected field, diffracted field and the surface wave are obtained. The numerical examples for these fields are given and the characteristics of the surface wave are discussed.

The genetic algorithm is used to reconstruct the shapes of multiple perfectly conducting cylinders. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an optimization problem. The genetic algorithm is then employed to find out the global extreme solution of the object function. Numerical examples are given to demonstrate the capability of the inverse algorithm. Good reconstruction is obtained even when the multiple scattering between two conductors is serious. In addition, the effect of Gaussian noise on the reconstruction results is investigated.

In this paper, we report on our recent work in designing and developing an optical waveguide and optical integrated circuit for optical BFN in adaptive multibeam array antenna. We introduce a new integrated Ti:LiNbO3 waveguide and prove that it is able to yield large birefringence and birefringence dispersion. We present a new technique using a microwave-modulated optical wave to measure the birefringence in integrated Ti:LiNbO3 optical waveguides. The measuring results show that the new waveguide has a birefringence of 0.08 and birefringence dispersion of 0.05 µm-1 at optical wavelength of 1.55 µm. When the new Ti:LiNbO3 is applied to form a integrated optical waveguide array in optical beamforming network, it is shown that microwave phase shifts within the range of [-180, +180] is achieved by tuning the optical wavelength 10 nm around 1.55 µm.

A new approach for extracting significant characteristic within speech signal for distinct speaker is presented. Based on the multiresolution property of wavelet transform, quadrature mirror filters (QMFs) derived by Daubechies is used to decompose the input signal into varied frequency channels. Owning to the uncorrelation property of each resolution derived from QMFs, Linear Predict Coding Cepstrum (LPCC) of lower frequency region and entropy information of higher frequency region for each decomposition process are calculated as the speech feature vectors. In addition, a hard thresholding technique for lower resolution in each decomposition process is also used to remove the effect of noise interference. The experimental result shows that by using this mechanism, not only effectively reduce the effect of noise inference but improve the recognition rate. The proposed feature extraction algorithm is evaluated on MAT telephone speech database for Text-Independent speaker identification using vector quantization (VQ). Some popular existing methods are also evaluated for comparison in this paper. Experimental results show that the performance of the proposed method is more effective and robust than that of the other existing methods. For 80 speakers and 2 seconds utterance, the identification rate is 98.52%. In addition, the performance of our method is very satisfactory even at low SNR.

Fingerprint recognition is a well-researched problem, and there are several highly accurate systems commercially available. However, this biometric technology still suffers from problems with the handling of bad quality prints. Recent research has begun to tackle the problems of poor quality data. This paper takes a new approach to one problem besetting fingerprints--that of distortion. Previous attempts have been made to ensure that acquired prints are not distorted, but the novel approach presented here corrects distortions in fingerprints that have already been acquired. This correction is a completely automatic and unsupervised operation. The distortion modelling and correction are explained, and results are presented demonstrating significant improvements in matching accuracy through the application of the technique.

This paper discusses an application of fingerprint identification technology to enhanced human-machine interaction, and also to information systems, specifically to a mobile authentication terminal for secure networked services and to digital appliances. A "Fingerprint User Interface (FpUI)," exploits information regarding not only who put a finger on its sensor but which specific finger it was. With this user-friendly interface, a user can assign commands, data objects, status, or personalized settings to individual fingers. A functional architecture for a mobile authentication terminal, "Pocket-PID," with fingerprint identification capability is proposed which features an easy-to-use FpUI and high security, where the identification function is totally enclosed within the unit. This enables a user's identity authenticated without any possibility of actual fingerprint data being disclosed. The Pocket-PID facilitates implementation of networked services based on secure biometric user identification.

Efficient query processing in multi-dimensional indexing structures is an important issue for multimedia data applications. In this paper, we propose incremental k-nearest neighbor query (k-NNQ) and range query algorithms for R-tree based structures. The novel aspect of these algorithms is that they make use of the notion of VP filtering, a concept borrowed from the MVP-tree. The filtering notion allows for delaying of computational overhead until absolutely necessary. By so doing, we attain considerable performance benefits while paying insignificant overhead during the construction of the index structure. We implemented our algorithms and carried out experiments to demonstrate the capability and usefulness of our method. Results show that improvements range from 8% to 23% in response time for the experimental environment that we considered.

A 2-step deposition technique was introduced in the heteroepitaxial growth of barium titanate (BaTiO3) thin films. Heteroepitaxial BaTiO3 films were prepared on a SrRuO3/SrTiO3 substrate by radio frequency (RF) magnetron sputtering with three kinds of deposition method: low RF-power deposition, 2-step deposition, and high power deposition. The crystallographic and ferroelectric properties were evaluated for the heteroepitaxial films. When the epitaxial capacitor was prepared by the 2-step deposition technique, the ferroelectric remanent polarization, 2Pr, was maximized. The optimized deposition condition to improve the crystal quality is discussed in terms of damage and diffusion, which could be introduced into the oxide films during the epitaxial growth, and controlled by the RF-power and deposition time, respectively.

This paper proposes a λ-ring system that is a wavelength-based self-healing-ring application unlike ordinary fiber-based ones. To design survivable networks of interconnected such self-healing ring systems, a virtual mesh network scheme is used, in which wavelength assignment in virtual links can be considered according to the λ-ring-system or fiber-ring-system applications of the bidirectional wavelength-path switched architecture. Integer-programming-based design problems are then formulated that minimize the total fiber length in these self-healing-ring applications. Numerical examples show that the λ-ring-system application is always superior to 4-fiber and 2-fiber-ring-system applications and 1+1 end-to-end path protection.

In future mobile communication systems, forward link may be a limiting one because emerging data services are likely to require higher data rates in the forward link than in the reverse link. In this paper, we derive joint Erlang capacity of a DS/CDMA forward link in terms of both outage probability and blocking probability for each type of traffic in a mixed traffic environment. Resource sharing algorithm and generalized Erlang model are employed to derive joint Erlang capacity of the DS/CDMA system with various types of traffics. The joint Erlang capacity reflecting both outage probability and blocking probability of each type of traffic is obtained by an approach based on virtual circuit switching perspective. We take into account effect of closed loop power control in the analysis. From numerical results, it is confirmed that blocking probability as a QoS (quality of service) parameter has a significant impact on the forward link capacity. The results of this paper can be applied to design of the DS/CDMA systems supporting wireless multimedia traffics.

Effects of imprint on signal margin in FeRAM with Pt/SrBi2Ta2O9/Pt capacitors have been investigated. Imprint, induced during high temperature storage, significantly reduced the signal margin and hence determines lifetime of FeRAM. Initial signal margin of 470 mV is reduced to 290 mV after storage at 175C for 96 hours. From the reduction rate of the signal margin, it is estimated that imprint lifetime of the FeRAM is more than 10 years even though the storage temperature is 175C.

This paper concerns resource planning in a VLSI assembly facility. The facility can process more than 100 sorts of WIPs (Works-In-Process) simultaneously. Specifically it performs product-mix production. An old resource estimation system, which gave a good estimation for a memory VLSI production facility, went wrong for an assembly facility. To adjust the estimation of required machinery resources of the assembly facility, a new parameter--the tuning value for the service time--is introduced. The tuning value expresses the reduction in machine utilization in the processing steps due to the product-mix. The value is empirically determined and the machinery resources can be estimated in good accuracy. Also the waiting time for processing in the incoming buffer is successfully considered in the estimation of turnaround time. However the tuning value is not enough in estimating human resources. A novel algorithm to estimate the resources for machine adjustments is proposed. The algorithm is based on a periodic assignment of multiple sorts of WIPs in a single machine, where the adjustments of machines for the product-mix are considered. The adjustments are additional operator's jobs in the product-mix. It estimates the operator request rate and machine utilization rate when multiple sorts of WIPs with different arrival rates are processed in a single machine. Finally, this resource estimation system considers the operator allocated not only to the preprocessing and postprocessing but also to the adjustments of machines for the product-mix. The estimated machinery, human resources, and turnaround time were evaluated in a real facility, and the proposed method is confirmed to be applicable in the weekly or monthly resource planning for the facility.

In this paper, we propose an efficient linear ordering algorithm for netlist partitioning. The proposed algorithm incrementally merges two segments which are selected based on the proposed cost function until only one segment remains. The final resultant segment then corresponds to the linear order. Compared to the earlier work, the proposed algorithm yields an average of 11.4% improvement for the ten-way scaled cost partitioning.

Various shadows are one of main factors that cause errors in vision based vehicle detection. In this paper, two simple methods, land mark based method and BS & Edge method, are proposed for vehicle detection and shadow rejection. In the experiments, the accuracy of vehicle detection is higher than 98%, during which the shadows arisen from roadside buildings grew considerably. Based on these two methods, vehicle counting, tracking, classification, and speed estimation are achieved so that real-time traffic parameters concerning traffic flow can be extracted to describe the load of each lane.

In this paper, under the assumption that all the eigenvalues of a linear nominal discrete time-delay system lie within a specified ring region, a sufficient condition is proposed to preserve the assumed property when the structured parameter perturbations are added into the linear nominal discrete time-delay system. For the case of eigenvalue-clustering in a circular region, and for the case of not including time delays, the presented sufficient condition is mathematically proved to be less conservative than those reported recently in the literature.

An important goal in communication theory is to construct good minimum squared Euclidean distance (MSED) codes for transmission over additive white Gaussian noise (AWGN) channels. In this paper, a new construction method for the M-ary phase-shift-keyed (M-PSK) codes over the ring structure ZM, the ring of integers modulo M, with a good minimum Euclidean distance, is proposed. The proposed codes are linear when multiple coset leaders are considered. The characteristics and performance levels of the newly constructed codes are analyzed for code length up to n 8. It is found that the proposed codes compare favorably with Piret's codes and Graeffe's method codes on Gaussian channels in terms of decoding complexity, coding gain, and error performance.

We present a new family of algorithms that solve the bias problem in the equation-error based adaptive infinite impulse response (IIR) filtering. A novel constraint, called the constant-norm constraint, unifies the quadratic constraint and the monic one. By imposing the monic constraint on the mean square error (MSE) optimization, the merits of both constraints are inherited and the shortcomings are overcome. A new cost function based on the constant-norm constraint and Lagrange multiplier is defined. Minimizing the cost function gives birth to a new family of bias-free adaptive IIR filtering algorithms. For example, two efficient algorithms belonging to the family are proposed. The analysis of the stationary points is presented to show that the proposed methods can indeed produce bias-free parameter estimates in the presence of white noise. The simulation results demonstrate that the proposed methods indeed produce unbiased parameter estimation, while being simple both in computation and implementation.

Adaptation of software components to the requirements is one of the key concerns in Component Based Software Development (CBSD). In this paper, we propose a formal approach to compose component based systems which are adaptable to the requirements. We focus on the functional aspects of software components and requirements, which are expressed in S-sorted functions. Those S-sorted functions are transformed into Colored Petri Nets (CPN) models in order to evaluate connectivity between the components, and to evaluate adaptability of composed systems to the requirements. The connectivity is measured based on colors or data types in CPN, while the adaptability is measured based on functional equivalency. We introduce simple glue codes to connect the components each other. The paper focuses on business applications, however the proposed approach can be applied to any other domains as far as the functional adaptability is concerned.

Using the chirped grating with temperature control, we demonstrated the adaptive dispersion compensation at 40 Gbit/s RZ transmission. The simple monitoring of the 40 GHz frequency component enables us to automatic control of the adaptive dispersion compensator.