In this paper, we briefly review the recent research on CMOS gigahertz-rate communication circuits. Then, we describe design innovations we have made to overcome limitations on communication speed. Using 0. 25-µm CMOS technology, we developed a 4.25-Gb/s Fibre Channel transceiver that features an asynchronous tree-type 1 : 8 demultiplexer and an 8-bit-to-10-bit frequency-conversion architecture. And using 0. 15-µm CMOS technology, we developed an 11. 8-GHz frequency divider that introduces the novel idea of a hysteresis-controlled latch (HC-latch). With these results, we discuss high-speed LSI design issues and future prospects.

The reconstruction of motion and structure from multiple images is fundamental and important problem in computer vision. This paper highlights the recovery of the camera motion and the object shape under some camera projection model from feature correspondences especially the epipolar geometry and the factorization method for mainly used projection models.

In this article we present a survey of medical image processing with the stress on applications of image generation and pattern recognition / understanding to computer aided diagnosis (CAD) and surgery (CAS). First, topics and fields of research in medical image processing are summarized. Second the importance of the 3D image processing and the use of virtualized human body (VHB) is pointed out. Thirdly the visualization and the observation methods of the VHB are introduced. In the forth section the virtualized endoscope system is presented from the viewpoint of the observation of the VHB with the moving viewpoints. The fifth topic is the use of VHB with deformation such as the simulation of surgical operation, intra-operative aids and image overlay. In the seventh section several topics on image processing methodologies are introduced including model generation, registration, segmentation, rendering and the use of knowledge processing.

In this paper, the authors present general views of computer vision and image processing based on optimization. Relaxation and regularization in both broad and narrow senses are used in various fields and problems of computer vision and image processing, and they are currently being combined with general-purpose optimization algorithms. The principle and case examples of relaxation and regularization are discussed; the application of optimization to shape description that is a particularly important problem in the field is described; and the use of a genetic algorithm (GA) as a method of optimization is introduced.

In this paper, the generalized learning vector quantization (GLVQ) algorithm is applied to design a hand-written Chinese character recognition system. The system proposed herein consists of two modules, feature transformation and recognizer. The feature transformation module is designed to extract discriminative features to enhance the recognition performance. The initial feature transformation matrix is obtained by using Fisher's linear discriminant (FLD) function. A template matching with minimum distance criterion recognizer is used and each character is represented by one reference template. These reference templates and the elements of the feature transformation matrix are trained by using the generalized learning vector quantization algorithm. In the experiments, 540100 (5401 100) hand-written Chinese character samples are used to build the recognition system and the other 540100 (5401 100) samples are used to do the open test. A good performance of 92.18 % accuracy is achieved by proposed system.

A new dynamic programming (DP) based algorithm for monotonic and continuous two-dimensional warping (2DW) is presented. This algorithm searches for the optimal pixel-to-pixel mapping between a pair of images subject to monotonicity and continuity constraints with by far less time complexity than the algorithm previously reported by the authors. This complexity reduction results from a refinement of the multi-stage decision process representing the 2DW problem. As an implementation technique, a polynomial order approximation algorithm incorporated with beam search is also presented. Theoretical and experimental comparisons show that the present approximation algorithm yields better performance than the previous approximation algorithm.

In this paper, we discuss the problem of active training data selection for improving the generalization capability of a neural network. We look at the learning problem from a function approximation perspective and formalize it as an inverse problem. Based on this framework, we analytically derive a method of choosing a training data set optimized with respect to the Wiener optimization criterion. The final result uses the apriori correlation information on the original function ensemble to devise an efficient sampling scheme which, when used in conjunction with the learning scheme described here, is shown to result in optimal generalization. This result is substantiated through a simulated example and a learning problem in high dimensional function space.

Wavelength Division Multiplex (WDM) photonic networks are expected as key for global communication infrastructure. The accurate measurement methods for AWG-MUX/DMUX are desirable for WDM network design. We measured a transfer function matrix of an AWG-MUX to find that polarization mode dispersion (PMD) and polarization dependent loss (PDL) shows the bandpass characteristics, which may limit the maximum size and the bit rate of the system. These bandpass characteristics of PMD and PDL are reproduced by a simple AWG-MUX model: The phase constant difference of 0.5% between orthogonal modes in arrayed waveguides is sufficient to obtain the measured passband characteristics of PMD and PDL. We find phase distribution difference between two orthogonal modes in the arrayed waveguide grating gives arise to complex PMD.

Wavelength Division Multiplex (WDM) photonic networks are expected as key for global communication infrastructure. The accurate measurement methods for AWG-MUX/DMUX are desirable for WDM network design. We measured a transfer function matrix of an AWG-MUX to find that polarization mode dispersion (PMD) and polarization dependent loss (PDL) shows the bandpass characteristics, which may limit the maximum size and the bit rate of the system. These bandpass characteristics of PMD and PDL are reproduced by a simple AWG-MUX model: The phase constant difference of 0.5% between orthogonal modes in arrayed waveguides is sufficient to obtain the measured passband characteristics of PMD and PDL. We find phase distribution difference between two orthogonal modes in the arrayed waveguide grating gives arise to complex PMD.

A pipelined architecture is proposed for the normalized least mean square (NLMS) adaptive digital filter (ADF). Pipelined implementation of the NLMS has not yet been proposed. The proposed architecture is the first attempt to implement the NLMS ADF in the pipelined fashion. The architecture is based on an equivalent expression of the NLMS derived in this study. It is shown that the proposed architecture achieves a constant and a short critical path without producing output latency. In addition, it retains the advantage of the NLMS, i. e. , that the step size that assures the convergence is determined automatically. Computer simulation results that confirm that the proposed architecture achieves convergence characteristics identical to those of the NLMS.

The hybrid electrical/optical multi-chip integration technique for optical modules for optical network system has been developed. Employing the technique, a 44 broadcast-and-select type optical matrix switch module has been realized. The module consists of four sets of silica waveguide 1 : 4 splitters/4 : 1 combiners, four 4-channel arrays of polarization insensitive semiconductor optical amplifiers with spot-size converters as optical gates, printed wiring chips for electrical wiring and single mode fibers for optical signal interface on planar waveguide platform fabricated by atmospheric pressure chemical vapor deposition. All the gates and the wiring chips were mounted precisely onto the platform at once in flip-chip manner by self-align technique using AuSn solder bumps. Coupling loss between the waveguide and the SOA gate was estimated to be 4.5 dB. Averaged fiber-to-fiber signal gain, on-off ratio and polarization dependent loss for each of the signal paths was 7 dB 2 dB, more than 40 dB and 0.5 dB, respectively. High speed 10 Gb/s photonic cell switching as short as 2 nsec has been successfully achieved.

State of the arts on guided-wave optical switch arrays are reviewed. In this paper, electro-optic Ti:LiNbO3 devices are mainly described in comparison with crosspoint switch element structures and switch array architectures. Packaging technologies and stability problems are discussed for practical system applications. Recent development on other materials such as semiconductor waveguides, thermo-optic glass/polymer waveguides are also reviewed briefly.

The frequency-offset estimation of a wireless asynchronous transfer mode (ATM) modem based on the orthogonal frequency division multiplexing (OFDM) is discussed. For burst synchronization operating under the time-division multiple access (TDMA) medium access control (MAC), an OFDM preamble using a multistage frequency-offset estimation technique is proposed and shown to have a good accuracy with a large estimation range. And also an averaged decision-directed channel estimation (ADDCE) technique suitable for burst data is proposed.

To enhance the extinction ratio (ER) of NRZ-to-inverted-RZ converter based on cross-gain compression of a semiconductor optical amplifier (SOA), a modified terahertz optical asymmetric demultiplexer (TOAD) is cascaded. ER is improved from 1.6-6.7 dB to 5.4-14.5 dB, depending on the intensity of input optical NRZ signal. The proposed NRZ-to-inverted-RZ converter enhances and regulates ER to a high value (14.5 dB) for very wide optical NRZ signal intensity range.

Spot-size-converter integrated semiconductor optical amplifiers have been developed as gate elements for optical switch matrices. An S-shape waveguide has been introduced to prevent re-coupling of unguided light to the output fiber. An angled-facet structure effectively suppressed light reflection at the end facets. Consequently, a high extinction ratio of 70 dB and a high fiber-to-fiber gain of 20 dB were achieved. Sufficient optical coupling characteristics to a flat-ended single-mode fiber with a coupling loss of 3.5 dB were also demonstrated.

In this paper, we present an efficient approach for technology scaling of MOS analog circuits by using circuit optimization techniques. Our new method is based on matching equivalent circuit parameters between a previously designed circuit and the circuit undergoing redesign. This method has been applied to a MOS operational amplifier. We were able to produce a redesigned circuit with almost the same performance in under 4 hours, making this method 5 times more efficient than conventional methods

The hybrid electrical/optical multi-chip integration technique for optical modules for optical network system has been developed. Employing the technique, a 44 broadcast-and-select type optical matrix switch module has been realized. The module consists of four sets of silica waveguide 1 : 4 splitters/4 : 1 combiners, four 4-channel arrays of polarization insensitive semiconductor optical amplifiers with spot-size converters as optical gates, printed wiring chips for electrical wiring and single mode fibers for optical signal interface on planar waveguide platform fabricated by atmospheric pressure chemical vapor deposition. All the gates and the wiring chips were mounted precisely onto the platform at once in flip-chip manner by self-align technique using AuSn solder bumps. Coupling loss between the waveguide and the SOA gate was estimated to be 4.5 dB. Averaged fiber-to-fiber signal gain, on-off ratio and polarization dependent loss for each of the signal paths was 7 dB 2 dB, more than 40 dB and 0.5 dB, respectively. High speed 10 Gb/s photonic cell switching as short as 2 nsec has been successfully achieved.

State of the arts on guided-wave optical switch arrays are reviewed. In this paper, electro-optic Ti:LiNbO3 devices are mainly described in comparison with crosspoint switch element structures and switch array architectures. Packaging technologies and stability problems are discussed for practical system applications. Recent development on other materials such as semiconductor waveguides, thermo-optic glass/polymer waveguides are also reviewed briefly.

To enhance the extinction ratio (ER) of NRZ-to-inverted-RZ converter based on cross-gain compression of a semiconductor optical amplifier (SOA), a modified terahertz optical asymmetric demultiplexer (TOAD) is cascaded. ER is improved from 1.6-6.7 dB to 5.4-14.5 dB, depending on the intensity of input optical NRZ signal. The proposed NRZ-to-inverted-RZ converter enhances and regulates ER to a high value (14.5 dB) for very wide optical NRZ signal intensity range.

Spot-size-converter integrated semiconductor optical amplifiers have been developed as gate elements for optical switch matrices. An S-shape waveguide has been introduced to prevent re-coupling of unguided light to the output fiber. An angled-facet structure effectively suppressed light reflection at the end facets. Consequently, a high extinction ratio of 70 dB and a high fiber-to-fiber gain of 20 dB were achieved. Sufficient optical coupling characteristics to a flat-ended single-mode fiber with a coupling loss of 3.5 dB were also demonstrated.