The UWB (ultra-wideband) pulse radar is a promising candidate as an environment measurement method for rescue robots. Radar imaging to locate a nearby target is known as an ill-posed inverse problem, on which various studies have been done. However, conventional algorithms require long computational time, which makes it difficult to apply them to real-time operations of robots. We have proposed a fast radar imaging algorithm, the SEABED algorithm, for UWB pulse radars. This algorithm is based on a reversible transform, BST (Boundary Scattering Transform), between the target shape and the observed data. This transform enables us to estimate target shapes quickly and accurately in a noiseless environment. However, in a noisy environment the image estimated by the SEABED algorithm is degraded because BST utilizes differential operations. We have also proposed an image stabilization method, which utilizes the upper bound of the smoothness of received data. This method can be applied only to convex objects, not to concave ones. In this paper, we propose a fractional BST, which is obtained by expanding the conventional BST, and an image stabilization method by using the fractional BST. We show that the estimated image can be stabilized regardless of the shape of target.

In this paper, we describe a novel focusing mechanism that uses a varifocal mirror and its application to measuring the shape of solder bumps arrayed on an LSI package board based on the shape-from-focus technique. We used a copper-alloy mirror deformed by a piezoelectric actuator as a varifocal mirror to build a simple yet fast focusing mechanism. The varifocal mirror was situated at the focal point of the image-taking lens in image space so that the lateral magnification was constant during focusing and an orthographic projection was perfectly established. The focused plane could be shifted along the optical axis with a precision of 1.4 µm in a depth range of 1.3 mm by driving the varifocal mirror. A magnification of 1.97 was maintained during focusing. Evaluating the curvature of field and removing its effect from the depth data reduced errors. The shapes of 208 solder bumps, 260 µm high and arrayed at a pitch of 500 µm on the board, were measured. The entire 10 mm10 mm board was segmented into 34 partly overlapping sections. We captured 101 images in each section with a high-resolution camera at different focal points at 15 µm intervals. The shape of almost the entire upper hemisphere of a solder bump could be measured. The error in measuring the bump heights was less than 12 µm.

A novel UWB system for a new indoor short distance radio-communication is examined. Various types of UWB systems have been proposed in the literature. Particularly direct sequence (DS) systems and time hopping (TH) systems are attractive due to low power consumption and a simple transceiver construction. In this paper, we consider to apply modulated and modified Hermite pulses (MMHP) for both DS-UWB and TH-UWB systems. Furthermore, MMHP are extended to a novel pulse set referred as limited bandwidth MMHP set in order to reduce various interferences. It is composed of pseudo-orthogonal pulses that have both good auto-correlation characteristics in all orders and low cross-correlation characteristics between different orders. The proposed pulse set also have some specific notches, which can be used to reduce narrow-band interference (NBI). Additionally, we propose a novel pulse shape hopping that employs the proposed MMHP set. Multi-user interference (MUI) and inter-symbol interference (ISI) can be reduced by such a pulse shape hopping scheme for the DS or TH UWB signal format. Simulation results show significant performance improvements by using the proposed UWB system.

In this paper, we propose a new vertex adjustment method which is based on the size ratio of an object and that of a polygon. In the conventional polygonal approximation methods, the sizes of an object and an approximating polygon are quite different, therefore there are so many error pixels between them. The proposed method reduces the size of error regions by adjusting the size of the polygon to that of an object. Simulation results show outstanding performance of the proposed method.

Nonlinear modeling of complex irregular systems constitutes the essential part of many control and decision-making systems and fuzzy logic is one of the most effective algorithms to build such a nonlinear model. In this paper, a new approach to fuzzy modeling is proposed. The model considered herein is the well-known Sugeno-type fuzzy system. The fuzzy modeling algorithm suggested in this paper is composed of two phases: coarse tuning and fine tuning. In the first phase (coarse tuning), a successive clustering algorithm with the fuzzy validity measure (SCFVM) is proposed to find the number of the fuzzy rules and an initial fuzzy model. In the second phase (fine tuning), a moving genetic algorithm with partial encoding (MGAPE) is developed and used for optimized tuning of membership functions of the fuzzy model. Two computer simulation examples are provided to evaluate the performance of the proposed modeling approach and compare it with other modeling approaches.

UWB pulse radars that offer target shape estimation are promising as imaging techniques for household or rescue robots. We have already proposed an efficient algorithm for a shape estimation method SEABED which is a fast algorithm based on a reversible transform. SEABED extracts quasi wavefronts from received signals with the filter that matches the transmitted waveform. However, the scattered waveform is, in general, different from the transmitted one depending on the shape of targets. This difference causes estimation errors in SEABED. In this paper, we propose an accurate algorithm for a polygonal-target based on scattered waveform estimation. The proposed method is presented first, followed by results of numerical simulations and experiments that show the efficiency of the proposed method.

The mechanism of dark bridge formed with very slow contact separating speed was empirically shown with some discussions from the experimental results which the authors have obtained by using the cantilever system for controlling contact gap. By analyzing the obtained results, we will assume some concept of formation mechanism of dark bridge. Since the thermal effect is inevitable in the bridge formation, this will be inferred from two points; one is the a-spot change at initial state of bridge forming, and another one is the thermal expansion due to bridge current that affects the shape of bridge. This paper will show from these two points the conceptual bridge formation mechanism in case of non-melting state of contact bridge which is called here dark bridge.

Active Shape Model (ASM) has been shown to be a powerful tool to aid the interpretation of images, especially in face alignment. ASM local appearance model parameter estimation is based on the assumption that residuals between model fit and data have a Gaussian distribution. Moreover, to generate an allowable face shape, ASM truncates coefficients of shape principal components into the bounds determined by eigenvalues. In this paper, an algorithm of modeling local appearances, called AdaBoosted ASM, and a shape parameter optimization method are proposed. In the algorithm of modeling the local appearances, we describe our novel modeling method by using AdaBoosted histogram classifiers, in which the assumption of the Gaussian distribution is not necessary. In the shape parameter optimization, we describe that there is an inadequacy on controlling shape parameters in ASM, and our novel method on how to solve it. Experimental results demonstrate that the AdaBoosted histogram classifiers improve robustness of landmark displacement greatly, and the shape parameter optimization solves the inadequacy problem of ASM on shape constraint effectively.

A small microstrip-fed monopole antenna using an L-shaped notch is presented for ultra wideband applications. The proposed antenna, with compact size of 15.521 mm2 including the ground plane, is designed to operate over the frequency band between 3.05 and 10.9 GHz for S11 < -10 dB. Good return loss and radiation pattern characteristics are obtained in the frequency band of interest.

A probe-fed U-shaped cross-sectional antenna with tuning stubs on a U-shaped ground plane is proposed for wideband applications. The bottom of the antenna is etched to form tuning stubs for impedance matching. The simulated results of return loss, co- and cross-polarized patterns are presented and compared with the measured ones. Characteristics of a constructed antenna prototype at the operating frequency show that the antenna has an impedance bandwidth (2:1 VSWR) of 37.44% and average gain level of 8.5 dBi. Good radiation characteristics of the proposed antenna have been obtained that is the cross-polarization level and front-to-back ratio in both E- and H-planes across the large bandwidth are better than 22 dB and 12 dB, respectively.

Recently, researches and developments for measuring and modeling of the human body have been receiving much attention. Our aim is to reconstruct an accurate shape of a human foot from multiple camera images, which can capture dynamic behavior of the object. In this paper, a foot-shape database is used for accurate reconstruction of human foot. By using Principal Component Analysis, the foot shape can be represented with new meaningful variables. The dimensionality of the data is also reduced. Thus, the shape of object can be recovered efficiently, even though the object is partially occluded in some input views. To demonstrate the proposed method, two kinds of experiments are presented: reconstruction of human foot in a virtual reality environment with CG multi-camera images, and in real world with eight CCD cameras. In the experiments, the reconstructed shape error with our method is around 2 mm in average, while the error is more than 4 mm with conventional volume intersection method.

The Japan Aerospace Exploration Agency (JAXA) plans to launch a geostationary satellite called Engineering Test Satellite VIII (ETS-VIII) in FY 2006. In this paper, a microstrip line array antenna, which has a very simple structure, is introduced to radiate a circularly polarized wave aiming at ETS-VIII applications. This antenna consists of a triangular conducting line with its vertexes rounded off, located above a ground plane, with a gap on one of its side to produce a circular polarization. The proposed antenna is analyzed by numerical simulations for a single element as well as for a three elements array configuration and the possibility of beam-switching in the azimuth space is experimentally confirmed in the latter case. It is found that by properly feeding the elements constituting the array antenna, for an elevation angle El = 48in Tokyo area, three beams are created in the conical-cut direction with a minimum gain more than 6.6 dBic and an axial ratio less than 3 dB.

A statistic based algorithm for watermarking 2D vector maps is proposed. Instead of 2D coordinates, a one-dimensional distance sequence extracted from the original map is used as the cover data to achieve the shape-preserving ability. The statistical feature of the cover data is utilized for data embedding. Experiment results indicate the scheme's better performance in invisibility, as well as its robustness to certain attacks.

This paper describes a method of generating F0 contours from natural F0 segmental shapes for speech synthesis. The extracted shapes of the F0 units are basically held invariant by eliminating any averaging operations in the analysis phase and by minimizing modification operations in the synthesis phase. The use of natural F0 shapes has great potential to cover a wide variety of speaking styles with the same framework, including not only read-aloud speech, but also dialogues and emotional speech. A linear-regression statistical model is used to "manipulate" the stored raw F0 shapes to build them up into a sentential F0 contour. Through experimental evaluations, the proposed model is shown to provide stable and robust F0 contour prediction for various speakers. By using this model, linguistically derived information about a sentence can be directly mapped, in a purely data-driven manner, to acoustic F0 values of the sentential intonation contour for a given target speaker.

A network for the detection of an approaching object with simple-shape recognition is proposed based on lower animal vision. The locust can detect an approaching object through a simple process in the descending contralateral movement detector (DCMD) in the locust brain, by which the approach velocity and direction of the object is determined. The frog can recognize simple shapes through a simple process in the tectum and thalamus in the frog brain. The proposed network is constructed of simple analog complementary metal oxide semiconductor (CMOS) circuits. The integrated circuit of the proposed network is fabricated with the 1.2 µm CMOS process. Measured results for the proposed circuit indicate that the approach velocity and direction of an object can be detected by the output current of the analog circuit based on the DCMD response. The shape of moving objects having simple shapes, such as circles, squares, triangles and rectangles, was recognized using the proposed frog-visual-system-based circuit.

The shape-based routing needs a routing architecture with a geometrical computation framework on it. This paper introduces a novel routing architecture, Oct-Touched Tile (OTT), with a geometrical computation method along the horizontal- and vertical-constraints. The architecture is represented by the tiles spreading over the 2-D plane. Each tile is flexible to satisfy the constraints imposed for non-overlapping and sizing request. In this framework, path finding and shape-based sizing are executed on the same architecture. In experiments, our system demonstrates the performance comparable to a commercial tool. In addition, we show potential of OTT by introducing several ideas of extensions to analog layout constraints.

In this paper, we propose a novel virtual display system for a real object surface by using a video projector, so that the viewer can feel as if digital images are printed on the real surface with arbitrary shape. This system consists of an uncalibrated camera and video projector connected to a same PC and creates a virtual object by rendering 2D contents preserved beforehand onto a white object in a real world via a projector. For geometry registration between the rendered image and the object surface correctly, we regard the object surface as a set of a number of small rectangular regions and perform geometry registration by calculating homographies between the projector image plane and the each divided regions. By using such a homography-based method, we can avoid calibration of a camera and a projector that is necessary in a conventional method. In this system, we perform following two processes. First of all, we acquire the status of the object surface from images which capture the scene that color-coded checker patterns are projected on it and generate image rendered on it without distortion by calculating homographies. After once the projection image is generated, the rendered image can be updated if the object surface moves, or refined when it is stationary by observing the object surface. By this second process, the system always offers more accurate display. In implementation, we demonstrate our system in various conditions. This system enables it to project them as if it is printed on a real paper surface of a book. By using this system, we expect the realization of a virtual museum or other industrial application.

To develop human interfaces such as home information equipment, highly capable word learning ability is required. In particular, in order to realize user-customized and situation-dependent interaction using language, a function is needed that can build new categories online in response to presented objects for an advanced human interface. However, at present, there are few basic studies focusing on the purpose of language acquisition with category formation. In this study, taking hints from an analogy between machine learning and infant developmental word acquisition, we propose a taxonomy-based word-learning model using a neural network. Through computer simulations, we show that our model can build categories and find the name of an object based on categorization.

The authors propose a system for searching the shape of human hands and fingers in real time and with high accuracy, without using any special peripheral equipment such as range sensor, PC cluster, etc., by a method of retrieving similar image quickly with high accuracy from a large volume of image database containing the complicated shapes and self-occlusions. In designing the system, we constructed a database in a way to be adaptable even to differences among individuals, and searched CG images of hand similar to unknown hand image, through extraction of characteristics using high-order local autocorrelational patterns, reduction of the amount of characteristics centering on principal component analysis, and prior rearrangement of data corresponding to the amount of characteristics. As a result of experiments, our system performed high-accuracy estimation of human hand shape where mean error was 7 degrees in finger joint angles, with the processing speed of 30 fps or over.

In order to study the growth of transferred pips, we operated Ag/SnO212 wt% contacts mounted on an electromagnetic relay in a DC14 V-21 A the resistive circuit as make-only contacts, and took photographs of the transferred pips formed on a cathode surface. In this experiment, the pip shape was different depending on whether the movable contact was the cathode or anode. When the movable contact was the cathode, pip grew high, and became 0.7 mm height at maximum. Sometimes, the pip collapsed. Sticking occurred, when the pip shape became H/Dr0.5 and H/Ga0.5, where H is pip height, Dr is diameter of pip root, and Ga is gap length of open contacts. Judging from this result, we can predict that when a pip grows to H/Dr0.5 and H/Ga0.5, sticking will easily the occur. When the movable contact was the anode, no tall pip was formed, because of pip breakages. Sticking occurred for three samples although the pips grew to H/Dr0.5 and H/Ga0.5. In this case we could not obtain a numerical relationship between of the pip shape and the occurrence of sticking.