It is widely recognized that IP-based mobile network will be a dominant trend. For mobile IP networks, the address starvation problem and scalable mobility management for mobile nodes are important issues. In order to cope with these issues, we propose an approach to realize mobile IP network supporting private addresses for mobile nodes. Our approach introduces regional registration of mobile nodes (Hierarchical Mobile IPv4) and coordinates NAT and DNS functions with the Mobile IP protocol. It enables a mobile node to be assigned a global address temporally in a visited network and to accept a call initiated by a correspondent node connected to the global IP network. This paper describes the detailed design of our approach and the implementation of proposed procedures based on the Mobile IPv4 software developed by the CMU Monarch project.

In content-based image retrieval (CBIR), the content of an image can be expressed in terms of different features such as color, texture, shape, or text annotations. Retrieval methods based on these features can be varied depending on how the feature values are combined. Many of the existing approaches assume linear relationships between different features, and also require users to assign weights to features for themselves. Other nonlinear approaches have mostly concentrated on indexing technique. While the linearly combining approach establishes the basis of CBIR, the usefulness of such systems is limited due to the lack of the capability to represent high-level concepts using low-level features and human perception subjectivity. In this paper, we introduce a Neural Network-based Image Retrieval (NNIR) system, a human-computer interaction approach to CBIR using the Radial Basis Function (RBF) network. The proposed approach allows the user to select an initial query image and incrementally search target images via relevance feedback. The experimental results show that the proposed approach has the superior retrieval performance over the existing linearly combining approach, the rank-based method, and the BackPropagation-based method.

We have developed a novel human facial tracking system that operates in real time at a video frame rate without needing any special hardware. The approach is based on the use of Lie algebra, and uses three-dimensional feature points on the targeted human face. It is assumed that the roughly estimated facial model (relative coordinates of the three-dimensional feature points) is known. First, the initial feature positions of the face are determined using a model fitting technique. Then, the tracking is operated by the following sequence: (1) capture the new video frame and render feature points to the image plane; (2) search for new positions of the feature points on the image plane; (3) get the Euclidean matrix from the moving vector and the three-dimensional information for the points; and (4) rotate and translate the feature points by using the Euclidean matrix, and render the new points on the image plane. The key algorithm of this tracker is to estimate the Euclidean matrix by using a least square technique based on Lie algebra. The resulting tracker performed very well on the task of tracking a human face.

Techniques for human-motion recovery are applicable to a variety of areas, such as sports, dancing, virtual reality, and video-game production. The people who work in this area focus their attention on recovering information on the motion of individuals rather than groups of people. It is important to demonstrate the possibility of recovering descriptions of the 3-D motion in team sports, since such information is able to provide us with a variety of information on the relations among players. This paper presents a new experimental result on 3-D motion recovery from a team sport. The result was obtained by a non-rigid shape recovery technique based on images from uncalibrated cameras. The technique was applied to recovering the 3-D motion of the players in a mini-basketball game which was played in a gymnasium. Some attention is focused on the analysis of the players' motion. Satisfactory results were obtained.

As a new category of the optical application system integrated with electronics, the opto-electronic information system (OEIS) is presented. Combination of the different characteristic technologies, optics and electronics, is expected to be useful for development of an effective and high-performance information systems. The properties of the optical technologies such as parallelism, high-speed, and large information capacity can be utilized for information processing. Even if some of the functions are emulated by the electronics, the optics give more effective solutions. To implement the OEIS, various optoelectronic devices and fabrication technologies are available including vertical cavity surface emitting lasers and spatial light modulators. There are two forms of system construction for the OEIS: an application of optics to an electronic-based system and the reversed form. As examples of the OEIS, the parallel matching architecture (PMA) and the thin observation module by bound optics (TOMBO) are presented. The PMA is an architecture of parallel computing system specified for global processing. This architecture shows a typical strategy to utilize the optical interconnection capability with flexibility of the electronic technology. The TOMBO presents possibility of morphological conversion using combination of the optical and electronic technologies. A compound-eye imaging system and post digital processing enable us to realize a very thin image capturing system. The issues related on development of the OEIS are proper usage of optics, effective fusion of the optical and electronic technologies, methodologies for system construction, fabrication supporting tools, and development of attractive demonstrators other than communication and interconnection fields.

Antialiased is one of challenging problems to be solved for the high fidelity image synthesis in 3D graphics. In this paper a rasterization processor which is capable of single-pass full-screen antialiasing is presented. To implement a H/W accelerated single-pass antialiased rasterization processor at the reasonable H/W cost and minimized processing performance degradation, our work is mainly focused on the efficient H/W implementation of a modified version of the A-buffer algorithm. For the efficient handling of partial-pixel fragments of the rasterization phase, a new partial-pixel-merging scheme and a simple and efficient new dynamic memory management scheme are proposed. For the final blending of partial-pixels without loss of generality, a parallel subpixel blender is introduced. To study the feasibility of the proposed rasterization processor as a practical rasterization processor, a prototype processor has been designed using a 0.35 µm EML technology. It operates 100 MHz @3.3 V and has the rendering performance from 25M to 80M pixel-fragments/sec depending on the scene complexity.

The smart vision chip has a large potential for application in general purpose high speed image processing systems. In order to fabricate smart vision chips including photo detector compactly, we have proposed the application of three dimensional LSI technology for smart vision chips. Three dimensional technology has great potential to realize new biologically inspired systems inspired by not only the biological function but also the biological structure. In this paper, we describe our three dimensional LSI technology for biologically inspired circuits and the design of smart vision chips.

The recent progress of the performance of a CMOS-LSI is rapid and continuous, and the required bandwidth for communication between chips will be enormous. Dense optical interconnects by smart pixels may be used to such an application because it would have enough bandwidth and short delay of signaling. On-chip and chip-to-chip optical interconnects and electrical interconnects were compared and the advantages of the use of optics were indicated. For on-chip communication, high-speed (70% of the velocity of the light) propagation of signals by optical interconnects are useful and it enables whole chip synchronization. The considerable reduction of power dissipation using optics was estimated for chip-to-chip interconnects. The effect of hybrid integration with small parasitic capacitance was simulated and the sensitivity improvement of more than 13 dB was expected. How to fabricate a smart pixel is the most difficult subject. We had successfully fabricated smart pixels with VCSELs and PDs using polyimide bonding technique. CW lasing of the VCSEL was observed and it proved that the polyimide bonding technique was useful to making smart pixels. The integrated receiver was also fabricated in the same manner. It showed a high sensitivity of -9.2 dBm for a bit-rate of 622 Mbit/s. High-performance characteristics of the receiver resulted from the low parasitic integration with polyimide bonding technique.

In this paper, genetic algorithms is employed to determine the shape of a conducting cylinder buried in a half-space. Assume that a conducting cylinder of unknown shape is buried in one half-space and scatters the field incident from another half-space where the scattered filed is measured. 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 nearly global extreme solution of the object function such that the shape of the conducting scatterer can be suitably reconstructed. In our study, even when the initial guess is far away from the exact one, the genetic algorithm can avoid the local extremes and converge to a reasonably good solution. In such cases, the gradient-based methods often get stuck in local extremes. Numerical results are presented and good reconstruction is obtained both with and without the additive Gaussian noise.

Partially depleted SOI technology with body-tied hybrid trench isolation was developed in order to counteract floating body effects which offers negative impact on the drive current of transistors and the stability of circuit operation while maintaining SOI's specific merits such as high speed operation and low power consumption. The feasibility of this technology and its superior soft error effects were demonstrated by a fully functional 4M-bit SRAM. Its radio frequency characteristics were also evaluated and it was verified that high-performance transistors and passive elements can be realized by the combination of the SOI structure and a high-resistivity substrate. Moreover, its application to a 2.5 GHz digital IC for optical communication was also demonstrated. Thus it was proven that the body-tied SOI devices with the hybrid trench isolation is suitable to realize intelligent and reliable high-speed system-on-a chip integrating various IP's.

Bidirectional reflection distribution functions (BRDFs) of commercially pure titanium sheets with three different kinds of surface morphology were measured. Those experimental BRDFs were analyzed by using Phong's reflection model. Topographic measurements of the specimens' surfaces were performed with using a stylus-method. An explicit microfacet model based on topographic data was proposed. With using the explicit microfacet model and geometrical optics the calculated BRDFs were obtained and then compared with the experimental BRDFs. Both of them were in a good agreement. Through this comparison physical meanings of Phong's reflection model were discussed. We concluded that with using the explicit microfacet model it will be possible to calculate the BRDF of the materials' surface in arbitrary illumination conditions and that this modeling will be useful to develop new aesthetic surface appearance in material industries, computer graphics, architectural design and surface science.

In order to maintain the diversity of structures in the population and prevent premature convergence, I have developed a new genetic algorithm called DCGA. In the experiments on many standard benchmark problems, DCGA showed good performances, whereas with harder problems, in some cases, the phenomena were observed that the search was stagnated at a local optimum despite that the diversity of the population is maintained. In this paper, I propose methods for escaping such phenomena and improving the performance by reinitializing the population, that is, a method called each-structure-based reinitializing method with a deterministic structure diverging procedure as a method for producing new structures and an adaptive improvement probability bound as a search termination criterion. The results of experiments demonstrate that DCGA becomes robust in harder problems by employing these proposed methods.

A lower bound for the generalized Hamming weight of linear codes is proposed. The proposed bound is a generalization of the bound we previously presented and gives good estimate for generalized Hamming weight of Reed-Muller, some one point algebraic geometry, and arbitrary cyclic codes. Moreover the proposed bound contains the BCH bound as its special case. The relation between the proposed bound and conventional bounds is also investigated.

This paper investigates the interference suppression effect from much higher rate dedicated physical channels (DPCHs) of a parallel-type coherent multistage interference canceller (COMSIC) with iterative channel estimation (ICE) by laboratory experiments in the transmit-power-controlled W-CDMA reverse link. The experimental results elucidate that when two interfering DPCHs exist with the spreading factor (SF) of 8 and with the ratio of the target signal energy per bit-to-interference power spectrum density ratio (Eb/I0) of fast transmit power control, ΔEb/I0, of -6 dB (which corresponds to 64 simultaneous DPCHs with SF = 64, i.e., the same symbol rate as the desired DPCH), the implemented COMSIC receiver with ICE exhibits a significant decrease in the required transmit signal energy per bit-to-background noise power spectrum density ratio (Eb/N0) at the average bit error rate (BER) of 10-3 (while the matched filter (MF)-based Rake receiver could not realize the average BER of 10-3 due to severe multiple access interference (MAI)). It is also found that the achieved BER performance at the average BER of 10-3 of the COMSIC receiver with the A/D converter quantization of 8 bits in the laboratory experiments is degraded by approximately 1.0 dB and 4.0 dB compared to the computer simulation results, when ΔEb/I0=-6 dB and -9 dB, respectively, due to the quantization error of the desired signal and path search error for the Rake combiner. Finally, we show that the required transmit Eb/N0 at the average BER of 10-3 of the third-stage COMSIC with ICE is decreased by approximately 0.3 and 0.5 dB compared to that of COMSIC with decision-feedback type channel estimation (DFCE) with and without antenna diversity reception, respectively.

This letter describes a new parallel combinatorial delayed multiplexing CDMA system for high-bit-rates mobile communications. It combines delayed multiplexing and parallel combinatory methods with the CDMA system to provide higher bit rates without the use of complex receivers. The results of computer simulations using the double-spike Rayleigh fading channel model in a multiple-user environment show that its down-link BER performance is the same as that of the conventional multicode system.

Internet access via mobile communications networks is growing rapidly; NTT DoCoMo's Internet access service using cellular phones, known as i-mode and started in February 1999, is no exception. The i-mode service enables the user to send e-mail and access Web sites for a variety of information through simple operation of a mobile terminal equipped with a browser. As a result, the traffic to be carried by the PDC (Personal Digital Cellular)-- Packet mobile communication network, which is used to provide the i-mode service, is also increasing rapidly. To meet this growing demand, the switching systems in place are being either increased in capacity or replaced by more powerful ones. To plan this effectively, it is necessary to make an accurate evaluation of the i-mode processing capacity. We have developed a new method of evaluating processing capacity, which is based on the conventional method but takes account of the characteristics specific to the PDC-Packet network. This paper discusses the method of evaluating the processing capacity of switching systems used in the PDC-Packet mobile network.

Recently, it becomes popular to synthesize new viewpoint images based on some sampled viewpoint images of real scene using technique of computer vision. 3D shape reconstruction in Euclidean space is not necessarily required, but information of dense matching points is basically enough to synthesize new viewpoint images. In this paper, we propose a new method for 3D reconstruction from three cameras based on projective geometry. In the proposed method, three input camera images are rectified based on projective geometry, so that the vertical and horizontal directions can be completely aligned with the epipolar planes between the cameras. This rectification provides Projective Voxel Space (PVS), in which the three axes are aligned with the directions of camera projection. Such alignment simplifies the procedure for projection between the 3D space and the image planes in PVS. Taking this advantage of PVS, silhouettes of the objects are projected into PVS, so that the searching area of matching points can be reduced. The consistency of color value between the images is also evaluated for final determination of the matching point. The finally acquired matching points in the proposed method are described as the surface of the objects in PVS. The acquired surface of the objects in PVS also includes knowledge about occlusion. Finally, images from new viewpoints can be synthesized from the matching points and occlusions. Although the proposed method requires only weak calibration, plausible occlusions are also synthesized in the images. In the experiments, images of virtual viewpoints, which were set among three cameras, are synthesized from three real images.

Recently a high-resolution image that has more than one million pixels is available easily. However, such an image requires much processing time and memory for an image understanding system. In this paper, we propose an integrated image understanding system of multi-resolution analysis and multi-agent-based architecture for high-resolution images. The system we propose in this paper has capability to treat with a high-resolution image effectively without much extra cost. We implemented an experimental system for images of indoor scenes.

The paper proposes a vision-based system for adaptively inferring the interactional intention of a person coming close to a robot, which plays an important role in the succeeding stage of human/robot cooperative handling of works/tools in production lines. Here, interactional intention is ranged in the meaning of the intention to interact/operate with the robot, which is proposed to be estimated by the human head moving path during an incipient period of time. To implement this intention inference capability, first, human entrance is detected and is modeled by an ellipse to supply information about the head position. Second, B-spline technique is used to approximate the trajectory with reduced control points in order that the system acquires information about the human motion direction and the curvature of the motion trajectory. Finally, Hidden Markov Models (HMMs) are applied as the adaptive inference engines at the stage of inferring the human interactional intention. The HMM algorithm with a stochastic pattern matching capability is extended to supply whether or not a person has an intention toward the robot at the incipient time. The reestimation process here models the motion behavior of an human worker when he has or doesn't have the intention to operate the robot. Experimental results demonstrate the adaptability of the inference system using the extended HMM algorithm for filtering out motion deviation over the trajectory.

Complex-valued region-based-coupling image clustering (continuous soft segmentation) neural networks are proposed for interferometric radar image processing. They deal with the amplitude and phase information of radar data as a combined complex-amplitude image. Thereby, not only the reflectance but also the distance (optical length) are consistently taken into account for the clustering process. A continuous complex-valued label is employed whose structure is the same as that of input raw data and estimation image. Experiments demonstrate successfully the clustering operations for interferometric synthetic aperture radar (InSAR) images. The method is applicable also to future radar systems for image acquisition in, e.g., invisible fire smoke places and intelligent transportation systems by generating a processed image more recognizable by human and automatic recognition machine.