Ultrasound imaging is used in medical applications, as well as various other fields, such as nondestructive inspection and environmental measurement. We have proposed a super-resolution ultrasound imaging method based on multiple transmission and reception with different carrier frequencies. In this methods, it is assumed that array transducers with a sufficient number of elements are used. From the viewpoint of manufacturing cost, it is desirable to have a small number of elements. However, conventional methods tend to generate grating lobes, which negatively affect performance. In the current study, we aimed to develop an approach for avoiding grating lobes by improving on our previous methods, which is a super-resolution method applicable to transducers with a small number of elements.

This paper based on user's questionnaire data to discuss and suggest appearance/function of robotics for older adults. It starts from people's familiar view, particularly makes robot a rule that help people but not let people feel disturb. Questionnaire data are collected as basic data, data analysis and data mining are applied for distinguish people's different needs and situations. The questionnaire includes people's background data and the trend of using electronic equipment, which helps construct different clusters and image of robot. According to user's opinions, the ideal robot/robotics' image can be made, and the possible of useful robot/robotics and its background system is probably to be created. This paper is not only a self-criticism for developed robot and robotic system, but also hoping to provides a new way for researches on developing a better assistant robot for older adults.

Nowadays, people have richer life than hundred years ago. Thus, we have times to notice and consider our life quality. Life quality includes many important factors, which includes food, emotion, exercise amount, etc., and one of the important factors is sleep. We are hard to deny that having a sleepless night seems became a common experience for all of us. This paper discuss an application that focus on support people's daily life using life logs. Life logs means the activities that people takes in their daily life. The research based on exist research results and presents methods to improve current research. The exist application has considered every people's different exercise and life style, thus this paper will focus on people's sleep quality, and how a factors effective people's daily life. Several experiment results will be shown, and some data analysis methods will be discussed. For described the research specifically, an application will be described.

In this paper, the authors present a user-centered concept for the operation experience of human-robot interface. For showing a concrete concept of our research, we design an assistant robot system. There are several stages for developing this system. Firstly, it is to obtain user's data. The authors obtained static data from Internet, and activity data from capturing humans' a motion data. The authors adapt accelerator sensor and image data, to capture human motion. Secondly, the authors use association rule of data mining technique to find the hiding knowledge from user's data. The system can base on the found knowledge, which includes the relation about life patterns, psychological conditions and etc., to provide appropriate assistance. The system mainly includes the following steps: capture user's motion data by accelerator sensor and stereo camera in indoor environment, analysis captured motion data, found the hiding knowledge from user's data, recognize the environment through user's data, and based on these data and knowledge to provide service. In this paper, we design a human-centered assistant system for adapting to human-robot interface. The system not only uses static data, but also activity data using capture methods. We briefly describe the assistant robotic system's overall concept, and discuss the motion captures methods and knowledge finding. Simple experiment results will also be shown.

In recently years, human's life became convenient because various services or assistances supplied. However, because these services are developed for major users, they are provided for users in a uniform manner. The way of service or assistant is not always appropriate, because there always exists some people who are not major users. Thus, sometimes a gap, which exists between the service and user's thought, will appear when a system provides service to users. Hence, the author thought that a system, which is called useful, has to include the ability of understanding user, and more over, being able to change the way of service or assistance like human. Thus, if user models are acquired by a system appropriately, the system will have the ability of serving or assisting a person who is not major user appropriately. And if the user use the system, he will allow use it without learning, and only to behave naturally. In this research, the authors use 3D accelerometer sensor to obtain data and data mining to construct user model. The user models are applied in an assistance system. Here we focus on assisting user in walking and driving a car. The experiment result shows assistance system in which the authors applied user model is effective.

Small vibrations of eyeball, which occur when we fix our gaze on object, is called "fixational eye movements.'' It has been reported that such the involuntary eye movements work also for monocular depth perception. In this study, we focus on "tremor'' which is the smallest type of fixational eye movement, and construct depth perception model based on tremor using MAP-EM algorithm. Its effectiveness is confirmed through numerical evaluations using artificial images.

We propose a new method for recovering a 3-D object shape from an image sequence. In order to recover high-resolution relative depth without using the complex Markov random field (MRF) that includes a line process, we construct a recovery algorithm based on a belief propagation scheme using a multi-scale Bayesian network. With this algorithm, relative 3-D motion between a camera and an object can be determined together with relative depth, and the maximum a posteriori expectation-maximization (MAP-EM) algorithm is effectively used to determine a suitable approximation.

A simple algorithm is proposed for calculating strain directly from a tagged magnetic resonance (MR) image via Moire analysis. Tagged MR images are used to obtain strains in internal organs, particularly myocardial strain. Although signal processing-based analysis has recently been investigated, the reliability of the strain cannot be obtained. In the present paper, a simple, fast, and accurate algorithm is proposed that applies the principle of Moire topography for extracting strains in tissues. The proposed method provides reliability from the tagged image without prior knowledge of regularization.

The expectation-maximization (EM) algorithm with split-and-merge operations (SMEM algorithm) proposed by Ueda, Nakano, Ghahramani, and Hinton (2000) is a nonlocal searching method, applicable to mixture models, for relaxing the local optimum property of the EM algorithm. In this article, we point out that the SMEM algorithm uses the acceptance-rejection evaluation method, which may pick up a distribution with smaller likelihood, and demonstrate that an increase in likelihood can then be guaranteed only by comparing log likelihoods.

Compared with passive methods, the moire/spl acute/ method for restoring three-dimensional shape is advantageous with respect to the stability of the estimated shape and processing time. However, the fundamental problem associated with moire/spl acute/ analysis is that the absolute number of the base fringe cannot be determined directly. Here the authors focus on the method by which the absolute number of the base fringe is determined using shading information. For this method, the conventional approach simply adopts Lambert's reflection model and excludes the specular reflection factor, thus the result tends to differ slightly from the true value. The authors propose a method that uses a reflection model which combines Lambert's and specular reflection. The proposed method gives a result closer to the true value and can also determine optimal relative reflectance. The effectiveness of the proposed method is confirmed by simulation and experiment.

We prove that the maximum likelihood estimator (MLE) for estimating 3-D motion from noisy optical flow is not "optimal". The MLE minimizes the mean square error of the observed optical flow. We show that the MLE's covariance matrix does not reach the Cramer-Rao lower bound, and that there is an unbiased estimator whose covariance matrix is smaller than that of the MLE when a Gaussian noise distribution is assumed for a sufficiently large number of observed points. We propose a new estimator whose covariance matrix is smaller than that of the MLE under certain conditions.>

This paper describes a new objective function for estimating 3-D motion from an optical flow. We construct a generalized Rayleigh-quotient form objective function, which provides an unbiased estimator and whose use drastically reduces the computational cost. This function includes an arbitrary weighting function. We show by numerical evaluations that with a suitable weighting function it provides an estimator whose variance is smaller than that of the maximum likelihood estimator.>

This paper describes a telerobot system and its application to space antenna assembly experiments. In this system, the operator utilizes an Integrated Teleoperation Console to operate multiple arms and cameras from a remote site, employing such system supports as visual guidance, ForcelTorque sensing, interactive user interface, and real-time graphic kzsk simulation. Visual guidance is semi-autonomous in that the robot itself is also capable of interpreting visual information and grasping target objects. In the study, assemblyldisassembly experiments are carried out on an space antenna consisting of a center dish surrounded by eight separate outer antenna segments. The accuracy of visual guidance positioning is evaluated experimentally. Results prove the effectiveness of both the telerobot experiment system and the space antenna structure. investigate this system's potential effectiveness for use in space. The antenna used was a version with improved assembly reliability. The positioning accuracy of the semi- autonomous visual guidance system was first evaluated experimentally, and then multiple segments were assembled and disassembled. In the segment grasping stage of the assembly experiments, the segment holder position was shifted to verify visual guidance. Positioning shifts were intentionally applied to robot motion commands in the assembly stage of the experiments to simulate actual robot motion in space. In spite of these shifts, accurate coupling was successfully achieved and the effectiveness of the system demonstrated.

A high-sample-rate robot controller has been designed to resolve computational requirements in advanced algorithms, such as the computed torque method or various impedance control algorithms. An active stiffness control algorithm for a six-degree-of-freedom manipulation has been implemented on the controller, and a 1 kHz sampling rate has been achieved. The design assumes no specific algorithm and robot configuration, and it is easy to increase the number of drive joints. The controller is equipped with a general-purpose vector/matrix calculation engine, servo drivers, and a 16-bit microcomputer system. The calculation engine, which accelerates hole computation for advanced control methods, is based on a 13.4 MFLOPS single-chip floating-point digital signal processor (DSP). This engine was developed to simplify DSP programming without degrading its high-performance computation capabilities. Basic vector/matrix functions and general functions for scalar value computation are mask ROMed on the DSP chip. The controller construction and calculation engine functions, and their performance, are addressed.>