A computational model of emotion through the perspective of benevolent agents for a cooperative task

This paper deals with a computational model of emotions and its application for cooperative benevolent agents. A stochastic emotion model based on Markov theory is adapted to perform their well organized tasks to achieve goal. The emotional model consists of four basic emotions: joy, anger, fear and sad. Different emotional behavior is obtained by updating the state transition matrix of stochastic model. Perception of stimuli has an impact on emotion inducing factors and thus, affects on emotion dynamics. With the developed model, a Matlab based simulation is performed to analyze the behavior of the agents with the emotional capability. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

A comprehensive study on development of a small-sized self-propelled robot for bridge inspection

Application of maintenance to ensure the safety, extend the service life and reduce the life-cycle cost of civil structures is important. In this paper, a new inspection method is proposed using a robot which can effectively approach target sections of structures, such as areas that are either too narrow or too dangerous to approach and perform both visual and detailed inspection with various devices. The small-sized self-propelled robot was initially developed. The test model can freely move on the surfaces of various types of structures. Next, the function to detect the deterioration of concrete or steel surfaces by attached cameras to the robot was examined. Moreover, a function was installed to identify the location of the robot automatically using a phase-only correlation method and to determine structural behaviours using an accelerometer. Finally, the applicability of robotic movement and all installed functions was tested on an existing bridge.     

Three-dimensional laparoscope based on the manipulation of polarized light by a cellophane half-wave plate

A three-dimensional laparoscope that can capture three-dimensional images during surgery is reported. The principle is solely based on the manipulation of polarized light by a cellophane half-wave plate rather than computer processing; hence there is no time delay (it operates in real time) and lesions are viewed in true color, which is important for diagnostics. Three-dimensional images are obtained with a single laparoscope. A unique feature of this three-dimensional laparoscope is that it includes a virtual ruler to measure distances without physically touching the affected areas. The structure is simple, sturdy, lightweight, and its diameter is no bigger than a standard 10 mm diam laparoscope.     

An automatic parking system using an optimized image-based fuzzy controller by genetic algorithms

An automatic parking system of a car-like mobile robot is an important issue in commercial applications. An image-based fuzzy controller for an automatic parking system of a car-like mobile robot was developed in previous work, where the membership functions were tuned by experimentally. The aim of this paper is to optimize the parameters of the membership functions, which were performed in previous work, using a genetic algorithm against the complicated tuning of the controller. The details of GA implementation, such as the design parameters and choice of fitness function, are described. Simulation results illustrate the effectiveness of the developed schemes.     

A Neuro-interface with fuzzy compensator for controlling nonholonomic mobile robots

This paper describes a control method for mobile robots represented by a nonlinear dynamical system, which is subjected to an output deviation caused by drastically changed disturbances. We here propose some controllers in the framework of neuro-interface. It is assumed that a neural network (NN)-based feedforward controller is construcetd by following the concept of virtual master-slave robot, in which a virtual master robot as a feedforward controller is used to control the slave (i.e., actual) robot. The whole system of the present neuro-interface consists of an NN-based feedforward controller, a feedback PD controller and an adaptive fuzzy feedback compensator. The NN-based feedforward controller is trained offline by using a gradient method, the gains of the PD controller are to be chosen constant, and the adaptive fuzzy compensator is constructed with a simplified fuzzy reasoning. Some simulations are presented to confirm the validity of the present approach, where a nonholonomic mobile robot with two independent driving wheels is assmued to have a disturbance due to the change of mass for the robot.     

Control of Underactuated Manipulators using Fuzzy Logic Based Switching Controller

This paper introduces a new concept for designing a fuzzy logic based switching controller in order to control underactuated manipulators. The proposed controller employs elemental controllers, which are designed in advance. Parameters of both antecedent and consequent parts of a fuzzy indexer are optimized by using evolutionary computation, which is performed off-line. Design parameters of the fuzzy indexer are encoded into chromosomes, i.e., the shapes of the Gaussian membership functions and corresponding switching indices of the consequent part are evolved to minimize the angular position errors. Such parameters are trained for different initial configurations of the manipulator and the common rule base is extracted. Then, these trained fuzzy rules can be brought into the online operations of underactuated manipulators. 2-DOF underactuated manipulator is taken into consideration so as to illustrate the design procedure. Computer simulation results show that the new methodology is effective in designing controllers for underactuated robot manipulators.     

Preparation and properties of Lanthanum lead zirconate titanate thin films by hydrothermal method

Abstract

Ferroelectric polycrystalline Lanthanum lead zirconate titanate (abbreviated to PLZT) thin films with perovskite structure were prepared by hydrothermal method. Ferroelectric polycrystalline PLZT thin films with perovskite structure on titanium substrate were obtained at 180°C for 5 hr. The film thickness was easily controlled by repeating hydrothermal method. The densities of the PLZT thin films measured by Archimedes’ method were lower than those of ceramics. We fabricated bimorph-type bending actuators using these thin films and analyzed the displacement induced by the electric field. The actuators were bent by applied voltage without poling, because the polar axis in the as-deposited these thin films were aligned in the direction from the thin films surface to the substrate. The dielectric constant of these films were about 600 at room temperature for 1 kHz.     

Xylanase-Resistant Xylan In Unbleached Kraft Pulp

A water-soluble chromophoric xylanase-resitant xylan fraction (LF-D) was separated from a hardwood unbleached kraft pulp (UKP) after hydrolysis with a cellulase/ xylanase-membrane bioreactor. LF-D contained over 70% unremovable inorganic atoms including Si, Na, and S, together with a β-1,4- linked xylan. A nucleus exchange reaction and a nitrobenzene oxidation showed that LF-D contained a trace amount of a lignin component abundant in quinoid structures which had been partly demethylated during the course of kraft pulping. On the other hand, a higher molecular weight residual lignin fraction (HF-P), which was obtained from an impermeable part of the enzymatic digests, was found to have a diphenylmethane structure. LF-D was partially decolorized by Coriolus versicolor and bacterial microflora without action of extracellular lignin peroxidase, Mn-peroxidase, laccase or xylanase.     

New chitin-based polymer hybrids, 4: soil burial degradation behavior of poly(vinyl alcohol)/chitin derivative miscible blends

Soil burial degradation behavior of miscible blend systems of poly(vinyl alcohol) (PVA)/partially deacetylated chitin (1), PVA/chitin-graft-poly(2-methyl-2-oxazoline) (2), and PVA/chitin-graft-poly(2-ethyl-2-oxazoline) (3) was investigated in comparison with the case of a pure PVA film. The degradation of the blend films was followed by the weight changes, scanning electron microscopic observation, Fourier transform infrared spectroscopy, ¹H-NMR, and size exclusion chromatography analyses. The rate of weight decrease in these PVA/chitin derivative hybrids was higher than that of control PVA in the soil burial test. Fourier transform infrared spectra of the recovered samples of the blends showed an apparent increase of the absorption intensity due to β-diketone structure in PVA, which reflects the progress of biodegradation of PVA by PVA-oxidizing enzymes. Scanning electron microscopic observation revealed that these blend films were degraded by bacteria and actinomycetes. The triad tacticity and number-average molecular weight of PVA in the hybrids after soil burial determined by ¹H-NMR and size exclusion chromatography, respectively, were almost the same as those before soil burial. These results suggested that enzymatic degradation of the hybrid films occurred mainly on the surface and that degradation of the PVA-based samples in the soil was accelerated by blending the chitin derivatives. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1171–1179, 1999