Active adaptation in human-agent collaborative interaction

When a human user interacts with an adaptive agent to achieve human-agent collaboration, active adaptation is considered to be one of the critical characteristics of the agent. In order to investigate the principal features of active adaptation, we developed a human-agent collaborative experimental environment called WAITER (waiter agent interactive training experimental restaurant) and conducted two types of experiments, a Wizard of OZ (WOZ) agent experiment and an autonomous agent experiment. The objective of these experiments is to observe how human users perceive the agents and change their instructions when interacting with adaptive agents. The results indicate that humans can recognize changes in the agent’s actions and change their instruction methods accordingly. This implies that active adaptation of the agents may encourage the adaptation of the human users and help to build an adaptation loop between them. The experimental results also suggest that active adaptation may play an important role in a human-agent collaborative task.     

Capillary rise properties of porous geopolymers prepared by an extrusion method using polylactic acid (PLA) fibers as the pore formers

The geopolymers were prepared from sodium silicate, metakaolinite, NaOH and H₂O at SiO₂:Al₂O₃:Na₂O:H₂O of 3.66:1:1:x, where x = 8–17, and curing temperatures of 70–110 °C. Since the bending strength of the geopolymers was highest (36 MPa) where H₂O/Al₂O₃ = 9 and the curing temperature = 90 °C, these conditions were adopted. The porous geopolymers were prepared by kneading PLA fibers of 12, 20 and 29 μm diameter into the geopolymer paste, at fiber volumes of 13–28 vol%. The resulting paste was extruded using a domestic extruder, cured at 90 °C for 2 days then dried at the same temperature. The PLA fibers in the composites were removed by alkali treatment and/or heating. The highest capillary rise was achieved in the porous geopolymers containing 28 vol% of 29 μm fibers. The capillary rise of this sample, estimated by the equation of Fries and Dryer¹ was 1125 mm.     

Drying behavior of sludge with drying accelerator

Abstract

For fuelization of high moisture content sludge, efficient sludge drying technique using a drying accelerator was investigated. In the experiment, drying accelerator types and drying conditions were changed and the effect of accelerator type and/or drying condition on sludge drying behavior was evaluated by analyzing drying characteristic curve. Depending on drying accelerator type, the addition of drying accelerator did not always exert superiority in drying rate, but sludge with added acrylic resin having low glass transition temperature (DA10) demonstrated significantly enhanced drying rate. Addition of surface activating agent (SAA) instead of resin type drying accelerator also enhanced the sludge drying rate. The highest drying rate was obtained by addition of DA10 and SAA together, and the sludge drying rate has significantly been augmented at the high drying temperature condition.     

Surface modification of titanium oxide in pulse-modulated induction thermal plasma

Recently, it was reported that RF induction plasma of a pulse-modulated operating mode had been successfully generated, for the first time, at a sufficiently high electric power level for materials processing. The unique conditions in the plasma, such as a non-equilibrium situation at the instance of pulse-on and -off and the increase of chemically reactive radical species, as well as the time-dependent change of plasma temperature, is expected to offer the unique physico–chemical conditions necessary for materials processing. As the first step of the work directed to materials processing, the thermal and chemical interactions between plasma and solid materials were examined for both cases of pulse-modulated and continuous modes. Green compacts of titanium dioxide (TiO₂), whose characteristics strongly depend on the formation of lattice defects and the incorporation of hydrogen, were treated in Ar---H₂ plasma of continuous and pulse-modulated generation modes. The oxide disks were placed at the downstream of plasma flow. The sample position and the plasma generation pressure were changed as processing parameters. The plasma-treated specimens were characterized by X-ray diffractometry and the hydrogen content was measured. The plasma treatment gave a thermal effect, rather than a chemical one, on the surface of oxide specimens. The oxides were thermally reduced by the plasma treatment and showed a change of color at the surface, while XRD did not show a change of crystal structure. Comparing specimens treated in the pulse-modulated plasma with those treated in the continuous plasma, the disk specimens had less of a thermal effect on the plasma.     

An engine control systems design for low‐emission vehicles by generalized predictive control based on identified model

Conservation of the environment has become critical to the automotive industry. Recently, requirements for on‐board diagnostic and engine control systems have been strictly enforced. In the present paper, in order to meet the requirements for low‐emission vehicles, a novel method for construction of the air‐fuel ratio (A/F) control system is proposed. The method of construction of the system is divided into two steps. The first step is to design the A/F control system for the engine based on an open loop design. The second step is to design the A/F control system for the catalyst system. The design method is based on generalized predictive control in order to assure robustness to open loop control as well as model uncertainty. The effectiveness of the proposed A/F control system is verified through experiments using full‐scale products. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 169(3): 47–55, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20907     

Characteristics of piezoelectric lead zirconate titanate fourteen-layered detector bombarded with high-energy xenon beam

A radiation detector composed of fourteen lead zirconate titanate (PZT) disks was studied by directly irradiating it using a 400 MeV/n xenon beam while changing the beam intensity and beam pulse duration. The results obtained indicated that the sensitivity of the detector per xenon ion was explicitly dependent on the beam pulse duration. Comparing the sensitivity among PZT detectors with one, fourteen and one hundred layers, it was also found that the sensitivity of the fourteen-layered detector was highest under the experimental conditions.     

Analysis of the photofading of phenylazo-aniline and phenylazo-pyridone disperse dyes on poly(ethylene terephthalate) substrate using the semiempirical molecular orbital PM5 method

The photofading characteristics of six monoazo disperse dyes on polyester fabric upon exposure to a carbon arc in air were analyzed in terms of the reactivity (k₀) towards ¹O₂ and the photosensitivity (f). The photochemical properties of the dyes were estimated by catalytic fading in mixture dyeings of two yellow (pyridone-azo and quinolone-azo) dyes. The k₀ ratios for the componential dyes in the 1:1 mixture dyeings varied with the partner yellow dye, implying that they depend upon the f values and the concentrations of the component dyes as well as the superposition of absorption spectra, and the changes in their concentration, even in the initial stages of fading. The relative k₀ values, as estimated by the sum of the electrophilic frontier densities using the PM5 method were demonstrated experimentally, while taking the influencing factors into consideration. The assumption that the rates of oxidative fading on PET were proportional to the product of two factors of k₀ and f was confirmed as reasonable based on the fading behavior upon exposure to a carbon arc in air of eight disperse azo dyes with a wide range of two factors.     

Study on voltage regulation methods for distribution systems with dispersed generators

Connection of a large number of the dispersed generators to distribution networks is not easy due to various technical considerations. Thus, we have been trying to devise a concept for future electrical distribution systems with many dispersed generators. In this work, it has been considered that each customer's load and each generator's active and reactive power should be controlled in order to stabilize and optimize the networks. Under this consideration, two control methods for future distribution systems are proposed, a cooperative control and an independent control. We have confirmed experimentally that the voltage regulation ability is higher with the cooperative control than with the independent control, especially in cases of an eccentric load profile in a feeder and a heavy load. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 154(4): 16–23, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20246