Codevelopmental learning between human and humanoid robot using a dynamic neural-network model.

This paper examines characteristics of interactive learning between human tutors and a robot having a dynamic neural-network model, which is inspired by human parietal cortex functions. A humanoid robot, with a recurrent neural network that has a hierarchical structure, learns to manipulate objects. Robots learn tasks in repeated self-trials with the assistance of human interaction, which provides physical guidance until the tasks are mastered and learning is consolidated within the neural networks. Experimental results and the analyses showed the following: 1) codevelopmental shaping of task behaviors stems from interactions between the robot and a tutor; 2) dynamic structures for articulating and sequencing of behavior primitives are self-organized in the hierarchically organized network; and 3) such structures can afford both generalization and context dependency in generating skilled behaviors.     

process and mechanism of growth of YBa2Cu3O6+x single crystal by the pulling method

Continuous growth of YBa₂Cu₃O_6+x(Y123) single crystals was achieved by the modified pulling method1 using BaO+CuO(3:5) solvent and Y₂BaCuO₅(Y211) solute. Y211 solid was placed at the bottom of the crucible. Temperature was set ten degrees higher at the bottom than on the surface of the solution. The crystal rotation speed was 120 rpm at first; but as the crystal radius increased, it was reduced to prevent increasing the interface temperature. The maximum crystal growth rate was about 0.2 mm/h. The crystal growth direction was controlled by the seed crystal direction.2 Two-dimensional numerical simulation was performed using a finite-difference method by a supercomputer to investigate the solution flow and temperature distribution.     

Accidental printing effect of magnetic recording tapes using ultrafine particles of acicular γ-Fe2O3

Five kinds of acicular γ-Fe2O3powder of which axial length varies from 0.17 to 0.80 μm with almost the same axial ratio are manufactured. The variance of coercive force and printing effect as the average axial length of the particles varies is shown. Coercive force of which particle axial length is about 0.35 μm shows maximum value. The printing effect increases according to the decrease of axial length. The printing effect increases with contacting time. The temperature dependence of coercive force and remanent magnetization are measured from 25 to 200°C. These two properties decrease as the temperature increases, but the decreasing inclination becomes steeper as the axial length is smaller. The relationship between the printing effect and the decreasing inclination of coercive force is nearly linear. From the temperature dependence of the printing effect, the activation energy of the printing effect can be calculated. The activation energy of the smallest particle is about 0.05 eV and the others are about 0.15 eV. This measured activation energy is discussed in connection with the relaxation equation.     

Successful treatment of a giant bulla by thoracoscopic excision and laser ablation

A 39-year-old male complaining of shortness of breath on mild exertion. Radiographs revealed that a giant bulla occupied more than half the area of the right lung field. Thoracoscopic excision of the giant bulla was performed using some autosutures. After the emphysematous lesion was consolidated by laser ablation, it was sutured using PDS thread. The bulla in the left lung was similarly excised 3 weeks after the first procedure. The FEV1.0% improved from 72% to 89% after excision and laser ablation of a giant bulla and bullae. Thoracoscopic excision and laser ablation of a giant bulla appears to be an effective alternative to conventional thoracotomy.     

Enhancement of extracellular glutamate scavenge system in injured motoneurons

An increase in glutamine synthetase (GS) mRNA expression after peripheral motor nerve injury was demonstrated by differential display PCR using single arbitrary primer coupled with in situ hybridization screening called in situ display. Differential display PCR was carried out to compare differences in mRNA expression between axotomized (6 h after the transection) and normal hypoglossal nuclei in mice. Several gene fragments were increased after nerve injury; one was identified as GS. Subsequent emulsion autoradiography of hybridization tissue sections revealed that the increase in GS mRNA was observed in injured motoneurons. As GS is a key enzyme participating in the metabolism of the major excitatory neurotransmitter glutamate, we examined the significance of increased GS expression on glutamate-uptake kinetics. GS-transfected human embryonic kidney cells showed an up-regulation in glutamate-uptake kinetics. Therefore, newly expressed GS together with an increased expression of the neuronal glutamate transporter EAAC1 in the injured motoneurons accelerates glutamate uptake. The present results may suggest that the glutamate-uptake system involving the neuronal glutamate transporter and GS in injured neurons is enhanced so as to provide resistance against neurotoxic glutamate accumulation during the early process of nerve regeneration.     

Fulminant myasthenia gravis manifested after removal of anterior mediastinal tumor

Myasthenia gravis developed in a 35-year-old man after removal of an encapsulated anterior mediastinal tumor that was preoperatively diagnosed as a teratoma based on a computed tomographic image. Postoperative pathologic diagnosis of the excised tumor was thymoma. The patient was in crisis after the initiation of immunosuppressive treatment. The therapy was changed to immunoadsorbent perfusion therapy because of concurrent severe pneumonia and an extremely high serum concentration of anti-acetylcholine receptor antibodies. Respiratory support was necessary for 2 months after reoperation.     

Effects of silicon content,thickness and heat treatment on iron loss properties of high silicon electrical steel sheets

The magnetic properties of high-silicon steel sheets ranging in thickness from 0.35 to 0.03 mm and silicon content from 3 to 7.5 percent is investigated. The minimum iron losses are obtained with the silicon higher than 6.5 percent at the high-frequency range over 30 kHz. The sheet thickness dependency index m is estimated. The heat treatment effects to soft magnetic properties also are studied.     

On the texture of γFe2O3particles in magnetically and mechanically oriented magnetic tape

The degree of preferred orientation in magnetic recording tape was investigated by an X-ray pole figure technique and by measuring magnetic properties. Acicular γFe2O3particles dispersed in PVA film were oriented by mechanical stretching and magnetic orientation. The pole figures of these samples indicated the texture with [110] to the orientating direction. The degree of orientation in stretched film was much higher than in magnetically oriented film. Further, it was observed that the particles tend to align uniaxially in mechanical orientation, and biaxially in magnetic orientation.     

Magnetic Properties and Workability of 6.5% Si Steel Sheet Manufactured by Siliconizing Process

1. IntroductionIt is well known that increasing the St content improves the soft magnetic properties of St steel sheet.Steel sheet containing about 6.5% St exhibits excelledssoft magnetic properties. However, increasing the St.content makes the steel brittl.11]. A steel containingmore than 4.5% St has no elongation at room temperature, and a thin sheet cannot be made by coldrolling.Recently, the siliconning method to manufacture6.5% St steel sheet has been developedl2]. As a result,6.5% St…