Flux pining properties of columnar defects nucleated by gold ion irradiation was investigated for DyBCO coated conductor. The energy of irradiated gold ions was 320 MeV and 200 MeV and the matching field was 1.0 and 2...
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Performance of a Bi-2223 superconducting magnet consisted by ten double-pancake coils was improved by using iron plates (SS400) for top and bottom flanges. The magnetic field dependence of the critical current density...
Performance of a Bi-2223 superconducting magnet consisted by ten double-pancake coils was improved by using iron plates (SS400) for top and bottom flanges. The magnetic field dependence of the critical current density of Bi-2223 tape for magnetic field normal to the tape was determined the maximum magnetic field of the magnet. Hence, a reduction of the normal component of the magnetic field to the tape was achieved by using the iron plates. The magnetic field distribution in the magnet was calculated by a finite element method, and the reduction of the normal magnetic field component was confirmed. The maximum magnetic field at the center of the magnet bore reached 1.30 T at 65.0 K of subcooled liquid nitrogen and 0.70 T at 77.3 K. These values were about 1.6 times higher than the previous magnet and agreed well with the calculated result.
The superconducting SmFeAsO1−xFx (x=0.2) polycrystalline bulks were prepared by the powder-in-tube (PIT) method. The magnetic field and temperature dependences of critical current densities in the samples were investi...
The superconducting SmFeAsO1−xFx (x=0.2) polycrystalline bulks were prepared by the powder-in-tube (PIT) method. The magnetic field and temperature dependences of critical current densities in the samples were investigated by resistive and ac inductive (Campbell's) methods. It was found that a fairly large shielding current density over 109 A/m2, which is considered to correspond to the local critical current density, flows locally with the perimeter size similar to the average grain size of the bulk samples, while an extremely low transport current density of about 105 A/m2 corresponding to the global critical current density flows through the whole sample. Furthermore, a unique history dependence of global critical current density was observed, i.e., it shows a smaller value in the increasing-field process than that in the decreasing-field process. The history dependence of global critical current characteristic in our case can be ascribed to the existence of the weak-link property between the grains in SmFeAsO1−xFx bulk.
We describe a unique competition based on the novel concept of robotics and mechatronics products that included evaluation of the products' engineering function and interface design. Seventy-seven students of elev...
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We report noise-controlled electrohydrodynamic pattern formations and threshold shifts in nematic liquid crystals. In the electrohydrodynamic system superposed with noise, experimental results obtained in the dielectr...
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We report noise-controlled electrohydrodynamic pattern formations and threshold shifts in nematic liquid crystals. In the electrohydrodynamic system superposed with noise, experimental results obtained in the dielectric regime are compared to those in the conventional conduction regime. The noise intensity dependences of thresholds and pattern evolution processes are remarkably different for each regime. The pattern formation mechanisms in the presence of noise for both regimes are discussed based on the results. Moreover, it is found that the thresholds and characteristic wavelengths of dissipative structures can be effectively controlled by external multiplicative noises with appropriate intensity and correlation times.
Recently, there are many studies on brain computer interface (BCI) system and some use EEG response at oddball paradigms. The aim of this paper is to extract feature (i.e. P300 response) from the EEG signals to improv...
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Recently, there are many studies on brain computer interface (BCI) system and some use EEG response at oddball paradigms. The aim of this paper is to extract feature (i.e. P300 response) from the EEG signals to improve the spelling system. We propose the method to analyze the averaged EEG signal concerned time and spatial. It is confirmed that the processing period with feature extraction is able to be shortened by averaging multi-channels. Effective information is obtained from the EEG signal near of the center part.
In this paper, we demonstrate how to characterize transactions executed on multi-server systems. The characterization is performed with the help of readily available open source components, and is used to build a mean...
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In this paper, we demonstrate how to characterize transactions executed on multi-server systems. The characterization is performed with the help of readily available open source components, and is used to build a mean value analysis model in order to estimate transaction response times for arbitrary loads, as well as system capacity. Although an e-commerce system is used, the characterization method described is applicable to any multi-server system.
This paper presents our investigation on performance enhancement due to the implementation of low density parity check (LDPC) codes on IEEE 802.11n system and its Application Specific Integrated Circuit design. Simula...
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In response to the need for enhanced user affinity for robots, we are attempting to give robots a "consciousness" such as that identified in humans and animals. We developed software to control a robot's...
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