4,008 research outputs found
Bio-Artificial Synergies for Grasp Posture Control of Supernumerary Robotic Fingers
A new type of wrist-mounted robot, the Supernumerary Robotic (SR) Fingers, is proposed to work closely with the human hand and aid the human in performing a variety of prehensile tasks. For people with diminished functionality of their hands, these robotic fingers could provide the opportunity to live with more independence and work more productively. A natural and implicit coordination between the SR Fingers and the human fingers is required so the robot can be transformed to act as part of the human body. This paper presents a novel control algorithm, termed “Bio-Artificial Synergies”, which enables the SR and human fingers to share the task load together and adapt to diverse task conditions. Through grasp experiments and data analysis, postural synergies were found for a seven-fingered hand comprised of two SR Fingers and five human fingers. The synergy-based control law was then extracted from the experimental data using Partial Least Squares (PLS) regression and tested on the SR Finger prototype as a proof of concept
Enhanced Polarized Emission from the One-Parsec-Scale Hotspot of 3C 84 as a Result of the Interaction with Clumpy Ambient Medium
We present Very Long Baseline Array polarimetric observations of the
innermost jet of 3C84 (NGC1275) at 43GHz. A significant
polarized emission is detected at the hotspot of the innermost re-started jet,
which is located 1 pc south from the radio core. While the previous
report presented a hotspot at the southern end of the western limb, the hotspot
location has been moved to the southern end of the eastern limb. Faraday
rotation is detected within an entire bandwidth of the 43-GHz band. The
measured rotation measure (RM) is at most
(6.31.9)radm and might be slightly time
variable on the timescale of a month by a factor of a few. Our measured RM and
the RM previously reported by the CARMA and SMA observations cannot be
consistently explained by the spherical accretion flow with a power-law
profile. We propose that a clumpy/inhomogeneous ambient medium is responsible
for the observed rotation measure. Using equipartition magnetic field, we
derive the electron density of cm. Such an electron
density is consistent with the cloud of narrow line emission region around the
central engine. We also discuss the magnetic field configuration from black
hole scale to pc scale and the origin of low polarization.Comment: 8 pages, 8 figures, accepted for publication in Ap
R&D Status of Nuclear Emulsion For Directional Dark Matter Search
In this study, we are doing R&D for directional dark matter search with
nuclear emulsion. First of all, higher resolution nuclear emulsion with fine
silver halide crystals was developed in the production facility of emulsion at
Nagoya university, and we confirmed that it can detect the expected nuclear
recoil tracks. The readout of submicron tracks was required the new technology.
We developed the expansion technique, and could readout the signal by shape
analysis with optical microscopy. The two dimensional angular resolution is 36
degrees at the original track length of range from 150nm to 200nm with optical
microscopy. Finally we demonstrated by using recoiled nuclei induced by 14.8MeV
neutron, and confirmed the technique.Moreover, we developed the X-ray
microscope system with SPring-8 as final check with higher resolution of
selected candidate tracks with optical microscopy. The angular resolution was
improved from 31 degrees with optical microscopy to 17degrees with X-ray
microscopy at the track length of range from 150nm to 250nm. We are developing
the practical system and planning for start of the test running with prototype
detector.Comment: Proceedings of the 3rd International conference on Directional
Detection of Dark Matter (CYGNUS 2011), Aussois, France, 8-10 June 201
Vsop2/Astro-G Project
We introduce a new space VLBI project, the Second VLBI Space Observatory
Program (VSOP2), following the success of the VLBI Space Observatory Program
(VSOP1). VSOP2 has 10 times higher angular resolution, up to about 40 micro
arcseconds, 10 times higher frequency up to 43 GHz, and 10 times higher
sensitivity compared to VSOP1. Then VSOP2 should become a most powerful tool to
observe innermost regions of AGN and astronomical masers. ASTRO-G is a
spacecraft for VSOP2 project constructing in ISAS/JAXA since July 2007. ASTRO-G
will be launched by JAXA H-IIA rocket in fiscal year 2012. ASTRO-G and
ground-based facilities are combined as VSOP2. To achieve the good observation
performances, we must realize new technologies. They are large precision
antenna, fast-position switching capability, new LNAs, and ultra wide-band down
link, etc.. VSOP2 is a huge observation system involving ASTRO-G, ground radio
telescopes, tracking stations, and correlators, one institute can not prepare a
whole system of VSOP2. Then we must need close international collaboration to
get sufficient quality of resultant maps and to give a sufficient quantity of
observation time for astronomical community. We formed a new international
council to provide guidance on scientific aspects related of VSOP2, currently
called the VSOP2 International Science Council (VISC2).Comment: 10 pages, 9 figures, proceedings of The Universe under the Microscope
Astrophysics at High Angular Resolutio
Anderson transition in the three dimensional symplectic universality class
We study the Anderson transition in the SU(2) model and the Ando model. We
report a new precise estimate of the critical exponent for the symplectic
universality class of the Anderson transition. We also report numerical
estimation of the function.Comment: 4 pages, 5 figure
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