Development of a multipurpose hand controller for JEMRMS

A prototype multipurpose hand controller for the JEMRMS (Japanese Experiment Module Remote Manipulator System) was developed. The hand controller (H/C) is an orthogonal type, with 6 degrees of freedom (DOF) and small size. The orthogonal type H/C is very simple for coordinate transformations and can easily control any type of manipulators. In fact, the JEMRMS is planned to have two manipulators controlled by a common H/C at this stage. The H/C was able to be used as a rate control joystick and a force reflection master arm, using an experimental 6 DOF manipulator. Good maneuverability was confirmed in the verification test. The orthogonal type H/C is suitable for use as a common H/C for the two manipulators of the JEMRMS

Capture of free-flying payloads with flexible space manipulators

A recently developed control system for capturing free-flying payloads with flexible manipulators is discussed. Three essential points in this control system are, calculating optimal path, using a vision sensor for an external sensor, and controlling active vibration. Experimental results are shown using a planar flexible manipulator

Development of a High-performance Optical System and Fluorescent Converters for High-resolution Neutron Imaging

AbstractTwo novel devices for use in neutron imaging technique are introduced. The first one is a high-performance optical lens for video camera systems. The lens system has a magnification of 1:1 and an F value of 3. The optical resolution is less than 5 μm. The second device is a high-resolution fluorescent plate that converts neutrons into visible light. The fluorescent converter material consists of a mixture of 6LiF and ZnS(Ag) fine powder, and the thickness of the converter is material is as little as 15 μm. The surface of the plate is coated with a 1 μm-thick gadolinium oxide layer. This layer is optically transparent and acts as an electron emitter for neutron detection. Our preliminary results show that the developed optical lens and fluorescent converter plates are very promising for high-resolution neutron imaging

「レシピ」による大地震の強震動予測

A recipe is proposed for estimating strong ground motions from specific earthquakes based on source characteristics from waveform inversion using strong motion data. The main features of the source model are characterized by three kinds of fault parameters, which we call: outer, inner, and extra fault parameters. The outer fault parameters provide overall pictures of the target earthquakes such as entire source area and seismic moment. The inner fault parameters characterize stress heterogeneity inside the fault area. The extra fault parameters are considered to complete the source model, and include starting point and propagation pattern of the rupture. The seismic hazard maps for future large earthquakes with a high probability of occurrence potential are based on the idea of the recipe proposed here by two governmental organizations, the Headquarters of Earthquake Research Center and Central Disaster Prevention Council in Japan

Scaling relations, virial theorem and energy densities for long-range and short-range density functionals

We analyze a decomposition of the Coulomb electron-electron interaction into a long-range and a short-range part in the framework of density functional theory, deriving some scaling relations and the corresponding virial theorem. We study the behavior of the local density approximation in the high-density limit for the long-range and the short-range functionals by carrying out a detailed analysis of the correlation energy of a uniform electron gas interacting via a long-range only electron-electron repulsion. Possible definitions of exchange and correlation energy densities are discussed and clarified with some examples.Comment: 7 pages, 3 figure

The Quantified NTO Analysis for the Electronic Excitations of Molecular Many-Body Systems

We show that the origin of electronic transitions of molecular many-body systems can be revealed by a quantified natural transition orbitals (QNTO) analysis and the electronic excitations of the total system can be mapped onto a standard orbitals set of a reference system. We further illustrate QNTO on molecular systems by studying the origin of electronic transitions of DNA moiety, thymine and thymidine. This QNTO analysis also allows us to assess the performance of various functionals used in time-dependent density functional response theory.Comment: Main Text+Supplemental Material; G09 reference correcte

A new generalized Kohn-Sham method for fundamental band-gaps in solids

We developed a method for calculating solid-state ground-state properties and fundamental band-gaps using a generalized Kohn-Sham approach combining a local density approximation (LDA) functional with a long-range explicit exchange orbital functional. We found that when the range parameter is selected according to the formula \gamma=A/(\eps_\inf - \eps_\tilde) where \eps_\inf is the optical dielectric constant of the solid and \eps_\tilde= 0.84 and A= 0.216a0^(-1), predictions of the fundamental band-gap close to the experimental values are obtained for a variety of solids of different types. For most solids the range parameter \gamma is small (i.e. explicit exchange is needed only at long distances) so the predicted values for lattice constants and bulk modulii are similar to those based on conventional LDA calculations

Intracule densities in the strong-interaction limit of density functional theory

The correlation energy in density functional theory can be expressed exactly in terms of the change in the probability of finding two electrons at a given distance $r_{12}$ (intracule density) when the electron-electron interaction is multiplied by a real parameter $\lambda$ varying between 0 (Kohn-Sham system) and 1 (physical system). In this process, usually called adiabatic connection, the one-electron density is (ideally) kept fixed by a suitable local one-body potential. While an accurate intracule density of the physical system can only be obtained from expensive wavefunction-based calculations, being able to construct good models starting from Kohn-Sham ingredients would highly improve the accuracy of density functional calculations. To this purpose, we investigate the intracule density in the $\lambda\to\infty$ limit of the adiabatic connection. This strong-interaction limit of density functional theory turns out to be, like the opposite non-interacting Kohn-Sham limit, mathematically simple and can be entirely constructed from the knowledge of the one-electron density. We develop here the theoretical framework and, using accurate correlated one-electron densities, we calculate the intracule densities in the strong interaction limit for few atoms. Comparison of our results with the corresponding Kohn-Sham and physical quantities provides useful hints for building approximate intracule densities along the adiabatic connection of density functional theory.Comment: 20 pages, 8 figures. Submitted to Phys. Chem. Chem. Phy