Scalable rank-mapping algorithm for an icosahedral grid system on the massive parallel computer with a 3-D torus network

In this paper, we develop a rank-mapping algorithm for an icosahedral grid system on a massive parallel computer with the 3-D torus network topology, specifically on the K computer. Our aim is to improve the weak scaling performance of the point-to-point communications for exchanging grid-point values between adjacent grid regions on a sphere. We formulate a new rank-mapping algorithm to reduce the maximum number of hops for the point-to-point communications. We evaluate both the new algorithm and the standard ones on the K computer, using the communication kernel of the Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a global atmospheric model with an icosahedral grid system. We confirm that, unlike the standard algorithms, the new one achieves almost perfect performance in the weak scaling on the K computer, even for 10,240 nodes. Results of additional experiments imply that the high scalability of the new rank-mapping algorithm on the K computer is achieved by reducing network congestion in the links between adjacent nodes.     

Modeling of humanoid dynamics including slipping with nonlinear floor friction

Biped locomotion created by controlling methods based on zero-moment point has been realized in real world and been well verified its efficacy for stable walking. However, the walking strategies that have been proposed so far seems to avoid such considerations as slipping of foot on the floor, even though there should exist the slipping large or small in real world. In this research, a dynamical model of humanoid robot including slipping of foot is proposed, which is derived by the Newton–Euler method. To confirm the veracity of the derived dynamical model, the model has been verified from the view point that when all friction coefficients are identical to zero, the total kinetic energy should be conserved to be unchanged, and when the coefficients are not zero, the total kinetic energy should decrease monotonously.     

Hardware neural network models of CPG and PWM for controlling servomotor system in quadruped robot

This paper discusses the pulse-type hardware neural networks (P-HNNs) that contain a central pattern generator (CPG) and a pulsewidth modulation (PWM) servomotor controller and the application to quadruped robots. The purpose of our study is mimicking the biological neural networks and reproducing the similar motion of the living organisms in the robot. The CPG of the living organism generates the walking rhythms. We mimicked this CPG by modeling the cell body and the synapse of the living organism. The developed CPG composed of the P-HNN output four pulse signal sequences and the four outputs are introduced to each leg of the quadruped robot. On the other hand, the angle of the servomotor is controlled by the PWM. The PWM is obtained by modeling the axon of the living organism. The CPG and the PWM servo control system perform the walking motion of the quadruped robot. Moreover, the gate pattern change of quadruped animals is reproduced by these P-HNNs.     

Experimental observations of bands of suspended colloidal particles subject to shear flow and steady electric field

Manipulating suspended colloidal particles flowing through a microchannel is of interest in microfluidics and nanotechnology. However, the flow itself can affect the dynamics of these suspended particles via wall-normal “lift” forces. The near-wall dynamics of particles suspended in shear flow and subject to a dc electric field was quantified in combined Poiseuille and EO flow through a?~?30 μm deep channel. When the two flows are in opposite directions, the particles are attracted to the wall. They then assemble into very high aspect ratio structures, or concentrated streamwise “bands,” above a minimum electric field magnitude, and, it appears, a minimum near-wall shear rate. These bands only exist over the few micrometers next to the wall and are roughly periodic in the cross-stream direction, although there are no external forces along this direction. Experimental observations and dimensional analysis of the time for the first band to form and the number of bands over a field of view of ~?200 μm are presented for dilute suspensions of polystyrene particles over a range of particle radii, concentrations, and zeta potentials. To our knowledge, there is no theoretical explanation for band assembly, but the results presented here demonstrate that it occurs over a wide range of different particle and flow parameters.     

Docking at pool and sea by using active marker in turbid and day/night environment

Nowadays, autonomous underwater vehicle (AUV) is playing an important role in human society in different applications such as inspection of underwater structures (dams, bridges). It has been desired to develop AUVs that can work in a sea with a long period of time for the purpose of retrieving methane hydrate, or rare metal, and so on. To achieve such AUVs, the automatic recharging capability of AUVs under the sea is indispensable and it requires AUVs to dock itself to recharging station autonomously. Therefore, we have developed a stereo-vision-based docking methodology for underwater battery recharging to enable the AUV to continue operations without returning surface vehicle for recharging. Since underwater battery recharging units are supposed to be installed in a deep sea, the deep-sea docking experiments cannot avoid turbidity and low-light environment. In this study, the proposed system with a newly designed active—meaning self-lighting—3D marker has been developed to improve the visibility of the marker from an underwater vehicle, especially in turbid water. Experiments to verify the robustness of the proposed docking approach have been conducted in a simulated pool where the lighting conditions change from day to night. Furthermore, sea docking experiment has also been executed to verify the practicality of the active marker. The experimental results have confirmed the effectiveness of the proposed docking system against turbidity and illumination variation.     

Effects of cicletanine on the urinary excretion of prostanoids and kallikrein, and on renal function in man

The effects of cicletanine, a new antihypertensive agent, on the prostaglandin-kallikrein system and the renin-angiotensin system were studied. A single oral dose of 200 mg cicletanine or placebo was administered to 9 healthy male volunteers, with samples of blood and urine obtained before and 2 hours after drug administration. Cicletanine increased the urine flow, urinary excretion of sodium, and fractional excretion of sodium by 47%, 115%, and 104%, respectively. While the excretion of 6-keto-prostaglandin-F1 alpha was enhanced significantly, urinary excretion of thromboxane-B2, prostaglandin-E2, and kallikrein were unchanged. Cicletanine also did not alter plasma renin activity, plasma aldosterone concentration, or creatinine clearance. These observations suggest that cicletanine may suppress sodium reabsorption at the nephron, and it may stimulate prostacyclin generation with no effect on that of thromboxane-A2. Thus cicletanine may be beneficial in the management of cardiovascular disorders in which the equilibrium between prostacyclin and thromboxane is disturbed.     

Effects of nitroglycerin on hemodynamics in dogs with experimentally inserted heartworms

6,7-Dihydroxy-N-cyanomethyl-1,2,3,4-tetrahydroisoquinoline, a cyanomethyl derivative of dopamine formed from cigarette smoke, was found to inhibit the activity of tryptophan hydroxylase. The inhibition was non-competitive to the substrate L-tryptophan (the Ki value 7.25 +/- 0.81 microM), but not to the biopterin cofactor. The inhibition is irreversible. 6-Hydroxy-N-cyanomethyl-tetrahydro-beta-carboline, a cyanomethyl derivative of serotonin, is inactive towards the hydroxylase. 6,7-Dihydroxy-N-cyanomethyl-1,2,3,4-tetrahydroisoquinoline may affect the serotonin biosynthesis in vivo as a consequence of cigarette smoking.     

Apoptotic DNA fragmentation and upregulation of Bax induced by transient ischemia of the rat retina

We have previously shown that methionine-enkephalin (MENK) alters in dose-dependent fashion the capacity of human neutrophils to produce superoxide anion. The response of neutrophils from different donors was diverse and this effect could be due to variable activity of proteolytic enzymes involved in the degradation of the neuropeptide. In this study, we have demonstrated a highly individual aminopeptidase N (APN) activity of neutrophils from different donors. Preincubation of neutrophils with MENK, but not with the synthetic agonist of the mu (DAGO) or the delta (DPDPE) opioid receptor, down-regulated the APN activity. This was paralleled by a loss in cell surface expression of APN at physiological (10(-10) M) concentrations of MENK. The level of APN activity from different donors correlated with the effect of MENK on superoxide anion release. Neutrophils with low APN activity, if preincubated with MENK, released reduced amounts of superoxide anion. In contrast, neutrophils with high APN activity released increased amounts of superoxide anion after preincubation with MENK. Thus, the highly individual APN activity on the surface of neutrophils from different donors seems to be altered by MENK and to be related to the respiratory burst.     

Surface features of uniaxial tensile fractures and their relation to rock anisotropy in Inada granite

Uniaxial tensile fractures parallel to the rift, grain and hardway planes were formed in Inada granite. Most of the fractures split the rock-forming mineral grains as transgranular paths under microscopic observations. The surface topography of the fractures was measured by the stereo-photogrammetric technique, and is different in different orientations. The rift-parallel uniaxial fracture has the smoothest surface, and the grain-parallel fractures are smoother than hardway-parallel fractures. The mineral compositions are also different on the failed surfaces of different directions. The rift-parallel fractures have almost the same constituent mineral ratio as the parent rock. However, the grain-parallel fractures pass preferentially through feldspar grains, and contain less quartz grains as compared to the bulk composition of the parent rock. In addition, it is remarkable on hardway-parallel fractures. It is considered that the differences of surface topography and mineral compositions are caused by preferred orientations and spatial distributions of pre-existing microcracks in Inada granite.