Chiba Institute of Technology

About: Chiba Institute of Technology is a education organization based out in Narashino, Japan. It is known for research contribution in the topics: RNA & Magnet. The organization has 2663 authors who have published 4999 publications receiving 56870 citations. The organization is also known as: Chiba kōgyō daigaku & Kōa Institute of Technology.

Novel Step Climbing Control for Power Assisted Wheelchair Based on Driving Mode Switching

Abstract: This paper describes a novel step climbing control scheme for electric power assisted wheelchairs. "Electric power assisted wheelchair" which assists the driving force by electric motors is expected to be widely used as a mobility support system for elderly people and disabled people. This research aims at realizing the safe and reliable step climbing motion control of power assisted wheelchairs because power assisted wheelchairs are in danger of overturning backward when raising the front wheels due to the excessive driving torque and of stopping in front of steps when the rear wheels try to climb over steps due to the insufficient driving torque. This paper proposes a novel step climbing control scheme for power assisted wheelchairs based on driving mode switching. The first driving mode, "front wheel raising mode", applies torque control system with the variable assistance ratio to prevent the dangerous overturning. The second driving mode, "rear wheel climbing mode", applies position control system based on the polynomial trajctory to surely climb over steps and stop at the suitable position. The mode switching control based on these two driving modes can generate the safe and reliable step climbing motions. Some experiments show the effectiveness of the proposed control system.

Missing western half of the Pacific Plate: Geochemical nature of the Izanagi-Pacific Ridge interaction with a stationary boundary between the Indian and Pacific mantles

Abstract: The source mantle of the basaltic ocean crust on the western half of the Pacific Plate was examined using Pb–Nd–Hf isotopes. The results showed that the subducted Izanagi–Pacific Ridge (IPR) formed from both Pacific (180–∼80 Ma) and Indian (∼80–70 Ma) mantles. The western Pacific Plate becomes younger westward and is thought to have formed from the IPR. The ridge was subducted along the Kurile–Japan–Nankai–Ryukyu (KJNR) Trench at 60–55 Ma and leading edge of the Pacific Plate is currently stagnated in the mantle transition zone. Conversely, the entire eastern half of the Pacific Plate, formed from isotopically distinct Pacific mantle along the East Pacific Rise and the Juan de Fuca Ridge, largely remains on the seafloor. The subducted IPR is inaccessible; therefore, questions regarding which mantle might be responsible for the formation of the western half of the Pacific Plate remain controversial. Knowing the source of the IPR basalts provides insight into the Indian–Pacific mantle boundary before the Cenozoic. Isotopic compositions of the basalts from borehole cores (165–130 Ma) in the western Pacific show that the surface oceanic crust is of Pacific mantle origin. However, the accreted ocean floor basalts (∼80–70 Ma) in the accretionary prism along the KJNR Trench have Indian mantle signatures. This indicates the younger western Pacific Plate of IPR origin formed partly from Indian mantle and that the Indian–Pacific mantle boundary has been stationary in the western Pacific at least since the Cretaceous.

User's favorite scent design using paired comparison-based Interactive Differential Evolution

Abstract: This study proposes a method that creates a scent suited with a user's favor using paired comparison-based Interactive Differential Evolution. In the proposed method, the user smells two scents and selects the preferred one by simple comparison. Based on the repetitive comparisons, Differential Evolution (DE) optimizes the scent suited with the user. Each scent is composed of several source scents, and strength of each source scent is described as values in DE's vector. To investigate the efficacy of the proposed method fundamentally, smelling experiments composed of comparing experiment and evaluating experiment are performed. In the comparing experiment, the subjects compare presented pair scents and select the preferred one through ten generations, and DE evolves scent to user's favor based on the comparisons. In the evaluating experiment, the subjects evaluate four representative scents picked from 0-, 3-, 6-, 9-th generations, respectively. The results of the experiments showed a tendency of the increase of fitness value in accordance with evolution.

Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki

Abstract: The Venusian atmosphere is in a state of superrotation where prevailing westward winds move much faster than the planet's rotation. Venus is covered with thick clouds that extend from about 45 to 70 km altitude, but thermal radiation emitted from the lower atmosphere and the surface on the planet's nightside escapes to space at narrow spectral windows of the near-infrared. The radiation can be used to estimate winds by tracking the silhouettes of clouds in the lower and middle cloud regions below about 57 km in altitude. Estimates of wind speeds have ranged from 50 to 70 m/s at low to mid-latitudes, either nearly constant across latitudes or with winds peaking at mid-latitudes. Here we report the detection of winds at low latitude exceeding 80 m/s using IR2 camera images from the Akatsuki orbiter taken during July and August 2016. The angular speed around the planetary rotation axis peaks near the equator, which we suggest is consistent with an equatorial jet, a feature that has not been observed previously in the Venusian atmosphere. The mechanism producing the jet remains unclear. Our observations reveal variability in the zonal flow in the lower and middle cloud region that may provide clues to the dynamics of Venus's atmospheric superrotation.

Biotransformation of valencene by cultured cells of Gynostemma pentaphyllum

Abstract: It has been found that the suspension cultures of Gynostemma pentaphyllum convert valencene (1) into nootkatone (2) as the major product and nootkatol (3) as the minor product. Based on this finding, a further study was conducted to investigate the biotransformation of 1 by other cultured plant cells (Caragana chamlagu, Hibiscus cannabinus).