87 research outputs found
Task-Space Control of Articulated Mobile Robots With a Soft Gripper for Operations
A task-space method is presented for the control of a head-raising articulated mobile robot, allowing the trajectory tracking of a tip of a gripper located on the head of the robot in various operations, e.g., picking up an object and rotating a valve. If the robot cannot continue moving because it reaches a joint angle limit, the robot moves away from the joint limit and changes posture by switching the allocation of lifted/grounded wheels. An articulated mobile robot with a gripper that can grasp objects using jamming transition was developed, and experiments were conducted to demonstrate the effectiveness of the proposed controller in operations
Robust optimal damper placement based on robustness index simultaneously considering variation of elastoplastic design criteria and input level
Dampers should be installed at appropriate quantities and locations to control building vibrations against excitations such as earthquakes and wind loads. One of the objectives of the structural optimization problem for damper placement is to minimize the initial cost of damper installation to satisfy various structural constraints under a set of input levels and target performance values. However, it is arbitrary what input levels should be used in the design, and it is also necessary to account for various uncertainties in the inputs and structural properties. This study presents a new method for assessing the robustness of building structures with design variables while simultaneously considering various phases of structural performance criteria and input amplitudes. The proposed robustness index is a multidimensional function that can take into account the influence of different input levels on the structural performance. In this paper, the proposed new robustness index is applied to the robust optimal design of the damper placement, where the damping coefficient of the linear oil damper added to the building is uncertain. The worst resonant seismic motion for the building is investigated based on the critical double impulse method and its equivalent one-cycle sine wave, which is used as the input seismic motion. By applying the equivalent one-cycle sine wave to the structural response analysis with variations in the input velocity amplitude, the proposed robustness index is effective in comprehensively assessing the relationships between the input velocity amplitude of the seismic motion and the upper response limit of the structure under the variation of the damping coefficient of the oil damper. The comprehensive and efficient evaluation of these relationships enables a more detailed assessment of the influence of uncertainties in design variables on structural performance. In the numerical examples, the optimal damper placement for a 12-story building model is discussed based on the robustness and structural performance of both acceleration and story ductility distribution
Regulating divergent transcriptomes through mrna splicing and its modulation using various small compounds
Human transcriptomes are more divergent than genes and contribute to the sophistication of life. This divergence is derived from various isoforms arising from alternative splicing. In addition, alternative splicing regulated by spliceosomal factors and RNA structures, such as the RNA G-quadruplex, is important not only for isoform diversity but also for regulating gene expression. Therefore, abnormal splicing leads to serious diseases such as cancer and neurodegenerative disorders. In the first part of this review, we describe the regulation of divergent transcriptomes using alternative mRNA splicing. In the second part, we present the relationship between the disruption of splicing and diseases. Recently, various compounds with splicing inhibitor activity were established. These splicing inhibitors are recognized as a biological tool to investigate the molecular mechanism of splicing and as a potential therapeutic agent for cancer treatment. Food-derived compounds with similar functions were found and are expected to exhibit anticancer effects. In the final part, we describe the compounds that modulate the messenger RNA (mRNA) splicing process and their availability for basic research and future clinical potential
Charge excitations associated with charge stripe order in the 214-type nickelate and superconducting cuprate
Charge excitations were studied for stipe-ordered 214 compounds,
LaSrNiO and 1/8-doped La(Ba, Sr)CuO
using resonant inelastic x-ray scattering in hard x-ray regime. We have
observed charge excitations at the energy transfer of 1 eV with the momentum
transfer corresponding to the charge stripe spatial period both for the
diagonal (nikelate) and parallel (cuprates) stripes. These new excitations can
be interpreted as a collective stripe excitation or charge excitonic mode to a
stripe-related in-gap state.Comment: 5 pages, 4 figure
MPP6 stimulates both RRP6 and DIS3 to degrade a specified subset of MTR4-sensitive substrates in the human nucleus
ヒト細胞内でRNA分解時に働く因子の役割を解明 --細胞内におけるRNA分解機構の全容解明に期待--. 京都大学プレスリリース. 2022-08-05.Recent in vitro reconstitution analyses have proven that the physical interaction between the exosome core and MTR4 helicase, which promotes the exosome activity, is maintained by either MPP6 or RRP6. However, knowledge regarding the function of MPP6 with respect to in vivo exosome activity remains scarce. Here, we demonstrate a facilitative function of MPP6 that composes a specific part of MTR4-dependent substrate decay by the human exosome. Using RNA polymerase II-transcribed poly(A)⁺ substrate accumulation as an indicator of a perturbed exosome, we found functional redundancy between RRP6 and MPP6 in the decay of these poly(A)⁺ transcripts. MTR4 binding to the exosome core via MPP6 was essential for MPP6 to exert its redundancy with RRP6. However, at least for the decay of our identified exosome substrates, MTR4 recruitment by MPP6 was not functionally equivalent to recruitment by RRP6. Genome-wide classification of substrates based on their sensitivity to each exosome component revealed that MPP6 deals with a specific range of substrates and highlights the importance of MTR4 for their decay. Considering recent findings of competitive binding to the exosome between auxiliary complexes, our results suggest that the MPP6-incorporated MTR4-exosome complex is one of the multiple alternative complexes rather than the prevailing one
Development of a folding arm on an articulated mobile robot for plant disaster prevention
In this work, we develop a folding arm on an articulated mobile robot to inspect an industrial plant. The design targets of the arm, its operations, measurement ability, and mobility, were set for the task of inspecting an industrial plant. To accomplish the targets, we designed the folding arm considering both accessibility to high locations and the mobility of the articulated mobile robot to which it is attached. The arm has links, joints, dummy wheels, and sensors and enables the robot to which it is attached to manipulate objects, e.g. rotating valves, opening a door, or inspecting by accessing high locations. In addition, changing the posture of the arm and touching the dummy wheel in the arm to the surrounding terrain can reduce any negative effect of the arm on the robot\u27s mobility when it encounters narrow spaces, stairs, steps, and trenches. The arm is controlled as a six degrees-of-freedom manipulator without redundancy by an operator who directly sets two joint angles. The effectiveness of the developed arm was demonstrated not only through experiments in a laboratory but also in a field test at the Plant Disaster Prevention Challenge of the World Robot Summit 2018
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