Park M.,Kyushu University |
Hagishima A.,Kyushu University |
Tanimoto J.,Kyushu University |
Narita K.-I.,Nippon Institute of Technology
Building and Environment | Year: 2012
The goal of this research is to bridge the gap between numerical studies and field measurements on thermal environment of a real urban street and to present information on the effects of urban vegetation suitable for use by designers and planners. Outdoor measurements were conducted at a scale model site consisting of an array of concrete cubes each 1.5 m high. Eight urban street units with various vegetation conditions were reproduced to examine the quantitative effects of vegetation along the sidewalk and in median strips on the thermal environment in summer. The results can be summarized as follows. The presence of four sidewalk trees reduces the wind speed inside the canopy by up to 51%. Trees along the sidewalk also decrease the globe temperature; the reduction is attributed mainly to the decrease in radiation flux resulting from the shade they cast. Moreover, thermal mitigation due to vegetation persists even when an area is shaded. In contrast, the mitigating effect of a vegetated median strip is not remarkable. A sidewalk facing a southwestern wall exhibited the most significant thermal mitigation. © 2012 Elsevier Ltd.
Kambayashi Y.,Nippon Institute of Technology
Algorithms | Year: 2013
A survey on the routing protocols based on ant-like mobile agents is given. These protocols are often employed in Mobile Ad Hoc Networks (MANET). Mobile Ad Hoc Networks are collections of wireless mobile nodes such as PDAs, laptop computers, and cellular phones having wireless communication capability that dynamically form a temporary network without using any existing network infrastructures such as wireless access points. The only infrastructure in MANET is the wireless communication interfaces on the devices. In such a circumstance, where some of the wireless devices are not within wireless range of each other, multi-hop routing is required to transmit messages to the destination. A node that wants to start communication with other nodes that are not within its one-hop wireless transmission range has to request intermediate nodes to forward their communication packets to the destination. In this paper, we survey a variety of proposed network protocols to accommodate this situation. We focus especially on biologically-inspired routing algorithms that are based on the ant colony optimization algorithm. © 2013 by the authors.
Suzuki H.,Nippon Institute of Technology
Procedia Computer Science | Year: 2013
This study applies a particle filter (PF) and an unscented Kalman filter (UKF) to estimate the headway and velocity of a six- vehicle platoon system. These two feedback estimators were used to estimate headway and velocity indirectly from several measurement variables, such as acceleration rate and velocity, of selected vehicles in the platoon. To evaluate the performance of the proposed two estimators, artificial car-following data were created to cover various speed ranges that include some acceleration and deceleration scenarios. Also, a comparison of estimation accuracy is conducted when varying the number of probe cars installed in the platoon system. Numerical analysis showed that the PF succeeded in estimating headway and velocity more accurately than the UKF, even when the number of probe cars installed is fewer and their location is varied within the platoon. The estimations by the UKF were inaccurate and the filter was unstable during all probe car penetrations except during the 100% installation scenario. The UKF is considered to yield stable and accurate estimates only when all vehicles are equipped with the sensing system, whereas the PF does not require numerous probe cars to generate accurate estimates regardless of their location in the platoon. © 2013 The Authors.
Haga K.,Nippon Institute of Technology |
Hayashi K.-I.,Okayama University of Science |
Sakai T.,Niigata University
Plant Physiology | Year: 2014
Several members of the AGCVIII kinase subfamily, which includes PINOID (PID), PID2, and WAVY ROOT GROWTH (WAG) proteins, have previously been shown to phosphorylate PIN-FORMED (PIN) auxin transporters and control the auxin flow in plants. PID has been proposed as a key component of the phototropin signaling pathway that induces phototropic responses, although the responses were not significantly impaired in the pid single and pid wag1 wag2 triple mutants. This raises questions about the functional roles of the PID family in phototropic responses. Here, we investigated hypocotyl phototropism in the pid pid2 wag1 wag2 quadruple mutant in detail to clarify the roles of the PID family in Arabidopsis (Arabidopsis thaliana). The pid quadruple mutants exhibited moderate responses in continuous light-induced phototropism with a decrease in growth rates of hypocotyls and normal responses in pulse-induced phototropism. However, they showed serious defects in enhancements of pulse-induced phototropic curvatures and lateral fluorescent auxin transport by red light pretreatment. Red light pretreatment significantly reduced the expression level of PID, and the constitutive expression of PID prevented pulse-induced phototropism, irrespective of red light pretreatment. This suggests that the PID family plays a significant role in phytochrome-mediated phototropic enhancement but not the phototropin signaling pathway. Red light treatment enhanced the intracellular accumulation of PIN proteins in response to the vesicle-trafficking inhibitor brefeldin A in addition to increasing their expression levels. Taken together, these results suggest that red light preirradiation enhances phototropic curvatures by upregulation of PIN proteins, which are not being phosphorylated by the PID family. Ó 2014 American Society of Plant Biologists. All rights reserved.
Thipprakmas S.,King Mongkuts University of Technology Thonburi |
Thipprakmas S.,Nippon Institute of Technology
Materials and Design | Year: 2010
Considering the advantages of the V-bending die, the economical set-up time and the fabrication of a wide range of part size and complex shape, the V-bending die is generally used, especially in the Press Brake machine. However, the punch heights in the partial V-bending die affected the bending angle. In this study, the finite element method (FEM) was used to investigate the effects of punch height. The FEM simulation results revealed that the effects of punch height on the bending angle were clearly theoretically clarified based on the material flow analysis and stress distribution. The punch height affected the gap between the workpiece and the die, as well as the reversed bending zone, which resulted in a non-required bending angle. Therefore, applying a suitable punch height created a balance of compensating the gap between the workpiece and the die, and the stress distribution on the bending allowance and the reversed bending zone. This resulted in achieving the required bending angle. © 2009 Elsevier Ltd. All rights reserved.