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排序方式: 共有443条查询结果,搜索用时 15 毫秒
131.
This paper addresses a local rescheduling procedure for a distributed routing system of multiple Automated Guided Vehicles in dynamic environments where the requests for transportation are given in real time. The effectiveness of the proposed method is investigated for a transportation system of 143 nodes and 10–30 AGV systems in a semi-conductor fabricating bay. A distributed and parallel routing system (DPRS) is implemented and tested on an experimental five mobile robot system. The results demonstrate that the proposed method can reduce the total computation time by 39% compared with the conventional method without lowering the performance level. It is also experimentally verified that the rescheduling procedure can deal with disturbances in a significantly short computation time. 相似文献
132.
In this paper, an optimization method of low‐order multivariable controllers for H∞ control is proposed. Starting from a low‐order stabilizing controller, our method gives a sequence of controllers for which the H∞ norm performance index is monotonically non‐increasing by tuning the numerator coefficient matrices of the low‐order controller. This controller class includes multivariable PID controllers. The proposed method is a descent method where the feasible direction is calculated by solving a linear matrix inequality that represents a sufficient condition for the H∞ criterion for each frequency. Usefulness is shown by two numerical examples. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
133.
Manabu Horiuchi Ryo Yoshida Masami Nirei Mitsuhide Sato Tsutomu Mizuno 《Electrical Engineering in Japan》2023,216(3):e23430
An interior permanent magnet synchronous motor (IPMSM) is characterized by its high efficiency. However, torque ripple and loss occur because of the spatial harmonics generated by air-gap permeance fluctuations. This study clarified that slot harmonic components can be suppressed by inserting magnetic wedges made of magnetic composite material in the slot opening of an IPMSM. First, the authors examined the torque and loss characteristics by varying relative permeability and saturation magnetic flux density of magnetic wedges using finite element analysis (FEA). Results indicated that the torque ripple and loss could be suppressed when the relative permeability of the magnetic wedge was μr = 10 to 22 and the saturation magnetic flux density was Bs = 0.5 to 0.75 T. Furthermore, the authors produced magnetic composite materials made of various soft magnetic material powders and examined their magnetic properties and viscosities. Results showed that a magnetic composite material with optimal magnetic properties and injectable viscosity could be manufactured using Fe-Si-Al with a low volume fraction. 相似文献
134.
Masami Ishiguro Hiroshi Nakayama Yuki Shimauchi Noriyuki Aibe Ikuo Yoshihara Moritoshi Yasunaga 《Artificial Life and Robotics》2010,15(3):325-329
Nowadays, a GHz frequency signal needs to be propagated on a printed circuit board (PCB) with low distortions. In addition,
a higher-frequency signal of 10 GHz or more will also need to be propagated with low distortion in very-large-scale integration
(VLSI) in the future. However, signal propagation with low distortion is getting more and more difficult as the frequency
increases. In order to solve this problem and to ensure signal integrity, we have proposed a novel transmission line called
a “segmental transmission line” (STL). In the STL, a transmission line is divided into multiple segments of individual characteristic
impedance. The multiple segments are designed to fix the waveform distortion on the transmission line by solving a combinatorial
explosion problem using a genetic algorithm. In a previous article, we have shown the effectiveness of an STL designed for
a GHz clock signal in computer simulations. We have also fabricated two scaled-up STL prototypes for a clock signal using
real printed circuit boards (PCBs). In this article, we input a random signal by changing its frequency to the scaled-up STL
prototype designed for a 150-MHz clock signal. We show that the STL has high robustness to the random signals and the frequency
fluctuations, which indicates the generality of the STL technique. 相似文献
135.
Chapell Mark S.; Blanding Z. Benjamin; Silverstein Michael E.; Takahashi Masami; Newman Brian; Gubi Aaron; McCann Nicole 《Canadian Metallurgical Quarterly》2005,97(2):268
This study investigated the relationship between test anxiety and academic performance in 4,000 undergraduate and 1,414 graduate students and found a significant but small inverse relationship between test anxiety and grade point average (GPA) in both groups. Low-test-anxious undergraduates averaged a B+, whereas high-test-anxious students averaged a B. Low-test-anxious female graduate students had significantly higher GPAs than high-test-anxious female graduate students, but there were no significant GPA differences between low- and high-test-anxious male graduate students. Female undergraduates had significantly higher test anxiety and higher GPAs than male undergraduates, and female graduate students had significantly higher test anxiety and higher GPAs than male graduate students. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
136.
Katsuhiro Yokota Kazuhiro Nakamura Tomohiko Kasuya Katsuhisa Mukai Masami Ohnishi 《Thin solid films》2005,473(2):340-345
Titanium nitride (TiN) films were deposited onto silicon wafers using an ion beam assisted deposition (IBAD) method with an electron cyclotron resonance (ECR) ion source for ionizing the nitrogen (N2) gas under a condition of high nitrogen ion to titanium neutral ratio. The deposition rate of the TiN films was strongly dependent on the evaporation rate, dTi, of Ti metal and decreased with increasing nitrogen ion current. The deposition rate can be approximated as d=βdTi?N2/{1/k+?N2}−αI, where β, k and α are proportional constants, ?N2 is the sum rate of neutral and ionized nitrogen impinging onto the substrate, and I is the nitrogen ion current. 相似文献
137.
We propose a neural network model generating a robot arm trajectory. The developed neural network model is based on a recurrent-type neural network (RNN) model calculating the proper arm trajectory based on data acquired by evaluation functions of human operations as the training data. A self-learning function has been added to the RNN model. The proposed method is applied to a 2-DOF robot arm, and laboratory experiments were executed to show the effectiveness of the proposed method. Through experiments, it is verified that the proposed model can reproduce the arm trajectory generated by a human. Further, the trajectory of a robot arm is successfully modified to avoid collisions with obstacles by a self-learning function.This work was presented, in part, at the 9th International Symposium on Artificial Life and Robotics, Oita, Japan, January 28–30, 2004 相似文献
138.
Kazuhiko Masuda Yuzo ManoHiroshi Ishimoto Masami TokunoYoshito Yoshizaki Nozomu OkawaraRyutaro Yamagiwa Akihiro UchiyamaAkihiro Yamazaki Yukitomo Tsutsumi 《Remote sensing of environment》2003,85(4):484-488
Optical thickness of the Asian dust aerosols over the ocean near Japan was retrieved from the visible data of the Geostationary Meteorological Satellite (GMS-5) from April 7 to 22, 2002 using the method by Masuda et al. [Remote Sens. Environ. 82 (2002) 238] in which the nonsphericity of dust particles was taken into account. The retrieved optical thicknesses were then compared with those derived from the sunphotometer and the skyradiometer measurements. The mean and the standard deviation of the optical thickness difference, GMS minus radiometers, were −0.03 and 0.17, respectively, for 85 samples where the optical thickness ranges from 0.25 to 1.07. 相似文献
139.
Clevenger法萃取草果获得草果精油,采用GC-MS分析检测出38个成分,通过保留指数解析出占总成分9714%的30个成分,主要成分为1,8-桉树脑(4089%) , α-水芹烯(977%) , 4-丙基苯甲醛(699%)等. 与匹配度对照解析法比较,有24个成分一致,占总成分的9281%. 用外标法定量分析了主要成分1,8-桉树脑含量,其质量分数为480%. 然后,研究了草果精油和1,8-桉树脑的抗菌活性. 结果显示,精油具有明显的抗菌活性,而1,8-桉树脑几乎无抗菌活性. 精油对细菌的抗菌活性由大到小依次是枯草芽孢杆菌、白葡萄球菌、大肠杆菌;对霉菌的抑菌活性由大到小依次是米曲霉菌、根霉、青霉. 相似文献
140.
Hideyuki Ohi Noriko Okazaki Shusei Uno Masami Miura Ryuji Hiramatsu 《Yeast (Chichester, England)》1998,14(10):895-903
We have clearly resolved four chromosomal bands from four Pichia pastoris (Komagataella pastoris) strains by using contour-clamped homogeneous electric field gel electrophoresis. The size of the P. pastoris chromosomal bands ranged from 1·7 Mb to 3·5 Mb and total genome size was estimated to be 9·5 Mb to 9·8 Mb; however, chromosome-length polymorphisms existed among four strains. Thirteen cloned genes isolated from strain GTS115 were assigned to the separated chromosomes, revealing that different hybridization patterns were observed in the AOX2 and URA3 genes among strains. P. pastoris is frequently used as an efficient host for heterologous gene expressions. We analysed chromosomal stability of strain GTS115-derived recombinant cell expressing human serum albumin during serial cultivation under the condition of vegetative and non-selective growth. No chromosomal rearrangements were observed and the expression constructs integrated into the his4 locus on chromosome I were very stable even at 83 generations, suggesting that stable expression would be carried out even in large-scale fermentation. © 1998 John Wiley & Sons, Ltd. 相似文献