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排序方式: 共有792条查询结果,搜索用时 15 毫秒
21.
Chao Fu Yadong Chen Xiaofei Yuan Sammy Tin Stoichko Antonov Koichi Yagi Qiang Feng 《材料科学技术学报》2019,35(4):687-694
To minimize the deviation of the predicted creep curves obtained under constant load conditions by the original θ projection model, a new modified version that can be expressed by , was derived and experimentally validated in our last study. In the present study, the predictive capability of the modified θ projection model was investigated by comparing the simulated and experimentally determined creep curves of K465 and DZ125 superalloys over a range of temperatures and stresses. Furthermore, the linear relationship between creep temperature and initial stress was extended to the 5-parameter model. The results indicated that the modified model could be used as a creep life prediction method, as it described the creep curve shape and resulted in predictions that fall within a specified error interval. Meanwhile, this modified model provides a more accurate way of describing creep curves under constant load conditions. The limitations and future direction of the modified model were also discussed. In addition, this modified θ projection model shows great potential for the evaluation and assessment of the service safety of structural materials used in components governed by creep deformation. 相似文献
22.
Hiroyuki Fujishiro Manabu Ikebe Masayuki Yagi Kiminari Nakasato Yuzo Shibazaki Tetsuo Fukase 《Journal of Low Temperature Physics》1996,105(3-4):981-986
The thermal conductivity of high density La2–xMxCuO4 (M=Ba, Sr) sintered materials was measured between 15K and 150K for the various concentrations of Ba and the phonon thermal conductivity was analyzed comparing with that of Nd2–xCexCuO4. The pretty large value for pure La2CuO4 was drastically diminished by substituting La by a small amount of Ba atoms especially at low temperatures. It was found that a new type of the phonon scattering center such as a two-level tunneling must be taken account of in order to explain the observed reduction. 相似文献
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The effect of lutein supplementation on visual fatigue: A psychophysiological analysis 总被引:1,自引:0,他引:1
Akihiro Yagi Kiyoshi Fujimoto Kazumi Michihiro Bevy Goh Daniel Tsi Hajime Nagai 《Applied ergonomics》2009,40(6):1047-1054
We used psychophysiological technology to examine the effect of an oral supplement, a combination of lutein, zeaxanthin and blackcurrant extract (LUT), on visual fatigue, within the context of a randomized, double-blind, placebo-controlled cross-over trial. The LUT supplement and placebo samples were randomly assigned to thirteen participants, who took the samples for two LUT (and vice versa) for another 2 week. Each participant completed visual proof reading tasks for 2 h during each of four testing sessions. Saccade tests were administered before and after the proof reading task, during which the participants moved their eyes back and forth between two targets positioned in the center of two checkerboards. We recorded EEG, EOG, heart rate, and facial muscle potential/performance during the saccade tests. Blood pressure was measured and subjective fatigue and stress scores were collected before and after the proof reading task. We averaged EEG starting at saccade offset in order to analyze eye fixation related potentials (EFRP). Our results suggested that the proof reading task induced visual fatigue. An analysis of EFRP and other psychophysiological data revealed significant differences between the LUT and placebo conditions. These results suggest that supplementation with LUT could help to reduce symptoms of visual fatigue. 相似文献
25.
The purpose of this study was to design an endoscopic dissector handle and objectively assess its usability. The handles were designed with increased contact area between the fingers and thumb and the eye rings, and the eye rings were modified to have a more perpendicular insertion angle to the finger midline. Four different handle models were compared, including a conventional product. Subjects performed dissection, exclusion, grasping, precision manipulation and precision handling tasks. Electromyography and subjective evaluations were measured. Compared to conventional handles, the designated handle reduced the muscle load in the extensor and flexor muscles of the forearm and increased subjective stability. The activity of the first dorsal interosseous muscle was sometimes influenced by the shape of the other parts. The ergonomically designed endoscopic dissector handle used in this study achieved high usability. Medical instrument designs based on ergonomic concepts should be assessed with objective indices.
Practitioner Summary: The endoscopic dissector handles were designed with increased contact area and more suitable insertion angle between the fingers and thumb and the eye rings. Compared to conventional handles, the designated handle reduced the muscle load in the extensor and flexor muscles of the forearm and increased subjective stability. 相似文献
26.
Yasushi Yagi Wataru Nishi Nels Benson Masahiko Yachida 《Machine Vision and Applications》2003,14(2):112-120
Described here is a method for estimating rolling and swaying motions of a mobile robot using optical flow. We have proposed
an image sensor with a hyperboloidal mirror for the vision-based navigation of a mobile robot. Its name is HyperOmni Vision.
The radial component of optical flow in HyperOmni Vision has a periodic characteristic. The circumferential component of optical
flow has a symmetric characteristic. The proposed method makes use of these characteristic to estimate robustly the rolling
and swaying motion of the mobile robot.
Correspondence to: Y. Yagi e-mail: y-yagi@sys.es.osaka-u.ac.jp 相似文献
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28.
Li Xiang Makihara Yasushi Xu Chi Yagi Yasushi Ren Mingwu 《Multimedia Tools and Applications》2018,77(21):28333-28354
Multimedia Tools and Applications - Human age estimation from gait is expected to be an important technology for a variety of applications such as automatic customer counting for marketing research... 相似文献
29.
Hydrogenases catalyze uptake and production of H2. Heterolytic cleavage of H2 bound on [NiFe]-hydrogenase (E) produces two unequal H species to form E:HaHb, where Ha and Hb behave differently. The structures of various states of the enzyme established by crystallography and spectroscopy were used to construct a catalytic cycle of the enzyme. The Ni–Fe center of the active enzyme has the Ni–Fe bridging site vacant. The enzyme is suggested to bind H2 either at Ni or Fe atom. In E:HaHb, Ha is considered to be a protein-bound hydron (proton or deuteron) at the entrance to the hydrophobic gas tunnel. The structure of a synthetic hydrogenase-mimic suggests Hb to be the 6th ligand to Fe. Two successive one-electron processes from E:HaHb complete the catalytic cycle of H2 uptake. The reverse of the cycle operates in the H2 production. The proposed catalytic cycle is consistent with the kinetic, crystallographic and spectroscopic studies. 相似文献
30.
AI & SOCIETY - The purpose of our study is to (i) investigate the effects of the number of products, product attributes, and prices on consumer confusion, (ii) conduct a numerical analysis to... 相似文献