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161.
针对一种垂直弹跳机器人,利用Pro/E软件创建三维实体模型,然后利用Pro/E与ADAMS的数据接口软件Mechanism/Pro将模型及其特征参数导入ADAMS中,并在几何模型上施加适当的约束、接触力、驱动、传感器等,最后进行动力学仿真,主要分析了弹簧刚度对机器人的弹跳高度、弹跳速度和弹跳加速度等的影响。 相似文献
162.
163.
Sai Hung CheungTodd A. Oliver Ernesto E. Prudencio Serge PrudhommeRobert D. Moser 《Reliability Engineering & System Safety》2011,96(9):1137-1149
In this paper, we apply Bayesian uncertainty quantification techniques to the processes of calibrating complex mathematical models and predicting quantities of interest (QoI's) with such models. These techniques also enable the systematic comparison of competing model classes. The processes of calibration and comparison constitute the building blocks of a larger validation process, the goal of which is to accept or reject a given mathematical model for the prediction of a particular QoI for a particular scenario. In this work, we take the first step in this process by applying the methodology to the analysis of the Spalart-Allmaras turbulence model in the context of incompressible, boundary layer flows. Three competing model classes based on the Spalart-Allmaras model are formulated, calibrated against experimental data, and used to issue a prediction with quantified uncertainty. The model classes are compared in terms of their posterior probabilities and their prediction of QoI's. The model posterior probability represents the relative plausibility of a model class given the data. Thus, it incorporates the model's ability to fit experimental observations. Alternatively, comparing models using the predicted QoI connects the process to the needs of decision makers that use the results of the model. We show that by using both the model plausibility and predicted QoI, one has the opportunity to reject some model classes after calibration, before subjecting the remaining classes to additional validation challenges. 相似文献
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165.
Sai Madhukar Reddy Jung Jin Park Suok‐Min Na Mazin M. Maqableh Alison B. Flatau Bethanie J. H. Stadler 《Advanced functional materials》2011,21(24):4677-4683
Arrays of nanowires are fabricated with alternating segments of the magnetostrictive alloy Fe1–xGax and Cu using electrochemical deposition in nanoporous anodic aluminium oxide (AAO) templates. The difficult nature of Ga‐alloy electrochemistry is overcome by controlling mass‐transfer and hydrodynamic conditions using novel rotating disk electrode templates to obtain highly uniform segment lengths throughout the arrays. Extensive structural characterization by XRD, EBSD and TEM reveals a strong <110> textured Fe1–xGax growth. Furthermore, using vibrating sample magnetometry (VSM), we demonstrate that control of magnetization reversal processes is possible once uniform aspect ratios are obtained for both the Fe–Ga and Cu segments. 相似文献
166.
Chossegros L Hours M Charnay P Bernard M Fort E Boisson D Sancho PO Yao SN Laumon B 《Accident; analysis and prevention》2011,43(1):471-477
Background
This study sets out to identify risk factors for post-traumatic stress disorder (PTSD) after a road traffic accident with a view to improving prevention.Methods
The study used a prospective cohort of road traffic accident casualties. All subjects over 15 years of age were recruited in the course of an interview conducted while they were receiving care in a hospital of the Rhône area administrative département. Six months after their accident, they answered a self-administered postal questionnaire that included the Post-traumatic Check-List Scale (PCLS) in order to evaluate PTSD. Multivariate logistic regression analysis was conducted to compare those subjects with a PCLS score of 44 or over with those with a lower score, in order to identify factors that might be associated with PTSD.Results
592 subjects (out of 1168) returned the 6-month questionnaire and 541 completed the PCLS test. One hundred subjects had a PCLS score ≥44, suggesting PTSD, and 441 subjects did not. The factors associated with PTSD were initial injury severity, post-traumatic amnesia, the feeling of not being responsible for their accident and persistent pain 6 months after it. A lower odds-ratio was associated with users of two-wheel than four-wheel motor vehicles (OR = 0.4; 0.2–0.9).Conclusion
Besides predictive factors for PTSD (injury severity, post-traumatic amnesia and the feeling of not being responsible for their accident), our study suggested a reduced risk of PTSD among two-wheel motor vehicle users. 相似文献167.
168.
Terahertz (THz) technology promises important applications including imaging, spectroscopy, and communications. However, one of limitations at present for advancing THz applications is the lack of efficient devices to manipulate THz waves. Here, our recent important progresses in THz functional devices based on artificial microstructures, such as photonic crystal, metamaterial, and plasmonic structures, have been reviewed in this paper, involving the THz modulator, isolator, and sensor. These THz microstructure functional devices exhibit great promising potential in THz application systems. 相似文献
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170.
Results of 21 cases of squamous cell carcinoma of anal canal treated by continuous infusion of 5-fluorouracil 1000 mg/sqm for 4 days and mitomycin-C 15 mg/sqm on 1st day by i.v. route with concurrent external beam radiotherapy of 42 Gy from 1st day of chemotherapy were analysed. Out of 21 patients, 16(76.19%) achieved complete remission, 3 (14.28%) partial remission and 2 (9.52%) cases did not respond at all. On follow-up, 7 (33.33%) histopathological positive cases needed abdominoperineal resection with good recovery. After 2 years of follow-up 14 (66.67%) cases were free from the disease and 3 (14.28%) were alive with the disease. The median duration of follow-up was 36 months. 相似文献