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1.
This article presents an intelligent control system for a redundant manipulator to avoid physical limits such as joint angle
limits and joint velocity limits. In this method, a back-propagation neural network (NN) is introduced for the kinematic inversion
of the manipulator. Since this inverse kinematics has an infinite number of joint angle vectors, a fuzzy-neuro system is constructed
to provide an approximate value for that vector. This vector is fed into the NN as a hint input vector in order to guide the
output of the NN within the self-motion. Simulations and a comparative study are made based on a four-link redundant manipulator
to prove the efficacy of the proposed control system. 相似文献
2.
Jérôme Assal Bengt Hallstedt Ludwig J. Gauckler 《Journal of the American Ceramic Society》1999,82(3):711-715
The Ag-Bi-O system has been experimentally studied using differential thermal analysis (DTA) and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), and thermodynamically optimized. The temperatures of the eutectic, monotectic, and Bi2 O3 allotropic transformations have been measured in N2 , in air, and in O2 by DTA. There are no ternary phases stable at ambient pressure. Presently measured transformation temperatures have been combined with existing oxygen activity measurements in the metal liquid to optimize thermodynamic parameters describing the liquid phase. The resulting fit is excellent. EDX measurements of the composition in the oxide liquid have a rather low precision but confirm the thermodynamic optimization. However, some uncertainties remain concerning the liquid composition at the eutectic transformation and the shape of the miscibility gap at higher temperatures. 相似文献
3.
Advances in multibeam communications satellite antennas 总被引:3,自引:0,他引:3
Zaghloul A.I. Hwang Y. Sorbello R.M. Assal F.T. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1990,78(7):1214-1232
The evolution of satellite antennas over the past quarter of a century is presented. Five major areas of advances in communications satellite antenna technology are reviewed: single offset reflectors with feed arrays, shaped reflector systems, active phased arrays, phased-array-fed dual reflector systems, and lightweight feed elements. Examples are given of existing systems and of the ongoing development of new technologies 相似文献
4.
Alessandro Tocchio Naside Gozde Durmus Kaushik Sridhar Vigneshwaran Mani Bukre Coskun Rami El Assal Utkan Demirci 《Advanced materials (Deerfield Beach, Fla.)》2018,30(4)
In nature, cells self‐assemble at the microscale into complex functional configurations. This mechanism is increasingly exploited to assemble biofidelic biological systems in vitro. However, precise coding of 3D multicellular living materials is challenging due to their architectural complexity and spatiotemporal heterogeneity. Therefore, there is an unmet need for an effective assembly method with deterministic control on the biomanufacturing of functional living systems, which can be used to model physiological and pathological behavior. Here, a universal system is presented for 3D assembly and coding of cells into complex living architectures. In this system, a gadolinium‐based nonionic paramagnetic agent is used in conjunction with magnetic fields to levitate and assemble cells. Thus, living materials are fabricated with controlled geometry and organization and imaged in situ in real time, preserving viability and functional properties. The developed method provides an innovative direction to monitor and guide the reconfigurability of living materials temporally and spatially in 3D, which can enable the study of transient biological mechanisms. This platform offers broad applications in numerous fields, such as 3D bioprinting and bottom‐up tissue engineering, as well as drug discovery, developmental biology, neuroscience, and cancer research. 相似文献
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G Assal 《Canadian Metallurgical Quarterly》1976,32(1-3):5-12
In all clinics we are faced with questions about certain aspects of cerebral dominance. We consider first the problem of recognition of faces where the right hemisphere plays a leading role. However, the disorders manifesting that function appear only bilateral lesions. This suggests that the left hemisphere participates in this process. The reception of language raises a problem which is analogous with the preceding: we propose the participation of both hemispheres in this activity: the left hemisphere is dominant in the analysis of phonemes and syntax, the right hemisphere seems implicated above all in the processing of prosodic aspects--in particular intonations and individual features of the voice. 相似文献
7.
Transient axons reaching the medialmost part of area 17 were demonstrated with anterogradely transported biocytin injected in the dorsal part of the lateral gyrus in kittens during the first and second postnatal weeks. The axons decreased in number during the third postnatal week and were only exceptionally found thereafter. Computer-aided reconstructions from serial sections demonstrated axons with different degrees of complexity. The most complex ones were found at postnatal days 7-9 and were characterized by multiple branches terminating with growth cones in the white matter. Characteristically, endings of axons that entered the cortex remained confined to the infragranular layers V and VI. A few axons entered the supragranular layers. Transient axons terminated with different endings, which may indicate different stages of maturation. A few, possibly permanent, axons were still found in the medial part of area 17 at the end of the first, and during the second postnatal months; they arborized widely in the infragranular layers, and modestly or not at all supragranularly. 相似文献
8.
本文详细介绍了巴西标准化体系、标准化机构概况和标准制修订情况。作者利用较新的数据,对巴西标准制定和分布情况进行了介绍和说明。最后简要介绍了巴西合格评定体系、所涉及的监管机构以及所依据的相关标准。 相似文献
9.
For the systemdot{w} = Sw wherew = (xover{z}) , this note states and proves necessary and sufficient conditions under which a)z is an estimate of a linear function ofx (i.e.,z estimatesTx ), or b) a linear function ofz is an estimate ofx (i.e.,Vz estimatesx ). The mappingT has been used previously by the authors to compute the estimator-controller form of a compensator whose state vectorz had the same dimension as the plant state vectorx . 相似文献
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