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11.
This is the first of two papers comparing connectionist and traditional stochastic latency mechanisms with respect to their ability to account for simple judgments. In this paper, we show how the need to account for additional features of judgment has led to the formulation of progressively more sophisticated models. One of these, a self-regulating, generalized accumulator process, is treated in detail, and its simulated performance across a sample of tasks is described. Since an adaptive decision module of this kind possesses all the ingredients of intelligent behavior, it is eminently suited as a basic computing element in more complex networks. 相似文献
12.
13.
S. T. Swift R. A. d'Inverno J. A. G. Vickers 《General Relativity and Gravitation》1986,18(11):1093-1103
We define an everywhere invariant space of metricsU to be one for which the set of diffeomorphisms, which leaveU invariant, contains all the isometries of the individual metrics inU. We also generalize Killing's equation to a new equation, the invariance equation, which has as solutions those vector fields which leaveU invariant. By combining these ideas we give a new method for finding the isometries of a given metric. 相似文献
14.
Nonlinear Dynamics, Psychology, and Life Sciences - 相似文献
15.
By subtly varying crystallization conditions, four distinct cadmium acetate coordination networks with unit cell formulas Cd(87)(H(2)O)(36)(EtOH)(18)(OH)(12)(CH(3)CO(2))(162) (1), Cd(87)(H(2)O)(72)(OH)(12)(CH(3)CO(2))(162) (2), Cd(10)(H(2)O)(6)(OH)(2)(CH(3)CO(2))(18) (3), and Cd(20)(H(2)O)(20)(OH)(4)(CH(3)CO(2))(36) (4) have been isolated. The coordination networks exhibit interesting structural diversity and have been investigated by powder X-ray diffraction, elemental analysis, thermal gravimetric analysis, infrared spectroscopy, and single-crystal X-ray diffraction. All four complexes are composed of secondary building units with the general formula [Cd(4)(OAc)(9)(μ(3)-OH)](2-). Complexes 1 and 2 exhibit a remarkable three-dimensional network composed of aligned columns, each 4.5 nm long, containing three different cadmium acetate clusters. Complexes 3 and 4 extend in two-dimensions with each unit cell repeating a different linkage isomer of the [Cd(4)(OAc)(9)(μ(3)-OH)](2-) cluster. 相似文献
16.
Valerie Belton Stephen P. Vickers 《The Journal of the Operational Research Society》1993,44(9):883-896
Both Data Envelopment Analysis (DEA) and Multiple Criteria Analysis (MCA) can be used to assess the efficiency with which units perform similar tasks. This paper describes an approach derived from the integration of data envelopment analysis and a multi-attribute value function. This approach is implemented as a visual interactive decision support system, the use of which is illustrated by a practical application. The authors feel that this approach overcomes some of the limitations of the original DEA approach and, in particular, increases users' understanding of DEA. The approach is particularly well suited to the analysis of the efficiency of a small number of units. 相似文献
17.
A. J. Vickers S. Alleston R. Gupta P. O. Müller D. Erasme 《Optical and Quantum Electronics》1996,28(7):983-989
A model is presented which determines the output from a semiconductor laser as a function of the direct current (d.c.) and radio frequency (r.f.) current applied to the laser. It is shown that by adjusting these two components the output optical pulse from a laser can be shifted in time without change to the pulse shape or height. Experimental results are presented which support the model. It is suggested how these results can be used to produce a semiconductor pump-probe source, which is essential for the development of optical probing. 相似文献
18.
Time-resolved fluorescence measurements are made with an optical-fiber probe approximately 16 m long. Fluorescence lifetimes for 1.00 μM solutions of rhodamine-B and rose bengal in ethanol were found to be 2.78 ± 0.04 ns and 0.77 ± 0.07 ns, respectively, similarin accuracy and precision to values obtained with conventional techniques. Calculations are used to investigate the limitations in remote determinations caused by temporal broadening. Results indicate that fiber lengths approaching 1 km can be used without significant loss in accuracy or precision. 相似文献
19.
Shan N Ingram JD Easun TL Vickers SJ Adams H Ward MD Thomas JA 《Dalton transactions (Cambridge, England : 2003)》2006,(23):2900-2906
Using a [Ru(II)([9]aneS3)] templating moiety, kinetically-locked, metallomacrocycles incorporating adenine based ligands have been synthesised through self-assembly. The kinetically robust nature of these structures is confirmed by electrochemical studies: each can be reversibly oxidised in a four-member redox series, containing two formally mixed valence states. Unusually, the electrochemically derived comproportionation constants for these mixed valence states are very different, suggesting that intermetallic coupling differs between the two states. Spectroelectochemistry studies confirm that while the [Ru(II)2Ru(III)] state is valence localised, the [Ru(II)Ru(III)2] state is electronically delocalised. Mechanisms by which this switching effect could occur, which involve the unusual connectivities in these mixed valence species, are presented. 相似文献
20.
M. Henini P. A. Crump P. J. Rodgers B. L. Gallagher A. J. Vickers G. Hill 《Journal of Crystal Growth》1995,150(1-4):446-450
We report on a series of Be-doped GaAs/AlGaAs two-dimensional hole gas (2DHG) structures grown on (110), (111)B, (211)B and (311)B oriented substrates and compare their properties with high-mobility samples grown on (311)A using Si doping. The samples were prepared and grown under the same conditions so as to render them comparable. They are found to have mobilities which are strongly anisotropic within the plane. The highest mobility is found on the (110) surface with 100,000 cm2 V−1 s−1, while the (211) surface gave the lowest values 10,000 cm2 V−1 s−1. However, the later samples are found to have quantum Hall effect critical currents of >70 μA: an exceptionally high value for a hole gas which makes them suitable for metrology. All the samples show strong low-field positive magnetoresistance with resistance increases of up to 30% at magnetic fields of only 0.1 T. The presence of this feature on all the different planes shows that it does not depend upon the details of the band structure. It is identified with the lifting of the degeneracy of the spin sub-bands by the asymmetrical potential giving rise to a classical two-band magnetoreresistance. 相似文献