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排序方式: 共有434条查询结果,搜索用时 15 毫秒
1.
Uses a Markov process to model a real-time expert system architecture characterized by message passing and event-driven scheduling. The model is applied to the performance evaluation of rule grouping for real-time expert systems running on this architecture. An optimizing algorithm based on Kernighan-Lin heuristic graph partitioning for the real-time architecture is developed and a demonstration system based on the model and algorithm has been developed and tested on a portion of the advanced GPS receiver (AGR) and manned manoeuvring unit (MMU) knowledge bases 相似文献
2.
BB Horswell CL Castiglione AE Poole LA Assael 《Canadian Metallurgical Quarterly》1993,51(2):145-9; discussion 149-50
The double-reversing Z-plasty of Furlow for closure of the soft palate was used in 34 children with various types of cleft palate. Mean age at repair was 12.8 months. Intraoperative experience was favorable, with acceptable operating time and blood loss. Length of hospitalization averaged 1.9 days. Postoperatively, two children experienced temporary stridor, which resolved within 24 to 48 hours. One child had dehiscence of the hard palate (Von Lagenbeck repair) 4 weeks postoperatively, and three children developed small oronasal fistulae. Early speech evaluation demonstrated adequate soft palate mobility in 33 of 34 patients, with observable velopharyngeal function. Twelve children had mild velar compromise, with eight exhibiting slight nasal air escape. 相似文献
3.
The fabrication, properties and composition of heated phosphate-bonded clay bricks are reported. The strength of phosphate-bonded clay bodies is shown to be related to the equilibrium pH of the clay mix. The highest strengths were obtained for mixes with equilibrium pH 7 fired at 500°C which gave a modulus of rupture 60% higher than the unmodified clay heated under similar conditions but at 800°C firing temperature. The phosphate-bonded products were also of low porosity and improved dimensional stability. An insight into the probable mechanism of strength development of the heated product has been obtained from XRD, SEM and DSC studies. The results show that the properties of the phosphate-bonded clay bodies are critically affected by new mineral phases resulting from the reactions of phosphates with clay which subsequently undergo physico-chemical changes above 550°C. 相似文献
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Efficient conversion between the LP01 and LP11 modes in a two-mode fibre is achieved by periodically ablating the fibre surface with a CO2 laser and then annealing the fibre with an electric arc. The resulting periodic core deformation produces 99% mode conversion over a 37 nm bandwidth around 1540 nm and 0.38 dB insertion loss 相似文献
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A Monte-Carlo reliability simulator for integrated circuits (IC) that incorporates the effects of process flaws, material properties, the mask layout, and use conditions is presented. The mask layout is decomposed into distinct objects, such as contiguous metal runs, vias, contacts, and gate-oxides, for which user-defined distributions are used for determining the failure probability. These distributions are represented by a mixture of defect-related and wearout-related distributions. The failure distributions for nets (sets of interconnected layout objects) are obtained by combining the distributions of their component objects. System reliability is obtained by applying control variate sampling to the logic network which is comprised of all nets. The effects of k-out-of-n substructures within the reliability network are accounted for. The methodology is illustrated by the effect of particulate-induced defects on metal runs and vias in a simple test circuit. The results qualitatively verify the methodology and show that predictions which incorporate failures due to process flaws are appreciably more pessimistic than those obtained from current practice 相似文献
9.
P.J. Poole S. Charbonneau M. Dion G.C. Aers M. Buchanan R.D. Goldberg I.V. Mitchell 《Photonics Technology Letters, IEEE》1996,8(1):16-18
A technique for fabricating many different wavelength lasers on the same wafer has been developed. High energy ion implantation was used to selectively blue shift the emission wavelength of an InP-based quantum well laser structure. This structure was then processed into fully functional broad-area lasers whose current threshold was unaffected by the implantation process, indicating extremely high material quality after bandgap-shifting. This process has the potential for the integration of not only different wavelength lasers, but also other devices, such as waveguides, detectors, modulators, etc., on a single wafer. 相似文献