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Weight smoothing to improve network generalization   总被引:2,自引:0,他引:2  
A weight smoothing algorithm is proposed in this paper to improve a neural network's generalization capability. The algorithm can be used when the data patterns to be classified are presented on an n-dimensional grid (n>/=1) and there exists some correlations among neighboring data points within a pattern. For a fully-interconnected feedforward net, no such correlation information is embedded into the architecture. Consequently, the correlations can only be extracted through sufficient amount of network training. With the proposed algorithm, a smoothing constraint is incorporated into the objective function of backpropagation to reflect the neighborhood correlations and to seek those solutions that have smooth connection weights. Experiments were performed on problems of waveform classification, multifont alphanumeric character recognition, and handwritten numeral recognition. The results indicate that (1) networks trained with the algorithm do have smooth connection weights, and (2) they generalize better.  相似文献   
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Serum total cholesterol, high density lipoprotein (HDL) cholesterol, and triglyceride levels were studied in healthy male and female subjects consuming for one-week periods a diet of conventional food (CF) providing 42% of energy as fat, principally butter fat, and then in random order nutritionally complete, defined formula diets of moderate (32%) to very low (1%) fat content. Compared to CF, the formula with 32% of energy as corn oil lowered serum cholesterol by 25% and the ratio of total to HDL-cholesterol by 13%. Low (9%) and very low (1–3%) fat formulas reduced HDL-cholesterol by as much as 40%, raised the total: HDL-cholesterol ratio by about 20% and raised serum triglyceride levels by as much as 100%. When low and very low fat formulas were ingested for three weeks, these effects persisted although maximal responses occurred during the first week. These results demonstrated that a moderate fat formula diet with a high P/S ratio had a more favorable effect on serum lipid levels than various low fat formulas. Low fat conventional food diets should be studied in long-term controlled metabolic experiments before such diets are recommended to the general population for coronary heart disease or cancer prevention.  相似文献   
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Hypersonic flight powered by airbreathing engines offers the potential for faster response time at long ranges, and reduced cost for access-to-space. In the present paper the operating environment of typical hypersonic vehicles are discussed, including results for the radiation equilibrium wall temperature of external vehicle surfaces and the flow properties through three sample engines spanning the range of hydrocarbon-fueled Mach 4-8 flight and hydrogen-fueled flight at speeds up to Mach 17. Flow conditions at several locations through the sample engines were calculated to provide indications of the required operating flow environment. Additional system consideration such a seals, joints, vehicle integration and in-service engineering are addressed.  相似文献   
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BACKGROUND: In the framework of biological processes used for waste gas treatment, the impact of the inoculum size on the start‐up performance needs to be better evaluated. Moreover, only a few studies have investigated the behaviour of elimination capacity and biomass viability in a two‐phase partitioning bioreactor (TPPB) used for waste gas treatment. Lastly, the impact of ethanol as a co‐substrate remains misunderstood. RESULTS: Firstly, no benefit of inoculation with a high cellular density (>1.5 g L?1) was observed in terms of start‐up performance. Secondly, the TPPB was monitored for 38 days to characterise its behaviour under several operational conditions. The removal efficiency remained above 63% for an inlet concentration of 7 g isopropylbenzene (IPB) m?3 and at some time points reached 92% during an intermittent loading phase (10 h day?1), corresponding to a mean elimination capacity of 4 × 10?3 g L?1 min?1 (240 g m?3 h?1) for a mean IPB inlet load of 6.19 × 10?3 g L?1 min?1 (390 g m?3 h?1). Under continuous IPB loading, the performance of the TPPB declined, but the period of biomass acclimatisation to this operational condition was shorter than 5 days. The biomass grew to approximately 10 g L?1 but the cellular viability changed greatly during the experiment, suggesting an endorespiration phenomenon in the bioreactor. It was also shown that simultaneous degradation of IPB and ethanol occurred, suggesting that ethanol improves the biodegradation process without causing oxygen depletion. CONCLUSION: A water/silicone oil TPPB with ethanol as co‐substrate allowed the removal of a high inlet load of IPB during an experiment lasting 38 days. Copyright © 2008 Society of Chemical Industry  相似文献   
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The core of the electric cable is a heterogeneous medium; the conducting wires are periodically distributed and the period is small compared with the diameter of the core. Moreover, the insulating medium is not perfectly thermally insulating but its thermic conductivity is small. We study the evolution of the global temperature in the core and find two different types of results, depending upon how small are the two small parameters.  相似文献   
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Elder mistreatment, both abuse and neglect, is an important health care problem for women since they are involved as victims and as perpetrators. The incidence of both forms of such mistreatment is increasing, and both often occur within the context of long-term care. Elder abuse occurs in both unidirectional and dual directional forms, and includes parent abuse and spouse abuse. Elder neglect occurs in two forms; neglect by others and self-neglect. While elderly men and women are both neglected and/or abused, women may suffer greater physical and psychological consequences. To date, researchers have inadequately addressed the relevance of gender to both forms of elder mistreatment. This literature review addresses what is currently known about elder abuse and neglect that is of particular relevance to older women.  相似文献   
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Tight frequency-to-amplitude relationships are observed in spontaneous human steady gait. If required, however, they can be modified. The following experiments were aimed at the processes underlying this flexibility, which forms the fundamental basis of the intentional adaptive capabilities of locomotion. In Exp 1, Ss had to intentionally modify the frequency-to-amplitude relationship (leading to preferred or nonpreferred steady states). In Exp 2, they had to temporarily perturbate the stride-frequency-to-amplitude relationship to intentionally shorten or lengthen 1 stride. Within the important constraints exerted by the head–arm–trunk system on leg movement, the results pointed out 2 main strategies that allow the S to intentionally adapt stride organization on-line: adjustment of the tonic properties of the oscillating leg to achieve nonpreferred steady states and phasic action to ensure temporary movement away from a steady state. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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