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51.
The analysis, parameter estimation and optimal control of linear time-varying digital systems are facilitated in this study. The discrete pulse orthogonal functions (DPOFs) and their operational matrices are taken as a sharp tool. The applications of DPOFs to digital control systems are analogous to those of the known block pulse functions (BPFs) in continuous systems. By applying the DPOFs, approximate solutions of digital time-varying systems can easily be obtained by convenient algorithms. Three examples are illustrated to demonstrate the proposed DPOF technique, and the approximate results are very accurate and satisfactory. 相似文献
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Both natural and engineered systems are fundamentally dynamical in nature: their defining properties are causal, and their organisational and functional capacities are causally grounded. Among dynamical systems, an interesting and important sub-class are those that are autonomous, anticipative and adaptive (AAA). Living systems, intelligent systems, sophisticated robots and social systems belong to this class, and the use of these terms has recently spread rapidly through the scientific literature. Central to understanding these dynamical systems is their complicated organisation and their consequent capacities for re- and self-organisation. But there is at present no general analysis of these capacities or of the requisite organisation involved. We define what distinguishes AAA systems from other kinds of systems by characterising their central properties in a dynamically interpreted information theory. 相似文献
54.
SEPARATION OF STEROLS AND TRITERPENE ALCOHOLS FROM UNSAPONIFIABLE FRACTIONS OF THREE PLANT SEED OILS 总被引:2,自引:0,他引:2
Preparative HPLC was used to separate sterols and triterpene alcohols from the unsaponifiable matters in plant oils from Camellia weiningensis L., Brassica juncea L. and Microula sikkimensis . The isolated sterols and triterpene alcohols were acetylated and further purified by AgNO3 impregnated silica gel preparative thin layer chromatography (TLC). The isolated acetyl derivatives of sterols and triterpene alcohols were identified by melting point, specific rotation, infrared and mass spectrometry. The sterols were brassicasterol, campesterol, stigmasterol, β-sitosterol and Θ5 -avenasterol, Θ7 -avenasterol, Θ7 -stigmastenol and α-spinasterol. The triterpene alcohols were cycloartanol, cycloartenol, 24-methylenecycloartanol, cyclobranol, dammaradienol, tirucalla-7,24-dienol, butyrospermol, β-amyrin, germanicol, α-4-taraxasterol and lupeol. 相似文献
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Breen G. Collier D. Craig I. Quinn J. 《IEEE engineering in medicine and biology magazine》2008,27(2):103-108
The explosion of genetic data availability in the last decade has opened up many new avenues for the application of genetics to the improvement of human health, particularly, the common and complex disorders, which previously largely defied researchers seeking to understand their etiology. However, the utilization of this data in healthcare and by the pharmaceutical industry is still in its infancy, with the current focus being almost solely on two forms of genetic variation single nucleotide polymorphisms (SNPs), involving the substitution of one base in DNA for another and copy number variations, involving the deletion and multiplication of regions > 1,000 base pairs (bp). However, there is currently a relative paucity of funding and general interest in a third form of variation called microsatellites and mini- satellites. 相似文献
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AM Hodge RA Westerman MP de Courten GR Collier PZ Zimmet KG Alberti 《Canadian Metallurgical Quarterly》1997,21(1):50-53
We performed a case-control study to investigate the association of the poor metaboliser genotype of the cytochrome P450 2D6 gene with Parkinson's disease (PD). Genotyping was determined by the polymerase chain reaction followed by digestion with restriction enzymes. The poor metaboliser genotype was more frequent in 112 patients with PD than in 206 matched controls (odds ratio 1.7, 95% CI: 0.94-2.45). A meta-analysis of these results together with ten other published studies gave a pooled odds ratio for the poor metaboliser genotype of 1.47 (95% CI: 1.18-1.96, P=0.01). Thus, the poor metaboliser genotype has a small but highly significant association with PD which would be easily missed in small studies. Research now should focus on the mechanism of this association. 相似文献
60.
A total of 29 volatile nitrogen-containing compounds were identified from model systems containing glutamine, glutamic acid, asparagine and aspartic acid, respectively, with glucose under simulated deep-fat frying conditions in corn oil. Alkylpyrazines were the most important flavor compound generated. Glutamine, which released free ammonia easily under this condition gave the highest yield of alkylpyrazines. The profiles of pyrazines produced by each amino acid were significantly different. In a glutamine system, 2-(2-furyl)pyrazine, 2-(2-furyl)- 5-methylpyrazine and 2-(2-furyl)-6-methylpyrazine were the major compounds generated. 相似文献