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排序方式: 共有353条查询结果,搜索用时 14 毫秒
311.
The purpose of this paper is to give a crisp introduction to three algorithms for sorting in situ, viz. insertion sort, heapsort and smoothsort. The more complicated the algorithm, the more elaborate the justification for the design decisions embodied by it. In passing we offer a style for the presentation of non-trivial algorithms that seems to have its merits. 相似文献
312.
Infrared spectroscopy can be a more powerful tool for fat analysis as is generally thought. Infrared spectra of solid triglycerides, unlike spectra of fats in the liquid form or in solutions, can namely give information about the following items: crystallization form, chain length of the fatty acid moieties, isomeric form, unsaturated fatty acid moieties, cis or trans unsaturation, and position of double bonds. This is illustrated by some examples. Almost all bands have been assigned, even in the fingerprint region. To understand the observed phenomena, the new concept ‘diathesis’ has been used with success. 相似文献
313.
Edsger W. Dijkstra 《Science of Computer Programming》1982,1(3):223-233
Like heapsort - which inspired it - smoothsort is an algorithm for sorting in situ. It is of order N · log N in the worst case, but of order N in the best case, with a smooth transition between the two. (Hence its name.) 相似文献
314.
Allen Rebecca S.; Burgio Louis D.; Roth David L.; Ragsdale Rachael; Gerstle John; Bourgeois Michelle S.; Dijkstra Katinka; Teri Linda 《Canadian Metallurgical Quarterly》2003,18(4):886
Confirmatory factor analysis of the Revised Memory and Behavior Problems Checklist--Nursing Home (RMBPC) replicated the factor structure of the community-based RMBPC (L. Teri et al, 1992). The reliability of the total score was high as indexed by estimates of internal consistency (α=.95), test-retest reliability (r=.86), and interrater reliability between 2 interviewers (r=.88). Notably, the interrater reliability between 2 independent certified nursing assistants (CNAs) regarding residents' behavior problem frequency was more modest (r=.46), possibly reflecting the degree to which resident behaviors capture individual CNA's attention. This may have implications for the interpretation of data from the Minimum Data Set. CNAs reported moderately severe burden associated with behavior problems in 47% of residents under their care. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
315.
J Zguricas PF Dijkstra ES Gelsema PJ Snijders HP Wüstefeld HW Venema SE Hovius D Lindhout 《Canadian Metallurgical Quarterly》1997,34(1):55-62
A new two-step high-performance liquid chromatography (HPLC) procedure has been developed to separate modified histone H1 subtypes. Reversed-phase (RP) HPLC followed by hydrophilic-interaction liquid chromatography (HILIC) was used for analytical and semi-preparative scale fractionation of multi-phosphorylated H1 histone subtypes into their non-phosphorylated and distinct phosphorylated forms. The HILIC system utilizes the weak cation-exchange column PolyCAT A and an increasing sodium perchlorate gradient in a methanephosphonic acid-triethylamine buffer (pH 3.0) in the presence of 70% (v/v) acetonitrile. The identity and purity of the individual histone subfractions obtained was assayed by capillary electrophoretic analysis. The results demonstrate that application of the combined RP-HPLC-HILIC procedure to the analysis and isolation of modified H1 histone subtypes provides an innovative and important alternative to traditional separation techniques that will be extremely useful in studying the biological function of histone phosphorylation. 相似文献
316.
An oversampled A/D (analog-to-digital) converter that can be configured as either a sigma-delta converter or an incremental converter is presented. This is an oversampled instrumentation converter that cancels offset and 1/f noise. The converter architecture is based on a mixed analog-digital integrator (MADI) concept. This concept is shown to lead to a very simple and modular architecture. The implemented converter also allows selection of the converter order and the decimation factor in order to find the best tradeoff between resolution, conversion time or bandwidth, and power consumption. As the converter architecture is completely modular, it can rapidly be tailored for a specific application with minimized silicon area. The circuit achieves a resolution of 16 b on a range of ±650 mV and compensates the offset and the even-order harmonics to a nonobservable level 相似文献
317.
This article addresses the questions of how and when lexical information influences phoneme identification in a series of phoneme-monitoring experiments in which conflicting predictions of autonomous and interactive models were evaluated. Strong facilitatory lexical effects (reflected by large differences in detection latencies to targets in words and matched nonwords) were found only when targets came after the uniqueness point of the target-bearing word. Furthermore, no evidence was obtained for lexically mediated inhibition on phoneme identification as predicted by the interactive activation model TRACE. These results taken together point to strong limitations in the way in which lexical information can affect the perception of unambiguous speech. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
318.
Albert J. Dijkstra 《European Journal of Lipid Science and Technology》2006,108(3):249-264
The decisions to limit (Europe) or declare (USA) the trans isomer content of certain fatty foodstuffs have caused a demand for hardstocks with a reduced trans isomer content. One way to produce such hardstocks is by interesterifying high‐melting components such as palm stearin or fully hydrogenated vegetable oils with lauric or liquid oils. Another way is to modify the hydrogenation process. Possible modifications are reviewed. A moderate reduction in trans isomer content results from operating the hydrogenation process at much reduced temperature, but this also leads to an increase in saturates. Larger reductions in trans isomers may well be made possible by the recent development of new catalysts. One development involves the use of zeolites that allow the rather straight trans isomer to enter the pores while keeping the more curved cis isomers outside. The other development involves a precious metal catalyst that may have been modified in such a way that it has a reduced affinity for monounsaturated fatty acid moieties. 相似文献
319.
L. H. H. Olde Damink P. J. Dijkstra M. J. A. Van Luyn P. B. Van Wachem P. Nieuwenhuis J. Feijen 《Journal of materials science. Materials in medicine》1995,6(8):460-472
The formation of Schiff bases during crosslinking of dermal sheep collagen (DSC) with glutaraldehyde (GA), their stability and their reactivity towards GA was studied. All available free amine groups had reacted with GA to form a Schiff base within 5 min after the start of the reaction under the conditions studied (0.5% (w/w) GA). Before crosslinks are formed the hydrolysable Schiff bases initially present were stabilized by further reaction with GA molecules. An increase in shrinkage temperature (T
s) from 56°C for non-crosslinked DSC (N-DSC) to 78°C for GA crosslinked DSC (G-DSC) was achieved after crosslinking for 1 h. From the relationship between the free amine group content and the T
s during crosslinking it was concluded that higher GA concentrations and longer reaction times will result in the introduction of pendant-GA-related molecules rather than crosslinks. After 24 h crosslinking an average uptake of 3 GA molecules per reacted amine group was found. No increase in the tensile strength of the materials was observed after crosslinking, which may be a result of formation of crosslinks within the fibres rather than in between fibres. Aligning of the fibres by applying a pre-strain to the samples and subsequent crosslinking yielded materials with an increased tensile strength. 相似文献
320.
D. Dijkstra 《Journal of scientific computing》2002,17(1-4):513-527
In the conventional pseudo-spectral collocation method to solve an ordinary first order differential equation, the derivative is obtained from Lagrange interpolation and has degree of precision N for a grid of (N+1) points. In the present, novel method Hermite interpolation is used as point of departure. From this the second order derivative is obtained with degree of precision (2N+1) for the same grid as above. The associated theorem constitutes the main result of this paper. Based on that theorem a method in put forward in which the differential equation and the differentiated differential equation are simultaneously collocated. In this method every grid point counts for two. The double collocation leads to a solution accuracy which is superior to the precision obtained with the conventional method for the same grid. This superiority is demonstrated by 3 examples, 2 linear problems and a non-linear one. In the examples it is shown that the accuracy obtained with the present method is comparable to the solution accuracy of the standard method with twice the number of grid points. However, the condition number of the present method grows like N
3 as compared to N
2 in the standard method. 相似文献