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Switching Modes (switching + mode)
Selected AbstractsSimultaneous determination of melamine and related compounds by hydrophilic interaction liquid chromatography,electrospray mass spectrometryJOURNAL OF SEPARATION SCIENCE, JSS, Issue 17-18 2010Jingen Xia Abstract A hydrophilic interaction liquid chromatography coupled to ESI-MS (HILIC/ESI-MS) method for the simultaneous determination of melamine and related compounds, i.e. ammeline, ammelide and cyanuric acid in foods was developed and validated. The separation was accomplished on a Venusil HILIC column with a mobile phase of acetonitrile + 10,mM ammonium formate buffer solution at pH 3.5 (88:12, v/v) under isocratic elution mode. For the detection of the targets, the ESI probe worked in the positive and negative switching mode. For each compound, three ions were selected as qualitative ions to obtain high specificity, and the most abundant ion of each compound was selected for quantification to obtain high sensitivity. The target compounds were quantified using SIM with 15N3-melamine and 13C3-cyanuric acid being used as an internal standards in the positive and negative modes, respectively. Compared with RP separation mode, HILIC has merits such as high separation and anti-interference efficiency. The method validation including linearity, LOD, LOQ, precision and recovery proved that the method has merits such high sensitivity, specificity and simplicity versus the other methods reported in the literature. [source] Mixture-based adaptive probabilistic controlINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 2 2003Miroslav Kárný Abstract Quasi-Bayes algorithm, combined with stabilized forgetting, provides a tool for efficient recursive estimation of dynamic probabilistic mixture models. They can be interpreted either as models of closed-loop with switching modes and controllers or as a universal approximation of a wide class of non-linear control loops. Fully probabilistic control design extended to mixture models makes basis of a powerful class of adaptive controllers based on the receding-horizon certainty equivalence strategy. Paper summarizes the basic elements mentioned above, classifies possible types of control problems and provides solution of the key one referred to as ,simultaneous' design. Results are illustrated on mixtures with components formed by normal auto-regression models with external variable (ARX). Copyright © 2003 John Wiley & Sons, Ltd. [source] Performance comparison between fixed length switching and variable length switchingINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2008Chengchen Hu Abstract Fixed length switching (FLS) and variable length switching (VLS) are two main types of switching architecture in high-speed input-queued switches. FLS is based on a cell-by-cell scheduling algorithm, while VLS operates on the variable packet granularity. This paper aims to make a comprehensive comparison between these two switching modes to guide the industrial design and academic research. We use stochastic models, Petri net models, analysis and simulations to investigate various performance measures of interest. Average packet latency, bandwidth utilization, segmentation and reassembly overhead, as well as packet loss are the identified key parameters that influence the outcome of the comparison. The results achieved in this paper are twofold. On one hand, it is shown that FLS enables smaller packet loss and lower packet delay in case of a short packet. On the other hand, VLS favors better bandwidth utilization, reduced implementation complexity and lower average packet delay. We recommend VLS in the conclusion since its disadvantages can be compensated by some methods, while the problems in FLS are difficult to be solved. Copyright © 2007 John Wiley & Sons, Ltd. [source] Two-species asymmetric competition: effects of age structure on intra- and interspecific interactionsJOURNAL OF ANIMAL ECOLOGY, Issue 1 2007TOM C. CAMERON Summary 1The patterns of density-dependent resource competition and the mechanisms leading to competitive exclusion in an experimental two-species insect age-structured interaction were investigated. 2The modes of competition (scramble or contest) and strength of competition (under- to overcompensatory) operating within and between the stages of the two species was found to be influenced by total competitor density, the age structure of the competitor community and whether competition is between stages of single or two species. 3The effect of imposed resource limitation on survival was found to be asymmetric between stages and species. Environments supporting both dominant and subordinate competitors were found to increase survival of subordinate competitors at lower total competitor densities. Competitive environments during development within individual stage cohorts (i.e. small or large larvae), differed from the competitive environment in lumped age classes (i.e. development from egg,pupae). 4Competition within mixed-age, stage or species cohorts, when compared with uniform-aged or species cohorts, altered the position of a competitive environment on the scramble-contest spectrum. In some cases the competitive environment switched from undercompensatory contest to overcompensatory scramble competition. 5Such switching modes of competition suggest that the relative importance of the mechanisms regulating single-species population dynamics (i.e. resource competition) may change when organisms are embedded within a wider community. [source] | ||||||||||