滑坡预报模型的质量检验研究

 
滑坡预报模型主要用来预报滑坡发生的时间,但是如何检验效果是滑坡预报者和决策者面临的一个重要课题。本文通过提出滑坡拟合效果指标（包括后验差指标、模型拟合效率指数和均方根误差）和试预报效果指标（包括试报效果指标和相关系数指标）,初步建立了滑坡的预报质量检验模型。依据建立的检验模型,针对链子崖危岩体监测资料分别采用灰色GM（1, 1）数学模型、三次指数平滑模型和时间序列模型进行预报。预报结果表明：三种模型中,综合指标GM（1, 1）数值最高,建议该滑坡采用GM（1, 1）进行预报。通过模型的综合分析评判,不仅分析了模拟效果,而且直接比较了模型间的拟合效果,并为建立模拟效果好的模型提供了充分的依据,从而表明滑坡预报质量检验模型是一种有效、实用的方法。


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The cold quality Qcold for magnicon on resonator in the rotating TMn10 mode

Cold quality Q_cold is an important parameter in microwave electronic tube design. Magnicon works in a rotrating TM_n10 mode in the cylindracl cavity, its field distribution is different from the static state. But up to now researchers simply assume its cold quality to be two times of the static one, which usually results in big errors. Here in this paper, based on the rotating field distribution, and using the integrated Bessel function, we deduced the cavity’s storage and the rotating field dissipated power expressions, and obtained a modified cold quality formula for rotating TM_n10 mode in the magnicon, which shows a good agreement with the experimental data. This work supported sci. & Tech. Funds of CAEP. Associate professor.     

Instability and heterogeneity: a new approach needed!

The outcome of routine testing for instability and heterogeneity of materials used in proficiency tests tends to be weakly informative because of the unacceptable cost of obtaining enough data to support a suitably powerful statistical test. A better strategy would be to spend considerably more on a large initial validation of a type of material or a procedure for preparing it, and then to monitor all subsequent batches of material of that type by a much cheaper quality control system. The expense of a powerful validation would be quickly recouped by savings in the longer term. Papers published in this section do not necessarily reflect the opinion of the Editors, the Editorial Board and the Publisher.     

FTIR应用于原产地中药材白芍的测定方法研究

采用傅里叶变换红外光谱不同的测定方法进行了白芍的测试比较,并对白芍木质部及外表皮部、不同产地的药典白芍进行了质量分析,结果显示白芍木质部与外表皮部含有相同的化学成分,但所含的芍药苷及其衍生物的含量木质部比外表部要高,而在杭白芍、亳白芍及川白芍中,以杭白芍的质量为佳.     

Location choices under quality uncertainty

We examine a linear city duopoly where firms choose their locations to maximize expected profits, uncertain about how consumers will assess the relative quality of their products. Equilibrium locations depend on the ratio of the expected quality superiority and the strength of horizontal differentiation. When this ratio is small, firms locate at opposite endpoints. As it becomes larger, agglomeration also emerges as an equilibrium with both firms choosing the same location within an interval around the center. Eventually, when the ratio is large enough, agglomeration becomes the only equilibrium and can occur at any point of the linear city.     

Enhancement of pullulan production by aureobasidium pullulans in batch culture using olive oil and sucrose as carbon sources

The production of pigment-free pullulan byAureobasidium pullulans, using olive oil and sucrose as carbon (C) sources, in shake flasks, was investigated. Optimum medium composition for pullulan elaboration was 80 g/L sucrose, 25 mL/L olive oil, 5 mL/L Tween-80, 10 g/L glutamic acid, and an initial pH of 5.5. Maximum pullulan concentration (51.5 g/L), productivity (8.6 g/L·d), and yield (80.3%) were achieved under these conditions after 120 h of fermentation. The principal advantage of using olive oil and sucrose simultaneously as C sources was the elimination of the inhibitory effect of high sucrose concentrations (> 60 g/L) on pullulan production by the microorganism. Structural characterization by¹³C-NMR, monosaccharide, and methylation analyses, and pullulanase digestion, combined with size-exclusion chromatography, confirmed the identity of pullulan and the homogeneity of the released polysaccharide in the fermentation broths. There were no significant differences in structure between pullulan samples isolated from either olive oil-supplemented media or olive oil-free media. The molecular size of pullulan from the combined olive oil-sucrose fermentation was slightly lower (1.1 X 10⁶) than that of conventional fermentation with sucrose as a single C source (1.4 X 10⁶). Lowering the initial pH of the medium resulted in increased molecular size for the released polymer, but a lower pullulan yield.     

Investigation of the performance of the instrument by nonlinear calibration

In the search for high reliability in chemical analysis, a straightforward method of nonlinear calibration is presented. The corresponding standard deviation (SD) was calculated by the law-of-propagation of errors that allowed the determination of uncertainties as a function of concentration within the range of concentrations defined by the lower limit of analysis (LLA) and the upper limit of analysis (ULA). The advantage of using nonlinear calibrations was demonstrated by the correspondence of average values to the peak position of the normal distribution. The concentration of cobalt in two certified reference materials (CRMs) was determined by flame absorption spectrometry (FAAS) that is recognised as an experiment of very high precision. In order to ensure the determination of a reliable value for the SD, a high number of repetitions were required for the analysis. It was thus demonstrated that results that apparently deviated significantly from the certified values, actually belonged to the overall normal distribution of results. The data of experiments were grouped according to Scott’s method, and the distribution of experiments showed a particularly high frequency of results at the peak position that exceeded the expected value predicted by the normal distribution. It also deviated from the distribution peak of experiments, which demonstrates the importance of a full investigation of the distribution of results using more than 100 repetitions. The skewness of the distribution of results was eliminated by the nonlinear calibration. Correspondence: Jens E. T. Andersen, Department of Chemistry, Technical University of Denmark, Kemitorvet building 207, DK-2800 Kgs. Lyngby, Denmark     

An Evolutionary Algorithm and discrete event simulation for optimizing inspection strategies for multi-stage processes

The problem of determining the optimal inspection strategy for a given multi-stage production process, i.e. the inspection strategy that results in the lowest total inspection cost, while still assuring a required output quality, is modelled as a joint optimization of inspection location, type and inspection limits. A fusion between a discrete event simulation to model the multi-stage process subject to inspection and to calculate the resulting inspection costs, and an Evolutionary Algorithm (EA) to optimize the inspection strategies, is suggested.     

Shape up or ship out: social networks,turnover, and organizational culture

This paper considers a formal model of cultural transmission in organizations, examining the interplay of structured social influence and organizational demography. A set of focused and fine-grained computational experiments elucidates this model’s assumptions, facilitates deeper explanations for some of its behavior, and explores the robustness and scope conditions of previously published conclusions. In doing so, this investigation highlights several important issues in the design and evaluation of computational experiments.