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51.
以国际贸易理论为基础,利用广东省若干宏观经济数据,对广东省进出口额进行实证分析.本文采用了季节性ARIMA模型并结合离群值分析的方法对进出口额进行研究.实证分析此方法具有良好的效果. 相似文献
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《Journal of mass spectrometry : JMS》2017,52(5):315-318
MathIOmica‐MSViewer is an add‐on graphical user interface utility for the Mathematica software system which facilitates the visualization and exploration of spectra from open format mass spectrometry files (mzXML and mzML standard community formats). The viewer was designed for simplicity and handling of large mass spectrometry data files. To facilitate searches, users may use search filters for the spectra based on mass to charge ratios and retention times, and visualize precursor spectra associated to a parent spectrum. Availability: The viewer is available as a Mathematica notebook (MathIOmica‐MSViewer.nb) at https://doi.org/10.5281/zenodo.321385 . The software is provided under an MIT License. © 2017 The Authors. Journal of Mass Spectrometry published by John Wiley & Sons, Ltd. 相似文献
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提出一种交互式自动挖掘知识的模型,论述了该模型的原理、实现机制,并讨论了模型中数据宝藏和影响域及其相互关系.该模型同时具有在线性与深入挖掘的优点,能灵活有效地满足实际应用的需求. 相似文献
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A scheme is developed for analysing the interaction between a foundation and a nonlinear rock and soil medium, in which the
foundation is considered as a linear elastic body and a typical boundary integral equation method (BIEM) is employed. On the
basis of taking the nonlinear properties of the medium into account, a perturbation BIEM is developed. The fundamental equations
for the nonlinear coupling analysis are formulated, and typical problems are solved and discussed by the present method. 相似文献
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ZHANG Zhenyue & ZHA Hongyuan Department of Mathematics Zhejiang University Yuquan Campus Hangzhou China Department of Computer Science Engineering The Pennsylvania State University University Park PA U.S.A. 《中国科学A辑(英文版)》2004,47(6):908-920
We present our recent work on both linear and nonlinear data reduction methods and algorithms: for the linear case we discuss results on structure analysis of SVD of column-partitioned matrices and sparse low-rank approximation; for the nonlinear case we investigate methods for nonlinear dimensionality reduction and manifold learning. The problems we address have attracted great deal of interest in data mining and machine learning. 相似文献
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Ramji Balakrishnan Xin Ying Qiu Padmini Srinivasan 《European Journal of Operational Research》2010,202(3):789-801
We investigate whether narrative disclosures in 10-K and 10K-405 filings contain value-relevant information for predicting market performance. We apply text classification techniques from computer science to machine code text disclosures in a sample of 4280 filings by 1236 firms over five years. Our methodology develops a model using documents and actual performance for a training sample. This model, when applied to documents from a test set, leads to performance prediction. We find that a portfolio based on model predictions earns significantly positive size-adjusted returns, indicating that narrative disclosures contain value-relevant information. Supplementary analyses show that the text classification model captures information not contained in document-level features of clarity, tone and risk sentiment considered in prior research. However, we find that the narrative score is not providing information incremental to traditional predictors such as size, market-to-book and momentum, but rather affects investors’ use of price momentum as a factor that predicts excess returns. 相似文献