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在分析电子商务信息系统安全现状的基础上,构造一种包括信息资产、脆弱性、威胁等关键要素的风险计算模型,通过信息资产风险的量化分析进而确定风险等级和可接受的风险等级. 相似文献
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We extract information on relative shopping interest from Google search volume and provide a genuine and economically meaningful approach to directly incorporate these data into a portfolio optimization technique. By generating a firm ranking based on a Google search volume metric, we can predict future sales and thus generate excess returns in a portfolio exercise. The higher the (shopping) search volume for a firm, the higher we rank the company in the optimization process. For a sample of firms in the fashion industry, our results demonstrate that shopping interest exhibits predictive content that can be exploited in a real‐time portfolio strategy yielding robust alphas around 5.5%. 相似文献
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An econometric model for exchange rate based on the behavior of dynamic international asset allocation is considered. The capital movement intensity index is constructed from the adjustment of a fully hedged international portfolio. Including this index as an additional explanatory variable helps to explain the fluctuation of the exchange rate and predict better than the competing random walk model. Supporting empirical evidence is found in Germany–USA, Japan–USA, Singapore–USA and Taiwan–USA exchange markets. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
96.
针对航运资产整合后新企业的海运网络重建问题,从营运船舶的角度提出了轴-辐式网络和多港挂靠相结合的混合模式.结合混合模式对基于航线、路径、船舶一体化决策的可能约束,建立了总成本最小化为目标函数的线性混合0-1规划问题,设计了拉格朗日分解、次梯度、预处理与可行解构造的求解算法.通过一组准实例的数值仿真,验证了该求解算法在解决大规模问题时具有较强的计算性能.结果表明:航运资产整合可为新企业带来明显的规模优势,但海运网络重建成本控制的关键在于船队规模及其结构的再优化;新企业应选择合适数量的枢纽港口来布局主干网络,并通过优先保证分支网络上适当船型的配置和兼顾主干网络上大型船舶的充分利用的方式来提升船舶利用率. 相似文献
97.
In this study, a non‐stationary Markov chain model and a vector autoregressive moving average with exogenous variables coupled with a logistic function (VARMAX‐L) are used to analyze and predict the stability of a retail mortgage portfolio, based on the stress test framework. The method introduced in this paper can be used to forecast the transition probabilities in a retail mortgage over pre‐specified states, given a shock with a certain magnitude. Hence this method provides a dynamic picture of the portfolio transition process through which one can assess its behavior over time. While the paper concentrates on retail mortgages, the methodology of this study can be adapted also to analyze other credit products in banks. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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The P/E ratio is often used as a metric to compare individual stocks and the market as a whole relative to historical valuations. We examine the factors that affect changes in the inverse of the P/E ratio (E/P) over time in the broad market (S&P 500 Index). Our model includes variables that measure investor beliefs and changes in tax rates and shows that these variables are important factors affecting the P/E ratio. We extend prior work by correcting for the presence of a long‐run relation between variables included in the model. As frequently conjectured, changes in the P/E ratio have predictive power. Our model explains a large portion of the variation in E/P and accurately predicts the future direction of E/P, particularly when predicted changes in E/P are large or provide a consistent signal over more than one quarter. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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