基于时间序列的BP神经网络预测鄂尔多斯市的GDP

国内生产总值(GDP)是制定经济发展战略、规划、年度计划以及各种宏观经济政策的重要依据,研究GDP预测方法具有重要的现实意义。在对鄂尔多斯市GDP数据序列分析的基础上,考虑到BP神经网络可以通过简单非线性函数的复合能够实现对于复杂函数的映射,本文采用BP神经网络方法来预测鄂尔多斯市的GDP,取得了较好的预测效果。     

Labor Income Taxation,Human Capital,and Growth: The Role of Childcare*

In this paper, we examine the effects of labor income taxation on growth in an overlapping generations model in which schooling and childcare play a role in the production of human capital. We compare such effects with those obtained in a model in which only schooling matters for skill formation. We show that the omission of childcare from the technology of skill formation can bias the results related to the impact of labor income taxation on growth.     

规划理论和实践中的空间观念辨析

规划理论和实践中的空间观念塑造着我们周围的人造环境。空间观念的发展呈现出从绝对到相对、从时空分离转向时空关联、从一元到多元的变化趋势。20世纪以来规划理论逐渐吸纳相对空间观念,但迄今为止规划实践仍以绝对空间观念为主导。绝对空间观念成为规划实践低效性的深层原因,但是完全放弃绝对空间观念而将相对空间观念引入规划理论和实践不仅存在很多困难,而且会造成认识和实践上的混乱,科学的空间观念应该将绝对和相对结合起来形成多元空间观。我国规划理论研究和实践仍以绝对空间观念为主导,了解绝对空间观念的不足和吸纳相对空间观念的合理性具有重要的理论和实践意义。     

Exogenous and Endogenous Attention and the Convergence of Analysts’ Forecasts

The propensity of the forecasts of sell-side financial analysts to converge (or diverge) is a function of their exogenous and endogenous selective attention and overconfidence. When returns are negative, the endogenous form of selective attention—a static measure of analysts’ goal-driven attention at a particular point in time—has a positive association with convergence. The exogenous form of selective attention—a relatively involuntary dynamic process of exogenous attentional shift driven by external changes in the market over time—is associated with a tendency for forecasts to diverge.     

河南省粮食应急供应链响应能力的理论分析

粮食应急供应链的主要功能是为应对自然灾害和突发事件提供有力的粮食物资保证。河南省是中国重要的粮食主产区之一,在保障国家安全方面具有不可替代的特殊地位,这必然要建立、健全粮食应急供应链。研究粮食应急供应链体系的建设问题,对于提高政府危机管理的水平,增强应对自然灾害和突发事件的能力,具有重要而深远的意义。     

Prediction of the next hypercalcemia free period: application of random effect models with selection on first event

The length of repeated hypercalcemia free periods of patients with bone metastasis of breast cancer with at least one hypercalcemic event was modelled according to a generalized linear mixed model formulated in terms of transition probabilities and according to a latent variable model. In the former case the periods were assumed to be lognormally distributed with two variance components (patients and residue). In the latter case the conditional intensity given a patient was assumed to be the intensity of the Weibull distribution, while the random patient effect (frailty) was assumed to be drawn from a gamma distribution. In both cases the selection of only patients with at least one hypercalcemic event was taken into consideration. In both models the variance of the patient effect turned out to be negligible. For the second and later periods the Weibull appeared to fit better than the lognormal model. For the first period there was almost no information available.     

COMMUNICATION ABOUT FUTURE POLICY RATES IN THEORY AND PRACTICE: A SURVEY

We discuss the theoretical rationale for central bank communication about future policy rates, either as part of inflation targeting or in the form of forward guidance. We also summarize both actual central bank communication about future policy rates and empirical evidence on the effectiveness of these types of communication. We argue that there is a disconnect between the theory and practice of forward guidance, as theory assumes commitment on the part of the central bank, while in practice central banks generally do not commit. Future theoretical research on forward guidance should therefore take the absence of commitment by central banks into account.     

When do sell-side analysts switch industries they follow?

Between 1984 and 2014 over 3400 sell-side analysts changed the primary industry they followed. This article documents that analysts are more likely to change their industries when their absolute and relative forecasting accuracy in that industry is low and when the accuracy in the new industry is high. Analysts are more likely to switch industries at the beginning of their careers, after a recent change of an employing brokerage house, and if they have a history of switching industries before. Analysts are less likely to make a switch when their forecasting activity in the industry is high, when the industry is followed by many analysts and when they are employed by a top brokerage house.     

旅游形象认知的时间顺序对旅游目的地形象认知的影响研究--以银川沙湖与榆林红碱淖为例

旅游者对旅游目的地的形象认知是影响旅游活动的重要因素,对旅游目的地形象定位和市场营销策略的选择都具有重要的参考价值。许多因素对旅游目的地形象认知都产生影响,其中认知的时间特征对旅游目的地形象认知的影响是一个值得关注的新课题:旅游者对不同旅游目的地形象认知的先后顺序对旅游目的地形象认知是否产生影响以及这种影响的程度如何。文章以银川沙湖与榆林红碱淖为例,对旅游者对旅游目的地形象认知中的“先入为主”与“既成事实”效应进行了分析,初步证明旅游者对不同旅游目的地形象感知的先后顺序对旅游目的地形象认知产生影响,并针对案例景区的情况,强调了旅游形象定位与市场营销中的先发优势,提出了自己的观点。     

精益化物流管理对药品供应仓储能力及药品周转时间的影响

目的探讨精益化物流管理对药品供应仓储能力及药品周转时间的影响。方法回顾性分析2013年8月至2014年7月中山大学附属第三医院粤东医院传统物流管理模式下的药品管理情况,以及2014年8月至2015年7月施行精益化物流管理模式后的药品管理情况。比较分析两种模式下的药品缺货率、仓储能力及药品周转时间情况。结果精益化物流管理下的A、B、C类药品所占实际面积与传统物流管理比较下降19.25%,总量增加9.86%;精益化物流管理下的A、B、C类药品周转率高于传统物流管理,差异有统计学意义(P<0.05);精益化物流管理下的A、B、C类药品周转时间短于传统物流管理,差异有统计学意义(P<0.05)。结论精益化物流管理模式可显著提升医院药品供应仓储能力,缩短药品周转时间,从而可提升药品管理整体水平,为医院带来效益,为患者提供高质量药品服务。