随机蕨丛算法匹配识别性能研究

为了改进基于特征点的图像匹配识别方法的精确度,文章对特征点匹配算法随机蕨丛的性能进行评估,并与尺度不变特征变换算法SIFT的匹配性能进行对比研究。通过实验将随机蕨丛算法参数进行优化配置,分别测试两种算法的鲁棒性能和匹配速度。实验结果表明,随机蕨丛算法的匹配精度能达到85%左右,明显高于SIFT算法,匹配速度也远快于SIFT算法,但仍然有待提高。     

迪维西亚(Divisia)货币总量VAR模型的预测分析

本文针对最新编制的我国迪维西亚(Divisia)货币总量(指数)数据,运用向量自回归(VAR)模型预测实际产出和物价指数并与简单加总货币总量所得到的结果进行比较.结果显示,在预测我国实际产出值的VAR模型中,含有Divisia狭义货币(M1)总量的模型比含有简单加总货币总量M1的模型更精确;在预测我国的物价指数值的VAR模型中,含有Divisia广义货币(M2)总量的模型比含有简单加总货币总量M1和M2的模型更精确.     

How Stable is the Forecasting Performance of the Yield Curve for Output Growth?*

We provide an extensive evaluation of the predictive performance of the US yield curve for US gross domestic product growth by using new tests for forecast breakdown, in addition to a variety of in‐sample and out‐of‐sample evaluation procedures. Empirical research over the past decades has uncovered a strong predictive relationship between the yield curve and output growth, whose stability has recently been questioned. We document the existence of a forecast breakdown during the Burns–Miller and Volker monetary policy regimes, whereas during the early part of the Greenspan era the yield curve emerged as a more reliable model to predict future economic activity.     

高校教师教学工作绩效评估与人岗分配问题研究

高校教师的教学岗位分配问题属人力资源管理中的配置问题,合理的配置能充分利用教学资源,提高教师教学质量。文章运用运筹学的知识,利用与学分相结合的360度绩效评估方法,按照效益最大化的原则给出了指派问题的数学模型,并且结合实例进行分析,证明了模型的有效性、实用性,从而为解决高校教师人员配置问题提供决策参考。     

Spatial Mismatch and Social Acceptability

Research on spatial mismatch has focused on its effects on job access, but not on the mechanisms through which the effects operate. We explore one such mechanism—namely, that blacks do not search for suburban jobs because they are not socially accepted in the suburbs. Using data from the Greater Atlanta Neighborhood Study, we find that a black person's perception of his or her acceptance in a job search area has a small, but statistically significant effect on the probability of searching for a job in that area. Limitations associated with our measure of social acceptance suggest that the results should be considered suggestive.     

Mismatch Shocks and Unemployment During the Great Recession

We investigate the macroeconomic consequences of fluctuations in the effectiveness of the labor market matching process with a focus on the Great Recession. We conduct our analysis in the context of an estimated medium‐scale dynamic stochastic general equilibrium model with sticky prices and equilibrium search unemployment that features a shock to the matching efficiency (or mismatch shock). We find that this shock is not important for unemployment fluctuations in normal times. However, it plays a somewhat larger role during the Great Recession when it contributes to raise the actual unemployment rate by around 1.3 percentage points and the natural rate by around 2 percentage points. The mismatch shock is the dominant driver of the natural rate of unemployment and explains part of the recent shift of the Beveridge curve. Copyright © 2016 John Wiley & Sons, Ltd.     

Leading for Long‐Term Performance: Matching the Behavior to the Situation

Is there one right way to lead, or does it all “depend?” The right answer will inform the right leadership development strategy. A recent study by McKinsey & Co. using survey data collected from 165 organizations and over 365,000 respondents globally suggests that the answer is both. Two types of behavior sets emerged from organizations that enjoyed higher member perceptions of leadership effectiveness and attained higher levels of organizational health (the latter predicts long‐term financial and operational performance). We combined these into a model that prescribes a set of “baseline” behaviors that should always be evident, complemented by another set of behaviors (“situational behaviors”) that should be differentially emphasized depending on the level of organizational health. Both the content of the behavior and its relative emphasis are critical to either set. The current paper combines these into a model of organization‐wide leadership and concludes with action implications for organizations’ leadership development strategy.     

Macroeconomic Forecasting Performance under Alternative Specifications of Time‐Varying Volatility

This paper compares alternative models of time‐varying volatility on the basis of the accuracy of real‐time point and density forecasts of key macroeconomic time series for the USA. We consider Bayesian autoregressive and vector autoregressive models that incorporate some form of time‐varying volatility, precisely random walk stochastic volatility, stochastic volatility following a stationary AR process, stochastic volatility coupled with fat tails, GARCH and mixture of innovation models. The results show that the AR and VAR specifications with conventional stochastic volatility dominate other volatility specifications, in terms of point forecasting to some degree and density forecasting to a greater degree. Copyright © 2014 John Wiley & Sons, Ltd.     

货币错配、汇率升值和经济波动

本文在考虑当前东亚各国普遍存在的资产型货币错配情况下,将Ber-nanke等(1999)模型推广到小国开放经济中,分析了由外生冲击导致的汇率升值影响经济的传导路径,以及这种影响程度所取决的因素。研究发现,当一个国家存在资产型货币错配时,汇率升值降低企业净值,并通过金融加速器机制提高企业的外部融资成本,进而影响企业的投资和产出。模型的数值模拟结果表明,升值导致的产出下降幅度与该国的货币错配程度和金融加速器效应直接相关。当该国货币错配程度较高,金融加速器效应显著时,外部冲击导致的升值可能使经济陷入流动性陷阱。     

董事会职能变迁轨迹及职能重塑

董事会在公司治理机制中发挥关键作用。伴随着公司治理的发展,董事会职能经历了由经营管理到监督,再从监督到监督和决策并重的变迁过程。股权分置改革后,我国公司治理呈现以下特征:国有股"一股独大"状况得到改善;公司控制权市场逐步形成;中小股东的利益逐渐得到保护;公司治理目标由股东价值最大化转变为企业价值最大化。公司治理的变化促使董事会职能发生相应的调整,董事会职能应从权利格局、组织结构、董事素质与激励约束机制、董事会与经理的职责方面实现重塑。     

Forecasting the Past

Bezien wij het probleem van economische voorspelling. Wij nemen aan dat dit met een model gebeurt. Over dit model wordt de volgende veronderstelling gemaakt: Het model is een lineair stelsel van stochastische differentie-vergelijkingen. Om een voorspelling te kunnen doen met behulp van het model, hebben wij cijfers nodig omtrent de uitgangstoestand. Deze uitgangstoestand behoort tot het recente verleden, waaromtrent de statistische informatie nog on-volledig is. Dit doet het volgende probleem rijzen: Kan men het model ook gebruiken om de uitgangstoestand te "voorspellen"? Dit probleem verschilt van dat van het voorspellen van de toekomst, doordat we een additionele eis moeten stellen. De "voorspelde" vector van uitgangswaarden moet in overeenstemming zijn met de beperkte statistische informatie die wèl beschikbaar is. De auteur pakt dit probleem aan, door het minimaliseren van een gewogen som van de storingstermen in de afzonder-lijke relaties van het model. Het algoritme, waartoe dit aanleiding geeft, wordt tamelijk gedetailleerd besproken.     

Forecasting the Past

Bezien wij het probleem van economische voorspelling. Wij nemen aan dat dit met een model gebeurt. Over dit model wordt de volgende veronderstelling gemaakt: Het model is een lineair stelsel van stochastische differentie-vergelijkingen. Om een voorspelling te kunnen doen met behulp van het model, hebben wij cijfers nodig omtrent de uitgangstoestand. Deze uitgangstoestand behoort tot het recente verleden, waaromtrent de statistische informatie nog on-volledig is. Dit doet het volgende probleem rijzen: Kan men het model ook gebruiken om de uitgangstoestand te “voorspellen”? Dit probleem verschilt van dat van het voorspellen van de toekomst, doordat we een additionele eis moeten stellen. De “voorspelde” vector van uitgangswaarden moet in overeenstemming zijn met de beperkte statistische informatie die wèl beschikbaar is. De auteur pakt dit probleem aan, door het minimaliseren van een gewogen som van de storingstermen in de afzonder-lijke relaties van het model. Het algoritme, waartoe dit aanleiding geeft, wordt tamelijk gedetailleerd besproken.     

建筑物沉降的组合预测模型应用研究

提出采用组合模型预测建筑物沉降,并以常用的三种建筑物沉降预测模型组成组合模型进行了计算分析,结果表明组合预测模型具有较高的预测精度,值得推广应用.     

空间失配研究态势的文献计量分析

采用文献引文网络分析可视化软件Citcspacc Ⅱ对SSCI中有关“空间失配”主题的研究丈献进行分析,判明国外“空间失配”的研究热点和趋势。研究热点主要是空间失配带来的各种问题以及造成空间失配的原因。研究趋势是更加注重空间数据和实证研究。     

解析函数、共轭解析函数及复调和函数的一个充要条件

给出了复形式的解析函数、共轭解析函数及复调和函数充要条件的证明及其重要应用。     

Forecasting and loss functions

This paper considers two problems of interpreting forecasting competition error statistics. The first problem is concerned with the importance of linking the error measure (loss function) used in evaluating a forecasting model with the loss function used in estimating the model. It is argued that because the variety of uses of any single forecast, such matching is impractical. Secondly, there is little evidence that matching would have any impact on comparative forecast performance, however measured. As a consequence the results of forecasting competitions are not affected by this problem. The second problem is concerned with the interpreting performance, when evaluated through M(ean) S(quare) E(rror). The authors show that in the Makridakis Competition, good MSE performance is solely due to performance on a small number of the 1001 series, and arises because of the effects of scale. They conclude that comparisons of forecasting accuracy based on MSE are subject to major problems of interpretation.     

Forecasting the US housing market

The recent housing market boom and bust in the United States illustrates that real estate returns are characterized by short-term positive serial correlation and long-term mean reversion to fundamental values. We develop an econometric model that includes these two components, but with weights that vary dynamically through time depending on recent forecasting performances. The smooth transition weighting mechanism can assign more weight to positive serial correlation in boom times, and more weight to reversal to fundamental values during downturns. We estimate the model with US national house price index data. In-sample, the switching mechanism significantly improves the fit of the model. In an out-of-sample forecasting assessment the model performs better than competing benchmark models.     

Forecasting the Malmquist productivity index

The Malmquist Productivity Index (MPI) suggests a convenient way of measuring the productivity change of a given unit between two consequent time periods. Until now, only a static approach for analyzing the MPI was available in the literature. However, this hides a potentially valuable information given by the evolution of productivity over time. In this paper, we introduce a dynamic procedure for forecasting the MPI. We compare several approaches and give credit to a method based on the assumption of circularity. Because the MPI is not circular, we present a new decomposition of the MPI, in which the time-varying indices are circular. Based on that decomposition, a new working dynamic forecasting procedure is proposed and illustrated. To construct prediction intervals of the MPI, we extend the bootstrap method in order to take into account potential serial correlation in the data. We illustrate all the new techniques described above by forecasting the productivity index of 17 OECD countries, constructed from their GDP, labor and capital stock.