从美国90年代以来科技政策的发展谈我国21世纪科技政策的制定

本文分析了美国90年代以来科技政策的发展过程，认为可分为三个阶段，并对每个阶段美国的科技政策及其背景，研究开发的技术重点与科技发展有拳重大计划作了介绍，把重点放在了对美国布什新政府的科技政策的论述上。最后，文章在就美国科技政策演变过程对我国的启示进行了讨论，并指出了对于美国当前科技政策中的国防科技内涵，我国在科技政策中应控制出相应的策略。     

上海石库门里弄演替历程与再生模式新探

本文从上海石库门里弄源流再探和价值再识,到城市更新中的石库门里弄现状问题和再生模式,分三个部分展开讨论.第一部分再次追溯了“石库门”的词源及意涵, 19世纪中至20世纪初的建造缘起与早期形态,中英宅形间两次形态更替和交融,以及后期演进的境况.第二部分结合国际遗产宪章和话语背景,对石库门里弄在上海城市遗产体系中的定位和分类,在保护和活化中的复杂与矛盾、问题与症结和活化途径与方式等,进行了多维度的讨论.第三部分对石库门里弄再生典型案例的四种模式作了批判性反思,对石库门里弄再生的未来走向提出了策略建议.     

二战后美国科技政策的演变以及对我国的启示

本文分析了美国二战后科技政策的演变过程，认为可以分为五个阶段。文章介绍了每个阶段美国的科技政策及其背景，研究开发的技术重点，研究开发经费情况，与科技发展有关的重大计划，与科技政策有关的相关法律。重点介绍了美国现政府的科技政策及其对美国经济的影响，最后，文章还就美国科技政策及其演变过程对我国的启示进行了讨论。     

后工业化时代城市老工业区发展更新策略——以瑞士“苏黎世西区”为例

本文对“苏黎世西区”城市老工业区改造进行了详细介绍和分析，提出系统综合的目标设定、广泛协作的论证决策以及融合共生的设计思想是其获得成功的关键，值得借鉴和学习．文章结合我国老工业区改造的现状，提出了建议．     

Mecanum三轮多向行走系统结构与运动原理

常规Mecanum轮一般用于组成四轮全方位系统。将三个完全相同的常规Mecnum轮放置在等边三角形的三个顶点，能构成一种具有实用价值的多向行走系统。该系统不需转向轮或转向机构，仪利用3个轮子旋转速度大小和旋向组合实现平面上一个绕车身中心的定轴旋转、三个沿车身三角形对角线的直线运动。并给出了该系统的结构图，分析了系统实现上述运动的运动学原理。     

稀土材料的展望

文章讨论了稀土的特性及其在新材料中的应用，当前研究开发稀土新材料的热点，以及发展稀土新材料的几个化学课题，并提出了几点建议。     

基于城市设计的大尺度城市空间形态研究

在当今中国史无前例的城市化进程中,相当多的中国城市都不同程度地经历了城市规模的急剧扩张．伴随着城市规划的持续编制、修编和实施,城市的功能结构、空间环境、街廓肌理乃至社会等发生了显著的变化,而所有这些都直接发生在某一城市尺度、甚至是发生在某一城市的大尺度空间形态上．本文通过对城市空间形态构成、演进和外显表征的描述和分析,尝试建构城市形态影响要素模型,进而讨论与形态密切相关的城市用地属性及保护、调整和开发潜力．同时,基于城市设计参与良好城市空间形态塑造和建设管理的专业特征,提出针对大尺度城市空间形态的量化评析技术方法,从而为城市政府和规划建设管理部门提供技术支持．     

当前我国垄断现状及反垄断立法指向—兼论垄断与资源配置的关系

本文首先阐述我国垄断现状。目前我国经济生活中的垄断现象主要表现为两种形式：经济垄断和行政垄断，其中行政垄断表现得尤为普遍和突出，并且已对我国经济产生了许多不利的影响。其次从垄断与资源配置的关系讨论我国反垄断立法的指向。由于垄断结构的大企业更易提高生产效率，节约交易费用和提高技术效率，从而优化资源配置，所以我国反垄断立法的指向不应是垄断结构，更不应是垄断结构下的大企业，而应是限制竞争和不正当竞争的垄断行为。对于行政垄断，应针对不同表现形式具体对待，最后还提到在制定反垄断法时应同步配套地制定反垄断适用除外立法。     

局地气温与人为热释放关系的模型研究

近几十年来全球变暖的同时,城市局部区域普遍出现了更为突出的气温上升.城市通常是人类社会的中心,研究城市局地气温的变化规律有助于我国进行城市发展规划以减缓城市气温上升、以及更全面的认识气候变暖的原因,并能够为我国提出更合理的国际能源制度提供一定的理论支撑.局地温升与全球变暖的机理有所不同：能源消费产生的热量（人为热释放）在短期内集中于城市区域,会对局地气温产生明显的影响.基于这一观点,本文建立了结构化热力学模型,将城市局地环境划分为Human,Local,Outer三个区域,结合热力学基本定律分析了各区域热量和气温的变化规律,明确了Human区域人为热释放对城市局地气温的作用.研究表明：人为热释放对局地气温的升高起着近似线性的推动作用,人为热释放越强这种推动作用越明显.之后本文对模型研究结论进行了验证,验证研究以国家统计数据为依据,运用线性拟合外推法以及Pearson统计相关方法,对我国各省会城市以往气温与人为热释放数据进行了分析.结果表明：大部分省会城市的气温变化与人为热释放之间基本遵循线性的依赖关系,而且在空间和时间维度上这种线性关系都随着人为热释放的增加而更加明显.统计研究得到的规律与模型结论有着较好的对应,较好的验证了模型研究的合理性.     

质量管理模型在教育管理领域中的实践应用

近年来,我国许多学校开始把质量管理的相关理论应用于教育管理中,并在质量管理工具的使用方面也达成一定的共识.然而,对于教育质量管理的模型却没有过多的讨论,更没有一个普遍认同的教育质量管理模型.本文根据朱兰质量管理理论,提出一种教育质量管理模型,其包括三个构成元素：质量设计（quality of design）,质量保证（quality of conformance）和质量绩效（quality of performance）,希望该模型对学校的教学、科研及管理运作的质量改进提供借鉴.     

Can online search data improve the forecast accuracy of pork price in China?

Online search data provide us with a new perspective for quantifying public concern about animal diseases, which can be regarded as a major external shock to price fluctuations. We propose a modeling framework for pork price forecasting that incorporates online search data with support vector regression model. This novel framework involves three main steps: that is, formulation of the animal diseases composite indexes (ADCIs) based on online search data; forecast with the original ADCIs; and forecast improvement with the decomposed ADCIs. Considering that there are some noises within the online search data, four decomposition techniques are introduced: that is, wavelet decomposition, empirical mode decomposition, ensemble empirical mode decomposition, and singular spectrum analysis. The experimental study confirms the superiority of the proposed framework, which improves both the level and directional prediction accuracy. With the SSA method, the noise within the online search data can be removed and the performance of the optimal model is further enhanced. Owing to the long-term effect of diseases outbreak on price volatility, these improvements are more prominent in the mid- and long-term forecast horizons.     

Trading volume and prediction of stock return reversals: Conditioning on investor types' trading

We show that contrasting results on trading volume's predictive role for short‐horizon reversals in stock returns can be reconciled by conditioning on different investor types' trading. Using unique trading data by investor type from Korea, we provide explicit evidence of three distinct mechanisms leading to contrasting outcomes: (i) informed buying—price increases accompanied by high institutional buying volume are less likely to reverse; (ii) liquidity selling—price declines accompanied by high institutional selling volume in institutional investor habitat are more likely to reverse; (iii) attention‐driven speculative buying—price increases accompanied by high individual buying‐volume in individual investor habitat are more likely to reverse. Our approach to predict which mechanism will prevail improves reversal forecasts following return shocks: An augmented contrarian strategy utilizing our ex ante formulation increases short‐horizon reversal strategy profitability by 40–70% in the US and Korean stock markets.     

民机客舱热载荷的数值计算

以桌型客机为例,将客舱复杂围护结构划分为三部分。据此建立各区域单元结构的三维数值计算模型,并对不同外界环境下客舱的热流密度及传热量进行了数值仿真。结果与传统计算方法吻合良好,研究工作对于我国大型飞机热载荷的计算具有参考价值。     

Mise en évidence d'un système de corrélations intervenant dans la régénération des Planaires d'eau douce

Summary We show that there are correlations in regenerative fresh water planarians between all the parts of the body. When planarians are wounded in any part of the body, this mutilation will set regenerative cells in movement, which are able to travel a very long way in their migration. The extent and the speed of migration haves been shown by the method of localized X-ray irradiations.When the regenerative cells that are nearest to the wound have been killed with X-rays, regeneration occurs through the access of cells from the farther parts of the body. The nature of the stimulus is not yet known.     

WTI crude oil option implied VaR and CVaR: An empirical application

Using option market data we derive naturally forward‐looking, nonparametric and model‐free risk estimates, three desired characteristics hardly obtainable using historical returns. The option‐implied measures are only based on the first derivative of the option price with respect to the strike price, bypassing the difficult task of estimating the tail of the return distribution. We estimate and backtest the 1%, 2.5%, and 5% WTI crude oil futures option‐implied value at risk and conditional value at risk for the turbulent years 2011–2016 and for both tails of the distribution. Compared with risk estimations based on the filtered historical simulation methodology, our results show that the option‐implied risk metrics are valid alternatives to the statistically based historical models.     

Forecasting volatility in commodity markets

This paper uses recent advances in time-series modeling to derive long-horizon forecasts of commodity price volatility which incorporate investors' expectations of volatility. Our results are promising. We compare several different forecasts of commodity price volatility, which we divide into three categories: (1) forecasts using only expectations derived from options prices; (2) forecasts using only time-series modeling; and (3) forecasts which combine market expectations and time-series methods. The forecasts in (1) and (2) are used extensively in the literature, while those in (3) are new in this paper. On comparing these different forecasts, we find that our proposed forecasts from category (3) outperform both market expectations forecasts and time-series forecasts. This result holds both in and out of sample for virtually all commodities considered.     

天津市中心商业区停车行为实证研究

通过对天津市大胡同商业区、滨江道商业区和小白楼商业区的停车情况进行实地调研,分析了中心商业区的停车现状,并给出了停车者的停车目的、停车场选择影响因素、停车时间、停车步行距离、费用支付的情况和停车价格的满意度,以及可接受的价格上涨幅度等方面的分析结果;并利用调查数据和Logit模型建立了天津市中心商业区停车选择行为模型.模型结果表明,停车费和步行距离是停车者在选择路外、路边停车场时的主要影响因素,为城市中心商业区交通需求管理提供了依据.     

Investigating the relationship between gold and silver prices

This paper analyses the long-run relationship between gold and silver prices. The three main questions addressed are: the influence of a large bubble from 1979:9 to 1980:3 on the cointegration relationship, the extent to which by including error-correction terms in a non-linear way we can beat the random walk model out-of-sample, and the existence of a strong simultaneous relationship between the rates of return of gold and silver. Different efficient single-equation estimation techniques are required for each of the three questions and this is explained within a simple bivariate cointegrating system. With monthly data from 1971 to 1990, it is found that cointegration could have occurred during some periods and especially during the bubble and post-bubble periods. However, dummy variables for the intercept of the long-run relationships are needed during the full sample. For the price of gold the non-linear models perform better than the random walk in-sample and out-of-sample. In-sample non-linear models for the price of silver perform better than the random walk but this predictive capacity is lost out-of-sample, mainly due to the structural change that occurs (reduction) in the variance of the out-of-sample models. The in-sample and out-of-sample predictive capacity of the non-linear models is reduced when the variables are in logs. Clear and strong evidence is found for a simultaneous relationship between the rates of return of gold and silver. In the three type of relationships that we have analysed between the prices of gold and silver, the dependence is less out-of-sample, possibly meaning that the two markets are becoming separated. © 1998 John Wiley & Sons, Ltd.     

Analyzing Macroeconomic Forecastability

This paper estimates, using stochastic simulation and a multi‐country macroeconometric model, the fraction of the forecast error variance of output changes and the fraction of the forecast error variance of inflation that are due to unpredictable asset price changes. The results suggest that between about 25% and 37% of the forecast error variance of output growth over eight quarters is due to asset price changes and between about 33% and 60% of the forecast error variance of inflation over eight quarters is due to asset price changes. These estimates provide limits to the accuracy that can be expected from macroeconomic forecasting. Copyright © 2011 John Wiley & Sons, Ltd.     

The Relation Between Overreaction in Forecasts and Uncertainty: A Nonlinear Approach

This paper examines overreaction of oil price forecasters. It takes into account impacts of uncertainty, measured by VSTOXX volatility; noisy signals, measured by oil price volatility; and oil price return on forecast changes. The panel smooth transition regression model is applied with different specifications of the transition function to account for nonlinear relations. Data on oil price expectations for different time horizons are taken from the European Central Bank Survey of Professional Forecasters. The results show that forecast changes are governed by overreaction. However, overreaction is markedly reduced when high levels of uncertainty prevail. On the other hand, noisy signals and positive oil price return tend to cause higher overreaction. Copyright © 2016 John Wiley & Sons, Ltd.