数字化虚拟现实技术时代的建筑设计教学模式变革

数字化虚拟现实技术的产生带来建筑设计领域乃至建筑学专业教育模式的变革。数字建筑大师作品冲击人们的视觉,建筑设计教学方向、建筑设计应该何去何从?通过对数字化虚拟现实技术在建筑设计中的应用、建筑师角色改变、建筑设计教学模式变革、建筑学专业设计优势的阐述,来探讨在计算机数字化虚拟现实技术时代基于系统理论基础之上形成的建筑学专业教育设计体系是计算机相关技术无法替代,任何相关技术变革都应转变成建筑设计的活力来源。     

Error correction modelling and dynamic specifications as a conduit to outperforming the random walk in exchange rate forecasting

The proposition that dynamic exchange rate models can outperform the random walk in out-of-sample forecasting, in the sense that they produce lower mean square errors, is examined and disputed. By using several dynamic versions of three macroeconomic exchange rate models, it is demonstrated that dynamic specifications outperform the corresponding static models but improvement in the forecasting power may not be sufficient for the dynamic models to perform better than the random walk. The results are explained by suggesting that any dynamic specification or transformation of the static model leads to the introduction of a lagged dependent variable, which in effect is a random walk component. The analysis leads to the conclusion that it is implausible to aim at beating the random walk by augmenting a static model with a random walk component.     

Adjusting the model to adjust the world: constructive mechanisms in postwar general equilibrium theory

Economic methodologists most often study the relations between models and reality while focusing on the issues of the model's epistemic relevance in terms of its relation to the ‘real world’ and representing the real world in a model. We complement the discussion by bringing the model's constructive mechanisms or self-implementing technologies in play. By this, we mean the elements of the economic model that are aimed at ‘implementing’ it by envisaging the ways to change the reality in order to bring it more in line with the model. We are thus concerned mainly not with the ways to change the model to ‘fit’ the reality, but rather with the model's own armature that is supposed to transform the world along theoretical lines. The case we study is Arrow–Debreu–McKenzie general equilibrium model. In particular, we show the following: gradient methods and stability could be regarded as constructive mechanisms of general equilibrium modeling in the context of market socialism debates; the obsession of general equilibrium theorists with these concepts can be partly explained by the fact that they hoped not to be faithful to reality, but rather to adjust it to fit the theoretical model; mechanism design theory initiated by the stability theorist Leonid Hurwicz could be seen as a successor of this position. We conclude by showing the relevance of this analysis for epistemic culture of much of contemporary economics and hence, claim that it is an important complement to the traditional philosophy of economic modeling.     

Bootstrapping structural VARs: Avoiding a potential bias in confidence intervals for impulse response functions

Constructing bootstrap confidence intervals for impulse response functions (IRFs) from structural vector autoregression (SVAR) models has become standard practice in empirical macroeconomic research. The accuracy of such confidence intervals can deteriorate severely, however, if the bootstrap IRFs are biased. We document an apparently common source of bias in the estimation of the VAR error covariance matrix which can be easily reduced by a scale adjustment. This bias is generally unrecognized because it only affects the bootstrap estimates of the error variance, not the original OLS estimates. Nevertheless, as we illustrate here, analytically, with sampling experiments, and in an example from the literature, the bootstrap error variance bias can have significant distorting effects on bootstrap IRF confidence intervals. We also show that scale-adjusted bootstrap confidence intervals can be expected to exhibit improved coverage accuracy.     

人文学的学品基质

这里讲人文学学品基质,旨在厘定人文学的基本素质,领悟人文学的学术品格。人文学的学品基质可以从三个方面概括：那就是海纳百川,通和致化与虚实相间。海纳百川关键在纳,通和致化要义在化,虚实相间重点在间。纳是包容,有容乃大。化为会通,能通斯达。间成契合,在合即和。我们把这三点看作人文学的学科品性,她们不是文学、史学、哲学、艺术学、人类学等某一学科,但是凝聚着人文群科的学术精华。她们没有胶着于某一种思维机制（诸如逻辑之类）,然而包容和提炼了人类思想文化的契合智慧。     

Empirical likelihood confidence intervals for the Gini measure of income inequality

Gini coefficient is among the most popular and widely used measures of income inequality in economic studies, with various extensions and applications in finance and other related areas. This paper studies confidence intervals on the Gini coefficient for simple random samples, using normal approximation, bootstrap percentile, bootstrap-t and the empirical likelihood method. Through both theory and simulation studies it is shown that the intervals based on normal or bootstrap approximation are less satisfactory for samples of small or moderate size than the bootstrap-calibrated empirical likelihood ratio confidence intervals which perform well for all sample sizes. Results for stratified random sampling are also presented.     

The consequences of the introduction of the euro: a nested mixed-effects analysis of the international banking positions

In this paper, we will examine the effects of the launch of the euro from the perspective of the international banking positions by a combination of the gravity model, widely used to explain the structure of world trade, and the mixed effects model, which is a hybrid version of the fixed and random effects models of panel data analysis. The specification could be examined by the likelihood ratio tests by decomposing the model into fixed and random effects elements. The empirical study indicates that the new currency is certain to benefit the euro area, but the effects on the non-euro members of the EU are not as clear as superficial analysis suggests.     

Bootstrap Methods in Econometrics*

There are many bootstrap methods that can be used for econometric analysis. In certain circumstances, such as regression models with independent and identically distributed error terms, appropriately chosen bootstrap methods generally work very well. However, there are many other cases, such as regression models with dependent errors, in which bootstrap methods do not always work well. This paper discusses a large number of bootstrap methods that can be useful in econometrics. Applications to hypothesis testing are emphasized, and simulation results are presented for a few illustrative cases.     

On Blending Competitive Trade Models

Three standard models typically discussed in the theory of international trade are the Ricardian model, the Heckscher‐Ohlin model and the Specific‐Factors model. Models are often compared with each other, in an attempt to analyze which model is best or fits reality better. Instead, I suggest that these international trade models can often be blended to take account of finite changes when, as a country develops, the appropriate model to be used changes as the pattern of production changes. Trade allows countries to produce fewer commodities than it consumes, and which commodities are selected to be produced may change as the economy grows in the size of its endowment bundle and/or technology changes. At issue is not only the question of which commodities are produced, but also how many commodities are produced, especially with reference to the number of productive factors.     

城市模型的发展及其存在问题

本文回顾了城市模型由城市形态与结构模型、静态城市模型、动态城市模型的发展历程,讨论了各种城市模型存在的基本问题,指出了构建生物激发的模型、应用虚拟现实技术、建立决策支持系统等城市模型未来趋势。     

Inertia Risk: Improving Economic Models of Catastrophes*

We model endogenous catastrophic risk in a new way. We call it “inertia risk”, which accounts for delays between physical variables and the hazard rate – a characteristic often observed in reality. The added realism significantly affects optimal policies relative to the standard model of catastrophic risk. The probability of a catastrophe occurring at some point in time can span the entire interval [0,1], and is not 0 or 1 as is typical in standard models. Inertia risk can also generate path dependences. We illustrate the implications for policy in a simple model of climate change.     

空中庭院与半围合式住宅感知密度的关联性研究——以广州万科峯境为例

在半围合式城市住宅中,感知密度是居住体验的重要环节。空中庭院能够缓解高密度环境中的拥挤感,优化其空间形态,是改善环境感知的建构基础。使用虚拟现实技术进行密度感知实验,能探讨与空中庭院形态相关的视觉因素——可视性和绿视率对环境感知密度的影响。将广州万科峯境作为原型建立15组以可视性与绿视率为变量的实验模型,通过采集受试者对不同环境感知密度的主观评价,反映实验样本的空间特征,进而分析主观评价与客观量化之间的关联机制。分析结果表明：半围合式城市住宅空中庭院的可视性与绿视率是影响居住环境感知密度的重要因素;呈线状分布的、具有视觉层次性的空中庭院更受大众青睐。     

Bootstrap Testing in Nonlinear Models

Bootstrap testing of nonlinear models normally requires at least one nonlinear estimation for every bootstrap sample. We show how to reduce computational costs by performing only a fixed, small number of Newton or quasi-Newton steps for each bootstrap sample. The number of steps is smaller for likelihood ratio tests than for other types of classical tests and smaller for Newton's method than for quasi-Newton methods. The suggested procedures are applied to tests of slope coefficients in the tobit model and to tests of common factor restrictions. In both cases, bootstrap tests work well, and very few steps are needed.     

Bootstrap and Pretest J-Type Non-Nested Tests for Orthogonal Regression Models: Some Monte Carlo Evidence

This paper compares the size and power of two J-type tests for weakly correlated or nearly orthogonal non-nested regression models: a bootstrap and a pretest test. The latter seems to outperform the former in terms of its size characteristics, especially when the alternative model has more non-nested regressors and the orthogonality between the two sets of regressors is severe. The bootstrap test does better in terms of power.

     

Bias correction and bootstrapping of error component models for panel data: Theory and applications

The wellknown Wallace-Hussain estimator is applied in pooled models with random individual effects, and the magnitude of the bias caused by the estimator is estimated by bootstrap methods. Furthermore, the significance of the bias is tested using an asymptotic test based on the bootstrap results.A preliminary version of this paper was presented at the Econometric Society European Meeting ESEM '88 in Bologna. The authors thank an anonymous referee for helpful comments. The data for one of the applications (the earnings function) are from the German Socio-Economic Panel and we thank the DIW and the Sfb 3 for the permission to use these data.     

The equivalence between costly and probabilistic voting models

In costly voting models, voters abstain when a stochastic cost of voting exceeds the benefit from voting. In probabilistic voting models, they always vote for a candidate who generates the highest utility, which is subject to random shocks. We prove an equivalence result: In two-candidate elections, given any costly voting model, there exists a probabilistic voting model that generates winning probabilities identical to those in the former model for any policy announcements, and vice versa. Thus many predictions of interest established in one of the models hold in the other as well, providing robustness of the conclusions to model specifications.     

基于结构方程模型的我国3G消费市场研究

目前在中国,移动商务产业链存在着严重的＂木桶现象＂,即由于对顾客行为缺乏必要的研究,因此难以制定有针对性的营销策略和商业模式,市场潜力开发不足已经成为牵制全局的那块最短的木板。基于以上原因,本文以结构方程模型原理为支撑,构造了以3G市场顾客需求为外源潜变量,以应用类别为内源潜变量的一阶因子验证模型,采用递归迭代方法对该模型进行了详尽的验证性因子分析;并进一步给出了一个具有良好拟合优度和统计检验的3G市场需求二阶因子模型,结合通径系数与因子负荷系数,面向顾客需求角度分析了各种移动商务应用模式对3G市场顾客需求影响的强度和程度,从而得出了3G市场环境下移动商务消费市场的一般规律。该结论对于揭示我国3G市场的特点,降低市场风险,推进我国3G市场的快速发展做出了有益的探索。     

On the distance between cross-impact models: A set of metric measures for cross-impact analysis

This paper attempts to add to the Leibnizian or mathematical side of Technological Forecasting. Given two distinct cross impact models, the paper shows that there exists a set of appropriate metric measures such that the distance between any two cross impact models can be determined. That is, it is possible to say how close or how far apart two or more cross impact models are to one another. It is argued that the ability to make such determinations is vital to the formal and mathematical development and growth of Technological Forecasting.     

基于零度管理的虚拟企业结构模型研究

零度管理为管理学家提供了一个绝好的战略目标,虚拟企业是实现零度管理最好的手段,结合两者的优点,探讨了基于零度管理的虚拟企业结构模型,分析了基于零度管理知识转化价值的过程,为虚拟企业组建、运行提供了一个可操作的结构模型,实现了零度管理虚拟企业模型构造的突破。