Stochastic optimal growth with a non-compact state space

This paper studies the stability of a stochastic optimal growth economy introduced by Brock and Mirman [Brock, W.A., Mirman, L., 1972. Optimal economic growth and uncertainty: the discounted case. Journal of Economic Theory 4, 479–513] by utilizing stochastic monotonicity in a dynamic system. The construction of two boundary distributions leads to a new method of studying systems with non-compact state space. The paper shows the existence of a unique invariant distribution. It also shows the equivalence between the stability and the uniqueness of the invariant distribution in this dynamic system.     

When product type experimental design is optimal? Brief survey and new results

In the paper the problem of optimum experimental design for estimating parameters of multivariate regression functions is considered. We address the question: under what conditions one can compose the optimal design from partial designs, obtained by considering partial regressions, which depend on reduced number of variables. After reinterpreting and reviewing briefly existing results we provide some new conditions.     

Exact D-optimal designs for first-order trigonometric regression models on a partial circle

Recently, various approximate design problems for low-degree trigonometric regression models on a partial circle have been solved. In this paper we consider approximate and exact optimal design problems for first-order trigonometric regression models without intercept on a partial circle. We investigate the intricate geometry of the non-convex exact trigonometric moment set and provide characterizations of its boundary. Building on these results we obtain a solution of the exact $D$ -optimal design problem. It is shown that the structure of the optimal designs depends on both the length of the design interval and the number of observations.     

On the optimal design of disaster insurance in a federation

Recent experience with disasters and terrorist attacks in the US indicates that state and local governments rely on the federal sector for support after disasters occur. But these same governments invest in infrastructure designed to reduce vulnerability to natural and man-made hazards. We show that when the federal government is committed to full insurance against disasters, regions will have incentives to under-invest in ex-ante protective measures. We derive the structure of the optimal second-best insurance system when regional governments choose investment levels non-cooperatively and the central government cannot verify regional investment choices. For low probability disasters this will result in lower ex-post intergovernmental transfers (and hence less ex-post redistribution) and greater ex-ante investment. However, the second-best transfer scheme suffers from a time-inconsistency problem. Ex-post, the central government will be driven towards full insurance rather than the second-best grants, which results in a type of soft budget constraint problem. Sub-national governments will anticipate this and reduce their investment in protective infrastructure even further. The result is that the central government may be better off suffering the underinvestment that results with first-best transfers because investment is even lower under second-best transfers when the central government is unable to commit.     

以人为本的地下公共空间设计

地下空间的开发利用已逐步成为现代大城市规划建设的重要组成部分.由于地下空间固有的特点及人的习惯性思维定势,地下公共空间难以吸引人气.以满足人的生理、心理要求为基本出发点,从安全、舒适、便利、健康等角度分析了地下公共空间的空间形象,指出其内在的特点,并提出了相应的设计原则和设计要求,以期建立一个以人为本的城市地下公共空间.     

On the queueing problem of correlated arrivals with many servers in a finite waiting space

This paper provides an analysis of the steady state behaviour of a discrete time, first come first served limited space queueing problem with many serers. The arrival probabilities at two consecutive time-marks are correlated, whereas the departure probabilities, though depending on the queue length, are assumed to be statistically independent. Probability generating functions for the queue length for the various cases have also been listed. A few particular cases have also been derived. Mean queue lengths are also found out.     

An optimum sampling design to base HT-method of estimating a finite population total

The problem of constructing a sampling design with the value of the sum of second order inclusion probabilities attaining its lower bound for non-integral values of the expected effective size of a sample in the design has been considered in this paper. If the values of the characteristic of interest on all the units in the population are non-negative the design is admissible (in the sense of variance) with respect to Horvitz-Thompson estimator in the class of designs with the same set of values of the first order inclusion probabilities of the units. Again such a design is best to use Horvitz-Thompson estimator of population total in the sense of smallest average variance of the estimator under a special superpopulatio model.     

"工业设计"依然陌生的概念

"工业设计"这一要领起源于17世纪初的欧洲工业革命.工业设计历经了许多流派的演变,最终于1919年在德国伴随着世界上第一所专门培养工业设计人才的学校--包豪斯的成立而诞生.     

城市用地功能置换中的公共空间设计--旧金山滨水区公共空间设计的成败分析

旧金山滨水区公共空间设计为我们提供了如何在城市用地功能置换中创造城市公共空间的经验,其成功的方面有:空间的形成模式,创造公共空间活力发动元素,公共交通,场所特性与空间情趣等.同时,其设计也存在不足之处,如绿地空间缺乏活力,空间铺装过于繁琐,连续空间过于单调等.借鉴旧金山滨水区公共空间设计的成功与失败,提出了7条公共空间设计的建议作为研究的结论.     

基于模糊理论的滚子活齿行星传动可靠性优化设计

文章利用模糊可靠性优化设计方法,综合考虑了滚子活齿行星传动中有关设计参数、约束条件的随机性和模糊性,建立了基于模糊可靠性分析的以材料最省为目标的优化设计模型,并进行了实例计算和结果分析。     

Another view on optimal design for estimating the point of extremum in quadratic regression

In this paper we illustrate how certain design problems can be simplified by reparametrization of the response function. This alternative viewpoint provides further insights than the more traditional approaches, like minimax, Bayesian or sequential techniques. It will also improve a practitioner’s understanding of more general situations and their “classical” treatment.     

Inter-jurisdiction subsidy competition for a new production plant: What is the central government optimal policy?

This paper models inter-jurisdiction competition for foreign direct investment and optimal government policy intervention to protect the national interest. The inter-jurisdiction competition for a multinational has the potential of favouring the multinational and of becoming detrimental for the host country. The central government wants to limit such competition but it cannot tax-discriminate between different types of multinationals. We find that the central government would use tax policy to create asymmetries even when the underlying structure is symmetrical. This offers a novel explanation for the creation of ‘Special Economic Zones’ in many countries, which are well known to be aimed at the attraction of foreign direct investment.     

On the finite sample behavior of testing whether new is better than used of a specified age

Hollander, Park and Proschan (1986) proposed a test of new is better than used of a specified age. It is based on large sample normality of the test statistic. There is, however, no study in the literature on its actual size for small and moderate sample sizes. To shed some lights on this, the results of a Monte Carlo simulation study as well as two real data examples are reported and these indicate that the test can have a quite liberal size, especially for small to moderate sample sizes. In order to improve on this weakness, a modified test is proposed and studied. It is noticed that this modified test seems to over-correct the original test to an extent that it becomes unduly conservative sometimes. Hence we propose another modification that combines the original test and the modified test turns out to have its size quite close to the nominal level and is therefore preferable to both the original and modified tests.     

Continuous representation of a preference relation on a connected topological space

Necessary and sufficient conditions are given for the existence of two continuous real valued functions u and v on a connected topological space X endowed with a preference relation ≺ (i.e., an asymmetric binary relation) such that y is preferred to x if and only if v(y)>u(x). It is shown that these conditions - a slight generalization of the usual ones encountered in classical utility theory - entail the existence of such a continuous representation u, v with u and v continuous utility functions for two complete preorders intimately connected with the preference relation ≺.     

北京城市的开放空间和景观设计——以王府井商业街为例

针对北京王府井商业街公共空间现状的重点问题进行了调查研究.在此基础上,从提升城市生活环境质量的角度,就空间场所营造、景观设计、环境设施、交通规划等提出构想和建议,旨在探索提高城市开放空间品质的景观学路径,并通过该典型个案的研究为北京市乃至其他城市公共空间的设计提供借鉴.     

Some results on analytic optimal control solution of a simple rational expectations model

In this note, we correct a technical error in a well-known stabilization analysis in the context of a simple macroeconomic model, formulated as an optimal control problem. This error originated in a slip in an unpublished but widely circulated paper by D.A. Livesey, suggesting a procedure for obtaining a solution to a class of optimal control problems frequently encountered in a stabilization literature. We then propose an ad hoc solution method which makes clear the intuition of the solution to the particular model to which the Livesey method was applied, and of the larger class of models to which it belongs. Our solution is so formulated that the contrast between it and the Livesey result is made transparent.     

城市空间的社会与"城市文化资本"论--城市公共空间市民属性研究

城市社会空间作为城市的要素,具有典型的社会关系与社会资本属性,在不同的社会和不同的文化环境中,城市社会空间表现为不同的意义和符号价值.在当代中国城市化高速发展的今天,城市社会空间结构在发生巨变,传统的城市社会空间的意义和理念,被现代意义上的空间意涵所取代,同时,城市化的高速增长,使属于大众的城市社会空间变得越来越狭小,城市社会竞争的本质就是在竞争城市社会空间的占有形式.因此,重新认识城市社会空间的社会属性和文化价值,已经成为城市公共管理的重要内容.本文从城市社会空间属性的角度入手,研究城市社会空间的价值,以求对构建属于市民社会的新型城市社会空间有所裨益.