Identifying the internal structure evolution of urban built-up land sprawl (UBLS) from a composite structure perspective: A case study of the Beijing metropolitan area,China

Differences in the internal composite structure during urban built-up land sprawl (UBLS) will generate different effects, and thus, a city’s spatial structure has important bearings on urban sustainability. This study investigates the spatial and temporal characteristics of the internal structure and allocation relationship of UBLS using multivariate spatial correlation and the Weaver-Tomas composite coefficient based on site data of granted built-up land parcels. Moreover, the composite structure evolution process of UBLS and its driving mechanism are examined in this study. The results reveal that the amount structure of the three types of UBLS (i.e. industrial land sprawl, residential land sprawl and commercial land sprawl) tended to be balanced during the study period. Following the transformation and upgrade of the urban industry structure, the overall composite structure of UBLS ranged from single residential land-use structure (Res.) to industrial-residential land-use structure (Ind.-Res.) In the early period of land marketization, the marketization land granting mechanism caused low spatial correlation between the various types of UBLS and a single composite structure, i.e. Res., single commercial land-use structure (Com.), and residential-commercial land-use structure (Res.-Com.). Subsequently, a dual-driving force including the market economy and government interventions caused a relatively high degree of spatial correlation and a multiple composite structure, i.e. Ind.-Res. and industrial-residential-commercial land-use structure (Ind.-Res.-Com.). However, the evolution characteristics of the composite structure in various regions illustrate some problems, such as the spatial isomorphism phenomenon of the composite structure and the dislocation of urban built-up land allocation. The urban internal built-up land spatial layout pattern is the embodiment of two dominant driving forces, the market and the government, interacting with each other according to natural and socioeconomic conditions. Therefore, we suggest that it is necessary to reform the future urban built-up land granting mechanism based on market guidance, and the composite structure of UBLS should be adjusted according to the regional function. The government should reinforce the macro-control of land-use planning for the dispersed granted land parcels so as to optimize the urban land-use structure.     

多级斜坡路基软弱地基变形机理和稳定性数值分析

山区公路路基往往是在斜坡上填筑的,这种填筑形式更易于发生变形破坏,故本文以某斜坡路基为研究对象,研究斜坡路基地基变形机理,并用强度折减法分析该斜坡路基的稳定性。结果表明:①地基形变的总体趋势以沉降变形为主,随填筑高度的增加,水平位移逐渐趋于均匀,并表现为侧向外鼓,沉降最大值集中在与填筑体中心相交的区域。②路基中心的最终沉降位移相较于坡脚的2倍;路基整体有向斜坡下滑移的趋势;短坡脚的水平位移发展最快。③斜坡路基随填筑高度的增加,从深层滑动发展为浅层滑动,滑体集中于长坡脚。④随填筑高度的增加,安全系数逐渐降低。     

江苏省物联网产业培育机制研究

物联网产业培育机制的设计是物联网产业化发展的关键,对物联网产业培育机制进行研究具有重要的现实意义。文章从物联网产业市场培育、技术培育、政策支撑的角度对江苏省物联网产业的培育机制设计进行了系统的研究。从产业属性、产业培育原则、产业培育内容三个维度构设计了江苏省物联网产业的整体培育思路,并提出了建立江苏省物联网产业市场培育机制、技术培育机制、政策支撑体系的对策,将为江苏省物联网产业的培育提供参考。     

The willingness to pay–willingness to accept gap: A failed replication of Plott and Zeiler

The well-known willingness to pay–willingness to accept (WTP–WTA) gap refers to the observation that individuals attach a higher value to objects they own (WTA) than to objects they do not own (WTP). We report on experiments to re-investigate the possibility that the WTP–WTA gap arises from subject misconceptions due to experimental procedures as suggested by Plott and Zeiler (2005). The contribution of this paper is two-fold: first, we attempt to replicate the findings by Plott and Zeiler that the WTP–WTA gap disappears when using procedures that are aimed at reducing misconceptions, such as extensive training and practice rounds for the BDM mechanism. However, we fail to do so as the WTP–WTA gap persists in the main task where subjects state their WTA or WTP for a mug. Second, we use the paid practice rounds to identify subjects without apparent misconceptions and find that also for those subjects who never make dominated choices in the lottery tasks, the WTP–WTA gap in the mug task exists. Thus, we find no evidence of the idea that subject misconceptions are the main source of the WTP–WTA gap.     

Sources of business fluctuations: Financial or technology shocks?

Despite the widespread belief that technology shocks are the main source of business fluctuations, recent empirical studies indicate that in the absence of financial frictions, a shock to the marginal efficiency of investment is the main source and is closely related to financial conditions for investment. We incorporate a financial accelerator mechanism and two types of financial shocks to the external finance premium and net worth in a dynamic stochastic general equilibrium model with shocks to the marginal efficiency of investment, the investment-good price markup, and the rates of neutral and investment-specific technological changes. This model is estimated using eleven US time series that include data on loan, net worth, the loan rate, and the relative price of investment. Our estimation results show that the (non-stationary) neutral and investment-specific technology shocks primarily drive output and investment fluctuations, while the external finance premium shock plays an important role for investment fluctuations. This financial shock induced substantial falls and subsequent sharp hikes in the external finance premium and caused boom–bust cycles over the past two decades.     

Truthful germs are contagious: A local-to-global characterization of truthfulness

We study the question of which social choice functions from an abstract type space to a set of outcomes are truthful, i.e., implementable by truthful mechanisms, when utilities are quasi-linear. For convex domains, our main theorem characterizes truthful social choice functions as those satisfying two properties: local weak monotonicity and vortex-freeness. The first of these constrains the function values at any two sufficiently proximal points, while the second asserts that its line integrals around sufficiently small triangular loops must vanish.The characterization implies a local-to-global principle that allows one to deduce truthfulness of a function from its behavior on arbitrarily small neighborhoods of each point. Other consequences include a simple alternate derivation of the Saks–Yu Theorem that weak monotonicity characterizes truthfulness of functions having a convex domain and finite range, and a sufficient condition for constructing truthful functions by “stitching together” truthful subfunctions on different subsets of the domain.     

酒店行业协会的运行机制及其变迁——以广州地区酒店行业协会为例

行业协会在酒店业发展进程中发挥越来越大的作用,但在国内现行条件下,行业协会发展面临多重困难。文章以广州地区酒店行业协会为案例,采用实地调查和深度访谈的方法,讨论行业协会的运行机制及其变迁。研究认为,第一,"政会不分"是目前行业协会管理的主要问题,政府应创新行业协会管理机制,加快"政会分开"的进程,推进部分行业职能向协会转移;第二,酒店行业协会应大胆创新,依据地区、行业发展环境动态调整组织架构,丰富协会职能发挥,以此达到激活协会运行机制的目标。基于此,酒店行业协会可以更好地为会员酒店服务,提升行业专业化管理水平。     

The veto mechanism in atomic differential information economies

We establish new characterizations of Walrasian expectations equilibria based on the veto mechanism in the framework of differential information economies with a complete finite measure space of agents. We show that it is enough to consider the veto power of a single coalition, consisting of the entire set of agents, to obtain the Aubin private core. Moreover, we investigate on the veto power of arbitrarily small and big coalitions, providing an extension to mixed markets of well known Schmeidler (1972) and Vind’s (1972) results in terms of Aubin private core allocations.     

Impossibilities for strategy-proof committee selection mechanisms with vetoers

When a group of voters selects a committee out of a set of candidates, it is common and often desirable to endow these voters with some veto power. I present impossibility results showing that even limited veto power makes many mechanisms of interest manipulable. This applies in particular (i) to mechanisms the range of which contains a degenerate lottery in which a committee is chosen for sure and (ii) to mechanisms that are constructed from extensive game forms with a finite number of strategies. These impossibilities hold on a large set of domains including the domain of additive preferences, and even when probabilistic mechanisms are allowed and voters can report cardinal preferences.