城市造林工程农户行为意向影响因素研究——以北京市平原造林工程为例

以北京市平原造林工程为例,利用典型项目区调查数据建立结构方程模型,探讨影响退耕农户行为意向的主要因素。结果表明:农户综合素质、家庭经济基础和农户土地依赖性对农户满意度和农户行为意向具有显著正向影响;同时,农户综合素质、家庭经济基础和农户土地依赖性还会通过农户满意度对农户行为意向产生影响。据此,后续城市造林过程中应进一步加强对农户满意度的服务工作,同时根据个体农户特征,对被征地农户在再就业、技能培训、农地补偿等方面开展更具针对性的服务工作。     

基于结构方程模型的集聚农户共生认知及影响因素分析:以重庆市为例

研究目的:探讨对集聚农户共生、集聚区土地利用率提高的影响因素,为提升农户共生的认知水平、优化农户共生关系及促进资源的节约集约利用提供有效路径及理论指导。研究方法:参与式农户调查,结构方程模型。研究结果:(1)户主自身特征、农户家庭特征、集聚共生效益特征及外部环境与政策特征这4类外源潜变量对农户共生认知产生重要影响且影响程度大小不同,其中,集聚共生效益特征的影响最为显著,外部环境与政策特征、户主自身特征和农户家庭特征的影响依次减弱;(2)是否为干部、对原集聚模式的满意度、是否促进农户生产生活条件和政府对集聚区的补贴力度分别对这4类外源潜变量具有较好的解释能力。研究结论:显化农户共生效益、增强"精英"农户及村干部的正向引导、提升农户成员受教育水平、培养农户"共生共荣"理念等是深化农户共生关系,促进和谐乡村人居环境建设的重要路径。     

Information congruity in scarcity appeal: A structural equation modeling study of time-limited promotions

Although market scarcity such as time restriction is widely used in retail advertisements, its impact on product message processing and product evaluation is still subject to controversy. In this study, analyses through structural equation modeling indicated that (i) scarcity had no impact on product message processing, (ii) scarcity had a direct impact on product evaluation as a heuristic cue when the value inferred from scarcity was congruous with the worth derived from product message, and (iii) scarcity lost its impact on product evaluation when the value inferred from scarcity was incongruous with the worth derived from product message, and the incongruity prompted scrutiny of product message, resulting in a mediated impact of product message on product evaluation through product message processing. In conclusion, the results supported an information congruity theory of market scarcity.     

Convergence analysis and optimal strike choice for static hedges of general path-independent pay-offs

In this paper, we propose a new algorithm to find the optimal static replicating portfolios for general path-independent nonlinear pay-off functions and give an estimate for the rate of convergence that is absent in the literature. We choose the static replication by designing an adaptation function arising in the error bound between the nonlinear pay-off function and the linear spline approximation and derive the equidistribution equation for selecting the optimal strikes. The numerical tests for variance swaps, swaptions, static quadratic hedges and also for a jump-diffusion process, allowing for the default of the underlying asset, show that the proposed iterative equidistribution equation algorithm is simple, fast and accurate. The paper generalizes and improves the results on static replication and approximation in the literature.     

将数学建模引入高等数学教学中的典型案例

首先阐述了将数学建模思想融入高等数学教学内容中的意义,接着从高等数学中的基本概念和基本定理出发,通过具体案例说明如何将数学建模案例融入在高等数学教学中。最后给出了根据高等数学内容选编的典型建模案例。     

Optimal constrained investment in the Cramer-Lundberg model

We consider an insurance company whose surplus is represented by the classical Cramer-Lundberg process. The company can invest its surplus in a risk-free asset and in a risky asset, governed by the Black-Scholes equation. There is a constraint that the insurance company can only invest in the risky asset at a limited leveraging level; more precisely, when purchasing, the ratio of the investment amount in the risky asset to the surplus level is no more than a; and when short-selling, the proportion of the proceeds from the short-selling to the surplus level is no more than b. The objective is to find an optimal investment policy that minimizes the probability of ruin. The minimal ruin probability as a function of the initial surplus is characterized by a classical solution to the corresponding Hamilton-Jacobi-Bellman (HJB) equation. We study the optimal control policy and its properties. The interrelation between the parameters of the model plays a crucial role in the qualitative behavior of the optimal policy. For example, for some ratios between a and b, quite unusual and at first ostensibly counterintuitive policies may appear, like short-selling a stock with a higher rate of return to earn lower interest, or borrowing at a higher rate to invest in a stock with lower rate of return. This is in sharp contrast with the unrestricted case, first studied in Hipp and Plum, or with the case of no short-selling and no borrowing studied in Azcue and Muler.     

关于复数运算在高次方程中的运用

随着office2010版开发,复数函数的运算的完善为高次方程的完整解提供了技术上的有力保障。     

水库库区运营管理政策满意度的空间异质性分析

针对水库库区政策体系因自然资源禀赋差异性导致的政策满意度异质问题,引入顾客满意度理论,基于结构方程模型,构建了异质资源禀赋下库区居民政策感知的结构方程模型,揭示水库库区政策满意度空间分异特征,提出异质资源禀赋下水库库区政策制定的对策建议。并以浯溪口水库为例,应用本文研究框架,探究库区居民政策感知偏好的空间分异特征。     

The role of destination personality fit in destination branding: Antecedents and outcomes

Drawing from fit research in strategic management, this study develops and investigates a model predicting destination attitude and (re)visit intention. The study introduces the concept of destination personality fit on the basis of how well consumer perceptions of a tourist destination's brand personality fits that of what the destination brand manager wishes to convey. A model incorporating destination advertising awareness as an antecedent of destination personality and consumer‐manager destination personality fit is tested on international consumers with the destination personality of Switzerland as the study setting. Structural equation modeling results reveal that destination advertising awareness does indeed relate positively to both stronger perceived destination personality and destination personality fit in consumers’ minds. Interestingly, the subsequent destination personality–destination attitude relationship is moderated by consumer–manager destination personality fit in such a way that the link grows stronger in cases where fit is high. The results have important implications for destination brand managers in that they reinforce the importance of strong and distinct destination personalities. The findings also show the importance of actively communicating the destination brand to consumers since the positive outcomes of a strong destination personality increase in magnitude when successfully communicated, and the vision of the destination brand manager has been adopted by the consumer.     

Distance-sensitivity of German exports: first evidence from firm-product level data

This article uses a tailor-made new data set of 7 580 251 observations for German exports at the firm-product-destination level to estimate a gravity equation and to investigate the link between the amount of firms’ exports and the distance to destination countries. It is shown that, in line with stylized facts based on aggregate data, the quantity of exports declines significantly with distance within a firm for a given product.