On dynamic behavior of a hyperbolic system derived from a thermoelastic equation with memory type

In this paper, we study the Riesz basis property of the generalized eigenfunctions of a one-dimensional hyperbolic system in the energy state space. This characterizes the dynamic behavior of the system, particularly the stability, in terms of its eigenfrequencies. This system is derived from a thermoelastic equation with memory type. The asymptotic expansions for eigenvalues and eigenfunctions are developed. It is shown that there is a sequence of generalized eigenfunctions, which forms a Riesz basis for the Hilbert state space. This deduces the spectrum-determined growth condition for the C₀-semigroup associated with the system, and as a consequence, the exponential stability of the system is concluded.     

I would walk 500 miles (if it paid): Vouchers and school choice in Chile

One of the pillars of the educational voucher system is that competition among schools to attract students would improve the quality of the education. Surveys to parents and previous work suggested that families rank the distance of the school from their home as the most important factor for choosing a school. They also suggest that parents largely ignore the results of standardized tests. We use a novel data-set which includes precise measures of the distance between homes and schools to analyze the determinants of school choice in Chile. Economic theory suggests, and the estimations confirm, that parents consider quality and the location when choosing schools. The paper quantifies the relevant trade-offs.     

Do R&D subsidies affect SMEs’ access to external financing?

Many countries spend sizeable sums of public money on R&D grants to alleviate debt and equity gaps for small firms’ innovation projects. In making such awards, knowledgeable government officials may certify firms to private financiers. Using a unique Belgian dataset of 1107 approved requests and a control group of denied requests for a specific type of R&D grant, we examine the impact of subsidies on small firms’ access to external equity, short term and long term debt financing. We find that obtaining an R&D subsidy provides a positive signal about SME quality and results in better access to long-term debt.     

New product introduction and product tenure: What effects on firm growth?

This study contributes to the recent empirical literature on the innovation-firm performance relationship by investigating the effect of product introduction on firm growth in a sample of Italian firms from 2000 to 2006. We adopted a novel approach that exploits the interpretative content of the tenure of the last product introduced (i.e., the number of years since its first introduction) as an additional variable into the explanatory scheme of firm sales growth rate. This variable aims to capture peculiar characteristics of new goods, such as their novelty and complexity. The estimated results confirmed the relevance of this model specification and helps in understanding the reason why previous studies have failed to find a statistically robust relationship between product innovation and growth. Moreover, we found the following: first, the release of a new product enhances growth opportunity among multiproduct firms; second, product development promotes the growth of firms belonging to sectors with stronger commitment to research and development; and third, new product development enhances firm growth substantially in those sectors that absorb externally originated patents.     

Tax incentives and R&D activity: Firm-level evidence from Taiwan

This paper investigates the effect of tax incentives on R&D activities in Taiwanese manufacturing firms. The propensity score matching (PSM) estimates show that recipients of R&D tax credits appear on average to have 53.80% higher R&D expenditures than that they do without receiving tax credits, while there is no significantly higher growth rate of R&D expenditure. This study further employs the panel instrumental variable (IV) and generalized method of moment (GMM) techniques to control for endogeneity of R&D tax credits and firm heterogeneity in determining R&D expenditure. The R&D tax credit is witnessed to exhibit a significantly positive influence on R&D expenditure and its growth, especially for electronics firms. The marginal effect is moderate, ranging from 0.094 to 0.120. Specifically, the R&D elasticity concerning tax credits tends to increase gradually along with the approaching expiration of R&D tax credits measure, lending a supportive view on its efficacy.     

从第25届亚锦赛中国与伊朗、黎巴嫩两强比赛略论中国男篮的走向

采用文献资料法、数理统计法和对比分析法,对中国男篮在第25届亚洲锦标赛与伊朗、黎巴嫩两强的三场比赛进行技术统计分析。统计数据表明中国男篮各项指标与亚洲强队优势不明显,中国男篮整体水平发挥不稳定,没有继承北京奥运会上所表现的精神风貌和战术风格,集体凝聚力不够,作风不顽强,技、战术打法都需要改进。     

亚洲男子篮球竞技格局的变化及发展趋势——以第25届男篮亚锦赛为例

文章运用文献资料、观察法和比较法等研究方法,以第25届男篮亚锦赛比赛数据为依据,分析了亚洲男子篮球竞技格局的变化,并对亚洲男子篮球的发展趋势提出见解。     

Uniform separable differential operators with parameters

In this paper we study boundary value problems for anisotropic partial differential-operator equations with parameters. The principal part of the appropriate differential operators are not self-adjoint. Several conditions for the uniform separability in weighted Banach-valued L_p-spaces are given. Sharp estimates for the resolvent of the corresponding differential operator are obtained. In particular the positivity and R-positivity of these operators are established. As an application we study the separability of degenerate DOEs, maximal regularity for degenerate abstract parabolic problem with parameters, the uniform separability of finite and infinite systems for degenerate anisotropic partial differential equations with parameters.     

第25届亚洲男篮锦标赛中、伊男篮攻防能力的对比分析

对第25届亚洲男篮锦标赛中、伊比赛的技术数据进行了统计,分析对比了中国队与上届冠军伊朗队在攻守两方面技、战术运用的情况,寻找与伊朗的差距。,力争对中国男篮今后的发展提出了对策和建议。     

第25届亚锦赛中国男篮与前四名球队比赛情况对比分析

本文运用文献法、录像法和数理统计法,对第25届亚洲男篮锦标赛中国队对西亚的黎巴嫩、约旦和伊朗四场篮球比赛技术指标进行了统计和对比分析,得出中国男篮在各项指标全面落后于伊朗,在3分球和失误方面落后于黎巴嫩和约旦。