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41.
This paper examines seasoned equity offerings in France.Even though a rights offering is the primary flotation method, French companies are increasingly usingthe relatively expensive public offering method. We show that the market reaction to the announcementof seasoned equity issues is significantly negative for rights issues and insignificantly negative forpublic offerings. Our results suggest that the adverse selection effect is greater for rights issues thanfor public offerings, due to stronger underwriter certification for the public offerings. We find that theshare price effect is positively related to blockholders take-up renouncements for firms with priorconcentrated ownership. For these firms, the favourable ownership dispersion effect offsets the adverse selection effect.  相似文献   
42.
本系统主要通过对模糊控制器的设计 ,将异步电动机的起动电流既限制在了一定的范围内 ,又可得到较大的起动力矩。由于又采用了参数自调整作为辅助控制 ,不但改善了起动时的动态性能 ,而且改善了稳定运行时的静态性能  相似文献   
43.
This paper is motivated by automated valuation systems, which would benefit from an ability to estimate spatial variation in location value. It develops theory for the local regression model (LRM), a semiparametric approach to estimating a location value surface. There are two parts to the LRM: (1) an ordinary least square (OLS) model to hold constant for interior square footage, land area, bathrooms, and other structural characteristics; and (2) a non-parametric smoother (local polynomial regression, LPR) which calculates location value as a function of latitude and longitude. Several methods are used to consistently estimate both parts of the model. The LRM was fit to geocoded hedonic sales data for six towns in the suburbs of Boston, MA. The estimates yield substantial, significant and plausible spatial patterns in location values. Using the LRM as an exploratory tool, local peaks and valleys in location value identified by the model are close to points identified by the tax assessor, and they are shown to add to the explanatory power of an OLS model. Out-of-sample MSE shows that the LRM with a first-degree polynomial (local linear smoothing) is somewhat better than polynomials of degree zero or degree two. Future applications might use degree zero (the well-known NW estimator) because this is available in popular commercial software. The optimized LRM reduces MSE from the OLS model by between 5 percent and 11 percent while adding information on statistically significant variations in location value.  相似文献   
44.
This article empirically explores the effects of oil price on the Korean economy using a Global VAR model. First, we evaluate the average connectedness of oil price with the Korean domestic variables over the precrisis period. We then investigate the time-varying contribution of oil price to the Korean financial and real sectors during and after the global financial crisis through recursive estimation. It is found that the contribution of oil price becomes very large in the case of real exports, equity prices, and real output, but plays a much less prevalent role in the remaining cases. In the meantime, the time-varying contribution of oil price to the Korean economy has not changed during and after the global financial crisis. Interestingly, we find that the Korean economy is affected mostly by overseas financial conditions in the short-term but it becomes more susceptible to oil price fluctuations in the long run, suggesting that Korea’s reliance on energy imports leaves the economy exposed to volatility in energy prices.  相似文献   
45.
While Open Source Software (OSS) communities provide opportunities for knowledge creation, we have a limited understanding of how entrepreneurs leverage OSS communities for their entrepreneurial ventures. Using social capital theory in a mixed methods case study, we compare entrepreneur and non-entrepreneur behaviors to investigate how entrepreneurs build social capital within an OSS community. This study shows that entrepreneurs differentiate themselves from non-entrepreneurs by focusing on cognitive and relational capital building activities, which in return makes it possible for them to leverage their social capital to influence and shape the environment in which they are operating. Our findings suggest that entrepreneurs strategically select which activities within the community to expend their limited resources on (e.g., developing code over participating in email conversations) and build their social capital more through their actions than through their words (e.g., showing their commitment to the community through code commits, bug fixes, and documentation). Given the liabilities of newness and smallness as well as other challenges faced by entrepreneurs, applying an open innovation strategy in OSS communities could be one approach where entrepreneurs, by developing and freely revealing their intellectual property to the community, share their way to success via OSS-infused entrepreneurial business ventures.  相似文献   
46.
刘强  吕晶  白文琦 《价值工程》2015,(11):163-166
本试验以砂浆性能为研究对象,采用Box-Behnken的中心组合实验设计及响应面分析方法对腻子粘结强度进行预测研究。试验选用三因素三水平的响应曲面分析法,建立了粘结强度的二次多项数学模型,并以粘结强度为响应值作响应面和等高线,考察了水粉比、灰粉比和胶粉比对粘结强度的影响,并根据实际选择响应曲面方程,利用最小二乘法估计相应的系数,剔除最不显著因素,建立最终的数学方程。结果表明:该预测模型能很好地描述粘结强度与水粉比、灰粉比和胶粉比之间的关系,可以对腻子粘结强度进行分析和预测,为砂浆性能研究提供一种新方法。  相似文献   
47.
For quantitative water management, fine analysis of spatial and temporal interactions between cropping systems and water resources helps identify time and site-specific withdrawal situations. However, it is a methodological challenge to provide fine-resolution analyses at the scale of large watersheds used for crises management. In this study, we present a methodology based on multiple methods and mixed sources of information to finely model an agricultural landscape (AL) that represents the spatial distribution of cropping systems. Our approach is based on progressively hybridizing databases and local actors' and experts' knowledge to produce a spatially explicit and dynamic model. The Land Parcel Identification System database, which resulted from the European Common Agricultural Policy, is crucial for our method since it provides the spatial and temporal basis of our model (i.e., geographic delineation of islets and information about crop sequences). Local knowledge is used to identify factors determining spatial distribution of cropping systems and to build a generic model that simulates farmers' crop-management strategies. The model was qualitatively and quantitatively evaluated using a multi-agent simulation platform (MAELIA). We asked local experts on quantitative water management to evaluate the ability of the platform to reproduce intra- and inter-annual dynamics at different levels when using our model of the AL as input. The experts were satisfied with the results; they validated the predicted dynamics of the variables, and some discussed the objectivity of the values. We discuss the method’s contribution to current challenges in modeling large agricultural areas and the associated tradeoffs. The approach is promising for policy makers who wish to develop integrated, locally adapted land-management strategies.  相似文献   
48.
赵以宪 《价值工程》2014,(2):170-171
为了进一步提高劳动生产率、提高企业经济效益,根据施工单位机械设备数量不足、严重老化、技术性和配套性落后等问题,进行分析和探讨解决的方法及措施。  相似文献   
49.
基于中国劳动力动态调查(CLDS)数据,运用广义有序Logit模型实证分析户籍、家庭禀赋和城市特征三类因素对城市家庭住房不平等的影响;运用夏普利值分解、Oaxaca-Blinder分解区分"努力"和"环境"因素、户籍歧视和禀赋效应的贡献。研究发现:户籍可解释住房等级不平等的54.2%;"努力"因素对住房水平起正向作用;在户籍间住房等级不平等中户籍歧视效应占主导,在住房面积不平等中禀赋效应占主导,外地户口居民住房水平低源于"环境"因素趋弱,农业户口居民则源于"努力"和"环境"因素叠加趋弱;由于生活成本效应占主导,城市规模和流动人口占比越大,居民住房等级趋低,而城市土地供给增长有助于提升住房水平。  相似文献   
50.
王旭东 《价值工程》2014,(27):117-118
试验检测技术作为当前对公路路面施工中工程质量保证当中的重要环节,对路面工程施工的质量有着重要的作用。本文以公路路面养护中的主要材料试验检测方法和指标作为基础,从材料试验检测的作用和实际应用对其进行阐述,并指出在养护中运用这些指标和方法的重要性。  相似文献   
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