社区媒体的广告价值探析

随着新的媒体形式的涌现,社区媒体广告逐渐引起了人们的关注。本文分析了社区媒体的特征与广告价值,以及社区媒体广告中存在的主要问题,并就此提出了如何规避问题、提升社区媒体广告价值的策略和方法。     

Sociotechnical regimes,technological innovation and corporate sustainability: from principles to action

Increased environmental and social responsibility awareness, while producing unique opportunities for sustainability-oriented innovations, has generated important challenges for companies. The path to sustainability requires corporate strategies that guarantee profitability, managing simultaneously environmental and social responsibilities. An attempt is made to provide an understanding of sustainable development thinking in business, discussing how the combination of the transition management, adaptive planning and sociotechnical approaches can contribute towards an effective implementation of sustainability-oriented innovations in business context. The article proposes a conceptual model, which incorporates this contribution, developed through a four-year action-research project carried out within a large Brazilian energy company – Petrobras. The authors argue that the adoption of the proposed model by other large firms operating in different societal sectors might trigger organisational changes related to current corporate practices of technological innovation management.     

基于局部网络效应的数字信息产品竞争兼容策略研究

采用基于复杂社会网络的产品竞争微观扩散模型,应用计算实验的方法分析在局部网络效应作用下,不同网络拓扑结构及产品完全兼容策略、部分兼容策略和完全不兼容策略对产品竞争扩散的影响。研究结果表明,不兼容策略下不同消费者群体之间的联系越少,局部偏差值越大,越有可能出现厂商共享市场份额的局面。此外,新产品进入市场的时机、消费者之间的交互作用和产品的内在价值是影响厂商选择不同兼容策略的关键因素。     

空间经济学的现实机制与发展路径

空间经济学利用非现实系统假设能否得出有效的现实结论学术界存在争议。指出空间经济学所揭示的聚集生成机制作为一种自组织机制,超越了非现实系统假设与模型等理论形式,是一种真实存在的现实机制,其生成论的范式指明了空间经济学未来的发展路径,具有现实应用价值。     

中小企业内部审计外部化实现途径分析

内部审计外部化能有效实现成本效益的平衡并提升企业的经济效率,在西方国家已经是普遍现象,在我国刚刚起步,尤其在中小企业中鲜有例子。文章分析了我国中小企业实施内部审计外部化的意义,并建议中小企业应权衡各种内部审计外部化形式的利弊,进行成本效益分析,从而在不同的发展时期,恰当选择适用内部审计的全部外包或部分外包以及协力式委外等三种实现途径。     

我国民营酒店的发展现状及对策分析

通过分析我国民营酒店的发展状况(即现存的几种管理模式)及存在问题,总结出民营酒店合适的发展对策。     

HYDRODYNAMIC STUDY ON A PECTORAL FIN ROWING MODEL OF A FISH

Fish pectoral fin movement involves primarily a drag-based and a lift-based mechanisms to produce thrust. A numerical study on a pectoral fin rowing propulsion model based on the drag-based mechanism is presented in this article. The propulsive mechanism of the pectoral fin rowing model is related with the voriticity and pressure in the flow field. The relationship between the thrust and kinematic parameters and the wake-captured problem are analyzed. It is shown that a high thrust is produced in the power stroke, mainly due to the backward translation acceleration, the anticlockwise angular acceleration and the absence of stall in the uniform translation. Moreover, the flow control mechanism and the effect of dynamic flexible deformation are further analyzed. To properly choose controllable factors and adopt an appropriate dynamic deformation can improve the propulsive performance.     

基于非对称扰动的负荷建模新方法及工程应用

影响总体测辨法广泛应用的主要障碍在于电力系统中自然扰动所提供的有效数据严重不足。这是因为目前总体测辨法只能从三相对称扰动数据中辨识出负荷模型,而大多数电力系统故障是非对称的,人工大扰动试验又难以得到许可。文中提出基于非对称扰动的负荷动态模型建模方法。通过将感应电动机Park方程直接用于动态过程求解,解决了负荷动态模型辨识源数据严重不足的问题;通过将改进的免疫算法用于模型参数优化,解决了参数辨识过程中的不收敛现象。最后讨论了上海电网实测负荷模型对线路极限切除时间的影响。     

Pricing Options under Stochastic Interest Rates: A New Approach

We will generalize the Black-Scholes option pricing formula by incorporating stochastic interest rates. Although the existing literature has obtained some formulae for stock options under stochastic interest rates, the closed-form solutions have been known only under the Gaussian (Merton type) interest rate processes. We will show that an explicit solution, which is an extended Black-Scholes formula under stochastic interest rates in certain asymptotic sense, can be obtained by extending the asymptotic expansion approach when the interest rate volatility is small. This method, called the small-disturbance asymptotics for Itô processes, has recently been developed by Kunitomo and Takahashi (1995, 1998) and Takahashi (1997). We found that the extended Black-Scholes formula is decomposed into the original Black-Scholes formula under the deterministic interest rates and the adjustment term driven by the volatility of interest rates. We will illustrate the numerical accuracy of our new formula by using the Cox–Ingersoll–Ross model for the interest rates.