关于最大方向导数的一些问题

本文通过例子分析最大方向导数的两个不同方面,以供师生参考。     

The switchover to digital broadcasting in Korea

This study investigates the development of Korean digital TV transition by tracing the interaction between social and technological entities from various perspectives at different developmental stages. A socio-technical analysis examines the dynamic interactions among the stakeholders in the switchover to digital broadcasting, showing how the various actions taken by leading stakeholders affect diverse groups of stakeholders. The overall findings show that Korean digital TV transition is the outcome of a proactive strategy by industry stakeholders and the Korean government's top–down policy of supporting such a transition. It is argued that the policy of a top–down transition, which overlooks coordination among stakeholders, harms consumers and hinders effective and sustainable development. The case of Korea has implications for other countries that are pursuing digital transition strategies.     

新形势下中国经济转型刍议

随着国际经济形势变换,我国依靠投资和出口来驱动经济增长的原有发展模式已经逐渐失效,廉价劳动力的优势已经丧失,中国经济面临转型的严峻挑战。中国现有的产权制度即资产和土地的国有化是形成当前经济发展模式的根本原因,经济转型必须对现有产权制度进行变革,以刺激消费,扩大内需,使经济发展模式转向依靠技术进步和内需增长驱动,这注定是一个漫长曲折的过程。     

谈公路工程监理及质量控制措施

监理在公路工程建设中是一项非常关键的基础性工作,它贯穿整个公路建设的全过程,这项工作若有闪失,给整个工程造成的负面影响是显著的,重则工程报废,少则部分返工。对于监理工程师来说,不仅要有认真、踏实的工作作风和工程建设的专业知识,还必须同时具备监理工作的相关理论基础和实践经验,从而对工程施工进行有效的监控。文章结合我国公路工程监理工作的特点,就公路工程监理过程中一些质量控制问题进行探讨及建议。     

基于Hopfield神经网络的字符识别

噪声字符识别具有很好的应用前景，也是图像后期处理的基础。基于离散Hopfield神经网络的联想记忆能力，通过修整噪声强度将0～9这10个数字和A—Z这26个大写英文字母正确的识别出来。仿真结果表明，当字符被一定的噪声干扰后，仍具有较好的识别效果。     

金融增长的决定因素及其分析框架

一、资金融通与金融资产的构成 本文所说的金融增长是指金融资产、金融工具或信用工具的规模扩大和增速提高。 在货币信用条件下,社会再生产活动中的消费行为和投资行为都可能造成经济主体各自的收支不平衡,这必然要求资金从盈余主体向赤字主体流动。“资金融通”,简称“融资”,它是指以信用方式调剂资金余缺的一种经济活动。资金融通需要各种金融工具作为载体,这些金融工具余额之和就构成金融资产总量,广义货币则是金融资产总量的重要组成部分。广义货币是由现金、活期存款和定期存款所构成,统称为流动性金融资产。现金是所有资产中最具流动性的资产。活期存款和定期存款与那些个人或企业所拥有的存货、黄金和土地等非金融资产不同,它们能被迅速和方便地变成现金等价物。随着收入的继续增长和金融制度的成     

产融结合的区域经济联动分析

从东西方政治经济学解析金融体系与产业经济的影响，具体是区域地理大发现和现代产业经济革命的渊源，以及世界上最早的宋朝纸币货币发展历史追溯，揭示现代金融学的产业渊源。并且通过1997年亚洲金融危机和美国次贷危机对我国经济的影响，阐述世界金融和货币体系对实体经济的影响，尤其是产业龙头、产业七寸和产业配套的产业链条的市场销售额的时间序列分析、销售额分析、带动力分析。从市场和价格两个角度剖析扩大内需和协调外贸市场对经济的改善作用，通过发展交通、扩大物流实现区域经济联动，使区域经济和产融结合。     

PERSPECTIVE: Cross‐Functional Integration in Spanish Firms

Published studies of new product development in Spain provide conflicting evidence regarding the role of cross‐functional integration in new product success. One possible explanation for these results is the use of idiosyncratic scales for measuring the level of cross‐functional integration. This study adopts the scale items used in a previous study and replicates that research process using data collected from managers of 134 Spanish companies involved in new product development. Findings confirm the appropriateness of these scales in a Spanish context and the importance of cross‐functional integration to new product success in Spanish firms. No support is found for the hypothesis that participative management is positively correlated with the level of cross‐functional integration. Cross‐functional integration is found to be negatively related to goal incongruity and positively related to top‐management support for integration.     

Legitimacy and the Value of Early Customers

To overcome resource constraints and achieve exponential growth, a new venture must rely on early customers of its products to communicate value and commitment to others. For this reason, founders of new ventures focus more on early customers as a key element of their founding strategy than on other elements. But when do early customers really add value to new ventures? Scholars have used legitimacy theory to examine the benefits of gaining acceptance and conveying firm quality through conforming to social norms and following similar methods and forms. It has been argued that, independent of the customers of products and services, observable legitimacy characteristics of a new organization function as signals and are used by critical external constituents to infer the quality of the firm. This research, however, sheds little light on the manner in which firm legitimacy influences how potential customers respond to the existence of early customers. The current study therefore proposes that, depending on types of legitimacy (cognitive, regulative, and normative), early customers may have a different impact on subsequent firm performance. While a young firm may reduce information asymmetry that hampers their attractiveness to customers and other external stakeholders via the costly signal of obtaining early customers, the signal fit argument suggests that discrepancy between a signal and the characteristics of the signaler can lead to unreliable quality and lower signaling value. Legitimacy is critical because, when legitimacy is absent, early customers may not serve as an effective signal for the new venture. This study therefore explores the extent to which the signaling effect of early customers depends on these three types of legitimacy. This study employs the Kauffman Firm Survey (KFS) public database, a panel study of 4928 new businesses founded in the United States in 2004. Four surveys (baseline, first follow‐up, second follow‐up, and third follow‐up) were conducted using self‐administered Web survey and computer‐assisted telephone interview methods. In this study, the independent variables include early customers and the three types of legitimacy (cognitive, regulative, and normative) as well as a set of control variables. All independent variables were measured at the founding of the businesses in the KFS baseline survey. Dependent variables in this study include second‐year revenue, third‐year revenue, and fourth‐year revenue as measured in the KFS first, second, and third follow‐up surveys, respectively. The multinomial logistic regression and Heckman sample selection model is used to analyze the data. Results show that early customers are beneficial to new ventures, and the benefits of early customers to firm performance are higher when there is cognitive legitimacy from a capable founding team and regulative legitimacy from paying federal Social Security and Medicare taxes. Surprisingly, while incorporation improves performance for new ventures, the benefit of having early customers relative to not having early customers is lower, not higher, when the firm is incorporated than when the firm is not incorporated. Early customers have the same benefit regardless of the presence of normative legitimacy through the presence of a network with suppliers. This study therefore offers insights into the role of early customers at founding. Early customers can be very useful for founders with significant experience, and it may be a good strategy to seek them out. However, it appears that there are specific conditions under which pursuing early customers may not be an effective strategy. Founders can make strategic decisions not to pursue early customers if there are no anticipated payoffs.     

物流配送成本优化估计的数学模型研究

为了有效地利用物流成本估计中线性和非线性数学模型的优点,把线性预测性能优异的ARIMA数学模型和RBF神经网络相结合,使模型非线性数学变化上形成估计优化,可以捕捉物流成本价格的线性和非线性规律,有效地减少传统预测数学模型中一些非线性因素的影响。以某物流公司1991～2012年物流操作成本为数据,将所提出的数学模型与网格搜索SVR模型、PSO-SVR模型、Levenberg-Marquardt BP神经网络模型及背景值优化GM(1,1)模型进行对比实验。结果表明所提出的优化数学模型能够解决上述问题且具有更高的预测精度。