区域耕地数量变化预测方法的对比研究

研究目的:对区域耕地数量变化预测方法进行对比分析,科学合理确定区域耕地数量。研究方法:通过Pearson相关分析法筛选影响耕地变化的关键因子,利用改进的BP神经网络算法、灰色模型和多元线性回归模型法对费县耕地数量变化进行预测。研究结果:改进的BP神经网络算法相对传统的灰色模型和多元线性回归模型等预测方法具备较高的预测精度。研究结论:改进的BP神经网络算法是进行耕地数量变化预测的较好方法,具有实际指导意义,其预测结果可以为当地相关部门合理地确定耕地保有量、推进耕地保护提供科学依据。     

The impact of external forces on cartel network dynamics: Direct research in the diamond industry

This paper describes the impact of external environmental forces on cartel networks. Using a case research approach, this report examines two leading business networks within one industry, over time. The results suggest that (a) bargaining power of intermediaries increases with the advent of new and powerful actors, (b) process activities that cartels previously controlled are being outsourced to new actors sometimes based in developing countries, (c) other actors are acquiring resources once dominated by a cartel, (d) external forces triggered by the illegal diamond trade, such as international regulatory constraints, no longer favour cartels like De Beers, and (e) over time, these and additional environment factors are forcing actors like De Beers who perform rigid process activities to become more flexible. For example, forces are moving cartels which relied previously on hand-picked intermediaries in highly controlled networks to market their products to adopt a flexible market-focused expansion of operations in retail contexts.     

论网络文化环境中的网络道德教育

随着信息产业的发展,网络已经遍布我们生活和工作的各个领域。网络文化也正急剧地改变着人们的道德观念、价值取向以及行为模式。数字化、网络化、信息化改变了人们的生产方式、生活方式和思维方式,网络信息的确给人们带来了诸多方便。然而,网络中的不良现象却影响了网络环境建设,并干扰着正常秩序,危害着传统道德,侵蚀着人们的思想。为了确保网络环境建设的健康进行,网络道德教育势在必行。     

Tradable travel credits for congestion management with heterogeneous users

This paper carries on the recent work of Yang and Wang (2011) on tradable credit schemes by considering heterogeneous users with different value of time (VOT). Given a tradable credit scheme, the user equilibrium (UE) and market equilibrium (ME) conditions with heterogeneous users are formulated into a variational inequalities (VI) problem. Sufficient conditions for uniqueness of the aggregate UE link flows and then the ME credit price are established. Appropriate tradable credit schemes are developed to decentralize system optimal and Pareto-improving network flow patterns. Extension is made to the elastic demand case.     

Migrant networks, language learning and tourism employment

This paper examines the relationship between migrants’ social networks, the processes of language acquisition and tourism employment. Data collected using netnography and interviews are used to identify the strategies that Polish workers in the UK use to develop their language skills. The paper highlights the roles played by co-workers, co-nationals and customers in migrants’ language learning, both in the physical spaces of work and the virtual spaces of internet forums. It also shows how migrant workers exchange knowledge about the use of English during different stages of their migration careers: prior to leaving their country of origin and getting a job, during their employment and after leaving their job. Implications for academic inquiry and human resource management practice are outlined.     

Enterprises,incentives and networks: The formative years of the electrical network in Portugal, 1920–1947

Path-dependence, the formation of technological irreversibilities and ownership patterns, have recently been salient aspects in the study of historical networks. This article analyses the formative years of public utilities in a period where the advantages of co-ordination, interconnection or integration between enterprises was still incipient. The purpose is to understand what happens when the competition to expand the physical extensions of nodes and links is suddenly blocked, and the enterprises can only compete to increase supply. The theme is thus of network enterprises operating without some of the standard incentives to economies of scale. The allocational and distributional consequences of this particular situation are exposed through an examination of the case study of Portuguese electrification in the first half of the twentieth century.     

应用数据挖掘技术识别财务报表舞弊的方法研究

如何识别财务报表舞弊成为国内外学者普遍关注的问题。基于传统识别技术的诸多固有缺陷,近年来数据挖掘技术应用到识别财务报表舞弊领域成为发展趋势。数据挖掘技术包括统计方法、人工神经网络和其他数据挖掘技术。文章不仅对各种识别模型和技术进行了归纳,而且比较分析了各种模型和方法的优缺点、判别正确率以及适用条件,为下一步实施实证研究提供支持。     

Segmenting a market in the making: Industrial market segmentation as construction

This paper takes an empirical starting point in a claim that Biacore, a pioneering Swedish producer of affinity biosensors, was “in the enviable position of creating its own market” (Abelin, 1997). An in-depth case study traces how Biacore undertook segmentation activities while shaping the market for its new product technology, affinity biosensors. This involved stabilising the modes of exchange with customers, the product and the identity of the company. The efforts of Biacore highlight a constructive dimension of market segmentation that hitherto has received little attention. Rather than a process of describing, deciding and taking action, Biacore engaged in the gradual construction of market segments through an interactive and iterative process involving close collaboration with early users. Simultaneously, the market for the new technology gained shaped. Thus, the paper reports a ‘markets from networks’ story illustrating how the practice of segmenting a market may have consequences for that market.     

一种全新的两阶段个人信用评分方法探究

目前我国还没有一套规范的个人信用评分指标体系和方法。本文利用真实的个人消费信贷数据,首先建立了个人信用评分的多元线性判别分析模型和BP神经网络模型,然后将线性判别分析模型的结果与其它变量一起作为输入变量建立了混合两阶段个人信用评分模型。实证研究表明,混合两阶段个人信用评分模型相对于前两种单一模型能同时满足预测精度和稳健性的双重要求,从而,突破了通常应用单一模型于个人信用评分领域的局限。