Term frequency – function of document frequency: a new term weighting scheme for enterprise information retrieval

In today's business environment, enterprises are increasingly under pressure to process the vast amount of data produced everyday within enterprises. One method is to focus on the business intelligence (BI) applications and increasing the commercial added-value through such business analytics activities. Term weighting scheme, which has been used to convert the documents as vectors in the term space, is a vital task in enterprise Information Retrieval (IR), text categorisation, text analytics, etc. When determining term weight in a document, the traditional TF-IDF scheme sets weight value for the term considering only its occurrence frequency within the document and in the entire set of documents, which leads to some meaningful terms that cannot get the appropriate weight. In this article, we propose a new term weighting scheme called Term Frequency – Function of Document Frequency (TF-FDF) to address this issue. Instead of using monotonically decreasing function such as Inverse Document Frequency, FDF presents a convex function that dynamically adjusts weights according to the significance of the words in a document set. This function can be manually tuned based on the distribution of the most meaningful words which semantically represent the document set. Our experiments show that the TF-FDF can achieve higher value of Normalised Discounted Cumulative Gain in IR than that of TF-IDF and its variants, and improving the accuracy of relevance ranking of the IR results.     

A Monopoly Classroom Experiment

The author uses a simple classroom experiment to develop the economic model of monopoly. As a pedagogical tool, the experiment introduces students to the nature of the monopoly problem and motivates them to think of the associated efficiency issues as a divergence between private benefits and social contributions. As a test of economic principles, the experiment highlights the role of information and fairness ideals in determining economic outcomes.     

民营银行并购国有银行的动机、成本与风险探析

当前,在世界范围内特别是在发展中国家,掀起了一股民营银行并购国有银行的浪潮。这种并购容易产生现金流风险、信息不对称风险、政策诱导性风险、管理效率风险、并购失败风险。民营银行应通过以下措施和方法将风险消除,从而实现并购成功:结合银行实际,选用适合自身发展的并购方式;努力消除信息不对称;优化决策程序;妥善处理好与政府的关系。     

基于政府信息公开视角的档案信息化建设研究

近年来,随着计算机网络的不断发展,档案管理工作也必须实现信息化,从而才能跟上时代前进的步伐,不断提高档案工作的效率。文章基于政府信息公开视角,通过对于我国当前档案信息化存在的问题研究,为我国今后档案信息化工作的进一步发展和完善提供相关的对策建议。     

我国中小民营企业融资问题探讨

本文首先分析了导致我国中小民营企业融资困难的主要原因,然后针对问题提出引导民间资金进入实体经济、加快建立和完善地方信用担保体系等具体政策建议。     

A security evaluation approach for information systems in telecommunication enterprises

In recent years, information systems in telecommunication enterprises have been characterised by boundary expansion and increase of departmental-level applications. These changes increase the complexity of security evaluation and pose new challenges to enterprises' information security. Taking into account the behaviour characters of system users, we put forward a system security evaluation approach based on access paths. This approach can help evaluators and users find out potential security risks without figuring out the boundary of systems explicitly. It has no special requirements for system scale and can be used in the evaluation of enterprise-level and departmental-level systems. This paper also presents the formal definition of access path and related evaluation rules.     

A Reduced‐Form Model for Warrant Valuation

This paper studies warrant valuation using a reduced‐form model. Analogous to the credit risk literature, structural models require complete information about the asset value process and the firm’s liabilities. In contrast, reduced‐form models require only information about the firm’s stock price process. We introduce a reduced‐form model where the warrant holder is a price taker, and we relate our model to structural models appearing in the literature.     

Herding behaviour and the declining value relevance of accounting information: evidence from an emerging stock market

This article sheds light on the underlying mechanisms behind the changes in the value relevance of accounting information in the Karachi Stock Exchange (KSE) during the 1999–2010 period. We find that neither changes in earnings quality nor the earnings lack of timeliness hypothesis can explain the decline in the value relevance of accounting information in the KSE. Based on the stylized facts associated with the growth of the KSE and the broader economics literature, we argue that the reduction in the explanatory power of accounting information vis-à-vis stock returns was caused by herding behaviour. Empirical estimates from state-space model of herding behaviour confirm the existence of herding, and we find that the value relevance of accounting information is significantly lower in periods characterized by herding behaviour. This article is also amongst the first attempts to empirically demonstrate that an expansionary monetary policy and increases in foreign portfolio investment lead to increased levels of herding.     

对我国高校文献检索课教学改革的几点建议

高校文献检索课是我国高校培养学生信息素养的重要阵地,其作用的发挥受到诸多因素的影响。为了确保我国的文献检索课能符合现今学生信息素养的培养要求,本文提出在对其进行改革的同时,对支撑其改革的影响因素也要彻底的改革。