SDQE: towards automatic semantic query optimization in P2P systems

Conventional information retrieval technology (i.e. VSM) faces many difficulties when being implemented in complex P2P systems for the lack of global statistic information (e.g. IDF) and central services. In this paper, we suggest a novel query optimization scheme (Semantic Dual Query Expansion, SDQE) that makes full use of the context information supplied by the local document collection. Latent Semantic Indexing (LSI) is used to explore the local context information. By comparing the different local context information hidden in different document collections, it is possible to solve the synonymy–polysemy problem in VSM. The experiments prove that our scheme is effective to improve the retrieval performance in P2P systems without knowing the global statistic information.     

Characterising and evaluating information seeking behaviour in a digital environment: Spotlight on the ‘bouncer’

The paper delineates and explains an emerging, but significant, form of digital information seeking behaviour among information consumers, which the authors have called ‘bouncing’. The evidence for this behaviour has emerged from five years of deep log analysis studies – an advanced form of transaction log analysis – of a wide range of users of digital information resources. Much of the evidence and discussion provided comes from the scholarly communication field. Two main bouncing metrics were applied in the log studies: site penetration, which is the number of items or pages viewed in a session, and return visits. The evidence shows that (1) a high proportion of people view just a few items or pages during a visit to a site and, (2) a high proportion of visitors either do not come back to the site or they did so infrequently. Typically those who penetrated a site least tended to return the least frequently. These people are termed ‘bouncers’. They bounce into the site and then bounce out again, presumably, to another site, as a high proportion of them do not appear to come back again. Possible explanations – negative and positive, for the form of behaviour are discussed.     

基于语义对等网的分布式知识管理研究

如何在语义层面有效地管理和利用分散的知识资源是知识型企业面临的难题。文章基于分布式知识管理的研究现状,将语义网和对等网相结合应用于知识管理,提出了一种基于语义对等网的分布式知识管理模型,详细描述了知识检索的流程和功能,并为实施该模型构建了技术平台,为高效率、高质量分布式知识管理提供有力支撑。     

对等管理信息系统平台研究

摘要：为了解决大规模分布式管理信息系统中的高速信息共享等问题,提出了基于对等结构的管理信息系统平台。给出了该系统平台的节点模型、管理策略及信息共享流程;提出了一种结合分布式哈希表和聚类的高速检索方法,保证了用户能够在分布式管理系统中快速的精确检索和分类检索;实现了系统的用户透明;为了保证分布式管理信息系统中的分布式多副本同步,提出了“对等锁”作为数据一致性维护方法。同时,给出了平台的具体实现方法,并给出了实例;实验结果表明,该平台具有良好的信息共享性能、高效的搜索能力和相当的容错能力。     

In search of query patterns: A case study of a university OPAC

A transaction log analysis of the Nanyang Technological University (NTU) OPAC was conducted to identify query and search failure patterns with the goal of identifying areas of improvement for the system. One semester’s worth of OPAC transaction logs were obtained and from these, 641,991 queries were extracted and used for this work. Issues investigated included query length, frequency and type of search options and Boolean operators used as well as their relationships with search failure. Among other findings, results indicate that a majority of the queries were simple, with short query lengths and a low usage of Boolean operators. Failure analysis revealed that on average, users had an almost equal chance of obtaining no records or at least one record to a submitted query. We propose enhancements and suggest future areas of work to improve the users’ search experience with the NTU OPAC.     

基于用户行为P2P网络全文搜索机制

在对P2P用户行为进行分析的基础上，提出了一种自动机制，能够区分出用户对不同主题领域的关注度，计算出邻居节点查询各关注主题领域相关文档的能力，通过选择对特定领域查询能力最强的k个邻居节点转发查询消息提高效率，该机制能够区分出用户的典型行为和即兴行为，通过采用不同策略进一步提高即兴查询的效率。     

Evaluation of a mobile information system in context

The motivation for this work has been to provide relevant information to the right situation for mobile phone users. We have iteratively developed applications for travellers and tourists to provide a general travel guide with local tourist information. This used a combination of wireless tag technology and information from content service providers. The paper presents our evaluation methodology and how we used it to develop the applications.     

The weighted Condorcet fusion in information retrieval

The Condorcet fusion is a distinctive fusion method and was found useful in information retrieval. Two basic requirements for the Condorcet fusion to improve retrieval effectiveness are: (1) all component systems involved should be more or less equally effective; and (2) each information retrieval system should be developed independently and thus each component result is more or less equally different from the others. These two requirements may not be satisfied in many cases, then weighted Condorcet becomes a good option. However, how to assign weights for the weighted Condorcet has not been investigated.     

A reliable FAQ retrieval system using a query log classification technique based on latent semantic analysis

To obtain high performances, previous works on FAQ retrieval used high-level knowledge bases or handcrafted rules. However, it is a time and effort consuming job to construct these knowledge bases and rules whenever application domains are changed. To overcome this problem, we propose a high-performance FAQ retrieval system only using users’ query logs as knowledge sources. During indexing time, the proposed system efficiently clusters users’ query logs using classification techniques based on latent semantic analysis. During retrieval time, the proposed system smoothes FAQs using the query log clusters. In the experiment, the proposed system outperformed the conventional information retrieval systems in FAQ retrieval. Based on various experiments, we found that the proposed system could alleviate critical lexical disagreement problems in short document retrieval. In addition, we believe that the proposed system is more practical and reliable than the previous FAQ retrieval systems because it uses only data-driven methods without high-level knowledge sources.     

Ｐ２Ｐ系统中基于信誉感知的超级节点选择算法研究

对层次式Ｐ２Ｐ系统中恶意超级节点频繁离开网络导致系统不稳定甚至崩溃的问题,提出一种新的基于信誉的超级节点选择算法．建立节点基于历史交换回馈信息的信誉评估算法,以信誉评估为基础,构建信誉感知的超级节点选择算法,选择信誉高的节点为超级节点．理论分析和仿真结果表明,该算法有效地提高了系统的稳定性．     

Exploring and modelling elements of information management that contribute towards making positive impacts: An outcome based approach for senior managers in a local government setting

This paper reports on the first stage of an investigation into monitoring and evaluating the impact of information management (IM) within a local government context. The overall study will utilise a combination of principles from various results-based, outcomes-based and social change approaches (Logical Framework Analysis, Most Significant Change, and Outcomes Mapping) in an attempt to move Leicestershire County Council away from a culture focused on traditional performance measurement, i.e. percentage change in use of services provided to the public, to something of real value. Interviews with 20 senior managers highlighted the important IM issues for Leicestershire County Council as a local government. These initial findings showed that maintaining high quality, trusted, and governed information and knowledge resources were of great value to the organisation. Analysis showed that 85% of senior managers interviewed considered IM to be “critical” in the achievement of organisational outcomes. Further analysis enabled the development of an initial framework indicating key areas where IM can have impact. These key areas will become the focus of further research, where applying a combination of approaches aforementioned will define the boundary partners, their specific outcomes and progress markers with possible impacts proposed. This detail will help to develop a framework for measuring the impact of IM.     

Predicting semantic preferences in a socio-semantic system with collaborative filtering: A case study

This paper proposes collaborative filtering as a means to predict semantic preferences by combining information on social ties with information on links between actors and semantics. First, the authors present an overview of the most relevant collaborative filtering approaches, showing how they work and how they differ. They then compare three different collaborative filtering algorithms using articles published by New York Times journalists from 2003 to 2005 to predict preferences, where preferences refer to journalists’ inclination to use certain words in their writing. Results show that while preference profile similarities in an actor’s neighbourhood are a good predictor of her semantic preferences, information on her social network adds little to prediction accuracy.     

A new variant of the Pathfinder algorithm to generate large visual science maps in cubic time

In the last few years, there is an increasing interest to generate visual representations of very large scientific domains. A methodology based on the combined use of ISI–JCR category cocitation and social networks analysis through the use of the Pathfinder algorithm has demonstrated its ability to achieve high quality, schematic visualizations for these kinds of domains. Now, the next step would be to generate these scientograms in an on-line fashion. To do so, there is a need to significantly decrease the run time of the latter pruning technique when working with category cocitation matrices of a large dimension like the ones handled in these large domains (Pathfinder has a time complexity order of O(n⁴), with n being the number of categories in the cocitation matrix, i.e., the number of nodes in the network).     

An approach for selecting and using a method of inter-coder reliability in information management research

Qualitative researchers in information management research often need to evaluate inter-coder reliability (ICR) to test the trustworthiness of their content analysis. A suitable method of evaluating ICR enables researchers to rigorously assess the degree of agreement among two or more independent qualitative coders. This allows researchers to identify mistakes in the content analysis before the codes are used in developing and testing a theory or a measurement model and avoid any associated time, effort and financial cost. Different methods have been proposed, but little guidance is available on which approach to evaluating ICR should be used. In this paper, we review and compare leading ICR methods that are suitable for qualitative information management research. We propose an approach for selecting and using an ICR method, supported by an illustrative example. The five steps in our proposed approach include: selecting an ICR method based on its characteristics and requirements of a project; developing a coding scheme; selecting and training independent coders; calculating the ICR coefficient and resolving discrepancies; and reporting the process of evaluating ICR and its results.     

Organizational identity challenges in a post-merger context: A case study of an information system implementation project

This study examines the effects of the differences in organizational identities that emerged during a post-merger project that aimed at unifying the laboratory services of a large healthcare center that resulted from the merging of three hospitals by supporting them with a unique information system. We draw on the concepts of organizational identity and sensemaking to analyze the laboratory information system implementation project. Organizational identity is conceptualized as the mental representation that organizational members have of themselves as a social group in terms of practices, norms, and values and how they understand themselves to be different from members of other organizations. Data analysis suggests that divergent organizational identities and team members’ alternative interpretations of others’ practices, norms and organizational symbols, coexist during the post-merger integration phase. These interpretations are reflected in the final functionality of the information system that was different from the planned one.     

Exploring CO2 mitigation pathway of local industries using a regional-based system dynamics model

Low-carbon development based on low energy consumption, low pollution and low emissions has become an important strategic choice for worldwide governments to achieve sustainable development. In order to support smart government in decision making, information systems have been developed to monitor and predict CO₂ emissions. Most of the existing studies investigate CO₂ emission amounts, identify influencing factors of CO₂ emission and discuss potential suggestions to mitigate CO₂ emission for different industries. They often focus on CO₂ emission research of industries in a region or country, while the integration of carbon flow in the neighboring regions is not well studied. Therefore, this paper proposes a system dynamics model to explore an optimal carbon emission reduction path of a regional industry by integrating regional differences, i.e., industrial comparative advantages, technology advantages and the inter-regional context between the neighboring regions. In the case study, we use a key industry in a typical industrial region of Western China, the cement industry in Chongqing, as a scenario to simulate the CO₂ emission, possible energy demand and cement production of the cement industry in this region for recent years. Simulation results show that by leveraging the regional differences, especially the collaboration of the industrial chain and production capacity among regions, the cement industry in Chongqing can achieve the low-carbon target. In addition, through the analysis and discussions about the features of our model and Chongqing’s cement industry, it reflects that our model using regional differences is applicable to industries with a common demand market at the regional level such as energy, chemical and steel industries.     

国家重点生态功能区人类活动空间变化及其聚集分析

国家重点生态功能区是国家为保护、恢复和提高区域水源涵养、防风固沙、保持水土、调蓄洪水、 保护生物多样性等重要生态功能而划定的需要重点保护和限制开发的区域。分析国家重点生态功能区人类活动空间变化,是环保等相关部门把握国家生态功能区宏观生态环境状况,并对其进行量化监管的重要手段。为此,本文基于面向对象方法提取了国家重点生态功能区510个县2010年、2015年两期的生态环境变化空间分布信息,并在此基础上采用土地利用转移矩阵及核密度法对两期人类活动造成的生态环境变化时空分布进行了分析。研究结果表明：国家重点生态功能区的生态环境变化中,71.77%的变化为耕地、工矿、建设用地的转入,27.53%为植被的转入;核密度提取出5个热点区域,包括燕山地区、吕梁山地区、黄土高原地区、武当山地区、大别山地区,占总变化图斑数的24.64%,黄土高原地区和大别山地区变化主要来自于工矿和建设用地的扩张,燕山地区和吕梁山地区变化主要来自于工矿用地的扩张,武当山地区变化主要来自于建设用地的扩张;以变化面积加权的核密度提取出1个热点区域,即西拉木伦河地区,占总变化面积的20.53%,该地区的变化主要来自于耕地的扩张。