Using e-learning standards in educational video games

The integration of educational video games in Virtual Learning Environments (VLEs) is a challenging task in need of standardization to improve interoperability and to safeguard investment. The generalized use of VLEs has fostered the emergence of rich contents, and different standards exist to improve their interoperability and reusability. This work describes a proposal of how existing e-learning standards can be used to improve the integration of educational games in VLEs, while introducing a set of models that take into account the features of the selected standards. A specific implementation of this approach in the eAdventure game platform is also presented.     

地理信息元数据及系统

作为数字地球重要支撑技术之一的地理信息元数据技术随着信息技术的飞速发展显得越来越重要。该文对现有的典型地理信息元数据内容和标准以及实现系统进行了分析和综合比较,然后对地理信息元数据内容与标准的制订、地理信息元数据系统的建设提出了一点思考,希望能够对相关的研究有所启发。     

基于CWM的企业元数据集成中元数据抽取与导出研究

公共仓库元模型（CwM）是为了在数据仓库和业务分析环境之间方便交换元数据而制定的一个标准,并已经成为模型驱动体系结构（MDA）新策略方向中的核心组成部份。基于CWM的企业元数据集成相关技术,重点探讨集成中元数据的抽取与导出问题,给出相应的导出规则以及一个应用实例。     

Improving Metadata Caching Efficiency for Data Deduplication via In-RAM Metadata Utilization

We describe a data deduplication system for backup storage of PC disk images, named in-RAM metadata utilizing deduplication (IR-MUD). In-RAM hash granularity adaptation and miniLZO based data compression are firstly proposed to reduce the in-RAM metadata size and thereby reduce the space overheads required by the in-RAM metadata caches. Secondly, an in-RAM metadata write cache, as opposed to the traditional metadata read cache, is proposed for further reducing metadata-related disk I/O operations and improving deduplication throughput. During deduplication, the metadata write cache is managed following the LRU caching policy. For each manifest that is hit in the metadata write cache, an expensive manifest reloading operation from the disk is avoided. After deduplication, all the manifests in the metadata write cache are cleared and stored on the disk. Our experimental results using 1.5 TB real-world disk image dataset show that 1) IR-MUD achieved about 95% size reduction for the deduplication metadata, with a small time overhead introduced, 2) when the metadata write cache was not utilized, with the same RAM space size for the metadata read cache, IR-MUD achieved a 400% higher RAM hit ratio and a 50% higher deduplication throughput, as compared with the classic Sparse Indexing deduplication system where no metadata utilization approaches are utilized, and 3) when the metadata write cache was utilized and enough RAM space was available, IR-MUD achieved a 500% higher RAM hit ratio compared with Sparse Indexing and a 70% higher deduplication throughput compared with IR-MUD with only a single metadata read cache. The in-RAM metadata harnessing and metadata write caching approaches of IR-MUD can be applied in most parallel deduplication systems for improving metadata caching efficiency.     

Metadata management for scientific databases

Most scientific databases consist of datasets (or sources) which in turn include samples (or files) with an identical structure (or schema). In many cases, samples are associated with rich metadata, describing the process that leads to building them (e.g.: the experimental conditions used during sample generation). Metadata are typically used in scientific computations just for the initial data selection; at most, metadata about query results is recovered after executing the query, and associated with its results by post-processing. In this way, a large body of information that could be relevant for interpreting query results goes unused during query processing.In this paper, we present ScQL, a new algebraic relational language, whose operations apply to objects consisting of data–metadatapairs, by preserving such one-to-one correspondence throughout the computation. We formally define each operation and we describe an optimization, called meta-first, that may significantly reduce the query processing overhead by anticipating the use of metadata for selectively loading into the execution environment only those input samples that contribute to the result samples.In ScQL, metadata have the same relevance as data, and contribute to building query results; in this way, the resulting samples are systematically associated with metadata about either the specific input samples involved or about query processing, thereby yielding a new form of metadata provenance. We present many examples of use of ScQL, relative to several application domains, and we demonstrate the effectiveness of the meta-first optimization.     

工程化学数据库元数据标准的制定

元数据是关于数据的数据。元数据对于数据共享具有重要作用。本文分析了国内外元数据的发展状况,从工程化学数据库存在的基本问题出发,针对工程化学数据的特点,并参考国内外通用的元数据标准,提出了工程化学数据库元数据设计方案,并对其各部分的内容和功能进行了比较详细的介绍。     

地学元数据结构分析及其管理系统设计

在分析了地学数据的Web共享需求及其多学科特点基础上,设计了地学数据的可扩展元数据结构,它包括地学核心元数据、模式核心元数据、模式(专用)扩展元数据等三层体系,并利用W3C推荐的RDF/XML数据模型和方法开发了地学数据共享平台的元数据管理系统(MMS)。该系统的应用验证了地学数据共享元数据构架体系的可靠性和适用性。     

Web Service技术在教育资源整合中的研究与实现

分析了教育资源的特点和教育资源整合中面临的问题,在深入研究Web Service技术的基础上,给出基于Web Service技术的教育资源整合系统的体系结构及实现中的关键技术,并将解决方案应用于无线接入远程教育系统,取得了良好的应用效果。     

WebGIS中的元数据研究

论述了元数据的定义及其在WebGIS中的作用;同时,基于“辽宁省统计信息辅助决策支持系统”的开发实践,从数据存储、数据传输和数据展现三个角度探讨了元数据在WebGIS的表示与实现．     

A Statistical Metadata Model for Simultaneous Manipulation of both Data and Metadata

There is a growing demand for more cost-efficient production processes in Statistical Institutes. One way to address this need is to equip Statistical Information Systems (SIS) with the ability to automatically produce statistical data and metadata of high quality and deliver them to the user via the Internet. Current approaches, although provide for the storage of appropriate metadata, do not use process metadata for guiding the production process. In this paper we present an approach on creating SISs that permits metadata-guided statistical processing based on an object-based, statistical metadata model. The model is not domain specific and can accommodate both microdata and macrodata. We have equipped the model with a set of transformations that can be used to automatically manipulate data and metadata. We show the applicability of transformations with some examples using actual statistical data for R&D expenditures. Finally, we demonstrate how the presented framework can be exploited for the construction of a web site that offers ad hoc query capabilities to the users of statistical data.     

数据仓库系统中的元数据管理

人们对数据分析的要求的不断提高导致了数据仓库的发展,而在建设数据仓库的过程中元数据管理起着至关重要的作用。详细而准确的元数据对于数据仓库的创建、数据加载、运行维护、清理脏数据等工作都必不可少。文章在对数据仓库系统中的元数据以及元数据管理进行全面分析的基础上,较为详细地介绍了笔者自行开发的数据仓库系统SEUwarehouse中的元数据及其管理的设计与实现。     

教育资源网格体系结构及元数据模型研究*

服务器瓶颈、资源副本管理、资源发现、网络带宽问题等若干因素致使传统的Web方式不能满足互联网络环境下的文件资源管理需求。网格是架构在互联网络上的一个全面共享资源的基础设施,利用网格进行高效的分布式资源管理是解决以上问题的一个有效手段。为此,提出了一种教育资源网格的体系结构模型,分析了其各部分的功能,并给出了一个教育网格资源的元数据模型。     

Linking learning goals and educational resources through interactive concept map visualizations

Concept browsing interfaces can help educators and learners to locate and use learning resources that are aligned with recognized learning goals. The Strand Map Service enables users to navigate interactive visualizations of related learning goals and to request digital library resources aligned with learning goals. These interfaces are created using a programmatic Web service interface that dynamically generates interactive visual components. Preliminary findings suggest that these library interfaces appear to help users stay focused on the scientific content of their information discovery task, as opposed to focusing on the mechanics of searching.     

面向多维元数据模型构造的数据字典

针对应用系统数据采集和管理功能的需要，通过对数据库管理系统而设计的传统数据字典技术的改造并引入XML技术，提出面向Web应用系统设计过程的，能够跨平台实现集数据内容定义、表现形式定义、校验和统计定义等功能为一体，面向多维元数据模型构造的数据字典。     

BESⅢ分布式计算的元数据管理

北京谱仪III(BESIII)高能物理实验产生PB量级的实验数据,海量数据的处理和分析对计算资源提出较大挑战。分布式计算是整合异构计算资源和解决计算资源短缺的可行方案。根据BESIII实验需求对分布式计算所需的元数据管理进行研究,提出数据文件的元数据模型,利用中间件软件DIRAC的目录服务设计并实现元数据管理系统。该系统利用树型目录结构、物理文件名动态构建和虚拟数据集等技术,组织和存储各种类型的元数据,实现查询请求、逻辑文件以及物理文件之间的映射,使用数字证书和开放安全套接层协议保证系统安全。将该系统应用于实验数据分析和处理中,测试结果表明,当并发用户访问量为300时,查询时间仅为0.3 s,证明该系统性能较好,可以满足BESIII实验的应用需要。     

Factors that influence student teacher’s interest to achieve educational technology standards

Bearing in mind the importance of a transition from teacher-centred, lecture-based teaching to student-centred, technology-based learning, this study examined teachers’ interest to achieve educational technology standards (Interest) in terms of their computer attitude (Attitude), computer experience (Experience) and the professional support to achieve these standards offered to them from their institutions (Support). The study used a sample of 129 elementary student teachers from Finland and Serbia. The two groups of teachers differed in all examined variables: Experience was higher for the Finnish students, whereas Attitude, Interest and Support were higher for the Serbian students. Furthermore, contrary to the Finnish students, the Serbian student indicated that they received some instruction on ET standards during their studies and designed learning activities to promote the examined standards. By applying a two-group path analysis, it was found that to improve Interest, we need to improve Attitude by means of Experience. The analyzed data evidence that a desired role of Support (positive impact on Experience and Attitude) can be achieved when Support respects Experience. Implications for practice and directions for further research are examined.     

一种约束CWM元数据的方法

公共仓库元模型为构造数据仓库领域的元数据提供了统一的标准。该文对元数据交换环境作了具体分析,提出了一种基于约束模型的方法来约束CWM中的元数据,并通过一个实例说明该方法可使CWM元数据满足各种交换环境。     

基于XML的地理信息元数据存储策略

GeoMeta是一个基于XML的地理信息元数据系统。该文在简要介绍了GeoMcta系统的系统结构和系统组成后,对GeoMeta系统中基于XML的地理信息元数据存储策略进行了详细的阐述,主要包括无结构的存储、基于线性域段结构的存储和基于结构的存储等3种存储策略。