Strong controllability and extendibility of discrete multidimensional behaviors

In this paper we propose definitions of strong controllability and extendibility for discrete multidimensional behaviors. After characterizing extendibility in algebraic terms, we show that strong controllability is equivalent to simultaneous controllability and extendibility, thus obtaining an algebraic characterization for that property.     

多媒介数据库系统的分析及设计

本文论述了多媒介数据库系统的一些基本问题,并介绍了一个新型的多媒介数据库管理系统ＣＤＢ／Ｍ的设计．     

Effects on learning of multimedia animation combined with multidimensional concept maps

This study investigates whether teaching materials combining multimedia animation and multidimensional concept maps (MAMCMs) improve learning achievement, retention, and satisfaction more than multidimensional concept maps (MCMs), as suggested by Huang et al. (2012) in Computers & Education. Learning retention, learning achievement, and learning satisfaction associated with two sets of course materials were compared in this quasi-experimental study. In total, 114 students from two classes at one private university in Taiwan participated in this 6-week teaching experiment. Analytical results indicate that learning achievement, learning satisfaction, and learning retention of the MAMCM group were better than those of the MCM group. Pedagogical implications and suggestions are given.     

分布式超媒体数据库系统的系统结构和组成

叙述了一种分布式超媒体数据库系统（ＨＤＢ）的系统结构、节点和链模型以及系统的组成。ＨＤＢ具有分布式宏文献结构,采用超媒体形式的节点和链来管理多媒体信息,可以实现过滤浏览、基于内容检索、多级导航等功能。ＨＤＢ由超媒体数据库创建、表现与查询、宏文献服务器、媒体服务器、脚本语言等模块组成。     

Effects of multidimensional concept maps on fourth graders’ learning in web-based computer course

This study explores the effect of multidimensional concept mapping instruction on students’ learning performance in a web-based computer course. The subjects consisted of 103 fourth graders from an elementary school in central Taiwan. They were divided into three groups: multidimensional concept map (MCM) instruction group, Novak concept map (NCM) instruction group, and traditional textbook (TT) instruction group. Four weeks of experimental instructions were given to the three groups, respectively. Students’ progresses were examined by pre-test and post-test measurements. The experimental results suggested that subjects in the MCM group performed significantly better than those in the NCM group which in turn performed significantly better than those in the TT group. Pedagogical implications were addressed, and conclusion and some suggestions were given.     

Investigation of multidimensional data using the interactive pattern analysis system ispahan

In 1972, Kanal has enumerated some reasons for the desirability of interactive pattern analysis and classification systems (IPACS). One such system, ISPAHAN, was developed at the Department of Medical Informatics of the Free University in Amsterdam. Although this system is still expanding, it is now in operation. In order to obtain some experience with its properties three data sets, varying in complexity were analysed. Especially the possibility of applying various pattern recognition techniques in succession is shown to lead to an unsupervised classification scheme which may yield essentially the same results as the maximum likelihood decision rule applied to the labelled data set. The results of unsupervised methods are generally influenced by user chosen initial conditions. An objective criterion should therefore be used to compare different configurations. The use of one such criterion, measuring the compactness of the resulting clusters, is demonstrated in this paper.     

Scalable multi-feature index structure for music databases

The management of large collections of music data in a multimedia database has received much attention in the past few years. In the majority of current work, researchers extract the features, such as melodies, rhythms, and chords, from the music data and develop indices that will help to retrieve the relevant music quickly. Several reports have pointed out that these music features can be transformed and represented in forms of music feature strings or numeric values so that indices can be created for music retrieval. However, there are only a small number of existing approaches which introduce multi-feature index structures for music queries while most of the others are for developing single feature indices. The existing music multi-feature index structures are memory consuming and have lack of scalability. In this paper, we will propose a two-tier music index structure which is an efficient and scalable approach for multi-feature music indexing. Our experimental results show that this new approach outperforms existing multi-feature index schemes.     

Audio support for an object-oriented database-management system

We describe the development of the data type audio in an object-oriented database management system (DBMS). The interface of the data type includes operations to store, retrieve, and manipulate audio data. Additionally, a transport protocol supports continuous recording and presentation at the users' workstations in a client-server environment. Design considerations are outlined and lead us to use no compression algorithms and to handle parametrized sample rates and sizes transparently for the user. Specific manipulation operations, such as low-pass filtering and dynamic compression, are described in detail. The implementation of an interactive audio tool shows that the data type audio can be used in the same way as conventional data types. We give an outlook on further built-in support of time-dependent media that a comprehensive multimedia DBMS should offer.     

关系数据库中多维数据分析及展现的研究

在对关系数据库业务模型分析的基础上通过建立多维模型定义使数据具有多维的概念,并在此基础上提供了一种B/S模式的多维数据查询和展现的方法,该方法充分利用了多种数据存储结构来优化数据的查询和显示.通过建立维度间的层次关系可实现多维数据的钻取、旋转、切片等操作,结合JFreeChart的图形功能提供了一种多维图形展现和分析的方法.     

机器学习化数据库系统研究综述

数据库系统经过近50年的发展,虽然已经普遍商用,但随着大数据时代的到来,数据库系统在2个方面面临挑战.首先数据量持续增大期望单个查询任务具有更快的处理速度;其次查询负载的快速变化及其多样性使得基于DBA经验的数据库配置和查询优化偏好不能实时地调整为最佳运行时状态.而数据库系统的性能优化进入瓶颈期,优化空间收窄,进一步优化只能依托新的硬件加速器来实现,传统的数据库系统不能够有效利用现代的硬件加速器;数据库系统具有成百个可调参数,面对工作负载频繁变化,大量繁琐的参数配置已经超出DBA的能力,这使得数据库系统面对快速而又多样性的变化缺乏实时响应能力.当下机器学习技术恰好同时符合这2个条件：应用现代加速器以及从众多参数调节经验中学习.机器学习化数据库系统将机器学习技术引入到数据库系统设计中.一方面将顺序扫描转化为计算模型,从而能够利用现代硬件加速平台;另一方面将DBA的经验转化为预测模型,从而使得数据库系统更加智能地动态适应工作负载的快速多样性变化.将对机器学习化数据库系统当前的研究工作进行总结与归纳,主要包括存储管理、查询优化的机器学习化研究以及自动化的数据库管理系统.在对已有技术分析的基础上,指出了机器学习化数据库系统的未来研究方向及可能面临的问题与挑战.     

Systolic arrays for multidimensional discrete transforms

An active area of research in supercomputing is concerned with mapping certain finite sums, such as discrete Fourier transforms, onto arrays of processors. This paper presents systolic mapping techniques that exploit the parallelism inherent in discrete Fourier transforms. It is established that, for anM-dimensional signal, parallel executions of such transforms are closely related to mappings of an (M + 1)-dimensional finite vector space into itself. Three examples of such parallel schemes are then described for the discrete Fourier transform of a two-dimensional finite extent sequence of sizeN ₁ ×N ₂. The first is a linear array ofN ₁ +N ₂ – 1 processors and takesO(N ₁ N ₂) steps. The second is anN ₁ ×N ₂ rectangular array of processors and takesO(N ₁ +N ₂) steps, and the third is a hexagonal array which usesN ₁ N ₂ + (N ₂ – 1)(N ₁ +N ₂ – 1) processors andO(N ₁ +N ₂) steps. All three mappings are optimal in that they achieve asymptotically the highest speedup possible over the sequential execution of the same transform, and can easily be generalized to higher dimensions.     

海量影像数据库管理系统关键技术研究

随着卫星遥感以及航空摄影技术的发展,人们可以更快、更廉价地获得各种高分辨率的影像。为了对这些不断增加的海量数据进行管理,空间数据库无疑是一种最好的方法,它不但可以提供更快、更方便的数据管理,同时还支持不同用户对数据同时安全访问。由于影像数据库中会存储各种异构的数据源,在目前的影像数据库管理系统中,只提供分散的元数据的管理策略,但是用户在进行搜索和定位的过程中需要一种全局的元数据。论文研究如何利用分散的元数据生成一种查询所需的集中存储的元数据信息,同时提出了如何利用空间元数据来辅助快速搜索和定位所需要的影像资料的策略。最后在系统中实现了基于关键词和空间范围的搜索,实验表明具有较高的效率。     

一种全新的 R树节点选择算法 *

在 R树插入算法中采用全新的节点选择算法 ,一改传统的从根节点开始自上而下的节点选择方案 ,而是从叶节点层开始 ,先自下而上再自上而下地选择叶节点 ,较好地解决了同层节点重叠所导致的查询效率低下的问题。实验证明 ,提出的 R树空间索引方法 ,不仅在查询效率上明显优于 R*树,而且 R树生成的时间开销也减少了 50%左右 ,综合性能超过了 R*树 ,便于扩展到三维甚至多维空间中 ,以实现对空间数据和时空数据的高效查询功能。     

WebWork: METEOR2's Web-Based Workflow Management System

METEOR₂ workflow management systems consist of both (1) design/build-time and (2) run-time/enactment components for implementing workflow applications. An enactment system provides the command, communication and control for the individual tasks in the workflow. Tasks are the run-time instances of intra- or inter-enterprise applications. We are developing three implementations of the METEOR₂ model: WebWork, OrbWork and NeoWork. This paper discusses WebWork, an implementation relying solely on Web technology as the infrastructure for the enactment system. WebWork supports a distributed implementation with participation of multiple Web servers. It also supports automatic code generation of workflow applications from design specifications produced by a comprehensive graphical designer. WebWork has been developed as a complement of its more heavyweight counterparts (OrbWork and NeoWork), with the goal of providing ease of workflow application development, installation, use and maintenance. At the time of this writing, WebWork has been installed by several of the LSDIS Lab's industrial partners for testing, evaluation and building workflow applications.     

多媒体技术与CAD

论述了ＣＡＤ系统与多媒体技术相结合的意义，讨论了多媒体系统的主要特性，基本组成和关键技术以及ＣＡＤ及其环境对多媒体数据库的特殊要求，介绍了新一代计算机图形用多媒体标准ＰＲＥＭＯ－多媒体对象描述环境。     

多媒体DBMS的需求

本文在深入分析多媒体应用（包括多媒体ＭＩＳ）特点的基础上，逐条论述了多媒体应用对多媒体ＤＢＭＳ的十项需求。ＤＢＭＳ的需求可以划分为三类，第一类属于多媒体应用对标准ＤＢＭＳ功能的需求，第二类是对多媒体对象建模方面的需求，第三类反映多媒体应用独有的特殊功能需求。关于ＭＤＢＭＳ目前尚无明确的定义，本文实际上从多媒体应用的特殊功能需求方面，给ＭＤＢＭＳ下了个初步的定义。     

Case studies in intelligent multimedia presentation design systems in terms of the standard reference model: the IMMPS project, the PreGen system, and the StrMP system

This paper contributes to a Standard Reference Model (RM) for intelligent multimedia presentation systems. In the past few years, we have developed several intelligent presentation systems at the Multimedia Information NEtwork (MINE) Lab at Tamkang University. We describe these systems in terms of architecture and function of components. The first system, Intelligent MultiMedia Presentation System (IMMPS), allows a presentation designer to construct knowledge rules reflecting the background of individual audiences. Therefore, the generated presentation is able to learn from the audiences, which results in different presentation for each individual. The second system (PreGen) uses inference rules for the automatic generation of multimedia presentations. An ICON programming technique is also used in the PreGen project. Another system for designing structured multimedia presentations using data flow/control flow diagrams is also discussed. In order to run multimedia presentations generated by different systems, we are developing a multimedia abstract machine, which is a time Petri net based software simulator for running multimedia assembly instructions.