基于关键类型的对象抽取工具的设计与实现

提出了一种新的基于子程序关键类型的对象抽取方法,使用该方法实现的对象抽取工具通过计算面向过程的C系统中各子程序参数的类型复杂度,找出每个子程序的关键类型,将子程序与关键类型打包,抽取出独立的对象。本文还提出了可以简化数据类型复杂度计算的类型系数概念,这些概念及方法对非面向对象系统的软件维护与代码重用技术的研究具有一定的参考价值。     

对象类型作为对象和对象作为对象类型

对象类型作为对象和对象作为对象类型Ｏｂｊｅｃｔｔｙｐｅａｓｏｂｊｅｃｔｓ—ａｎｄｖｉｃｅｖｅｒｓ￥ＪａｍｅｓＯｄｅｌｌ正确的对象类型是对象这个事实是面向对象的一个基本概念。然而，大多数面向对象环境都不能很好地支持这个概念。但是这个概念对许多面向对象技...     

对象在类型系统λω×≤中的表示

类型系统是研究面向对象技术形式理论基础的重要工具 类型系统λω×≤ 是一个带高阶子类型关系的多态类型系统 ,对其性质和范畴论语义模型进行了研究 在此基础上 ,讨论了如何以类型系统λω× ≤ 为工具 ,研究对象、类、继承等面向对象技术的基本概念的形式语义 结合类POINT和CPOINT等例子 ,讨论了基于递归类型和基于存在类型的两种对象表示方法 ,并对它们的特点进行了总结与比较     

对象视图模型及其创建和删除算法*

提出了一种面向对象的实视图模型——对象视图模型。它利用了面向对象技术,能够清楚地表达多维数据的语义和操作,因而便于在数据仓库中描述复杂对象,并且有利于前端分析工具OLAP的实现。定义了对象视图模型的概念,并给出了对象视图模型的创建和删除算法,该算法能够有效地实现从数据源到数据仓库中对象（数据）的抽取和加载。     

面向对象数据库管理系统的对象管理系统的研究

数据库是实现CAD/CAM系统集成的主要方法和工具。当前,面向对象数据库管理系统已成为数据库管理系统研究的主要方向,而对象管理是实现面向对象数据库管理系统的关键技术。本文结合华中理工大学CAD中心开发的面向对象数据库管理系统GHEODB的对象管理系统GHOMS,研究了对象管理系统的结构组成并给出了相关算法和加速机制     

分布式对象数据库系统中的对象管理策略

本文提出了分布式对象数据库系统中的对象迁移和对象调度的概念,对系统中的对象迁移策略和对象调度策略作了详细的研究和讨论。针对系统负载不平衡的问题,给出了对象迁移的动态调整模型和对象迁移时目标地址选择的判定条件及其相应算法。针对对象的调度,本文运用扩展的时间Petri网其调度策略作了模拟,给出了对象最优调度优调度策略的算法实现,事实证明面向对象的技术应用于分布式数据库系统不仅可以提高系统的性能、优化系统的结构、有助于在虚拟网上实现分布式数据库,而且具有一定的实用性。     

持久层实现研究

开发一个同时使用面向对象技术和关系型数据库技术的项目是一件困难的事情。为了解决面向对象技术和非面向对象技术之间存在阻抗不匹配问题,在企业应用开发过程中需要使用持久层来减少不匹配带来的影响。持久层是根据分层思想的指导,通过建立逻辑门户,采取一定的对象-关系映射策略,隐藏所有数据库访问代码细节,向开发人员提供的透明的对象持久化机制。在对现今流行的持久层设计技术、DAO模式和CMP模式的实现,进行深入分析的基础上,讨论了一个良好的持久层所应具备的功能,提出了一个持久层实现模型。     

Java虚拟机面向对象原理及应用

通过对面向对象系统中的关键技术,如对象、类等的实现,阐述Java虚拟机的面向对象机理。     

面向对象方法中的类型概念

本文讨论了面向对象方法中非常重要的类型概念，指出对象类型由对象集、状态集、运算集、方法集和约束组成，并进一步阐述了对象类型的层次结构、对象的动态类型集和静态类型、对象方法的封闭性以及对象方法的动态定连等问题，为进一步的研究奠定了基础。     

Java 虚拟机的面向对象性

通过对面向对象系统中的关键技术,如对象,类等的实现,结合实际项目,阐述Java虚拟机的面向对象性。     

TGMS: An object-oriented system for programming geometry

TGMS (tiered geometric modelling system) is an experimental system intended to reduce the difficulty and cost of developing new solid modelling applications while preserving investment in an existing, time-tested, solid modeller. The application developer writes programs in the TGMS language, which consists of a base language augmented by data types (classes) for geometry. The base programming language is AML/X, an object-oriented language intended for use in design and manufacturing applications. Solid modelling is done using an interface to GDP (geometric design processor), an existing, production-quality solid modelling system. TGMS shows how a system written in a non-object-oriented language can be used as a base for an object-oriented application programming environment. This paper presents the design of TGMS and discusses important aspects of its implementation. The TGMS language defines classes and methods that provide an interface to functions and data represented in a non-object-oriented language. To implement TGMS, issues related to communication, storage management and consistency were addressed. These, and other, implementation issues are discussed. The paper includes sample programs and a summary of feedback from TGMS users. It concludes that the use of object-oriented programming for geometry has many benefits, and that an object-oriented system can be built on top of a non-object-oriented system at less cost than building the equivalent object-oriented system from scratch.     

API-Based and Information-Theoretic Metrics for Measuring the Quality of Software Modularization

We present in this paper a new set of metrics that measure the quality of modularization of a non-object-oriented software system. We have proposed a set of design principles to capture the notion of modularity and defined metrics centered around these principles. These metrics characterize the software from a variety of perspectives: structural, architectural, and notions such as the similarity of purpose and commonality of goals. (By structural, we are referring to intermodule coupling-based notions, and by architectural, we mean the horizontal layering of modules in large software systems.) We employ the notion of API (application programming interface) as the basis for our structural metrics. The rest of the metrics we present are in support of those that are based on API. Some of the important support metrics include those that characterize each module on the basis of the similarity of purpose of the services offered by the module. These metrics are based on information-theoretic principles. We tested our metrics on some popular open-source systems and some large legacy-code business applications. To validate the metrics, we compared the results obtained on human-modularized versions of the software (as created by the developers of the software) with those obtained on randomized versions of the code. For randomized versions, the assignment of the individual functions to modules was randomized     

Managing object-oriented software development

Managing object-oriented projects is subtly different than managing non-object-oriented ones. Object-oriented projects employ a different unit of decomposition, they encourage an incremental and iterative process, and quantitatively, they demand different kinds of measures. This paper examines the nature of managing object-oriented projects, and offers a variety of lessons learned from a number of real projects.Portions of this article are adapted from [Booch 1995].     

A portable approach to dynamic optimization in run-time specialization

This paper proposes arun-time bytecode specialization (BCS) technique that analyzes programs and generates specialized programs at run-time in an intermediate language. By using an intermediate language for code generation, a back-end system canoptimize the specialized programs after specialization. The system uses Java virtual machine language (JVML) as the intermediate language, which allows the system to easily achieve practicalportability and to use existing sophisticated just-in-time (JIT) compilers as its back-end. The binding-time analysis algorithm is based on a type system, and covers a non-object-oriented subset of JVML. The specializer generates programs on a per-instruction basis, and can performmethod inlining at run-time. Our performance measurements show that a non-trivial application program specialized at run-time by BCS runs approximately 3–4 times faster than the unspecialized one. Despite the large overhead of JIT compilation of specialized code, we observed that the overall performance of the application can be improved. This paper is an extended version of “A Portable Approach to Generating Optimized Specialized Code”, inProceedings of Second Symposium on Programs as Data Objects (PADO-II), Lecture Notes in Computer Science, vol. 2053, pp. 138–154, Aarhus, Denmark, May 2001.²³) Hidehiko Masuhara, D.Sc.: He is an Assistant Professor at Department of Graphics and Computer Science, Graduate School of Arts and Sciences, University of Tokyo. He received his B.S., M.S. and D.Sc. degrees from Department of Information Science, University of Tokyo in 1992, 1994, and 1999, respectively. His research interests are in programming languages, especially in mechanisms to support flexible and efficient computation such as dynamic optimization and reflection. He received the best-paper award from Information Processing Society of Japan in 1996. Akinori Yonezawa, Ph.D.: He is a Professor of computer science at Department of Computer Science, University of Tokyo. He received Ph.D. in Computer Science from the Massachusetts Institute of Technology in 1977. His current major research interests are in the areas of concurrent/parallel computation models, programming languages, object-oriented computing, and distributed computing. He is the designer of an object-oriented concurrent language ABCL/1 and the editor of several books and served as an associate editor of ACM Transaction of Programming Languages and Systems (TOPLAS). Since 1998, he has been an ACM Fellow.     

改进型时间触发嵌入式系统编程模式

对于成本敏感的嵌入式系统,通常因为资源有限而难以采用抢先式实时多任务操作系统。传统的基于超级循环的前后台编程方法和基于时间触发的合作式多任务编程方法对任务的划分需要较高的技巧。本文通过对基于时间触发合作式调度器的改进,建立了一种适用于小型嵌入式系统的通用编程模式,使这类系统的编程变得清晰、简单。     

源程序在线评测系统的设计与实现

源程序在线评测系统是一个基于网络的通用程序设计语言的自动评测系统,该系统为学生学习基本的程序设计语言提供了良好的训练平台,培养学生程序设计的兴趣,提高学生程序设计的能力。     

Java编程语言在大数据开发中的应用探究

文章首先分析Java编程语言系统概论﹐并且结合Java编程语言系统的特点以及Java编程语言系统现状,进一步总结了Java编程语言系统应用策略。     

Development of game-based learning features in programming learning support system

In this research, a programming learning support system incorporating game-based learning is proposed. The aim of the game-based learning approach is to stimulate and sustain the motivation of the learner during programming training. In the developed system, a puzzle-solving interface to programming training and a competitive scoring system was implemented to incorporate game-based learning. The proposed system was applied to an actual college programming course to verify the effectiveness of the proposed system. Finally, future works based on the results are discussed.