ND—Polya类比实现技术

从认识论和方法论的角度来看,分类不是认识事物解决问题的唯一方法,类比同样十分重要然而传统的继承只体现分类的方法,自行设计的面向对象语言ＮＤ－Ｐｏｌｙａ通过引和新的继承机制－柔性继承来支持类比方法。     

柔性继承机制的设计与实现

继承是面向对象程序设计方法中的重要特征之一。在分析了传统继承机制不足的基础上,将类比理论引入面向对象,提出了一种新的继承机制－－柔性继承机制。该机制在面向对象程序设计中增加了相似类、相似属性和相似方法的类比应定义及类比分析和推导方法,同时支持子类关系和类比关系,从而可增加灵活而有效地对已有软件进行复用。最后,介绍了支持柔性继承机制的语言ND＿Polya及其支撑系统的设计和实现。     

ND-P0lya中协变-反变问题的处理方法

协变－反变问题讨论面向对象语言中继承机制和多态计算的关系,晃当前面向对象程序设计语言中的一个重要的理论问题。反变的方法重定义不符合思维习惯,一盘采用协变精化的设计方法。但抛弃反变后的面向对象程序设计,在多态计算中会产生类型问题。针对这一问题,该文基于Ｃａｓｔａｇｎａ的重载函数模型,提出处理协变相关类型问题的类型系统和计算模型,并在ＮＤ－Ｐｏｌｙａ语言及系统中具体实现。该方法可以应用到其它协变面向对     

基于m类逻辑的模式分类方法及其硬件实现

基于ｍ类逻辑的模式分类方法及其硬件实现张自力（西南师范大学计算机科学系重庆６３０７１５）ＴＨＥｍ－ＣＬＡＳＳＬＯＧＩＣＢＡＳＥＤＰＡＴＴＥＲＮＣＬＡＳＳＩＦＩＣＡＴＩＯＮＡＮＤＩＴＳＨＡＲＤＷＡＲＥＩＭＰＬＥＭＥＮＴＡＴＩＯＮ￥ＺｈａｎｇＺｉｌｉ（Ｄ...     

型构兼容的继承及其语义

本文揭示了在面向对象程序设计语言中,若劲旅子类重定义其继承的分类方法以发迹这些方法的规约,并且采用类似于Ｓｍａｌｔａｌｋ－８０中的继承机制的语义,将导致封将与继承之间的一个新总是为此,本文提出了一种新的继承机制－型构兼容的继承,以代替传统的增量继承。型构兼容的继承是一种灵活的代码复用机制,并且能够充分支持封装。     

对Modula－2进行面向对象扩充

本文阐述了ＮＤＯＯＭ的设计和实现的主要思想．ＮＤＯＯＭ是一个Ｍｏｄｕｌａ－２的面向对象扩充，是Ｍｏｄｕｌａ－２的超集，其既充分支持面向对象程序设计，又保持了ＭＯｄｕｌａ－２的原有风格．     

ORDBMS的继承语义及其实现

介绍了在ＡＮＧＥＬ这样一个典型的ＯＲＤＢ系统中继承机制的设计思想与实现技术,首先详细阐述系统卡富的继承语义,包括属性继承、约束继承、触发器继承及函数继承,并给出对多重继承所带来各种冲突的处理办法。然后讨论继承机制的实现手段及有关继承机制的模式演变问题。     

对象-关系数据库对多媒体的支持技术

对象－关系型数据库已成为当今数据库领域研究和发展的热点。文章以多媒体数据管理和应用的需求为出发点,讨论了对象－关系型数据库对多媒体数据的管理方法,即通过对关系数据库管理系统（ＲＤＢＭＳ）进行扩展,使之能支持新引入的用户定义类型（ＵＤＴ）、用户定义函数（ＵＤＦ）、大对象（ＬＯＢ）、关系扩展器（ＲＥＬＡＴＩＯＮＡＬ ＥＸＴＥＮ－ＤＥＲ）等对象－关系模型特色,并通过数据链技术控制机制来实现对数据库及外部文件系统中大量的复杂多媒体数据的管理。这些多媒体扩展机制保留了所有的ＲＤＢＭＳ的长处和优点,增加了对复杂的多媒体应用的支持。     

对象-关系数据库对多媒体的支持技术

对象－关系型数据库已成为当今数据库领域研究和发展的热点。文章以多媒体数据管理和应用的需求为出发点,讨论了对象－关系型数据库对多媒体数据的管理方法,即通过对关系数据库管理系统（ＲＤＢＭＳ）进行扩展,使之能支持新引入的用户定义类型（ＵＤＴ）、用户定义函数（ＵＤＦ）、大对象（ＬＯＢ）、关系扩展器（ＲＥＬＡＴＩＯＮＡＬ ＥＸＴＥＮ－ＤＥＲ）等对象－关系模型特色,并通过数据链技术控制机制来实现对数据库及外部文件系统中大量的复杂多媒体数据的管理。这些多媒体扩展机制保留了所有的ＲＤＢＭＳ的长处和优点,增加了对复杂的多媒体应用的支持。     

基于物理的准D—NURBS造型方法

该文提出了基于物理的推Ｄ－ＮＵＲＢＳ的概念。ＮＵＲＢＳ由于既能够表示自由形状，又能够表示标准解析形状（即初等曲线曲面）而成为商业造型系统的标准。但直到目前，ＮＵＲＢＳ仍被看成是纯几何的设计工具，它要求我们手工调整控制顶点和相应权值来设计满足要求的形状。准Ｄ－ＮＵＲＢＳ则基于物理定律，将物体的质量分布，阻尼，内部变形能和其它物理特性与普通ＮＵＲＢＳ基结合，这使得我们不仅可以使用手工调整控制顶点和相应权值的传统方法，也可以施加模拟的外力和局部与全局几何约束而使设计形状依时间动态变形的方法来设计出满足要求的形状，通过物理变形的方法得到要求的形状使得设计更加直观，高效。同时，基于物理的准Ｄ－ＮＵＲＢＳ模型还用于柔性物体的运动、变形仿真。     

用变换型方法模拟开发电话交换系统

本文给出了用变换软件开发方法模拟开发电话交换系统的描述，由抽象的软件规范出发，通过一系列变换实现了数据的精化和操作的分解，最终得到可在机器上运行的程序，整个开发过程是用变换型语言Ｐｏｌｙａ写的，最后提出了Ｐｏｌｙａ的改进建议。     

Agent规范与编程语言SPLAW的语法和语义

本文描述了Ａｇｅｎｔ规范与编程语言ＳＰＬＡＷ的语法，为ＳＰＬＡＷ中的各种语言成分提供了操作语义，并基于标记转换系统给出Ａｇｅｎｔ性质的证明规则。由于ＳＰＬＡＷ的通信部分采用不依赖于具体应用的Ａｇｅｎｔ交互语言ＫＱＭＬ，使遵循同一标准的Ａｇｅｎｔ之间能进行协作问题求解。ＳＰＬＡＷ首次为Ａｇｅｎｔ提供继承支持，使其可以实现具有面向对象特征的多线程系统。ＳＰＬＡＷ屏了为语言引入内部模态词的缺陷，试图从外     

New constant service time Polya/D/n traffic model with peaked input stream

In this paper, we study the buffer queueing behaviour in high-speed networks. Some limited analytical derivations of queue models have been proposed in literature but their solutions are often a great mathematical challenge. We propose to use the Polya distribution to overcome such limitations. The specific behaviour of an IP interface with bursty traffic and long-range dependence is investigated by a version of the “classical” M/D/n queueing model called Polya/D/n. This is queueing system with a Polya input stream (a negative binomial distributed number of arrivals in a fixed time interval), a constant service time, multiple servers, and infinite waiting rooms. The model is considered a renewal process because of its quasi-random input stream and constant service time. We develop balance equations for the state of the system and obtain results for the packet loss and delay. The finding that the Polya distribution is adequate to model bursty input streams in IP network interfaces has motivated the proposal to evaluate the Polya/D/n system. It is shown that the variance in the input stream significantly changes the characteristics of the waiting system. The suggested model is new and allows defining different bursty traffic and evaluating losses and delays relatively easily.     

Concept classifier for knowledge acquisition in frame-based systems

Frame-based systems that employ inheritance networks as a form of knowledge representation have a number of inherent knowledge acquisition problems, one of the most significant being the transfer to the representation system of knowledge itself. The problem of concept classification, and specifically that of determining the location of a new concept in an existing network inheritance hierarchy, is discussed here using an experimental knowledge-base editor, KRE. Tools which support the process of knowledge base construction must allow the user to concentrate on the domain problems, and not on low level, representation system decisions. KRE, written in C, is a knowledge acquisition tool which assists the knowledge engineer by using an interactive acquisition strategy during the process of concept classification. The processes of classification, and its advantages over other knowledge representation systems, are presented.     

MINAS: multiclass learning algorithm for novelty detection in data streams

Data stream mining is an emergent research area that aims at extracting knowledge from large amounts of continuously generated data. Novelty detection (ND) is a classification task that assesses if one or a set of examples differ significantly from the previously seen examples. This is an important task for data stream, as new concepts may appear, disappear or evolve over time. Most of the works found in the ND literature presents it as a binary classification task. In several data stream real life problems, ND must be treated as a multiclass task, in which, the known concept is composed by one or more classes and different new classes may appear. This work proposes MINAS, an algorithm for ND in data streams. MINAS deals with ND as a multiclass task. In the initial training phase, MINAS builds a decision model based on a labeled data set. In the online phase, new examples are classified using this model, or marked as unknown. Groups of unknown examples can be used later to create valid novelty patterns (NP), which are added to the current model. The decision model is updated as new data come over the stream in order to reflect changes in the known classes and allow the addition of NP. This work also presents a set of experiments carried out comparing MINAS and the main novelty detection algorithms found in the literature, using artificial and real data sets. The experimental results show the potential of the proposed algorithm.     

面向对象逻辑语言LKO的类型系统

文中主要介绍面向对象逻辑语言ＬＫＯ中基于声明和推理的有序类型系统，在谓词声明中，类型由有序的构子构造而成，子句中变量类型由类型推理决定，对象类型由方法声明决定，独立于便于代码复用，它可作为基类型参与项类型构造。