On the ontological expressiveness of information systems analysis and design grammars

Abstract. Information systems analysis and design (ISAD) methodologies provide facilities for describing existing or conceived real-world systems. These facilities are ontologically expressive if they are capable of describing all real-world phenomena completely and clearly. In this paper we formally examine the notion of the ontological expressiveness of a grammar and discuss some of its implications for the design and use of ISAD methodologies. We identify some generic ways in which ontological expressiveness may be undermined in a grammar and some potential consequences of these violations. We also examine ontological expressiveness within the context of some other desirable features that might be considered in the design of ISAD methodologies.     

Post-Supervised Template Induction for Information Extraction from Lists and Tables in Dynamic Web Sources

Dynamic web sites commonly return information in the form of lists and tables. Although hand crafting an extraction program for a specific template is time-consuming but straightforward, it is desirable to automatically generate template extraction programs from examples of lists and tables in html documents. Supervised approaches have been shown to achieve high accuracy, but they require manual labelling of training examples, which is also time consuming. Fully unsupervised approaches, which extract rows and columns by detecting regularities in the data, cannot provide sufficient accuracy for practical domains. We describe a novel technique, Post-supervised Learning, which exploits unsupervised learning to avoid the need for training examples, while minimally involving the user to achieve high accuracy. We have developed unsupervised algorithms to extract the number of rows and adopted a dynamic programming algorithm for extracting columns. Our method achieves high performance with minimal user input compared to fully supervised techniques.     

规则库冗余性控制策略的研究

冗余性控制是研究知识库组织、管理和维护中的一个问题．本文通过对智能型机译系统中规则知识表示方法的分析，提出了将冗余规则划分为显式冗余规则和隐式冗余规则分别予以处理的思想，给出了显式冗余规则的判别算法和部分隐式冗余规则的检测标准，并提出了控制机译系统规则库冗余性的基本原则.     

科技写作与一般写作在语法运用上的比较与分析

科技写作作为写作学的一个分支，有它自身的特点与要求。它同时使用自然语言符号系统和人工语言符号系统。它的语言特点为：①客观纪实性；②抽象精练性；③表达方式规范化。它的语法特点为：①科技术语多而稳定；②句式单一而少变化；③结构严谨而规范。它与文艺写作在语法运用上的不同主要表现在：①科技写作的客观纪实与文艺写作的主观抒情；②科技写作的语言精炼与文艺写作的语言丰富；③科技写作的规范化与文艺写作的个性化。     

Formatting texts accessed randomly

Full-text systems that access text randomly cannot normally determine the format operations in effect for a given target location. The problem can be solved by viewing the format marks as the non-terminals in a format grammar. A formatted text can then be parsed using the grammar to build a data structure that serves both as a parse tree and as a search tree. While processing a retrieved segment, a full-text system can follow the search tree from root to leaf, collecting the format marks encountered at each node to derive the sequence of commands active for that segment. The approach also supports the notion of a ‘well formatted’ document and provides a means for verifying the well-formedness of a given text. To illustrate the approach, a sample set of format marks and a sample grammar are given suitable for formatting and parsing the article as a sample text.     

一种非限制性的手写数字的识别方法

本文从语义，句法模式识别观点，提出一种基于模型指导的有限状态属性自动机，进行特征抽取。对每一种典型的畸变模型设计一个有限状态属性文法及其相应的属性自动机，采用自下而上和自上而下相结合的控制策略，并在低层次引入知识指导，减少了工作量和不确定性。基于上述方法实现的非限制性手写数字识别系统，经过对１１００个非限制性手写数字样本的测试，平均识别率达９５．２％，拒识率为４．６％，误识率为０．２％。     

一种基于语料库的日语动词格框架自动构造技术*

结合一个基于格语法的日汉机器翻译系统,针对现有系统日语动词格框架缺乏的现状,提出一种日语动词格框架自动构造方法.该方法基于类比与统计思想,从现有的少量人工构造的动词格框架和大量生语料出发,自动构造日语动词格框架.     

基于启发式搜索与预标注的中文CCG句法分析

针对中文组合范畴语法(CCG)分析困难的特点,研究如何将两种彼此相互独立的技术共同应用在中文CCG句法分析上。首先使用预标注算法,使用对数线性模型通过去除那些概率较低的词汇范畴来对句子的潜在分析空间进行剪枝。然后应用启发式搜索算法进一步加速分析过程。最后从时间效率和分析精度两个维度对所使用的方法进行验证。实验表明,基于启发式搜索与预标注的句法分析算法可以显著地提高分析效率与分析精度。     

Creature grammar for creative modeling of 3D monsters

Monsters and strange creatures are frequently demanded in 3D games and movies. Modeling such kind of objects calls for creativity and imagination. Especially in a scenario where a large number of monsters with various shapes and styles are required, the designing and modeling process becomes even more challenging. We present a system to assist artists in the creative design of a large collection of various 3D monsters. Starting with a small set of shapes manually selected from different categories, our system iteratively generates sets of monster models serving as the artist’s reference and inspiration. The key component of our system is a so-called creature grammar, which is a shape grammar tailored for the generation of 3D monsters. Creature grammar governs the evolution from creatures with regular structures gradually into monsters with more and more abnormal structures through evolving the arrangement and number of shape parts, while preserving the semantics prescribed as prior knowledge. Experiments show that even starting with a small set of shapes from a few categories of common creatures (e.g., humanoids, bird-like creatures and quadrupeds), our system can produce a large set of unexpected monsters with both shape diversity and visual plausibility, thus providing great support for the user’s creative design.