TransWiki - an Open Translation Project(OTP)

摘要_文档状态_目录 第1节 第2节 第3节 第4节 第5节 第6节 第7节 鸣谢_词汇表_术语索引_参考文献 附录

1. Introduction

"Tell me what wines I should buy to serve with each course of the following menu. And, by the way, I don't like Sauternes."
It would be difficult today to construct a Web agent that would be capable of performing a search for wines on the Web that satisfied this query. Similarly, consider actually assigning a software agent the task of making a coherent set of travel arrangements. (For more use cases see the OWL requirements document (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#Requirements).)
“告诉我应该买什么酒搭配菜单中的每道菜，另外，我不喜欢苏特恩白葡萄酒”。
目前，构造一个Web代理来实现搜索这些酒的查询是非常困难的。类似地，给软件代理的旅行任务做一个合理的、紧凑的安排也是很不容易的。（更多的用例，参考OWL需求文档 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#Requirements)）。

To support this sort of computation, it is necessary to go beyond keywords and specify the meaning of the resources described on the Web. This additional layer of interpretation captures the semantics of the data.
为了支持这种计算，不仅仅需要关键词，还要说明被描述在Web上的资源的含义。这一层附加的解释，表述了数据的“语义”。

The OWL Web Ontologoy Language is a language for defining and instantiating Web ontologies. Ontology is a term borrowed from philosophy that refers to the science of describing the kinds of entities in the world and how they are related. An OWL ontology may include descriptions of classes, properties and their instances. Given such an ontology, the OWL formal semantics (http://www.w3.org/TR/2004/REC-owl-semantics-20040210/) specifies how to derive its logical consequences, i.e. facts not literally present in the ontology, but entailed by the semantics. These entailments may be based on a single document or multiple distributed documents that have been combined using defined OWL mechanisms (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#import).

Web本体语言OWL是一种定义和实例化“Web本体”的语言。“本体”这个术语来自于哲学，这部分哲学研究世界上的各种实体以及它们之间的关联。一个“Web本体”可能包含了对类，属性以及它们的实例的描述。比如这个本体OWL形式语义 (http://www.w3.org/TR/2004/REC-owl-semantics-20040210/)，它说明了怎样获得它的逻辑结论，也就是说，“事实”不是逐字被写在本体中，而是蕴含在语义中。这些蕴涵可能是基于单个文档的，也可以是基于多个分布文档的，这些分布的文档通过OWL机制 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#import)进行关联。

This document is one component of the description of OWL, the Web Ontology Language, being produced by the W3C Web Ontology Working Group (WebOnt). The Document Roadmap (http://www.w3.org/TR/2004/REC-owl-features-20040210/#s1.1) section of the Overview ([Overview (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#FeatureList)], 1.1) describes each of the different parts and how they fit together.

本文档是W3CWeb本体工作组（WebOnt）制定的Web本体语言的描述的一部分。 OWL综述([Overview (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#FeatureList)], 1.1)的文档指南 (http://www.w3.org/TR/2004/REC-owl-features-20040210/#s1.1) 部分描述了不同部分的文档以及他们怎样结合的。

One question that comes up when describing yet another XML/Web standard is "What does this buy me that XML and XML Schema don't?" There are two answers to this question.
当描述另外一个XML/Web标准时，会产生一个问题：哪些是该标准可以给我而XML和XML Schema不能给我的。这个问题有两个答案。

• An ontology differs from an XML schema in that it is a knowledge representation, not a message format. Most industry based Web standards consist of a combination of message formats and protocol specifications. These formats have been given an operational semantics, such as, "Upon receipt of this PurchaseOrder message, transfer Amount dollars from AccountFrom to AccountTo and ship Product." But the specification is not designed to support reasoning outside the transaction context. For example, we won't in general have a mechanism to conclude that because the Product is a type of Chardonnay it must also be a white wine.
  
  

• 本体和XML Schema的区别：本体是一种知识表示，而不是一种消息格式。大多数来自工业界的Web标准都包含了消息格式和协议规范。这些格式已经被赋予一个操作语义，例如，"一旦收到订单（PurchaseOrder）的消息，从AccountFrom账号转移Amount数量的美元到AccountTo账号，并且发货(Product)"，但是这些规范并没有被设计为支持此事务上下文之外的推理。例如，一般来说，没有机制可以让我们做出推理：因为这个产品是一种夏敦埃酒（Chardonnay，一种无甜味白葡萄酒），它必定也是一种白酒。

• One advantage of OWL ontologies will be the availability of tools that can reason about them. Tools will provide generic support that is not specific to the particular subject domain, which would be the case if one were to build a system to reason about a specific industry-standard XML schema. Building a sound and useful reasoning system is not a simple effort. Constructing an ontology is much more tractable. It is our expectation that many groups will embark on ontology construction. They will benefit from third party tools based on the formal properties of the OWL language, tools that will deliver an assortment of capabilities that most organizations would be hard pressed to duplicate.
  
  
• OWL本体的一个优点是容易获得能够对其做推理的工具。这些工具提供了不限定于某个指定领域的通用支持，比如，构建能对一个特定的工业界标准XML Schema做推理的系统，就是限定定于一个领域的。构建一个可靠的和有用的推理系统不是一项简单的工作，而创建一个本体则比较容易。我们期望许多组织将会着手创建本体，他们会从使用第三方的、基于OWL语言形式属性的工具中获益，因为，这些工具提供多种多样的能力，而这些能力是大部分组织都难以复制的。

1.1. The Species of OWL

The OWL language provides three increasingly expressive sublanguages designed for use by specific communities of implementers and users.
OWL提供了三种表达能力递增的子语言，以分别用于特定的实现者和用户团体。

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OWL Lite supports those users primarily needing a classification hierarchy and simple constraint features. For example, while OWL Lite supports cardinality constraints, it only permits cardinality values of 0 or 1. It should be simpler to provide tool support for OWL Lite than its more expressive relatives, and provide a quick migration path for thesauri and other taxonomies.

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OWL Lite用于提供给那些只需要一个分类层次和简单约束的用户。例如，OWL Lite支持基数限制，只允许基数为0或1。提供支持OWL Lite的工具比提供支持表达能力更强的其他OWL语言的工具更简单，并且从辞典（thesauri）和分类系统（taxonomy）转换到OWL Lite更为迅速。

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OWL DL supports those users who want the maximum expressiveness without losing computational completeness (all entailments are guaranteed to be computed) and decidability (all computations will finish in finite time) of reasoning systems. OWL DL includes all OWL language constructs with restrictions such as type separation (a class can not also be an individual or property, a property can not also be an individual or class). OWL DL is so named due to its correspondence with description logics [Description Logics (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#DescriptionLogics)], a field of research that has studied a particular decidable fragment of first order logic. OWL DL was designed to support the existing Description Logic business segment and has desirable computational properties for reasoning systems.

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OWL DL 支持那些需要最强表达能力的推理系统的用户，且这个推理系统能够保证计算的完全性（computational completeness，即所有的结论都能够保证被计算出来）和可判定性（decidability，即所有的计算都在有限的时间内完成）。它包括了OWL语言的所有成分，但有一定的限制，如类型的分离（一个类不能同时是一个个体或属性，一个属性不能同时是一个个体或类）。OWL DL 这么命名是因为它对应于[描述逻辑 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#DescriptionLogics)]，这是一个研究一阶逻辑的一个特定可判定片断的领域。OWL DL旨在支持已有的描述逻辑商业处理（business segment）和具有良好计算性质的推理系统。

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OWL Full is meant for users who want maximum expressiveness and the syntactic freedom of RDF with no computational guarantees. For example, in OWL Full a class can be treated simultaneously as a collection of individuals and as an individual in its own right. Another significant difference from OWL DL is that a owl:DatatypeProperty can be marked as an owl:InverseFunctionalProperty. OWL Full allows an ontology to augment the meaning of the pre-defined (RDF or OWL) vocabulary. It is unlikely that any reasoning software will be able to support every feature of OWL Full.

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OWL Full 支持那些需要尽管没有可计算性保证，但有最强的表达能力和完全自由的RDF语法的用户。例如，在OWL Full中，一个类可以被同时看为许多个体的一个集合以及本身作为一个个体。另外一个和OWL DL的重要区别是owl:DatatypeProperty（数据类型属性）能作为一个owl:InverseFunctionalProperty（逆函数型属性）。OWL full允许一个本体增加预定义的（RDF、OWL）词汇的含义。这样，不太可能有推理软件能支持对OWL FULL的所有成分的完全推理。

Each of these sublanguages is an extension of its simpler predecessor, both in what can be legally expressed and in what can be validly concluded. The following set of relations hold. Their inverses do not.

• Every legal OWL Lite ontology is a legal OWL DL ontology.
  
• Every legal OWL DL ontology is a legal OWL Full ontology.
  
• Every valid OWL Lite conclusion is a valid OWL DL conclusion.
  
• Every valid OWL DL conclusion is a valid OWL Full conclusion.
  

在表达能力和推理能力上，每个子语言都是前面的语言的扩展。这三种子语言之间有如下关系成立，但这些关系反过来并不成立。

• 每个合法的OWL Lite本体都是一个合法的OWL DL本体；
• 每个合法的OWL DL本体都是一个合法的OWL Full本体；
• 每个有效的OWL Lite结论都是一个有效的OWL DL结论；
• 每个有效的OWL DL结论都是一个有效的OWL Full结论。

Ontology developers adopting OWL should consider which species best suits their needs. The choice between OWL Lite and OWL DL depends on the extent to which users require the more expressive restriction constructs provided by OWL DL. Reasoners for OWL Lite will have desirable computational properties. Reasoners for OWL DL, while dealing with a decidable sublanguage, will be subject to higher worst-case complexity. The choice between OWL DL and OWL Full mainly depends on the extent to which users require the meta-modelling facilities of RDF Schema (i.e. defining classes of classes). When using OWL Full as compared to OWL DL, reasoning support is less predictable. For more information about this issue see the OWL semantics document (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#FormalModel).

使用OWL的本体开发者要考虑哪种语言最符合他们的需求。选择OWL Lite还是OWL DL主要取决于用户在多大程度上需要OWL DL提供的表达能力更强的成分。OWL Lite的推理机会有良好的计算性质。而OWL DL的推理机处理的尽管是一个可判定的子语言，会有更高的最坏情况复杂度。选择OWL DL还是OWL Full主要取决于用户在多大程度上需要RDF的元模型机制（如定义关于类的类）；使用OWL Full相比于OWL DL，对推理的支持是更难预测的。关于此问题的更多信息参考OWL语义文档 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#FormalModel)。

Users migrating from RDF to OWL DL or OWL Lite need to take care to ensure that the original RDF document complies with the constraints imposed by OWL DL and OWL Lite. The details of these constraints are explained in Appendix E (http://www.w3.org/TR/2004/REC-owl-ref-20040210/#app-DLinRDF) of the OWL Reference.
When we introduce constructs that are only permitted in OWL DL or OWL Full, they are marked by "[OWL DL]".
用户在把RDF文档转换到OWL DL或OWL Lite文档时必须谨慎，以保证原来的RDF文档是否满足 OWL DL 或OWL Lite对RDF的一些附加的限制。这些限制在文档OWL参考的附录E (http://www.w3.org/TR/2004/REC-owl-ref-20040210/#app-DLinRDF)中有详细的解释。
当我们介绍只在 OWL DL或 OWL Full中允许的构词时，他们被标记为"[OWL DL]"。

1.2. Structure of the Document

In order to provide a consistent set of examples throughout the guide, we have created a wine (http://www.w3.org/TR/2004/REC-owl-guide-20040210/wine.rdf) and food (http://www.w3.org/TR/2004/REC-owl-guide-20040210/food.rdf) ontology. This is an OWL DL ontology. Some of our discussion will focus on OWL Full capabilities and is so marked. The wine and food ontology is a significant modification of an element (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#wine1) of the DAML ontology library with a long history. It was originally developed by McGuinness as a CLASSIC description logic example (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#wine3), expanded to a description logic tutorial (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#wine4), and expanded to an ontology tutorial (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#wine2).

为了在这个指南中提供一个一致的例子，我们创建了一个关于酒 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/wine.rdf)和食物 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/food.rdf)的本体。它是一个OWL DL本体。我们有些讨论会集中于OWL Full的表达能力，因此会标注出来。这个酒和食物本体是对历史悠久的DAML本体库中的一个元素 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#wine1) 的重大修改而成的。它最初由McGuinness作为一个描述逻辑CLASSIC的例子 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#wine3)开发的，后来扩充为一个描述逻辑教程 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#wine4)和一个本体教程 (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#wine2)。

In this document we present examples using the RDF/XML syntax (http://www.w3.org/TR/REC-rdf-syntax/#grammar) ([RDF (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#RDF1)], 5), assuming XML will be familiar to the largest audience. The normative OWL exchange syntax is RDF/XML. Note that OWL has been designed for maximal compatibility with RDF and RDF Schema. These XML and RDF formats are part of the OWL standard.
在这个文档中，我们假设大部分读者熟悉XML，因此用RDF/XML语法 (http://www.w3.org/TR/REC-rdf-syntax/#grammar)表示例子([RDF (http://www.w3.org/TR/2004/REC-owl-guide-20040210/#RDF1)], 5)。标准的OWL交换语法是RDF/XML。注意OWL在设计时保持了与RDF和RDF Schema的最大兼容性。这些XML和RDF格式是OWL标准的一部分。

All of the examples presented in this document are taken from the ontologies contained in wine.rdf (http://www.w3.org/TR/2004/REC-owl-guide-20040210/wine.rdf) and food.rdf (http://www.w3.org/TR/2004/REC-owl-guide-20040210/food.rdf), except those marked with  ?  in the bottom right corner.
本文档中引进的所有例子都是从本体wine.rdf (http://www.w3.org/TR/2004/REC-owl-guide-20040210/wine.rdf) 和 food.rdf (http://www.w3.org/TR/2004/REC-owl-guide-20040210/food.rdf)中摘取的，除了那些在右下角用 ?  标注的。

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