图 书 馆
Cyc词典The Cyc Lexicon |
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| 课程网址: | http://videolectures.net/brownbag_coppock_tcl/ |
| 主讲教师: | Elizabeth Coppock |
| 开课单位: | 赛科公司 |
| 开课时间: | 2010-04-21 |
| 课程语种: | 英语 |
| 中文简介: |  Cyc知识库（KB）是大量人类基本知识的形式化表示：事实，经验法则和用于推理日常生活中事物和事物的启发式方法。表示的媒介是形式语言CycL，如下所述。 KB由构成CycL词汇的术语和与这些术语相关的断言组成。这些断言包括简单的地面断言和规则。 Cyc不是基于框架的系统：Cyc团队将KB看作是断言的海洋，每个断言与另一个涉及的术语不再“约”。 Cyc KB是分为许多（目前成千上万个）“微观理论”，每个微观理论本质上都是一束断言，它们共享一组共同的假设；一些微观理论专注于特定的知识领域，特定的细节水平，特定的时间间隔等。微观理论机制使Cyc能够独立维护与表面相矛盾的断言，并通过集中精力来增强Cyc系统的性能。 目前，Cyc KB包含近五十万个术语，包括约一万五千种关系，以及约五百万个与这些术语相关的事实（断言）。通过自动和手动方式的组合，新的断言不断添加到知识库中。另外，术语表示功能允许自动创建数百万个非原子术语，例如（LiquidFn Nitrogen）；而Cyc本身就是推理过程的产物，向KB本身添加了大量断言。 |
| 课程简介: | The Cyc knowledge base (KB) is a formalized representation of a vast quantity of fundamental human knowledge: facts, rules of thumb, and heuristics for reasoning about the objects and events of everyday life. The medium of representation is the formal language CycL, described below. The KB consists of terms--which constitute the vocabulary of CycL--and assertions which relate those terms. These assertions include both simple ground assertions and rules. Cyc is not a frame-based system: the Cyc team thinks of the KB instead as a sea of assertions, with each assertion being no more "about" one of the terms involved than another. The Cyc KB is divided into many (currently thousands of) "microtheories", each of which is essentially a bundle of assertions that share a common set of assumptions; some microtheories are focused on a particular domain of knowledge, a particular level of detail, a particular interval in time, etc. The microtheory mechanism allows Cyc to independently maintain assertions which are prima facie contradictory, and enhances the performance of the Cyc system by focusing the inferencing process. At the present time, the Cyc KB contains nearly five hundred thousand terms, including about fifteen thousand types of relations, and about five million facts (assertions) relating these terms. New assertions are continually added to the KB through a combination of automated and manual means. Additionally, term-denoting functions allow for the automatic creation of millions of non-atomic terms, such as (LiquidFn Nitrogen); and Cyc adds a vast number of assertions to the KB by itself as a product of the inferencing process. |
| 关 键 词: | Cyc知识库; 微观理论; 形式语言CycL; Cyc系统 |
| 课程来源: | 视频讲座网 |
| 数据采集: | 2021-05-26：zyk |
| 最后编审: | 2021-05-26：zyk |
| 阅读次数: | 78 |