Tài liệu hạn chế xem trước, để xem đầy đủ mời bạn chọn Tải xuống
1
/ 17 trang
THÔNG TIN TÀI LIỆU
Thông tin cơ bản
Định dạng
Số trang
17
Dung lượng
82,75 KB
Nội dung
om nh Vi en Zo ne C Knowledge Representation Si Chapter SinhVienZone.com https://fb.com/sinhvienzonevn om What is KR? ne C R Davis, H Schrobe, P Szolovits (1993): Zo A surrogate nh Vi en A set of ontological commitments A fragmentary theory of intelligent reasoning A medium for efficient computation Si A medium of human expressions SinhVienZone.com https://fb.com/sinhvienzonevn om Representation and Mapping ne C • Facts: things we want to represent Si nh Vi en Zo • Representations of facts: things we can manipulate SinhVienZone.com https://fb.com/sinhvienzonevn Internal Representations Zo Facts ne C om Representation and Mapping Si nh Vi en English understanding reasoning programs English generation English Representations SinhVienZone.com https://fb.com/sinhvienzonevn om Representation and Mapping C desired real reasoning Zo ne Initial facts nh Vi en forward representation mapping Si Internal representations of initial facts Final facts backward representation mapping operation of program Internal representations of final facts SinhVienZone.com https://fb.com/sinhvienzonevn om Representation and Mapping ne Zo Si nh Vi en • Every dog has a tail C • Spot is a dog Spot has a tail SinhVienZone.com https://fb.com/sinhvienzonevn om Representation and Mapping C • Spot is a dog Zo • Every dog has a tail ne dog(Spot) Si nh Vi en ∀x: dog(x) → hastail(x) hastail(Spot) Spot has a tail SinhVienZone.com https://fb.com/sinhvienzonevn om Representation and Mapping ne C • Fact-representation mapping is not one-to-one • Good representation can make a reasoning program Si nh Vi en Zo trivial SinhVienZone.com https://fb.com/sinhvienzonevn om Representation and Mapping C The Multilated Checkerboard Problem Zo ne “Consider a normal checker board from which two squares, in opposite corners, have been removed Si nh Vi en The task is to cover all the remaining squares exactly with donimoes, each of which covers two squares No overlapping, either of dominoes on top of each other or of dominoes over the boundary of the multilated board are allowed Can this task be done?” SinhVienZone.com https://fb.com/sinhvienzonevn No black squares = 30 No white square = 32 Si nh Vi en Zo ne C om Representation and Mapping 10 SinhVienZone.com https://fb.com/sinhvienzonevn Good representation: nh Vi en Inferential efficiency Zo Inferential adequacy ne Representational adequacy Acquisitional efficiency Si • • • • C om Representation and Mapping 11 SinhVienZone.com https://fb.com/sinhvienzonevn .C Simple relational knowledge: om Approaches to KR Si nh Vi en Zo ne • Provides very weak inferential capabilities • May serve as the input to powerful inference engines 12 SinhVienZone.com https://fb.com/sinhvienzonevn om Approaches to KR C Inheritable knowledge: ne • Objects are organized into classes and classes are Zo organized in a generalization hierarchy Si adequate nh Vi en • Inheritance is a powerful form of inference, but not 13 SinhVienZone.com https://fb.com/sinhvienzonevn om Approaches to KR C Inferential knowledge: ne • Facts represented in a logical form, which facilitates Zo reasoning Si nh Vi en • An inference engine is required 14 SinhVienZone.com https://fb.com/sinhvienzonevn om Approaches to KR C Procedural knowledge: ne • Representation of “how to make it” rather than “what Zo it is” nh Vi en • May have inferential efficiency, but no inferential Si adequacy and acquisitional efficiency 15 SinhVienZone.com https://fb.com/sinhvienzonevn om Approaches to KR C Choosing the Granularity: Si nh Vi en Zo ne • High-level facts may not be adequate for inference • Low-level primitives may require a lot of storage 16 SinhVienZone.com https://fb.com/sinhvienzonevn om Homework C Reading Si nh Vi en Zo ne R Davis, H Schrobe, P Szolovits (1993): “What is a knowledge representation?” 17 SinhVienZone.com https://fb.com/sinhvienzonevn ... https://fb.com/sinhvienzonevn om Representation and Mapping C desired real reasoning Zo ne Initial facts nh Vi en forward representation mapping Si Internal representations of initial facts Final facts backward representation. .. https://fb.com/sinhvienzonevn Internal Representations Zo Facts ne C om Representation and Mapping Si nh Vi en English understanding reasoning programs English generation English Representations SinhVienZone.com... tail SinhVienZone.com https://fb.com/sinhvienzonevn om Representation and Mapping ne C • Fact -representation mapping is not one-to-one • Good representation can make a reasoning program Si nh Vi