trí tuệ nhân tạo cao hoàng trứ chương ter6 1 knowledge representation sinhvienzone com

om C ne nh Vi en Zo Knowledge Representation Si Chapter SinhVienZone.com https://fb.com/sinhvienzonevn .C om What is KR? Si nh Vi en Zo ne R Davis, H Schrobe, P Szolovits (1993): “What is a knowledge representation?” Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 03 April 2010 https://fb.com/sinhvienzonevn .C om What is KR? ne 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 Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 03 April 2010 https://fb.com/sinhvienzonevn .C om Representation and Mapping ne • Facts: things we want to represent Si nh Vi en Zo • Representations of facts: things we can manipulate Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 03 April 2010 https://fb.com/sinhvienzonevn ne C om Representation and Mapping Internal Representations nh Vi en Zo Facts Si English understanding Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com reasoning programs English generation English Representations 03 April 2010 https://fb.com/sinhvienzonevn .C om Representation and Mapping desired real reasoning Zo ne Initial facts nh Vi en forward representation mapping Si Internal representations of initial facts Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com Final facts backward representation mapping operation of program Internal representations of final facts 03 April 2010 https://fb.com/sinhvienzonevn om Representation and Mapping Si nh Vi en • Every dog has a tail Zo ne C • Spot is a dog Spot has a tail Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 03 April 2010 https://fb.com/sinhvienzonevn om Representation and Mapping ne C • Spot is a dog nh Vi en • Every dog has a tail Zo dog(Spot) Si "x: dog(x)  hastail(x) hastail(Spot) Spot has a tail Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 03 April 2010 https://fb.com/sinhvienzonevn .C om Representation and Mapping ne • Fact-representation mapping is not one-to-one Zo • Good representation can make a reasoning program Si nh Vi en trivial Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 03 April 2010 https://fb.com/sinhvienzonevn .C om Representation and Mapping ne The Multilated Checkerboard Problem Zo “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?” Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 10 03 April 2010 https://fb.com/sinhvienzonevn No black squares = 30 No white square = 32 Si nh Vi en Zo ne C om Representation and Mapping Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 11 03 April 2010 https://fb.com/sinhvienzonevn .C om Representation and Mapping ne Good representation: nh Vi en • Inferential adequacy Zo • Representational adequacy • Inferential efficiency Si • Acquisitional efficiency Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 12 03 April 2010 https://fb.com/sinhvienzonevn ne Simple relational knowledge: C om Approaches to KR Zo • Provides very weak inferential capabilities Si nh Vi en • May serve as the input to powerful inference engines Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 13 03 April 2010 https://fb.com/sinhvienzonevn .C om Approaches to KR ne Inheritable knowledge: Zo • Objects are organized into classes and classes are nh Vi en organized in a generalization hierarchy • Inheritance is a powerful form of inference, but not Si adequate Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 14 03 April 2010 https://fb.com/sinhvienzonevn .C om Approaches to KR ne Inferential knowledge: Zo • Facts represented in a logical form, which facilitates nh Vi en reasoning Si • An inference engine is required Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 15 03 April 2010 https://fb.com/sinhvienzonevn .C om Approaches to KR ne Procedural knowledge: Zo • Representation of “how to make it” rather than “what nh Vi en it is” • May have inferential efficiency, but no inferential Si adequacy and acquisitional efficiency Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 16 03 April 2010 https://fb.com/sinhvienzonevn .C om Approaches to KR ne Choosing the Granularity: Zo • High-level facts may not be adequate for inference Si nh Vi en • Low-level primitives may require a lot of storage Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 17 03 April 2010 https://fb.com/sinhvienzonevn .C om Homework ne Reading Si nh Vi en Zo R Davis, H Schrobe, P Szolovits (1993): “What is a knowledge representation?” Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 18 03 April 2010 https://fb.com/sinhvienzonevn ... Representation and Mapping Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 11 03 April 2 010 https://fb.com/sinhvienzonevn .C om Representation and Mapping ne Good representation: nh Vi en •... English Representations 03 April 2 010 https://fb.com/sinhvienzonevn .C om Representation and Mapping desired real reasoning Zo ne Initial facts nh Vi en forward representation mapping Si Internal representations... en Zo ne R Davis, H Schrobe, P Szolovits (19 93): “What is a knowledge representation? ” Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 03 April 2 010 https://fb.com/sinhvienzonevn .C om What