It avoids repeated states as for as its memory allow. It is complete if the available memory is sufficient to store the shallowest path. It is optimal if enough memory is available to store the shallowest optimal solution path.
Otherwise it returns the best solution that can be reached with the available memory. When enough memory is available for entire search tree, the search is optimally efficient. Hill climbing. Simulated annealing. List some drawbacks of hill climbing process. Local maxima: A local maxima as opposed to a goal maximum is a peak that is lower that the highest peak in the state space.
Once a local maxima is reached the algorithm will halt even though the solution may be far from satisfactory. Plateaux: A plateaux is an area of the state space where the evaluation fn is essentially flat. The search will conduct a random walk. Define a knowledge Base: Knowledge base is the central component of knowledge base agent and it is described as a set of representations of facts about the world. Define a Sentence?
Each individual representation of facts is called a sentence. The sentences are expressed in a language called as knowledge representation language. Define an inference procedure An inference procedure reports whether or not a sentence?? If i can derive?? Alpha is derived from KB or i derives alpha from KB 4. What are the three levels in describing knowledge based agent? Logical level Implementation level Knowledge level or epistemological level 5.
Define Syntax? Syntax is the arrangement of words. Syntax of a knowledge describes the possible configurations that can constitute sentences.
Syntax of the language describes how to make sentences. Define Semantics The semantics of the language defines the truth of each sentence with respect to each possible world. With this semantics, when a particular configuration exists within an agent, the agent believes the corresponding sentence. Define Logic Logic is one which consist of i. A formal system for describing states of affairs, consisting of a Syntax b Semantics.
Proof Theory — a set of rules for deducing the entailment of set sentences. What is entailment The relation between sentence is called entailment. The formal definition of entailment is this:???? Informally the truth of? What is truth Preserving An inference algorithm that derives only entailed sentences is called sound or truth preserving. Define a Proof A sequence of application of inference rules is called a proof. Finding proof is exactly finding solution to search problems.
If the successor function is defined to generate all possible applications of inference rules then the search algorithms can be applied to find proofs. Define a Complete inference procedure An inference procedure is complete if it can derive all true conditions from a set of premises. Define Interpretation Interpretation specifies exactly which objects, relations and functions are referred to be the constant predicate, and function symbols.
Define Validity of a sentence A sentence is valid or necessarily true if and only if it is true under all possible interpretation in all possible world. Define Satisfy-ability of a sentence A sentence is satisfy-able if and only if there is some interpretation in some world for which it is true. Define true sentence A sentence is true under a particular interpretation if the state of affairs it represents is the case.
What are the basic Components of propositional logic? Logical Constants True, False Define AND —Elimination rule in propositional logic AND elimination rule states that from a given conjunction it is possible to inference any of the conjuncts.
Define OR-Introduction rule in propositional logic OR-Introduction rule states that from, a sentence, we can infer its disjunction with anything. Why does uncertainty arise? State the reason why first order, logic fails to cope with that the mind like medical diagnosis. Three reasons a. Laziness: o it is hard to lift complete set of antecedents of consequence, needed to ensure and exception less rule. Theoretical Ignorance: medical science has no complete theory for the domain. Practical ignorance: even if we know all the rules, we may be uncertain about a particular item needed.
Define the term utility? The term utility is used in the sense of "the quality of being useful. What is the need for probability theory in uncertainty? Probability provides the way of summarizing the uncertainty that comes from our laziness and ignorance.
Probability statements do not have quite the same kind of semantics known as evidences. Utility theory says that every state has a degree of usefulness, or utility to in agent, and that the agent will prefer states with higher utility.
The use utility theory to represent and reason with preferences. What is called as principle of maximum expected utility? The basic idea is that an agent is rational if and only if it chooses the action that yields the highest expected utility, averaged over all the possible outcomes of the action. This is known as MEU.
Define Prior Probability? It is important to remember that p a can only be used when there is no other information. Define probability distribution: Eg. This type of notations simplifies many equations. What is an atomic event? An atomic event is an assignment of particular values to all variables, in other words, the complete specifications of the state of domain. Define joint probability distribution This completely specifies an agent's probability assignments to all propositions in the domain.
Give the Baye's rule equation W. What is meant by belief network? A belief network is a graph in which the following holds - A set of random variables - A set of directive links or arrows connects pairs of nodes. What are the ways in which one can understand the semantics of a belief network? There are two ways to see the network as a representation of the joint probability distribution to view it as an encoding of collection of conditional independence statements.
What is the basic task of a probabilistic inference? The basic task is to reason in terms of prior probabilities of conjunctions, but for the most part, we will use conditional probabilities as a vehicle for probabilistic inference. What are called as Poly trees? What are the two commitments of logic and define them? What are the components of a first order logic? What is the difference between the two quantifiers in the logics? What is synchronic and diachronic? What are casual rules? What are diagnostic rules?
What is a model based reasoning systems? What are the various steps in knowledge engineering process of a first order logic? What are the various resolution strategies? What is ontological engineering? What is upper ontology? What distinguish general purpose ontology and special purpose ontology? What are categories and objects? Describe default logic What do you understand by logical reasoning State the reasons when the hill climbing often gets stuck Define unification Define resolution What is reification?
Give the Syntax and Semantics of a first order logic in detail with an eg. Give Syntax and Semantics of a first order logic for a family domain. Explain about unification with an algorithm in a first order logic. Explain in detail the concept of theorem proverbs. Explain forward chaining and backward chaining in detail for a first order definite clauses. Explain how categories and objects are presented in any four sets. Elaborate upon the ontology for situation calculus.
Elaborate upon the ontology for event calculus. How facts are represented using prepositional logic? Define partial order planner June 07 2. Define planning with state space search 3. What is a planning graph 4. What is planning and acting in real world 5. Define forward state space search 6. Define backward state space search 7. Heuristics for state space search 8. Describe the differences and similarities between problem solving and planning 9.
What is a planning graph What is sub goal independence assumption What is empty — delete — list heuristic What is least commitment strategy How do they differ from semantic nets. What is meant by decision network June 06 What do you understand by logical reasoning What is ontological engineering?
What are different types of machine translation? Distinguish between full joint probability distribution and joint probability distribution List the general classification of languages. Explain about unification with an algorithm in a first order logic. What is smoothing What are its use? Anna University — Artifiical. What is planning and acting in real world 5. Elaborate upon the ontology for situation calculus. Describe the four categories under which AI is classified with examples.
What is sub goal independence assumption Explain the various forms of learning. Define partial order planner June 07 2. Draw a learning curve for the decision tree algorithm State the factors that play a role in the design of learning systems.
Explain Heuristics for state space search State the decision tree as a performance element. List any two NLP systems. List the characteristic features of a expert system.
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