Pruning and sorting, Computer Engineering

Assignment Help:

Pruning and Sorting:

This means we can test where each hypothesis explains as entails a common example that we can associate to a hypothesis a set of positive elements in which it explains and a similar set of negative elements. Moreover there is also a similar analogy with general and specific hypotheses as described above as: whether a hypothesis G is more practical than hypothesis S so then the examples explained by S will be a subset of those explained by G.

In fact we will assume the following generic search strategy for an ILP system as: (i) is a set of current hypotheses is maintained and QH (ii) is at each step in the search, a hypothesis H is taken from QH and some inference rules applied to it in order to generate some new hypotheses that are then added to the set as we say that H has been expanded (iii) is, this continues until a termination criteria is met.
However this leaves many questions unanswered. By looking first at the question of that hypothesis to expand at a particular stage, ILP systems associate a label with each hypothesis generated that expresses a probability of the hypothesis holding which is given the background knowledge and examples are true. After then there hypotheses with a higher probability are expanded rather than those with a lower probability and hypotheses with zero probability are pruned from the set QH entirely. However this probability calculation is derived using Bayesian mathematics and we do not go into the derivation here. Moreover we hint at two aspects of the calculation in the paragraphs below.

In just specific to general ILP systems there the inference rules are inductive so each operator takes a hypothesis and generalizes it. However as mentioned above that this means like the hypothesis generated will explain more examples than the original hypothesis. In fact as the search gradually makes hypotheses more generally there will come a stage where a newly formed hypothesis H is common enough to explain a negative example as e- . Thus this should therefore score zero for the probability calculation is just because it cannot possibly hold given the background and examples being true. This means the operators only generalize so there is no way through H can be fixed to not explain e-, so pruning it from QH means the zero probability score is a good decision.


Related Discussions:- Pruning and sorting

What are the requirements of the user, This step of systems examination is ...

This step of systems examination is one of the most difficult. In this stage systems specifications are identified by asking what, who, when, where and how. A few questions address

Disadvantages of stateful multi-layer inspection, Disadvantages of Stateful...

Disadvantages of Stateful Multi-Layer Inspection A firewall such as the SMLI remains completely transparent to both users and applications. Consequently, SMLI firewall does no

The alignment of a type ''c'' field in a report, The alignment of a type 'c...

The alignment of a type 'c' field in a report is? ? Left Aligned.

Diffrentiate b/w shared memory and distributed memory, Shared Memory  ...

Shared Memory  Shared Memory refers to memory component of a computer system in which the memory can accessed directly by any of the processors in the system. Distributed

And-elimination-introduction rule - artificial intelligence, And-Eliminatio...

And-Elimination-Introduction rule - Artificial intelligence: And-Elimination In English, this says that "if you know that many things are all true, then you know that any

Explain parallelism conditions, Parallelism Conditions As discussed ear...

Parallelism Conditions As discussed earlier, parallel computing needs the segments to be executed in parallel should be independent of each other. So before executing paralleli

Simplify using k-map, Q. Simplify Using K-Map 1. M2 + M3 + M5 + M7 + M1...

Q. Simplify Using K-Map 1. M2 + M3 + M5 + M7 + M12 + M13 + M8 + M9 2. M0 + M2 + M4 + M5 + M8 + M10 + M12 3. F(W,X,Y,Z) = ∑ (0,1,2,4,5,6,8,9,12,13,14)

Explain the significance of binary data, Explain the Significance of Binary...

Explain the Significance of Binary Data Controlled devices generally contain registers that are made up of binary digits (bits). The following illustration shows how these regi

Explain parsing, What is parsing? The target of parsing is to find out...

What is parsing? The target of parsing is to find out the syntactic validity of a source string. A tree is built for use through subsequent phase of compiler, if the string is

What is data link layer, Q. What is Data link layer? Data link layer: ...

Q. What is Data link layer? Data link layer: data link layer is responsible for transmitting a group of bits between adjacent nodes. Group of bits is termed as frame. Network

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd