A rule-based system uses predefined rules to make logical deductions and choices to perform automated actions. It consists of a database of rules representing knowledge, a database of facts as inputs, and an inference engine that controls the process of deriving conclusions by applying rules to facts. A rule-based system mimics human decision making by applying rules in an "if-then" format to incoming data to perform actions, but unlike AI it does not learn or adapt on its own.
Artificial Intelligence: Introduction, Typical Applications. State Space Search: Depth Bounded
DFS, Depth First Iterative Deepening. Heuristic Search: Heuristic Functions, Best First Search,
Hill Climbing, Variable Neighborhood Descent, Beam Search, Tabu Search. Optimal Search: A
*
algorithm, Iterative Deepening A*
, Recursive Best First Search, Pruning the CLOSED and OPEN
Lists
Knowledge representation and Predicate logicAmey Kerkar
This presentation is specifically designed for the in depth coverage of predicate logic and the inference mechanism :resolution algorithm.
feel free to write to me at : amecop47@gmail.com
Artificial Intelligence: Introduction, Typical Applications. State Space Search: Depth Bounded
DFS, Depth First Iterative Deepening. Heuristic Search: Heuristic Functions, Best First Search,
Hill Climbing, Variable Neighborhood Descent, Beam Search, Tabu Search. Optimal Search: A
*
algorithm, Iterative Deepening A*
, Recursive Best First Search, Pruning the CLOSED and OPEN
Lists
Knowledge representation and Predicate logicAmey Kerkar
This presentation is specifically designed for the in depth coverage of predicate logic and the inference mechanism :resolution algorithm.
feel free to write to me at : amecop47@gmail.com
Query Processing : Query Processing Problem, Layers of Query Processing Query Processing in Centralized Systems – Parsing & Translation, Optimization, Code generation, Example Query Processing in Distributed Systems – Mapping global query to local, Optimization,
Knowledge representation In Artificial IntelligenceRamla Sheikh
facts, information, and skills acquired through experience or education; the theoretical or practical understanding of a subject.
Knowledge = information + rules
EXAMPLE
Doctors, managers.
Problem Characteristics in Artificial Intelligence,
Unit -2 Problem Solving and Searching Techniques
o choose an appropriate method for a particular problem first we need to categorize the problem based on the following characteristics.
Is the problem decomposable into small sub-problems which are easy to solve?
Can solution steps be ignored or undone?
Is the universe of the problem is predictable?
Is a good solution to the problem is absolute or relative?
Is the solution to the problem a state or a path?
What is the role of knowledge in solving a problem using artificial intelligence?
Does the task of solving a problem require human interaction?
1. Is the problem decomposable into small sub-problems which are easy to solve?
Can the problem be broken down into smaller problems to be solved independently?
See also Water Jug Problem in Artificial Intelligence
The decomposable problem can be solved easily.
Example: In this case, the problem is divided into smaller problems. The smaller problems are solved independently. Finally, the result is merged to get the final result.
Is the problem decomposable
2. Can solution steps be ignored or undone?
In the Theorem Proving problem, a lemma that has been proved can be ignored for the next steps.
Such problems are called Ignorable problems.
In the 8-Puzzle, Moves can be undone and backtracked.
Such problems are called Recoverable problems.
In Playing Chess, moves can be retracted.
Such problems are called Irrecoverable problems.
Ignorable problems can be solved using a simple control structure that never backtracks. Recoverable problems can be solved using backtracking. Irrecoverable problems can be solved by recoverable style methods via planning.
3. Is the universe of the problem is predictable?
In Playing Bridge, We cannot know exactly where all the cards are or what the other players will do on their turns.
Uncertain outcome!
For certain-outcome problems, planning can be used to generate a sequence of operators that is guaranteed to lead to a solution.
For uncertain-outcome problems, a sequence of generated operators can only have a good probability of leading to a solution. Plan revision is made as the plan is carried out and the necessary feedback is provided.
4. Is a good solution to the problem is absolute or relative?
The Travelling Salesman Problem, we have to try all paths to find the shortest one.
See also Generate and Test Heuristic Search - Artificial Intelligence
Any path problem can be solved using heuristics that suggest good paths to explore.
For best-path problems, a much more exhaustive search will be performed.
5. Is the solution to the problem a state or a path
The Water Jug Problem, the path that leads to the goal must be reported.
Query Processing : Query Processing Problem, Layers of Query Processing Query Processing in Centralized Systems – Parsing & Translation, Optimization, Code generation, Example Query Processing in Distributed Systems – Mapping global query to local, Optimization,
Knowledge representation In Artificial IntelligenceRamla Sheikh
facts, information, and skills acquired through experience or education; the theoretical or practical understanding of a subject.
Knowledge = information + rules
EXAMPLE
Doctors, managers.
Problem Characteristics in Artificial Intelligence,
Unit -2 Problem Solving and Searching Techniques
o choose an appropriate method for a particular problem first we need to categorize the problem based on the following characteristics.
Is the problem decomposable into small sub-problems which are easy to solve?
Can solution steps be ignored or undone?
Is the universe of the problem is predictable?
Is a good solution to the problem is absolute or relative?
Is the solution to the problem a state or a path?
What is the role of knowledge in solving a problem using artificial intelligence?
Does the task of solving a problem require human interaction?
1. Is the problem decomposable into small sub-problems which are easy to solve?
Can the problem be broken down into smaller problems to be solved independently?
See also Water Jug Problem in Artificial Intelligence
The decomposable problem can be solved easily.
Example: In this case, the problem is divided into smaller problems. The smaller problems are solved independently. Finally, the result is merged to get the final result.
Is the problem decomposable
2. Can solution steps be ignored or undone?
In the Theorem Proving problem, a lemma that has been proved can be ignored for the next steps.
Such problems are called Ignorable problems.
In the 8-Puzzle, Moves can be undone and backtracked.
Such problems are called Recoverable problems.
In Playing Chess, moves can be retracted.
Such problems are called Irrecoverable problems.
Ignorable problems can be solved using a simple control structure that never backtracks. Recoverable problems can be solved using backtracking. Irrecoverable problems can be solved by recoverable style methods via planning.
3. Is the universe of the problem is predictable?
In Playing Bridge, We cannot know exactly where all the cards are or what the other players will do on their turns.
Uncertain outcome!
For certain-outcome problems, planning can be used to generate a sequence of operators that is guaranteed to lead to a solution.
For uncertain-outcome problems, a sequence of generated operators can only have a good probability of leading to a solution. Plan revision is made as the plan is carried out and the necessary feedback is provided.
4. Is a good solution to the problem is absolute or relative?
The Travelling Salesman Problem, we have to try all paths to find the shortest one.
See also Generate and Test Heuristic Search - Artificial Intelligence
Any path problem can be solved using heuristics that suggest good paths to explore.
For best-path problems, a much more exhaustive search will be performed.
5. Is the solution to the problem a state or a path
The Water Jug Problem, the path that leads to the goal must be reported.
The first lecture of expert system with python course.
Enjoy!
you can find the second lecture here:
https://www.slideshare.net/ahmadhussein45/expert-system-with-python-2
KScope14 Understanding the Zombies that lurk within your systemAlithya
Understanding the Zombies that lurk within your system: The Rules. This presentation assumes an HFM administrator level understanding of the system in general. But no familiarity with rules or how they run.
An intrusion detection system (IDS) is a device or software application that monitors network or system activities for malicious activities or policy violations and produces reports to a management station
When building digital products and services, we are designing complex systems.We need to think the customer experience through on several channels, figure out the system architecture, gain understanding through data and research, decide what to iterate... - not easy, but fun!
In this keynote talk given at Agile Cambridge 2016, Johanna introduces core systems thinking principles for designing better services, discussed how data and feedback mechanisms help us understand what is going on in a system, and addressed the challenge of bringing about change in a system.
Beyond pretty charts, Analytics for the rest of us. Toufic Boubez DevOps Days...tboubez
Current monitoring tools are clearly reaching the limit of their capabilities. That's because these tools are based on fundamental assumptions that are no longer true such as assuming that the underlying system being monitored is relatively static or that the behavioral limits of these systems can be defined by static rules and thresholds. Interest in applying analytics and machine learning to detect anomalies in dynamic web environments is gaining steam. However, understanding which algorithms should be used to identify and predict anomalies accurately within all that data we generate is not so easy.
This talk builds on an Open Space discussion that was started at DevOps Days Austin. We will begin with a brief definition of the types of anomalies commonly found in dynamic data center environments and then discuss some of the key elements to consider when thinking about anomaly detection such as:
Understanding your data and the two main approaches for analyzing operations data: parametric and non-parametric methods
The importance of context
Simple data transformations that can give you powerful results
This presentation discusses the following topics:
Basic features of R
Exploring R GUI
Data Frames & Lists
Handling Data in R Workspace
Reading Data Sets & Exporting Data from R
Manipulating & Processing Data in R
A study on “Diagnosis Test of Diabetics and Hypertension by AI”, Presentation slides for International Conference on "Life Sciences: Acceptance of the New Normal", St. Aloysius' College, Jabalpur, Madhya Pradesh, India, 27-28 August, 2021
A study on “impact of artificial intelligence in covid19 diagnosis”Dr. C.V. Suresh Babu
A study on “Impact of Artificial Intelligence in COVID-19 Diagnosis”, Presentation slides for International Conference on "Life Sciences: Acceptance of the New Normal", St. Aloysius' College, Jabalpur, Madhya Pradesh, India, 27-28 August, 2021
A study on “impact of artificial intelligence in covid19 diagnosis”Dr. C.V. Suresh Babu
Although the lungs are one of the most vital organs in the body, they are vulnerable to infection and injury. COVID-19 has put the entire world in an unprecedented difficult situation, bringing life to a halt and claiming thousands of lives all across the world. Medical imaging, such as X-rays and computed tomography (CT), is essential in the global fight against COVID-19, and newly emerging artificial intelligence (AI) technologies are boosting the power of imaging tools and assisting medical specialists. AI can improve job efficiency by precisely identifying infections in X-ray and CT images and allowing further measurement. We focus on the integration of AI with X-ray and CT, both of which are routinely used in frontline hospitals, to reflect the most recent progress in medical imaging and radiology combating COVID-19.
A study on “the impact of data analytics in covid 19 health care system”Dr. C.V. Suresh Babu
A Study on “The Impact of Data Analytics in COVID-19 Health Care System”, Presentation slides for International Conference on "Life Sciences: Acceptance of the New Normal", St. Aloysius' College, Jabalpur, Madhya Pradesh, India, 27-28 August, 2021
A study on the impact of data analytics in COVID-19 health care systemDr. C.V. Suresh Babu
Through the disperse of novel coronavirus illness globally, existence became considerably contrived. Data analytics have experienced powerful development over the past few years. As it happens, it’s exceptionally considerable to take advantage of data analytics to assist mankind in a prompt as well as factually precise method to forestall additionally restrain the advancement of the widespread, sustain gregarious balance and evaluate the influence of the widespread. The unforeseen significant number of coronavirus disease instances has disturbed medical care system in many economies furthermore eventuated in an insufficiency of dormitory in the hospices. For this reason, prognosticating quantity of coronavirus infection instances is indispensable for administrations to adopt the necessary measures. The count of coronavirus disease instances could be correctly anticipated by taking into account historical records of announced instances side by side few extraneous components that impact the disseminate of the COVID-19 . Hence, the principal aim out of this research is to contemporaneously consider historical data and the extraneous components. This paper explores how data analytics can play a role in health care especially in novel coronavirus illness.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
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Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
2. (CentreforKnowledgeTransfer)
institute
Objective
■ As you look to automate parts of your business, you’ve no doubt come across the
term ‘rule-based system’. (Alongside other, flashier terms like AI, RPA and software
“robots”.) But what is a rule-based system, exactly?
■ Rule-based logic is at the heart of most automated software processes.
Unfortunately, there are a lot of easy-to-make misconceptions of what a rule-based
system is and does.
■ So, to help clarify any confusion, here’s a closer look at rule-based systems and
how they work.
3. (CentreforKnowledgeTransfer)
institute
What is a rule-based system?
■ A rule-based system or production systems is a computer system that applies
human-made rules to store, sort and manipulate data to provide recommendations
or diagnoses, or to determine a course of action in a particular situation or to solve
a particular problem. In doing so, it mimics human intelligence.
4. (CentreforKnowledgeTransfer)
institute
Components of RBS
A rule-based system consists of a number of components:
1. Database of rules (also called a knowledge base)
– It consists of a set of rules that represent the knowledge that the system has.
2. Database of facts
– It represents inputs to the system that are used to derive conclusions, or to cause
actions.
3. Interpreter, or inference engine
– It is the part of the system that controls the process of deriving conclusions. It uses
the rules and facts, and combines them together to draw conclusions.
6. (CentreforKnowledgeTransfer)
institute
How rule-based system works?
■ To work, rule-based systems require a set of facts or source of data, and a set of
rules for manipulating that data. These rules are sometimes referred to as ‘If
statements’ as they tend to follow the line of ‘IF X happens THEN do Y’.
■ It automates processes by breaking them down into steps.
– First comes the data or new business event
– Then comes the analysis: the part where the system conditionally processes
the data against its rules
– Then comes any subsequent automated follow-up actions
7. (CentreforKnowledgeTransfer)
institute
Example
■ Rule-based systems, unsurprisingly, work based on rules. These rules outline triggers
and the actions that should follow (or are triggered). For example, a trigger might be an
email containing the word “invoice”. An action might then be to forward the email to
the finance team.
■ These rules most often take the form of if statements. ‘IF’ outlines the trigger, ‘THEN’
specifies the action to complete. So, if you want to create a rule-based system capable
of handling 100 different actions, you’d have to write 100 different rules. If you want to
then update the system and add actions, then you would need to write new rules.
■ In short, you use rules to tell a machine what to do, and the machine will do exactly as
you tell it. From there, rule-based systems will execute the actions until you tell it to
stop.
■ But remember: if you tell it to do something incorrectly, it will do it incorrectly.
8. (CentreforKnowledgeTransfer)
institute
What is a rule-based system not?
■ Due to early use in the fields, rule-based systems are commonly confused with
artificial intelligence and machine learning. However, they are not AI, and they are
not machine learning.
■ It’s easy to confuse the two as they can look very similar. Both involve machines
completing tasks, seemingly on their own. The difference is that AI can determine
the action to take itself; it can learn and adapt. Meanwhile, rule-based systems do
exactly as instructed by a human.
■ In other words, unlike artificial intelligence and machine learning, the actions
carried out by rule-based systems (the rules that they follow) are determined by a
human.
■ The system doesn’t work it out for itself, or intelligently make decisions.
10. (CentreforKnowledgeTransfer)
institute
Summary
■ What is a rule-based system? It’s not AI, and it’s not machine learning. (Thought it
might be used within them, to power certain aspects.)
■ Rather, rule-based systems simply follow rules laid out by humans. But in doing so,
they are incredibly useful.
https://www.youtube.com/watch?v=bes9e96stk8
11. (CentreforKnowledgeTransfer)
institute
Types of RBS
Using deduction to reach a conclusion from a
set of antecedents is called forward chaining.
An alternative method, backward chaining,
starts from a conclusion and tries to show it by
following a logical path backward from the
conclusion to a set of antecedents that are in
the database of facts.
12. (CentreforKnowledgeTransfer)
institute
Forward Chaining
■ Forward chaining employs the system starts from a set of facts, and a set of rules,
and tries to find a way of using those rules and facts to deduce a conclusion or
come up with a suitable course of action.
■ This is known as data-driven reasoning because the reasoning starts from a set
of data and ends up at the goal, which is the conclusion.
■ When applying forward chaining, the first step is to take the facts in the fact
database and see if any combination of these matches all the antecedents of one
of the rules in the rule database.
■ When all the antecedents of a rule are matched by facts in the database, then this
rule is triggered.
■ Usually, when a rule is triggered, it is then fired, which means its conclusion is
added to the facts database.
■ If the conclusion of the rule that has fired is an action or a recommendation, then
the system may cause that action to take place or the recommendation to be
made.
13. (CentreforKnowledgeTransfer)
institute
For example, consider the following set of
rules that is used to control an elevator in a
three-story building:
Rule 1
IF on first floor and button is pressed on first floor
THEN open door
Rule 2
IF on first floor
AND button is pressed on second floor
THEN go to second floor
Rule 3
IF on first floor
AND button is pressed on third floor
THEN go to third floor
Rule 4
IF on second floor
AND button is pressed on first floor
AND already going to third floor
THEN remember to go to first floor later
This represents just a subset of the rules that would be needed,
but we can use it to illustrate how forward chaining works.
Let us imagine that we start with the following facts in our
database:
Fact 1: At first floor
Fact 2: Button pressed on third floor
Fact 3: Today is Tuesday
• Now the system examines the rules and finds that Facts 1
and 2 match the antecedents of Rule 3.
• Hence, Rule 3 fires, and its conclusion “Go to third floor”
is added to the database of facts.
• Presumably, this results in the elevator heading toward
the third floor.
• Note that Fact 3 was ignored altogether because it did not
match the antecedents of any of the rules.
14. (CentreforKnowledgeTransfer)
institute
Now let us imagine that the elevator is on its way to the third floor and has
reached the second floor, when the button is pressed on the first floor. The
fact Button pressed on first floor
Is now added to the database, which results in Rule 4 firing.
Now let us imagine that later in the day the facts database contains the following
information:
Fact 1: At first floor
Fact 2 : Button pressed on second floor
Fact 3: Button pressed on third floor
In this case, two rules are triggered—Rules 2 and 3. In such cases where there is
more than one possible conclusion, conflict resolution needs to be applied to
decide which rule to fire.
15. (CentreforKnowledgeTransfer)
institute
Conflict Resolution
In a situation where more than one conclusion can be deduced from a set of
facts, there are a number of possible ways to decide which rule to fire.
For example, consider the following set of rules:
IF it is cold
THEN wear a coat
IF it is cold
THEN stay at home
IF it is cold
THEN turn on the heat
If there is a single fact in the fact database, which is “it is
cold,” then clearly there are three conclusions that can be
derived. In some cases, it might be fine to follow all three
conclusions, but in many cases the conclusions are
incompatible.
16. (CentreforKnowledgeTransfer)
institute
In one conflict resolution method, rules are given priority levels, and when a
conflict occurs, the rule that has the highest priority is fired, as in the following
example:
IF patient has pain
THEN prescribe painkillers priority 10
IF patient has chest pain
THEN treat for heart disease priority 100
• Here, it is clear that treating possible heart problems is more important than
just curing the pain.
• An alternative method is the longest-matching strategy.
• This method involves firing the conclusion that was derived from the longest
rule.
17. (CentreforKnowledgeTransfer)
institute
IF patient has pain
THEN prescribe painkiller
IF patient has chest pain
AND patient is over 60
AND patient has history of heart conditions
THEN take to emergency room
• Here, if all the antecedents of the second rule match,
then this rule’s conclusion should be fired rather than
the conclusion of the first rule because it is a more
specific match.
• A further method for conflict resolution is to fire the rule
that has matched the facts most recently added to the
database.
For example:
In each case, it may be that the system fires one rule and then stops, but in many cases, the system simply
needs to choose a suitable ordering for the rules because each rule that matches the facts needs to be fired at
some point.
18. (CentreforKnowledgeTransfer)
institute
Meta Rules
In designing an expert system, it is necessary to select the conflict resolution method that
will be used, and quite possibly it will be necessary to use different methods to resolve
different types of conflicts.
For example, in some situations it may make most sense to use the method that involves firing the most
recently added rules.
This method makes most sense in situations in which the timeliness of data is important. It might be, for
example, that as research in a particular field of medicine develops, and new rules are added to the system
that contradicts some of the older rules.
It might make most sense for the system to assume that these newer rules are more accurate than the older
rules.
It might also be the case, however, that the new rules have been added by an expert whose opinion is less
trusted than that of the expert who added the earlier rules.
In this case, it clearly makes more sense to allow the earlier rules priority.
This kind of knowledge is called meta knowledge—knowledge about knowledge. The rules that define how
conflict resolution will be used, and how other aspects of the system itself will run, are called meta rules.
19. (CentreforKnowledgeTransfer)
institute
Knowledge engineer
■ The knowledge engineer who builds the expert system is responsible for
building appropriate meta knowledge into the system (such as “expert A
is to be trusted more than expert B” or “any rule that involves drug X is
not to be trusted as much as rules that do not involve X”).
■ Meta rules are treated by the expert system as if they were ordinary
rules but are given greater priority than the normal rules that make up
the expert system.
■ In this way, the meta rules are able to override the normal rules, if
necessary, and are certainly able to control the conflict resolution
process
20. (CentreforKnowledgeTransfer)
institute
Backward Chaining
■ Forward chaining applies a set of rules and facts to deduce whatever
conclusions can be derived, which is useful when a set of facts are present,
but you do not know what conclusions you are trying to prove.
■ Forward chaining can be inefficient because it may end up proving a number of conclusions
that are not currently interesting.
■ In such cases, where a single specific conclusion is to be proved, backward chaining is
more appropriate.
■ In backward chaining, we start from a conclusion, which is the hypothesis we wish to prove,
and we aim to show how that conclusion can be reached from the rules and facts in the
database.
■ The conclusion we are aiming to prove is called a goal, and so reasoning in this way is
known as goal-driven reasoning.
■ Backward chaining is often used in formulating plans.
■ A plan is a sequence of actions that a program decides to take to solve a particular problem.
■ Backward chaining can make the process of formulating a plan more efficient than forward
chaining.
21. (CentreforKnowledgeTransfer)
institute
■ Backward chaining in this way starts with the goal state, which is the
set of conditions the agent wishes to achieve in carrying out its plan.
It now examines this state and sees what actions could lead to it.
For example,
■ if the goal state involves a block being on a table, then one possible action would be to
place that block on the table.
■ This action might not be possible from the start state, and so further actions need to be
added before this action in order to reach it from the start state.
■ In this way, a plan can be formulated starting from the goal and working back toward the
start state.
■ The benefit in this method is particularly clear in situations where the first state allows a
very large number of possible actions.
■ In this kind of situation, it can be very inefficient to attempt to formulate a plan using
forward chaining because it involves examining every possible action, without paying
any attention to which action might be the best one to lead to the goal state.
■ Backward chaining ensures that each action that is taken is one that will definitely lead
to the goal, and in many cases this will make the planning process far more efficient.