Rule-base Expert System

 

Rule ·Î Ç¥ÇöµÇ´Â »ý¼º½Ã½ºÅÛ (Production System) ÀÇ ±¸¼ºÀº ´ÙÀ½°ú °°´Ù.

  1. Production Memory (Long Term Memory) : Rule µéÀ» ±â¾ïÇÏ°í ÀÖ´Â Hard Disk ¿¡ ÇØ´çµÈ´Ù.
  2. Working Memory (Short Term Memory) : Ã߷аúÁ¤ Áß¿¡ Àü¹®°¡ ½Ã½ºÅÛ¿¡ ÀÔ·ÂÇÑ Facts µéÀ» Àá½Ã ±â¾ïÇÑ´Ù.
  3. Ã߷п£Áø (Inference Engine) : Ã߷аúÁ¤ Àü¹ÝÀ» Control ÇÑ´Ù.

term :

Àü¹®°¡½Ã½ºÅÛ (Expert System)   Ãß·Ð (Reasoning)   Ã߷п£Áø (Inference Engine)   ´Ü±â±â¾ï (Short Term Memory)    Àå±â±â¾ï (Long Term Memory)   ÀÛ¾÷±â¾ï (Working Memory)   ¹®Á¦ÇØ°á (Problem Solving)   »ç°í (Thinking)   ÀΰøÁö´É (Artificial Intelligence)   ½Å°æ¸Á (Neural Network)

site :

AI Topics : Rule-Based Reasoning

paper :

±ÔÄ¢ (Rule) °ú »ý¼º½Ã½ºÅÛ (Production System) : ±èÀçÈñ

±ÔÄ¢À» ÀÌ¿ëÇÑ Áö½Ä Ç¥Çö : ÀÌÀç±Ô

»ý¼º½Ã½ºÅÛ (Production System)   ÀüÇâ »ý¼º ½Ã½ºÅÛ (forward production system)   ÈÄÇâ »ý¼º ½Ã½ºÅÛ (backward production system) : À¯¼®ÀÎ

Rule-Based Expert Systems: The MYCIN Experiments of the Stanford Heuristic Programming Project  : Edward H. Shortliffe. Bruce Buchanan

º¸Åë Rule Based Àü¹®°¡ ½Ã½ºÅÛ¿¡¼­´Â 1,000°³ ÀüÈÄÀÇ RuleÀ» »ç¿ëÇÑ´Ù. ±×·¯³ª RuleµéÀÇ °³¼ö°¡ Áõ°¡ÇÔ¿¡ µû¶ó ¼º´É¸é¿¡¼­ ÇöÀúÇÑ ¹®Á¦Á¡À» ¾ß±âÇÏ°Ô µÈ´Ù. ÀÌ°ÍÀº ´ÙÀ½ÀÇ ¿øÀÎ ¶§¹®ÀÌ´Ù.

  1. Sequential Processing ¿¡¼­ÀÇ Bottle neck Çö»ó
  2. Rule »ý¼ºÀº ÀÚµ¿ÀûÀ¸·Î ÀÌ·ç¾îÁöÁö ¾Ê´Â´Ù. Àΰ£ÀÌ ³ÖÀº Rule¿¡ ´ëÇؼ­¸¸ ±× ±â´ÉÀ» ¹ßÈÖÇÑ´Ù. Àΰ£Ã³·³ ÀÚµ¿ÀûÀ¸·Î ÇнÀÀÌ ÀÌ·ç¾îÁöÁö ¾Ê´Â´Ù.
  3. RuleÀÇ ¼ö°¡ ¸¹À» ¶§ Logic »óÀÇ ¹®Á¦°¡ Çϳª¸¸ ¹ß»ýÇصµ ¹®Á¦°¡ »ý±ä´Ù. ¹°·Ð °á·ÐÀÇ Á¤È®¼ºÀÌ Á¶±Ý ¶³¾îÁú »ÓÀ̶óÁö¸¸ ±×°ÍÀº ¸Å¿ì Áß¿äÇÏ´Ù.

À§¿Í °°Àº ÀÌÀ¯·Î ÇÏ¿© ´ëµÎµÇ´Â Neural Net¿¡¼­ÀÇ Àü¹®°¡ ½Ã½ºÅÛÀº ´ÙÀ½ÀÇ Æ¯Â¡À» °¡Áø´Ù.

  1. Parallel ProcessingÀ¸·Î Àΰ£°ú °°ÀÌ µ¿½Ã¿¡ ¿©·¯ °¡Áö ÀÏÀ» ÁøÇà½ÃŲ´Ù.
  2. ÇнÀ °úÁ¤ÀÌ Àΰ£°ú ºñ½ÁÇÏ¿© ¸ñǥġ¿Í Ãâ·ÂÄ¡ °£ÀÇ Error¸¦ ÁÙ¿©³ª°¡´Â ¹æÇâÀ¸·Î Weight Update¸¦ ÅëÇÑ ÇнÀÀ¸·Î »ç½Ç»ó RuleÀ» ÀÚµ¿ »ý¼ºÇÏ´Â È¿°ú¸¦ °¡Áø´Ù.
  3. NNÀ» ±¸¼ºÇÏ´Â ¼ö ¸¹Àº nodeµéÀº Àü¹®°¡ ½Ã½ºÅÛ¿¡¼­ ´Ù·ç´Â ¾öû³­  ¼öÀÇ FactorµéÀ» ´Ù·ê ¼ö ÀÖ°Ô ÇÑ´Ù. »ç½Ç»ó RuleÀÌ 10,000 °³¸¦ ³Ñ¾î °¡´Â °æ¿ì Rule Base Àü¹®°¡ ½Ã½ºÅÛÀº Á¦´ë·Î ¿î¿µµÉ ¼ö ¾ø´Ù.

°á±¹ Àΰ£ÀÎ Àü¹®°¡ÀÇ »ç°í °úÁ¤À» ±×´ë·Î ¹¦»çÇÏ·Á´Â Àü¹®°¡ ½Ã½ºÅÛÀº Àΰ£ÀÇ NeuronÀ» ±×´ë·Î º»µý NN Model·Î ±¸Çö½Ã Á» ´õ Á¤È®ÇÏ¿© Áú °ÍÀÌ´Ù. NNÀ» ÀÌ¿ëÇÑ ÀÇÇпë Áø´Ü Àü¹®°¡ ½Ã½ºÅÛµµ ¿©·¯ °³ ¹ßÇ¥µÇ¾î ÀÖÀ¸¸ç ½ÇÁ¦·Î ¾î¶°ÇÑ ¼º´ÉÀ» ¹ßÈÖÇÏ´ÂÁö´Â ¾ËÁö ¸øÇÑ´Ù.

 Çö´ëÀûÀÎ Rule-base Expert System ÀÇ ±âÃÊ 

Rules

Post Production Rules

Inference Engine

 1. Efficient Pattern Matching  <--  Rete Algorithm <--  Markov Algorithm

 2. Conflict Resolution

 3. Execution of RHS of Rules

Facts

 

ÀÇ·áÁø´ÜÀ» À§ÇÑ Rule base systemÀÇ ÀåÁ¡
 

the use of general knowledge : Ã¥¿¡ ¹¦»çµÇ¾îÀÖ´Â °Í°ú ¿ÏÀüÈ÷ ¶È°°Áö ¾ÊÀº ȯÀÚ¸¦ ´Ù·ï¾ß ÇÒ °æ¿ì¿¡ ¾Æ¹«¸® Àß Á¤¸®µÈ Ã¥ÀÌ¶óµµ ºñÀü¹®°¡°¡ »ç¿ëÇϱâ´Â ¾î·Á¿ï¼ö ÀÖ´Ù. µû¶ó¼­ general knowledge¸¦ »ç¿ëÇÏ¿© ÀÌÇØ°¡ ½±°Ô »ó´ã.

the use of judgmental knowledge : Èñ±ÍÇÑ º´À» °¡Áø ¼Ò±Ô¸ðÀÇ È¯ÀÚÀÇ °æ¿ì ¾ÆÁ÷ ÀÌ¿ëÇÒ¸¸ÇÑ Åë°èÀû data°¡ ¾ø´Â °æ¿ì¿¡ ÀÌÀÇ °í·Á¸¦ À§ÇÑ judgmental (ÆÇ°áÀÇ,°áÁ¤ÀûÀÎ) knowledgeÀÇ »ç¿ë

ease of modification : ruleµéÀº ¼­·Î°£¿¡ ¸íÈ®ÇÏ°Ô relatedµÈ °ÍÀº ¾Æ´Ï°í ¹Ì¸® ±¸ÃàµÈ decision tree°¡ ÀÖÀ» ÇÊ¿äµµ ¾ø±â ¶§¹®¿¡ rule modificationÀ̳ª »õ·Î¿î rule additionÀÌ ±×¸® º¹ÀâÇÑ °ÍÀÌ ¾Æ´Ï´Ù.Áï ½Ã½ºÅÛÀÇ ±âÁ¸ Áö½Ä°úÀÇ interactionÀ» ±×¸® °í·ÁÇÏÁö ¾Ê¾Æµµ µÈ´Ù.

facilitated (¿ëÀÌÇÑ) search for potential inconsistencies and contradictions (¸ð¼ø) in the knowledge base : rule °ú °°Àº packetÀ¸·Î ¸íÈ®ÇÏ°Ô ÀúÀåµÈ criteria´Â ±×¸® Å« ¾î·Á¿ò¾øÀÌ Å½»öÇÏ°í ºñ±³µÉ¼ö ÀÖ´Ù.

straightforward mechanisms for explaining decisions : »ç¿ëÀÚ°¡ ã´Â ÀûÀýÇÑ (relevant) ruleµéÀ» ã¾Æ³»°í ±³·ù½ÃÄѼ­ (identify and communicate) »ç¿ëÀÚ¿¡°Ô °áÁ¤À» ¼³¸íÇÏ´Â mechanism.

an augmented (ÁõÁøµÈ) instructional capability : ½Ã½ºÅÛ »ç¿ëÀÚ´Â ¼±ÅÃÀûÀÎ ¹æ¹ýÀ¸·Î ½Ã½ºÅÛÁö½ÄÀ» Ãë±ÞÇϵµ·Ï ±³À°¹ÞÀ»¼ö ÀÖ´Ù. Áï È¥¶õ½º·¯¿î decision processºÎºÐ¸¸À» °Ë»çÇÒ ÇÊ¿ä°¡ ÀÖ´Ù.

(Edward H. Shortliffe 1984) 

 Rule base expert systemÀÇ ´ÜÁ¡
 

Àü¹®°¡·ÎºÎÅÍ Áö½ÄȹµæÀÇ ¾î·Á¿ò : ruleÀÌ Àü¹®°¡ÀÇ Áö½Ä ü°è¿Í ´Þ¶ó¼­ ¹®Á¦ÇØ°áÀ» À§ÇÑ Áö½ÄÀ» ¹Ý¿µÇÏÁö ¸øÇϸç Àü¹®°¡ÀÇ »ç°í°³³äÀ» Ç¥ÇöÇÏ´Â ´ÜÀ§·Î ÀûÇÕÇÏÁö ¸øÇÏ´Ù. Àΰ£ Àü¹®°¡´Â ¼ö¸¹Àº »ç·Ê·ÎºÎÅÍ ±¤¹üÀ§ÇÏ°í Àü¹®ÀûÀÎ °æÇèÀ» ½×°ÔµÇ¸ç, »õ·Î¿î »óȲ¿¡ Àû¿ëÇϱâÀ§ÇØ ÀÌ·¯ÇÑ °æÇèÀ» ÀϹÝÈ­ÇÏ¿© ÇØ°áÃ¥À» ã´Â´Ù. ´Ü¼øÈ÷ Ã¥¿¡ ÀÖ´Â Áö½ÄÀÌ ¾Æ´Ñ °æÇè¿¡¼­ ¿ì·¯³­ Áö½ÄÀ» rule·Î Ç¥ÇöÇϴµ¥ Àü¹®°¡´Â ¾î·Á¿òÀ» ´À³¤´Ù. Àü¹®°¡ÀÇ Áö½ÄÀº °æÇèÀ¸·ÎºÎÅÍ À¯µµµÇ´Â °ÍÀ̸ç Áö½ÄÀDZ⺻´ÜÀ§´Â ruleÀÌ ¾Æ´Ï¶ó »ç·ÊÀÎ °ÍÀÌ´Ù.ÇØ°áÃ¥À¸·Î neural net, case based reasoning, model based reasoning, explanation based reasoning µîÀÌ »ç¿ëµÈ´Ù.

ruleÀº °ú°ÅÀÇ °á°ú¸¦ ±â¾ïÇÏÁö ¸øÇÑ´Ù : µ¿ÀÏÇÑ ¹®Á¦¸¦ ÇØ°áÇÔ¿¡ À־ ¼ö¹é°³ÀÇ ruleÀ» ¶È°°ÀÌ Àû¿ëÇØ¾ß ÇÏ°í computational efficiency´Â ¶³¾îÁø´Ù. ruleÀ» ¼öÁ¤ÇÏÁö ¾Ê´ÂÇÑ µ¿ÀÏÇÑ ½Ç¼ö¸¦ ¹Ýº¹ÇÑ´Ù. Áï °ú°ÅÀÇ ½Ç¼ö¸¦ ±â¾ïÇÏÁö ¸øÇϱ⠶§¹®¿¡ ÀÚµ¿À¸·Î Á»´õ ³ªÀº °á°ú¸¦ ±â´ëÇÒ¼ö ¾ø´Ù. È¿°úÀûÀ¸·Î ȯÀÚ¸¦ Ä¡·áÇϴµ¥ ½ÇÆÐÇÑ ÀÇ»ç´Â µ¿ÀÏÇÑ È¯ÀÚ¸¦ Ä¡·á½Ã ½Ç¼ö¸¦ ¹Ýº¹ÇÏÁö ¾Ê´Â´Ù.

rule¿¡¼­ ºÒÈ®½ÇÇÑ ÀÚ·áÀÇ Ç¥Çö°ú 󸮰¡ ºÒ°¡´ÉÇÏ´Ù : ruleÀÇ Á¶°Ç°ú ¿ÏÀüÈ÷ µ¿ÀÏÇÏÁö ¾ÊÀº À¯»çÇÑ (similarity) ¹®Á¦ÀÇ ÇØ°á¿¡ À־ ´ëÀÀÃ¥À» ¾ò±â°¡ ¾î·Æ´Ù. fuzzy °¡ ÇϳªÀÇ ÇØ°áÃ¥ÀÌ µÉ¼ö ÀÖÀ» °ÍÀÌ´Ù. Àΰ£ Àü¹®°¡´Â Analogy¿¡ ÀÇÇØ Ãß·ÐÇÒ¼ö ÀÖ´Ù. ÀÇ»ç´Â À¯»çÇÑ ÀÌÀü »ç·Ê·ÎºÎÅÍ ´Ù¸¥ Áø´Ü ¶Ç´Â Ä¡·á¸¦ ¼±ÅÃÇÑ´Ù.

Áö½ÄÀÇ ¼öÁ¤ ¹× Ãß°¡¿¡ ¾î·Á¿òÀÌ ¸¹´Ù : À̸¦ À§Çؼ­ ½Ã½ºÅÛÀ» Àç°³¹ßÇØ¾ß ÇÏ´Â °æ¿ì°¡ ¸¹À¸¸ç Áö½ÄÀÇ Ãß°¡·Î ÀÎÇÑ Áö½ÄÀû¿ë°ú ÅëÁ¦°¡ ¾î·Á¿öÁ® ½Ã°£ÀÌ ¸¹ÀÌ °É¸°´Ù. Àΰ£ Àü¹®°¡´Â Áö½ÄÀÇ Ãß°¡°¡ ÀÚ¿¬½º·´°Ô ÀÌ·ç¾îÁö¸ç ¸¹Àº Áö½ÄÀ» °¡Áú¼ö·Ï ¿ÀÈ÷·Á ºü¸¥ ½Ã°£³»¿¡ °á·ÐÀ» ³»¸°´Ù