Knowledge Learning by Using Case Based Reasoning (CBR) Knowledge Learning by Using Case Based Reasoning (CBR) Jun Yin and Yan Meng Department of Electrical and Computer Engineering Stevens Institute of Technology Hoboken, NJ, USA 4/9/2015 1 Knowledge Learning by Using Case Based Reasoning (CBR) What’s CBR? • Case-Based Reasoning (CBR) is a name given to a reasoning method that solves a new problem by remembering a previous similar experiences and by reusing information and knowledge of that situation. • Ex: Medicine – doctor remembers previous patients especially for rare combinations of symptoms • Ex: Law – English/US law depends on precedence – case histories are consulted 4/9/2015 2 Knowledge Learning by Using Case Based Reasoning (CBR) CBR System Components • Case-base – database of previous cases (experience) • Retrieval of relevant cases – matching most similar case(s) – retrieving the solution(s) from these case(s) • Adaptation of solution – alter the retrieved solution(s) to reflect differences between new case and retrieved case(s) 4/9/2015 3 Knowledge Learning by Using Case Based Reasoning (CBR) The Case Based Reasoning Cycle Problem SIMILAR CASES New case RETAIN RETRIEVE PRIOR CASES R E U S E CASE-BASE Solution REVISE Solution Knowledge Learning by Using Case Based Reasoning (CBR) Case Retrieval and Adaptation • Case retrieval – the process of finding within the case base those cases that are the closest to the current case. Nearest Neighbor Retrieval Inductive approaches Knowledge Guided Approaches Validated Retrieval • Case Adaptation – the process of translating the retrieved solution into the solution appropriate for the current problem. 4/9/2015 5 Knowledge Learning by Using Case Based Reasoning (CBR) Open Tools • freeCBR is a free open source Java implementation of a "Case Based Reasoning" engine. (http://freecbr.sourceforge.net/) • myCBR is an open-source case-based reasoning tool developed at DFKI. (http://mycbr-project.net/index.html) 4/9/2015 6 Knowledge Learning by Using Case Based Reasoning (CBR) freeCBR a very small case set: 4/9/2015 7 Knowledge Learning by Using Case Based Reasoning (CBR) freeCBR (cont.) search from the case set: the result of the search: 4/9/2015 8 Knowledge Learning by Using Case Based Reasoning (CBR) Open Tool – myCBR 4/9/2015 9 Knowledge Learning by Using Case Based Reasoning (CBR) Open Tools – freeCBR & myCBR Modeling Similarity Measures: These two tools follow the approach in which, for an attribute-value based case representation consisting of n attributes, the similarity between a query q and a case c may be calculated as follows: n Sim(q, c) i simi (qi , ci ) i 1 Here, simi and wi denote the local similarity measure and the weight of attribute i, and Sim represents the global similarity measure. 4/9/2015 10 Knowledge Learning by Using Case Based Reasoning (CBR) Case Retrieval • Nearest Neighbor Retrieval Retrieve most similar k-nearest neighbor - k-NN - like scoring in bowls or curling Example - 1-NN - 5-NN 4/9/2015 11 Knowledge Learning by Using Case Based Reasoning (CBR) Case Retrieval • Decision Tree e.g. Case-Base indexed using a decision-tree 4/9/2015 12 Knowledge Learning by Using Case Based Reasoning (CBR) Case Retrieval • We propose a self-organizing reservoir computing based network for case retrieval. Case Base Query Previous Cases q Case Retriecal The Most Similar Case y(t) Self-organizing RC based network x(t) Self-Organizing Topology with SNN Self-organizing Reservoir Computing based Network architecture 4/9/2015 13 , Knowledge Learning by Using Case Based Reasoning (CBR) Case Retrieval • Benchmark to evaluate the performance of proposed RC based network. NARMA task - The Nonlinear Auto-Regressive Moving Average (NARMA) task consists of modeling the output of the following tenth-order system : y (t 1) 0.3 y (t ) 0.05 y (t )[ i 0 y (t i)] 1.5u (t 9)u (t ) 0.1 9 4/9/2015 14 Knowledge Learning by Using Case Based Reasoning (CBR) NARMA task: #1 0.6 #2 expected values estimated values expected values estimated values 0.6 0.5 0.5 0.4 values values 0.4 0.3 0.2 0.2 0.1 0 0.3 0.1 10 20 30 40 50 number 60 70 80 90 100 0 10 20 30 40 50 number 60 70 80 90 100 Mean squared error = 0.128221, std = 0.0200301 4/9/2015 15 Knowledge Learning by Using Case Based Reasoning (CBR) Future Work • Integrate RC based network into CBR system • Develop the CBR system based on existing tools for more complicated tasks 4/9/2015 16