Wednesday 30th May

I went through the PROMPT criteria for evaluating information from the literature search in preparation for the TMA. Have booked 2 days off to get it done. Have been trawling around for information in journal articles to include in the project. The MIT course lecture notes for Medical Artificial Intelligence are heavy going but there is some relevant information about neural networks.

Tuesday 29th May

Have now finished preprocessing the data for the neural network and created a training file of 50 random patients. Have also created the test file of all 285 cases for the neural network. I created a multi-layered perceptron with 32 input neurons, 10 hidden layer neurons and 2 output neurons and tried to train this simple network. However neural works errors with the training file. This is a text file with a .nnb file extension. I will make sure that this file is the correct format for neural work and recheck the number of neurons.

Sunday 27th May

Have been spending a lot of time preprocessing the breast cancer data for the neural network. Until this is complete I cannot start testing. I have taken my tutors advice and tried to reduce the number of input neurons, though I have still probably got too many. The statistical analysis of the data suggested that some attributes have no influence on tumour recurrance. The location of the tumour in the breast which I took a long time converting into quadrants (and the centre) seems to have no influence on recurrance, because there is a roughly 70% / 30% split between non-recurrence and recurrance which is the same as looking at the overall ratio of non-recurrence to recurrence. Also some attributes are related. For example the menopausal status is age related so I have removed menopausal status.

I will now carry on with this preprocessing which is rather laborious because I am doing it manually. I do not have the expertise to covert the raw data into the format required by the neural network any other way. There are likely to be mistakes in this conversion but I am trying to be as meticulous as I can.

Saturday 19th May

May have been a bit hasty declaring I had preprocessed all the data. I have been looking at the statistical analysis of the data today and have identified an number of rules. After having read through the T396 project I have decided to handle uncertainty using certainty factors as I seem to ba able to understand this more than fuzzy logic and baysian updating. After the statistical analysis I have decided that I will not use all the possible attributes as input neurons for the neural network.

For example there seems to be no significance between the location of the tumour in the breast and the chances of reccurence of the tumour, apart from a much lower incidence of reccurence if the tumour is located centrally. Therefore I will cut this down from 5 input neurons (one for each quadrant) to 2 input neurons (central or not). There are several other possible situations where the number of input neurons could be reduced.

I hope to very shortly complete the rules identification. I have four rules that are always true and the rest are mostly true so will need to be used with the certainty factors.

As an aside and worth remembering when discussing this project is that there is no indication of how long was it from when the tumour was removed to the assessment of whether there was reccurence or not, i.e. if the patients without reccurence were followed up a few years later would the tumour still not have reoccured.

16th May

Did some statistical analysis on the breast data in a similar way to the T396 project I did in 2005. I am trying to look for some rules in the data but they are not obvious. Looked at the examples on the course for using certainty factors in flex. Still not sure which way to do this, uncertainty factors, fuzzy logic or baysian updating.

Am spending so much time configuring the order comms system at work that I am less than keen to spend time using a computer when I get home. Still the weather's crap which helps.

15th May

Football season over. West Ham safe, now to pull my finger out again. Finished preprocessing the data for the neural network.