Thursday 11 August 2011

Not for a while!

I haven't posted anything since March, so this blog post is well over due. I will begin to get back into blogging my Phd progress again so expect frequent updates! Since the last blog post I have fully implemented and tested the dynamic programming algorithm applied to electricity tree networks and have thoroughly tested the algorithm using the centralised algorithm I have previously mentioned. A brief overview of the algorithm is as follows:

1. Leaf nodes send messages to their parent describing their ability to generate power such that their loads are satisfied. Each message consists of the power travelling along the parents transmission line, the carbon intensity of the flow, and resulting carbon dioxide emissions.

2. When a node receives all of the messages from its children, it generates its own set of messages which it sends to its parent. A node calculates its ability to generate power and the carbon dioxide emissions that result from satisfying its own loads and all of its children's loads.

It should be noted that each node maintains a mapping from their generated messages to the amount of power they produce and the states that their children are in which result in the flow, carbon intensity and carbon dioxide emissions of the message. This represents the dynamic programming aspect of the algorithm

3. When the root node has received messages from all of its children, it calculates the best possible output it can be in such that it minimises the carbon dioxide emissions of the entire network. The root then calculates what flow will be travelling down each transmission line when outputting this optimal power and propagates this to its children. Each children will then look up what state it is in, and each of its children are in, when it has the specified power travelling along its parents transmission line. The children's optimal states are sent to its children, who in turn do the same calculation until the leaf nodes.


During the last three months I have been implementing the above algorithm and writing my nine month report. I had my nine month report viva on the 17th July 2011 at the University of Barcelona during the IJCAI-11 conference. I am pleased to say that I passed! Dr. Alessandro Farinelli was my examiner and gave me very good feedback regarding my motivation and direction of work. Particularly I needed to make clear the motivation for decomposing the problem and then using agents to decentralise the computation.

Having survived the first part of my PhD, I now have a clear plan for the direction of my work. Initially I will construct proofs for the completeness and optimality of my algorithm. Once this is complete I will refine the algorithm to work in cyclic networks and will then submit a paper to the AAMAS conference.

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