Month: May 2006

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RLAI Tea-time Talks

Starting today, we will have a RLAI Tea-time talks almost everyday. I do not know how effective this will be; but if it becomes effective (=many good relevant presentations), it can be quite joyful.
I heard from a friend that this idea of tea-time talks comes from Richard Hamming who forces his students to present their research in a similar fashion. However, I doubt about it (I even guess these kinds of things have been existed from the ancient Greek time; imagine Aristotle and Plato talking with each other about the world’s most recent findings (e.g. Archimedes, “Eureka!,” Hellenic Journal of Natural Sciences, 220BC (*)) and Aristotle does not accept vague metaphysical viewpoints of Plato).

(*): Aristotle could not talk about Eureka! paper of Archimedes as this latter one did not publish his paper very soon. Actually, he was born much after those mentioned philosophers.

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Feelings

-Have I evered told you how do I feel about you?!
+No fool.
-I hate you!

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A Quintessential Introduction to Dark Energy

There are a whole lot of things in the world that I do not know that much. It is true that I cannot learn all of them (or even a small portion of them) in my lifetime. Actually, it is not necessary for most cases, e.g. I do not need to know how that technology works if I do not want to use it. However, some kinds of knowledge is just essential. They shape our viewpoint to the world and “may” answer questions like “where do you live?”, “how do you live?”, and etc.
All intro. things said, I want to read this paper later. You may like to take a look at it some time:

Paul J. Steinhardt, A Quintessential Introduction to Dark Energy

Abstract:Most of the energy in the universe consists of some form of dark energy that is gravitationally self-repulsive and that is causing the expansion rate of the universe to accelerate. The possible can-didates are a vacuum energy density (or, equivalently, a cosmological constant) and quintessence, a time-evolving, spatially inhomogeneous component with negative pressure. In this review, we focus on quintessence and ideas on how it might solve the cosmic coincidence problem, how it might be distinguished observationally from a cosmological constant, and how it may affect the overall cosmic history of the universe.

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Pascal Poupart

Last week, Pascal Poupart came to our university. He gave two talks and had several private meetings.
I wanted to talk to him sometime but unfortunately I could only attend one of his talks as the previous week was a hazard for me.
I was curious to talk to him about POMDP (which is his speciallity) and try to see the similarities/differences between POMDP and the concept of partial observablity in control theory from his perspective. For sure, both of them are talking about the same thing, but the goal of investigating PO is not completely the same. One reason might be due to discrete/continuous state differences between those two which leads to different approaches of the problem, i.e. state reconstruction might be easier if we assume that the dynamical system obeys some regularities such as linearity. Anyway …